An image forming apparatus includes a housing, a drum, a toner processing module and a first mounting space. The drum is disposed in the housing. The toner processing module supplies toners to the drum. The first mounting space accommodates a first print head. The first print head provides a light ray to perform a writing operation on the drum. When the first print head is present, the light ray of the first print head disposed in the first mounting space passes through an optical channel of the toner processing module to perform the writing operation on the drum. Thus, the optimum configurations of the print head and the drum can be achieved, to effectively reduce a size of the image forming apparatus and satisfy diversified requirements without spending a high cost.

An image forming apparatus includes: an image carrier on which an image is formed; a light source that generates a light beam; an optical scanner that executes scanning of the light beam; a reflection surface identifier that identifies each reflection surface of a rotary polygon mirror; a sub-scanning direction driver that relatively moves the image carrier and the light beam to each other; a storage that stores first jitter information; a photodetector that detects scanning of the light beam; a measurement device that generates second jitter information; and a hardware processor that uses the first and second jitter information to change a frequency of a write clock and adjust a phase of the write clock, wherein the hardware processor obtains a correction characteristic for a dot position shift, and changes the frequency of the write clock and adjusts the phase of the write clock.

In an optical scanning device, light emitting start timings of light emitting parts with respect to a reference light emitting part are stored in a storage part. In a correction mode, a light emitting timing correction control part performs first control for allowing positions of beam spots of the light beams emitted from the light emitting parts to be equal to each other, second control for allowing a light emitting part LD4 to emit a light beam at a plurality of different start timings and patch images to be formed on a intermediate transfer belt 281, and third control for correcting light emitting start timings of light emitting parts LD2 to LD4 on the basis of the start timing of the light emitting part LD4 at which the patch images has the highest concentration.

An image forming apparatus, having a photosensitive drum assembly, an exposure head, and a bearing, is provided. The photosensitive drum assembly includes a photosensitive drum and a flange disposed at an end of the photosensitive drum in an axial direction of an axis of the photosensitive drum. The flange contacts an inner surface of the photosensitive drum. The exposure head includes a plurality of light emitters aligned along the axial direction of the photosensitive drum, a lens array focusing light from the light emitters on the photosensitive drum, and a head frame to support the light emitters and the lens array. The bearing has a first contact face to contact the exposure head to define a distance between the lens array and the photosensitive drum along a direction of an optical axis of the light.

An image forming apparatus, including a photosensitive drum, an exposure head, a base frame, and a spring, is provided. The exposure head includes light emitters, a lens array, and a head frame, and is movable between an exposable position and a retracted position. The base frame supports the photosensitive drum and includes a reference face. The reference face is configured to define a position of the exposure head with regard to a sub-scanning direction, which is orthogonal to a direction of an optical axis of the light from the light emitters and to a direction of a rotation axis of the photosensitive drum, by being contacted by the head frame of the exposure head when the exposure head is at the exposable position. The spring is arranged in the head frame and presses the head frame toward the reference face.

A scanning optical apparatus includes a light source, a deflector and an imaging optical system. The deflector deflects a beam emitted from the light source to scan a scanning surface with the beam in a main scanning direction. The imaging optical system focuses the beam on the scanning surface. The imaging optical system includes a first lens having negative power in a sub scanning direction and a second lens having positive power in the sub scanning direction, in which the sub scanning direction is parallel to the scanning surface and perpendicular to the main scanning direction. The power 1 of the first lens, the power 2 of the second lens and a magnification in the sub scanning direction of the imaging optical system satisfy the conditions 1.21/20.9 and 1.30.8.

An image forming apparatus, including: a light source; a deflection device; a lens configured to image a light beam emitted from the light source based on an image signal and deflected by the deflection device on a surface of a photosensitive member; and a controller configured to execute partial magnification correction for correcting a partial magnification as a deviation amount of a scanning speed of the light beam at a position different from a reference position in a main scanning direction with respect to a scanning speed at the reference position, wherein the controller is configured to: execute, when an image type of the image is a line image, the partial magnification correction on the image signal at a resolution less than one pixel; and execute, when the image type is a graphic image, the partial magnification correction on the image signal at a resolution in unit of one pixel.

An exposure device according to an embodiment includes: a substrate in which light-emitting elements are mounted; an optical system which converges light emitted from the light-emitting elements; a holding member includes a holding member body which holds the substrate and the optical system, and a cut fringe projected from the holding member body; and a support member provided at a predetermined position in the holding member between the substrate and the optical system. The support member is formed of a cured agent attached to a shear surface of the cut fringe of the holding member, and the support member includes a contact surface with which the substrate is in contact.

An image forming apparatus including a controller, which starts rotation of a rotary polygon mirror when a predetermined condition is satisfied, rotates the rotary polygon mirror at a predetermined rotation speed based on a first pulse in a first state in which light beams are not emitted from a light source, thereafter starts emission of the light beams, switches a rotation control based on the first pulse to a rotation control based on the second pulse, and rotates the rotary polygon mirror at the predetermined rotation speed based on the second pulse in a second state in which the light beams are emitted from the light source, and thereafter detects a temperature of a drive circuit board by a temperature detector, and corrects color misregistration using a detected temperature of the temperature detector and the detection result of a pattern detector.

An image forming apparatus includes a controller, wherein the controller execute first control of controlling a rotational frequency of the motor based on a light receiving signal, wherein, when the target rotational frequency changes from a first rotational frequency to a second rotational frequency that is lower than the first rotational frequency, the controller executes speed change control of: stopping execution of the first control; and changing a rotational frequency of the motor, and non-lighting period change control of changing the non-lighting period in the lighting control from a first non-lighting period corresponding to the first rotational frequency to a second non-lighting period corresponding to the second rotational frequency, and the controller starts the first control in response to satisfying a condition where the deflection period of the mirror obtained based on a position signal of a rotor of the motor is longer than the second non-lighting period.