Apparatus for providing light shielding in a liquid crystal display

• US 6,717,633 B2
• Filed: 03/19/2001
• Issued: 04/06/2004
• Est. Priority Date: 02/27/1997
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Murade, Masao
• Primary Examiner(s): TON, MINH TOAN T
• Application Number:
  US09/810,615
• Publication Number:
  US 20010019384A1
• Time in Patent Office: 1,114 Days
• Field of Search: 399/44, 399/110, 399/111, 399/43, 399/139, 399/38
• US Class Current: 349/44
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: H01L 29/78633 with a light shield
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells

Abstract

A leak current due to the effect of light reflected by a polarizing plate or the like is suppressed in pixel switching TFTs in a liquid crystal device and a projection type display device comprising the liquid crystal device, and the characteristics of pixel switching TFT are stabilized. In a liquid crystal device substrate of a liquid crystal device, a first light shielding film is provided below at least the channel region of pixel switching TFTs, extending along scanning lines and connected to constant potential wiring for supplying a constant potential on an outside of the pixel region to fix the potential of the first light shielding film.

Claims

1. A liquid crystal device, comprising:

a liquid crystal device substrate including a display region in which pixels are formed in a matrix by a plurality of data lines and a plurality of scanning lines, a peripheral circuit electrically connected to at least one of the data lines and the scanning lines on an outer peripheral side of the display region, and a plurality of thin film transistors disposed corresponding to an intersection of the data lines and the scanning lines, and a liquid crystal held between the liquid crystal device substrate and an opposite substrate;

a peripheral partitioning light shielding film formed in an outer peripheral of the display region;

a plurality of conductive first light shielding films that shield respective channel regions of the thin film transistors, the plurality of conductive first light shielding films being formed below at least the respective channel regions of the thin film transistors so as to extend along at least one of the scanning line and the data line; and

a constant potential wiring electrically connected to the conductive first light shielding films, the films being connected with each other and below the peripheral partitioning light shielding film.

2. The liquid crystal device according to claim 1, wherein the constant potential wiring being disposed below the peripheral partitioning light shielding film.

3. The liquid crystal device according to claim 2, wherein the constant potential wiring and the conductive light shielding film being connected to each other via a contact hole.

4. The liquid crystal device according to claim 3, wherein the contact hole is positioned below a region of the peripheral partitioning light shielding film which is extended from a plurality of contact holes, and which is connected to the data lines and the thin film transistors.

5. The liquid crystal device according to claim 2, wherein the constant potential wiring and the conductive light shielding film being connected via a junction electrode.

6. The liquid crystal device according to claim 5, wherein a contact hole connecting the constant potential wiring and the junction electrode and a contact hole connecting the conductive light shielding film and the junction electrode are positioned offset.

7. The liquid crystal device according to claim 2, wherein the constant potential wiring is connected to a capacitance electrode.

8. The liquid crystal device according to claim 7, wherein the capacitance electrode extends parallel to the conductive first light shielding film.