Liquid crystal display device

Abstract

The utility model provides a liquid crystal display device. According to one embodiment, a display device includes: a first substrate; a second substrate; a liquid crystal layer; a plurality of light emitting elements arranged in the first direction; a third transparent substrate having a side surface facing the plurality of light-emitting elements; and a transparent layer having a refractive index lower than that of the third transparent substrate, the third transparent substrate having a linear portion located on the light emitting element side in plan view and along the first direction, and a curved portion connected to the linear portion. The transparent layer is provided with a plurality of tape sections arranged side by side in the first direction and extending in the second direction, each of the plurality of tape sections is provided with a first end section on the light-emitting element side and a second end section on the opposite side from the first end section, and the width of the first end section is larger than the width of the second end section. Each of the plurality of belt portions has the same width in the first direction at positions equidistant from the linear portion in the second direction.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority based on Japanese Patent Application No. 2024-033460 filed on March 6, 2024, and incorporates by reference the entire disclosure of that Japanese Patent Application. TECHNICAL FIELD

[0003] Embodiments of the present application relate to a display device. BACKGROUND

[0004] Various display devices using a high-molecular dispersion type liquid crystal, which can switch between a scattering state that scatters incident light and a transparent state that transmits incident light, have been proposed. In the display devices using the high-molecular dispersion type liquid crystal, an edge illumination method in which light emitting modules are arranged at end portions of a display panel is sometimes used. Since such a display device has high transmittance, use in various fields is expected. On the other hand, in such a display device, it is desirable to improve the phenomenon that luminance decreases as distance from the light emitting module increases. SUMMARY

[0005] Generally, according to an embodiment, a display device includes: a first substrate including a first transparent substrate and pixel electrodes respectively arranged in respective ones of a plurality of pixels on the first transparent substrate; a second substrate including a second transparent substrate; a liquid crystal layer arranged between the first substrate and the second substrate, including a stripe-shaped polymer and liquid crystal molecules; a plurality of light emitting elements arranged in a first direction; a third transparent substrate including a side surface facing the plurality of light emitting elements; and a transparent layer arranged between the second substrate and the third transparent substrate, having a lower refractive index than the third transparent substrate, the third transparent substrate having a linear portion on a side of the plurality of light emitting elements and extending in the first direction in a plan view and a curved portion connected to the linear portion, the transparent layer including a plurality of band portions arranged in the first direction and extending in a second direction orthogonal to the first direction, each of the plurality of band portions including a first end portion on the side of the plurality of light emitting elements and a second end portion on a side opposite to the first end portion, a width of the first end portion being greater than a width of the second end portion, each of the plurality of band portions having the same width in the first direction at positions equidistant from the linear portion in the second direction.

[0006] According to the above-described configuration, a display device that can suppress a decrease in display quality can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1is a plan view showing a configuration example of the display device DSP of the present embodiment.

[0008] Figure 2 is a plan view showing a configuration example of the display device DSP of the present embodiment. Figure 1 is an exploded perspective view of the main part of the display device DSP shown in

[0009] Figure 3 is a plan view showing a configuration example of the display device DSP of the present embodiment. Figure 1 is a sectional view of the display device DSP shown in

[0010] Figure 4 is a plan view showing a configuration example of the display device DSP of the present embodiment. Figure 2 is a plan view showing a configuration example of the light guide element LG shown in

[0011] Figure 5 is a sectional view showing a configuration example of the display device DSP of the present embodiment.

[0012] Figure 6 is a plan view showing the light guide element LG' of the comparative example.

[0013] Figure 7 is a plan view showing a configuration example of the display device DSP of the present embodiment. Figure 2 is a plan view showing another configuration example of the light guide element LG shown in

[0014] Figure 8 is a plan view showing a configuration example of the display device DSP of the present embodiment. Figure 2 is a plan view showing another configuration example of the light guide element LG shown in

[0015] Figure 9 is a plan view showing another configuration example of the light guide element LG shown in Figure 2

[0016] Figure 10 is a plan view showing another configuration example of the light guide element LG shown in Figure 2 DETAILED DESCRIPTION

[0017] Hereinafter, the present embodiment will be described with reference to the drawings.

[0018] Note that the disclosed content is only one example, and appropriate modifications that a person skilled in the art can easily conceive while maintaining the gist of the utility model are of course included in the scope of the utility model. In addition, in the drawings, the width, thickness, shape, and the like of each portion are sometimes schematically shown compared to the actual mode in order to make the explanation more clear, but this is only one example and is not limited to the explanation of the utility model. In addition, in the present specification and each drawing, a constitution element that has the same or similar function to the constitution element explained with respect to the already appeared drawing is denoted by the same reference numeral, and sometimes the detailed explanation of the overlap is appropriately omitted.

[0019] ​​Figure 1 is a plan view showing a configuration example of the display device DSP of the present embodiment. In one example, the first direction X, the second direction Y, and the third direction Z are orthogonal to each other, but can intersect at an angle other than 90 degrees. The first direction X and the second direction Y correspond to directions parallel to a main surface of a substrate constituting the display device DSP, and the third direction Z corresponds to a thickness direction of the display device DSP. In the present specification, a direction from the first substrate SUB1 toward the second substrate SUB2 is referred to as an "upper side" (or simply, upper), and a direction from the second substrate SUB2 toward the first substrate SUB1 is referred to as a "lower side" (or simply, lower). In the case of being referred to as "a second member above a first member" and "a second member below a first member", the second member can be in contact with the first member, or can be separated from the first member. In addition, there is an observation position at which the display device DSP is observed, on the front end side of the arrow indicating the third direction Z, and a case where observation is performed from the observation position toward an X-Y plane defined by the first direction X and the second direction Y is referred to as planar observation.

[0020] In the present embodiment, a liquid crystal display device to which a high-molecular dispersion type liquid crystal is applied is described as an example of the display device DSP. The display device DSP includes a display panel PNL, an IC chip 1, and a wiring substrate 2.

[0021] The display panel PNL includes a first substrate SUB1, a second substrate SUB2, a liquid crystal layer LC, and a sealant SE. The first substrate SUB1 and the second substrate SUB2 are formed in a flat plate shape parallel to the X-Y plane. The first substrate SUB1 has a straight portion S1 extending along the first direction X and a curved portion C1 connected to the straight portion S1. The second substrate SUB2 has a straight portion S2 extending along the first direction X and a curved portion C2 connected to the straight portion S2. The curved portion C2 overlaps the curved portion C1 in planar observation. The straight portion S2 does not overlap the straight portion S1. The first substrate SUB1 has an extension portion Ex extending toward the second direction Y from the straight portion S2 in planar observation.

[0022] The first substrate SUB1 and the second substrate SUB2 overlap in planar observation. The first substrate SUB1 and the second substrate SUB2 are bonded by the sealant SE. The extension portion Ex does not overlap the second substrate SUB2 in planar observation. The liquid crystal layer LC is held between the first substrate SUB1 and the second substrate SUB2, and is sealed by the sealant SE. In Figure 1 , the liquid crystal layer LC and the sealant SE are indicated by different hatchings.

[0023] As shown in Figure 1As schematically shown in the magnified view, the liquid crystal layer LC comprises a polymeric dispersion liquid crystal including a polymer 51 and liquid crystal molecules 52. In one example, the polymer 51 is a liquid crystal polymer. The polymer 51 is formed as stripes extending along a first direction X. The liquid crystal molecules 52 are dispersed in the gaps between the polymer 51 and oriented with their long axes along the first direction X. The polymer 51 and the liquid crystal molecules 52 each have optical anisotropy or refractive index anisotropy. The polymer 51 has a lower response to an electric field than the liquid crystal molecules 52.

[0024] In one example, the orientation of polymer 51 remains almost unchanged regardless of the presence or absence of an electric field. On the other hand, the orientation of liquid crystal molecules 52 changes according to the electric field when a high voltage above a threshold is applied to the liquid crystal layer LC. When no voltage is applied to the liquid crystal layer LC, the optical axes of polymer 51 and liquid crystal molecules 52 are parallel to each other, and light incident on the liquid crystal layer LC is almost not scattered but transmitted (transparent state). When a voltage is applied to the liquid crystal layer LC, the optical axes of polymer 51 and liquid crystal molecules 52 intersect each other, and light incident on the liquid crystal layer LC is scattered (scattered state).

[0025] The display panel PNL has a display section DA for displaying images and a non-display section NDA surrounding the display section DA in the area where the first substrate SUB1 and the second substrate SUB2 overlap when viewed from above. A seal SE is located in the non-display section NDA. Figure 1 In the example shown, the display unit DA has an edge portion E1 that is close to the straight section S2 and extends along the first direction X, and an edge portion E2 that is close to the curved section C2 and connected to the edge portion E1. The display unit DA has pixels PX arranged in a matrix in the first direction X and the second direction Y.

[0026] As in Figure 1 As shown in the enlarged view, each pixel PX includes a switching element SW, a pixel electrode PE, a common electrode CE, and a liquid crystal layer LC. The switching element SW is, for example, composed of a thin-film transistor (TFT) and electrically connected to the scan line G and the signal line S. The scan line G extends along a first direction X and is electrically connected to the switching element SW of each pixel PX arranged in the first direction X. The signal line S extends along a second direction Y, intersects the scan line G, and is electrically connected to the switching element SW of each pixel PX arranged in the second direction Y. The pixel electrode PE is electrically connected to the switching element SW. Each pixel electrode PE is opposite to the common electrode CE, and the liquid crystal layer LC (especially liquid crystal molecules 52) is driven by the electric field generated between the pixel electrode PE and the common electrode CE. A capacitor CS is formed, for example, between the common electrode CE and an electrode at the same potential, and between the pixel electrode PE and an electrode at the same potential.

[0027] IC chip 1 and wiring substrate 2 are respectively connected to the extension portion Ex. IC chip 1 may contain, for example, a display driver for outputting signals required for image display. Wiring substrate 2 is a flexible printed circuit board that can be bent. It should be noted that IC chip 1 can also be connected to wiring substrate 2. IC chip 1 and wiring substrate 2 may sometimes read signals from the display panel PNL, but they mainly function as signal sources that supply signals to the display panel PNL.

[0028] Figure 2 It means Figure 1 The diagram shows an exploded perspective view of the main components of the display device's DSP. Figure 2 In the middle, the side of the straight section S2 of the second substrate SUB2 is indicated by a dashed line.

[0029] In addition to the display panel PNL, the display device DSP also includes a light guide element LG and a light-emitting module LM. The first substrate SUB1, the second substrate SUB2, and the light guide element LG are arranged sequentially along the third direction Z.

[0030] The light-emitting module LM has multiple light-emitting elements LD, light guide LB and wiring substrate F.

[0031] Multiple light-emitting elements (LDs) are arranged at intervals along a first direction X. Each of the multiple light-emitting elements (LDs) is connected to a wiring substrate F. Figure 2 In the example shown, each of the multiple light-emitting elements (LDs) overlaps with the extension portion Ex when viewed from above. The light-emitting element LD is, for example, a light-emitting diode (LED). Although not described in detail, the light-emitting element LD has a red light-emitting portion, a green light-emitting portion, and a blue light-emitting portion. Light emitted from the light-emitting element LD travels along the direction indicated by the arrow representing the second direction Y. The light guide LB is formed as a rod extending along the first direction X and is disposed between the light-emitting element LD and the light guide element LG in the second direction Y.

[0032] The light guide element LG has a transparent substrate 30 and a transparent layer 40.

[0033] The transparent substrate 30 has a straight portion S3 extending along a first direction X and a curved portion C3 connected to the straight portion S3. The straight portion S3 is located on the light-emitting element (LD) side in the transparent substrate 30. The straight portion S3 has one end 33b along the first direction X and another end 33c on the opposite side of the first end 33b. The curved portion C3 is connected to the straight portion S3 at one end 33b and the other end 33c. The position equidistant from the first end 33b and the other end 33c is called the center 33a of the straight portion S3. Figure 2In the example shown, the distance R1 from the center 33a of the straight section S3 to one end 33b of the straight section S3 has the same length as the distance R2 along the second direction Y from the center 33a of the straight section S3 to the curved section C3. Furthermore, in the illustrated example, the curved section C3 is formed in an arc shape, and the transparent substrate 30 has a semi-circular shape when viewed from above.

[0034] Curved sections C1, C2, and C3 overlap when viewed from above. Straight sections S2 and S3 overlap when viewed from above. Straight section S3 is located between straight section S1 and display section DA when viewed from above.

[0035] exist Figure 2 In the example shown, the first substrate SUB1, the second substrate SUB2, and the light guide element LG each have a reflective member RM disposed on the side surfaces along the curved portions C1, C2, and C3. The reflective member RM is formed, for example, from a highly reflective metallic material such as aluminum, silver, or titanium. The reflective member RM can be a sheet bonded to the side surface, or it can be a thin film formed directly on the side surface by a method such as vapor deposition.

[0036] The transparent substrate 30 has a side surface 31 along the straight section S3. The side surface 31 is a plane substantially parallel to the XZ plane defined by the first direction X and the third direction Z. When viewed from above, the side surface 31 is located on the side of the light-emitting element LD, and in the second direction Y, it is positioned opposite to a plurality of light-emitting elements LD via a light guide LB. Additionally, the transparent substrate 30 has a side surface 32 along the curved section C3. The side surface 32 is connected to the side surface 31.

[0037] A transparent layer 40 is disposed between the transparent substrate 30 and the second substrate SUB2. In the illustrated example, the transparent layer 40 is formed on the surface of the transparent substrate 30 opposite to the second substrate SUB2. It should be noted that the transparent layer 40 may also be formed on the surface of the second substrate SUB2 opposite to the transparent substrate 30. The transparent layer 40 has a plurality of strips 41 arranged in the first direction X. Each strip 41 extends along the second direction Y and is formed into a generally isosceles triangular shape.

[0038] exist Figure 2 When the display panel PNL and the light guide element LG are overlapped, multiple strips 41 overlap with the display unit DA when viewed from above.

[0039] Figure 3 It means Figure 1 This is a cross-sectional view of one configuration example of the display device DSP shown. Here, the cross-section of the display section DA defined by the first direction X and the third direction Z in the XZ plane will be described.

[0040] The first substrate SUB1 includes a transparent substrate 10, insulating films 11, 12, and 13, a capacitor electrode 14, a metal line ML, a signal line S, a pixel electrode PE, and an alignment film AL1. The first substrate SUB1 also includes a switching element SW and a scan line G as illustrated. Figure 1 The scan line G is disposed, for example, between the transparent substrate 10 and the insulating film 11.

[0041] The transparent substrate 10 includes a main surface (lower surface) 10A and a main surface (upper surface) 10B on the opposite side of the main surface 10A. The main surfaces 10A and 10B are surfaces that are substantially parallel to the X-Y plane. The insulating film 11 covers the main surface 10B. The signal line S is disposed on the insulating film 11.

[0042] The insulating film 12 covers the signal line S. Although not described in detail, the insulating film 12 is formed in a lattice shape so as to overlap the scan line G and the signal line S. The capacitor electrode 14 is disposed on the insulating film 12. The metal line ML is disposed on the capacitor electrode 14. Although not described in detail, the capacitor electrode 14 and the metal line ML are formed in a lattice shape so as to overlap the insulating film 12.

[0043] The insulating film 13 covers the insulating film 11, the capacitor electrode 14, and the metal line ML. The pixel electrode PE is disposed on the insulating film 13 in each pixel PX. The pixel electrode PE is electrically connected to the switching element SW. The pixel electrode PE opposes the capacitor electrode 14 with the insulating film 13 interposed therebetween, and forms a capacitor CS of the pixel PX. The alignment film AL1 covers the pixel electrode PE and the insulating film 13.

[0044] The second substrate SUB2 includes a transparent substrate 20, a black matrix BM, a common electrode CE, and an alignment film AL2.

[0045] The transparent substrate 20 includes a main surface (lower surface) 20A and a main surface (upper surface) 20B on the opposite side of the main surface 20A. The main surfaces 20A and 20B are surfaces that are substantially parallel to the X-Y plane. The main surface 10B of the transparent substrate 10 faces the main surface 20A of the transparent substrate 20.

[0046] The black matrix BM and the common electrode CE are disposed on the main surface 20A. The black matrix BM is disposed, for example, directly above the signal line S, and directly above the switching element SW and the scan line G, which are not illustrated. The common electrode CE is disposed so as to oppose each pixel electrode PE with the liquid crystal layer LC interposed therebetween in the third direction Z, and directly covers the black matrix BM. The common electrode CE is electrically connected to the capacitor electrode 14, and is at the same potential as the capacitor electrode 14.

[0047] The alignment film AL2 covers the common electrode CE. The liquid crystal layer LC is located between the main surface 10B and the main surface 20A, and is in contact with the alignment films AL1 and AL2.

[0048] In the first substrate SUB1, the insulating films 11, 12, and 13, the capacitor electrode 14, the signal line S, the pixel electrode PE, and the alignment film AL1 are located between the main surface 10B and the liquid crystal layer LC. In the second substrate SUB2, the black matrix BM, the common electrode CE, and the alignment film AL2 are located between the main surface 20A and the liquid crystal layer LC.

[0049] The transparent substrates 10 and 20 are insulating substrates such as glass substrates, plastic substrates, and the like. The insulating film 11 is an inorganic insulating film formed of silicon oxide, silicon nitride, silicon oxynitride, and the like. The insulating film 12 is, for example, an organic insulating film formed of an acrylic resin or the like. The insulating film 13 is an inorganic insulating film formed of silicon nitride.

[0050] The capacitor electrode 14, the pixel electrode PE, and the common electrode CE are transparent electrodes formed of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), and the like. The black matrix BM can be a conductive layer or an insulating layer.

[0051] The alignment films AL1 and AL2 are horizontal alignment films having an alignment restricting force substantially parallel to the X-Y plane. In one example, the alignment films AL1 and AL2 are subjected to an alignment treatment along the first direction X. Note that the alignment treatment can be a rubbing treatment or a photo-alignment treatment.

[0052] The light guide element LG includes a transparent substrate 30 and a transparent layer 40.

[0053] The transparent substrate 30 is an insulating substrate having a refractive index n1. The transparent substrate 30 is, for example, a glass substrate, but can be a plastic substrate formed of polymethyl methacrylate (PMMA), polycarbonate (PC), or the like. In one example, the transparent substrate 30 is not a substrate formed by bonding a plurality of substrates, but is a single substrate. The transparent substrate 30 includes a main surface (lower surface) 30A and a main surface (upper surface) 30B on the opposite side from the main surface 30A. The main surfaces 30A and 30B are surfaces substantially parallel to the X-Y plane. The main surface 30A faces the main surface 20B of the transparent substrate 20.

[0054] The transparent layer 40 is disposed on the main surface 30A. The transparent layer 40 is, for example, formed of an organic material such as a silicone resin, a fluorine resin, or the like. The transparent layer 40 includes a plurality of band portions 41 arranged in the first direction X. Each of the band portions 41 extends along the second direction Y. The main surface 30A is exposed between the adjacent band portions 41. The band portions 41 are, for example, formed of a material having a refractive index n2 higher than the refractive index n1 of the transparent substrate 30. Figure 3 In the example shown in FIG. 1, the band portions 41 are located above the signal lines S and overlap when viewed in plan. Details of the shape of the transparent layer 40 will be described later.

[0055] In the example shown in FIG. 1, the band portions 41 are located above the signal lines S and overlap when viewed in plan. Details of the shape of the transparent layer 40 will be described later. Figure 3In the example shown, the transparent substrate 30 is bonded to the transparent substrate 20 of the second substrate SUB2 via a transparent adhesive layer AD. The transparent adhesive layer AD is in contact with almost the entire surface of the main surface 20B. In addition, the transparent adhesive layer AD covers the transparent layer 40 and is in contact with the main surface 30A in the areas where the transparent layer 40 is missing.

[0056] The transparent substrate 10 has a thickness T1, the transparent substrate 20 has a thickness T2, the transparent substrate 30 has a thickness T3, the transparent layer 40 has a thickness T4, and the transparent adhesive layer AD has a thickness T5. It should be noted that the thicknesses in this specification correspond to the length along the third direction Z.

[0057] In the illustrated example, thickness T1 is the same as thickness T2, and thickness T3 is thicker than both T1 and T2. It should be noted that thickness T3 can also be the same as thicknesses T1 and T2. In one example, thickness T3 is 200 μm to 2000 μm. The thickness T4 of the transparent layer 40 is below the maximum wavelength of light L1 emitted from the light-emitting element LD (described later). In one example, thickness T4 is 250 nm to 1500 nm. The thickness T5 of the transparent adhesive layer AD is 4 μm to 4000 μm.

[0058] The transparent layer 40 has a refractive index n2 that is smaller than the refractive index n1 of the transparent substrate 30. The refractive index n1 of the transparent substrate 30 is approximately 1.5, and the refractive index n2 of the transparent layer 40 is approximately 1.0 to 1.4. The refractive indices of the transparent substrates 10 and 20, and the transparent adhesive layer AD, are equal to the refractive index n1 of the transparent substrate 30, and are higher than the refractive index n2 of the transparent layer 40. "Equal" here is not limited to the case where the refractive index difference is zero, but includes cases where the refractive index difference is less than 0.03.

[0059] Figure 4 It means Figure 3 The image shows a top view of one configuration example of the light guide element LG. Figure 4 In the diagram, the strip 41 is schematically shown with its width enlarged in the first direction X. Additionally, in... Figure 4 In the middle, the light guide element LG is superimposed on Figure 2 The area where the display panel PNL overlaps with the display section DA is indicated by a single-dot dashed line.

[0060] The strip portion 41 has a first end portion 411 on the side of the light-emitting element LD, a second end portion 412 on the opposite side of the first end portion 411, a first edge 413, and a second edge 414. Each of the strip portions 41 is arranged in a first direction X. Each of the first ends 411 is arranged on the same straight line along the first direction X.

[0061] As for the length of each of the belt portions 41 along the second direction Y, the length of the belt portion 41a extending along the second direction Y from the vicinity of the center 33a of the straight portion S3 is the largest, and the lengths of the belt portions 41b extending along the second direction Y from the vicinity of the one end 33b of the straight portion S3 and the belt portions 41c extending along the second direction Y from the vicinity of the other end 33c are each the smallest. In addition, the length of the belt portions 41 gradually becomes shorter between the belt portion 41a and the belt portion 41b, and likewise, the length of the belt portions 41 gradually becomes shorter between the belt portion 41a and the belt portion 41c.

[0062] In Figure 4 In the example illustrated, each of the first end portions 411 overlaps the edge portion E1 of the display portion DA in plan view, and each of the second end portions 412 overlaps the edge portion E2 of the display portion DA in plan view, but the present application is not limited to this. From the viewpoint of suppressing light leakage between the straight portion S3 and the display portion DA, it is desirable that each of the first end portions 411 approach the straight portion S3 beyond the display portion DA.

[0063] Each of the first end portions 411 and the second end portions 412 has a first width W1 and a second width W2. Note that the width in this specification corresponds to the length along the first direction X. The first width W1 is larger than the second width W2. In one example, the first width W1 is smaller than the width WLD of one light emitting element LD, and one light emitting element LD is disposed across a plurality of the belt portions 41 arranged in the first direction X. In addition, the first width W1 is equal to or smaller than the width WP of one pixel electrode PE (or the pitch of the pixel electrodes PE arranged in the first direction X).

[0064] As for all of the belt portions 41, the first width W1 is set to be substantially the same. On the other hand, the second width W2 of the belt portion 41a is smaller than the second width W2 of each of the belt portions 41b and 41c.

[0065] The first edge 413 and the second edge 414 extend between the first end portion 411 and the second end portion 412 in a direction different from the first direction X and the second direction Y. For example, a direction that crosses the second direction Y clockwise at an acute angle is defined as the direction D1, and a direction that crosses the second direction Y counterclockwise at an acute angle is defined as the direction D2. Note that the angle θ1 between the second direction Y and the direction D1 is the same as the angle θ2 between the second direction Y and the direction D2, but the present application is not limited to this, and the angle between the second direction Y and the direction D1 and the angle between the second direction Y and the direction D2 can be different.

[0066] The first edge 413 extends along the direction D1, and the second edge 414 extends along the direction D2. Here, the first edge 413 and the second edge 414 each extend linearly, but can also be formed in a curved shape. The first width W1 and the second width W2 correspond to the interval between the first edge 413 and the second edge 414 along the first direction X.

[0067] The band portion 41 of such a shape has a width that gradually decreases at a certain ratio or an arbitrary ratio as it goes from the first end portion 411 toward the second end portion 412. Each of the band portions 41 has the same width WL along the first direction X at positions that are equally spaced by a distance L from the straight portion S3 along the second direction Y. The positions that are equally spaced by the distance L are positions on the curved portion C3 side from the first end portion 411, and the distance L is, for example, about 1 / 4 of the distance R2 to about 1 / 2 of the distance R2 as shown. It is desirable that the pitch of the adjacent band portions 41 be 2 times or less the width WP of the pixel electrode PE (or the pitch of the pixel electrodes PE arranged in the first direction X). Figure 2

[0068] The pixel electrode PE overlaps two adjacent band portions 41 in plan view. The pixel electrode PE overlaps the main surface 30A of the transparent substrate 30 between the adjacent band portions 41.

[0069] In the display portion DA, attention is directed to the pixel electrode PE1 closest to the light emitting element LD and the pixel electrode PE2 farthest from the light emitting element LD. The area of the pixel electrode PE1 overlapping the transparent layer 40 is larger than the area of the pixel electrode PE2 overlapping the transparent layer 40. In other words, the area of the main surface 30A overlapping the pixel electrode PE1 without the transparent layer 40 is smaller than the area of the main surface 30A overlapping the pixel electrode PE2 without the transparent layer 40. In this way, in the region close to the light emitting element LD, the area of the pixel electrode PE overlapping the transparent layer 40 is larger than in the region far from the light emitting element LD.

[0070] In addition, in the display portion DA, attention is directed to the pixel electrode PE3 located in the center of the first direction X and the pixel electrode PE4 located at the end of the first direction X among the pixel electrodes PE arranged at a distance L from the straight portion S3 along the second direction Y. The area of the pixel electrode PE3 overlapping the transparent layer 40 is the same as the area of the pixel electrode PE4 overlapping the transparent layer 40. In addition, the area of the pixel electrode PE3 overlapping the main surface 30A is the same as the area of the pixel electrode PE4 overlapping the main surface 30A.

[0071] The area overlapping the transparent layer 40 corresponds to an area in which light from the light emitting element LD hardly enters the display panel PNL, and the area overlapping the main surface 30A without the transparent layer 40 corresponds to an area in which light from the light emitting element LD can enter the display panel PNL, about which will be described later. ​

[0072] Figure 5 It means Figure 1 This is a cross-sectional view of one configuration example of the display device DSP shown. It should be noted that only the main parts of the display panel PNL are shown. (Refer to...) Figure 5 Meanwhile, the emitted light from the light-emitting element LD is explained.

[0073] The light-emitting element LD emits light L1 towards the side 31. After passing through the light guide LB, the light L1 emitted from the light-emitting element LD is refracted at the side 31 and incident on the transparent substrate 30. Of the light L1 incident on the transparent substrate 30, a portion traveling from the transparent substrate 30 towards the transparent layer 40 is reflected at the interface between the transparent substrate 30 and the transparent layer 40 and does not reach the second substrate SUB2, the liquid crystal layer LC, or the first substrate SUB1. Additionally, of the light traveling from the transparent substrate 30 towards the transparent layer 40, light with an incident angle smaller than the critical angle passes through the transparent layer 40 and reaches the liquid crystal layer LC, as shown by the dashed line.

[0074] Furthermore, of the light L1 incident on the transparent substrate 30, the light traveling towards the main surface 30B is reflected at the interface between the transparent substrate 30 and the air layer. Thus, most of the light L1 travels within the transparent substrate 30 while being repeatedly reflected near the side surface 31 (or in the area where the transparent layer 40 exists). Of the traveling light L1, the light traveling towards the area where the transparent layer 40 does not exist, i.e., towards the area where the transparent substrate 30 is in contact with the transparent adhesive layer AD, passes through the transparent substrate 30, and then through the transparent adhesive layer AD to the transparent substrate 20.

[0075] In the liquid crystal layer LC of a pixel where a voltage is applied, light L1 is scattered. Conversely, in the liquid crystal layer LC of a pixel where no voltage is applied, light L1 is transmitted.

[0076] In such Figure 5 In the example shown, where a reflective member RM is provided on the opposite side of the light-emitting element LD, light L1 arriving at side 32 is reflected towards the display unit by the reflective member RM. Therefore, light leakage from side 32 can be prevented, and the utilization efficiency of light L1 can be improved compared to the case where no reflective member RM is provided.

[0077] For reference Figure 4 As explained, in the region near the light-emitting element (LD), the overlap area between the pixel electrode PE and the strip 41 is larger than in the region farther from the LD. Therefore, in the region near the LD, the incidence of light L1 onto the pixel electrode PE is suppressed; conversely, in the region farther from the LD, the incidence of light L1 onto the pixel electrode PE is promoted. It should be noted that in the region near the LD, light L1 is not completely prevented from incident onto the display panel PNL; for example...Figure 4 As shown, the light L1 is incident on the display panel PNL from the gap of the adjoining band portion 41, and in addition, light of an incident angle that does not satisfy the total reflection condition is also incident on the display panel PNL. In the region that is separated by the same distance L from the light emitting element LD, the overlapping area of the pixel electrode PE and the transparent layer 40 is the same. Therefore, in the region that is separated by the same distance L from the light emitting element LD, the light L1 is incident on the respective pixel electrodes PE by the same degree, respectively.

[0078] Among the light incident on the liquid crystal layer LC, the light that travels toward the transparent layer 40 is reflected at the interface of the transparent substrate 30 and the transparent layer 40. The light L1 incident on the liquid crystal layer LC is transmitted through the pixel in the transparent state, and is scattered by the pixel in the scattering state. With the display device DSP, it is possible to observe from the main face 10A side, and it is also possible to observe from the main face 30B side. In addition, the display device DSP is a so-called transparent display, and it is possible to observe the background of the display device DSP through the display device DSP, both in the case of observing from the main face 10A side and in the case of observing from the main face 30B side.

[0079] According to the present embodiment, it is possible to suppress the luminance of the display panel PNL from becoming uneven.

[0080] If the luminance distribution of the light L1 from the light emitting element LD is taken into account, in the region that is far from the light emitting element LD, the luminance tends to decrease. One reason for such a decrease in luminance is absorption and scattering of the light L1 that is not desired, due to the liquid crystal layer LC, the signal line S, various insulating films, and the like.

[0081] In addition, in the display device DSP having a shape other than a rectangle, the distance from the side face 31 of the transparent substrate 30 on which the light L1 is incident to the side face 32 that is continuous with the side face 31 is not fixed. If the same intensity of light L1 is respectively emitted from each of the light emitting elements LD, the farther the region in the second direction Y from the side face 31 to the side face 32, the more the luminance of the display panel PNL tends to decrease compared to the region that is relatively close in the second direction Y. In this way, in the display device DSP having a shape other than a rectangle, there is a concern that the luminance of the display panel PNL becomes uneven.

[0082] The region in which the transparent layer 40 overlaps with the pixel electrode PE corresponds to a region in which the light L1 from the light emitting element LD hardly enters the display panel PNL, and the region in which the transparent layer 40 does not overlap with the pixel electrode PE (or the region between the adjoining band portions 41) corresponds to a region in which the light L1 from the light emitting element LD enters the display panel PNL.

[0083] In the region close to the light emitting element LD, the area of each pixel electrode PE overlapping with the transparent layer 40 is larger than that in the region away from the light emitting element LD. Therefore, in the region close to the light emitting element LD, the incidence of the light L1 to the display panel PNL is suppressed, and the absorption and scattering of the light L1 by the liquid crystal layer LC, the signal line S, various insulating films, and the like are suppressed. On the other hand, in the region away from the light emitting element LD, the incidence of the light L1 to the display panel PNL is promoted. As described above, the light from the light emitting element LD attenuates as it moves away from the light emitting element LD. Figure 4 The overlapping area of the pixel electrode PE1 and the transparent layer 40 is larger than that of the pixel electrode PE2 and the transparent layer 40. Therefore, the area of the region where the light L1 can be incident to the pixel electrode PE1 is smaller than that of the region where the light L1 can be incident to the pixel electrode PE2. On the other hand, the intensity of the light incident to the pixel electrode PE1 is stronger than that of the light incident to the pixel electrode PE2. Therefore, it is possible to equalize the luminance of the display panel PNL in the pixel electrode PE1 and the pixel electrode PE2.

[0084] Figure 4 The overlapping area of the pixel electrode PE3 and the transparent layer 40 is equal to that of the pixel electrode PE4 and the transparent layer 40. In addition, the intensity of the light L1 incident to the pixel electrode PE3 is equal to that of the light L1 incident to the pixel electrode PE4. Therefore, it is possible to equalize the luminance of the display panel PNL in the pixel electrode PE3 and the pixel electrode PE4.

[0085] Thus, according to the present embodiment, it is possible to suppress the luminance of the display panel PNL from becoming non-uniform even in a display device having a shape different from a rectangle. Thus, it is possible to suppress the reduction in the display quality of an image displayed by the display panel PNL.

[0086] Figure 6 is a plan view showing a light guide element LG' of a comparative example. The light guide element LG' of the comparative example differs from the light guide element LG in that each of the strip portions 41 does not have the same width along the first direction X at a position that is equally distant L from the straight portion S3 along the second direction Y.

[0087] In Figure 6 In the comparative example shown, each of the strip portions 41 has an isosceles triangle shape extending along the second direction Y. In Figure 6In the comparative example shown, regarding the width WL of the strip 41 at equidistant points L along the second direction Y from the straight section S3, the length of the strip 41a extending along the second direction Y from near the center 33a of the straight section S3 is the longest, while the lengths of the strip 41b extending along the second direction Y from near one end 33b of the straight section S3 and the strip 41c extending along the second direction Y from near the other end 33c are the shortest. The width WL gradually decreases between the strip 41a and the strip 41b, and similarly, it also gradually decreases between the strip 41a and the strip 41c.

[0088] exist Figure 6 In the comparative example shown, we focus on the pixel electrode PE, which is disposed at a distance L away from the straight section S3 along the second direction Y. The pixel electrode PE3 is located at the center in the first direction X, and the pixel electrode PE4 is located at the end in the first direction X. The area where pixel electrode PE3 overlaps with the transparent layer 40 is larger than the area where pixel electrode PE4 overlaps with the transparent layer 40. Therefore, the area where light L1 can incident on pixel electrode PE3 is smaller than the area where light L1 can incident on pixel electrode PE4. On the other hand, as described above, the intensity of light L1 incident on pixel electrode PE3 is equal to the intensity of light L1 incident on pixel electrode PE4. Therefore, the brightness of pixel electrode PE3 is lower than the brightness of pixel electrode PE4, making it impossible to equalize the brightness of the display panel PNL in pixel electrode PE3 and pixel electrode PE4.

[0089] In such Figure 6 In the comparative example shown, each of the light guide elements LG' in the strip portion 41 has a different width WL at a distance L from the straight portion S3 along the second direction Y and along the first direction X. Therefore, it is impossible to suppress the uneven brightness of the display panel PNL and the reduction in the display quality of the image displayed by the display panel PNL.

[0090] Next, other configuration examples of this embodiment will be described.

[0091] Figure 7 It means Figure 2 A top view of another configuration example of the light guide element LG shown. Figure 7 The example shown is similar to Figure 2Compared to the configuration example shown, the difference lies in the fact that the distance R2 along the second direction Y from the center 33a of the straight section S3 to the curved section C3 is different from the distance R1 from one end 33b of the straight section S3 to the center 33a. The distance R1 from the center 33a of the straight section S3 to one end 33b of the straight section S3 is longer than the distance R2 along the second direction Y from the center 33a of the straight section S3 to the curved section C3. The transparent substrate 30 has a generally semi-circular shape when viewed from above. Each of the strips 41 is arranged in the first direction X.

[0092] Regarding the length of each of the belt portions 41 along the second direction Y, the belt portion 41a extending along the second direction Y from near the center 33a of the straight portion S3 has the longest length, while the belt portions 41b extending along the second direction Y from near one end 33b of the straight portion S3 and the belt portions 41c extending along the second direction Y from near the other end 33c of the straight portion S3 each have the shortest lengths. Furthermore, the length of the belt portion 41 gradually decreases between belt portions 41a and 41b, and similarly, the length of the belt portion 41 also gradually decreases between belt portions 41a and 41c. Each of the belt portions 41 has the same width WL along the first direction X at equidistant positions L along the second direction Y from the straight portion S3.

[0093] In such a configuration example, one can also obtain... Figure 2 The example shown has the same effect.

[0094] Figure 8 It means Figure 2 A top view of another configuration example of the light guide element LG shown. Figure 8 The example shown is similar to Figure 2 Compared to the configuration example shown, the difference lies in that the distance R2 along the second direction Y from the center 33a of the straight section S3 to the curved section C3 is different from the distance R1 from one end 33b of the straight section S3 to the center 33a. The distance R1 from the center 33a of the straight section S3 to one end 33b of the straight section S3 is shorter than the distance R2 along the second direction Y from the center 33a of the straight section S3 to the curved section C3. The transparent substrate 30 has a generally semi-circular shape when viewed from above. Each of the strips 41 is arranged in the first direction X.

[0095] Regarding the length of each of the belt portions 41 along the second direction Y, the belt portion 41a extending along the second direction Y from near the center 33a of the straight portion S3 has the longest length, while the belt portions 41b extending along the second direction Y from near one end 33b of the straight portion S3 and the belt portions 41c extending along the second direction Y from near the other end 33c of the straight portion S3 each have the shortest lengths. Furthermore, the length of the belt portion 41 gradually decreases between belt portions 41a and 41b, and similarly, the length of the belt portion 41 also gradually decreases between belt portions 41a and 41c. Each of the belt portions 41 has the same width WL along the first direction X at equidistant positions L along the second direction Y from the straight portion S3.

[0096] Figure 9 It means Figure 2 A top view of another configuration example of the light guide element LG shown. Figure 9 The example shown is similar to Figure 2 Compared to the illustrated configuration, the transparent substrate 30 differs in that it has a straight portion S3 extending along the first direction X, a straight portion S31 extending along the second direction Y, and a curved portion C3 connecting the straight portions S3 and S31. The straight portion S3 has one end 33b connected to the curved portion C3 and another end 33c connected to the straight portion S31. The transparent substrate 30 has a fan-shaped form when viewed from above. The strip portions 41 are respectively arranged along the first direction X.

[0097] Regarding the length of each of the belt portions 41 along the second direction Y, the belt portion 41b extending along the second direction Y from near one end 33b of the straight portion S3 has the shortest length, while the belt portion 41c extending along the second direction Y from near the other end 33c of the straight portion S3 has the longest length. Furthermore, the length of the belt portion 41 gradually increases from belt portion 41b to belt portion 41c. Each belt portion 41 has the same width WL along the first direction X at equidistant positions L along the second direction Y from the straight portion S3.

[0098] Figure 10 It means Figure 2 A top view of another configuration example of the light guide element LG shown. Figure 10 The example shown is similar to Figure 2 The difference between the illustrated example and the cutout 33 is that the transparent substrate 30 has a cutout 33 located on the opposite side of the straight section S3. In the illustrated example, the cutout 33 is located between the curved section C31 connected to one end 33b of the straight section S3 and the curved section C32 connected to the other end 33c of the straight section S3. The cutout 33 has a straight section S32 along the first direction X.

[0099] As for the length of each of the belt portions 41 along the second direction Y, the length of the belt portion 41 extending toward the straight portion S32 is substantially fixed and substantially equal. The length of the belt portion 41d adjoining one end 33d of the straight portion S32 and extending toward the curved portion C31 and the length of the belt portion 41e adjoining the other end 33e of the straight portion S32 and extending toward the curved portion C32 are the largest. The length of the belt portion 41b extending from the vicinity of one end 33b of the straight portion S3 and the length of the belt portion 41c extending from the vicinity of the other end 33c of the straight portion S3 are the smallest. The length of the belt portion 41 gradually becomes shorter as it extends from the belt portion 41d toward the belt portion 41b. The length of the belt portion 41 gradually becomes shorter as it extends from the belt portion 41e toward the belt portion 41c. Each of the belt portions 41 has the same width WL along the first direction X at positions equidistant L from the straight portion S3 along the second direction Y, respectively.

[0100] In such a configuration example, the same effects as those of the configuration example shown in FIG. 1 can be obtained. Figure 2

[0101] As described above, according to the present embodiment, a display device capable of suppressing a decrease in display quality can be provided.

[0102] In the present embodiment, for example, the transparent substrate 10 corresponds to the first transparent substrate, the transparent substrate 20 corresponds to the second transparent substrate, the transparent substrate 30 corresponds to the third transparent substrate, the pixel electrode PE1 corresponds to the first pixel electrode, the pixel electrode PE2 corresponds to the second pixel electrode, the pixel electrode PE3 corresponds to the third pixel electrode, and the pixel electrode PE4 corresponds to the fourth pixel electrode.

[0103] Note that the embodiments of the present application have been described, but these embodiments are presented as examples and are not intended to limit the scope of the present application. These new embodiments can be implemented in various other forms and various omissions, substitutions, and changes can be made without departing from the spirit of the present application. These embodiments and modifications are included in the scope, spirit of the present application, and are included in the scope of the present application and equivalents thereof recited in the claims.​

Claims

1. A display device comprising: a first substrate comprising a first transparent substrate and a respective pixel electrode disposed in each of a plurality of pixels on the first transparent substrate; a second substrate comprising a second transparent substrate; a liquid crystal layer disposed between the first substrate and the second substrate, the liquid crystal layer comprising a stripe-shaped polymer and liquid crystal molecules; a plurality of light emitting elements arranged in a first direction; a third transparent substrate comprising a side surface facing the plurality of light emitting elements; and a transparent layer disposed between the second substrate and the third transparent substrate, the transparent layer having a lower refractive index than the third transparent substrate, wherein the third transparent substrate has a linear portion on the side of the plurality of light emitting elements and along the first direction and a curved portion connected to the linear portion in a plan view, the transparent layer comprises a plurality of band portions arranged in the first direction and extending along a second direction orthogonal to the first direction, each of the plurality of band portions comprises a first end portion on the side of the plurality of light emitting elements and a second end portion on the opposite side of the first end portion, the width of the first end portion is greater than the width of the second end portion, each of the plurality of band portions has the same width along the first direction at positions equally spaced along the second direction from the linear portion, the first transparent substrate and the second transparent substrate each have a curved portion overlapping the curved portion of the third transparent substrate in a plan view, the second transparent substrate has a linear portion overlapping the linear portion of the third transparent substrate in a plan view, the first transparent substrate has an extension portion extending along the second direction from the linear portion of the second transparent substrate in a plan view, and the light emitting elements overlap the extension portion in a plan view.

4. The display device according to claim 2, further comprising a reflection member disposed on a side surface of each of the first substrate, the second substrate, and the third transparent substrate along the curved portion. Each of the first end portions of the plurality of band portions is disposed on the same straight line along the first direction. A length along the second direction from a center of the linear portion to the curved portion is equal to a length from an end portion of the linear portion to the center. The curved portion is formed in a circular arc shape. A length along the second direction of each of the plurality of band portions becomes longer as it goes from the end portion of the linear portion toward the center of the linear portion. The length along the second direction from the center of the linear portion to the curved portion is different from the length from the end portion of the linear portion to the center. The length along the second direction from the center of the linear portion to the curved portion is shorter than the length from the end portion of the linear portion to the center. The length along the second direction from the center of the linear portion to the curved portion is longer than the length from the end portion of the linear portion to the center. The third transparent substrate has a cutout on the opposite side of the linear portion in the second direction. ​ ​ ​ 2. The display device according to claim 1, wherein ​ 3. The display device of claim 2, wherein, ​ ​ ​ ​ 5. The display device according to claim 1, wherein ​ 6. The display device according to claim 1, wherein ​ 7. The display device of claim 6, wherein, ​ 8. The display device according to claim 5, wherein ​ 9. The display device according to claim 1, wherein ​ 10. The display device of claim 9, wherein, ​ 11. The display device of claim 9, wherein, ​ 12. The display device of claim 1, wherein, ​ 13. The display device of claim 12, wherein, A length of the belt portion of the plurality of belt portions extending toward the cutout in the second direction is substantially equal.

14. The display device of claim 1, wherein, The first substrate further includes scan lines, signal lines intersecting the scan lines, and switching elements electrically connected to the scan lines and the signal lines, Each of the plurality of belt portions respectively overlaps the signal line.

15. The display device of claim 1, wherein, As the pixel electrode, a first pixel electrode and a second pixel electrode arranged in the second direction are included, The second pixel electrode is closer to the curved portion than the first pixel electrode, An area in which the first pixel electrode overlaps the transparent layer is larger than an area in which the second pixel electrode overlaps the transparent layer.

16. The display device of claim 1, wherein, As the pixel electrode, a third pixel electrode and a fourth pixel electrode arranged in the first direction are included at positions equidistant from the straight portion in the second direction, The third pixel electrode is located at a center of the first direction, The fourth pixel electrode is closer to the curved portion than the third pixel electrode, An area in which the third pixel electrode overlaps the transparent layer is equal to an area in which the fourth pixel electrode overlaps the transparent layer.

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