Liquid crystal display and method of manufacturing liquid crystal display

• US 8,659,726 B2
• Filed: 12/27/2007
• Issued: 02/25/2014
• Est. Priority Date: 04/13/2007
• 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, Kikuchi, Tetsuo, Kitagawa, Hideki, Hara, Yoshihito, Shimada, Junya, Imade, Mitsunori, Kataoka, Yoshiharu
• Primary Examiner(s): Glick, Edward
• Assistant Examiner(s): CHUNG, DAVID Y
• Application Number:
  US12/595,782
• Publication Number:
  US 20100053517A1
• Time in Patent Office: 2,252 Days
• Field of Search: 349/38, 349/39, 349/113, 349/114, 349/129, 349/130
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps
• CPC Class Codes: G02F 1/136236 using a grey or half tone lithographic process
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line

Abstract

Transflective-type and reflection type liquid crystal display devices having a high image quality are provided with a good production efficiency.

A liquid crystal display device according to the present invention is a liquid crystal display device which includes; a first substrate and a second substrate between which liquid crystal is interposed; a first electrode and a second electrode formed on the first substrate for applying a voltage for controlling an orientation of the liquid crystal; a transistor having an electrode which is electrically connected to the first electrode; a metal layer being formed on the first substrate and including a protrusion, a recess, or an aperture; and a reflective layer formed above the metal layer on the first substrate for reflecting incident light toward a display surface. The metal layer is made of a same material as that of a gate electrode of the transistor. The reflective layer includes a protrusion, a recess, or a level difference which is formed in accordance with a protrusion, a recess, or an aperture of the metal layer.

Claims

1. A liquid crystal display device comprising:

a first substrate and a second substrate between which liquid crystal is interposed;

a first electrode and a second electrode formed on the first substrate for applying a voltage for controlling an orientation of the liquid crystal;

a transistor having an electrode which is electrically connected to the first electrode;

a metal layer formed on the first substrate, the metal layer including a protrusion, a recess, or an aperture;

a reflective layer formed above the metal layer in the first substrate, the reflective layer reflecting incident light toward a display surface, wherein,

the metal layer is made of a same material as that of a gate electrode of the transistor; and

the reflective layer includes a protrusion, a recess, or a level difference which is formed in accordance with the protrusion, recess, or aperture of the metal layer; and

under the reflective layer, a semiconductor layer made of a same material as a semiconductor portion of the transistor, the semiconductor layer including a protrusion, a recess, or an aperture, wherein, the reflective layer includes a protrusion, a recess, or a level difference which is formed in accordance with the protrusion, recess, or aperture of the semiconductor layer.

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

the second electrode includes a protrusion, a recess, or an aperture;

and

the reflective layer includes a protrusion, a recess, or a level difference which is formed in accordance with the protrusion, recess, or aperture of the second electrode.

3. The liquid crystal display device of claim 1, wherein the reflective layer is made of a same material as that of a source electrode or a drain electrode of the transistor.

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

an insulating layer is formed between the metal layer and the second electrode;

and

a contact hole electrically connecting the metal layer and the second electrode is formed in the insulating layer.

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

the second electrode is formed under the metal layer, and includes a protrusion, a recess, or an aperture;

and

the metal layer includes a protrusion, a recess, or a level difference which is formed in accordance with the protrusion, recess, or aperture of the second electrode.

7. The liquid crystal display device of claim 1, wherein the first electrode is a pixel electrode, and the second electrode is a counter electrode formed under the first electrode.

8. The liquid crystal display device of claim 1, wherein the first electrode is a pixel electrode, and the second electrode is a counter electrode formed on a same plane as the first electrode.

5. A liquid crystal display device comprising:

a first substrate and a second substrate between which liquid crystal is interposed;

a first electrode and a second electrode formed on the first substrate for applying a voltage for controlling an orientation of the liquid crystal;

a transistor having an electrode which is electrically connected to the first electrode;

a metal layer formed on the first substrate, the metal layer including a protrusion, a recess, or an aperture;

a reflective layer formed above the metal layer in the first substrate, the reflective layer reflecting incident light toward a display surface, wherein,

the metal layer is made of a same material as that of a gate electrode of the transistor; and

the reflective layer includes a protrusion, a recess, or a level difference which is formed in accordance with the protrusion, recess, or aperture of the metal layer; and

wherein the reflective layer includes an aperture.

9. A production method for a liquid crystal display device including a first substrate and a second substrate between which liquid crystal is interposed and a first electrode and a second electrode for applying a voltage for controlling an orientation of the liquid crystal, the liquid crystal display device having:

a reflection region including a reflective layer for reflecting incident light toward a display surface; and

a TFT region, the production method comprising the steps of;

(a) forming a gate layer in the TFT region;

(b) forming a semiconductor layer above the gate layer in the TFT region;

wherein, at step (b), in the reflection region a semiconductor layer including a protrusion, a recess, and/or an aperture is formed from a same material as that of the semiconductor layer in the TFT region; and

(c) forming a source electrode and a drain electrode above the semiconductor layer in the TFT region, wherein,

at step (a), a first metal layer including a protrusion, a recess, or an aperture is formed in the reflection region, from a same material as that of the gate layer of the TFT region, or

at step (c), a second metal layer including a protrusion, a recess, or an aperture is formed in the reflection region, from a same material as that of the source electrode or drain electrode in the TFT region.

10. The production method for a liquid crystal display device of claim 9, wherein the first metal layer or the second metal layer constitutes the reflective layer.

11. The production method of claim 9, wherein, at step (c), in the second metal layer, a protrusion, a recess, or a level difference which is in accordance with the protrusion, recess, or aperture of the first metal layer is formed.