The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 30, 2003
Filed:
Jan. 05, 2001
Haruo Tanaka, Kyoto, JP;
Masahiko Tsumori, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
A light emitting portion ( ) and an objective lens ( ) for collecting a light of the light emitting portion are provided. The light receiving portion ( ) is provided in the vicinity of the light emitting portion ( ) such that the light can be collected by the objective lens and the light reflected by an optical disk ( ) to be an object can be detected. The light emitting portion and the light receiving portion are formed to get in a range of 1.22 &lgr;/NA (beam waist BW) wherein a numerical aperture of the objective lens is represented by NA and a wavelength of the light emitting portion is represented by &lgr; or the light receiving portion is multi-split such that a focal shift of a beam having an astigmatism formed thereon can be detected. As a result, it is possible to obtain a light receiving and emitting compound element capable of surely detecting a focal position without adjusting a positional relationship between the light emitting portion and the light receiving portion and an optical pick-up device capable of being easily assembled and of detecting and correcting a shift in a focus or a tracking with a high sensitivity.