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:
Jun. 24, 2003
Filed:
Jun. 24, 1999
Ricoh Company, Ltd., Yokohama, JP;
Abstract
An optical pick-up device for recording/reading an optical recording medium is provided, which can efficiently utilize light emitted from the laser light source. The optical pick-up device includes a light source, an optical system, a quarter-wave plate, a diffraction component, and a photodetector unit. The photodetector unit may further include a transmitting portion for transmitting the light beam emitted from the light source, and may be disposed opposite the light source in a vicinity of the light source so that light emitted from the light source is transmitted through the transmitting portion. The transmitting portion may be an aperture provided in the photodetector unit. Alternatively, the optical pick-up device may further include an optical path separator for separating the diffracted returning light beam from the light beam that passes from the light source to the diffraction component.