Liquid crystal display panel, liquid crystal display device, and method for manufacturing a liquid crystal display device.

Abstract

To provide a liquid crystal display panel, a liquid crystal display device, and a manufacturing method for a liquid crystal display device in which display unevenness is suppressed.SOLUTION: A liquid crystal display panel 100 comprises: a first substrate 110 curved in a first direction; a second substrate 120 curved in the first direction and facing the first substrate 110; a liquid crystal sandwiched between the first substrate 110 and the second substrate 120; and a sealing part that bonds the first substrate 110 and the second substrate 120 to each other, and seals the liquid crystal. When cross-sectionally viewed on a cross-section including the first direction and a display direction, a curved surface 160 conforming to a first main surface 110a of the first substrate 110 facing the second substrate 120 has at least one of inflection points P1, P2 in a region surrounded by the sealing part, and tangent planes 162a, 162b of the curved surface 160 at each of inner peripheral end parts 130a of the sealing part are parallel to each other.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a liquid crystal display panel, a liquid crystal display device, and a method for manufacturing a liquid crystal display device.

Background Art

[0002] Display devices having a shape according to the design, installation location, etc. of the equipment to be mounted are required, and liquid crystal display devices having a curved display surface have been developed. For example, Patent Document 1 discloses a liquid crystal panel in which the curvature of the four corner portions is smaller than the curvature of other regions other than the four corner portions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, by making the curvature of the four corner portions of the curved liquid crystal panel smaller than the curvature of other regions other than the four corner portions, the light leakage at the four corner portions of the display region is reduced. On the other hand, when the liquid crystal panel is curved, due to the stress applied to the substrates (TFT circuit substrate and color filter substrate), there is a possibility that the distance between the substrates in the vicinity of the sealant provided along the non-curved side (non-curved side) fluctuates. In this case, display unevenness occurs along the sealant provided on the non-curved side. In the liquid crystal panel of Patent Document 1, it only reduces the light leakage at the four corner portions, and it is difficult to sufficiently suppress the display unevenness along the sealant.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal display panel, a liquid crystal display device, and a method for manufacturing a liquid crystal display device in which display unevenness is suppressed.

Means for Solving the Problems

[0006] To achieve the above objective, the liquid crystal display panel relating to the first aspect is: A first substrate that curves in a first direction, A second substrate that is curved in the first direction and faces the first substrate, A liquid crystal sandwiched between the first substrate and the second substrate, The first substrate and the second substrate are bonded together, and a sealing portion is provided for enclosing the liquid crystal, When viewed in cross-section with a cross-section including the first direction and the display direction, Formed in the display area surrounded by the inner circumferential end of the seal portion The curved surface of the first substrate along the first main surface facing the second substrate is , small It has at least one inflection point, and the tangent planes of the curved surface at each of the inner circumferential ends of the seal portion are parallel to each other. the law of nature, The curved surface has at least one convex surface and at least one concave surface continuous with the convex surface, and the radius of curvature of the convex surface and the radius of curvature of the concave surface are different. The sum of the central angles of each of the convex surfaces is equal to the sum of the central angles of each of the concave surfaces. In the display area, the length of the center line in the thickness direction of the first substrate is equal to the length of the center line in the thickness direction of the second substrate.

[0007] The liquid crystal display device relating to the second aspect is, The liquid crystal display panel described above, The system includes a cover provided on the display surface of the liquid crystal display panel, or on the surface of the liquid crystal display panel opposite to the display surface, which supports the liquid crystal display panel in a curved state via an adhesive layer.

[0008] The method for manufacturing a liquid crystal display device relating to the third aspect is: A step of forming a seal portion for encapsulating liquid crystal on one of the first substrate and the second substrate, A step of stacking one of the first substrate and the second substrate, on which the sealing portion is formed, and the other of the first substrate and the second substrate, The steps include curing the seal portion and bonding the first substrate and the second substrate together, The first substrate and the second substrate that have been bonded together, In the display area surrounded by the inner circumferential end of the seal portion, the length of the center line in the thickness direction of the first substrate and the length of the center line in the thickness direction of the second substrate are made equal. The process includes bending in a first direction, In the bending process, when viewed in cross-section with respect to the first direction and the display direction, Formed in the aforementioned display area The curved surface along the first main surface of the first substrate facing the second substrate has , small at least one inflection point, and the first substrate and the second substrate are curved such that the tangent planes of the curved surface at each of the inner peripheral ends of the seal portion are parallel to each other 、 The curved surface has at least one convex surface and at least one concave surface continuous with the convex surface, and the radius of curvature of the convex surface and the radius of curvature of the concave surface are different. The sum of the central angles of each of the convex surfaces is equal to the sum of the central angles of each of the concave surfaces.

Advantages of the Invention

[0009] According to the present disclosure, when viewed in cross-section in a cross-section including the bending direction and the display direction, the curved surface has an inflection point in the region surrounded by the seal portion, and the tangent planes of the curved surface at each of the inner peripheral ends of the seal portion are parallel to each other. Therefore, the length of the center line in the thickness direction of the first substrate and the length of the center line in the thickness direction of the second substrate are equal in the region surrounded by the seal portion, and the difference in stress applied to the first substrate and the second substrate is alleviated. As a result, the variation in the distance between the first substrate and the second substrate at the end of the display region can be suppressed, and display unevenness can be suppressed.

Brief Description of the Drawings

[0010] [Figure 1] It is a schematic diagram showing a cross-section of a liquid crystal display device according to Embodiment 1. [Figure 2] It is a plan view of a liquid crystal display panel according to Embodiment 1. [Figure 3] It is a cross-sectional view of the liquid crystal display panel shown in FIG. 2 as viewed along line A-A. [Figure 4] It is a schematic diagram for explaining the bending of a liquid crystal display panel according to Embodiment 1. [Figure 5] It is a schematic diagram for explaining the lengths of the center lines in the thickness directions of the first substrate and the second substrate according to Embodiment 1. [Figure 6] It is a flowchart showing a method of manufacturing a liquid crystal display device according to Embodiment 1. [Figure 7] It is a schematic diagram for explaining the bending of a liquid crystal display panel according to Embodiment 2. [Figure 8]It is a schematic diagram for explaining the length of the center line in the thickness direction of the first substrate and the second substrate according to Embodiment 2. [Figure 9] It is a schematic diagram for explaining the length of the center line in the thickness direction of the first substrate and the second substrate according to Embodiment 3. [Figure 10] It is a plan view of a liquid crystal display panel according to Embodiment 4. [Figure 11] It is a perspective view of a liquid crystal display panel according to Embodiment 4. [Figure 12] It is a schematic diagram showing a curved surface according to Embodiment 4. [Figure 13] It is a perspective view of a liquid crystal display panel according to Embodiment 5. [Figure 14] It is a plan view of a liquid crystal display panel according to Embodiment 5. [Figure 15] It is a schematic diagram showing a curved surface according to Embodiment 5. [Figure 16] It is a schematic diagram showing a cross section of a liquid crystal display device according to Embodiment 6. [Figure 17] It is a schematic diagram showing a cover according to a modification example. [Figure 18] It is a schematic diagram showing a liquid crystal display panel according to a modification example. [Figure 19] It is a schematic diagram showing a liquid crystal display panel according to a modification example. [Figure 20] It is a schematic diagram showing a liquid crystal display device according to a modification example. [Figure 21] It is a schematic diagram showing a liquid crystal display device according to a modification example. [Figure 22] It is a schematic diagram showing a liquid crystal display panel according to a modification example. [Figure 23] It is a schematic diagram showing a curved surface according to a modification example. [Figure 24] It is a schematic diagram showing a curved surface according to a modification example. [Figure 25] It is a schematic diagram showing a liquid crystal display panel according to a modification example.

Modes for Carrying Out the Invention

[0011] Hereinafter, a liquid crystal display panel and liquid crystal display device according to the embodiment will be described with reference to the drawings.

[0012] <Embodiment 1> Referring to Figures 1 to 6, the liquid crystal display device 10 and the liquid crystal display panel 100 according to this embodiment will be described. As shown in Figure 1, the liquid crystal display device 10 comprises a liquid crystal display panel 100, a cover 200, and a backlight unit 300. The liquid crystal display panel 100 is a transmissive liquid crystal display panel having a curved display surface 102 (the side of the second polarizing plate 150 opposite to the second substrate 120, which will be described later). The liquid crystal display panel 100 displays characters, color images, etc., based on signals from a display control unit and a drive circuit (not shown). The cover 200 supports the liquid crystal display panel 100 in a curved state via an adhesive layer 202. The backlight unit 300 irradiates the liquid crystal display panel 100 with light and functions as a light source for the liquid crystal display panel 100. In this specification, for ease of understanding, the rightward direction (rightward direction on the page) of the liquid crystal display device 10 in Figure 1 is described as the +X direction, the upward direction (upward direction on the page) as the +Z direction, and the direction perpendicular to the +X and +Z directions (backward direction on the page) as the +Y direction. The +Z direction is defined as the display direction in which the liquid crystal display panel 100 displays characters, color images, etc. Note that in Figure 1, the liquid crystal display panel 100 is shown in a simplified form for ease of understanding. Also, in Figure 1, the hatching of the adhesive layers 202 and 302 is omitted.

[0013] The liquid crystal display device 10 is mounted on vehicles and electronic devices. The liquid crystal display device 10 can also be used as a signage display.

[0014] The liquid crystal display panel 100 of the liquid crystal display device 10 is a liquid crystal display panel driven by, for example, a TFT (Thin Film Transistor). The liquid crystal display panel 100 operates, for example, by a transverse electric field method. As shown in Figure 2, the liquid crystal display panel 100 has a display area 104 surrounded by a seal portion 130, which will be described later. Pixels PX are arranged in a matrix within the display area 104. Furthermore, as shown in Figure 1, the liquid crystal display panel 100 is curved in the X direction. In this specification, the X direction corresponds to the first direction. The curvature of the liquid crystal display panel 100 will be described later.

[0015] As shown in Figures 2 and 3, the liquid crystal display panel 100 includes a first substrate 110, a second substrate 120, a liquid crystal (LC), and a sealing portion 130. The liquid crystal display panel 100 also includes a first polarizing plate 140 and a second polarizing plate 150. The first substrate 110 and the second substrate 120 sandwich the liquid crystal (LC). The sealing portion 130 adheres the first substrate 110 and the second substrate 120 together, sealing the liquid crystal (LC). The first polarizing plate 140 is attached to the first substrate 110, and the second polarizing plate 150 is attached to the second substrate 120. Note that in Figure 3, the hatching of the liquid crystal (LC) is omitted for ease of understanding.

[0016] The first substrate 110 of the liquid crystal display panel 100 is, for example, a glass substrate. The first substrate 110 has a first main surface 110a and a second main surface 110b opposite to the first main surface 110a. As shown in Figure 3, the first substrate 110 has a uniform thickness and is curved in the X direction (first direction). The first substrate 110 has TFTs, wiring, electrodes, alignment films, etc. (none of which are shown) on the first main surface 110a facing the second substrate 120. In addition, a first polarizing plate 140 is attached to the second main surface 110b of the first substrate 110.

[0017] The second substrate 120 of the liquid crystal display panel 100 is a glass substrate, similar to the first substrate 110. The second substrate 120 also has a uniform thickness and is curved in the X direction (first direction). The second substrate 120 has a first main surface 120a and a second main surface 120b opposite to the first main surface 120a. The first main surface 120a of the second substrate 120, which faces the first substrate 110, has a striped color filter, a black matrix, an alignment film, etc. (none of which are shown). A second polarizing plate 150 is attached to the second main surface 120b of the second substrate 120.

[0018] The first substrate 110 and the second substrate 120 are bonded together by a sealing portion 130 via a spacer (not shown), with the first main surface 110a of the first substrate 110 and the first main surface 120a of the second substrate 120 being parallel to each other at a predetermined distance (i.e., a predetermined gap).

[0019] The liquid crystal (LC) of the liquid crystal display panel 100 is sandwiched between a first substrate 110 and a second substrate 120. The liquid crystal (LC) is a nematic liquid crystal.

[0020] The sealing portion 130 of the liquid crystal display panel 100 is provided between the first substrate 110 and the second substrate 120, and adheres the first substrate 110 and the second substrate 120 together. The sealing portion 130 also encloses the liquid crystal LC between the first substrate 110 and the second substrate 120.

[0021] As shown in Figure 2, the sealing portion 130 has a frame shape and is formed along the outer shapes of the first substrate 110 and the second substrate 120. The sealing portion 130 also surrounds the display area 104. The sealing portion 130 is formed from, for example, a UV (UltraViolet) curing adhesive.

[0022] As shown in Figure 3, the first polarizing plate 140 of the liquid crystal display panel 100 is attached to the second main surface 110b of the first substrate 110. The second polarizing plate 150 of the liquid crystal display panel 100 is attached to the second main surface 120b of the second substrate 120. The second polarizing plate 150 is attached to the cover 200 via an adhesive layer 202. In this embodiment, the side of the second polarizing plate 150 opposite to the second substrate 120 corresponds to the display surface 102 of the liquid crystal display panel 100.

[0023] Next, the curvature of the liquid crystal display panel 100 will be explained with reference to Figures 4 and 5. As shown in Figure 4, when the liquid crystal display panel 100 is viewed in cross-section (XZ cross-section) including the X direction (i.e., the first direction) and the Z direction (i.e., the display direction), the curved surface 160 along the first main surface 110a of the first substrate 110 has two inflection points P1 and P2 in the display area 104 surrounded by the seal portion 130, and the tangent planes 162a and 162b of the curved surface 160 at each of the inner peripheral ends 130a of the seal portion 130 are curved so that they are parallel to each other. Note that in Figure 4, for ease of understanding, the liquid crystal LC, the first polarizing plate 140, etc. are omitted and the liquid crystal display panel 100 is shown in a simplified manner. The curved surface 160 may also be the first main surface 110a of the first substrate 110, and in this embodiment, the first main surface 110a of the first substrate 110 is used as the curved surface 160. Since the first main surface 110a of the first substrate 110 and the first main surface 120a of the second substrate 120 are parallel, the curved surface 160 may be the first main surface 120a of the second substrate 120. Furthermore, the display surface 102 has a shape similar to the curved surface 160.

[0024] Specifically, when viewed in cross-section in the XZ direction, the curved surface 160 curves in the +Z direction at its center and in the -Z direction at its +X and -X ends, making it symmetrical with respect to the Z direction. An inflection point P1 is formed at the boundary between the curved surface (concave) 502 at the +X end and the curved surface (convex) 504 in the center, and an inflection point P2 is formed at the boundary between the curved surface 502 in the center and the curved surface (concave) 506 at the -X end. Furthermore, the tangent plane 162a of the curved surface 160 at the inner circumference end 130a of the seal portion 130 located on the +X side and the tangent plane 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 located on the -X side are parallel. As a result, as will be described later, the length L1 of the center line 112 in the thickness direction of the first substrate 110 and the length L2 of the center line 122 in the thickness direction of the second substrate 120 are equal in the display area 104. As a result, the difference between the stress on the first substrate 110 and the stress on the second substrate 120 is reduced, suppressing fluctuations in the distance between the first substrate 110 and the second substrate 120 at the edges of the display area 104 (near the inner circumference ends 130a of the seal portions 130 located on the +X and -X sides), thereby suppressing display unevenness. In this embodiment, the tangent planes 162a and 162b are parallel to the XY plane. In this specification, a surface curved in the +Z direction is defined as a convex surface, and a surface curved in the -Z direction is defined as a concave surface.

[0025] The length L1 of the centerline 112 in the thickness direction of the first substrate 110 and the length L2 of the centerline 122 in the thickness direction of the second substrate 120 will be explained. For example, as shown in Figure 5, in the curved surface 160, if the radius of curvature and central angle of the curved surface 502 at the +X end are r and θ, the radius of curvature and central angle of the curved surface 504 in the center are s and φ, the radius of curvature and central angle of the curved surface 506 at the -X end are t and ω, half the thickness of the first substrate 110 is D1, and half the thickness of the second substrate 120 is D2, then the lengths L1 of the centerline 112 and L2 of the centerline 122 are expressed by the following equations (1) and (2). Also, from equations (1) and (2), the difference between the length L1 of the centerline 112 and the length L2 of the centerline 122 is expressed by the following equation (3).

[0026]

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[0027] When the tangent plane 162a of the curved surface 160 at the inner circumference end 130a of the seal portion 130 located on the +X side and the tangent plane 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 located on the -X side are parallel, then θ+ω=φ, and according to equation (3), the length L1 of the center line 112 and the length L2 of the center line 122 become equal. Therefore, when viewed in cross-section in the XZ section, the curved surface 160 has two inflection points P1 and P2 in the display area 104, and by making the tangent planes 162a and 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 parallel to each other, the length L1 of the center line 112 and the length L2 of the center line 122 are made equal, thereby suppressing fluctuations in the distance between the first substrate 110 and the second substrate 120 at the edge of the display area 104 and suppressing display unevenness.

[0028] Returning to Figure 1, the cover 200 of the liquid crystal display device 10 is provided on the display surface 102 side of the liquid crystal display panel 100 and supports the liquid crystal display panel 100 in a curved state via an adhesive layer 202. The main surface 200a of the cover 200 facing the display surface 102 is molded to a curved surface that matches the curved display surface 102 of the liquid crystal display panel 100. The end of the cover 200 is fixed to the housing 320 of the backlight unit 300, which will be described later. The cover 200 is formed from, for example, a translucent resin.

[0029] The adhesive layer 202 of the liquid crystal display device 10 is provided on the main surface 200a of the cover 200. The adhesive layer 202 attaches the liquid crystal display panel 100 to the main surface 200a of the cover 200. The adhesive layer 202 is, for example, OCA (Optical Clear Adhesive).

[0030] The backlight unit 300 of the liquid crystal display device 10 is the light source for the liquid crystal display panel 100. The backlight unit 300 has a light source unit 310 and a housing 320.

[0031] The light source unit 310 of the backlight unit 300 is located on the -Z side of the liquid crystal display panel 100 and irradiates the liquid crystal display panel 100 with light. In this embodiment, the light source unit 310 is embedded in the bottom plate 321 of the housing 320. The light source unit 310 also includes a white LED (light emitting diode) element, a reflective sheet, a diffusion sheet, etc. (none of which are shown).

[0032] The housing 320 of the backlight unit 300 is box-shaped and houses the light source unit 310. The end of the cover 200 is attached to the upper surface of the side wall 322 of the housing 320 via an adhesive layer 302.

[0033] Next, a method for manufacturing the liquid crystal display device 10 will be described. Figure 6 is a flowchart showing the method for manufacturing the liquid crystal display device 10. The method for manufacturing the liquid crystal display device 10 includes the steps of: preparing a first substrate 110 and a second substrate 120 (step S10); forming a seal portion 130 for encapsulating liquid crystal LC in one of the first substrate 110 and the second substrate 120 (step S12); dropping liquid crystal LC into the area surrounded by the seal portion 130 (step S14); stacking one of the first substrate 110 and the second substrate 120 with the seal portion 130 formed on it and the other of the first substrate 110 and the second substrate 120 (step S16); curing the seal portion 130 and bonding the first substrate 110 and the second substrate 120 together (step S18); and attaching a first polarizing plate 140 to the first substrate 110 and attaching a second polarizing plate 150 to the second substrate 120 (step S20).

[0034] The manufacturing method for the liquid crystal display device 10 further includes a step of curving the bonded first substrate 110 and second substrate 120 in a first direction (X direction) (step S22), and a step of mounting the backlight unit 300 (step S24).

[0035] In step S10, a glass substrate (so-called TFT substrate) with TFTs, wiring, etc. formed on it is prepared as a first substrate 110 in a flat state. Also, a glass substrate (so-called color filter substrate) with color filters, black matrices, etc. formed on it is prepared as a second substrate 120 in a flat state.

[0036] In step S12, a UV-curing resin is applied to the first main surface 120a of the second substrate 120 using a dispenser to form a frame-shaped seal portion 130 for enclosing the liquid crystal LC. The UV-curing resin includes spacers.

[0037] In step S14, liquid crystal LC is dropped onto the area surrounded by the sealing portion 130 on the first main surface 120a of the second substrate 120. Then, in step S16, the second substrate 120, on which the liquid crystal LC has been dropped, and the first substrate 110 are stacked together in a flat state. In step S18, UV light is irradiated onto the sealing portion 130 to bond the flat first substrate 110 and the second substrate 120 together. Furthermore, in step S20, the first polarizing plate 140 is attached to the second main surface 110b of the first substrate 110, and the second polarizing plate 150 is attached to the second main surface 120b of the second substrate 120. Thus, a flat liquid crystal display panel 100 is manufactured.

[0038] In step S22, the second polarizing plate 150 is attached to the main surface 200a of the cover 200 via an adhesive layer 202, thereby curving the bonded first substrate 110 and second substrate 120 in the first direction (X direction). The main surface 200a of the cover 200 is shaped into a curved surface that matches the curved display surface 102 of the liquid crystal display panel 100.

[0039] Here, when viewed in cross-section along the XZ line, the curved surface 160 curves in the +Z direction at the center of the display area 104 surrounded by the seal portion 130, and curves in the -Z direction at the +X and -X ends (i.e., it has two inflection points P1 and P2), causing the first substrate 110 and the second substrate 120 to curve so that the tangent planes 162a and 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 are parallel to each other. This makes the length L1 of the center line 112 in the thickness direction of the first substrate 110 equal to the length L2 of the center line 122 in the thickness direction of the second substrate 120, thereby suppressing fluctuations in the distance between the first substrate 110 and the second substrate 120 at the edges of the display area 104 and suppressing display unevenness.

[0040] In step S24, the end of the cover 200 is attached to the side wall 322 of the housing 320 of the backlight unit 300 via the adhesive layer 302, thereby mounting the backlight unit 300 to the liquid crystal display panel 100. The liquid crystal display device 10 can then be manufactured.

[0041] As described above, when viewed in cross-section along the XZ line, the curved surface 160 has two inflection points P1 and P2 in the display area 104, and the tangent planes 162a and 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 are parallel to each other. Therefore, in the liquid crystal display device 10 and the liquid crystal display panel 100, the length L1 of the center line 112 and the length L2 of the center line 122 are made equal, thereby suppressing fluctuations in the distance between the first substrate 110 and the second substrate 120 at the edge of the display area 104 and suppressing display unevenness.

[0042] <Embodiment 2> In the liquid crystal display panel 100 of Embodiment 1, the curved surface 160 has two inflection points P1 and P2. The curved surface 160 only needs to have at least one inflection point. Here, the curvature of the liquid crystal display panel 100 of this embodiment will be described. The other configurations of the liquid crystal display panel 100 and the liquid crystal display device 10 of this embodiment are the same as in Embodiment 1.

[0043] As shown in Figure 7, the liquid crystal display panel 100 (first substrate 110 and second substrate 120) of this embodiment is curved in the X direction, similar to Embodiment 1. In the liquid crystal display panel 100 of this embodiment, when viewed in cross-section in the XZ section, the curved surface 160 curves in the +Z direction on the +X side and in the -Z direction on the -X side. One inflection point P3 is formed at the boundary between the curved surface (convex surface) 508 on the +X side and the curved surface (concave surface) 510 on the -X side, which is continuous with the curved surface (convex surface) 508. Also, when viewed in cross-section in the XZ section, the tangent planes 162a and 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 are parallel to each other. Note that in this embodiment, the radius of curvature of the curved surface 508 and the radius of curvature of the curved surface 510 are different.

[0044] As a result, as will be described later, the length L1 of the center line 112 in the thickness direction of the first substrate 110 and the length L2 of the center line 122 in the thickness direction of the second substrate 120 become equal in the display area 104. As a result, similar to Embodiment 1, the difference in stress on the first substrate 110 and the second substrate 120 is mitigated, suppressing fluctuations in the distance between the first substrate 110 and the second substrate 120 at the edge of the display area 104 and suppressing display unevenness. Note that in Figure 7, for ease of understanding, the liquid crystal LC, the first polarizing plate 140, etc. are omitted and the liquid crystal display panel 100 is shown in a simplified manner. Also, in this embodiment, the display surface 102 of the liquid crystal display panel 100 has the same shape as the curved surface 160.

[0045] Next, we will explain the length L1 of the centerline 112 in the thickness direction of the first substrate 110 and the length L2 of the centerline 122 in the thickness direction of the second substrate 120. As shown in Figure 8, in the curved surface 160, if the radius of curvature and central angle of the curved surface 508 on the +X side are r and θ, the radius of curvature and central angle of the curved surface 510 on the -X side are s and φ, half the thickness of the first substrate 110 is D1, and half the thickness of the second substrate 120 is D2, then the lengths L1 of the centerline 112 and L2 of the centerline 122 are expressed by the following equations (4) and (5). Also, from equations (4) and (5), the difference between the length L1 of the centerline 112 and the length L2 of the centerline 122 is expressed by the following equation (6).

[0046]

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[0047] When the tangent plane 162a of the curved surface 160 at the inner circumference end 130a of the seal portion 130 located on the +X side and the tangent plane 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 located on the -X side are parallel, then θ = φ, and according to equation (6), the length L1 of the center line 112 and the length L2 of the center line 122 are equal.

[0048] As described above, when viewed in cross-section along the XZ line, the curved surface 160 has one inflection point P3 in the display area 104, and the tangent planes 162a and 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 are parallel to each other. Therefore, in the liquid crystal display panel 100 of this embodiment, the length L1 of the center line 112 and the length L2 of the center line 122 are made equal, thereby suppressing fluctuations in the distance between the first substrate 110 and the second substrate 120 at the edge of the display area 104 and suppressing display unevenness.

[0049] <Embodiment 3> In Embodiment 2, the curved surface 160 is formed from a surface curved in the +Z direction (convex surface) and a surface curved in the -Z direction (concave surface) that is continuous with the surface curved in the +Z direction. The curved surface 160 may also be formed from two continuous surfaces with different radii of curvature, one curved in the +Z direction and the other curved in the -Z direction. Here, the length L1 of the center line 112 in the thickness direction of the first substrate 110 and the length L2 of the center line 122 in the thickness direction of the second substrate 120 will be described.

[0050] When viewed in cross-section along the XZ line, the curved surface 160 of this embodiment is formed from two consecutive surfaces (convex surfaces) 512 and 514 that are curved in the +Z direction and have different radii of curvature, as shown in Figure 9, and a surface (concave surface) 516 that is located on the -X side and is continuous with the surface 514 that is curved in the +Z direction. An inflection point P3 is formed at the boundary between the surface 514 that is curved in the +Z direction and the surface 516 that is curved in the -Z direction. Furthermore, when viewed in cross-section along the XZ line, the tangent planes 162a and 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 are parallel to each other. In this embodiment as well, the display surface 102 of the liquid crystal display panel 100 has a shape similar to the curved surface 160.

[0051] In the curved surface 160, if the radius of curvature and central angle of the surface 512 curved in the +Z direction on the +X side are r and θ, the radius of curvature and central angle of the surface 514 curved in the +Z direction on the -X side are s and φ, the radius of curvature and central angle of the surface 516 curved in the -Z direction are t and ω, half the thickness of the first substrate 110 is D1, and half the thickness of the second substrate 120 is D2, then the length L1 of the centerline 112 in the thickness direction of the first substrate 110 and the length L2 of the centerline 122 in the thickness direction of the second substrate 120 are expressed by the following equations (7) and (8). Also, from equations (7) and (8), the difference between the length L1 of the centerline 112 and the length L2 of the centerline 122 is expressed by the following equation (9).

[0052]

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[0053] When the tangent plane 162a of the curved surface 160 at the inner circumference end 130a of the seal portion 130 located on the +X side and the tangent plane 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 located on the -X side are parallel, then ω = θ + φ, and by equation (9), the length L1 of the center line 112 and the length L2 of the center line 122 are equal.

[0054] As described above, even when the curved surface 160 is formed from two consecutive surfaces 512 and 514 that are curved in the +Z direction and have different radii of curvature, the length L1 of the center line 112 and the length L2 of the center line 122 can be made equal. Therefore, fluctuations in the distance between the first substrate 110 and the second substrate 120 at the edge of the display area 104 can be suppressed, and display unevenness can be suppressed.

[0055] <Embodiment 4> In Embodiment 1, when the curved surface 160 is viewed in cross-section along the XZ cross-section, the shape of the curved surface 160 is the same for all XZ cross-sections. The shape of the curved surface 160 (position of inflection point, height of apex, etc.) may vary for each XZ cross-section (i.e., along the Y direction). Here, the curvature of the liquid crystal display panel 100 in this embodiment will be described. The other configurations of the liquid crystal display panel 100 and the liquid crystal display device 10 in this embodiment are the same as in Embodiment 1.

[0056] As shown in Figure 10, when viewed from above, the liquid crystal display panel 100 (first substrate 110 and second substrate 120) of this embodiment has a rectangular shape, similar to Embodiment 1. Also, as shown in Figure 11, the liquid crystal display panel 100 of this embodiment is curved in the X direction, curves in the +Z direction at the center, and curves in the -Z direction at the +X and -X ends, similar to Embodiment 1. Furthermore, when viewed in cross-section along the XZ cross-section, the liquid crystal display panel 100 of this embodiment is symmetrical with respect to the Z direction. Note that in Figure 11, for ease of understanding, the liquid crystal LC, the first polarizing plate 140, etc., are omitted, and the liquid crystal display panel 100 is shown in a simplified manner. In the following figures as well, the liquid crystal display panel 100 may also be shown in a simplified manner.

[0057] Furthermore, similar to Embodiment 1, when viewed in cross-section along the XZ line, the curved surface 160 (curved surfaces 160a to 160c, described later) curves in the +Z direction at its center and in the -Z direction at its +X and -X ends, thus being symmetrical with respect to the Z direction. Moreover, similar to Embodiment 1, the tangent plane 162a of the curved surface 160 at the inner circumferential end 130a of the seal portion 130 located on the +X side and the tangent plane 162b of the curved surface 160 at the inner circumferential end 130a of the seal portion 130 located on the -X side are parallel to each other. The tangent planes 162a and 162b are parallel to the XY plane.

[0058] In this embodiment, the height H of the apex 164 of the curved surface 160 from the tangent planes 162a and 162b differs for each XZ cross section. For example, as shown in Figure 12, the height H of the apex 164 decreases sequentially for the curved surface 160a in the XZ cross section viewed along the BB line in Figure 10, the curved surface 160b in the XZ cross section viewed along the CC line in Figure 10, and the curved surface 160c in the XZ cross section viewed along the DD line in Figure 10. That is, the liquid crystal display panel 100 in this embodiment is curved such that the height H of the apex 164 of the curved surface 160 decreases along the +Y direction. In this embodiment as well, the display surface 102 of the liquid crystal display panel 100 has the same shape as the curved surface 160.

[0059] As described above, the height H from the tangent planes 162a and 162b of the apex 164 of the curved surface 160 may differ for each XZ cross section. Also, in this embodiment, when viewed in cross-section in the XZ cross section, the curved surface 160 (curved surfaces 160a to 160c) has two inflection points P1 and P2 in the display area 104, and the tangent planes 162a and 162b of the curved surface 160 at the inner circumference end 130a of the seal portion 130 are parallel to each other, so the length L1 of the center line 112 and the length L2 of the center line 122 can be made equal. Therefore, fluctuations in the distance between the first substrate 110 and the second substrate 120 at the edge of the display area 104 can be suppressed, and display unevenness can be suppressed. Furthermore, since the shape of the curved surface 160 (display surface 102) changes for each XZ cross section, the design of the liquid crystal display panel 100 and the liquid crystal display device 10 can be improved.

[0060] <Embodiment 5> In Embodiment 4, the height H from the tangent planes 162a and 162b of the top 164 of the curved surface 160 differs for each XZ cross section. The position of the inner circumferential end 130a of the seal portion 130 may also differ for each XZ cross section.

[0061] As shown in Figure 13, the liquid crystal display panel 100 (first substrate 110 and second substrate 120) of this embodiment is curved in the X direction, curved in the +Z direction in the central part, and curved in the -Z direction at the +X side end and the -X side end. Furthermore, when viewed in cross-section in the XZ cross section, the liquid crystal display panel 100 of this embodiment is symmetrical with respect to the Z direction.

[0062] Furthermore, similar to Embodiment 1, when viewed in cross-section along the XZ cross-section, the curved surface 160 (curved surfaces 160d to 160f, described later) curves in the +Z direction at its center and in the -Z direction at its +X and -X ends, thus being symmetrical with respect to the Z direction. Moreover, similar to Embodiment 1, the tangent plane 162a of the curved surface 160 at the inner circumferential end 130a of the seal portion 130 located on the +X side and the tangent plane 162b of the curved surface 160 at the inner circumferential end 130a of the seal portion 130 located on the -X side are parallel to each other. The tangent planes 162a and 162b are parallel to the XY plane.

[0063] On the other hand, when viewed from above, the liquid crystal display panel 100 of this embodiment has a trapezoidal shape that is narrower on the +Y side, as shown in Figure 14. The seal portion 130 of this embodiment is formed along the outer shapes of the first substrate 110 and the second substrate 120, and the spacing of the seal portion 130 narrows in the +Y direction. Therefore, as shown in Figure 15, the position of the inner circumference end 130a of the seal portion 130 differs for each XZ cross-section in the curved surface 160d viewed along the EE line in Figure 14, the curved surface 160e viewed along the FF line in Figure 14, and the curved surface 160f viewed along the GG line in Figure 14.

[0064] As described above, the position of the inner circumferential end portion 130a of the seal portion 130 may differ for each XZ cross-section. In this embodiment as well, when viewed in cross-section in the XZ cross-section, the curved surface 160 (curved surface 160d~160f) has two inflection points P1 and P2 in the display area 104, and the tangent planes 162a and 162b of the curved surface 160 at the inner circumferential end portion 130a of the seal portion 130 are parallel to each other. Therefore, the length L1 of the center line 112 and the length L2 of the center line 122 can be made equal, and display unevenness can be suppressed. Furthermore, since the shape of the curved surface 160 (display surface 102) changes for each XZ cross-section, the design of the liquid crystal display panel 100 and the liquid crystal display device 10 can be improved.

[0065] <Embodiment 6> In Embodiment 1, the liquid crystal display panel 100 is bonded to the cover 200 and supported in a curved state. The liquid crystal display panel 100 may also be supported in a curved state by the cover 200 and the backlight unit 300.

[0066] In this embodiment, similar to Embodiment 1, the end of the cover 200 to which the liquid crystal display panel 100 is bonded is bonded to the side wall 322 of the housing 320 of the backlight unit 300. In this embodiment, as shown in Figure 16, the liquid crystal display panel 100 is supported in a curved state by having its end 106 sandwiched between the cover 200 and the bottom plate 321 of the housing 320 of the backlight unit 300. This allows the liquid crystal display panel 100 to be supported more stably.

[0067] <Variation> While embodiments have been described above, this disclosure can be modified in various ways without departing from its essence.

[0068] For example, a striped color filter, a black matrix, an alignment film, etc., may be formed on the first main surface 110a of the first substrate 110, and a TFT, wiring, electrodes, an alignment film, etc., may be formed on the first main surface 120a of the second substrate 120.

[0069] As shown in Figure 17, the cover 200 may have a groove 210 on its main surface 200a for housing the end portion 106 of the liquid crystal display panel 100. This prevents interference between the end portion 106 of the liquid crystal display panel 100 and the main surface 200a of the cover 200. Furthermore, the display-side surface of the cover 200 can be molded into a freely curved surface, improving the aesthetic design of the liquid crystal display device 10. Note that in Figure 16, the adhesive layer 202, the second polarizing plate 150, etc., are omitted for ease of understanding.

[0070] Furthermore, the liquid crystal display panel 100 may have a chamfered portion 106a at its end 106, as shown in Figures 18 and 19. This prevents interference between the end 106 of the liquid crystal display panel 100 and the main surface 200a of the cover 200. In addition, the display side surface of the cover 200 can be formed into a freely curved surface, improving the design of the liquid crystal display device 10. As shown in Figure 18, if the chamfered portion 106a is provided only on the second substrate 120, cracking and chipping of the first substrate 110 can be suppressed.

[0071] As shown in Figures 17 to 19, the liquid crystal display panel 100 and the cover 200 may be bonded together by an adhesive 204 that bonds the end portion 106 of the liquid crystal display panel 100 to the main surface 200a of the cover 200. The adhesive 204 may be a photocurable adhesive or a thermosetting adhesive. By having the adhesive 204 broadly cover the end portion 106 of the liquid crystal display panel 100, the curved liquid crystal display panel 100 can be supported even more stably. The configuration in which the adhesive 204 bonds and supports the end portion 106 of the liquid crystal display panel 100 is not limited to this. For example, the chamfered portion 106a and the adhesive 204 may be provided only on one end portion 106 of the liquid crystal display panel 100.

[0072] Instead of providing adhesive 204, for example, in Embodiment 6 (Figure 16), the bottom plate 321 of the housing 320 of the backlight unit 300 may be molded to conform to the end 106 of the liquid crystal display panel 100, thereby supporting the end 106 of the liquid crystal display panel 100 with the housing 320 of the backlight unit 300.

[0073] As shown in Figure 20, the cover 200 may be provided on the side of the liquid crystal display panel 100 opposite to the display surface 102, supporting the liquid crystal display panel 100 in a curved state. In this case, a protective cover 402 made of translucent resin is provided on the display surface 102 side of the liquid crystal display panel 100. The protective cover 402 is bonded to the housing 320 of the backlight unit 300 by, for example, an adhesive layer 302. The cover 200 is also bonded to the bottom plate 321 of the housing 320 of the backlight unit 300 by, for example, an adhesive layer 206. Note that in Figure 20, the hatching of adhesive layers 202, 302, etc., is omitted.

[0074] As shown in Figure 21, the liquid crystal display panel 100 may be supported in a curved state by the light source unit 310 of the backlight unit 300 via an adhesive layer 304. In this case, the light source unit 310 is molded to a shape that matches the curvature of the liquid crystal display panel 100.

[0075] In Embodiment 2, the radius of curvature r of the curved surface 508 of the curved surface 160 and the radius of curvature s of the curved surface 510 of the curved surface 160 are different, but the radius of curvature r of the curved surface 508 and the radius of curvature s of the curved surface 510 may be the same. Also, the curved surface 160 may have a flat surface. For example, as shown in Figure 22, the curved surface 160 may have a first flat surface 552 that is continuous with the convex curved surface 508 and a second flat surface 554 that is continuous with the concave curved surface 510. In this case, at the inner circumferential end 130a of the seal portion 130, the curved surface 160 is a flat surface, so the curved surface 160 corresponds to the tangent planes 162a and 162b of the curved surface 160 at the inner circumferential end 130a of the seal portion 130.

[0076] In Embodiment 5, the position of the inner circumferential end 130a of the seal portion 130 differs for each XZ cross section. For each XZ cross section, at least one of the following may differ: the height H from the tangent planes 162a and 162b of the apex 164 of the curved surface 160, the position of the inner circumferential end 130a of the seal portion 130, and the positions of the inflection points P1 and P2. For example, as shown in Figure 23, the height H from the tangent planes 162a and 162b of the apex 164 of the curved surface 160 and the position of the inner circumferential end 130a of the seal portion 130 may differ for each XZ cross section. Also, as shown in Figure 24, the positions of the inflection points P1 and P2 and the position of the inner circumferential end 130a of the seal portion 130 may differ for each XZ cross section.

[0077] The liquid crystal display device 10 may include two liquid crystal display panels 100. The two liquid crystal display panels 100 are bonded together by an adhesive layer 108, as shown in Figure 25. For example, of the two liquid crystal display panels 100, the liquid crystal display panel 100 located on the display side (+Z side) displays a color image, and the liquid crystal display panel 100 located on the opposite side (-Z side) displays a monochrome image.

[0078] While preferred embodiments have been described above, this disclosure is not limited to these specific embodiments, and includes the invention described in the claims and its equivalents. [Explanation of Symbols]

[0079] 10 Liquid crystal display device, 100 Liquid crystal display panel, 102 Display surface, 104 Display area, 106 Edge, 106a Chamfered part, 108, 202, 206, 302, 304 Adhesive layer, 110 First substrate, 110a First main surface, 110b Second main surface, 112 Center line, 120 Second substrate, 120a First main surface, 120b Second main surface, 122 Center line, 130 Seal part, 130a Inner edge, 140 First polarizing plate, 150 Second polarizing plate, 160, 160a~160f Curved surface, 162a, 162b Tangent plane, 164 Top, 200 Cover, 200a Main surface, 204 Adhesive, 210 Groove, 300 Backlight part, 310 Light source part, 320 Enclosure, 321 Bottom plate, 322 Side wall, 402 Protective cover, 502, 504, 506, 508, 510, 512, 514, 516 Curved surface, 552 First plane, 554 Second plane, D1, D2 Half of thickness, H Height, LC LCD, L1, L2 Length, PX Pixel, P1~P3 Inflection point, r, s, t Radius, θ, φ, ω Radius of curvature

Claims

1. A first substrate that curves in a first direction, A second substrate that is curved in the first direction and faces the first substrate, A liquid crystal sandwiched between the first substrate and the second substrate, The first substrate and the second substrate are bonded together, and a sealing portion is provided for enclosing the liquid crystal, When viewed in cross-section with a cross-section that includes the first direction and the display direction, A curved surface formed in the display area surrounded by the inner circumferential ends of the seal portion and along the first main surface of the first substrate facing the second substrate has at least one inflection point, and the tangent planes of the curved surface at each of the inner circumferential ends of the seal portion are parallel to each other. The curved surface has at least one convex surface and at least one concave surface continuous with the convex surface, and the radius of curvature of the convex surface and the radius of curvature of the concave surface are different. The sum of the central angles of each of the convex surfaces is equal to the sum of the central angles of each of the concave surfaces. In the display area, the length of the center line in the thickness direction of the first substrate and the length of the center line in the thickness direction of the second substrate are equal. LCD display panel.

2. When viewed in cross-section, the display area has a first plane continuous with the convex surface and a second plane continuous with the concave surface. The liquid crystal display panel according to claim 1.

3. When the position of the cross section is changed along a direction perpendicular to the first direction and the display direction, at least one of the following changes in the cross-sectional view: the height of the apex of the curved surface from the tangent plane, the position of the inner circumference end of the seal portion, and the position of the inflection point. A liquid crystal display panel according to claim 1 or 2.

4. A liquid crystal display panel according to any one of claims 1 to 3, The liquid crystal display panel comprises a cover provided on the display surface of the liquid crystal display panel, or on the surface of the liquid crystal display panel opposite to the display surface, and supporting the liquid crystal display panel in a curved state via an adhesive layer. LCD display device.

5. The cover has a groove on the surface facing the liquid crystal display panel for housing the end of the liquid crystal display panel. The liquid crystal display device according to claim 4.

6. The edges of the aforementioned liquid crystal display panel have a chamfered portion. The liquid crystal display device according to claim 4.

7. At least one end of the liquid crystal display panel is fixed to the cover with adhesive. A liquid crystal display device according to any one of claims 4 to 6.

8. The device comprises two stacked liquid crystal display panels, A liquid crystal display device according to any one of claims 4 to 7.

9. The aforementioned liquid crystal display panel is equipped with a backlight unit that illuminates it with light, The cover and the backlight section sandwich the liquid crystal display panel, thereby supporting the liquid crystal display panel in a curved state. A liquid crystal display device according to any one of claims 4 to 8.

10. A step of forming a seal portion for encapsulating liquid crystal on one of the first substrate and the second substrate, A step of stacking one of the first substrate and the second substrate, on which the sealing portion is formed, and the other of the first substrate and the second substrate, The process of curing the seal portion and bonding the first substrate and the second substrate together, The process includes the step of curving the bonded first substrate and the second substrate in a first direction such that the length of the center line in the thickness direction of the first substrate and the length of the center line in the thickness direction of the second substrate are equal in the display area surrounded by the inner peripheral end of the seal portion, In the bending process, when viewed in cross-section including the first direction and the display direction, the first substrate and the second substrate are bent such that the curved surface formed in the display area and along the first main surface of the first substrate facing the second substrate has at least one inflection point, and the tangent planes of the curved surface at each of the inner circumferential ends of the sealing portion are parallel to each other. The curved surface has at least one convex surface and at least one concave surface continuous with the convex surface, and the radius of curvature of the convex surface and the radius of curvature of the concave surface are different. The sum of the central angles of each of the convex surfaces is equal to the sum of the central angles of each of the concave surfaces. A method for manufacturing liquid crystal display devices.

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