What is the difference between a side-emitting patch led and a straight light?

- May 30, 2019-

The side-emitting patch LED backlight is a backlight made by placing a linear or point-shaped light source on the side of a specially designed light guide plate. The direct-type backlight process is relatively simple, and does not require a light guide plate. The light source (LED chip array) and the PCB are placed at the bottom of the backlight. After the light is emitted from the LED, the reflective sheet passes through the bottom, and then passes through the surface diffusion plate to brighten the light. The film is uniformly emitted.

Extended answer: When the side-emitting patch LED backlight is applied to a medium-sized LCD, the weight and cost of the light guide plate will increase with the increase of the size, and the brightness and uniformity of the light is not ideal, and the side-emitting patch LED backlight LCD TVs can not achieve regional dynamic control of LCD TVs because of the use of light guides, and can only achieve simple one-dimensional dimming, while direct-lit LED backlights perform better, enabling dynamic control of LCD TVs. The edge-lit backlight can be made very thin, but the light utilization of the backlight is small, and the thinner the utilization is, the core of the technology is the design and manufacture of the light guide plate.

At present, there are mainly two types of light guide plates, such as print shape and injection molding shape. Others such as injection molding plus printing, laser spotting, corrosion, etc. occupy a small proportion, which is not suitable for mass production. The advantages of the direct-lit backlight technology are high luminance, good light viewing angle, high light utilization efficiency, and simple structure.

A certain space is reserved between the diffusion sheet and the LED light source to improve the brightness uniformity, so the direct-type backlight also increases the thickness, weight, and power consumption of the module, so the number of light sources, the brightness of the light, and the power consumption are larger than the sides. Optical backlight.