Q1.

A1.
















Q2.

A2.


















Q3.

A3.












































































Q4.

A4.















Q5.

A5.
































Q6.

A6.









Q7.

A7.

Q8.

A8.

Q9.

A9.

HOW DOES A LCD TV WORKS?

LCD is an abbreviation of Liquid Crystal Display, a type of display used in digital watches and many portable computers. Liquid Crystal Display is a technology which uses millions of crystals, which are suspended in a liquid that is sandwiched between transparent panels. The cells of Liquid Crystals behave in different ways when they are exposed to varying electrical voltages. Behind this liquid crystal sandwich is bright florescent light. The crystals are instructed to either let the light pass or not. To create colour, a set of three LCD's are required per pixel, one for each primary colour (red, green and blue). By giving each of these LCD's a different voltage, different colours can be produced.



HOW DOES A PLASMA TV WORKS?

Plasma television technology is based loosely on the fluorescent lightbulb. The display itself consists of cells. Within each cell two glass panels are separated by a narrow gap in which neon-xenon gas is injected and sealed in plasma form during the manufacturing process. The gas is electrically charged at specific intervals when the Plasma set is in use.

At the heart of the plasma TV are chemical compounds called phosphors. In a plasma TV, each pixel is made up of three phosphors – one red, one blue, and one green.  These phosphors emit light when struck by beams of electrons. The intensity of the electron beam determines the amount of light emitted. The charged gas then strikes red, green, and blue phosphors, thus creating a television image. Each group of red, green, and blue phosphors is called a pixel (picture element).


WHAT IS THE DIFFERENCE BETWEEN AN LCD TV AND PLASMA TV?

Power Comsumption
Unlike standard CRT and Plasma televisions, since there are no phosphors that light up, less power is need for operation and the light source in an LCD television generates less heat than a Plasma or traditional television. Also, because of the nature of LCD technology, there is no radiation emitted from the screen itself.

Viewing Angle
Apart from better contrast due to its ability to show deeper blacks, plasma screens typically have better viewing angles than LCD. Viewing angles are how far you can sit on either side of a screen before the picture's quality is affected. You tend to see some brightness and colour shift when you're on too far of an angle with LCDs, while a plasma's picture remains fairly solid. This is steadily changing, however, with more and more LCDs entering the market with viewing angles equal to or greater than some plasmas. Plasmas can also produce a brighter colour, once again due to light leakage on an LCD affecting its colour saturation.



Screen Burn-in
Although Plasma television technology eliminate the need for the bulky picture tube and electron beam scanning of traditional televisions, because it still employs the burning of phosphors to generate an image, Plasma televisions still suffer from some of the drawbacks of traditional televisions, such as heat generation and screen-burn of static images. Screen burn in occurs when an image is left too long on a screen, resulting in a ghost of that image burned in permanently. Newer plasmas are less susceptible to this thanks to improved technology and other features such built-in screen savers.

Viewing Environment
Consider your home's lighting conditions for a more accurate assessment of the brightness level. Plasma TVs produce warm realistic colours with crisp black levels in your living room, making them perfect for watching movies and TV dramas. In contrast, LCD colour displays which look sharp and vibrant in brightly-lit retail stores may appear washed out in normal living room ambient lighting.

Fast-moving Scenes
Plasma TVs are highly responsive with moving images, producing crisp images even during quick movements, such as in a soccer match. LCD TVs generally lack responsiveness when displaying fast-paced motion sequences, resulting in blurred images and trailing effect. However, do check the refresh rate of the newer generation LCD TVs as newer models have improved significantly.



Black Levels
Plasma displays the best black levels among all the TV technologies. Plasma TVs reproduce fine detail in darker scenes and provide a fuller spectrum of colour for more realistic images, which means better contrast and detail in dark-coloured television or movie scenes. . LCD TVs generally have lower quality black levels, so images appear relatively washed out and flat, and colours appear to have a slight grey sheen.


WHAT DOES ANSI LUMEN MEAN?

Lumens refers to the measurement of brightness at the screen. This measurement is very vague as it does not take factors like screen size, projection lens, projector settings and aperture size into account. This is the brightness measurement initially used for overhead projectors.

ANSI Lumens is a standard, laid down by the American National Standards Institution, to objectively measure the brightness of the image that a projector can project. The higher the value, the brighter the image, although the perceived brightness will depend on the screen size being used.

A higher lumen value is required in environments where the projector will have to compete with high levels of ambient lighting. ANSI Lumens is a good indication of the average brightness of the image, taking the brightness uniformity, screen size, aspect ratio of the image, lens throw distance and type as well as colour temperature into account. A small room typically requires from 200 to 300 ANSI lumens, whereas a large room may require from 400 to 600. A large auditorium may need 2000 or more.


MEANING OF RESOLUTION AND VGA, SVGA, XGA, SXGA?

Refers to the sharpness and clarity of an image. The term is most often used to describe monitors, printers, and bit-mapped graphic images. In the case of dot-matrix and laser printers, the resolution indicates the number of dots per inch. For example, a 300-dpi (dots per inch) printer is one that is capable of printing 300 distinct dots in a line 1 inch long. This means it can print 90,000 dots per square inch.

For graphics monitors, the screen resolution signifies the number of dots (pixels) on the entire screen. For example, a 640-by-480 pixel screen is capable of displaying 640 distinct dots on each of 480 lines, or about 300,000 pixels. This translates into different dpi measurements depending on the size of the screen. For example, a 15-inch VGA monitor (640x480) displays about 50 dots per inch.

VGA - Video Graphics Array
Currently, the most widely accepted graphics hardware standard for all graphics cards and monitors manufactured to date. Originally supported an output resolution of up to 640 x 480 pixels at 16 colours. Virtually all current graphics cards and monitors can handle resolutions higher than 640x480 pixels in high colour (64000 to 16 million colours).

SVGA - Super Video Graphics Array
Super Video Graphics Array. A term used to denote a resolution higher than VGA (640x480 pixels, 16 colours). Most Super VGA cards output a resolution of up to 1024x768 pixels using at least 256 colours.

XGA - eXtended Graphics Array
IBM's graphics standard which supports an output resolution of up to 1024 x 768 pixels.

Super XGA (SXGA) Super eXtended Graphics Array
A standard capable of an output resolution of up to 1600 x 1200 pixels, using at least 256 colours.

Printers, monitors, scanners, and other I/O devices are often classified as high resolution, medium resolution, or low resolution . The actual resolution ranges for each of these grades is constantly shifting as the technology improves.


WHAT IS THE DEFINITION OF ASPECT RATIO?

The term "aspect ratio" describes the relationship between the width and height of a TV screen. Traditional TVs have an aspect ratio of 4:3, meaning that for every 4 inches of width, there are 3 inches of height. This results in a screen that looks almost like a square. Many newer TVs have an aspect ratio of 16:9, so their screens are almost twice as wide as they are tall. Also referred to as "wide screen," 16:9 TVs are better suited to wide screen DVDs and HDTV broadcasts. The term "aspect ratio" can also be used to describe the dimensions in which film or TV shows are shot. Traditional broadcasts are usually in 4:3 format, while HDTV broadcasts have an aspect ratio of 16:9.


WHY USE REAR PROJECTION?

There are four basic advantages with rear projection:

• Activities such as writing can be performed while visual contact between the audience and the presenter maintained. Rear projection is preferred in any presentation area where close to normal room lighting is desirable at all times.
• Rear projection allows the freedom to walk in front of the screen without obstructing the projection beam.
• The distraction of projector noise is virtually eliminated by placing it behind the screen, in a separate projection room.
• Risk of theft is also diminished by locking equipment in a separate room and the equipment is always set up, ready to operate.

Rear projection is therefore ideally suited for use in:

• Conference Rooms
• Boardrooms
• Training Rooms
• Classrooms
• Lecture Halls

DA-PLEX rigid rear projection screen material consists of an extremely fine, precisely applied, optical coating, on a translucent acrylic substrate. The coating is designed to provide the highest resolution and most accurate colour fidelity and it gives the best balance between image brightness and viewing angle. The rigid acrylic base is breakage resistant for safety and security and affords excellent sound isolation.

DA-TEX flexible rear projection screen material consists of an extremely fine precisely applied optical coating on a translucent flexible vinyl base, which is least affected by temperature and humidity changes. DA-TEX screens are neutral grey in colour and provides excellent contrast and colour reproduction. They are high in transmission values and use projected light to maximum advantage in normal room lighting.


HOW DO I SELECT WHICH PROJECTOR IS SUITABLE?

Choosing the right projector is an important step.
Here are some tips on what to look out for:

SVGA or XGA?
Determine your projection needs for at least the foreseeable future. Will SVGA resolution suffice or will you soon be using XGA resolution? Most SVGA projectors can project XGA images using compression techniques, but the quality is not as good as a true XGA projector. XGA may be more expensive, but it will have a longer product life. Remember to plan for the future!

Will the projector be used for a permanent installation or for portable use?
If you will be using the projector for portable use, size and weight are very important considerations. However, you will generally pay more for a smaller, lighter projector.

If the projector will be used for a fixed installation, size and weight are not as important as image quality, brightness and remote control of basic functions, i.e. contrast, focus, zoom and colour balance.

What light output do you require?
Most of the newer SVGA projectors project images of at least 500 ANSI Lumens, powerful enough for most situations (room with all the lights on). However, you may need a brighter projector. Try the projector out in all the situations in which it will be used, to ensure it meets your needs.

What is your budget?
Once you have narrowed down the selection, fitting the projector into the budget is the next step. If no projector falls within your budget, look into other financing options such as rental agreements, which may offer a more attractive method of acquiring product.

What unique features would be very useful?

Flash card
Some newer projectors now use a PCMCIA flash memory card to store a presentation using the JPEG picture format. The card is small (the size of a credit card), fast and can store anything from 8 to 64 megabytes of information.

A flash card is very useful when you need to do portable presentations and do not wish to additionally carry around a notebook. Simply download your presentation to the flash card, insert the flash card into the projector and play back your presentation.

Motorised zoom
A motorised zoom allows for a professional, hands-off operation and is also useful for fixed installations, where it might be difficult to adjust the zoom and focus if the projector is mounted from the ceiling.

Automatic synchronisation feature
One touch automatic synchronisation means plug 'n project. If you want a one touch set-up, you'll want an automatic synchronisation feature as standard.

Do you require a ceiling mounted projector?
Not all projectors can be ceiling mounted. If you need this feature, ensure the projector supports ceiling mounting.

Do you require rear-projection?
Not all projectors support rear-projection. If you require rear-projection, ensure the projector supports this function.


What is the definition of the term "smart home"?


As a basic definition, a smart home is a home where the systems (security, lighting, sensors, heating and air-conditioning, audio-video etc.) are interconnected to allow the automatic or remote control of the home to save energy, improve comfort, safety and or convenience for the homeowner. A smart home enhances the value of a home.

Elements of a Smart Home
Three things a home needs to make it smart:
1. Internal network – wire, cable, wireless
2. Intelligent control – gateway to manage the systems
3. Home automation – products within the homes and links to services/systems outside the home

Appliances and services – six main areas
1. Environmental (heating/water, lighting, energy management, metering)
2. Security (alarms, motions detectors, environmental detectors)
3. Home entertainment (audio visual, Internet, lighting)
4. Domestic appliances (cooking, cleaning, maintenance alerts)
5. Information and communication (phone, Internet)
6. Health (telecare, home assistance)

++ Back to Top ++