What is the meaning of TFT-LCD?
Author:Zhang Gaobo Time:2021-07-20 08:21 Browse(384)
TFT (thin film transistor) LCD is a kind of active matrix liquid crystal display (am-lcd).

What is the meaning of TFT-LCD?

LCD flat panel display.
Special TFT-LCD is the only display device that can catch up with and surpass CRT in brightness, contrast, power consumption, life, volume and weight Large scale production features good, high degree of automation, low cost of raw materials, broad development space, will quickly become the mainstream products in the new century, It is a bright spot of global economic growth in the 21st century.
TFT LCD is the abbreviation of thin film transistor liquid crystal display.
TFT LCD technology is a technology that combines microelectronic technology and liquid crystal display technology skillfully.
people use the technology of microelectronic fine processing on Si.
transplant it to the technology of t-lcd on large area glass Then, the array substrate is combined with another substrate with color filter film to form a liquid crystal cell by using the mature LCD technology, and then through the post process such as polarizer coating, In TFT LCD,
the function of TFT is equivalent to a switch tube.
the commonly used TFT is a three terminal device.
the semiconductor layer is usually made on the glass substrate.
there are source and drain connected with it at both ends.
and the gate is set opposite to the semiconductor through the gate insulating film.
the source and drain are controlled by the voltage applied to the gate The current between leakage electrodesFor the display screen,
each pixel can be regarded as a layer of liquid crystal sandwiched between the pixel electrode and the common electrode in terms of structure.
more importantly, it can be regarded as a capacitor in terms of electricity.
its equivalent circuit is shown in Figure 1.
to charge the pixel P (I.
J) in row J and column I, the switch t (I, J) must be turned on, The target voltage is applied to the signal line D (I).
when the pixel electrode is fully charged.
even if the switch is off, the charge in the capacitor is preserved, The data (column) driver is used to apply the target voltage to the signal line.
while the gate (row) driver is used to turn on and off the switch.
because the display voltage applied on the liquid crystal layer can be stored in the storage capacitance of each pixel.
the liquid crystal layer can work stably.
the display voltage is transmitted through the liquid crystal layer TFTs can also be rewritten in a short time.
therefore, even for high-definition LCDs, It can also meet the requirements of image quality.
the key to display image lies in the orientation of liquid crystal molecules under the action of electric field.
generally, different display modes can be realized through the orientation treatment on the inner side of the substrate.
a certain display mode can be selected.
under the action of electric field, the orientation of liquid crystal molecules changes, In a word, the simple matrix of TFT LCD is different from that of passive TN LCD and STN LCD. It has a thin film transistor (TFT) on each pixel of LCD,The static characteristic of LCD is independent of the number of scan lines, so the image quality is greatly improved.
the characteristics of switching unit (TFT).
should meet the requirements of low on state resistance and very large off state resistance.
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