Televisions slimming down for the future

As anyone with a big-screen television knows, the cathode-ray tube that forms the heart of most TVs is often as deep as it is wide. That bulk causes problems for computer users and pretty much rules out using conventional tubes in the very large sets needed to appreciate new high-definition television (HDTV) broadcasts. An appropriately scaled-up cathode-ray tube wouldn't leave much room for the sofa in the living room, and it would be prohibitively expensive.

Companies have worked for years to develop slimmer or flat-screen televisions. Liquid crystal displays (LCDs) have already found widespread use in calculators, laptops and the just-released flat desktop computer screens. The liquid crystals consume little power, but they respond too slowly to make a good TV picture. Plasma displays, which emit light when a small pocket of gas is ionized, produce bright and consistent images, and consequently are a leading contender for the HDTVs of the future. Their main drawback is cost. A big-screen plasma TV can run in the neighborhood of $10,000.

There is also a dark-horse contender, a compressed version of the familiar cathode ray tube. Experimental thin-cathodes could also be used to make very thin TVs, but at present they are neither as economical as LCDs nor as bright as plasma displays, and they have some thorny technical drawbacks.

HDTV 101

The original impetus for HDTV came from wide-screen movies. Soon after wide-screen was introduced, movie producers discovered that individuals seated in the first few rows enjoyed a level of participation in the action not possible with conventional movies. Evidently, having the screen occupy a great field of view significantly increases the sense of "being there".

Early in the 1980s, movie producers were offered a high-definition television system developed by Sony and NHK in the late 70s. This system (called NHK Hi-vision) and its variants are capable of producing images having essentially the same detail as 35 mm film. With these systems, a scene could be recorded, played and edited immediately, and then transferred to film. As a consequence, many of the intermediate delays in conventional film production were eliminated. The new medium also offered a number of possibilities for special effects not possible in conventional film production.

Following the introduction of HDTV to the film industry, interest began to build in developing an HDTV system for commercial broadcasting. Such a system would have roughly double the number of vertical lines and horizontal lines when compared to conventional systems.

Now, the most significant problem faced with HDTV is exactly the same problem faced with color TV in 1954. There are approximately 600 million television sets in the world and approximately 70% of them are color TVs. An important and critical consideration is whether the new HDTV standard should be compatible with the existing color TV standards, supplant the existing standards, or be simultaneously broadcast with the existing standards (with the understanding that the existing standards would be faded out over time).

There is precedence for both compatibility and simultaneous broadcast. In 1957, the U.S. chose compatibility when developing the color TV standard. Although there were some minor carrier interference problems due to the additional chrominance signal -- to a large extent, both monochrome and color TVs could read the same signal.

The basic concept behind high-definition television is actually not to increase the definition per unit area, but rather to increase the percentage of the visual field contained by the image.

The majority of proposed analog and digital HDTV systems are working toward approximately a 100% increase in the number of horizontal and vertical pixels. This typically results in a factor of 2-3 improvement in the angle of the vertical and horizontal fields. The majority of HDTV proposals also change the aspect ratio to 16/9 from 4/3 -- making the image more �movie-like.�

InTOUCH TVTM turns viewers into participants

Kopler Interactive Systems International has introduced a new project that uses current television and telephony infrastructures with the newest technologies to deliver a brand new range of interactive and on-line services that meets the needs of the viewer, the advertiser and most of all, the broadcaster.

The project ties together television and telephony to provide a great variety of new services to viewers, broadcasters and advertisers across the existing infrastructures. Such services include interactive programming and allows viewers to play along with game shows, react instantaneously to polls and surveys, purchase merchandise while watching television, controlling programming in the home, and receive E-mail.

This new technology will also offer verification of programming and advertising for content suppliers as well as provision of the most accurate tracking information available on the viewing habits and responsiveness of consumers in particular programs and advertising campaigns.

Television viewers can instantly download a coupon, order food for delivery or save an Internet address or phone number while watching their favorite sitcom; play along with game shows or participate in a news poll; know more about a topic covered in a given newscast, program, or commercial; or access a web site from a commercial without leaving the programs without ever getting off the couch.

Advertisers can track the actual results of advertising, make ads stand out from the clutter, and pinpoint a message to a specific demographic, geographic, individual zip code or household.

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