Abstract: An image forming apparatus includes a photosensitive member and a scanning unit including a light source, a rotatable polygonal mirror, and a sensor. The image forming apparatus includes setting of an operation in a first mode and setting of an operation in a second mode. The image forming apparatus further comprises, a surface identifying portion and a correction data storing portion configured to prestore correction data including first correction data for a first rotational speed and second correction data for a second rotational speed. Positional deviation in a main scan direction of laser light is corrected on the basis of the first correction data or the second correction data.

Abstract: An image forming apparatus to form an image on a recording material includes a photosensitive member, an exposure device to form a latent image on the photosensitive member, a tubular body defining a space in which at least a part of the exposure device is contained, and a support portion that supports the exposure device and is provided along a rotation axis direction of the photosensitive member in the space of the tubular body. The image forming apparatus further includes, in the rotation axis direction, a first side plate fixed to one end portion of the tubular body, and a second side plate fixed to another end portion of the tubular body. One support portion end portion in the rotation axis direction is fixed to the first side plate, and another support portion end portion in the rotation axis direction is fixed to the second side plate.

Abstract: An image forming apparatus includes a photosensitive member and a scanning unit including a light source, a rotatable polygonal mirror, and a sensor. The image forming apparatus includes setting of an operation in a first mode and setting of an operation in a second mode. The image forming apparatus further comprises, a surface identifying portion and a correction data storing portion configured to prestore correction data including first correction data for a first rotational speed and second correction data for a second rotational speed. Positional deviation in a main scan direction of laser light is corrected on the basis of the first correction data or the second correction data.

Abstract: An image forming apparatus to form an image on a recording material includes a photosensitive member, an exposure device to form a latent image on the photosensitive member, a tubular body defining a space in which at least a part of the exposure device is contained, and a support portion that supports the exposure device and is provided along a rotation axis direction of the photosensitive member in the space of the tubular body. The image forming apparatus further includes, in the rotation axis direction, a first side plate fixed to one end portion of the tubular body, and a second side plate fixed to another end portion of the tubular body. One support portion end portion in the rotation axis direction is fixed to the first side plate, and another support portion end portion in the rotation axis direction is fixed to the second side plate.

Abstract: In an optical scanning device, an outer wall closest to a circumscribed circle of a rotating polygon mirror has a space in a position facing to a position of a reflection surface of the rotating polygon mirror in an axial direction of a rotating shaft. A part of a cover is provided in a position farther from the circumscribed circle than the outer wall so as to close the space, when the optical scanning device is viewed in a direction perpendicular to the axial direction of the rotating shaft.

Abstract: A manufacturing method of a polygonal mirror using a metal mold including a first mold, a second mold, a third mold, and a fourth mold includes a step of forming the molded member by providing the third mold and the fourth mold between the first mold and the second mold in a state in which the third mold and the fourth mold are in contact with each other and then by injecting a resin material into the metal mold, and a step of separating the third mold from the first crossing surface of the molded member in a direction crossing the first crossing surface.

Abstract: A polygonal mirror includes reflecting surfaces, a molded member including a first surface and a second surface, a contact portion, and gate marks. Each of said first surface and said second surface has a polygonal shape. The contact portion and the gate marks are formed at non-overlapping positions with a line segment connecting a vertex of the polygonal shape with a rotation center. The gate marks and the reflecting surfaces are the same in number. A perpendicular bisector of a line segment connecting centers of the gate marks adjacent to each other with respect to a rotational direction of the polygonal mirror is formed at a position passing through an associated vertex of the polygonal shape and the rotation center.

Abstract: An image forming apparatus to form an image on a recording material includes a photosensitive member, an exposure device to form a latent image on the photosensitive member, a tubular body defining a space in which at least a part of the exposure device is contained, and a support portion that supports the exposure device and is provided along a rotation axis direction of the photosensitive member in the space of the tubular body. The image forming apparatus further includes, in the rotation axis direction, a first side plate fixed to one end portion of the tubular body, and a second side plate fixed to another end portion of the tubular body. One support portion end portion in the rotation axis direction is fixed to the first side plate, and another support portion end portion in the rotation axis direction is fixed to the second side plate.

Abstract: A rotary polygon mirror has no recess in a thickness region of one of the reflecting surfaces of the rotary polygon mirror in the direction of the rotation axis of the rotary polygon mirror and has a protruding portion protruding from the thickness region in a direction away from the thickness region.

Abstract: An image forming apparatus to form an image on a recording material includes a photosensitive member, an exposure device to form a latent image on the photosensitive member, a tubular body defining a space in which at least a part of the exposure device is contained, and a support portion that supports the exposure device and is provided along a rotation axis direction of the photosensitive member in the space of the tubular body. The image forming apparatus further includes, in the rotation axis direction, a first side plate fixed to one end portion of the tubular body, and a second side plate fixed to another end portion of the tubular body. One support portion end portion in the rotation axis direction is fixed to the first side plate, and another support portion end portion in the rotation axis direction is fixed to the second side plate.

Abstract: An image forming apparatus for forming an image on a recording material includes a photosensitive member; an optical scanning unit including a light source, an optical box, and a cover; and a fan. The fan is provided so that air from the fan directly impinges on the cover of the optical scanning unit. As seen in a direction perpendicular to a rotational axis of the rotatable polygonal mirror, a rib extending from a top plate of the cover toward an optical box side is provided at a portion of the cover in the neighborhood of a light beam emitting port of the optical scanning unit. The cover is provided with an extended portion extended from the rib in a light beam emitting direction.

Abstract: An image forming apparatus to form an image on a recording material includes a photosensitive member, an exposure device to form a latent image on the photosensitive member, a tubular body defining a space in which at least a part of the exposure device is contained, and a support portion that supports the exposure device and is provided along a rotation axis direction of the photosensitive member in the space of the tubular body. The image forming apparatus further includes, in the rotation axis direction, a first side plate fixed to one end portion of the tubular body, and a second side plate fixed to another end portion of the tubular body. One support portion end portion in the rotation axis direction is fixed to the first side plate, and another support portion end portion in the rotation axis direction is fixed to the second side plate.

Abstract: An image forming apparatus to form an image on a recording material includes a photosensitive member, an exposure device to form a latent image on the photosensitive member, a tubular body defining a space in which at least a part of the exposure device is contained, and a support portion that supports the exposure device and is provided along a rotation axis direction of the photosensitive member in the space of the tubular body. The image forming apparatus further includes, in the rotation axis direction, a first side plate fixed to one end portion of the tubular body, and a second side plate fixed to another end portion of the tubular body. One support portion end portion in the rotation axis direction is fixed to the first side plate, and another support portion end portion in the rotation axis direction is fixed to the second side plate.

Abstract: In an optical scanning device, an outer wall closest to a circumscribed circle of a rotating polygon mirror has a space in a position facing to a position of a reflection surface of the rotating polygon mirror in an axial direction of a rotating shaft. A part of a cover is provided in a position farther from the circumscribed circle than the outer wall so as to close the space, when the optical scanning device is viewed in a direction perpendicular to the axial direction of the rotating shaft.

Abstract: An image forming apparatus for forming an image on a recording material includes a photosensitive member; an optical scanning unit including a light source, an optical box, and a cover; and a fan. The fan is provided so that air from the fan directly impinges on the cover of the optical scanning unit. As seen in a direction perpendicular to a rotational axis of the rotatable polygonal mirror, a rib extending from a top plate of the cover toward an optical box side is provided at a portion of the cover in the neighborhood of a light beam emitting port of the optical scanning unit. The cover is provided with an extended portion extended from the rib in a light beam emitting direction.

Abstract: A rotary polygon mirror has no recess in a thickness region of one of the reflecting surfaces of the rotary polygon mirror in the direction of the rotation axis of the rotary polygon mirror and has a protruding portion protruding from the thickness region in a direction away from the thickness region.

Abstract: In one embodiment, an optical scanning device includes a board and a light receiving member, the positional accuracy of which is improved. When a length in a scanning direction and a length in an intersection direction of a body portion of the light receiving member are denoted by Lx0 and Ly0, respectively, and a length in the scanning direction and a length in the intersection direction of a through-hole formed in the board are denoted by Lx1 and Ly1, respectively, the lengths Lx0, Ly0, Lx1, and Ly1 satisfy the following formula: (Lx1?Lx0)>(Ly1?Ly0).

Abstract: An image forming apparatus includes a photosensitive member and a scanning unit including a light source, a rotatable polygonal mirror, and a sensor. The image forming apparatus includes setting of an operation in a first mode and setting of an operation in a second mode. The image forming apparatus further comprises, a surface identifying portion and a correction data storing portion configured to prestore correction data including first correction data for a first rotational speed and second correction data for a second rotational speed. Positional deviation in a main scan direction of laser light is corrected on the basis of the first correction data or the second correction data.

Abstract: A manufacturing method of a polygonal mirror using a metal mold including a first mold, a second mold, a third mold, and a fourth mold includes a step of forming the molded member by providing the third mold and the fourth mold between the first mold and the second mold in a state in which the third mold and the fourth mold are in contact with each other and then by injecting a resin material into the metal mold, and a step of separating the third mold from the first crossing surface of the molded member in a direction crossing the first crossing surface.

Abstract: A polygonal mirror includes a reflecting surface capable of reflecting laser light emitted from a light source, a base material made of a metal material, and a molded member molded outside the base material and including a first surface and a second surface which crosses the first surface and which corresponds to the reflecting surface.