Brother Kogyo Kabushiki-kaisha

Hironori Hirata

Tasuku Sugimoto

Tsuyoshi Ohashi

Takuya Nagai

Shingo Itoh

Toru Tsuzuki

Koyo Yamamoto

Kazushi Shumiya

Masafumi Ito

Yasuhisa Ichikawa

Ryo Ito

Kohei Kanehara

Takayuki Tsuji

A brushless motor device including: a rotor; a stator including a first coil, a second coil and a third coil, first ends of which are Y-connected to each other; a motor driver including an inverter circuit including switching elements and configured to: switch ON and OFF states of each switching element of the inverter circuit, wherein by switching the ON and OFF states of each switching element of the inverter circuit, the motor driver is configured to switch an energization time period from a first time period in which current is caused to flow from the first coil to the third coil to a second time period in which current is caused to flow from the second coil to the third coil and set both voltages of second ends of the second coil and the third coil to a power supply voltage during the second time period.

Brushless motor device, image forming apparatus, and control method for controlling brushless motor

A brushless motor device configured to: determine a first upper limit of a current value which flows through a coil when a rotation speed of a rotor is accelerated from a first speed to a second speed, wherein, in a case where the current value of the first upper limit flows through the coil when the rotor is rotated at the second speed, a first time period, which is from a start of a non-energization time period of the coil until an induced voltage reaches a threshold value, is longer than a second time period, which is from the start of the non-energization time period until a counter-electromotive voltage becomes zero; and change switching of each switching element of an inverter circuit by using a second upper limit greater than the first upper limit and the first upper limit.

An image forming apparatus includes a controller, wherein the controller execute first control of controlling a rotational frequency of the motor based on a light receiving signal, wherein, when the target rotational frequency changes from a first rotational frequency to a second rotational frequency that is lower than the first rotational frequency, the controller executes speed change control of: stopping execution of the first control; and changing a rotational frequency of the motor, and non-lighting period change control of changing the non-lighting period in the lighting control from a first non-lighting period corresponding to the first rotational frequency to a second non-lighting period corresponding to the second rotational frequency, and the controller starts the first control in response to satisfying a condition where the deflection period of the mirror obtained based on a position signal of a rotor of the motor is longer than the second non-lighting period.

Image forming apparatus and method of controlling image forming apparatus including exposure lighting and mirror rotation control

In a brushless motor apparatus, a brushless motor has a rotor and Y-connected coils, and a controller has an inverter circuit selectively driving the coils. The controller detects an induced voltage generated in a specific coil which is not driven by the inverter circuit while the rotor rotates. The controller acquires a positional signal of the rotor on a basis of a timing at which the induced voltage reaches the reference value. The timing is obtained through comparison between the detected induced voltage and a reference value. The controller switches a coil driven by the inverter circuit on a basis of the positional signal, and sets a mask period on a basis of a result of comparison between voltage of the specific coil and a coil other than the specific coil. The comparison between the induced voltage and the reference value is not executed in the mask period.

Brushless motor apparatus setting mask period on the basis of comparison between voltage of specific coil and voltage of coil other than the specific coil

In the image processing device, a power supply unit outputs a drive voltage. The control unit is driven by the drive voltage and control the image processing unit. The monitoring unit performs a monitoring operation to determine whether the receiving unit receives the operation instruction. A monitoring unit outputs an activation instruction to the voltage conversion unit when the monitoring unit determines that the receiving unit receives the operation instruction. In response to the activation instruction from the monitoring unit, a voltage conversion unit performs a voltage conversion operation for converting a voltage applied by an external power source to the drive voltage. The voltage generating unit generates a control voltage based on a voltage applied by the external power source and applies the control voltage to both the monitoring unit and the voltage conversion unit.

Image processing device having voltage generating unit outputting control voltage

An image forming apparatus includes: a light source; a polygon mirror; a brushless motor rotating a rotary polygon mirror; a light receiver configured to receive the light beam reflected by the polygon mirror; and a controller configured to perform driving control; detect a value related to an induced voltage; and perform a phase switching process. In a start-up period, the controller performs a control switching process of performing switching from rotation speed control based on the induced voltage to rotation speed control based on the light receiving timing of the light beam in a specific range in which a length from a start timing of an interruption period of the power to a timing when the detected value reaches the reference value does not become shorter than a length of a reference-disabled period.

Image forming apparatus, method of controlling image forming apparatus, and storage medium

A brushless motor has a rotor and a stator, the stator having coils corresponding to respective phases of the brushless motor. A polygon mirror has a plurality of mirror surfaces and is configured to rotate together with the rotor. When executed by the processor, the instructions cause the processor to: detect first timing at which the light sensor receives a light beam emitted from the light source and reflected by one of the plurality of mirror surfaces when the rotor is rotating; acquire first information identifying a relationship between the first timing and second timing at which an inductive voltage reaches a particular reference value, the inductive voltage being generated in at least one coil in a non-energization state due to rotation of the rotor; and perform a phase switching control of the brushless motor based on the first timing and the first information.

Image forming apparatus

A light source is provided in the casing and emits a light beam for forming an image. A first sensor receives the light beam emitted by the light source and outputs a light reception signal. A cover opens and closes relative to the casing. A shutter prevents the first sensor from receiving the light beam when the cover is at an open position, and allows the first sensor to receive the light beam when the cover is at a closed position. A controller is configured to: execute a lighting process of lighting the light source; execute a first determining process of determining whether the light reception signal is outputted from the first sensor, in response to the lighting process; and determine that the cover is at the open position upon determination in the first determining process that no light reception signal is outputted.

An image forming apparatus includes a control unit performing a first rotation control process of switching on and off current-supplying in accordance with a change in a first deviation between a first rotation speed of a brushless motor and a target speed regardless of a change in an integrated value of the first deviation; a second rotation control process of calculating an integrated value of a second deviation between a second rotation speed of the brushless motor and the target speed, and switching on and off the current-supplying in accordance with a change in the second deviation and a change in the integrated value of the second deviation; and a rotation control switching process of switching to the second rotation control process when it is determined that the first deviation has entered a prescribed range during the first rotation control process.

A processing apparatus includes a photosensor, a processing unit and a control unit. The control unit detects a light receiving signal output from the photosensor during a first light emission period and obtains a first detection result, and makes first determination based on the first detection result by determining whether the processing unit can execute a function. The control unit detects the light receiving signal after a waiting period and obtains a second detection result. The control unit makes second determination based on the second detection result by determining whether the processing unit can execute the function. The control unit makes the second determination in a second mode that requires small consumption power, and according to determination in the second determination in the second mode that the processing unit can execute the function, the control unit keeps the second mode and makes the first determination.

Processing apparatus capable of switching operation mode and computer readable device

Since signal transmittance adjustment devices that can suppress transmittance of a receiving signal to a DSP as a receiving processing device from an antenna for reception and a signal transmittance control device configured to control the signal transmittance adjustment devices so that the transmittance of the receiving signal to the DSP from the antenna for reception is suppressed at least when a transmission signal including a modulation signal is transmitted from an antenna for transmission are provided, occurrence of a trouble in which a head portion of a reply signal is crushed by a wrap around signal from a transmission side can be suitably prevented, and particularly, favorable communication can be realized at start of a response from a RFID tag. That is, an apparatus for communicating with a RFID tag that can suitably suppress an influence of a transient response can be provided.

Signal processing unit

There is provided a radio-frequency communication device that can sufficiently eliminate a leakage signal from a transmission side included in a received signal. The communication device includes a cancel amplitude controlling unitselectively suppressing supply of a cancel signal to a cancel signal synthesizing unit, a received-signal terminating unitselectively terminating a received-signal input terminal, a signal strength detecting unitdetecting a signal strength, a memory unitstoring a signal strength detected by the signal strength detecting unit, a signal strength comparing unitcomparing a plurality kinds of signal strengths read out from the memory unit, and a cancel signal controlling unitcontrolling an amplitude and/or a phase of the cancel signal based on a result of the comparison by the signal strength comparing unit. Thus, suppressing the cancel signal by the cancel amplitude controlling unitenables accurate detection of a strength of the received signal, as well as terminating the received signal by the received-signal terminating unitenables accurate detection of a strength of the cancel signal.

Growing community of inventors

Nagoya, Japan

Hironori Hirata