DEVICE AND A METHOD FOR RESTORING POSITIONAL INFORMATION OF ROBOT

A device for restoring positional information of a robot provided with a first member and a second member; a motor moving the second member; and a sensor outputting a sensor signal. The device includes an imaging section obtaining an image signal in a region including a first mark and a second mark; a mark position computation section computing a first positional relationship between the first mark and the second mark at a first time and a second positional relationship at a second time, based on an image signal obtained by the imaging section at the first time and at the second time; and a correction section correcting positional information depending on a sensor signal, based on the first and second positional relationship, a first sensor signal output by the sensor at the first time and a second sensor signal output by the sensor at the second time.