| CCD |
CCD is the abbreviation of Charge Coupled Device. CCD sensors consist of a one- or two-dimensional array of memory elements. They are mainly useful as image sensor in video cameras, scanners and digital cameras. |
| CE |
All electrical and electronic devices which have been available for sale in the EU as of 01.01.96 have to bear this official seal. It provides information on the electromagnetic compatibility of the device. |
| Cinch |
A connector primarily used for the transmittance of video - and audio signals. |
| Cinch connector and jack |
(Also called RCA) are today mainly used in the consumer electronics. Usually audio adapters are marked red and white (for Audio right/left) and video adapters are marked yellow. |
| Colour temperature |
A measure for the predominant colour portion of the light, measuring unit Kelvin. The higher the blue share in the light, the higher the colour temperature. |
| Compact flash card |
Mobile memory medium for presentations without PC |
| Component signal |
Also described as colour difference or YUV signal. The video signal is split into one brightness and two colour difference signals, which are transferred separately. The image quality of the component signal is better than S-Video and therefore is employed frequently e.g. for the connection to DVD-players. |
| Compression |
Many projectors are able to display higher resolutions than they actually have by skipping lines and columns. As this affects the picture quality, several manufacturers have developed special compression methods, which actually compress with only the slightest loss of information. |
| Condenser lens |
Additional light focusing for improved sharpness of projection image along the margins. |
| Continuous projection |
Continuous slide shows either via built-in timer or via IR-remote control with the help of the autotimer function. Different slide change times are possible. |
| Contrast |
Indicates the difference between the darkest black and the brightest white. The higher the contrast ratio, the darker the black value on the projection screen. There are two different measuring methods: Full on/off: In a dark room the brightness of the projection screen is measured at full white and full black. This process does not consider the refraction of light within the lens and therefore produces a very high contrast ratio.ANSI: A chess board pattern of 16 fields black and white is projected to the screen. The brightness in the fields is evaluated and the contrast ratio is calculated accordingly. This process is far more practical and the numerical value is always lower than with the full on/off process. |
| Convergence |
The congruence of the three LCD panels (red,green,blue) in a projector. Convergence error: Chromatic aberration in data projectors with three modules. Lines and outlines have coloured margins. The reason: The three projected component images for red, green, blue do not exactly comply with each other. Convergence errors mainly appear in corners. |
| CRT projectors |
Three-tube projector for ceiling mounting. Unlike digital projectors, CRT projectors are considerably heavier, more expensive and the adjustment requires a great effort. |
| Cushion distortion |
Geometry error of lenses during projection which leads to a pin-cushion distorted image. Horizontal and vertical margin lines of the image are distorted up to the image centre. This is caused by reproduction errors of lenses. Opposite barrel distortion. |
