Abstract: A power converting apparatus includes a main inverter having a high-voltage DC power supply that operates at a low frequency employing SiC MOSFETs having a high withstand voltage exceeding 600 V and a sub-inverter having a low-voltage capacitor that operates through high-frequency PWM employing Si MOSFETs having a low withstand voltage. With AC sides of the main inverter and the sub-inverter connected in series, the power converting apparatus outputs AC power having a prescribed voltage waveform by adding voltages individually generated by the main inverter and the sub-inverter. Specifically, the SiC MOSFETs are used only in the main inverter of which devices are required to have a high withstand voltage and the Si MOSFETs are used in the sub-inverter of which devices may have a relatively low withstand voltage, whereby conduction loss is reduced with an inexpensive circuit configuration.

Abstract: A printing apparatus includes a printhead configured to array a nozzle array in which a plurality of nozzles for discharging ink are arrayed in the first direction, a reading unit configured to read, as a plurality of luminance values aligned in a nozzle arrayed direction, an inspection pattern formed by discharging ink from the plurality of nozzles of the printhead, a calculation unit configured to calculate a plurality of difference values each by calculating a difference between two luminance values spaced apart by a predetermined number of luminance values, and an analysis unit configured to analyze an ink discharge state in the plurality of nozzles based on the plurality of difference values.

Abstract: A printing method is performed on a plurality of inkjet print heads to which humidified air is supplied to retain the humidity in the print heads. Ink colors for the plurality of heads are arranged in a sequence corresponding to ink characteristics. The plurality of print heads is divided into groups, with one of the groups being subjected to preliminary ejection on a sheet. The other print head group not subjected to preliminary ejection is located in a more upstream area with respect to a conveyance direction of the sheet.

Abstract: A power conversion device includes an inverter that drives a motor; a fin that cools down the inverter; a first core including a through hole that allows passage of a positive side conductor that connects a power supply system and the inverter and a negative side conductor that grounds the inverter; a ground conductor that grounds the fin; a ground conductor that grounds a motor yoke via a capacitor; and a ground conductor including one end that is connected to the negative side conductor or the ground conductor and the other end that is grounded.

Abstract: A printing apparatus includes a plurality of inkjet print heads to which humidified air is supplied to retain the humidity in the print heads. Ink colors for the plurality of heads are arranged in a sequence corresponding to ink characteristics. The plurality of print heads are arranged in a sequence such that a print head configured to eject ink characterized by having a larger amount of volatile components evaporated within a predetermined time is located in a more upstream area.

Abstract: Three-phase windings 11-13 and 21-23 of a first common-mode transformer 1 and a second common-mode transformer 2 are connected in series through connecting lines 8r-8t, respectively. The windings 11-13 are connected to an unillustrated AC power supply by connecting lines 91r-91t. The windings 21-23 are connected to a three-phase motor by connecting lines 93r-93t and through a converter and an inverter which are unillustrated. A winding 14 for common-mode voltage detection detects high-frequency leakage currents flowing through the connecting lines 91r-91t as a common-mode voltage V1, and an output voltage V2 obtained by voltage amplification by a voltage amplifier 3 is applied to a winding 24 for common-mode voltage application in such a manner that the output voltage V2 works in generally the same direction as the common-mode voltage V1, thereby canceling out the high-frequency leakage currents through the windings 21-23.

Abstract: An apparatus includes a printing unit configured to eject ink from a print head onto a sheet conveyed in a direction to perform printing on the sheet; a conveying unit configured to be provided on a downstream side of the print head in the direction, and configured to include a rotating member in contact with the sheet; and a reading unit configured to read a surface of the sheet on a downstream side of the rotating member in the direction, in which information on ink adhesion to the rotating member is obtained based on a result read by the reading unit.

Abstract: A process of detecting a defective recording element and a process of correcting the defective recording element are performed with appropriate processing loads. When the detection process and the correction processes are performed with small loads, for example, at a time of recording, a resolution used for reading an inspection pattern is set lower than that set in a case where the processes can be performed with small loads, for example, at down time before recording. The reading resolution to be set may be determined by an apparatus in accordance with a processing load or may be arbitrarily determined by a user.

Abstract: A waiting time Ts is decided on the basis of ink type information and ink feed amount information, referring to waiting time table A (Step 6). Along with this, a dried printing paper is carried to and stopped in a waiting area 9 (Step 7), a time period T is measured after stopping, and measurement processing in the next step is delayed until the time period T reaches the waiting time Ts. Then, when the time period T reaches the waiting time Ts, a measuring instrument 10 is used to measure a density of a patch printed on the printing paper (Steps 8 and 9).

Abstract: First windings of a first common mode transformer and second windings of a second common mode transformer are connected in series via connection lines. The windings are connected to an AC power supply via connection lines. The first windings are connected to a three-phase motor via connection lines, a converter, and an inverter. High-frequency leakage currents flowing in the connection lines are detected as a common mode voltage by a winding for common mode voltage detection. An output voltage is inputted via a filter to a voltage amplifier unit that amplifies the output voltage, and the amplified voltage is applied to a winding via a capacitor in substantially a same direction as a direction of the common mode voltage. As a result, leakage currents are reduced by induced voltages on the windings.

Abstract: The present invention provides a recording apparatus including recording heads each including a plurality of nozzle arrays that are arranged so as to overlap, wherein the width with which the overlapping portions of the recording heads for colors that are simultaneously used with a relatively high frequency overlap in an intersecting direction that intersects an array direction of nozzles is smaller than the width with which the overlapping portions of the recording heads for colors that are simultaneously used with a relatively low frequency overlap in the intersecting direction.

Abstract: A process of detecting a defective recording element and a process of correcting the defective recording element are performed with appropriate processing loads. When the detection process and the correction processes are performed with small loads, for example, at a time of recording, a resolution used for reading an inspection pattern is set lower than that set in a case where the processes can be performed with small loads, for example, at down time before recording. The reading resolution to be set may be determined by an apparatus in accordance with a processing load or may be arbitrarily determined by a user.

Abstract: The effects on an image are maximally decreased with respect to ejection by printing elements included in the low flow rate areas of a serial channel in an inkjet printing apparatus that uses a joined head in which multiple chips provided with multiple printing element arrays are disposed. For this purpose, print data is distributed to individual printing elements at a joining portion between two chips, such that fewer printing elements execute ejection operations on a printing element array A distanced farther from the center line of a base plate than a printing element array D nearer the center line. Doing so suppresses ejection by printing elements included in low flow rate areas which manifest near the turns of an ink channel, and reduces density defects due to ejection by such printing elements.

Abstract: An aspect of this invention is directed to efficiently sorting printed products into non-defective ones and defective ones even when a discharge failure occurs during the printing operation. In the aspect, two inspection patterns for detecting discharge failure are printed before and after a plurality of images. The inspection patterns are read to determine the type of discharge failure. Printed media are sorted based on whether it is determined that there is a continuous discharge failure, whether it is determined that there is an accidental discharge failure, or whether it is determined that the discharge is normal.

Abstract: The present invention provides a recording apparatus including recording heads each including a plurality of nozzle arrays that are arranged so as to overlap, wherein the width with which the overlapping portions of the recording heads for colors that are simultaneously used with a relatively high frequency overlap in an intersecting direction that intersects an array direction of nozzles is smaller than the width with which the overlapping portions of the recording heads for colors that are simultaneously used with a relatively low frequency overlap in the intersecting direction.

Abstract: An electric motor driving apparatus having a failure detection circuit includes: a bridge circuit driving an electric motor; a PWM control circuit generating voltage instruction for driving the electric motor; a PWM signal generation circuit generating a PWM signal; a DC current detection circuit detecting DC current of the bridge circuit; a phase current calculation circuit calculating output phase current of the bridge circuit, based on the DC current and PWM signal; and a failure detection circuit detecting failure of the DC current detection circuit. The failure detection circuit determines failure of the DC current detection circuit from the DC current detected values in a zero voltage period in which the high-potential-side arms of the bridge circuit are all ON and in a zero voltage period in which the low-potential-side arms are all ON.

Abstract: A printing apparatus conducts inspection associated with printing by changing a relative positional relationship between a line print head and a sheet feeding position for a sheet in a direction perpendicular to a direction in which the sheet is fed, forming an image on the sheet using the line print head a plurality of times, and reading the formed images using a reading unit.

Abstract: The present invention provides a recording apparatus including recording heads each including a plurality of nozzle arrays that are arranged so as to overlap, wherein overlapping portions of the recording heads for two different colors are separated from each other with a distance therebetween in an array direction of nozzles.

Abstract: When an overcurrent detection section detects an overcurrent, a control circuit performs ON-OFF control for switching devices each switchable between a forward direction and a reverse direction, in a mode in which a current having flowed is reduced, such that when the mode is a mode in which a current is passed through any of diodes, a switching device connected in parallel with the current-passed diode is turned ON. Thus, even when an overcurrent occurs, the current flowing in the diode connected in parallel with the switching device is reduced, and the diode is protected from being deteriorated or broken by the overcurrent.

Abstract: An AC-DC converter is provided which suppresses a harmonic current and improves power factor at low cost. Such an AC-DC converter includes a rectifier connected to an AC power supply via a reactor, capacitors connected in series across the output terminals of the rectifier, a first bidirectional switch having one end connected to one input terminal of the rectifier and the other end connected to a connecting point of capacitors, a second bidirectional switch having one end connected to the other input terminal of the rectifier and the other end connected to the other end of the first bidirectional switch, and a control circuit for actuating the first and second bidirectional switches during a half cycle of the AC power supply so as to control a voltage inputted to the rectifier to a desired output voltage.