Semiconductor device and display device

• US 20110122108A1
• Filed: 11/19/2010
• Published: 05/26/2011
• Est. Priority Date: 11/20/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kurokawa, Yoshiyuki, Ikeda, Takayuki, Kozuma, Munehiro
• Granted Patent: US 8,686,972 B2
• Time in Patent Office: Days
• US Class Current: 345/207
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: H01L 27/14665 Imagers using a photoconductor layer
• CPC Class Codes: H04N 23/62 Control of parameters via user interfaces
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls
• CPC Class Codes: H04N 25/443 by reading pixels from selected 2D regions of the array, e.g. for windowing or digital zooming
• CPC Class Codes: H04N 25/70 SSIS architectures; Circuits associated therewith

Abstract

It is an object to perform imaging a high-resolution image in a display device including a photosensor regardless of the intensity of incident light on the photosensor. A display device including a display panel which is provided a photosensor and having a function of imaging by a change of the sensitivity of the photosensor in accordance with the incident light is provided. The sensitivity of the photosensor is improved when the intensity of the incident light is low, so that the imaging accuracy is improved; therefore, misperception of contact is prevented and an obtained image can be clear.

Claims

1. A semiconductor device comprising:

an input portion; and

a photosensor provided in the input portion,

wherein the semiconductor device is configured to change sensitivity of the photosensor in accordance with incident light on the photosensor by measuring the incident light.

2. The semiconductor device according to claim 1, wherein the sensitivity of the photosensor is changed by adjustment of voltage applied to the photosensor.

3. The semiconductor device according to claim 1,

wherein the photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the photosensor is changed by adjustment of voltage applied to the photodiode.

4. The semiconductor device according to claim 1,

wherein the photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the photosensor is changed by adjustment of voltage applied between a source and a drain of the transistor.

5. The semiconductor device according to claim 1,

wherein the photosensor has a function of performing reset operation, accumulating operation, and selecting operation, and

wherein the sensitivity of the photosensor is changed by adjustment of time for the accumulating operation.

6. A display device comprising:

a display panel; and

a photosensor provided in the display panel,

wherein the display device is configured to change sensitivity of the photosensor in accordance with incident light on the photosensor by measuring the incident light.

7. The display device according to claim 6, wherein the display panel includes a pixel and the photosensor is provided in the pixel.

8. The display device according to claim 6, wherein the display panel includes a pixel circuit including a plurality of pixels arranged in a matrix and the photosensor is provided outside the pixel circuit.

9. The display device according to claim 6, wherein the sensitivity of the photosensor is changed by adjustment of voltage applied to the photosensor.

10. The display device according to claim 6,

wherein the photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the photosensor is changed by adjustment of voltage applied to the photodiode.

11. The display device according to claim 6,

wherein the photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the photosensor is changed by adjustment of voltage applied between a source and a drain of the transistor.

12. The display device according to claim 6,

wherein the photosensor has a function of performing reset operation, accumulating operation, and selecting operation, and

wherein the sensitivity of the photosensor is changed by adjustment of time for the accumulating operation.

13. A display device comprising:

a display panel;

a pixel provided in the display panel; and

a photosensor provided in the pixel,

wherein the display device is configured to change sensitivity of the photosensor in accordance with incident light on the photosensor by performing a first imaging in the photosensor to generate an image of a detected object and by measuring the incident light based on the image, before performing a second imaging.

14. The display device according to claim 13, wherein the sensitivity of the photosensor is changed by adjustment of voltage applied to the photosensor.

15. The display device according to claims 13,

wherein the photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the photosensor is changed by adjustment of voltage applied to the photodiode.

16. The display device according to claims 13,

wherein the photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the photosensor is changed by adjustment of voltage applied between a source and a drain of the transistor.

17. The display device according to claims 13,

wherein the photosensor has a function of performing reset operation, accumulating operation, and selecting operation, and

wherein the sensitivity of the photosensor is changed by adjustment of time for the accumulating operation.

18. A display device comprising:

a display panel;

a pixel circuit provided in the display panel;

a first photosensor provided in the pixel circuit; and

a second photosensor provided outside the pixel circuit,

wherein the display device is configured to change sensitivity of the first photosensor in accordance with incident light detected with the second photosensor, before imaging is performed.

19. The display device according to claim 18, wherein the sensitivity of the first photosensor is changed by adjustment of voltage applied to the first photosensor.

20. The display device according to claims 18,

wherein the first photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the first photosensor is changed by adjustment of voltage applied to the photodiode.

21. The display device according to claims 18,

wherein the first photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the first photosensor is changed by adjustment of voltage applied between a source and a drain of the transistor.

22. The display device according to claims 18,

wherein the first photosensor has a function of performing reset operation, accumulating operation, and selecting operation, and

wherein the sensitivity of the first photosensor is changed by adjustment of time for the accumulating operation.

23. A semiconductor device comprising:

an input portion;

a photosensor provided in the input portion; and

an image processing portion configured to receive an output signal from the photosensor and supply a control signal to the photosensor so as to change sensitivity of the photosensor in accordance with incident light on the photosensor.

24. The semiconductor device according to claim 23, wherein the sensitivity of the photosensor is changed by adjustment of voltage applied to the photosensor.

25. The semiconductor device according to claim 23,

wherein the photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the photosensor is changed by adjustment of voltage applied to the photodiode.

26. The semiconductor device according to claim 23,

wherein the photosensor comprises a transistor and a photodiode electrically connected to a gate of the transistor, and

wherein the sensitivity of the photosensor is changed by adjustment of voltage applied between a source and a drain of the transistor.

27. The semiconductor device according to claim 23,

wherein the photosensor has a function of performing reset operation, accumulating operation, and selecting operation, and

wherein the sensitivity of the photosensor is changed by adjustment of time for the accumulating operation.