how MF produce lens for LED lights?

2 years ago
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Ming Feng Lighting Produce all kinds of LED lens for indoor and outdoor light, what is so called lens? why it is so important?

Usually speaking, there are 4 types of lens,

Silicone lens

a. Because of the high temperature resistance of silica gel (reflow soldering is also possible), it is often used to directly package LED light-emitting devices.

b. Generally, the silica gel lens has a small volume and a diameter of 3-10mm.

PMMA lens

a. Optical grade PMMA (polymethylmethacrylate, commonly known as acrylic).

B. plastic materials, advantages: high production efficiency (can be completed by injection molding and extrusion); High light transmittance (about 93% at 3mm thickness); Disadvantages: the temperature shall not exceed 80 ° (thermal deformation temperature 92 ℃).

PC lens

a. Optical grade polycarbonate (PC for short) polycarbonate.

b. Plastic materials, advantages: high production efficiency (can be completed by injection molding and extrusion); The light transmittance is slightly low (about 89% when the thickness is 3mm); Disadvantages: the temperature shall not exceed 110 ° (thermal deformation temperature 135 °).


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Ming Feng Lighting Co., Ltd.
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4YRS
Weng Tang Aministration, HengLing 2rd,East District, Dongguan City, Guangdong Province, P.R.C.
Product details
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Primary lens

a. The primary lens is directly encapsulated (or bonded) on the LED chip support and integrated with the LED.

b. Theoretically, the light emission of the LED chip is 360 degrees, but in fact, the chip can be fixed and encapsulated on the LED bracket, so the maximum light emission angle of the chip is 180 degrees (there is a small amount of residual light in the range greater than 180 °). In addition, the chip will also have some stray light. In this way, all the light of the chip can be effectively concentrated through one lens, such as 180 °, 160 °, 140 °, 120 ° 90 °, 60 ° and other different light output angles, but the light output efficiency of LEDs with different light output angles is different (the general rule is: the greater the angle, the higher the efficiency).

c. PMMA, PC, optical glass, silica gel and other materials are generally used for primary lens.

Secondary lens

a. Secondary lens and LED are two independent objects, but they are inseparable in application.

b. The function of the secondary lens is to condense the luminous angle of the LED light source into any desired angle between 5 ° and 160 °. The distribution of the light field can be mainly divided into circle, ellipse and rectangle.

c. Secondary lens materials generally use optical grade PMMA or PC; Glass can be selected under special circumstances.

1. First, depending on the light source (high-power LED), the chip structure, packaging mode and light characteristics of high-power LED of different brands (such as Cree, Lumileds, SSC, OSRAM, Everlight, Edsion, etc.) will be different, resulting in differences when the same lens is matched with LED of different specifications and brands; Therefore, targeted development (oriented by mainstream brands) is required to achieve the actual effect;

2. Use optical design software (such as code V, ZEMAX, TracePro, ASAP, ligtools, etc.) and mechanical modeling software (such as Pro / E, UG, Solidworks, etc.) for design and optical simulation, and continuously optimize to obtain the corresponding optical lens

3. The LED lens itself is a precision optical accessory, so it has high requirements for the accuracy of the mold, especially the processing accuracy of the lens optical surface should reach 0.1 μ m. Generally, the machining of such high-precision molds must have the following equipment: ultra precision machining machine (such as precitech nanoform 350), CNC integrated machining machine, precision grinder, precision milling machine, drilling machine, CNC precision spark machine, surface profiler, interferometer, etc..

4. The most precise part of the mold is the optical mold core. First, the special mold core steel (such as Swedish S136 mirror steel) must be selected to complete the rough embryo after heat treatment to 55 °, and then the rough embryo is obtained by surface machining with ultra precision machining machine after nickel plating treatment.

1. No matter far or near, the lampshade (reflective cup) is not much different from the lens. In terms of uniformity, the lens will be better than the reflective cup;

2. With a small angle LED lens, the effect is better than the lampshade, because it has to shoot far! The lampshade spotlight has passed through the lens (because the LED itself must have a lens) and then passes through the lampshade spotlight again. This time, a lot of light will be wasted. It's better to focus on the lens, and the luminous angle of the lens is very easy to deal with!

Another: if the space is OK, the effect of using three 1W is much better than using one 3W!

3. In contrast, the lampshade has a wide range of uniform luminous points, but the projection is not good, and the lens is the opposite;

4. Led penetration is more high-grade.

1. As an optical product, LED lens has strict requirements for light transmittance, thermal stability, density, refractive index uniformity, refractive index stability, water absorption, turbidity, maximum long-term working temperature, etc. Therefore, the material of the lens must be selected according to the actual situation. In principle, optical grade PMMA shall be selected. If there are special needs, optical grade PC can be selected. At present, Japan's Mitsubishi PMMA material is the best (vh001 is a frequently selected brand), and Nantong Liyang, a branch of Mitsubishi in China, will be slightly inferior;

2. 10000 or even higher level dust-free workshops must be equipped. Operators must wear anti-static clothes, finger covers, masks and other anti-static and dust-proof measures, and regularly inspect and clean the workshops.

3. There must be professional optical injection molding machines, such as Toshiba, Demag, Haitian, Zhenxiong and other brands, and the injection molding process must be strictly controlled to obtain qualified products.

4. Product inspection: no bubble, depression, shrinkage mark, flow pattern and crescent; Shape accuracy RT < 0.005 and surface roughness Ra < 0.0002.

5. The products must be packed in anti-static and dust-proof PVC, and must be completely sealed. The temperature and humidity must be strictly controlled during storage, and it is best not to store for more than one year.

From the above design and production process of LED lens, the seemingly simple LED lens has very high requirements for software and hardware from design to finished product, which also leads to great differences in the price of LED lens in the market. From the perspective of the bright prospect of the popularization of LED lighting, as a necessary component of LED lighting lamps, the market prospect will be better and better.