The working principle of tet LCD

- Feb 09, 2018-

You know how the CRT works is the power of lights wire heating, the cathode is stimulated, the emission of electronic flow, electronic flow by the internal metal layer with high voltage acceleration, through the lens focus to form a very fine electron beam, hit on the screen, so that phosphor light-emitting. And the principle of the CRT is completely different, LCD needs to come from behind the light source, when the beam through this layer of liquid crystal, LCD side or irregular twist shape, so the LCD is more like a gate, choose the light penetrate or not, we can see the different shades of the screen, patchwork image.

The current mainstream liquid crystal display is thin film transistor LCD (TFTLCD), is by the original liquid crystal display technology development expansion. Tft LCD For each pixel has a semiconductor switch, so as to complete a separate control of a pixel, liquid crystal material is sandwiched between the TFT glass layer and color filter layer, by changing the voltage of the LCD to control the final appearance of light intensity and color.

In general, the liquid crystal is transparent unless the voltage is applied. When pressurized, part of it changes and becomes opaque. This conversion speed of liquid crystals is usually very slow (detailed description later). In 1992, EMI announced the invention of a new liquid crystal display technology Ferroelectric liquid crystal FLCD (FERROELECTRICLCDS). The advantage of ferroelectric liquid crystal is that the response speed is fast and can reach microsecond level. And without changing the voltage can also maintain the current state, that is, more power, which for laptops, PDAs and other portable devices is very meaningful. FLCD has many advantages, but at present there are few products on the market, because the FLCD is very sensitive to vibration, it is easy to damage the crystal, but there will be some improvement in the future.

Although the future of ferroelectric liquid crystal FLCD is still unknown, but it also has a high contrast and large visual angle of the advantages of the mainstream of the market TFT will cause a certain impact.

At normal working temperature, the reaction time of FLCD only 70us! such a short time can almost be neglected.