PURPOSE: To set a slant angle of a collective rod lens array to a prescribed angle, by pivoting the center of a conjugate length of the collective rod lens array as a turning center to make the array turnable and to make the lens movable in parallel with an original plane.

CONSTITUTION: Screw holes are provided at positions corresponding to holes 90a, 90c, 90e of an angle adjusting plate of the collective rod array 12. An adjusting screw 83 is penetrated into the hole 90a and the like and screwed to the angle adjusting plate. In this case, the distance between, e.g., the hole 90a and the hole of the angle adjusting plate is adjusted by the screw amount of the angle adjusting plate. In inserting an adjusting screw 82 to holes 90b, 90d and 90f, the screw 82 and the plate 81 are screwed. The array 12 is turned around the center of conjugate length of the array 12 and this lens is made movable in parallel with the original plane.