It is known that the principle of CRT is that the filament is heated after electricity, the cathode is excited and the electron flow is emitted. The electron flow is accelerated by the inner metal layer with high voltage. The electron beam is focused by the lens to form a very fine electron beam, which is hit on the screen to make the phosphor luminescent. The principle of the CRT is completely different. LCD needs the light source behind it. When the beam passes through the liquid crystal, the liquid crystal feels parallel or irregularly torsional. So the liquid crystal is more like a gate.
At present, the mainstream liquid crystal displays are thin film transistors LCD (TFTLCD), which are expanded from the original LCD technology development. The TFT LCD has a semiconductor switch for each pixel to complete a single point of control. The liquid crystal material is sandwiched between the TFT glass layer and the color filter layer. The final light intensity and color can be controlled by changing the voltage of the liquid crystal.
In general, liquid crystal is transparent unless applied voltage. After pressure, part of it will change and become opaque. The conversion speed of liquid crystal is usually very slow. 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 fast response, reaching microsecond level. And there is no need to change the voltage to maintain the current state, that is, more power saving, which is very meaningful for portable devices such as laptops, PDA, and so on. FLCD has many advantages, but at present, there are few products in the market, because FLCD is very sensitive to vibration and can easily damage the crystal, but it will be improved in the future.
Although the future of ferroelectric liquid crystal FLCD is still an unknown number, it also has the advantages of high contrast and ultra large visual angle, which will impact the mainstream TFT in the market.
Under normal working temperature, the reaction time of FLCD is only 70us! In such a short time, it can almost be ignored.