LCD Polarizer sheet applications
May 31, 2022
Liquid Crystal Display
LCD displays include cell phones, computers, TVs, etc. Most LCD display modes require two polarizers, which can be orthogonal (TN-LCD normally white), parallel (TN-LCD normally black), or at a certain angle (High Twist Nematic LCD HTN-LCD, Super Twist Nematic LCD STN-LCD). There are also LCD display modes that only need a polarizer, such as the bin-major effect type display, dye LCD box itself is also equivalent to a polarizer; and then some kind of reflective display mode, a polarizer and a reflective film combination, the LCD box to play a spin or wave sheet role. Of course, there are also non-mainstream liquid crystal display modes that do not require a polarizer, such as dynamic scattering display (DS-LCD), reflective cholesteric liquid crystal bistable display and polymer dispersive liquid crystal (PDLC) display, etc.
Liquid crystal light valve
Not for displaying information, there are also many kinds of liquid crystal electro-optical devices, such as liquid crystal photo-valves, liquid crystal lenses, liquid crystal filters, liquid crystal gratings, liquid crystal sensors, etc. Liquid crystal light valves include liquid crystal solder mask, liquid crystal dimming glasses, liquid crystal optical shutter, etc. Liquid crystal displays have a large number of pixels, and each pixel is a liquid crystal photo valve. All electro-optical devices manufactured by applying the principle of liquid crystal birefringence almost always use polarizers.
Polarized Glasses
There are various products and uses of polarized glasses, such as 3D glasses for watching three-dimensional (3D) stereoscopic movies, anti-glare LCD dimming glasses for drivers' night driving meetings, and anti-glare sunglasses for the general public.
Polarized light microscope
Many kinds of optical instruments began to use polarizing film long before LCDs became popular, such as the polarizing microscope shown in Figure 1-15. However, polarizers for optical instruments can be expensive, and before there were film-type polarizers, polarizing elements such as tourmaline and Nikkor prisms were used, and with modern polarizers, polarizers were switched to polarizers and detectors that sandwiched the polarizer between thin glass sheets. Tourmaline crystals belong to the tripartite/hexagonal crystal system, and the hexagonal flakes of natural tourmaline crystals are selected for easy processing into polarizers. These crystals were all early materials used to make polarizing elements and phase compensation elements, but none of them could be easily thin-filmed over large areas and were not suitable for the needs of flat panel display technology. Nowadays, with the availability of polymer-based polarizers and compensators, which are cheap, large-area and easy to use, crystal polarizers have almost become "collector's items" and can only be used in special technical fields that cannot be replaced by polymer-based polarizers, such as special light bands, strong lasers, high-temperature extreme environments, etc.
Polarized photographic lenses
Photographic lens polarizing filter is a professional photographer's treasure, is in front of the camera, camera and other lenses plus a polarizer, you can greatly reduce the interference of strong direct reflection of light, reduce the intensity of the sky background light, increase the level of sky clouds, etc..
Other applications
Photoelasticity is used to analyze the stress in the structure of a material. An isotropic material subjected to stress will produce anisotropic optical properties, called photoelasticity or stress birefringence. When a transparent object subjected to stress is placed between two polarizers for observation, some curved stripes of different widths and densities can be seen, and the analysis of these stripes can yield quantitative data on the distribution of stress in the object, which is useful in scientific research, engineering construction and industrial production.
