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:
Sep. 29, 2009
Filed:
May. 29, 2001
Sören Dambach, Karlsruhe, DE;
Hartmut Richter, Villingen-Schwenningen, DE;
Sören Dambach, Karlsruhe, DE;
Hartmut Richter, Villingen-Schwenningen, DE;
Thomson Licensing, Boulogne, Billancourt, FR;
Abstract
The present invention relates to an appliance for reading from and/or writing to optical recording mediahaving a first laser diode LDfor producing a first scanning beam ASat a first wavelength λand having a second laser diode LDfor producing a second scanning beam ASat a second wavelength λ, with the scanning beams AS, ASrunning along a common optical axis, scanning an information layeron the recording mediumand falling on a single photodetectorin order to produce an information signal IS, with a beam combination element being arranged at one point on the optical axis. According to the invention, the beam combination element is a diffraction grating