WO1991010929A1 - Electronic printer using a fiber optic bundle and a linear, one-dimensional light source - Google Patents
Electronic printer using a fiber optic bundle and a linear, one-dimensional light source Download PDFInfo
- Publication number
- WO1991010929A1 WO1991010929A1 PCT/US1990/005755 US9005755W WO9110929A1 WO 1991010929 A1 WO1991010929 A1 WO 1991010929A1 US 9005755 W US9005755 W US 9005755W WO 9110929 A1 WO9110929 A1 WO 9110929A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- light
- linear
- face
- array
- accordance
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/04—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
- G02B6/06—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres the relative position of the fibres being the same at both ends, e.g. for transporting images
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/435—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of radiation to a printing material or impression-transfer material
- B41J2/447—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of radiation to a printing material or impression-transfer material using arrays of radiation sources
- B41J2/46—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of radiation to a printing material or impression-transfer material using arrays of radiation sources characterised by using glass fibres
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
- G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
- G06K15/12—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers
- G06K15/1238—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point
- G06K15/1242—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point on one main scanning line
- G06K15/1247—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point on one main scanning line using an array of light sources, e.g. a linear array
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
- G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
- G06K15/12—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers
- G06K15/1238—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point
- G06K15/1242—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point on one main scanning line
- G06K15/1252—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point on one main scanning line using an array of light modulators, e.g. a linear array
Definitions
- This invention relates to electronic printers and more particularly to such printers utilizing a plurality of light conduits such as a bundle of optical fibers.
- U.S. patent No. 4,760,421 issued July 26, 1988, and now assigned to the assignee of the present application discloses an electronic printer which utilizes a noncoherent bundle of optical fibers.
- the fiber ends at one face of the bundle are organized in a linear array.
- the ends of the same fibers in a second face are organized in an area array which may be, for example, rectangular. square or circular.
- the fiber bundle is used to transmit light from an array of light sources optically coupled to the area array face of the bundle to, for example, photosensitive, photographic, or electrophotographic medium coupled to the linear array face of the bundle.
- Each of the fibers in the linear array face represents a pixel in a line of pixels.
- the light source comprises a cathode ray tube (CRT) operative to generate a localized area of light at each of a sequence of electron beam addresses on the face plate of the tube which is coupled to the area array face and produces the desired sequence of pixels generated at the linear face of the bundle.
- CTR cathode ray tube
- the sequence of tube face plate addresses which corresponds to the sequence of pixels in the linear array face of the fiber optic bundle is obtained in accordance with the above-mentioned patent, during an initialization procedure in which light is introduced into individual fibers in the area face of the bundle by a CRT, and a photosensor is moved incrementally along the linear face of the bundle.
- the photo-sensor is covered by an opaque hood with a narrow transparent slit in it.
- the slit is narrow compared to a fiber diameter and is moved in increments also small compared to a fiber diameter. Light passing through the slit is incident on the photosensor. This procedure results in the photosensor measuring light unambiguously from only one fiber at a time.
- a CRT is used to direct electrons to each of the preestablished beam addresses on the face plate while the photosensor is stationary at a selected position in the linear face.
- the photosensor indicates the presence of light in the fiber
- the set of electron address for which light appears in the fiber is associated with the
- photosensor slit position in each instance, to determine the correspondence between the electron addresses and a pixel position (presumably a fiber end) in the linear face.
- An optimum address for each pixel is chosen from each set. Because the photosensor is moved from pixel position to
- a sequence of associated addresses is thus obtained.
- the resulting table of pixel positions vs. electron beam addresses is stored in a PROM which is interrogated during normal operation of the printer. The interrogation of the sequence of addresses occurs each time a line of pixels is to be generated. Pixels are excited, at the positions so obtained, during normal operation of the printer, to discharge, for example, consecutive (imaginary) linear segments of a moving electrostatic drum or belt in an electrophotographic process.
- the CRT useful in such a printer is relatively small, essentially about the size of a conventional cigar.
- the face plate for such a CRT advantageously comprises a disc of small diameter optical fibers.
- the area face of the fiber optic bundle is abutted against or optically coupled to the fiber optic face plate and permanently fixed in position with respect to the face plate so that light generated at a selected one of the face plate addresses enters the end of a fiber in the area face of the bundle and excites a corresponding pixel in the linear face.
- Two dimensional commercial displays which use a linear array of light emitting elements to define a horizontal sequence of pixels within a row with mechanical deflection to achieve a vertical sequence of rows to simulate a two- dimensional array. Because the TV field rate in the US is 60 fields per second, a vertical scan rate of 60 per second is implied and not excessive for mechanical scanners. Such arrangements produce useful TV, computer and helmet mounted displays.
- the above- noted linear scan display technique is adapted to replace the CRT of the printer arrangement of patent 4,260,421 mentioned above to provide, not only the option to generate light signals on a flying spot basis as in a CRT, but also on a basis of all light signals of a line being generated simultaneously.
- the invention specifically is directed at a printer which includes a fixed linear array of discrete light-generating elements which is relatively inexpensive, relatively small and low power, and can be assembled from commercially available components.
- the size of the spot is also invariant.
- the adaptation includes a digitizing arrangement for the movement of the image of the linear array through a sequence of reproducible vertical positions to achieve the equivalent of a two-dimensional field of discrete light sources.
- the adaptation also includes a unique initialization procedure which relates the addresses for the light generating elements of light patterns introduced at an area face of a fiber optic bundle to pixel positions at a linear opposite face of the bundle.
- a linear array of light sources such as a linear light emitting diode (LED) array or liquid crystal shutter (LCS) array is imaged onto a linear segment (i.e. aligned with one axis) of the area face of a fiber optic bundle.
- LED linear light emitting diode
- LCD liquid crystal shutter
- these fibers are excited close together in time and relative vertical displacement of adjacent pixels in the linear array face can be kept to an insignificant amount. Thus, vertical tearing does occur, but it is not visible to the eye. Further, judicious selection and timing of the light-emitting source corresponding to a fiber end in the area face of the fiber optic bundle permits compensation for any distortions due to tearing.
- the area face of the bundle is organized in a rectangular geometry, illustratively a random arrangement nominally almost ninety fibers wide by thirty fibers high, for a 2550 element linear fiber array suitable for a three hundred dot per inch resolution over eight and one half inch wide output common to presently-available, commercially available printers.
- the 256 LED or LCS linear array is imaged onto consecutive (imaginary) linear segments of the area face by a lens system and a moving mirror.
- the light from the LED or LCS linear array is turned off between each linear segment to permit entry of data for the LED or LCS from memory for the next linear segment before movement of the image to the position of the next linear segment occurs.
- appropriate elements in the linear array are turned on simultaneously to inject light into the appropriate fibers of the area array face.
- the photosensitive medium although moving, is for all practical purposes, made
- the light spots corresponding to the totality of fibers in the linear end of the fiber optic bundle are generated during the time the mirrored image moves vertically through, for
- the width of the rectangular area face is along an x- axis (the height is along a y-axis) and the image of the linear LED or LCS array is moved along the y- axis.
- the precise y-axis position of the mirrored image is determined conveniently by a single large area sensor or a linear array of photosensors positioned along the y-axis of the area face of the bundle. This large area photosensor is, for example, covered by a series of transparent and opaque lines
- the mirrored light of the index source impinges on the grid in a manner to identify the y-axis position of the image of the linear array during the
- the LCS is operative as a shutter of light generated by a backside lamp.
- the LCS array thus shutters all the light from the lamp
- associated addresses in the area face of the fiber optic bundle selectively during the time period when the LCS image is at a particular vertical position.
- An initialization procedure to obtain the LCS or LED array addresses associated with the sequence of pixels in the linear face of the fiber optic bundle is obtained, in accordance with the present invention, conveniently by activating all the LCS or LED elements, for example, and then rotating the mirror through the succession of (y) positions corresponding to the linear segments of fibers of the bundle.
- the LCS or LED element addresses are ascertained for each vertical position corresponding only to the positions of maximum light intensities rather than to all the addresses as described above.
- an individual light source usually is illuminated for more than one vertical position and consecutive y positions may overlap one another.
- the light source addresses so determined are placed in proper sequence by moving the hooded photosensor to consecutive maximum intensity
- a linear array of photo sensor cells such as a charge-coupled device may be
- Fig. 1 is a representative block diagram of a printer engine in accordance with this
- Fig. 2 is an expanded representation of a portion of the engine of figure 1;
- Fig. 3 is a schematic representative of the components of the engine of figures 1 and 2;
- Figs. 4 and 5 are representative block and expanded detail views of a component of the engine of figures 1 and 2;
- Fig. 6 is a flow diagram of procedure for initializing the optical subsystem of the printer engine of figures 1 and 2;
- Fig. 7 is a representative block diagram of apparatus used for performing the method
- FIG. 1 shows a printer engine assembly 10 in accordance with the principles of this
- the assembly comprises an image
- the image formation subassembly is
- Box 11 comprises an
- xerographic module including an electrostatic drum or belt, a toner station, a transfer station and a fixer station.
- This subassembly operates in a manner well understood in the art to transfer to plain paper a charge image formed on the electrostatic medium by optical exposure.
- the optical subassembly is operative to develop the charge image on the electrostatic medium.
- the electrostatic medium is represented by cylinder 12 and is adapted to rotate about axis 13 as shown.
- the optical subassembly for forming the charge image on medium 12 includes a fiber optic bundle shown encompassed by imaginary tie 15.
- the fiber ends are arranged linearly in a first face 17 of the bundle and arranged illustratively in a rectangular geometry in a second face 18.
- the area face can be represented as having x and y axes with the fibers arranged roughly in rows along the x axes. These rows are imaginary and the row
- the illustrative optical subassembly also includes a linear array 19 of liquid crystal
- Array 19 also includes a number, N, of LCS devices which is large compared to the number, S, of fibers along the x axis of the area face of the bundle.
- N the number of LCS devices which is large compared to the number, S, of fibers along the x axis of the area face of the bundle.
- a rectangular (but random) array of fibers approximately 30 x 90 is used where the ninety fibers are positioned along the x axis and the thirty fibers are positioned along the y axis, the fiber positions being entirely random and not actually occurring in rows or columns.
- a linear array of LCS's would include perhaps 256 individual shutter elements. The excess number of elements over the number of fibers in the row will be seen to be important as explained below.
- Linear array 19 is operated as a line of individual light valves shuttering light according to data applied to it.
- an output of memory 20 is connected to array 19 and is operative to shift a set of data into array 19 under the direction of control circuit 21.
- Light for LCS embodiments, is provided by a backplane lamp 23 and is selectively shuttered by the LCS device.
- Any light exiting LCS array 19 is directed at a mirror 24.
- Mirror 24 is rotated about its axis 25 by a motor 26 also under the direction of control circuit 21.
- Axis 25 is aligned with the x axis of area face 18 of the fiber optic bundle.
- the light from LCS array 19 is imaged onto consecutive y positions of the linear segments of the area face where the long dimension of each linear segment is parallel to the x axis of the area face.
- Mirror 24 also is rotated in a manner so that memory 20 operates to move pixel data into the LCS array 24 many times, say 100 times, during the rotation of the mirror over the area face. Thus, there are perhaps three times as many vertical addresses as there are fibers in the columns. The number 100 rows times 256 elements per row (25600) is
- initialization procedure need select only one series of addresses for each fiber (one address if
- Control circuit 21 also controls a motor 28.
- Motor 28 drives electrostatic medium 12 with which all the functions of the image-formation subassembly are synchronized in a well known manner.
- control circuit 21 moves the electrostatic medium properly in synchronism with the movement of mirror 24 to achieve a vertical pixel height approximately equal to the pixel width.
- Figure 2 shows an enlarged fragment of the electrostatic medium coupled to a corresponding fragment of the fiber optic bundle.
- the fibers 30, 31, 32, 33, - - shown by solid lines all originate at the same row ( y 2) in figure 2. It should be noted that the ends of these fibers at linear end 17 are in no predictable positions there. Similarly, fibers 40, 41, 42, 43 - - originate at row y 1 in area face 18 and again assume no predictable
- the memory operates to provide the proper pixel data for each pixel at linear end 17 of the fiber optic array even though that array is totally noncoherent.
- the y-axis address vector is determined conveniently by including an extra index element in array 19.
- the extra index element is designated 50 in figure 2.
- the extra element is termed "extra” because it does not correspond in position to any portion of area face 18 of the fiber optic bundle. Rather, the light exiting element 50 is directed onto a single sensor 60 through a mask 61.
- Mask 61 includes a grid of opaque and transparent spaces (an optical grating) which responds to the position of the light exiting element 50 to represent the y-axis address vector corresponding to the image of the linear light source array.
- sensor 60 may comprise, for example, a photosensor array to provide the y-axis vector for each image position.
- FIG 3 shows a schematic representation of the various elements of the optical subassembly of figure 1.
- Lamp 70 is shown as having a filament 73.
- the subassembly also includes a reflector or metallized coating (not shown) used (in practice) to double the light introduced into the system by the lamp. Light from lamp 70 is transmitted by
- LCS array 19 condensing lens 76 to LCS array 19.
- the light pattern passing LCS array 19, in each instance, is directed to the mirror (24) for reflection onto a linear segment of the area face 18 of the fiber optic bundle through projection lens 78.
- LCS array 19 has been described as a single linear array of liquid crystal light valves. In practice, array 19 might be arranged in other than a single linear row, for example, in two rows assembled like bricks in a wall where the bricks of one row are offset one half brick from the bricks in the next row. The arrangement is shown in figures 3 and 4 where elements 90 and 91 in row 93 are shown offset from elements 95 and 96 in row 97.
- Figure 5 shows the array in greater detail showing an LCS cell size of 37 p wide by 67 ⁇ high and intercell gaps of 11.15 p. Such a LCS array is available commercially from Displaytech Inc. of Boulder,
- the arrangement displayed for the liquid crystal shutters in figure 3 is consistent with the brick-like LCS organization.
- the operation of the printer engine of figures 1 and 2 can be summarized as follows:
- the data to be printed on a page is already stored in memory 20 which may be a computer memory such as a disk.
- Memory 20 shifts shutter (open and closed) data into LCS array 19.
- Mirror 24 directs the resulting light pattern to a linear segment of area face 18 of the fiber optic bundle for exposing medium 12 to a discharge pattern.
- Memory 20 shifts a next subsequent pattern into LCS array 19.
- mirror 24 rotates to a position
- the arrangement operates as an all- digital printer engine.
- LCS array 19 comprises a ferroelectric liquid crystal shutter (FE-LCS) the state of the art time to switch the shutter is 10 ⁇ s or less in a nonmultiplexed configuration such as is used here.
- FE-LCS ferroelectric liquid crystal shutter
- voltage is applied and the shutter begins to open at 5 ⁇ s.
- 10 ⁇ s the shutter is fully open and exposure has begun.
- a pulse is applied to close the shutter; the shutter begins to close at 25 ⁇ s and exposure is over at 30 ⁇ s.
- the shift register (memory 20) is filled with new data.
- the cycle is then repeated providing an effective exposure time of more than 15 ⁇ s, although the shutter may remain open for several periods
- the shift register includes 128 elements for one row of LCS array 19.
- the data rate is about 5 MB/s.
- the necessary exposure energy passing out of the FE-LCS array is 2.4 ⁇ watts per pixel during 15 ⁇ s exposure.
- the energy incident on the shutter continuously is about 10 ⁇ watts per pixel.
- the pixel footprint is 50 ⁇ on a side and the pixel area is 2.5 x 10 -5 cm 2 .
- the continuous incident optical power density is about 1 watt/cm 2 .
- the FE-LCS can sustain an energy density of about 4 watts/cm 2 .
- the required continuous optical power incident on the shutter is 2.6 m watts.
- the required optical power from the lamp is about 0.2 watts.
- a 100 watt Tungsten filament operated at 3200 degrees k has adequate brightness to produce this even with filtering.
- the shift register driver chips for the shutter can be attached directly to LCS array 19 as shown in figure 3.
- the description has been rendered in terms of a LCS shutter arrangement. Other arrangements also can be used such as light emitting diodes
- LEDs magneto-optic light valve and edge- emitting, thin film, electroluminescence devices (EE-TF-EL).
- EE-TF-EL electroluminescence devices
- TF transmission factor for a Lambertian emitter such as LED
- TF [4F 2 (1+1/M) 2 +1] -1 in which F is the F-number of the lens and M is the linear magnification, i.e. the linear dimension of the spot in the plane of the fiber array divided by the linear dimension at the emitting array.
- the spot size on the fiber is fixed.
- M is the variable.
- M -2 is the available energy
- the transmitted energy decreased
- the consideration above is valid so long as the effective numerical aperture of the lens is less than that of the fiber.
- the energy transmitted to the fiber increases with source size.
- the dimension of the LED is about equal to the fiber diameter, i.e. 85 microns. We want this to be about 28.33 microns in the image plane.
- the transmission factor is 0.02.
- magnification is 0.1 and the transmission factor is 2.1 x 10 -3 or 10 times lower.
- the available energy is at least 16 times greater.
- the actual gain from using larger LEDs may be much greater.
- Large LEDs offer substantial opportunities for improving brightness.
- the maximum line time is 3 ms
- the necessary power out of the LED is 60 ⁇ watts. With reflection losses of about 15% this requirement becomes 70 ⁇ watts.
- the LED emits 20 ⁇ watt/ma. This corresponds to a power efficiency of about 1.3%, typical of small, diffused-junction LED arrays in GaAlAs.
- the drive current requirement is 3.5 ma to achieve 70 ⁇ watts. This is a reasonable drive current for such a small LED.
- the LEDs tend to saturate with
- the LED on time is probably of order 60 ⁇ s.
- the exposure requirement is the same.
- the NA of a suitable selfoc lens array is 0.1-0.2 at best.
- the energy transmission factor can be
- the initialization procedure for the optical subassembly of the printer engine of figures 1 and 2 is directed at determining the addresses of light imposed on the area face 18 of the fiber optic bundle and the relationship between those addresses and the pixels exiting the linear face 17 of that bundle. In the absence of the establishment of such relationship, light patterns directed at the area face will be scrambled at the linear face.
- no two-dimensional, addressable, light- generating means such as a CRT is present. Instead, a linear, light-generating means is made two- dimensional by rotating a mirror which sweeps an image of a linear array of light-generating means onto consecutive linear segments of the area face of the fiber optic bundle, the light patterns being changed "on the fly.”
- eight bits (x axis bits) of a sixteen bit address code are supplied by an address register (not shown) which is part of the linear LCS array 19.
- the other eight bits (y axis bits) are supplied by sensor 60 and mask 61 to correspond to the angular orientation of mirror 24.
- mirror 24 of figure 1 is an elongated polygon as shown in figure 3, for example, and motor 26 of figure 1 is a stepper motor, the mirror can be maintained in consecutive fixed positions during an initialization procedure.
- the relationship between the pixel positions in the linear end and those addresses are determined during the initialization procedure by opening all light valves of LCS array 19 and by directing light through all the open shutters to a linear segment of the area face. While light is incident on all of the instant linear segment, a hooded sensor with a transparent slit is moved along the linear face of the bundle in increments small compared to a fiber diameter. In this manner, all slit positions for which maximum intensity peaks occur for that linear segment (i.e. see figure 2) are obtained. The light valves remain on and the process is repeated for the next linear segment. The process continues until all the linear segments are exposed. At this
- the proper sequence for those addresses is obtained by opening shutter only those shutters (LCS's) of array 19 at addresses (x and y) which correspond to one of the maximum intensity positions previously obtained one at a time while the hooded photosensor is in one of the consecutive maximum intensity positions.
- the address for which light exists at the photosensor position is recorded in each instance as described above. It takes about 100 ms to move the hooded photosensor to a new fiber (pixel) position and scan the mirror. Thus, the total line time is 255 seconds for 2550 fibers.
- FIG. 6 shows a flow diagram of the initialization procedure where the linear face is scanned by the hooded photosensor each time a linear segment of the area face is illuminated.
- Block 100 indicates that a linear segment of the area face is illuminated.
- Block 101 indicates that the hooded sensor is moved to determine all addresses at which maximum light intensity occurs.
- Block 102 indicates that those addresses are stored. This procedure is repeated until light has been generated at all linear segments as indicated by arrow 105. It is helpful to remember that there are about ten
- the sensor selects the set of addresses, amongst the ten for each fiber, at which the maximum intensity occurs.
- the addresses at which maximum intensity occur in one linear segment of the area face are interleaved with the addresses from other segments.
- the addresses of maximum intensity positions are placed in a sequence to correspond the sequence of pixels in the linear face of the fiber optic bundle. This is accomplished by moving the slit (photosensor) to a now known position of maximum light intensity and, while the photosensor is in that position,
- Figure 7 shows an arrangement for carrying out the initialization procedure.
- the fiber optic bundle 120 again extends from an area face 121 to a linear face 122 as in figure 1.
- a photosensor 124 covered with a hood having a slit 125 is moved along track 127.
- the incremental movement of the sensor is carried out by a motor 130 under the control of control circuit 131 which may be control circuit 21 of figure 1.
- Control circuit 131 typically comprises a relatively fast computer programmed for the initialization procedure operation. A much less sophisticated control circuit can be used for the finished printer.
- control circuit (131) is operative, as is control circuit 21 of figure 1, to control the light generating means LCS 19 (or LED equivalent), the liquid crystal shutters, and mirror 24 and to synchronize the operation of the light-generating means with the movement of sensor 124 along track 127.
- Figure 7 also shows a lamp 135 for illuminating the entire area face of the fiber optic array if required by the chosen initialization procedure.
- the image of the linear LCS light valve (LV) array (19 of figure 3) is scanned mechanically by a rotating polygon (24) across the area face 18 of the fiber optic bundle as described above.
- Particular shutters in the linear array are turned on to transmit light into particular fibers.
- the image of the linear array scans at approximately constant velocity across the area face (18) of the fiber optic bundle.
- An index light source at the end of the linear LCS array generates timing signals from a transmission grid photodetector in the plane of the area face of the fiber optic bundle
- the system turns on the particular pixels in the row at just the right time to excite the appropriate fibers.
- the incoming pixel stream is reordered so as to produce pixels at the right position in the written line on the photosensitive medium.
- the indexing light source (shutter) is designated 200 in figure 3.
- photodetector is designated 201 and the timing signals are designated 202.
- Polygon 24, in one specific embodiment is a 20 facet, 38 mm radius mirror arrangement and lens 76 is a 50 mm, F/3.1, 1:1 focusing lens.
- a typical scan configuration there are at least 100 linear segments and 256 elements in the segment (and the segments may overlap). Thus, there are for any segment on average, about 25.5 elements that are in the correct position to excite a fiber. Each segment is in its position for 25 ⁇ s.
- the 100 segments are executed in time sequence with no dead time.
- the time to write a linear segment of the page is 2.5 ms with a cycle time of 3 ms to cover (inter-facet) dead time in the polygon.
- 3300 linear segments it takes about 10 seconds to write a page.
- a polygon with 20 sides performs the scanning.
- the time for one complete turn of the polygon is 60 ms corresponding to 1000 revolutions per minute.
- Each pixel in the linear array is turned on every 10 rows on average or about 10 times during exposure cycle.
- 256 light sources write into 2550 fibers.
- the timing is consistent with 6 pages per minute.
- Groups of fibers in the fiber linear array emit the light simultaneously. There is not a progressive sequence of light spots for exposing the pixels as in a flying spot (CRT) scanner. As a result there is the possibility that two adjacent fibers in the linear array would not be excited with a non trivial time gap as mentioned above. With a continuously moving photosensitive medium, the pixels would exhibit small, random vertical
- the distance between two fibers in the area face which are adjacent in the linear face is typically a small fraction of the length of the fiber optic bundle, area array side.
- the time lapse in writing the two adjacent fibers in the linear array face is at most a small fraction of the time to write a horizontal line.
- the photosensitive medium moves a distance equal to the height of one pixel. Consequently, the vertical displacement of adjacent pixels and the related tear is never more than a small fraction of the pixel height.
- the photosensitive medium is moved stepwise during the dead time of the polygon and is held stationary during the writing period, then all pixels fall on the same straight line. Based on simulations, the small vertical displacements that occur with a continuously moving medium are not observable and it is not expected that step motion will be necessary.
- Fiber ends in the area face of a fiber optic bundle which have adjacent ends in the linear face, actually end up in closely- spaced (although random) positions is a result of the manufacturing procedure for the fiber optic bundle.
- Optical fibers are drawn and captured on a drum in a manner well understood in the art.
- a fiber optic bundle is made from these captured fibers by placing an adhesive tape across the fibers, say every foot along the drum and by cutting the fibers at the tape. The fibers thus, are captured in a linear arrangement at one end and just hang at the other.
- the LCS array is controlled by dedicated drivers; it is not multiplexed.
- the elements comprise a special, high speed liquid crystal shutter with cross polarizers. Typical contrast ratio exceeds 500:1. Since there are on average five LCS elements potentially illuminating each fiber core, a non excited fiber receives about 5 times the dark output of one element. So the actual contrast ratio of the emission into the fiber is about 100:1.
- the excitation wave form is a +15 v pulse for black and a -15 v pulse for white.
- the light turn-on and turn-off is delayed by about 7 ⁇ s and the 10 to 90% rise time is also about 7 ⁇ s.
- the 25 ⁇ s light pulse is roughly bell-shaped with a flattened top, thereby slightly reducing the available light. This further reduces the contrast ratio, but not by much, perhaps 20%.
- the shutter without polarizers has an absorption loss of 1/2% and can handle a kilowatt/cm 2 of optical flux. However, even with a polarizer/cell sandwich and no cooling, the rated incident optical power capability is 4 watts/cm 2 .
- the total flux in the pulse can be varied by controlling pulse width or height, so gray scale is inherent. Gray scale also can be achieved by time modulation. Color can be achieved by putting three linear fiber arrays together in parallel in the same fiber optic bundle using separate drive sources. The fiber lines are spaced by one pixel height. The color for three adjacent lines are written
- An initialization procedure for color embodiments requires, for example, three consecutive procedures, one for each color with light of red, green and blue, where each procedure is analogous to that described above.
- procedures also may be carried out by using a color wheel.
- one or more linear array of light sources can be imaged onto an area face of a fiber bundle which is in the shape of an annulus where the images are rotated by, for example, a Dove Prism to move from (radial) segment to segment about the annulus.
Abstract
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP90514377A JPH05506409A (en) | 1990-01-22 | 1990-10-02 | Electronic printer using fiber optic bundle and linear one-dimensional light source |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/468,833 US4975729A (en) | 1990-01-22 | 1990-01-22 | Electronic printer using a fiber optic bundle and a linear, one-dimensional light source |
US468,833 | 1990-01-22 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1991010929A1 true WO1991010929A1 (en) | 1991-07-25 |
Family
ID=23861428
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1990/005755 WO1991010929A1 (en) | 1990-01-22 | 1990-10-02 | Electronic printer using a fiber optic bundle and a linear, one-dimensional light source |
PCT/US1990/005699 WO1991010928A1 (en) | 1990-01-22 | 1990-10-04 | Electronic printer using a fiber optic bundle and a linear, one-dimensional light source |
PCT/US1991/000455 WO1991010930A1 (en) | 1990-01-22 | 1991-01-22 | Electronic printer using a fiber optic bundle and a linear, one-dimensional light source |
Family Applications After (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1990/005699 WO1991010928A1 (en) | 1990-01-22 | 1990-10-04 | Electronic printer using a fiber optic bundle and a linear, one-dimensional light source |
PCT/US1991/000455 WO1991010930A1 (en) | 1990-01-22 | 1991-01-22 | Electronic printer using a fiber optic bundle and a linear, one-dimensional light source |
Country Status (6)
Country | Link |
---|---|
US (1) | US4975729A (en) |
EP (1) | EP0511960A1 (en) |
JP (1) | JPH05506409A (en) |
AU (3) | AU6539790A (en) |
CA (1) | CA2074469A1 (en) |
WO (3) | WO1991010929A1 (en) |
Families Citing this family (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE59005903D1 (en) * | 1989-09-01 | 1994-07-07 | Gretag Imaging Ag | Photoelectric scanner. |
DE59005727D1 (en) * | 1989-09-07 | 1994-06-23 | Gretag Ag | Photoelectric scanner. |
EP0433232B1 (en) * | 1989-12-13 | 1994-03-09 | Gretag Imaging Ag | Photographic colour copier |
US5075716A (en) * | 1990-11-29 | 1991-12-24 | Eastman Kodak Company | Apparatus and method for precisely exposing radiation sensitive materials |
US5159656A (en) * | 1991-04-29 | 1992-10-27 | Advanced Technology Consortium, Inc. | Optical fiber scanning/imaging/printing system |
WO1993002522A1 (en) * | 1991-07-22 | 1993-02-04 | Photon Imaging Corporation | Electronic scanner or printer with ordered fiber optic array |
DE4203727A1 (en) * | 1992-02-06 | 1993-08-12 | Siemens Ag | Light guide esp. for high-resolution optical LED-type print head - has fibre=optic cross=section converter providing required resolution and separation, arranged opposite focussing elements |
US5293437A (en) * | 1992-06-03 | 1994-03-08 | Visual Optics, Inc. | Fiber optic display with direct driven optical fibers |
US5353705A (en) * | 1992-07-20 | 1994-10-11 | Presstek, Inc. | Lithographic printing members having secondary ablation layers for use with laser-discharge imaging apparatus |
AU674518B2 (en) * | 1992-07-20 | 1997-01-02 | Presstek, Inc. | Lithographic printing plates for use with laser-discharge imaging apparatus |
US5379698A (en) * | 1992-07-20 | 1995-01-10 | Presstek, Inc. | Lithographic printing members for use with laser-discharge imaging |
US5339737B1 (en) * | 1992-07-20 | 1997-06-10 | Presstek Inc | Lithographic printing plates for use with laser-discharge imaging apparatus |
US5351617A (en) * | 1992-07-20 | 1994-10-04 | Presstek, Inc. | Method for laser-discharge imaging a printing plate |
USRE35512F1 (en) * | 1992-07-20 | 1998-08-04 | Presstek Inc | Lithographic printing members for use with laser-discharge imaging |
US5604607A (en) * | 1992-10-19 | 1997-02-18 | Eastman Kodak Company | Light concentrator system |
US5712674A (en) * | 1994-05-02 | 1998-01-27 | Fuji Photo Film Co., Ltd. | Exposure device utilizing differently colored light emitting elements |
DE4422414A1 (en) * | 1994-06-29 | 1996-01-04 | Bfi Entsorgungstech | Optical monitoring arrangement |
US5933213A (en) * | 1995-09-26 | 1999-08-03 | Imation Corp. | Apparatus and method for imparting a succession of predetermined latent images on a strip of unexposed light sensitive film |
US5684620A (en) * | 1996-01-30 | 1997-11-04 | Schoonscan, Inc. | High resolution imaging system and method of imaging using the same |
US6188425B1 (en) * | 1996-04-12 | 2001-02-13 | Minolta Co., Ltd | Exposure device capable of reducing unevenness in quantity of light |
DE69841039D1 (en) * | 1997-12-22 | 2009-09-17 | Citizen Holdings Co Ltd | OPTICAL PRINTER WITH CURRENT PASSING |
US6148134A (en) * | 1999-03-25 | 2000-11-14 | Schoonscan, Inc. | Fiber mounts for fiber optic harness in a fiber optic-based imaging system |
JP3642975B2 (en) * | 1999-03-30 | 2005-04-27 | フジノン株式会社 | Exposure equipment |
US6647164B1 (en) | 2000-10-31 | 2003-11-11 | 3M Innovative Properties Company | Gimbaled micro-mirror positionable by thermal actuators |
US6711318B2 (en) | 2001-01-29 | 2004-03-23 | 3M Innovative Properties Company | Optical switch based on rotating vertical micro-mirror |
JP2005199477A (en) * | 2004-01-13 | 2005-07-28 | Fuji Photo Film Co Ltd | Light emitting device |
US9395296B1 (en) | 2015-02-20 | 2016-07-19 | The United States Of America, As Represented By The Secretary Of The Army | Two-dimensional optical spot location using a one-dimensional detector array |
WO2018015850A2 (en) | 2016-07-17 | 2018-01-25 | Io Tech Group Ltd. | Kit and system for laser-induced material dispensing |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3232201A (en) * | 1963-08-14 | 1966-02-01 | Eastman Kodak Co | Fiber optical scanning system |
US3234329A (en) * | 1963-02-20 | 1966-02-08 | Bell Telephone Labor Inc | Device for the instantaneous sequential display of individual characters in superimpoed relation |
GB2042746A (en) * | 1979-02-23 | 1980-09-24 | Savin Corp | Multiple Variable Light Source Photographic Printer |
US4702552A (en) * | 1985-07-03 | 1987-10-27 | Photon Devices, Ltd. | Document scanner employing a fiber optic bundle and exhibiting grey scale |
DE3728238A1 (en) * | 1987-08-25 | 1989-03-09 | Lothar Sachsse | Transmission device for transmitting picture points (pixels) |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4791494A (en) * | 1979-02-23 | 1988-12-13 | Savin Corporation | Multiple variable light source printer |
US4297022A (en) * | 1979-12-03 | 1981-10-27 | Static Systems Corporation | Light pipe valve liquid crystal transmissive display for direct imaging on photosensitive materials |
US4367946A (en) * | 1981-01-29 | 1983-01-11 | Eastman Kodak Company | Light valve imaging apparatus having improved optical configuration |
DE3146872A1 (en) * | 1981-11-26 | 1983-06-01 | Philips Patentverwaltung Gmbh, 2000 Hamburg | OPTICAL PRINTER |
US4478504A (en) * | 1981-12-22 | 1984-10-23 | Minolta Camera Kabushiki Kaisha | Electrostatic recording apparatus |
US4640601A (en) * | 1983-12-20 | 1987-02-03 | Sanyo Electric Co., Ltd. | Patent image reproducing electrophotographic machine |
US4760421A (en) * | 1984-02-17 | 1988-07-26 | Photon Devices, Ltd. | Graphic printing device including a fiber optic bundle with electronic means for providing coherence |
US4674834A (en) * | 1984-02-17 | 1987-06-23 | Photon Devices, Ltd. | Graphic input or output device including a fiber optic bundle with electronic means for providing coherence |
JPS60231278A (en) * | 1984-04-28 | 1985-11-16 | Brother Ind Ltd | Optical reader |
US4727380A (en) * | 1984-05-31 | 1988-02-23 | Seiko Epson Corporation | Photosensitive printing apparatus |
JPS60254126A (en) * | 1984-05-31 | 1985-12-14 | セイコーエプソン株式会社 | Imaging device |
JPH0647300B2 (en) * | 1984-12-13 | 1994-06-22 | 三洋電機株式会社 | Image forming device |
JPS6250775A (en) * | 1985-08-29 | 1987-03-05 | Canon Inc | Exposing device |
US4752806A (en) * | 1986-06-23 | 1988-06-21 | Xerox Corporation | Multi-mode imaging system |
US4748680A (en) * | 1986-08-08 | 1988-05-31 | Photon Devices, Ltd. | Color document scanner |
-
1990
- 1990-01-22 US US07/468,833 patent/US4975729A/en not_active Expired - Fee Related
- 1990-10-02 CA CA002074469A patent/CA2074469A1/en not_active Abandoned
- 1990-10-02 EP EP90915355A patent/EP0511960A1/en not_active Withdrawn
- 1990-10-02 AU AU65397/90A patent/AU6539790A/en not_active Abandoned
- 1990-10-02 WO PCT/US1990/005755 patent/WO1991010929A1/en not_active Application Discontinuation
- 1990-10-02 JP JP90514377A patent/JPH05506409A/en active Pending
- 1990-10-04 AU AU74929/91A patent/AU7492991A/en not_active Abandoned
- 1990-10-04 WO PCT/US1990/005699 patent/WO1991010928A1/en unknown
-
1991
- 1991-01-22 AU AU72413/91A patent/AU7241391A/en not_active Abandoned
- 1991-01-22 WO PCT/US1991/000455 patent/WO1991010930A1/en unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3234329A (en) * | 1963-02-20 | 1966-02-08 | Bell Telephone Labor Inc | Device for the instantaneous sequential display of individual characters in superimpoed relation |
US3232201A (en) * | 1963-08-14 | 1966-02-01 | Eastman Kodak Co | Fiber optical scanning system |
GB2042746A (en) * | 1979-02-23 | 1980-09-24 | Savin Corp | Multiple Variable Light Source Photographic Printer |
US4702552A (en) * | 1985-07-03 | 1987-10-27 | Photon Devices, Ltd. | Document scanner employing a fiber optic bundle and exhibiting grey scale |
DE3728238A1 (en) * | 1987-08-25 | 1989-03-09 | Lothar Sachsse | Transmission device for transmitting picture points (pixels) |
Non-Patent Citations (1)
Title |
---|
Navy Technical Disclosure Bulletin, Volume 2, No. 7, July 1977, Navy Tech. Cat. No. 4900, Navy Case No. 61261 P.C. FLETCHER et al.: "Liquid Crystal-Fiber Opti c Cockpit Display", pages 15-20 see the whole article * |
Also Published As
Publication number | Publication date |
---|---|
AU6539790A (en) | 1991-08-05 |
AU7492991A (en) | 1991-08-05 |
WO1991010928A1 (en) | 1991-07-25 |
US4975729A (en) | 1990-12-04 |
AU7241391A (en) | 1991-08-05 |
EP0511960A1 (en) | 1992-11-11 |
CA2074469A1 (en) | 1991-07-23 |
WO1991010930A1 (en) | 1991-07-25 |
JPH05506409A (en) | 1993-09-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4975729A (en) | Electronic printer using a fiber optic bundle and a linear, one-dimensional light source | |
EP0620676B1 (en) | Process for digital micromirror printer | |
CA1232018A (en) | Graphic input/output device with fiber optic bundle having electronic means for providing coherence | |
KR950014547B1 (en) | Display unit | |
US4900130A (en) | Method of scanning | |
EP0088555B1 (en) | Dot matrix printing method and printer therefor | |
CN1140844A (en) | Printing system and method using staggered array statial light modulator | |
KR20040010549A (en) | Light beam display with interlaced light beam scanning | |
US5684620A (en) | High resolution imaging system and method of imaging using the same | |
US4551737A (en) | Optical data pattern generation device comprising phosphor member | |
US5612728A (en) | Full color TFEL edge emitter printing system | |
EP0337812A2 (en) | Method and apparatus for creating a photomask for projecting an image | |
EP0645924A1 (en) | Method and apparatus for exposing photosensitive media with multiple light sources | |
WO1989003151A1 (en) | System for high resolution exposure address with coarser resolution exposing array | |
EP0716537B1 (en) | Exposure apparatus | |
US4668071A (en) | Character generator using cathode ray tube activated liquid crystal display | |
US6342940B1 (en) | Optical printer | |
US5170270A (en) | Image writing device | |
EP0679520A2 (en) | Multi-position lens assembly apparatus for exposing photosensitive media in a rotary printer | |
US5771415A (en) | Data imprinting device | |
CN1325999C (en) | Laser exposure appts. | |
SU1326451A1 (en) | Photosetting apparatus | |
JPH08310193A (en) | Multi-beam image forming recorder | |
JPH08310195A (en) | Multi-beam image forming recorder | |
JPH08310194A (en) | Multi-beam image forming recorder |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AT AU BB BG BR CA CH DE DK ES FI GB HU JP KP KR LK LU MC MG MW NL NO RO SD SE SU |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE BF BJ CF CG CH CM DE DK ES FR GA GB IT LU ML MR NL SE SN TD TG |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2074469 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1990915355 Country of ref document: EP |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
WWP | Wipo information: published in national office |
Ref document number: 1990915355 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1990915355 Country of ref document: EP |