Abstract: Paper physical property detecting device includes a first detector that measures a sheet of paper (hereinafter, merely referred to as a paper) made to stop temporarily on a conveyance path and acquires a first value corresponding to a first physical property, a second detector that measures a paper while conveying the paper on the conveyance path and acquires a second value corresponding to a second physical property with regard to a physical property different from the first physical property; and a corrector that corrects the first value on a basis of the second value and creates post correction data.

Abstract: An image forming device includes: a transfer unit transferring a toner image to a sheet; a resistance measurement member disposed on the upstream side in a sheet carriage direction of the transfer unit and for measuring resistance of the sheet; a charge elimination member disposed between the transfer unit and the resistance measurement member in the sheet carriage direction; a first voltage applying unit applying voltage for resistance measurement to the resistance measurement member; and a second voltage applying unit applying voltage of reverse bias of the voltage for resistance measurement to the charge elimination member. The width of a charge elimination region by the charge elimination member is wider than that of a charged region by the resistance measurement member in a direction perpendicular to the sheet carriage direction. The absolute value of the voltage for charge elimination is smaller than that of the voltage for resistance measurement.

Abstract: An image forming apparatus forms an image on a sheet, and includes: a rotator used to form the image; a motor that drives the rotator rotationally; a current measurer that measures motor current flowing through a current-carrying path including a winding of the motor, at measurement timing that is timing after the motor starts up; a torque acquirer that acquires a torque value of the motor based on a measured value of the motor current; and a corrector that performs correction for cancellation of an amount of error based on one or both of a variation in characteristic corresponding to motor speed of the motor and a variation in characteristic corresponding to the motor current at the measurement timing, at the acquisition of the torque value by the torque acquirer.

Abstract: A motor controller includes: a velocity calculation unit for obtaining an angle ?(n), which shows a rotation position, and an angular velocity ?(n) of a rotor at a time point n; a compensation amount calculation unit for calculating a compensation angle ?? by which the rotor advances from the time point n to a (n+1)th control cycle (a control cycle starting from a time point n+1), based on an angular acceleration a(n) of the rotor, an angular velocity ?(n) of the rotor at the time point n and a time length T of the control cycle; and a PWM inverter for controlling a voltage to be applied to a coil such that a rotating magnetic field based on a rotation position of the rotor advanced by the compensation angle ?? from the rotation position of the rotor at the time point n is formed in the (n+1)th control cycle.

Abstract: An image forming device includes: a conductive roller that abuts an image carrier to rotate; a power supply circuit that applies voltage to the roller; a controller that controls the power supply circuit so as to apply the voltage to the roller over a predetermined detection period in a state in which the image carrier and the roller are rotated; a detection value acquirer that acquires a detection value acquired by the application of the voltage indicating a state of the image carrier in the detection period; and a state detector that detects a state of the image carrier on the basis of a plurality of acquired detection values, wherein a length of the detection period is set to a length at which both the numbers of rotations of the image carrier and the roller from a start of the detection period are integers.

Abstract: A controller for a sensorless permanent magnet synchronous motor having a rotor using a permanent magnet, the rotor rotating by a rotating magnetic field caused by a current flowing through an armature is provided. The controller is configured to apply a pulse voltage for generating a magnetic field vector for searching for the initial position to each of search sections obtained by dividing a target range, narrow down a target range in such a manner that a search section in which a largest amount of current flows through the armature by application of the pulse voltage is selected as a subsequent target range, and repeat the application processing and the narrow-down processing to estimate the initial position.

Abstract: A method for controlling a permanent magnet synchronous motor having a rotor using a permanent magnet, the rotor rotating by a rotating magnetic field caused by a current flowing through an armature is provided. The method includes: presuming, based on a target speed and an estimated speed that is an estimated value of a rotational speed of the rotor, whether or not a step-out occurs; correcting, when it is presumed that a step-out occurs, an estimated angle that is an estimated value of a position of magnetic poles of the rotor; and controlling, based on a post-correction estimated angle that is the estimated angle after the correction, a current flowing through the armature to cause the rotating magnetic field rotating at the target speed.

Abstract: A control method for a three-phase DC brushless motor including a rotor that includes a plurality of magnetic poles and that is rotatable, a stator that includes a plurality of magnetic field generation parts to generate a magnetic field to be a driving source of the rotor, and a sensor to detect a magnetic pole of the rotor which pole passes through a first position in the stator is provided, the method including: detecting in which the sensor detects a first magnetic pole of the rotor which pole passes through the first position; estimating, based on a result of the detection of the first magnetic pole, time until the first magnetic pole reaches a second position in the stator; and controlling the plurality of magnetic field generation parts in such a manner that a suitable magnetic field is generated when the first magnetic pole passes through the second position.

Abstract: A controller for a permanent magnet synchronous motor includes an estimating portion configured to determine an estimated value of a rotational speed of the rotor and an estimated value of a position of magnetic poles of the rotor based on a value of the current detected by the current detector and a parameter value indicating an interlinkage magnetic flux caused by the permanent magnet across the winding; a control unit configured to control the drive portion to cause the rotating magnetic field based on the estimated value of the rotational speed and the estimated value of the position of the magnetic poles; and a correction portion configured to correct the parameter value indicating the interlinkage magnetic flux based on correction information, the correction information being determined based on a temperature of the winding and a relationship between the temperature of the winding and a temperature of the permanent magnet.

Abstract: In a device for controlling a motor mounted on a system with different operation modes, a controller unit calculates an input value for the motor based on an output value of the motor and a target value depending on operation modes of the system, and instructs a driver circuit of the motor to apply the input value to the motor. An estimation unit estimates an amount of rise in temperature of the motor by applying the input value for the motor to a thermal model of the motor. A notification unit compares a value estimated by the estimation unit with a threshold value. When the estimated value exceeds the threshold value, the notification unit sends a request for change of operation mode to the system.

Abstract: An image forming apparatus includes: a photosensitive member rotated in a predetermined direction; a charging unit configured to charge a circumferential surface of the photosensitive member; a developing unit carrying a developer including toner and carriers, and including a developer bearing member configured to apply toner charged in a first polarity to the circumferential surface of the photosensitive member; a first voltage applying unit configured to apply a first voltage of the first polarity to the charging unit; a second voltage applying unit configured to apply a second voltage of the first polarity to the developer bearing member; a first voltage detecting unit configured to detect the first voltage; a second voltage detecting unit configured to detect the second voltage; and a controller, wherein the controller determines whether or not to make a second rate lower than a first rate according to the second voltage at a first timing.

Abstract: An antiferroelectric liquid crystal compound represented by the following general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are each independently selected from the group consisting of alkyl groups having from 3 to 18 carbon atoms, Rf is a lower alkyl group or a fluorinated lower alkyl group, (A) and (B) are each independently selected from the group consisting of 1,4-phenylene, 4,4'-biphenylene, and 2,6-naphthalene which may be substituted at least with a halogen atom, and * shows an asymmetric carbon atom.