Transflective LCD driven by bi-gamma curve

• US 6,806,929 B2
• Filed: 11/15/2002
• Issued: 10/19/2004
• Est. Priority Date: 03/28/2002
• Status: Expired due to Term

• Current Assignee: InnoLux Corporation
• Original Assignee: Industrial Technology Research Institute
• Inventors: Shen, Yuh-Ren, Chen, Ching-Yih
• Primary Examiner(s): NGO, HUYEN LE
• Application Number:
  US10/294,751
• Publication Number:
  US 20030184695A1
• Time in Patent Office: 704 Days
• Field of Search: 349/114, 349/113, 349/38, 349/143, 349/92, 257/59, 257/72
• US Class Current: 349/114
• 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 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 2203/09 transflective
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• CPC Class Codes: G09G 2310/02 Addressing, scanning or driving the display screen or processing steps related thereto
• CPC Class Codes: G09G 2310/0281 Arrangement of scan or data electrode driver circuits at the periphery of a panel not inherent to a split matrix structure
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A transflective LCD. The transflective LCD includes multiple pixels. Each pixel includes a reflective cell and a transmission cell. The reflective cell has a first storage capacitor and a first active device, receiving a first driving voltage and coupling to the first capacitor. The transmission cell has a second storage capacitor and a second active device, receiving a second driving voltage and coupling to the second capacitor. Different from only single driving voltage in conventional transflective LCD, the first driving voltage and the second voltage are generated according to a reflective gamma curve and a transmission gamma curve respectively.

Claims

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

plural pixels wherein each pixel comprises a reflective region and a transmission region, wherein the reflective region has a first storage capacitor and a first active device, the first active device receiving a first driving voltage and coupling to the first capacitor, and the transmission region has a second storage capacitor and a second active device, the second active device receiving a second driving voltage and coupling to the second capacitor.

2. The transflective LCD as claimed in claim 1, wherein:

the reflective region has a first liquid-crystal layer with a first cell gap; and

the transmission region has a second liquid-crystal layer with a second cell gap.

3. The transflective LCD as claimed in claim 1, wherein:

the first driving voltage is generated according to a reflective gamma curve; and

the second driving voltage is generated according to a transmission gamma curve.

4. The transflective LCD as claimed in claim 3, wherein:

the reflective gamma curve is used for quarter wave mode; and

the transmission gamma curve is used for quarter wave mode.

5. The transflective LCD as claimed in claim 3, wherein:

the reflective gamma curve is used for half wave mode; and

the transmission gamma curve is used for half wave mode.

6. The transflective LCD as claimed in claim 3, wherein:

the reflective gamma curve is used for half wave mode; and

the transmission gamma curve is used for quarter wave mode.

7. The transflective LCD as claimed in claim 3, wherein:

the reflective gamma curve is used for quarter wave mode; and

the transmission gamma curve is used for half wave mode.

8. The transflective LCD as claimed in claim 3, wherein:

the reflective region has a first liquid-crystal layer with a first cell gap;

the transmission region has a second liquid-crystal layer with a second cell gap;

the reflective gamma curve is in according to a phase difference through the first cell gap; and

the transmission gamma curve is in according to another phase difference through the second cell gap.

9. The transflective LCD as claimed in claim 1, wherein:

the first active device has a first control end coupled to a first scan line;

the second active device has a second control end coupled to a second scan line; and

the first driving voltage and the second driving voltage are provided by a first driving line at different times.

10. The transflective LCD as claimed in claim 9, further comprising:

a first scan-signal driving circuit coupled to the first scan line;

a second scan-signal driving circuit coupled to the second scan line; and

a first image-signal driving circuit coupled to the first driving line.

11. The transflective LCD as claimed in claim 9, further comprising:

a multiplex coupled to the first scan line and the second scan line;

a first scan-signal driving circuit coupled to the multiplex; and

a first image-signal driving circuit coupled to the first driving line.

12. The transflective LCD as claimed in claim 1, wherein:

the first active device has a first control end;

the second active device has a second control end;

wherein the first control end and the second control end are enabled by a first scan line at different times;

the first driving voltage is provided by a first driving line; and

the second driving voltage is provided by a second driving line.

13. The transflective LCD as claimed in claim 12, wherein:

a first image-signal driving circuit coupled to the first driving line;

a second image-signal driving circuit coupled to the second driving line; and

a first scan-signal driving circuit coupled to the first scan line.

14. The transflective LCD as claimed in claim 12, wherein:

a multiplex coupled to the first driving line and the second driving line;

a first image-signal driving circuit coupled to the multiplex; and

a first scan-signal driving circuit coupled to the first scan line.

15. The transflective LCD as claimed in claim 1, wherein:

the first active device has a first control end coupled to the first scan line;

the second active device has a second control end coupled to the second scan line;

the first driving voltage is provided by a first driving line; and

the second driving voltage is provided by a second driving line.

16. The transflective LCD as claimed in claim 15, further comprising:

a first image-signal driving circuit coupled to the first driving line;

a second image-signal driving circuit coupled to the second driving line;

a first scan-signal driving circuit coupled to the first scan line; and

a second scan-signal driving circuit coupled to the second scan line.

17. The transflective LCD as claimed in claim 15, further comprising:

a first multiplex coupled to the first driving line and the second driving line;

a first image-signal driving circuit coupled to the first multiplex;

a second multiplex coupled to the first scan line and the second scan line; and

a first scan-signal driving circuit coupled to the second multiplex.