An image forming apparatus operable at a plurality of image forming speeds includes a pattern detection unit configured to detect a registration correction pattern at a first image forming speed, a writing start timing determination unit configured to determine writing start timing at which an electrostatic latent image is started to be written on a photosensitive member by a light beam emitted from a light source, and a storage unit configured to store in advance a correction amount for correcting the writing start timing. When the image forming apparatus operates at the first image forming speed set in advance, an image is formed at the writing start timing determined by the writing start timing determination unit. When the image forming apparatus operates at a second image forming speed, an image is formed at a writing start timing corrected based on the correction amount and a speed ratio.

An image forming apparatus capable of controlling density of an output image with high accuracy regardless of variation of internal temperature. A controller controls an image forming unit to form a measurement image, controls a light receiving unit to receive reflected light from the measurement image, controls a conversion unit to convert an output value of the light receiving unit, and controls an image formation condition based on a value that is obtained by converting the output value. An adjustment unit controls the light receiving unit to receive reflected light from an image bearing member, and adjusts the emission light amount of an emission unit based on the reflected light from the image bearing member. A selection unit selects a conversion condition from among conversion conditions based on a reference temperature that is detected when the adjustment unit adjusts the emission light amount and a current temperature.

An image forming apparatus includes: an image forming unit configured to form an image pattern on a medium, a predetermined image repeatedly appearing in a first cycle in a sub scanning direction in the image pattern; a density detector configured to optically detect a density of the image pattern in the sub scanning direction; a cyclic image detector configured to detect a feature image having a second cycle corresponding to the first cycle in accordance with a result of the detection; and a state determining unit configured to determine whether a cycle depending on an outer circumference of a rotary member included in the image forming apparatus corresponds to the second cycle when the feature image is detected by the cyclic image detector, and determine that a state of the rotary member has deteriorated when the cycle depending on the outer circumference is determined to correspond to the second cycle.

An image density detector for detecting image density of an image borne by an image bearer includes a reference board, a light emitter, a light receiver, an image density calculator, and an image density detecting condition corrector. The reference board has a spectral reflectance distribution closer to a spectral reflectance distribution of the image forming material than a spectral reflectance distribution of white. The light emitter emits light to the reference board and the image borne by the image bearer. The light receiver receives the light reflected from the image and the reference board. The image density calculator calculates the image density of the image based on an output of the light receiver receiving the light reflected from the image. The image density detecting condition corrector corrects an image density detecting condition based on an output of the light receiver receiving the light reflected from the reference board.

Printing by determining target color values based on first color outputs, determining current color values based on current color outputs, and calculating color compensation values to compensate for a difference between the target color values and the current color values.

A processor selects a target sheet from a plurality of predetermined sheet candidates in accordance with selection information that is input via an input device. Furthermore, the processor derives feature information regarding a noise point from a target image that is obtained through an image reading process performed on an output sheet output from an image forming device, the noise point being a dot-like noise image included in the target image. Furthermore, the processor determines whether or not the noise point is a dot-like sheet noise by applying the feature information to a determination algorithm that corresponds to the target sheet, the sheet noise being included in a sheet of the output sheet itself, the determination algorithm being one of a plurality of determination algorithms that respectively correspond to the plurality of sheet candidates.

An image forming apparatus, configured to operate in first and second modes of which color gamut is different from each other, includes an exposure unit configured to expose a photosensitive drum; a developing roller configured to form a toner image; a detection unit configured to detect density of the toner image transferred to an intermediate transfer member; and a controller configured to adjust the density based on a value of input image data. A dithering process for the controller's controlling of the exposure unit is different depending on whether the operation is in the first mode or the second mode, and in at least a part of the input image data, the density of the toner image formed by the dithering process in the first mode is higher than the density of the toner image formed by the dithering process in the second mode.

Method and devices for calibrating optical density reflective color fluids to be deposited on substrate are disclosed. Some methods comprise depositing a quantity of a keying color fluid on a first region of the substrate; applying a voltage level to a reflective color fluid application device; depositing, in response to the voltage level applied, a quantity of reflective color fluid on the first region of the substrate and on a second region of the substrate; performing reflectance measurements of the first region and of the second region; performing optical density calculations as a function of the reflectance measurements; varying the voltage level applied to the reflective color fluid application device in response to said optical density calculation until the optical density calculation is within a calibrated range of optical densities.

An image forming apparatus includes an image bearing member, an image forming unit, a detection unit, and a control portion. The detection unit includes a casing, an optical sensor, a shutter portion, a moving member, a groove portion, and a project portion. The optical sensor is disposed within the casing facing the image bearing member to detect the toner image and comprises a light emitting portion emitting light to the image bearing member through the opening portion and a light receiving portion receiving the light reflected from the image bearing member. The shutter is configured to open/close the opening portion as the project portion moves in a direction intersecting with the predetermined direction as the moving member moves in the predetermined direction. The groove portion is disposed perpendicularly above an extension line of an optical axis of the light irradiated from the light emitting portion to the image bearing member.

An image forming apparatus includes a density sensing portion, a cleaning portion, and a control portion. The density sensing portion includes a substrate and a sensor package and outputs a sensing value related to a toner density of a toner image formed on an outer circumferential surface of an image carrier. The control portion performs control so that, when the cleaning portion performs cleaning of a sensing surface, a brush is moved to a cleaning position where the brush contacts the sensing surface. The control portion also performs control so that, when the cleaning portion does not perform the cleaning of the sensing surface, the brush is moved to a retracted position where the brush does not contact the sensor package and the substrate.