| 摘要 |
PURPOSE:To obtain a projection system advantageous as goods where the variance of the quantity of light due to a mask is reduced considerably, by providing masks, which control luminous fluxed on and outside the axis, in prescribed positions between respective lenses of the projection system consisting of three lenses having the common axis. CONSTITUTION:The projection system is an erect unmagnification system which transmits an object plane O to a focal plane C and consists of plural projection lenses L1, L2, and L3 having the common axis. The first lens L1 for forming an inverted intermediate image M, the second lens L2 which is arranged near the intermediate image M to prevent the loss of the quantity of light, and the third lens L3 which transmits the intermediate image M to the focal plane C are arranged in order from the side of the object plane O, and masks M1 and M2 which control luminous fluxes on and outside the axis are provided in positions near the first lens L1 and the third lens L3 between the first and the second lenses L1 and L2 and between the second and the third lenses L2 and L3 respectively. |
