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. 27, 1995
Filed:
Sep. 15, 1993
Shigeru Ohuchida, Zama, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
The present invention relates to an optical head for recording, reproducing and erasing data on an optical data recording medium. The optical head has a fixed optical system having a laser optical source for emitting a light and a signal detecting optical system for detecting an error signal. A movable optical system having a beam splitter provided with a prism boundary face and having an objective at a position thereof opposing a surface of the optical data recording medium for receiving the emitted light through the beam splitter and focusing the received light onto the surface of the optical data recording medium as an optical spot. The beam splitter has, at the prism boundary face thereof, a polarizing film for transmitting one portion of the emitted light from the laser light source. The beam splitter has, at one side face thereof, reflective face for reflecting one portion of or all of the transmitted light through the polarizing film, and has, at another side face thereof, a light receiving element thereof for receiving the reflected light from the reflective face and one portion of said reflected light from the surface of the optical data recording medium.