Patent ID: 8625151

Claim:
An apparatus comprising: a conveyance mechanism including a conveyance belt on which detection patterns containing a plurality of isolated patterns are intentionally marked, configured to convey a medium in a predetermined direction; a sensor configured to capture an image of an area on the conveyance belt containing at least a part of the detection patterns to acquire first and second data; and a processing unit configured to extract a template pattern containing a part of the detection patterns from the first data, and seek an area having a correlation with the template pattern within a seek area of the second data to obtain a moving state of the conveyance belt, wherein state of the plurality of isolated patterns contained in the detection patterns, size of the template pattern, and size of the seek area are associated with each other so that the part of the detection patterns contained in the template pattern serves as a unique pattern in the seek area, wherein each of the isolated patterns is given uniqueness with which each pattern is distinguishable from other patterns, by a combination of or at least any one of size, shape, contrast, density, color, and interval arrangement.