Iwatsu Electric Company Ltd.

Masanori Kai

Yousuke Igarashi

Toshio Koike

Satoshi Okabe

Tamio Iwamoto

Minehiro Sakata

Nobuyoshi Hatori

Satoshi Hisabayashi

Yasuyuki Yokoyama

Seiichi Homma

Shuichi Kudo

A printing-plate making apparatus is constructed such that a mode selecting switch adapted to change a master supplying process depending on properties of a master X is disposed on a housing 1 of the printing-plate making apparatus and various conditions, e.g., a master supplying process, locking member 4 for a master supplying roller 3, a temperature preset for a panel heater 33 and a compressing force given by press rollers 35a and 35b are automatically changed to optimal conditions corresponding to masters selected by the mode selecting switch. The printing-plate making apparatus is provided with a master heating switch on the housing 1 of the printing-plate making apparatus and when the master heating switch is actuated, applying of a certain voltage to at least a charger is stopped so that the panel heater 33 arranged at a fixing step is kept in the heated state so as to serve as a master heating unit.

Printing plate making apparatus for two different kinds of masters

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

Disclosed is an improved electrophotographic copying machine in which a black frame eliminating mechanism and a random cutting assembly adapted to cut a roll of photosensitive paper to a required length are incorporated. The black frame eliminating mechanism comprises an original supporting window, the length of which is longer than that of an original, an original depressing plate having a white surface facing and covering over the supporting window, means for depositing a charge over the length of a portion of a photosensitive paper, which length corresponds to that of the original, and means for exposing the paper placed at a predetermined position to the light from the entire area of the supporting window. The cutting assembly comprises first, second and third feed rollers arranged in this order along a paper feed passage, first means for driving the first and second feed rollers so as to feed the paper at a first synchronous feeding speed and second means for driving the third feed rollers so as to feed the paper at second feeding speed which is lower than the first speed, a one-way clutch adapted to allow the second rollers to feed the paper only in a downstream direction and cutting means adapted to cut the paper portion between the first and second rollers, wherein cutting of the paper is effected at the location between the first and second rollers when the drive of the first and second rollers is stopped, feeding of the paper is stopped at a position at the first rollers or upstream thereof, and slack of the paper portion between the second and third rollers, caused by difference between the first and second feeding speeds, is being changed to a tensioned condition.

Electrophotographic copying machines

Growing community of inventors

Hachioji, Japan

Masanori Kai