DETAILED DESCRIPTION OF THE INVENTION

[0001] 1. Technical Field of the Related Art

[0002] The present invention relates to a method for depositing a film, a device for depositing a film, a device for discharging droplets, a method for manufacturing a color filter, a display device including a color filter, a method for a manufacturing display device, a display device, and an electronic apparatus, and particularly to a technique for depositing a film by discharging droplets.

[0003] 2. Description of the Related Art

[0004] Various types of display devices using electro-optic devices, such as liquid crystal display devices and electroluminescent display devices (hereinafter referred to as EL devices), as display means and electronic apparatuses having such a display device, such as cellular phones and personal digital assistants, have been generally known. Since it is becoming common that these display devices display color images, the display devices often include a color filter in which R (red), G (green), and B (blue) dots serving as filter elements are arrayed on the surface of a substrate formed of glass, resin, or the like in a predetermined arrangement, such as a striped arrangement, a delta arrangement, or a mosaic arrangement.

[0005] In an EL device capable of displaying color images, display dots comprising R (red), G (green), and B (blue) dots serving as EL luminescent films disposed in a predetermined arrangement, such as a striped arrangement, a delta arrangement, a mosaic arrangement, or the like between pairs of electrodes are formed on a substrate of glass, resin, or the like. The display dots each emit light having predetermined color and gradation by controlling voltage applied to the electrodes from one display dot to another.

[0006] When these display devices are manufactured, the filter elements for colors of the color filter and the luminescent films for colors of the EL device are generally patterned by photolithography. Unfortunately, such a patterning step using photolithography requires complicated, time-consuming treatments, such as material deposition, exposure, and development. Also, the patterning step undesirably consumes a large amount of color materials and resist, consequently increasing costs.

[0007] In order to solve this problem, a method has been proposed in which droplets containing a filter element material or an EL luminescent material and a solvent are discharged by an ink jet technique to land on the surface of a substrate, thus forming filter elements or luminescent films arrayed in a dot manner. A process of forming filter elements 303 will now be illustrated in which filter elements 303 are arrayed by a ink jet technique, in a dot manner as shown in FIG. 61(b), in a plurality of unit regions 302 on a so-called mother substrate 301, which is a large-area substrate formed of glass, resin, or the like, as shown in FIG. 61(a).

[0008] In this instance, for example, while an ink jet head 306 having a nozzle line 305 comprising a plurality of nozzles 304 as shown in FIG. 61(c) linearly sweeps over each unit region 302 a plurality of times (two times in FIG. 61), as designated by the arrows A1 and A2 in FIG. 61(b), the plurality of nozzles 304 selectively discharge ink, or a filter material, to form filter elements 303 in desired positions.

[0009] These filter elements 303 are formed by arraying colors, such as R, G, and B, in a predetermined arrangement pattern, such as a striped arrangement, a delta arrangement, or a mosaic arrangement, as described above. Therefore, it is generally needed to use R, G, and B color ink jet heads 306 one by one in order to form a color filter in a predetermined color arrangement on the mother substrate 301.

[0010] In the ink jet head 306, the discharge quantity from the nozzles 304 constituting the nozzle line 305 generally varies. The ink jet head 306 has an ink discharge quality Q in that, for example, nozzles 304 at both ends of the nozzle line 305 offer the largest discharge quantity, nozzles 304 in the center of nozzle line 305 offer the larger discharge quantity, and the other nozzles 304 offer the smallest discharge quantity, as shown in FIG. 62(a).

[0011] As a result, when the filter elements 303 are formed with the ink jet head 306, as shown in FIG. 61(b), dense lines, that is, striped color shadings, are formed in either positions P1 at both ends of the ink jet head 306 or positions P2 at the middle of the ink jet head 306, or in both positions P1 and P2. As a result, light-transmission characteristics of the color filter disadvantageously have variation when viewd from above.

[0012] Accordingly, a method for reducing the unevenness of film deposition resulting from variation of the discharge quantity of droplets has been known (for example, refer to patent document 1 listed later) in which while sweeping and gradually shifting in the shifting direction (the horizontal direction in FIG. 61(b)), the ink jet head 306 discharges droplets a plurality of times to form each filter element 303 (hereinafter simply referred to as the “error variance” method).

[0013] Unfortunately, the error variance method greatly increases the times of sweeping in comparison with the known method even if an identical product is manufactured, thus increasing manufacturing time and reducing production efficiency. Accordingly, in order to solve the problem, a device is proposed (for example, patent document 2 listed below) in which a plurality of heads whose attitudes can be controlled are incorporated into a common carriage so that the heads sweep over a wide range at a time to increase the production efficiency.

[0014] [Patent Document 1]

[0015] Japanese Unexamined Patent Application Publication No. 20021-221616

[0016] [Patent Document 2]

[0017] Japanese Unexamined Patent Application Publication No. 2002-273868

PROBLEMS TO BE SOLVED BY THE INVENTION

[0018] Although various attempts including the above-described method and device are proposed in order to reduce the nonuniformity of film deposition or to suppress the reduction of production efficiency, it is difficult, in practice, to sufficiently reduce the unevenness of film deposition extending in a striped manner in the sweeping direction of the liquid discharge head. In particular, as the sweeping speed is set higher to increase productivity, the reduction of the striped nonuniformity becomes difficult even if the above-described method or device is employed.

[0019] On the other hand, when the plurality of unit regions 302 are formed on the mother substrate 301, different arrangement patterns (such as a striped arrangement, a delta arrangement, and a mosaic arrangement) are formed in the unit regions 302 in some cases so that the unit regions 302 correspond to the size or shape of the display of a resulting display device. Also, in order to increase the number of the unit regions 302, the number of or the intervals between display dots having the same color in a certain direction on the mother substrate 301 are often varied from one model to another. If the ink jet head is swept over such a mother substrate 301 without variation, process efficiency is undesirably reduced. In this instance, ink jet heads having different structures may be prepared for respective models to increase process efficiency. However, the preparation of many ink jet heads increases costs.

[0020] The present invention is intended to solve the above-described problems, and an object of the invention is to provide a technique for reducing the unevenness of film deposition in a method and a device for depositing films by discharging droplets with liquid discharge means. Another object of the present invention is to provide a device and a method for forming a film by discharging a liquid material with a liquid discharge head or the like, such as an ink jet head, and which can reduce the unevenness of film deposition resulting from variation of the quantity of the discharged liquid material. Still another object of the present invention is to provide a device and a method for forming a film by discharging a liquid material and which can increase process efficiency while suppressing the increase of costs, even if the liquid material is discharged onto various discharge objects.

MEANS FOR SOLVING PROBLEMS

[0021] In order to solve the problems, a method for forming a film by discharging a liquid material onto the surface of an object with a liquid discharge means is provided. The method comprises: a first sweeping step of discharging a plurality of droplets of the liquid material onto the surface of the object while the liquid discharge means sweeps over the object in a first direction with respect to the object, along the surface of the object; and a second sweeping step of discharging a plurality of droplets of the liquid material onto the surface while the liquid discharge means sweeps over the object in a second direction different from the first direction with respect to the object, along the surface of the object.

[0022] By varying the sweeping direction of the liquid discharge means with respect to the object between the first sweeping step and the second sweeping step and setting it in the first direction and the second direction, respectively, so that a plurality of droplets are sequentially deposited to form each film while sweeping is performed in two different directions, unevenness of film deposition resulting from the sweeping direction can be reduced. In particular, striped unevenness of film deposition extending in two different directions cancels each other out to become inconspicuous, even if such unevenness results from each sweeping step. Thus, uniform film deposition can be achieved on the whole.

[0023] Preferably, the first direction and the second direction are selected by rotating the object to orient in a direction different from each other between the first movement step and the second movement step such that the first direction and the second direction intersect each other. Since the orientation of the object is changed, it is not necessary to change the sweeping direction of the liquid discharge means. Consequently, film deposition can be performed by a simple system, but not a large mechanism.

[0024] According to another aspect, the present invention provides a film forming device comprising: liquid discharge means for discharging droplets of a liquid material onto the surface of an object; and shifting means for relatively moving the object and the liquid discharge means, along the surface of the object. The liquid discharge means is relatively moved in at least two directions with respect to the object along the surface of the object, and the liquid discharge means discharges the droplets one after another while moving in any direction of said at least two directions.

[0025] In the present invention, the sweeping direction can be selected from at least two directions, according to the film formation pattern which will be deposited onto an object. By discharging droplets one by one while sweeping is performed in at least two directions with respect to the object, unevenness of film formation resulting from the sweeping direction can be reduced.

[0026] Preferably, the film forming device further comprises an orientation means for orienting the object in at least two directions by rotating the object. By rotating the object with the orientation means to orient the object, the shifting means can become a simple structure in which the shifting means drives sweeping in only one direction. Thus, a miniaturized device and a reduced cost can be achieved on the whole.

[0027] According to another aspect, the present invention provides a liquid discharge device for discharging a liquid material onto an object. The liquid discharge device comprises a liquid discharge head for discharging the liquid material; shifting means for relatively moving the liquid discharge head and the object in a direction along the surface of the object, the liquid discharge head and the object opposing each other; and orientation means for horizontally orienting the object. The orientation means is capable of horizontally orienting the object in at least two different directions.

[0028] In the present invention, the orientation means for horizontally orienting the object is capable of horizontally orienting the object in at least two different directions. Therefore, the sweeping direction of the liquid discharge head relative to the object can be selected from at least two directions according to the arrangement of the regions on the object in which droplets will be discharged. Thus, efficiency of discharge can be increased. Also, the sweeping direction of the liquid discharge head driven by the shifting means can be varied by changing the horizontal orientation of the object. As a result, by sweeping the liquid discharge head in two different directions to discharge droplets onto one object for depositing a film, striped unevenness of the material resulting from the sweeping direction can be reduced.

[0029] Preferably, the orientation means comprises a plurality of observing means for observing different portions of the object. Some of the observing means are used in one orientation relationship and the other observing means are used in the other orientation relationship.

[0030] In the present invention, when the object is placed in different orientations, different observing means are used from each other. Therefore, since it is not needed to expand the observing area or to shift the observing means, the cost of the device can be reduced and the accuracy of observation can be increased.

[0031] Preferably, the observing means is capable of observing a plurality of portions of the object.

[0032] Since the plurality of observing means can each observe the plurality of portions of the object, the horizontal orientation of the object can be precisely observed. The observing means capable of observing a plurality of portions of the object may include two imaging devices.

[0033] Preferably, the observing position by the observing means is fixed in the device.

[0034] By fixing the observing position by the observing means in the device, no structure for shifting the observing means is needed, and thus, the accuracy of the observation can be increased.

[0035] Preferably, the two orientations are offered by rotating one horizontal orientation of the object about 90° on the normal of the surface of the object.

[0036] Thus, the liquid discharge head can be swept in two directions perpendicular to each other, with respect to the object. Consequently, striped unevenness of the material resulting from the sweeping direction of the liquid discharge head with respect to the object can be reduced most effectively.

[0037] According to another aspect, the present invention provides a liquid discharge device for discharging a liquid material onto an object. The liquid discharge device comprises: a liquid discharge head for discharging the liquid material; shifting means for relatively moving the liquid discharge head and the object in a direction along the surface of the object, the liquid discharge head and the object opposing each other; and orientation means for horizontally orienting the object. The sweeping direction in which the liquid discharge head moves while discharging droplets of the liquid material onto the object and the orientation of the object oriented by the orientation means have at least two orientation relationships.

[0038] In the present invention, the sweeping direction in which the liquid discharge head moves while discharging droplets of the liquid material onto the object and the orientation of the object oriented by the orientation means have at least two orientation relationships. Therefore, the sweeping direction of the liquid discharge head relative to the object can be selected from at least two directions according to the arrangement of the regions on the object in which droplets will be discharged. Thus, efficiency of discharge can be increased. Also, the sweeping direction of the liquid discharge head can be varied to two different directions with respect to the object. As a result, by sweeping the liquid discharge head in two different directions to discharge droplets onto one object, striped unevenness of the material resulting from the sweeping direction can be reduced.

[0039] Preferably, the orientation means comprises a plurality of observing means for observing different portions of the object. Some of the observing means are used in one orientation relationship and the other observing means are used in the other physical relationship.

[0040] In the present invention, when the object is placed in different orientations, different observing means are used from each other. Therefore, since it is not needed to expand the observing area or to shift the observing means, the cost of the device can be reduced and the accuracy of observation can be increased.

[0041] Preferably, the observing means is capable of observing a plurality of portions of the object.

[0042] Since the plurality of observing means can each observe the plurality of portions of the object, the horizontal orientation of the object can be precisely observed. The observing means capable of observing a plurality of portions of the object may include two imaging devices.

[0043] Preferably, the observing position by the observing means is fixed in the device.

[0044] By fixing the observing position by the observing means in the device, no structure for shifting the observing means is needed, and thus, the accuracy of the observation can be increased.

[0045] Preferably, the two orientations are offered by rotating one horizontal orientation of the object about 90° on the normal of the surface of the object.

[0046] Thus, the liquid discharge head can be swept in two directions perpendicular to each other, with respect to the object. Consequently, striped unevenness of the material resulting from the sweeping direction of the liquid discharge head with respect to the object can be reduced most effectively.

[0047] According to another aspect, the present invention provides a liquid discharge device for discharging a liquid material onto an object to form a film. The liquid discharge device comprises: a liquid discharge head for discharging the liquid material; shifting means for relatively moving the liquid discharge head and the object in a direction along the surface of the object, the liquid discharge head and the object opposing each other; and orientation means for horizontally orienting the object. The sweeping direction in which the liquid discharge head moves while discharging droplets of the liquid material onto the object is changed with respect to the orientation of the object oriented by the orientation means, during operation.

[0048] The sweeping direction of the liquid discharge head can be varied with respect to the object, during operation. As a result, by sweeping the liquid discharge head in two different directions to discharge droplets onto one object, striped unevenness of the material resulting from the sweeping direction can be reduced.

[0049] Preferably, the orientation means comprises a plurality of observing means for observing different portions of the object. Some of the observing means are used before the sweeping direction is changed and the other observing means are used after the sweeping direction is changed.

[0050] In the present invention, when the sweeping direction is changed, different observing means are used between before change and after change. Therefore, since it is not needed to expand the observing area or to shift the observing means, the cost of the device can be reduced and the accuracy of observation can be increased.

[0051] Preferably, the observing means is capable of observing a plurality of portions of the object.

[0052] Since the plurality of observing means can each observe the plurality of portions of the object, the horizontal orientation of the object can be precisely observed. The observing means capable of observing a plurality of portions of the object may include two imaging devices.

[0053] Preferably, the observing position by the observing means is fixed in the device.

[0054] By fixing the observing position by the observing means in the device, no structure for shifting the observing means is needed, and thus, the accuracy of the observation can be increased.

[0055] Preferably, the angle of the change in sweeping direction is about 90° C. on the normal of the surface of the object.

[0056] Thus, the liquid discharge head can be swept in two directions perpendicular to each other, with respect to the object. Consequently, striped unevenness of the material resulting from the sweeping direction with respect to the object can be reduced effectively.

[0057] The liquid material may be a liquid filter material capable of forming filter elements on the object, or a liquid luminescent material capable of forming EL films on the object. Thus, a color filter or EL elements included in a display device can enhance the quality of displayed color images.

[0058] According to another aspect, the present invention provides a method for manufacturing a color filter in which filter elements are formed by discharging a liquid material onto an object. The method comprises: a first discharge step of continuously discharging droplets of the liquid material onto the object, in a first sweeping direction; and a second discharge step of continuously discharging droplets of the liquid material onto the object, in a second sweeping direction.

[0059] When filter elements of a color filter is formed by discharging droplets of a liquid material, by performing sweeping in two directions of the first sweeping direction and the second sweeping direction, striped unevenness of color shading resulting from the sweeping direction can be reduced.

[0060] Preferably, in the first discharge step, first filter elements having a first color are formed in a first region of the object, and, in the second discharge step, second filter elements having a second color different from the first color are formed in a second region of the object, different from the first region.

[0061] By forming filter elements of different colors in different sweeping direction from one another, the manners of color shadings can be varied from one color to another. Thus, the resulting color shading is reduced on the whole.

[0062] Preferably, the filter elements comprises three types of filter elements having three colors, and one type of the filter elements, having one color exhibiting the strongest color shading resulting from the sweeping direction of droplets of a liquid material is discharged in one of the discharge steps and the other types having the other two colors are discharged in the other discharge step.

[0063] The sweeping direction of one type of the filter elements, having one color exhibiting the strongest color shading and the sweeping direction of the other types having the other two colors are different from each other. The difference between color shadings resulting from the difference between the sweeping directions easily cancels each other. Thus, color shading can be further reduced on the whole.

[0064] Preferably, the filter elements are formed with both the droplets discharged in the first discharge step and the droplets discharged in the second discharge step.

[0065] Since the filter elements are formed with a plurality of droplets discharged in different sweeping directions, variation of the amount of the discharged filter element material, resulting from the sweeping direction can be reduced. Thus, striped color shading resulting from the sweeping direction can be reduced.

[0066] Preferably, the first sweeping direction and the second sweeping direction form an angle of about 90° on the normal of the surface of the object.

[0067] Thus, the liquid discharge head can be swept in two directions perpendicular to each other, with respect to the object to discharge droplets. Consequently, striped unevenness of the material resulting from the sweeping direction with respect to the object can be reduced most effectively.

[0068] According to another aspect, the present invention provides a display device comprising a color filter having filter elements formed by discharging a liquid material onto an object. The color filter includes droplets of the liquid material which are continuously discharged in a plurality of sweeping directions.

[0069] The display device has a color filter formed with droplets of the liquid material which are continuously discharged in a plurality of sweeping directions. Specifically, the color filter is formed by mixing the droplets continuously discharged along one sweeping direction and the droplets continuously discharged along a different sweeping direction. Therefore, striped color shading resulting from the sweeping direction can be reduced, and the resulting display device can thus display a high quality images.

[0070] Preferably, the filter elements comprise a plurality of types of filer elements having different colors from one another. The types of filter elements are formed by continuously discharging droplets of the liquid material in sweeping directions different from one another.

[0071] Since the filter elements include a plurality of types of filer elements having different colors from one another and which are formed by continuously discharging droplets of the liquid material in sweeping directions different from one another, striped color shading resulting from the sweeping direction in which droplets are continuously discharged can be reduced.

[0072] Preferably, the filter elements comprise three types of filter elements having three colors, and one type of the filter elements having one color exhibiting the strongest color shading resulting from the sweeping direction is discharged in a sweeping direction different from the sweeping direction in which the other types, having the other two colors, are discharged.

[0073] Since the strongest color shading of one color mixed with the other color shadings, of the other two colors, color shading can be further reduced on the whole.

[0074] Preferably, the filter elements are formed by mixing droplets of the liquid material which are continuously discharged in different sweeping directions.

[0075] Since the filter elements are formed with a plurality of droplets discharged in different sweeping directions, variation of the amount of the discharged filter element material, resulting from the sweeping direction can be reduced. Thus, striped color shading resulting from the sweeping direction can be reduced.

[0076] Preferably, the different sweeping directions form an angle of about 90° on the normal of the surface of the color filter.

[0077] Thus, the color filter is formed by discharging droplets with sweeping in two directions perpendicular to each other. Consequently, striped unevenness of the material resulting from the sweeping direction of droplets can be reduced most effectively.

[0078] The display device of the present invention may be an electro-optic device in which an electro-optic material serves to display images. The electro-optic device may include a liquid crystal panel laid and the color filter laid one upon the other, or an EL layer and the color filter laid one upon the other.

[0079] According to another aspect, the present invention provides an electronic apparatus comprising a display device having any one of the color filters described above. The electronic apparatus of the present invention is not particularly limited, but is may be a personal digital assistant such as a cellular telephone, a mobile computer, or a portable electronic apparatus such as an electronic wrist watch.

[0080] According to another aspect, the present invention provides a method for manufacturing a display device, comprising: a first discharge step of continuously discharging droplets of a liquid material onto an substrate, in a first sweeping direction; and a second discharge step of continuously discharging droplets of the liquid material onto the substrate, in a second sweeping direction different from the first sweeping direction for depositing a film.

[0081] By discharging droplets onto the substrate to form a film with sweeping in two different directions, striped unevenness of the material resulting from the sweeping direction during discharge can be reduced. In particular, this is effective for a method for manufacturing an electronic apparatus.

[0082] Preferably, discharged droplets of the liquid material form display dots.

[0083] Thus, unevenness of the material in display dots resulting from the sweeping direction can be reduced and, consequently, unevenness of displayed images can be reduced. Thus, high-quality images can be achieved.

[0084] Preferably, each of the display dots is formed of a plurality of droplets of the liquid material, and some of the plurality of droplets are discharged in the first discharge step and the other droplets are discharged in the second discharge step.

[0085] Since each display dot is formed of a plurality of droplets discharged in different sweeping directions, unevenness of the material can be further reduced, and consequently, the quality of displayed images can be enhanced.

[0086] The display dots may have an EL layer. In this instance, preferably, the EL layer is formed by discharged droplets of a liquid material described above. The display dots may include an EL layer, a hole transport layer, and a pair of electrodes separated by these layers. In this instance, at least one of the EL layer, the hole transport layer, and the pair of electrodes may be formed by discharged droplets of a material described above.

[0087] Preferably, the first sweeping direction and the second sweeping direction form an angle of about 90° on the normal of the surface of the substrate.

[0088] By discharging droplets with sweeping in two directions perpendicular to each other, unevenness of the material can be reduced on the whole effectively.

[0089] According to another aspect, the present invention provides a display device comprising display dots discharging droplets of a liquid material onto a substrate for depositing a film. Preferably, the display dots each include droplets of the liquid material which are continuously discharged in a plurality of sweeping directions.

[0090] By discharging droplets onto the substrate to form display dots with sweeping in two different directions for depositing a film, striped unevenness of the material resulting from the sweeping direction during discharge can be reduced, and consequently, the quality of the displayed images can be enhanced. In particular, the present invention is effective for electronic apparatuses such as liquid crystal devices and EL devices.

[0091] Preferably, the display dots are formed by mixing droplets of the liquid material which are continuously discharged in different sweeping directions.

[0092] Since the display dots are formed with a plurality of droplets discharged in different sweeping directions, variation of the amount of the discharged material, resulting from the sweeping direction can be reduced. Thus, striped unevenness of displayed images resulting from the sweeping direction can be further reduced.

[0093] The display dots may have an EL layer. In this instance, preferably, the EL layer is formed by discharge described above. The display dots may include an EL layer, a hole transport layer, and a pair of electrodes separated by these layers. In this instance, at least one of the EL layer, the hole transport layer, and the pair of electrodes may be formed by discharged droplets described above.

[0094] Preferably, the different sweeping directions form an angle of about 90° on the normal of the surface of the color filter.

[0095] Thus, the display dots are formed by discharging droplets with sweeping in two directions perpendicular to each other. Consequently, striped unevenness of the material resulting from the sweeping direction of droplets can be reduced most effectively.

[0096] According to another aspect, the present invention provides an electronic apparatus comprising any one of the display devices described above. The electronic apparatus of the present invention is not particularly limited, but may be a personal digital assistant such as a cellular telephone, a mobile computer, or a portable electronic apparatus such as an electronic wrist watch.

DESCRIPTION OF THE EMBODIMENTS

[0097] Embodiments of a method for forming a film, a film forming device, a liquid discharge device, a method for manufacturing a color filter, a display device including a color filter, a method for manufacturing a display device, a display device, and an electronic apparatus will now be described in detail with reference to drawings.

[0098] [Device for Discharging Liquid]

[0099] First, embodiments of a film forming device and a liquid discharge device will be described. As shown in FIG. 8, a liquid discharge device 16 has a head unit 26 including a liquid discharge head 22 serving as liquid discharge means, which may be an ink jet head used for a printer. The liquid discharge device 16 also has a head position controller 17 for controlling the position of the liquid discharge head 22, a substrate position controller 18 for controlling the position of a mother substrate 12, a sweeping driver 19 serving as sweeping operation driving means for sweeping the liquid discharge head 22 over the mother substrate 12 in a sweeping direction X, a shifting driver 21 for shifting the liquid discharge head 22 in a shifting direction Y intersecting (perpendicular to) the sweeping direction with respect to the mother substrate 12, a mother substrate feeding device 23 for feeding the mother substrate 12 to a predetermined position in the liquid discharge device 16, and a control apparatus 24 for generally controlling the liquid discharge device 16.

[0100] The head position controller 17, the substrate position controller 18, the sweeping driver 19, and the shifting driver 21 are disposed above a base 9. These devices may be provided with a cover 14 over them, if necessary. The head position controller 17, the sweeping driver 19, and the shifting driver 21 constitute shifting means.

[0101] The liquid discharge head 22 has a nozzle line 28 comprising a plurality of nozzles 27, as shown, for example, in FIG. 10. The number of nozzles 27 is, for example, 180, and the diameter of the nozzles 27 is, for example, 28 μm. The pitch t between the nozzles 27 is, for example, 141 μm. The width direction M shown in FIG. 10 designates a standard direction in which the liquid discharge head sweeps, and the aligning direction T designates a direction in which the nozzles 27 in the nozzle line 28 align.

[0102] The liquid discharge head 22 has a nozzle plate 29 formed of stainless steel or the like, a diaphragm 31 opposing the nozzle plate 29, and a plurality of partition members 32 joining the nozzle plate 29 to the diaphragm 31, for example, as shown in FIG. 12(a) and FIG. 12(b). The partition members 32 define a plurality of ink chambers 33 and a liquid pool 34 between the nozzle plate 29 and the diaphragm 31. The ink chambers 33 communicate with the liquid pool 34 through passages 38.

[0103] The diaphragm 31 is provided with an ink supply port 36 in a proper position thereof. The ink supply port 36 is connected to an ink supply device 37. The ink supply device 37 supplies a filter element material M for one of R, G, and B colors, which may be an R-color filter element material, to the ink supply port 36. The supplied filter element material M fills the liquid pool 34 and then flows through the passages 38 to fill the ink chambers 33.

[0104] The nozzle plate 29 has nozzles 27 for jetting the filter element material M from the ink chambers 33. Ink pressurizers 39 are disposed, corresponding to the ink chambers 33, on the back surface of the diaphragm 31 opposite the surface opposing the ink chambers 33. The ink pressurizers 39 each have a piezoelectric element 41 and a pair of electrodes 42a and 42b separated by the piezoelectric element 41, as shown in FIG. 12(b). The piezoelectric element 41 is bent in the external direction designated by the arrow C by energization so that the volume of the corresponding ink chamber 33 increases. Accordingly, the filter element material M flows in an amount equivalent to the increased volume from the liquid pool 34 into the ink chamber 33 through the passage 38.

[0105] When current is removed from the piezoelectric element 41, the piezoelectric element 41 and the diaphragm 31 return to their original shapes. Since the ink chamber 33 also returns to its original shape, the pressure of the filter element material M in the ink chamber 33 increases to jet a droplet 8 of the filter element material M from the nozzle 27. In this instance, ink-repellent films 43 formed of, for example, Ni-tetrafluoroethylene eutectoid by plating are provided in the regions surrounding the nozzles 27 for preventing droplets 8 from being discharged in a wrong direction and from clogging the nozzles 27.

[0106] The head position controller 17, the substrate position controller 18, the sweeping driver 19, and the shifting driver 21, and other means disposed around the above-described liquid discharge head 22 will now be described with reference to FIG. 9. The head position controller 17 includes an α motor 44 for horizontally rotating the liquid discharge head 22 incorporated in the head unit 26, a β motor 46 for rotating the liquid discharge head 22 with reciprocation on an axis parallel to the shifting direction Y, a γ motor 47 for rotating the liquid discharge head 22 with reciprocation on an axis parallel to the sweeping direction X, and a z motor 48 for moving the liquid discharge head 22 in the vertical direction.

[0107] The substrate position controller 18 includes a table 49 on which the mother substrate 12 is placed and a θ motor 51 for horizontally rotating the table 49. The sweeping driver 19 has an X guide rail 52 extending in the sweeping direction X and an X slider 53 containing, for example, a pulse-driven linear motor. The X slider 53 moves in the sweeping direction X along the X guide rail 52 by, for example, activating the linear motor contained therein.

[0108] The shifting driver 19 has a Y guide rail 54 extending in the shifting direction Y and a Y slider 56 containing, for example, a pulse-driven linear motor. The Y slider 56 moves in the shifting direction Y along the Y guide rail 54 by, for example, activating the linear motor contained therein.

[0109] The linear motors contained in the X and Y sliders 53 and 56 can precisely control rotation angles of the output shafts by pulse signals applied thereto. Consequently, the position of the liquid discharge head 22, which is supported by the X slider 53, in the sweeping direction X and the position of the table 49 in the shifting direction Y can be controlled with high accuracy. The positions of the liquid discharge head 22 and the table 49 may be controlled by feedback with a servomotor or other desired methods, and the control of the positions is not limited to that by the pulse motor.

[0110] The table 49 is provided with positioning pins 50a and 50b thereon for controlling the horizontal position of the mother substrate 12. The mother substrate 12 is positioned by the substrate feeding device 23, which will be described later, such that end faces thereof in the sweeping direction X and the shifting direction Y are pressed to the positioning pins 50a and 50b. Preferably, the table 49 has known fixing means for fixing the positioned mother substrate 12 by, for example, air aspiration (vacuum drawing).

[0111] The liquid discharge device 16 of the present embodiment is provided with a plurality of pairs (two pairs in the drawing) of imaging devices 91R and 91L and 92R and 92L above the table 49, as shown in FIG. 9. The drawing illustrates only the barrels of the imaging devices 91R and 91L and 92R and 92L, and the other parts and the structure of supporting the imaging devices are omitted. The imaging devices used for observation may be CCD cameras. FIG. 8 does not show the imaging devices.

[0112] The structure of the imaging devices 91R and 91L and 92R and 92L will now be illustrated in detail. FIGS. 22(a< /italic>) and 22(b< /italic>) are plan views of the mother substrate 12 positioned on and supported by the table 49. The mother substrate 12 may be supported on the table 49 such that the longitudinal direction L thereof is parallel to the sweeping direction X when viewed from above, as shown in FIG. 22(a), or such that the longitudinal direction L is parallel to the shifting direction Y, as shown in FIG. 22(b). The positioning pins 50a, here in the drawing, can move in the horizontal direction of the drawing according to the horizontal position of the mother substrate 12 and the positioning pins 50b are fixed on the table 49. However, both the positioning pins 50a and 50b may be fixed on the table 49, as in the positioning pins 50b, or movable, as in the positioning pins 50a.

[0113] The mother substrate 12 is previously provided with two pairs, and a total of four, of alignment marks 12ar and 12al and 12br and 12bl in the outer region thereof. The alignment marks 12ar and 12al are provided at both sides of the mother substrate 12 in the longitudinal direction L, respectively. The alignment marks 12br and 12bl are provided at both sides of the mother substrate 12 in the width-extending direction, that is, in the width direction M, respectively. When the mother substrate 12 is supported on the table 49 such that the longitudinal direction L thereof is parallel to the sweeping direction X, as shown in FIG. 22(a), the imaging devices 91R and 91L shoot the alignment marks 12ar and 12al< /italic>, respectively. When the mother substrate 12 is supported on the table 49 such that the longitudinal direction L thereof is parallel to the shifting direction Y, as shown in FIG. 22(b), the imaging devices 92R and 92L shoot the alignment marks 12br and 12bl< /italic>, respectively.

[0114] The imaging devices 91R and 91L and 92R and 92L are each directly or indirectly fixed to a fixing portion (for example, the base 9) of the liquid discharge device 16. Thus, the position of the mother substrate 12 on the table 49 are accurately detected by observing the mother substrate 12 with the fixed imaging devices.

[0115] Returning to FIG. 8, description will be continued. The mother substrate feeding device 23 shown in FIG. 8 includes a mother substrate holder 57 for accommodating mother substrates 12 and a mother substrate carrier 58 for carrying the mother substrates 12, such as a robot. The mother substrate carrier 58 includes a base 59, an up-and-down shaft 61 rising and lowering with respect to the base 59, a first arm 62 rotating on the up-and-down shaft 61, a second arm 63 rotating on the basis of the movement of the first arm 62, and a sucking pad 64 provided on the undersurface of the end of the second arm 63. The sucking pad 64 is intended to hold the mother substrate 12 by air aspiration (vacuum drawing) or the like.

[0116] A capping device 76 and a cleaning device 77 are disposed at one side of the shifting driver 21 and under the sweeping locus of the liquid discharge head 22, as shown in FIG. 8. Furthermore, an electronic balance 78 is disposed at the other side of the shifting driver 21. The capping device 76 is intended to prevent the nozzles 27 (see FIG. 10) from drying while the liquid discharge head 22 is in standby. The cleaning device 77 is intended to clean the liquid discharge head 22. The electronic balance 78 is intended to weigh the ink droplet 8 discharged from each nozzle 27. Also, a head camera 81 shifting together with the liquid discharge head 22 is attached in the vicinity of the liquid discharge head 22.

[0117] The control apparatus 24 shown in FIG. 8 includes a computer main body 66 containing a processor, an input device 67, such as a keyboard, and a display device 68, such as a CRT. The computer main body 66 includes a CPU (central processing unit) 69 shown in FIG. 14 and an information-recording medium 71 serving as a memory for storing various types of information.

[0118] The head position controller 17, the substrate position controller 18, the sweeping driver 19, the shifting driver 21, and a head driving circuit 72 for driving the piezoelectric elements 41 (see FIG. 12(b)) in the liquid discharge head 22 are connected to the CPU 69 through an input-output interface 73 and a bus 74, as shown in FIG. 14. The substrate feeding device 23, the input device 67, the display device 68, the capping device 76, the cleaning device 77, and the electronic balance 78 are also connected to the CPU 69 through the input-output interface 73 and the bus 74, as in above.

[0119] Memories, such as the information-recording medium 71, generally include semiconductor memories, such as a RAM (random access memory) and a ROM (read only memory), and external storages, such as a hard disk, a CD-ROM reading device, and a disk-shaped recording medium. The information-recording medium 71 has: memory areas for storing software in which procedures for controlling the liquid discharge device 16 are programmed, coordinate data defining positions in the mother substrate 12 to which the liquid discharge head 22 discharges ink, and the distance at which the mother substrate 12 is shifted in the shifting direction Y in FIG. 9; areas for functioning as a working area of the CPU 69, temporary files, and the like; and other various memory areas.

[0120] The CPU 69 functions as a control to discharge ink in predetermined positions on the surface of the mother substrate 12, according to the software stored in the memory, or the information recording medium 71. As for portions for embodying concrete functions, the CPU 69 has a cleaning operation part for performing arithmetic computation for cleaning, a capping operation part for performing capping operation, a weighing operation part for performing arithmetic computation for measuring weight with the electronic balance 78, and a drawing operation part for drawing a predetermined pattern by discharging ink droplets onto the surface of the mother substrate 12, as shown in FIG. 14.

[0121] The drawing operation part has various controlling operation parts for performing arithmetic computations such as a drawing initial position operating part for locating the liquid discharge head 22 at an initial position, a sweeping control operation part for sweeping the liquid discharge head 22 in the sweeping direction X at a predetermined speed, a shifting operation part for shifting the mother substrate 12 a predetermined distance in the shifting direction Y, and a nozzle discharge control operation part for determining which of the plurality of nozzles 27 of the liquid discharge head 22 discharges ink.

[0122] The above-described control functions are embodied by software used with the CPU 69, in the embodiment. However, these functions may be embodied by an electronic circuit, but not CPUs, if such an electronic circuit is applicable.

[0123] Turning now to the flow chart shown in FIG. 15, the operation of the liquid discharge device 16 structured as described above will be illustrated. When an operator turns on the liquid discharge device 16, initialization is performed in step S1. Specifically, the head unit 26, the substrate feeding device 23, control apparatus 24, and other devices are restored to the initial settings.

[0124] When weighing timing comes (step S2), the sweeping driver 19 moves the head unit 26 shown in FIG. 9 to the position of the electronic balance 78 shown in FIG. 8 (step S3). The electronic balance 78 weighs the ink droplet discharged from the nozzles 27 (step S4). Voltage applied to the piezoelectric elements 41 of the nozzles 27 is adjusted according to the ink-discharge performance of the nozzles 27 evaluated by the weigh (step S5).

[0125] When cleaning timing comes (step S6), the sweeping driver 19 moves the head unit 26 to the cleaning device 77 (step S7). The cleaning device 77 cleans the liquid discharge head 22 (step S8).

[0126] Before weighing timing and cleaning timing come, or after weighing and cleaning are completed, the substrate feeding device 23 shown in FIG. 8 is activated to feed the mother substrate 12 to the table 49 in step S9. Specifically, the sucking pad 64 draws one of the mother substrates 12 in the mother substrate holder 57 to hold it up. The up-and-down shaft 61, the first arm 62, and the second arm 63 are moved to carry the mother substrate 12 to the table 49 and, then, press the mother substrate 12 to the pins 50a and 50b (see FIG. 9) previously provided in proper places on the table 49. In order to prevent displacement of the mother substrate 12, it is preferable to fix the mother substrate 12 to the table 49 by means of air aspiration (vacuum drawing) or the like.

[0127] Then, while the imaging devices 91R and 91L, shown in FIG. 9, observe the mother substrate 12, the table 49 is horizontally rotated to position the mother substrate 12 by rotating the output shaft of the θ motor 51 in small angles (step S10). More specifically, the pairs of imaging devices 91R and 91L and 92R and 92L shoot the alignment marks 12ar and 12al and 12br and 12bl provided at the sides of the mother substrate 12. The horizontal posture of the mother substrate 12 is calculated from the positions where the alignment marks are shot. The rotation angle θ is adjusted by rotating the table 49 according to the horizontal posture of the mother substrate 12.

[0128] Then, while the head camera 81 shown in FIG. 8 observes the mother substrate 12, the position where the liquid discharge head 22 starts drawing is determined by calculation (step S11). The liquid discharge head 22 is shifted to the starting position of drawing by appropriately operating the sweeping driver 19 and the shifting driver 21 (step S12).

[0129] In this instance, the standard direction S shown in FIG. 10 of the liquid discharge head 22 is not necessarily parallel to the sweeping direction X, and it may form an angle φ1 or φ2 with respect to the sweeping direction X, as shown in FIGS. 1 and 2. These angles φ1 and φ2 are intended to geometrically equalize the pitch of the nozzles 27 arranged in the T direction to the pitch of droplets landing on the mother substrate 12 in the shifting direction Y because the pitch of the ink droplets to be discharged onto the surface of the mother substrate 12 is often different from the pitch of the nozzles 27.

[0130] When the liquid discharge head 22 is placed in the starting position of drawing in step S12 shown in FIG. 15, the liquid discharge head 22 is linearly moved to sweep in the sweeping direction X at a constant speed in step S13. The liquid discharge head 22 continuously discharges ink droplets from the nozzles 27 thereof onto the surface of the mother substrate 12 during sweeping.

[0131] The amount of an ink droplet may be set such that the entire amount of ink is discharged to an area covered by a series of sweeping operation of the liquid discharge head 22. Alternatively, when the liquid discharge head 22 sweeps several times as described later with reference to FIGS. 3 and 4, the amount of the ink droplet may be set such that a fraction (for example, one fourth) of the entire amount of ink required in one series of sweeping operation is discharged. The sweeping operation is repeated several times (for example, four times) so as to overlap parts of sweeping areas in the shifting direction Y and to cover the entire area where the ink should be discharged.

[0132] After the completion of a series of sweeping on the mother substrate 12 (step S14), the liquid discharge head 22 reverses the shifting direction to return to the initial position (step S15), and shifts a predetermined distance (by a shifting distance set in advance) in the shifting direction Y (step S16). The ink is then swept again and discharged in step S13, and the above-described procedure is repeated to sweep over a plurality of lines. After the completion of a series of sweeping, the liquid discharge head 22 may be driven so as to shift a predetermined distance in the shifting direction Y and, then, turn to sweep in the opposite direction, as described later with reference to FIG. 2.

[0133] In the case of forming a plurality of color filters in the mother substrate 12, as described later, the liquid discharge head 22 shifts a predetermined distance in the shifting direction Y after the completion of ink discharge to the entirety of a line over the color filter regions on the mother substrate 12 (step S17), and repeats steps S13 to S16. After ink discharge is completed to all lines in the color filter region on the mother substrate 12 (step S18), the substrate feeding device 23 or another transport means carries the treated mother substrate 12 to the outside in step S20. Then, the feed of the mother substrate 12 and the discharge of ink are repeated as in above until an operator give a direction to terminate the procedure.

[0134] When the operator directs the CPU 69 to terminate the procedure (step S21), the liquid discharge head 22 is carried to the capping device 76. The capping device 76 caps the liquid discharge head 22 (step S22).

[0135] In the liquid discharge device 16 structured as in above, ink can land on the entire surface of the mother substrate 12 by continuously discharging ink droplets while the liquid discharge head 22 sweeps in the sweeping direction X and by shifting the sweeping operation in the shifting direction Y and then repeating the sweeping operation. In the present embodiment, the mother substrate 12 on the table 49 can be positioned using the imaging devices 91R and 91L which shoot the alignment marks 12ar and 12al< /italic>, as shown in FIG. 22(a). At the same time, the mother substrate 12 put on the table 49 in a different horizontal posture (the posture in which the mother substrate 12 is rotated 90° on the normal thereof) can be positioned using the imaging devices 92R and 92L which shoot the alignment marks 12br and 12bl< /italic>, as shown in FIG. 22(b). Therefore, two different sweeping directions X (perpendicular to each other) can be set with respect to the mother substrate 12.

[0136] It is generally assumed that mother substrates 12 having various ink-landing-position arrangements are fed to the liquid discharge device 16. For example, when a plurality of unit regions 11 are arrayed on the mother substrate 12, as shown in FIG. 22, the size of the unit regions 11 or the dot array pattern may be varied between product models, or the arrangement manner of the unit regions 11 may be varied in order to increase productivity by increasing the number of unit regions 11 as many as possible. Accordingly, in the case of the mother substrate 12 in which the unit regions 11 are arranged as shown in FIG. 22, it is suitable for efficiently treating the mother substrate 12 to allow the longitudinal direction L of the mother substrate 12 to be parallel to the sweeping direction X of the liquid discharge head 22, as shown in FIG. 22(a). On the other hand, in the case of another mother substrate 12′ in which different types of unit regions 11′ are arranged as shown in FIG. 23 or in which the unit regions 11 are arranged in a manner different from the manner shown in FIG. 22, it may be suitable for efficiently treating the mother substrate 12′ to allow the longitudinal direction L of the mother substrate 12′ to be parallel to the shifting direction Y, as shown in FIG. 23(a).

[0137] Since the liquid discharge device 16 can treat the mother substrate 12 regardless of the horizontal posture in which the mother substrate 12 is placed in either of the two different directions as shown in FIGS. 22 and 23 (perpendicular to each other in the drawings), the mother substrate 12 can be placed on the table 49 in a horizontal posture according to the ink-landing-position arrangement. As a result, the liquid discharge device 16 can efficiently treat a discharge object, or the mother substrate 12, according to the posture of the object.

[0138] In the present embodiment, the substrate feeding device 23 is used for placing the mother substrate 12 on the table 49. In order to place the mother substrate 12 so as to orient in either direction of the two different directions as shown in FIGS. 22 and 23, the feeding posture of the substrate feeding device 23 may be changed. Alternatively, a mechanism for rotating the table 49 may be used to rotate it, for example, 90°, and whether the horizontal orientation of the mother substrate 12 is changed is selected after the mother substrate 12 is placed on the table 49.

[0139] It has been described in association with FIG. 56 that the amount of ink droplets discharged from the nozzles 27 constituting the nozzle line 28 of the liquid discharge head 22 is liable to vary, and, for example, that some nozzles 27 at both ends of the nozzle line 28 (for example, 10 nozzles at each end) particularly discharge a large amount of ink. It is not preferable to use the nozzles 27 discharging ink in an amount larger than that of the other nozzles 27 because it results in films having nonuniform thicknesses. It is preferable to set some, for example, ten nozzles or so, of the nozzles 27 constituting the nozzle line 28, at both ends E of the nozzle line 28 so as not to discharge ink and to use the other nozzles in the other region F, as shown in FIG. 13.

[0140] Also, in order to reduce the nonuniformity of film thickness, each film is formed of a plurality of droplets from the liquid discharge head 22, but not only one droplet, in a predetermined region. Specifically, in the case of depositing films in a plurality of regions, even if with a certain variety in the amount of each of droplets by forming the films of a plurality of droplets, the nonuniformity of the film thickness in each region can be reduced.

[0141] The structure of the liquid discharge head 22 is not limited to the one described above, but various structures may be applied. For Example, a liquid discharge head 22A shown in FIG. 11 has two nozzle lines 28 disposed in the standard direction S. Each of these nozzle lines 28 includes a plurality of nozzles 27, as in above. Another liquid discharge head 22B shown in FIG. 16 has three nozzle lines 28R, 28G, and 28B disposed in the standard direction S. In each of the liquid discharge heads 22A and 22B, the liquid material discharged from the nozzles 27 in the nozzle lines 28 may be the same or different between the lines. For example, in the liquid discharge head 22A shown in FIG. 11, the nozzles 27 in both nozzle lines 28 discharge the same ink. In the liquid discharge head 22B shown in FIG. 16, the material of ink discharged from the nozzles 27 is different between the nozzle lines 28R, 28G, and 28B such that, for example, filter element materials 13R, 13G, and 13B are discharged, as described later.

[0142] [Color Filter and Method for Manufacturing the Same]

[0143] An embodiment of a method for manufacturing a color filter will now be described. This embodiment illustrates a method in which the above-described liquid discharge device 16 is used for forming the color filter, but the method is not limited by the device used.

[0144] FIG. 5(a) schematically shows the plan structure of an exemplary color filter. FIG. 6(d) shows the structure in a sectional view taken along line VI-VI of FIG. 5(a).

[0145] The color filter 1 of the present embodiment includes a substrate (base material) 2 formed of glass, resin, or the like and a plurality of filter elements 3 deposited on the surface of the substrate 2, in a dot pattern, which may be a dot matrix as shown in the drawing. The color filter 1 also includes a protective layer 4 deposited on the filter elements 3, as shown in FIG. 6(d). FIG. 5(a) shows the color filter 1 without the protective layer 4 in plan view.

[0146] Barrier walls 6 are formed of a light-shielding resin in a grid pattern on the substrate 2. The regions partitioned by the barrier walls 6 are filled with a color material to form filter elements 3. The filter elements 3 are each formed of one of the color materials of R (red), G (green), and B (blue), and the resulting filter elements 3 each having one of the colors are arrayed in a predetermined arrangement. Exemplary arrangements include striped arrangement (in which all the filter elements in a column in the matrix have the same color) shown in FIG. 7(a), mosaic arrangement (in which any series of three filter elements 3 aligned in a column or a row includes R, G, and B colors) shown in FIG. 7(b), and delta arrangement (in which the filter elements 3 are arrayed so as to be staggered one another and any unit consisting of three adjacent filter elements includes R, G, and B colors) shown in FIG. 7(c). The “barrier walls” in the present invention include “banks”, referring to protrusions from the substrate, and the side faces thereof may be substantially perpendicular to the substrate or sloped.

[0147] The color filter 1 has a size of, for example, about 4.57 cm (1.8 inches). The filter elements 3 each have dimensions of 30 μm×100 μm. The interval between adjacent filter elements 3, that is, the filter element pitch, is, for example, 75 μm.

[0148] When the color filter 1 of the present invention is used as an optical element for displaying color images (full color images), three filter elements of R, G, and B colors constitute a unit acting as a pixel. Color images are displayed by selectively passing light through one of the R, G, and B filter elements in a pixel or a combination of the filter elements. In this instance, the barrier walls 6 formed of a light-shielding resin serve as a black matrix.

[0149] The color filter 1 is cut off from the substrate, that is, the mother substrate 12 having a large area as shown in FIG. 5(b). Specifically, a color filter pattern is formed in each of a plurality of color-filter-forming regions (unit regions) 11 defined in the mother substrate 12. Grooves for cutting into pieces are formed in the surroundings of the color-filter-forming regions 11. The mother substrate 12 is divided (cut) into pieces to form the color filters 1, one of which is shown in FIG. 5(a), by applying a stress to the grooves or other methods.

[0150] A method for manufacturing the color filter 1 will now be described in detail. FIG. 6 schematically shows a procedure of manufacturing the color filter 1 step by step. First, the barrier walls 6 are formed of a light-shielding resin in a grid pattern viewed in the direction of arrow B, on the mother substrate 12. The hollows 7 of the grid pattern define regions where the filter elements 3 are formed, that is, filter-element-forming regions. The plan dimension of each filter-element-region 7 separated by the barrier walls 6 is, for example, 30 μm×100 μm, when viewed in the direction of arrow B.

[0151] The barrier walls 6 serve to stop the flow of a liquid filter element material 13 and as a black matrix. Also, the barrier walls 6 are formed by an arbitrary patterning technique, such as photolithography, and may further be heated with a heater if necessary.

[0152] After the formation of the barrier walls 6, the droplets 8 of the filter element material 13 are supplied to the filter-element-forming regions 7 as shown in FIG. 6(b). Thus, the filter-element-regions 7 are filled with the filter element material 13. This process is performed by, for example, discharging the droplets 8 of the ink (filter element material 13) from the liquid discharge head 22 of the above-described liquid discharge device 16 to deposit the droplets 8 in the filter-element-forming regions 7. Reference numerals 13R, 13G, and 13B in FIG. 6(b) represent filter element materials having R (red), G (green), and B (blue) colors, respectively.

[0153] After a predetermined amount of the filter element material 13 fills the filter-element-forming regions 7, the mother substrate 12 is heated to, for example, about 70° C. by a heater to vaporize the solvent of the filter element material 13. This vaporization reduces the volume of the filter element material 13 and, thus, the filter element material 13 become flattened, as shown in FIG. 6(c). If the volume is excessively reduced, the supply of the droplets 8 of the color filter material 13 and the heating of the droplets 8 are repeated until the thickness of filter element material reaches a level satisfactory for the resulting color filter 1. Only the remaining solid constituents of the color filter material 13 result in a film, thus forming the color filter elements 3, each having a desired color.

[0154] After the filter elements 3 are formed as above, the color filter elements 3 are subjected to heat treatment at a predetermined temperature for a predetermined time to be completely dried. Then, the protective layer 4 is deposited by a proper method, such as spin coating, roll coating, dipping, or ink jetting. The protective layer 4 is intended to protect the filter elements 3 and flatten the surface of the color filter 1. In the embodiment, the barrier walls 6 are formed of a light-shielding resin to serve to block light (as a black matrix). Alternatively, instead of using a light-transmissive resin, barrier walls 6 may be covered with a light-shielding layer formed of a metal, such as Cr, having a size larger than that of the barrier walls thereunder.

[0155] In the present embodiment, as shown in FIG. 6(b), the filter element material 13 is used as ink discharged from the above-described liquid discharge device 16, and the droplets 8 of the ink are deposited in the filter-element-forming regions 7 to from the filter element 3. In this instance, if the three types of filter element material 13R, 13G, and 13b are discharged together while the liquid discharge head 22 is swept in an identical sweeping direction X with respect to the mother substrate 12, unevenness occurs in a striped manner in the sweeping direction X due to the variation of the discharge rate between the nozzles 27 of the liquid discharge head 22, as described above, and changes of the discharge rate of the nozzles 27 with time.

[0156] In the present embodiment, accordingly, any one of the three types of filter element material 13R, 13G, and 13B is discharged while the liquid discharge head 22 is swept in a different direction from that for the other types of filter element materials. For example, two of the above-described three color materials (for example, 13R and 13G) are discharged while the liquid discharge head 22 is swept in a sweeping direction X parallel to the longitudinal direction L of the mother substrate 12, as shown in FIG. 22(a); and the other color material (for example, 13B) is discharged while the liquid discharge head 22 is swept in a different sweeping direction X perpendicular to the longitudinal direction L of the mother substrate 12 (that is, the shifting direction Y is parallel to the longitudinal direction L of the mother substrate 12), as shown in FIG. 22(b). Alternatively, two of the above-described three color materials (for example, 13R and 13G) may be discharged while the liquid discharge head 22 is swept in a sweeping direction X perpendicular to the longitudinal direction L of the mother substrate 12, (that is, the shifting direction Y is parallel to the longitudinal direction L of the mother substrate 12) as shown in FIG. 23(a); and the other color material (for example, 13B) is discharged while the liquid discharge head 22 is swept in a different sweeping direction X parallel to the longitudinal direction L of the mother substrate 12, as shown in FIG. 23(b).

[0157] Thus, the sweeping direction for discharge of one of the three types of filter element material 13R, 13G, and 13B differs from (and becomes perpendicular to) the sweeping direction for the others, with respect to the mother substrate 12. As a result, the striped color shading of one color material occurs in a direction different from that of the other color materials and, thus, the color shading of the color filter 1 becomes inconspicuous on the whole, effectively decreasing.

[0158] FIGS. 1 to 4 are schematic illustrations showing procedures for discharging the above-described filter element materials 13R, 13G, and 13B onto the mother substrate 12 from the nozzles 27 of the liquid discharge head 22. FIG. 24 is a schematic illustration of the structure of a manufacturing apparatus for performing the procedures.

[0159] (Variation 1)

[0160] The apparatus for manufacturing color filters shown in FIG. 24 includes first, second, and third sections 16R, 16G, and 16B, each including substantially the same liquid discharge device 16. Only the first section 16R includes a substrate holder 57 but the second and third sections 16G and 16B do not. Preliminary dryers 96 each having a hot plate are disposed for preliminarily drying inks (filter element materials) discharged and deposited on the mother substrate 12, between the first and second sections 16R and 16G, between the second and third sections 16G and 16B, and downstream of the third section 16</