Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Kazunori Matsuo

Masahiro Samei

Keiichi Matsuzaki

Hideki Tatematsu

Tadafumi Shimizu

Kenji Asakura

Shoichi Kitagawa

Shouichi Kitagawa

Masaru Imai

Tomoyuki Noguchi

Yukinori Hara

Tadayuki Kajiwara

Kazuhiko Soeda

Yuichi Monda

Eiji Torikai

Masaya Shitami

Hironobu Kinoshita

Shunichi Itai

Disclosed is an image forming apparatus capable of preventing a paper jam in an arc-shaped sheet passing path for turning around a sheet and transporting the sheet in a double-sided transporting path. In this apparatus, a double-sided sheet passing path is formed so as to include: an arc-shaped interval that causes the sheet to turn around and to be transported to a registration sensor on an upstream side in the transport direction of a sheet and that includes the registration sensor as one end point; and an interval that transports the sheet having passed between ADU transport rollers, obliquely downward. A single-sided sheet passing path is formed so as to include an interval that transports the sheet having passed over the registration sensor in a substantially horizontal direction.

Image forming apparatus with an arc-shaped duplex feed path having increased radius of curvature

Disclosed is an image forming apparatus including: an ejection section including an ejection roller to eject a sheet from a first sheet passing path to a sheet ejection port and a reverse roller to reverse a transport direction of a sheet transported along a second sheet passing path, the ejection roller and the reverse roller being placed close to each other and close to the sheet ejection port; and a switching lever switches the transport destination of the sheet between the first and the second sheet passing paths for transporting the sheet to the ejection roller and to the reverse roller, respectively. A moving trajectory of a sheet transported along the first sheet passing path between the ejection roller and the switching lever is substantially identical to a moving trajectory of a sheet transported along the second sheet passing path between the reverse roller and the switching lever.

Image forming apparatus

The present invention relates to an image forming apparatus that enables the occurrence of print defects due to a first print start time delay to be eliminated without using a temperature sensor that has a small thermal time constant. When the temperature of a fixing belt serving as an image heating body is greater than or equal to a predetermined temperature following the elapse of a fixed time after an image forming operation is started, recording paper is transported to a nip area (fixing area) of a fixing apparatus before the temperature detected by a temperature sensor reaches a predetermined image fixing temperature, and an image forming operation is started immediately.

Method and apparatus for controlling image forming operation of an image forming apparatus

A fixing apparatus is provided that enables a recording medium that has undergone heat-fixing to be separated smoothly from a heating medium without causing a sheet jam or image disturbance. In this apparatus, there are provided on the guide surface of a separator two step parts raised along the guide surface guide width direction. Recording paper is transported gripped by a fixing nip, is guided so as to come into contact with only the apex parts of step parts, and is separated from the surface of a fixing belt. Thus, a gap is formed between the guide surface and the heat-fixing surface of recording paper guided along the guide surface, the contact area between the heat-fixing surface of recording paper and the guide surface decreases, the heat-fixing surface of recording paper becomes less prone to adhere to the guide surface of the separator, and recording paper is smoothly separated from the fixing belt without causing a sheet jam or image disturbance.

Fixing apparatus

An image heating device is operational to estimate a temperature of a pressure roller so as to determine a set temperature for a roller belt in a subsequent image heating period.

Image heating device, image forming apparatus, image copying machine, and method for controlling temperature

An image heating device is provided with reduced cost, by which a difference in glossiness among printed images on recording media is eliminated, and the wrapping of a belt and the like at a high temperature is prevented. In the image heating device, a controller estimates a temperature of a pressure roller according to at least one of a temperature of a belt detected by a temperature sensor and a variation with time in the detected temperature from completion of the heating after application of an electric power to the magnetization coil by an exciting circuit is stopped and the heating of the belt by the heating roller is stopped, so as to determine a set temperature for the belt in a subsequent image heating period.

In a fixing unit, a medium introducing portis provided near a gripping partof a housing, and a sheet materialto be subjected to a fixing process is guided to the medium introducing port. A shutteris provided slanted at a given angle with respect to a gripping surfaceof the gripping partof the fixing unitsuch that the shutter has a fulcrum at a part thereof, which is closer to the gripping partof the fixing unit, at the medium introducing port, and the shutteris turnable to a position to close the medium introducing portwhile resisting the urging forces of the twisted springs

Image forming apparatus having a removable fixing device

A fixing device as an image heating device is provided, by which a difference in glossiness is not caused in a recording medium in the axial direction of a pressure roller. When a print request is issued during the end-processing sequence, an electric power applied to a magnetization coil via an exciting circuit is dropped to 0 by controlling means during the start-processing sequence, and after an appropriate interval, the heating with full power is restarted by the controlling means. By so doing, the decrease in temperature at both ends of a fixing belt and a heat-generating roller in the axial direction can be compensated.

A fixing device is formed by using a heat generating roller having magnetism and electric conductive characteristics and a magnetizing coil opposed to the outer peripheral of the heat generating roller and generating heat on the heat generating roller by an electromagnetic induction. The magnetizing coil is formed in such a manner that 60 copper wires whose surfaces are insulated and have the outside diameter of 0.2 mm are bundled to form a bundle of wires and the bundle of wires is drawn in the direction of rotation axis of the heat generating roller and wound in the direction of a circumference of the heat generating roller. Further, the magnetizing coil is disposed so that the bundles of wires mutually come into close contact along the circumference of the heat generating roller to cover the upper half of the heat generating roller.

Fixing device and image forming apparatus using the same

A heating device utilizing electromagnetic induction is provided with an induction heating unit that is opposed to a heating member and causes the heating member to heat through electromagnetic induction. The induction heating unit has an exciting coil for generating a magnetic field and a coil guide member on which the exciting coil is wound. The exciting coil is formed in at least two layers in such a manner that a first layer is formed on a circumferential surface of the coil guide member by winding a plurality of turns and a second layer is formed around and outside the first layer on the side opposite to the coil guide member, and winding of each of the second layer and following layers is started from a position close to a winding start position of the first layer.

Heating device and fuser utilizing electromagnetic induction

A short ring is provided outside a support frame. In the short ring, eddy current is generated in such a direction as to cancel apart of a magnetic flux developed from the exciting coil when it is fed with current, which the part of the magnetic flux leaks to outside. When the eddy current is generated, a magnetic field is developed in such a direction as to cancel the magnetic field by the leaking flux, as taught by Fleming's law. The result is that unnecessary radiation by the leaking flux is prevented, and hence noise generation in other members or devices is suppressed.

Heating device using electromagnetic induction and fuser

An image heating apparatus and heat generating rotary member for use in the image heating apparatus has a fixing roller including a magnetic metal layer and a non-magnetic metal layer, and the non-magnetic metal layer is provided on the outer side of the magnetic metal layer and is thinner than the magnetic metal layer.

Image heating apparatus and heat generating rotary member for use in the same

A printer includes, in its fixing device operable to fix toner particles onto a recording medium, a heating roller containing magnetic metal, a fixing roller disposed parallel to the heating roller, an endless belt containing magnetic metal bridged across the heating roller and the fixing roller. The printer also includes a press roller pressed to the fixing roller via the endless belt and the recording medium, and a coil core being operable to produce magnetic fields so as to cause both of the heating roller and the endless belt to generate heat with the magnetic metals contained therein.

Printer and fixing device which maintain a stable temperature for fixing a toner image

The fixing device includes a heating roller made of magnetic metal and heated by electromagnetic induction; a fixing roller disposed parallel to the heating roller; an endless toner heating medium belt bridged across the heating roller and the fixing roller, and a press roller pressed to the fixing roller via the toner heating medium. The press roller rotates in the same direction as the toner heating medium belt to form a fixing nip region, and the belt is heated by the heating roller and rotated by the two rollers. The construction of the present invention achieves stable temperature control of the toner heating medium, and provides a stable fixing quality of the toner image.

Growing community of inventors

Fukuoka, Japan

Kazunori Matsuo