An image recording apparatus, having a power source, a drivable device, a head, a motor, a carriage, a sensor, and a controller, is provided. In a recording process, the controller sets a limitation current calculated by subtracting a variable first driving current from an allowable current to the power source, controls the power source to supply the first driving current to the drivable device and simultaneously supply a variable second driving current not exceeding the maximum current to the motor, and when the controller determines, based on a signal output from the sensor, that a behavior of the carriage satisfies an error condition, on condition that the drivable device has completed a targeted conveying action, issue an error alert, and on condition that the drivable device has not completed the targeted conveying action, control the motor to cause the carriage to continue moving without issuing the error alert.

A printer is provided with a front linear guide rail, a front linear guide block, a rear linear guide rail, a rear linear guide block, and a carriage. The front linear guide rail extends in a first direction. The front linear guide block is configured to move along the front linear guide rail. The rear linear guide rail is provided in a second direction with respect to the front linear guide rail, and extends in the first direction. The rear linear guide block is configured to move along the rear linear guide rail. The carriage is fixed to the front linear guide block and the rear linear guide block. One of the front linear guide block and the rear linear guide block positions the carriage in the second direction, and the other positions the carriage in a third direction.

A position measuring device and a position measuring method for accurately measuring a position of a movable member using a plurality of linear scales are provided. The position measuring device comprises a first linear scale elongated in a first direction, a second linear scale elongated in the first direction and separated from the first linear scale, and a head structure including a first scale head and a second scale head that are spaced apart from each other, wherein the head structure reads the first linear scale or the second linear scale while moving in the first direction, wherein the first scale head and the second scale head are activated or deactivated opposite to each other.

A printer includes a head having nozzles, a carriage with the head mounted thereon, a carriage motor to move the carriage along a scanning direction, an encoder including a scale having reference marks formed thereon along a particular direction, and a sensor to detect the reference marks while moving relative to the scale along with movement of the carriage along the scanning direction, and a controller configured to perform liquid discharging to control the head to discharge liquid from the nozzles toward a recording medium while performing feedback control of the carriage motor based on velocity information such that the carriage moves at a target velocity along the scanning direction, the velocity information representing a carriage velocity based on detection results of the sensor, and interrupt the liquid discharging when the carriage velocity exceeds an overshoot threshold higher than the target velocity during the liquid discharging.

A liquid ejection apparatus includes a liquid ejection head, a sensor, a carriage, and a controller. The controller is configured to perform: setting a first sheet at a first printing position; printing an image on the first sheet while conveying the first sheet from the first printing position; determining whether an interval is more than a predetermined period; in a case where the interval is determined to be more than the predetermined period: causing the carriage to move in a first direction to a first detection position at which a second sheet is detected; and in response to detecting the second sheet, causing the carriage to move in the first direction to a first carriage position.

A printer including: (i) a guide device extending in a first direction; (ii) a carriage reciprocateable in the first direction, while being guided by the guide device; (iii) a recording head carried by the carriage; (iv) a feed device for feeding the recording medium in a second direction perpendicular to the first direction; (v) a flexible ink-supply tube for supplying ink to the recording head; and (vi) a carriage movement detector including an encoder strip which extends in the first direction. The ink-supply tube has a U-shaped body including a pair of arm portions extending in the first direction and spaced apart from each other in the second direction. The guide device, the ink-supply tube and the encoder strip are located on respective different positions in a third direction that is perpendicular to the first and second directions. The ink-supply tube has a part that overlaps with the guide device and the encoder strip as seen in the third direction.

An image forming apparatus includes a recording head and processing circuitry. The recording head includes a plurality of nozzles. The processing circuitry prints a reference adjustment pattern on a recording medium using a reference nozzle, which is one of the nozzles. When the recording medium is conveyed from the reference nozzle in a sub-scanning direction by a predetermined conveyance amount, the processing circuitry prints an adjustment pattern on the recording medium using a designated nozzle, which is apart by a predetermined distance with respect to a nozzle apart from the reference nozzle in the sub scanning direction by the predetermined conveyance amount. The processing circuitry detects the reference adjustment pattern and the adjustment pattern, computes a distance between the reference adjustment pattern and the adjustment pattern in the sub-scanning direction, and determines whether a standard deviation of the distance computed is equal to or larger than a predetermined value.

There is provided a motor driving system in which an encoder sensor is configured to move with a driven object with respect to an encoder scale and output an encoder signal. A controller is configured to control a motor based on the encoder signal, thereby controlling movement of the driven object. The controller estimates an obstructing area. In the obstructing area, the encoder sensor reads a part of the encoder scale where an obstacle is adhered. The controller calculates a control error of the motor in the obstructing area based on the encoder signal output after the encoder sensor passes through the obstructing area, and determines a compensation amount of a controlling input value input during a period while the encoder sensor passes through the obstructing area.

A printer includes: a liquid discharger configured to discharge a liquid onto a print target; a carriage configured to move the liquid discharger in a main scanning direction; a holder configured to hold the print target and relatively move the print target in a sub-scanning direction orthogonal to the main scanning direction to cause the print target to face the liquid discharger; and multiple height detectors at different positions in the sub-scanning direction, the multiple height detectors configured to detect the print target on the holder.

A carriage is configured to move by receiving driving force from a carriage motor. A recording head is mounted on the carriage. A controller is configured to: control a power supply to supply a first driving current to a drive target, the first driving current being variable; when a second driving current for driving the carriage motor does not exceed a limiting current, control the power supply to supply the second driving current to the carriage motor, the second driving current being variable, the limiting current being obtained by subtracting the first driving current from an allowable current of the power supply; and when the second driving current exceeds the limiting current, control the power supply to supply a limited second driving current to the carriage motor, the limited second driving current being obtained by cutting a part of the second driving current, the part exceeding the limiting current.