WO2001014915A1

WO2001014915A1 - Ink-jet head and method of manufacturing color filter

Info

Publication number: WO2001014915A1
Application number: PCT/JP2000/005451
Authority: WO
Inventors: Koji Sone; Katsuhiko Bando; Naoyuki Seo; Masatomo Matsui; Yoshihisa Kouyama
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 1999-08-19
Filing date: 2000-08-14
Publication date: 2001-03-01
Also published as: ID30218A; JP2001056407A; CN1320218A; JP3400389B2; CN1129012C; KR20010085934A; TW470856B; KR100390119B1

Abstract

A method of manufacturing a low-cost color filter of uniform color density. Ink is sprayed through an ink-jet head onto pixel areas of a color filter substrate to form a colored layer of a color filter. A plurality of ink particles, identical in volume and speed, reach each pixel area simultaneously.

Description

Manufacturing method of color filter and inkjet head

The present invention relates to a method of manufacturing a color filter used for a liquid crystal display panel and the like, and an ink jet head, and more particularly, to a method of manufacturing a color filter by discharging color ink by an ink jet head, and a method of manufacturing the color filter. It relates to an improved ink jet head for realizing the manufacturing method.

Field background technology

In recent years, with the development of personal computers, especially portable personal computers, the demand for liquid crystal displays, especially color liquid crystal displays, has been increasing. However, the cost of liquid crystal displays is required for further widespread use. In particular, there is a growing demand for cost reduction of color filters, which have high specific gravity.

The main production methods for color filters include printing, electrodeposition, dyeing, and pigment dispersion. Hereinafter, each method will be described.

First, the printing method involves repeating printing on a thermosetting resin that is to become a colored layer, so that red (hereinafter, referred to as R), green (hereinafter, referred to as G), and blue (hereinafter, referred to as B). The above three colors are applied separately, and the thermosetting resin is heated and cured to form a colored layer. At this time, a paint in which a pigment is dispersed is used.

This printing method is simple, but has the disadvantage of poor resolution and flatness of the color filter:

Next, in the electrodeposition method, a transparent electrode is patterned on a transparent substrate, and the electrode is immersed in an electrodeposition coating solution containing a pigment, a resin, an electrolyte, and the like to electrodeposit a first color. This process is repeated three times to form R, G, and B colored layers, and finally baked.

This electrodeposition method has excellent flatness of the color filter, but has a drawback that the color arrangement pattern of the color filter that can be formed is limited. Next, in the dyeing method, a water-soluble polymer material, which is a material for dyeing, is added to a photosensitive agent on a glass substrate to sensitize, and the photosensitive layer is patterned into a desired shape by a photolithography process. Thereafter, the obtained pattern is immersed in a dyeing bath to obtain a colored pattern. This process is repeated three times to form R, G, B colored layers. This dyeing method has a disadvantage that the color of the color filter is clear, but the weather resistance, light resistance, heat resistance, and moisture absorption of the color filter are inferior.

Finally, in the pigment dispersion method, first, a photosensitive resin layer in which a pigment is dispersed is formed on a substrate, and this is patterned to obtain a monochromatic pattern. This process is repeated three times to form R, G, and B colored layers.

This pigment dispersion method has a disadvantage in that a large amount of material is lost because 70% or more of the applied material is discarded during patterning.

In any of these four methods, it is common to form a protective layer on the colored layer.

In each of the above four methods, the same process must be repeated three times in order to form three colored layers of R, G, and B, which inevitably increases the manufacturing cost. However, the yield and productivity are reduced. To solve these drawbacks, a method for manufacturing a color filter using an inkjet method has already been proposed. For example, JP-A-59-72505, JP-A-63-235901, JP-A-121730, JP-A-4-1212 It is disclosed in Japanese Patent Application Publication No. 2005-305, and Japanese Patent Application Laid-Open No. Hei 7-146406.

In the ink jet method, a colored liquid containing R, G, and B dyes (hereinafter, referred to as ink) is discharged to a color filter substrate by a nozzle, and the ink is used as a transparent substrate to be a color filter. It is dried on the top to form a colored layer.

According to this ink jet method, each of the R, G, and B colored layers can be formed at one time, and there is no waste in the amount of ink used. An effect such as down can be expected.

In the ink jet method, a thermal ink jet head (also referred to as a bubble nozzle head) that discharges liquid droplets using thermal energy, and a piezoelectric element Using a piezo head, which discharges droplets using the tato-mode deformation (the property that piezoelectric ceramics are distorted), a method of directly coloring the colored portion of the color filter with each color ink, and a method of forming the ink receiving layer first. There are two methods: a method of forming a liquid absorbing material such as cellulose, acrylic resin, and gelatin, and dyeing it with the ejected ink.

First, a method for directly coloring a color filter substrate is to discharge ink droplets into pixel sections separated by a frame (black matrix) on the color filter substrate, and fill the pixel sections with a predetermined ink amount. The ink is dried and solidified to form a colored layer.

At this time, the height of the frame is limited to the height when the ink is dried and solidified in order to ensure the flatness of the frame and the colored layer. For this reason, the ink is filled in an amount exceeding the height of the frame in anticipation of the volume reduction due to drying, and the frame made of the photosensitive resin material is stably held as a convex meniscus. Liquid repellency is added by including a fluorine-based material.

A method of filling the frame with ink by using an inkjet head will be described with reference to FIG.

FIG. 8 is an explanatory view showing a method of manufacturing a color filter by a conventional ink-jet method for directly coloring a color filter substrate, in which four ink droplets are ejected to one pixel section. Is shown.

Fig. 8 (a) shows the state before the first ink droplet lands, Fig. 8 (b) shows the state before the second ink droplet lands, and Fig. 8 (c) shows the third ink droplet. Fig. 8 (d) shows the state before landing of the fourth ink droplet, and Fig. 8 (e) shows the state after landing of the fourth ink droplet. These are shown below:

In FIG. 8, reference numeral 81 denotes an ink jet head provided with one nozzle 84 in one pressure chamber 82; reference numeral 82 denotes a pressure chamber filled with ink flooded by an ink supply source (not shown); 4 is a nozzle for discharging the ink filled in the pressure chamber 82, 85 is a pixel section, 86 is a transparent substrate to be a color filter (hereinafter, referred to as a color filter substrate), and 87 is a black matrix. Frame, 88a is the first ink droplet ejected first to pixel section 85, 88b is the pixel section The second ink droplet ejected second to 85, 88 c is the third ink droplet ejected third to pixel section 85, and 88 d is the pixel section 8 The fourth ink droplet ejected fourth from 5, 89 a, 89 b, 89 c, 89 d is the ink droplet 88 a, 88 b, 88 c, respectively. This is the filling ink after 88 d lands on pixel section 85.

In FIG. 8 (a), the ink head 81 has a pressure chamber 82 filled with ink, and the ink head 81 has a droplet of ink droplet flowing from the nozzle 84 toward the pixel section 85 of the color filter substrate 86. Discharge is performed.

When the ink droplets 88 a land on the surface of the color filter substrate 86, as shown in FIG. 8B, the filled ink 89 a lands between the frame bodies 87 and spreads. At this time, the ink jet head 81 and the color filter substrate 86 are continuously moving relative to each other so that the ink droplets do not land at the same point, and are sequentially moved in the order of FIGS. The second, third, and fourth ink droplets 88b, 88c, and 88d are ejected from the inkjet head 81, and the frame 87 is filled with the filling ink 89c. After filling the predetermined amount of ink into the frame 87, as shown in Fig. 8 (d), the height of the filling ink 89d becomes higher than the height of the frame 87, A convex meniscus is formed. In addition, a method of coloring the receiving layer with ink is to form an ink receiving layer on a pixel area defined by a black matrix film on a color filter substrate in advance, and directly apply a color filter to the receiving layer. This is a method of forming a color filter by ejecting ink droplets in the same manner as when coloring a substrate, and absorbing the landing ink in the receiving layer over the entire pixel region.

The conventional ink-jet method is configured as described above.Unlike the conventional method of forming a color filter by paint printing or a chemical process, it is not necessary to repeat the same process for each color. It can be expected that color filters will be manufactured without reducing the yield and increasing production costs due to the repetition of the above, and without wasting the filter material.

However, the conventional method for manufacturing a color filter by the ink jet method has the following problems.

Hereinafter, the problem of the conventional technology will be described with reference to FIGS. 8 and 9. Fig. 9 is a schematic diagram showing a colored layer of a color filter manufactured by a conventional inkjet method.Figs. 9 (a) and 9 (b) show a case where a color filter substrate is directly colored. FIG. 9 (c) shows a case where the receiving layer on the color filter substrate is colored.

In the figure, the same reference numerals as those in Fig. 8 indicate the same or equivalent ones, 90 denotes a color loss indicating a portion of the pixel division not filled with ink, 91a, 91b, 91c, 9 1d is the first ink dot, the second ink dot, the third ink dot, the fourth ink dot, 92 is the overlapping portion of the ink dot, and 93 is the ink dot. Single part, 94 is transboundary ink beyond frame 87, 95a, 95b, 95c, 95d, 95e, 95f, 95g, 95h, 95i Is a colored layer, and 99b and 99e are filling inks of the colored layers 95b and 95e, respectively.

In this conventional ink jet method, when the frame body 87 is filled with predetermined ink droplets from the ink jet head and the color filter substrate is directly colored, the last ink droplet enters the frame body 87. By the time, a large convex meniscus is formed on the frame 87, so that the impact of the last ink droplet collides produces waves in the filled ink, and the overflowing ink crosses the adjacent frame beyond the frame. May enter the body and cause color mixing.

Fig. 9 (a) shows that the ink 99b in the ink-filled area enters the coloring layers 95a and 95c adjacent to the original coloring layer 95b beyond the frame 87. This shows the state where the error occurred. This color mixing is likely to occur particularly in a portion where the ink holding ability is reduced due to the variation in the shape of the frame 87 or the liquid repellency added to the frame 87.

If liquid repellent material remains on the surface of the color filter substrate in the colored section defined by the frame, as shown in Fig. 9 (b), the filling ink extends to the corners in the pixel section. 9e may not be evenly distributed, and pixels with color loss 90 may occur in many pixels. This is likely to occur near the landing point of the final ink droplet, or at a corner in the pixel section.

On the other hand, when dyeing the ink receiving layer on the color filter substrate, as shown in Fig. 9 (c), after the ink droplets land on the receiving layer (not shown) at regular time intervals and the ink spreads, Form ink dots 9a, 9b, 9c, 9Id in sequence Due to absorption in the receiving layer, the ink dot has an overlapping portion 92 and a single portion 93, which may cause color unevenness.

As described above, the color filter manufactured by the conventional ink jet method has a problem that color mixing, color omission, or color unevenness of ink occurs, and the color density is not uniform.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and provides a method of manufacturing a color filter that can make the color density of a color filter uniform and can be manufactured at low cost. It is intended to provide an ink jet head for realizing a color filter manufacturing method. Disclosure of the invention

As described above, according to the first aspect of the present invention, there is provided a color filter manufacturing method of forming a colored layer by ejecting ink droplets to pixel sections on a color filter substrate using an inkjet head. In the case of directly coloring the color filter substrate by simultaneously ejecting multiple ink droplets to one pixel section, the collision energy is spent on the force to push and spread ink radially, and the frame body The ink is absorbed in the receiving layer after each ink dot is mixed when the receiving layer on the color filter substrate is colored. As a result, color unevenness can be prevented, and as a result, a color filter having a uniform color density can be manufactured in any case.

According to the second aspect of the present invention, there is provided: a nozzle plate in which a nozzle row including a plurality of nozzles is formed; and a flat plate in which an actuator deformed by an electric signal is installed. A pressure chamber is formed by the nozzle plate and a space surrounded by the flat plate, and the ink supplied from the ink supply source to the pressure chamber is pressurized by the actuator to discharge ink droplets from the nozzle. By doing so, it is possible to simultaneously eject ink at a small pitch without generating crosstalk, and obtain an ink jet head capable of manufacturing a color filter having a uniform color density. be able to. According to the third aspect of the present invention, a plurality of piezoelectric material substrates formed so that deep grooves deeper than the groove width are parallel to each other, and a nozzle row including a plurality of nozzles are provided at required locations. A plurality of nozzle plates formed so as to be parallel to each other, a cover plate for sealing the deep groove of the piezoelectric material substrate, and a potential difference applied to a partition of the deep groove of the piezoelectric material substrate, thereby forming the partition in a shear mode. And a space surrounded by the deep groove of the piezoelectric material substrate, the nozzle plate where the nozzle row is formed, the force bar plate, and the actuator; and a plurality of pressure chambers are provided. And is surrounded by the deep groove of the piezoelectric material substrate, the nozzle plate where the nozzle row is not formed, the cover plate, and the actuator. A plurality of air chambers that are deformed by the actuator are formed by the space, and the pressure chambers and the air chambers are installed so as to be alternately arranged. The ink that is filled in the plurality of pressure chambers from an ink supply source is formed by the space. Pressure is applied by an actuator, and ink droplets are ejected from the nozzles.This reduces interference when multiple pressure chambers are driven, eliminates crosstalk, and allows ink droplets to be ejected simultaneously and in ink. An ink jet head that can discharge liquid droplets with uniform characteristics such as volume and flying speed, and that can manufacture a color filter with uniform color density using equipment that is cost-effective be able to.

According to the fourth aspect of the present invention, the piezoelectric material substrate formed with a plurality of shallow grooves shallower than the groove width and the nozzle row composed of the plurality of nozzles are linearly arranged. A plurality of nozzle plates, an actuator for applying a potential difference to the piezoelectric material substrate to deform the piezoelectric material substrate in a transverse strain mode, and a vibration for sealing a shallow groove of the piezoelectric material substrate and displacing by the actuator. And a space surrounded by the shallow groove of the piezoelectric material substrate, the nozzle plate, and the vibration plate. A plurality of pressure chambers are formed, and the plurality of pressure chambers are filled from an ink supply source. By ejecting ink droplets from the nozzles by pressurizing the ink by the displacement of the diaphragm, the ink droplets are simultaneously ejected, and the characteristics such as the volume of the ink droplets and the flying speed are obtained. It is possible to obtain an ink jet head that can discharge the ink so as to have uniform properties and can manufacture a color filter having a uniform color density with low-cost equipment. According to the invention set forth in claim 5, in the ink jet head according to any one of claims 2 to 4, the shape is substantially rectangular, and the long side and the short side are provided. When forming a colored layer in a pixel section having a length ratio of 3 or more, the nozzle row includes a number of nozzles based on the shape of the pixel section, in parallel with a long side direction of the pixel section, In addition, by setting the nozzles at equal intervals, the ink droplets that have landed can efficiently spread within the pixel sections, and an ink jet head that can produce a color filter with uniform color density can be obtained. Can be.

Further, according to the invention set forth in claim 6, in the inkjet head according to any one of claims 2 to 5, the nozzle row is configured such that the nozzles located at both ends are controlled by the pressure. The ink liquid ejected by applying a uniform and large pressure to the ink filled in the pressure chamber by a slight deformation of the actuator by disposing the ink tank at a distance longer than the length of the short side wall from the short side wall of the chamber. It is possible to obtain an ink jet head that can make all the characteristics such as the volume of the droplet and the flying speed uniform, and can produce a color filter having a uniform color density.

According to the invention set forth in claim 7, in the inkjet head according to claim 3 or 4, the actuator includes the partition wall or the piezoelectric material substrate, the signal electrode, , And a common electrode, and all the barriers or the piezoelectric material substrates are simultaneously deformed based on the difference between the first and second signals and the potential applied to the signal electrode and the common electrode, respectively. By doing so, it is possible to make the above-mentioned ink jet head compact, simple, and low-cost, and to provide an ink jet head that can manufacture a color filter with a port-cost facility. Obtainable.

According to the invention set forth in claim 8, the inkjet head according to any one of claims 2 to 7 provides a plurality of ink solutions for one pixel section. Since the ink droplets are simultaneously ejected and the ejection characteristics of each ink droplet are made uniform, a color filter having a uniform color density can be manufactured at low cost by the inkjet method. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a schematic diagram showing a coloring pattern of a color filter.

FIG. 2 is an explanatory view showing a method of manufacturing a color filter according to Embodiment 1 of the present invention. FIG. 2 (a) shows a state immediately after ink ejection, and FIG. It is a figure which shows the state after landing.

FIG. 3 is a schematic view of the ink jet head in which a plurality of nozzles are installed in one pressure chamber as viewed from an ink discharge direction.

Figure 4 is a _c Fig. 5 is a schematic view seen from Inku discharge direction of the plurality of pressure chambers and Inkuji Ttoe' de that installing the air chamber that utilizes shear mode deformation of piezoelectric ceramics, the practice of the present invention FIG. 8 is an explanatory diagram showing the method for manufacturing the color filter according to Embodiment 2.

FIG. 6 is a schematic view of the ink jet head in which a plurality of pressure chambers utilizing the transverse strain mode deformation of the piezoelectric ceramic are provided, as viewed from the ink discharge direction.

FIG. 7 is an explanatory diagram showing a method for manufacturing a color filter according to Embodiment 3 of the present invention.

FIG. 8 is an explanatory view showing a method of manufacturing a color filter by a conventional ink jet method when directly coloring a color filter substrate, and FIG. 8 (a) shows a state before the first ink lands. Fig. 8 (b) shows the state before the second ink droplet lands, Fig. 8 (c) shows the state before the third ink droplet lands, FIG. 8D is a diagram showing a state before the fourth ink droplet lands, and FIG. 8E is a diagram showing a state after the fourth ink droplet lands.

FIG. 9 is a schematic diagram showing a colored layer of a color filter manufactured by a conventional ink jet method, and FIG. 9 (a) is a diagram showing a case where a color filter substrate is directly colored, and FIG. FIG. 9 is a diagram showing a case where the color filter substrate is directly colored, and FIG. 9 (c) is a diagram showing a case where the receiving layer on the color filter substrate is colored. BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1)

The method for manufacturing a color filter according to Embodiment 1 of the present invention uses an ink jet head in which a plurality of nozzles are installed in one pressure chamber, and a plurality of nozzles are provided in one pixel section. The ink droplets are simultaneously ejected so that the characteristics such as the volume and the flying speed of the ink droplets become uniform, thereby forming a colored layer of a color filter.

FIG. 1 is a schematic diagram showing a coloring pattern of a color filter manufactured by a method for manufacturing a color filter according to Embodiment 1 of the present invention.

In the figure, 6 is a transparent substrate to be a color filter (hereinafter referred to as a color filter substrate), R is a red coloring layer, G is a green coloring layer, B is a blue coloring layer. Three colors are striped colored patterns: 7 is a frame formed by a black matrix.

There are the following two methods for producing the colored layers R, G, and B using the inkjet head.

First, a method of directly forming a colored layer using an ultraviolet curable ink containing a pigment and a dye is as follows. A black matrix frame 7 having liquid repellency is filled with ink using an ink jet head. And dried and solidified to form a colored layer:

On the other hand, in the method using an ink mixed with a coloring dye and a layer to be dyed, an ink receiving layer is provided on a black matrix which is formed in a lattice pattern by chromium sputtering and photolithography. The colored layer is formed by attaching and absorbing the ink to the receiving layer with the 'Head'. First, fill the black matrix frame with the ink to form the colored layer. Will be described with reference to FIG.

FIG. 2 is an explanatory view showing a method of manufacturing a color filter according to Embodiment 1 of the present invention. FIG. 2 (a) shows a state immediately after ink ejection, and FIG. 2 (b) shows an ink applied state. The subsequent states are shown respectively.

In the drawing, the same reference numerals as those in FIG. 1 denote the same or corresponding components. Reference numeral 1 denotes an ink jet head in which a plurality of nozzles 4 (4a to 4d in this example) are installed in a pressure chamber 2, and 2 denotes a filter when ink is supplied from an ink supply source (not shown). A pressure chamber for pressurizing the ink to be filled in the substrate by an actuator, 3 is provided in front of the pressure chamber 2 to form a nozzle row 5 and a nozzle plate for sealing the pressure chamber 2, and 4 is a pressure chamber. A plurality of nozzles for discharging the ink filled in 2, and a plurality of nozzles 4 are arranged at equal intervals and in a row. A nozzle array, 7 is a frame formed by a black matrix, 8 is ink droplets ejected from a plurality of nozzles 4a to 4d, 9 is a pixel section divided by the frame 7, 10 is ink. The ejection direction, 11, is a filling ink forming a convex meniscus, which is formed by ink droplets 8 a to 8 d ejected simultaneously from the nozzles 4 a to 4 d.

Note that the ink ejection position of the inkjet head 1 is a position where the center of the nozzle row 5 overlaps with the center of the pixel section 9 when viewed from the ink ejection direction 10.

Further, when the shape of the pixel section 9 is substantially rectangular and the ratio of the long side to the short side is 3 or more, the number of the plurality of nozzles 4 provided in one pressure chamber 2 is An integer close to the ratio of the lengths of the long and short sides. This is to make the landed ink droplets spread efficiently in the pixel section.

Next, the operation will be described.

When the frame 7 on the upper surface of the color filter substrate 6 moves to the discharge position of the inkjet head 1, the inkjet head 1 is transferred from a movement control circuit (not shown) to the drive circuit of the inkjet head 1. On the other hand, an ink ejection signal is output, and based on the ink ejection signal, the ink filled in the pressure chamber 2 is pressurized by an actuator or the like, and the nozzles 4a, 4b, 4c, 4d of the nozzle row 5 are pressed. Ink droplets 8a, 8b, 8c and 8d are simultaneously ejected. The characteristics of these ink droplets 8a, 8b, 8c, 8d, such as the volume and the flight speed, are almost uniform. At the same time, they collide and are crushed the next moment, spreading radially around the point of impact, forming a thin cylindrical ink dot. Next, the ink dot flows in the pixel section 9 to break the shape of the dot, and becomes a filling ink 11 that forms a convex meniscus with other ink dots.

In the experiment, when an ink droplet having a viscosity of 10 to 15 cp and a volume of 15 to 30 p1 was made to collide with the pixel section 9 of the color filter substrate 6 at a flight speed of 4 to 7 mZs, The diameter of the dot dots was about 60-90 μπι. If the type of the ink and the color filter substrate are the same, the diameter of the ink dot is determined by the volume of the ink droplet and the flying speed of the droplet, so the size of the pixel section 9 and the amount of the filling ink 11 The optimal ink dot diameter can be selected from. As described above, in the first embodiment, since the plurality of ink droplets 8 land on the surface of the transparent substrate 6 at the same time, each ink dot is formed uniformly and simultaneously in the pixel region (ink-filled region) 8. At the same time, the ink is spread over the entire ink filling region by the interference force between the adjacent ink dots.

On the other hand, in the conventional ink filling method in which ink droplets are sequentially injected, ink droplets are ejected one by one. When the final ink droplet 8d enters the convex meniscus in the ink filling region formed by the above, a large wave is generated in the meniscus, and ink may overflow from the frame 7 to the adjacent pixels.

However, according to the ink filling method of the first embodiment, since all the ink droplets 8a, 8b, 8c, and 8d simultaneously strike the surface of the color filter substrate 6, the ink of each ink droplet is Energy is expended on the force pushing the substrate 6 over the surface, and the force of the ink trying to cross the frame 7 is suppressed.

In addition, in the conventional method, the ink may not penetrate into the corner of the ink filling area near the landing position of the final ink droplet 8d, causing color loss. This means that the final ink drop 8d will rush above the filling ink if the ink filled by the preceding ink drops 8a to 8c is full, leaving the corners of the ink filling area. Even so, pressure flows to the filling ink side, and it is difficult for the ink to penetrate into the corners. Also in this case, in the method according to the first embodiment, another ink droplet 8a is formed on the surface of the transparent substrate 6 near the corner of the ink filling area corresponding to the landing position of the final ink droplet 8d of the conventional method. , 8b, and 8c simultaneously, land directly on the surface of the transparent substrate 6, so that the ink penetrates the surface of the transparent substrate 6 radially after landing, and ink penetrates to the corners of the ink filling area 8 This has the effect.

Further, according to the first embodiment, even when ink droplets are ejected to the receiving layer, a plurality of ink droplets land on the receiving layer uniformly at the same time, so that adjacent ink droplets on the receiving layer can be formed. The liquid is absorbed after the interference part is mixed in a liquid state. Therefore, the density unevenness in the overlapping portion of the ink dots, which is seen by the conventional method, is eliminated.

Next, the relationship between the pressure chambers and the nozzles of the inkjet head according to the first embodiment will be described with reference to FIG. FIG. 3 is a schematic view of an inkjet head having a plurality of nozzles installed in one pressure chamber as viewed from an ink discharge direction.

Here, the case where four nozzles are formed is shown. These nozzles are arranged in a row according to the shape of the ink filling area of the force filter.

In the figure, the same reference numerals as those in FIG. 2 denote the same or corresponding parts. Reference numeral 1 2 denotes a plane plate 14 a and 14 b on which an actuator (not shown) is installed. Long side wall of the pressure chamber 2, 13 denotes a plane plate 14 and 14 d. Short side of the pressure chamber 2 Wall, L is the length inside pressure chamber 2 long side wall 12, W is the length inside pressure chamber 2 short side wall 13, S is nozzle 4 located at both ends of nozzle row 5 The distance from the center of a, 4d to the short side wall 13.

These four nozzles 4 a to 4 d are provided in one pressure chamber 2. The cross-sectional shape of the pressure chamber 2 is a rectangle having a long side wall 12 of the nozzle row 5 having an axial length L and a short side wall 13 having a width W perpendicular thereto. The distance S from the short side wall 13 to the center of the nozzles at both ends of the nozzle row 5 is longer than the width W of the short side wall 13. Further, an actuator (not shown) for pressurizing the ink in the pressure chamber 2 is provided on the long side wall 12 of the cross section of the pressure chamber 2 so as to be displaced in a direction perpendicular to the long side wall 12. It has been.

Here, the reason why the plurality of nozzles 4 are provided in one pressure chamber 2 is as follows.

That is, the pixel pitch of a typical color filter is about 300 / m. For example, for a 10.4 inch VGA (640 × 480 dot) liquid crystal panel, it is 330 μ τη ^ 18.1 inch SVGA (102 4 X 102 4 dots) For liquid crystal panel, it is 280 μm. The appropriate number of nozzles for this pixel section is four, but it is normal (printer) to arrange these four nozzles 4 at a pitch of 60 / m within 300 / zm and eject ink at the same time. It is very difficult to use the inkjet head 1 for piezos because, for example, the minimum pitch for a piezo method is about 141 m, that for a bubble jet method is about 71 m, and 60 μm Because it exceeds.

Moreover, in such a narrow-pitch head, the distance between adjacent channels is short, so-called crosstalk, that is, ink inside a certain channel is ejected. When the droplets are ejected from adjacent nozzles at the same time, the ejection performance changes when the droplets are ejected from adjacent nozzles at the same time. Because of the large occurrence of the problems of, the inkjet head for printers avoids simultaneous ejection of droplets from adjacent nozzles, and provides one nozzle in one pressure chamber and multiple pressures. The ejection timing of individual nozzles in the chamber is shifted to achieve ejection of ink droplets from all nozzles.

However, the concept of providing one nozzle in one pressure chamber is indispensable for printer applications, but is not necessary for manufacturing color filters. This is because, as described above, if ink droplets are ejected one by one, color unevenness or the like occurs.

Therefore, by specializing the inkjet head 1 for manufacturing color filters and providing nozzles 4 arranged in the compartment in the same pressure chamber 2, multiple droplets can be ejected simultaneously and the nozzles are arranged at a narrow pitch. The idea was to obtain an ink jet head optimized for the manufacture of color filters.

However, in such an ink jet head optimized for manufacturing a color filter, it is essential that the ejection characteristics of each nozzle are uniform and that no crosstalk occurs even though the nozzles have a narrow pitch. is there:

As a result of diligent research conducted by the present inventors, they have found that this can be realized with the following configuration.

First, the cross-sectional shape of the pressure chamber 2 of the ink jet head optimized for manufacturing such a color filter will be described.

In FIG. 3, in order to obtain the same ejection characteristics from any of the nozzles 4 in the nozzle row 5, it is effective to narrow the nozzle row 5 with parallel flat plates so that a parallel flat flow of ink is applied to all nozzles. is there.

The position of the short side wall 13 serving as the side wall of the parallel plate is determined by the central force of the nozzles 4a and 4d at both ends so that the short side wall 13 does not affect the flow of the nozzles at both ends of the nozzle row 5. The distance S to the short side wall 13 is set to be the distance between the parallel plates, that is, the short side length W or more. It is preferable that the short side length W be at least twice as large as the nozzle diameter. In order to effectively apply pressure to the ink in the pressure chamber 2 having such a shape, the length S from the nozzle at both ends to the short side wall is such that the flow of the ink ejected from the nozzles 4a and 4d at both ends is short. Installed more than the inner length W of the short side wall 1 3 so as not to be affected by the side wall 13, and the nozzle row 5 is on a straight line parallel to the long side wall 12 and passing through the center of the short side wall 13. And the length W of the inside of the short side wall 13 is preferably at least twice the nozzle diameter.

By doing so, a uniform and large pressure can be applied to the ink with a slight displacement of the long side wall 12.

From the above, according to the first embodiment of the present invention, a plurality of ink droplets 8a, 8b, 8c, and 8d are simultaneously placed in one pixel section 9, and the volume and the flying speed of the ink droplets In the case of coloring the color filter substrate 6, the collision energy is spent on the force to push and spread the ink radially, and the frame 7 The force that attempts to overcome the ink pressure is suppressed, preventing color mixing and color omission of the ink.In the case of coloring the receiving layer on the color filter substrate 6, the ink is absorbed by the receiving layer after each ink dot is mixed. As a result, color unevenness can be prevented, and as a result, a color filter having a uniform color density can be manufactured in any case.

Further, in the first embodiment of the present invention, by using the inkjet head 1 in which a plurality of nozzles 4 are installed in one pressure chamber 2, ink can be simultaneously injected at a small pitch without generating crosstalk. A color filter which can be discharged and has a uniform color density can be manufactured.

Further, in the first embodiment of the present invention, the pressure chamber 2 has a long side wall 12 formed of a flat plate on which an actuator is installed, and the length S from the nozzles at both ends to the short side wall 13 is defined as the short side wall. 1 3 By using the ink jet head 1 installed to be longer than the inner length W, a uniform and large pressure is applied to the ink filled in the pressure chamber 2 with slight deformation of the actuator. The characteristics of the ink droplets 8a, 8b, 8c, and 8d, such as the volume and the flying speed, can all be made uniform, and a color filter having a uniform color density can be manufactured.

Further, in Embodiment 1 of the present invention, when the shape of the pixel section 9 is substantially rectangular and the ratio of the length of the long side to the short side is 3 or more, a plurality of The number of nozzles 4 of each pixel is an integer close to the ratio of the length of the long side to the length of the short side of the pixel section 9, and by using an ink jet head in which those nozzles 4 are arranged at equal intervals and in a line, The landed ink droplets spread efficiently within the pixel section, and a color filter with uniform color density can be manufactured.

(Embodiment 2)

The method for manufacturing a color filter according to the second embodiment of the present invention uses an ink jet head in which a plurality of pressure chambers and air chambers utilizing the shear mode deformation of piezoelectric ceramics are provided. A colored layer of a color filter is formed by simultaneously ejecting ink droplets to a large number of same-color pixel sections in the side direction so that the characteristics such as the volume and flying speed of the ink droplets become uniform.

FIG. 4 is a schematic view of an ink jet head having a plurality of pressure chambers and air chambers and utilizing the shear mode deformation of the piezoelectric ceramic as viewed from the ink discharge direction. In the figure, reference numeral 41 denotes a partition separating the pressure chamber 42 and the air chamber 48. Reference numeral 42 denotes a plurality of pressure chambers for filling ink, and is composed of a nozzle plate, an actuator 100, a piezoelectric ceramic substrate 49, and a cover plate 50. 45 is a nozzle array in which a plurality of nozzles are installed in parallel to each other, 46 is a signal electrode formed of a metal film on the upper half of the pressure chamber wall, and 47 is air A common electrode formed of a metal film in a portion corresponding to the upper half of the indoor wall, and 48 are a plurality of air chambers filled with air therein, are a nozzle plate, an actuator, and a piezoelectric ceramic substrate 49 , And a cover plate 50, and has no nozzle. Reference numeral 49 denotes a piezoelectric ceramic substrate formed so that the deep grooves to become the pressure chambers 42 and the air chambers 48 are parallel to each other, and 50 denotes a pressure chamber 42 formed of a ceramic material or a resin material and the air. A cover plate that seals the opening of the deep groove to be the chamber 48, 52 is the polarization direction of the partition wall 41, V1 is the potential applied to the common electrode 47, and V2 is applied to the signal electrode 46. Potential.

Reference numeral 100 denotes an actuator, which is composed of a partition 41, a signal electrode 46, and a common electrode 47 .The deep groove of the piezoelectric ceramic substrate 49 has a predetermined space between the pressure chamber 42 and the air chamber 48. This is formed so as to be arranged at. The ink jet head 1 shown in FIG. 4 includes a piezoelectric ceramic substrate 49 polarized in the same direction as the polarization direction 52, a cover plate 50, a nozzle plate (not shown), and a driver substrate (not shown). ing. On the piezoelectric ceramic substrate 49, a plurality of deep grooves are formed in parallel at the same depth. The partition wall 41 made of piezoelectric ceramics polarized in the direction 52 between the deep grooves has a metal film formed only in the upper half, and is connected at the groove end in the depth direction to form one signal electrode 46 and a common electrode. 4 7 Further, the pressure chambers 42 and the air chambers 48 of the ink are alternately formed by these deep grooves. No nozzle is formed in the air chamber 48, and the air chamber 48 is sealed by a cover plate 50 at the end of the groove, and the pressure chamber 42 communicates with the ink supply path. The cover plate 50 is formed of a ceramic material, a resin material, or the like, and is firmly joined to the piezoelectric ceramic substrate 49 with an epoxy adhesive. A nozzle plate (not shown) having a nozzle row 45 provided corresponding to the pressure chamber 42 is joined to the front end surfaces of the piezoelectric ceramic substrate 49 and the cover plate 50. The nozzle array 45 is provided with its array axis parallel to the depth direction of the deep groove. The signal electrode 46 of the pressure chamber 42 and the common electrode 47 of the air chamber 48 are commonly connected to a driver circuit (not shown).

From this driver circuit, a voltage of V1 is applied to the common electrode 47 of the air chamber 48, and a potential of V2 is applied to the signal electrode 46 of the pressure chamber 42 to apply a potential difference between the partition walls 41. As a result, the polarization direction 52 and the electric field direction are orthogonal to each other, and the upper half of the partition wall is subjected to shearing force. The partition walls on both sides of the pressure chamber 42 are simultaneously displaced inward as shown by the broken lines in the figure, and Is applied. The pressurized ink is ejected as droplets from each nozzle of the nozzle array 45. In this case, droplets are simultaneously ejected from the four nozzles of the nozzle array 45.

That is, the partition wall 41 is polarized by the potential difference between V 1 and V 2, and the upper half of the partition wall 41 receives a shearing force when the polarization direction 52 is orthogonal to the electric field direction. As a result of the shearing force, the partition 41 of the pressure chamber 42 is deformed inward and pressurizes the ink filled in the pressure chamber 42, as shown by the broken line in FIG. Eighth partition 41 deforms outward. The ink pressurized by the partition walls 4 1 is applied to each nozzle row. It discharges simultaneously from 45 and colors a large number of same-color pixel sections in a column perpendicular to the moving direction of the color filter substrate.

Here, the air chamber 48 is provided in order to eliminate the influence of crosstalk caused by interference when the pressure chambers 42 adjacent to each other are driven. This is effective for discharging and landing droplets in a stable and accurate position and volume.

That is, in the piezo-type shear mode type head, ink is conventionally ejected from all the channels of the adjacent channels. This is an effective method for reducing the nozzle pitch, and is a printer head aiming at high speed. However, this method was effective, but had the disadvantage that crosstalk was inevitable due to the pressure vibration applied to the other channels through the ink on the channel side wall and adjacent channels. On the other hand, in the second embodiment, in order to optimize the production of a color filter having a relatively low resolution, emphasis is placed on high-precision ink ejection amount control. The nozzle was eliminated, and the channel was made an air layer. As a result, it is possible to prevent pressure fluctuations caused by ink in adjacent channels, which has occurred in the past, and it is possible to discharge ink with high accuracy and high stability without crosstalk.

This is because, compared to ink, the elastic modulus of air is extremely low, so that pressure vibration does not propagate through the air layer.

Even when these air chambers 48 are provided, it is sufficiently possible to match the pitch of the pressure chambers 42 with the pixel pitch of a specific color of the color filter. In addition, the provision of the air chamber 48 makes it possible to operate a large number of pressure chambers 42 with only the two signals VI and V2, so that the driver circuit is simplified and the overall cost is reduced. Contributes to downtime.

That is, in the conventional piezo-type shear mode head in which nozzles are provided in all of the continuous channels and ink can be ejected from each nozzle, a signal VI (negative pressure: ink filling) is sent to the ink ejection channel. By applying the signal V 2 (pressurization: ink ejection) to the adjacent channel, the ejection of one drop is completed. Next, if the signal is ejected now, the signal V 1 is applied to the channel. Then, the signal V 2 is given to the adjacent channel, and so on. It is necessary to give V 1 and V 2 to the channel by the discharge pattern, which complicates the driver circuit.

On the other hand, if a structure having air layers on both sides of the ink ejection channel according to the second embodiment is used, a signal V1 is applied to the ink ejection channel, and only a signal V2 is applied to the channels of the air layers on both sides. Will be given.

When the nozzle pitch of the head having the air layer is made to match the pixel pitch of the color filter, the head array is inclined because the pixel array axis of the color filter and the nozzle array axis of the head can be parallel. This eliminates the need for delay processing of the drive signal, which is sometimes required, and allows wiring to simultaneously discharge all nozzles, thus simplifying the driver circuit.

Therefore, it is possible to fan the signal V1 to a number of discharge channels and the signal V2 to a number of channels of an air layer.

FIG. 5 is an explanatory diagram showing a method for manufacturing a color filter according to Embodiment 2 of the present invention.

In the figure, the same reference numerals as those in FIG. 4 indicate the same or corresponding parts. 5 1 has a plurality of pressure chambers 42 and air chambers 48, an inkjet head utilizing the shear mode deformation of the piezoelectric ceramic, 53 a moving direction of the color filter substrate, and P 1 a short side of the pixel section. This is the distance between pixel sections of the same color in the direction. The pressure chambers 42, the air chambers 48, and the nozzle rows 45 are arranged so as to keep this interval P1.

Next, the manufacturing method will be described. A pressure chamber formed on the color filter substrate 56 and having the same pitch as the pitch P1 of the specific color of the pixel sections R, G, and B, and an ink jet having a nozzle row provided perpendicular to the direction in which the pressure chambers are arranged. The head 51 and the color filter substrate 56 are arranged in a positional relationship as shown in Fig. 5, and the substrate 56 is moved in the direction of the arrow 53 to the pixel section at the head discharge position. The ink is filled by depositing droplets sequentially. A color filter is manufactured by a manufacturing apparatus that performs such a manufacturing operation.

From the above, according to the second embodiment of the present invention, an ink jet apparatus in which a plurality of pressure chambers 42 and air chambers 48 utilizing the shear mode deformation of piezoelectric ceramics are provided. The use of the head 51 reduces cross-talk by reducing the interference when the plurality of pressure chambers 42 are driven, and eliminates ink droplets simultaneously, as well as the volume and flight of ink droplets. Discharge can be performed so that characteristics such as speed are uniform, and color filters with uniform color density can be manufactured with low-cost equipment.

In Embodiment 2 of the present invention, actuators provided in the pressure chamber 42 and the air chamber 48 are driven by two systems of electrodes consisting of the signal electrode 46 and the common electrode 47, whereby ink jet is performed. The head 51 can be made compact, simplified, and cost-effective, and color filters can be manufactured with low-cost equipment. (Embodiment 3)

The method of manufacturing a color filter according to the third embodiment of the present invention is directed to a method of manufacturing a color filter using an ink jet head provided with a plurality of pressure chambers utilizing transverse distortion mode deformation of a piezoelectric ceramic in a pixel section long side direction. Ink droplets are simultaneously ejected to a number of same-color pixel sections so that the characteristics such as the volume and flying speed of the ink droplets become uniform, thereby forming a colored layer of a color filter.

FIG. 6 is a schematic view of an inkjet head having a plurality of pressure chambers and utilizing the transverse distortion mode deformation of piezoelectric ceramics, as viewed from an ink ejection direction.

In the figure, reference numeral 62 denotes a plurality of pressure chambers to be filled with ink, and includes a nozzle plate, a piezoelectric ceramic substrate 69, and a vibration plate 70. 64 is a piezoelectric ceramics plate that deforms in the transverse distortion mode, 65 is a nozzle array linearly arranged on the nozzle plate, a nozzle array consisting of multiple nozzles, 66 is a signal electrode, 67 is a common electrode, and 69 is a groove A piezoelectric ceramic substrate formed with a plurality of shallow grooves shallower than the width of the piezoelectric ceramic substrate, 70 is a vibrating plate that seals the opening of the shallow groove of the piezoelectric ceramic substrate 69, and V1 is a common electrode 6. 7 and V 2 are potentials applied to the signal electrodes 66. Reference numeral 110 denotes an actuator, which is composed of a piezoelectric ceramics plate 64, a signal electrode 66, and a common electrode 67.

The ink jet head shown here is composed of a pressure chamber 62, a vibrating plate 70, and a piezoelectric ceramic plate 64. The pressure chamber 62 has a configuration in which an opening of a shallow groove formed on the upper end surface of the ceramic substrate 69 by molding or cutting is sealed with a diaphragm 70. The heater 110 is located on the upper surface of the diaphragm 70 corresponding to the pressure chamber 62. It is composed of a bonded piezoelectric ceramic plate 64, a common electrode 67 on the upper surface of the vibrating plate 70, and a signal electrode 66 on the upper surface of the piezoelectric ceramic plate 64. The piezoelectric ceramic plate 64 is subjected to polarization by applying a high voltage to the common electrode 67 and the signal electrode 66. When a drive level potential difference is applied between the common electrode 67 and the signal electrode 66 sandwiching the piezoelectric ceramic plate 64 thus polarized, an electric field in a direction parallel to the polarization direction is applied, and a piezoelectric ceramic plate is applied. 64 lateral distortion occurs and shrinks in the plate surface direction. A bending stress is applied to the vibration plate 70 due to the contraction of the piezoelectric ceramic plate 64, and the vibration plate 70 is displaced inward of the pressure chamber 62. A nozzle plate (not shown) is joined to the front surface of the pressure chamber 62, and a nozzle row 65 is provided corresponding to the position of the pressure chamber 62. The nozzle array axis of the nozzle array 65 is provided in parallel with the joining member of the vibration plate 70 and the piezoelectric ceramic plate 64, that is, the plate surface of the actuator. Even in the case of the transverse distortion mode, by forming a shallow groove in the ceramic substrate 69 and using the upper end wall of the substrate corresponding to the long side wall of the pressure chamber 62 as an actuator, an ink jet suitable for the present invention is provided. A head can be made.

The piezoelectric ceramic plate 64 is polarized by the potential difference between V 1 and V 2, and a transverse distortion occurs when the polarization direction and the electric field become parallel. The vibration plate 70 is subjected to bending stress due to the lateral strain of the piezoelectric ceramic plate 64, and is deformed inside the pressure chamber 62 as shown by the broken line in FIG. The pressure chamber 62 presses the ink to be filled by the deformation of the vibration plate 70 to simultaneously discharge ink droplets from the nozzle row 65, and a large number of rows in a row perpendicular to the direction of movement of the color filter substrate. The same color pixel section is colored. FIG. 7 is an explanatory diagram showing a method for manufacturing a color filter according to Embodiment 3 of the present invention.

In the figure, the same reference numerals as those in FIG. 6 denote the same or corresponding parts. 7 1 has a plurality of pressure chambers 6 2, an ink jet head utilizing transverse deformation mode deformation of a piezoelectric ceramic, 7 3 is a moving direction of a color filter substrate, and P 2 is a pixel section adjacent in a long side direction of the pixel section. It is an interval between each other. The pressure chambers 62 and the nozzle rows 65 are arranged so as to keep the interval P2.

Next, the manufacturing method will be described. Pressure chambers formed on the color filter substrate 76 at the same pitch as the pitch P2 of the specific color of the pixel sections R, G, and B, and nozzles provided in parallel with the arrangement direction of the pressure chambers An ink jet head 71 having a row 65 and a color filter substrate 76 are arranged in a positional relationship as shown in FIG. 7, and the substrate 76 moves in the direction of arrow 73 to reach the head discharge position. Droplets are sequentially landed and filled in the pixel sections. A color filter is manufactured by a manufacturing apparatus that performs such a manufacturing operation.

As described above, in the third embodiment of the present invention, the ink jet head 71 provided with the plurality of pressure chambers 62 utilizing the lateral distortion mode deformation of the piezoelectric ceramic is used, and the ink liquid is used. Droplets can be ejected simultaneously and with uniform characteristics such as the volume and flying speed of ink droplets, and a color filter with uniform color density can be manufactured with a cost-effective facility. .

In each of the first to third embodiments, a case has been described in which a color filter such as a liquid crystal display panel is manufactured. However, the present invention is not limited to this. It can be applied as long as it is filled by landing.

Industrial applicability

As described above, the method for manufacturing a color filter and the ink jet head according to the present invention are used for inexpensively manufacturing a color filter having uniform color density by discharging ink droplets on a color filter substrate of a liquid crystal display. Are suitable.

Claims

The scope of the claims

1. A method of manufacturing a color filter in which a colored layer is formed by discharging an ink droplet to a pixel section on a color filter substrate using an inkjet head.

A method for manufacturing a color filter, characterized in that a plurality of ink droplets are simultaneously ejected to one pixel section.

2. A nozzle plate on which a nozzle row including a plurality of nozzles is formed;

A flat plate on which an actuator deformed by an electric signal is installed, wherein a pressure chamber is formed by the nozzle plate, and a space surrounded by the flat plate,

An ink jet head, characterized in that ink supplied from an ink supply source to the pressure chamber is pressurized by the actuator and ejects ink droplets from the nozzle.

3. a plurality of piezoelectric material substrates formed such that deep grooves deeper than the groove width are parallel to each other;

A plurality of nozzle plates formed such that a plurality of nozzle rows are parallel to a required portion with each other;

A cover plate for sealing the deep groove of the piezoelectric material substrate,

An actuator which applies a potential difference to the deep groove partition walls of the piezoelectric material substrate to deform the partition walls in a shear mode;

A plurality of pressure chambers are formed by the deep groove of the piezoelectric material substrate, the nozzle plate at the location where the nozzle row is formed, the cover plate, and a space surrounded by the actuator.

A plurality of air chambers that are deformed by the actuator are formed by the deep groove of the piezoelectric material substrate, the nozzle plate at the location where the nozzle row is not formed, the cover plate, and the space surrounded by the actuator.

The pressure chamber and the air chamber are installed so as to be arranged alternately, An ink and a nozzle, wherein the ink filled in the plurality of pressure chambers from an ink supply source is pressurized by the actuator, and ink droplets are ejected from the nozzle.

4. a plurality of piezoelectric material substrates formed so that shallow grooves shallower than the groove width are parallel to each other;

A nozzle plate in which a plurality of nozzle rows each including a plurality of nozzles are formed on a straight line; an actuator which applies a potential difference to the piezoelectric material substrate to deform the piezoelectric material substrate in a transverse distortion mode;

A diaphragm that seals a shallow groove of the piezoelectric material substrate and is displaced by the actuator.

A plurality of pressure chambers are formed by a space surrounded by the shallow groove of the piezoelectric material substrate, the nozzle plate, and the vibration plate,

An ink jet jet, characterized in that the ink supplied to the plurality of pressure chambers from an ink supply source is pressurized by the displacement of the vibration plate to eject ink droplets from the nozzles.

5. In the ink jet head according to any one of claims 2 to 4,

When forming a coloring layer in a pixel section having a substantially rectangular shape and a ratio of the long side to the short side of 3 or more,

The above nozzle row is

An ink jet head, wherein a number of nozzles based on the shape of the pixel section are arranged in parallel with the long side direction of the pixel section and at equal nozzle intervals.

6. In the ink jet head according to any one of claims 2 to 5,

The above nozzle row is

An ink jet head, wherein nozzles located at both ends are arranged at least apart from the short side wall of the pressure chamber by the length of the short side wall.

7. The ink jet head according to claim 3 or 4, wherein: The above actuator is

The partition wall or the piezoelectric material substrate, a signal electrode, and a common electrode, and based on a difference between the first and second signals and the potential applied to the signal electrode and the common electrode, all of the partition walls or the common electrode An inkjet head characterized in that a piezoelectric material substrate is simultaneously deformed.

8. The ink jet head according to any one of claims 2 to 7, wherein a plurality of ink droplets are simultaneously applied to one pixel section and the ejection characteristics of each ink droplet are made uniform. A method for producing a color filter, characterized in that the color filter is ejected.