Sharp Kabushiki Kaisha Corporation

Yoshiaki Hiramoto

Yasushi Matsutomo

Shigeru Yoshida

Takashi Kubo

Yasuaki Fukada

Susumu Hashimoto

Motokazu Nakao

Masatsugu Hatanaka

Seiichi Kizu

Kayo Kamei

Susumu Murakami

Yoshie Iwakura

Hideshi Izumi

Yoshiharu Yoneda

Hideo Yoshikawa

Akira Nakashima

Naoaki Kurimoto

Yoshiyuki Nagai

An apparatus for image formation comprises a fixing member, a pressing member, a heating member, a sensor, and a controller. The heating member heats at least one of the fixing and pressing members during a heating operation. The sensor senses the surface temperature of at least one of the fixing and pressing members. If the surface temperature sensed by the sensor exceeds a threshold temperature, the controller stops the heating operation of the heating member. If the sensed temperature drops below the threshold temperature, the controller starts the heating operation of the heating member. The controller includes a period measuring unit for measuring the switching period at which the controller switches the starting and stopping of the heating operation of the heating member. The controller restrains the heating of the fixing and pressing members if the switching period exceeds a reference time.

Apparatus for image formation

Mechanism unit(s) functioning as automatic-feed cassette(s) and mechanism unit(s) functioning as manual-feed tray(s) together form a single integral module, constituting a hybrid paper supply module. A plurality of hybrid paper supply modules are stacked together to constitute a paper supply mechanism. Manual-feed tray(s) with which manual-feed mechanism unit(s) of respective hybrid paper supply module(s) is or are provided is or are maintained in stored state(s) as a result of electromagnetic attraction produced by electromagnet(s). In correspondence to image forming condition(s), electromagnetic attraction at one electromagnet is terminated, causing manual-feed tray(s) to assume deployed state(s). Furthermore, primary path(s) passing vertically through module interior(s) is or are formed so as to permit transport of recording paper toward printing unit(s) of hybrid device(s) regardless of from which hybrid paper supply module(s) it is that recording paper is taken up.

Hybrid paper supply module and image forming apparatus equipped with such hybrid paper supply module, and also paper supply mechanism and image forming apparatus equipped with such paper supply mechanism

An image forming apparatus includes: a paper conveying portion for conveying a paper; an image forming portion for forming a visible toner image on the paper being conveyed, with a toner in accordance with input image information; and a fixing unit for fusing and fixing an unfixed toner image formed on the paper to the paper by using a heat roller and a pressing roller, and is constructed such that the pressing roller is composed of a metal core that forms a core shaft of the pressing roller and an elastic part that covers an outer periphery of the metal core, and a heat capacity at a center portion of the pressing roller with respect to a direction perpendicular to a paper's direction of conveyance is smaller than heat capacities at both ends of the pressing roller.

Image forming apparatus with pressing roller

A shifter is equipped with a rack and a stopper. A transmission gear transmits power from an electric motor to the rack. A retention pin extends vertically downward from the transmission gear. When the shifter slides to an origin, the retention pin locks the stopper, which causes the electric motor to step out. On detecting the step-out of the electric motor, the position control device recognizes that the shifter has reached the origin (the reference position) and has been fixed at the position, thus setting the shifter position.

Position control device for moving member

Mechanism unit(s) functioning as automatic-feed cassette(s) and mechanism unit(s) functioning as manual-feed tray(s) together form a single integral module, constituting a hybrid paper supply module. In such constitution, paper transport path(s) may be formed between or among first guide member(s) provided at automatic-feed cassette mechanism unit(s) and second guide member(s) provided at manual-feed mechanism unit(s), and manual-feed mechanism unit(s) may be pulled outward and to side(s) of apparatus(es) so as to cause paper transport path(s) to be opened up to the exterior, facilitating removal of jammed paper. Furthermore, given such constitution, a plurality of hybrid paper supply modules may be stacked together to constitute a paper supply mechanism. Manual-feed tray(s) with which manual-feed mechanism unit(s) of respective hybrid paper supply module(s) is or are provided may be collapsible so as to permit extension and/or retraction. This will permit manual-feed tray(s) to be able to accommodate a plurality of types of recording media.

Mechanism unit(s)functioning as automatic-feed cassette(s) and mechanism unit(s)functioning as manual-feed tray(s) together form a single integral module, constituting hybrid paper supply module. Manual-feed mechanism unit(s)is or are arranged below transport paths, which extend toward printing unit(s). Furthermore, path(s) along which recording paper P taken up from automatic-feed cassette mechanism unit(s)is transported and path(s) along which recording paper P taken up from manual-feed mechanism unit(s)is transported are made to intersect within the module, decreasing length(s) of respective path(s).

Hybrid paper supply module and image forming apparatus equipped with such hybrid paper supply module

A roller turning force generator is connected to a driving gear which is mounted on a shaft. The shaft is connected to offset roller assemblies disposed in an offset mechanism via connecting gears. The offset roller assemblies rotatably supported inside the offset mechanism are turned by a driving force transmitted from the roller turning force generator to discharge individual sheets of a printing medium in a sheet transport direction. The offset mechanism is linked to an offsetting force generator so that the offset mechanism can be shifted along a direction perpendicular to the sheet transport direction.

Sheet delivery mechanism for image forming apparatus

An image forming apparatus, which has sophisticated functions of feeding recording paper of various sizes selectively and of sorting printed paper, is reduced in size. The feed bin sorters, the output bin sorters, and the output tray are arranged in tiers. Pre-printed paper is supplied from any of the feed bin sorters, and printed paper is delivered to any of the output bin sorters or the output tray.

Paper feed and output assembly, and image forming apparatus

A front access type image forming apparatus includes an image scanning section located at an upper part of a housing of the apparatus for obtaining image information from an original, a sheet feeding section located at a lower part of the housing, and an image forming section disposed between the image scanning section and the sheet feeding section at one side of the housing. The image scanning section, the image forming section and the sheet feeding section together form a generally U shape in frontal cross section, a sheet delivery portion being formed between the image scanning section and the sheet feeding section. The length of a sheet delivery tray as measured along a sheet transport direction is made smaller than the length of a maximum printable sheet size so that large-sized printed sheets discharged onto the sheet delivery tray stick out from one side of the apparatus.

Image forming apparatus

Shield members 9b-1 and 9b-2 constituting a transfer unit 9 for a transfer apparatus are inserted from the bottom of a transfer holder 40 fabricated by integrating a pre-transfer guide 31 and a post-transfer guide 34 together with wire fixing portions 41a and 41b for fixing a corona discharge wire 9a into one. Thereafter the shield members 9b-1, 9b-2 are positioned with respect to the transfer holder 40, and the assembly of the transfer apparatus is completed. The transfer apparatus is thus easily assembled, and the pre/post-transfer guides 31 and 34 can be positioned more accurately with respect to the transfer unit 9 and the corona discharge wire.

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Yamatokoriyama, Japan

Yoshiaki Hiramoto