Electro-optical device and electronic apparatus

• US 8,416,212 B2
• Filed: 11/14/2008
• Issued: 04/09/2013
• Est. Priority Date: 12/21/2007
• Status: Expired due to Fees

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Eguchi, Tsukasa, Kanda, Eiji
• Primary Examiner(s): Feild, Joseph
• Assistant Examiner(s): Sasinowski, Andrew
• Application Number:
  US12/270,936
• Publication Number:
  US 20090160822A1
• Time in Patent Office: 1,607 Days
• Field of Search: 345173-177, 345/104
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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

Abstract

An electro-optical device, which has a display area and a plurality of sensing areas for detecting capacitance in the display area, includes a black matrix that is provided in the vicinities of display pixels in the display area, pixel electrodes that individually form the display pixels, a common electrode, a liquid crystal layer that is interposed between the pixel electrodes and the common electrode, a plurality of pixel circuits that individually drive the pixel electrodes, a capacitance detection element that is provided in a corresponding one of the sensing areas to convert a change in thickness of the liquid crystal layer caused by external pressure into a change in capacitance, and a sensing circuit that outputs a sensing signal on the basis of the change in capacitance obtained by the capacitance detection element. The capacitance detection element overlaps the black matrix in planar view.

Claims

1. An electro-optical device that has a display area and a sensing area for detecting capacitance in the display area, the electro-optical device comprising:

a plurality of display pixels each including a plurality of sub-pixels in the display area;

a black matrix that is provided in the vicinity of the sub-pixels;

a pixel electrode, a common electrode and a liquid crystal layer that form the display pixel, the liquid crystal layer being interposed between the pixel electrode and the common electrode;

a pixel circuit that drives the pixel electrode;

a capacitance detection element that is provided between the display pixels in the sensing area such that a distance between adjacent sub-pixels is substantially equal throughout the display area; and

a sensing circuit that outputs a sensing signal on the basis of the change in capacitance obtained by the capacitance detection element,

wherein the capacitance detection element overlaps the black matrix in planar view, and

wherein a distance between sub-pixels in a same display pixel is greater than a distance between the capacitance detection element and an adjacent sub-pixel.

2. The electro-optical device according to claim 1, further comprising:

a driving circuit that, on the basis of the sensing signal, generates positional information about a position at which the external pressure is being applied.

3. The electro-optical device according to claim 1,

wherein the sensing circuit overlaps the black matrix in planar view.

4. The electro-optical device according to claim 1, further comprising;

another capacitance detection element electrically connected in parallel with the capacitance element.

5. An electronic apparatus comprising the electro-optical device according to claim 1.

6. The electro-optical device according to claim 1, wherein the capacitance detection element includes a protrusion provided at a portion of the second electrode opposing the first electrode.

7. The electro-optical device according to claim 1, wherein the capacitance detection element is between a first two sub-pixels in the same row and not between a second two sub-pixels in the same row, wherein a distance between the first two sub-pixels is substantially equal to a distance between the second two sub-pixels.

8. The electro-optical device according to claim 7,

wherein each of the sub-pixels includes a TFT, and the TFT is separate from the capacitance detection element between the second two sub-pixels.

9. The electro-optical device according to claim 1, wherein a distance between a first electrode and a second electrode of the capacitance detection element is smaller than a distance between the pixel electrode and the common electrode.

10. The electro-optical device according to claim 1, wherein

a fixed voltage is supplied to the capacitance detection element, and

a common voltage, separate from the fixed voltage, is provided to the pixel circuit.

11. The electro-optical device according to claim 10, wherein

the capacitance detection element is configured to perform sensing independently from image display.