Display devices

Patent metadata

Field	Value
Publication number	US-12158643-B2
Application number	US-202318250988-A
Country	US
Kind code	B2
Filing date	Mar 31, 2023
Priority date	Nov 14, 2022
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

The present disclosure discloses a display device including a display panel and a dimming apparatus located on a light-emitting side of the display panel. The dimming apparatus includes a cholesteric liquid crystal layer; when the display device is in an anti-peek mode, the cholesteric liquid crystal layer is in a reflective state.

First claim

What is claimed is:

1. A display device, operable in an anti-peek mode, comprising:
a display panel; and
a dimming apparatus, located on a light-emitting side of the display panel, wherein the dimming apparatus comprises a cholesteric liquid crystal layer which comprises cholesteric liquid crystals operable in a reflective state;
wherein upon a condition that the cholesteric liquid crystal layer is in the reflective state while the display device is in the anti-peek mode, a maximum of a reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle less than or equal to half of a visible angle in the anti-peek mode, is greater than a maximum of a reflectivity of the cholesteric liquid crystal layer to visible light with an incident angle less than or equal to half of the visible angle in the anti-peek mode; and a maximum of a reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle greater than half of the visible angle in the anti-peek mode, is less than a maximum of a reflectivity of the cholesteric liquid crystal layer to visible light with an incident angle greater than half of the visible angle in the anti-peek mode, where the incident angle is defined as an included angle between an incident direction and a helical axis of the cholesteric liquid crystals of the cholesteric liquid crystal layer in the reflective state, and the helical axis is parallel to a thickness direction of the cholesteric liquid crystal layer.

2. The display device of claim 1 , wherein half of the visible angle in the anti-peek mode ranges between 0 degrees and 30 degrees.

3. The display device of claim 1 , wherein the maximum of the reflectivity of the cholesteric liquid crystal layer in the reflective state to the visible light with the incident angle less than or equal to half of the visible angle in the anti-peek mode is less than or equal to 15%.

4. The display device of claim 1 , wherein the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light perpendicularly entering the cholesteric liquid crystal layer with a wavelength ranging between 760 nm and 900 nm is a maximum.

5. The display device of claim 4 , wherein a screw pitch of the cholesteric liquid crystals in the reflective state ranges between 460 nm and 600 nm.

6. The display device of claim 5 , wherein the cholesteric liquid crystals comprise chiral additives ranging between 10% and 15% by weight.

7. The display device of claim 1 , wherein a reflectivity of the cholesteric liquid crystal layer in the reflective state to green light with an incident angle greater than half of the visible angle in the anti-peek mode, is greater than a reflectivity of the cholesteric liquid crystal layer to blue light with an incident angle greater than half of the visible angle in the anti-peek mode.

8. The display device of claim 1 , further operable in a sharing mode, wherein the cholesteric liquid crystal layer further has a transparent state; and
wherein the cholesteric liquid crystal layer is in the transparent state when the display device is in the sharing mode.

9. The display device of claim 8 , further operable in an enhanced sharing mode, wherein the cholesteric liquid crystal layer further has a fog state; and
wherein the cholesteric liquid crystal layer is in the fog state when the display device is in the enhanced sharing mode.

10. The display device of claim 9 , wherein the cholesteric liquid crystal layer is located between a first electrode layer and a second electrode layer of the dimming apparatus;
when the cholesteric liquid crystal layer is in the reflective state, a first voltage difference is defined between the first electrode layer and the second electrode layer;
when the cholesteric liquid crystal layer is in the transparent state, a second voltage difference is defined between the first electrode layer and the second electrode layer;
when the cholesteric liquid crystal layer is in the fog state, a third voltage difference is defined between the first electrode layer and the second electrode layer; and
wherein an absolute value of the first voltage difference is less than an absolute value of the third voltage difference, and the absolute value of the third voltage difference is less than an absolute value of the second voltage difference.

11. A display device, operable in an anti-peek mode, wherein the display device comprises a liquid crystal display panel and a dimming apparatus located on a light-emitting side of the liquid crystal display panel, and the dimming apparatus comprises:
a cholesteric liquid crystal layer, comprising cholesteric liquid crystals operable in a reflective state;
wherein upon a condition that the cholesteric liquid crystal layer is in the reflective state while the display device is in the anti-peek mode, a maximum of a reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle less than or equal to half of a visible angle in the anti-peek mode, is greater than a maximum of a reflectivity of the cholesteric liquid crystal layer to visible light with an incident angle less than or equal to half of the visible angle in the anti-peek mode; and a maximum of a reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle greater than half of the visible angle in the anti-peek mode, is less than a maximum of a reflectivity of the cholesteric liquid crystal layer to visible light with an incident angle greater than half of the visible angle in the anti-peek mode, where the incident angle is defined as an included angle between an incident direction and a helical axis of the cholesteric liquid crystals of the cholesteric liquid crystal layer in the reflective state, and the helical axis is parallel to a thickness direction of the cholesteric liquid crystal layer.

12. The display device of claim 11 , further comprising a backlight module configured to emit backlight, wherein the dimming apparatus is located between the liquid crystal display panel and the backlight module.

13. The display device of claim 11 , wherein half of the visible angle in the anti-peek mode ranges between 0 degrees and 30 degrees.

14. The display device of claim 11 , wherein the maximum of the reflectivity of the cholesteric liquid crystal layer in the reflective state to the visible light with the incident angle less than or equal to half of the visible angle in the anti-peek mode is less than or equal to 15%.

15. The display device of claim 11 , wherein the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light perpendicularly entering the cholesteric liquid crystal layer with a wavelength ranging between 760 nm and 900 nm is a maximum.

16. The display device of claim 15 , wherein a screw pitch of the cholesteric liquid crystals in the reflective state ranges between 460 nm and 600 nm.

17. The display device of claim 16 , wherein the cholesteric liquid crystals comprise chiral additives ranging between 10% and 15% by weight.

18. The display device of claim 11 , wherein a reflectivity of the cholesteric liquid crystal layer in the reflective state to green light with an incident angle greater than half of the visible angle in the anti-peek mode, is greater than a reflectivity of the cholesteric liquid crystal layer to blue light with an incident angle greater than half of the visible angle in the anti-peek mode.

Assignees

• Wuhan China Star Optoelectronics Technology Co Ltd

Inventors

• Deng Qian
• Cheng Wei

Classifications

• G02F1/1347

  Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells · CPC title

• G02F1/13718

  based on a change of the texture state of a cholesteric liquid crystal · CPC title

• G02F1/1334

  based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals · CPC title

• G02F1/13

  based on liquid crystals, e.g. single liquid crystal display cells · CPC title

• G02F1/1323 Primary

  Arrangements for providing a switchable viewing angle · CPC title