| 摘要 |
PURPOSE:To provide the polygon mirror which highly maintains the plane accuracy and dividing angle accuracy of reflection surfaces and has high quality while the mirror is made of a synthetic resin by individually forming a mirror body and a reflection substrate as separate bodies. CONSTITUTION:The polygon mirror is composed of the thermoplastic mirror body 1 which is primarily molded by injection molding and has a polygonal shape in periphery and a shaft hole 2 in the central part and the reflection substrate 3 which is secondarily molded of a synthetic resin by injection molding around the peripheral side of the mirror body 1 with the mirror body 1 as a core. While the thermoplastic resin forming the mirror body 1 is not particularly limited, a polycarbonate, acrylic resin, etc., are used for the reflection substrate 3. Production is executed by first primarily molding the mirror body 1 of an ABS resin, etc., then inserting the mirror body 1 into metal molds for secondary molding and fixing the mirror body as the core. A molten resin, such as polycarbonate, is thereafter injected and packed into the space formed between the mirror body 1 and the wall surface of the cavity. As a result, the reflection substrate 3 is joined and integrated to the peripheral side of the mirror body 1. |
