Transflective LCD unit

• US 8,885,126 B2
• Filed: 07/31/2013
• Issued: 11/11/2014
• Est. Priority Date: 11/08/2007
• Status: Active Grant

• Current Assignee: NLT Technologies, Ltd.
• Original Assignee: NLT Technologies, Ltd.
• Inventors: Mori, Kenichi, Sakamoto, Michiaki, Nagai, Hiroshi
• Primary Examiner(s): Merlin, Jessica M
• Application Number:
  US13/955,995
• Publication Number:
  US 20130314654A1
• Time in Patent Office: 468 Days
• Field of Search: 349/114, 349/129, 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 1/134318 having a patterned common electrode
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

A transflective LCD unit includes a liquid crystal (LC) layer: first and second substrates sandwiching therebetween the LC layer to define an array of pixels each including a reflective area and a transmissive area; an electrode assembly for driving the LC layer such that the LC layer in the reflective area is driven in a longitudinal-electric-field mode and the LC layer in the transmissive area is driven in a lateral-electric-field mode; and a reverse-tilt control member for controlling a reverse tilt area in which a reverse tilt of LC molecules occurs near the boundary between the reflective area and the transmissive area.

Claims

1. A transflective liquid crystal display (LCD) unit comprising:

a liquid crystal (LC) layer;

first and second substrates sandwiching therebetween said LC layer to define an array of pixels in said LC layer, said pixels each including a reflective area and a transmissive area;

an electrode assembly for driving said LC layer such that said LC layer in said reflective area is driven in a longitudinal-electric-field mode and said LC layer in said transmissive area is driven in a lateral-electric-field mode; and

a reverse-tilt control member disposed in a vicinity of a boundary between said reflective area and said transmissive area for controlling a reverse tilt area in which a reverse tilt of LC molecules occurs in said LC layer,

wherein said electrode assembly includes a reflective-area pixel electrode, a transmissive-area pixel electrode and a transmissive-area common electrode formed on said first substrate, and a reflective-area common electrode formed on said second substrate, and said reverse-tilt control member restricts said reverse tilt area within a vicinity of said second substrate,

wherein said electrode assembly further comprises a subsidiary electrode formed on said first substrate and applied with a signal applied to said reflective-area common electrode,

wherein said reflective-area common electrode overlaps a boundary line formed by a line between said reflective area and said transmissive area, and

wherein said subsidiary electrode is formed independently from each of said reflective-area pixel electrode, said reflective-area common electrode, said transmissive-area pixel electrode and said transmissive-area common electrode, in an area between a first area where said reflective-area pixel electrode and said reflective area common electrode are formed and a second area where said transmissive-area pixel electrode and said transmissive-area common electrode are formed, on a planarization film on which both said transmissive area common electrode and said transmissive area pixel electrode are formed,

whereby said reverse tilt area is controlled to be generated between the first area and the second area.

2. The transflective LCD unit according to claim 1, wherein said reflective-area common electrode and said transmissive-area common electrode are applied with different signals.

3. A terminal device including the transflective LCD unit according to claim 1.