Konica Minolta, Inc.

Mita Industrial Co., Ltd.

Panasonic Corporation

Konica Minolta Business Technologies, Inc.

Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Hiroyuki Yoshikawa

Yuta Tachibana

Tetsuo Tomiyama

Yasushi Umeda

Daichi Suzuki

Yoshiki Shimomura

Shunsuke Hirano

Yuji Kobayashi

Sadao Tanigawa

Yasuhiro Koide

Harumitsu Fujimori

Kazumichi Yoshida

Hiroyuki Motozuka

Isao Watanabe

Teruhiko Fujikura

Munehiro Natsume

Kenichi Hayashi

Naoya Yosoku

Yukihiro Mori

Yasuhiro Ishihara

Yumiko Izumiya

Akihiro Hayashi

Katsuyuki Ikuta

Hitoshi Asano

Kosuke Sasaki

Mutsuto Oe

Yasuo Motegi

Yuichi Koike

Koichiro Tanaka

Naganori Shirakata

Hisashi Adachi

Takenori Sakamoto

Tatsuya Eguchi

Masakatsu Maeda

Hiroshi Kusumoto

Toshikazu Higashi

Tomonobu Tamura

Takayuki Tsukizawa

Satoshi Miyajima

Yoshinori Shirakawa

Akimasa Ishikawa

Kouei Cho

Yoshifumi Ishii

Takaki Kato

Makoto Shimazoe

Kazuto Hori

Yasuo Koyanagi

Tatsuto Oka

Toshimitsu Takakura

Naoki Ohashi

Yoshihiko Sezukuri

Tomohiko Sakao

Yasushi Hieno

Shintarou Ono

Iwao Fujii

A sheet characteristic detection device includes: a detector that is disposed on a sheet ejection path through which a sheet is ejected and that detects an electrical resistance value of the sheet; and a charge neutralizer that is disposed on a downstream side of the detector on the sheet ejection path and that neutralizes electric charge on the sheet.

Sheet characteristic detection device, image forming system including the same, and image forming apparatus

A rotation detector includes a motor, a current detector and a hardware processor. The motor includes coils of two or more phases and a rotor. The current detector detects currents flowing in coils of at least two phases among the coils of two or more phases. The hardware processor estimates an initial position of the rotor based on current values of the currents detected by the current detector to start the motor, controls an energization pattern on the phases to rotate and start the motor based on the estimated initial position, and determines whether the rotor stops or is rotating before completing the estimation of the initial position.

Rotation detector and image forming apparatus

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.

Paper physical property detecting device, image forming apparatus, paper physical property detecting method, and computer readable recording medium storing control program

A motor controller estimates an initial position of a magnetic pole of a rotor of a brushless DC motor in an inductive sensing scheme. The motor controller controls a drive circuit to apply an AC voltage to a stator winding at a first energization angle, and subsequently to apply an AC voltage to the stator winding at a second energization angle before a residual current flowing through the stator winding returns to zero. At each energization angle, the motor controller corrects a peak value of a current in the stator winding based on the residual current detected immediately before a voltage is applied to the stator winding or at a time when voltage application to the stator winding is started. Based on the corrected peak value, the control circuit estimates the initial position of the magnetic pole of the rotor.

Motor controller and image forming apparatus

A control circuit of a motor control device estimates an initial magnetic pole position of a rotor using an inductive sensing scheme. When estimating the initial magnetic pole position, a drive circuit applies a voltage to a stator winding at each of L electrical angles (L&#x2265;5) while changing the L electrical angles. An absolute value of an electrical angle difference of the voltage applied to the stator winding between an i-th time (2&#x2264;i&#x2264;L) and an i&#x2212;1st time is 180&#x2212;360/L degrees or more and 180+360/L degrees or less. An absolute value of an electrical angle difference of the voltage applied to the stator winding between a 1st time for initial position estimation and a last time before starting initial position estimation is 180&#x2212;360/L degrees or more and 180+360/L degrees or less.

Motor control device, image forming apparatus, and method for estimating initial position of magnetic pole of rotor

In a motor control device that controls a sensorless-type motor, a controller estimates an initial magnetic pole position of a rotor of a motor by an inductive sensing scheme while sequentially setting a plurality of energization angles. At each of the set energization angles, the controller converts peak values of currents flowing through a plurality of phases of a stator winding into a first current component having an electrical angle that is equal to a corresponding one of the set energization angles and a second current component that is different in electrical angle by 90 degrees from the first current component, to correct the first current component based on the second current component. The controller estimates the initial magnetic pole position of the rotor based on the corrected first current component that is obtained at each of the set energization angles.

Motor control device, method of estimating initial position of magnetic pole of rotor, and image forming apparatus

In a motor control device in one embodiment, an initial position estimation unit estimates an initial position of a magnetic pole of a rotor of a motor in an inductive sensing scheme. At each of energization angles, the initial position estimation unit multiplies a &#x3b3;-axis current component I&#x3b3; corresponding to a peak value of a current flowing through a stator winding by each of a cosine value and a sine value of a correction angle obtained by correcting each of the energization angles. The initial position estimation unit estimates the initial position of the magnetic pole of the rotor based on a ratio between an integrated value of a multiplication result about the cosine value and an integrated value of a multiplication result about the sine value.

In a motor control device, when estimating an initial position of a magnetic pole of a rotor of a motor, a drive circuit continuously or intermittently applies a voltage to a stator winding at each of a plurality of energization angles while sequentially changing the energization angles, and at a voltage value and for an energization time period, the voltage value and the energization time period being set such that the rotor does not rotate. An initial position estimation unit calculates an estimated initial position of the magnetic pole of the rotor based on a phase angle of a trigonometric function curve that approximates a change of a &#x3b3;-axis current I&#x3b3; with respect to each of the energization angles. The trigonometric function curve has a cycle equal to one electrical cycle of the motor.

A control device of a permanent magnet synchronous motor that is a control device of a sensorless-type permanent magnet synchronous motor in which a rotor using a permanent magnet rotates by a rotating magnetic field caused by a current flowing in an armature includes: a driver that applies a voltage to the armature and drives the rotor; an initial position estimator that estimates an initial position which is a magnetic pole position of the rotor that is stopped; and a controller that controls the driver so as to apply a pulse train including a voltage pulse for searching the initial position for each of n angle positions dividing a search range of an electrical angle of 360 degrees to the armature, wherein the pulse train includes a first pulse and a second pulse.

Control device of permanent magnet synchronous motor and image forming device

A motor controller includes: a velocity calculation unit for obtaining an angle &#x3b8;(n), which shows a rotation position, and an angular velocity &#x3c9;(n) of a rotor at a time point n; a compensation amount calculation unit for calculating a compensation angle &#x394;&#x3b8; 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 &#x3c9;(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 &#x394;&#x3b8; from the rotation position of the rotor at the time point n is formed in the (n+1)th control cycle.

Motor controller, image forming apparatus and motor controlling method

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.

Controller for permanent magnet synchronous motor, and control method for estimating initial position of rotor

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.

Controller for permanent magnet synchronous motor, control method, and image forming apparatus

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.

Controller for permanent magnet synchronous motor, image forming apparatus, and control method

A demodulation section demodulates a received signal. A decoding section decodes an output from the demodulation section. A buffer temporarily stores a portion of the received signal. A header analyzing section gives the buffer timing at which demodulation and decoding of a payload of the received signal are initiated, on the basis of a result of combination of a plurality of header sequences included in a header of the received signal and results of processing of the demodulation section and the decoding section. An improved SNR is achieved by means of combination of the plurality of header sequences, so that an iterative decoding count used for decoding the header become smaller.

Wireless communication device and method to detect header information errors

A storage which, in operation, stores a first minimum value and a second minimum value each time a plurality of data are input. Round-robin comparison circuitry which, in operation, makes a magnitude comparison among the plurality of data. First selection comparison circuitry and second selection comparison circuitry which, in operation, make a magnitude comparison between the first minimum value and each of the plurality of data and a magnitude comparison between the second minimum value and each of the plurality of data, respectively. Judgment circuitry which, in operation, judges a new first minimum value and a new second minimum value on the basis of a comparison result from the round-robin comparison circuitry and comparison results from the first and second selection comparison circuitry.

Decoder, minimum value selection circuit, and minimum value selection method

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Tokyo, Japan

Hiroyuki Yoshikawa