| 摘要 |
PURPOSE:To prolong the focal distance of a condensing lens without increasing the volume of a measuring apparatus, by arranging a reflecting mirror on the beam path of scanning beam between the condensing lens and a light receiving element and magnifying the length of the beam path on the basis of the mechanical distance between both of them. CONSTITUTION:The length of the beam path between a light receiving element 26 and a condensing lens 22 comes to about two times the mechanical distance between both of them by inserting a reflecting mirror 45 between them. The angle phi of reflection of the reflecting mirror 45 is adjusted by rotating the eccentric shaft 54 of a reflection angle mechanism 50 to rotate a mount stand 46 around a rotary center shaft 52 and fixing said stand 46 by a clamp 58. The reflecting position of the reflecting mirror 45 with respect to the element 26 in an up-and-down direction is adjusted by adjusting the distance between the free end of a cantilevered support plate 60 and the mount stand 46 by rotating the adjust screw 62 of a flap angle adjusting mechanism 48 to adjust an angle theta. By this constitution, the focal distance of the condensing lens can be extended without increasing the dimension of a light receiving apparatus and a measuring objective range can be enlarged. |
