A device for detection of signals for optical reading of information

摘要

In a signal detecting system in an optical information reading apparatus wherein, in order that a tracking signal having few errors can be obtained, the pupil of an objective used to project a light from a light source as a spot onto the information recording track of a disk, collect the light reflected on the disk and lead it to a light receiving device is covered in the form of a band or a cover plate placed in front of detectors of the light receiving device to intercept a part of the light entering the dectector.