Method and apparatus for auto-generation of horizontal synchronization of an analog signal to a digital display

• US 20050104907A1
• Filed: 12/21/2004
• Published: 05/19/2005
• Est. Priority Date: 09/20/2001
• Status: Active Grant

• Current Assignee: Tamiras Per Pte Ltd LLC (Intellectual Ventures LLC)
• Original Assignee: Tamiras Per Pte Ltd LLC (Intellectual Ventures LLC)
• Inventors: Neal, Greg
• Granted Patent: US 7,505,055 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/008 Clock recovery

Abstract

A method, apparatus, and system for determining a horizontal resolution and a phase of an analog video signal arranged to display a number of scan lines each formed of a number of pixels is described. A number of initialization values are set where at least one of the initialization values is a current horizontal resolution and then a difference value for each immediately adjacent ones of the pixels is determined. Next, an edge flag value based upon the difference value is stored in at least one of a number of accumulators such that when at least one of the accumulators has a stored edge flag value that is substantially greater than those stored edge flag values in the other accumulators, then the horizontal resolution is set to the current resolution.

Claims

1. A method of determining a phase of an analog video signal having a before edge region, a flat region, and an after edge region, comprising:

determining the flat region of the video signal;

determining a central portion of the flat region; and

setting the phase based upon the central portion of the flat region.

2. A method as recited in claim 1, wherein the determining a flat region comprises:

initializing a set of values;

reading a before edge value accumulator and an after edge value accumulator;

storing the before edge and the after edge values in a flatness accumulator; and

dividing the stored value by a sum of other remaining accumulators.

3. A method as recited in claim 1, wherein the set of initial values includes an H_total value, a phase value, a difference mode, a phase mode, and a minimum count.

4. A method as recited in claim 1, further comprising:

determining if all phases have been tested; and

if all phases have not been tested, then

setting the phase value to new phase value.

5. Computer program product for determining a phase of an analog video signal having a before edge region, a flat region, and an after edge region, comprising:

computer code for determining the flat region of the video signal;

computer code for determining a central portion of the flat region;

computer code for setting the phase based upon the central portion of the flat region; and

computer readable medium for storing the computer code

6. Computer program product as recited in claim 5, wherein the determining a flat region comprises:

computer code for initializing a set of values;

computer code for reading a before edge value accumulator and an after edge value accumulator;

computer code for storing the before edge and the after edge values in a flatness accumulator; and

computer code for dividing the stored value by a sum of other remaining accumulators.

7. Computer program product as recited in claim 5, wherein the set of initial values includes an H_total value, a phase value, a difference mode, a phase mode, and a minimum count.

8. Computer program product as recited in claim 5, further comprising:

computer code for determining if all phases have been tested; and

computer code for setting the phase value to new phase value if all phases have not been tested.