WO2001014936A1

WO2001014936A1 - Image forming device

Info

Publication number: WO2001014936A1
Application number: PCT/JP1999/004477
Authority: WO
Inventors: Tetsu Takahashi
Original assignee: Fujitsu Limited
Priority date: 1999-08-20
Filing date: 1999-08-20
Publication date: 2001-03-01

Abstract

An image-forming device comprises electrification means, latent electrostatic image formation means, and development means. A latent electrostatic image formed by the latent electrostatic image formation means is developed by the development means and printed on plain paper (P). Potential regulation means is also provided. The latent electrostatic image formation means forms a latent electrostatic image directly or indirectly on a rewritable medium (R), on which images can be repeatedly formed by application of electric fields, and images are formed by the electric field established between the latent electrostatic image and the potential regulation means.

Description

Image forming device

Technical field

The present invention relates to an image forming apparatus for forming an image on a rewritable medium that can be rewritten by applying an electric field. Rice field

Background art

JP-A-10-35095, JP-A-10-149118, JP-A-8-92509, etc. disclose rewritable media that can be rewritten by applying an electric field. Has been done.

In addition, the Imaging Society of Japan's “Technology Research Group Development of Electrophoretic Displays (Digital Paper) Using Micro-Powered Pixels” (pages 31 to 36) was published in the 1998 Institute of Technology's 2nd Technical Study Group. The print section and non-print section (image forming section and non-image forming section) have opposite polarities between the electrostatic latent image carrier such as a photosensitive drum and the transfer means such as a transfer roller. It is disclosed that a display on a rewritable medium can be performed by applying a certain electric field.

The above publication discloses a single-function device that only forms an image on a rewritable medium, and such a configuration makes it impossible to form an image including printing on an image forming medium such as paper. Therefore, there is a problem that the usage is limited and the usability is deteriorated for the user. Conversely, image formation on rewritable media is basically different from electrophotography such as laser printers, so image formation on both rewritable media and media that cannot be repeatedly imaged, such as paper, is performed. It is extremely difficult to develop a device that can do this.

Electrophotographic methods such as laser printers use an exposure device to form an electrostatic latent image on an electrostatic latent image carrier, but other methods can also print on paper. And the image forming apparatus of the above-described method, Whether it was possible to form an image on a double medium was even more unclear.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the related art, and has as its object to provide an image forming apparatus capable of forming an image on a rewritable medium and other image forming media.

In addition, an image forming apparatus capable of forming an image on a rewritable medium and another image forming medium by an image forming method other than the electrophotographic method is also proposed.

Further, the present invention proposes an improved configuration applicable not only to the image forming apparatus having the above configuration but also to a rewritable medium image forming apparatus.

Disclosure of the invention

In order to achieve the above object, the present invention provides a rewritable medium, comprising: placing a rewritable medium between a charged electrostatic latent image and a potential regulating means; The image is formed on the rewritable medium and the other image forming medium from the viewpoint of where the electrostatic latent image is formed and how to form the image. The possible configurations are clarified. At the same time, the configuration of rewritable media image forming devices (including dedicated devices) using image forming methods other than the electrophotographic method is clarified.

Here, the configuration of the rewritable medium will be clarified. As shown in FIG. 1 (a), for example, in a microcapsule 500, a solvent 501 and a charged particle 502 (in the figure, a negative charged particle, but a tens charged particle may be used). When the electrodes 503 and 504 are placed so as to sandwich them and an electric field is generated between them, the charged particles 502 electrophoreses in the solvent 501, Attracted to the electrode side. Therefore, if either the solvent 501 or the charged particles 502 is colored, or if there is a contrast between the solvent 501 and the charged particles 502, the direction of the electric field is adjusted. This makes it possible to display images. The charged particles 502 aggregated by applying an electric field in this manner retain their state for a long time even after the electric field is removed. It is equivalent to a printed one, but with the application of the above-mentioned electric field, a new image can be formed and rewritten.

Also, as shown in FIG. 1 (b), a configuration is also possible in which a partition 512 is provided between two membranes 5110 and 5111, and the solvent 501 and the charged particles 502 are dispersed and enclosed therebetween. The above principle is applicable. Further, as shown in FIG. 1 (c), one side of the large particle 520 is positively or positively charged and the charged side or the opposite side is colored, or a contrast of light and shade between the two is obtained. The above principle can be applied to the case where there is an antenna.

According to the present invention, image formation is performed by generating one of the electrodes 503 and 504 as an electrostatic latent image and the other as an electric potential defining means and generating an electric field in a specific direction therebetween. Become. In this case, the electrostatic latent image may be formed on an electrostatic latent image carrier such as a photoconductor or a dielectric, or may be formed directly on a rewritable medium without being formed on these. In the present invention, as described later, it is described that an electrostatic latent image is formed indirectly or directly on a rewritable medium. Hereinafter, the configuration of the present invention will be described.

A first configuration of the image forming apparatus of the present invention includes at least a charging unit, an electrostatic latent image forming unit, and a developing unit, and the electrostatic latent image formed by the electrostatic latent image forming unit. An image forming apparatus that develops an image by a developing unit to form an image on a medium on which an image is to be formed is provided with a means for defining a potential (for example, ± OV), and an image is formed by applying an electric field. A repeatable rewritable medium is used as the image forming medium, and an electrostatic latent image is directly or indirectly formed on the rewritable medium by the electrostatic latent image forming means. The basic feature is that an image is formed by generating an electric field with the defining means.

The above configuration uses a conventional electrophotography in which an exposure device such as an LED or laser light emitting device is used as an electrostatic latent image forming means, and the electrostatic latent image is developed with a developer and transferred to a medium on which an image is formed. Not only transfer the developed image to paper or other image forming medium, but also form an electrostatic latent image on an electrostatic latent image carrier such as a photoconductor (for rewritable media). Indirectly forms an electrostatic latent image), an electrostatic latent image The configuration includes a configuration capable of forming an image on a rewritable medium by generating an electric field between the electrostatic latent image formed on the carrier and the potential regulating means (therefore, a configuration in which development is not performed).

The configuration of the present invention also includes a configuration of a system for forming an electrostatic latent image by discharging instead of employing the configuration of the electrophotographic system as a configuration of the electrostatic latent image forming unit. There are two methods of forming an electrostatic latent image by discharging: a) a type that forms an electrostatic latent image by discharging from a needle electrode; and a) an opening electrode that pairs the flow of ions generated by corona discharge. Control (ion flow method) to form an electrostatic latent image, type c) using the charge generated by the fine electrode provided for each dot to discharge in a pulsed manner to form an electrostatic latent image There are types.

In these systems, a dielectric (usually composed of an insulator) capable of forming an electrostatic latent image by discharging is used as a configuration of the electrostatic latent image carrier, and the electrostatic latent image carrier is formed on the dielectric. An electrostatic latent image is formed once, the electrostatic latent image is developed, and a normal image is formed on the image forming medium such as paper. In the present application, an electric field is further generated between the electrostatic latent image formed on the electrostatic latent image carrier and the potential regulating means, and is used to form an image on a rewritable medium. On the other hand, according to the present invention, an electrostatic latent image is formed directly on a rewritable medium without using the electrostatic latent image carrier, and an electric field is generated between the electrostatic latent image and the potential regulating means, whereby an image is formed. Can also be formed. Even in the case of the third configuration, an image can be formed by developing an electrostatic latent image and transferring the image to an image forming medium such as paper.

In the case of a configuration in which an electrostatic latent image is formed directly on the third rewritable medium, and in the case of a dedicated rewritable medium image forming apparatus that does not form an image on an image forming medium such as paper, the electrostatic latent image is held. Eliminates the need for body composition.

Further, an electrostatic latent image is formed on the electrostatic latent image carrier by discharging, and the electrostatic latent image formed on the electrostatic latent image carrier is developed to form an image on an image forming medium such as paper. In such a configuration, if another image forming path is provided, an electrostatic latent image can be formed directly on a rewritable medium by discharging, and the electrostatic latent image forming means itself can be formed by a rewritable medium. If it can be moved to a position directly facing the surface, or if another electrostatic latent image forming means can be provided at such a position, it will A configuration in which an electrostatic latent image is directly formed on a medium may be employed, and the present configuration includes such a case.

While the first configuration does not necessarily require the configuration of the electrostatic latent image carrier, the configuration of the second image forming apparatus of the present invention is an image forming apparatus having the electrostatic latent image carrier. (Accordingly, the configuration of the rewritable medium image forming apparatus is not included), and the apparatus proposes a configuration capable of forming an image on both the image forming medium such as paper and the rewritable medium. It is.

The specific configuration includes at least an electrostatic latent image carrier, charging means for charging the electrostatic latent image carrier, and electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier. Developing means for developing the electrostatic latent image formed on the electrostatic latent image carrier, and transferring the image on the electrostatic latent image carrier developed by the developing means to an image forming medium An image forming apparatus comprising: a transfer unit; and a fixing unit for fixing an image transferred to an image forming medium. Used as the image forming medium, an electrostatic latent image is formed directly or indirectly on the rewritable medium by the electrostatic latent image forming means. Generates an electric field between It is characterized in that to perform.

In the above-described configuration, in the above-described electrophotographic image forming apparatus and discharge type image forming apparatus, an image can be formed on an image forming medium such as paper and a rewritable medium. Therefore, in the normal case where an image is formed on a rewritable medium, an electrostatic latent image is formed on the electrostatic latent image carrier, and an electric field is applied between the electrostatic latent image on the electrostatic latent image carrier and the potential regulating means. (The type that forms an electrostatic latent image indirectly on a rewritable medium) Force As a method of forming an electrostatic latent image, a method of forming an electrostatic latent image by discharging is used. In the case of a configuration that is used, in addition to such a configuration, another image forming path may be provided to directly form an electrostatic latent image on a rewritable medium by discharging. If the image forming means itself can be moved to a position directly facing the rewritable medium, or if another electrostatic latent image forming means can be provided at such a position, an electrostatic latent image is formed directly on the rewritable medium by discharging. Can be configured In the present invention, the rewritable The provision of a configuration for forming an electrostatic latent image on a portable medium means that such a configuration is included.

When an image is formed by an electrophotographic method, a photoconductor such as a photosensitive drum serves as an electrostatic latent image carrier, a corona charger or other charging structure serves as a charging means, and an LED or a laser light emitting device. The structure of the exposure device is an electrostatic latent image forming means, and the structure of the developing device for attaching a developer such as toner to the electrostatic latent image is the developing means. Other transfer for transferring an image to a transfer roller or a paper medium. The configuration is used as a transfer unit, and a configuration in which a transferred image is fixed by a heater or the like or another fixing configuration is used as a fixing unit. These are generally used in the configuration of an electrophotographic system such as a printer for printing on ordinary paper. On the other hand, when a discharge type image is formed, a dielectric composed of an insulator is used as an electrostatic latent image carrier, and the above discharge configuration is used as an electrostatic latent image forming means (others are of an electrophotographic type). The configuration can be the same as in the case).

According to a third configuration of the present invention, as the electrostatic latent image forming means, a configuration for forming an electrostatic latent image by exposure is used, whereby the electrostatic latent image formed on the electrostatic latent image carrier is used. An image is formed on the rewritable medium by an electric field generated between the rewritable medium and the potential regulating means.

This configuration stipulates a configuration in which an image is formed on a rewritable medium by using the above-described electrophotographic image forming apparatus. In this case, the electrostatic latent image formed on the electrostatic latent image carrier is specified. An image is formed on the rewritable medium by the electric field generated between the image and the potential regulating means. Therefore, the electrostatic latent image is not formed directly on the rewritable medium. It should be noted that the above configuration may be configured to print (image formation) on an image forming medium such as paper.

A fourth configuration of the present invention uses a configuration in which an electrostatic latent image is formed by electric discharge as the electrostatic latent image forming unit, and is provided between the formed electrostatic latent image and the potential defining unit. It is defined that an image is formed on the rewritable medium by the generated electric field.

This configuration stipulates a configuration in which an image is formed on a rewritable medium using the above-described discharge-type image forming apparatus. A configuration in which an electrostatic latent image is formed by discharging, and an image is formed on the rewritable medium by an electric field generated between the formed electrostatic latent image and the potential regulating means. . In the case of this discharge type configuration, as described above, the electrostatic latent image is formed on the electrostatic latent image carrier (the type in which the electrostatic latent image is formed indirectly on a rewritable medium), It may be formed directly on a rewritable medium.

A fifth configuration of the present invention is characterized in that when an electrostatic latent image is indirectly formed on the rewritable medium, the transfer unit is used as the potential regulating unit.

The above configuration corresponds to both the electrophotography type and the discharge type configuration. In the case where the formation of an electrostatic latent image on a rewritable medium is performed indirectly, that is, the electrostatic latent image The transfer means used to transfer the developed image to an image forming medium such as paper when an image is formed is replaced by a potential regulating means used when forming an image on a rewritable medium. It is clear that they can also be used.

According to a sixth configuration of the present invention, the electrostatic latent image forming unit is provided at a position facing the rewritable medium, or is moved to the position, and the electrostatic latent image forming unit forms an electrostatic latent image on the rewritable medium. An image is formed, and an image is formed on the rewritable medium by an electric field generated between the electrostatic latent image and the potential defining unit. As one mode of the above configuration, an image forming path for the rewritable medium is separately provided, and an electrostatic latent image is formed on the rewritable medium by the electrostatic latent image forming means on the pass side, and the electrostatic latent image is formed. The image is formed on the rewritable medium by the electric field generated between the image and the potential regulating means. By moving the electrostatic latent image forming means to the image forming path of the rewritable medium, or by providing another electrostatic latent image forming means exclusively for the path, it becomes possible to form an image on the rewritable medium in another pass. . In this case, it is advisable to adopt a configuration in which the rewritable medium is guided to the same path as necessary.

In addition, the above configuration is not limited to the case where such a separate path is provided. For example, in the image forming path of an image forming medium such as paper, the image forming path directly faces the rewritable medium. Moving the electrostatic latent image forming means to a position where the electrostatic latent image is formed, or providing another electrostatic latent image forming means at such a position to form an electrostatic latent image directly on a rewritable medium. Etc. are also included.

However, the above configuration is limited to the case where the electrostatic latent image is formed directly on the rewritable medium and the case where the electrostatic latent image is formed by the discharge method.

A seventh configuration of the present invention includes at least a charging unit, an electrostatic latent image forming unit, and a potential regulating unit that regulates an electric potential, and a rewritable image that can be repeatedly formed by applying an electric field. A medium is used as an image forming medium, and an electrostatic latent image is directly or indirectly formed on the rewritable medium by the electrostatic latent image forming means, and between the electrostatic latent image and the potential defining means. In an image forming apparatus that forms an image by generating an electric field (including a configuration of a dedicated device that forms an image only on a rewritable medium), a direction corresponding to the density of a predetermined image formed on the surface of the rewritable medium. An electrostatic latent image force capable of generating the electric field between the electric potential defining unit and the potential regulating unit defines that the electric field is formed by the electrostatic latent image forming unit.

Specific embodiments thereof are described in claims 8 and 9. That is, as shown in Fig. 2, the eighth configuration of the present invention is used for a rewritable medium R that has a high density display (dark colored display) when the direction of the electric field is from the back side to the display surface side. As a means for forming an electrostatic latent image, the polarity of the formed electrostatic latent image is negative with respect to the polarity before the latent image is formed. Stipulated).

Further, as shown in FIG. 3, the ninth configuration of the present invention is an electrostatic latent image forming means used for a rewritable medium R that provides a high density display when the direction of the electric field is from the display surface side to the back side. Assuming that the polarity of the formed electrostatic latent image is positive with respect to the polarity before the latent image is formed (the corresponding portion of the electrostatic latent image carrier 20 is shown as + in the figure). Stipulates use.

With the above configuration, when forming an electrostatic latent image, the smaller the duty (work amount) such as exposure or discharge by the electrostatic latent image forming means, the smaller the electrostatic latent image forming means ( Head, etc.) will last longer. In other words, when forming an image such as a general document, the area other than the portion displayed as characters or figures is It is really big. Therefore, it is desirable that the portion to be written by the head of the electrostatic latent image forming means be a colored portion such as black (or a portion having a higher density than the surroundings). According to a tenth aspect of the present invention, an image is formed on a rewritable medium by using an electrostatic latent image pattern developed at the time of development, and by an electric field generated between the electrostatic latent image pattern and the potential defining means. If the density of the portion corresponding to the electrostatic latent image pattern becomes lower than the others when forming, the electrostatic latent image is formed between when the image is formed by the developed pattern and when the image is formed on the rewritable medium. It stipulates that the latent image pattern be inverted.

In the above configuration, the electrostatic latent image pattern in the portion where the density is high when developed and the electrostatic latent image pattern in which the density is high when formed on the rewritable medium are the same as the developed image and the negative image of the photograph. When the image is in an inverted state, the electrostatic latent image pattern is inverted between the time of image formation using the electrostatic latent image pattern developed during development and the time of image formation on a rewritable medium. It is. In this configuration, the configuration of the dedicated image forming apparatus for rewritable media, the configuration in which an image forming path for rewritable media is separately provided, and the electrostatic latent image forming means itself are moved to a position directly facing the rewritable media. It does not apply to a configuration in which another electrostatic latent image forming means is provided at such a position.

More specifically, it is defined in claims 11 and 12. In the configuration of claim 11, the electrostatic latent image pattern is developed using a negatively charged developer, and when the image is formed, and when the direction of the electric field is from the display surface side to the back side, the density is reduced. Inverting the electrostatic latent image pattern formed by the electrostatic latent image forming means between the time when an image is formed on a rewritable medium, which results in a display at a low level and a display at a high density in the opposite case. Stipulates.

When the direction of the electric field is from the display surface side to the back side as shown in FIG. 4, for example, charged particles that are negatively charged move toward the positively charged electrostatic latent image side. If the charged particles have a low concentration, no image is formed at that portion. When a positively charged electrostatic latent image is developed and transferred to an image forming medium such as paper, if a negatively charged developer is used as the developer, the electrostatic latent image portion is developed exactly. And when the image is formed on the rewritable medium, The opposite is true (just the two images have the relationship of the inverted negative image). Therefore, in the above case, it is necessary to invert the electrostatic latent image pattern formed by the electrostatic latent image forming means.

Further, in the configuration of claim 12, the electrostatic latent image pattern is developed using a positively charged developer, and when the image is formed, and when the direction of the electric field is from the display surface side to the back side, the density is reduced. That the electrostatic latent image pattern formed by the electrostatic latent image forming means is inverted between when the image is formed on the rewritable medium, and when the image is formed on the rewritable medium, which becomes a display with a low density in the opposite case. are doing.

When the direction of the electric field is from the back side to the display surface side as shown in Fig. 5, for example, negatively charged particles are electrophoresed on the opposite side to the negatively charged electrostatic latent image side. I do. If the solvent portion on the side opposite to the side where the charged particles are collected has a low concentration, no image is formed there. When a negatively charged electrostatic latent image is developed and transferred to an image forming medium such as paper, if a positively charged developer is used as the developer, the electrostatic latent image portion is developed. This is exactly the opposite of the case where an image is formed on a rewritable medium (both images have a reversed negative image relationship). Therefore, in the above case, it is necessary to invert the electrostatic latent image pattern formed by the electrostatic latent image forming means.

According to a thirteenth aspect of the present invention, when forming an image on a rewritable medium, the voltage polarity of the developer carrier with respect to the electrostatic latent image carrier in the developing means is set to ± 0 V, or the electrostatic force applied to the developer. Stipulates that the polarity is from the electrostatic latent image carrier to the developer carrier. In this configuration, the configuration of the image forming apparatus exclusively for rewritable media, the configuration in which an image forming path for rewritable media is separately provided, and the electrostatic latent image forming means itself are moved to a position directly facing the rewritable media. This does not apply to a configuration in which another electrostatic latent image forming unit is provided at such a position. When forming an image on a rewritable medium, there is no need to develop the electrostatic latent image because only an electric field is generated between the electrostatic latent image and the potential regulating means. Rather, once the electrostatic latent image has been developed, stable image formation on rewritable media cannot be expected. Therefore, when forming an image on a rewritable medium, it is necessary to prevent a developer such as toner from adhering to the electrostatic latent image. The above structure The configuration provides a means for preventing the developer from adhering to such an electrostatic latent image. The voltage polarity of the developer carrier (for example, a developing roller) in the developing means with respect to the electrostatic latent image carrier is ± 0 V (No potential difference is generated, so no developer adheres to the electrostatic latent image carrier) The polarity of the electrostatic force applied to the developer from the electrostatic latent image carrier to the developer carrier (Reverse to the time when development is performed).

A fourteenth configuration of the present invention specifies that, when an image is formed on a rewritable medium, the voltage of the developer carrier in the developing unit with respect to the electrostatic latent image carrier is in a float state. In addition, this configuration is a configuration of a dedicated image forming apparatus for a rewritable medium, a configuration in which an image forming path for a rewritable medium is separately provided, and the electrostatic latent image forming unit itself is moved to a position directly facing the rewritable medium. It does not apply to a configuration in which a separate electrostatic latent image forming means is provided at such a position. The above configuration provides a means for preventing the developer from adhering to the electrostatic latent image in the same manner as described above, and floats the voltage of the developer carrier such as a developing roller to the electrostatic latent image carrier. It is realized by setting the state. The floating state refers to a state in which the portion in contact with the developing carrier is insulated, and there is no portion defining the potential with respect to the developer carrier anywhere. In this way, by making the potential of the developer carrier float, an electric field sufficient to develop the developer is not generated between the electrostatic latent image carrier and the developer carrier, so that the development is performed. It can be prevented.

A fifteenth configuration of the present invention specifies that an image is formed on a rewritable medium in a configuration in which development is performed in a state where the developer layer of the developing unit does not contact the electrostatic latent image carrier. I have.

In the case where the development is performed in a state where the developer layer of the developing means is in contact with the electrostatic latent image carrier, for the low-charged developer, regardless of the potential relationship between the electrostatic latent image carrier and the developer carrier, Some development on the electrostatic latent image carrier occurs due to intermolecular force, liquid crosslinking force, and the like. On the other hand, in the case of the non-contact developing method as in the above configuration, there is no concern about such a phenomenon occurring unless a potential difference occurs.

According to a sixteenth aspect of the present invention, the developer layer of the developing means or the magnetic brush is an electrostatic latent image. In an image forming apparatus that performs development by contacting with a carrier, an electrostatic latent image carrier and a developing unit are arranged so that the developer layer or the magnetic brush is not in contact with the electrostatic latent image carrier. It stipulates that a part or all can be relatively separated.

In the above configuration, the electrostatic latent image carrier and a part or all of the developing means can be relatively separated from each other so that the developer layer or the magnetic brush is not in contact with the electrostatic latent image carrier. With such a configuration, when forming an image on a rewritable medium, the developer is prevented from adhering (development is not performed). Further, by allowing such a separation, the driving of the developing means can be stopped, as will be described later, so that the deterioration of the developer is prevented and the life of the developing means is eventually prolonged. In the case where the above-mentioned configuration is separated, a force directed to a part or the whole of the developing means may be moved. Of course, all of the developing means may be moved. Alternatively, only the developer carrier may be moved so that the developer layer or the magnetic brush and the electrostatic latent image carrier are brought into a non-contact state. The constitutions of claims 17 and 18 are such that, as in the fifteenth constitution of the present invention, the development is performed in a state where the developer layer of the developing means does not contact the electrostatic latent image carrier, When an image is formed on a rewritable medium, the electrostatic latent image is held so that the developer layer or the magnetic brush and the electrostatic latent image carrier are not in contact with each other as in the sixth configuration. The developer layer or the magnetic brush does not contact the electrostatic latent image carrier when forming an image on a rewritable medium by relatively separating the body and a part or all of the developing means. In response to the above, a configuration for stopping the driving of the developing means is proposed.

That is, the seventeenth configuration of the present invention specifies that only the drive source of the developing unit is provided as a separate system and the drive control is performed. Here, the drive source of the developing means refers to a drive system involved in development such as a developer carrier such as a developing roller, a developer stirring device, and a developer reset device such as a reset roller. In addition, a separate drive system for the drive source of the developing means means that the above-described configuration is a drive system separate from the drive system for the electrostatic latent image carrier and the conveyance drive system for the image forming medium such as paper. That is. As a result, only the driving source of the developing means can be controlled, and the driving of the developing means can be stopped at the time of forming an image on a rewritable medium. And the life of the developing means is eventually prolonged.

Further, the eighteenth configuration of the present invention specifies that the drive source of the developing unit is made the same system as the other drive sources, and that the power supply to the developing unit can be cut off. Even if the driving source of the developing unit is the same system as the other driving sources, the power supply to the developing unit can be cut off, so that the image forming unit can The drive can be stopped, so that deterioration of the developer is prevented and the life of the developing means is eventually prolonged.

The ninth configuration of the present invention specifies that when forming an image on a rewritable medium, the rewritable medium transport path has a path that does not pass through a fixing unit.

When an image is formed on the rewritable medium, the developed pattern is not transferred to the image forming medium.Therefore, it is not necessary to fix the originally transferred pattern, and the effect of the rewritable medium passing through the fixing means, i.e., fixing The microcapsules and the membrane may be damaged by the heat of the unit, and the microcapsules and the membrane constituting the rewritable medium may be melted, or the pressure may be applied from the fixing unit, and the rewritable medium may be contaminated with the fixing oil. Therefore, a path that does not pass through the fixing means is provided as a rewritable medium transport path. The above configuration is generally applied to a configuration capable of performing both image formation for transferring a development pattern to an image formation medium such as paper and image formation on the rewritable medium. A separate image forming path, and further moving the electrostatic latent image forming means itself to a position directly facing the rewritable medium, or placing another electrostatic latent image forming means at such a position. The included configuration is included as long as it corresponds to the above configuration.

Further, even in a configuration in which the rewritable medium passes through the fixing means during image formation, the energy input from the fixing means to the rewritable medium during image formation of the rewritable medium is limited to the allowable energy tolerance of the rewritable medium (constant). (Within the allowable range in which the microcapsules and the film constituting the rewritable medium are not melted by the heat of the attaching means or the microcapsules and the film are not broken by applying pressure from the fixing means). There is no particular problem. A twenty-second configuration of the present invention specifies that a flash fixing device is used as the fixing unit. The flash fixing device has a configuration in which a transfer pattern is fixed to an image forming medium such as paper by light emission of a flash lamp, and the fixing is not performed unless the light emission is performed. When the light passes through the fixing means, it is sufficient that the light is not emitted. In addition, unless light is emitted, the heat of the fixing means does not melt the microphone opening capsule or the film constituting the rewritable medium, and since there is no compression by a roll or the like, pressure is applied from the fixing means. However, the microcapsule does not destroy the membrane. Furthermore, since no fixing oil is used, there is no need to worry about contamination of the rewritable medium. This configuration is not applied to the configuration of a rewritable medium dedicated to image formation.

The twenty-first configuration of the present invention specifies that a belt fixing device is used as the fixing unit. The belt fixing device is based on the structure of the roll (structure in which the contact surface is easily deformed) installed on the side where the image forming medium such as paper passes. It requires little use of fixing oil because it is good. Therefore, even if the rewritable medium passes here, there is no concern about contamination by the fixing oil. Note that this configuration does not apply to the configuration of a dedicated rewritable medium image forming apparatus.

According to a second configuration of the present invention, when an image is formed using a developed electrostatic latent image pattern, a current is supplied to the transfer unit by constant current control, and an image is formed on a rewritable medium. Specifies that a voltage is applied to the transfer unit by constant voltage control.

This configuration is a control configuration corresponding to the configuration described in claim 5 in which the transfer means is used as the potential regulating means. When an image is formed using a normally developed electrostatic latent image pattern, an electric current is applied to the transfer means by constant current control to transfer the developed pattern to an image forming medium such as paper. On the other hand, since an image is formed on a rewritable medium by applying an electric field, when an image is formed on a rewritable medium, a voltage is applied to the transfer means by constant voltage control, and the transfer is performed. Means used as potential regulating means It is.

The second configuration of the present invention specifies that the peripheral speed of the electrostatic latent image carrier and the transport speed of the rewritable medium are the same when forming an image on the rewritable medium.

When image transfer is performed by the electrophotographic method, the transfer efficiency is increased by slightly changing the peripheral speed of the electrostatic latent image carrier and the transport speed of the image forming medium such as paper. However, when an image is formed on a rewritable medium, the above-mentioned transfer is not performed. If the force and speed are not necessary, the surface of the rewritable medium can be easily damaged. Therefore, when an image is formed on a rewritable medium, it is better to control the two speeds to be the same as in the present configuration.

However, the process speed at the time of transferring the developing pattern to the image forming medium such as paper (the speed at which the developer passes through the portion facing the transfer means) and the process speed at the time of forming the image on the rewritable medium are as follows. It is also possible to make them different. That is, the time required to form an image per unit area when transferring the current image pattern to an image forming medium such as paper, and the time required to form an image per unit area when forming an image on a rewritable medium. If they are different, image defects will occur unless both process speeds are set to the appropriate speed for each.

A twenty-fourth configuration of the present invention includes at least a charging unit, an electrostatic latent image forming unit, and a potential regulating unit that regulates a potential, and a rewritable image forming device that can repeat image formation by applying an electric field. A medium is used as an image forming medium, and an electrostatic latent image is directly or indirectly formed on the rewritable medium by the electrostatic latent image forming means. In an image forming apparatus that performs image formation by generating an electric field between the rewritable medium and the other image forming medium before image formation, an image forming apparatus (including a configuration of a dedicated apparatus that forms an image only on a rewritable medium) performs image formation. Stipulates identification.

If the rewritable medium and the other medium are mixed in the supplied image forming medium, these image forming principles are different, so that there is a case where the image cannot be formed by any of the above configurations. Therefore, these types are discriminated, and image formation is performed with a configuration suitable for each of them, or a configuration conforming to the discrimination type image forming principle. If not, it is necessary not to perform image formation. Therefore, a configuration for determining the medium is specified.

A twenty-fifth configuration of the present invention is an image forming apparatus that forms an image only on a rewritable medium, and identifies a rewritable medium and other image forming mediums before forming an image, and determines whether or not the rewritable medium is a non-rewritable medium. When an image forming medium is supplied, it is processed as an error and does not form an image.

In a configuration of a rewritable medium dedicated to image formation, when an image forming medium other than a rewritable medium is supplied that does not conform to the principle of image formation, normal image formation is not performed or image formation is not performed at all. I can't. Therefore, in the above configuration, before forming an image, the rewritable medium and the other image forming medium are identified, and when an image forming medium other than the rewritable medium is supplied, it is processed as an error and the image is formed. I did not.

A twenty-sixth aspect of the present invention is an image forming apparatus for forming an image on an image forming medium other than a rewritable medium and forming an image on a rewritable medium. If a rewritable medium is supplied in a print mode in which an image is formed on an image forming medium other than a rewritable medium, or a rewritable medium on which an image is formed on a rewritable medium When an image forming medium other than a rewritable medium is supplied in the image forming mode, it is treated as an error and the image forming is not performed.

In a device capable of forming images on both rewritable media and other image forming media, when a rewritable medium is supplied in a print mode in which an image is formed on an image forming medium other than a rewritable medium, a normal Printing is performed, and image formation conforming to the image forming principle of the rewritable medium is not performed. On the other hand, when an image forming medium other than a rewritable medium is supplied in the rewritable medium image forming mode in which an image is formed on a rewritable medium, normal image forming is not performed or no image forming is performed. Will not be done. Therefore, in the above configuration, before forming an image, the rewritable medium and the other image forming medium are identified, and a mark for forming an image on the image forming medium other than the rewritable medium is formed. Processed as an error when a rewritable medium is supplied during the printing mode, or when an image forming medium other than the rewritable medium is supplied during the rewritable medium image forming mode in which an image is formed on the rewritable medium. And no image formation was performed.

The following 27th configuration and 28th configuration are specific methods for identifying the rewritable medium and other image forming media performed before image formation in the 24th to 26th configurations described above. It is stipulated.

The 27th configuration of the present invention forms an image on an image forming medium by applying an electric field, measures the display density of the image, and distinguishes the rewritable medium from the other image forming medium. Stipulates that

The above configuration uses the property that an image can be formed by applying an electric field to the rewritable medium as it is, forms an image by applying an electric field, and measures the display density of the image. It is to be distinguished from the medium. On an image forming medium other than a rewritable medium, an image is not formed by application of an electric field, so that the display density of the image is naturally different from that of a rewritable medium.

The twenty-eighth configuration of the present invention specifies that a rewritable medium is distinguished from another image forming medium by detecting an impedance or a resistance value of the image forming medium.

Naturally, the rewritable medium and the other image forming medium have different impedances and resistance values inherent in their materials. Therefore, by detecting these, the rewritable medium and the other image forming medium can be distinguished. Among them, the impedance can be detected as a remarkable difference compared to the resistance, but on the contrary, the detection of the resistance can be performed more easily than the detection of the impedance. In addition, both are less susceptible to contamination of the medium surface and the like than the 27th configuration, and can be easily identified.

A twentieth configuration of the present invention is directed to an image forming apparatus that forms an electrostatic latent image directly on a rewritable medium and forms an image by an electric field between the potential defining means (the configuration of a dedicated rewritable medium image forming apparatus). In the method, the surface is formed on the rewritable medium surface. It defines that the formed electrostatic latent image is removed after image formation. When an electrostatic latent image is formed directly on a rewritable medium and an image is formed by an electric field between the rewritable medium and the electric potential regulating means, the electrostatic latent image remaining on the rewritable medium after that becomes unnecessary. In addition, if the electrostatic latent image is left as it is, various objects will be attracted by the static electricity remaining on the rewritable medium. For example, when an image-formed rewritable medium is placed on top of Even if you try to take several sheets of media, they will stick together and stick together, reducing the handling. Further, in such a case, the electrostatic charge left in the electrostatic latent image attracts charged particles of another rewritable medium that is laid over, and the image of the latter rewritable medium itself may be disturbed. In the above configuration, in order to prevent the above problems in advance, the electrostatic latent image formed on the rewritable medium surface is removed after the image is formed. When an electrostatic latent image is indirectly formed on a rewritable medium (when an electrostatic latent image is formed on an electrostatic latent image carrier), the electrostatic latent image is formed on the rewritable medium after image formation. Since no image remains, there is no such problem, and therefore, this configuration is not applied.

According to a thirtieth configuration of the present invention, an electrostatic latent image is formed on an electrostatic latent image carrier, and the electrostatic latent image is conveyed therebetween by an electric field formed between the electrostatic latent image and the potential regulating means. An image forming apparatus that forms an image on a rewritable medium (a configuration in which an electrostatic latent image is formed indirectly on a rewritable medium, including a dedicated device that forms an image only on a rewritable medium) When forming on multiple rewritable media, it is stipulated that image formation is performed on the second and subsequent rewritable media using the first latent image without performing charging and latent image formation. .

When an image is formed on a rewritable medium using the electrostatic latent image formed on the electrostatic latent image carrier, erasing work is particularly performed on the electrostatic latent image carrier even after the image formation is completed. Unless otherwise, an electrostatic latent image will remain. Therefore, if a new electrostatic latent image is not formed and the electrostatic latent image left on the electrostatic latent image carrier is used, two or more identical images can be formed. As described above, since a new electrostatic latent image is not formed, the power consumption can be reduced by stopping the charging unit and the electrostatic latent image forming unit. A thirty-first configuration of the present invention includes at least a charging unit, an electrostatic latent image forming unit, and a potential regulating unit that regulates a potential, and a rewritable image that can repeat image formation by applying an electric field. A medium is used as an image forming medium, and an electrostatic latent image is directly or indirectly formed on the rewritable medium by the electrostatic latent image forming means. In an image forming apparatus that performs image formation by generating an electric field between the rewritable medium (including a configuration of a dedicated apparatus that forms an image only on a rewritable medium) before forming an image by applying an electric field to the rewritable medium, On the other hand, it specifies that an AC electric field is applied.

If the charged particles of the rewritable medium are left for a long period of time, they may agglomerate or adhere to the wall enclosing the solvent (the wall of the microcapsule or the wall of the membrane), causing image defects. In this configuration, before forming an image, an AC electric field is applied to the rewritable medium to oscillate the charged particles in the direction of the AC electric field, to eliminate the aggregation and adhesion, and to form an image on the rewritable medium. Is performed.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory diagram of a configuration of a rewritable medium, FIG. 2 is an explanatory diagram showing characteristics of a rewritable medium suitable for use of an electrostatic latent image forming means in which an electrostatic latent image has one polarity, and FIG. FIG. 4 is an explanatory view showing characteristics of a rewritable medium suitable for use in an electrostatic latent image forming means in which a latent image has ten polarities. FIG. 4 shows an image in which an electrostatic latent image pattern and an image forming pattern on a rewritable medium are reversed. FIG. 5 is an explanatory diagram showing that the electrostatic latent image pattern and the image forming pattern on the rewritable medium are in a relationship to be formed by reversing them. Fig. 6 is an embodiment conceptually showing the configuration of an image forming apparatus capable of both printing on plain paper P and forming an image on electrophoretic rewritable medium R by negatively charged non-magnetic one component jumping development method. Fig. 7 shows the conceptual diagram of Fig. 1, and Fig. 7 shows the configuration of Fig. 6. FIG. 8 is an explanatory diagram of a paper guide according to the first embodiment, and FIG. 9 is a diagram illustrating a plain paper print mode and a rewritable medium image forming mode according to the first embodiment. Processing steps FIG. 10 is a conceptual diagram showing the configuration of an image forming apparatus capable of both printing on plain paper P and forming an image on an electrophoretic rewritable medium R by a negatively charged non-magnetic one-component contact developing method. FIG. 11 is a conceptual diagram of Embodiment 2 shown in FIG. 11, FIG. 11 is an explanatory diagram showing a power supply configuration used in the configuration of FIG. 10, and FIG. 12 is development at the time of printing plain paper P and forming a rewritable medium R image. FIG. 13 is an explanatory view showing a contact or non-contact state between the mouth roller 31 and the photosensitive member 21. FIG. 13 shows processing steps of a plain paper printing mode and a rewritable medium image forming mode in the second embodiment. FIG. 14 is a flow chart, FIG. 14 is a conceptual diagram of an image forming apparatus that forms an electrostatic latent image on a dielectric 22 by discharging, and FIG. 15 is a conceptual diagram of a developing roller. The unit constituting the developing means 30 is separated from the dielectric 22 by the dielectric 1 FIG. 16 is an explanatory view showing a state of being retracted from 22. FIG. 16 is a conceptual diagram of Embodiment 4 conceptually showing the configuration of an image forming apparatus for forming an electrostatic latent image on dielectric 22 by discharging. FIG. 17 is an explanatory view of the configuration of the paper guide according to the fourth embodiment. FIG. 18 is a view in which the paper guide 113 and the head 12 of the electrostatic latent image forming means 10 rotate in conjunction with each other. FIG. 19 is a flowchart showing processing steps of a plain paper printing mode and a rewritable medium image forming mode in the fourth embodiment. FIG. 20 is an image forming apparatus such as plain paper by discharge. Embodiment 5 is a conceptual diagram of an image forming apparatus that directly forms an electrostatic latent image on an image forming medium, performs toner development, and also forms an image on a rewritable medium R. FIG. 21 is a rewritable embodiment shown as Embodiment 6. Enlarged view of the medium R detection device. FIG. 23 is an explanatory diagram of Embodiment 8 showing a configuration for removing an electrostatic latent image remaining on a rewritable medium R after image formation by an image forming apparatus that directly forms an electrostatic latent image on a medium R. FIG. 24 is an explanatory view of Embodiment 8 showing another configuration for removing the electrostatic latent image remaining on the rewritable medium R. FIG. 24 is an embodiment in which the electrophoretic particles in the rewritable medium R are vibrated by application of an AC electric field to dissolve the aggregation. 9 is an explanatory view of the configuration of FIG.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to the _drawings. (Embodiment 1)

The first embodiment relates to an image forming apparatus capable of performing both printing on plain paper P by a negatively charged non-magnetic one-component jumping developing method and image formation on an electrophoretic rewritable medium R. The figure shows the configuration conceptually. The developing means 30 of the present embodiment includes a developing roller 31 serving as a developer carrier, a reset roller 32, and a blade 33. The developing roller 31 is made of aluminum, the blade 33 is made of SUS, the reset roller 32 is made of urethane foam, and the photosensitive member 21 serving as an electrostatic latent image carrier is made of OPC (Organic Photo Conductor). The surface distance between the developing roller 31 and the photoconductor 21 is set to 350 / i in. The drive of the developing roller 31 and the reset roller 32 in the present embodiment, and the toner stirring paddle in the developing means 30 (not shown) is performed by another driving system (photoconductor 21, transfer port 40). —La 41, paper transport system, etc.) are linked via an electromagnetic clutch (not shown).

1) When printing on plain paper

The developing roller 3 1, the reset roller 3 2, and the blade 3 3 are controlled by the controller 101 of the image forming apparatus so that the relay 110 2 is switched so that a voltage is applied from the power supply A in FIG. Is done. The voltage applied from the power supply A is a DC voltage of 1550 V, a rectangular voltage of 2.6 kV with a V pp force of 2.6 kHz and a duty of 35% at a frequency of 2 kHz. A resistance of 300 kΩ is provided as a compensation resistance. The surface of the photoreceptor 21 is charged to −700 V. When the printing area, which is the electrostatic latent image forming means 10, is exposed by an exposure device 11 such as a laser or an LED, −100 V is applied. It becomes V. A current of 9 μA is supplied to the transfer roller 41 by the power supply C.

The transfer means 40 used in the present invention is not limited to the transfer roller 41, but may be any method capable of applying a predetermined electric field determined by the display characteristics of the medium to the rewritable medium R. Good (eg corona transfer unit).

In the present embodiment, the paper transport path that passes during the printing of the plain paper P is as shown in FIG. 6 by rotating the paper guide 110 to the position ①. When printing plain paper P according to the present embodiment, the electromagnetic clutch is controlled to be engaged (a state of transmitting torque). Note that the paper guide 110 has a step as shown in FIG. By rotating the guide plate 112 fixed to the spindle 111a of the motor by the bing motor 111, the paper transport path can be changed to ① or ②. Further, the exposure at the time of printing the plain paper P of the present embodiment exposes the toner developing unit (image display unit).

2) When forming rewritable media images

The relay 102 is switched under the control of the controller 101 so that a voltage is applied to the developing roller 3 1, the reset roller 3 2, and the blade 33 3 from the power source B in FIG. The voltage applied from the power supply B is a DC voltage of 100 V. The surface of the photoconductor 21 is charged to −700 V and becomes −100 V when exposed by an exposure device 11 such as a laser or an LED. In the present embodiment, the non-image display portion (the portion to be displayed in white) is exposed. A voltage of −400 V is applied to the transfer roller 41 from the power supply D. Note that the voltage of the developing roller 31 with respect to the photoconductor 21 may be controlled to be in a float state.

The rewritable medium R used in the present embodiment is configured by enclosing a colored dispersion medium (solvent) in which white negatively charged particles are dispersed in microcapsules, and forming the microcapsules into a sheet shape with a binder material. ing. The sheet may be formed by a method in which the microcapsule is fixed to another sheet-like base material by a binder material. The difference from the above-mentioned Japanese Patent Application Laid-Open No. H10-1414918 is that the rewritable medium R has no electrode. Note that the present invention has the same function even if it has an electrode, so that the electrode may be provided. The display principle is to apply an electric field to this sheet to cause electrophoresis of charged particles, and to display by expressing the contrast by the white of the charged particles and the color of the dispersion medium. In this embodiment, the electric field is applied by applying a voltage to the photoconductor 21 and the transfer roller 41.

In the present embodiment, the paper transport path that passes when printing the rewritable medium R is as shown in FIG. At this time, the rotatable paper guide 110 is in the position of ②. Further, a configuration may be adopted in which the fixing device 51 is allowed to pass through without being bypassed. In that case, as the configuration of the fixing device 51, a flash fixing device or a belt fixing device may be used. Furthermore, unlike when printing on plain paper, the photoconductor 2 The peripheral speed of 1 and the transport speed of the rewritable medium R are the same.

Further, in the present embodiment, the electromagnetic clutch is controlled to be in a cut-off state (a state in which torque is not transmitted) at the time of forming a rewritable medium R image. Of course, only the drive source of the developing means 30 (the drive system related to the development such as the developer reset device such as the developer roller 31, the developer stirring device, and the reset roller 32) is provided as a separate system, and the drive control thereof is performed. You can also do so.

FIG. 9 is a flowchart showing processing steps in the plain paper print mode and the rewritable medium image forming mode in the present embodiment.

When a print command is first given to the image forming apparatus, the print mode is checked (step S101), and in the plain paper print mode, the process proceeds to step S102 and subsequent steps. If the mode is the rewritable medium image forming mode, the flow shifts to step S109 or later.

In the plain paper printing mode, the fixing unit 51 is turned on to warm up (Step S102). Then, the photoreceptor 21 is charged by the charging device 60 as charging means (step S103).

Then, set the voltage supply to the developing roller 31, reset roller 32, and blade 33 to A, supply current from the power supply C to the transfer roller 41, and set the paper guide 110 to the position 、. Is set to ON (step S104).

Pick the plain paper P from the plain paper scoop and transport it (step S105). It is checked whether the transported medium is a rewritable medium R by a paper detection device (not shown) provided in the middle of the paper transport path (step S 10).

6) ₀

If the medium is a rewritable medium R (Step S106; Yes), the medium is discharged (Step S107). Conversely, if the medium is not a rewritable medium R (Step S106; No), it is determined that the medium is plain paper P, and normal printing processing (exposure, development, transfer, fixing, and discharge) is performed (Step S106). 1 day 8).

If it is determined in step S101 that the mode is the rewritable medium image forming mode, the fixing device 51 is turned off (step S109). Then, the voltage supply to the developing roller 31, the reset roller 32, and the blade 33 is set to B, the voltage is supplied to the transfer roller 41 by the power supply D, and the paper guide 110 is set to the position ②. To OFF (step S1 10).

Pick and transport the rewritable medium R from the rewritable medium hobber (Step S111).

The paper detection device checks whether the transported medium is a rewritable medium R (step S112).

If the medium is not a rewritable medium R (Step S112; No), the medium is ejected (Step S113). Conversely, if the medium is a rewritable medium R (step S112; Yes), it is determined that the medium is a rewritable medium R, and processing for image formation of the rewritable medium R (charging, exposure, and electric field of the photoconductor 21) is performed. (Application and discharge) (step S114).

(Embodiment 2)

The present embodiment relates to an image forming apparatus capable of performing both printing on plain paper P by a negatively charged non-magnetic one-component contact developing system and image formation on an electrophoretic rewritable medium R. Figure 10 conceptually shows the structure. The developing means 30 of the present embodiment includes a developing roller 31, a reset roller 32, and a blade 33. The developer port 31 is made of urethane rubber, the blade 33 is made of SUS, the reset roller 32 is made of urethane foam, and the photoconductor 21 is made of OPC. The drive of the developing roller 31 and the reset roller 32 of this embodiment, and the toner stirring paddle in the developing means 30 (not shown) are performed by other drive systems (photoconductor 21, transfer roller 41, paper transport system, etc.). And are linked via an electromagnetic clutch.

1) When printing on plain paper

During plain paper P printing, the developing roller 31 is in contact with the photoconductor 21. The relay 102 is switched under the control of the controller 101 so that a voltage is applied to the developing roller 31 and the blade 33 from the power supply A in FIG. The voltage applied from power supply A is a DC voltage of 320 V. Reset roller 3 The relay 102 is switched under the control of the controller 101 so that a voltage is applied to 2 from the power supply E in FIG. The voltage applied from power supply E is a DC voltage of 1450 V. The surface of the photoreceptor 21 is charged to −700 V, and becomes 110 V when the printing area is exposed by an exposure device 11 such as a laser or an LED. A current of 9 μm is supplied to the transfer roller 41 by the power supply C.

The transfer means used in the present invention is not limited to the transfer roller 41, and may be any method capable of applying a predetermined electric field determined by the display characteristics of the medium to the rewritable medium scale ( For example, corona transfer unit).

In this embodiment, the paper transport path that passes when printing plain paper P is as shown in FIG. At this time, the rotatable paper guide 110 is in the position of ①. When printing plain paper P in the present embodiment, the electromagnetic clutch is controlled to be engaged (a state of transmitting torque).

Further, in the exposure at the time of printing the plain paper P of the present embodiment, the toner developing unit (image display unit) is exposed.

The developing roller 31 and the photoreceptor 21 at the time of printing the plain paper P of the present embodiment, as shown in FIG. It is in the contact state shown.

2) When forming rewritable media images

At the time of rewritable medium R image formation, as shown in FIG. 12 (b), the unit constituting the developing means 30 is moved so that the developing roller 31 is not in contact with the photosensitive member 21. 2 Evacuate from 1.

The developing roller 3 1, the reset roller 3 2, and the blade 3 3 are controlled by the controller 101 so that the relay 102 is controlled by the controller 101 so that a voltage is applied from the power source B in FIG. Switched. As the voltage applied from the power supply B, a DC voltage of 100 V is added. The surface of the photoconductor 21 is charged to 170 V, and becomes 110 V when exposed by an exposure device 11 such as a laser or an LED. Then, the non-image forming portion (the portion to be displayed in white) is exposed. A voltage of 140 V is applied to the transfer roller 41 by the power supply D.

The rewritable medium R used in the present embodiment is the rewritable medium R of the first embodiment. The configuration is the same as that of the double medium R. In this embodiment, the electric field is applied by applying a voltage to the photoconductor 21 and the transfer roller 41.

In the present embodiment, as shown in the drawing, the paper transport path that passes during printing of the rewritable medium R is a path that goes around the fixing unit 51 that is the fixing unit 50. At this time, the rotatable paper guide 110 is in the position of ②.

At the time of forming the rewritable medium R image of the present embodiment, the electromagnetic clutch is controlled to a cut state (a state in which torque is not transmitted).

As described above, the developing roller 31 and the photoconductor 21 in the rewritable medium R image formation of the present embodiment are in a non-contact state as shown in FIG. 12 (b).

FIG. 13 is a flowchart showing processing steps in the plain paper print mode and the rewritable medium image forming mode in the present embodiment.

When a print command is first given to the image forming apparatus, the print mode is checked (step S201), and in the plain paper print mode, the process proceeds to step S202 and subsequent steps. In the rewritable medium image forming mode, the flow shifts to step S210 and subsequent steps.

If the printing mode is the plain paper printing mode, the fixing unit 51 is turned ON to warm up (Step S202).

Then, the unit of the developing means 30 is moved to a position where the developing roller 31 comes into contact with the photoreceptor 21 (step S203).

Further, the photoconductor 21 is charged by the charger 60 (step S204). Then, the voltage supply power to the developing roller 31 and blade 33 is set to A, the voltage supply power to the reset roller 32 is set to E, the current is supplied to the transfer roller 41 by the power supply C, and the paper guide 1 10 Set the 0 to the を position, and set the electromagnetic clutch

Set to ON (step S205).

Pick the plain paper P from the plain paper hopper and transport it (step S206). A check is performed as to whether the transported medium is a rewritable medium R by a paper detection device (not shown) provided in the middle of the paper transport path (step S20).

7).

If the medium is a rewritable medium R (step S2◦7; Yes), the medium Is discharged (step S208). Conversely, if the medium is not a rewritable medium R (Step S207; No), it is determined that the medium is plain paper P, and normal printing processing (exposure, development, transfer, fixing, and discharge) is performed (Step S207). 209).

If it is determined in step S201 that the mode is the rewritable medium image forming mode, the fixing device 51 is turned off (step S210).

Then, the unit of the developing means 30 is moved to a position where the developing roller 31 is not in contact with the photoconductor 21 (step S211).

Further, the voltage supply to the developing roller 31, the reset roller 32, and the blade 33 is set to B, the voltage is supplied to the transfer roller 41 by the power supply D, the paper guide 110 is set to the position ②, and the electromagnetic clutch is set. Set to OF F (step S2 12).

The rewritable medium R is picked from the rewritable medium hob and transported (step S213).

The paper detection device checks whether the conveyed medium is a rewritable medium R (step S214).

If the medium is not a rewritable medium R (step S214; No), the medium is ejected (step S215). On the other hand, if the medium is a rewritable medium R (Step S 214; Yes), it is determined that the medium is a rewritable medium R, and processing for image formation of the rewritable medium R (charging, exposure, and application of an electric field of the photoconductor 21) is performed. And paper discharge) (step S216).

(Embodiment 3)

In the present embodiment, as shown in FIG. 14, the configuration of an image forming apparatus for forming an electrostatic latent image on a dielectric 22 as an electrostatic latent image carrier by discharging is performed.

The head 12 of the electrostatic latent image forming means 10 may be any one of the methods of forming an electrostatic latent image by the above-described discharge, i), mouth), and c). An electrostatic latent image with negative ions is formed on the 22 image display units.

The dielectric 22 of the present embodiment is an aluminum drum whose surface is anodized. The inner surface of the drum is grounded. Further, the driving of the developing roller 31, the reset roller 32, and the toner stirring paddle in the not-shown developing means 30 of the present embodiment is performed by other driving systems (dielectric 22, transfer roller 41, paper (Such as a transfer system) via an electromagnetic clutch.

1) When printing on plain paper

At the time of image formation on plain paper P, as shown in FIG. 14, the developing roller 31 is brought into contact with the dielectric 22. At the time of plain paper printing of the present embodiment, the electromagnetic clutch is controlled to be engaged (a state of transmitting torque). The image forming process on plain paper P is shown below in order.

(i) Charging: The surface of the dielectric 22 is charged to 300 V by the charger 60. The charger 60 may be any type of charger such as a corona charger or a roller charger.

(ϋ) Latent image formation: In this embodiment, the electrostatic latent image formed on the dielectric material 22 has a portion which is patterned by discharge or ion flow at 300 V and a non-pattern portion has a voltage of 300 V. V. In the present embodiment, a portion where the electrostatic latent image is patterned is a non-image forming portion (a portion printed in white).

(iii) Development: This embodiment is an example of contact development using a non-magnetic one-component negatively charged toner. The developing roller 31 is made of urethane rubber, the blade 33 is made of SUS, and the reset roller 32 is made of urethane foam. 0 V is applied to the developing roller 31 and the blade 33, and 110 V is applied to the reset roller 32. Thereby, development to the electrostatic latent image is performed.

(iv) Transfer: The transfer from the dielectric 22 to the plain paper P is performed by applying a negative current of 9 A to the transfer roller 41. However, a 2 kV limiter is provided. The toner as a developer remaining on the dielectric 22 after the transfer is removed by the cleaning blade 70 and collected.

(V) Fixing: The toner transferred onto plain paper P is pressure-fused and fixed by fixing means 50 constituted by a heat roller.

2) When forming rewritable media images

When forming an image on the rewritable medium R, as shown in FIG. 15, the developing roller 31 is separated from the dielectric member 22 so that the unit constituting the developing means 30 is separated from the dielectric member 22. Evacuate from 2. Further, a voltage of 500 V is applied to the developing roller 31, the reset roller 32, and the blade 33.

The rewritable medium R used in this embodiment is the same as in the first and second embodiments. Then, by applying an electric field to the rewritable medium R, the charged particles are electrophoresed, and the contrast is expressed and displayed by the white of the charged particles and the color of the dispersion medium. In this embodiment, the color of the dispersion medium is blue.

The image forming process on the rewritable medium R will be described below in order.

(ϋ) Latent image formation: In this embodiment, the electrostatic latent image formed on the dielectric material 22 has a portion which is patterned by discharge or ion flow at 300 V and a non-pattern portion has a voltage of 300 V. V. In the present embodiment, the portion where the electrostatic latent image is patterned is an image forming portion (the portion printed in black).

(iii) Image formation on rewritable medium R: A voltage of 0 V is applied to dielectric 22 and transfer roller 41. The rewritable medium R is passed between the dielectric 22 and the transfer roller 41, and an image on the rewritable medium R is generated by an electric field generated between the electrostatic latent image formed on the dielectric 22 and the transfer roller 41. Perform formation.

The polarity of the charging by the charger 60, the polarity of the latent image, and the polarity of the toner in the present embodiment are a combination of 1 in Table 1 below, but may be a combination of 2 to 8. However, when the display color of the toner and the display color of the rewritable medium R are reversed, it is necessary to invert the latent image forming unit when printing the plain paper P and when forming the rewritable medium R image. 【table 1】

Note 1: The polarity of the latent image by the head is the potential polarity after the latent image is formed with respect to the potential before the latent image is formed.

Note 2: The display polarity of a rewritable medium is + when black is displayed by the electric field from the back surface of the medium to the display surface, and 1 when it is opposite.

Note 3: In the rewritable medium, the part described as black may be blue or red depending on the color of the dispersion medium and the charged particles. Black can be another color depending on the color of the toner.

(Embodiment 4)

In the present embodiment, as shown in FIG. 16, the configuration of an image forming apparatus for forming an electrostatic latent image on a dielectric body 22 serving as an electrostatic latent image carrier by discharging is performed.

The head 12 of the electrostatic latent image forming means 10 may be any one of the above-mentioned methods of forming an electrostatic latent image by discharging, such as a), mouth), and c). An electrostatic latent image is formed on the image display portion of the dielectric 22 by negative ions.

The dielectric 22 of the present embodiment is an aluminum drum whose surface is anodized. The inner surface of the drum is grounded.

The drive of the developing roller 31, the reset roller 32, and the toner agitating paddle in the image means 30 (not shown) is performed by another drive system (dielectric 22, transfer roller 41, (Paper transport system, etc.) via an electromagnetic clutch.

In order to form an electrostatic latent image on the rewritable medium R without direct contact, as shown in FIG. 16, the head 12 of the electrostatic latent image forming means 10 is made rotatable. The rotating mechanism of the head 12 will be described later.

In the present embodiment, a paper transport path for the rewritable medium R is provided separately. In that case, a corona charger 61 is separately provided in the middle of the paper transport path for the rewritable medium R. Such a paper transport path for the rewritable medium R is not separately provided, and the same paper transport path as the plain paper P is used. The dielectric 22 is evacuated from the transport path so that the rewritable medium R is not in contact with the rewritable medium R. Configuration may be adopted.

In the present embodiment, the potential regulating means 80 is fixed to the image forming apparatus main body. However, a sheet-like electrode is provided on the back surface of the rewritable medium R, and a brush contact or the like is provided to the sheet electrode. Good for applying voltage. 1) When printing on plain paper

The paper guide 1 13 and the head 12 of the electrostatic latent image forming means 10 are controlled to the position (1) in FIG.

As shown in Fig. 17, the paper guide 113 is rotated by a stepping motor 114 rotating a guide plate 115 fixed to a spindle 114a of the motor. The paper transport path can be changed to ① or ②. A pulley 1 16 for a toothed belt is provided on the upper part of the spindle 1 14 a. As shown in FIGS. 18 (a) and 18 (b), the pulley 1 Through the shaft 20, it can be rotated in synchronization with a pulley 1 17 for the toothed belt provided on a column (not shown) for supporting the head 12 of the electrostatic latent image forming means 10. It has become. Therefore, by rotating the stepping motor 114, the paper transport path is changed to the path of ① corresponding to FIG. 18 (a), and at that time, the electrostatic latent image forming means 10 is closed. The node 12 is set on the dielectric 22 side. Similarly, by rotating the stepping motor 114, the paper transport path is changed to the path indicated by ② corresponding to FIG. 18 (b). At this time, the head 12 of the electrostatic latent image forming means 10 is set on the potential regulating means 80 side.

When forming an image on plain paper P, the developing roller 31 is in contact with the dielectric 22.

At the time of plain paper P printing in the present embodiment, the electromagnetic clutch is controlled to be in a connected state (a state in which torque is transmitted). The image forming process on plain paper P is shown below in order.

(ϋ) Latent image formation: In this embodiment, the electrostatic latent image formed on the dielectric body 22 has a portion patterned by discharge or ion current of 300 V, and a non-pattern portion has 3 V. 0 V. In the present embodiment, the portion where the electrostatic latent image is patterned is a non-image forming portion (the portion printed white).

(ii) Development: This embodiment is an example of contact development using a non-magnetic one-component negatively charged toner. The developing roller 31 is made of urethane rubber, the blade 33 is made of SUS, and the reset roller 32 is made of urethane foam. For example, a voltage of 0 V is applied to the developing roller 31 and the blade 33, and a voltage of 110 V is applied to the reset roller 32. Thereby, development to the electrostatic latent image is performed.

(iv) Transfer: The transfer from the dielectric 22 to the plain paper P is performed by passing a negative current of 9 μm to the transfer roller 41. However, a 2 kV limiter is provided. The toner remaining on the dielectric 22 after the transfer is removed by the cleaning blade 70 and collected.

(v) Fixing: The toner transferred onto plain paper P is pressure-fused and fixed by fixing means (not shown) constituted by a heat roller.

2) When forming rewritable media images

The paper guide 1 13 and the electrostatic latent image forming means 10 head 12 are controlled to the position of ②.

When forming an image on the rewritable medium R, the unit of the developing means 30 is evacuated from the dielectric 22 so that the developer port 31 is separated from the dielectric 22. You.

The rewritable medium R used in this embodiment is the same as in the first, second, and third embodiments. Then, by applying an electric field to the rewritable medium R, the charged particles are electrophoresed, and the display is performed by expressing the contrast by the white of the charged particles and the color of the dispersion medium. In this embodiment, the color of the dispersion medium is blue.

The rewritable medium R transported to the rewritable medium transport path by the paper guides 113 passes between the ground potential regulating means 80 and the head 12 of the electrostatic latent image forming means 10. At the time of passage, an electrostatic latent image is formed directly on the rewritable medium R by the head 12, and an image is formed by an electric field generated between the electrostatic latent image and the potential defining means 80.

In this embodiment, the portion for patterning the electrostatic latent image is a non-image forming portion.

(Part displayed in white).

The charging polarity by the charger 60, the polarity of the latent image, and the polarity of the toner in the present embodiment may be a combination of forces 2 to 8, which is a combination of 1 in Table 1 above. However, when the display color of the toner and the display color of the rewritable medium R are reversed, it is necessary to invert the latent image forming unit when printing the plain paper P and when forming the rewritable medium R image.

FIG. 19 is a flowchart showing the processing steps of the plain paper print mode and the rewritable medium image forming mode in the present embodiment.

When a print command is first given to the image forming apparatus, the print mode is checked (step S301), and in the plain paper print mode, the process proceeds to step S302. In the rewritable medium image forming mode, the flow shifts to step S310 or later.

In the plain paper print mode, the fixing unit 51 is turned ON to warm up (step S302).

Then, the head 12 and the paper guide 113 of the electrostatic latent image forming means 10 are set to the position of ① (step S303). Further, the dielectric 22 is charged by the charger 60 (step S304). After that, developing roller 31, reset roller 32, blade 33, transfer roller 4

The power supply to 1 is turned on, and the electromagnetic clutch is turned on (step S305). Pick the plain paper P from the plain paper cutter and transport it (step S306). It is checked whether or not the transported medium is a rewritable medium R by a paper detection device (not shown) provided in the middle of the paper transport path (step S30).

7).

If the medium is a rewritable medium R (Step S307; Yes), the medium is ejected (Step S308). Conversely, if the medium is not a rewritable medium R (Step S307; No), it is determined that the medium is plain paper P, and normal printing processing (latent image formation, development, transfer, fixing, and discharge) is performed (Step S307). S 309).

If it is determined in step S301 that the mode is the rewritable medium image forming mode, the fixing device 51 is turned off (step S310).

Then, the head 12 and the paper guide 113 of the electrostatic latent image forming means 10 are set to the position of ② (step S311).

Further, the power supply to the developing roller 31, the reset roller 32, the blade 33, and the transfer roller 41 is turned off, and the electromagnetic clutch is turned off (step S312). The rewritable medium R is picked from the rewritable medium hob and transported (step S313).

The paper detection device checks whether the transported medium is a rewritable medium R (step S314).

If the medium is not a rewritable medium R (step S314; No), the medium is discharged (step S315). Conversely, if the medium is a rewritable medium R (Step S314; Yes), it is determined that the medium is a rewritable medium R, and processing for image formation of the rewritable medium R (charging of the dielectric 22, latent image formation, electric field (Application and discharge) (step S316).

(Embodiment 5)

In the present embodiment, as shown in FIG. 20, an image forming medium such as plain paper is discharged. An image forming apparatus of a type in which an electrostatic latent image is directly formed on a body and toner development is performed, and an apparatus capable of forming an image on a rewritable medium R is provided.

The head 12 of the electrostatic latent image forming means 10 may be any one of the above-described methods of forming an electrostatic latent image by discharge, such as a), mouth), and c). An electrostatic latent image by negative ions is formed on the image display section of the forming medium.

Although the potential regulating means 81 and 82 of the present embodiment are in the form of a roller, they may be in other forms represented by a plate. Although the potential regulating means 81 is fixed to the image forming apparatus main body, a sheet-like electrode is provided on the back surface of the rewritable medium R, and a brush contact or the like is provided with respect to the sheet electrode. It may be provided in the form of applying a voltage at. The potential applied to the potential regulating means 81 is a potential at which the discharge direction is on the side of the plain paper P or the rewritable medium R. In the present embodiment, the potential of the positive polarity is set based on the head 13.

In the present embodiment, the non-magnetic one-component negatively charged toner is developed by the jumping development method at the time of plain paper P printing. The developing port is kept at 0 V except during the time when the plain paper P passes between the developing roller 31 and the potential regulating means 82. The distance between the developing roller 31 and the plain paper P or the rewritable medium R is maintained at about 300 μιη. The potential regulating means 82 is always grounded.

1) When printing on plain paper

(i) The plain paper P is charged to 300 V by the corona charger 62.

(ϋ) Plain paper Ρ passes between the potential regulating means 81 and the head 13 of the electrostatic latent image forming means 10. At this time, the electrostatic latent image is patterned on the plain paper 放電 by the discharge from the head 13. The potential of the electrostatic latent image formed in this embodiment is 130 V.

(iii) A rectangular voltage of 2 kHz, 2.0 kV pp, and 35% duty (35% on the minus side) is applied to the developing roller 31. The non-magnetic one-component negatively charged toner formed on the developing roller 31 is developed into an image forming portion on the plain paper P. In this embodiment, the non-patterned portion of the electrostatic latent image is developed. (iv) The fixing unit (not shown) fixes the toner image on the plain paper P. 2) When forming rewritable media images

The developing roller 31 and the potential regulating means 82 are grounded.

(i) The rewritable medium R is charged to 30 OV by the corona charger 62. (ii) The rewritable medium R passes between the potential regulating means 81 and the head 13. At this time, the electrostatic latent image is patterned on the rewritable medium R by the discharge from the head 13. The potential of the electrostatic latent image formed in this embodiment is 130 V.

(iii) An image is displayed by an electric field generated between the electrostatic latent image on the surface of the rewritable medium R and the potential regulating means 81.

The charging polarity, the polarity of the latent image, and the polarity of the toner by the corner charger 62 of the present embodiment are a combination of 1 in Table 1 above, but may be a combination of 2 to 8. However, when the display color of the toner and the display color of the rewritable medium R are reversed, it is necessary to reverse the latent image forming section between printing on plain paper and forming an image on the rewritable medium.

(Embodiment 6)

A set of a photoreceptor 21 and a charger are used for both the plain paper printing mode using the normal electrophotographic method using the toner described in the first embodiment and the rewritable medium image forming mode for forming an image on the rewritable medium R. The present invention provides a configuration for detecting a rewritable medium R performed before image formation in these modes in an image forming apparatus performed by the exposure apparatus 11.

FIG. 21 is an enlarged view of a device for detecting the rewritable medium R indicated by 90 in FIG. The detection device 90 includes an electric field application unit 90a and a concentration detection unit 90b. The electric field applying section 90a is composed of conductive plates 91a and 91b installed opposite to each other with the paper transport path therebetween and a power supply section 92 for supplying a voltage thereto. Further, the density detecting section 90 b is provided downstream of the electric field applying section 90 a in the paper transport path, and detects a light source 93 for irradiating the image forming medium with light, and a reflection of the light from the light source 93. It is composed of a light receiving section 94 composed of a photodiode for receiving light. When the rewritable medium R or the plain paper P passes through the detection device 90, a predetermined electric field is applied by the electric field application section 90a. The electric field applied here is an electric field sufficient to display / non-display the rewritable medium R, and the direction of the electric field is a high-density portion (blue for a blue-white display medium, black for a black-white display). ) Is the direction displayed on the light receiving section 94 side of the density detecting section 9 Ob.

Therefore, if the medium that has passed through the electric field application unit 90a is plain paper P, the density detection unit 9Ob detects the density of the paper, and in the case of the rewritable medium R, the density detection unit 9Ob uses the rewritable medium R Will be detected.

When printing in plain paper print mode, if the detection result is plain paper P, printing is performed as is, and if it is rewritable medium R, printing is stopped and rewritable medium R is ejected.

At the time of printing in the rewritable medium image forming mode, if the detection result is the rewritable medium R, the image is displayed as it is, and if the detection is the plain paper P, the image formation is stopped and the plain paper P is discharged.

In the present embodiment, the detection of the rewritable medium R is performed by detecting the concentration when an electric field is applied by the detection device 90, but the detection of the impedance ゃ the detection of the resistance value allows the plain paper P and the rewritable medium R to be detected. A method for distinguishing R may be used. In these cases, the image forming surface is less affected by dirt.

(Embodiment 7)

Both the plain paper printing mode by the normal electrophotographic method using the toner described in the third embodiment and the rewritable medium image forming mode for forming an image on the rewritable medium R are performed by a set of dielectrics 22 and 23. An image forming apparatus provided with a charger 60 and a head 12 for forming a discharge or ion flow provides a structure for forming a plurality of images on a rewritable medium scale to display the same image.

The first image forming process will be described step by step.

(ii) Latent image formation: In this embodiment, the electrostatic latent image formed on the dielectric 22 is discharged or discharged. In this case, the portion patterned by the ion flow has a voltage of 300 V, and the non-pattern portion has a voltage of 300 V. In the present embodiment, the portion where the electrostatic latent image is putterung is the image forming portion (the portion printed black).

(iii) Image formation on rewritable medium R: A voltage of 0 V is applied to dielectric 22 and transfer roller 41. The rewritable medium R is passed between the dielectric 22 and the transfer roller 41, and the electric field generated between the electrostatic latent image formed on the dielectric 22 and the transfer roller 41 causes the rewritable medium R to be transferred to the rewritable medium R. An image is formed.

The image forming process for the second and subsequent sheets is as follows.

Since the electrostatic latent image is maintained on the dielectric 22 passing through the transfer roller 41, the second and subsequent images are directly formed without performing new charging and exposure.

(Embodiment 8)

The present embodiment provides a configuration for removing an electrostatic latent image remaining on the rewritable medium R after image formation in an image forming apparatus that directly forms an electrostatic latent image on the rewritable medium R by discharging.

As shown in FIGS. 22 and 23, the electrostatic latent image is formed directly on the rewritable medium R by the head 13 of the electrostatic latent image forming means 10 and the potential An image is formed by the generated electric field.

In the configuration of the present embodiment, after the image formation, the electrostatic latent image removing means 300 such as a conductive roller 301 shown in FIG. 22 or a conductive brush 302 shown in FIG. Thus, the electrostatic latent image formed on the surface of the rewritable medium R is removed.

(Embodiment 9)

The configuration of the present embodiment provides a configuration in which a screen display without image defects can be obtained by performing the process before forming an image on the rewritable medium R that has been left for a while.

Although the present invention can be implemented in all configurations in which an image is formed on the rewritable medium R by applying an electric field, in the present embodiment, as shown in FIG. A description will be given of a state in which the present invention is applied to an image forming apparatus that forms an electro-latent image directly on a rewritable medium R.

In the first stage of the image forming process, an AC electric field is applied by electric field applying means 400. In the present embodiment, the conductive plates 401a and 401b are arranged in parallel with the transport path of the rewritable medium R interposed therebetween, and an electric field is applied between the conductive plates 401a and 401b. Is applied, but a method of sandwiching between two conductive rollers (not shown) is also effective.

When an AC electric field is applied, the electrophoretic particles in the rewriter-tuple medium R vibrate due to the electric field, and the agglomerated particles also leave the individual particles. Thus, a normal image can be formed even with the rewritable medium R that has been left for a while.

(Embodiment 10)

In the present embodiment, an appropriate type of the electrostatic latent image forming means 10 is specified according to the type of the rewritable medium R.

As shown in FIG. 2, the rewritable medium R used in this embodiment has a dark color (for example, black) when the direction of the electric field is from the back side to the display surface side, and has a light color (for example, White). As the electrostatic latent image forming means 10 for directly or indirectly forming an electrostatic latent image on such a rewritable medium R, the polarity of the electrostatic latent image formed is the polarity before the latent image is formed. (The corresponding portions of the electrostatic latent image carrier 20 are shown as one unit in the figure).

If the configuration shown in FIG. 22 is described as an example, positive charging is performed so that the portion written by the head 13 for the electrostatic latent image forming means 10 has a dark colored display. The corona charger 62 is used, and the charging potential by this is set to 300 V. The head 13 for the electrostatic latent image forming means 10 is of a type that emits negative ions, and writes an electrostatic latent image on the rewritable medium R charged to 300 V. The potential of the written electrostatic latent image is −300 V. In this embodiment, the potential regulating means 81 is grounded to 0V. Potential defining means 8 Between 1 and electrostatic latent image An image is formed on the rewritable medium R by the generated electric field.

In addition, as shown in FIG. 3, a head 1 for the electrostatic latent image forming means 10 used in the rewritable ^ body R which has a high density display when the direction of the electric field is from the display surface side to the back side. As 3, it is preferable to use an electrostatic latent image to be formed in which the polarity is positive with respect to the polarity before the latent image is formed.

With the above configuration, when forming an electrostatic latent image, the smaller the duty (work amount) such as exposure or discharge by the electrostatic latent image forming means, the longer the head 13 S force lasts. . That is, when an image such as a general document is formed, the area other than the portion displayed as characters or figures is much larger. Therefore, it is desirable that the portion to be written by the head 13 be a colored portion such as black (or a portion having a higher density than the surroundings).

Industrial applicability

The image forming apparatus according to the present invention can print on a rewritable rewritable medium in an image forming apparatus such as a copying machine, a facsimile, a printer, and other information processing systems using an electrophotographic method. It is useful in the point that it can be used for a device that forms an image by a discharge method, and enables an image to be formed on a rewritable medium. It is also useful as

Claims

The scope of the claims

1. It has at least a charging unit, an electrostatic latent image forming unit, and a developing unit, and develops the electrostatic latent image formed by the electrostatic latent image forming unit by the developing unit. In an image forming apparatus for forming an image on an image forming medium, a rewritable medium having a potential defining means for defining a potential and capable of repeating image formation by applying an electric field is used as the image forming medium. An electrostatic latent image is directly or indirectly formed on a medium by the electrostatic latent image forming means, and an electric field is generated between the electrostatic latent image and the potential defining means to form an image. An image forming apparatus comprising:

2. At least an electrostatic latent image carrier, charging means for charging the electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and electrostatic Developing means for developing the electrostatic latent image formed on the latent image carrier; transfer means for transferring the image on the electrostatic latent image carrier developed by the developing means to an image forming medium; An image forming apparatus comprising: fixing means for fixing an image transferred to an image forming medium, comprising: a potential defining means for defining a potential; and a rewritable medium capable of repeating image formation by applying an electric field. An electrostatic latent image is directly or indirectly formed on the rewritable medium by the electrostatic latent image forming means, and an electric field is applied between the electrostatic latent image and the potential defining means. To generate images and perform image formation. An image forming apparatus symptoms.

3. As the electrostatic latent image forming means, a configuration in which an electrostatic latent image is formed by exposure is used, so that between the electrostatic latent image formed on the electrostatic latent image carrier and the potential regulating means. 3. The image forming apparatus according to claim 1, wherein an image is formed on the rewritable medium by the generated electric field.

4. As the electrostatic latent image forming means, a configuration for forming an electrostatic latent image by electric discharge is used, and the electric field generated between the formed electrostatic latent image and the potential regulating means causes the rewritable image to be formed. 3. The image forming apparatus according to claim 1, wherein an image is formed on a medium.

5. When the formation of the electrostatic latent image on the rewritable medium is performed indirectly, 5. The image forming apparatus according to claim 3, wherein the transfer unit is used as the potential regulating unit.

6. The electrostatic latent image forming means is provided at a position facing the rewritable medium, or is moved to the position, and the electrostatic latent image forming means forms an electrostatic latent image on the rewritable medium; 5. The image forming apparatus according to claim 4, wherein an image is formed on the rewritable medium by an electric field generated between the image and the potential defining means.

7. A rewritable medium that has at least a charging unit, an electrostatic latent image forming unit, and a potential regulating unit that regulates an electric potential, and uses a rewritable medium capable of repeating image formation by applying an electric field as an image forming medium, An electrostatic latent image is formed directly or indirectly on the rewritable medium by the electrostatic latent image forming means, and an electric field is generated between the electrostatic latent image and the potential defining means to form an image. The electrostatic latent image capable of generating an electric field in a direction corresponding to the density of a predetermined image formed on the surface of the rewritable medium between the rewritable medium and the potential regulating unit, the electrostatic latent image comprising: An image forming apparatus formed by image forming means.

8. When the direction of the electric field is from the back side to the display surface side, as the electrostatic latent image forming means used for a rewritable medium that displays high density, the polarity of the formed electrostatic latent image is changed before the latent image is formed. 8. The image forming apparatus according to claim 7, wherein a negative one is used based on the polarity of the image.

9. As a means for forming an electrostatic latent image used in a rewritable medium that provides high-density display when the direction of the electric field is from the display surface side to the back side, the polarity of the formed electrostatic latent image is changed before the latent image formation. The image forming apparatus according to claim 7, wherein a positive one is used based on the polarity of the image.

10. When an image is formed on a rewritable medium by using an electrostatic latent image pattern developed at the time of development and an electric field generated between the electrostatic latent image pattern and the potential regulating means, When the density of the portion corresponding to the electrostatic latent image pattern becomes lower than the others, it is necessary to invert the electrostatic latent image pattern between when the image is formed by the developed pattern and when the image is formed on the rewritable medium. The image forming apparatus according to any one of claims 1 to 5 and 7 to 9, which is a featured claim.

1 1. When the electrostatic latent image pattern is developed using a negatively charged developer and the image is formed, and when the direction of the electric field is from the display surface side to the back side, the density is low and the display is reversed. The image forming apparatus according to claim 10, wherein an electrostatic latent image pattern formed by the electrostatic latent image forming unit is inverted between when an image is formed on a rewritable medium that provides high-density display in the case of (1). Image forming device.

1 2. When the electrostatic latent image pattern is developed using a positively charged developer and image formation is performed, and when the direction of the electric field is from the display surface side to the back side, the display becomes high in density, and vice versa. 10. The image forming apparatus according to claim 10, wherein the electrostatic latent image pattern formed by the electrostatic latent image forming unit is inverted between the time when an image is formed on a rewritable medium that provides a display with a low density. apparatus.

13. When an image is formed on a rewritable medium, the voltage pole 14 of the developer carrier in the developing means with respect to the electrostatic latent image carrier is set to ± ov, or the electrostatic force applied to the developer is changed to an electrostatic latent image. The image forming apparatus according to any one of claims 2 to 5, and 7 to 12, wherein the polarity is from the carrier to the developer carrier.

14. An image forming method on a rewritable medium, wherein a voltage of the developer carrier in the developing means with respect to the electrostatic latent image carrier is floated. 13. The image forming apparatus according to any one of 1 to 2.

15. A range of claims 1 to 14, wherein an image is formed on a rewritable medium in a configuration in which development is performed in a state where the developer layer of the developing means does not contact the electrostatic latent image carrier. The image forming apparatus according to any one of the above.

16. In an image forming apparatus in which the developer layer or the magnetic brush of the developing means contacts the electrostatic latent image carrier to perform development, the developer layer or the magnetic brush and the electrostatic latent image carrier are in a non-contact state. Any one of claims 2 to 5 and 7 to 14 wherein the electrostatic latent image carrier and part or all of the developing means can be relatively separated so that An image forming apparatus according to claim 1.

17. The image forming apparatus according to claim 15, wherein only the drive source of the developing means is provided as a separate system and drive control is performed.

18. The method according to claim 15 or 16, wherein the drive source of the developing means is in the same system as the other drive sources, and the power supply to the developing means can be cut off. Image forming device.

19. The image forming apparatus according to any one of claims 1 to 18, wherein, when forming an image on a rewritable medium, the rewritable medium has a path that does not pass through a fixing unit as a conveyance path of the rewritable medium. apparatus.

20. The image forming apparatus according to any one of claims 1 to 5, and 7 to 18, wherein a flash fixing device is used as the fixing unit.

21. The image forming apparatus according to any one of claims 1 to 5, and 7 to 18, wherein a belt fixing device is used as the fixing unit.

22. When an image is formed using the developed electrostatic latent image pattern, a current is applied to the transfer unit by constant current control, and when an image is formed on a rewritable medium, 6. The image forming apparatus according to claim 5, wherein a voltage is applied by constant voltage control.

23. The method according to any one of claims 2 to 5, wherein the peripheral speed of the electrostatic latent image carrier and the transport speed of the rewritable medium are the same during image formation on the rewritable medium. The image forming apparatus according to any one of the above.

24. A rewritable medium that has at least a charging unit, an electrostatic latent image forming unit, and a potential specifying unit that specifies an electric potential, and uses a rewritable medium capable of repeating image formation by applying an electric field as an image forming medium An electrostatic latent image is directly or indirectly formed on the rewritable medium by the electrostatic latent image forming unit, and an electric field is generated between the electrostatic latent image and the potential defining unit. An image forming apparatus for forming an image, wherein a rewritable medium and another image forming medium are identified before the image is formed.

25. An image forming apparatus that forms an image only on a rewritable medium, identifies a rewritable medium and another image forming medium before image formation, and supplies an image forming medium other than the rewritable medium. 25. The image forming apparatus according to claim 24, wherein when the error occurs, the error is processed and image formation is not performed.

26. An image forming apparatus for forming an image on an image forming medium other than a rewritable medium and forming an image on a rewritable medium, wherein the rewritable medium and the other image forming medium are separated before forming the image. Identify and print non-rewritable media When a rewritable medium is supplied in a print mode in which an image is formed on an image forming medium, or in a rewritable medium in which an image is formed on a rewritable medium, an image forming medium other than the rewritable medium is used in an image forming mode. 25. The image forming apparatus according to claim 24, wherein when supplied, the image is processed as an error and image formation is not performed.

27. An image forming method for forming an image on an image forming medium by applying an electric field, measuring a display density of the image, and distinguishing between the rewritable medium and the other image forming medium. 24. The image forming apparatus according to claim 24, 25 or 26.

28. The method according to claim 24, wherein the rewritable medium and the other image forming medium are distinguished by detecting the impedance or resistance value of the image forming medium. Image forming device.

29. A rewritable medium that has at least a charging unit, an electrostatic latent image forming unit, and a potential specifying unit that specifies an electric potential, and uses a rewritable medium capable of repeating image formation by applying an electric field as an image forming medium An image for forming an image by forming an electrostatic latent image directly on the rewritable medium by the electrostatic latent image forming means and generating an electric field between the electrostatic latent image and the potential defining means An image forming apparatus, wherein an electrostatic latent image formed on a surface of the rewritable medium is removed after image formation.

30. A rewritable medium that has at least a charging unit, an electrostatic latent image forming unit, and a potential specifying unit that specifies an electric potential, and uses a rewritable medium capable of repeating image formation by applying an electric field as an image forming medium An electrostatic latent image is indirectly formed on the rewritable medium by the electrostatic latent image forming means, and an electric field is generated between the electrostatic latent image and the potential regulating means to form an image. When the same image is formed on a plurality of rewritable media, the charging and latent image formation are not performed.

An image forming apparatus for forming an image on a rewritable medium of a second or subsequent sheet using a first latent image.

31. A rewritable medium that has at least a charging unit, an electrostatic latent image forming unit, and a potential specifying unit that specifies an electric potential, and uses a rewritable medium capable of repeating image formation by applying an electric field as an image forming medium Used for this rewritable medium, In an image forming apparatus for forming an image by forming an electrostatic latent image directly or indirectly by an electrostatic latent image forming means and generating an electric field between the electrostatic latent image and the potential defining means, a rewritable image forming apparatus is provided. An image forming apparatus comprising: applying an AC electric field to a rewritable medium before forming an image by applying an electric field to the medium.