Liquid crystal display device

• US 8,390,772 B2
• Filed: 10/23/2008
• Issued: 03/05/2013
• Est. Priority Date: 11/28/2007
• Status: Expired due to Fees

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Mitsui, Masashi
• Primary Examiner(s): Merlin, Jessica M
• Application Number:
  US12/256,923
• Publication Number:
  US 20090135354A1
• Time in Patent Office: 1,594 Days
• Field of Search: 349/114, 349/141
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned

Abstract

A liquid crystal display device includes a first substrate, a second substrate, a liquid crystal layer arranged between the first substrate and the second substrate, a plurality of pixels each one of which has a tranmissive display portion for performing a tranmissive display operation and a reflective display portion for performing a reflective display operation, a first electrode provided in the first substrate, a second electrode provided in the first substrate and a third electrode provided in one of the first substrate and the second substrate. The first electrode is arranged both in the tranmissive display portion and in the reflective display portion. The second electrode is arranged in the tranmissive display portion. The first electrode and the second electrode are configured to control an alignment of liquid crystal molecules of the liquid crystal layer. At least one of the first electrode and the second electrode is provided with a plurality of slits formed to extend along a perpendicular axis that is perpendicular to an interface of the tranmissive display portion and the reflective display portion. The third electrode is arranged in the reflective display portion. The second electrode and the third electrode are configured to be provided with voltage independently.

Claims

1. A liquid crystal display device, comprising:

a first substrate;

a second substrate;

a liquid crystal layer arranged between the first substrate and the second substrate;

a plurality of pixels each one of which has a transmissive display portion for performing a transmissive display operation and a reflective display portion for performing a reflective display operation;

a first electrode provided in the first substrate, the first electrode arranged both in the transmissive display portion and in the reflective display portion;

a second electrode provided in the first substrate, the second electrode arranged in the transmissive display portion, the first electrode and the second electrode configured to control an alignment of liquid crystal molecules of the liquid crystal layer, at least one of the first electrode and the second electrode provided with a plurality of slits formed to extend along a perpendicular axis that is perpendicular to an interface of the transmissive display portion and the reflective display portion;

an insulating film formed on the second electrode;

a reflecting plate formed on the insulating film and positioned between the first electrode and the second electrode, the reflecting film being a conductive film that is electrically connected to the first electrode; and

a third electrode formed in the second substrate, the third electrode arranged in the reflective display portion, the second electrode and the third electrode configured to be provided with voltage independently,

wherein the transmissive display portion is driven by a first driving method, and the reflective display portion is driven by a second driving method that is different from the first driving method, and

wherein the first electrode and the second electrode are configured to hold capacitance.

2. The liquid crystal display device according to claim 1, wherein the slits extend parallel or inclined at −

15 to 15 degrees with respect to the perpendicular axis.

3. The liquid crystal display device according to claim 1, wherein an initial alignment of the liquid crystal molecules is arranged parallel or inclined at −

15 to 15 degrees with respect to an extending direction of the slits.

4. The liquid crystal display device according to claim 1, wherein the second electrode and the third electrode of the transmissive display portion and the reflective display portion are a pair of common electrodes provided with voltages in opposite phases.

5. The liquid crystal display device according to claim 1, wherein an the slits are formed in one of the first electrode and the second electrode arranged on a side of the liquid crystal layer.

6. The liquid crystal display device according to claim 1, wherein the slits are formed both in the first electrode and the second electrode.

7. The liquid crystal display device according to claim 1, wherein the slits are arranged only in the transmissive display portion.

8. The liquid crystal display device according to claim 1, wherein the first electrode is arranged on a face of the second electrode facing the liquid crystal layer.

9. The liquid crystal display device according to claim 1, wherein the first driving method is a fringe field switching (FFS) method, and the second driving method is an electronically controlled birefringence (ECB) method.

10. The liquid crystal display device according to claim 1, wherein the second electrode is arranged only in the transmissive display portion, and the third electrode is arranged only in the reflective display portion.