Patent ID: 8866897
Filing Date: 2014-10-21
Classification: G01N

Abstract:
1. An image pickup device for rotating a workpiece on which a shape portion containing at least one of a projecting portion and a recess portion is periodically and repetitively formed, and picking up images of the shape portion of the workpiece, comprising: a workpiece rotating mechanism including a motor for rotating the workpiece at a fixed rotational speed, and an encoder that is disposed on a rotational shaft of the motor to output reference pulses at a fixed interval; an image pickup controller for picking up images of the workpiece at an image pickup timing based on the reference pulses while rotating the workpiece; a workpiece pulse output mechanism for outputting workpiece pulses at an interval synchronized with the shape portion of the workpiece being rotated; and a pulse counter for counting an interval between the workpiece pulses on the basis of the reference pulses to obtain a pulse number corresponding to the interval, wherein the workpiece pulse output mechanism has a rotator that is formed separately from the workpiece, rotates integrally with the workpiece and has a detection target portion at the same angular interval as the shape portion of the workpiece with respect to the center of the rotation, and a proximity sensor for outputting the workpiece pulses every time the detection target portion of the rotator is detected, and the image pickup controller performs image pickup at the image timing based on the reference pulses by using the workpiece pulses as a trigger, and performs the image pickup at the image timing based on the reference pulses every time only reference pulses whose number corresponds to the pulse number are output from the image pickup timing.