Optical pickup device

Abstract

Abstract PURPOSE:To attain miniaturization of an optical pickup device with a simple mechanism by separating the light of an optical source from the reflected light sent from a disk through a diffracting means and receiving the diffracted light of a specific order of the disk reflected light. CONSTITUTION:The light radiated from a laser light source 1 is made incident to a diffraction grating 8 with an incident angle theta. The state of distribution of diffracted light is decided by the depth and the space of grooves forming the grating 8. Then only the primary diffracted light is led out with the depth d= lambda/2. Furthermore the irradiating angle of the primary light is decided by the space between gooves, and only the primary diffracted light is divided in two directions. One of these two divided light is made incident vertically to an objective lens 3. The light focused by the lens 3 and irradiated to a disk 4 is reflected on the recording surface. This a reflected light is made incident again to the lens 3 and then made incident vertically to the grating 8 in the form of parallel light beams. While the primary diffracted light of the other side is received by a photoreceptor 5.

Inventors

• 👤 Yoshiyuki Tsukai
• 👤 塚井　好之
• 👤 Akihiro Tachibana
• 👤 昭弘 橘

Bibliographic Details