Abstract: The present invention provides a sheet conveying apparatus, and an image reading apparatus and an image forming apparatus having such a sheet conveying apparatus, in which skew correction of a sheet can be effected with high accuracy. A sheet convey means is provided at an upstream side of a skew correction means for correcting skew-feed of a sheet, and the sheet convey means is shifted by a shift means in a direction substantially perpendicular to the sheet conveying direction. A control means drives the shift means to shift the sheet convey means pinching the sheet to be skew-corrected by the skew correction means by a distance corresponding to a sheet skew amount on the basis of sheet skew amount information from a sheet skew amount detection means for detecting a skew amount of the sheet, thereby shifting the sheet in a skew correction direction.

Abstract: An inverter-control device includes a subtractor for detecting an error between a waveform of a reference current signal generated in synchronization with a waveform of an inverter output current signal and the inverter output current signal, a delay portion for delaying by a prescribed time period a signal obtained by amplifying and removing high frequency component by filtering the error, an error waveform integrating portion for integrating the delayed signal f' output from delay portion, a proportional control portion for amplifying the error, and an adding portion for adding an error amplified signal output from the proportional control portion and an inverter driving waveform pattern output from the error waveform integrating portion.

Abstract: An object of the present invention is to improve an efficiency in using bins in a sorter of an image forming system, to which a plurality of personal computers are connected. If the number of the receptacles appointed in accordance with the receptacle appointment command or the number of sets of sheets to be sorted is larger than the number of empty receptacles, offset sorting is performed in which the position, at which the recording sheets are received, is shifted in the same receptacle. If the appointed number of the receptacles or the number of sets of sheets to be sorted is smaller than the number of empty receptacles, a normal sorting process is performed in such a manner that the bins are allotted in accordance with the position of the bins appointed with the command for appointing receptacles or the number of sets of sheets to be sorted.

Abstract: A copying apparatus includes a first cassette for stacking recording sheets each having a protruding portion, a second cassette for stacking recording sheets having no protruding portion, a detecting unit for detecting a protruding portion of an original to be copied, and a copy unit for copying an image of an original onto the recording sheet fed from the first cassette in the case where the protruding portion of the original is detected by the detecting unit and for copying the image of the original onto the recording sheet fed from the second cassette in the case where the protruding portion of the original is not detected by the detecting unit.

Abstract: A pulse width of a pulse train signal used for PWM (pulse width modulation) control is monitored. When a variation of the pulse width substantially disappears within a specified time, it is determined that an operating point on an output characteristic curve of a photovoltaic array is located on the open-circuit voltage side of a maximum power point. When the variation of the pulse width does not disappear after the elapse of the specified time, it is determined that the operating point is located on the short-circuit current side of the maximum power point. Based on the determination result, the inverter control is performed such that the operating point follows the maximum power point.

Abstract: In a method of controlling an inverter for adjusting a periodic inverter output waveform to a desired periodic waveform, an error waveform pattern between an inverter output waveform of the present prescribed period and a desired periodic waveform generated in synchronization with the prescribed period is formed, and the error waveform pattern is added to an inverter driving waveform pattern in the last prescribed period, whereby an inverter driving waveform pattern is updated.

Abstract: A pulse train pulse-width modulated by PWM control using a sine-wave signal and a carrier signal is inverted alternately in positive-negative polarity. With a high-frequency AC signal obtained by the inversion, a primary side of a transformer for insulating input and output from each other is excited. This arrangement makes it possible to employ a high-frequency transformer which has a capacity ratio of about 1/30 and a weight ratio of about 1/20 relative to a commercial-frequency transformer, instead of using it. Thus, an inverter apparatus can be reduced in size and weight as compared with the system using the power-frequency transformer. A sine-wave AC waveform with substantially less distortion similar to the waveform output by the conventional PWM control can be obtained with a simple construction.

Abstract: This electric power supply system includes an air conditioner serving as load, a solar photovoltaic cell for supplying power to the air conditioner, and a system power control circuit and further including a commercial power source for use in combination with the solar photovoltaic cell for supplying additional power when insufficient, power is supplied from the solar photovoltaic cell to the air conditioner. In an operation state of the air conditioner, the system power control circuit operates to regulate an operating point of the solar photovoltaic cell and variably regulate the supplied power from the solar photovoltaic cell while comparing required power of the air conditioner with the supplied power from the solar photovoltaic cell.

Abstract: A driving circuit for an inverter microwave oven which includes a push-pull voltage type inverter circuit having two sets of switching element groups each provided with more than two switching elements connected in parallel to each other for switching the D.C. current supplied from a D.C. power source, a control device arranged to set a period for simultaneously turning OFF the two sets of switching element groups and to alternately turn ON the switching element groups by the same duty cycle, a step up transformer supplied, at its primary winding having a center tap, with A.C. current from the inverter circuit, and a voltage doubler rectifier circuit connected to a secondary winding of the step-up transformer for supplying electric power to a magnetron through a capacitor.