How to distinguish between light guide plate and diffuser for LED panel lights
Aug 13, 2021
1) From the material point of view:
1. The base material of the diffuser plate is PC;
2. The base material of the light guide plate is PMMA.
(2) In terms of functionality:
1. The main functions of the diffuser are:
(1) Disperse the luminous flux and make the light evenly distributed (some composite diffusers can not only make the light uniform, but also control the exit angle).
(2) Support the backlight structure to protect the underlying optical materials from damage.
2. The main function of the light guide plate:
(1) Guide the luminous flux of the LED point light source to be evenly distributed in the entire surface, and its key role is to guide the distribution of light.
(2) Use the reflection mechanism to more efficiently use the luminous flux and control the light distribution.
(3) From the outside:
1. Light guide plate:
The biggest feature of the panel light is the side light. The so-called side light is the light from the side of the lamp, enters the light guide plate, and emits light from the front of the lamp after refraction. Therefore, the light guide plate is also the core component of the panel light. Without it, the panel light cannot emit light from the front.
2. Diffusion plate:
The light coming out of the light guide plate is not very regular, and from the surface, the panel lights without a diffuser plate are densely dotted. Students with intensive phobia must be very injured. At this time, a diffuser is needed to diffuse the light evenly. The diffusion effect is related to the haze of the material. At the same time, high haze will also affect the light extraction rate, which is a contradiction. In addition, the diffuser plate can also protect the light guide plate. The light guide plate is very easy to scratch and stick to dust, so the diffuser plate must be covered on the light guide plate.
The light guide plate is made of optical grade acrylic/PC sheet. The optical grade acrylic sheet is used to absorb the light emitted from the lamp and stays on the surface of the optical grade acrylic sheet. When the light hits each light guide point, the reflected light will spread to all angles, and then destroy the reflection condition and shoot out from the front of the light guide plate.
The light guide plate can emit light evenly through a variety of dense and different light guide points. The purpose of the reflective sheet is to reflect the light exposed on the bottom surface back into the light guide plate to improve the use efficiency of light; in the case of the same area of luminous brightness, the luminous efficiency is high and the power consumption is low.
The light diffusion plate uses chemical or physical means to use the physical phenomena of refraction, reflection and scattering when light encounters two media with different refractive indexes during its travel. It is used on PMMA, PC, PS, PP and other substrates Add inorganic or organic light diffusing agent to the foundation;
Or the light is adjusted artificially through the array of micro-feature structures on the surface of the substrate, so that the light is refracted, reflected, and scattered in different directions, thereby changing the path of light, and realizing the full dispersion of the incident light to produce the effect of optical diffusion. Light diffusers are widely used in liquid crystal displays, LED lighting and imaging display systems.
Reference material: Baidu Encyclopedia-Light Guide Plate
Diffusion Plate
1. Different features
The biggest feature of the diffuser is that it causes great interference to the light. No matter how much the light distribution curve of the original design is, as long as the light passes through the diffuser, it will make the beam angle become 160~176°. There is a layer of fog on the surface of the board.
The light guide plate uses optical grade acrylic/PC sheet, and then uses high-tech materials with extremely high reflectivity and non-light absorption. Laser engraving, V-shaped cross grid engraving, and UV screen printing technology are used on the bottom surface of the optical grade acrylic sheet. Print the light guide point.
2. The working principle is different
The light guide plate uses the optical grade acrylic sheet to absorb the light emitted from the lamp and stays on the surface of the optical grade acrylic sheet. When the light hits each light guide point, the reflected light will diffuse in all angles, and then destroy the reflection conditions and shoot out from the front of the light guide plate . The light guide plate can emit light evenly through a variety of dense and different light guide points.
The larger the beam angle of the diffuser, the lower the illuminance. Some will also produce light filtering, which makes some wavelengths unable to penetrate, causing color shift. The light rate is even lower due to the natural phenomenon of geometric optics, so the base material used to make the diffuser should choose the lower the refractive index as possible, and the lower the interference to light.
3. Different application
The light guide plate has a high light conversion rate (more than 30% higher than the traditional plate), uniform light, long life, and normal use in the room for more than 8 years. It is safe and environmentally friendly, durable and reliable, and can be used indoors and outdoors.
The diffuser plate is used in the direct backlight system used in LCD TVs. The diffuser plate has good properties such as heat resistance, dimensional stability, mechanical strength, flame resistance, etc., and has high light transmittance, excellent shielding and durability , Make its light diffusion effect reach the best condition, most suitable for direct-type backlight unit.
Reference source: Baidu Encyclopedia-Diffusion Board
Reference source: Baidu Encyclopedia-Light Guide Plate
The panel light diffuser refers to the scattering phenomenon caused by the light passing through other media in the process of advancing. As long as the light of two different media goes from A to B, it will cause the light to penetrate or reflect or be reflected or obstructed by the refractive index or interference material. The absorption and penetration part will cause dispersion and so-called light diffusion, which has three physical phenomena.
The light guide plate of the panel light is made of optical grade acrylic/PC sheet, and then high-tech materials with high reflectivity and non-light absorption are used to print the light guide on the bottom surface of the optical grade acrylic sheet with UV screen printing technology. point. Use optical grade acrylic sheet to absorb the light emitted from the lamp and stay on the surface of the optical grade acrylic sheet. When the light hits each light guide point, the reflected light will spread to all angles, and then destroy the reflection conditions. The light guide plate Shot from the front. The light guide plate can emit light evenly through a variety of dense and different light guide points. The purpose of the reflective sheet is to reflect the light exposed on the bottom surface back into the light guide plate to improve the efficiency of light use. Functional differences:
The main functions of the diffuser are:
1. Disperse the luminous flux and make the light evenly distributed (some composite diffusers can control the exit angle in addition to uniform light)
2. Support the backlight structure to protect the optical materials below from damage
The main functions of the light guide plate are:
1. Guide the luminous flux of the point light source of the LED panel light to be evenly distributed across the entire surface. His key role is to guide the distribution of light.
2. Use the reflection mechanism to more efficiently use the luminous flux and control the light distribution.
Differences in application areas:
1. Acrylic light guide plates are suitable for LED lighting fixtures with direct light sources, such as grille lights and high-end aluminum lights.
2. PC diffuser is suitable for side-source LED lighting fixtures, such as flat panel lights, professional film viewers, and is usually used with light guides
3. PS diffuser is mainly used for some low-grade ordinary LED lights.
The light guide plate is a transparent acrylic plate pasted with a light guide film. The thickness of 3mm/4mm is more widely used. The diffuser plate is a milky white smooth surface of PC/PS/acrylic or a single-sided frosted plastic plate.
The light guide plate is relatively thick, and the mesh is heavier, while the diffuser plate is much thinner, most of which are single-sided frosted milky white. The glossy surface is easy to recognize
