The high-power LED lens/reflector is mainly used for collecting and guiding light of high-power LED cold light source products. The high-power LED lens designs the light distribution curve according to the angle of the different LEDs, and increases the optical reflection to reduce the light loss and improve the light efficiency (and the set aspherical optical lens). The following focuses on the secondary concentrating high power LED lens of PMMA material.
The material type of an LED lens 1. Silicone lens
a. Because silicone is high temperature resistant (can also be reflow soldered), it is usually packaged directly on the LED chip ;
b. The general silicone lens is small in volume and 3-10 mm in diameter;
2, PMMA lens a. Optical grade PMMA (polymethyl methacrylate, commonly known as: acrylic)
b. Plastic materials, advantages: high production efficiency (can be completed by injection molding); high transmittance (93% penetration at 3mm thickness); disadvantages: 70% temperature resistance (heat distortion temperature 90 degrees);
3. PC lens a. Optical grade nylon material Polycarbonate (referred to as PC) polycarbonate b. Plastic materials, advantages: high production efficiency (can be completed by injection molding); high temperature resistance (130 degrees or more); disadvantages: light transmittance is slightly lower (87%);
4. Glass lens optical glass material, with high light transmittance (97%) high temperature resistance, shortcomings: fragile, aspherical accuracy is not easy to achieve, low production efficiency, high cost.
Application classification of two LED lenses 1. Primary lens a. The primary lens is directly encapsulated (or bonded) on the LED chip holder and integrated with the LED;
b. The LED chip is 360 degrees according to the theory, but in fact the chip is fixed and packaged on the LED bracket, so the maximum illumination angle of the chip is 180 degrees, and the chip will have some stray light, so The primary lens can effectively collect all the light of the chip and can obtain the light-emitting angle such as 160 degrees, 140 degrees, 120 degrees, 90 degrees or even 60 degrees (different needs);
c. Use a PMMA or silica gel material for the primary lens.
2. Secondary lens a. The secondary lens and the LED are two separate objects, but they are inseparable when applied;
b. The function of the secondary lens is to condense the large angle light of the LED (generally 90-120 degrees) into any desired angle of 5 to 80 degrees;
c. Most secondary lens materials use PMMA or glass.
Three LED lens specification classification
1. Penetrating (convex lens)
a. When the LED light passes through a curved surface of the lens (double convex has a curved surface), the light will be refracted and concentrated, and the angle will change when the distance between the lens and the LED is adjusted (in inverse proportion), after the aspheric surface The curved surface of the technical design will be very uniform, but due to the limitations of the lens diameter, the light on the side of the lens is not utilized (light leakage);
b. Generally used in large angle (40-80 degrees) concentrating, such as table lamps, street lamps, indoor lamps, etc.;
2. Fully reflective (cone or cup)
a. The design of the lens is concentrating in front of the concentrating light, and the tapered surface can collect and reflect all the side light, and the overlapping of the two kinds of light (the same angle) can obtain the most perfect light utilization. Beautiful spot effect;
b. It is also possible to make some changes on the surface of the conical lens, which can be designed as mirror surface, frosted surface, bead surface, striped surface, thread surface, convex or concave surface to obtain different spot effects.
3. LED lens module a. It is to complete a single multi-head lens by injection molding a plurality of single lenses. According to different requirements, it can be designed into a 3, 1, 5, or even dozens of lens modules.
b. This design effectively saves production costs, achieves consistent product quality, saves space in the lighting mechanism, and is easier to achieve "high power".
Four LED lens design and mold processing
1. First of all, depending on the light source (high-power LED), high-power LEDs of different brands (such as CREE, lumileds, Seoul, Osram , Edison, Changsen, etc.), the chip structure and packaging method, light characteristics, etc. will have The difference, so that the same lens with different specifications of the brand LED will be different; so requires targeted development (mainstream brand-oriented), in order to achieve actual needs;
2. The optical design software (such as Trace pro, CodeV, Zemax, etc.) is used to design and perform the simulated optical running light, and the corresponding optical aspheric surface is designed.
3. The LED lens itself is a precision optical component, so its precision for the mold is extremely high, especially the processing precision of the optical surface of the lens should be 0.1μm, and the lens eccentricity should be within 3μm. Generally, the processing of such high-precision molds must have the following equipment: ultra-precision processing machines (for example: PRECITECH NANOFORM 350), CNC integrated processing machines, surface grinders, milling machines, CNC electric discharge machines, surface profilometers, etc.
4. The most precise part of the mold lies in the optical mold. Firstly, the special mold steel is used to complete the initial embryo. After nickel plating, the surface is processed by an aspherical technology using an ultra-precision processing machine.
Five LED lens materials and production 1. As an optical grade product, LED lenses are extremely demanding for light transmission and water shrinkage. The raw materials are generally made of high-grade optical grade PMMA. At present, the Japanese Mitsubishi PMMA material is the best (now VH5 and VH001 are of higher quality), and the same is Mitsubishi's Nantong material will be slightly less;
2. Must be equipped with a 10,000-class or higher-level dust-free workshop, operators must wear anti-static clothing, as well as anti-static and dust-proof measures such as wearing finger cots and masks, and regularly inspect and clean the workshop;
3. Must have professional optical injection molding machine (electric) such as Farak, Toyo, Haitian, Jiaming and other brands with power above 35T, and strictly control the injection temperature and time, reduce the shrinkage rate of the product, and must not add the reuse of the nozzle material to ensure the product. More in line with the design;
4. Products must be packaged in anti-static, dust-proof PVC and must be completely sealed. Storage must be controlled to control temperature and humidity, and it is best not to store for more than one year.
Card Holder,Card Sleeve,Foil Holder
Smart Cards,RFID Cards And Tag Co., Ltd. , http://www.cnsmartcards.com