Canon Kabushiki Kaisha

Taro Minobe

Takeo Kawanami

Shinji Katagiri

Masaru Shimura

Tsuguhiro Yoshida

Yuji Kawaguchi

Masaru Ohno

Ryo Matsumura

Akira Yoshimura

Masafumi Maeda

Norikazu Sugiyama

Keizo Kojima

Hideo Nanataki

Atsushi Nakamoto

Toshihiko Takayama

Keisuke Samejima

Naoki Kanno

A control circuit executes voltage adjustment processing of adjusting a voltage output from a transfer power source so that a current detected by a detection circuit becomes a predetermined current value. The voltage adjustment processing is executed before a toner image is transferred from at least one of a first image bearing member and a second image bearing member to an intermediate transfer belt. A processor determines whether the second transfer member is in a state of contact or is in a state of separation on the basis of behavior of the current detected by the detection circuit in a period in which the control circuit is executing the voltage adjustment processing.

Image forming apparatus that determines whether or not plurality of rotating bodies are in state of contact

A printed circuit board comprises a first mounting surface, a second mounting surface, and a piezoelectric transformer. The piezoelectric transformer has a piezoelectric substance, external electrodes, and a frame substrate. The second mounting surface has a projection region. There is a first region from a first location, where an end portion further from the output electrode out of end portions of the input electrode is projected onto the second mounting surface in the projection region, to a second location, where an end portion closer to the output electrode out of the end portions of the input electrode is projected onto the second mounting surface, the first region being a mounting allowed region where an electronic component is mounted.

Printed circuit board mounting piezoelectric transformer

A controller can select and execute a full color mode of performing image formation in a first state in which each primary transfer member is in contact with an intermediate transfer belt, and a monochrome mode of performing image formation in a second state in which only a primary transfer member is in contact with the intermediate transfer belt. The controller determines which state of the first state and the second state is formed, based on a detection result obtained by a current detection circuit when a photosensitive drum is charged by a charging roller, and voltage is applied to the primary transfer member from a primary transfer power source.

Image forming apparatus

A voltage maintenance element is connected to a contact member that contacts a primary transfer surface area of an intermediate transfer belt to which toner images are transferred from a plurality of image carriers between stretch members, in such a way as to prevent the electric potential of the intermediate transfer belt from varying between respective image forming stations.

Image forming apparatus having transfer power source that applies voltage to secondary transfer member to perform secondary transfer of toner images from electrically conductive intermediate transfer belt to recording materials, toner images on image carrier primarily transferred to belt by transfer power source and contact member in which an electric potential is formed by constant-voltage element, transfer power source and auxiliary power source

The image forming apparatus includes a photosensitive drum, an intermediate transfer belt, a secondary transfer roller, a secondary transfer power supply, an opposing roller through which a current flows through the intermediate transfer belt when the voltage is applied to the secondary transfer roller by the secondary transfer power supply, metal rollers electrically connected to the opposing roller and contacting an inner peripheral surface of the intermediate transfer belt in vicinities of the photosensitive drums, a current restriction circuit connected to a path of a current flowing from the opposing roller to the metal rollers when the voltage is applied to the secondary transfer roller by the secondary transfer power supply, the current restriction circuit configured to restrict the current from the opposing roller to the metal rollers to a predetermined current.

The power supply apparatus is configured to detect the output voltage of a piezoelectric transformer and controls the frequency of a pulse signal to drive the piezoelectric transformer based on the detected output voltage and a preset target voltage so as to perform feedback control of the output voltage of the piezoelectric transformer, the gain when performing the feedback control is switched in accordance with the target voltage.

Power supply apparatus, image forming apparatus, and integrated circuit

Image forming apparatus having intermediate transfer belt, secondary transfer member that contacts outer surface of intermediate transfer belt, opposed member opposed to secondary transfer member via intermediate transfer belt, contact member that contacts inner surface of intermediate transfer belt, and constant-voltage element through which opposed member and contact member are grounded

An imaging forming apparatus includes a positive high-voltage circuit that generates voltage having a positive polarity, a negative high-voltage circuit connected in series with the positive high-voltage circuit and generates voltage having a negative polarity, a transfer roller to which the voltage generated by the positive high-voltage circuit or the negative high-voltage circuit is supplied, neutralizing pins to which the voltage generated by the negative high-voltage circuit is supplied, a current detection circuit that detects current flowing into the transfer roller, and a diode connected between the transfer roller and the neutralizing pins and that separates a path for the current flowing into the transfer roller and a path for current flowing into the neutralizing pins from each other.

Image forming apparatus including a power supply for forming an image on a recording material

Image forming apparatus using stretch member and contact member to maintain potential with a current flowing to intermediate transer belt

Image forming apparatus using stretch member and contact member to maintain potential with a current flowing to intermediate transfer belt

An image forming apparatus includes a main body of the apparatus, a plurality of cartridges each including a photosensitive member, and a transfer unit detachably mounted on the main body of the apparatus. The transfer unit includes an endless belt opposing the photosensitive member, a plurality of stretching members configured for stretching the belt, and a frame configured to axially support a plurality of rollers. The frame is provided with a plurality of positioning portions configured to allow abutment of the plurality of cartridges and determine the positions of the plurality of cartridges in the main body of the apparatus.

Image forming apparatus having a transfer unit frame

Image forming apparatus using stretch member and contact member to maintain potential with current flowing from current supply member to intermediate transfer belt

An image forming apparatus includes an apparatus main body, an image bearing member capable of bearing a toner image, a current supply member, and an intermediate transfer unit which is removably mounted to the apparatus main body. When the intermediate transfer unit is attached to the apparatus main body, the intermediate transfer unit includes an endless belt whose outer peripheral surface is configured to contact the current supply member, onto which the toner image is transferred from the image bearing member by current supplied from the current supply member, a contact member configured to contact an inner peripheral surface of the endless belt at a position opposed to the image bearing member through the endless belt, an opposing member configured to contact the inner peripheral surface of the endless belt at a position opposed to the current supply member through the endless belt, and a voltage maintaining element which is connected to the opposing member and the contact member.

A high-voltage power source includes a switching unit configured to be driven according to a frequency signal, a voltage resonance unit configured to generate a voltage according to driving of the switching unit, a rectification unit configured to rectify and amplify the voltage generated by the voltage resonance unit, a separation unit configured to separate an alternating current generated by the voltage resonance unit and a direct current generated by the rectification unit from each other, and a current detection unit configured to detect the current generated by the voltage resonance unit.

Growing community of inventors

Ichikawa, Japan

Taro Minobe