Sharp Kabushiki Kaisha Corporation

Ikuo Itoh

Kunio Ohashi

Masatsugu Nakamura

Shunju Anzai

Hiromu Sasaki

Masatoshi Kaneshige

Naotaka Funayama

Toshio Yamagishi

Yoshiaki Imanaka

Hiroaki Uchiyama

Toyoki Tanaka

Toshiyuki Kurosaka

The developing device, which is capable of mixing developers with magnetic toners and capable of providing the developers having a uniform magnetic toner density to a photoconductor for a copying machine, the device having a developing tank which contains a roller composed of a sleeve and a magnetic body with the magnetic body being disposed inside of the sleeve concentrically and rotatably with respect to each other, the device also having a magnetic toner supply tank disposed adjacent to the developing tank for supplying the magnetic toners to the developing tank through a toner supply port, the developing device includes a unit coupled to the developing tank for controlling an amount of the developers to be supplied to the sleeve, and a unit disposed between the toner supply port and the control unit for scraping the developers from the sleeve. The scraping unit is so arranged that a stirring portion is formed in association with the sleeve for stirring the developers scraped from the sleeve and the magnetic toners supplied from the toner supply tank through the toner supply port. The scaping unit has a throughhole for making the scraped developers to be mixed with the magnetic toners supplied from the toner supply tank through the toner supply port in accordance with a magnetic force produced by the magnetic body so as to produce a flow of the developers which passes through the throughhole.

Developing device with a scraping unit arranged to form a stirring area

An electrophotographic image forming apparatus having a photoreceptor for forming an electrostatic image thereon corresponding to an original, a main charger for uniformly charging the photoreceptor to a specific polarity interchangeable developer units each containing a toner or developer capable of being charged to the same polarity as that of the main charger, a transference charger for transferring the toner image from the surface of the photoreceptor, optimally charge removal charger and switching devices for changing the polarities of a voltage applied to the transference charger and charge removal charger.

Positive/negative image forming method and apparatus for

A copying machine utilizing a generally endless photoreceptor belt trained between reduced and large diameter rolls. At least one of the rolls is drivingly coupled with a drive unit and is driven at a low speed when and so long as the machine is in a standby condition to avoid localized heating of the photoreceptor belt.

Copying machine having means to eliminate local temperature changes in a

Disclosed is an extremely convenient copying machine for performing copying operations using a selected color toner of internally provided color toner developer containers, which copying machine effectively provides means for cumulatively counting the number of copied papers processed by each color toner developer container. The preferred embodiment provides a plurality of counters for counting the number of copied papers provided for each color toner developer container, and feeds the counter pulses generated in each copying cycle to these counters according to the selected color of the internally installed color toner developer containers. A display unit is also provided so that the actual number of copied papers processed by each color toner developer container can be cumulatively displayed as required.

Color copying machine with copy number counting device for individual

An electrophotographic copying machine includes a combined developing-cleaning magnetic brush element. When the copy sheet is smaller than half the size of a photosensitive drum surface, two sheets of copy are obtained by three revolutions of the photosensitive drum in a multi-copy mode. During the first revolution of the photosensitive drum, the combined developing-cleaning magnetic brush element conducts the developing operation onto a first half section of the photosensitive drum and conducts the cleaning operation onto a second half section of the photosensitive drum. During the second revolution of the photosensitive drum, the first half section is cleaned and the second half section is developed. During the third revolution of the photosensitive drum, the first and second half sections are cleaned by the combined developing-cleaning magnetic brush element.

Electrophotographic copying machine

An electrophotographic copying machine includes a housing which is separated into an upper body and a lower body along a path of a copy paper in order to facilitate the removal of a jammed paper. When the housing is separated into the upper and lower bodies, a light memory effect is created on a photosensitive drum due to the ambient light. When the upper body is closed after removal of the jammed paper, a light memory removing operation is conducted, wherein a transcription unit and an erase unit are activated without transferring a copy paper.

Growing community of inventors

Nara, Japan

Ikuo Itoh