Research And Design Of LED Direct-lit Backlight Lenses

Compared with the traditional Light source,LED(Light Emitting Diode)Light source has the advantage in terms of various important parameters.In the field of liquid crystal TV backlight,LED back light have advantages of energy saving,high efficiency,long life,environmental protection,fully replace CCFL(cold cathode tube)back light,become the core in the field of backlight.High quality,high grade of LED back light is often in short supply in the market,so LED back light source have positive significance for the development of LCD TV.Most of LED light source are Lambert illuminant,its main flux focus on the top of the small Angle range of the light source.If applied directly to the back light,it will result in poor visual experience,low optical grade,so we need to match the LED light source of optical components for the second light distribution.LED light source need the direct-lit backlight LED lens to achieve secondary light distribution,which belongs to the category of near-field nonlinear optics.In recent years,most industry internal backlight optical lens designed by adopting the method of trial and error,the precision and efficiency need to be improved.This paper based on the current industry design problem,described a variety of design scheme of the backlight lens,which including the design of a partial differential equation to solve free surface,a LightTools optimization design and a method of series of component design table,which have important significance for the efficiency and detail design.This paper mainly described three backlight lens design methods,and successfully produced for four backlight lens,including three different schemes of refraction type backlight lens and a reflection type backlight lens.First,this paper studies the predecessors put forward the thinking of the partial differential equations of free surface,combined with the author's design experience in the backlight lens,summed up a set of the backlight lens design method by solving a partial differential equation method of freeform surface.Second,for the LightTools software's optimization function is relatively perfect,the author combined with the advantages of the LightTools software,put forward modeling,simulation,optimization Integrated design method of the backlight lens,which improved the convenience of the backlight lens design.Finally,in order to solve the complexity problem of trial and error method,the author combined with SolidWorks software modeling convenience and Excel software editing,the design table method is proposed to design the backlight lens solution,and it successfully designed and production the main two types of backlight lens in the backlight industry: refraction and reflection type backlight lens.Aiming at the three most likely problems in the design(Angle,macular,intensity of illumination light evenness)has respectively made the optimization solution,the design results meet the design requirements in the product validation.The third case of this paper,the author put forward a refraction type backlight lens can be applied to 32 inches backlight module,which has light arrangement of 2 * 6,module thickness of 30 mm,compared with the market more mature arrangement scheme of 3 * 6,this case saved a third of the lamp use cost,and can satisfy the demands of more than 75% brightness uniformity,have started mass production in the marketplace.