Projection lens system having variable magnification

摘要

A projection lens system is constructed as a zoom lens system which is for use with a laser light source and performs magnification variation by moving at least a lens group along the optical axis, and the projection lens system fulfills the following conditional formula: (|AC(B2−G)|+|AC(R2−G)|)/(|AC(B1−G)|+|AC(R1−G)|)<0.8, where AC(B2−G) represents longitudinal chromatic aberration between the wavelengths λB2 and λG; AC(R2−G) represents longitudinal chromatic aberration between the wavelengths λR2 and λG; AC(B1−G) represents longitudinal chromatic aberration between the wavelengths λB1 and λG; and AC(R1−G) represents longitudinal chromatic aberration between the wavelengths λR1 and λG.

主权项

1. A projection lens system constructed as a zoom lens system which is for use with a laser light source and performs magnification variation by moving at least a lens group along an optical axis, the projection lens system fulfilling conditional formula (1) below:
(|AC(B2−G)|+|AC(R2−G)|)/(|AC(B1−G)|+|AC(R1−G)|)<0.8  (1) where AC(B2−G) represents longitudinal chromatic aberration between blue and green laser wavelengths; AC(R2−G) represents longitudinal chromatic aberration between red and green laser wavelengths; AC(B1−G) represents longitudinal chromatic aberration between (i) a middle value of a green laser wavelength and a blue laser wavelength, and (ii) the green laser wavelength; and AC(R1−G) represents longitudinal chromatic aberration between (i) a middle value of a green laser wavelength and a red laser wavelength, and (ii) the green laser wavelength.