DISPLAY DEVICE WITH TOUCH DETECTION FUNCTION

• US 20170010739A1
• Filed: 07/01/2016
• Published: 01/12/2017
• Est. Priority Date: 07/06/2015
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: SHIGEHIRO, Koji, YOKOO, Nobuhiko, ITO, Daisuke
• Granted Patent: US 10,162,457 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• 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: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A display device with a touch detection function includes a substrate, pixel electrodes arranged in a matrix in a display region on a plane parallel to the substrate, a display function layer having a function to display the image in the display region, drive electrodes provided facing the pixel electrodes, touch detection electrodes that form electrostatic capacitance between there and the drive electrodes, a control unit that generates a control signal to switch between a display operation period for applying a display signal between the pixel and drive electrodes and a display stop period for stopping the display operation. The control unit generates first and second control signals respectively having a first frequency and a second frequency that is different from the first frequency, and has first and second operation modes respectively including a period controlled by the first control signal and a period controlled by the second control signal.

Claims

1. A display device with a touch detection function that performs a display operation of displaying an image for one screen and a touch detection operation in a time-division manner, the display device comprising:

a substrate;

a plurality of pixel electrodes that are arranged in a matrix in a display region where the image is displayed, on a plane parallel to the substrate;

a display function layer having an image display function to display the image in the display region;

a plurality of drive electrodes provided so as to face the pixel electrodes;

a plurality of touch detection electrodes that form electrostatic capacitance between the touch detection electrodes and the drive electrodes;

a control unit that generates a control signal to perform switching between a display operation period for applying a signal for display between the pixel electrodes and the drive electrodes and a display stop period for stopping the display operation, wherein

the control unit generates a first control signal having a first frequency and a second control signal having a second frequency different form the first frequency, and

the control unit has;

a first operation mode including a period controlled by the first control signal; and

a second operation mode including a period controlled by the second control signal.

2. The display device with a touch detection function according to claim 1, wherein

the touch detection operation is performed in the display stop period controlled by the first control signal in the first operation mode, and

the touch detection operation is not performed in the display stop period controlled by the second control signal in the second operation mode.

3. The display device with a touch detection function according to claim 1, wherein the second frequency is a frequency outside a human audible range.

4. The display device with a touch detection function according to claim 3, wherein the second frequency is 20 kHz or higher.

5. The display device with a touch detection function according to claim 1, wherein the second frequency is 60 Hz or lower.

6. The display device with a touch detection function according to claim 1, wherein the display operation stops in the second operation mode.

7. The display device with a touch detection function according to claim 1, wherein the second operation mode is a sleep mode.

8. The display device with a touch detection function according to claim 1, wherein

the second operation mode further includes a period not controlled by the second control signal, and

the touch detection operation is performed to detect whether an external conductor is in contact with or in proximity to the display region at least once in the period in which the display operation is not controlled by the second control signal.

9. The display device with a touch detection function according to claim 1, further comprising:

a touch detection unit that detects a position of a touch input to the display region based on a detection signal from the touch detection electrodes in the first operation mode; and

a touch detection control unit that detects whether an external conductor is in contact with or in proximity to the display region in the second operation mode, wherein

the control unit performs switching between the first control signal and the second control signal based on a detection signal from the touch detection control unit.

10. The display device with a touch detection function according to claim 1, wherein a position of a touch input is detected based on mutual capacitance between the drive electrodes and the touch detection electrodes in the first operation mode.

11. The display device with a touch detection function according to claim 1, wherein whether an external conductor is in contact with or in proximity to the display region is detected based on self-capacitance of the touch detection electrodes.