Canon Kabushiki Kaisha

Masaki Inagaki

Junya Kobayashi

Teruhiko Namiki

Takao Kawazu

Hideaki Hirasawa

Mitsunori Oshima

Toshiyuki Ichino

Yuji Fujiwara

A switching control device, in a case where the overload state is detected after the switching operation is started and before the output voltage reaches a target voltage, performs a first process of maintaining a state where the switching operation is stopped and, in a case where the overload state is detected after the output voltage reaches the target voltage, performs a second process of stopping the switching operation and, after a lapse of a first time, resuming the switching operation.

Power supply apparatus and image forming apparatus

A metal frame provides a ground potential. An image forming unit forms a toner image on a sheet. A fixing apparatus fixes the toner image on the sheet. The fixing apparatus comprises a heating element for generating heat by being supplied with power from an alternating current power source. An insulating layer covers the heating element. A conductive layer contacts the insulating layer and insulated from the metal frame. A tube-shaped member is heated by the heating element. A pressing member is arranged opposing the tube-shaped member and forms a nip portion in cooperation with the tube-shaped member. A capacitive element whose one end is connected to the metal frame and whose other end is connected to the conductive layer of the fixing apparatus.

Structure for electrically protecting fixing apparatus provided in image forming apparatus

A power supply apparatus including a switching element configured to supply or cut off electric power to a primary coil of a transformer by a switching operation, and a control unit configured to control the switching operation. The control unit is configured to perform intermittent control of repeating a switching period for performing the switching operation and a stop period for stopping the switching operation. In the switching period, when the control unit performs the switching operation a predetermined number of times, the switching period is transitioned to the stop period. In the stop period, when the control unit determines that a voltage output from a secondary coil of the transformer falls below a target voltage, the stop period is transitioned to the switching period. The control unit is configured to change the switching operation based on a length of the stop period.

A power supply apparatus includes a transformer including a primary coil, a secondary coil, and an auxiliary coil; a switching element connected in series to the primary coil; a first rectifying/smoothing circuit including a first diode and a first capacitor and configured to rectify and smooth a voltage induced in the auxiliary coil; a second rectifying/smoothing circuit including a second diode and a second capacitor, connected in parallel with the first rectifying/smoothing circuit, and configured to rectify and smooth the voltage induced in the auxiliary coil; and a controller configured to control the switching element. The controller is configured to detect the voltage induced in the auxiliary coil based on an output voltage of the first rectifying/smoothing circuit. A responsiveness of the second diode is better than a responsiveness of the first diode.

An image forming apparatus includes an image forming unit and a power device. The power device includes a circuit board provided to intersect a horizontal plane. The power device includes an electrolytic capacitor, an electric element, and a plate-shaped member that is provided between the electrolytic capacitor and the electric element in a vertical direction and including a first surface extending in a second direction intersecting the vertical direction. The plate-shaped member includes a cutout or a hole, and a position of at least part of an area where the cutout or the hole is formed is farther in the first direction from the mounting surface of the circuit board than a position of the electric element.

Image forming apparatus

An optical scanning apparatus includes a first rotating polygonal mirror that deflects a light beam such that the light beam scans a surface of a first image carrier, and a second rotating polygonal mirror that deflects a light beam such that the light beam scans a surface of a second image carrier. The optical scanning apparatus further includes a first phase control unit that performs phase control of the first rotating polygonal mirror based on a first detection signal output from a first detection unit and a first target phase, and a second phase control unit that performs phase control of the second rotating polygonal mirror based on a second detection signal output from a second detection unit and a second target phase, which is set with respect to the first target phase.

Optical scanning apparatus having plural phase control units for a respective plurality of rotating polygonal mirrors and image forming apparatus therewith

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Mishima, Japan

Masaki Inagaki