| In contemporary information times, the information acquiring technology is in increasing high requirement. In the realm of optical imaging, the lens designed are always hoped to be characterized with long focal length, large angle of view and large relative aperture. panoramic lens can realize the360°panoramic annular imaging of the surrounding objects by using a special panoramic imaging device. Comparing with other panoramic lens, the two catadioptric panoramic lens have the advantages of a larger field of view, a larger relative aperture and a longer focal length, great real time response, high reliability.Through the analysis of the imaging relationship and the structure characteristics of the two catadioptric panoramic lens, the main factors affecting the panoramic lens imaging quality are:the lateral chromatic aberration generated by panoramic annular lens is difficult to be corrected; the stray light rays entering the panoramic annular lens are hard to be suppressed. The solution to the above problems is forming a special conjugation between the aperture stop and the entrance pupil, thus the conjugation between the aperture stop and "annular entrance pupil" are realized.Using a high order aspheric surface in the panoramic annular lens can increase the optical designing variables, and the special conjugation relation is formed, meanwhile the special imaging relations are achieved and this improves the panoramic lens focal length.The initial parameters of the panoramic annular lens are worked out based on the structure of annular lens, the path of the chief rays, the aplanatic principle, the law of reflection, the aperture stop and the "the annular entrance pupil" conjugation relationship. Then the initial parameters are entered into the Zemax software, and after the optimization, the focal length of10.787mm is calculated and the angle of view of the lens is360°×(45～85°). The designing results show that the panorama lens has a simple structure and good imaging quality.In addition, the tolerance analysis, the mechanical designing and the assembly adjustment are made, and then the panoramic image is obtained by the digital camera with macro objective distance mode. As a result, the resolution of the panoramic image is high and with little lateral distortion. |
