A scanning carriage of a printer includes a first emitter to emit first airborne charges, a second emitter to emit second airborne charges, and a fluid ejection device interposed between the first and second emitters to deposit droplets of ink particles within a non-aqueous fluid carrier onto a print medium to form an image. The carriage is movable relative to the print medium in a first direction and an opposite second direction. In the first direction, the first emitter is to electrostatically discharge the medium and the second emitter is to induce electrostatic fixation of the ink particles relative to the medium. In the opposite second direction, the second emitter is to electrostatically discharge the medium and the first emitter is to induce electrostatic fixation of the ink particles relative to the medium.

An image forming apparatus, including: a temperature detecting element provided on an opposite side of a first and a second light sources with respect to a deflection unit in an optical box and provided between a first lens and a second lens, which a first and a second light beams emitted from the first and second light sources and deflected by a rotary polygon mirror enter first, respectively, the temperature detecting element being configured to detect an internal temperature of the optical box; and a control unit configured to control lighting-up timings based on image data of the first and second light sources based on a detection result of the temperature detecting element so that misregistration between a first toner image and a second toner image transferred from the first and second photosensitive members onto the sheet is suppressed.

An optical scanning apparatus of the present invention includes: a splitting element which splits a light flux emitted from a light source into first and second light fluxes; a deflecting unit which deflects the first and second light fluxes to scan first and second scanned surfaces in a main scanning direction; and an imaging optical system which includes a first imaging lens on which both the first and second light fluxes deflected by the deflecting unit are incident and guides the first and second light fluxes to the first and second scanned surfaces. The condition expressed by

−1.1≦α1/α2≦−0.9

is satisfied where α1 and α2 are angles within a main scanning cross section between a first axis parallel to the main scanning cross section and directions of incidence of the first and second light fluxes on the deflecting unit, respectively.

An image forming apparatus, including: a light source configured to emit a light beam; a rotary polygon mirror having a plurality of reflection surfaces configured to deflect the light beam; a beam detector configured to receive the light beam to output a pulse; a pulse interval measurement unit configured to measure a pulse interval of pulses output from the beam detector; a reflection surface identification unit configured to identify each of the plurality of reflection surfaces; a storage portion configured to store a reference pulse interval of each of the plurality of reflection surfaces; a correction amount calculation unit configured to calculate a correction amount based on the pulse interval and the reference pulse interval for each of the plurality of reflection surfaces; and a light source control unit configured to control the light source based on the correction amount.

An optical scanning device includes a housing having light emitting ports extending in a predetermined direction, a transparent cover that closes the light emitting ports, a screw shaft arranged so as to extend in the predetermined direction along the transparent cover, a holding member having an engaging part engaged with the screw shaft, and a cleaning member held to the holing member. An abutting fulcrum is provided at an end of a movement path of the holing member, abuts a predetermined place of a surface of a front side in a progress direction of the holing member, allows the holing member to rotate by employing an abutting part of the holding member with the abutting fulcrum as a fulcrum, and reduces a position shift amount between the one side end portion and the other side end portion of the holing member in the progress direction.

An optical writing device and an image forming apparatus incorporating the optical writing device. The optical writing device includes two or more light sources, a pixel clock generator to measure a scanning speed of one of the two or more light sources and generate a pixel clock of a cycle corrected according to the measured scanning speed, a pulse data generation and output unit to generate pulse width data and shift data for the pixel clock generated by the pixel clock generator to output the generated pulse width data and the generated shift data for each one of the two or more light sources, and a plurality of image pulse generation and output units to generate an image pulse. In the optical writing device, the plurality of image pulse generation and output units are supplied with the pixel clock in common.

A light scanning device includes a light source, a deflector, a reflection mirror, and a light width regulating portion. The light source includes a plurality of light-emitting elements located at intervals one another. The deflector deflects to scan by reflecting a plurality of light beams. The plurality of light beams are emitted from the respective light-emitting elements. The reflection mirror is located in an optical path between the light source and the deflector and guides the plurality of light beams emitted from the plurality of light-emitting elements to the deflector. The light width regulating portion regulates widths of the plurality of light beams reflected by the reflection mirror in a main-scanning direction. The light width regulating portion is located adjacent to a reflecting surface of the reflection mirror and includes a pair of regulating wall portions located opposed one another in the main-scanning direction.

An emission unit of a displacement detector emits laser light to a range in a space in which a target moves. A detection unit detects a distribution of amounts of light reflected from a capture region in the predefined range. Based on a shift of speckle pattern indicated by a difference between the distributions of amounts of reflected light that the detection unit detects at different times, a calculation unit calculates a displacement of the target. A correction unit measures a speckle contrast from the distribution of amounts of reflected light, and based on an error between the measured value and a reference value, corrects the amount of laser light. The reference value is set to the value of a speckle contrast in a case in which the amounts of reflected light fall within the detectable range of the detection unit.

A semiconductor laser driver and an image forming apparatus incorporating the semiconductor laser driver. The semiconductor laser driver includes a light source including a plurality of laser-beam source units disposed in a sub-scanning direction that serves as a group direction, the laser-beam source units having a plurality of groups arranged in a main scanning direction, each of the laser-beam source units emitting a laser beam of a light quantity dependent upon a driving current, a shading corrector to correct, according to at least one shading correction value, the driving current given to the laser-beam source units for each of the groups, and a light quantity adjuster to adjust the driving current according to a light-quantity adjustment value for the laser-beam source units. The image forming apparatus includes a semiconductor laser drive circuit, and the semiconductor laser driver that serves as the semiconductor laser driver.

A light emitting element device includes: a light emitting thyristor having a layered structure including a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, a third semiconductor layer of the first conductivity type, and a fourth semiconductor layer of the second conductivity type that are layered in this order; and a gate electrode for supplying gate current to the light emitting thyristor. The light emitting thyristor includes an etching stop layer disposed on a surface of the third semiconductor layer or included in the third semiconductor layer, the etching stop layer being a semiconductor layer having an etching rate lower than an etching rate of a semiconductor layer adjacent to the etching stop layer.