Abstract: An opening, from which a cleaning member is inserted from the outer side of a main body of the image forming apparatus according to the present invention, is provided further toward the front side than an end portion of a front side of a holding member. The opening guides movement of the cleaning member in the direction of insertion as the inserted cleaning member moves toward the downstream side in the direction of insertion, so that downstream-side end portions of engaging portions in the insertion direction engage upstream-side end portions of protruding portions formed on the holding member in the direction of insertion.

Abstract: An optical scanning apparatus includes: a casing having a bottom face; a cylindrical portion having a first opening through which a laser beam from a light source passes; a light-transmitting member arranged between the cylindrical portion and a rotary polygon mirror; a plate spring fixing the light-transmitting member; and a sealing member between the cylindrical portion and the plate spring, wherein a width of the first opening narrows progressively in a insertion direction of the plate spring, the sealing member comes into contact with the cylindrical portion in a first region when the plate spring is inserted, and in a second region closer to the bottom face than the first region, a region, in which the sealing member comes into contact with the cylindrical portion, expands toward a center part from two end portions of a leading end portion of the sealing member as the plate spring is inserted further.

Abstract: The length of an abutting pin of an optical print head is decided such that the upper end of the abutting pin when at a cleaning position is on the opposite side of a movement path of a cleaning member, from the upper end of another abutting pin of the optical print head when in an exposure position.

Abstract: A holding member that holds an optical print head for exposing a photosensitive drum is provided with one abutting pin at each end thereof in the longitudinal direction. Each abutting pin has both a function of forming a gap between the optical print head and the photosensitive drum, and a function of restricting movement of the holding member in the X direction and Y direction. The holding member is supported by a link member further toward the side of the photosensitive drum than the lower end portion of the abutting pins.

Abstract: An exposing unit includes a holding member, an abutting pin protruding on both sides in the vertical direction at the rear side of the holding member, a second support portion provided further to the rear side than the holding member, and a movement mechanism that causes the holding member to move between an exposure position and a retracted position. The second support portion has a gap formed where the rear side of the holding member moves in the vertical direction, and this gap restricts movement of the holding member in the left-and-right direction. The holding member that is moved from the retracted position toward the exposure position by the movement mechanism is guided by the gap formed in the second support portion so that the abutting pin abuts a fitting portion.

Abstract: An image forming apparatus includes an optical print head, an optical print head moving mechanism, an abutting portion, a projected portion, an opposing portion, and a preventing portion provided on the projected portion so that in a state in which a drum cartridge is dismounted from a main assembly of the image forming apparatus, the preventing portion is contacted to the opposing portion by movement of the optical print head moved by the moving mechanism toward a side downstream of the exposure position with respect to the movement direction and prevents further movement of the optical print head in the movement direction and so that in a state in which the drum cartridge is mounted in the main assembly and the abutting portion contacts the drum cartridge, the preventing portion is in non-contact with the opposing portion.

Abstract: A light scanning apparatus including: a bottom surface on which a rotary polygon mirror is mounted; a housing including a bottom surface on which the rotary polygon mirror is mounted and a side wall portion on which a first light source and a second light source are mounted, the side wall portion standing from the bottom surface; and a wall portion standing from the bottom surface, the wall portion being configured to block a first light beam emitted from the first light source and reflected by an inner wall of a first holder holding the first light source and a second light beam emitted from the second light source and reflected by an inner wall of the second holder holding the second light source.

Abstract: An image forming apparatus includes a main assembly, a photosensitive drum, an optical print head, a receiving portion, a portion-to-be-engaged, and a guiding portion. The guiding portion is provided between the portion-to-be-engaged and the receiving portion with an interval from both the portion-to-be-engaged and the receiving portion. The guiding portion guides movement of the cleaning member in a direction from the receiving portion toward the portion-to-be-engaged while limiting movement of the cleaning member in a direction different from the longitudinal direction of the cleaning member to engage the engaging portion with the portion-to-be-engaged.

Abstract: An image forming apparatus includes: a photosensitive member; a process member configured to act on the photosensitive member; and a light scanning apparatus configured to emit a light beam to the photosensitive member. The light scanning apparatus includes: a light source; a rotary polygon mirror; a first signal generating unit configured to receive the light beam deflected by the rotary polygon mirror to generate a first signal indicating a scan starting position; and a second signal generating unit configured to generate a second signal based on a rotation angle of the rotary polygon mirror. A lighting-up timing of the light source for generating the first signal is determined based on a number of the second signals after a voltage for image formation is applied and a relationship between the first signal and the second signal is obtained before the voltage is applied and after the rotary polygon mirror is rotated.

Abstract: Provided is a casing of a light scanning apparatus accommodating a rotary polygon mirror and an optical member, the casing including: first seat surfaces arranged on a bottom surface of the casing to mount a first deflection portion that includes a first rotary polygon mirror, a first motor, and a first board on which the first rotary polygon mirror and the first motor are fixed; and second seat surfaces arranged on the bottom surface to mount a second deflection portion that includes a second rotary polygon mirror, a second motor having a maximum number of revolutions higher than that of the first motor, a second board on which the second rotary polygon mirror and the second motor are fixed, and a mounting portion supporting the second board, wherein at least one of the second seat surfaces is arranged outside of a region formed by connecting the first seat surfaces.

Abstract: Sealability between a cover member and a transparent member of an optical scanning apparatus is improved to improve dustproof performance. An optical scanning apparatus includes an elastic member 75 for sealing a portion between a cover member 70 and a glass member 90, the elastic member 75 being formed on the cover member 70 so as to surround an opening portion 42, the elastic member 75 being formed from a material that differs from that of the cover member 70. The elastic member 75 has a protrusion 75a that extends towards the glass member 90. The protrusion 75a fills a gap between the cover member 70 and the glass member 90 by contacting the glass member 90 and being elastically deformed.

Abstract: An image forming apparatus includes a drum unit, an optical print head, a moving mechanism, a moving mechanism supporting member, a main assembly, a flexible flat cable, a first cover portion made of a resin material and provided in the supporting member so as to cover a first portion of a cutting plane of the opening, the first portion opposing one surface of the flexible flat cable, and a second cover portion made of a resin material and provided in the supporting member so as to cover a second portion of the cutting plane of the opening, the second portion opposing the other surface of the flexible flat cable.

Abstract: An image forming apparatus includes an optical print head, an optical print head moving mechanism, an abutting portion, a projected portion, an opposing portion, and a preventing portion provided on the projected portion so that in a state in which a drum cartridge is dismounted from a main assembly of the image forming apparatus, the preventing portion is contacted to the opposing portion by movement of the optical print head moved by the moving mechanism toward a side downstream of the exposure position with respect to the movement direction and prevents further movement of the optical print head in the movement direction and so that in a state in which the drum cartridge is mounted in the main assembly and the abutting portion contacts the drum cartridge, the preventing portion is in non-contact with the opposing portion.

Abstract: An image forming apparatus includes a drum cartridge including a photosensitive drum, a movable optical print head including a light emitting element and a lens array, and a portion-to-be-contacted. The photosensitive drum and a light emergent surface of the lens array are spaced from each other to permit insertion of a cleaning member therebetween from an outside of the main assembly. The portion-to-be-contacted provided in a main assembly and configured to be contacted by the cleaning member to prevent further insertion of said cleaning member after said cleaning member cleans said light emergent surface by sliding on the light emergent surface from one end side toward the other end side of the light emergent surface with respect to a longitudinal direction of said lens array.

Abstract: A method of manufacturing a light scanning apparatus, including: forming an optical box having a plurality of protrusions arranged along a longitudinal direction of a reflection mirror and provided at positions corresponding to one end side and the other end side of the reflection mirror in the longitudinal direction, respectively; processing protrusions except protrusions that are used for supporting the reflection mirror so that the protrusions except the protrusions that are used for supporting the reflection mirror on the one end side and on the other end side of the reflection mirror are out of contact with the reflection mirror; placing the reflection mirror on the protrusions that have not been processed in the processing; and fixing the reflection mirror, which has been placed on the protrusions that have not been processed in the placing, to the optical box.

Abstract: A light scanning apparatus, including: a light source configured to emit a light beam; and a rotary polygon mirror configured to deflect the light beam emitted from the light source so that the light beam scans a surface of a photosensitive member, wherein the rotary polygon mirror is formed in a four-sided polygon, and wherein a difference between a pair of diametrically opposed interior angles of the rotary polygon mirror is larger than 0.03°, and a difference between another pair of diametrically opposed interior angles of the rotary polygon mirror is 0.03° or less.

Abstract: An image forming apparatus, including: a cartridge including a photosensitive drum and a regulation portion; a light emitting device configured to emit light from a light emission surface to the photosensitive drum; and a movement unit configured to reciprocate the light emitting device between an exposure position and a retracted position, wherein the regulation portion regulates a cleaning member, which includes a cleaning portion configured to rub and clean the light emission surface by a sliding movement of the cleaning member on the light emission surface of the light emitting device positioned at the retracted position so as to prevent the cleaning member from contacting the photosensitive drum and so as to bias the cleaning portion to prevent the cleaning portion from being separated from the light emission surface during the sliding movement of the cleaning member.

Abstract: A light scanning apparatus, including: a light source configured to emit a light beam; and a rotary polygon mirror configured to deflect the light beam emitted from the light source so that the light beam scans a surface of a photosensitive member, wherein the rotary polygon mirror is formed in a four-sided polygon, and wherein a difference between a pair of diametrically opposed interior angles of the rotary polygon mirror is larger than 0.03°, and a difference between another pair of diametrically opposed interior angles of the rotary polygon mirror is 0.03° or less.

Abstract: An optical scanning apparatus includes a light source, a deflecting unit, a reflection mirror, a casing, and first and second leaf springs. The casing includes first and second mirror supporting portions and a facing portion. The following relationship is satisfied: D2<L+W?D1. With respect to a longitudinal direction, L is a length of the reflection mirror, D1 is a longest distance between the first and second supporting portions, W is a contact width of the second supporting portion to the reflection mirror, and D2 is a distance between the facing portion and a closest position thereto of the first supporting portion. The first and second leaf springs urge the reflection mirror against the first and second mirror supporting portions, respectively. At least one of the first and second leaf springs is bonded to the reflection mirror with an adhesive.

Abstract: A resin holding member is supported by a one link member and another link member at positions further outside from both ends of a lens array and both ends of a circuit board in a rotational axis direction of a photosensitive drum, but further inside from an abutting pin and another abutting pin. Force in the opposite direction from the gravitational direction is applied to a portion of the holding member between the link members in a state where the abutting pins are abutting a drum unit. Accordingly, warping of the holding member is suppressed.