Hitachi Koki Co., Ltd.

Hitachi, Ltd.

Shinichi Nishino

Toshitaka Ogawa

Masayasu Anzai

Shigenobu Katagiri

Toshimitsu Harada

Teruaki Mitsuya

Takao Kumasaka

Osamu Nishino

Sadaki Maeda

Susumu Saito

Akira Arimoto

Takeshi Mochizuki

Yasuro Hori

Shigetaka Fujiwara

Hiroshige Nakano

Kazuyuki Kubo

Hiroomi Kozawa

Katsuya Kawai

Masato Yamada

Yosuke Saito

Takahiro Kikuchi

Shigetaka Fumiwara

A film photoconductor holding mechanism includes a substantially-cylindrical support having an opening which is shaped so as to have a notch at a part of a circumferential portion of the support in a longitudinal direction thereof. A bar-like photoconductor cap which is operative to engage with the opening of the support is provided. A film assembly is provided and has a peripheral length larger than an outer peripheral length of the support and is installed into the support in a state where the bar-like photoconductor cap is opened and is held in the support by the bar-like photoconductor cap. A guide bar and elastic member is disposed on the film assembly for guiding and tensioning the installation of the film assembly in the support, and a guide groove is defined in the bar-like photoconductor cap and is operative to be engaged with the guide bar.

Film photoconductor holding mechanism

An image forming apparatus includes a base machine; and a mounting device for interchangeably mounting any one of a plurality of different types of photoreceptor units to the base machine. The mounting device includes a print section module detachably mounted on the base machine, with the plural types of photoreceptor units being removably set to the print section module via an interface. The different types of photoreceptor units are different in a mounting structure for mounting a photoconductive layer on base.

Mounting device for interchangeably mounting different types of

In an electrophotograpic recording apparatus, a charge supply unit and a light erasing unit are disposed in the stated order when viewed in the direction in which a photoreceptor rotates, at a location between a transfer unit and a bias cleaning unit, and light from the light erasing unit is projected onto a photoreceptor surface area except the charge supplied area. A developing apparatus of the type in which a cleaner section for removing and collecting residual toner on a photoreceptor is coupled through a toner transport pipe with a toner hopper of a developing unit, wherein a meshed foreign material collector, which may be vibrated, is disposed at a location in a residual toner collecting path ranging from the cleaner section, the toner transport pipe, and the toner hopper.

Electrophotographic recording apparatus having improved residual toner

In an image forming method wherein a toner image formed on a photoreceptor by the sequence of a charging step, an imagewise exposure step and a development step is transferred and fixed on a recording sheet by a transfer and a fixing step, the improvement wherein the developer used in the development step comprises at least 30 wt % of a toner having a particle size of no more than 8 .mu.m and a magnetic carrier of low saturation magnetization, the toner being capable of carrying electric charges in a quantity greater than the value at which a maximum amount of the toner is deposited for development, the toner being electrified to have a charge quantity greater than a predetermined level by mixing the toner and the carrier under agitation before the effective development region is reached, a magnetic brush being formed after the toner electrification, the carrier and the toner being then given a localized movement and vibrational force in the effective development region, the toner being deposited on the latent electrostatic image under the action of an electrical or mechanical disturbance that promotes the supply and separation of the toner particles, whereby a toner image is formed on the photoreceptor, the toner image being then transferred onto the recording sheet by a transfer device holding a constant electric field and, following this transfer step, the residual toner on the photoreceptor being charged again and subsequently removed from the photoreceptor under the action of an electric field.

Method and apparatus for forming toner image

A light scanning device has a light deflector for deflecting in a scanning mode a light beam outputted by a light source; and an optical system for image-forming on a scanning medium the light beam deflected by the light deflecting means, with a convergent or divergent light beam in an optical path between the light source and the scanning medium. A plane-parallel plate is moved into and out of the optical path of the convergent or divergent light beam, so as to change a beam spot diameter on the scanning medium.

Multi-diameter record dot light scanning apparatus

A cleaning device for a dry electrophotographic device includes a cleaning brush brought into resilient contact with an object to be cleaned such as a photosensitive drum. A cleaning roll rotates while constantly being brought into contact with the cleaning brush and a cleaning blade is pressed against the cleaning roll to clean the cleaning roll. A rotation direction switching mechanism switches the rotation direction of the cleaning brush such that the rotation direction of the cleaning brush when cleaning the object, for example, during the formation of an image, is different from that when the brush is not cleaning the object.

Cleaning device for dry electrophotographic device

A cleaning unit for a xerographic printing machine, or the like. A system for mechanically or electrostatically removing objects, such a toner or paper particles in a printing machine from a photoreceptor or other member to be cleaned, includes a cleaning brush rotating in contact with the member to be cleaned, a cleaning roll brought into contact with the cleaning brush to electrostatically or magnetically remove toner from the cleaning brush, and a cleaning blade supported at the base by a blade holder. The cleaning blade is pressed against the cleaning roll, to remove toner deposited on the surface of the cleaning roll. The cleaning blade is a resilient, thin metal plate.

Cleaning unit for a xerographic printing machine

Disclosed is an electrical power supply for use, for example, for a flash fusing device in an electrophotographic recording apparatus, in which a DC high voltage is generated from a low voltage of an AC power supply so that the high voltage DC energy is momentarily consumed or discharged. The electrical power supply is configured in a manner so that, in order to make unnecessary a charging capacitor and a current limiting resistor for preventing rectifier elements from being damaged, at least some of the rectifier elements are constituted by rectifying control elements such as thyristors or transistors and a control signal is given to those rectifying control elements so as to make the rectifying control elements be in an isolated state. By use of such a configuration, the electrical power supply can be reduced in size as well as in power loss. The effect can be fully exhibited not only in a fusing apparatus employing the electrical power supply but in a recording apparatus employing such a fusing apparatus.

Electrical power supply, fusing apparatus and recording apparatus using

A flash lamp apparatus for reducing occurrence of spots on a recording paper wherein an overlapping portion formed between two adjacent fusing areas of the recording paper receives a first flash and a second flash from a flash lamp so as to heat and fuse a toner on the recording paper. The overlapping portion is controlled so as to reduce occurrence of spots on the recording paper by reducing an area of the overlapping portion on a recording paper. Such reduction in the overlapping portion may be obtained by controlling a frequency of the flash or controlling a feeding velocity of the recording paper. Alternatively, the fusing energy of the overlapping portion may be reduced by changing alternately the radiating energy.

Flash fusing apparatus for reducing occurrence of spots on recording

A driving motor of the type employing pneumatic bearings is improved by reducing a weight moment of an upper pad by cutting away a portion thereof, to make the gaps of the bearing pads of the motor more nearly uniform.

Rotary multi-mirror driving motor

In an impact printer or the like having a plurality of print-hammer drive electromagnets which are respectively connected in series with switching transistors between the terminals of a voltage source, the switching transistors are normally gated into conduction by gating signals with a duration sufficient to energize the electromagnets for operating the associated print hammers. In a test mode which occurs prior to the operation of the printer, the gating signals are successively applied to the switching transistors and the duration of each gating signal is reduced so that the gated transistor remains conductive for a short interval which is insufficient to operate the hammer. The potential at a circuit junction between the respective transistor and the associated electromagnet is coupled through a voltage divider to an input of a coincidence gate which receives its another signal from the gate electrode of the associated transistor to generate a failure indication signal when the input logic states have a predetermined relation therebetween.

Failure detection circuit for impact printers or the like

A printing device having a plurality of print hammers having striking surfaces arranged along a print line and print magnets provided adjacent to one another for driving the printing hammers. A magnetic interference preventing device comprises a memory for storing for each column the excitation lapse time information of the print magnets. A reader which, when exciting each print magnet is started, reads the excitation lapse time information of both print magnets adjacent to each print magnet out of the memory. The reader outputs a signal only when the excitation lapse times of both print magnets are in a predetermined range of time. An inhibitor is used for inhibiting the excitation of each print magnet when the excitation lapse times of both print magnets are within the predetermined range of time.

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Ibaraki, Japan

Shinichi Nishino