Indication device

Abstract

To provide a display device in which the brightness within the display surface is uniform. [Solution] The display device includes a first transparent substrate on which a first electrode is provided in each of a plurality of pixels, a second transparent substrate positioned opposite the first transparent substrate on which a second electrode is provided that supplies a potential common to the plurality of pixels, a liquid crystal layer in which liquid crystal is sealed between the first transparent substrate and the second transparent substrate, and a light source positioned on the first transparent substrate that irradiates light into the liquid crystal layer from the edge of the liquid crystal layer, wherein the plurality of pixels include a first pixel and a second pixel further away from the light source than the first pixel, the first pixel includes a first transparent insulating film between the first transparent substrate and the first electrode, the second pixel includes a second transparent insulating film between the first transparent substrate and the first electrode, and the first transparent insulating film and the second transparent insulating film are provided such that the volume of liquid crystal contained in the first pixel is smaller than the volume of liquid crystal contained in the second pixel.

Description

[Technical Field]

[0001] One embodiment of the present invention relates to a display device. [Background technology]

[0002] In recent years, progress has been made in the development of transparent displays that allow the background of one side to be seen from the other side (see Patent Document 1). Users can see images, figures, or characters displayed on the transparent display from either side. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-092702 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In transparent displays using liquid crystals, the light source must be placed at the edge of the substrate to ensure transparency. In this case, the light emitted from the light source enters from the edge of the liquid crystal layer, but a problem has arisen with brightness variations within the display surface, where the brightness is high in the area closer to the light source and low in the area further away from the light source.

[0005] One of the objectives of one embodiment of the present invention is to provide a display device in which the brightness within the display surface is uniform, in view of the above problems. [Means for solving the problem]

[0006] A display device according to one embodiment of the present invention includes a first transparent substrate provided with a first electrode included in each of a plurality of pixels, a second transparent substrate disposed opposite to the first transparent substrate and provided with a second electrode to which a potential common to the plurality of pixels is supplied, a liquid crystal layer in which liquid crystal is sealed between the first transparent substrate and the second transparent substrate, and a light source disposed on the first transparent substrate and irradiating light into the interior of the liquid crystal layer from the edge of the liquid crystal layer, wherein the plurality of pixels include a first pixel and a second pixel further away from the light source than the first pixel, the first pixel includes a first transparent insulating film between the first transparent substrate and the first electrode, the second pixel includes a second transparent insulating film between the first transparent substrate and the first electrode, and the first transparent insulating film and the second transparent insulating film are provided such that the volume of liquid crystal contained in the first pixel is smaller than the volume of liquid crystal contained in the second pixel. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic plan view showing the configuration of a display device relating to one embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view showing the configuration of a display device relating to one embodiment of the present invention. [Figure 3] This is a schematic cross-sectional view showing the pixel configuration of a display device according to one embodiment of the present invention. [Figure 4] This is a schematic cross-sectional view showing the pixel configuration of a display device according to one embodiment of the present invention. [Figure 5] This is a schematic cross-sectional view showing the pixel configuration of a display device according to one embodiment of the present invention. [Figure 6] This is a schematic plan view showing the pixel configuration of a display device according to one embodiment of the present invention. [Figure 7] This is a schematic plan view showing the pixel configuration of a display device according to one embodiment of the present invention. [Figure 8] This is a schematic plan view showing the pixel configuration of a display device according to one embodiment of the present invention. [Figure 9] This is a schematic cross-sectional view showing the pixel configuration of a display device according to one embodiment of the present invention. [Figure 10] This is a schematic cross-sectional view showing the pixel configuration of a display device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to the drawings. The following disclosure is merely an example. Configurations that a person skilled in the art could easily conceive by appropriately modifying the configuration of the embodiments while maintaining the spirit of the invention are naturally included within the scope of the present invention. In order to make the explanation clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual embodiment. However, the illustrated shapes are merely examples and do not limit the interpretation of the present invention. In this specification and drawings, components similar to those described above with respect to previously shown figures are denoted by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0009] In this specification, terms such as "up" and "down" describe the relative positional relationship between the structure of interest and other structures. In this specification, the direction from the first transparent substrate toward the second transparent substrate, as described later, is defined as "up," and the opposite direction is defined as "down." However, for the sake of explanation, the up-down relationship may be reversed from that shown in the illustration. "Plan view" refers to viewing from a direction perpendicular to the surface of either the first or second transparent substrate. In particular, viewing from the direction toward the first transparent substrate is sometimes referred to as a "top view."

[0010] In this specification, expressions such as "α includes A, B, or C," "α includes any one of A, B, and C," and "α includes one selected from the group consisting of A, B, and C" do not exclude cases where α includes multiple combinations of A, B, and C, unless otherwise specified. Furthermore, these expressions do not exclude cases where α includes other elements.

[0011] In this specification, the terms "membrane" and "layer" may be interchangeable as appropriate.

[0012] <First Embodiment> The display device 10 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

[0013] [1. Configuration of Display Device 10] [1-1. Outline of Configuration of Display Device 10] FIG. 1 is a schematic plan view showing the configuration of the display device 10 according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the configuration of the display device 10 according to an embodiment of the present invention. Specifically, FIG. 2 is a cross-sectional view of the display device 10 cut along line A1-A2 in FIG. 1.

[0014] As shown in FIGS. 1 and 2, the display device 10 includes a first transparent substrate 100, a second transparent substrate 200, a liquid crystal layer 300, and a light source 400. The second transparent substrate 200 is disposed opposite to the first transparent substrate 100. The liquid crystal layer 300 includes liquid crystal 310 and is located between the first transparent substrate 100 and the second transparent substrate 200. The first transparent substrate 100 and the second transparent substrate 200 are adhered by a sealing material 320 provided along the periphery of the second transparent substrate 200. That is, the liquid crystal 310 of the liquid crystal layer 300 is enclosed in a space surrounded by the sealing material 320 between the first transparent substrate 100 and the second transparent substrate 200.

[0015] The display surface of the display device 10 is formed in a region where the first transparent substrate 100, the second transparent substrate 200, and the liquid crystal layer 300 overlap each other, and an image, video, or the like is displayed. Here, for convenience of explanation, this region is referred to as the "display region". The display region includes a plurality of pixels PX. For example, the plurality of pixels PX are arranged in a matrix in a first direction D1 and a second direction D2 intersecting the first direction D1. The first direction D1 and the second direction D2 may be referred to as a row direction and a column direction, respectively. In the display device 10, various images, videos, or the like can be displayed on the display surface by controlling each of the plurality of pixels PX. Details of the configuration of the pixel PX will be described later.

[0016] The second transparent substrate 200 is smaller than the first transparent substrate 100, and in a plan view (top view), the first transparent substrate 100 includes an area exposed from the second transparent substrate 200. For the sake of explanation, this area is referred to as the "peripheral area." The peripheral area is located outside the display area. In the peripheral area, a light source 400 is positioned on the first transparent substrate 100, along the edge of the second transparent substrate 200. That is, the light source 400 is positioned along a first direction D1 and irradiates light in a second direction D2. The light irradiated from the light source 400 enters from the edge of the liquid crystal layer 300 and propagates inside the liquid crystal layer 300. In addition, an input / output unit IO is provided on the first transparent substrate 100 in the peripheral area. For example, the input / output unit IO includes connection terminals for inputting signals from the outside, and a drive circuit for controlling multiple pixels PX. The input / output unit IO may include a chip mounted on the first transparent substrate 100.

[0017] Although not shown in the diagram, a transparent protective member may be provided on the first transparent substrate 100 or the second transparent substrate 200. For example, the same material as the first transparent substrate 100 and the second transparent substrate 200 can be used for the transparent protective member. The transparent protective member may protect the first transparent substrate 100 or the second transparent substrate 200 and also function as a light guide plate that propagates light irradiated from the light source 400.

[0018] [1-2. Configuration of the first transparent substrate 100 and the second transparent substrate 200] The first transparent substrate 100 and the second transparent substrate 200 are light-transmitting. Specifically, the first transparent substrate 100 and the second transparent substrate 200 are transparent to visible light. As each of the first transparent substrate 100 and the second transparent substrate 200, a light-transmitting rigid substrate such as a glass substrate, a quartz substrate, or a sapphire substrate can be used. If the display device 10 needs to be flexible, a light-transmitting flexible substrate such as a polyimide substrate, an acrylic substrate, a siloxane substrate, or a fluororesin substrate can be used as the first transparent substrate 100 and the second transparent substrate 200. In this case, to improve the heat resistance of the first transparent substrate 100 and the second transparent substrate 200, a flexible substrate with impurities introduced can also be used. In order to match the display quality of the display surface on the first transparent substrate 100 with the display quality of the display surface on the second transparent substrate 200, it is preferable that the first transparent substrate 100 and the second transparent substrate 200 be made of the same material.

[0019] [1-3. Configuration of Light Source 400] The light source 400 is sometimes called an edge light source because it is positioned along the edge of the second transparent substrate 200. For example, the light source 400 includes light-emitting diodes (LEDs) arranged along the first direction D1. The light source 400 may also include optical components such as reflectors, diffusers, or lenses, and may include a control circuit to control the timing of LED emission.

[0020] [1-4. Composition of the liquid crystal layer 300] The liquid crystal 310 contained in the liquid crystal layer 300 is a polymer-dispersed liquid crystal. The orientation state of the liquid crystal 310 changes depending on the potential difference between the electrodes sandwiching the liquid crystal 310. When the liquid crystal 310 has an orientation state in which the optical axes of the liquid crystal molecules are aligned, light incident on the liquid crystal layer 300 is transmitted with almost no scattering. On the other hand, when the liquid crystal 310 has an orientation state in which the optical axes of the liquid crystal molecules are not aligned, light incident on the liquid crystal layer 300 is scattered. In the display device 10, the orientation state of the liquid crystal 310 in each of the multiple pixels PX is changed to control the transmission and scattering of light in the pixels PX. When light is transmitted in the pixels PX, the light passes through the first transparent substrate 100 and the second transparent substrate 200 and is not emitted to the outside. In this case, the pixels PX are light-transmitting. On the other hand, when light is scattered in the pixels PX, the light passes through the first transparent substrate 100 and the second transparent substrate 200 before being emitted. In this case, the pixels PX are not light-transmitting. By controlling the light transmission and opacity of each of the multiple pixels PX, the display surface on the first transparent substrate 100 or the display surface on the second transparent substrate 200 can display an image or video while maintaining light transmission.

[0021] [2. Pixel PX configuration] Figure 3 is a schematic cross-sectional view showing the configuration of pixels PX of a display device 10 according to one embodiment of the present invention. Figure 3 shows a first pixel PX-1, a second pixel PX-2, and a third pixel PX-3 arranged in the second direction D2 in Figure 2. The second pixel PX-2 is adjacent to the first pixel PX-1 in the second direction D2. The third pixel PX-3 is adjacent to the second pixel PX-2 in the second direction D2. The first pixel PX-1 is positioned closer to the light source 400 than the second pixel PX-2 and the third pixel PX-3. Conversely, the third pixel PX-3 is positioned further away from the light source 400 than the first pixel PX-1 and the second pixel PX-2.

[0022] As shown in Figure 3, a high-resistance insulating film 130, a black matrix 230, and a spacer 240 are provided between the first pixel PX-1 and the second pixel PX-2, and between the second pixel PX-2 and the third pixel PX-3. Although not shown, the high-resistance insulating film 130 and the black matrix 230 are arranged in a grid pattern to separate the spaces between multiple pixels PX in a plan view. Therefore, each of the multiple pixels PX can be defined as a region surrounded by the high-resistance insulating film 130 or the black matrix 230. The high-resistance insulating film 130 has the function of flattening irregularities such as wiring and elements formed on the first transparent substrate 100. A photosensitive resin such as polyimide or acrylic can be used as the high-resistance insulating film 130. A photosensitive resin containing carbon black can be used as the black matrix 230. The spacer 240 is provided between the high-resistance insulating film 130 and the black matrix 230 and maintains the gap between the first transparent substrate 100 and the second transparent substrate 200. For example, multiple spacers 240 are placed between the high-resistance insulating film 130 and the black matrix 230. A photosensitive resin such as polyimide or acrylic can be used as the spacer 240. Although the description above shows a configuration where the spacers 240 overlap the high-resistance insulating film 130 in a plan view, a configuration in which the spacers 240 do not overlap the high-resistance insulating film 130 can also be applied.

[0023] The first pixel PX-1 includes a first pixel electrode 110-1, a first transparent insulating film 120-1, and a first common electrode 210-1. The second pixel PX-2 includes a second pixel electrode 110-2, a second transparent insulating film 120-2, and a second common electrode 210-2. The third pixel PX-3 includes a third pixel electrode 110-3, a third transparent insulating film 120-3, and a third common electrode 210-3. Hereafter, when the first pixel electrodes 110-1 to the third pixel electrodes 110-3 are not specifically distinguished, they may be described as pixel electrode 110. Similarly, when the first common electrode 210-1 to the third common electrode 210-3 are not specifically distinguished, they may be described as common electrode 210.

[0024] The first pixel electrodes 110-1 to the third pixel electrodes 110-3, the first transparent insulating film 120-1 to the third transparent insulating film 120-3, and the high-resistance insulating film 130 are provided on the first transparent substrate 100. The first common electrodes 210-1 to the third common electrodes, the black matrix 230, and the spacer 240 are provided on the second transparent substrate 200. In the first pixel PX-1, the first transparent insulating film 120-1 is provided between the first transparent substrate 100 and the first pixel electrode 110-1, and the liquid crystal 310 is provided between the first pixel electrode 110-1 and the first common electrode 210-1. In the second pixel PX-2, the second transparent insulating film 120-2 is provided between the first transparent substrate 100 and the second pixel electrode 110-2, and the liquid crystal 310 is provided between the second pixel electrode 110-2 and the second common electrode 210-2. In the third pixel PX-3, the third transparent insulating film 120-3 is provided between the first transparent substrate 100 and the third pixel electrode 110-3, and the liquid crystal 310 is provided between the third pixel electrode 110-3 and the third common electrode 210-3.

[0025] The first pixel electrodes 110-1 to the third pixel electrodes 110-3 are each supplied with an independent potential. On the other hand, the first common electrode 210-1 to the third common electrode 210-3 are supplied with a common potential (for example, the ground potential). In the first pixels PX-1 to the third pixels PX-3, the orientation state of the liquid crystal 310 in each of the first pixels PX-1 to the third pixels PX-3 can be changed by independently controlling the potential supplied to the first pixel electrodes 110-1 to the third pixel electrodes 110-3. As mentioned above, the first common electrode 210-1 to the third common electrode 210-3 are supplied with a common potential, but the first common electrode 210-1 to the third common electrode 210-3 may be part of a single continuous conductive film provided across multiple pixels PX.

[0026] For each of the first pixel electrodes 110-1 to the third pixel electrodes 110-3 and the first common electrodes 210-1 to the third common electrodes 210-3, a transparent conductive oxide such as indium tin oxide (ITO) or indium zinc oxide (IZO) can be used.

[0027] Note that each of the plurality of pixels PX includes not only the pixel electrode 110 and the common electrode 210, but also a transistor that is electrically connected to the pixel electrode 110 and controls the supply of potential to the pixel electrode 110, and a holding capacitor that holds the potential difference between the pixel electrode 110 and the common electrode 210. The transistor and the holding capacitor are provided on the first transparent substrate 100 and covered by the high-resistance insulating film 130. Here, the illustration thereof is omitted and the detailed description thereof is also omitted.

[0028] As each of the first transparent insulating film 120-1 to the third transparent insulating film 120-3, an insulating inorganic material or an insulating organic material can be used. For example, as the insulating inorganic material, silicon oxide (SiO x ) or silicon oxynitride (SiO x N y ), or nitrides such as silicon nitride (SiN x ) or silicon oxynitride (SiN x O y ) can be used. Silicon oxynitride (SiO x N y ) is an oxide containing nitrogen (N) in a ratio less than that of oxygen (O) (x>y), and silicon oxynitride (SiN x O y ) is a nitride containing oxygen in a ratio less than that of nitrogen (x>y). Further, for example, as the insulating organic material, resins such as polyimide, acrylic, or siloxane can be used. The first transparent insulating film 120-1 to the third transparent insulating film 120-3 may have a single-layer structure or a laminated structure. Each of the first transparent insulating film 120-1 to the third transparent insulating film 120-3 may have a laminated structure in which an insulating organic material and an insulating inorganic material are laminated.

[0029] Preferably, each of the first transparent insulating film 120-1 to the third transparent insulating film 120-3 has a refractive index close to that of the first transparent substrate 100, but is not limited thereto. For example, each of the first transparent insulating film 120-1 to the third transparent insulating film 120-3 has a refractive index closer to that of the first transparent substrate 100 than each of the first pixel electrodes 110-1 to the third pixel electrodes 110-3.

[0030] Here, the structural features and functions of the first transparent insulating film 120-1 to the third transparent insulating film 120-3 will be described. In the following, when the first transparent insulating film 120-1 to the third transparent insulating film 120-3 are not specifically distinguished, they may be described as transparent insulating film 120.

[0031] The first transparent insulating film 120-1 to the third transparent insulating film 120-3 are spaced apart from each other. Furthermore, the first transparent insulating film 120-1 to the third transparent insulating film 120-3 each have a first thickness t1, a second thickness t2, and a third thickness t3, respectively. The first thickness t1 to the third thickness t3 are different from each other. Specifically, the first thickness t1, the second thickness t2, and the third thickness t3 decrease in that order. On the other hand, although not shown in the figures, in a plan view, the first transparent insulating film 120-1 to the third transparent insulating film 120-3 are the same size. The planar shape of the first transparent insulating film 120-1 to the third transparent insulating film 120-3 is, for example, circular, elliptical, or polygonal, but is not limited to these. Therefore, the first transparent insulating film 120-1 to the third transparent insulating film 120-3 have different volumes, with the volume decreasing in the order of the first transparent insulating film 120-1, the second transparent insulating film 120-2, and the third transparent insulating film 120-3.

[0032] In a pixel PX, there is a trade-off relationship between the volume of the transparent insulating film 120 and the volume of the liquid crystal 310. That is, as the volume of the transparent insulating film 120 in the pixel PX increases, the volume of the liquid crystal 310 in the pixel PX decreases. Also, the amount of light scattered in the pixel PX depends on the volume of the liquid crystal 310. Specifically, if the volume of the liquid crystal 310 in the pixel PX is large, the amount of scattered light increases, and if the volume of the liquid crystal in the pixel PX is small, the amount of scattered light decreases. Therefore, it can be said that the transparent insulating film 120 has the function of adjusting the volume of the liquid crystal 310 in the pixel PX (hereinafter, for convenience of explanation, it may be referred to as the "scattering volume").

[0033] Referring to Figure 3, the volume decreases in the order of the first transparent insulating film 120-1, the second transparent insulating film 120-2, and the third transparent insulating film 120-3. Therefore, the scattering volume of the liquid crystal 310 increases in the order of the first pixel PX-1, the second pixel PX-2, and the third pixel PX-3 (i.e., in order of moving away from the light source 400).

[0034] Generally, in display devices with edge light sources, the propagation of light emitted from the light source attenuates as the distance from the light source increases. Therefore, in conventional display devices where each of the multiple pixels has the same scattering volume, pixels closer to the light source have higher brightness, while pixels further away from the light source have lower brightness, resulting in brightness variations depending on the distance from the light source.

[0035] In contrast, in the pixels PX of the display device 10, the scattering volume of the liquid crystal 310 within the pixels PX is adjusted by the transparent insulating film 120. Specifically, in the display device 10, the transparent insulating film 120 is provided such that the scattering volume of the liquid crystal 310 within the pixels PX increases as it moves away from the light source 400. In other words, the scattering volume of the liquid crystal 310 within the pixels PX that is farther away from the light source 400 is greater than the scattering volume of the liquid crystal within the pixels PX that is closer to the light source 400. Therefore, even if the propagation of light within the liquid crystal layer 300 attenuates as it moves away from the light source 400, the scattering volume of the liquid crystal 310 within the pixels PX increases as it moves away from the light source 400, and as a result, the brightness on the display surface of the display device 10 is made uniform.

[0036] According to this embodiment, the brightness of not only the display surface on the first transparent substrate 100 side of the display device 10 but also the display surface on the second transparent substrate 200 side is made uniform, thereby improving the display quality of the display device 10.

[0037] <Modified form of the first embodiment> Referring to Figure 4, a modified example of the display device 10, the display device 10A, will be described. In the following, if the display device 10A has the same configuration as the display device 10, the description may be omitted.

[0038] Figure 4 is a schematic cross-sectional view showing the configuration of pixels PX of a display device 10A according to one embodiment of the present invention.

[0039] The first pixel PX-1 includes a first pixel electrode 110-1, a first transparent insulating film 120A-1, and a first common electrode 210-1. The second pixel PX-2 includes a second pixel electrode 110-2, a second transparent insulating film 120A-2, and a second common electrode 210-2. The third pixel PX-3 includes a third pixel electrode 110-3, a third transparent insulating film 120A-3, and a third common electrode 210-3. In the first pixel PX-1, the first transparent insulating film 120A-1 has a curved surface, on which the first common electrode 210-1 is provided. The second pixel PX-2 and the third pixel PX-3 have the same configuration as the first pixel PX-1.

[0040] The thickness of each of the first transparent insulating film 120A-1, the second transparent insulating film 120A-2, and the third transparent insulating film 120A-3 is not constant but varies. Even in this case, the volume of the first transparent insulating film 120A-1, the second transparent insulating film 120A-2, and the third transparent insulating film 120A-3 decreases in this order. Therefore, in the display device 10A, the scattering volume of the liquid crystal 310 increases in the order of the first pixel PX-1, the second pixel PX-2, and the third pixel PX-3 (i.e., in the order of moving away from the light source 400).

[0041] In this modified example as well, the scattering volume of the liquid crystal 310 within the pixel PX increases as it moves away from the light source 400, so the brightness on the display surface of the display device 10A is made uniform. Therefore, the brightness of not only the display surface on the first transparent substrate 100 side of the display device 10A but also the display surface on the second transparent substrate 200 side is made uniform, thus improving the display quality of the display device 10A.

[0042] <Second Embodiment> The display device 20 will be described with reference to Figures 5 and 6. In the following, if the display device 20 has the same configuration as the display device 10, its description may be omitted.

[0043] Figure 5 is a schematic cross-sectional view showing the configuration of pixels PX of a display device 20 according to one embodiment of the present invention. Figure 6 is a schematic plan view showing the configuration of pixels PX of a display device 20 according to one embodiment of the present invention. Specifically, for the sake of explanation, only a portion of the components are shown in Figure 6, which is a schematic top view.

[0044] As shown in Figure 5, the first pixel PX-1 includes a first pixel electrode 110-1, a first transparent insulating film 120-1, and a first common electrode 210-1. The second pixel PX-2 includes a second pixel electrode 110-2, a second transparent insulating film 120-2, and a second common electrode 210-2. The third pixel PX-3 includes a third pixel electrode 110-3, a third transparent insulating film 120-3, and a third common electrode 210-3. The first transparent insulating films 120-1 to the third transparent insulating films 120-3 have the same thickness and are part of a single continuous insulating film that extends from the first pixel PX-1 to the third pixel PX-3.

[0045] As shown in Figure 6, the insulating film, including the first transparent insulating film 120-1 to the third transparent insulating film 120-3, extends in the second direction D2. Furthermore, the width of the insulating film, including the first transparent insulating film 120-1 to the third transparent insulating film 120-3, decreases as it moves away from the light source 400. That is, in a plan view, the size (area) decreases in the order of the first transparent insulating film 120-1, the second transparent insulating film 120-2, and the third transparent insulating film 120-3. Therefore, the volume decreases in the order of the first transparent insulating film 120-1, the second transparent insulating film 120-2, and the third transparent insulating film 120-3, and the scattering volume of the liquid crystal 310 increases in the order of the first pixel PX-1, the second pixel PX-2, and the third pixel PX-3 (i.e., in order of moving away from the light source 400).

[0046] According to this embodiment, the scattering volume of the liquid crystal 310 within the pixel PX increases as it moves away from the light source 400, so the brightness on the display surface of the display device 20 is made uniform. Therefore, the brightness of not only the display surface on the first transparent substrate 100 side of the display device 20 but also the display surface on the second transparent substrate 200 side is made uniform, thus improving the display quality of the display device 20. Furthermore, since each transparent insulating film 120 of the multiple pixels PX can be formed by patterning one insulating film in one step, the display device 20 can be easily manufactured.

[0047] <Modification 1 of the second embodiment> Referring to Figure 7, a modified example of the display device 20, the display device 20B, will be described. In the following, if the display device 20B has the same configuration as the display device 20, the description may be omitted.

[0048] Figure 7 is a schematic plan view showing the configuration of pixels PX of a display device 20B according to one embodiment of the present invention. Specifically, for the sake of explanation, only a portion of the components are shown in Figure 7, which is a schematic top view.

[0049] As shown in Figure 7, the first pixel PX-1, the second pixel PX-2, and the third pixel PX-3 each include a first transparent insulating film 120B-1, a second transparent insulating film 120B-2, and a third transparent insulating film 120B-3, respectively. The first to third transparent insulating films 120B-1 to 120B-3 have the same thickness and are provided across the first to third pixels PX-1 to PX-3, forming part of a single continuous insulating film extending in the second direction D2. The insulating films, including the first to third transparent insulating films 120B-1 to 120B-3, decrease in width as they move away from the light source 400, but are mainly provided to overlap with the portion of the black matrix 230 extending in the second direction D2. Even in this case, the scattering volume of the liquid crystal 310 increases in the order of the first pixel PX-1, the second pixel PX-2, and the third pixel PX-3 (i.e., in the order of moving away from the light source 400).

[0050] In this modified example as well, the scattering volume of the liquid crystal 310 within the pixel PX increases as it moves away from the light source 400, thus uniformizing the brightness on the display surface of the display device 20B. Therefore, the brightness of not only the display surface on the first transparent substrate 100 side of the display device 20B but also the display surface on the second transparent substrate 200 side is uniformized, improving the display quality of the display device 20B. Furthermore, since the transparent insulating film 120B of each of the multiple pixels PX can be formed by patterning one insulating film in one step, the display device 20B can be easily manufactured.

[0051] <Modification 2 of the second embodiment> Referring to Figure 8, we will now describe another modified example of the display device 20, the display device 20C. In the following, if the display device 20C has a similar configuration to the display device 20, the description may be omitted.

[0052] Figure 8 is a schematic plan view showing the configuration of pixels PX of a display device 20C according to one embodiment of the present invention. Specifically, for the sake of explanation, only a portion of the components are shown in Figure 8, which is a schematic top view.

[0053] As shown in Figure 8, the first pixel PX-1, the second pixel PX-2, and the third pixel PX-3 each contain a first transparent insulating film 120C-1, a second transparent insulating film 120C-2, and a third transparent insulating film 120C-3, respectively. The first transparent insulating films 120B-1 to the third transparent insulating films 120B-3 have the same thickness and are part of a single continuous insulating film that extends across the first pixel PX-1 to the third pixel PX-3 and in the second direction D2. The width of the insulating films, including the first transparent insulating film 120C-1, the second transparent insulating film 120C-2, and the third transparent insulating film 120C-3, changes discontinuously rather than continuously. Specifically, the first transparent insulating film 120C-1 has a first width w1 within the first pixel PX-1, the second transparent insulating film 120C-2 has a second width w2 within the second pixel PX-2, and the third transparent insulating film 120C-3 has a third width w3 within the third pixel PX-3. The first width w1, the second width w2, and the third width w3 decrease in this order. That is, in a plan view, the size (area) decreases in the order of the first transparent insulating film 120C-1, the second transparent insulating film 120C-2, and the third transparent insulating film 120C-3. Even in this case, the scattering volume of the liquid crystal 310 increases in the order of the first pixel PX-1, the second pixel PX-2, and the third pixel PX-3 (i.e., in order of moving away from the light source 400).

[0054] In this modified example as well, the scattering volume of the liquid crystal 310 within the pixel PX increases as it moves away from the light source 400, thus uniformizing the brightness on the display surface of the display device 20C. Therefore, the brightness of not only the display surface on the first transparent substrate 100 side of the display device 20C but also the display surface on the second transparent substrate 200 side is uniformized, improving the display quality of the display device 20C. Furthermore, since each transparent insulating film 120C of multiple pixels PX can be formed by patterning one insulating film in one step, the display device 20C can be easily manufactured.

[0055] <Modification 3 of the second embodiment> Referring to Figures 9 and 10, we will now describe another modified example of the display device 20, the display device 20D. In the following, if the display device 20D has a configuration similar to that of the display device 20, we may omit its description.

[0056] Figure 9 is a schematic cross-sectional view showing the configuration of pixels PX of a display device 20D according to one embodiment of the present invention. Figure 10 is a schematic plan view showing the configuration of pixels PX of a display device 20D according to one embodiment of the present invention. Specifically, for the sake of explanation, only a portion of the components are shown in Figure 10, which is a schematic top view.

[0057] As shown in Figure 9, the first pixel PX-1 includes a first pixel electrode 110-1, a first transparent insulating film 120D-1, and a first common electrode 210-1. The second pixel PX-2 includes a second pixel electrode 110-2, a second transparent insulating film 120D-2, and a second common electrode 210-2. The third pixel PX-3 includes a third pixel electrode 110-3, a third transparent insulating film 120D-3, and a third common electrode 210-3.

[0058] As shown in Figure 10, the first transparent insulating film 120D-1 is a part of an insulating film having a first width w1 that extends over a plurality of pixels PX, including a first pixel PX-1 arranged along a first direction D1. The second transparent insulating film 120D-2 is a part of an insulating film having a second width w2 that extends over a plurality of pixels PX, including a second pixel PX-2 arranged along the first direction D1. The third transparent insulating film 120D-3 is a part of an insulating film having a third width w3 that extends over a plurality of pixels PX, including a third pixel PX-3 arranged along the first direction D1. The insulating films having the first width w1, the insulating film having the second width w2, and the insulating film having the third width w3 are separated from each other. Therefore, the first transparent insulating film 120D-1, the second transparent insulating film 120D-2, and the third transparent insulating film 120D-3 are separated from each other. However, by providing an insulating film extending in the first direction such that the first width w1, the second width w2, and the third width w3 decrease in that order, the scattering volume of the liquid crystal 310 can be increased in the order of the first pixel PX-1, the second pixel PX-2, and the third pixel PX-3 (i.e., in the order of moving away from the light source 400).

[0059] In this modified example as well, the scattering volume of the liquid crystal 310 within the pixel PX increases as it moves away from the light source 400, so the brightness on the display surface of the display device 20D is made uniform. Therefore, the brightness of not only the display surface on the first transparent substrate 100 side of the display device 20D but also the display surface on the second transparent substrate 200 side is made uniform, thus improving the display quality of the display device 20D. Furthermore, since the transparent insulating film 120D of each of the multiple pixels PX can be formed by patterning one insulating film in one step, the display device 20D can be easily manufactured.

[0060] The embodiments and modifications described above as embodiments of the present invention can be combined as appropriate, insofar as they do not contradict each other. Furthermore, any additions, deletions, or design changes to components, or additions, omissions, or changes to processes based on each embodiment, made by those skilled in the art, are also included within the scope of the present invention, as long as they retain the essence of the present invention.

[0061] Any effects or benefits other than those brought about by the embodiments and modifications described above, if they are clear from the description herein or easily predictable to those skilled in the art, are naturally considered to be brought about by the present invention. [Explanation of symbols]

[0062] 10, 10A, 20, 20B, 20C, 20D: Display device 100: First transparent substrate 110: Pixel electrode, 110-1: First pixel electrode, 110-2: Second pixel electrode, 110-3: Third pixel electrode 120, 120B, 120C, 120D: Transparent insulating film; 120-1, 120A-1, 120B-1, 120C-1, 120D-1: First transparent insulating film; 120-2, 120A-2, 120B-2, 120C-2, 120D-2: Second transparent insulating film; 120-3, 120A-3, 120B-3, 120C-3, 120D-3: Third transparent insulating film 130: High-resistance insulating film 200: Second transparent substrate 210: Common electrode, 210-1: First common electrode, 210-2: Second common electrode, 210-3: Third common electrode 230: Black Matrix 240: Spacer 300: Liquid crystal layer 310: LCD 320: Sealant 400: Light source IO: Input / output section PX: Pixel, PX-1: First pixel, PX-2: Second pixel, PX-3: Third pixel

Claims

1. A first transparent substrate on which a first electrode is provided in each of multiple pixels, A second transparent substrate is positioned opposite the first transparent substrate and is provided with a second electrode to which a common potential is supplied to the plurality of pixels, A liquid crystal layer in which liquid crystal is sealed between the first transparent substrate and the second transparent substrate, The system includes a light source disposed on the first transparent substrate and irradiating light into the interior of the liquid crystal layer from the edge of the liquid crystal layer, The plurality of pixels include a first pixel and a second pixel that is further from the light source than the first pixel. The first pixel includes a first transparent insulating film between the first transparent substrate and the first electrode. The second pixel includes a second transparent insulating film between the first transparent substrate and the first electrode. A display device in which the first transparent insulating film and the second transparent insulating film are provided such that the volume of liquid crystal contained in the first pixel is smaller than the volume of liquid crystal contained in the second pixel.

2. The display device according to claim 1, wherein the thickness of the first transparent insulating film is greater than the thickness of the second transparent insulating film.

3. The display device according to claim 1, wherein, in a plan view, the size of the first transparent insulating film is larger than the size of the second transparent insulating film.

4. The display device according to claim 1, wherein the first transparent insulating film and the second transparent insulating film are part of a single continuous insulating film.

5. The display device according to claim 4, wherein the single continuous insulating film extends such that its width decreases in the direction from the first pixel toward the second pixel.

6. The first transparent insulating film is a part of the first insulating film that extends over a plurality of pixels including the first pixel, The second transparent insulating film is a part of the second insulating film that extends over a plurality of pixels including the second pixel, The first insulating film and the second insulating film extend in a direction intersecting the direction from the first pixel to the second pixel, The display device according to claim 1, wherein the width of the second insulating film is smaller than the width of the first insulating film.

7. The display device according to claim 1, wherein the first transparent insulating film and the second transparent insulating film are separated insulating films.

8. The display device according to claim 1, wherein the first transparent insulating film and the second transparent insulating film have a refractive index closer to that of the second transparent substrate than that of the second electrode.

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