Transreflective liquid crystal display apparatus with single cell-gap and reduced power consumption

• US 7,961,279 B2
• Filed: 09/19/2006
• Issued: 06/14/2011
• Est. Priority Date: 12/21/2005
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Il Gon, Kim, Chul Ho
• Primary Examiner(s): KIANNI, KAVEH C
• Application Number:
  US11/524,010
• Publication Number:
  US 20070216821A1
• Time in Patent Office: 1,729 Days
• Field of Search: 349/48, 349/114, 349/39
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode

Abstract

A transreflective liquid crystal display (LCD) apparatus with a single cell gap is presented, along with a method of driving the apparatus. The apparatus operates with low power consumption because its electro-optical characteristics in a transmissive region and a reflective region are equalized. The transreflective LCD apparatus includes first and second liquid crystal cells formed respectively in transmissive and reflective regions of a first subpixel, first and second thin film transistors connected respectively to the first and second liquid crystal cells, and first and second storage capacitors connected respectively to the first and second liquid crystal cells.

Claims

1. A transreflective liquid crystal display apparatus, comprising:

first and second liquid crystal cells formed respectively in transmissive and reflective regions of a first subpixel;

first and second thin film transistors connected respectively to the first and second liquid crystal cells; and

first and second storage capacitors capacitively coupled to the first and second liquid crystal cells, respectively, the first and second storage capacitors having different capacitances from each other and including electrodes that are different from those of liquid crystal capacitors in the liquid crystal cells,

wherein the first and second storage capacitors receive a storage voltage, and

during a time period that the first and second thin film transistors are turned off, a transmissive voltage applied to the first liquid crystal cell and a reflective voltage applied to the second liquid crystal cell are controlled by the storage voltage and have different voltage levels from each other.

2. The transreflective liquid crystal display apparatus of claim 1, wherein areas of first and second storage electrodes of the first and second storage capacitors are different from each other.

3. The transreflective liquid crystal display apparatus of claim 1, further comprising:

third and fourth liquid crystal cells formed respectively in transmissive and reflective regions of a second subpixel adjacent to the first subpixel;

third and fourth thin film transistors connected respectively to the third and fourth liquid crystal cells; and

third and fourth storage capacitors connected respectively to the third and fourth liquid crystal cells.

4. The transreflective liquid crystal display apparatus of claim 3, wherein capacitances of the third and fourth storage capacitors are different from each other.

5. The transreflective liquid crystal display apparatus of claim 4, wherein areas of third and fourth storage electrodes of the third and fourth storage capacitors are different from each other.

6. The transreflective liquid crystal display apparatus of claim 4, further comprising:

fifth and sixth liquid crystal cells formed respectively in transmissive and reflective regions of a third subpixel adjacent to the second subpixel;

fifth and sixth thin film transistors connected respectively to the fifth and sixth liquid crystal cells; and

fifth and sixth storage capacitors connected respectively to the fifth and sixth liquid crystal cells.

7. The transreflective liquid crystal display apparatus of claim 6, wherein capacitances of the fifth and sixth storage capacitors are different from each other.

8. The transreflective liquid crystal display apparatus of claim 7, wherein magnitudes of fifth and sixth storage electrodes of the fifth and sixth storage capacitors are different from each other.

9. The transreflective liquid crystal display apparatus of claim 6, wherein capacitances of the first, third and fifth storage capacitors are different from each other.

10. The transreflective liquid crystal display apparatus of claim 9, wherein areas of the first, third and fifth storage electrodes of the first, third and fifth storage capacitors are different from each other.

11. The transreflective liquid crystal display apparatus of claim 6, wherein capacitances of the second, fourth and sixth storage capacitors are different from each other.

12. The transreflective liquid crystal display apparatus of claim 11, wherein areas of second, fourth and sixth storage electrodes of the second, fourth and sixth storage capacitors are different from each other.

13. The transreflective liquid crystal display apparatus of claim 6, wherein cell gaps of the first to sixth liquid crystal cells are the same.

14. The transreflective liquid crystal display apparatus of claim 6, further comprising:

a plurality of gate lines and a plurality of data lines intersecting each other to define the first to third subpixels; and

a storage line formed alternately with the plurality of gate lines and connected to the first to sixth storage capacitors.

15. The transreflective liquid crystal display apparatus of claim 1, wherein the first and second storage capacitors are connected to a same storage line.

16. The transreflective liquid crystal display apparatus of claim 1, wherein areas of first and second storage electrodes of the first and second storage capacitors are different from each other.

17. The transreflective liquid crystal display apparatus of claim 1, wherein the first and second thin film transistors are connected to a same data line and a same gate line.

18. The transreflective liquid crystal display apparatus of claim 1, wherein the first and second liquid crystal cells have a same cell gap.