Jan 03

How do Plasma TVs Work?

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Plasma TVPlasma display televisions, also known as plasma display panels or PDPs according to industry jargon, use the process of electrochemical to produce vivid pictures. The technology makes plasma televisions to offer the highest display quality available today. Plasma TVs use a display process that is quite different from conventional cathode ray tube (CRT) or Liquid crystal display (LCD) technologies.

Basic operation
Plasma TV sets are made out of a plasma layer that sits between two glass panes. The plasma itself is actually ionized gas. The plasma layer is a mixed solution of noble elements of gasses such as radon, xenon, krypton, argon, neon and helium. When electricity is charged through this plasma mixture, it engages phosphorescent elements in the plasma layer making them to emit light.

The layer of plasma is distributed into numerous small cells of chemicals. Each of these cells can be controlled to display a specific color. The outcome makes each cell acquire a desired color to display the preferred image. By electronically varying each cell’s color, the plasma is able to create an illusion of a picture in movement.

Advanced operation
Many commercial plasma TV sets use argon, xenon, neon and in few cases nitrogen gasses in their layer of plasma. Electrodes expand from the central processing unit of the plasma display to each of the thousands of cells located in the plasma layer. The electrodes are coated with magnesium oxide to protect them from the chemical process that produces light in the display screen. When these electrodes are charges to reach different capacities, the plasma cells conduct the energy and emit light on the screen.

To produce different colors, each of the cells in the plasma layers has three subpixels: green phosphor pixel, red phosphor pixel and blue phosphor pixel. Each of these subpixels can be activated at any level of intensity. The outcome of this activation results in blending the three pixels together to get a full color in each cell. Each of these cells can show billions or varying color combinations and can be changes thousands of times in a second.

Advantages
Plasma sets offer many advantages when compared to other TV displays. One of them is their capability to represent billions of color combinations. It allows accurate reproduction of the original picture that is a number of times better than LCD screens. The plasma display color process also enables the TV to achieve a better contrast ratio with deeper blacks and brighter whites.

Plasma TV allows the viewer to view the picture from different angles without compromising the picture clarity and color accuracy. The feature makes plasma TV sets perfect for industrial displays like in a sports field or a movie event.

Plasma TV’s also feature a quicker response time which means each of the cells in the plasma layers can be changes to another color quickly. It eliminates motion blur and artifacting in case of an object moving quickly on the screen.

Market segment and display size
Another aspect to consider in the application of plasma TV sets is their display size. Many plasma TV sets are up to or over 40 inches (when the screen is measured diagonally). Many brands offer plasma TV sets of varying sizes in the market.

Nov 27

What you Need to Know about LCD TVs

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LCD TVPurchasing a LCD TV can be a little confusing as there are different categories of contrast ratios, backlighting techniques, inputs, refresh rates and screen resolutions to consider. It is critical to buy a LCD TV based on the picture quality it offers and not just its size. Some LCD TVs can provide with extra features such as in-built Blu-ray/DVD players and internet widgets. If you are interested in purchasing an LCD TV, you will find the below information useful.

Screen resolution
LCD TVs are normally available in different resolutions: 1080p and 720p. 1080p LCD TV sets have 1920×1080 pixels and 720p LCD sets will have 1280×720 pixels of screen resolution. The higher the screen resolution of the TV, the sharper picture it will provide. The signals connecting to the LCD TV are converted into the native signal of the display. Try to purchase a LCD TV that provides the highest available resolution for get better picture quality. LCD sets featuring 1080p displays accept signals lower than its resolution like 480p, 1080i and 720p.

Refresh Rate
The refresh rates of LCD TVs in the total amount of time an image takes to change on the screen. If a LCD set has a higher refresh rate it will provide a decreased motion blur. Motion blur happens when an object in the picture featured on the screen moves faster than the time taken for the TV to refresh the picture. Many of the original LCD sets had a refresh rate of 60 Hz and had a lot of motion blur. Today, many LCDs have a higher refresh rate of 240Hz or 120Hz. The sets take the standard signals and make extra frames to provide a fluid motion to the object in movement on the LCD screen. Choose a LCD set that will provide you a high refresh rate.

LCD inputs
LCD TV sets have similar inputs that are found in other HDTV sets. Component inputs, DVI and HDMI will display HD signals form a Blu-ray player or a cable box, while s-video and standard composite accepts signals from analog sources like standard gaming connection consoles and VCRs. Fes LCD sets also offer a USB input to connect a camcorder or a digital camera or a PC input to connect a VGA cable.

Backlighting
Backlighting was not very efficient in the original LCD sets. However, it has been greatly improved in the current LCD TVs. Two main backlighting sources are used for LCD TV- LED lights and cold-cathode fluorescent lamps, LED lights utilize lesser power and create lesser heat. Cold-cathode lamps are cheaper but do not provide equal level of picture color and brightness LED backlighting offer. LED-backlit TVs are made by placing a row of LEDs behind the screen or placing them along the edge of the screen. LCD sets featuring clustered LED backlighting offer another feature called as ‘local dimming’. Local dimming turns the LED backlight off to enhance the contrast ratio of the screen and black levels. LED-backlit sets are more expensive but they are more long lasting- use lesser power and offer much better picture quality making them a good investment.

Apr 17

What you Need to Know about LED TVs

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LED TVs have become a popular in many homes. The TVs offer great picture and sound quality. Although these TVs have been around for quite some time now, a few people still find it difficult to differentiate between an LCD TV and a LED TV. LED TV is actually just another arrangement of a LCD TV. The main difference is that LED TVs use LED technology for their light source.

LCD TVs use a transmittive method of display technology – meaning the television does not produce its own light. The pixels in the LCD are lit by another lighting source to produce a picture on the flat panel display screen. Today, most LCD TVs use CCFL technology as their source of backlight. The technology delivers good brightness, contrast and colors on the LCD screen. It does not however, produce good levels of black. TV sets that utilize LED backlighting technology achieve better black levels, contrast ratios and brighter colors.

Types of LED TV
Different types of LED TVs are available in the market. Edge lit LEDs and full matrix LEDs are two popular types of LED TVs. The information provided below shows some differences in these two types of LED TVs.

LED TVEdge lit LED
Edge lighting method uses a sequence of LED backlights that are positioned along the outer edges of the TV screen. The light is distributed across the LED screen enabling the TV to be manufactured as thin as possible. The outcome of this lighting technique is better than CCFL screens. But the black levels in edge lit technology are not very deep. A closer inspection on the edge of the screen will show that the screen edge is brighter than the picture display at the center of the screen.

Full-array LED backlighting
Some LED manufacturers utilize full-array LED backlighting technique to take a complete advantage of LED lighting. In full-array backlighting, many rows of LED lights are put behind the surface of the LED screen. Even though it gives a thicker panel for the TV, the row of LEDs backlights provides much brighter, even colors and better contrast.

Each LED that is place behind the screen can be independently turned off or on inside the screen in a process called ‘local dimming’. The process gives a better control of darkness and brightness of the picture. Greater levels of contrasts can be achieved by decreasing the light effects from brightly lit surrounding areas leaking into the blackened portions of the LED screen.  So if a LED TV has good dimming control, it will provide good picture quality.

Features of LED TV

  • LED TVs can achieve deeper levels of blacks along with brighter images and in turn providing much better contrast.
  • LEDs are thinner- especially LED TV’s that use edge lighting systems.
  • LEDs provide better picture that can be viewed in all angles unlike LCD TVs.
  • LED TVs last longer
  • The TVs are much more energy efficient than their counterparts like CRTs, plasma and CCFL TVs.
  • LED TVs do not use mercury in their backlighting methods.

An LED TV provides you a much better picture quality compared to other TV sets. As LEDs are slimmer, they take up less space and also give you the option of setting them up on your wall.

Jan 03

Projection Televisions Explained

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Projection TVProjection televisions are TV sets that use video projectors to display pictures and videos. With the help of a projector the TV set is able to provide a larger image than most other standard models. Projection TV sets act as small-scale cinema screens which many viewers can utilize in their home theaters. A projection television may either be a front projection- similar to a movie projector or a rear projection- that functions the same as a standard television set.

Functions
In the past, television sets have utilized cathode ray tubes (vacuum tube in which electrons are blasted on a glass screen made from phosphorous) to create a picture by lighting up the phosphors. Projection television sets use a similar process to produce an image but after the picture is created, it is projected through a series of lenses to display a much bigger image. It allows projection television sets to produce much larger images than CRT TV’s as their screes would need a much larger glass piece to show an image of a similar size.

Front projection
Front projection technique in projection television sets basically functions similar to video projectors. In projection televisions the video projector can be connected to satellite/cable receiver box or an antenna. It functions similar to other projectors by sending the video through lenses to enlarge the image and project it out. A screen is required on the outside to hold the projected image. External speakers are also required that need to be connected to the televisions output source as the projector does not have in-built speakers.

Rear projection
A rear projection television sets use projectors within the limits of a regular frame of television, projecting the picture on the screen located on the back of the television set. It is accomplished by magnifying the picture using a series of lenses situated inside the television and then reflecting it off on mirrors. The process causes the image to be displayed in a reverse position on the back screen and the mirrors are used to display the image in a normal position on the actual viewing screen. DLP TVs and plasma TVs all use rear projector technique to display images on their screen.

Choosing a projection television set
Many projection television sets are available in the market, each having their own unique features and advantages. If you want a television set that does not take up much space, you can purchase a front projector. You will need to buy additional devices like speakers and a projection screen to get the complete experience of viewing a picture through front projectors. A rear projector provided better picture quality, resolution and contrast.

Advantages of projection television sets
Projection television sets are a better option than HDTV sets as they use a similar method that is used in previous CRT TVs .the method provides better color contrast compared to LCD TV sets with much larger picture of over 60 inches. The projection television sets are a great way to enjoy entertainment programs with a large audience at your home or office.