An image forming apparatus includes circuitry that detects a position at which a first image is formed on a first face of a recording medium between an instant when the first image is formed on the first face of the recording medium and an instant when a second image is formed on a second face of the recording medium, calculates a first adjustment value used to adjust a position at which the second image is formed on the second face of the recording medium, based on the detected position at which the first image is formed on the first face of the recording medium, adjusts the position at which the second image is formed on the second face of the recording medium, based on the first adjustment value, and detects the adjusted position at which the second image is formed on the second face of the recording medium.

An image forming apparatus includes an image forming unit configured to form a predetermined pattern image on a sheet, a notifying unit configured to provide a notification of an orientation for placing the sheet on which the predetermined pattern image is formed by the image forming unit, on a placement portion, a reading unit configured to read the sheet on a line to line basis, to generate image data, and a detection unit configured to detect a streak-shaped image extending in a direction along a predetermined edge of the sheet, by analyzing the image data generated by reading the sheet by the reading unit, wherein the notifying unit provides a notification of a placement orientation for allowing the sheet, on which the predetermined pattern image is formed, to be read on a line to line basis, the line extending in a direction along the predetermined edge.

An image forming apparatus includes circuitry that detects a position at which a first image is formed on a first face of a recording medium between an instant when the first image is formed on the first face of the recording medium and an instant when a second image is formed on a second face of the recording medium, calculates a first adjustment value used to adjust a position at which the second image is formed on the second face of the recording medium, based on the detected position at which the first image is formed on the first face of the recording medium, adjusts the position at which the second image is formed on the second face of the recording medium, based on the first adjustment value, and detects the adjusted position at which the second image is formed on the second face of the recording medium.

An image forming apparatus includes an image forming unit configured to form a predetermined pattern image on a sheet, a notifying unit configured to provide a notification of an orientation for placing the sheet on which the predetermined pattern image is formed by the image forming unit, on a placement portion, a reading unit configured to read the sheet on a line to line basis, to generate image data, and a detection unit configured to detect a streak-shaped image extending in a direction along a predetermined edge of the sheet, by analyzing the image data generated by reading the sheet by the reading unit, wherein the notifying unit provides a notification of a placement orientation for allowing the sheet, on which the predetermined pattern image is formed, to be read on a line to line basis, the line extending in a direction along the predetermined edge.

An image forming apparatus obtains a number of pixels to be developed on a downstream side in a sub-scanning direction from each one of the predetermined pixels, in order to correct a density increase that occurs at the trailing edge of an image to be formed in accordance with a peripheral speed difference between a photosensitive drum and a developing roller, determines a correction amount of light amount for each one of the predetermined pixels in accordance with the obtained number of pixels, and generates image formation data.

An image forming apparatus obtains a number of pixels to be developed on a downstream side in a sub-scanning direction from the each one of the predetermined pixels, in order to correct a density increase that occurs at the trailing edge of an image to be formed in accordance with a peripheral speed difference between a photosensitive drum and a developing roller, determines a correction amount of light amount for each one of the predetermined pixels in accordance with the obtained number of pixels, and generates image formation data.

An image forming apparatus includes a photosensitive member, an exposing unit scanning the photosensitive member with a laser, a generating unit generating a clock signal, a first correcting unit correcting a frequency of the clock signal for each position in a main scanning direction, a developing unit, a driving unit, a second correcting unit correcting an image date by a correction coefficient depending on the position in the main scanning direction, and a modulating unit modulating the image date corrected by the second correcting unit into the driving signal. The correction coefficient increases as it goes toward an end from a center in the main scanning direction and includes an inflection point where an inclination, which is an increase amount of the correction coefficient to a unit increase amount of the position, is changed. The inflection point is positioned near the end in the main scanning direction.