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:
Jul. 04, 2000
Filed:
Aug. 23, 1999
Kouki Kojima, Fukuoka, JP;
Fuminobu Furukawa, Onojo, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An optical pickup capable of recording or reproducing information from optical disks having different recording densities includes a first optical unit having a light source which emits rays having a first wavelength for DVDs and a first light sensor which detects reflected rays, a second optical unit having a light source which emits rays having a second wavelength for CDs and a second light sensor which detects reflected rays, a beam splitter which directs the rays having the first wavelength and the rays having the second wavelength along substantially the same optical axis, and directs reflected rays from an optical disk to the first light sensor and the second light sensor, and an objective lens which has a numerical aperture (NA) of 0.6 or more, a focal length of 2.5 mm or less, an effective diameter of incidence of 3.0 mm or less and a working distance of 1.2 mm or less. The light pickup as a whole has a thickness of 7.5 mm or less as measured from a bottom surface of the optical disk. The light pickup is capable of reproducing information from optical disks having different recording densities, is composed of a small number of parts, and is compact and thin.