Optical pickup system

• Main Authors: YANG, KEUN YOUNG, NOH, SUNG WOO
• Format: Patent
• Language: English; French; German
• Published: 30.08.1995
• Edition: 6
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

An optical pickup system simply formed to improve read-out speed and reduce manufacturing cost has a semiconductor laser as a light source, a polarizing beam splitter (PBS) which reflects all S-polarized beam and some of P-polarized beam and transmits the other P-polarized beam in the laser beam from the semiconductor laser while reflecting all S-polarized beam and some of P-polarized beam and transmitting the other P-polarized beam in beams reflected by a disc, a collimator lens for changing the laser beam into parallel beams to be incident to the PBS while focusing the P-polarized beam transmitted via the PBS before being reflected by the disc, a reflection mirror for reflecting the beams transmitted via the PBS to the disc while reflecting the beams reflected by the disc to the PBS, an objective lens for focusing the beams reflected by the reflection mirror to the disc and forming the beams reflected by the disc into parallel beams to be incident to the reflection mirror, a photodetector divided-by-six for detecting tracking and focus errors in view of the intensity of beams focusing onto six sections, a hologram device for diffracting to make the laser beam be incident to the collimator lens while diffracting to focus the P-polarized beam transmitted via the PBS onto the photodetector divided-by-six, a bisectional photodetector for detecting the information in view of the intensity of the beams focusing to two sections, a Wollaston prism for separating beams of P-wave and S-wave components from a mixed beam of P-wave and S-wave components from the PBS, and a focusing lens for focusing the P-wave and S-wave separated by the Wollaston prism into two sections of the bisectional photodetector.