The Micro-optics Label Receiving System Based On Annular Aperture Ultra-thin Lens

The micro-optics label system has very important application prospect and research value because of its advantages of miniaturization, large capacity and high security, and it avoids the defects of the current bar code and RFID tags. The micro-optics label technology has had a certain development since 2009 when it was proposed, but existing micro-optics label receiving system can achieve remote receiving for micro label only through the SLR cameras which have large aperture and long focal distance. The receiving distance is greatly restricted when the ordinary mobile phone camera is adopted in the receiving end, which is not conducive to its popularization and application.In this paper, a long distance receiving of micro-optical label based on new-type ultra-thin lens is come true.The micro-optics label receiving system is designed in this paper, a large aperture and long focal length lens called annular aperture which is used as mobile phone lens of system receiving terminal is proposed, a four-reflection folded annular aperture lens is designed with Zemax. Front and rear surfaces of lens are annual aspheric mirrors, the outer diameter of lens is 28 mm, the effective focal length is 36 mm, the thickness of lens is 7.6mm, this lens has large effective focal length, long aperture and ultra-thin characteristics in limited thickness and weight. Thus, a long distance receiving of micro-optical label with the mobile phone is come true.In addition, this paper also gives the corresponding processing for the radial distortion and uneven brightness of the received image, a image distortion correction program is developed on VC6.0 platform based on the OpenCV computer vision library in this paper, the radial distortion of receiving image simulation is modified and decoded accurately in order to obtaining the required information. Furthermore, the uneven brightness of the received image is analyzed in this paper,and the function expression of the image brightness surface is fitted by MATLAB software. In the end, the algorithm of homomorphic filtering based on incidence-reflection is used to do some rectification of the uneven image brightness.