LCD structure.How to overhaul the lack of color in the projector projection image? Check whether the color control parameters are improperly adjusted (generally due to the imbalance of the strength of the red, green and blue signals set in the machine).

2) check the quality of the light bulb.

3) check if there is something wrong with the projector transmission line (VGA).

4) check if there is something wrong with the interface circuit (such as AD9883, AD9884, AD9888, SAA7118, PW1231, etc.).

5) check whether there is something wrong with the drive circuit.

6) check whether there is something wrong with the image processing circuit (such as PW164, PW166, PW168, PW364, PW365, etc.).

7) check for problems with the LCD Panel (LCD projector) or color wheel (DLP projector).

8) check whether the polarizer is burnt out.

9) check if there is a problem with the power supply part of the projector.

There are relevant parameter settings in the main menu of the projector, which can be carefully adjusted according to the user’s guide or instructions, bring up the projector parameter menu, select the color reset under the display menu, and adjust the corresponding bias of red, green and blue. the problem of lack of projection color can be solved by changing the relative intensity of trichromatic light.

Cmur1: the so-called NW (Normally white).

NW means that when we do not apply voltage to the LCD panel, the panel we see is a bright picture, so it is called normally white. On the other hand, when no voltage is applied to the LCD panel, the panel is opaque and looks black, which is called NB (Normally black).

C Murray 2: why should there be these two structures?

Mainly for different application environments. General desktop computers or notebook computers, mostly NW configuration, that is because the general use of computer software environment, you will find that the whole screen is mostly bright spots, that is to say, computer software is mostly black-and-white applications. Since the bright spots account for the majority, it is of course more convenient to use NW, but also because the bright spots of NW do not need to add voltage, on average, it will save electricity.

TFT_LCD (thin Film Transistor liquid Crystal display), LCD requires voltage control to produce grayscale. TFT uses thin-film transistors to generate voltage to control the LCD steering of the display. From the section structure of figure (8), a parallel plate capacitor is formed when liquid crystal is sandwiched between the upper and lower layers of glass, which is called CLC (capacitor of liquid crystal). It is about the size of 0.1pF, but in practice, this capacitor cannot hold the voltage until the next time the picture data is updated. In other words, when the TFT charges the capacitor, it cannot hold the voltage until the next time TFT charges it again. (according to the general 60Hz screen update frequency, it is necessary to keep about 16ms time.). In this way, when the voltage changes, the gray scale displayed will be incorrect. Therefore, in general, a storage capacitor CS (storage capacitor is about 0.5pF) will be added to the design of the panel so that the charged voltage can be maintained until the next update of the screen. But correctly speaking, the TFT itself, which grows on the glass, is just a switch made of transistors. Its main job is to determine whether the voltage on the LCD source driver should be charged to this point. As for how high the voltage should be charged at this point, in order to show what kind of gray scale. It’s all decided by the outside LCD source driver.

Frame glue and spacer two kinds of structural components. The use of the frame glue is to make the upper and lower layers of glass in the liquid crystal panel stick closely and provide the barrier between the liquid crystal molecules in the panel and the outside world, so the frame glue, as its name, is around the face. limit the liquid crystal molecular frame to the panel. On the other hand, spacer mainly provides the support of the upper and lower layers of glass, which must be evenly distributed on the glass substrate, otherwise, as soon as the uneven distribution causes some spacer to gather together, it will hinder the passage of light and can not maintain the appropriate gap between the upper and lower glass (gap), which will lead to uneven electric field distribution, thus affecting the gray-scale performance of liquid crystals.