Transmissive display device having two reflection metallic layers of differing reflectances

• US 5,818,552 A
• Filed: 07/30/1996
• Issued: 10/06/1998
• Est. Priority Date: 07/31/1995
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sato, Takusei
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MALINOWSKI, WALTER J
• Application Number:
  US08/681,912
• Time in Patent Office: 798 Days
• Field of Search: 359/59, 359/67, 349/42, 349/43, 349/44, 349/110, 349/111
• US Class Current: 349/43
• 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

Abstract

A transmissive display device includes a driving substrate positioned on the emergent side which has both a group of pixels including component units each having a pixel electrode and a switching device, and a black matrix for shielding light from reaching the non-aperture part of each pixel from the incident side. The black matrix has an overlaid structure formed by overlaying a low-reflection metallic layer and a high-reflection metallic layer with an interlayer insulating film provided therebetween. Both layers are patterned, and partially overlap with each other as mutually complement to shield incident light. When observed in plan view from the incident side, the exposing area of the low-reflection layer is enlarged, while the exposing area of the high-reflection metallic layer is reduced to suppress the surface reflectance of the black matrix. Thereby, multiple reflection inside liquid crystal does not occur, and it is possible to prevent contrast deterioration caused by leaked rays.

Claims

1. A display device comprising:

a first substrate;

a second substrate spaced apart from the first substrate having a plurality of transistors formed thereon;

a first reflection metallic layer having a first reflectance formed above and at least partially covering one of said plurality of transistors;

an insulating film formed on the first reflection metallic layer;

a second reflection metallic layer formed on the insulating film over and at least partially covering said one of said plurality of transistors and also being over and at least partially covering a portion of the first reflection metallic layer, said second reflection metallic layer having a second reflectance higher than said first reflectance, wherein said first reflection metallic layer is closer to an incident side than said second reflection metallic layer, and a pattern of said first reflection metallic layer extends over a pattern of said second reflection metallic layer, and wherein said first reflection metallic layer comprises a light-shielding pattern positioned along a row direction and said second reflection metallic layer comprises a wiring pattern positioned along a column direction.

2. A display device according to claim 1, wherein said first reflection metallic layer comprises an extended light-shielding pattern having a floating potential, separated and isolated from a light-shielding pattern whose potential is fixed, and said extended light-shielding pattern is positioned above said wiring pattern.

3. A display device according to claim 2, further comprising electro-optical material comprised of a liquid crystal between said substrates.

4. A display device according to claim 2, wherein said plurality of transistors are thin film transistors.

5. A display device according to claim 2, wherein said first reflection metallic layer is comprised of Ti.

6. A display device according to claim 5, wherein said second reflection metallic layer is comprised of Al.

7. A display device comprising:

a first substrate;

a second substrate spaced apart from the first substrate having a plurality of transistors formed thereon;

a first reflection metallic layer having a first reflectance formed above and at least partially covering one of said plurality of transistors;

an insulating film formed on the first reflection metallic layer;

a second reflection metallic layer formed on the insulating film over and at least partially covering said one of said plurality of transistors and also being over and at least partially covering a portion of the first reflection metallic layer, said second reflection metallic layer having a second reflectance higher than said first reflectance, further comprising a planiarization layer formed above the second reflection metallic layer and a pixel electrode on the planiarization layer.

8. A display device according to claim 7, wherein said second reflection metallic layer is positioned closer to an incident side than said first reflection metallic layer.

9. A display device according to claim 7, further comprising electro-optical material comprised of a liquid crystal between said substrates.

10. A display device according to claim 7, wherein said plurality of transistors are thin film transistors.

11. A display device according to claim 7, wherein said first reflection metallic layer is comprised of Ti.

12. A display device according to claim 11, wherein said second reflection metallic layer is comprised of Al.