The most commonly used polarizing plate is the linearly polarizing plate. The structure is shown in Figure 4, which contains six layers of structure, including protective film, TAC, PVA, TAC, pressure-sensitive adhesive (PSA), and release film.

In TN (Twisted Nematic) type LCD, for example, the upper and lower glass substrates are coated with alignment layers that are perpendicular to the alignment grooves, and the liquid crystal molecules rotate 90 degree with the alignment layers. A polarizing plate with vertical polarization direction is applied to the outer side of the upper and lower glass, and when the incident light enters the upper polarizing plate to turn into polarized light, its polarization direction rotates by 90 degree with the alignment of liquid crystal, so that the light can pass through the lower polarizing plate to reach the bright state.

After the voltage is applied to the liquid crystal tank, the arrangement direction of the liquid crystal molecules is parallel to the direction of the electric field added in addition and no longer twisted. At this time, the polarized light of the incident light is not affected by the liquid crystal, and the original direction is maintained through the liquid crystal layer, while it is absorbed (masked) by the polarized plate exactly perpendicular to the bottom and becomes dark. In this way, a black-and-white display can be achieved with or without applied voltage.

Dye-based polarizer film

Iodine-based polarizer film

The polarization effect of the iodine-based polarizing plate is good, but the polarization brightness decreases more under high temperatures and high humidity.

Flat panel displays are commonly used in PC (notebook computers and LCD monitors) and non-PC fields (portable communication products, home appliances, audio-visual products, and industrial use products). From small watches, mobile phones, tablets, electronic calculators, notebooks, desktop LCDs, digital cameras, and portable DVDs to industrial automation control panels, measuring instruments, TVs, public access systems, etc., all use various grades of polarizing panels.

The main function of the protective film is to protect the screen of 3C products, using precision coating technology to make the protective film additional special functions, such as ultra-translucent high hardness HC, anti-blue light BLC, anti-glare AG, low reflection LR, and another functional film protective film.

Due to the high reliance on 3C products and the increasing demand for product appearance protection, the application of protective stickers is becoming more and more widespread, from small electronic watches, digital cameras, and cell phone screens, to large display panels and other easily scratched surfaces, can be protected by protective stickers to protect their appearance.

Explosion-proof film

The explosion-proof film mainly functions as a functional film to prevent the glass from flying apart when the touch screen glass is broken.

By using precision coating equipment to coat the polarizer with different functional HC or AG with different anti-glare capabilities on the TAC, the finished surface of the polarizer will have special functions. Functional film products are mainly used in various types of LCDs.