| 摘要 |
PURPOSE:To enable a lighting region to be arbitrarily changed corresponding to an objective region without changing NA of a lighting optical system as well as the lighting intensity to be augmented especially in smaller lighting region for making the lighting effective by a method wherein the lighting range in a specific surface is changed by changing the refractive power of an optical integrator. CONSTITUTION:When a light flux 5 from a laser 1 is adjusted to specific size through an adjusting optical system 2a so as to be entered as parallel light flux into an optical integrator 2b comprising multiple fine lenses for lighting a specific surface 4 using the light flux emitted from the optical integrator 2b, the lighting range on the specific surface 4 is to be changed by changing the refractive power of the integrator 2b. For example, the said optical integra tor 2b is composed of three each of lens units 7-9 comprising multiple fly-eye lenses. In such a constitution, the lighting range phi on the lighted surface 4 is to be changed by changing the focal length of the whole optical integrator 2b by shifting the lens units 8, 9 on an optical axis. |
