Display device and method for adjusting its display brightness

1. A display device, comprising:

a display screen; and

an ambient light sensor in the display screen;

wherein the ambient light sensor comprises a photodeformable element comprising a photodeformable material layer; and

the photodeformable element is configured to deform in response to a change in ambient light to obtain output of the ambient light sensor;

the display device is configured to adjust display brightness of the display screen according to the output of the ambient light sensor;

the display device further comprises a driving signal circuit and a metal wire, wherein one end of the photodeformable element is connected with the driving signal circuit, and the other end of the photodeformable element is deformed to electrically connect or disconnect with the metal wire in response to the change in ambient light.

2. The display device according to claim 1 , wherein the photodeformable element further comprises a conducting layer which is configured to transmit an electrical signal, and the photodeformable element is a laminate of the conducting layer and the photodeformable material layer.

3. The display device according to claim 1 , wherein:

the photodeformable element is electrically connected with the metal wire in a case that the photodeformable element senses the ambient light and deforms, or

the photodeformable element is disconnected with the metal wire in a case that the photodeformable element senses the ambient light and deforms.

4. The display device according to claim 3 , further comprising a signal acquisition circuit, wherein the signal acquisition circuit is connected with the metal wire, and configured to acquire information outputted from the ambient light sensor.

5. The display device according to claim 4 , further comprising a controller, wherein the controller is configured to receive the information outputted from the ambient light sensor, and to control display brightness of the display screen.

6. The display device according to claim 5 , wherein the controller is configured to adjust the display brightness of the display screen according to a piecewise function.

7. The display device according to claim 1 , wherein the display screen comprises a first substrate and a second substrate, and

both the ambient light sensor and the metal wire are arranged on the first substrate or the second substrate, or one of the ambient light sensor and the metal wire is arranged on the first substrate and the other is arranged on the second substrate.

8. The display device according to claim 1 , wherein the photodeformable element is deformed in response to at least one of ultraviolet light, visible light and infrared light.

9. The display device according to claim 8 , wherein the photodeformable element is sensitive to ultraviolet light, and the photodeformable material layer comprises a photodeformable liquid crystal elastomer having an azobenzene photoresponsive group.

10. The display device according to claim 8 , wherein the photodeformable element is sensitive to visible light, and the photodeformable material layer comprises a liquid crystal polymer having an azotolane long conjugated group.

11. The display device according to claim 8 , wherein the photodeformable element is sensitive to infrared light, and the photodeformable material layer comprises a composite material of an azobenzene liquid crystal polymer and rare earth luminescent nanoparticles.

12. The display device according to claim 2 , wherein the display device is configured to adjust display brightness of the display screen according to the output of the ambient light sensor.

13. The display device according to claim 12 , further comprising a driving signal circuit and a metal wire, wherein one end of the photodeformable element is connected with the driving signal circuit, and the other end of the photodeformable element is deformed to electrically connect or disconnect with the metal wire in response to the change in ambient light.

14. The display device according to claim 13 , wherein:

the photodeformable element is electrically connected with the metal wire in a case that the photodeformable element senses the ambient light and deforms, or

the photodeformable element is disconnected with the metal wire in a case that the photodeformable element senses the ambient light and deforms.

15. A method for adjusting display brightness of a display device, comprising:

sensing ambient light by a photodeformable element in an ambient light sensor, wherein the photodeformable element has a photodeformable material layer which is deformed in response to a change in ambient light to obtain output of the ambient light sensor; and

adjusting display brightness of a display screen in the display device according to the output of the ambient light sensor;

wherein the display device further comprises a driving signal circuit and a metal wire; and one end of the photodeformable element is fixedly connected to the driving signal circuit, and the other end of the photodeformable element is deformed in response to the change in ambient light to electrically connect or disconnect with the metal wire for obtaining the output of the ambient light sensor.

16. The method according to claim 15 , wherein the photodeformable element further comprises a conducting layer which is laminated and connected with the photodeformable material layer, and deformation of the photodeformable material layer causes deformation of the conducting layer so that the output of the ambient light sensor is obtained.

17. The method according to claim 15 , wherein:

the photodeformable element is electrically connected with the metal wire in a case that the photodeformable element senses the ambient light and deforms, or

the photodeformable element is disconnected with the metal wire in a case that the photodeformable element senses the ambient light and deforms.