DISPLAY DEVICE WITH TOUCH SENSOR

• US 20100182273A1
• Filed: 03/25/2009
• Published: 07/22/2010
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Takama, Daisuke, Kida, Yoshitoshi, Noguchi, Koji
• Granted Patent: US 8,786,557 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 2201/12 electrode
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/044 by capacitive means
• 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
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A common electrode 43 for display, which is originally provided in a liquid crystal display element, is also used as one (drive electrode) of a pair of electrodes for a touch sensor, and the other (detection-electrode-for-the-sensor 44) of the pair of electrodes is newly formed. An existing common drive signal Vcom as a drive signal for display is used in common for a drive signal for the touch sensor. A capacitance is formed between the common electrode 43 and the detection-electrode-for-the-sensor 44, and touch detection is performed by utilizing a change of this capacitance caused by a finger touch of a user. Thus, a display device with a touch sensor is also applicable to a mobile device in which electric potential of the user is inconstant in many cases. The newly-provided electrode is only the detection-electrode-for-the-sensor 44, and it is unnecessary to newly prepare a drive signal for the touch sensor. Therefore, the configuration is simple.

Claims

1. A display device with a touch sensor comprising:

a plurality of display pixel electrodes;

a common electrode facing the display pixel electrode;

a display function layer having an image display function;

a display control circuit performing an image display control by applying a voltage for display between the display pixel electrode and the common electrode, based on an image signal, so that the display function of the display function layer is exhibited; and

a touch detection electrode disposed oppositely to the common electrode, or beside the common electrode, and forming a capacitance between the common electrode and the touch detection electrode.

2. The display device with the touch sensor according to claim 1, further comprising:

a touch detection circuit detecting a position touched with an object, based on a detection signal obtained from the touch detection electrode, by utilizing a drive voltage for display as a drive signal for the touch sensor, the drive voltage for display being applied to the common electrode with the display control section.

3. The display device with the touch sensor according to claim 2, comprising:

a circuit substrate in which the display control circuit is formed; and

an opposed substrate facing the circuit substrate, wherein

the display pixel electrode is disposed on a side close to the opposed substrate, in the circuit substrate,

the common electrode is disposed on a side close to the circuit substrate, in the opposed substrate, and

the display function layer is inserted between the display pixel electrode in the circuit substrate and the common electrode in the opposed substrate.

4. The display device with the touch sensor according to claim 3, wherein the touch detection electrode is disposed on a side opposite from the circuit substrate, in the opposed substrate.

5. The display device with the touch sensor according to claim 3, wherein the touch detection electrode is divided to a plurality of electrode patterns.

6. The display device with the touch sensor according to claim 3, wherein the touch detection circuit is formed in the circuit substrate.

8. The display device with the touch sensor according to claim 2, comprising:

a circuit substrate in which the display control circuit and the touch detection electrode are formed; and

an opposed substrate facing the circuit substrate, wherein

the common electrode and the display pixel electrode are stacked in order with an insulating layer in between, in the circuit substrate, and

the display function layer is inserted between the display pixel electrode in the circuit substrate and the opposed substrate.

10. The display device with the touch sensor according to claim 8, wherein

the common electrode is disposed inside a display region in the circuit substrate, and

the touch detection electrode is formed as an electrode layer in a layer level similar to that of the common electrode, in a frame region surrounding the display region on the circuit substrate, separately from the common electrode.

11. The display device with the touch sensor according to claim 8, wherein

the common electrode extends from the display region on the circuit substrate to the frame region, and

the touch detection electrode is formed as an electrode layer in a layer level different from that of the common electrode, and faces the common electrode, in the frame region on the circuit substrate.

12. The display device with the touch sensor according to claim 8, wherein a shield electrode electromagnetically shielding the touch detection electrode is disposed.

13. The display device with the touch sensor according to claim 2, comprising:

a circuit substrate in which the display control circuit is formed; and

an opposed substrate in which the touch detection electrode facing the circuit substrate is formed, wherein

the common electrode and the display pixel electrode are stacked in order with the insulating layer in between, in the circuit substrate, and

the display function layer is inserted between the display pixel electrode in the circuit substrate, and the opposed substrate.

14. The display device with the touch sensor according to claim 13, wherein the touch detection electrode is disposed on a side close to the circuit substrate, in the opposed substrate.

15. The display device with the touch sensor according to claim 13, wherein the touch detection electrode is disposed on a side opposite from the circuit substrate, in the facing electrode.

16. The display device with the touch sensor according to claim 15, wherein the touch detection electrode is formed directly on the opposed substrate through use of thin film process.

17. The display device with the touch sensor according to claim 15, wherein the touch detection electrode is formed on a film substrate, and the film substrate on which the touch detection electrode is formed is attached to the opposed substrate.

18. The display device with the touch sensor according to claim 13, wherein the touch detection circuit is formed in the circuit substrate.

19. The display device with the touch sensor according to claim 18, wherein a conductive path connecting between the touch detection electrode in the opposed substrate, and the touch detection circuit in the circuit substrate is formed.

20. The display device with the touch sensor according to claim 18, wherein a capacity coupling path capacitively coupling between the touch detection electrode in the opposed substrate, and the touch detection circuit in the circuit substrate is formed.

21. The display device with the touch sensor according to claim 20, wherein the touch detection electrode in the opposed substrate is grounded through a high resistance.

23. The display device with the touch sensor according to claim 8, wherein the display function layer is made of a liquid crystal layer, and performs a liquid crystal display in a lateral electric field mode.

7. (canceled)

9. (canceled)

22. (canceled)