An image forming apparatus includes a first light source, a second light source, an optical sensor, a storage, and a hardware processor, wherein the storage stores a first threshold for determining a type of the recording material based on the basis weight, and the hardware processor calculates a first transmittance from the mount of the first emission light and the amount of the first transmission light, calculates a second transmittance from the amount of the second emission light and the amount of the second transmission light, derives a first basis weight corresponding to the first transmittance and a second basis weight corresponding to the second transmittance, by using predetermined determination criteria, determines the type of the recording material based on the first basis weight and the second basis weight, and derives the basis weight according to the determination criteria based on the determined type of the recording material.

An image forming apparatus includes a third link portion which is rotatably connected to said first link portion at a position between said first connecting portion and said first moving portion so that said first moving portion and said second moving portion are moved toward said drum unit by rotation of said first link portion about said first connecting portion as a rotation shaft and by rotation of said second link portion about said second connecting portion as a rotation shaft in interrelation with slide of said slidable portion, and which is rotatable relative to the apparatus main assembly. The third link portion is out of contact with the optical print head at a portion corresponding to an end portion on the optical print head side.

An image forming apparatus includes a photoconductor, a light emitting substrate, and imaging optical systems, wherein an optical axis of the imaging optical systems are parallel, imaging magnifications of the imaging optical systems are substantially equal for the light emitting point groups, the imaging optical systems includes a first lens array, a second lens array, and apertures, central points of the light emitting point group exist in a first plane, central points of the imaging lenses exist in a second plane, central points of the apertures exist in a third plane, central points of the imaging lenses exist in a fourth plane, the first plane forms a non-zero predetermined angle with respect to a plane perpendicular to an optical axis direction, and the angle formed with respect to the plane perpendicular to the optical axis direction is greater in the order of the first, second, third, and the fourth plane.

A light emitter includes: plural light emitting thyristors that each have an anode, a cathode, and a gate and are connected in parallel between a reference voltage line to which a reference voltage is supplied and a lighting voltage line to which a lighting start voltage for starting lighting is supplied, in which the anode and the cathode are connected respectively to the reference voltage line and the lighting voltage line; and a gate voltage setting section that, when at least one of the plural light emitting thyristors transitions from an off-state to an on-state, sets a voltage on the gate of each of the plural light emitting thyristors to a voltage between the lighting start voltage and an on-state voltage of the light emitting thyristor.

In an optical writing device that deflects light beams from first and second light source sections and performs scanning by first and second scanning optical systems, in reflective optical elements disposed in the optical axis direction from after the polygon mirror to before a separation mirror, a number of hold points on each of a writing start side and a writing end side in scanning is same, and in reflective optical elements disposed from after the separation mirror up to a surface to be scanned, a number of hold points on a writing start side of the first scanning optical system is same (one) with that on a writing end side of the second scanning optical system, and a number of hold points on a writing end side of the first scanning optical system is same (two) with that on a writing start side of the second scanning optical system.

Provided is an optical scanning device, which includes a bottomed box-like casing (31) in which a ceiling side is opened, a rotating polygon mirror (35) housed in the casing (31) to deflect and scan light beams emitted from a light source, a driving motor (41) fixed to a bottom wall of the casing (31) to drive the rotating polygon mirror (35), and a lid member (37) that closes the ceiling side of the casing (31) and is fixed to the casing (31) via a fixing mechanism (311), wherein the fixing mechanism (311) is provided adjacent to a minimum separation part (B) of a sidewall of the casing (31) in which a distance from the rotating polygon mirror (35) is minimum.

An image forming apparatus includes a photosensitive drum to rotate as to an apparatus main body, a print head having a connector and a light emitting element, a movement mechanism to move the print head between an exposing position and a retracted position, a support part rotatable and to support the movement mechanism, a cable, and an abutting portion. The cable supplies drive signals for driving the light emitting element to the print head. The cable extends toward an opposite side of the connector and is bent toward one direction or another direction of the support part. The abutting portion is provided to the support part, and abuts the cable bent portion in a direction from the retracted position toward the exposing position to cause the cable to flex between a connected portion to the connector and the bent portion, when the print head is at the retracted position.

An electrophotographic imager includes a photoconductive element, a charger, and a light source to expose areas of a charged surface of the photoconductive element to form a latent image. A development element is coupled relative to the photoconductive element to develop, via charged marking agent, the latent image on the photoconductive element. An exposure adjustment factor is selectively applied, prior to the exposing, to a first printable area of the latent image.

An exposure device irradiates a photoconductor with light on the basis of an exposure signal and thereby forms an electrostatic latent image. A toner amount calculating unit (a) determines a distribution pattern of the electrostatic latent image on the basis of the exposure signal, (b) determines an electric field variation level of a target pixel, (c) determines an electric field intensity of the target pixel on the basis of a value of the target pixel in the distribution pattern and the electric field variation level, and (d) determines a toner consumption amount corresponding to the electric field intensity. Further, using spatial filters independently of each other in a primary scanning direction and in a secondary scanning direction, the toner amount calculating unit determines the electric field variation level on the basis of (a) the distribution pattern or (b) the exposure signal.

An image forming apparatus including: an exposure head including light emitting elements arranged in an intersecting direction intersecting with a rotation direction of a photosensitive member to form an image at a first resolution corresponding the light emitting elements in the intersecting direction; a data generating unit configured to generate pixel data corresponding to a second resolution higher than the first resolution associating with positions of the pixel data; a correction unit configured to correct associations between the positions and the pixel data to adjust a position of an image in the intersecting direction; a conversion unit configured to convert the pixel data corresponding to the second resolution to pixel data corresponding to the first resolution; and a drive unit configured to drive the light emitting elements based on the pixel data corresponding to the first resolution.