LIQUID CRYSTAL DISPLAY DEVICE AND A METHOD OF MANUFACTURING THE SAME

• US 20100033448A1
• Filed: 08/03/2009
• Published: 02/11/2010
• Est. Priority Date: 08/07/2008
• Status: Active Grant

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Koito, Takeo, Noguchi, Koji
• Granted Patent: US 8,786,571 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

A liquid crystal display device includes a first substrate on a display surface side; a second substrate on a back surface side; a liquid crystal layer formed between the first and second substrates; an alignment film formed on one of the first and second substrates so as to contact the liquid crystal layer; a first sensor electrode formed on a surface, of the alignment film, contacting the liquid crystal layer; and a second sensor electrode formed on the other of the first and second substrates, and adapted to either contact or approach the first sensor electrode when the first substrate is pressed from the display surface side.

Claims

1. A liquid crystal display device, comprising:

a first substrate on a display surface side;

a second substrate on a back surface side;

a liquid crystal layer formed between said first and second substrates;

an alignment film formed on one of said first and second substrates so as to contact said liquid crystal layer;

a first sensor electrode formed on a surface, of said alignment film, contacting said liquid crystal layer; and

a second sensor electrode formed on the other of said first and second substrates, and adapted to either contact or approach said first sensor electrode when said first substrate is pressed from said display surface side.

2. The liquid crystal display device according to claim 1, wherein

a planar surface when viewed from said display surface is partitioned into a plurality of pixels,

each of said plurality of pixels has a light blocking area and a light transmitting area, and

said first sensor electrode is formed in said light blocking area.

3. The liquid crystal display device according to claim 1, wherein

a planar surface when viewed from said display surface is partitioned into a plurality of pixels,

a common electrode common to said plurality of pixels is formed, and

said first sensor electrode is electrically connected to said common electrode.

4. The liquid crystal display device according to claim 1, wherein

a height adjusting layer is formed on the other of said first and second substrates,

said second sensor electrode is formed on said height adjusting layer so as to partially overlap said height adjusting layer,

an alignment film on the other substrate side is formed on said second sensor electrode, and

said height adjusting layer has a predetermined height in a thickness direction of said liquid crystal layer, so that in an area contacting a protrusion end face of said height adjusting layer, said alignment film on the other substrate side is not formed on said second sensor electrode, or a portion of said alignment film on the other substrate side contacting said second sensor electrode is thinner than any of other portions in a periphery thereof.

5. The liquid crystal display device according to claim 4, wherein said height adjusting layer is made of a light blocking material.

6. The liquid crystal display device according to claim 1, wherein

said one of said first and second substrates has a recess portion in a part of a surface on which said alignment film is formed, and

said alignment film continuing between an inside and an outside of said recess portion, and said first sensor electrode formed within said recess portion are laminated within said recess portion.

7. The liquid crystal display device according to claim 6, wherein

a color filter layer is formed between said one of said first and second substrates and said alignment film so as to correspond to a light transmitting portion, and

said recess portion is formed so as to reflect an edge shape of said adjacent color filter layer in a portion having no color filter layer formed therein.

8. The liquid crystal display device according to claim 1, wherein in said first sensor electrode, a planar pattern when viewed from said display surface side has either a rectangular or line-like shape lengthwise in one direction at least within an effect pixel area.

9. The liquid crystal display device according to claim 8, wherein portions of said first sensor electrode having said rectangular or line-like shape are electrically connected to one another outside said effective pixel area.

10. The liquid crystal display device according to claim 1, wherein

a plurality of pixel electrodes disposed in a matrix so as to be adapted to locally apply different electric fields to said liquid crystal layer, a wiring group for matrix-driving applied voltages corresponding to respective pixels, and transistors for controlling connection between signal lines within said wiring group, and said plurality of pixel electrodes are formed on the other of said first and second substrates, thereby partitioning a planar surface when viewed from said display surface by said plurality of pixels,

said second sensor electrode is provided every pixel so as to be used as said pixel electrode as well, and

said signal lines are disposed so as to correspond to pixel columns, respectively, on the matrix distribution of said plurality of pixels,

said liquid crystal display device further comprising

a circuit connected to a plurality of said signal lines for reading out electrical changes between the first sensor electrodes and said plurality of pixel electrodes.

11. The liquid crystal display device according to claim 1, wherein

a plurality of pixel electrodes disposed in a matrix so as to be adapted to locally apply different electric fields to said liquid crystal layer, a wiring group for matrix-driving applied voltages corresponding to respective pixels, and transistors for controlling connection between signal lines within said wiring group, and said plurality of pixel electrodes are formed on the other of said first and second substrates, thereby partitioning a planar surface when viewed from said display surface by said plurality of pixels,

a detection area is disposed within said planar surface in one in said plurality of pixels, and

said detection area includes

said second sensor electrode, and

a detection line for outputting therethrough an electrical change when said second sensor electrode either contacts or approaches said first sensor electrode.

12. The liquid crystal display device according to claim 1, wherein a plurality of pixel electrodes disposed in a matrix so as to be adapted to locally apply different electric fields to said liquid crystal layer, a wiring group for matrix-driving applied voltages corresponding to respective pixels, transistors for controlling connection between signal lines within said wiring group and said plurality of pixel electrodes, said second sensor electrode, a detection line for outputting therethrough an electrical change when said second sensor electrode either contacts or approaches said first sensor electrode, and a detecting transistor for controlling connection between said detection line and said second sensor electrode are formed on the other of said first and second substrates, thereby partitioning a planar surface when viewed from said display surface by said plurality of pixels.

13. The liquid crystal display device according to claim 1, wherein

in said first sensor electrode, a planar pattern when viewed from said display surface side has either a rectangular or line-like shape lengthwise in one direction at least within an effect pixel area,

in said second sensor electrode, a planar pattern when viewed from said display surface side has either a long rectangular or line-like shape lengthwise in the other direction perpendicularly intersecting with said one direction at least within said effective pixel area, and

a change in potential of said second sensor electrode is detected when a voltage is applied to said first sensor electrode in a longitudinal direction of the rectangular or line-like shape, a change in potential of said first sensor electrode is detected when a voltage is applied to said second sensor electrode in a longitudinal direction of the rectangular or line-like shape, and a portion in which said first sensor electrode and said sensor electrode either contact or approach each other is detected based on potential changes in the two detection results.

14. A method of manufacturing a liquid crystal display device, comprising:

a first step of forming a predetermined functional film on a first substrate;

a second step of forming a predetermined functional film on a second substrate; and

a third step of disposing said first substrate and said second substrates on a display surface side and on a back surface side, respectively, to fix said first substrate and said second substrates to a panel frame, and injecting a liquid crystal between said first substrate and said second substrates to seal said liquid crystal between said first substrate and said second substrates;

said second step including the step of

forming a second sensor electrode on a partial area of said second substrate, and

said first step including the steps of

forming an alignment film on said first substrate,

forming a first sensor electrode on a partial area on said alignment film in a position where said first sensor electrode faces said second sensor electrode through a layer of said liquid crystal formed in said third step, and

rubbing said alignment film in one direction in a state in which said first sensor electrode is formed.

15. The method of manufacturing a liquid crystal display device according to claim 14, wherein in the step of forming said first sensor electrode, said first sensor electrode is formed so as to become a pattern having either a rectangular or line-like shape lengthwise in a direction of the rubbing at least within an effective pixel area.