System and method for color and grayscale drive methods for graphical displays utilizing analog controlled waveforms

• US 20010043177A1
• Filed: 12/14/2000
• Published: 11/22/2001
• Est. Priority Date: 04/14/2000
• Status: Abandoned Application

• Current Assignee: Snap, Inc.
• Original Assignee: Snap, Inc.
• Inventors: Kang, Jinsuk, Huston, James R.
• Application Number:
  US09/737,418
• Publication Number:
  US 20010043177A1
• Time in Patent Office: Days
• US Class Current: 345/87
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0804 Sub-multiplexed active matrix panel, i.e. wherein one active driving circuit is used at pixel level for multiple image producing elements
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0857 Static memory circuit, e.g. flip-flop
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/065 Waveforms comprising zero voltage phase or pause
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• 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 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 2340/145 related to small screens
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2033 with splitting one or more sub-frames corresponding to the most significant bits into two or more sub-frames
• CPC Class Codes: G09G 3/2051 : with use of a spatial dither pattern
• CPC Class Codes: G09G 3/2092 : Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165
• CPC Class Codes: G09G 3/3406 : Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3614 : Control of polarity reversal in general
• CPC Class Codes: G09G 3/3648 : using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 5/14 : Display of multiple viewports
• CPC Class Codes: G09G 5/34 : for rolling or scrolling
• CPC Class Codes: G09G 5/346 : for systems having a bit-mapped display memory

Abstract

A system and method are provided for driving a display. A voltage value is stored in an analog memory associated with each pixel of a display, where each of the pixels has a comparator associated with it. A reference voltage and the voltage values stored in the analog memory are applied to the comparators of the pixels. The comparators are used to compare the voltage values with the reference voltage for determining which of the voltage values matches the reference voltage. The state of the pixels whose voltage value matches the reference voltage is changed.

Claims

1. A method for driving a display, comprising the steps of:

(a) storing a voltage value in an analog memory associated with each pixel of a display, wherein each of the pixels has a comparator associated therewith;

(b) applying a reference voltage and the voltage values stored in the analog memory to the comparators of the pixels;

(c) comparing the voltage values with the reference voltage for determining which of the voltage values matches the reference voltage; and

(d) changing the state of the pixels whose voltage values match the reference voltage.

2. The method as recited in

claim 1

, wherein the display is an active matrix panel display.

3. The method as recited in

claim 1

, and further comprising the step of applying illumination.

4. The method as recited in

claim 3

, wherein the reference voltage is changed as a function of time for causing each pixel to change state at a desired time.

5. The method as recited in

claim 1

, wherein the states of groups of the pixels are changed, and further comprising the step of changing the states of the groups of the pixels in multiple phased cycles.

6. The method as recited in

claim 5

, wherein the groups are interspersed on the display to avoid flicker at low update rates.

7. The method as recited in

claim 1

, wherein the pixel provides illumination.

8. The method as recited in

claim 7

, wherein the display is an organic light emitting diode display (OLED).

9. The method as recited in

claim 8

, wherein the states of groups of the pixels are changed, and further comprising the step of changing the states of the groups of the pixels in multiple phased cycles.

10. The method as recited in

claim 9

, wherein the groups are interspersed on the display to avoid flicker at low update rates.

11. The method as recited in

claim 1

, wherein the voltage value in at least a portion of the analog memories is adjusted for providing gamma correction.

12. A system for driving a display, comprising:

(a) a plurality of pixels;

(b) an analog memory associated with each pixel of a display, wherein a voltage value associated with each of the pixels is stored in the analog memory;

(c) a comparator associated with each of the pixels, wherein the comparators compare the voltage values with a reference voltage for determining which of the voltage values match the reference voltage; and

(d) logic for changing the state of the pixels whose voltage values match the reference voltage.

13. The system as recited in

claim 12

, wherein the display is an active matrix panel display.

14. The system as recited in

claim 12

, and further comprising logic that applies illumination after the change of state of the at least one pixel.

15. The system as recited in

claim 14

, wherein the reference voltage is changed as a function of time for causing each pixel to change state at a desired time.

16. The system as recited in

claim 12

, wherein the states of groups of the pixels are changed in multiple phased cycles.

17. The system as recited in

claim 16

, wherein the groups are interspersed on the display to avoid flicker at low update rates.

18. The system as recited in

claim 12

, wherein the pixel provides illumination.

19. The system as recited in

claim 18

, wherein the display is an organic light emitting diode display (OLED).

20. The system as recited in

claim 19

, wherein the states of groups of the pixels are changed, and further comprising the step of changing the states of the groups of the pixels in multiple phased cycles.

21. The system as recited in

claim 20

, wherein the groups are interspersed on the display to avoid flicker at low update rates.

22. The system as recited in

claim 12

, wherein the voltage value in at least a portion of the analog memories is adjusted for providing gamma correction.

23. The system as recited in

claim 12

, wherein each of the pixels includes a level shifter for changing a lower voltage to a higher voltage for output to a pixel electrode of the associated pixel.