Liquid crystal display device and electronic apparatus

• US 7,602,463 B2
• Filed: 07/13/2006
• Issued: 10/13/2009
• Est. Priority Date: 07/15/2005
• Status: Expired due to Fees

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sanyo Epson Imaging Devices Corporation (Seiko Group)
• Inventors: Matsushima, Toshiharu, Tsuchiya, Hitoshi
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): Vu; Phu
• Application Number:
  US11/485,382
• Publication Number:
  US 20070013773A1
• Time in Patent Office: 1,188 Days
• Field of Search: 349/114, 349/117
• US Class Current: 349/117
• 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 1/133631 with a spatial distribution of the retardation value
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

A liquid crystal display device includes a first substrate and a second substrate opposed to each other with a liquid crystal layer therebetween, in which a first electrode and a second electrode are provided on a side of the first substrate opposed to the liquid crystal layer and the liquid crystal layer is driven by means of an electric field generated between the first electrode and the second electrode. A reflective display area for reflective display and a transmissive display area for transmissive display are formed in a sub pixel area. The thickness of the liquid crystal layer in the reflective display area is greater than the thickness of the liquid crystal layer in the transmissive display area. A retardation layer is selectively formed in an area corresponding to at least the reflective display area on a side of the second substrate opposed to the liquid crystal layer.

Claims

1. A liquid crystal display device, comprising:

a first substrate and a second substrate opposed to each other;

a liquid crystal layer between the first substrate and the second substrate, liquid crystal molecules of the liquid crystal layer aligning with a first direction in an initial state;

a first electrode and a second electrode between the liquid crystal layer and the first substrate, an electric field being generated between the first electrode and the second electrode and driving the liquid crystal layer;

a sub pixel area including a reflective display area for reflective display and a transmissive display area for transmissive display, a thickness of the liquid crystal layer in the reflective display area being less than a thickness of the liquid crystal layer in the transmissive display area; and

a retardation layer in between the liquid crystal layer and the second substrate selectively in an area corresponding to at least the reflective display area, the retardation layer having a phase-lag axis in a second direction intersecting the first direction, the first direction and the second direction defining an acute angle and an obtuse angle,

wherein when the electric field is generated between the first electrode and the second electrode, the liquid crystal molecules move from alignment in the first direction in the initial state, through a region that corresponds to the obtuse angle, and into alignment with the electric field.

2. The liquid crystal display device according to claim 1, wherein the liquid crystal layer in the reflective display area causes a phase difference of about λ

/4 to incident light at a time of non-driving.

3. The liquid crystal display device according to claim 2, the retardation layer causing a phase difference of about λ

/2 to the incident light.

4. The liquid crystal display device according to claim 1, the thickness of the liquid crystal layer being adjusted by stacking the retardation layer and a resin layer.

5. The liquid crystal display device according to claim 3, the first electrode and the second electrode having a plurality of band-shaped electrodes.

6. The liquid crystal display device according to claim 3, the first electrode being a two-dimensional solid electrode and the second electrode having a plurality of band-shaped electrodes.

7. The liquid crystal display device according to claim 1, a color material layer having a plane area corresponding to the sub pixel area being formed on a side of the second substrate opposed to the liquid crystal layer, the color material layer having a first color material area corresponding to the transmissive display area and a second color material area corresponding to the reflective display area, and a recessed portion being formed in the second color material area by removing a part of the color material layer;

and

a planarization layer that makes at least the recessed portion of the color material layer flat being formed on the color material layer and the retardation layer being formed on the planarization layer.

8. An electronic apparatus, comprising:

the liquid crystal display device according to claim 1.