Optical pickup device with diffraction sensing

Details Optical pickup device with diffraction sensing Optical pickup device with diffraction sensing

1988-12-09

1990-02-27

Nelms, David C.

Radiant energy

Photocells; circuits and apparatus

Photocell controls its own optical systems

369 46, G01J 120

Patent

active

049048562

ABSTRACT:
An optical pickup device includes a light source, an optical lens system that converges light beams from the light source onto a recording medium, a photodetector with three divided regions that detects light beams reflected from the recording medium, and a hologram optical element that introduces the reflected light beams from the recording medium into the photodetector. The hologram optical element is divided into two regions, a part of the reflected light beams from the recording medium is diffracted by the first region of the hologram optical element and focused on a division line in the direction of the diffraction of the hologram optical element. The division line divides the photodetector into two regions, the first region and the second region. The other part of the reflected light beams is diffracted by the second region of the hologram optical element and focused on the third region of the photodetector. A difference in the output intensity between the first and second regions of the photodetector results in a focus error signal and the total of the output intensity of the first, second and third regions of the photodetector results in an information signal.

REFERENCES:
patent: 4665310 (1987-05-01), Heemskerk
patent: 4750162 (1988-06-01), Tajima
patent: 4817072 (1989-03-01), Toide et al.

Affiliated with

Also associated with

Rating

Optical pickup device with diffraction sensing 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 pickup device with diffraction sensing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical pickup device with diffraction sensing will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-175535