One-mirror and two-mirror optical scanners with variable focus lens

摘要

The paper presents formulas for a ray tracing in the optical system of one-mirror and two-mirror optical scanners with a variable focus lens. The procedures for modelling of one-mirror and two-mirror systems, which are used frequently in practice, are described. The result of the analysis describes a general calculation of the position of the beam spot in the detection plane with respect to deflection angles of scanner mirrors. Furthermore, equations for the calculation of the focal length which ensure focusing of a beam at the desired point in a detection plane are derived. The chosen vector approach is general. Thus, the application of the formulas in various configurations of the optical systems is possible. An uncertainty analysis of the position of the beam spot in the detection plane is performed. Using derived formulas one can calculate deflection angles of scanner mirrors and required focal length of the variable focus lens provided that the position of the focused beam in space is given with a required tolerance. Computer simulations are performed on examples of one-mirror and two mirror optical scanners with a variable focus lens.