LED performance enhancement to become the best candidate for light source components

In recent years, the luminous efficiency and output brightness of LED has been greatly improved, but even so, LED is still unable to compete with luminous efficiency of 60lm/W, all beam 10 thousand lumens of traditional light source. This means that the use of LED as the main source of micro projector, we must consider the overall efficiency of the use of optical engines, including optical.

At present, the global industry has published projected small size screen portable micro projector, or provide mobile phone projection function, although most of the micro projector screen brightness, are less than 100ANSI lumens, it can only be confined to dark environment, but the relevant industry are of the view that the micro projector has considerable potential for development and technology breakthrough space.

As mentioned above, LED must use the low beam light source, light control technology to improve the utilization rate of light, such as traditional lighting, most of the mirror in focus, try to focus on the light direction, but because the light emitted by the light source is not precise, just trying to get ahead toward the light emitted by the change. This structure is very simple, but the control efficiency of light is very poor.

Therefore, the traditional LED lighting to improve the control of the light, the usual method is to increase the area of the reflector or a set of lens, a slight increase in the control of light. The other 1 kinds of LED light source control mode, is set in the front of the light source collimating lens, its light control is better than the former.

The reflective LED structure with traditional coating resin as shell type LED front light control is very different, and it set the chip type LED light emitting component, surrounded around the structure of the reflector is not the same in high heat dissipation circuit substrate. Mirror and the light emitting component basically reflected LED is to set up, use of the light reflecting surface generated light components of the receiver, under the control of the light and then exit to the outside of the LED, then only the transparent resin penetration rate and the reflection surface reflectivity and wire shadow, will cause the loss of light weak, light component theory light, close to control about 90% of the light can be removed to the outside.

LED was unable to compete with the traditional light bulb luminous efficiency 60lm/W, optical beam of 10 thousand lumens, so micro projector using LED as light source, the light use efficiency including optical engine, the projection is the key of quality.

The relative optical system of the luminescent component and surface reflection, this structure can make the LED shape smaller, compared with the traditional structure of LED package shape, has almost become the general design standards, so the traditional LED to improve the utilization efficiency of light, usually need to increase the external shape.

To obtain high brightness light beam, light emitting component size but has become a major problem, the main reason is to improve the amount of light, the fastest way is to increase the current; however, will need to increase the LED chip, can bear high current input. But from the perspective of optical system, light emitting component is small, but the light utilization efficiency is higher, the two appear contradictory, especially for a projector light emitting component in addition to the requirements of small, also requires packaging skills with high radiating performance, the technical difficulty is not low.

The new structure of LED with high output and excellent light control is to purify the heat dissipation path, and increase the basal area of the light emitting module Lead to maintain the necessary heat dissipation.

Although the reflective LED light-emitting component, also set in the vicinity of the surface of the transparent epoxy resin, but the epoxy itself is also a thermal insulation material, so the radiation surface has a considerable degree of heat.

Design of micro optical system with complex and difficult

The optical system of micro LED projector is composed of LED chip and optical lens, Condenser lens and then through the LighttunnEL, obtain high uniformity of beam, the overall system size should be controlled at about 400 mm ^ 3, light output is about 60lm.

LED optical system, light emitting component and optical lens, or mirror the size of light control on distribution have a decisive influence, according to the experimental results, using the same set of optical lenses or mirrors, simply increase the luminous component, the light distribution angle becomes larger, the difference is the illumination axis disappear completely. So according to the requirements of parallel light projector components, must use small luminous components optical system of projector way.

The use of the reflection type monochrome LED basic structure, improve the utilization efficiency of light based on considerations such as, are generally reflective LED using 4 1W grade a module, so we can get the LED below 20mm, the half angle value of + 70 light distribution characteristic, the external shape to LED beam convergence in 17mm Affirmative range.

In the illumination part, 800mA light red light illumination 330klx, green illumination 650klx, blue light illumination is 470klx; the basic characteristics of the DC light, due to the actual conditions of use will become so 1/3Duty pulse lighting, rectangular pulse light, electric current can be regarded as the integral value of the current, but the current value with the ambient temperature change, so the rectangular wave lighting, etc. the best wavelength stable before use.

In addition, for the module to improve the integrity of the whole, developers tend to use prism, catheter, liquid crystal to improve efficiency, and placed in front of the Cellhooklens, condenser lens, PS polarizer, etc..

The realization of the use of small batteries as a handheld projector power supply is very important, for handheld products, to abandon the AC power supply and switch to a small battery powered, is the 1 essential conditions. In the past, the projector used high-pressure mercury lamp environment,