Photoreceiver amplifier circuit and optical pickup employing the same
AssigneeSharp Kabushiki Kaisha
InventorKatsuyuki Kawamura
Life of this patent
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Abstract
A photoreceiver amplifier circuit has an amplifier for amplifying the detection signal of a photoreceiver device, a plurality of negative feedback circuits connected between the input terminal and the output terminal of the amplifier in parallel with one another so as to form different negative feedback loops, and a switch circuit for selecting one among the plurality of negative feedback circuits. The frequency band and/or the gain of the photoreceiver amplifier circuit is varied according to the detection signal of the photoreceiver device. This makes it possible to switch the frequency band without degradation in amplification characteristics.
Claims9
A photoreceiver amplifier circuit comprising:
- an amplifier for amplifying a detection signal of a photoreceiver device;
- a plurality of negative feedback circuits connected between an input terminal and an output terminal of the amplifier in parallel with one another so as to form different negative feedback loops;
- and
- a switch circuit for selecting one among the plurality of negative feedback circuits,
- wherein a frequency band and/or a gain of the photoreceiver amplifier circuit is varied according to the detection signal of the photoreceiver device.
An optical pickup comprising:
- a photoreceiver amplifier circuit including an amplifier for amplifying a detection signal of a photoreceiver device, a plurality of negative feedback circuits connected between an input terminal and an output terminal of the amplifier in parallel with one another so as to form different negative feedback loops, and a switch circuit for selecting one among the plurality of negative feedback circuits, a frequency band and/or a gain of the photoreceiver amplifier circuit being varied according to the detection signal of the photoreceiver device,
- wherein the optical pickup is for reading data from and writing data to an optical disk.
Dependencies are inferred from the claim text.