The optical performance of TFT LCD polarizer includes three main performance indexes:

polarizability, transmittance and tone, and other indicators include uv resistance and transmittance, total reflectance and diffuse reflectance of semi-transmittance polarizer.In the general use of LCD products, the requirement of polarization and transmittance of the higher the better.The higher the polarizability and transmittance, the higher the display efficiency of LCD display device, and the lower the relative energy consumption.But for the conventional iodine dyeing polarizing products, polarizing and transmittance is a pair of contradictions, the higher the polarizing degree, transmittance will be lower, but also subject to the constraints of color, so the general type of polarizing products are between 90% - 99%, transmittance between 41% - 44%.Tonal indicators mainly to satisfy people's visual habit, also requires polaroid product color deviation is smaller, to ensure the consistency of the end product appearance color LCD, it mainly by the polaroid products chromaticity coordinate parameters of L, a, b value and their control to identify the tolerance range, generally the scope of its control tolerance as small as possible.

The durability technical indexes of LCD polarizer

The durability technical indexes of LCD polarizer include  high temperature resistance, heat and humidity resistance, low temperature resistance and heat and cold impact resistance.High temperature resistance refers to the temperature resistance working condition of polarizer under constant baking temperature. At present, according to the technical level of polarizer, it is usually divided into general types: working temperature is 70℃×500HR;Medium endurance type: working temperature is 80℃×500HR;High endurance type: operating temperature above 90℃×500H these three grades.

Heat and humidity resistance of LCD

Heat and humidity resistance technical index refers to the heat and humidity resistance performance of LCD polarizer under constant temperature and humidity conditions. It is usually divided into three technical grades, namely, general type: heat and humidity working condition: 40℃×90%RH×500HR;Medium endurance type: hot and humid working condition: 60℃×90%RH×500HR;High endurance type: hot and humid working conditions: 70℃×95%RH×500HR or above.

Due to constitute the basic materials of polarizing film containing PVA membrane and iodine and iodide are easy to hydrolysis of materials, and at the same time because the LCD polarizing piece by using pressure sensitive adhesive under high temperature and high humidity conditions also easy degradation, therefore, the durability of the LCD polarizing piece the most important technique index is resistant to high temperature and damp and hot, if resistance to heat and humid indexes through, other type durability index usually won't be a problem.

The bonding characteristics of LCD polaroid sheet mainly refer to the various characteristics of polaroid pressure-sensitive adhesive

including: pressure sensitive adhesive and glass substrate, pressure sensitive adhesive and peel film, polaroid protective film and peel film, and bonding durability of pressure sensitive adhesive.Pressure sensitive adhesive and glass substrate between the peeling force is also known as adhesive bonding strength, which is the most important bonding characteristics of LCD polaroid products.This technical index is usually measured by the standard of eiaj-ed-2521a of the specification of Japan electronics and machinery industry association. It is expressed in unit of g/25mm. Generally, the stripping force of pressure sensitive adhesive of LCD polarizing plate on glass substrate is stipulated to be above 500g/25mm, while the upper limit in actual use is generally below 1000g/25mm.There are practical examples that show that when the adhesive to the glass substrate peeling force of 500g/25mm or less, will occur in the glass screen surface after the polaroid adhesive automatic peeling and warping phenomenon.

The technical indicators of the appearance performance of the LCD polarizer mainly refer to the surface flatness of the polarizer products and the number of appearance defects. These technical indicators mainly affect the utilization ratio of the polarizer products in the patch.These technical indicators usually have relatively consistent technical provisions in the polarizing disc industry, usually for each polarizing disc product (500×1000 mm) less than 15 points less than 150 microns.

Because LCD polaroid product final inspection are using artificial visual inspection, therefore in the process of the batch production of polaroid, appearance owe point will have certain discrete distribution, the distribution of the every polaroid production enterprise is to use a certain internal control specifications and delivery specifications difference to ensure delivery of quality standards.It should be noted, however, that as 150ms is already near the minimum limit of visual resolution for the human eye, especially in industrial mass production where inspectors experience visual fatigue over long periods of time, the 150ms off-point inspection standard is reasonable and reliable.

Performance and index of TFT LCD polarizer