Liquid crystal display in which at least one pixel includes both a transmissive region and a reflective region

• US 6,452,654 B2
• Filed: 12/20/2000
• Issued: 09/17/2002
• Est. Priority Date: 07/28/1997
• 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: Ban, Atsushi, Nishiki, Hirohiko, Yoshimura, Yoji, Shimada, Takayuki, Kubo, Masumi, Ishii, Yutaka, Narutaki, Yozo, Katayama, Mikio
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Chowdhury, Tarifur R.
• Application Number:
  US09/739,697
• Publication Number:
  US 20010020991A1
• Time in Patent Office: 636 Days
• Field of Search: 349/43, 349/44, 349/113, 349/112, 349/114, 349/147, 349/143
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• 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 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/13712 the liquid crystal having negative dielectric anisotropy
• CPC Class Codes: G02F 1/13725 based on guest-host interaction G02F1/13762, G02F1/13737, take precedence

Abstract

A liquid crystal display device according to the present invention includes a first substrate, a second substrate, and a liquid crystal layer interposed between the first substrate and the second substrate. The first substrate includes: a plurality of gate lines; a plurality of source lines arranged to cross with the plurality of gate lines; a plurality of switching elements disposed in the vicinity of crossings of the plurality of gate lines and the plurality of source lines; and a plurality of pixel electrodes connected to the plurality of switching elements. The second substrate includes a counter electrode. A plurality of pixel regions are defined by the plurality of pixel electrodes, the counter electrode, and the liquid crystal layer interposed between the plurality of pixel electrodes and the counter electrode, and each of the plurality of pixel regions includes a reflection region and a transmission region.

Claims

1. A liquid crystal display element comprising:

a liquid crystal layer;

a pair of substrates having the liquid crystal layer interposed therebetween;

a pixel region formed within the pair of substrates being defined by pixel electrodes for applying a voltage to the liquid crystal layer; and

wherein the pixel region includes a first region having a non-transmissive reflection layer with light-reflectivity and a second region having light-transmissivity, and reflected light from the first region and transmitted light from the second region are adapted to contribute to display so that the display can operate in a transmissive mode and in a reflective mode; and

wherein within the pixel region the first region is formed in a central portion of a pixel and the second region substantially surrounds the first region in the pixel.

2. A liquid crystal display element according to claim 1, wherein a switching device is provided in the pixel region, and a transparent electrode connected to the switching device functions as a pixel electrode within the first or the second region.

3. A liquid crystal display element according to claim 2, wherein the transparent electrode functions as a pixel electrode within the first and second regions.

4. A liquid crystal display element according to claim 2, wherein the reflection layer is made of the same material as an address line connected to the switching device.

5. A liquid crystal display element according to claim 1, wherein the liquid crystal device is a simple matrix type, and the pixel region is defined by two strip electrodes crossing each other.

6. A liquid crystal display element according to claim 1, wherein within the pixel region, an area of first region is substantially at least 10% of a total area of the pixel region.

7. A liquid crystal display element according to claim 1, further comprising a diffusion means for diffusing reflected light from the first region.

8. A liquid crystal display device according to claim 1, wherein the reflection layer in the first region is adapted to function as one of a respective pair of pixel electrodes.

9. A liquid crystal display device according to claim 8, wherein the reflection layer in the first region is formed in a plane.

10. A liquid crystal display device according to claim 8, wherein the reflection layer in the first region has a configuration for diffusing and reflecting light simultaneously.

11. The display element of claim 1, wherein the display operates in a transmissive mode using a backlight and in a reflective mode using ambient light.

12. A liquid crystal display element comprising:

a liquid crystal layer;

a pair of substrates having the liquid crystal layer interposed therebetween;

a pixel region formed within the pair of substrates being defined by pixel electrodes for applying a voltage to the liquid crystal layer;

wherein the pixel region includes a first region having a reflection layer with light-reflectivity and a second region having light-transmissivity, and reflected light from the first region and transmitted light from the second region are adapted to contribute to display; and

wherein between the first and second regions there is provided a further separate region which has a characteristic of reflection or transmission different from that of the first and second regions.

13. A liquid crystal display element comprising:

a liquid crystal layer;

a pair of substrates having the liquid crystal layer interposed therebetween;

a pixel region formed within the pair of substrates being defined by pixel electrodes for applying a voltage to the liquid crystal layer;

wherein the pixel region includes a first region having a reflection layer with light-reflectivity and a second region having light-transmissivity, and reflected light from the first region and transmitted light from the second region are adapted to contribute to display; and

wherein the reflection layer with light-reflectivity of the first region is provided to function as a pixel electrode within the first region, and within the second region a transmission layer is provided with a light-transmissivity which is more than that of the reflection layer in the first region.