Characteristic value and detection method of diffuser plate

 We understand that the optical characteristics of plastic sheets represented by acrylic include two types: one is transmission characteristics, including light transmission, reflection, scattering and refraction; the other is light conversion characteristics, including light absorption, Photothermal, actinic, photoelectric and photochromic, etc.

Commonly used indicators of light transmission characteristics include transmittance, haze, refractive index, birefringence and dispersion. Among the above indicators, light transmittance and haze are two main indicators. Here we separate these two indicators, and focus on the characteristic value and detection method of the light diffusion plate:

1. Optical eigenvalues of the diffuser

Generally, for the quality control of optical properties of transparent and translucent plastics such as plate, sheet, film, and tube, it is mainly tested to evaluate indicators such as transmittance and haze. which are defined as follows:

1. Light transmittance—the ratio of the luminous flux (Luminous Flux) passing through the sample to the luminous flux hitting the sample, expressed as a percentage.

2. Haze—the ratio of the scattered luminous flux deviating from the incident light direction through the sample to the transmitted luminous flux, expressed as a percentage (for this method, only the scattered luminous flux deviating from the incident light direction by more than 2.5 degrees is used to calculate the haze) . The cloudy or cloudy appearance of the interior or exterior of a transparent or translucent material due to light scattering. Expressed as a percentage of the ratio of the scattered luminous flux to the luminous flux transmitted through the material. It is an important parameter for the optical transparency of transparent or translucent materials. Anti-glare diffuser

This method can be used to control certain optical properties of products and research products. Transparent plastics are only comparable in light transmittance and haze as long as they are of the same thickness. Haze and transmittance are two different concepts.

Both light transmittance and haze are important indicators to weigh the transparency of materials. Generally speaking, there is an inverse relationship between light transmittance and haze, that is, materials with high light transmittance have low haze, and vice versa.

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However, materials with high haze can also have low light transmittance. This is the case for light diffusing materials and light diffusing products. With the improvement of LED light sources and LED lighting, their applications are showing a rapid growth momentum. If such a material is used as window glass, the room will appear bright during the day, but it is moderately mild, with shade and privacy at the same time. At the same time, it can make the dazzling LED light source become average, gentle and beautiful, and the inner lamp beads can not be seen.

2. Optical eigenvalue detection method of diffuser plate

1. Illuminance meter, this kind of instrument is cheap, convenient and portable, but due to the interference of external natural light, the value of ordinary test will generally be high. This type of instrument is only suitable for reference and comparison, and cannot be used as an accurate instrument.

2. Light transmission haze tester: This kind of instrument is less affected by the outside world during the test, so the test result is lower than the contrast meter, which is more accurate. Generally, diffuser panel manufacturers use this instrument to test the transmittance and haze of their own products.

3. Integrating sphere: The light transmittance of the integrating sphere is very accurate to test the diffuser plate, and it is almost not disturbed by the external environment. Therefore, the data obtained by testing the same plate is lower than the above two. Because the instrument is relatively expensive, as long as the large Lighting companies use this equipment to detect light transmittance. (Note: The size of the integrating sphere, the placement position, the distance from the probe, the angle between the probe and the light source and other factors will affect the test results).

Therefore, in view of the different testing instruments used, the measured light transmittances are not the same. When choosing a diffuser, you must ask what kind of instrument is used to detect the light transmittance. This will not be far from the product you expect. . Double-sided frosted diffuser

The PC diffuser board adopts special light diffusing materials and silicones, and is an optical material extruded and produced in a 10,000-level dust-free workshop. While showing the optical characteristics of high light transmittance, it has good light source coverage and can handle LED points. The problem of dazzling light source and glare is a new type of ideal material for secondary light distribution of LED lamps and lanterns, and it is also a retrofit material for the light efficiency of lighting lamps.