Automatic focus control for facsimile cameras
Abstract
An electronic circuit for controlling the focus of facsimile cameras is described. The circuit consists of balanced a.c. amplifiers, two square law function generators, and a differential amplifier and power drive. The invention includes a method for maintaining the imaging sensor at the expected location of the focal plane as the facsimile camera scans a scene or terrain. A block diagram of the electronic circuitry is provided.
- Publication:
-
National Aeronautics and Space Administration Report
- Pub Date:
- December 1974
- Bibcode:
- 1974nasa.rept.....S
- Keywords:
-
- Amplifiers;
- Automatic Control;
- Cameras;
- Electronic Equipment;
- Focusing;
- Image Correlators;
- Positioning Devices (Machinery);
- Circuit Diagrams;
- Focal Plane Devices;
- Optical Scanners;
- Patents;
- Product Development;
- Instrumentation and Photography