Charge-coupled device camera with PC video digitizer

Abstract

This project incorporates the design and construction of a charge-coupled device (CCD) camera and a PC video digitizer card for it. The camera could then be used as a standalone unit to produce live images on a standard TV receiver or else in conjunction with the dedicated PC digitizer in order to capture images on an IBM compatible computer. These Images are then stored in a standard graphic.al file format. The charge coupled device was initially conceived in 1970 at Bell Labs by W.Boyle and G. Smith. The researchers were interested in producing an electronic analogue to the then commonly used bubble memory in order to improve computer mass storage capability. Stored charge readout along the registers of the CCD would then allow this device to be a serial memory device. The first imaging CCD was produced by Fairchild Electronics in 1974 and had a format of lOOXlOO pixels. The charge transfer efficiency was so low, that overall yield was less than 0.5% (slightly less than good photographic plates at that time). Needless to say, people such as observational astronomers were less than enthusiastic about replacing glass plates with digital electronics. But by 1979, this had all changed as an RCA 320X512 cooled CCD system would see the first light on a 1-meter telescope at Kitt Peak National Observatory. Early observations on this CCD would quickly show its superiority over photographic plates: its quantum efficiency was at least a factor of 50 higher (in the red region) and the device itself was highly linear, unlike its counterpart, making it easy to calibrate besides eliminating chemical processes and waste of time due to immediate storage of the digital image data. Over the last 20 years, the silicon CCD has been steadily improved and is evolving towards the ideal detector, with quantum efficiencies close to 100%, near perfect uniform response and a large number of pixels. Today's current generation of multi-phase pin, thinned, black illuminated 4096X4096 devices come close to reaching their goals. Modem CCD video cameras are light-weight, require little power and are more sensitive to light than the large, bulky and power-hungry vacuum tubes previously used on television cameras.