Sabtu, 15 Februari 2014

HDTV,plasma,LCD differentiate?

Q.

A. plasma and LCD are both HDTV

Plasma: This new technology utilizes a unique display panel that alleviates the need for a cathode ray type picture tube. At the present time this type of TV is somewhat expensive. A major benefit of the plasma display is that it has been sized to accommodate new HDTV 16:9 aspect ratio's and is similar in pixel resolution to a personal computer monitor, thus allowing drastically improved picture clarity.

LCD: Liquid crystal display television is, as indicated by its name, a television using LCD technology (generally TFT), as opposed to cathode ray or plasma for its visual output.

HDTV: Regular NTSC signals have 525 lines of resolution. HDTV has 1125 lines of resolution having over five times the video information than that of a conventional NTSC-type TV set. In spite of its obvious advantages, transmission requires extraordinary bandwidth of five times the capacity of a conventional TV signal. TV receivers are estimated to be 30% more expensive than today's most costly sets.

Plasma technology has certainly achieved quite high contrast ratios, a measure of the blackest black compared to the whitest white. Many plasma display manufacturers boast a contrast ratio of 3000:1 these days though our tests have not proven these numbers out. Panasonic has long been the leader in plasma black levels and we measure contrast of a 42" HD Panasonic plasma at about ANSI 1450:1 - still impressive. Plasma displays achieve such impressive black levels by using internal algorithms to block the power to particular pixels in order to render a pixel "dark" or black. While this can limit a plasma television's gray scaling, it does produce exceptionally black blacks - depending on the manufactured plasma display element (i.e. glass). A plasma TV uses the most power when it is producing full white. As a result, some 2nd tier manufactured brands of plasma TVs have an audible buzz or whining sound when displaying white or very light images.

LCD (liquid crystal diode) displays, by contrast, utilize electric charges to twist and untwist liquid crystals, which causes them to block light and, hence, emit blacks. The higher the voltage passing through the liquid crystals in a given pixel, the more fully those crystals untwist and effectively block light - all of which makes these pixels darker. As opposed to plasma, LCD TVs use the most power when displaying a very dark or black image. This is a difficult process, and despite recent improvements in LCD black levels, only the best LCD televisions (like those produced by Sharp and Sony) have managed to topple the 1000:1 contrast ratio barrier. Recent improvements have brought LCD displays up to the level of plasma. The one continual drawback here for LCD is off axis viewing, when black levels consistently drop.


Blue Blob on my LG LCD HDTV. Problems and solutions?
Q. So I've got this LG HDTV, and its developing this blue blob in the center of the screen. It gets progressively worse. I cleaned the filter, and it was okay for about ten minutes, but then the blob is back. I don't know whats wrong, and I enjoy playing my PS3, but this blob is really bugging me. I bought it from Millard Electronics, as a refurb, so I don't think there's any warranty involved, so thats out of the question. Any suggestions?

A. LCD PROJECTION RIGHT?
Of couse, it has filters.....

Your blue blob is caused by red/green lcd panels taking a dump on you....they need replaced.

You can get a brand new LIGHT ENGINE or you can have it sent to PTS for a rebuild....

Either one will fix it. But you need to find a TV tech that knows of PTS and can pull the engine out for servicing....

I won't recommend any normal person pull the engine, it's way too complicated installing it again and getting a square/rectangle picture out of it....





Powered by Yahoo! Answers

Tidak ada komentar:

Posting Komentar