PURPOSE: To automatically adjust a nip width on a blanket by a method wherein a contact part between the blanket and a form bed or a printing surface plate is measured from the reverse side of the form bed through windows made of transparent materials provided to the form bed, and the form bed is adjusted vertically in accordance with the results of comparison between the measured values and preset values.
CONSTITUTION: A nip width (the width of a contact part between a form bed and a blanket) 11a on the form bed of a flat-bed offset press is measured with a CCD camera and an illuminating device 9 provided on the underside of a glass window 10a, and the measured values are taken into an image processing device, then a form bed base 5 and the form bed 3 are moved up and down by operations of a driving device 7 and a transmission device 8, and thereby the nip width 11a is automatically adjusted. At the same time, the pressure applied by the blanket 1 is measured with a pressure measuring device 6. Furthermore, inclination of the form bed in the direction to which a blanket cylinder 2 proceeds is made discernible by providing the glass windows 10a and 10b on two places, and by making the measurement of the nip width executable through said two windows.
IWASAKI KATSUMI
NEMOTO SHIRO
