Multi-Pixel Addressing Method for Video Display Drivers

• US 20100225679A1
• Filed: 03/04/2010
• Published: 09/09/2010
• Est. Priority Date: 03/05/2009
• Status: Active Grant

• Current Assignee: Ostendo Technologies Inc.
• Original Assignee: Ostendo Technologies Inc.
• Inventors: Guncer, Selim E.
• Granted Patent: US 8,681,185 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2340/02 Handling of images in compressed format, e.g. JPEG, MPEG
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3625 using active addressing

Abstract

A video display system is described which is formed by an array of pixels comprised of fast responding light elements, row select and column select switches and pixel data drivers, and a computation subsystem which generates the control signals for the select lines and the video data. The overall system reconstructs the intended image or video to be displayed through successively displaying subframes of images corresponding to orthogonal image basis function components of the original image acting on a grouping of pixels selected using multiple row and column lines. The resultant system is an architecture which enables one to implement certain video decompression techniques directly on the light elements, as opposed to implementing these techniques in digital processing, and can have a considerably reduced raw video data requirement than a system in which pixels are addressed individually, and enables higher dynamic range to be achieved with similar digital-analog-converter specifications. Embodiments with LED based displays are described herein.

Claims

1. A video system comprising:

a video display having M by N pixels, each pixel having red, blue and green light elements for color operation, or a white light element for gray-scale operation, the intensity of each light element being controllable by a voltage or current;

a switch network coupled to address any pixel of the video display through row and column select switches;

switch driver circuitry coupled to select each of a plurality of macro-pixel groupings, the macro-pixel groupings collectively forming the M by N pixel video display, and to select pixels within each macro-pixel to generate switch patterns corresponding to orthogonal basis functions;

at least one digital-to-analog converter or pulse width modulator circuitry coupled to supply image information to the switch driver circuitry;

a digital computation device coupled to receive video information to be displayed and to control the switch driver circuitry and the light elements corresponding to the switch patterns corresponding to orthogonal basis functions;

whereby the video system is capable of displaying video and still images with programmable resolution depending on the video content.

2. A method of displaying an image having M by N pixels, comprising;

selecting each of a plurality of macro-pixel groupings collectively forming the M by N pixel display;

generating switch patterns corresponding to on-off switch states of orthogonal basis functions for each macro-pixel;

determining image coefficients for respective switch patterns;

controlling a switch drive network by the switch patterns to generate masking patterns for each macro-pixel corresponding to the orthogonal basis functions for image decomposition; and

controlling pixel illumination within a macro-pixel for masking patterns responsive to an image coefficient for the respective masking pattern.

3. The method of claim 2 further comprising:

correcting for the averaging artifact which arises from using blocking patterns corresponding to orthogonal basis functions which multiply the light by 0 or 1 (on-off switch states instead of −

1 or 1 for a discrete Walsh transform type basis function implementation) by determining the average image coefficient applicable to the entire macro-pixel (a zero coefficient), and correcting the average image coefficient applicable to the entire macro-pixel by subtracting the average image coefficients applicable to all other masking patterns (the averages of nonzero coefficients).

4. The method of claim 3 wherein when the averages of the non-zero coefficients are greater than the zero coefficient, then spatial frequency filtering to eliminate some non-zero coefficients and respective masking patterns employed to keep the sum of the non-zero averages equal to or smaller than the zero coefficient.

5. The method of claim 3 wherein when the averages of the non-zero coefficients are greater than the zero coefficient, then reducing the number of pixels in the macro-pixel grouping to keep the sum of non-zero averages equal to or smaller than the average component term.

6. The method of claim 3 further comprising:

for image coefficients which are negative, reversing the spatial masking pattern from blocking to passing state (‘

0’

to ‘

1’

) and vice versa by inverting the switch pattern for the respective orthogonal basis functions.

7. The method of claim 3 wherein only a subset of image coefficients to which human eye is sensitive to are displayed used, and image coefficients which human eyes are not sensitive to are discarded.

8. The method of claim 3 wherein the image coefficients to be used to reconstruct an image is varied for different macro-pixels within an image, and image to image.

9. The method of claim 3 wherein lower order image coefficients have a greater bit precision than higher order image coefficients.

10. A method of displaying an image having M by N pixels, comprising;

selecting each of a plurality of macro-pixel groupings collectively forming the M by N pixel display;

generating switch patterns corresponding to on-off switch states of orthogonal basis functions for each macro-pixel;

determining image coefficients for respective switch patterns;

correcting for the averaging artifact which arises from using blocking patterns corresponding to orthogonal basis functions which multiply the light by 0 or 1 (on-off switch states instead of −

1 or 1 for a discrete Walsh transform type basis function implementation) by determining the average image coefficient applicable to the entire macro-pixel (a zero coefficient), and correcting the average image coefficient applicable to the entire macro-pixel by subtracting the average image coefficients applicable to all other masking patterns (the averages of nonzero coefficients);

for image coefficients which are negative, reversing the spatial masking pattern from blocking to passing state (‘

0’

to ‘

1’

) and vice versa by inverting the switch pattern for the respective orthogonal basis functions.

controlling a switch drive network by the switch patterns to generate masking patterns for each macro-pixel corresponding to the orthogonal basis functions for image decomposition; and

controlling pixel illumination within a macro-pixel for masking patterns responsive to an image coefficient for the respective masking pattern.

11. The method of claim 10 wherein when the averages of the non-zero coefficients are greater than the zero coefficient, then spatial frequency filtering to eliminate some non-zero coefficients and respective masking patterns employed to keep the sum of the non-zero averages equal to or smaller than the zero coefficient.

12. The method of claim 10 wherein when the averages of the non-zero coefficients are greater than the zero coefficient, then reducing the number of pixels in the macro-pixel grouping to keep the sum of non-zero averages equal to or smaller than the average component term.

13. The method of claim 10 wherein only a subset of image coefficients to which human eye is sensitive to are displayed used, and image coefficients which human eyes are not sensitive to are discarded.

14. The method of claim 10 wherein the image coefficients to be used to reconstruct an image is varied for different macro-pixels within an image, and image to image.

15. The method of claim 10 wherein lower order image coefficients have a greater bit precision than higher order image coefficients.