| 摘要 |
<p>PURPOSE:To easily and highly accurately detect the presence/absence of an object by comparing the integrated value of video signals corresponding to a monitoring area with a reference value when the scanning value of video signals coincides with the set position of the monitoring area. CONSTITUTION:When the counted contents of an (x) and (y) counters 48 and 43 are given to a monitoring position designating memory 42 through an address converter 44 in the fetching signal generation circuit 41 of a timing generating device, the numbers of the scanning line of video signals from a camera and of an x-direction monitoring point are successively designated. When the scanning position of the video signals coincides with set position data stored in the memory 42, a fetching signal generation circuit 50 sends designating signals SW1 and SW2 corresponding to the content of an integration circuit designating register 46 by means of a coincidence signal PS to the analog integration circuit of a holding device during the period of the pulse width generated from a pulse generation circuit 49. The analog integration circuit integrates the video signals corresponding to a relevant monitoring area and confirms the presence/absence of an object by comparing the integrated value with a reference value as information representing the light energy of the monitoring area.</p> |
