| 摘要 |
PURPOSE: To vary the timing when a freeze operation is performed according to the motion of a screen or a reception C/N level when sufficient C/N can not be obtained. CONSTITUTION: A freeze circuit for satellite broadcasting having an image memory 1 for extracting the video signals corresponding to an image from composite signals, storing the signals and displaying these stored video signals is provided with a C/N detection circuit 2 detecting a C/N value based on a noise detection signal and a motion detection circuit 3 comparing the luminance of the video signal this time with that of the signal just previous time and detecting the movement of the image based on the difference. A threshold part 4 has two C/N thresholds which are different in size, the larger C/N threshold is selected when the movement of the image does not exist by the motion detection circuit 3 and the smaller C/N threshold is selected when the movement exists. A decision circuit 5 compares the detected C/N value and the selected C/N threshold and inhibits the storage of an image signal in an image memory 1 when the detected C/N value becomes smaller than the selected C/N threshold.
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