METHOD FOR OPTICAL AXIS ADJUSTMENT BETWEEN LIGHT BEAM PROJECTOR AND COLLIMATION TELESCOPE

PURPOSE:To improve the accuracy after the adjustment by setting an optical system so that a parallel light beam is converged on a screen through a condenser lens when aligning a light beam irradiation point with a cross mark projected through the collimation telescope on a screen. CONSTITUTION:A concave reflecting mirror 11 is installed on the reflector side of the condenser lens 10 and a light transmission hole 12 is bored in the center of the concave reflecting mirror 11. Further, a small convex reflecting mirror 13 is arranged and the optical axes of the condenser lens 10, concave reflecting mirror 11, and small convex reflecting mirror 13 are aligned with one another. Then an adjusting mechanism 15 is so adjusted that the cross mark 6 is aligned with the irradiation point of the light beam 5 on the screen 17. When the parallel light beam enters the condenser lens 10, the optical system 14 is so set as to converge the light beam on the screen 17 and while the cross mark 6 is aligned with the irradiation point of the light beam 5, the optical axis of a projector 1 and the optical axis of the collimation telescope 3 are completely parallel to each other. Consequently, distance (d) becomes constant at any distance from the projector 1 and corrections are easily made.