An image forming apparatus includes an image forming device and circuitry. The image forming device forms an image. The circuitry corrects an amount of deviation based on a pattern formed by the image forming device, changes a magnification of the pattern, and calculates the amount of deviation based on the magnification.

An image forming apparatus includes an image forming unit configured to form an image on an image carrier, a transfer unit configured to transfer the image from the image carrier to a sheet, a reader configured to read a pattern image on the sheet while conveying the sheet, a sensor configured to measure a measuring image on the image carrier, and a controller configured to control the image forming unit to form the pattern image and the measuring image while forming images on a plurality of sheets, control the reader to read the pattern image, control the sensor to measure the measuring image, and generate an image forming condition based on a result of reading the pattern image by the reader and a result of measuring the measuring image by the sensor.

An optical scanning device includes a laser driver, an offset value determiner, a bias current setter, and a laser driver controller. The laser driver controls a laser light emitter to increase or decrease an excess of a current over a bias current in response to an input analog signal. The offset value determiner determines an offset value of the analog signal input to the laser driver based on a target light quantity of the laser light emitter. The bias current setter controls the bias current of the laser driver to a setting value in accordance with laser characteristics or lens transmittance of the laser light emitter. The laser driver controller controls a light emission quantity of the laser light emitter by inputting, to the laser driver, the analog signal offset based on a signal of the determined offset value.

An optical scanning device includes a laser driver, an offset value determiner, a bias current setter, and a laser driver controller. The laser driver controls a laser light emitter to increase or decrease an excess of a current over a bias current in response to an input analog signal. The offset value determiner determines an offset value of the analog signal input to the laser driver based on a target light quantity of the laser light emitter. The bias current setter controls the bias current of the laser driver to a setting value in accordance with laser characteristics or lens transmittance of the laser light emitter. The laser driver controller controls a light emission quantity of the laser light emitter by inputting, to the laser driver, the analog signal offset based on a signal of the determined offset value.

An image forming apparatus includes: an image forming unit configured to form an image on a sheet based on an image forming condition; an image reader configured to read an image for adjustment of the image forming condition, which is formed on the sheet; and a controller configured to: control, in a case of a job for which printing of the image for adjustment is set, the image forming unit to form the image for adjustment on the sheet, and generate a correction value for the image forming condition based on a reading result of the image for adjustment, which has been obtained by the image reader, to thereby adjust the image forming condition based on the correction value.

An image forming apparatus includes: an image forming unit configured to form an image on a sheet based on an image forming condition; an image reader configured to read an image for adjustment of the image forming condition, which is formed on the sheet; and a controller configured to: control, in a case of a job for which printing of the image for adjustment is set, the image forming unit to form the image for adjustment on the sheet, and generate a correction value for the image forming condition based on a reading result of the image for adjustment, which has been obtained by the image reader, to thereby adjust the image forming condition based on the correction value.

A charge removing unit emits light onto a surface of an image bearing member for removing charge on the surface. The charge removing unit includes a light source configured to emit the light, and a light guide that is configured to guide the light to irradiate the surface of the image bearing member with the light and has a cylindrical shape extending in an axial direction of the image bearing member. At both ends in a longitudinal direction of the light guide, one end portion and another end portion are respectively provided. The light is introduced to the one end portion. The another end portion includes an inclined surface inclining in a direction from the one end portion to the another end portion, toward a central axis of a circumference of the light guide.

A charge removing unit emits light onto a surface of an image bearing member for removing charge on the surface. The charge removing unit includes a light source configured to emit the light, and a light guide that is configured to guide the light to irradiate the surface of the image bearing member with the light and has a cylindrical shape extending in an axial direction of the image bearing member. At both ends in a longitudinal direction of the light guide, one end portion and another end portion are respectively provided. The light is introduced to the one end portion. The another end portion includes an inclined surface inclining in a direction from the one end portion to the another end portion, toward a central axis of a circumference of the light guide.

An apparatus includes a reflecting element with first, second and third reflecting surfaces, and a receiving element configured to receive a light flux from a light source reflected by the reflecting element. A value of an inner product of a unit normal vector of the first reflecting surface and a unit normal vector of the second reflecting surface, a value of an inner product of the unit normal vector of the first reflecting surface and a unit normal vector of the third reflecting surface, and a value of an inner product of the unit normal vector of the second reflecting surface and the unit normal vector of the third reflecting surface are appropriately set.

An apparatus includes a reflecting element with first, second and third reflecting surfaces, and a receiving element configured to receive a light flux from a light source reflected by the reflecting element. A value of an inner product of a unit normal vector of the first reflecting surface and a unit normal vector of the second reflecting surface, a value of an inner product of the unit normal vector of the first reflecting surface and a unit normal vector of the third reflecting surface, and a value of an inner product of the unit normal vector of the second reflecting surface and the unit normal vector of the third reflecting surface are appropriately set.