TOUCH PANEL, DISPLAY DEVICE, AND ELECTRONIC DEVICE

• US 20100156850A1
• Filed: 12/16/2009
• Published: 06/24/2010
• Est. Priority Date: 12/24/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KUROKAWA, Yoshiyuki
• Granted Patent: US 9,035,908 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

It is an object to provide a touch panel with high precision, high-speed operation, and low power consumption, which is caused by reduction of power consumption in an A/D converter circuit is reduced. In the touch panel in which a photo sensor is included in a pixel and an A/D converter circuit is provided every one column or a plurality of columns of the pixels, a control signal of the A/D converter circuit is sequentially supplied by a shift register included in an ADC (A/D converter circuit) control circuit, and respective periods when the plurality of A/D converter circuits operates are not overlap with each other. Accordingly, the number of A/D converter circuits which operate at the same time is decreased, and instantaneous power consumption in the A/D converter circuit is decreased.

Claims

1. A touch panel comprising:

a pixel circuit including a plurality of pixels, each pixel including a photo sensor; and

a photo sensor signal line reading circuit for taking an output signal of the photo sensor, the photo sensor signal line reading circuit including a plurality of A/D converter circuits and an ADC control circuit;

wherein the plurality of A/D converter circuits are provided every one column or every a plurality of columns of the plurality of pixels; and

wherein the ADC control circuit includes a shift register configured to sequentially supply control signals to the plurality of A/D converter circuits.

2. A display device comprising the touch panel according to claim 1, wherein each of the plurality of pixels includes a display element.

3. A display device according to claim 2, wherein the display element comprises a thin film transistor.

4. An electronic device wherein the touch panel according to claim 1 is used in a display portion.

5. An electronic device according to claim 4, the electronic device is one of a monitor, a portable game machine, and a mobile phone.

6. A touch panel comprising:

a pixel circuit including a plurality of pixels, each pixel including a photo sensor; and

a photo sensor signal line reading circuit for taking an output signal of the photo sensor, the photo sensor signal line reading circuit including a plurality of A/D converter circuits and an ADC control circuit;

wherein the plurality of A/D converter circuits are provided every one column or every a plurality of columns of the plurality of pixels; and

wherein during a period when one of the plurality of A/D converter circuits operates, at least one of the other A/D converter circuits does not operate.

7. A display device comprising the touch panel according to claim 6, wherein each of the plurality of pixels includes a display element.

8. A display device according to claim 7, wherein the display element comprises a thin film transistor.

9. An electronic device wherein the touch panel according to claim 6 is used in a display portion.

10. An electronic device according to claim 9, the electronic device is one of a monitor, a portable game machine, and a mobile phone.

11. A touch panel comprising:

a pixel circuit including a plurality of pixels, each pixel including a photo sensor; and

a photo sensor signal line reading circuit for taking an output signal of the photo sensor, the photo sensor signal line reading circuit including a plurality of A/D converter circuits and an ADC control circuit;

wherein the plurality of A/D converter circuits are provided every one column or every a plurality of columns of the plurality of pixels; and

wherein each of the plurality of A/D converter circuits has a comparator circuit; and

wherein during a period when one comparator circuit operates, at least another one comparator circuit does not operate.

12. A display device comprising the touch panel according to claim 11, wherein each of the plurality of pixels includes a display element.

13. A display device according to claim 12, wherein the display element comprises a thin film transistor.

14. An electronic device wherein the touch panel according to claim 11 is used in a display portion.

15. An electronic device according to claim 14, the electronic device is one of a monitor, a portable game machine, and a mobile phone.

16. A touch panel comprising:

a pixel circuit including a plurality of pixels over a substrate, each pixel including a photo sensor; and

a photo sensor signal line reading circuit for taking an output signal of the photo sensor over the substrate, the photo sensor signal line reading circuit including a plurality of A/D converter circuits and an ADC control circuit;

wherein the plurality of A/D converter circuits are provided every one column or every a plurality of columns of the plurality of pixels; and

wherein the ADC control circuit includes a shift register configured to sequentially supply control signals to the plurality of A/D converter circuits.

17. A display device comprising the touch panel according to claim 16, wherein each of the plurality of pixels includes a display element.

18. A display device according to claim 17, wherein the display element comprises a thin film transistor.

19. An electronic device wherein the touch panel according to claim 16 is used in a display portion.

20. An electronic device according to claim 19, the electronic device is one of a monitor, a portable game machine, and a mobile phone.