CID Cameras
Charge injection device (CID) cameras are used in analytical instrumentation, industrial machine vision, medical, scientific and aerospace applications. CID cameras use photosensitive silicon capacitor components as image sensors, arranged in an addressable array. By using the electrical indexing of row and column electrodes in the array, each pixel in the CID camera can be individually addressed. The current between the capacitors is amplified and converted to voltage, providing a composite video or digitized video signal.
CID cameras offer a high degree of exposure control in low-light settings. An operator can suspend the charge injection and use the camera for time-lapse exposures. This technique is useful in a variety of scientific photography applications, including astronomy, inspection and measurement applications, laser beam profiling, semiconductor inspection and process manufacturing monitoring. CID cameras are also designed to be tolerant of radiation, including gamma, neutron, and proton radiation. CID digital camera systems use camera controller circuitry for data acquisition and real-time video processing.
CID cameras offer unique technical advantages over charge coupled device (CCD) imagers and other camera systems. A CCD camera is subject to image distortion called blooming or smearing that can occur with bright light intensities. CID cameras eliminate many distortion problems because the optical overloads in the array are confined to the illuminated pixels, and the excess charge is drawn into a charge collector.
Because CID cameras are capable of discerning weak optical signals from strong optical signals, they are commonly used in spectroscopy, X-ray crystallography, and biological imaging applications. A CID camera system for spectroscopic applications may also use a cooling system to reduce dark current, or the current that flows into a photosensitive detector when it is not exposed to light. CID video cameras can also capture images using a wide spectral response, making them useful to record images produced in the ultraviolet to near infrared range.
