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US 6,272,087 B1Granted
Optical disc apparatus
AssigneeFunai Electric Co., Ltd.
InventorMinoru Hirashima
Life of this patent
Estimating the term…
Abstract
An optical disc apparatus includes an optical pickup. When an optical disc is mounted, a focus search is carried out for a lens provided on the optical pickup, and the optical disc is discriminated as to its disc type. At this time, an AGC circuit of an RF amplifier is turned off. The reproduced signal from the RF amplifier is compared with a constant voltage. A measurement is made for a time for which an output from the comparator is at a high level. The high level time is compared with a reference time, thereby discriminating the type of the optical disc.
Claims6
An optical disc apparatus, comprising:
- an RF amplifier having an input for receiving an RF signal outputted from an optical pickup and an outputs for issuing a reproduced signal;
- discriminating means for discriminating between different types of discs depending upon a level of the reproduced signal outputted from said RF amplifier;
- and
- switching means for turning off the AGC circuit of said RF amplified when said discriminating means discriminates the type of said disc.
1 more element
Dependencies are inferred from the claim text.