Patent ID: 7760225

Claim:
An image forming apparatus, comprising: an electrostatic latent image carrier to carry an electrostatic latent image; and an optical writing device, including a housing including a side wall; at least one light source to generate a plurality of light beams at a time, the at least one light source including, a plurality of laser diodes to emit the plurality of light beams; a plurality of collimate lenses corresponding to the plurality of laser diodes, a cylindrical positioner, a holder provided with the cylindrical positioner to rotate around the cylindrical positioner to adjust a pitch between the plurality of light beams in a sub-scanning direction, and an inner wall provided inside the housing at an interior position of the side wall of the housing to cut off the plurality of light beams emitted by the plurality of laser diodes, at least one aperture including a plurality of openings formed on the inner wall to adjust the corresponding plurality of light beams generated by the at least one light source into a reference shape, at least one cylindrical light shield provided between the side wall and the inner wall continuously without gap or opening to shield an optical path formed between the at least one light source and the at least one aperture by the plurality of light beams generated by the at least one light source such that the at least one cylindrical light shield does not leak the light beams from the at least one light source to the inner wall, a light deflector to deflect the plurality of light beams generated by the at least one light source to scan at a time in a main scanning direction, an image forming lens to focus the plurality of light beams deflected by the light deflector to scan on the surface of the electrostatic latent image carrier to form an electrostatic latent image on the surface of the electrostatic latent image carrier, the housing to contain the at least one light source, the light deflector, and the image forming lens, and a cylindrical mounting opening formed on the side wall of the housing, wherein the cylindrical positioner of the at least one light source is detachably inserted into the cylindrical mounting opening formed on the side wall of the housing, wherein the side wall of the housing is integrally molded with the inner wall, the at least one light shield, and the cylindrical mounting opening by injection molding with a resin to form the cylindrical mounting opening and the at least one cylindrical light shield into a cylinder, and wherein the at least one aperture and the at least one cylindrical light shield are formed by a cylindrical insert and a protruding portion formed on a foremost surface of the cylindrical insert, the protruding portion being attached to the inner wall of the housing during a molding process.