TV: TelevisionAll about TV, Satellite TV and future developments.

Television (TV) is a telecommunication medium for transmitting and receiving moving images that can be monochrome (black-and-white) or colored, with or without accompanying sound. "Television" may also refer specifically to a television set, television programming, or television transmission.

Commercially available since the late 1920s, the television set has become commonplace in homes, businesses and institutions, particularly as a vehicle for advertising, a source of entertainment, and news. Since the 1970s the availability of video cassettes, laserdiscs, DVDs and now Blu-ray Discs, have resulted in the television set frequently being used for viewing recorded as well as broadcast material. In recent years Internet television has seen the rise of television available via the Internet, e.g. iPlayer and Hulu.

Although other forms such as closed-circuit television (CCTV) are in use, the most common usage of the medium is for broadcast television, which was modeled on the existing radio broadcasting systems developed in the 1920s, and uses high-powered radio-frequency transmitters to broadcast the television signal to individual TV receivers.

The broadcast television system is typically disseminated via radio transmissions on designated channels in the 54–890 MHz frequency band. Signals are now often transmitted with stereo or surround sound in many countries. Until the 2000s broadcast TV programs were generally transmitted as an analog television signal, but in 2008 the USA went almost exclusively digital.

A standard television set comprises multiple internal electronic circuits, including those for receiving and decoding broadcast signals. A visual display device which lacks a tuner is properly called a video monitor, rather than a television. A television system may use different technical standards such as digital television (DTV) and high-definition television (HDTV). Television systems are also used for surveillance, industrial process control, and guiding of weapons, in places where direct observation is difficult or dangerous.
Amateur television (ham TV or ATV) is also used for non-commercial experimentation, pleasure and public service events by amateur radio operators. Ham TV stations were on the air in many cities before commercial TV stations came on the air.

Some TV channels are partly funded from subscriptions therefore the signals are encrypted during broadcast to ensure that only the paying subscribers have access to the decryption codes to watch pay television or specialty channels. Most subscription services are also funded by advertising.

Worldwide large-screen television technology brand revenue share in Q3 2011
Manufacturer Display Search.
LG 13.1%
Sony 9.9%
Panasonic 8.4%
Sharp Corporation 7.6%
Others 38.2%

Worldwide TV Shipments by Technology in Q3 2011
Technology Display Search
LCD TV 83.1%
PDP TV 6.7%
OLED TV 0.0%
CRT TV 10.2%
RPTV 0.0%
Total 100%

Aspect ratio incompatibility: 16:9 & 4:3

The television industry's changing of aspect ratios is not without difficulties, and can present a considerable problem. Displaying a widescreen aspect (rectangular) image on a conventional aspect (square or 4:3) display can be shown: in "letterbox" format, with black horizontal bars at the top and bottom
with part of the image being cropped, usually the extreme left and right of the image being cut off (or in "pan and scan", parts selected by an operator or a viewer) with the image horizontally compressed A conventional aspect (square or 4:3) image on a widescreen aspect (rectangular with longer horizon) display can be shown: in "pillar box" format, with black vertical bars to the left and right
with upper and lower portions of the image cut off (or in "tilt and scan", parts selected by an operator) with the image vertically compressed

A common compromise is to shoot or create material at an aspect ratio of 14:9, and to lose some image at each side for 4:3 presentation, and some image at top and bottom for 16:9 presentation. In recent years, the cinematographic process known as Super 35 (championed by James Cameron) has been used to film a number of major movies such as Titanic, Legally Blonde, Austin Powers, and Crouching Tiger, Hidden Dragon (see also: Films shot in Super 35). This process results in a camera-negative which can then be used to create both wide-screen theatrical prints, and standard "full screen" releases for television/VHS/DVD which avoid the need for either "letterboxing" or the severe loss of information caused by conventional "pan-and-scan" cropping.

Understanding Different Types of TV ( 2012-06-03) by Matt Whitlock
(Author's Note: This is the third in a series of articles that explain the differences among the many television technologies and help the consumer with a purchase decision. Follow the red links within this article to learn more about each type of TV or TV technology. This article is continued from the article Factors to Consider When Choosing a TV.)

Each particular category of TV offers advantages and disadvantages in a television experience. If you've narrowed the playing field down, follow the appropriate red link under the categories below.

It's important to note that many of the advantages and disadvantages listed are with respect to other products in their category.

1. Direct-View TVs : Available Sizes: 9" - 40"
Excellent image quality - In many ways superior to other newer technologies.
The prices are affordable - Many tube sets cost way less than flat panel competitors.
Familiar technology - Who hasn't owned a tube TV at one point or another?
Excellent Viewing Angles - You can see the image from nearly any angle.
Sizes are limited - If you want an immersive experience, but sit more than 6 feet away, forget the tube and move to a different technology.
Weight - The largest tube TVs can weigh in over 250 pounds!
Depth - Most tube TVs range between 18-24 inches deep.
Value per inch - The largest tubes often cost more than other larger display types.

2. Rear-Projection TVs
Rear-Projection is a general category for many different types of TVs. To learn more about Rear-Projection TVs in general, click here. Click below to learn more about a particluar kind of rear-projection display.
CRT Rear-Projection.
Available sizes: 42"-73"
Excellent image quality - in many ways superior to the even the newest technologies. Black level - CRT rear-projection produces the most rich and subtle blacks of any other TV type to date.
Value - Even the best CRT projection displays are less expensive than the worst quality alternatives.
Cabinet size - CRT RPTVs are often very deep, reaching nearly 30" on the biggest models.
Maintenance - Though they should rarely require service, CRT RPTVs often need fine tuning adjustments to look their best.
Viewing angle - The image on a CRT RPTV will begin to dim at any angle greater than 120-140 degrees off axis.
Weight - Due to the mass of the display, you'll rarely want to move one once it's in place.

3. Microdisplays
Microdisplays are still rear-projection TVs, but differ in the kinds of technologies used to create the image. For more on microdisplays in general click here. The types of microdisplay TVs are LCD Rear-Projection, DLP Rear-Projection, and LCoS (and varients) Rear-Projection TVs. Each is described below.
LCD Rear-Projection
Available sizes: 42"-70"
Ultra sharp image - Due to the large pixel gap, these displays can look extremely sharp at the right distance.
No rainbow effect - unlike DLP, there is no possibility for a rainbow effect.
Black level - While LCD is getting better black levels with each passing model year, the other microdisplay technologies are usually a little bit better.
Screen door effect - Due to the large pixel gap, sitting too close to one can make it look like you're watching TV through a screen door.

4. DLP Rear-Projection
Available sizes: 42" - 67"
Black level - Currently sports better black levels than LCD.
Smoothness - DLP offers a smooth picture due to the smaller pixel gap.
Video noise - Random sparkles in darker areas of the screen
Possible rainbow effect - Moving your eyes quickly may cause you to see a rainbow of color

5. LCoS (and variants) Rear-Projection
Available screen sizes: 52" - 82"
Smoothness - Due to the very small pixel gap, the images are smooth as glass
High resolutions - Many options are available at 1080x1920
Price - These sets tend to be more expensive than DLP and LCD options
Black Level - Many LCoS sets don't handle blacks as well as DLP or LCD

6. Flat Panel TVs
Flat-panel is a generic term for very thin TVs. To learn more about flat panel TVs in general, click here. There are two types of Flat-panel TVs - Plasma Display Panels and LCD Flat-Panels as described below.
Plasma Display Panels
Available sizes: 32" - 76"
Black levels - Plasma displays typically have better black levels than LCD displays
Size - Though LCD displays are emerging at larger sizes, the current max is around 45"
Value per inch - Plasma offers a better value for your dollar at larger sizes
Burn-in - Static images have the potential to burn into the display
Price - Though cheaper than LCD at large sizes, they're way more expensive than other options

7. LCD Flat-Panel
Available sizes: 10" - 45"
Solid image - The image on an LCD flat panel is rock solid
No burn in - LCD displays are essentially immune to burn-in
Price - The price for larger LCD TVs is extremely high
Viewing angles - Many flat-panel LCDs are difficult to see at wide angles


As you can probably see, choosing the right TV for you involves many different factors. Once you've determined the right category or technology for you, the last step is to go to your local dealer and see it for yourself. Many dealers are good about answering your questions and helping you choose a specific model to meet your needs. It's recommended to bring your own DVD disc to evaluate the image, and don't be fooled by evaluating the image without checking the picture controls on each set. Dealers will often try to fool customers by deliberately making the out-of-stock model look worse than in-stock options.

There are many salesmen in the world that truly want to help you get what's right, and not what's most expensive. Listen, but double check any unusual facts you're presented with the TechLore community before believing them.

One way or another, if you follow the steps presented in the many articles devoted to helping you pick out a new TV, you'll wind up making a choice you'll be happy with for years. Buying a TV is not a one day process, so take your time to truly think about what kind you need, evaluating different models, and selecting a dealer that will be there to service you. And of course, the TechLore community will be here to help answer any of your questions, both before and after you make your decision.

Understanding Your TV Connection Options
by Paul Sanders

Audio and video technology continues to reveal new, more advanced devices that bring home entertainment to new levels. New televisions now feature more connection options in order to be compatible with a larger number of audio and video sources, like Blu-ray disc players and MP3 players. Here are some details on the most common connection types to help you make sense of the connection options available for your TV.

TV Connection Types:

HDMI cables: HDMI connections are the latest breakthrough in HDTV technology. You'll find HDMI ports in TVs, computers and even some cameras. These cables transfer both high-definition digital audio and video in a single cable. If you have a LCD TV or plasma TV and want to use a Blu-ray player, HDMI is probably the best connection choice.

Composite cables: Also known as RCA cables, composite video connectors carry a standard definition signal and are usually paired with red and white audio connectors for sound. You'll find these connections on most DVD players, VCRs and laser disc players. Most HDTVs still feature the red, white and yellow ports for composite cables, so your old players will still work with your TV.

Component cables: This type of connection splits an analog video signal into three separate "components" so they don't interfere with one another. The connectors, as well as the ports on your TV, are typically colored red, green and blue. The three component signals are reassembled by your TV into a high-quality picture. You can connect many DVD players, Blu-ray players and video game consoles to your TV with component cables, but you'll need separate cables for sound.

RGB cables: RGB is a kind of component video cable used primarily with computer monitors. Some HDTVs feature a similar port to accept RGB cables. If you're using your TV as a display for your computer and you don't have HDMI as an option, you can adjust your TV and computer resolution settings to make the display work.

DVI cables: DVI is primarily used by computer monitors to transfer digital video signals, but some TVs feature DVI ports, too. You can connect your computer to your TV using DVI, but a DVI connection is usually not standard. DVI ports can be added to a desktop computer with a video card.

S-video cables: This is another component video type. If you connect a video source to your TV with S-video, it won't quite match the quality of RGB or component cables. It's best to use this video connection for presentations and TV displays where image quality isn't a major concern.