Transflective liquid crystal display device including transmissive and reflective areas in each pixel

• US 8,773,623 B2
• Filed: 03/15/2013
• Issued: 07/08/2014
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: NLT Technologies, Ltd. (Tianma Microelectronics Company Limited)
• Original Assignee: NLT Technologies, Ltd. (Tianma Microelectronics Company Limited)
• Inventors: Sakamoto, Michiaki, Matsushima, Jin, Nagai, Hiroshi, Mori, Kenichi, Ikeno, Hidenori, Kudo, Yasuki, Sumiyoshi, Ken
• Primary Examiner(s): NGO, HUYEN LE
• Application Number:
  US13/834,011
• Publication Number:
  US 20130208217A1
• Time in Patent Office: 480 Days
• Field of Search: 349/114, 349/141, 349/96, 349/103
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0456 with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes

Abstract

An IPS-mode transflective LCD device includes an array of pixels each including a reflective region and a transmissive region. A first pixel electrode and a first common electrode are formed in the reflective region, and a second pixel electrode and a second common electrode are formed in the transmissive region. The first and second pixel electrodes receive a common pixel signal. The first common electrode receives a first common signal which is common among the reflective regions of a plurality of pixels, and the second common electrode receives a second common signal which is common among the transmissive regions of the plurality of pixels.

Claims

1. A transflective liquid crystal display (LCD) device comprising first and second polarizing films having polarizing axes perpendicular to one another, a liquid crystal (LC) layer interposed between said first polarizing film and said second polarizing film, said LC layer defining an array of pixels each including a reflective region and a transmissive region juxtaposed, wherein:

LC molecules of said LC layer have a longer axis extending parallel to or normal to the polarization direction of the light incident onto said LC layer in said reflective region; and

each of said pixels includes a pixel electrode receiving a pixel signal which is common between said reflective region and said transmissive region, a first common electrode, formed in said reflective region, receiving a first common signal which is common among said reflective regions of a plurality of said pixels, and a second common electrode, formed in said transmissive region, receiving a second common signal which is common among said transmissive regions of said plurality of said pixels, wherein said pixel electrode includes a first pixel electrode formed in said reflective region and a second pixel electrode formed in said transmissive region, and each of said pixels is associated with a first switching device for coupling a data line to said first pixel electrode, and a second switching device for coupling said data line to said second pixel electrode, and

wherein said reflective region includes therein a reflection film having a potential substantially equal to a median between a potential of said first pixel electrode and a potential of said first common electrode.

2. The LCD device according to claim 1, wherein a first interconnect applied with the equi-potential with said first pixel electrode and a second interconnect applied with the equi-potential with said first common electrode are provided on the rear side of said reflection film, wherein said potential of said reflection film is determined by a capacitive coupling between said first common electrode and said first pixel electrode.

3. The LCD device according to claim 1, wherein said potential of said reflection film is determined by a potential setting circuit, wherein said potential is applied directly to said reflection film through the potential setting circuit.

4. The LCD device according to claim 1, wherein a portion of said reflection film is omitted in an area directly behind said first pixel electrode and said first common electrode.

5. The LCD device according to claim 1, wherein a portion of said reflection film in an area directly behind said first pixel electrode and said first common electrode has a flat surface, and another portion of said reflection film has an uneven surface.

6. A transflective liquid crystal display (LCD) device comprising a liquid crystal (LC) layer defining an array of pixels arranged in a matrix, each of said pixels including therein a reflective region and a transmissive region juxtaposed, wherein:

each of said pixels includes a first pixel electrode formed in said reflective region, and a second pixel electrode formed in said transmissive region; and

each of said pixels is associated with a first switching device for coupling said first electrode to a data line supplying a data signal, and a second switching device for coupling said second electrode and said data line, each of said pixels including a first common electrode formed in said reflective region, said first common electrode connected in common with common electrodes disposed in said reflective regions of a plurality of said pixels, and a second common electrode formed in said transmissive region, said second common electrode connected in common with common electrodes disposed in said transmissive regions of a plurality of said pixels, wherein said first and second switching devices are connected to a common data line.