G - Physics – 11 – B
Patent
G - Physics
11
B
352/32.4
G11B 7/09 (2006.01) G11B 7/12 (2006.01) G11B 7/135 (2006.01)
Patent
CA 1329262
ABSTRACT OF THE DISCLOSURE An optical pick-up device which is capable of letting the laser beam emitted from a light emitting element focus through an optical system on a recording medium, also of focusing a reflected beam from the recording medium through the same optical system on a photo-detecting element, and also capable of detecting a tracking error signal and a focusing error signal from the output signals from the photo-detecting element, characterized in that there is arranged a diffracting element before the light emitting element and the photo-detecting element, the region on the diffracting element is divided into two sub-regions by a parting line substantially perpendicular to the track direc- tion, in one of these sub-regions there is formed a diffrac- tion grating for separating two sub-spots in the two direc- tions from the laser beam emitted from the light emitting element for applying the so-called 3-spot method, and in the other sub-region there is arranged a diffraction grating causing the reflected beams from the recording medium focus- ed on the photo-detecting element respectively, and, the focusing error signal is detected by the so-called knife edge method, the tracking error signal is detected by the so-called 3-spot method to thereby prevent the occurrence of offset with regard to the tracking error signal due to dis- placement of the optical axis of the optical system, and 23 moreover the number of the optical parts can be reduced. 24
597187
Kurata Yukio
Nagahama Toshiya
Yoshida Yoshio
G. Ronald Bell & Associates
Sharp Kabushiki Kaisha
LandOfFree
Optical pick-up device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical pick-up device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical pick-up device will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1168804