Glossary

Pincushion Distortion

Is a type of distortion caused due to non uniform scanning in the monitor which makes the picture to bulge inward.

Pinhole Lens

Is a lens with a small diameter used for covert surveillance.

Pixel

(picture element) is the basic unit of a CCD chip which accumulates charge depending upon the amount of light falling upon it. A typical CCD chip has over 300,000+ pixels.

Polarizing Filter

Is a type of filter which reduces glare by intercepting reflected light from surfaces like water, glass etc.

Polycarbonate

Is a type of toughened glass which can be used in housings for use in areas of high vandalism.

Polyethylene

Is a type of plastic used to make outer jackets for cables.

Potentiometer

Is an electronic component in which the resistance can be changed by a movable contact point. It is used in pan tilt heads and zoom lenses to record preset positions.

Power Line Interference

Is a type of interference caused by main power lines and usually seen as horizontal bands on the monitor.

Preamplifier

Is a type of amplifier used to increase the output of a low level source allowing the signal to be processed by other devices.

Preset

Is a term used in CCTV to define pre determined position of a pan and tilt head and zoom lens.

Primary Colour

Is a colour which cannot be obtained by mixing other colours. Red, green and blue are the three primary colours which can be mixed to produce other colours.

PSTN

Public Switched Telephone Network is an analogue telephone net- work currently in use all over the world.

PTZ Controller

Is a device used to control the movement of the pan tilt head and zoom lens from a remote location.

Quad

Is a device which used to display pictures from 4 cameras on a single monitor.

Read Out Time

Is the time taken to read the charge from the pixels in a CCD chip.

Real Time Video

Is a picture with more than 24 frames per sec and therefore looks continuous.

Receiver Driver

Placed at the camera point and connected by either a coaxial or twisted twisted pair cable. It is used to decode the incoming control signals for the Pan, Tilt and Zoom functions.

Reed Switch

An alarm is activated when the reed switch is opened or closed. It is widely used with doors, windows, roller shutters etc and can be used to activate equipment to bring the nominated camera up for extended viewing.

Regulated Power Supply

DC power supply in which the ripple factor is minimal.

Remote Head Camera

In this type of camera, the CCD chip is separated from the camera body by cable. It is used in applications where the amount of space available to fit the camera is limited.

Resolution

A measure of picture definition and clarity and is represented by the number of lines. Greater the number of lines, higher the resolution.

RG-11

Coaxial cable with a thicker centre core and used for transmission of video signals up to 500m.

RG-59

Coaxial cable used for transmission of video signals up to 250 m. It is probably the most popular cable used in CCTV.

Ripple Factor

Is the amplitude variation present in a DC power supply due to insuf- ficient filtering. A large variation can damage a DC camera.

RS-232

Is a communication protocol used for communication between microprocessor based devices.

S-VHS

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Super VHS is a type of video format in which the illuminance and

 

chrominance signals are sent separately resulting in improved pic-

 

ture quality.

 

Salvo Switching

 

Is a feature in matrix switchers. On command from the matrix

 

switcher or an alarm event, a group of cameras can be switched

 

simultaneously onto a group of monitors.

 

Screen

 

Is a copper braid which covers the dielectric and centre core of a

 

coaxial cable.

 

© Siemens Building Technologies Group

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Siemens TFT, CRT manual Pstn

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.