| 摘要 |
PURPOSE:To utilize the direction of the high resolving power of a lens for forming a belt-like picture image by providing a screw hole to a mounting seat having a pair of V-shaped receiving faces that receive the circumferential surface of a cylindrical elns, and fixing the cylindrical lens therein by means of a holding band. CONSTITUTION:A through-hole 48 is punched at the center of the front wall 26a of a light shielding box 26, and a mounting seat 23 for a projection lens is provided on a bottom wall 16. A pair of receiving faces 49 (49A, 49B) of a V-shape in parallel with the central axial line of the hole 48 are provided to the seat 23. A projection lens 24 to be placed on the seat 49 is made in a cylindrical shape and has high resolving power in an arrow direction X. The optical axis of an exposure optical system and the center of the lens 24 are aligned simply by placing the lens 24 on the faces 49. The best picture image obtainable with the lens 24 is obtained if the lens 24 is turned so as to direct the high resolving power direction X of the lens 24 to the direction in parallel with the slit of a slit plate in this state and if the lens is fixed to the seat 23 by means of a holding band 25. |
