DISPLAY DEVICE WITH TOUCH DETECTION FUNCTION AND ELECTRONIC APPARATUS

• US 20140210779A1
• Filed: 01/24/2014
• Published: 07/31/2014
• Est. Priority Date: 01/25/2013
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: MIZUHASHI, Hiroshi, KATSUTA, Tadayoshi
• Granted Patent: US 10,884,554 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: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 3/044 by capacitive means
• 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

According to an aspect, a display device with a touch detection function includes: a display area where a plurality of pixel electrodes are arranged; drive electrodes provided so as to face the pixel electrodes; a control device for performing image display control; a touch detection electrode facing the drive electrodes; a touch detection unit for detecting a position of a proximity object; a wiring arranged in a frame area positioned outside the display area; and a plurality of selection switches for selecting the drive electrodes to be coupled to the wiring based on a selection signal of the control device. The control device supplies the display drive voltage and a touch drive signal to the same wiring at different times.

Claims

1. A display device with a touch detection function, comprising:

a display area where a plurality of pixel electrodes are arranged in a matrix shape above a substrate;

multi-divided drive electrodes provided so as to face the pixel electrodes;

a display functional layer having an image display function of displaying an image on the display area;

a control device for performing image display control by applying a display drive voltage between the pixel electrodes and the drive electrodes based on an image signal to exert the image display function of the display functional layer;

a touch detection electrode facing the drive electrodes and forming a capacitance between the touch detection electrode and the drive electrodes;

a touch detection unit for detecting a position of a proximity object based on a detection signal from the touch detection electrode;

a wiring arranged in a frame area positioned outside the display area; and

a plurality of selection switches for selecting the drive electrodes to be coupled to the wiring based on a selection signal of the control device, wherein

the control device supplies the display drive voltage and a touch drive signal to the same wiring at different times.

2. The display device with a touch detection function according to claim 1, wherein when the touch drive signal is provided to the wiring, the control device makes a selection switch corresponding to the selection signal among the plurality of selection switches perform a closing operation so as to apply the touch drive signal to a selected one of the drive electrodes.

3. The display device with a touch detection function according to claim 2, wherein the control device makes the plurality of selection switches excluding the selection switch corresponding to the selection signal perform an opening operation so as not to fix a potential of an unselected one of the drive electrodes.

4. The display device with a touch detection function according to claim 1, wherein when the display drive voltage is provided to the wiring, the control device makes all of the plurality of selection switches perform a closing operation so as to apply the display drive voltage to the plurality of drive electrodes.

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

the control device further includes a drive signal generator for generating the display drive voltage and the touch drive signal;

the drive signal generator includes

a first voltage generator for generating a first voltage,

a second voltage generator for generating a second voltage lower than the first voltage, and

a switching circuit for generating the touch drive signal by switching between the first voltage and the second voltage according to a pulse of a drive control signal; and

when the pulse of the drive control signal does not exist, the switching circuit outputs one of the first voltage and the second voltage as the display drive voltage, and when the pulse of the drive control signal exists, the switching circuit outputs a rectangular wave switched between the first voltage and the second voltage as the touch drive signal.

6. The display device with a touch detection function according to claim 5, wherein the drive signal generator identifies a period during which the touch drive signal is supplied to the wiring and a period during which the display drive voltage is supplied to the wiring, and changes the first voltage accordingly.

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

the control device further includes a drive signal generator for generating the display drive voltage and the touch drive signal;

the drive signal generator includes

a first voltage generator for generating a first voltage,

a second voltage generator for generating a second voltage lower than the first voltage,

a switching pulse selecting circuit for selecting between a pulse of an inversion control signal inverted for every one horizontal period and a pulse of a drive control signal, and

a switching circuit for switching between the first voltage and the second voltage; and

when the pulse of the inversion control signal is selected, the switching circuit outputs a rectangular wave switched between the first voltage and the second voltage according to the pulse of the inversion control signal as the display drive voltage, and when the pulse of the drive control signal exists, the switching circuit outputs a rectangular wave switched between the first voltage and the second voltage according to the pulse of the drive control signal as the touch drive signal.

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

the control device further includes a drive signal generator for generating the display drive voltage and the touch drive signal;

the drive signal generator includes;

a first voltage generator for generating a first voltage,

a second voltage generator for generating a second voltage lower than the first voltage, and

a switching circuit for outputting the touch drive signal or the display drive voltage based on the first voltage, the second voltage, and a third voltage which is a constant voltage according to an identification signal for identifying a touch detection operation period during which a touch detection operation is performed and a display operation period during which a display operation is performed; and

in the case of the display operation period, the switching circuit outputs the second voltage as the display drive voltage, and in the case of the touch detection operation period, the switching circuit outputs a rectangular wave switched between the first voltage and the third voltage as the touch drive signal.

9. An electronic apparatus comprising a display device with a touch detection function capable of detecting an external proximity object, wherein

the display device with a touch detection function comprises:

a display area where a plurality of pixel electrodes are arranged in a matrix shape above a substrate;

multi-divided drive electrodes provided so as to face the pixel electrodes;

a display functional layer having an image display function of displaying an image on the display area;

a control device for performing image display control by applying a display drive voltage between the pixel electrodes and the drive electrodes based on an image signal to exert the image display function of the display functional layer;

a touch detection electrode facing the drive electrodes and forming a capacitance between the touch detection electrode and the drive electrodes;

a touch detection unit for detecting a position of a proximity object based on a detection signal from the touch detection electrode;

a wiring arranged in a frame area positioned outside the display area; and

a plurality of selection switches for selecting the drive electrodes to be coupled to the wiring based on a selection signal of the control device, and

the control device supplies the display drive voltage and a touch drive signal to the same wiring at different times.