Full-color liquid crystal display device and fabrication process therefor

• US 5,625,474 A
• Filed: 05/31/1996
• Issued: 04/29/1997
• Est. Priority Date: 06/02/1995
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tanaka, Atsushi, Mitsui, Seiichi, Aomori, Shigeru
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGUYEN, TIEP HUU
• Application Number:
  US08/658,891
• Time in Patent Office: 333 Days
• Field of Search: 359/59, 359/53, 359/87, 359/60
• US Class Current: 349/79
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
• CPC Class Codes: G02F 1/13475 in which at least one liquid crystal cell or layer is doped with a pleochroic dye, e.g. GH-LC cell G02F1/13476 takes precedence

Abstract

A full-color liquid crystal display device is provided which includes: a first substrate formed with a plurality of liquid crystal driving active elements; and first, second and third liquid crystal cells stacked one on another on an inter-layer film formed on the first substrate; the first liquid crystal cell including a first liquid crystal driving electrode connected to a first liquid crystal driving active element formed on the first substrate; the second liquid crystal cell formed on the second substrate and including a second liquid crystal driving electrode connected to a second liquid crystal driving active element formed on the first substrate via a lower stereo-interconnection extending through the first liquid crystal cell; the third liquid crystal cell formed on the third substrate and including a third liquid crystal driving electrode connected to a third liquid crystal driving active element formed on the first substrate via another lower stereo-interconnection extending through the first liquid crystal cell and an upper stereo-interconnection extending through the second liquid crystal cell.

Claims

1. A full-color liquid crystal display device comprising:

a plurality of liquid crystal driving active elements formed on a first substrate; and

first, second and third liquid crystal cells stacked one on another on an inter-layer film formed on the first substrate;

the first liquid crystal cell including a first liquid crystal driving electrode connected to a first liquid crystal driving active element formed on the first substrate, a first counter electrode facing opposite the first liquid crystal driving electrode, a second substrate having the first counter electrode formed on an lower surface thereof, and a first liquid crystal layer sandwiched between the first liquid crystal driving electrode and the first counter electrode;

the second liquid crystal cell formed on the second substrate and including a second liquid crystal driving electrode connected to a second liquid crystal driving active element formed on the first substrate via a lower stereo-interconnection extending through the first liquid crystal cell, a second counter electrode facing opposite the second liquid crystal driving electrode, a third substrate having the second counter electrode formed on a lower surface thereof, and a second liquid crystal layer sandwiched between the second liquid crystal driving electrode and the second counter electrode;

the third liquid crystal cell formed on the third substrate and including a third liquid crystal driving electrode connected to a third liquid crystal driving active element formed on the first substrate via another lower stereo-interconnection extending through the first liquid crystal cell and an upper stereo-interconnection extending through the second liquid crystal cell, a third counter electrode facing opposite the third liquid crystal driving electrode, a fourth substrate having the third counter electrode formed on a lower surface thereof, and a third liquid crystal layer sandwiched between the third liquid crystal driving electrode and the third counter electrode.

2. A full-color liquid crystal display device as set forth in claim 1, wherein the first, second and third liquid crystal layers respectively comprise liquid crystal compositions containing different dyes.

3. A full-color liquid crystal display device as set forth in claim 1, wherein the upper and lower stereo-interconnections each include a metal interconnection or an anisotropic conductive member and an electrode pad.

4. A full-color liquid crystal display device as set forth in claim 1, wherein the first liquid crystal driving electrode is a reflective type electrode, the liquid crystal display device further comprising a 1/4-wave plate provided between the first liquid crystal driving electrode and the first liquid crystal layer.

5. A full-color liquid crystal display device as set forth in claim 1, wherein the first, second and third liquid crystal driving electrodes are transparent electrodes, the liquid crystal display device further comprising a polarizer and a back light provided on an opposite side of the first substrate to the first liquid crystal cell.

6. A process for fabricating a full-color liquid crystal display device, comprising the steps of:

(i) forming a plurality of liquid crystal driving active elements on a first substrate, and forming an inter-layer film on the entire surface of the first substrate including the liquid crystal driving active elements, the inter-layer film having a plurality of contact holes extending therethrough to the liquid crystal driving active elements;

(ii) forming on the inter-layer film a first liquid crystal driving electrode connected to a first liquid crystal driving active element and electrode pads respectively connected to second and third liquid crystal driving active elements, and forming lower stereo-interconnection layers respectively connected to the electrode pads formed on the inter-layer film;

(iii) forming electrode pads and a first counter electrode on one surface of a second substrate, and bonding the second substrate to the first substrate in such a manner that the first counter electrode and the first liquid crystal driving electrode face opposite to each other to define a desired space therebetween;

(iv) forming on the other surface of the second substrate an electrode pad and a second liquid crystal driving electrode connected to one of the lower stereo-interconnection layers, and forming an upper stereo-interconnection layer connected to the electrode pad formed on the other surface of the second substrate;

(v) forming a second counter electrode and an electrode pad on one surface of a third substrate, and bonding the third substrate to the second substrate in such a manner that the second counter electrode and the second liquid crystal driving electrode face opposite to each other to define a desired space therebetween;

(vi) forming on the other surface of the third substrate a third liquid crystal driving electrode connected to the upper stereo-interconnection layer;

(vii) forming a third counter electrode on a surface of a fourth substrate, and bonding the fourth substrate to the third substrate in such a manner that the third counter electrode and the third liquid crystal driving electrode face opposite to each other to define a desired space therebetween; and

(viii) filling liquid crystal compositions into the spaces defined between the first counter electrode and the first liquid crystal driving electrode, between the second counter electrode and the second liquid crystal driving electrode and between the third counter electrode and the third liquid crystal driving electrode to form first, second and third liquid crystal layers, respectively.

7. A process as set forth in claim 6, wherein the liquid crystal compositions of the first, second and third liquid crystal layers respectively contain different dyes.

8. A process as set forth in claim 6, wherein metal interconnections or anisotropic conductive members are formed as the upper and lower stereo-interconnection layers.

9. A process as set forth in claim 6, wherein the first liquid crystal driving electrode is formed of a reflective type electrode material in step (ii), the process further comprising the step of forming a 1/4-wave plate on the first liquid crystal driving electrode.

10. A process as set forth in claim 6, wherein the first, second and third liquid crystal driving electrodes are formed of a transparent electrode material, the process further comprising the step of forming a polarizer and a back light on an opposite side of the first substrate to the first liquid crystal cell.