Method and system for automatically selecting a vertical refresh rate for a video display monitor

• US 6,862,022 B2
• Filed: 07/20/2001
• Issued: 03/01/2005
• Est. Priority Date: 07/20/2001
• Status: Expired due to Term

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Slupe, James P.
• Primary Examiner(s): Wu, Xiao
• Assistant Examiner(s): Nguyen, Kevin M.
• Application Number:
  US09/910,645
• Publication Number:
  US 20030016215A1
• Time in Patent Office: 1,320 Days
• Field of Search: 345/102, 345/207, 345/211, 345/213, 345/204, 345/212, 345/690, 345/699, 348/602, 348/227.1, 348/366
• US Class Current: 345/207
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 5/18 Timing circuits for raster scan displays specially adapted for television H04N ; synchronisation between the display unit and other display units, videodisc player G09G5/12

Abstract

A system and method of automatically selecting a vertical refresh rate for a video display monitor is disclosed.

The system includes an ambient light frequency identifier and a vertical refresh rate selector. The ambient light frequency identifier is configured for capturing lightwaves from an ambient light source and for identifying a frequency of the lightwaves. The vertical refresh rate selector is configured for automatically selecting a vertical refresh rate for the video display monitor based on the identified ambient light frequency.

Claims

1. An automatic vertical refresh rate selection system for a video display monitor comprising:

an ambient light frequency identifier configured for capturing lightwaves from an ambient light source and for identifying a frequency of the lightwaves; and

a vertical refresh rate selector configured for selecting a vertical refresh rate for the video display monitor based on the identified ambient light frequency with the selected vertical refresh rate being substantially different than the identified ambient light frequency.

2. The system of claim 1 wherein the ambient light frequency identifier comprises:

a photo sensor configured for capturing the ambient lightwaves;

a frequency generator configured for generating a plurality of select light frequencies for comparison with the ambient light waves; and

a frequency comparator configured for comparing a frequency of the captured ambient lightwaves with the select frequencies from the frequency generator to determine the ambient light frequency and configured for producing an identification code signal corresponding the determined ambient light frequency.

3. The system of claim 2 wherein the select frequencies comprise the frequencies of:

56 Hz, 60 Hz, 65 Hz, 70 Hz, 72 Hz, 75 Hz, and 85 Hz.

4. The system of claim 2 wherein the vertical refresh rate selector comprises:

a decoder module configured for determining the ambient light frequency value based on the identification code and configured for selecting the vertical refresh rate to be sufficiently different than the ambient light frequency by at least 10 Hertz to minimize flicker of the video display monitor.

5. The system of claim 4 wherein the vertical refresh rate selector further comprises at least one of:

a refresh rate register configured with selectable vertical refresh rates with each selectable vertical refresh rate corresponding to a different ambient light frequency wherein the correspondence reflects each refresh rate being suitable for minimizing flicker for the corresponding ambient light frequency; and

a refresh rate logic operator configured for performing a logic operation on the value of the ambient light frequency to determine the vertical refresh rate.

6. A computing system with an automatic vertical refresh rate selection system for a video display of the computing system, the system comprising:

a video display monitor;

a photosensor located externally of the video display monitor and configured for capturing ambient lightwaves adjacent the video display monitor; and

a computing workstation comprising a graphics adapter including;

an ambient light frequency identifier configured for receiving a signal from the photosensor corresponding to the captured lightwaves and configured for identifying a frequency of the ambient lightwaves;

a vertical refresh rate selector configured for selecting a vertical refresh rate for the video display monitor based on the identified ambient light frequency, with the selected vertical refresh rate being at least one of about 10 Hertz greater than the identified ambient light frequency and about 10 Hertz less than the identified ambient light frequency, and configured for producing a signal indicating the selected vertical refresh rate; and

a graphics controller configured for receiving the signal from the vertical refresh rate selector that identifies the selected vertical refresh rate and configured for sending a synchronized video signal to the video display monitor that includes a vertical refresh rate signal having the selected vertical refresh rate.

7. The system of claim 6 wherein the photosensor is mounted externally from the video display monitor.

8. The system of claim 6 wherein the photosensor is mounted on the video display monitor.

9. A video display monitor having an automatically selectable vertical refresh rate, the monitor comprising:

a display screen;

an ambient light frequency identifier configured for measuring lightwaves from an ambient light source adjacent the video display monitor and for identifying a frequency of the lightwaves;

a vertical refresh rate selector configured for selecting a vertical refresh rate for the video display monitor based on the identified ambient light frequency, with the selected vertical refresh rate being substantially different than the identified ambient light frequency and for producing a signal that identifies the selected vertical refresh rate; and

monitor control circuitry configured to receive a synchronized video signal including a vertical refresh rate signal having the selected vertical refresh rate and configured to send the synchronized video signal to the display screen.

10. The monitor of claim 9 wherein the ambient light frequency identifier includes a photosensor mounted on the video display monitor and configured for capturing the lightwaves from the ambient light source.

11. An automatic vertical refresh rate selection system for a video display monitor comprising:

a photosensor configured for capturing light waves from an ambient light source and configured for disposition near the light waves; and

a graphics adapter configured for connection to a computing device including;

an ambient light frequency identifier in coupled communication with the photosensor and configured for identifying a frequency of the captured ambient light waves; and

a vertical refresh rate selector configured for selecting a vertical refresh rate for a video display monitor based on the identified ambient light frequency, with the selected vertical refresh rate being at least one of about 10 Hertz greater than the identified ambient light frequency and about 10 Hertz less than the identified ambient light frequency, and producing a signal configured for sending a value of the vertical refresh rate to a graphics controller.

12. The system of claim 11 and further comprising:

a housing configured for containing the ambient light frequency identifier and the vertical refresh rate selector and configured for securing the photosensor on an exterior surface of the housing.

13. A graphics adapter having an automatic vertical refresh rate selection system for a video display monitor, the graphics adapter comprising:

an ambient light frequency identifier configured for receiving a signal of captured ambient light waves and configured for identifying a frequency of the captured ambient light waves;

a vertical refresh rate selector in communication with the ambient light frequency identifier and configured for selecting a vertical refresh rate for a video display monitor based on the identified ambient light frequency with the selected vertical refresh rate being substantially different than the identified ambient light frequency; and

a graphics controller configured for implementing the selected vertical refresh rate in a synchronized video signal for transmission to a video display monitor with the synchronized video signal including a horizontal refresh rate signal, a red, green, blue video signal, and a vertical refresh rate signal having the selected vertical refresh rate.

14. A vertical refresh rate selection graphics co-adapter for a video display monitor, the co-adapter comprising:

an ambient light frequency identifier configured for receiving a signal of captured ambient light waves and configured for identifying a frequency of the captured ambient lightwaves;

a vertical refresh rate selector configured for selecting a vertical refresh rate for a video display monitor based on the identified ambient light frequency with the selected vertical refresh rate being substantially different than the identified ambient light frequency and configured for producing a signal identifying the selected vertical refresh rate; and

a connector configured for coupled communication with a graphics controller of a graphics adapter and configured to transmit the signal identifying the selected vertical refresh rate to the graphics controller of the graphics adapter.

15. The graphics co-adapter of claim 14 and further comprising:

an expansion circuit board configured for carrying the ambient light frequency identifier, the vertical refresh rate selector, and the connector, and configured for removable insertion into an expansion slot of a computing workstation.

16. A method for minimizing flicker of a video display monitor comprising:

determining an ambient light frequency adjacent the video display monitor; and

selecting a vertical refresh rate of the video display monitor, based on the determined ambient light frequency, to be substantially different than the determined ambient light frequency to minimize flicker of the video display monitor.

17. The method of claim 16 wherein determining the ambient light frequency comprises:

capturing the ambient light frequency with a photo sensor; and

identifying the ambient light frequency by comparing the ambient light frequency with a plurality of select frequencies to match the ambient light frequency with one of the select frequencies.

18. The method of claim 17 wherein identifying the ambient light frequency further comprises:

selecting an identification code corresponding with the identified ambient light frequency and submitting that identification code to a vertical refresh rate selector.

19. The method of claim 17 wherein selecting the identification code further comprises:

submitting an identification of the ambient light frequency to a refresh rate monitor for selecting the refresh rate to be substantially different than the ambient light frequency by about 10 Hertz with the selected refresh rate being at least one of about 10 Hertz greater than the identified ambient light frequency and about 10 Hertz less than the identified ambient light frequency.

20. The method of claim 16 and further comprising:

synchronizing a vertical refresh rate signal having the automatically selected vertical refresh rate with a horizontal refresh rate signal and a red, green, blue video signal.

21. An automatic vertical refresh rate selection system for a cathode ray tube video display monitor comprising:

an ambient light frequency identifier configured for capturing lightwaves from an ambient light source and for identifying a frequency of the lightwaves; and

a vertical refresh rate selector configured for selecting a vertical refresh rate for the cathode ray tube video signal monitor based on the identified ambient light frequency wherein the selected vertical refresh rate is substantially different than the identified ambient light frequency.

22. The system of claim 21 wherein the selected vertical refresh rate is substantially different than the identified ambient light frequency by about 10 Hertz with the selected refresh rate being at least one of about 10 Hertz greater than the identified ambient light frequency and about 10 Hertz less than the identified ambient light frequency.

23. A computing system with an automatic vertical refresh rate selection system for an analog video display of the computing system, the system comprising:

an analog video display monitor;

a photo sensor located externally of the analog video display monitor and configured for capturing ambient lightwaves adjacent the analog video display monitor; and

a computer workstation comprising a graphics adapter including;

an ambient light frequency identifier configured for receiving a signal from the photosensor corresponding to the captured lightwaves and configured for identifying a frequency of the ambient lightwaves;

a vertical refresh rate selector configured for selecting a vertical refresh rate for the analog video display monitor based on the identified ambient light frequency wherein the selected vertical refresh rate is substantially different than the identified ambient light frequency, and configured for producing a signal indicating the selected vertical refresh rate; and

a graphics controller configured for receiving the signal from the vertical refresh rate selector that identifies the selected vertical refresh rate and configured for sending a synchronized analog video signal to the analog video display monitor that includes a vertical refresh rate signal having the selected vertical refresh rate.