Abstract: An image measurement sheet for measuring an image formed on a recording medium includes a sheet having a plurality of medium scan windows used for detecting the recording medium, a plurality of image scan windows used for detecting the image formed on the recording medium, and an information scan window used for detecting imaging condition information recorded on the recording medium with the image, the plurality of medium scan windows to be corresponded to a portion of sides and a corner of the recording medium, the plurality of image scan windows to be corresponded to a portion of the image formed on the recording medium, and the information scan window to be corresponded to the imaging condition information recorded on the recording medium.

Abstract: A sheet discriminator, which can be included in an image forming apparatus, includes an optical information detector, a sheet distinguisher, and a sheet thickness detector. The optical information detector includes a light emitter to emit light to a recording medium and a light receiver to receive the light and detects information of the recording medium. The sheet distinguisher distinguishes a type of the recording medium based on the information detected by the optical information detector. The sheet thickness detector includes a displacement gauge to sandwich the recording medium with an opposing member disposed facing the displacement gauge and to move from an initial position thereof and a displacement detector to detect an amount of displacement of the displacement gauge. The sheet thickness detector detects a thickness of the recording medium based on detection results obtained by the displacement detector.

Abstract: A position measurement reference sheet for image position measurement on a recording medium includes a body having a front face to face an image reading face of a reading device, a recording medium detection window in the body to measure a position of an end of the recording medium, and an image detection window in the body to measure a position of an image on the recording medium. The position measurement reference sheet is interposed between the image reading face and the recording medium.

Abstract: An image forming apparatus includes an information obtainer, a memory, a candidate determining unit, and an image forming device. The information obtainer obtains feature information from the target recording medium. The memory stores at least one set of recording medium information regarding the target recording medium associated with the feature information and at least one set of image forming condition information corresponding to the recording medium information. The recording medium information is identification information. The candidate determining unit determines a candidate recording medium information from the recording medium information stored in the memory based on the feature information of the target recording medium obtained by the information obtainer. The image forming device forms an image on the target recording medium based on the image forming condition information in the memory according to the candidate recording medium information determined by the candidate determining unit.

Abstract: A sheet discriminator, which can be included in an image forming apparatus, includes a sheet loader on which a recording medium is loaded, an information detector including a light emitter to emit light to a surface of the recording medium loaded on the sheet loader and a light receiver to receive the light emitted by the light emitter and detecting information of the recording medium, a sheet distinguisher to distinguish a type of the recording medium based on the information detected by the information detector, and a detector body encasing at least the information detector therein and having an opening formed on an opposing face facing the sheet loader. The opposing face has an opening formed thereon. The opening has at least one arc-shaped side.

Abstract: A sheet discriminator, which can be included in an image forming apparatus, includes an optical information detector, a sheet distinguisher, and a sheet thickness detector. The optical information detector includes a light emitter to emit light to a recording medium and a light receiver to receive the light and detects information of the recording medium. The sheet distinguisher distinguishes a type of the recording medium based on the information detected by the optical information detector. The sheet thickness detector includes a displacement gauge to sandwich the recording medium with an opposing member disposed facing the displacement gauge and to move from an initial position thereof and a displacement detector to detect an amount of displacement of the displacement gauge. The sheet thickness detector detects a thickness of the recording medium based on detection results obtained by the displacement detector.

Abstract: An image reading device includes an imaging device including a plurality of imaging elements, a color measuring unit that detects color of an object at a color measurement area, a calibration plate having a surface on which a plurality of color patches is formed, and a processor that causes the color measuring unit to read the plurality of color patches while changing a relative position between the plurality of color patches and the plurality of imaging elements to output color measurement results of the plurality of color patches, and generates a set of reference values for the plurality of color patches based on the color measurement results of the plurality of colors. The set of reference values are compared with the reading results of the plurality of color patches to generate a set of correction values for correcting the reading results of the plurality of color patches.

Abstract: An optical scanner includes a light source to project light, a light deflector to deflect light, an optical element, and a holder to hold an optical element in place. The holder includes a curve adjustment mechanism, a first pressing member, a second pressing member, and a retainer. The curve adjustment mechanism adjusts a shape of the optical element in a sub-scanning direction relative to a scanning surface and perpendicular to a main scanning direction. The first pressing member is disposed at a first side from which the first pressing member presses the optical element in the sub-scanning direction. The second pressing member is disposed at a second side opposite the first side, to press the optical element from the second side. The retainer fixes substantially a center of the optical element in a main scanning direction of the light striking the optical element to the first side.

Abstract: An image reading device includes an imaging device including a plurality of imaging elements, a color measuring unit that detects color of an object at a color measurement area, a calibration plate having a surface on which a plurality of color patches is formed, and a processor that causes the color measuring unit to read the plurality of color patches while changing a relative position between the plurality of color patches and the plurality of imaging elements to output color measurement results of the plurality of color patches, and generates a set of reference values for the plurality of color patches based on the color measurement results of the plurality of colors. The set of reference values are compared with the reading results of the plurality of color patches to generate a set of correction values for correcting the reading results of the plurality of color patches.

Abstract: An image reading device includes an imaging device including a plurality of imaging elements, and a calibration plate having a surface on which a plurality of color patches is formed, and a processor that instructs the imaging device to read the plurality of color patches while changing a relative position between the plurality of color patches and the plurality of imaging elements, to output reading results of the plurality of color patches.

Abstract: An optical scanner includes a light source to project light, a light deflector to deflect light, an optical element, and a holder to hold an optical element in place. The holder includes a curve adjustment mechanism, a first pressing member, a second pressing member, and a retainer. The curve adjustment mechanism adjusts a shape of the optical element in a sub-scanning direction relative to a scanning surface and perpendicular to a main scanning direction. The first pressing member is disposed at a first side from which the first pressing member presses the optical element in the sub-scanning direction. The second pressing member is disposed at a second side opposite the first side, to press the optical element from the second side. The retainer fixes substantially a center of the optical element in a main scanning direction of the light striking the optical element to the first side.

Abstract: In a multi-beam scanning device including a laser diode array having three or more light emitting points, the interval Pi between one of the three or more light emitting points and the adjacent light emitting point is set so as to be not greater than the minimum recording interval Pi? of image information to be recorded on a recording medium. In addition, the three or more light emitting points are arranged such that the corresponding laser beam spots formed on the recording medium are arranged in a line or substantially in a line in the sub-scanning direction B. Thereby recording speed and recording density can be increased.

Abstract: A multi-beam scanning device including a multi-beam light source including plural laser diode arrays emitting plural laser beams and at least one coupling lens; a deflector configured to deflect the plural laser beams; an optical system configured to guide the deflected plural laser beams to an image forming surface; a body configured to contain the multi-beam light source, deflector and scanning optical system; and an adjustment member located between the body and the multi-beam light source and configured to adjust the beam pitch of the plural laser beams in the sub-scanning direction. An image forming apparatus including an image bearing member, the above-mentioned scanning device and an image forming device.

Abstract: In a multi-beam scanning device including a laser diode array having three or more light emitting points, the interval Pi between one of the three or more light emitting points and the adjacent light emitting point is set so as to be not greater than the minimum recording interval Pi? of image information to be recorded on a recording medium. In addition, the three or more light emitting points are arranged such that the corresponding laser beam spots formed on the recording medium are arranged in a line or substantially in a line in the sub-scanning direction B. Thereby recording speed and recording density can be increased.

Abstract: In a multi-beam scanning device including a laser diode array having three or more light emitting points, the interval Pi between one of the three or more light emitting points and the adjacent light emitting point is set so as to be not greater than the minimum recording interval Pi? of image information to be recorded on a recording medium. In addition, the three or more light emitting points are arranged such that the corresponding laser beam spots formed on the recording medium are arranged in a line or substantially in a line in the sub-scanning direction B. Thereby recording speed and recording density can be increased.

Abstract: A multibeam light source for use in information recording, including a semiconductor laser array provided with a plurality of light emitting points in a single package, in which the plurality of light emitting points are positioned in linear relationship to one another and have an equidistant pitch so as to respectively emit laser beams to be simultaneously scanned over a recording substrate. The position of the semiconductor laser array is adjustable so as to satisfy the relation ??tan?1{1/(n?1)}, where the angle ? is defined by two straight lines, the one drawn perpendicular to the primary scanning direction on an image recording substrate and the other drawn through respective centers of the first and n-th laser beam spots formed on the image recording substrate by projecting laser beams emitted respectively from the plurality of light emitting points.

Abstract: A multibeam light source includes a plurality of semiconductor laser arrays, and a deflector. A sub-scanning beam pitch is defined by a distance between an arbitrary point on a line connecting focuses of a preceding array and a point that corresponds to the arbitrary point on a line connecting focuses of an adjoining array. The sub-scanning beam pitch is set as P−(A/VM)·VS+C, where P is a recording density interval on the recoding medium, VM is a main scanning velocity, VS is a sub-scanning velocity, A is an interval between the focuses on the recording medium in a main scanning direction, and C is a correction amount of the beam pitch.

Abstract: A multi-beam scanning device including a multi-beam light source including plural laser diode arrays emitting plural laser beams and at least one coupling lens; a deflector configured to deflect the plural laser beams; an optical system configured to guide the deflected plural laser beams to an image forming surface; a body configured to contain the multi-beam light source, deflector and scanning optical system; and an adjustment member located between the body and the multi-beam light source and configured to adjust the beam pitch of the plural laser beams in the sub-scanning direction. An image forming apparatus including an image bearing member, the above-mentioned scanning device and an image forming device.

Abstract: A multibeam light source includes a plurality of semiconductor laser arrays, and a deflector. A sub-scanning beam pitch is defined by a distance between an arbitrary point on a line connecting focuses of a preceding array and a point that corresponds to the arbitrary point on a line connecting focuses of an adjoining array. The sub-scanning beam pitch is set as P−(A/VM)·VS+C, where P is a recording density interval on the recoding medium, VM is a main scanning velocity, VS is a sub-scanning velocity, A is an interval between the focuses on the recording medium in a main scanning direction, and C is a correction amount of the beam pitch.

Abstract: A multi-beam light source unit is provided with a light source emitting a plurality of light beams from corresponding light emitting points arranged in an array at equal intervals, a collimator lens forming the plurality of light beams into parallel bundle of rays, and an adjusting mechanism adjusting relative positions of the light source and the collimator lens so that a central part between the light emitting points at both ends of the light source matches an optical axis of the collimator lens. The collimator lens is rotatable about the optical axis of the collimator lens.