TOUCH SENSOR AND METHOD FOR DRIVING THE SAME AND DISPLAY DEVICE

• US 20110043473A1
• Filed: 08/23/2010
• Published: 02/24/2011
• Est. Priority Date: 08/24/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kozuma, Munehiro
• Granted Patent: US 9,542,022 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

It is an object to suppress malfunction of a touch sensor, a touch panel, and a device using them by accurate determination whether inputting is performed or not. In addition, it is also an object to enhance the response speed of the determination. A touch panel including a plurality of pixels having photosensors and an image processing portion are included. The photosensor forms a contact image of a portion of an object which touches the touch panel. The image processing portion calculates the area of the contact portion from color data of the contact image and determines on the basis of the area whether inputting to the touch panel is performed or not.

Claims

1. A touch sensor comprising:

an input portion including a plurality of photosensors; and

an image processing portion,

wherein the photosensor is configured to form a contact image of a portion of an object which touches the input portion,

wherein the image processing portion is configured to calculate an area of a contact portion from color data of the contact image, and

wherein the image processing portion is configured to detect an input to the input portion based on the area.

2. A touch sensor according to claim 1, wherein a threshold value is set for an area and an input to a touch panel is detected depending on the result of the comparison between the threshold value and the area.

3. A touch sensor according to claim 1, wherein a plurality of threshold values are set for an area and an input to a touch panel is detected in multi-level depending on the result of the comparison between the threshold values and the area.

4. A display device comprising:

a touch panel including a plurality of pixels having photosensors; and

an image processing portion,

wherein the photosensor is configured to form a contact image of a portion where a touch panel is touched by an object,

wherein the image processing portion is configured to calculate an area of a contact portion from color data of the contact image, and

wherein the image processing portion is configured to detect an input to the touch panel based on the area.

5. A display device according to claim 4, wherein a threshold value is set for an area and an input to the touch panel is detected depending on the result of the comparison between the threshold value and the area.

6. A display device according to claim 4, wherein a plurality of threshold values are set for an area and an input to the touch panel is detected in multi-level depending on the result of the comparison between the area and the threshold values.

7. A display device comprising:

a touch panel including a plurality of pixels having photosensors; and

an image processing portion including an input process portion and a response process portion,

wherein the photosensor is configured to form a contact image of a portion where a touch panel is touched by an object,

wherein the input process portion is configured to calculate an area of a contact portion from color data of the contact image, and

wherein the response process portion is configured to detect an input to the touch panel based on the area.

8. A display device according to claim 7, wherein a threshold value is set for an area and an input to the touch panel is detected depending on the result of the comparison between the threshold value and the area.

9. A display device according to claim 7, wherein a plurality of threshold values are set for an area and an input to the touch panel is detected in multi-level depending on the result of the comparison between the area and the threshold values.

10. A display device comprising:

a touch panel including a plurality of pixels having photosensors; and

an image processing portion including an input process portion and a response process portion,

wherein the photosensor is configured to form a contact image of a portion where a touch panel is touched by an object,

wherein the input process portion is configured to calculate an area of a contact portion by subjecting color data of the contact image to a converting process from RGB value to HSV value, a binarizing process, a noise removing process, and a labeling process, and

wherein the response process portion is configured to detect, an input to the touch panel based on the area.

11. A display device according to claim 10, wherein a threshold value is set for an area and an input to the touch panel is detected depending on the result of the comparison between the threshold value and the area.

12. A display device according to claim 10, wherein a plurality of threshold values are set for an area and an input to the touch panel is detected in multi-level depending on the result of the comparison between the area and the threshold values.

13. A method for driving a touch sensor comprising:

forming a contact image of a portion of an object which touches an input portion including a plurality of photosensors;

calculating an area of a contact portion from color data of the contact image by an image processing portion; and

detecting an input to the input portion based on the area by the image processing portion.

14. The method for driving a touch sensor according to claim 13, wherein a threshold value is set for an area and an input to a touch panel is detected depending on the result of the comparison between the threshold value and the area.

15. The method for driving a touch sensor according to claim 13, wherein a plurality of threshold values are set for an area and an input to a touch panel is detected in multi-level depending on the result of the comparison between the threshold values and the area.