Fujitsu Corporation

Naoto Hirao

Kiyoshi Chinzei

Toshimasa Toyama

Katsuya Shimatsu

Masaaki Ohyama

Katsumi Adachi

Yoshihiro Tonomoto

Makoto Maki

Yasuharu Takeuchi

Mituaki Ono

Hiroaki Yoshida

Yoshinori Wada

Kenji Fuke

Toshio Hino

Daisuke Fujii

Shinji Ohshima

Amiko Chihara

The invention provides a continuous medium printing apparatus which can exert a transporting force to act upon a continuous medium without additional provision of a new tractor mechanism or some other transport mechanism. In the continuous medium printing apparatus, upon automatic loading of a continuous medium, a control section controls a charging operation of a charging section so that a leading end portion of the continuous medium may be electrostatically attracted to an image forming drum. The image forming drum to which the continuous medium is attracted is rotated in a printing transporting direction to exert a transporting force to act upon the continuous medium to transport the continuous medium in the printing transporting direction. The present invention is applicable to an apparatus which prints on a continuous medium such as continuous recording paper (continuous paper), for example, by electrophotography.

Continuous medium printing apparatus

An image forming apparatus includes a reverse side print mechanism for printing on the reverse side of continuous paper, a surface print mechanism for printing on the surface of the continuous paper, and a width detecting mechanism for detecting a width of the continuous paper. The apparatus further includes a controller which, based on the detected paper width, determines a print start position on the reverse side of the continuous paper and controls the reverse side print mechanism to start printing from the determined print start position. Thus, even if the paper width is changed, the reverse side print start position can be set to a predetermined position.

Image forming apparatus with width detection

The invention provides a double-sided printing apparatus which includes a first image forming process unit, a second image forming process unit, a first fixing station, a second fixing station and a transport system all disposed in a first housing. The transport system includes a transport direction changing element which contacts with one of surfaces of a medium to change the transporting direction of the medium so that the medium is sent out to the second fixing station. While the medium is transported in a substantially vertical direction in the single double-sided printing apparatus, the height of the transport path of the medium is suppressed so as not to become very high, thereby miniaturizing the apparatus. Further, intense light leaking from the fixing stations is intercepted so that deterioration of photosensitive drums of the image forming process units is prevented and a drop of the surface potentials of the photosensitive drums is prevented to extend the life of each photosensitive drum and prevent deterioration of the printing quality.

Double-sided printing apparatus

The present invention is a duplex printing apparatus, which is equipped with a first image forming process unit, a second image forming process unit, a fixing section, a conveyance system, and said fixing section, and a control section. In making a switch-over between printing modes (one-sided copying, both-sided copying), the control section fixes by the fixing section the unfixed toner image on the medium formed in the printing mode preceding before the switch-over and then conveys the medium by the conveyance system to a printing start position in the printing mode following after the switch-over. With this, in making a switch-over between printing modes, even when the medium is fed back, there is no possibility that the unfixed toner image formed on the medium will be disturbed. Therefore, printing quality can be maintained and printing can be performed on the medium without waste.

Duplex printing apparatus and control method of the same apparatus

An image forming apparatus includes a plurality of process units contacting a continuous recording medium and transferring images on the recording medium, a separating and contacting mechanism for controlling at least one of the recording medium and each of the process units to a separated state where the recording medium and the process unit are separated from each other and a contacting state where the recording medium and the process unit contact each other, and a controller for controlling the separating and contacting mechanism at a position where the process unit confronts a non-printing region on the recording medium so as to put the recording medium and the process unit to the contacting state.

Image forming apparatus

An image forming apparatus includes a fixing unit including at least a pair of rollers which thermally fix a toner image formed on a surface of a recording medium by pressing against the recording medium, and a separating and contacting mechanism supporting the pair of rollers so that the rollers can separate from and make contact with the recording medium, where the separating and contacting mechanism controls the rollers when contacting the rollers to the recording medium, by contacting each of the rollers approximately perpendicularly to the surface of the recording medium and so that the recording medium thereafter makes contact with a surface of each of the rollers for a wrap-around angle greater than 0.degree..

An image forming apparatus is constructed to include a first fixing unit fixing a toner image transferred on a first side of a recording medium by a flash, a second fixing unit fixing a toner image transferred on a second side of the recording medium by a flash, and a leak preventing mechanism for preventing the flash of the first fixing unit to the second side and the flash of the second fixing unit to the first side via a region which is within a fixing region of the first and second fixing units and where no recording medium exists due to a size of the recording medium used.

An electrophotographic image forming apparatus suitable especially for double-side printing or double-side copying. A pressure roller for pressing a sheet of paper against an electrostatic latent image retaining body is rotatably provided on the upstream side of a transfer unit. The pressure roller is elastically mounted through a cushion member, thereby preventing transmission of vibration of the pressure roller itself to the paper. As the paper is positively pressed against the retaining body by the pressure roller, the paper can be brought into close contact with the retaining body even when the paper is wrinkled, thus obtaining a good transfer characteristic.

Electrophotographic image forming apparatus having a pre-transfer

A toner image fixing device is disposed above a passageway along which a sheet of paper carrying toner images recorded thereon is moved, and has a lamp for emitting heat-radiation toward the sheet of paper to thermally fuse and fix the toner images thereon. Emission of the heat-radiation from the lamp is controlled such that the energy of the heat-radiation, to which a high-density toner image zone of the sheet of paper is subjected, is smaller than that of the heat-radiation to which a low-density toner image zone of the sheet of paper is subjected, to thereby prevent undulation of the sheet of paper. Where two-sided recording is applied to the sheet of paper, the prevention of undulation of the sheet of paper is especially significant because then the two-sided recording can be properly carried out.

Flash-radiation type toner image fixing device

A sheet paper feed apparatus has a hollow center shaft, a roller which has peripheral holes and rotates around the center shaft, and a negative pressure source communicating with the center shaft. Rotation of the roller causes the peripheral holes to successively create a suction action to adhere and feed the sheet paper. The center shaft has an opening at a position shifted by a predetermined angle in the direction of sheet feed with respect to a surface that is vertical with respect to the sheet paper feed surface and passes through a center of the center shaft.

Growing community of inventors

Kawasaki, Japan

Naoto Hirao