Display device

Patent metadata

Field	Value
Publication number	US-9092087-B2
Application number	US-82068510-A
Country	US
Kind code	B2
Filing date	Jun 22, 2010
Priority date	Jun 30, 2009
Publication date	Jul 28, 2015
Grant date	Jul 28, 2015

Abstract

A display device includes: a display functional layer that can change display for each pixel in accordance with an application voltage; a plurality of driving electrodes separately disposed in one direction; a plurality of pixel signal lines to which pixel signals used for applying the application voltage to the display functional layer in accordance with an electric potential difference from the display reference electric potential are applied; a plurality of detection electrodes that are separately disposed in a direction other than the one direction, are coupled with the driving electrodes as electrostatic capacitance, generate detection electric potentials in response to the detection driving signal, and change the detection electric potential in accordance with approach of a detection target object; and a pixel signal control unit that controls the pixel signals so as to include pixel signals having different polarities during the display period.

First claim

The invention claimed is:

1. A display device comprising:
a display functional layer that can change display for each pixel in accordance with an application voltage;
a plurality of driving electrodes, disposed in a first direction so as to be separated from one another, to which a display reference electric potential maintained at a constant level is applied during a display period in which display is performed in a pixel arrangement along the first direction and to which a detection driving signal is applied when detection scanning is performed by changing the display reference electric potential to another electric potential;
a plurality of pixel signal lines to which pixel signals used for applying the application voltage to the display functional layer in accordance with an electric potential difference from the display reference electric potential are applied;
a plurality of detection electrodes that are disposed so as to be separated from one another in a direction other than the first direction, are coupled with the plurality of the driving electrodes as electrostatic capacitance, generate detection electric potentials in response to the detection driving signal that is applied to the plurality of driving electrodes, and change the detection electric potential in accordance with approach of a detection target object; and
a pixel signal control unit that controls the plurality of pixel signals applied to the plurality of pixel signal lines so that pixel signals in one display period have at least one pulse whose polarity is inverted with respect to the display reference electric potential from another pulse in the one display period, while the display reference electric potential is maintained at a constant level in the one display period.

2. The display device according to claim 1 ,
wherein the inside of one pixel is divided into two areas, and a pixel electrode and a switching device are disposed in the areas, and
wherein the pixel signal control unit controls polarity control and supply timings of the pixel signals and opening or closing of the switching device such that the same pixel signal is supplied from one pixel signal line to the two areas inside the same pixel with opposite polarities.

3. The display device according to claim 1 ,
wherein the inside of one pixel is divided into two areas, and each of the areas is configured so as to be able to maintain different pixel signals, and
wherein the pixel signal control unit controls polarity control of the pixel signals and discharge timings for two different pixel signal lines adjacent to each other such that the same pixel signal is supplied from the two different pixel signal lines to the two areas inside the same pixel with opposite polarities.

4. The display device according to claim 1 , wherein the pixel signal control unit controls the pixel signals having opposite polarities so as to be simultaneously discharged to a plurality of pixel signal lines when an operation of supplying the pixel signal to one pixel electrode inside one pixel through a switching device is performed for a plurality of pixels in a parallel manner.

5. The display device according to claim 1 , wherein the pixel signal control unit controls the number of the pixel signals having the positive polarity with respect to a center electric potential to be the same as the number of the pixel signals having the negative polarity with respect to the center electric potential within the fixed display period.

6. The display device according to claim 1 , wherein the pixel signal control unit controls the polarities of the pixel signals of adjacent pixels so as to be inverted within the fixed display period.

7. The display device according to claim 6 , wherein the pixel signal control unit controls the polarities of the pixel signals that are adjacent to each other in a row direction and a column direction so as to be inverted between the fixed display period and another fixed display period next thereto.

8. The display device according to claim 7 , wherein the pixel signal control unit controls dot-inversion driving in which the polarity of the pixel signal of the same pixel is inverted between a display period of one screen and a display period of another screen next thereto.

9. The display device according to claim 1 , wherein the display functional layer is a liquid crystal layer.

10. The display device according to claim 1 ,
wherein the plurality of detection electrodes are disposed on a display surface side of the display functional layer,
wherein the plurality of driving electrodes are disposed on a side of the display functional layer that is opposite to the display surface, and
wherein a plurality of pixel electrodes, separated for each pixel, that apply the application voltage to the display functional layer with respect to an electric potential of a corresponding driving electrode used as a reference for each pixel when the pixel signal is supplied are disposed between the display functional layer and the plurality of driving electrodes.

11. The display device according to claim 1 , wherein the number of the inverted pulses is equal to the number of not-inverted pulses.

12. The display device according to claim 1 , wherein the pixel signal control unit controls the plurality of pixel signals applied to the plurality of pixel signal lines so that pixel signals in 1H display period have at least one pulse whose polarity is inverted with respect to the display reference electric potential from another pulse in the 1H display period, while the display reference electric potential is maintained at a constant level in the 1H display period.

13. The display device according to claim 12 , wherein the detection scanning is performed in a period that is different from the 1H display period.

Assignees

• Ishizaki Koji
• Noguchi Kouji
• Nakanishi Takayuki
• Teranishi Yasuyuki
• Takeuchi Takeya
• Japan Display Inc

Inventors

• Ishizaki Koji
• Noguchi Kouji
• Nakanishi Takayuki
• Teranishi Yasuyuki
• Takeuchi Takeya

Classifications

• G06F2218/04

  Denoising · CPC title

• G09G3/3614

  Control of polarity reversal in general · CPC title

• G06F3/0412 Primary

  Digitisers structurally integrated in a display · CPC title

• G06F3/0446

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title

• G06F3/04166 Primary

  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 title