Philips 150C5BS Инструкция по эксплуатации онлайн [35/88] 42176

FAQs (Frequently Asked Questions)

light is not turned through 90 degrees. In this case, light that comes through the top

polarized panel may not go through the polarized panel at the bottom.

Q: What are the advantages of TFT LCD compared with CRT?

A: In a CRT monitor, a gun shoots electrons and general light by colliding polarized

electrons on fluorescent glass. Therefore, CRT monitors basically operate with an analog

RGB signal. A TFT LCD monitor is a device that displays an input image by operating a

liquid crystal panel. The TFT has a fundamentally different structure than a CRT: Each cell

has an active matrix structure and independent active elements. A TFT LCD has two glass

panels and the space between them is filled with liquid crystal. When each cell is connected

with electrodes and impressed with voltage, the molecular structure of the liquid crystal is

altered and controls the amount of inlet lighting to display images. A TFT LCD has several

advantages over a CRT, since it can be very thin and no flickering occurs because it does

not use the scanning method.

Q: Why is vertical frequency of 60Hz optimal for an LCD monitor?

A: Unlike a CDT monitor, the TFT LCD panel has a fixed resolution. For example, an XGA

monitor has 1024x3 (R, G, B) x 768 pixels and a higher resolution may not be available

without additional software processing. The panel is designed to optimize the display for a

65MHz dot clock, one of the standards for XGA displays. Since the vertical/horizontal

frequency for this dot clock is 60Hz/48kHz, the optimum frequency for this monitor is 60Hz.

Q: What kind of wide-angle technology is available? How does it work?

A: The TFT LCD panel is an element that controls/displays the inlet of a backlight using the

dual-refraction of a liquid crystal. Using the property that the projection of inlet light refracts

toward the major axis of the liquid element, it controls the direction of inlet light and

displays it. Since the refraction ratio of inlet light on liquid crystal varies with the inlet angle

of the light, the viewing angle of a TFT is much narrower than that of a CDT. Usually, the

viewing angle refers to the point where the contrast ration is 10. Many ways to widen the

viewing angle are currently being developed and the most common approach is to use a

wide viewing angle film, which widens the viewing angle by varying the refraction ratio. IPS

(In Plane Switching) or MVA (Multi Vertical Aligned) is also used to give a wider viewing

angle.

Q: Why is there no flicker on an LCD Monitor?

A: Technically speaking, LCDs do flicker, but the cause of the phenomenon is different from

that of a CRT monitor -- and it has no impact of the ease of viewing. Flickering in an LCD

monitor relates to usually undetectable luminance caused by the difference between

positive and negative voltage. On the other hand, CRT flickering that can irritate the human

eye occurs when the on/off action of the fluorescent object becomes visible. Since the

reaction speed of liquid crystal in an LCD panel is much slower, this troublesome form of

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