全通光半球透镜弹性镀膜夹具设计

A Design of Elastic Coating Fixture for Full Pass Hemispherical Lens

在光学行业内,当有的镜片需要镀膜100%有效通光孔时,常采用先镀膜后磨边的加工工艺。但是有些膜系如果采用先镀膜后磨边工艺时会破坏膜层,而且在凸面接近半球(D(球面口径)/R(曲率半径)>1.6)的透镜,外径没有较多的余量(<0.3 mm)的情况下,这种加工工艺就不适用,且合格率低。因此,需要设计一款全通光半球透镜弹性镀膜夹具来解决这一问题,进而使镜片镀膜有效通光孔径达到100%。该夹具用弹性钢材制作,采用夹持镜片外径方式和弹性结构弥补镜片和夹具的热涨冷缩,可将镜片装到夹具上进行超洗后直接镀膜,而且不需要二次上盘和专用的超洗夹具。试验结果表明,采用该镀膜夹具镀膜后,镜片镀膜有效孔径可达100%,并且不会出现卡裂、崩边和表面出现压痕等现象,而且膜色均匀一致性好。该夹具设计合理,制造工艺简单,成本低廉。

In the optical industry,when some lenses require coating with 100%effective through-hole,the processing process of coating first and then grinding the edges is often used.However,some film systems may damage the film layer when using the coating first and then edge grinding process,and this processing process is not applicable when the convex surface is close to the hemisphere(D(spherical aperture)/R(curvature radius)>1.6)of the lens,and there is not much margin(<0.3 mm)on the outer diameter.And the qualification rate is low.Therefore,it is necessary to design a fully transparent hemispherical lens elastic coating fixture to solve this problem,so as to achieve 100%effective aperture for lens coating.The fixture is made of elastic steel and uses a clamping method for the outer diameter of the lens and an elastic structure to compensate for the thermal expansion and contraction of the lens and fixture.The lens can be installed on the fixture for super washing and directly coated,without the need for a secondary hanging plate and a dedicated super washing fixture.The experimental results show that after using the coating fixture for coating,the effective aperture of the lens coating can reach 100%,and there will be no phenomena such as cracking,edge collapse,and surface indentation,and the film color is uniform and consistent.The fixture design is reasonable,the manufacturing process is simple,and the cost is low.This paper briefly describes the design and experimental results of an all pass hemispherical elastic fixture.