The liquid crystal molecules of a TFT display do not emit light themselves, but display images by adjusting the transmission rate of light. The polarizer transforms the natural light emitted by the backlight into linearly polarized light through the principle of polarized light, and works with the liquid crystal layer to regulate the amount of light transmitted to form an image.
The role of polarizers in TFT displays:
Polarizer has the ability to decompose the incident light into two polarized components orthogonal to each other, allowing only one direction of the component to pass, while the other direction of the component is absorbed or scattered. In a TFT display, two polarizers are affixed to the upper and lower sides of the glass substrate. The lower polarizer is used to convert the light beam generated by the backlight into polarized light, and the upper polarizer is used to resolve the polarized light modulated by the liquid crystal to produce a contrast between light and dark, thus producing the display image.
Polarizer:
Lower Polarizer (Bottom Layer): Located underneath the liquid crystal layer, it converts the natural light emitted from the backlight into linearly polarized light.
Upper Polarizer (Top Layer): Located above the liquid crystal layer, the upper polarizer interacts with the modulated light from the liquid crystal, thereby determining the outgoing direction and brightness of the light and displaying the final image.
Polarizers also enable anti-glare, anti-scratch, anti-reflective/low-reflective functions to further enhance the display effect. Polarizers can optimize the contrast and brightness of the display, resulting in clearer images and fuller colors.
POL Angle:
The initial twist angle of the liquid crystal molecules determines the light transmission state of the display when it is not energized, i.e., normally black or normally white. The cooperation between the absorption axis of the polarizer and the initial twist angle of the liquid crystal is the key to achieving this effect. Liquid crystal molecules change their alignment direction under the action of an electric field, thus changing the direction of polarization of the transmitted light. The direction of the polarization axis of the polarizer must match the characteristics of the liquid crystal molecules in order to effectively regulate the transmittance of light and display the desired gray scale and color. The thickness of the liquid crystal layer, the drive voltage and the optical compensation film in different TFT panel designs all affect the optimal polarization direction, so the angle of the polarizer needs to be adjusted for the specific design. For example, a BOE panel may require a polarization angle of 0 degrees/90 degrees, while an HSD panel may require 8 degrees/73 degrees.
TN Polarizer:
Various thicknesses: 0.13-0.15mm, 0.17mm, 0.22mm, etc.
Angle selection: 45°, depending on the viewing angle of the glass.
Various materials: normal glossy, anti-scratch glossy, AG25 regular frosted, AG40 fine sanded, AG13 fine sanded, etc.
IPS Polarizer:
Various thicknesses: 0.08mm, 0.11mm, 0.15mm, 0.17mm, etc.
A variety of angle combinations are available, such as 7°/83°, 0°/90°, 183°/7°, etc., to accommodate different IPS LCD panel designs. Materials likewise include normal glossy, scratch-resistant glossy, and multiple frosted grades.
Polarizers that increase brightness:
DBEF Polarizer: A reflective polarizer that enhances LCD display brightness by selectively reflecting light from the backlighting system.DBEF Polarizer is a TAC film that adds high transmittance and reduces light absorption loss. Reflective polarizers (e.g. DBEF, bi-directional brightening film) are introduced to reuse the light not fully transmitted by the backlight.
AR Polarizer: By coating the surface of the polarizer with an anti-reflective film layer, the reflection of light on the surface is reduced and the transmittance is increased. This helps to reduce screen reflections and improve the viewing angle and brightness of the display while reducing eye fatigue.
AG Polarizer: By applying special treatment to the surface of polarizer, such as spraying, coating or chemical etching, a matte surface is formed to reduce the glare.AG Polarizer is widely used in touch screen, display screen, touch panel, window, etc. to improve the display effect and user experience.
ICP DAS understands the importance of polarizer to the display effect, so we purchase polarizers from Sunnypol, a high-quality supplier that meets high quality standards, to ensure the picture quality and color performance of the display. In the production process of TFT panels, Tricolor adopts advanced fully automated equipment to attach the polarizers to ensure that the angle and position of the polarizers are accurate. This is crucial for the correct modulation of light through the liquid crystal layer, which directly affects the quality of the display.
