An On-Line Computerized Light Valve Monitor System

Edward H. Reichard, Howard T. La Zare, Edward Efron

In making motion-picture prints in color, the scene-to-scene color and intensity modulators (vanes in the Light Valve System) respond to a punched-paper control tape in accordance with pre-programed information obtained through color timing procedures. Any error in any one of the vanes may cause a mislight or unbalance in the intensity and color of the particular scene being printed. In order to monitor any inaccurate positions of the light modulating vane, an automatic On-Line Computerized Vane Checking System has been developed. In this system the actual angular position of each light-controlling vane is monitored and compared to a standard that is in the computer memory system. Any out-of-tolerance deviation between the desired vane position and actual position starts an automatic computer procedure resulting in a stop of the printing machine and immediate identification of the error. The system consists of electromechanical sensing equipment attached to the light vanes with signal conditioning circuitry, reader interfacing and multiplex interfacing between the film printing machine and the IBM System/7 sensor-based computer.

Print ISSN
Published
1973-10
Content type
Original Research
DOI
10.5594/J08143