Liquid crystal display overdrive interpolation circuit and method

Patent metadata

Field	Value
Publication number	US-9390663-B2
Application number	US-201414175159-A
Country	US
Kind code	B2
Filing date	Feb 7, 2014
Priority date	Feb 7, 2014
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A liquid crystal display (LCD) overdrive interpolation circuit and method, and an LCD drive system incorporating the circuit or method. In one embodiment, the circuit includes: (1) a diagonal interpolator operable to perform a diagonal interpolation along a diagonal direction in a lookup table based on TO and FROM gray levels and (2) a further interpolator coupled to the diagonal interpolator and operable to perform a further interpolation based on a result of the diagonal interpolation and the FROM gray level.

First claim

What is claimed is:

1. A liquid crystal display overdrive interpolation circuit, comprising:
a diagonal interpolator operable to perform a diagonal interpolation along a diagonal direction in a lookup table based on TO and FROM gray levels; and
a further interpolator coupled to said diagonal interpolator and operable to perform a further interpolation based on a result of said diagonal interpolation and said FROM gray level.

2. The overdrive interpolation circuit as recited in claim 1 further comprising another interpolator coupled to said diagonal and further interpolators and operable to perform another interpolation along a first orthogonal direction of said lookup table.

3. The overdrive interpolation circuit as recited in claim 2 wherein said further interpolation is an interpolation along a second orthogonal direction of said lookup table based on results of said diagonal and another interpolations, said second orthogonal direction being normal to said first orthogonal direction.

4. The overdrive interpolation circuit as recited in claim 3 wherein said another interpolation uses an entry in said lookup table not on a diagonal of said lookup table and on a same side of said diagonal as an interpolation target.

5. The overdrive interpolation circuit as recited in claim 4 wherein said further and other interpolators are further operable to approximate any division operations by multiplication based on three most significant bits of a division fraction as an index into a multiplication table.

6. A method for overdriving a liquid crystal display, said method comprising:
performing, by a liquid crystal display overdrive interpolation circuit coupled to said liquid crystal display, a diagonal interpolation along a diagonal direction in a lookup table;
performing another interpolation along a first orthogonal direction of said lookup table;
performing a further interpolation along a second orthogonal direction of said lookup table based on results of said diagonal and another interpolations; and
employing a result of said further interpolation to overdrive said liquid crystal display.

7. The method as recited in claim 6 wherein said said second orthogonal direction is normal to said first orthogonal direction.

8. The method as recited in claim 7 further comprising conducting said another interpolation using an entry in said lookup table not on a diagonal thereof and on a same side of the diagonal as an interpolation target.

9. The method as recited in claim 8 further comprising approximating any division operations by multiplication by based on three most significant bits of a division fraction as an index into a multiplication table.

10. A liquid crystal display drive system, comprising:
a graphics subsystem having a graphics processing unit and a frame buffer coupled thereto operable to store a TO gray level;
a previous frame buffer operable to store a FROM gray level; and
an interpolation circuit coupled to said frame buffer and said previous frame buffer and including:
a diagonal interpolator operable to perform a diagonal interpolation along a diagonal direction in a lookup table based on said TO and FROM gray levels, and
a further interpolator coupled to said diagonal interpolator and operable to perform a further interpolation based on a result of said diagonal interpolation; and
another interpolator coupled to said diagonal and further interpolators.

11. The drive system as recited in claim 10 wherein said another interpolator is operable to perform another interpolation along a first orthogonal direction of said lookup table.

12. The drive system as recited in claim 11 wherein said further interpolation is an interpolation along a second orthogonal direction of said lookup table based on results of said diagonal and another interpolations, said second orthogonal direction being normal to said first orthogonal direction.

13. The drive system as recited in claim 12 wherein said another interpolation uses an entry in said lookup table not on a diagonal thereof and on the same side of the diagonal as an interpolation target point.

Assignees

• Nvidia Corp

Inventors

• Schutten Robert
• Verbeure Tom
• Bloks Rudi

Classifications

• G09G2320/0261

  in the context of movement of objects on the screen or movement of the observer relative to the screen · CPC title

• G09G2320/0252

  Improving the response speed · CPC title

• G09G2320/0257

  Reduction of after-image effects · CPC title

• G09G2340/16

  Determination of a pixel data signal depending on the signal applied in the previous frame · CPC title

• G09G5/395

  Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen (G09G5/399 takes precedence) · CPC title