Brief introduction and replacement method of polarizer film
In household appliances, the scratches and gouges on the LCD screen of many appliances are actually caused by the damage to the external polarizer. As long as the internal LCD glass plate is not damaged, it can be repaired by changing the film, commonly known as LCD screen changing (polarizer) film, that is, replacing the external polarizer to avoid affecting the display quality.
Many customers here may not understand what the polarizer is, It is also unclear how to correctly replace the polarizer of the LCD screen,
Brief introduction and replacement method of polarizer film
LCD polarizer structure:
The basic structure of the polarizer includes: the middle PVA (polyvinyl alcohol), two layers of TAC (cellulose triacetate), PSA film (pressure sensitive adhesive), Release film and ProtecTIve film.
The PVA layer plays the role of polarization, but PVA is very easy to hydrolyze. In order to protect the physical properties of the polarizing film, a layer of TAC film with high light transmittance, good water resistance and a certain mechanical strength is compounded on both sides of the PVA for protection, which forms the original polarizer plate.
In the production of ordinary TN type LCD polarizers, according to different use requirements, one side of the original plate of the polarizer needs to be coated with PSA of a certain thickness, and the isolation film protecting PSA is compounded;
On the other side, the protective film, reflective film and semi transparent and semi reverse adhesive film shall be respectively compounded according to the product type to form the finished polarizer.
For STN type LCD polarizer products, the phase difference film and protective film with a certain phase difference compensation value should be compounded at a certain compensation angle on the PSA side according to the different needs of customers, thus forming STN type LCD polarizer products. This is the basic structure and operating principle of LCD polarizers.
Raw material of polarizer
The pressure sensitive adhesive used is high temperature and moisture resistant pressure sensitive adhesive, and PVA is specially dipped (dye series products).
The polarizer made is a wide temperature polarizer; The used pressure-sensitive adhesive can be made into an anti ultraviolet polarizer by adding an ingredient that prevents ultraviolet rays from passing through; A polarizer for STN can be made by adding a birefringent optical compensation film on the transmission original plate;
A light steering film is compounded on the transmission original film to make a wide viewing angle polarizer or a narrow viewing angle polarizer; Coloring the used pressure-sensitive adhesive, PVA film or TAC film is called color polarizer. In fact, with the continuous development of new LCD products, there are more and more types of polarizers.
Brief introduction and replacement method of polarizer film
Method for replacing polarizer of LCD:
1. Tool preparation: printer rubber roll, 3M vacuum cloth, alcohol, cotton swab, small flat screwdriver, paper cutter, sponge pad. The roller on the waste printer can be used as the rubber roller of the printer, and the length is selected according to the size of the screen. The role of the roller is to use rolling compaction to make the film fit smoothly with the LCD screen when pasting the film.
Polarizer replacement tool
2. Remove the old film: first remove the outer frame of the LCD screen to be replaced to expose the edge of the external polarizer. Then use the blade to slowly remove the polarizer at the corners. Be sure not to scratch the internal glass plate, because the scratch on the glass plate is irreparable. After uncovering a corner, slowly tear off the external polarizer with your hand. The larger the screen is, the more trouble it will be when removing the polarizer. If you are not careful, you will crush or scratch the glass. If the back glue of the original polarizer is difficult to remove, drop alcohol on the seam, which will make the back glue easy to be removed.
Replacement of polarizer
3. Select the polarizer, that is, select the film: the angle of the polarizer is generally 45 degrees, 135 degrees, and 90 degrees, which is not easy to distinguish from the appearance. First, buy a polarizer with a certain angle. The size does not matter. For example, buy a 135 degree polarizer for standby. After the old film is removed, connect the drive plate and backlight to the screen. After power on, the screen should be white.
Then place the polarizer with known angle on the screen to observe the image. If the color is normal, it means the original polarizer angle is 135 degrees. If there is an image display but the color is reversed, such as white turning black, it means the angle is incorrect, and it should be 45 degrees. Generally, the angle of polarizer is only 45 °, 90 ° and 135 °, among which 90 ° is rare.
Flatten the polarizer after replacement
Brief introduction and replacement method of polarizer film
4. Film pasting: put the screen in a dust-free room, and operate in a clean room without this environment. Two people are required to cooperate in the operation. One person will remove some of the adhesive stickers of the new film and align them with one side of the screen and the edge of the screen.
Another person gently rolls the polarizer with the printer rubber roller until the whole polarizer is pasted on the glass. If there are small bubbles or strip marks after replacement, the external protective film of the polarizer can be removed and left overnight, and the permeability of the polarizer can be used to make it disappear gradually.