DISPLAY DEVICE

• US 20150220212A1
• Filed: 01/30/2015
• Published: 08/06/2015
• Est. Priority Date: 02/03/2014
• Status: Abandoned Application

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Jinhwan
• Application Number:
  US14/609,760
• Publication Number:
  US 20150220212A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/13471 in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells G02F1/13475 takes precedence
• CPC Class Codes: G02F 1/294 Variable focal length devices
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A display device that includes: a light source that emits a visible light and a detection light having a wavelength range different from a wavelength range of the visible light; an optical member disposed on the light source; a display panel disposed on the optical member and including a pixel configured to receive the visible light to generate an image; a liquid crystal lens that includes a liquid crystal layer and first electrodes, wherein the first electrodes form a first lens unit, the first lens unit having a first focal point located in the optical member to condense the detection light exiting from the display panel to an input device disposed outside the display panel; and a light sensor that receives the detection light reflected by the input device to sense an external input.

Claims

1. A display device, comprising:

a light source that emits a visible light and a detection light having a wavelength range different from a wavelength range of the visible light;

an optical member disposed on the light source;

a display panel disposed on the optical member and including a pixel configured to receive the visible light to generate an image;

a liquid crystal lens that includes a liquid crystal layer and first electrodes, wherein the first electrodes form a first lens unit, the first lens unit having a first focal point located in the optical member to condense the detection light exiting from the display panel to an input device disposed outside the display panel; and

a light sensor that receives the detection light reflected by the input device to sense an external input.

2. The display device of claim 1, wherein the first lens unit has a numerical aperture of about 0.3 or more and the numerical aperture satisfies the following equation, NA=sin(θ

_T), where θ

_T is a maximum incident angle of the first lens unit and is smaller than about 90 degrees, and NA denotes the numerical aperture.

3. The display device of claim 2, wherein the first lens unit has a width and a first focal length, and the width and the first focal length satisfy the following equation, W/2K=tan(θ

_T), where W denotes the width and K denotes the first focal length.

4. The display device of claim 3, wherein the optical member comprises a prism sheet and a diffusion sheet disposed on the prism sheet, and the first focal point is located on a diffusion surface of the diffusion sheet.

5. The display device of claim 1, wherein the liquid crystal lens further comprises second electrodes that form a second lens unit having a second focal point located in the pixel.

6. The display device of claim 5, wherein the first electrodes are spaced apart from the second electrodes and the liquid crystal layer is disposed between the first electrodes and the second electrodes.

7. The display device of claim 5, wherein the pixel comprises:

a liquid crystal capacitor;

a thin film transistor that applies a pixel voltage to the liquid crystal capacitor; and

a color filter overlapped with the liquid crystal capacitor.

8. The display device of claim 7, wherein the second focal point is located in the color filter.

9. The display device of claim 8, wherein each of the first and second lens units is a Fresnel zone plate lens.

10. The display device of claim 1, wherein the light sensor comprises a photo-transistor configured to generate a photocurrent corresponding to an amount of the received detection light.

11. A display device, comprising:

a light source that emits a visible light in display periods and an infrared light in detection periods;

an optical member disposed on the light source;

a display panel disposed on the optical member and configured to generate a two-dimensional image in a two-dimensional mode display period of the display periods and a three-dimensional image in a three-dimensional mode display period of the display periods;

a light sensor disposed on the optical member and configured to receive a portion of the infrared light reflected by an input device to sense an external input; and

a liquid crystal lens that includes a liquid crystal layer, first electrodes and second electrodes, wherein the first electrodes form a first lens unit having a first focal point located in the optical member, and the second electrodes form a second lens unit having a second focal point located in the display panel.

12. The display device of claim 11, wherein the first electrodes are spaced apart from the second electrodes and the liquid crystal layer is disposed between the first electrodes and the second electrodes.

13. The display device of claim 12, wherein the first electrodes have a same electric potential as the second electrodes during the two-dimensional mode display period.

14. The display device of claim 11, wherein the optical member comprises a prism sheet and a diffusion sheet disposed on the prism sheet, and the first focal point is located on a diffusion surface of the diffusion sheet.

15. The display device of claim 14, wherein the display panel comprises:

a first substrate;

a second substrate spaced apart from the first substrate; and

a plurality of pixels disposed between the first and second substrates, and at least one of the pixels comprises;

a liquid crystal capacitor;

a thin film transistor that applies a pixel voltage to the liquid crystal capacitor; and

a color filter overlapped with the liquid crystal capacitor.

16. The display device of claim 15, wherein the second focal point is located in the color filter.

17. The display device of claim 14, wherein the light sensor comprises a photo transistor configured to generate a photocurrent corresponding to an amount of the received detection light.

18. The display device of claim 17, wherein the photo-transistor is disposed on the first substrate.

19. The display device of claim 11, wherein each of the first and second lens units is a Fresnel zone plate lens.

20. The display device of claim 19, wherein the first lens unit has a numerical aperture of about 0.3 or more and the numerical aperture satisfies the following equation, NA=sin(θ

_T), where θ

_T is a maximum incident angle of the first lens unit and is smaller than about 90 degrees, and NA denotes the numerical aperture.