How does the TFT-LCD LCD optical film increase the brightness of the LCD screen?

2022 07/22

TFT-LCD light-enhancing film is the main component of TFT-LCD backlight module, also known as Prism Sheet, and its cost accounts for the highest proportion of total cost. The backlight module also accounts for 2-8% of the total cost. Its optical film can focus the scattered light on the light source in front, focus the original scattered light to a range of about 70 degrees, and focus the unused light out of the viewing angle, using reflected light recycling is to reduce LCD loss. an important energy-saving element. BEF can usually improve the glow by about 40-60%, if the brightness of the 90 degree film with 2 vertical positions can achieve a higher glow effect.

Classification of Brightness Enhancement Film/Prism Sheet:

There are four main types, namely normal prism sheet, multifunctional prism, micro-lens film, reflective polarizer, etc. Each optical film also has different market characteristics.

1. Normal prism sheet

The main function of prism lenses is to direct and direct light from light sources including CCFLs and LEDs to improve lighting efficiency. The main supplier is 3M, other suppliers are Mitsubishi Rayon, LG Electronics, MNTech, Shinoha, DNP, LGS, Gamma (Taiwan Jiawei), E-funny Suntech, SKC Haas and Samsung SHELL.

2. Multi-Functional Prism Sheet

Multifunctional prism sheet is a higher-level product, which integrates the functions of prism sheet and diffuser sheet, and is more effective than general prism sheet. The main suppliers are 3M, Xinhua, Mingda, Samsung Cheil, E-Fun and LG Electronics. At the same time, Korean board makers are faster than Japanese and Taiwanese board makers to convert ordinary prismatic lenses into multifunctional prismatic lenses, while Taiwanese board makers are faster to achieve the goal of reducing CCFL lamps.

3. Thin film microlenses

The microlens film is integrated into the prism film through the microlens array structure, and the diffusion function of the chip is used to replace the prism with two microlens films. Except for the upper and lower structures, the main application products are 32", 37" and 40" LCD TV panels , the main suppliers are Korean companies such as MNTech, SKC Hass, Xinhua, LG and LG Micron.

4. Reflective Polarizer

DBEF (Improved Dual Brightness Film) is a unique product, with 3M patent, it belongs to reflective polarizer, its most important is the film brightness, its design principle is to use the light recycling mechanism, will use the backlight output light, with different The high and low light material layers of refractive index are layered one after another, so that the light is not absorbed in the total reflection medium with more than 800 layers. The absorption process is through the two-color absorption of the polarizer to reach 100 layers. The performance can be improved by 1.6 times, which is better than BEF. But some Korean manufacturers are now starting to offer similar features, such as MNTech's NPRF, Chinalco's Shinoha Woongin and Japan's Zeinor.