An image forming apparatus includes a sheet transport path that transports a sheet on which an image has been recorded, the sheet transport path including a first guide surface and a second guide surface opposed to the first guide surface, an image reading unit disposed on the same side as the first guide surface of the sheet transport path to read the image, and a rotary element disposed on the same side as the second guide surface, the rotary element being rotatably disposed with a gap between the rotary element and the first guide surface.

The present invention performs inplane uneven density correction that suppresses a number of tone correction properties and has few correction residuals. Accordingly, a holding unit of an apparatus of the present invention holds a plurality of tone correction properties respectively corresponding to a plurality of spot diameters that divide a range of a spot diameter of a light exposed on a surface of a photoreceptor by a predetermined interval. In addition a setting unit sets a tone correction property selected from the plurality of tone correction properties based on a spot diameter on the photoreceptor for a pixel corresponding to pixel data C. A correction unit corrects the pixel data C based on the set tone correction property, to generate tone correction data Cc.

A color processing apparatus includes an area group manager, a predictor, and a conversion relationship generator. The area group manager extracts, as an area group, a particular area on each page from image data in which one copy is constituted of multiple pages, and manages the area group in association with a page number. The predictor obtains color data of the image data output by an image forming section, and predicts a color variation on the basis of color data corresponding to the area group. The conversion relationship generator generates, on the basis of the color variation of the area group corresponding to a particular page number, a conversion relationship unique to the particular page number as a conversion relationship for performing color adjustment of the image forming section.

An image forming apparatus includes: a light-receiving unit that includes light-receiving elements arranged along a movement direction of a target formed on an image carrier, and is arranged so as to receive light emitted from a light-emitting unit and specularly reflected off the image carrier; a member configured to limit a size of diffused reflection light that is incident on the light-receiving unit in the movement direction; a selection unit configured to select whether or not each of the light-receiving elements in the light-receiving unit is a effective light-receiving element; a generation unit configured to generate a detection signal from an output of the effective light-receiving element; and a detection unit configured to detect a target formed on the image carrier based on the detection signal.

An image forming apparatus forms a measurement image, controls a sensor to measure light reflected from a first area of an intermediate transfer member, controls the sensor to measure light reflected from a measurement image, and controls the sensor to measure light reflected from a second area of the intermediate transfer member. The apparatus determines first information relating to a tendency of the measurement results of the first area, determines second information relating to a tendency of the measurement results of the second area, and selects a computational equation for computing a correction value of a measurement result of the measurement image. The apparatus generates a correction value. The apparatus adjusts an image forming condition.

The circuit substrate includes at least two lands formed on a substrate, wherein one electrode is to be mounted on the at least two lands, an electronic part having electrodes, one of the electrodes is soldered on the at least two lands with solders whose amounts are adjusted by a metal mask having at least two opening parts, positions of the at least two opening parts corresponding to the at least two lands when the solders are applied and melted, areas of the at least two opening parts being different with each other, wherein a height of one of the solders is different from a height of the other of the solders according to the difference of the areas of the at least two opening parts of the metal mask, whereby the electronic part is mounted on the circuit substrate in an inclined state.

An image forming apparatus includes a control unit configured to detect a misregistration amount and densities of the toner images by detecting first and second detection patterns. The first detection pattern includes black and color portions, and the control unit is further configured to set a light-emitting amount of a detection unit, a threshold, or a sensitivity of a detection unit so that a received light amount of diffuse reflection light from the black portion is less than the threshold and a received light amount of diffuse reflection light from the color portion exceeds the threshold, and to set the light-emitting amount or the sensitivity so that the received light amount of the diffuse reflection light from the color portion is less than an upper limit of the detection unit.

An image forming apparatus includes: an output unit configured to receive light reflected from a measurement image on an image carrier and output a signal corresponding to a light receiving result; a detection unit configured to detect a temperature of the output unit; a conversion unit configured to convert an output value output from the output unit, based on a conversion condition; a controller configured to control an image forming condition for adjusting a density of an image to be formed based on a converted output value by the conversion unit; and a generation unit configured to, at a predetermined timing, acquire an output value output from the output unit without emitting light, control the detection unit to detect the temperature, and generate the conversion condition based on the acquired output value and the detected temperature.

An image forming system includes an image output device, a measurement sensor, a tone correction value generation unit, and a tone correction unit. The image output device outputs an image on a recording medium with a mixture of a plurality of basic colors based on an image data array combining the basic colors. The measurement sensor measures a reflection characteristic of at least a part of the image output by the image output device. The tone correction value generation unit generates, for each of the basic colors, a tone correction value for correcting a tone characteristic of the basic color by synthesizing a correction array forming a regular matrix based on the reflection characteristic measured by the measurement sensor and the image data array. The tone correction unit corrects an image output by the image output device with the tone correction value.

An image forming apparatus includes a detector for detecting one of position and density information of a detection image based on a signal corresponding to a difference between a value of a detection signal corresponding to a first position of one of the detection image on an image carrier and a surface of the image carrier and an average value of a value of the detection signal corresponding to a second position on a downstream side with respect to the first position in a moving direction of the detection image and a value of the detection signal corresponding to a third position on an upstream side with respect to the first position in the moving direction during a time when the detection image formed on the image carrier passes through an irradiation region of an irradiation device.