Canon Kabushiki Kaisha

Katsumi Takahashi

Tsuyoshi Moriyama

Takahiko Yamaoka

Tatsuhito Kataoka

Kazuhiko Hirooka

Yoshihiro Funamizu

Junichi Noguchi

Atsushi Chaki

Shinya Suzuki

Yushi Oka

Yuzo Matsumoto

Takuya Kawamura

Kazunori Togashi

Yuichiro Maeda

Kenji Kuroki

Kazuhisa Koizumi

A power supply circuit includes a first power supply for a normal power mode, a second power supply for a power saving mode, which is connected in parallel with the first power supply, a controller to which power from the first power supply and power from the second power supply are supplied via a common connection point, and a switch element which is connected between an output terminal of the first power supply and the connection point and controls power that is supplied to the controller, wherein the switch element includes a diode between a source terminal and a drain terminal of the switch element, the drain terminal of the switch element is connected to the first power supply side to prevent current flowing from the connection point toward the first power supply, and the source terminal of the switch element is connected to the connection point side.

Power supply circuit

An image forming apparatus includes an image forming unit having an exposure unit configured to irradiate each of a plurality of photosensitive members with a corresponding light beam, a light amount control unit configured to control a light amount of the light beams, a plurality of developing units configured to develop electrostatic latent images formed on the photosensitive members by exposure with the light beams, and a transfer unit configured to transfer toner images formed on the photosensitive members onto an image carrier; a pattern forming unit configured to control the image forming unit to form a misalignment detection pattern for detecting a relative misalignment between the toner images transferred onto the image carrier; a pattern reading unit configured to read the misalignment detection pattern; and a correction unit configured to correct the relative misalignment between the toner images based on the reading result obtained by the pattern reading unit.

Image forming apparatus configured to control a light amount of a light beam for forming a misalignment detection pattern

An image forming apparatus includes an image forming unit, a fixing unit, a temperature sensor including an element in which a resistance value increases as a temperature decreases and configured to detect a temperature of the fixing unit, a connector configured to transmit an output signal of the temperature sensor, a control unit disposed on a side opposed to the temperature sensor with respect to the connector and configured to control the temperature of the fixing unit based on the output signal of the temperature sensor, a resistor disposed on the same side of the temperature sensor with respect to the connector and connected to the temperature sensor in parallel, and a power source disposed on the side opposed to the temperature sensor with respect to the connector and configured to supply currents to the temperature sensor and the resistor via the connector.

Image forming apparatus

An image forming apparatus includes a scanner motor and a rotary polygonal mirror which is driven by the scanner motor to rotate, and reflects a modulated beam emitted from a light source by a plurality of reflection surfaces. The image forming apparatus includes a rotation and carrier unit which, while rotating, carries an image formed on the basis of a laser beam reflected by the rotary polygonal mirror, a speed detection unit which detects a rotation speed of the rotation and carrier unit. The image forming apparatus includes a tracking characteristic detection unit which detects a tracking delay of the scanner motor from a target rotation speed and a control unit which controls, on the basis of the rotation speed detected by the speed detection unit and a tracking characteristic detected by the tracking characteristic detection unit, a rotation speed of the scanner motor that drives the rotary polygonal mirror.

Adjusting the speed of a scanner motor in an image forming apparatus

A magnetic material detecting device, in which a concentration of magnetic material can be correctly detected, even when the magnetic material with unevenness in its density distribution flows. A magnetic field generating device is arranged in a two-component developer composed of magnetic carrier and non-magnetic toner and generates a magnetic field. A signal output device is arranged in the developer and outputs a signal depending on a magnetic permeability of the developer due to the magnetic field generated by the magnetic field generating device. An agitating unit agitates the developer and makes the developer flow between the magnetic field generating device and the signal output device. A detecting unit detects a proportion of the toner in the developer based on a result of multiple times sampling of the signal outputted from the signal output device after the agitating unit starts to operate.

Magnetic material detecting device

An image formation apparatus for executing image formation by exposing an image carrier with irradiation light emitted from a laser source on the basis of an input signal to drive the laser source includes a correction amount calculation unit configured to calculate, on the basis of a generated correction pattern, a correction amount to control the ON or OFF timing to drive the laser source, and a signal generation unit configured to generate, on the basis of image data and the correction amount calculated by the correction amount calculation unit, a corrected signal obtained by correcting the input signal to drive the laser source so as to form the image data by controlling the ON or OFF timing.

Image formation apparatus and image formation method

An image forming apparatus forms a toner image onto sheets at the first feeding interval on a photoconductor or intermediate transfer member and, if the temperature of a fixing unit falls outside a set temperature range, the sheet layout is changed to a feeding interval wider than the first feeding interval. Adjustment processing is performed based on the image forming condition so that the feeding interval is changed to a wider one in the feeding interval changing step during image formation and it is determined in the determination step to perform adjustment processing, toner patch images are formed in an area where no toner image is formed on the photoconductor or intermediate transfer member . The adjustment processing is performed based on reading toner patch images.

Image adjusting method and image forming apparatus

Whether an image to be formed has a prescribed M&#xd7;N pixel pattern is determined by a comparator. If it is determined that the image has the prescribed M&#xd7;N pixel pattern, then a light-quantity correction signal that is for reducing the current that flows through a semiconductor laser is output to a laser driving circuit when the laser emits a laser beam of a pixel of interest contained in the M&#xd7;N pixel pattern.

Image forming apparatus and method of controlling same

An image forming apparatus includes an intermediate transfer member position detection unit configured to detect a position of the intermediate transfer member to output an image forming operation start signal, a pattern detection unit configured to detect a registration correction pattern formed on the intermediate transfer member based on the image forming operation start signal, a misregistration variation detection unit configured to read the registration correction pattern detected by the pattern detection unit based on the image forming operation start signal and to generate a reference clock signal based on the read registration correction pattern, and a polygonal mirror drive motor control unit configured to adjust a rotation speed of the polygonal mirror drive motor based on the reference clock signal generated by the misregistration variation detection unit.

The image forming apparatus includes a rotatable first rotary member, a rotatable second rotary member brought into pressure contact with the first rotary member, and forming a nip part for nipping and conveying a recording material, first recording material detector located at the vicinity of the nip part downstream of the nip part with respect tot he conveying direction of the recording material for detecting the passage of the recording material, a drive unit for rotatively driving the first rotary member, a brake for applying the brakes to the rotation of the first rotary member, and a controller for controlling the brake, and during jam near the first rotary member, the driving of the drive unit is stopped. Thereby, the amount of wrapping during the wrapping jam of the recording material around the fixing rotary member can be made small.

Image heating apparatus with mechanism to prevent twining recording material

Image heating apparatus includes an image heating rotation member, for heating an image on a recording material, a driving device rotationally driving the image heating rotation member, an external heating member including an exothermic member heating the image heating rotation member in a way that contacts the image heating rotation member, a contacting-and-separating device for making the external heating member contact and separate from the image heating rotation member, a conduction control device for controlling conduction to the exothermic member so that a temperature of the external heating member becomes a target temperature, a contacting-and-separating state detecting device for detecting a contacting-and-separating state of the external heating member, and an abnormality detecting device for detecting an abnormality of the contacting-and-separating state of the external heating member rendered contacting and separating by the contacting-and-separating device, based on the detection by the contacting-and-separating state detecting device.

Fixing apparatus

An image forming apparatus is provided with a sheet support on which sheets are supported thereon, a sheet feeding unit for feeding the sheets from the sheet support, a first conveying unit for conveying the sheets fed by the sheet feeding unit to the vicinity of an image forming device for forming images on the sheets, a second conveying unit for feeding the sheets conveyed by the first conveying unit to the image forming device so as to be cable of forming images thereon, and a control for controlling the sheet conveying speed of the sheet feeding unit, the first conveying unit and the second conveying unit, and the control controls so that the sheet conveying speed may become higher in the order of the sheet feeding unit, the second conveying unit and the first conveying unit.

Image forming apparatus with control of conveying speeds

A sheet conveying apparatus is provided with a sheet feeding device for feeding sheets from a sheet supporting device on which the sheets are supported, a first sheet conveying device, a second sheet conveying device and a third sheet conveying device successively disposed downstream of the sheet supporting device with respect to the feeding direction of the sheets for conveying the sheets, a sheet interval judging device for detecting the passage of the sheets between the second sheet conveying device and the third sheet conveying device, and judging whether the interval between the sheets is a predetermined interval, and control device for controlling the sheet feeding device, the first sheet conveying device and the second sheet conveying device so that the sheets can be conveyed at the predetermined interval on the basis of the judgement of the sheet interval judging device.

Growing community of inventors

Toride, Japan

Katsumi Takahashi