DISPLAY DEVICE

• US 20150015538A1
• Filed: 07/08/2014
• Published: 01/15/2015
• Est. Priority Date: 07/10/2013
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: TANAKA, Hiroshi, TERAMOTO, Masahiro
• Granted Patent: US 9,841,851 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

In a capacitive touch panel, edge regions of the panel display generally have poor accuracy of coordinate detection of a touch point as compared to the intermediate region of the panel display. A display device includes a plurality of first electrodes arranged at predetermined pitches and extending in a X-direction; and a plurality of second electrodes arranged at predetermined pitches and extending in a Y-direction, wherein both endmost first electrodes of the plurality of first electrodes have a smaller pitch than the other first electrodes, both endmost second electrodes of the plurality of second electrodes have a smaller pitch than the other second electrodes, and the display device is configured to detect a touch based on a capacitance variation at one or more of intersections of the plurality of first electrodes with the plurality of second electrodes.

Claims

1. A display device comprising:

a plurality of first electrodes arranged at predetermined pitches and extending in a first direction; and

a plurality of second electrodes arranged at predetermined pitches and extending in a second direction,

wherein the plurality of first electrodes and the plurality of second electrodes are arranged so that the first electrodes are overlapped with the second electrodes in plan view and spaced from the second electrodes in cross-sectional view,

both endmost first electrodes of the plurality of first electrodes have a smaller pitch than the other first electrodes,

both endmost second electrodes of the plurality of second electrodes have a smaller pitch than the other second electrodes, and

the display device is configured to detect a touch based on a capacitance variation at one or more of intersections of the plurality of first electrodes with the plurality of second electrodes.

2. The display device according to claim 1, being configured to correct touch response values of both the endmost first electrodes and both the endmost second electrodes and configured to calculate a centroid of touch response values to obtain a touch detection coordinate.

3. The display device according to claim 2, being configured to subject the touch detection coordinate to a peripheral coordinate correction.

4. The display device according to claim 1, being configured to make a calibration for each of the intersections of the plurality of first electrodes with the plurality of second electrodes.

5. The display device according to claim 1,

wherein both the endmost first electrodes have a smaller width than the other first electrodes, and

both the endmost second electrodes have a smaller width than the other second electrodes.

6. The display device according to claim 1, wherein the distance between each of the endmost second electrodes and the second electrode next to the endmost second electrode is equal to the distance between each adjacent pair of the second electrodes other than the endmost second electrodes.

7. The display device according to claim 1, wherein the distance between each of the endmost second electrodes and the second electrode next to the endmost second electrode is smaller than the distance between each adjacent pair of the second electrodes other than the endmost second electrodes.

8. The display device according to claim 1, further comprising:

a first substrate on which pixels are formed; and

a second substrate on which a color filter is formed,

wherein the plurality of first electrodes are formed between the first substrate and the second substrate.

9. The display device according to claim 7, further comprising a liquid crystal layer disposed between the first substrate and the second substrate,

wherein the plurality of second electrodes are formed on a surface of the second substrate opposite to the liquid crystal layer.

10. The display device according to claim 1,

wherein portions of the first and second electrodes not overlapped with each other in plan view have a rhombic shape,

both the endmost first electrodes have a smaller width than the other first electrodes, and

both the endmost second electrodes have a smaller width than the other second electrodes.

11. The display device according to claim 10, further comprising:

a display panel on which pixels are formed; and

a surface glass,

wherein the plurality of first electrodes and the plurality of second electrodes are formed between the display panel and the surface glass.

12. The display device according to claim 11, wherein the display panel is a liquid crystal display panel.

13. A display device comprising:

a first substrate;

a second substrate; and

a liquid crystal layer sandwiched between the first substrate and the second substrate,

wherein the first substrate includes a plurality of first electrodes arranged at predetermined pitches and extending in a first direction,

the second substrate includes a plurality of second electrodes arranged at predetermined pitches and extending in a second direction,

the plurality of first electrodes function as a common electrode for image display,

the plurality of first electrodes and the plurality of second electrodes are arranged so that the first electrodes are overlapped with the second electrodes in plan view and spaced from the second electrodes in cross-sectional view,

both endmost first electrodes of the plurality of first electrodes have a smaller pitch than the other first electrodes,

both endmost second electrodes of the plurality of second electrodes have a smaller pitch than the other second electrodes, and

the display device is configured to detect a touch based on a capacitance variation at one or more of intersections of the plurality of first electrodes with the plurality of second electrodes.

14. The display device according to claim 13, being configured to correct touch response values of both the endmost first electrodes and both the endmost second electrodes and configured to calculate a centroid of touch response values to obtain a touch detection coordinate.

15. The display device according to claim 14, being configured to subject the touch detection coordinate to a peripheral coordinate correction.

16. The display device according to claim 13, being configured to make a calibration for each of the intersections of the plurality of first electrodes with the plurality of second electrodes.

17. The display device according to claim 13, wherein

both the endmost first electrodes have a smaller width than the other first electrodes, and

both the endmost second electrodes have a smaller width than the other second electrodes.

18. The display device according to claim 13, wherein the distance between each of the endmost second electrodes and the second electrode next to the endmost second electrode is equal to the distance between each adjacent pair of the second electrodes other than the endmost second electrodes.

19. The display device according to claim 13, wherein the distance between each of the endmost second electrodes and the second electrode next to the endmost second electrode is smaller than the distance between each adjacent pair of the second electrodes other than the endmost second electrodes.