LIGHT PICKUP

PURPOSE:To exactly read out a light beam from an information recorder without requiring severe mounting accuracy of a hologram, and also, without shifting a focus of incident light to an optical disk due to a vibration, etc. of an actuator, by using the hologram instead of the reflected light of a m...

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Bibliographic Details
Main Authors HASEGAWA SHINYA, KATO MASAYUKI, YAMAGISHI FUMIO, IKEDA HIROYUKI, INAGAKI MASAFUMI
Format Patent
LanguageEnglish
Published 26.09.1987
Subjects
INFORMATION STORAGE
INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER
PHYSICS
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Summary:PURPOSE:To exactly read out a light beam from an information recorder without requiring severe mounting accuracy of a hologram, and also, without shifting a focus of incident light to an optical disk due to a vibration, etc. of an actuator, by using the hologram instead of the reflected light of a mirror. CONSTITUTION:A light beam which is made on a lambda/4 plate 20 is emitted to a beam splitter 19. The beam splitter 19 curves the incident light beam by 90 deg., and makes it incident on a converging lens 21. The light beam which is made incident on the converging lens 21 is irradiated by the converging lens 21, to a detector 22 which exists in a focal position of the converging lens 21. Also, the light beam which is irradiated to this detector 22 is the reflected light from a disk 14 which scarcely causes an error by a hologram 23. Such an error is smaller error than that of a shift angle (DELTA...)=2DELTAtheta which is generated in case when for instance, the incident light A is shifted by an angle DELTAtheta, by using a conventional mirror, and a data of the disk 14, which is detected by the detector 22 goes to a more accurate data.
Bibliography:Application Number: JP19860060822