Iwatsu Electric Company Ltd.

Satoshi Hisabayashi

Toshio Koike

Kiyohito Ebisawa

Kazuyuki Hashimoto

Yousuke Igarashi

Masanori Kai

Mitsuo Kuromori

Seiichi Homma

A method of controlling a position of a plate material sheet in a platemaking machine for feeding the plate material sheet in an exposure region and forming a document image on the plate material sheet. A plate material sheet length sensor detects that the plate material sheet to be fed to the exposure region has passed by the sensor. The overall length of the plate material sheet is calculated in accordance with the number of pulses supplied to a plate material sheet drive motor while the plate material sheet length sensor generates an output. Also calculated is a first predetermined number of pulses to be supplied to the plate material sheet drive motor so as to feed the plate material sheet by a first predetermined length within the exposure region. A stop sensor detects a front edge of the plate material sheet, the stop sensor being arranged such that a center thereof is aligned with the axis of the optical system; and the first predetermined number of pulses is supplied to the plate material sheet drive motor after the stop sensor generates an output, so that a center of a first portion of the plate material sheet is aligned with the axis of the optical system.

Method of controlling platemaking positions and errors

An exposure device of an electrographic copying apparatus including at least one heat generative exposure lamp for exposing a photosensitive paper corresponding to an original to be copied. A paper detector detects the photosensitive paper at an inlet of the apparatus. A rotatable cam is actuated by a signal from the paper detector and, in turn, actuates a switching apparatus in a predetermined sequence during one revolution thereof. A relay is actuated by one of said switches so as to be self-latched for a predetermined time, to activate the exposure lamp for the predetermined time.

Exposure device of an electrographic copying apparatus

An electrographic copying apparatus which includes a paper feeding device, a charging device, an exposure device, a developing device including a developing vessel, a developer feed pump, and pressure rollers, and a paper conveyor, wherein each operational device is operated in a predetermined sequence, the original to be copied can be easily set into place, photographic papers of various sizes are usable, the developer can easily be replenished, and a pressing roller can be easily removed when desired.

Electrographic copying apparatus

Growing community of inventors

Hachioji, Japan

Satoshi Hisabayashi