| 摘要 |
PURPOSE: To enhance the productivity while assuring optical performance and to provide an optical apparatus which are higher in accuracy, lighter in weight and fewer in parts when a resin reflection plate is used for a polygon mirror for a scanning optical system by continuously forming V-grooves on this reflection plate at a specific pitch, thereby forming roof surface. CONSTITUTION: The V-grooves 11 having an opening angle of 90 deg. are continuously formed on one surface of a planar transparent body at a pitch of 1 to 2000μm by integral molding of a resin. The light made incident orthogonally with the arraying direction of the V-grooves 11 from the other surface is reflected in the exit angle (=θ) corresponding to the incident angleθin a direction where the V-grooves 11 extend by the multiple continuous prism structure of the V- grooves 11. The V-grooves 11 of a small forming pitch are formable on a resin forming mold by machining, such as diamond cutter of a diamond turning machine or chemical machining by etching using a photolithography method. Resin molding is thus possible. Since the V-grooves 11 are formed at the pitch of 1 to 2000μm, the forming molds are made shallower and the shape transfer at the time of resin molding is improved. |
