Active matrix display device and driving method thereof

• US 20020047823A1
• Filed: 11/02/2001
• Published: 04/25/2002
• Est. Priority Date: 10/08/1991
• Status: Active Grant

• Current Assignee: Masaaki Hiroki, Shunpei Yamazaki, Yasuhiko Takemura
• Original Assignee: Masaaki Hiroki, Shunpei Yamazaki, Yasuhiko Takemura
• Inventors: Hiroki, Masaaki, Takemura, Yasuhiko, Yamazaki, Shunpei
• Granted Patent: US 7,079,124 B2
• Time in Patent Office: Days
• US Class Current: 345/90
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/2029 the sub-frames having non-binary weights
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

For a gradation displaying operation of an electro-optical device, a gradation display method and an electro-optical device therefor which can be controlled with a digital signal, and which is hard to be affected by variation in characteristics between elements and can achieve high gradation display are provided. In the active matrix type of electro-optical device and method, the input analog signal is converted to a numerical value of N-radix notation, and pulses whose pulse height and width correspond to the numerical value. By applying these plural pulses to each picture element electrode, an average voltage of one frame of an image can be made an arbitrary value to finally display an intermediate color tone or gradation. The display device comprises a device for converting an input analog signal to a digital signal, a device for converting the digital signal to a numerical value of N-radix notation or a digital signal corresponding thereto (including digital signal), and a device for inputting this signal to an active matrix type device.

Claims

1. A method of driving an active matrix display device comprising the steps of:

converting a signal into a numerical value of N-radix notation where N>

3 or a signal corresponding to said numerical value of N-radix notation where N>

3; and

applying a plurality of voltage pulses having pulse heights and pulse widths based on said numerical value or said signal corresponding to said numerical value of N-radix notation where N>

3 to a pixel of said display device,

wherein said active matrix display device comprises a plurality of switching elements arranged in a matrix form.

2. The method according to claim 1 wherein said active matrix display device is a liquid crystal display.

3. The method according to claim 1 wherein said active matrix display device is a plasma display.

4. The method according to claim 1 wherein said active matrix display device is a vacuum microelectronics display.

5. The method according to claim 1 wherein the plurality of switching elements are thin film transistors.

6. The method according to claim 1 wherein the plurality of switching elements are diodes.

7. A method of driving an active matrix display device comprising the steps of:

converting a signal into a numerical value of N-radix notation where N>

3; and

applying a plurality of voltage pulses having pulse heights and pulse widths based on said numerical value to a pixel of said display device,

wherein said active matrix display device comprises a plurality of switching elements arranged in a matrix form.

8. The method according to claim 7 wherein said active matrix display device is a liquid crystal display.

9. The method according to claim 7 wherein said active matrix display device is a plasma display.

10. The method according to claim 7 wherein said active matrix display device is a vacuum microelectronics display.

11. The method according to claim 7 wherein the plurality of switching elements are thin film transistors.

12. The method according to claim 7 wherein the plurality of switching elements are diodes.

14. The device according to claim 13 wherein said active matrix display device is a liquid crystal display.

15. The device according to claim 13 wherein said active matrix display device is a plasma display.

16. The device according to claim 13 wherein said active matrix display device is a vacuum microelectronics display.

17. The device according to claim 13 wherein the plurality of switching elements are thin film transistors.

18. The device according to claim 13 wherein the plurality of switching elements are diodes.

20. The device according to claim 19 wherein said active matrix display device is a liquid crystal display.

21. The device according to claim 19 wherein said active matrix display device is a plasma display.

22. The device according to claim 19 wherein said active matrix display device is a vacuum microelectronics display.

23. The device according to claim 19 wherein the plurality of switching elements are thin film transistors.

24. The device according to claim 19 wherein the plurality of switching elements are diodes.

13. An active matrix type display device comprising:

a device for converting an input analog signal into a digital signal;

a device for converting said digital signal into a numerical value of N-radix notation where N>

3 or a digital signal corresponding to said numerical value of N-radix notation where N>

3; and

a device for generating N-stage voltages having pulse heights and pulse widths on the basis of said digital signal corresponding to said numerical value of N-radix notation where N>

3,

wherein said active matrix display device comprises a plurality of switching elements in a matrix form.

19. An active matrix type display device comprising:

a device for converting an input signal into a numerical value of N-radix notation where N>

3 or a digital signal corresponding to said numerical value of N-radix notation where N>

3; and

a device for generating N-stage voltages having pulse heights and pulse widths on the basis of said digital signal corresponding to said numerical value of N-radix notation where N>

3,

wherein said active matrix display device comprises a plurality of switching elements in a matrix form.