SVSi | Scientific Vision Systems

Scientific Vision Systems (SVSi) is the leading supplier of scientific professional medical imaging equipment including medical printers, medical cameras, medical display monitors, & medical recorders for Endoscopy & Ultrasound, from top brand names as Sony, Hitachi, Panasonic, Tatung, Mitsubishi, National Displays, Double Black Imaging, and hard to find items. Also featuring the most complete glossary of medical digital imaging video electronic terms.

CCD (Charge Coupled Device): Semiconductor device made of a matrix (or lines) of individual photosensitive elementss, called pixels. The optics focus the scene onto the matrix and each pixel accumulates an electric charge proportional to the local intensity of received light and to the integration time. At read out time, all charges are transferred at the same time to an output matrix protected from light, where a sequential reading may take place while a new picture starts integrating. The output matrix size is half that of the sensitive matrix size for interlaced mode CCD's, and the same size for progressive scan CCDS.

CCD IRIS: Special operating mode of the electronic shutter of a CCD camera. The shutter timing is automatically adjusted to maintaint the same video output level, irrespective of the scene illumination. Can only reduce the camera sensitivity. Allows the use of a fixed iris lens under variable lighting conditions. Often combined with AGC.

CCIR: B/W video standard with 625 lines / frame, 2 interlaced fields / frame, 25 frames / second. Monochrome version of PAL.

CCU (Camera Control Unit): The CCU provides a means of controlling a remote camera. So that the remote camera can be as small and light as possible, the CCU also includes all electronic circiuts that do not have to be fitted inside the remote head, these are typically signal processing circuitry, input/output interfaces and power supply.

Chrominance: Color part of the composite video signal. Also called C. Separately transmitted in Y/C (S-video). It is the combination of the two color difference signals (U or R-Y) and (V or B-Y) modulated on to a subcarrier. See also YUV.

CHU (Camera Head Unit): In a remote head camera system, the CHU is a small unit that only includes the sensor, its optical interface, the cable coupling to a CCU and the minimum amount of electronic circuitry.

C-Mount: Type of camera mount in which there is 17.526 mm clearance between the lens rear mounting sufrace and the camera's CCD.

Composite sync: Combintation of the HD and VD in one signal. Commonly used as a synchronizinag or genlock signal in B/W systems.