Hartmann-based Small Lens Image Quality Detection Technology Research

Earlier,lenslets(less than 5 mm in diameter)were used primarily in the field of optical fiber communications for coupling into optical fibers as semiconductor lasers.With the continuous improvement of technology,the lens is more and more widely applied.For example,with the continuous thinning and reduction of the size of mobile phone,the lens of camera on a cell phone is required to keep smaller.More and more portable electronic devices require a camera lens with smaller size.Of course,the higher demand of pepole’s life,also need these small lenses with higher and higher performance,and a better imaging quality.The only way is to improve competitiveness and meet market demand.The main research purpose of this subject is to find a way to measure the imaging quality of these lens elements conveniently,quickly and accurately.The main research work of this thesis is as follows:First of all,this thesis researches the current situation of the method of the image quality detection in the world,compares several different image quality detection methods to judge their advantages and disadvantages for the detection of the image quality of the small lens,analyzes by combining the actual work experience.It is determined that ourresearch is based on the Shack-Hartmann wavefront detection method.Secondly,the basic principle of the Shack-Hartmann wavefront detection method is introduced,the detection method of the spot centroid is analyzed,and the wavefront reconstruction method is analyzed.According to the actual situation,the suitable wavefront fitting method is selected between the pattern method and the regional method.Thirdly,according to the existing conditions in the laboratory,we design the Hartmann wavefront detector and design three different F-number standard lens and a collimation system respectively,and ccordingly desigin corresponding mechanical structure design and related device selection,Then finish the final setup and debugging of the instrument.Finally,the imaging quality of the small lens is detected by the assembled Hartmann wavefront detection device.Accordingly,the wavefront image of the lens and the related experimental data are obtained.The obtained data are compared with the detection result of the ZYGO interferometer to judged the device whether the detection accuracy meets the requirements.The accuracy erroneous of the device is analyzed.The final results show that the Hartmann wavefront detection device can meet the requirements for accuracy.Compared with the ZYGO interferometer,the designed instrument is not affected by environmental factors and can be applied to the factory mass production detection.