[elektro] A 16:9 képarányú tévé mire is jó?

[Szali Sandor]

Anonymus wrote:
> Semmi. :) Nyilván a gyorsabb részeken a képtartalom kiolvasása is
> gyorsabb. Egyébként a geometriája ezeknek a gépeknek meglehetõsen jó.
> Mondjuk a szervízmódja se egy piskóta. Mondjuk nem véletlenül
> kerültek annyiba, amennyibe. :)
> Nyilvánvalóan ezt csak 100 Hz-es tv-nél célszerû alkalmazni, mert
> rendelkezésre áll a képtartalom a memóriában. Analóg is meg lehetne
> csinálni, de ott csak változtatható késleltetéssel, ami azért nem
> annyira egyszerû.

en 50Hz-es analogban lattam konturelesitesre
Scan Velocity Modulation (SVM)

letezett ezek szerint bonyolultabb, 100Hz-es es ami az egesz keptartalomnal 
csinalta?

mi volt ennek a neve?

na meg hogyan vezerli a sorvegfokot?


What is Scan Velocity Modulation?
(From: Jeroen H. Stessen (Jeroen.Stessen at philips.com).)
Scan velocity modulation occurs around the transients in the luminance 
signal. The beam is sped up just before and just after the edge and it is 
slowed down during the edge. This makes for a sharper edge. On an 
alternating B/W pattern (stripes, checkerboard) you will see that the white 
parts get smaller and the black parts get whiter. This geometry error is a 
side-effect. Some say that this is the main intended effect of SVM.

SVM is *supposed* to be used to compensate for the spot blowup at high beam 
current. Peaking does not help to improve sharpness because the higher peak 
beam current also gives a fatter spot. SVM *can* work in that case. 
Unfortunately it is often misapplied, too much SVM will give a very 
unnatural picture, with obvious horizontal geometry errors.

If applied properly, SVM can improve the picture. Unfortunately there has 
been a rat race, led by Japanese, suggesting that more is better.

Some people will simply advise turning the contrast down. At low beam 
current the spot size will be acceptably small and SVM is not needed. In 
most, if not all, cases they will disable the SVM circuit, usually by 
pulling the supply connector to the SVM panel. That panel is often fixed to 
the neck of the picture tube, behind the video amplifier panel.