LIQUID CRYSTAL DEVICE, ELECTRONIC APPARATUS AND POSITION DETECTING METHOD

• US 20080231607A1
• Filed: 02/04/2008
• Published: 09/25/2008
• Est. Priority Date: 03/19/2007
• Status: Abandoned Application

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: KOSHIHARA, Takeshi, UTSUNOMIYA, Sumio
• Application Number:
  US12/025,493
• Publication Number:
  US 20080231607A1
• Time in Patent Office: Days
• US Class Current: 345/173
• 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
• 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

A liquid crystal device includes a liquid crystal panel, a touch panel, a position signal generating device, and a display control device. The liquid crystal panel is formed so that a liquid crystal is sealed in a gap between an element substrate and an opposite substrate, which are opposed to each other, and a transmittance ratio of the liquid crystal is controlled on the basis of a voltage applied between a first electrode and a second electrode. The touch panel is arranged on a side of the opposite substrate and provided with a plurality of detection electrodes. The position signal generating device specifies one or plurality of the plurality of detection electrodes in conformity with a predetermined rule and generates a position signal that indicates a position of a pointing body on the basis of an electric potential of the specified detection electrode or on the basis of electric potentials of the specified detection electrodes. The display control device displays an image of a fixed luminance level on a display area of the liquid crystal panel, which overlaps the detection electrode or detection electrodes specified by the position signal generating device.

Claims

1. A liquid crystal device comprising:

a liquid crystal panel that is formed so that a liquid crystal is sealed in a gap between an element substrate and an opposite substrate, which are opposed to each other, and a transmittance ratio of the liquid crystal is controlled on the basis of a voltage applied between a first electrode and a second electrode;

a touch panel that is arranged on a side of the opposite substrate and provided with a plurality of detection electrodes;

a position signal generating device that specifies one or plurality of the plurality of detection electrodes in conformity with a predetermined rule and that generates a position signal that indicates a position of a pointing body on the basis of an electric potential of the specified detection electrode or on the basis of electric potentials of the specified detection electrodes; and

a display control device that displays an image of a fixed luminance level on a display area of the liquid crystal panel, which overlaps the detection electrode or detection electrodes specified by the position signal generating device.

2. The liquid crystal device according to claim 1, wherein the first electrode and the second electrode are formed on the element substrate.

3. The liquid crystal device according to claim 1, wherein the position signal generating device includes:

a selection device that selects each of the plurality of detection electrodes;

a detection device that outputs a detection signal by detecting an electric potential of the detection electrode or detection electrodes selected by the selection device; and

a position identification device that generates a position signal that indicates a position of the pointing body on the basis of the detection signal, wherein

the display control device determines the detection electrode or detection electrodes selected by the selection device as a detection electrode or detection electrodes specified, and displays an image of a fixed luminance level on a display area of the liquid crystal panel, which overlaps the specified detection electrode.

4. The liquid crystal device according to claim 1, wherein the position signal generating device includes:

a selection device that sequentially selects each of the plurality of detection electrodes;

a detection device that detects an electric potential of the detection electrode or detection electrodes sequentially selected by the selection device, and that outputs a detection signal; and

a position identification device that generates a position signal that indicates a position of the pointing body on the basis of the detection signal acquired from the detection electrode or detection electrodes specified in conformity with the predetermined rule among the detection electrodes sequentially selected by the selection device.

5. The liquid crystal device according to claim 1, wherein the plurality of detection electrodes include a plurality of first detection electrodes that are formed parallel to a first direction and a plurality of second detection electrodes that are formed parallel to a second direction that intersects with the first direction.

6. The liquid crystal device according to claim 5, further comprising:

a plurality of scanning lines;

a plurality of data lines;

a plurality of pixels that are provided at positions corresponding to intersections of the scanning lines and the data lines, wherein the plurality of scanning lines, the plurality of data lines and the plurality of pixels are formed on the element substrate; and

a driving device that is provided to write a voltage, corresponding to a gray-scale level to be displayed, to a pixel corresponding to a selected one of scanning lines through the a corresponding one of the data lines, wherein

the first direction is the same direction as a direction in which the plurality of scanning lines are formed, and wherein

the second direction is the same direction as a direction in which the plurality of data lines are formed.

7. The liquid crystal device according to claim 5, further comprising:

a plurality of scanning lines;

a plurality of data lines;

a plurality of pixels that are provided at positions corresponding to intersections of the scanning lines and the data lines, wherein the plurality of scanning lines, the plurality of data lines and the plurality of pixels are formed on the element substrate; and

a driving device that is provided to write a voltage, corresponding to a gray-scale level to be displayed, to a pixel corresponding to a selected one of the scanning lines through the a corresponding one of the data lines, wherein

the first direction and the second direction are oblique directions to a direction in which the plurality of scanning lines are formed.

8. An electronic apparatus comprising the liquid crystal device according to claim 1.

9. A method of detecting a position of a pointing body in a liquid crystal device that includes a liquid crystal panel and a touch panel, wherein the liquid crystal panel is formed so that a liquid crystal is sealed in a gap between an element substrate and an opposite substrate, which are opposed to each other, and a transmittance ratio of the liquid crystal is controlled on the basis of a voltage applied between a first electrode and a second electrode, wherein the touch panel is arranged on a side of the opposite substrate and provided with a plurality of detection electrodes, the method comprising:

specifying one or plurality of the plurality of detection electrodes in conformity with a predetermined rule;

detecting the position of the pointing body on the basis of an electric potential of the specified detection electrode or on the basis of electric potentials of the specified detection electrodes; and

displaying an image of a fixed luminance level on a display area of the liquid crystal panel, which overlaps the detection electrode or detection electrodes specified.