| 摘要 |
PURPOSE: An apparatus and a method for detecting a synchronous signal and a mode are provided to simply detect vertical and horizontal synchronous signals without generating an extra mask signal, and generate new synchronous signals to display a video signal according to the frequency of the detected synchronous signals. CONSTITUTION: An amplifier(100) amplifies a complex video signal inputted from an external video equipment. A synchronous signal detector(110) compares an output signal of the amplifier with a reference voltage for detecting horizontal and vertical synchronous signals. A switching unit(120) switches an output signal of the synchronous signal detector or separative type vertical synchronous signal. A microcomputer(130) selectively receives the output signal of the synchronous signal detector, the separative type horizontal synchronous signal or vertical synchronous signal while controlling a switching action of the switching unit. The microcomputer detects frequency of the inputted synchronous signal for generating a resolution mode detecting signal, and controls generation of the vertical and horizontal synchronous signals to display the video signal to be appropriate for the size of a picture. A synchronous signal generator(140) generates the vertical and horizontal synchronous signals according to control of the microcomputer.
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