Roll mark inspection apparatus

A roll mark inspection apparatus which is applied to a system for rolling and moving a strip material using reduction rolls, comprising:

• first means for scanning widthwise said strip material rolled and moved by said reduction rolls, and outputting a first signal representing a surface state of said strip material;
• second means for generating a second signal synchronized with running of said strip material moved by said reduction rolls;
• third means for sequentially receiving the first signal in synchronism with the second signal, and outputting a third signal obtained by performing predetermined autocorrelation calculation processing to contents of the received signal;
• fourth means for comparing a predetermined comparison level for discriminating information corresponding to a roll mark on the surface of said strip material with the third signal, and outputting a fourth signal discriminated from the third signal by the predetermined comparison value;
• and
• fifth means for updating and displaying image information corresponding to the fourth signal each time said strip material runs by a predetermined distance corresponding to a circumferential length of said reduction rolls.

A roll mark inspection apparatus which receives roll mark data from an inspection head for scanning widthwise a strip running material rolled and moved by rolls and stores the roll mark data in an image memory having a storage area corresponding to a circumferential length of said rolls, sequentially reads out the roll mark data stored in said memory in synchronism with a running rate of said strip running material to calculate an autocorrelation value, and compares the autocorrelation value with a set value by a comparator, thereby inspecting a periodic roll mark formed on said strip running material, comprising:

• a sync signal generator for generating a sync signal synchronized with the running rate of said strip running material;
• latch means connected to said sync signal generator for receiving the sync signal from said sync signal generator to detect that said strip running material runs by the roll circumferential length, and latching a comparison result output from said comparator;
• and
• display means connected to said latch means for causing a CRT display device to display the comparison result output latched by said latch means as one raster.