IP Library Granted Patent US 7,907,225
Granted Patent B2
US 7,907,225 · App. 12/562,636 · Granted Mar 15, 2011

Liquid crystal display device

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Quick Facts
Patent No.
US 7,907,225
App. No.
12/562,636
Granted
Mar 15, 2011
Kind
B2
Abstract

A display device includes a substrate, a gate line formed over the substrate, a first insulating film formed over the substrate and the gate line, a semiconductor film formed over the first insulating film, a drain electrode formed over the semiconductor film, a source electrode formed over the semiconductor film, a data line connected to the drain electrode and formed over the first insulating film, a second insulating film formed over the source electrode and the data line, a pixel electrode electrically connected to the source electrode and formed over the second insulating film, and a transparent conductive film connected to the data line through a contact hole formed in the second insulating film. The transparent conductive film includes a first portion which none of the first insulating film and the second insulating film underlie.

Claims (31)

1. A display device comprising:

a substrate;

a plurality of gate lines formed over the substrate;

a first insulating film formed over the substrate and the plurality of gate lines;

a plurality of data lines formed over the first insulating film, each of the plurality of data lines being formed of a first electrically conductive film;

a plurality of thin film transistors, each of the plurality of thin film transistors having a semiconductor layer comprising an i-type semiconductor and an impurity doped semiconductor laminated over the first insulating film, a first electrode formed over the semiconductor layer, and a second electrode formed by a part of a corresponding one of the plurality of data lines;

a second insulating film formed over the plurality of data lines and the plurality of thin film transistors;

a plurality of pixel electrodes formed over the second insulating film, each of the plurality of pixel electrodes comprising a second electrically conductive film and being coupled to the first electrode of a corresponding one of the plurality of thin film transistors via a first opening formed in the second insulating film;

a plurality of transparent conductive films, each of the plurality of transparent conductive films comprising the second electrically conductive film and being coupled to a corresponding one of the plurality of data lines via a second opening formed in the second insulating film;

wherein each of the plurality of transparent conductive films, extending from the second opening, includes a first portion;

wherein none of the first insulating film and the second insulating film exist between the substrate and the first portion; and

wherein, in a cross section of an end portion of the first electrode in a direction of a length of a channel of the plurality of thin film transistors, the impurity doped semiconductor is configured to extend a minimum distance of 0.2 μm beyond the first electrode in the direction of a length of a channel of the plurality of thin film transistors in order to prevent overhang of the first electrode beyond the impurity doped semiconductor, and the i-type semiconductor is configured to extend beyond the impurity doped semiconductor in the direction of a length of a channel of the plurality of thin film transistors.

2. A display device according to claim 1 , wherein the second electrically conductive film is comprised of an oxide.

3. A display device according to claim 1 , wherein the second electrically conductive film is comprised of indium-tin-oxide and overlaps an end portion of the first electrode.

4. A display device according to claim 1 , wherein the i-type semiconductor and the impurity-doped semiconductor are in contact with each other in the neighborhood of a channel region of the thin film transistor.

5. A display device according to claim 1 , wherein, in a cross section of an end portion of the first electrode in a direction of a length of a channel of the plurality of thin film transistors, the impurity-doped semiconductor is configured to extend a distance of 0.2 μm to 0.7 μm beyond the first electrode in the direction of the length of a channel of the plurality of thin film transistors.

6. A display device comprising:

a substrate;

a plurality of gate lines formed over the substrate;

a first insulating film formed over the substrate and the plurality of gate lines;

a plurality of data lines formed over the first insulating film, each of the plurality of data lines being formed of a first electrically conductive film;

a plurality of thin film transistors, each of the plurality of thin film transistors having a semiconductor layer comprising an i-type semiconductor and an impurity doped semiconductor laminated over the first insulating film, a first electrode formed over the semiconductor layer, and a second electrode formed by a part of a corresponding one of the plurality of data lines;

a second insulating film formed over the plurality of data lines and the plurality of thin film transistors;

a plurality of pixel electrodes formed over the second insulating film, each of the plurality of pixel electrodes comprising a second electrically conductive film and being coupled to the first electrode of a corresponding one of the plurality of thin film transistors via a first opening formed in the second insulating film;

a plurality of transparent conductive films, each of the plurality of transparent conductive films comprising the second electrically conductive film and being coupled to a corresponding one of the plurality of data lines via second opening formed in the second insulating film;

wherein each of the plurality of transparent conductive films, extending from the second opening, has a portion thereof directly on the substrate; and

wherein, in a cross section of an end portion of the first electrode in a direction of a length of a channel of the plurality of thin film transistors, the impurity-doped semiconductor is configured to extend a minimum distance of 0.2 μm beyond the first electrode in the direction of a length of a channel of the plurality of thin film transistors in order to prevent overhang of the first electrode beyond the impurity doped semiconductor, and the i-type semiconductor is configured to extend beyond the impurity doped semiconductor in the direction of a length of a channel of the plurality of thin film transistors.

7. A display device according to claim 6 , wherein the second electrically conductive film is comprised of an oxide.

8. A display device according to claim 6 , wherein the second electrically conductive film is comprised of indium-tin-oxide and overlaps an end portion of the first electrode.

9. A display device according to claim 6 , wherein the i-type semiconductor and the impurity-doped semiconductor are in contact with each other in the neighborhood of a channel region of the thin film transistor.

10. A display device according to claim 6 , wherein, in a cross section of an end portion of the first electrode in a direction of a length of a channel of the plurality of thin film transistors, the impurity-doped semiconductor is configured to extend a distance of 0.2 μm to 0.7 μm beyond the first electrode in the direction of the length of a channel of the plurality of thin film transistors.

Assignments (3)
COMPANY SPLIT PLAN TRANSFERRING FIFTY (50) PERCENT SHARE OF PATENTS AND PATENT APPLICATIONS Recorded Dec 12, 2011
From: HITACHI DISPLAYS, LTD.
To: IPS ALPHA SUPPORT CO., LTD.
Reel/Frame 027362/0466 →
COMPANY SPLIT PLAN TRANSFERRING ONE HUNDRED (100) PERCENT SHARE OF PATENT AND PATENT APPLICATIONS Recorded Dec 12, 2011
From: HITACHI, LTD.
To: HITACHI DISPLAYS, LTD.
Reel/Frame 027362/0612 →
MERGER/CHANGE OF NAME Recorded Dec 12, 2011
From: IPS ALPHA SUPPORT CO., LTD.
To: PANASONIC LIQUID CRYSTAL DISPLAY CO., LTD.
Reel/Frame 027363/0315 →