Active matrix liquid crystal display device

• US 6,690,434 B1
• Filed: 03/10/2000
• Issued: 02/10/2004
• Est. Priority Date: 03/15/1999
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Murakami, Satoshi, Koyama, Jun, Yamazaki, Shunpei, Tanaka, Yukio
• Primary Examiner(s): CHOWDHURY, TARIFUR RASHID
• Application Number:
  US09/523,661
• Time in Patent Office: 1,432 Days
• Field of Search: 349/44, 349/42, 349/110, 349/111, 349/138, 257/59, 257/72, 345/55
• US Class Current: 349/42
• CPC Class Codes: G02F 1/133509 Filters, e.g. light shielding masks
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/13456 Cell terminals located on one side of the display only
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52

Abstract

An active matrix liquid crystal display device capable of good quality image display is provided by disposing a shielding film on the active matrix substrate side and a shielding film on the opposing substrate side as overlapped. The active matrix liquid crystal display device is characterized by comprising a first substrate comprising a source signal line driver circuit and a first shielding film and a second substrate comprising a second shielding film, in that the second shielding film is overlapped with a portion of, or all of the source signal line driver circuit and the first shielding film and that the second shielding film are partially overlapped.

Claims

1. An active matrix liquid crystal display device comprising:

a first substrate comprising a plurality of source signal lines, a plurality of pixel TFTs, a source signal line driver circuit and a first shielding film; and

a second substrate having a second shielding film, wherein;

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film;

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film is floating;

the plurality of pixel TFTs are connected to the plurality of source signal lines, and the plurality of source signal lines are connected to the source signal line driver circuit; and

the source signal line driver circuit applies signals of an opposite polarity to each adjacent source signal line, and the polarity of the signals applied to the plurality of source signal lines is inverted by each frame.

4. An active matrix liquid crystal display device according to any one of claims 1, 2 and 3 wherein the first shielding film or the second shielding film comprises an element selected from a group consisting of aluminum (Al), titanium (Ti), chromium (Cr) and tantalum (Ta).

5. An active matrix liquid crystal display device according to any one of claims 1, 2 and 3 wherein the first shielding film or the second shielding film comprises a resin in which a black pigment is dispersed.

6. An active matrix liquid crystal display device according to any one of claims 1, 2 and 3 wherein the first shielding film has a thickness between 100 nm and 300 nm.

7. An active matrix liquid crystal display device according to any one of claims 1, 2 and 3, wherein the second shielding film has a thickness between 1000 Å

and 2000 Å

.

8. An active matrix liquid crystal display device according to any one of claims 1, 2 and 3 wherein a distance between the first shielding film and the second shielding film is 20 μ

m or greater.

2. An active matrix liquid crystal display device comprising:

a first substrate comprising a source signal line driver circuit, an ITO wiring, a first shielding film and a common line held at a constant electric potential; and

a second substrate comprising a second shielding film, wherein

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film;

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film and the ITO wiring are connected to the common line; and

a dielectric is held between the first shielding film and the ITO wiring.

9. An active matrix liquid crystal display device according to any one of claims 2 and 3 wherein the dielectric is an anodically oxidized film formed by anodic oxidation of the first shielding film.

3. An active matrix liquid crystal display device comprising:

a first substrate comprising a plurality of source signal lines, a plurality of pixel TFTs, a source signal line driver circuit, an ITO wiring, a first shielding film and a common line held at a constant electric potential; and

a second substrate having a second shielding film, wherein;

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film;

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film is floating;

the ITO wiring is connected to the common line;

a dielectric is held between the first shielding film and the ITO wiring;

the plurality of pixel TFTs are connected to the plurality of source signal lines, and the plurality of source signal lines are connected to the source signal line driver circuit; and

the source signal line driver circuit applies signals of an opposite polarity to each adjacent source signal line, and the polarity of the signals applied to the plurality of source signal lines is inverted by each frame.

10. A rear projector comprising 3 active matrix liquid crystal display devices, wherein the active matrix liquid crystal display device comprises:

a first substrate comprising a plurality of source signal lines, a plurality of pixel TFTs, a source signal line driver circuit and a first shielding film; and

a second substrate comprising a second shielding film, wherein

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film; and

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film is floating;

the plurality of pixel TFTs are connected to the plurality of source signal lines, and the plurality of source signal lines are connected to the source signal line driver circuit; and

the source signal line driver circuit applies signals of an opposite polarity to each adjacent source signal line, and the polarity of the signals applied to the plurality of source signal lines is inverted by each frame.

11. A single plate type rear projector comprising an active matrix liquid crystal display device, wherein the active matrix liquid crystal display device comprises:

a first substrate comprising a plurality of source signal lines, a plurality of pixel TFTs, a source signal line driver circuit and a first shielding film; and

a second substrate comprising a second shielding film, wherein

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film; and

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film is floating;

the plurality of pixel TFTs are connected to the plurality of source signal lines, and the plurality of source signal lines are connected to the source signal line driver circuit; and

the source signal line driver circuit applies signals of an opposite polarity to each adjacent source signal line, and the polarity of the signals applied to the plurality of source signal lines is inverted by each frame.

12. A front projector comprising 3 active matrix liquid crystal display devices, wherein the active matrix liquid crystal display device comprises:

a first substrate comprising a plurality of source signal lines, a plurality of pixel TFTs, a source signal line driver circuit and a first shielding film; and

a second substrate comprising a second shielding film, wherein

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film; and

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film is floating;

the plurality of pixel TFTs are connected to the plurality of source signal lines, and the plurality of source signal lines are connected to the source signal line driver circuit; and

the source signal line driver circuit applies signals of an opposite polarity to each adjacent source signal line, and the polarity of the signals applied to the plurality of source signal lines is inverted by each frame.

13. A notebook type personal computer comprising an active liquid crystal display matrix device, wherein the active matrix liquid crystal display device comprises:

a first substrate comprising a plurality of source signal lines, a plurality of pixel TFTs, a source signal line driver circuit and a first shielding film; and

a second substrate comprising a second shielding film, wherein

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film; and

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film is floating;

the plurality of pixel TFTs are connected to the plurality of source signal lines, and the plurality of source signal lines are connected to the source signal line driver circuit; and

the source signal line driver circuit applies signals of an opposite polarity to each adjacent source signal line, and the polarity of the signals applied to the plurality of source signal lines is inverted by each frame.

14. A mobile computer comprising an active matrix liquid crystal display device, wherein the active matrix liquid crystal display device comprises:

a first substrate comprising a plurality of source signal lines, a plurality of pixel TFTs, a source signal line driver circuit and a first shielding film; and

a second substrate comprising a second shielding film, wherein

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film; and

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film is floating;

the plurality of pixel TFTs are connected to the plurality of source signal lines, and the plurality of source signal lines are connected to the source signal line driver circuit; and

the source signal line driver circuit applies signals of an opposite polarity to each adjacent source signal line, and the polarity of signals applied to the plurality of source signal lines is inverted by each frame.

15. A goggle type display comprising two active matrix liquid crystal display devices, wherein the active matrix liquid crystal display device comprises:

a first substrate comprising a plurality of source signal lines, a plurality of pixel TFTs, a source signal line driver circuit and a first shielding film; and

a second substrate comprising a second shielding film, wherein

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film; and

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film is floating;

the plurality of pixel TFTs are connected to the plurality of source signal lines, and the plurality of source signal lines are connected to the source signal line driver circuit; and

the source signal line driver circuit applies signals of an opposite polarity to each adjacent source signal line, and the polarity of the signals applied to the plurality of source signal lines is inverted by each frame.

16. A goggle type display comprising an active matrix liquid crystal display device, wherein the active matrix liquid crystal display device comprises:

a first substrate comprising a plurality of source signal lines, a plurality of pixel TFTs, a source signal line driver circuit and a first shielding film; and

a second substrate comprising a second shielding film, wherein

a portion of, or all of the source signal line driver circuit is disposed over a portion of or all of the second shielding film; and

a portion of the second shielding film is disposed over a portion of the first shielding film;

the first shielding film is floating;

the plurality of pixel TFTs are connected to the plurality of source signal lines, and the plurality of source signal lines are connected to the source signal line driver circuit; and

the source signal line driver circuit applies signals of an opposite polarity to each adjacent source signal line, and the polarity of the signals applied to the plurality of source signal lines is inverted by each frame.