To simplify dampening water supply control and to inhibit the development of a short supply state or an oversupply state of dampening water, in a dampening water feeder and an offset printing machine.
The dampening water feeder comprises dampening rollers 41 and 61 contacting the outer circumferential surface of plate cylinders 32 and 52, water jet devices 42 and 62 which feed dampening water to the outer circumferential surface of the dampening rollers 41 and 61 by jetting the dampening water, and rider rollers 43 and 63 which can adjust the film thickness of the dampening water on the outer circumferential surface of the dampening rollers 41 and 61. A controlling device 71 controls the water jet devices 42 and 62 by setting the dampening water supply in the width direction of a web W according to pictorial pattern information.
TASAKA NORIBUMI
TOSHITO TAKAHIDE
NISHIYAMA KOJI
Jun Takamura