Abstract: An image processing apparatus includes a solenoid, a power supply switch element, a control device, a current value integrator circuit, a state determination circuit, and a cut-off circuit. The current value integrator circuit outputs an integral signal that increases in level, in response to an integral value of an operation current, when the operation current is conducted to the solenoid, and otherwise decreases in level. The state determination circuit maintains a state determination signal in an active state when the level of the integral signal exceeds a maximum level. The cut-off circuit conducts the operation current when the state determination signal in a negative state is input to a power supply line that extends to a circuit between the power supply switch element and the solenoid, and cuts off the operation current when the state determination signal in the active state is input to the power supply line.

Abstract: A control unit for a copying machine is equipped with a first rotation speed detecting unit for detecting a first rotation speed as a rotation speed of a polygon mirror; a switching judging unit for judging whether the first rotation speed reaches a value equal to or higher than a first switching speed set in advance; and a driving control unit for causing a second motor to start driving of a photoconductive drum, while causing a first motor unit to stop driving of polygon mirror for a mirror stop period set in advance, in the case that the switching judging unit judges that the first rotation speed reaches a value equal to or higher than the first switching speed, and, after the mirror stop period is over, causes the first motor to restart driving of the polygon mirror.

Abstract: A motor is equipped with a magnetic-flux detector, which detects magnetic fluxes from magnets of the motor. A position signal converter finds a position of the motor using a value detected by magnetic-flux detector. A speed controller throws the motor in sine wave drive using the detected motor position.

Abstract: A motor is equipped with a magnetic-flux detector, which detects magnetic fluxes from magnets of the motor. A position signal converter finds a position of the motor using a value detected by magnetic-flux detector. A speed controller throws the motor in sine wave drive using the detected motor position.

Abstract: A sheet post-processing apparatus having a sheet tray, a sheet transportation path for guiding a sheet into the sheet tray, a bypass path bypassing a part of the sheet transportation path for guiding a sheet into the sheet tray, a post-processing mechanism for performing a post-processing operation on one set of sheets retained in the sheet tray, and a sheet transportation mechanism for feeding the sheet into the sheet tray. During the post-processing operation performed on the one set of sheets previously fed into the sheet tray, the first sheet of the next sheet set is once stopped in one of the transportation path and the bypass path, and the second sheet of the next sheet set is introduced into the other of the bypass path and the transportation path. Upon completion of the post-processing operation performed on the one sheet set, the first and second sheets of the next sheet set are fed into the sheet tray.

Abstract: A torque current component and an exciting current component of primary AC currents which are supplied to a stator of a three-phase induction motor are commanded independently of each other in accordance with a command rotational angular velocity and a rotational angular velocity of the three-phase induction motor rotating an agitator, and the rotational angular velocity of the three-phase induction motor is controlled by changing the magnitude and frequency of each of the primary AC currents. Furthermore, a test operation is carried out by giving the command angular velocity so as to make constant the angular velocity of the motor, and the laundry amount is estimated corresponding to an output torque of the motor in the test operation.

Abstract: A method for readily measuring each motor parameter with high precision, with an induction motor at rest, and an apparatus for controlling the induction motor using these motor parameters are provided. The induction motor is set to a single-phase feed state or a feed state equivalent to that state. First, a stator resistance is measured from a current value and a voltage value at the time when a direct current command is given. Then, the current command of a current having an appropriately high frequency and a known current differential value is given to find a rotor resistance and a leakage inductance from current values and voltage values at two different times and the previously obtained stator resistance value. Then, the current command of a sine wave current having an appropriately low frequency is given to find a mutual inductance using the current value and the voltage value at the time. These measured values are used for a slip frequency operation and a speed estimation operation.

Abstract: This invention relates to an image forming apparatus provided with a punching unit and a paper refuse collecting box (container). The apparatus has a controller provided with a counter and monitor. The counter counts the total number of binder holes formed in paper by a punching operation by multiplying the number of sheets of paper to be punched by the punching unit with the number of binder holes formed in one sheet of paper that is designated by an operator. The monitor converts the total number of binder holes calculated by the counter into the amount of paper refuse accumulated in the container each time the punching operation is finished, while integrating the amount of paper refuse accumulated in the container. When it is judged that the integral value exceeds a predetermined maximum value, the controller causes a display device to display the necessity of emptying the container.

Abstract: A control system for an induction motor of the present invention independently commands the torque current component and the exciting current component of a stator current group supplied to the stator of an induction motor so as to feed-back control the amplitude and phase of the stator current group. The torque current component is commanded to control the output torque of the induction motor in correspondence with the output of a steering force sensor for detecting the steering force. According to an electric power steering apparatus using an induction motor controlled by the control system, a permanent magnet is not used for the motor so additional equipment such as a clutch is not required. Consequently, the structure can be simplified and the size of the unit can be reduced. Further, manual steering operation can be performed in the case of failure.

Abstract: A control system for an induction motor of the present invention independently commands the torque current component and the exciting current component of a stator current group supplied to the stator of an induction motor so as to feed-back control the amplitude and phase of the stator current group. The torque current component is commanded to control the output torque of the induction motor in correspondence with the output of a steering force sensor for detecting the steering force. According to an electric power steering apparatus using an induction motor controlled by the control system, a permanent magnet is not used for the motor so additional equipment such as a clutch is not required. Consequently, the structure can be simplified and the size of the unit can be reduced. Further, manual steering operation can be performed in the case of failure.

Abstract: In an electrophotographic apparatus, densities of toner images of a light reference mark and a dark reference mark are detected by a density sensor, and input voltages such as an illumination power source voltage and an electrostatic charge voltage are varied by small values on the basis of a difference between detected densities and an aimed density, the small values are determined on the basis of a predetermined qualitative model. Subsequently, a line width of the toner image of a reference mark having a striped pattern is detected by a line width sensor and a developer bias voltage is varied by a small value in a similar manner as mentioned above.