| 摘要 |
<p>PROBLEM TO BE SOLVED: To record a stored video image before an alarm signal is received with high density by varying a prescribed interval at which a video signal stored in a storage memory is extracted and fed to a recording means. SOLUTION: An input circuit 111 extracts a video signal from a camera at a 1st interval and gives it to a memory circuit 112 and an output circuit 123. The memory circuit 112 stores the received and extracted video signal at a 2nd interval that is slightly longer than the 1st interval. An output control circuit 113 under the control of an input control circuit 114 provides an output of the video signal at the 1st interval, the video signal stored at the 2nd interval video signal that is the stored video signal and thinned at a 3rd interval to a video recording section 120. Upon the receipt of an alarm signal from a control terminal Tcont , the input control circuit 114 allows the video recording section 120 to record at the 2nd interval the stored video image having been recorded at the 3rd interval and to record a monitor video image at the 1st interval when the storage of the video recording is finished.</p> |
