Research On The Mold Designing And Light Effect Of LED Optical Lens

LED optical lens is widely used in our everyday lives.In recent years,it has also been used in the direct-lit LED TV.However,due to the large angle lens,the special shape,the great thickness variation,affected by the thermoplastic deformation of the resin and the uncertainty of the refractive index,it is difficult to achieve the optical effect of the original design.It is easy to cause uneven brightness,dark lines,bright spots and other display defects.Therefore,how to achieve mass production of lenses such as 32-cavity molds to achieve uniformity of light efficiency has always been a problem in the industry.This subject is guided by the results of light effect.First study the light effect of a single lens,and then expand to the uniformity of the entire backlight module.This research includes the following works.The first part of this article,the author used the optical analysis software named Trace Pro to analyze the lens to simulate the throughput of each curved surface,and finded the main surface position that affects the light effect of the lens.Then the theoretically designed spot shape was simulated to provide a basis for the judgment of light effect.The author proposes a method to study the influence of light effect changes.It is to change the positions of the light entrance and exit surfaces during the simulation process to calculate the influence on the light effect.In this way,the purpose of guiding the structural design of the mold forming part can be achieved.Then,the filling behavior of resin was simulated by using Moldflow injection molding simulation software.The conditions such as holding pressure,holding time,melting temperature,mold temperature and cooling time were changed respectively under the premise that other conditions were unchanged,so as to study the influence law of various forming parameters on the lens deformation.Furthermore,the author creatively proposed the mold structure of changing the core position by changing the gasket quickly.A single cavity quick change experimental mold was designed and made.Combined with the advanced processing and testing technology,the optical core is manufactured,and then through the injection molding condition analysis,size and appearance testing and various injection molding conditions combination trial production products,the actual luminous effect evaluation is conducted to find the best core position and forming conditions combination.Finally,according to the structure and test results of the experimental die,and the particularity of the mass production die,the detailed design of each system of the 32 cavity formal die was carried out.By adjusting the core position and forming conditions,the light effect consistency and overall light effect were studied.Finally,the difference between the lowest brightness and the highest brightness of the backlight is not more than 10%,the uniformity of light effect meets the design requirements,and the mass production is successful.In this paper,software simulation is used to guide design and experiment,and experimental results are used to verify the accuracy of theoretical analysis.The author first designed and manufactured the quick-change experimental mold for single cavity to find the best core position and forming conditions,and then combined with the design experience to guide the completion of mass production mold.Finally,the success of mass production of 32 cavities was achieved.The research process and results have certain theoretical significance and practical value for the application of LED lens in many fields.