| 摘要 |
An apparatus for correcting camera output data for excessive voltage build up on the camera image tube target during active video scan and retrace time periods as well as d.c. restoration error. The apparatus includes an A/D converter which converts the raw analog camera video output into a plurality of digital data values during each active scan period. The digital values are stored in a memory or register. The voltage on the camera image tube target is sampled during the retrace period of the camera beam. The magnitudes of the voltages sampled during all or a portion of the retrace period are averaged to generate an average value corresponding to the excess voltage built up on the screen during the scan and retrace time periods plus the d.c. restoration error. The average value is then added or subtracted from the digital data signals generated during the active beam scan period to generate output data which has been adjusted for the d.c. errors during a single scan of the camera beam.
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