Abstract: An optical scanning apparatus includes a light source, a polygon mirror including a plurality of reflecting surfaces configured to reflect light emitted from the light source, the polygon mirror being configured to be rotated around a rotary shaft, and a casing configured to accommodate the light source and the polygon mirror. The casing defines a first space that accommodates the polygon mirror and a second space that is different from the first space, the casing including a partition wall disposed between the first space and the second space. The second space is disposed further from the rotary shaft than the partition wall in a radial direction orthogonal to an axial direction of the rotary shaft, and is disposed such that the second space overlaps with the first space in the axial direction.

Abstract: An optical scanning device includes a plurality of light source units and a casing of the optical scanning device. The plurality of light source units includes a light source and a holder for holding the light source, respectively. The casing includes a plurality of mounting surfaces for holding a cylindrical portion of the holder. Each of the holders includes two projecting portions at one end portion of the holder with respect to a direction of a central axis of the cylindrical portion, perpendicular to the central axis of the cylindrical portion and extending in a direction away from the central axis each other when viewing the light source unit in the axial direction of the central axis, the projecting portions being provided with a U-shaped cut-way portion, respectively.

Abstract: An image forming apparatus includes a detection unit configured to detect a first scan beam from a first light source; and a control unit. The control unit performs corrections in which a light emission period of scan beams per pixel is changed in accordance with which section is scanned by the scan beams, performs corrections in which a light exposure amount by which the photosensitive member is exposed to light by the scan beams is changed in accordance with which section in the main scanning direction is scanned by the scan beams. Based on a detection timing at which the detection unit has detected the first scan beam. the control unit controls scan start timings at which the scan beams start scanning of the photosensitive member.

Abstract: An image forming apparatus to form a toner image on a recording material includes a photosensitive member and an optical scanning unit. The optical scanning unit includes an optical scanning unit, an optical box, a cover member, and a moving unit movable to an outside of the image forming apparatus. The optical scanning unit and the moving unit are arranged so that the moving unit and the optical scanning unit are opposed to each other when the moving unit is located in an inside of the image forming apparatus. The optical scanning unit is disposed so as to allow a user to touch the optical scanning unit through a space generated in the inside of the image forming apparatus when the moving unit is moved to the outside of the image forming apparatus. Between the optical box and the cover member, the cover member is opposed to the moving unit.

Abstract: An image forming apparatus to form a toner image on a recording material includes a photosensitive member and an optical scanning unit. The optical scanning unit includes an optical scanning unit, an optical box, a cover member, and a moving unit movable to an outside of the image forming apparatus. The optical scanning unit and the moving unit are arranged so that the moving unit and the optical scanning unit are opposed to each other when the moving unit is located in an inside of the image forming apparatus. The optical scanning unit is disposed so as to allow a user to touch the optical scanning unit through a space generated in the inside of the image forming apparatus when the moving unit is moved to the outside of the image forming apparatus. Between the optical box and the cover member, the cover member is opposed to the moving unit.

Abstract: An image forming apparatus to form a toner image on a recording material includes a photosensitive member and an optical scanning unit. The optical scanning unit includes an optical scanning unit, an optical box, a cover member, and a moving unit movable to an outside of the image forming apparatus. The optical scanning unit and the moving unit are arranged so that the moving unit and the optical scanning unit are opposed to each other when the moving unit is located in an inside of the image forming apparatus. The optical scanning unit is disposed so as to allow a user to touch the optical scanning unit through a space generated in the inside of the image forming apparatus when the moving unit is moved to the outside of the image forming apparatus. Between the optical box and the cover member, the cover member is opposed to the moving unit.

Abstract: A collimator lens is held by a holder so that, while viewing the collimator lens in an axial direction of a plurality of beams passing through the collimator lens, a straight line connecting between a center of the collimator lens and a gate portion is substantially parallel or substantially orthogonal to a straight line connecting between centers of the plurality of beams transmitting through the collimator lens.

Abstract: An image forming apparatus to form a toner image on a recording material includes a photosensitive member and an optical scanning unit. The optical scanning unit includes an optical scanning unit, an optical box, a cover member, and a moving unit movable to an outside of the image forming apparatus. The optical scanning unit and the moving unit are arranged so that the moving unit and the optical scanning unit are opposed to each other when the moving unit is located in an inside of the image forming apparatus. The optical scanning unit is disposed so as to allow a user to touch the optical scanning unit through a space generated in the inside of the image forming apparatus when the moving unit is moved to the outside of the image forming apparatus. Between the optical box and the cover member, the cover member is opposed to the moving unit.

Abstract: A laser marking method of performing marking by irradiating an object made of a resin with laser light, the laser marking method including: a first step of melting of carbonizing a first region of the object; and a second step of engraving a mark by irradiating a second region in the first region with the laser light.

Abstract: An optical scanning device includes a plurality of light source units and a casing of the optical scanning device. The plurality of light source units includes a light source and a holder for holding the light source, respectively. The casing includes a plurality of mounting surfaces for holding a cylindrical portion of the holder. Each of the holders includes two projecting portions at one end portion of the holder with respect to a direction of a central axis of the cylindrical portion, perpendicular to the central axis of the cylindrical portion and extending in a direction away from the central axis each other when viewing the light source unit in the axial direction of the central axis, the projecting portions being provided with a U-shaped cut-way portion, respectively.

Abstract: An image forming apparatus includes an optical scanning unit including a rotatable polygonal mirror and a detecting portion; and a controller. A rotation center of the rotatable polygonal mirror is made eccentric with respect to a center of gravity of the rotatable polygonal mirror by 7.5 ?m or more. The controller identifies one of reflecting surfaces of the rotatable polygonal mirror as a reference surface by using a signal outputted from the detecting portion for each of the reflecting surfaces of the rotatable polygonal mirror and a period of signals from light beams reflected by consecutive two reflecting surfaces with respect to a rotational direction of the rotatable polygonal mirror.

Abstract: An image forming apparatus includes an optical scanning unit including a rotatable polygonal mirror and a detecting portion; and a controller. A rotation center of the rotatable polygonal mirror is made eccentric with respect to a center of gravity of the rotatable polygonal mirror by 7.5 ?m or more. The controller identifies one of reflecting surfaces of the rotatable polygonal mirror as a reference surface by using a signal outputted from the detecting portion for each of the reflecting surfaces of the rotatable polygonal mirror and a period of signals from light beams reflected by consecutive two reflecting surfaces with respect to a rotational direction of the rotatable polygonal mirror.

Abstract: An image forming apparatus includes an optical scanning unit including a rotatable polygonal mirror and a detecting portion; and a controller. A rotation center of the rotatable polygonal mirror is made eccentric with respect to a center of gravity of the rotatable polygonal mirror by 7.5 ?m or more. The controller identifies one of reflecting surfaces of the rotatable polygonal mirror as a reference surface by using a signal outputted from the detecting portion for each of the reflecting surfaces of the rotatable polygonal mirror and a period of signals from light beams reflected by consecutive two reflecting surfaces with respect to a rotational direction of the rotatable polygonal mirror.

Abstract: An image forming apparatus includes an optical scanning unit including a rotatable polygonal mirror and a detecting portion; and a controller. A rotation center of the rotatable polygonal mirror is made eccentric with respect to a center of gravity of the rotatable polygonal mirror by 7.5 ?m or more. The controller identifies one of reflecting surfaces of the rotatable polygonal mirror as a reference surface by using a signal outputted from the detecting portion for each of the reflecting surfaces of the rotatable polygonal mirror and a period of signals from light beams reflected by consecutive two reflecting surfaces with respect to a rotational direction of the rotatable polygonal mirror.