PURPOSE: To obtain an image clarity steel sheet with an excellent workability by limiting a well-regulated projecting part on the surface of a steel sheet to a specific range.
CONSTITUTION: After irradiating and developing the surface of a roll 1 on which resist material which is photosensitive with a specific wave length light is applied, the surface of the roll is etched by chemical etching or vapor phase etching to remove a hardened resist part, and fine projecting and recessed patterns 2 are provided. The size D of the top surface of a well-regulated projecting part on the surface of a steel sheet, is 10 to 1000μm, a difference between the projecting and recessed parts is 2 to 20μm, and a distance between peaks of the projecting parts is 20 to 2200μm and 1<P/D<2.2, where P is a distance between peaks of the projecting parts, D is the diameter of the projecting part and the distance of the one side of the projecting part. When the size D of the top surface of the projecting part is <10μm, since the size of the top surface of the projecting part is acicular, the projecting part is broken by a pressing load. Also, when the size D of the top surface of the projecting part exceeds 1000μm, the supply of lubricating oil to the surface of the projecting part of the steel sheet is insufficient.
NISHIURA TETSUYA
YAMADA MASATO
KAWANO HIROYUKI
