Q-type Aspheres And Its Application In Optical System Design

As rotationally symmetrical aspheres,Q-type aspheres have an orthogonal polynomial as its additional polynomial.It can control the shape of aspheres by controlling the root mean square departure of aspheres or the root mean square slope of the aspheres,which can make aspherical lenses easier to process and inspect.Therefore,Q-type aspheres has higher optimization design efficiency and has a larger advangtage in optical design.This paper mainly studies Q-type aspheres and its application in optical system design.First,this paper studies and derives the aspherical expressions based on even power series polynomials,Zernike polynomials and Q-type polynomials as additional polynomials,and compares the coefficients and surface slopes of these aspheres based on different additional polynomials.It proves that Q-type aspheres has certain advantages in optical design with the comparison of optical design examples and their differences in optical designSecond,this paper studies the application of Q-type aspheres in the optical design of high-pixel and large-image mobile phone lens.Based on the Q-type aspheres.a mobile phone lens with 40 mega-pixels and large image surface is designed.The MTF value of the mobile phone lens at 2501p/mm is greater than 0.25,and the image quality is great.On this basis,the optical structure,optical performance and aspherical coefficients of the mobile phone lens based on Q-type aspheres and even aspheres are analyzed and compared.The mechanical structure design and stray light analysis and suppression of the mobile phone lens based on Q type aspheres are also carried out.Third,this paper studies the application of Q-type aspheres in the optical design of day and night lens with short focal length and ultra wide angle.Based on Q-type aspheres,a day and night lens with short focal length and ultra wide angle is designed,which F number is 2.2 and the angle of full field is 170°.The day and night lens with short focal length and ultra wide angle has a total length of less than 15mm and a maximum image circle diameter of 6.80mm.At 1721p/mm,the MTF value of the central field of view of all visible light configurations is above 0.5,and the MTF value of the central field of view of infrared light is around 0.4,the imaging performance is stable when the working wavelength is switched between visible light and infrared light.It can achieve constant-thickness day and night confocal,and can maintain good imaging performance in the temperature of-40??+85? in the working environment,which can meet the actual needs of the lens.On this basis,the optical structure and image quality of the lens based on Q-type aspheres optimization,even aspheres optimization,and Q-type aspheres conversion to even aspheres are compared.In addition,tolerance analysis,mechanical structure design and stray light analysis of the designed day and night lens with short focal length and ultra wide angle are carried out,and the methods to suppress the stray light of the lens are proposed.Finally,this paper verifies the real shot effect of the processed lens with short focal length and ultra wide angle and tests and analyzes its imaging quality.The actual shooting effect shows that the lens with short focal length and ultra wide angle of this paper has clear imaging,balanced picture color,and good actual shooting effect.The results show that the resolution of the central area and the four corners of the lens reaches the high-profile standard of a 2 mega-pixel lens when the working wavelength is visible light.And the resolution of the central area and the four corners of the lens is close to the conventional standard of a 2 mega-pixel lens when the working wavelength is infrared light.In visible and infrared wavelengths,the lens has excellent chromatic aberration control.The lens has good color saturation,and the total color reproduction error and hue error are small.The actual measured field angle and the theoretical design value have a small error,and the overall illumination is uniform without obvious vignetting.Therefore,the overall image quality of the day and night lens with short focal length and ultra wide angle in this paper is great,which basically meets the requirements of theoretical design and reaches the imaging standard of a 2 mega-pixel lens.