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Method of low cost self-test in a video display system system

  • US 4,772,948 A
  • Filed: 10/26/1987
  • Issued: 09/20/1988
  • Est. Priority Date: 10/26/1987
  • Status: Expired due to Fees
First Claim
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1. A display system with video analog self-test capability comprising:

  • means, including a graphics processor, for generating digital video data;

    the processor having means for generating a variable duty cycle squarewave and having a digital input port;

    a digital to analog converter (DAC) for receiving the digital video data and converting the digital video data to an analog signal for input to a cathode ray tube monitor to display a graphics image;

    an integrator circuit for integrating said variable duty cycle squarewave;

    an analog comparator for comparing the analog signal to the integrated variable duty cycle squarewave; and

    means for connecting the output of said analog comparator to the digital input port.

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