Liquid crystal display device

• US 8,289,461 B2
• Filed: 12/06/2007
• Issued: 10/16/2012
• Est. Priority Date: 01/24/2007
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Imai, Hajime, Matsumoto, Hitoshi
• Primary Examiner(s): NGO, HUYEN LE
• Application Number:
  US12/523,935
• Publication Number:
  US 20100045885A1
• Time in Patent Office: 1,776 Days
• Field of Search: 349/39, 349/113, 349/141
• US Class Current: 349/39
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 2201/34 reflector

Abstract

A transflective-type liquid crystal display device with a high image quality which has a high aperture ratio and an excellent efficiency of utility of reflected light is provided at low cost. A liquid crystal display device according to the present invention is a liquid crystal display device having a transistor and a reflection section in each of a plurality of pixels; the reflection section includes a metal layer, an insulating layer formed on the metal layer, a semiconductor layer formed on the insulating layer, and a reflective layer formed on the semiconductor layer; a plurality of recesses are formed on the surface of the reflective layer; a storage capacitor is formed between at least a portion of the metal layer and at least a portion of the reflective layer; and at least one of the metal layer and the reflective layer includes two portions which are electrically isolated from each other.

Claims

1. A liquid crystal display device comprising:

gate lines, source lines, and a plurality of pixels, and comprising, in each of the plurality of pixels, a transistor and a reflection section for reflecting incident light toward a display surface, wherein,

the reflection section includes a metal layer, an insulating layer formed on the metal layer, a semiconductor layer formed on the insulating layer, and a reflective layer formed on the semiconductor layer;

the metal layer is electrically connected to neither the gate lines nor the source lines;

a plurality of recesses are formed on a surface of the reflective layer;

a storage capacitor is formed between at least a portion of the metal layer and at least a portion of the reflective layer; and

at least one of the metal layer and the reflective layer includes two portions which are electrically isolated from each other.

2. The liquid crystal display device of claim 1, wherein,

the metal layer includes a first portion and a second portion which are electrically isolated from each other;

the first portion of the metal layer is connected to a storage capacitor line;

the reflective layer is connected to a drain of the transistor; and

the storage capacitor is formed between the first portion of the metal layer and the reflective layer.

3. The liquid crystal display device of claim 1, wherein,

the reflective layer includes a first portion and a second portion which are electrically isolated from each other;

the first portion of the reflective layer is connected to a drain of the transistor;

the metal layer is connected to a storage capacitor line; and

the storage capacitor is formed between the metal layer and the first portion of the reflective layer.

4. The liquid crystal display device of claim 1, wherein,

the metal layer includes a first portion and a second portion which are electrically isolated from each other;

the reflective layer includes a first portion and a second portion which are electrically isolated from each other;

the first portion of the metal layer is connected to a storage capacitor line;

the first portion of the reflective layer is connected to a drain of the transistor; and

the storage capacitor is formed between the first portion of the metal layer and the first portion of the reflective layer.

5. The liquid crystal display device of claim 1, wherein the plurality of recesses include a first recess and a second recess overlapping the first recess.

6. The liquid crystal display device of claim 5, wherein the first recess is formed so as to conform to the shape of the metal layer, and the second recess is formed so as to conform to the shape of the semiconductor layer.

7. The liquid crystal display device of claim 5, wherein the metal layer includes an aperture or a recess, and the first recess is formed correspondingly to the aperture or recess in the metal layer.

8. The liquid crystal display device of claim 5, wherein the semiconductor layer includes an aperture or a recess, and the second recess is formed correspondingly to the aperture or recess in the semiconductor layer.

9. The liquid crystal display device of claim 5, wherein a level difference is formed on a side face of the plurality of recesses.

10. The liquid crystal display device of claim 5, wherein the first recess and the second recess are formed based on the shape of an aperture or a recess which is included in at least two layers among the metal layer, the insulating layer, and the semiconductor layer.

11. The liquid crystal display device of claim 1, wherein the metal layer, the semiconductor layer, and the reflective layer are formed from same materials as, respectively, a gate electrode, a semiconductor portion, and source and drain electrodes of the transistor.

12. The liquid crystal display device of claim 1, comprising:

a liquid crystal layer; and

an interlayer insulating layer and a pixel electrode interposed between the liquid crystal layer and the reflective layer, wherein a face of the pixel electrode facing the liquid crystal layer is formed flat without conforming to shapes of the recesses in the reflective layer.

13. The liquid crystal display device of claim 1, wherein the metal layer is a Cs metal layer.

14. The liquid crystal display device of claim 1, wherein the metal layer and a drain of the transistor in a given pixel are formed in different layers.

15. The liquid crystal display device of claim 1, wherein the metal layer includes two portions in the given pixel which are (i) electrically isolated from each other, and (ii) not electrically connected to the gate or source lines.

16. The liquid crystal display device of claim 1, wherein the reflective layer includes two portions in the given pixel which are (i) electrically isolated from each other, and (ii) not electrically connected to the gate or source lines.