Liquid crystal display device with touch screen

• US 9,081,449 B2
• Filed: 02/27/2012
• Issued: 07/14/2015
• Est. Priority Date: 11/29/2006
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Japan Display Incorporated, Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Inventors: Furuhashi, Tsutomu, Mamba, Norio
• Primary Examiner(s): Ghebretinsae, Temesgh
• Assistant Examiner(s): Ketema, Benyam
• Application Number:
  US13/405,892
• Publication Number:
  US 20120154334A1
• Time in Patent Office: 1,233 Days
• Field of Search: 345/173, 345/174, 345/87
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires
• CPC Class Codes: G09G 2300/0404 Matrix technologies
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/18 Timing circuits for raster scan displays specially adapted for television H04N ; synchronisation between the display unit and other display units, videodisc player G09G5/12

Abstract

A liquid crystal display device includes a first substrate, a second substrate, and a liquid crystal material sandwiched between the first and second substrate. The second substrate has a touch screen electrode directly on a front-side surface of the second substrate. The first substrate has a wiring line for supplying a position detection voltage. A conductive tape electrically connects between the touch screen electrode and a driver circuit. A polarization plate is disposed above the touch screen electrode.

Claims

1. A liquid crystal display device comprising:

a first substrate;

a second substrate; and

a liquid crystal material sandwiched between the first and second substrates;

wherein the second substrate has a touch screen with a touch screen electrode enabling detection of a position on the touch screen without requiring compression of the touch screen being disposed directly on an upper surface of a front-side surface of the second substrate;

the touch screen electrode has a first side surface and a second side surface which is opposed to the first side surface, the first side surface of the touch screen electrode being disposed directly on the upper surface of the front-side surface of the second substrate,

wherein the first substrate has a wiring line for supplying a position detection voltage;

wherein a conductive tape electrically connects between the touch screen electrode and a driver circuit;

wherein a polarization plate is disposed directly on the second side surface of the touch screen electrode;

wherein an outer edge of the touch screen electrode protrudes beyond an outer edge of the polarization plate at least in an area of the outer edge of the touch screen electrode between two adjacent corners of the outer edge of the polarization plate;

wherein the conductive tape is electrically connected at a position of a corner of the outer edge of the second side surface of the touch screen electrode which protrudes beyond the outer edge of the polarization plate; and

wherein the touch screen electrode is sandwiched between the second substrate and the polarization plate.

2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is an IPS liquid crystal display device.

3. The liquid crystal display device according to claim 1, wherein the driver circuit includes a coordinate detection circuit.

4. The liquid crystal display device according to claim 1, wherein the touch screen electrode is strip-shaped.

5. The liquid crystal display device according to claim 1, wherein the touch screen electrode is sandwiched between only the second substrate and the polarizing plate.

6. The liquid crystal display device according to claim 1, wherein the touch screen electrode has a rear-side surface directly on the upper surface of the front-side surface of the second substrate and a front-side surface directly on a rear-side surface of a layer of the polarization plate.

7. The liquid crystal display device according to claim 1, wherein the touch screen electrode is only a single touch screen electrode of the touch screen.

8. The liquid crystal display device according to claim 1, wherein the touch screen electrode comprises a transparent conductive layer connected to an input voltage generation circuit and a coordinate detection circuit, wherein the coordinate detection circuit detects the state of differential voltage between voltage waveforms so as to detect the position on the touch screen.

9. The liquid crystal display device according to claim 1, wherein the touch screen is a capacitive touch screen.

10. The liquid crystal display device according to claim 1, wherein the touch screen has only a single touch screen electrode.

11. The liquid crystal display device according to claim 1, wherein the upper surface of the front-side surface of the second substrate is a surface of the second substrate facing away from the liquid crystal material sandwiched between the first and second substrates and is the surface which is opposite to a lower surface of a rear-side surface of the second substrate which faces the liquid crystal material sandwiched between the first and second substrates.

12. A liquid crystal display device comprising:

a first substrate including a comb-shaped pixel electrode and a counter electrode;

a second substrate including a color filter layer; and

a liquid crystal material sandwiched between the first and second substrate;

wherein the second substrate has a touch screen with only a single touch screen electrode enabling detection of a position on the touch screen being disposed directly on an upper surface of a front-side surface of the second substrate, the touch screen electrode having a first side surface and a second side surface which is opposed to the first side surface, the first side surface of the touch screen electrode being disposed directly on the upper surface of the front-side surface of the second substrate;

wherein the first substrate has a wiring line for supplying a position detection voltage and a terminal which electrically connects the wiring line;

wherein a conductive tape electrically connects between the touch screen electrode and a driver circuit;

wherein the terminal electrically connects between the wiring line and the driver circuit;

wherein a polarization plate is disposed directly on the second side surface of the touch screen electrode;

wherein an outer edge of the touch screen electrode protrudes beyond an outer edge of the polarization plate at least in an area of the outer edge of the touch screen electrode between adjacent corners of the outer edge of the polarization plate;

wherein the conductive tape is electrically connected at a position of a corner of the outer edge of the second side surface of the touch screen electrode which protrudes beyond the outer edge of the polarization plate; and

wherein the touch screen electrode is sandwiched between the second substrate and the polarization plate.

13. The liquid crystal display device according to claim 12, wherein the liquid crystal display device is an IPS liquid crystal display device.

14. The liquid crystal display device according to claim 12, wherein the driver circuit includes a coordinate detection circuit.

15. The liquid crystal display device according to claim 12, wherein the touch screen electrode is strip-shaped.

16. The liquid crystal display device according to claim 12, wherein the touch screen electrode is sandwiched between only the second substrate and the polarizing plate.

17. The liquid crystal display device according to claim 12, wherein the touch screen electrode has a rear-side surface directly on the upper surface of the front-side surface of the second substrate and a front-side surface directly on a rear-side surface of a layer of the polarization plate.

18. The liquid crystal display device according to claim 12, wherein the single touch screen electrode enables detection of the position on the touch screen without requiring compression of the touch screen.

19. The liquid crystal display device according to claim 12, wherein the touch screen electrode comprises a transparent conductive layer connected to an input voltage generation circuit and a coordinate detection circuit, wherein the coordinate detection circuit detects the state of differential voltage between voltage waveforms to detect the position on the touch screen.

20. The liquid crystal display device according to claim 12, wherein the touch screen is a capacitive touch screen.