How to design a zoom system, today I will share the relevant methods for everyone in optics. Welcome to study and discuss!

First, determine the system parameters according to the application scope and practical occasions of the system, and select the zoom form according to the system parameters.

2. After determining the zoom form, carry out Gaussian optical analysis on the zoom form, consult domestic and foreign patent documents of zoom systems, and analyze the focal length value, optical power distribution and lens of each component with the patent similar to the design index as the reference structure. combination, etc.

3. On the basis of the reference structure, according to the optical power and declination of each component of the zoom system during the zooming process, determine the number and structure of lenses contained in each component of the system, and select an appropriate lens combination and reasonable Distributing the optical power makes the system beam transition smoothly, and then constructs the initial structure of the zoom system.

Fourth, import the initial structure of the system into the optical design software (Zemax) for simulation design, adjust the system structure parameters and set the corresponding constraints to make the system meet the main parameter requirements.

Fifth, aberration correction and evaluation. Different from the aberration of the fixed focus system, the aberration of the zoom system is constantly changing during the zooming process, and balancing the system aberration to make it relatively stable during the zooming process is the key to optimizing the zoom system aberration. According to the causes and characteristics of each aberration, the system structure parameters are adjusted, and each aberration optimization scheme is set to complete the aberration optimization using the number of aberration optimization operations in the optical design software (Zemax). After completing the system aberration correction, the system image quality is comprehensively evaluated through the dot diagram, transfer function (MTF) diagram, relative illuminance, distortion and geometric aberration diagrams.

Sixth, tolerance analysis. The tolerance value of the system is set according to the machining process accuracy, and random simulation is carried out by the Monte Carlo method, and the inspection system yield provides guidance for its processing and production.

Seven, zoom curve renormalization design. Optimally design each focal length value according to a specific focal length interval in the entire zoom range, record the corresponding position distribution of the zoom group and the compensation group at the corresponding focal length value, and fit the zoom curve according to the sufficient position parameters of the zoom group and the compensation group .

Eight, temperature compensation design. According to the defocus value of the image plane of the system in the high and low temperature environment, the appropriate temperature compensation method is selected to complete the athermal design of the system, so that the system has good environmental adaptability.