Canon Kabushiki Kaisha

Yasukazu Maeda

Takuya Miyashita

Eijiro Ohashi

Nozomu Nakajima

Kiyoto Toyoizumi

An image forming apparatus includes a first motor that drives an image forming unit and that includes a motor of a type that lacks a sensor for detecting a rotational position of a rotor of the first motor, and a second motor that drives a fixing unit. A control unit causes rotational driving of the second motor to start after completion of a first operation for detecting a rotational position of the first motor or a second operation for causing the rotor to rotate to a predetermined rotational position, such that an execution timing of the first operation or the second operation and a timing at which rotational driving of the second motor is started do not overlap.

Image forming apparatus

A motor control apparatus includes: an excitation unit configured to excite a plurality of excitation phases of each of a plurality of motors that include first to Nth motors and a control unit configured to control the excitation unit so as to perform detection excitation processing for sequentially exciting the plurality of excitation phases for each excitation cycle during each excitation period, regarding each of the first to Nth motors, and thereby detect rotor positions of the respective first to Nth motors. When detecting rotor positions of the respective first to Nth motors, the control unit delays a start timing of the detection excitation processing of at least one motor out of the first to Nth motors relative to a start timing of the detection excitation processing of another motor by a period shorter than the excitation period.

Motor control apparatus for detecting rotor positions of a plurality of motors and image forming apparatus

A motor control apparatus includes an excitation unit and a control unit. The excitation unit includes switching elements connected to a power supply and to different motor coils. The excitation unit excites an excitation phase targeted for excitation among motor excitation phases by the control unit driving the switching elements. When the excitation phases are excited, the control unit drives, in a first time period and based on a first PWM signal, a first switching element connected to a first phase coil corresponding to a first phase of the excitation phase targeted for excitation and, in a second time period and based on a second PWM signal, drives a second switching element connected to a second phase coil corresponding to a second phase of the excitation phase. The control unit controls outputting a duty ratio of the second PWM signal to the second switching element in the second time period.

Motor control apparatus and image forming apparatus

A motor control apparatus excites an excitation phase targeted for excitation among a plurality of excitation phases of a motor. The motor control apparatus, in a state in which a rotor of the motor is stopped, excites an excitation phase corresponding to a stop position of the rotor among the plurality of the excitation phases, and measures a physical quantity which changes in accordance with an inductance of at least one of a plurality of coils configuring the plurality of excitation phases. The motor control apparatus estimates a temperature of the rotor from a measurement value of the measured physical quantity, and decides a parameter value for control of the motor based on the estimated temperature.

A heating apparatus including: a first load; a first switch element configured to switch between supply of power from an AC power source to the first load and shut-off of power supply; a second load; a second switch element configured to switch between supply of power from the AC power source to the second load and shut-off of power supply; and a control unit configured to control the first and the second switch elements to prevent power from being supplied to both of the first load and the second load. The first switch element has the T1 terminal connected to one end of the first load, and the T2 terminal connected to the AC power source. The second switch element has the T2 terminal connected to one end of the second load, and the T1 terminal connected to the AC power source.

Heating apparatus configured to prevent power from being supplied to both of first load and second load, and image forming apparatus

A motor control apparatus includes: an excitation unit configured to excite a plurality of excitation phases of a motor; a measurement unit configured to measure a physical amount that changes according to an inductance of at least one of a plurality of coils that make up the plurality of excitation phases, when each of the plurality of excitation phases is excited; and a determination unit configured to determine a type of the motor based on measurement values of the physical amount measured by the measurement unit when each of the plurality of excitation phases is excited.

Motor control apparatus for determining motor type and image forming apparatus

A motor control apparatus includes: an excitation unit configured to excite a plurality of excitation phases of a motor; a measurement unit configured to measure a physical amount that changes according to an inductance of a plurality of coils that make up the plurality of excitation phases when the plurality of excitation phases are excited; and a control unit configured to control the excitation unit to excite the plurality of excitation phases sequentially, determine a first excitation phase by comparing a measurement value measured by the measurement unit in excitation of each of the plurality of excitation phases with a first threshold, and determine that a rotational position of a rotor of the motor is a rotational position at which the rotor stops when the first excitation phase is excited. The first excitation phase is determined, the control unit stops excitation.

A period in which an adjustment unit adjusts a driving current such that the light irradiation unit emits a third light emission amount of light is switched to a period in which a light irradiation unit emits a second light emission amount of light, and the period in which the light irradiation unit emits the second light emission amount of light is switched to a period in which the light irradiation unit emits a first light emission amount of light.

Image forming apparatus adjusting driving current for emitting light

A printed circuit board of which a part of at least one side of the circuit board is divided by a division process including a first area where a component is placed, and a divided portion where the component is not placed, and which includes the part of the at least one side. Silk is applied to an entire area of the divided portion.

Printed circuit board, exposure device having printed circuit board, and image forming apparatus

An adjustment includes a first current adjustment for adjusting a first current Idrv by supplying a superimposed current of the first current Idrv and a second current Ib to an LD, and a second current adjustment for adjusting the second current Ib by supplying the second current Ib to the LDwithout supplying the first current Idrv thereto. Upon reception of an image forming instruction, a control unit performs adjustment in order of the second current adjustment for the first time, the first current adjustment for the first time, the second current adjustment for the second time, and the first current adjustment for the second time. An execution period of the second current adjustment for the first time is longer than an execution period of the second current adjustment for the second time.

Image forming apparatus having controlled light emission using current adjustment

A light irradiating device causes a light source to emit light with normal emitted light quantity sufficient for adhering toner on a photosensitive member, on an image portion of the photosensitive member, and causes the light source to emit light with minute emitted light quantity sufficient for preventing toner from being adhered on the photosensitive member, which is smaller than normal emitted light quantity. The light irradiating device includes a determining unit to determine a reference value input to the light irradiating device. Minute emitted light quantity is set based on the reference value input to the light irradiating device. The determining unit determines the reference value to be input to the light irradiating device based on information of relationship between a predetermined reference value and the light quantity in the position of the photosensitive member when causing the light source to emit light, based on the predetermined reference value.

Growing community of inventors

Yokohama, Japan

Yasukazu Maeda