JP2007163540A - Electro-optical device, method for manufacturing the same, and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device which is provided with high contrast and a high opening ratio, by preventing light leakage even when a level difference is produced between a color layer and a bank. <P>SOLUTION: Widths H2 (H2a-H2h) of the bank 15 are formed so as to be narrower than widths H1 (H1a, H1b) of scanning lines 22a or widths H1 (H1c-H1h) of signal lines 22b on every place. With such formation, light rays B, C are made to be unable to reach alignment disturbance of a liquid crystal 30 occurring on the level difference section 12c as a boundary section between the bank 15 and the color layers 16, 17. "Light leakage" is prevented by forming the widths H2 (H2a-H2h) of the bank 15 to be narrower than the widths H1 (H1a, H1b) of the scanning lines 22a or the widths H1 (H1c-H1h) of the signal lines 22b on every place. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a color filter and wiring of an electro-optical device, a method for manufacturing the electro-optical device, and an electronic apparatus equipped with the electro-optical device.

  A method for manufacturing a color filter formed by forming a plurality of filter elements on a surface of a rectangular substrate made of glass, plastic, or the like in a dot matrix form by an ink jet method and laminating a protective film thereon is known. (For example, Patent Document 1).

JP 2002-221616 A (page 7, FIG. 6)

  However, there is a step between the plurality of filter elements and the partition walls formed in the dot matrix on the surface of the substrate by the inkjet method, and the surface of the protective film formed on the plurality of filter elements and the partition walls is flat. In addition, a level difference substantially corresponding to the level difference between the plurality of filter elements and the partition walls also occurs in the protective film.

  For this reason, the alignment film formed on the surface of the protective film also has a level difference substantially corresponding to the level difference between the plurality of filter elements and the partition walls. When an alignment treatment such as rubbing is performed on the alignment film in which the step is generated, alignment failure occurs at a position where the step is generated.

  When the incident light strikes the liquid crystal at the position where the alignment defect has occurred, the light is refracted or reflected by the liquid crystal. Since the phase of the light whose direction is disturbed is not controlled, a phenomenon in which light leaks without being controlled by a pair of polarizing plates (hereinafter referred to as light leakage) occurs, and the contrast as a display device is impaired. Become.

  In addition, the color filter is formed without considering any relative positional relationship between wirings, pixel electrodes and the like arranged on the substrate opposite to the substrate on which the color filter is formed and the color filter. Accordingly, there are problems such as a decrease in aperture ratio.

  Therefore, an object of the present invention is to prevent light leakage even when a step occurs between a plurality of filter elements (referred to as color layers in the present invention) and partition walls (referred to as banks in the present invention), and has a high contrast and a high aperture ratio. To provide an electro-optical device.

  In order to solve the above-described problems, an electro-optical device having a color filter in which a color layer is formed between banks according to the present invention has a wiring formed on another substrate facing the substrate on which the bank is formed. The gist is that the width of the bank is narrower than the width.

  A step is generated between the bank and the color layer formed between the banks, and the alignment process is non-uniform due to the step, and the direction of the liquid crystal sealed and sandwiched between the substrates is different from the desired direction. It becomes like this. When the light incident on the electro-optical device hits the liquid crystal whose direction is disturbed, the light is refracted or reflected in an arbitrary direction to cause light leakage. According to the present invention, there is provided an electro-optical device having a color filter in which a color layer is formed between banks, and the bank is wider than the width of a wiring formed on another substrate facing the substrate on which the bank is formed. Since the width of the bank is narrower, even if liquid crystal alignment is disturbed between the bank and the color layer, the bank is narrower than the width of the wiring. Thus, the light can be blocked by the wiring to prevent light leakage, and an electro-optical device having high contrast can be provided. In addition, since the display area is determined by the wiring, an electro-optical device having a high aperture ratio can be provided.

  The gist of the electro-optical device of the invention is that the wiring is a scanning line or a signal line. According to this configuration, even if the liquid crystal alignment is disturbed between the bank and the color layer due to the scanning line or the signal line, the width of the bank is narrower than the width of the scanning line or the signal line. The light incident on can be blocked by a scanning line or a signal line to prevent light leakage, and an electro-optical device with high contrast can be provided. In addition, since the display area is determined by the scanning line or the signal line, an electro-optical device having a high aperture ratio can be provided.

  The electro-optical device manufacturing method of the present invention is a method for manufacturing an electro-optical device having a color filter between substrates, wherein a bank is formed on one substrate, and a plurality of color layers are formed in a region partitioned by the bank. The gist is to have at least a step of forming and a step of forming a wiring on the other substrate, and the bank is formed to be narrower than the wiring.

  According to this, a method for manufacturing an electro-optical device having a color filter between substrates, which is formed by forming a bank on one substrate and forming a plurality of color layers in a region partitioned by the bank. The bank is formed so that the width of the bank is narrower than the width of the wiring formed by the process of forming the wiring on the other substrate. For this reason, the light incident on the electro-optical device can be blocked by the wiring to prevent light leakage. In addition, since the display area is determined by the wiring, an electro-optical device having a high aperture ratio can be provided.

  In the electro-optical device manufacturing method of the present invention, the wiring is a scanning line or a signal line.

  According to this, the light incident on the electro-optical device can be blocked by the scanning line or the signal line to prevent light leakage. In addition, since the display area is determined by the scanning line or the signal line, an electro-optical device having a high aperture ratio can be provided.

  The gist of the electro-optical device manufacturing method of the present invention is that the plurality of color layers are formed by an inkjet method.

  According to this, a bank is formed on one substrate, and a plurality of color layers are formed between the banks by the ink jet method. Therefore, by forming the bank width narrower, it is formed on the other substrate facing each other. Thus, the width of the wiring can be narrowed, and an electro-optical device having a high aperture ratio can be provided.

  The gist of the electronic apparatus of the present invention is that the electro-optical device of the present invention is mounted.

  According to this, the electro-optical device having the high contrast and the high aperture ratio according to the present invention can provide an electronic apparatus in which the display unit is easy to see.

  The gist of the electronic apparatus of the present invention is that the electro-optical device manufactured by using the method of manufacturing the electro-optical device of the present invention is mounted.

  According to this configuration, it is possible to provide an electronic apparatus in which the display unit is easy to see by the electro-optical device having the high contrast and the high aperture ratio manufactured by using the method for manufacturing the electro-optical device of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing the structure of the liquid crystal display device 1. The liquid crystal display device 1 as an electro-optical device includes a color filter substrate 10, an element substrate 20 as a counter substrate facing the color filter substrate 10, and a liquid crystal 30 sandwiched and sealed between both substrates. .

  The color filter substrate 10 includes a relatively transparent substrate 2 such as glass, quartz, and plastic, a bank 15 provided on the substrate 2, color layers 16 and 17 provided between the banks 15, and the bank 15. And the overcoat layer 13 provided on the surface of the color layers 16 and 17, the transparent electrode 11 provided on the surface of the overcoat layer 13, and the alignment film 12 provided on the surface of the transparent electrode 11. I have.

  The element substrate 20 includes a scanning line 22a as a wiring and a signal line 22b as a wiring for connecting a relatively transparent substrate 3 such as glass, quartz, and plastic and each pixel electrode 21 corresponding to a display pixel in a matrix. A TFT (Thin Film Transistor) element (hereinafter referred to as a TFT element) 35 (see FIG. 2) as a switching element for selectively applying a voltage to each pixel electrode 21 and at least a region including the pixel electrode 21. And at least an alignment film 23.

  The banks 15 of the color filter substrate 10 are formed on the substrate 2 in a rectangular shape having a height of about 2 μm, for example, by photolithography, and the rectangular banks 15 are arranged with regularity. .

  Color layers 16 and 17 are formed in the recesses formed by the bank 15 and the substrate 2. The color layers 16 and 17 are composed of any one of two or more colors including colors such as red, blue, and green. As a method of arranging the colors of the color layers 16 and 17, there are a stripe arrangement, a mosaic arrangement, a delta arrangement, and the like. In the present invention, any arrangement or other arrangement may be used.

  A thickness t1 of the bank 15 is formed to be thicker than a thickness t2 of the color layers 16 and 17. This is because, for example, when the ink jet method is used as a method of forming the color layers 16 and 17, the colored droplets discharged to the color layer 16 and the color layer 17 are not mixed.

  If color mixing occurs between the adjacent color layers 16 and 17, the color function of the liquid crystal display device 1 is impaired. Therefore, the present invention sets the thickness t 1 of the bank 15 to the thickness of the color layers 16 and 17. It is formed so as to be thicker than the length t2 to prevent color mixing between adjacent color layers 16 and 17.

  An overcoat layer 13 is provided on the surfaces of the bank 15 and the color layers 16 and 17. The transparent electrode 11 provided on the surface of the overcoat layer 13 is one electrode that controls the orientation of molecules of the liquid crystal 30 by applying a voltage between the pixel electrodes 21 of the opposing element substrate 20.

  The alignment film 12 provided on the surface of the transparent electrode 11 has a function of aligning the directions of the molecules of the liquid crystal 30 in a desired direction by an alignment process such as rubbing, oblique deposition, or water repellent process.

  On the other hand, each pixel electrode 21 corresponding to the display pixel of the element substrate 20 is a substantially transparent electrode, and a voltage is applied between the opposing transparent electrodes 11 to control the direction of molecules of the liquid crystal 30. is there. Each pixel electrode 21 is disposed to be opposed to each of the color layers 16 and 17 of the color filter substrate 10 as a pair.

  Each pixel electrode 21 is electrically connected to a scanning line 22a as a wiring and a signal line 22b as a wiring through a TFT element 35 (see FIG. 2), and keeps the scanning line 22a at a high potential. When a conductive state is established by the signal 35, a signal voltage is applied to the liquid crystal 30 by the signal line 22b. The scanning line 22a and the signal line 22b are made of a metal thin film such as aluminum, tantalum, or tungsten.

  The TFT element 35 (see FIG. 2) is made of amorphous silicon (a-Si, amorphous silicon) or polysilicon, and is connected between each pixel electrode 21, the scanning line 22a as a wiring, and the signal line 22b as a wiring. It functions as a switching element.

  A backlight (not shown) or a reflective layer (not shown) is provided below the surface of the liquid crystal display device 1, and light emitted from the backlight or light reflected by the reflective layer is provided on the liquid crystal display device 1. Light incident on the liquid crystal display device 1 from the lower side of the drawing is indicated by an arrow.

  The light A that has entered the region where the scanning line 22a or the signal line 22b is disposed from the lower side of the page is the scanning line 22a because the scanning line 22a and the signal line 22b are made of a metal thin film such as aluminum, tantalum, or tungsten. And cannot pass through the signal line 22b. An area where the scanning line 22a or the signal line 22b is provided and the light A cannot be transmitted is referred to as a non-transmission area T1. In addition, light B and C incident on the area where each pixel electrode 21 is disposed from below in the drawing can be transmitted because each pixel electrode 21 is made of substantially transparent indium oxide, tin oxide, or the like. it can. A region through which the light B and C can be transmitted is referred to as a transmission region T2. The transmissive region T2 is a region that functions as a so-called display region in which the orientation of molecules of the liquid crystal 30 is controlled by a voltage applied between each pixel electrode 21 and the transparent electrode 11 facing the pixel electrode 21.

  As described above, the thickness t1 of the bank 15 is formed to be thicker than the thickness t2 of the color layers 16 and 17. Accordingly, the overcoat layer 13, the transparent electrode 11 and the alignment film 12 provided on the surfaces of the bank 15 and the color layers 16 and 17 are formed following the surfaces of the bank 15 and the color layers 16 and 17. . Therefore, the alignment film 12 that controls the orientation of the molecules of the liquid crystal 30 also has the concave portions 12a and the convex portions 12b. The above-described alignment treatment performed on the step portion 12c between the concave portion 12a and the convex portion 12b of the alignment film 12 generates a non-uniform portion as compared with the alignment treatment performed on the concave portion 12a and the convex portion 12b.

  When the above-described light B and C is incident on the portion where the alignment of the liquid crystal 30 generated at the step portion 12c is non-uniform, the light B and C is diffused by the molecules of the liquid crystal 30 with non-uniform alignment, and the liquid crystal display device 1 The light whose phases are aligned by a polarizing plate (not shown) disposed in the state is not in phase.

  For this reason, for example, when the liquid crystal 30 is subjected to a substantially horizontal alignment process and there is no voltage in the display area, the light B and C are not transmitted, but the stepped portion 12c positioned at the outline of the display area Due to the generated molecules of the liquid crystal 30 with non-uniform orientation, a phenomenon in which part of the light B and C leaks from the periphery of the display area (hereinafter referred to as light leakage) occurs, and the liquid crystal display device 1 has a contrast. Will be damaged.

  Therefore, in the present invention, the relationship between the width H1 of the scanning line 22a or the signal line 22b and the width H2 of the bank 15 is set so that the width H2 of the bank 15 is narrower than the width H1 of the scanning line 22a or the signal line 22b. The light B and C cannot reach the disordered alignment of the liquid crystal 30 generated in the step portion 12c. As a result, an electro-optical device having high contrast can be provided. Further, since the region other than the width H1 of the scanning line 22a or the signal line 22b can be a transmission region (display region), the width H2 of the bank 15 is set to be narrow so that the scanning line 22a or the signal line 22b The width H1 can be reduced, and an electro-optical device having a high aperture ratio can be provided.

  FIG. 2 is a schematic plan view showing the structure of the liquid crystal display device 1. The state of FIG. 2 shows the a-a ′ cross section shown in FIG. 1 and is shown in a state where the color filter substrate 10 is seen through for easy understanding. Further, the banks 15 disposed on the color filter substrate 10 and the color layers 16 and 17 provided between the banks 15 are indicated by two-dot chain lines. A region where the color layers 16 and 17 are formed is indicated by hatching.

  On the element substrate 20, scanning lines 22 a (221 a, 222 a) as wirings are arranged in the left-right direction on the paper surface, and signal lines 22 b (221 b, 222 b) as wirings are arranged in the vertical direction on the paper surface. A portion where the scanning line 22a and the signal line 22b intersect is electrically insulated. In the region surrounded by the scanning line 22a and the signal line 22b, the pixel electrode 21 is disposed in a state where it is not electrically connected to the scanning line 22a and the signal line 22b. In this embodiment, for the sake of easy understanding, the stacking relationship that overlaps vertically is omitted, and the pixel electrode 21 does not overlap with the scanning line 22a and the signal line 22b in a plane. However, if the pixel electrode 21 and the scanning line 22a and the signal line 22b are electrically insulated, they may be stacked in a plane.

  Further, TFT elements 35 (35a, 35b) are formed between the scanning line 22a, the signal line 22b, and the pixel electrode 21. The TFT element 35 functions as a switching element among the scanning line 22 a, the signal line 22 b, and the pixel electrode 21, and is disposed on the transparent electrode 11 and the element substrate 20 disposed on the color filter substrate 10. The voltage applied to the pixel electrode 21 is controlled. The direction of the molecules of the liquid crystal 30 is controlled by the applied voltage, and the amount of transmitted light is thereby controlled to constitute the liquid crystal display device 1 as an electro-optical device.

  Further, as described above, the color filter substrate 10 is provided with the banks 15, and the color layers 16 and 17 are provided between the banks 15 to form a color filter. The step 12c described in FIG. 1 occurs near the boundary (indicated by a two-dot chain line) between the bank 15 and the color layers 16 and 17 shown in FIG.

  The relationship between the width H1 (H1a, H1b) of the scanning line 22a or the width H1 (H1c to H1h) of the signal line 22b and the width H2 (H2a to H2h) of the bank 15 will be described in detail. Here, in order to describe the adjacent relationship, the pixel electrodes 21 in the column at the center of the paper are respectively referred to as a pixel electrode 21a, a pixel electrode 21b, and a pixel electrode 21c, and are opposed to the pixel electrode 21a, the pixel electrode 21b, and the pixel electrode 21c. The color layers 17 formed on the color filter substrate 10 are referred to as a color layer 17a, a color layer 17b, and a color layer 17c, respectively.

  In addition, the pixel electrodes 21 in the column on the left side of the drawing are the pixel electrode 21d, the pixel electrode 21e, and the pixel electrode 21f, respectively, and are formed on the color filter substrate 10 so as to face the pixel electrode 21d, the pixel electrode 21e, and the pixel electrode 21f. The color layer 16 is a color layer 16a, a color layer 16b, and a color layer 16c, respectively.

  The banks 15 are arranged on the color filter substrate 10 in a lattice pattern to form the color layers 16 and 17. The widths H2 (H2a to H2h) of the banks 15 are substantially equal, but may not necessarily be equal. Further, the width H1 (H1a, H1b) of the scanning line 22a disposed on the element substrate 20 or the width H1 (H1c to H1h) of the signal line 22b is disposed substantially equal, but does not necessarily have to be equal. .

  As shown in FIG. 2, the width H2 (H2a to H2h) of the bank 15 is greater than the width H1 (H1a, H1b) of the scanning line 22a or the width H1 (H1c to H1h) of the signal line 22b at any location. It is narrowly formed. By forming in this way, the light B, C (FIG. 1) is caused by the disorder of the alignment of the liquid crystal 30 (see FIG. 1) generated in the step 12c as the boundary between the bank 15 and the color layers 16, 17. Reference) is not reachable.

  “Light leakage” means that the width H2 (H2a to H2h) of the bank 15 is narrower than the width H1 (H1a, H1b) of the scanning line 22a or the width H1 (H1c to H1h) of the signal line 22b at any location. It can prevent by forming.

  The present invention is not limited by the type of liquid crystal 30, and the same effect can be obtained with any liquid crystal 30. Further, the method for aligning the liquid crystal, the method for manufacturing the color layers 16 and 17, and the method for manufacturing the bank 15 are not particularly limited, and the same effect can be obtained even if manufactured by other methods. Similar effects can be obtained if the hues of the color layers 16 and 17 have two or more hues including colors such as red, blue and green. In addition, the bank 15 is not particularly limited in material such as a resin material having a light shielding property or a laminated structure of an inorganic material and an organic material having a light shielding property. Can be obtained. In addition, as described above, the bank may be a stripe bank in addition to the lattice bank.

  The electronic device on which the liquid crystal display device 1 of the above embodiment is mounted is, for example, a portable information device called PDA (Personal Digital Assistants), a portable terminal device, a personal computer, a word processor, a digital still camera, a vehicle-mounted monitor, a monitor direct view It can be suitably used as an image display means for a digital video recorder, car navigation device, electronic notebook, workstation, video phone, POS terminal, etc.

FIG. 2 is a schematic cross-sectional view illustrating a structure of a liquid crystal display device. The schematic plan view which shows the structure of a liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device as an electro-optical device, 2, 3 ... Substrate, 10 ... Color filter substrate, 11 ... Transparent electrode, 12, 23 ... Orientation film, 12a ... Concave part, 12b ... Convex part, 12c ... As a boundary part Stepped portion, 13 ... Overcoat layer, 15 ... Bank, 16, 17, 16a-16c, 17a-17c ... Color layer, 20 ... Element substrate as counter substrate, 21, 21a-21f ... Pixel electrode, 22a, 221a, 222a ... scanning lines as wiring, 22b, 221b, 222b ... signal lines as wiring, 30 ... liquid crystal, 35, 35a, 35b ... TFT elements, A, B, C ... light, H1, H2, H1a to H1h, H2a ~ H2h ... width, t1, t2 ... thickness, T1 ... non-transmissive region, T2 ... transmissive region.

Claims (7)

An electro-optical device having a color filter in which a color layer is formed between banks,
An electro-optical device, wherein a width of the bank is narrower than a width of a wiring formed on another substrate facing the substrate on which the bank is formed.   2. The electro-optical device according to claim 1, wherein the wiring is a scanning line or a signal line. A method of manufacturing an electro-optical device having a color filter between substrates,
Forming a bank on one substrate and forming a plurality of color layers in a region partitioned by the bank;
Forming a wiring on the other substrate;
Having at least
The method of manufacturing an electro-optical device, wherein the bank is formed to be narrower than the wiring.   4. The method of manufacturing an electro-optical device according to claim 3, wherein the wiring is a scanning line or a signal line.   4. The method of manufacturing an electro-optical device according to claim 3, wherein the plurality of color layers are formed by an inkjet method.   An electronic apparatus comprising the electro-optical device according to claim 1. An electronic apparatus comprising an electro-optical device manufactured by using the electro-optical device manufacturing method according to claim 3.

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