Dynamic information storage or retrieval – Specific detail of information handling portion of system – Radiation beam modification of or by storage medium
Patent
1992-06-17
1993-10-05
Sniezek, Andrew L.
Dynamic information storage or retrieval
Specific detail of information handling portion of system
Radiation beam modification of or by storage medium
369 54, 369 4411, 369 4425, G11B 700
Patent
active
052511995
ABSTRACT:
In an apparatus for detecting an abnormality of an optical system in a reproducing and recording apparatus of an optical recording medium and executing a driving control of a laser diode, detection of abnormality is performed with the optical system set into a de-focusing state. The apparatus has control device for comparing a level of a first detection signal having the level according to the level of first light beam which is led to the optical recording medium and a level of a second detection signal having the level of the second light beam, thereby controlling a driving current. The control device turns off a loop switch of a focusing servo loop of an objective lens, thereby setting the lens into a de-focusing mode, compares the levels of the first and second detection signals after the de-focusing state of the lens by the actuator is obtained, to discriminates whether a ratio of those levels lies within a predetermined range or not; and shuts off the driving current when it is determined that the ratio is out of the predetermined range.
REFERENCES:
patent: 4516242 (1985-05-01), Yokota
patent: 4800548 (1989-01-01), Koishi et al.
patent: 4890273 (1989-12-01), Takeuchi et al.
patent: 4982397 (1991-01-01), Yokota
patent: 5101392 (1992-03-01), Yoshimani et al.
patent: 5101396 (1992-03-01), Takeuchi et al.
patent: 5136569 (1992-08-01), Fennema et al.
Kakuta Yoshiyuki
Utsumi Yoshihiro
Pioneer Electronic Corporation
Sniezek Andrew L.
Tran Thang V.
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