Dynamic information storage or retrieval – Specific detail of information handling portion of system – Radiation beam modification of or by storage medium
Patent
1999-03-19
2000-05-02
Dinh, Tan
Dynamic information storage or retrieval
Specific detail of information handling portion of system
Radiation beam modification of or by storage medium
369124, 369 4441, 369 4432, G11B 1103, G11B 1112
Patent
active
060580933
ABSTRACT:
A pre-pit detecting apparatus detects a pre-pit with respect to an information record medium having a record track and a guide track which is to guide a light beam onto the record track and on which the pre-pit to record control information is formed in advance. The first pre-pit detecting apparatus is provided with: a light receiving device having four divided light detection areas each for receiving a reflection light of the light beam emitted on the record track. The four divided light detection areas are divided such that the reflection light beam is divided by a first division line which is optically in substantially parallel to the record track and a second division line which is optically in substantially orthogonal to the record track. The light receiving device outputs first to fourth light detection signals corresponding to the first to the fourth division areas respectively. The pre-pit detecting apparatus is also provided with: a first difference signal generation device for generating a first difference signal by subtracting the third light detection signal from the first light detection signal; a second difference signal generation device for generating a second difference signal by subtracting the second light detection signal from the fourth light detection signal; a correction device for delaying the second difference signal by a delay time; and a pre-pit detection signal output device for adding the first difference signal and the delayed second difference signal to output it as a pre-pit detection signal.
REFERENCES:
patent: 4550394 (1985-10-01), Maeda et al.
patent: 4961182 (1990-10-01), Saito et al.
patent: 5070492 (1991-12-01), Ogawa et al.
patent: 5297114 (1994-03-01), Itoh et al.
patent: 5406536 (1995-04-01), Doi
patent: 5408452 (1995-04-01), Sakemoto et al.
patent: 5917793 (1999-06-01), Uchiumi
"Optical Disc System, Applied Physics Academy/Optics Conversazioine Book, published by Asakura Bookstore" (English translation).
Kato Masahiro
Muramatsu Eiji
Chu Kim-Kwok
Dinh Tan
Pioneer Electronic Corporation
LandOfFree
Pre-pit detecting apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pre-pit detecting apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pre-pit detecting apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1599498