A control system controls an image forming unit that includes a charging device, an image bearer to be charged by the charging device, a light-emitting device array including a plurality of light emitting devices, and a driving causing the light emitting devices to emit light to form a latent image on the image bearer. The control system includes a storage unit, a corrector, and a controller. The storage unit is configured to store a light-amount correction value of each of the light emitting devices. The corrector is configured to correct a pixel value of each pixel in image data, based on the light-amount correction value of each light emitting device stored in the storage unit. The controller is configured to control the driver to cause each light emitting device to emit light based on image data for which a pixel value of each pixel has been corrected.

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.

An image forming apparatus includes: a speed setting portion configured to set a rotation speed of a drive motor to one of a plurality of predetermined specific speeds; a measurement processing portion configured to, in each of a plurality of detection cycles in which light is detected after scanning by a polygon mirror, measure an interval between a detection timing of the light and an output timing at which a drive signal input to the drive motor of the polygon mirror first after the detection timing, is output; and an identification processing portion configured to identify a reference reflection surface that corresponds to a reference interval, based on the measured interval and the reference interval corresponding to a specific speed at a time when the measured interval was measured, the reference interval being among reference intervals that have been set in advance for each of the specific speeds.

An image processing device includes circuitry to: acquire an image matrix including a target pixel from first image data having a first resolution; determine whether one or more detection patterns match the image matrix; and perform edge enhancement on the target pixel and convert the first resolution into a second resolution to convert the target pixel into second image data, if the image matrix matches any of the one or more detection patterns. The first image data includes a plurality of pixels each including first and second pixel values respectively indicating image information and whether each of the plurality of pixels is an area where a specific object is drawn. The one or more detection patterns, each including a plurality of pixels each including the first and second pixel values, are patterns to detect a pixel forming an edge portion where the first and second pixel values vary between pixels.

An image forming apparatus, based on print target image data, obtains a video count of a developer unit that forms an image on a photoconductor for each of regions divided in a scanning direction of a laser that exposes the photoconductor. Also after obtaining the video count, halftone processing is performed on the image data. Based on the obtained video count, patch data for cleaning the photoconductor corresponding to each region is generated. The developer unit is controlled to execute image formation based on image data for which the halftone processing is performed, and to execute image formation based on the generated patch data.

An image forming apparatus of the present invention acquires first correction characteristics representing an output density for an input gradation value at a reference position in a main scanning direction and second correction characteristics representing a relative relationship of an output density at a predetermined position in the main scanning direction with the output density at the reference position in the main scanning direction. Then, the image forming apparatus corrects image data corresponding to the predetermined position in the main scanning direction based on the first correction characteristics and the second correction characteristics.

An image forming apparatus includes a detecting unit detecting a value of a current flowing to a photosensitive member when a voltage is supplied to a voltage applying member or a value of a voltage applied to the photosensitive member when a current is supplied to the voltage applying member, an acquiring unit acquiring information concerning a difference between potentials of the unexposed portion and the exposed portion, based on detection results of the detecting unit at times when the voltage is applied by the voltage applying member to each of an unexposed portion formed in a region chargeable by a charging member in a rotation axis direction of the photosensitive member and an exposed portion formed in a region exposable by the exposure device in the rotation axis direction of the photosensitive member, and a control unit controlling an image forming condition based on the information concerning the difference.

In an image forming apparatus that employs a laser scanning optical system that does not use an f lens, in the case where magnification correction by insertion/removal of an auxiliary pixel is performed based on the premise of digital PWM, an insertion/removal position of an auxiliary pixel is controlled in accordance with a purpose of each piece of image processing.

Separately providing a shift register for performing serial-to-parallel conversion on a BD signal and a shift register for performing parallel-to-serial conversion on a bit pattern to generate a PWM signal increases the scale of a circuit for adjusting a writing start position in the scanning direction of a light beam. Therefore, the shift register for performing serial-to-parallel conversion on a BD signal and the shift register for performing parallel-to-serial conversion on a bit pattern to generate a PWM signal are configured as a common register.

An image forming apparatus includes (a) a plurality of image forming unit arranged along a transfer medium, each of which is arranged movable between a lower position and an upper position; (b) an estrangement controller to move each of the image forming units between these positions; (c) a print mode management part to determine a designated print mode; (d) an image forming part to select one or more of the image forming units corresponding to the designated print mode, and to form an image to be transferred to the transfer medium by using the selected image forming units; and (e) a correction process part that performs a correction process. Wherein (f) the correction process part regularly judges whether or not a correction process execution condition is satisfied, and performs a regular correction process when the correction process execution condition is satisfied, and (g) the print mode management part judges whether or not another print process in the designated print mode has been performed after a previous regular correction process, and sets a print mode based on a judgment result by the print mode management part.