Automated system and method for high-frequency signal attenuation compensation

• US 8,031,169 B2
• Filed: 12/17/2003
• Issued: 10/04/2011
• Est. Priority Date: 12/17/2003
• Status: Active Grant

• Current Assignee: RIIP, Inc.
• Original Assignee: RIIP, Inc.
• Inventors: Hoerl, David
• Primary Examiner(s): Nguyen-Ba; Hoang-Vu A
• Application Number:
  US10/740,381
• Publication Number:
  US 20050134748A1
• Time in Patent Office: 2,848 Days
• Field of Search: 725/127, 725/133, 725/141, 725/153, 345/156, 345/157, 345/163, 345/168, 345/204, 345/210, 345/214, 345/1.1, 345/3.4, 345/30, 345/10, 710/15
• US Class Current: 345/156
• CPC Class Codes: H04N 5/208 for compensating for attenuation of high frequency components, e.g. crispening, aperture distortion correction

Abstract

Disclosed is a high-frequency boost circuitry for use with a computer management system. Detection circuitry at the receiving end of a video signal measures the amplitudes of various frequency components of the video signal. If the amplitudes of the high-frequency components of the video signal are substantially lower than the amplitudes of the low frequency components of the video signal, the detection circuitry sends the amplitude information to analysis circuitry located at the transmitting end of the video signal. The analysis circuitry utilizes this information to determine the appropriate level of amplification needed for the video signal. This results in improved signal to noise ratio at the receiver in the computer management system.

Claims

1. A system for compensating for high-frequency attenuation of transmitted video signals, said system comprising:

a user workstation of the type including a keyboard, cursor control device and monitor;

an interface module;

a communications link for providing video signals transmitted from a remote device and data signals transmitted from the remote device;

a video receiving circuit in the user workstation for receiving said transmitted video signals from said remote device and for measuring amplitudes of a low frequency component and a high frequency-component of said transmitted video signals;

a video signal analyzing circuit in the interface module coupled to said video receiving circuit for determining an attenuation of said high frequency component components of said transmitted video signals based on said measuring and for generating a control signal; and

a video signal amplifying circuit in the interface module for amplifying the transmitted video signals to compensate for the amplitude attenuation of said high frequency component components of said the transmitted video signals in response to the control signal.

2. The system according to claim 1, wherein said control signal identifies an amount of amplification to be applied to said high frequency component by said amplifying circuit.

3. The system according to claim 1, wherein said video signal analyzing circuit compares amplitudes of a first group of said high frequency component of said transmitted video signals having a magnitude greater than a first predetermined magnitude to amplitudes of a second group of said low frequency component of said transmitted video signals having a magnitude less than a second predetermined magnitude.

4. The system according to claim 1, wherein said amplifying circuit amplifies said high frequency component of said transmitted video signals having a magnitude greater than a first predetermined magnitude.

5. The system according to claim 1, further comprising a tuning circuit for adjusting said amplifying circuit.

6. The system according to claim 5, wherein said tuning circuit is manually controlled.

7. A video signal system for enhancing high frequency video signal components for transmission, said system comprising:

a user workstation of the type including a keyboard, cursor control device and monitor;

an interface module;

a communications link for providing video signals transmitted from a remote device and data signals transmitted from the remote device;

an extraction circuit in the user workstation for extracting video components and synchronization signals from a composite video signal transmitted from said remote device;

a synchronization signal analyzing circuit in the user workstation for analyzing said synchronization signals to determine an attenuation of high frequency components of said synchronization signals and for generating a control signal; and

a signal amplifying circuit in the interface module for amplifying one or more of said high frequency video components of the composite video signal in response to said control signal.

8. The system according to claim 7, said system further comprising:

a tuning circuit for adjusting said amplifying circuit.

9. The system according to claim 8, wherein said tuning circuit is manually controlled.

10. The system according to claim 7, wherein said synchronization signal analyzing circuit includes circuitry for converting said synchronization signals to ramp signals.

11. The system according to claim 10, wherein said synchronization signal analyzing circuit further includes an analog to digital converter for digitizing said ramp signals.

12. The system according to claim 11, wherein said synchronization signal analyzing circuit further includes a processor for analyzing said digitized ramp signals.

13. The system according to claim 12, wherein said control signal is indicative of a maximum value for said ramp signals.

14. The system according to claim 13, wherein said synchronization signal analyzing circuit includes circuitry for shifting a voltage of said composite video signal by a predetermined positive amount.

15. The system according to claim 14, wherein said synchronization signal analyzing circuit includes circuitry for removing a portion of said synchronization signals having a voltage below zero volts.

16. The system according to claim 15, wherein said circuitry for removing said portion of said synchronization signals provides said converting circuitry for converting said synchronization signals with a signal of known amplitude.

17. The system according to claim 13, wherein said synchronization signal analyzing circuit includes circuitry for filtering said maximum value of said ramp signals.

18. The system according to claim 10, wherein said synchronization signal analyzing circuit includes circuitry for conditioning said ramp signals.

19. A method of compensating for attenuation of high frequency components of video signals, said method comprising the steps of:

receiving video signals and data signals at an interface module from a remote device over a single communications link;

measuring amplitudes of a plurality of high frequency components and low frequency components of said received video signals at a user workstation of the type containing at least one of a monitor, keyboard or cursor control device;

analyzing at the interface module said high frequency components of said received video signals to determine an attenuation of the high frequency components of said received video signals based on the measuring step;

generating a control signal in the interface module indicative of said attenuation of said high frequency components; and

amplifying said high frequency components of said video signals at the interface module to compensate for the attenuation of the high frequency components in response to said control signal.

20. The method according to claim 19, wherein said control signal identifies an amount of amplification to be applied to said video signals.

21. A method of compensating for high frequency attenuation of transmitted video signals, said method comprising the steps of:

receiving composite video signals and data signals at an interface module from a remote device over a single communications link;

separating the received composite video signals from the received data signals;

extracting video components and synchronization components at a user station from said composite video signals transmitted from the remote device;

analyzing high frequency and low frequency components of said synchronization components to determine an attenuation of said high frequency synchronization components;

generating a control signal indicative of said attenuation of said high frequency synchronization components;

transmitting said control signal to the interface module; and

amplifying high frequency video components of the video signals based on said determined attenuation in response to said control signal.

22. The method according to claim 21, said method further comprising the step of:

generating said control signal in response to said analyzing step, wherein said amplifying step is performed in response to said control signal.

23. The method according to claim 21, wherein said amplifying step is manually controlled.

24. The method according to claim 21, wherein said analyzing step further includes the step of converting said synchronization components to ramp signals.

25. The method according to claim 24, wherein said analyzing step further includes the step of digitizing said ramp signals.

26. The method according to claim 25, wherein said analyzing step further includes the step of processing said digitized ramp signals.

27. The method according to claim 26, wherein said control signal identifies a maximum value of said ramp signals.

28. The method according to claim 27, wherein said analyzing step further includes the step of shifting a voltage of said composite video signals by a predetermined positive amount.

29. The method according to claim 28, wherein said analyzing step further includes the step of removing synchronization components of said composite video signals having a voltage at zero volts to remove a portion of said synchronization components having a voltage below zero volts.

30. The method according to claim 27, wherein said analyzing step further includes the step of filtering said maximum value of said ramp signals.

31. The method according to claim 24, wherein said analyzing step further includes the step of conditioning said ramp signals.

32. The method according to claim 24, wherein said converting step further includes the step of providing a voltage signal of known amplitude.

33. A keyboard, video and mouse (“

KVM”

) system for selectively connecting a plurality of remote workstations each including a video monitor and an input device to a plurality of servers having video signal outputs comprising;

a switch to connect selected ones of the plurality of remote workstations to selected ones of the plurality of servers, wherein the switch routes input device signals to and from the selected ones of the plurality of remote workstations and to and from the selected ones of the plurality of servers, and routes video signals from the selected ones of the plurality of servers to the video monitors of the selected ones of the remote workstations, and wherein the switch contains a circuit for separating video signals received from the remote servers from data signals received from the remote servers; and

a plurality of video signal conditioning circuits each comprising a video signal analysis circuit and a video amplification circuit,

wherein selected ones of the plurality of video signal conditioning circuits operate on the video signals from the selected ones of the plurality of servers,

wherein the video signal analysis circuit of each of the selected ones of the video signal conditioning provides a high frequency correction signal and a low frequency correction signal according to an analysis of the video signals, and

wherein the video amplification circuit of each of the selected ones of the video signal conditioning circuits receives the high frequency correction signal from the video signal analysis circuit of the selected video signal conditioning circuit.

34. The system according to claim 33, wherein said high frequency correction signal identifies an amount of amplification to be applied by said video amplification circuit.

35. The system according to claim 33, wherein said video signal analysis circuit compares amplitudes of a first group of high frequency components of the video signals having a magnitude greater than a first predetermined magnitude to amplitudes of a second group of low frequency components of the video signals having a magnitude less than a second predetermined magnitude.

36. The system according to claim 33, wherein said video amplification circuit amplifies said high frequency components having a magnitude greater than a first predetermined magnitude.

37. The system according to claim 33, further comprising a tuning circuit for adjusting said video amplification circuit.

38. The system according to claim 37, wherein said tuning circuit is manually controlled.

39. A keyboard, video and mouse (“

KVM”

) system for selectively connecting a plurality of remote workstations each including a video monitor and a input device to a plurality of servers each having video signal outputs, the KVM system comprising;

a switch to connect selected ones of the plurality of remote workstations to selected ones of the plurality of servers, wherein the switch routes input device signals to and from the selected ones of the plurality of remote workstations and to and from the selected ones of the plurality of servers, and routes video signals from the selected ones of the plurality of servers to the video monitors of selected ones of the remote workstations;

a circuit in an interface module for separating the video signals from the input device signals, wherein the video signals and the input device signals are transmitted to the interface module on a single communications link;

a plurality of video signal conditioning circuits located in the interface module each comprising a synchronization signal analyzing circuit and a video amplification circuit, wherein selected ones of the plurality of video signal conditioning circuits operate on the video signals from the selected ones of the plurality of servers;

an extraction circuit for extracting video components and synchronization signals from the video signals transmitted from one of the selected ones of the plurality of servers; and

a synchronization signal analyzing circuit for analyzing said synchronization signals to determine an attenuation of high frequency components of said synchronization signals and to provide a high frequency correction signal according to an analysis of the extracted synchronization signals,

wherein the video amplification circuit of each of the selected ones of the video signal conditioning circuits receives the high frequency correction signal from the synchronization signal analyzing circuit of the selected video signal conditioning circuit.

40. The system according to claim 39, further comprising a tuning circuit for adjusting said video amplification circuit.

41. The system according to claim 40, wherein said tuning circuit is manually controlled.

42. The system according to claim 39, wherein said synchronization signal analyzing circuit includes circuitry for converting said synchronization signals to ramp signals.

43. The system according to claim 42, wherein said synchronization signal analyzing circuit includes an analog to digital converter for digitizing said ramp signals.

44. The system according to claim 43, wherein said synchronization signal analyzing circuit includes a processor for analyzing said digitized ramp signals.

45. The system according to claim 44, wherein said high frequency correction signal is indicative of a maximum value for said ramp signals.

46. The system according to claim 45, wherein said video signal conditioning circuit includes circuitry for shifting a voltage of said video signals by a predetermined positive amount.

47. The system according to claim 46, wherein said synchronization signal analyzing circuit includes circuitry for removing a portion of said synchronization signals having a voltage below zero volts.

48. The system according to claim 47, wherein said circuitry for removing said portion of said synchronization signals provides said circuitry for converting said synchronization signals with synchronization signals of known amplitude.

49. The system according to claim 45, wherein said synchronization signal analyzing circuit includes circuitry for filtering said maximum value of said ramp signals.

50. The system according to claim 42, wherein said synchronization signal analyzing circuit includes circuitry for conditioning said ramp signals.