DISPLAY DEVICE WITH TOUCH SENSOR

• US 20140292718A1
• Filed: 06/12/2014
• Published: 10/02/2014
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Inventors: Noguchi, Koji, Takama, Daisuke, Kida, Yoshitoshi
• Granted Patent: US 9,542,047 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 for a 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) of the pair of electrodes is newly formed. An existing common drive signal 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 and the detection-electrode-for-the-sensor, 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, and it is unnecessary to newly prepare a drive signal for the touch sensor.

Claims

1. A display device comprising:

a pixel substrate;

a common electrode disposed on the pixel substrate;

at least one touch detecting electrode disposed on the pixel substrate;

an opposed electrode facing the pixel substrate;

at least one pixel electrode arranged between the pixel substrate and the opposed substrate; and

a display function layer interposed between the pixel substrate and the opposed substrate within an image display area,

wherein,

the common electrode and the at least one touch detecting electrode are formed on a substantially same plane of the pixel substrate, and electrically isolated each other.

2. The display device set forth in claim 1, wherein each of the at least one touch electrode is located outside of the image display area.

3. The display device set forth in claim 2, wherein each of the at least one touch electrode is located along at least a side of the circumference of the image display area.

4. The display device set forth in claim 3, wherein each of the at least one touch electrode is located in parallel to the at least a side of the circumference of the image display area.

5. The display device set forth in claim 4, wherein each of the at least one touch electrode is located with substantially same interval.

6. The display device set forth in claim 1, wherein a top surface of the common electrode and a top surface of the at least one touch detecting electrode provide a substantially same plane.

7. The display device set forth in claim 1, wherein a metal shield is embedded in the pixel substrate within an area where the at least one touch detecting electrode are formed.

8. The display device set forth in claim 1, wherein the common electrode functions not only as a drive electrode of image display but also as a drive electrode of touch detection.

9. A touch detecting unit for using with a display device including:

a pixel substrate;

an opposed electrode facing the pixel substrate;

at least one pixel electrode arranged between the pixel substrate and the opposed substrate;

a common electrode facing at least one pixel electrode; and

a display function layer interposed between the pixel substrate and the opposed substrate within an image display area,

wherein,

the touch detecting unit comprises at least one touch detecting electrode disposed on the pixel substrate, the at least one touch detecting electrode functioning not only as a drive electrode of image display but also as a drive electrode of touch detection, and

the common electrode and the at least one touch detecting electrode are formed on a substantially same plane of the pixel substrate, and electrically isolated each other.

10. A display device comprising:

a pixel substrate;

an opposed electrode facing the pixel substrate;

at least one pixel electrode arranged between the pixel substrate and the opposed substrate;

a display function layer interposed between the pixel substrate and the opposed substrate within an image display area; and

a plurality of electrodes associated with the pixel substrate and/or the opposed substrate,

wherein,

the plurality of electrodes are formed on a substantially same plane.

11. The display device set forth in claim 10, wherein the plurality of electrodes are formed on the pixel substrate.

12. The display device set forth in claim 10, wherein voltages to be applied to the plurality of electrodes are controlled so that image display and/or touch detection are performed.