The development of LED operation shadowless lamp with new medical

Medical institutions now commonly used relatively inexpensive bulb type operation shadowless lamp, so that problems such as improper measures emerge in an endless stream, filtering effect is not good, will produce radiation infrared photothermal excess, blood coagulation in patients with accelerated wound, the damage on the patients can not be measured, will produce thermal sunburn of the doctors and nurses. The traditional medical operation shadowless lamp with many shortcomings based on the development of high-power white light LED as the light source for operation shadowless lamp "model for medical led operation shadowless lamp, can completely solve the problem.

The research work on the application of LED in medical equipment has been made by the 863 project supported by Harbin science and Technology Development Co., ltd.. The main content of this paper is the heat problem with shadowless lamp with high power LED of medical operation; optimization of optical design; meet with the national standard of medical operation shadowless lamp; more than 1 goals for the development of a LED operation shadowless lamp samples reached the national standards: color index Ra = 85; 40klx = Ec = center illumination 160klx; color: 3000K = Tc = 6700k; completed more than 1 patents, the formation of independent intellectual property rights; cultivate a group of high power LED design and packaging, LED light source design, LED medical equipment research and design talent.

Developed more than four holes, five holes shadowless lamp prototype

Since the start of the project in October 2006, the work proceeded smoothly according to plan. Complete LED shadowless lamp market research first, and the future development situation existing market market trend to understand the shadowless lamp. Patent search, domestic and international standard shadowless lamp collection, on the basis of this and the project coordination unit together, jointly determine the overall plan and the development of the technical index of LED shadowless lamp. According to the overall plan, the development of detailed design for the selection and application circuit of LED power devices, the design of power supply and drive circuit, the development of the remote control system, the structure design of the system, two optical design and cooling system design etc.. Each subsystem is responsible for the division of labor and the development of a detailed plan, the development of the work carried out in full swing.

The development process is progressing smoothly, but also encountered some difficulties to solve a lot of problems:

1 Tradeoff Problem of high light efficiency, high color index. Due to the development of LED shadowless light effect and color index has a very high demand, the market mature products are not up to the requirements. Developers can only be based on the company's existing LED high-power products for improvement.

Staff development is based on the analysis of the luminescence mechanism of high power LED, after a lot of research and improvement of the structure of package support, the combination of a large number of test chip, phosphor and packaging materials, to produce to meet the requirements of high power LED lamp device.

High power LED products based on the company's own development, with high luminous efficiency, high color index, low thermal resistance and high reliability for the whole development of the successful completion of the work to lay a solid foundation. In the study of the structure of the packaging support, there is a national patent application.

2 in two times in the optical design, the initial reference of similar foreign technology, using the method of Finel lens, to achieve light gathering. In the experiment, due to the different wavelengths of light in the lens refractive index is different, resulting in shadowless lamp working face light color temperature is not uniform, the edge of a yellow circle, use effect. Through the experiment, and by means of computer simulation analysis, developed successfully the compound parabolic concentrator array for two optical design of LED shadowless lamp has achieved a satisfactory result.

The principle for each high-power LED light emitted by a compound parabolic concentrator, converging parallel light, multiple compound parabolic array, a plurality of groups of parallel light on the working plane composed of approximately 20cm diameter uniform spot, each with a hole array as the LED operation shadowless lamp. According to need, can form a porous shadowless lamp.

The utility model has the advantages of simple structure, low cost, good light gathering effect and uniform light, and can not generate harmful color unevenness. The compound parabolic concentrator array provides a new way for the optical design of LED shadowless lamp.

3 in development, but also successfully overcome the high reliability of the LED constant current technology, high power LED cooling technology, PWM dimming and remote control technology driven shadowless lamp. In the study of heat dissipation methods, in order to reduce the system resistance, after repeated tests, successfully developed a low thermal resistance of the radiator and the new power device bonding structure, the technology is the radiator and high power devices joint surface is electroplated on the weldability of metal conducting layer, solderability of metallic heat conducting layer is coated with a low heat resistance metal solder, the solder can be reduced by high temperature curing materials with high thermal conductivity metal.

High power LED is placed in a low thermal resistance metal solder coating layer, through appropriate heating process, the low resistance metal solder solidification reduced to metal, high power LED and the radiator are welded together, the low thermal resistance of high power LED and radiator joint, forming a heat radiation substrate of LED from work, after low thermal resistance and weldability of metal metal heat conduction layer to the high-efficiency heat conduction channel radiator.

By adopting the technology, the low thermal resistance joint between the high power LED heat dissipation substrate and the aluminum substrate, the aluminum substrate and the radiator is realized, which effectively reduces the system thermal resistance and prolongs the service life of the LED. The technology through