小型数字投影结构光三维测量仪镜头设计

为了解决三维测量仪器的小型化问题,设计了一种数字投影结构光三维测量仪光路结构,并用Zemax软件进行了性能优化。该结构分为投影光路和照相光路,投影镜头采用反远距结构,由5片透镜组成,全视场调制传递函数大于0.35。照相镜头采用双高斯结构,由6片透镜组成,全视场调制传递函数大于0.12。两镜头口径均小于14mm,长度小于40mm,像面照度均大于90%,可以对80~120mm远的物体进行测量。投影图像像素密度为1 028×768,相机拍摄图像像素密度为1 280×960,在工作距离100mm处可以测量28mm×21mm的表面。镜头全部采用球面透镜。该结构具有测量精度高、成本低、加工容易、体积小等优点。

Design of lens structure used in small structured light 3D measurement instrument based on digital projection

As domestic industrial 3D measurement instruments are large and inconvenient to carry,a lens structure used in small structured light 3D measuring techniques was designed and optimized by Zemax.The structure consists of two lenses,projection lens and photographic lens.The projection lens adopts the structure of retro focus lens and is composed of 5 lenses.Its modulated transfer function in the central field is higher than 0.7 and in the edge field is higher than 0.35 at 50 lp/mm.The photographic lens adopts the structure of double Gauss lenses and is composed of 6 lenses.Its modulated transfer function in the central field is higher than 0.3 and in the edge field is higher than 0.12 at 133 lp/mm.The largest diameters of both lenses are less than 14 mm.The optical tracks are less than 40 mm,and the relative illuminations are higher than 90%.The structure can measure the object at 80-120 mm away.The pixel density of projection image is 1 028×768 and the pixel density of photo is 1 280×960.The structure is able to measure the surface of 28 mm×21 mm at the distance of 100 mm.The lenses are all spherical lenses.The system has such advantages as high precision,low cost,excellent processability and small size.