Patent ID: 7241126

Claim:
An apparatus for imparting concaves/convexes to a sheet-like object, comprising: a pair of rollers that are axially parallel and radially opposite to each other, said pair of rollers including a first roller and a second roller; each roller including axially adjacent and circumferentially extending contours, each contour defined by circumferentially alternating convex and concave surfaces, said contours disposed so that a peak of a convex surface on said first roller radially opposes a trough of a concave surface on said sceond roller; at least two axially adjacent contours on at least one roller are distanced by a predetermined axial segment, wherein an outermost diameter of said axial segment is constant and either smaller than a trough of an axially adjacent concave surface or larger than a peak of an axially adjacent convex surface; said sheet like object being passed between said pair of rollers facing each other and being thereby imparted with concaves/convexes; wherein at least one of the rollers is a roller formed with a roller surface by laminating a number of circular plates each provided with concaves/convexes at an outer periphery thereof; and wherein a shape of concaves/convexes of the circular plate the outer periphery of which is provided with concaves/convexes is a shape of concaves/convexes formed by synthesizing two kinds or more of patterns of concave/convexes.