An image forming apparatus includes a laser scanner unit, an engine controller, and an image controller. The laser scanner unit includes a polygon mirror configured to reflect a laser beam to scan a photosensitive drum, and a BD sensor configured to detect the laser beam reflected by the polygon mirror to output a BD signal. The engine controller generates an image formation BD signal synchronized with the BD signal. The image controller identifies a reference reflection face based on the number of times of low levels of an image formation BD signal that has been sampled for a predetermined period from a falling edge of the image formation BD signal. The image controller corrects image data based on the identified reflection face to control image formation processing.

A light-emitting component includes a substrate, a light-emitting element, a thyristor, and a light-transmission reduction layer. The light-emitting element is disposed on the substrate. The thyristor causes the light-emitting element to emit light or causes an amount of light emitted by the light-emitting element to increase, upon entering an on-state. The light-transmission reduction layer is disposed between the light-emitting element and the thyristor such that the light-emitting element and the thyristor are stacked, and suppresses light emitted by the thyristor from passing therethrough.

An optical scanning apparatus includes a first light source, a second light source, a first driving element, a second driving element, a rotatable polygonal mirror, a first scanning optical portion, a second scanning optical portion, a detecting element, and a circuit board. The first light source, the first driving element and the detecting element are arranged in a named order on the circuit board. The following relationship is satisfied: 1>2, where 1 is an angle formed by a direction of the first laser light and a first direction, and 2 is an angle formed by a direction of the second laser light and a second direction.

An image forming apparatus includes a rotatable image bearing member and a rotatable developer bearing member. The image bearing member, configured to carry a toner image, includes first recess portions provided at intervals substantially equal to a first pitch Pdr (mm) in a rotation direction of the image bearing member. The developer bearing member, configured to carry developer comprising toner and carrier and to form the toner image on the image bearing member, includes second recess portions provided at intervals substantially equal to a second pitch Ps (mm) in a rotation direction of the developer bearing member. The following relationship is satisfied
Vs/Vdr<Ws/Pdr where Vdr represents a movement speed (mm/sec) of the first recess portions, Vs represents a movement speed (mm/sec) of the second recess portions, and Ws represents a length (mm) of each of the second recess portions in the rotation direction of the developer bearing member.

An image forming apparatus includes a groove, an exposure device and an adjustment member. In the groove, each of end portions of a rotation shaft of a photosensitive drum is inserted. The exposure device is configured to emit a laser light on the photosensitive drum to form an electrostatic latent image. An adjustment member is configured to shift each of the end portions of the rotation shaft to adjust a skew of the laser light.

A layered structure includes a thyristor and a light-emitting element. The thyristor at least includes four layers. The four layers are an anode layer, a first gate layer, a second gate layer, and a cathode layer arranged in this order. The light-emitting element is disposed such that the light-emitting element and the thyristor are connected in series. The thyristor includes a semiconductor layer having a bandgap energy smaller than bandgap energies of the four layers.

An image forming apparatus includes an image bearing member, a transfer member, an acquiring portion, an applying portion, and a controller. When a transfer voltage is subjected to constant-voltage control so that the transfer voltage applied to the transfer member by the applying portion is substantially constant, in a case that the transfer voltage, when a toner amount used for a toner image is a first toner amount, is a first voltage, the controller controls the applying portion so that the transfer voltage is a second voltage lower in absolute value than the first voltage in a case that the toner amount is a second toner amount greater than the first toner amount. The acquiring portion acquires toner amount information on the toner amount for each toner image transferred onto a single recording material.

A laser scanning device includes a light source, a rotary polytope, a motor, a bearing, and a detection processing portion. The rotary polytope scans light emitted from the light source. The motor rotates the rotary polytope. The bearing rotatably supports a rotation shaft of the motor. The detection processing portion, in a case where the motor is driven at a first speed that is higher than a predetermined reference speed, performs detection of an abnormal state based on an atmospheric temperature detected at a position located within a predetermined first range from the bearing, and in a case where the motor is driven at a second speed that is lower than the reference speed, does not perform the detection of the abnormal state, wherein the abnormal state is a state where the temperature of the bearing has exceeded a predetermined allowable temperature.

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.

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.