US-12625317-B2 - Display device

Abstract

According to one embodiment, a display device includes a display panel, a transparent substrate, a fixing member, and a first light source unit. The transparent substrate has a first main face, a first incident face which is a first side face in contact with the first main face at a first edge, and a first non-incident face which is a second side face in contact with the first main face at a second edge. A shape of the first incident face and a shape of the first non-incident face are different from each other.

Inventors

• Kentaro Okuyama
• Yuuji Oomori
• Makoto MIYAO

Assignees

• JAPAN DISPLAY INC.

Dates

Publication Date

20260512

Application Date

20240927

Priority Date

20230929

Claims (10)

1. 1 . A display device comprising: a display panel having a display area where an image is displayed and external light is transmitted; a transparent substrate overlapping with the display area, and having a first main face which has a first edge and a second edge, a first incident face which is a first side face in contact with the first main face at the first edge, and a first non-incident face which is a second side face in contact with the first main face at the second edge; a fixing member located between the transparent substrate and the display panel and fixing the display panel to the transparent substrate; and a first light source unit which is opposed to the first incident face of the transparent substrate and is configured to apply light to the first incident face, wherein the transparent substrate further has a first corner portion located at the first edge and a second corner portion located at the second edge, the second corner portion has a chamfered shape, the first corner portion is sharper than the second corner portion, the transparent substrate further has a fifth corner portion located at the fifth edge with which the first incident face and the first non-incident face are in contact, and the fifth corner portion is sharper than the second corner portion.
2. 2 . The display device of claim 1 , wherein a surface of the second corner portion is a curved surface which protrudes outside the transparent substrate or a sloped surface which is sloped from each of the first main face and the first non-incident face.
3. 3 . The display device of claim 1 , further comprising: a second light source unit, wherein the transparent substrate further has a second incident face which is a third side face in contact with the first main face at the third edge and which is located on a side opposite to the first incident face, the first non-incident face is located between the first incident face and the second incident face, the second light source unit is opposed to the second incident face of the transparent substrate to apply light to the second incident face, the transparent substrate further has a third corner portion located at the third edge, and the third corner portion is sharper than the second corner portion.
4. 4 . The display device of claim 3 , wherein the transparent substrate further has a second non-incident face which is a fourth side face in contact with the first main face at the fourth edge and which is located on a side opposite to the first non-incident face, and a fourth corner portion located at the fourth edge, the fourth corner portion has a chamfered shape, and the third corner portion is sharper than the fourth corner portion.
5. 5 . The display device of claim 1 , wherein the transparent substrate further has a first top portion located at a first vertex with which the first edge, the second edge, and the fifth edge are in contact, and the first top portion has a chamfered shape.
6. 6 . The display device of claim 1 , wherein the transparent substrate further has a second main face which is in contact with the first incident face at the sixth edge and is in contact with the first non-incident face at the seventh edge and which is located on a side opposite to the first main face, a sixth corner portion located at the sixth edge, and a seventh corner portion located at the seventh edge, the seventh corner portion has a chamfered shape, and the sixth corner portion is sharper than the seventh corner portion.
7. 7 . The display device of claim 6 , wherein the transparent substrate further has a second top portion located at a second vertex with which the fifth edge, the sixth edge, and the seventh edge are in contact, and the second top portion has a chamfered shape.
8. 8 . The display device of claim 1 , wherein a shape of the first incident face and a shape of the first non-incident face are different from each other.
9. 9 . The display device of claim 8 , wherein the first incident face is a fracture surface.
10. 10 . The display device of claim 8 , wherein surface roughness on the first non-incident face is larger than surface roughness on the first incident face.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2023-170051, filed Sep. 29, 2023, the entire contents of which are incorporated herein by reference. FIELD Embodiments described herein relate generally to a display device. BACKGROUND Recently, display devices comprising a polymer dispersed liquid crystal (hereinafter referred to as “PDLC”) panel capable of switching a diffusing state of diffusing incident light and a transmitting state of allowing the incident light to be transmitted, displaying an image, and allowing a background to be transmitted and the image to be visually recognized, have been proposed. In such a display device, one frame period includes sub-frame periods, and multi-color display is implemented by displaying the image while changing a display color in each of the sub-frame period. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a configuration example of a display device of a first embodiment. FIG. 2 is a developed cross-sectional view showing the display device shown in FIG. 1. FIG. 3 is a diagram showing main constituent elements of the display device shown in FIG. 1. FIG. 4A is a diagram showing a part of a display panel of the display device, schematically showing a liquid crystal layer in a transparent state. FIG. 4B is a diagram showing a part of the display panel, schematically showing the liquid crystal layer in a scattered state. FIG. 5A is a developed cross-sectional view showing the display panel in a case where when the liquid crystal layer is in a transparent state and a transparent substrate, together with a light emitting element. FIG. 5B is a developed cross-sectional view showing the display panel in a case where when the liquid crystal layer is in a scattered state and the transparent substrate, together with a light emitting element. FIG. 6 is a graph showing scattering characteristic of the liquid crystal layer. FIG. 7A is a diagram showing an outline of one-line inversion drive. FIG. 7B is a diagram showing an outline of two-line inversion drive. FIG. 7C is a diagram showing an outline of frame-inversion drive. FIG. 8 is a chart showing an example of a common voltage and a source line voltage in a display drive. FIG. 9 is a chart showing an example of a common voltage and a source line voltage in a transparent drive. FIG. 10 is a chart showing another example of the common voltage and the source line voltage in the transparent drive. FIG. 11 is a diagram showing a configuration example of a timing controller shown in FIG. 3. FIG. 12 is an exploded perspective view showing the display panel and the cover panel of the display device, illustrating a state in which the display panel is to be adhered to the cover panel. FIG. 13 is a cross-sectional view showing the display device. FIG. 14 is a developed perspective view showing the transparent substrate of the first embodiment. FIG. 15 is a cross-sectional view showing the transparent substrate in FIG. 14 along XV-XV line. FIG. 16 is a cross-sectional view showing the transparent substrate in FIG. 14 along XVI-XVI line. FIG. 17 is a cross-sectional view showing the transparent substrate in FIG. 14 along XVII-XVII line. FIG. 18 is a cross-sectional view showing the transparent substrate in FIG. 14 along XVIII-XVIII line. FIG. 19 is an enlarged perspective view showing a part of the transparent substrate in FIG. 14. FIG. 20 is a cross-sectional view showing the transparent substrate of a modified example of the first embodiment. FIG. 21 is a cross-sectional view showing a display device of a second embodiment. FIG. 22 is a plan plan view showing a cover panel, first light source units, and second light source units of the second embodiment. FIG. 23 is a cross-sectional view showing the transparent substrate of the second embodiment. FIG. 24 is a cross-sectional view showing the transparent substrate of modified example 1 of the second embodiment. FIG. 25 is a cross-sectional view showing the transparent substrate of modified example 2 of the second embodiment. FIG. 26 is a cross-sectional view showing a display device of a third embodiment. FIG. 27 is a plan plan view showing a cover panel, a first light source unit, and an optical member in the display device of the third embodiment. FIG. 28 is a perspective view showing a part of the optical member of the third embodiment. DETAILED DESCRIPTION In general, according to one embodiment, there is provided a display device comprising: a display panel having a display area where an image is displayed and external light is transmitted; a transparent substrate overlapping with the display area, and having a first main face which has a first edge and a second edge, a first incident face which is a first side face in contact with the first main face at the first edge, and a first non-incident face which is a second side face in contact with the first main face at the seco