Canon Kabushiki Kaisha

Junji Ishikawa

Mitsuo Shiraishi

Toshiyuki Sekiya

Ryuta Mine

Katsuyuki Yamazaki

Koji Doi

Takeshi Kinoshita

Hiroki Uzawa

A heating efficiencyincludes a substrateand a plurality of heat generating elementstowhich are provided on both surfaces of the substrateand which generate heat, and heats a fixing belt in contact with an inner peripheral surface of the fixing belt. The plurality of heat generating elementstoare different from each other in length with respect to a widthwise direction, and at least three of the heat generating elements are provided on a front surface of the substratewhich is a side where the heatercontacts the inner peripheral surface of the fixing belt, and at least one of the heat generating elements is provided on a back surface. A longest heat generating element, in length with respect to the widthwise direction, of the plurality of heat generating elements-is provided on the front surface. Further, as regards the heat generating elements-provided on the front surface, with respect to a rotational direction of the fixing belt, the longest heat generating elementin length with respect to the widthwise direction is disposed between the heat generating elementand the heat generating element

Fixing belt unit and fixing device

A power supply device includes a first circuit, a second circuit and a second detector. The first circuit includes an adjustment unit, a first controller which controls the adjustment unit, a first detector which detects a parameter about electric power supplied to a load, a first communication unit. The second circuit includes a second communication unit which performs wireless communication with the first communication unit and a second controller. The second detector detects a temperature of the load. The first controller is operated by electric power supplied thereto by a voltage output to the second communication unit. The first communication unit transmits information about a result of detection by the first detector to the second communication unit. The second controller controls the first controller via the first communication unit and the second communication unit based on the information. In a case where the temperature is higher than a predetermined temperature, supplying of the electric power is blocked off.

Power supply device and image forming apparatus

A power supply apparatus including a first circuit and a second circuit insulated from the first circuit includes an adjustment unit and a detector in the first circuit, a controller in the second circuit, and first and second communication units in the first and second circuits, respectively. The adjustment unit is configured to adjust power. The controller is configured to control the adjustment unit. The detector is configured to detect a parameter. The second communication unit is configured to perform wireless communication with the first communication unit. The first communication unit is operated with power supplied to the first communication unit by a signal generated in the first communication unit due to a signal output from the controller to the second communication unit, and transmits information about a result of detection by the detector to the second communication unit. The controller controls the adjustment unit based on the information.

Power supply apparatus and image forming apparatus having adjusted load power

An image forming apparatus includes a fixing device, a driver, and a relay. A control board controls supply of power to a heater based on an output of a temperature detector. A connector includes a first connection portion to be connected to the fixing device, and a second connection portion to be connected to the control board, and connects the fixing device and the control board to each other. A loopback path is configured such that a direct current (DC) voltage to be applied, via a first terminal of the second connection portion, to a second terminal of the first connection portion is applied to a fourth terminal of the second connection portion via a third terminal of the first connection portion. Further, the DC voltage to be applied to the fourth terminal via the loopback path is applied to the relay as a drive voltage for the relay.

Image forming apparatus with fixing device, the image forming apparatus controlling supply of power to a heater by a driver based on an output of a temperature detector

An image forming apparatus including: an image forming portion; a fixing portion; an electric storage portion configured to supply electric power to a load; a first power supply configured to supply electric power to the load; a second power supply configured to supply electric power to the fixing portion; and a controller configured to supply electric power from the electric storage portion to the load and supply a predetermined maximum allowable power from an AC power supply to the second power supply when an image formation request is input, wherein in a case where a remaining amount of the electric storage portion becomes lower than a predetermined value, the controller reduces electric power supplied from the second power supply to the fixing portion lower than the maximum allowable power, and thereafter switches an electric power supply to the load from the electric storage portion to the first power supply.

Image forming apparatus including electric storage portion

By connecting a first diode between a conductive heating element of a fixing roller and ground, electric charge with the same polarity as the charged polarity of toner can be held on the surface of the fixing roller. Meanwhile, by connecting a second diode between the surface of a pressing roller that does not contact an un-fixed toner image and ground, electric charge with the reverse polarity of the charged polarity of the toner can be held at the surface of the pressing roller. The polarity of the electric charge induced by electromagnetic induction is held at the polarity determined by the two diodes, and as a result the fixing offset can be suppressed without adding a collector member or a charging capacitor.

Image forming and fixing apparatuses having fixing and pressing rotating member and rectification element

A fixing apparatus includes an induction heating coil configured to heat a heat generating member including a conductive heating element, a boosting circuit configured to boost a DC voltage obtained by rectifying AC power, a switching element configured to input a DC voltage boosted by the boosting circuit and to supply a high-frequency current to the induction heating coil, a driving circuit configured to drive the switching element, a temperature detection unit configured to detect a temperature of the heat generating member, and a control unit configured to control power supplied to the induction heating coil by controlling a boosting ratio of the boosting circuit and a driving frequency of the switching element by the driving circuit so that the temperature detected by the temperature detection unit reaches a target temperature.

Fixing apparatus of induction heating type for fixing image formed on sheet

An image forming apparatus including a fixing device using an induction heating method determines a driving frequency for a switching element configured to drive an induction coil, according to a difference between a detected temperature of an electrically conductive heating element provided in the fixing device and a target temperature. When the determined frequency is a predetermined minimum frequency and a current flowing through the induction coil is at a predetermined value or less, the image forming apparatus generates a signal indicating the abnormality of electric power supplied to the induction coil.

Serial communication apparatus and image forming apparatus including the same

Power supply circuitry for inductive heating element and capable of minimizing losses to switching element

The present invention provides an image forming apparatus comprising an image forming unit configured to form an image on an image carrier, a transfer unit configured to transfer the image formed on the image carrier onto a transfer medium, a voltage applying unit configured to apply a voltage to the transfer unit, a current detection unit configured to detect a current that flows through the transfer unit when the voltage applying unit applies the voltage, and a control unit configured to control the voltage applying unit based on a detection result of the current detection unit.

Image forming apparatus and control method

A fixing controller capable of rapidly detecting an excessive temperature rise, even if an abnormal temperature rise takes place in a state that a rotor of a fixing unit, such as a thin-walled roller or belt, stops rotating. A rotating belt is heated by a coil, a belt temperature is detected by a thermistor, and a drive frequency of a driving circuit for driving the coil is controlled by a control circuit. When the temperature detected by the thermistor becomes equal to or higher than a predetermined temperature, the drive circuit is stopped by an excessive temperature rise detecting circuit. The thermistor is heated such that a difference between the temperatures detected by the thermistor when the belt is rotating and when the belt stops rotating becomes equal to or larger than a predetermined temperature difference.

Fixing controller and image forming apparatus

This invention provides a power supply which supplies an AC electric current to the coil of a heating unit employing the electromagnetic induced heating method via a connector connecting a plurality of wires, and a method for the power supply. The method includes the steps of supplying electric currents to the coil via 1st and 2nd wires from 1st and 2nd electric current supply units and detecting feedback electric currents via 3rd and 4th wires through the coil. Whether an electric current is abnormally supplied to the coil is monitored on the basis of these detected electric currents. It is controlled in accordance with the monitoring result to stop driving the 1st and 2nd electric current supply units and supply an electric current to the coil.

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Moriya, Japan

Junji Ishikawa