公开(公告)号：US20170263280A1

公开(公告)日：2017-09-14

申请号：US15377044

申请日：2016-12-13

Applicant: Panasonic Intellectual Property Management Co., Ltd.

Inventor： Kazuo MOMOO ,  Junichi ASADA ,  Yasushi KOBAYASHI ,  Kousei SANO ,  Yuichi TAKAHASHI

IPC: G11B7/09

CPC classification number: G11B7/0901 ,  G11B7/094 ,  G11B7/0943 ,  G11B7/131 ,  G11B7/133

Abstract: The first, third, fourth, and seventh photosensors are disposed on one side with respect to the centerline, and the second, fifth, sixth, and eighth photosensors are disposed on another side with respect to the centerline. The first and seventh photosensors are positioned between the third and fourth photosensors in the direction parallel to the centerline. The second and eighth photosensors are positioned between the fifth and sixth photosensors in the direction parallel to the centerline. The first photosensor receives overlapped light of the 0th-order light with the +1st-order diffracted light, the second photosensor receives overlapped light of the 0th-order light with the −1st-order diffracted light, each of the third to sixth photosensors receives the 0th-order light, and does not receive the +1st-order diffracted light and the −1st-order diffracted light, and each of the seventh and eighth photosensors receives at least the 0th-order light.