Liquid crystal display devices with increased viewing angle capability and methods of operating same

• US 5,923,310 A
• Filed: 01/20/1997
• Issued: 07/13/1999
• Est. Priority Date: 01/19/1996
• Status: Expired due to Term

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Dong-gyu
• Primary Examiner(s): WU, XIAO MIN
• Application Number:
  US08/786,474
• Time in Patent Office: 904 Days
• Field of Search: 345/90-96, 345/205-206, 345/208-210, 345/100, 345/87, 345/98, 345/99
• US Class Current: 345/90
• 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 2300/0447 for multi-domain technique to improve the viewing angle in a liquid crystal display, such as multi-vertical alignment [MVA]
• CPC Class Codes: G09G 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• 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 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• 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

Liquid crystal display devices with increased viewing angle capability include a plurality of configurable liquid crystal sub-pixels which form each pixel image in the display. The voltages appearing across the liquid crystal capacitors in each sub-pixel representing a pixel image (i.e., V_LC) are preferably set to different values by connecting the storage capacitor in each sub-pixel (i.e., liquid crystal display cell) to a gate line (or control line) which is different from the gate line connected to the sub-pixel'"'"'s switching device (e.g., thin-film transistor TFT) and also by designing the storage capacitors in each sub-pixel to have different capacitance values. By establishing different voltages across the liquid crystal capacitors in each sub-pixel within a pixel image, the maximum viewing angle of a liquid crystal display device formed thereby can be improved because each sub-pixel element within a pixel image can be set to have a different transmittivity.

Claims

1. A method of operating a liquid crystal display device having first and second display cells in first and second rows therein, respectively, said method comprising the steps of:

loading first data from a first data line onto a first pixel electrode in the first display cell during a first selection time interval, while simultaneously driving a first electrode of a first storage capacitor in the first display cell with a first signal so that the loaded first data is represented as a first voltage across a first liquid crystal capacitor in the first display cell during a first non-selection time interval which follows the first selection time interval; and

loading the first data from the first data line onto a second pixel electrode in the second display cell during a second selection time interval, while simultaneously driving a first electrode of a second storage capacitor in the second display cell with a second signal so that the loaded first data is represented as a second voltage, unequal in magnitude to the first voltage, across a second liquid crystal capacitor in the second display cell during a second non-selection time interval which follows the second selection time interval.

2. The method of claim 1, wherein a magnitude of a potential of the first signal during the first selection time interval is unequal to a magnitude of a potential of the second signal during the second selection time interval.

3. The method of claim 2, wherein the second selection time interval commences upon termination of the first selection time interval.

4. The method of claim 1, wherein a capacitance of the first storage capacitor is unequal to a capacitance of the second storage capacitor.

5. The method of claim 4, wherein a magnitude of a potential of the first signal during the first selection time interval is equal to a magnitude of a potential of the second signal during the second selection time interval.

6. The method of claim 5, wherein the first electrode of the second storage capacitor is electrically connected to a gate electrode of a thin-film transistor in the first display cell.

7. The method of claim 3, wherein the first electrode of the second storage capacitor is electrically connected to a gate electrode of a thin-film transistor in the first display cell.

8. The method of claim 5, wherein the second selection time interval commences upon termination of the first selection time interval.

9. The method of claim 6, wherein a capacitance of the first liquid crystal capacitor equals a capacitance of the second liquid crystal capacitor.

10. The method of claim 7, wherein a capacitance of the first liquid crystal capacitor equals a capacitance of the second liquid crystal capacitor.

11. The method of claim 7, wherein the first non-selection time interval overlaps the second selection time interval;

and wherein the second non-selection time interval commences upon termination of the second selection time interval.

12. A method of operating a liquid crystal display device having first and second display cells in first and second rows therein, respectively, said method comprising the steps of:

loading first data from a first data line onto a first pixel electrode in the first display cell during a first selection time interval, while simultaneously driving a first electrode of a first storage capacitor in the first display cell with a first signal so that the loaded first data on the first pixel electrode is represented as a first waveform during a first plurality of non-selection time intervals which follow the first selection time interval, said first waveform having a first average voltage; and

loading the first data from the first data line onto a second pixel electrode in the second display cell during a second selection time interval, while simultaneously driving a first electrode of a second storage capacitor in the second display cell with a second signal so that the loaded first data on the second pixel electrode is represented as a second waveform during a second plurality of non-selection time intervals which follow the second selection time interval, said second waveform having a second average voltage which is unequal in magnitude to the first average voltage.

13. The method of claim 12, wherein a magnitude of a potential of the first signal during the first selection time interval is unequal to a magnitude of a potential of the second signal during the second selection time interval.

14. The method of claim 13, wherein the second selection time interval commences upon termination of the first selection time interval.

15. The method of claim 12, wherein a capacitance of the first storage capacitor is unequal to a capacitance of the second storage capacitor.

16. The method of claim 15, wherein a magnitude of a potential of the first signal during the first selection time interval is equal to a magnitude of a potential of the second signal during the second selection time interval.

17. The method of claim 16, wherein the first electrode of the second storage capacitor is electrically connected to a gate electrode of a thin-film transistor in the first display cell.

18. The method of claim 14, wherein the first electrode of the second storage capacitor is electrically connected to a gate electrode of a thin-film transistor in the first display cell.

19. The method of claim 16, wherein the second selection time interval commences upon termination of the first selection time interval.