Glossary

Average Video Signal

Represents the average light level of the whole picture used to open or close the automatic iris in the lens.

AVG

Alphanumeric Video Generator is a device for providing additional information, normally superimposed on the picture being displayed. This can range from one or two characters to full screen alphanu- meric text. Such generators use the incoming video signal sync pulses as a reference point for the text insertion position, which means if the video signal is of poor quality, the text will also be of poor quality.

Backlight compensation

Special feature of video cameras. Prevents the effect that everything appears dark in front of a brigt object (e.g. a window).

Back Focus

The back focus is a procedure of fine mechanical adjustment in the camera, which moves the CCD or the lens mount to compensate for different back focal lengths of different lenses.

Backlash

An error present in a pan and tilt head due to the play in the mechan- ical components like gears, pulleys etc. This results in the Pan Tilt head not stopping instantaneously. This error is critical in preset PTZ cameras and is measured in degrees.

Back Porch

The back porch is the portion of a video signal that occurs during blanking from the end of the horizontal sync to the beginning of active video. It is also the blanking signal portion that lies between the trailing edge of a horizontal sync pulse and the trailing edge of the corresponding blanking pulse. The colour burst is located on the back porch.

Balanced Signal

In CCTV this refers to the transmission of a video signal through a twisted pair cable. It is called balanced because the signal travels through both cables, using opposing polarities to help reduce any losses due to interference.

Balun

A balun is a device used to match or transform an unbalanced coax- ial cable to a balanced twisted pair system.

Bandwidth

Is the range of frequencies which pass through an electronic amplify- ing, processing or transmission equipment without attenuation or loss.

Barrel Distortion

Is a distortion in the monitor due to non uniform scanning which causes the image to bulge outward like a barrel.

Baud

The term baud is used to express the data exchange rate, typically the baud settings of two devices must match if the devices are to communicate with one another.

Beam Angle

Is the angular beam width of a conical beam of light and is measured in degrees.

Bifurcator

An adapter used to split a loose tube containing two optical fibres into two single fibre cables.

B-ISDN

Broadband Integrated Services Digital Network. An improved ISDN composed of an intelligent combination of more ISDN channels into one that can transmit more data per second.

Bitmap

A bitmap is a pixel by pixel description of an image each pixel is a separate element.

BlackBurst

A composite colour video signal. The signal has composite sync, ref- erence burst and a black video signal, which is usually at a level of 7.5 (50mV) above the blanking level.

Black Level

It electronically represents the black part of an image corresponding to approximately 0.3 volts.

Blanking Pulse

Is a black pulse added during the fly back period to make the video signal invisible on the screen.

BNC Connector

Is a type of connector used to interconnect two coaxial cables or con- nect a cable with other CCTV components.

Bridging Switcher

Is a type of sequential switcher which has two outputs. The sequenc- ing output sequences all the camera inputs whereas the other out- put is a spot output where any camera can be called up for extended viewing.

Brightness

Represents the intensity of illumination of the reproduced picture.

Brightness Control

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Is a control in the monitor which does not change the amplitude of

 

the video signal but increases or decreases the illumination of the

 

phosphors on the screen.

 

Broadcasting Camera

 

Is a high quality camera using three CCD chips. It is used extensively

 

in the BroaDCasting professional industry.

 

C-mount

 

Is a lens mount with 17.526mm back flange. The back flange is the

 

distance between the lens mounting surface and the CCD chip. Cam-

 

eras with CS-mount need a special adapter ring to be used with C-

 

mounted lenses (supplied with every camera).

 

© Siemens Building Technologies Group

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CRT, TFT specifications

Siemens, a prominent name in electronics and engineering, has made significant contributions to display technology, particularly in the realms of Thin Film Transistor (TFT) and Cathode Ray Tube (CRT) displays. These technologies have paved the way for advancements in visual media, ranging from television sets to computer monitors.

TFT display technology, a type of LCD (Liquid Crystal Display), employs thin film transistors to produce brighter and more vibrant images. One of the main features of TFT displays is their ability to deliver high resolution and excellent color reproduction, making them ideal for various applications such as smartphones, tablets, and laptops. TFT screens utilize an active matrix approach, which allows each pixel to be controlled individually. This method results in faster response times and improved image quality, with less motion blur, compared to older passive matrix displays.

One of the key characteristics of TFT technology is its versatility in different settings. It supports a wide range of viewing angles, which enhances the user experience whether one is viewing the display head-on or at an angle. Additionally, TFT displays are known for their thin profile and lightweight design, contributing to the overall portability of devices that incorporate them.

On the other hand, CRT technology, which was once the standard for televisions and computer monitors, uses electron beams and phosphorescent screens to produce images. One of the defining features of CRTs is their ability to display deep blacks and a wide color gamut. CRT technology can achieve high refresh rates, reducing flicker and improving the quality of fast-paced visuals. However, CRTs tend to be bulkier and heavier than modern display technologies like TFT.

Despite the evolution towards flat-panel displays, CRT technology is still appreciated for its natural color and motion portrayal. Siemens has leveraged these characteristics to produce quality CRT monitors that were favored in professional settings, including graphic design and medical imaging, where color accuracy is paramount.

In summary, Siemens has played a vital role in advancing both TFT and CRT technologies. TFT displays are recognized for their high resolution, fast response times, and design versatility, while CRTs are celebrated for their rich color and depth. As technology continues to advance, the legacy of these display types remains influential in shaping modern electronic devices.
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