OPTICAL PICKUP

PURPOSE:To reduce the number of parts and to realize miniaturization and lightening by using a plaid square inline type grating lens in a concentric shape for a diffraction grating and generating a side spot at both sides of a main spot. CONSTITUTION:The inline type grating lens 31 having an about c...

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Bibliographic Details
Main Authors KATO MASAYUKI, YAMAGISHI FUMIO, IKEDA HIROYUKI, MAEDA TOMOJI, INAGAKI MASAFUMI
Format Patent
LanguageEnglish
Published 23.01.1989
Subjects
INFORMATION STORAGE
INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER
PHYSICS
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Summary:PURPOSE:To reduce the number of parts and to realize miniaturization and lightening by using a plaid square inline type grating lens in a concentric shape for a diffraction grating and generating a side spot at both sides of a main spot. CONSTITUTION:The inline type grating lens 31 having an about concentric plaid square is used as the diffraction grating of an optical pickup. The specified light using efficiency relaying on a polarizing state is given to this lens 31 and side spots 13b, 13c are generated at both sides of the beam spot (main spot) 13a for reading a signal according to the diffraction efficiency distribution of a laser light thereby. The conventional beam focusing lens is made unnecessary, the number of parts is reduced and the miniaturization and lightening are realized by using the grating lens equipped with both of a side spot forming function and beam focusing function.
Bibliography:Application Number: JP19870173860