Display device and display device provided with sensor

• US 9,891,748 B2
• Filed: 03/03/2016
• Issued: 02/13/2018
• Est. Priority Date: 03/06/2015
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Nakamura, Takashi, Tada, Masahiro, Tsunashima, Takanori, Hayashi, Hirotaka, Mochizuki, Kazuhide
• Primary Examiner(s): Taylor, Jr., Duane N
• Application Number:
  US15/059,450
• Publication Number:
  US 20160259475A1
• Time in Patent Office: 712 Days
• Field of Search: None
• 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 3/041662 using alternate mutual and self-capacitive scanning
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• 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 one embodiment, a display device includes plural display pixels arranged in a matrix, plural gate lines, plural source lines and a control circuit which controls by applying intermittent driving and a column-inversion drive scheme, an operation in which drive signals are supplied to the gate lines and the source lines, and an image signal is supplied to the display pixels and held thereby, wherein the display pixels each include a liquid crystal in which alignment of liquid crystal molecules is changed by a voltage between pixel electrodes and a common electrode, and the control circuit applies in a signal stop period in the intermittent driving, a voltage corresponding to a gradation higher than or equal to white gradation to the source lines in a case where a display mode of the liquid crystal is a normally-black mode.

Claims

1. A display device comprising:

plural display pixels arranged in a matrix;

plural gate lines extending along rows in which the display pixels are arranged;

plural source lines extending along columns in which the display pixels are arranged; and

a control circuit which controls by applying intermittent driving and a column-inversion drive scheme, an operation in which drive signals are supplied to the gate lines and the source lines, and an image signal is supplied to the display pixels and held thereby,

wherein the display pixels each include a liquid crystal in which alignment of liquid crystal molecules is changed by a voltage between pixel electrodes and a common electrode, and

the control circuit applies in a signal stop period in the intermittent driving, a voltage corresponding to a gradation higher than or equal to white gradation to the source lines in a case where a display mode of the liquid crystal is a normally-black mode.

2. The display device according to claim 1, wherein the control circuit applies in the signal stop period in the intermittent driving, a voltage corresponding to white gradation to the source lines in the case where the display mode of the liquid crystal is the normally-black mode.

3. The display device according to claim 1, wherein the control circuit applies in the signal stop period in the intermittent driving, a voltage exceeding white gradation to the source lines in the case where the display mode of the liquid crystal is the normally-black mode.

4. The display device according to claim 1, wherein in the signal stop period in the intermittent driving, in the case where the display mode of the liquid crystal is the normally-black mode, a voltage which is applied to the source lines when polarity of the voltage is positive in the column-inversion drive scheme is a voltage corresponding to a higher gradation than a gradation corresponding to a voltage which is applied to the source lines when polarity of the voltage is negative in the column-inversion drive scheme.

5. A display device provided with a sensor, comprising:

a pair of groups of electrodes for a touch sensor, one of the groups of electrodes extending in a single direction, the other group of electrodes being arranged to intersect the one group of electrodes;

plural display pixels arranged in a matrix;

plural gate lines extending along rows in which the plural display pixels are arranged;

plural source lines extending along columns in which the plural display pixels are arranged; and

a control circuit which controls by applying intermittent driving and a column-inversion drive scheme, an operation in which drive signals are supplied to the gate lines and the source lines, and an image signal is supplied to the display pixels and held thereby,

wherein;

the display pixels each include a liquid crystal in which alignment of liquid crystal molecules is changed by a voltage between a pixel electrode and a common electrode;

the control circuit applies in a signal stop period in the intermittent driving, a voltage corresponding to a gradation higher than or equal to white gradation to the source lines in a case where a display mode of the liquid crystal is a normally-black mode; and

the source lines are also used as the one of groups of electrodes for the touch sensor.

6. The display device provided with the sensor, according to claim 5, wherein the signal stop period in the intermittent driving includes a touch detection period in which the pair of groups of electrodes for the touch sensor are driven to perform a touch detection operation and a source-line charge period in which the voltage is applied to the source lines.

7. The display device provided with the sensor, according to claim 6, wherein in the case where the display mode of the liquid crystal is the normally-black mode, in the touch detection period, a string of drive pulses an average voltage of which corresponds to white gradation is supplied to the source lines.

8. The display device provided with the sensor, according to claim 6, wherein in the signal stop period in the intermittent driving, the touch detection period and the source-line charge period are alternately repeatedly applied.

9. The display device provided with the sensor, according to claim 6, wherein a touch detection method is switchable between a self-detection method and a mutual detection method.