Screen input type image display

• US 20090002338A1
• Filed: 05/30/2008
• Published: 01/01/2009
• Est. Priority Date: 06/27/2007
• Status: Abandoned Application

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Kinoshita, Masayoshi, Mamba, Norio
• Application Number:
  US12/155,209
• Publication Number:
  US 20090002338A1
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0444 using a single conductive element covering the whole sensing surface, e.g. by sensing the electrical current flowing at the corners
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

In an image display device incorporating a touch sensor capable of detecting coordinates with simple structure and high precision, a transparent conductive film on a substrate SUB forming a display screen of the image display device is patterned to form detection electrodes taking the shape of a plurality of pad electrodes SSP arranged in a two-dimensional matrix form of rows (X direction) and columns (Y direction). Row connection electrodes LNL and column connection electrodes LNC connecting the detection electrodes in rows and columns of the two-dimensional matrix to each other are formed of the same transparent conductive film as the pad electrodes. By arranging the pad electrodes in the matrix form, the contact area of a finger or the like touching the screen can be made large, resulting in improved detection precision (resolution). The pad electrodes are connected at four corners to coordinate detection terminals PDT1 to PDT4.

Claims

1. A screen input type image display device including a touch sensor to detect two-dimensional coordinates of a touch position on a display screen,

wherein the touch sensor comprises:

a plurality of pad electrodes forming detection electrodes arranged in a two-dimensional matrix form on a substrate which forms the display screen of the image display device;

a transparent conductive film forming row connection electrodes and column connection electrodes to connect the pad electrodes included in the two-dimensional matrix to each other; and

coordinate detection terminals provided respectively in a plurality of places in a fringe of the transparent conductive film.

2. The screen input type image display device with touch sensor according to claim 1, wherein

the coordinate detection terminals are connected to the transparent conductive film via wires at ends including a plurality of corners of the transparent conductive film, and

two-dimensional coordinates of a touch position on the transparent conductive film are detected on the basis of currents which flow through the coordinate detection terminals in response to touch with the pad electrodes.

3. The screen input type image display device with touch sensor according to claim 2, comprising:

an alternating current generation circuit connected to the coordinate detection terminals via detection resistors; and

a signal processing circuit for generating coordinate data which represent the two-dimensional coordinates of the touch position on the basis of voltages generated across the detection resistors connected to a plurality of places which are preferably the corners by the currents.

4. The screen input type image display device with touch sensor according to claim 1, comprising:

row spine electrodes for connecting the column connection electrodes in a row connection; and

column spine electrodes for connecting the row connection electrodes in a column direction,

wherein

the coordinate detection terminals are connected to the row spine electrode and the column spine electrode located on outermost sides of the matrix by the wires.

5. The screen input type image display device with touch sensor according to claim 1, comprising:

an outside row spine electrode for connecting ends of the column connection electrodes in a row connection; and

an outside column spine electrode for connecting ends of the row connection electrodes in a column direction,

wherein

the outside row spine electrode and the outside column spine electrode comprise corner connection points at ends of them, and comprise the coordinate detection terminals at the corner connection points.

6. The screen input type image display device with touch sensor according to claim 1, wherein wiring widths of the column connection electrodes and the row connection electrodes become gradually wider as the location approaches the pad electrode side located inside the matrix.

7. The screen input type image display device with touch sensor according to claim 6, wherein the column connection electrode and the row connection electrode having widest wiring widths are located in one place on the inside of the matrix.

8. The screen input type image display device with touch sensor according to claim 7, wherein the column connection electrode and the row connection electrode having widest wiring widths are located in a center part on the inside of the matrix.

9. The screen input type image display device with touch sensor according to claim 7, wherein the column connection electrode and the row connection electrode having widest wiring widths are located in a part which is eccentric from a center part on the inside of the matrix.

10. The screen input type image display device with touch sensor according to claim 6, wherein the column connection electrode and the row connection electrode having widest wiring widths are located in a plurality of places on the inside of the matrix.

11. The screen input type image display device with touch sensor according to claim 1, wherein

a substrate forming the display screen of the image display device comprises an indispensable substrate included in the image display device and an additional substrate stacked on the indispensable substrate, and

the additional substrate comprises the transparent conductive film.

12. The screen input type image display device with touch sensor according to claim 1, wherein an indispensable substrate included in the image display device comprises a substrate forming the display screen of the image display device.