H-power LEDlens professional explained

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Preface: LED lens with LED linked closely, such as a camera lens, telescope and the other does not belong to the scope of this paper to explain, this paper focuses on the PMMA materials of secondary high power LED lens.

一variety of materials for LED lens:

1 silicone lens;

A because silicone can bear high temperature (it can bear reflow ), so commonly used in direct encapsulated in LED chip;

B. General silicone lens has the advantages of small volume,  the diameter is 3-10mm;

PMMA lens

A. Optical grade PMMA (chemical name: poly methyl methacrylate,  commonly known as: acrylic, plexiglass )

B. Plastic material, it has the advantages of: high production efficiency (it can be completed by injection ); high transmittance ( on 3mm thickness penetration rate is about 93% ); disadvantages: bearing temperature is 70 DEG C ( heat distortion temperature is 90 DEG C)

PC lens

A. Optical grade Polycarbonate (PC, chemical name: polycarbonate )

B plastic material, has the advantages of: high production efficiency ( it can be completed by injection ); high temperature resistance ( 130 DEG C ); disadvantages: transmittance is Lower (87% );

Glass lens

Optical glass material, with the transmission rate is high (97%), high temperature. Disadvantages are fragile, aspheric precision is not easy realization, low production efficiency, high cost

二．LED lens application classification

1. For the first lens

A. the firth lens is the direct encapsulation ( or bound ) in the LED chip holder, and LED as a whole;

B .LED chip (chip ) according to the theory of light emission is 360 degrees, but in fact the chip in placed in the LED bracket is fixed and sealed, so the chip maximum luminous angle is 180 degrees, the chip will also have some stray light, through a lens can effectively collect all chip light and can obtain such as 160 degrees, 140 degrees, 120 degrees, 90 degrees, and 60 degrees needed light angle.

C. For the first lens is using PMMA or silicone material

The second lens

A The second lens and LED are two separate objects, but they are in the application are inseparable;

B For secondary lens is the function of LED wide angle light ( typically 90 to 120 DEG ) again focusing light into 5 DEG to 80 DEG angle at any desired angle, because the spot is reduced, so that the illumination is improved;

C second lens materials is using PMMA, PC or glass

三，LED lens specification classification

1 penetrating lens(convex )

A. When LED light through the lens surface ( double convex has two surface ),the light refraction and reach the effect, as the adjustment of the lens distance between lens and LED ,angle will change ( inversely), by aspheric technology designed ,facula will be very average. because of limitations of the lens, a part of light does not use ( there will be inevitable phenomenon of light leakage, at present, optical techniques cannot solve feasible improvement program );

B. Generally used in large angle (40 degrees - 80 degrees) light, such as table lamps, street lamps, indoor lighting;

2．Total reflection type (entire reflection or cup)

A, lens face design is using a penetration , and the entire reflection surface can be completely collected and side light reflected out, so the two light ( basically the same overlap angle ) can be the most perfect light utilization and beautiful facula.

B we can also make some changes in the entire reflection surface of the lens, it can be designed into clear surface, frosting surface, ledns surface, linearity surface, Fresnel surface, convex surface and so on, then it get different facula

3，Lens module

A It is a single by injection to complete the whole lens, according to the different needs can be designed into 3 in one, 5 in one or even dozens of lens module;

B. This design effectively saves production cost, realize the consistency of product quality, saving lamp bodies in space, more easily reflect the" high power" etc.

四，LED lens design and mold processing

1 At first it depends on the light source ( high power LED ), different brands of high power LED ( such as CREE, Lumileds,  Osram, Z-power, Edison etc..), the chip structure and package, light characteristics are different, thus causing the same lens with different specifications of brand LED clubs difference; so the requirements of targeted development (being subject to the famous brand ), to achieve the actual needs

2．  Using the optical design software ( such as Trace pro, CodeV, Zemax ) design and Simulation of optical flat, design corresponding optical asphericsurface
3．LED lens belongs to precision optical parts, so it is on the very high precision, especially the lens optical surface machining precision to achieve 0.1μm, the lens eccentricity should achieve 3μm.. General on the high precision mold processing must have the equipment: ultra precision machine ( for example: PRECITECH NANOFORM 350 ), CNC, comprehensive processing machine, surface grinder, milling machine, CNC discharge machine, surface profileinstrument etc.
4．ForMold ,the precision parts is the optical cavity, the first selection of special mold steel completed in early embryos, after nickel and ultra precision machining technology of aspheric surface machining curved surface

五，LED lens materials and production

1 LED lens is as the optical products, on high light transmittance and high shrinkage. The materials are generally using in high- optical grade PMMA. Currently for the Japanese Mitsubishi PMMA material is preferably ( Mitsubishi VH5 is better than the commonly VH001 ), the Nantong of Mitsubishi material will slightly

2 It must be equipped with 10000 level dust-free workshop, workers must be the anti-static clothing, wear finger sleeve, wear masks, good anti-static, dust control measures, and regularly to do inspection and cleaning workshop;

3 there shall be a professional optical injection molding machine: such as FoLarke, Toyo, Haitian, JiaMing brand is more than 35T,it must strictly control the molding temperature, time, in order to reduce the product shrinkage. In addition, it must not be added materials recycling, in order to ensure that the products conform to the design scheme;

4 Lens must use anti-static, dust-proof PVC packaging, it must be completely sealed packaging, storage must pay attention to control temperature and humidity, it should not be stored for more than a year

From the LED lens design and production process, the seemingly simple LED lens, from design to finished lens, the software, the hardware requirements are very high, it also causes the market price difference of LED lens. From LED lighting popularization prospects, lens for LED lighting accessory products, market prospect will be better and better.