1980 RCA TC-2811 First Generation CCD Surveillance Camera

  
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RCA made some of the first commercially available CCD chips. A CCD (Charge Couple Device) is a silicon solid state imaging device that replaces the vidicon tubes of the past. CCD`s are made up a two dimensional array of photo detectors coupled to an array of shift registers. In operation, the imaging cy
1980 RCA TC-2811 First Generation CCD Surveillance Camera - schematic

cle is roughly as follows: The device is "reset" or cleared. Then some time is allowed to pass. This is called the integration time. I think of it "staring time". The charges that have accumulated on the photo sites are shifted to a second portion of the chip called the storage registers. The photo sites are now rest again and begin staring for the next frame cycle. The charges, now being held in what is essentially an analog memory are fed into a second one dimensional shift register for read out on a line by line basis. This continues until all of the charges have been read out of the storage array. At the end of the integrating cycle, this process is repeated. CCD`s can actually be read out at any speed, up to their maximum, or even "frozen" and read out continuously. In a video camera application, things are simpler. The cycle is just a canned set of pulses that repeats 60 times a second, forming a continuous output know as "video". If you examine a modern CCD video camera, it may have shutter speed settings. These are the length of time that the photo sensors are allowed to stare before they are read out. The "sports shutter" setting is one that only integrates for 1/10, 000 of a second, before the read out cycle begins and essentially freezes live action. While watching pro sports broadcasts, you may see this in the form of distinctly individual frames. It is a kind of motion artifact in the real time video. But, it...



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