What is the difference between LED diffuser sheet and light guide plate?

Make it clear first.

Diffuser (English diffuser), as the name suggests, is to diffuse light around. The light passes through the diffuser from below and is diffused by scattering and reflection. Remember that the light source is below the diffuser. The main light exit is above the diffuser.

The diffuser is generally composed of PET substrate plus various particles scattered on the surface. Some special uses use PC substrate.

Light guide plate (English LGP), as the name suggests, is a plate that guides light. The light guide plate is a fully radiating plate, the light enters from one end and basically all comes out from the other end. Therefore, the light source is on the side of the light guide plate. The LGP used in the LCD needs to destroy the total emission by printing dots, etc., so that the light of the side light source can overflow on the surface of the LGP. Of course, the damaged surface needs to have reflective paper for reflection. Therefore, in the LCD, the light source is on the side of the LGP, and the main light-emitting surface is on the LGP. The general material of LGP is PMMA, and PC material is also used on NB.

That is to say, the light at the bottom can only use the diffuser but not the LGP. The light on the side needs to use the LGP to bend the light, and then the diaphragm can be used (the diffuser can also be used on the LGP).

  The diffuser plate is equivalent to adding some craftsmanship on the basis of the light guide plate to make the luminous effect better

The functions and functions of the LED diffuser plate and the light guide plate are completely different

In terms of material:

Diffuser base material is PC

Light guide plate base material is PMMA

 Functionally:

The main functions of the diffuser are:

1: Disperse the luminous flux and distribute the light evenly (some composite diffusers can control the exit angle in addition to homogenizing the light)

2: Support the backlight structure to protect the underlying optical material from damage

  The main function of the light guide plate:

1: The luminous flux that guides the LED point light source is evenly distributed in the entire surface. His key role is to guide the distribution of light.

2: Use the reflection mechanism to utilize the luminous flux more efficiently and control the light distribution.