US. Patent Oct. 9, 1990 4,962,425 Sheet 1 of 8 38m V-LAMBDA FILTER VIDEO CAMERA 20 2| 22 IO VARIABLEAPERTURE ZOOM LENS IMAGE VIDEO MONITOR CAPTURE BOARD R COMPUTER - 640 kbyte - 80287 24 COMPUTER MONITOR KEYBOARD - 70 Mbyte On 1.2 Mbyte