Abstract: A side wall surface of a carriage is disclosed with two first projection parts and a second projection part that define the inclination of a reflective optical sensor in its vertical direction. The two first projection parts are arranged at the same height position with a detection surface as a reference, and the second projection part is arranged at a position higher than the first projection parts with the detection surface as the reference. The second projection part has a first part higher in position from the side wall surface of the carriage than the first projection parts and has a second part lower in position than the first part. The second part has a screw hole into which a clamping member for fixing the reflective optical sensor to the second part is tightened.

Abstract: An image forming apparatus including a first carriage having at least two first recording heads, a second carriage separatably dockable with the first carriage, a pattern forming unit to control the at least two first recording heads to form on a recording medium adjustment patterns for correcting a shift in landing positions of liquid droplets ejected from the at least two first recording heads, a pattern detector provided to the first carriage to read the adjustment patterns, and a landing position corrector to correct the shift in the landing positions of the liquid droplets based on a result obtained by the pattern detector. The at least two first recording heads form multiple rows of the adjustment patterns, and the pattern detector successively reads at least two rows of the multiple rows of the adjustment patterns without docking and separation of the first and second carriages.

Abstract: An image forming apparatus including a first carriage movable in a main scanning direction, a second carriage separatably dockable with the first carriage, a first positioning unit to position the second carriage relative to the first carriage in a sub-scanning direction, a second positioning unit to position the second carriage relative to the first carriage in a rotary direction, and a third positioning unit to position the second carriage relative to the first carriage in the main scanning direction. The first positioning unit includes a reference shaft and notched positioning members to engage the reference shaft. The second positioning unit contacts one of the first and second carriages in the rotary direction upon docking of the first and second carriages. The third positioning unit includes a positioning member, parallel grooved members in the sub-scanning direction, and parallel shafts extending in the sub-scanning direction to engage the grooved members.

Abstract: An image forming apparatus including a first carriage having a first recording head to eject black liquid droplets, a second carriage having a second recording head to eject color liquid droplets and separatably dockable with the first carriage, a position detector to detect a position of the second carriage relative to the first carriage in a state in which the first and second carriages are docked with each other, and a landing position corrector to correct landing positions of liquid droplets ejected from at least one of the first and second recording heads. The landing position corrector holds the position of the second carriage obtained by the position detector as a reference position and adjusts a correction amount for correcting the landing positions based on an amount of shift between the reference position and a present position of the second carriage docked with the first carriage.

Abstract: An adjustment pattern, which is composed of a reference pattern made of plural independent liquid droplets and a pattern to be measured made of plural independent liquid droplets ejected under an ejection condition different from the reference pattern, is formed on a water-repellent conveying belt. Then, light is applied to the adjustment pattern to receive the regular reflection light from the adjustment pattern, so that the adjustment pattern is scanned. The distance between the respective patterns is measured based on the measured result. Finally, liquid droplet ejection timing of the recording head is corrected based on the result thus measured.

Abstract: An image forming apparatus including a first carriage having a first recording head and a first lifting/lowering unit, a second carriage having a second recording head and a second lifting/lowering unit, a drive source, a drive coupling unit provided to the drive source, a first coupling unit, a second coupling unit, a docking/separation unit that docks and separates the first and second carriages, and an accommodation/coupling unit. A first end of the second coupling unit is coupled to the drive coupling unit, and the accommodation/coupling unit couples the first coupling unit to a second end of the second coupling unit and accommodates the first coupling unit within the first carriage to uncouple the first coupling unit from the second end of the second coupling unit. Accommodation and coupling of the first coupling unit are performed in conjunction with docking and separation of the first and second carriages.

Abstract: An image forming apparatus including a first carriage having a recording head that ejects black liquid droplets and is movable in a main scanning direction, a second carriage having a recording head that ejects color liquid droplets and is detachably attachable to the first carriage to move in the main scanning direction together with the first carriage while attached to the first carriage, and a cap member that caps the recording head of the second carriage while the first carriage is moving with the second carriage separated from the first carriage. Attachment and detachment of the second carriage to and from the first carriage are performed within a scanning range through which the first carriage is movable.

Abstract: An image forming apparatus including a first carriage having a recording head that ejects black liquid droplets and is movable in a main scanning direction and a second carriage having a recording head that ejects color liquid droplets and is detachably attachable to the first carriage within a scanning range of the first carriage in the main scanning direction. The second carriage when attached to the first carriage is movable in the main scanning direction together with the first carriage. Attachment and detachment of the second carriage to and from the first carriage are performed based on a predetermined reference position of the first carriage in the main scanning direction.

Abstract: A disclosed image forming apparatus includes a recording head configured to jet liquid droplets; a pattern forming unit configured to form, on a water-repellent surface of a water-repellent sheet member, an adjustment pattern used for correcting shifts in landing positions of the liquid droplets, wherein the adjustment pattern includes plural liquid droplets that are separated from each other, and the water-repellent surface having a water-repellent property is formed on at least a part of a surface of the water-repellent sheet member; a reading unit including a light emitting unit configured to irradiate light onto the adjustment pattern and a light receiving unit configured to receive specular reflection light from the adjustment pattern; and a landing position correction unit configured to correct, based on a reading result obtained by the reading unit, the shifts in the landing positions of the liquid droplets that are jetted from the recording head.

Abstract: A liquid-ejection-type image forming apparatus includes a recording head configured to print by ejecting ink liquid, and an electrostatic-absorption belt configured to convey printing paper. The liquid-ejection-type image forming apparatus performs a cockling-preventing mode operation which stops printing operation, separates the printing paper from the electrostatic-absorption belt, and restarts the printing operation after replacing the printing paper on the electrostatic-absorption belt.

Abstract: A disclosed image forming apparatus includes a carriage having a head for jetting droplets; a pattern forming unit configured to form, on a belt, a pattern used for detecting displacement of landing positions of the droplets; a reading unit configured to scan the belt before the pattern formation to output a first result, and scan the pattern to output a second result; a correcting unit configured to correct the displacement based on the second result; a frequency analyzing unit configured to calculate frequencies of the belt and amplitudes of respective frequency components based on the first result; and a peak frequency calculating unit configured to calculate peak frequencies of the belt based on the frequencies of the belt and the amplitudes of the frequency components, the peak frequencies being frequency components whose amplitude exceeds a predetermined level. The pattern is formed at a frequency different from the peak frequencies.

Abstract: An image forming apparatus includes a carriage carrying a recording head configured to discharge a droplet. A landing position error detecting pattern is formed on a pattern forming member. Based on a result of reading the landing position error detecting pattern, a landing position error of the droplet discharged by the recording head is corrected. Either a first pattern or a second pattern is selected as the landing position error detecting pattern, depending on a surface condition of the pattern forming member. The first pattern produces a relatively small amount of specular reflection compared with diffused reflection, while the second pattern produces a relatively large amount of specular reflection compared with diffused reflection, upon irradiation with light.

Abstract: An inkjet-type image forming apparatus includes a recording head configured to eject ink to form an image; a carriage where the recording head is provided, the carriage being configured to reciprocate in a direction orthogonal to a sheet transport direction; a transport unit disposed upstream of a print area in the sheet transport direction, the transport unit being configured to intermittently transport a sheet to the print area; a transport control unit configured to control the transport unit; a platen guide plate; a suction unit configured to suction the sheet onto the platen guide plate; and a control unit.

Abstract: A sheet feeding device comprises a sheet feeding roller, having a first circumferential section and a second circumferential section, configured to rotate in a direction from the first circumferential section to the second circumferential section; and a pressure plate provided apart from the sheet feeding roller and configured to mount thereon a recording sheet stack having recording sheets ranging from a maximum number to a minimum number. The first circumferential section includes a first contact point for contacting, when the sheet feeding roller is rotated, a leading top edge of the recording sheet stack having the maximum number of recording sheets; and a second contact point for contacting, when the sheet feeding roller is rotated, a leading top edge of the recording sheet stack having the minimum number of recording sheets.

Abstract: A disclosed image forming apparatus includes a carriage on which a recording head is mounted that has a nozzle array where plural nozzles for ejecting droplets are arranged, the carriage being configured to be moved in a direction orthogonal to a nozzle arrangement direction; a transport belt facing the recording head and configured to transport a sheet; a print pattern forming unit configured to form a print pattern on the transport belt by causing at least the nozzles at opposing ends of the nozzle array to eject the droplets onto the transport belt while stopping the carriage; a reading unit configured to read the print pattern; a measuring unit configured to measure print positions of plural points of the print pattern in a direction orthogonal to the nozzle arrangement direction; and a detecting unit configured to detect an inclination of the recording head.

Abstract: A disclosed image forming apparatus includes a carriage having a head for jetting droplets; a pattern forming unit configured to form, on a belt, a pattern used for detecting displacement of landing positions of the droplets; a reading unit configured to scan the belt before the pattern formation to output a first result, and scan the pattern to output a second result; a correcting unit configured to correct the displacement based on the second result; a frequency analyzing unit configured to calculate frequencies of the belt and amplitudes of respective frequency components based on the first result; and a peak frequency calculating unit configured to calculate peak frequencies of the belt based on the frequencies of the belt and the amplitudes of the frequency components, the peak frequencies being frequency components whose amplitude exceeds a predetermined level. The pattern is formed at a frequency different from the peak frequencies.

Abstract: An image forming apparatus includes a carriage carrying a recording head configured to discharge a droplet. A landing position error detecting pattern is formed on a pattern forming member. Based on a result of reading the landing position error detecting pattern, a landing position error of the droplet discharged by the recording head is corrected. Either a first pattern or a second pattern is selected as the landing position error detecting pattern, depending on a surface condition of the pattern forming member. The first pattern produces a relatively small amount of specular reflection compared with diffused reflection, while the second pattern produces a relatively large amount of specular reflection compared with diffused reflection, upon irradiation with light.

Abstract: A side wall surface of a carriage is disclosed with two first projection parts and a second projection part that define the inclination of a reflective optical sensor in its vertical direction. The two first projection parts are arranged at the same height position with a detection surface as a reference, and the second projection part is arranged at a position higher than the first projection parts with the detection surface as the reference. The second projection part has a first part higher in position from the side wall surface of the carriage than the first projection parts and has a second part lower in position than the first part. The second part has a screw hole into which a clamping member for fixing the reflective optical sensor to the second part is tightened.

Abstract: An image forming apparatus includes a recording head, a water-repellent transfer belt, a pattern formation controller, a read unit, and a detection unit. The recording head has a plurality of nozzles aligned in a given direction, and ejects droplets of a liquid therefrom. The pattern formation controller directs each of the plurality of nozzles to eject the liquid to form a detection pattern on the transfer belt. The detection pattern has multiple droplets ejected from each of the plurality of nozzles sequentially arranged and spaced apart from each other both in the given direction and in a direction orthogonal to the given direction. The read unit includes a light emitting element and a light receiving element, and reads the detection pattern to output a read result. The detection unit detects a defective nozzle according to the read result.

Abstract: A disclosed image forming apparatus for forming an image on a recording medium being conveyed includes: a recording head discharging droplets; a pattern forming unit forming an adjustment pattern for detecting displacement of landing positions of droplets on a water-repellent member, the adjustment pattern including a minimum block pattern for each detection item and being formed with plural droplets independent of one another; a reading unit including a light emitting unit projecting a light onto the adjustment pattern and a light receiving unit receiving a regular reflection light from the adjustment pattern; and a landing position correcting unit correcting the landing positions of the droplets discharged from the recording head based on a result of reading by the reading unit.