US 5,311,493 A · Data reproduction circuit for converting a read analog signal

Abstract

A data reproduction circuit for converting a read analog signal into digital data corresponding to recording data, has a second order differential circuit for emitting a second order differentiated signal of the read analog signal read from a data recording medium, an inverter for generating a comparative voltage that is switched between a plurality of levels, and a comparator for comparing the second order differentiated signal and the comparative voltage to release digital data. This permits to cancel a DC component of the read analog signal and to adopt a 2,7 NRZI method for recording and reproduction enabling to achieve a high recording density. The circuit further comprises a peak detecting circuit for detecting and converting a peak of the read analog signal into digital data, and that has a first order differential circuit for emitting a first order differentiated signal of the read analog signal, a three-state inverter for generating a second comparative voltage that is switched between a plurality of levels, and a comparator for comparing the first order differentiated signal and the second comparative voltage to release digital data. The circuit may thus be adopted for both RZ and NRZI methods.

Claims14

Dependent claims

A data reproduction circuit for converting a read analog signal read from a data recording medium into digital data corresponding to recording digital data, comprising:

(a) first order differential means for emitting a first order differentiated signal derived from the read analog signal,
(b) second order differential means for emitting a second order differentiated signal of the read analog signal derived from the read analog signal or said first order differentiated signal,
(c) an edge detecting circuit for detecting and converting a leading edge and a trailing edge of the read analog signal into the digital data, and
(d) a peak detecting circuit for detecting and converting a peak of the read analog signal into the digital data,
said edge detecting circuit including
(1) first comparative voltage generating means for generating a first comparative voltage that has a plurality of levels, and
(2) first comparing means for comparing said second order differentiated signal and said first comparative voltage to generate first digital data;
and said peak detecting circuit including
(1) second comparative voltage generating means for generating a second comparative voltage that has a plurality of levels, and
(2) second comparing means for comparing said first order differentiated signal and said second comparative voltage to generate second digital data;
and
(e) means for switching said comparative voltage for obtaining said plurality of levels.

9 more elements

A data reproduction circuit comprising:

a first differential circuit for emitting a first order differentiated signal derived from a read analog signal read from a data recording medium;
a second differential circuit for emitting a second order differentiated signal derived from said first order differentiated signal;
an edge detecting circuit for releasing a first comparative voltage, and comparing said second order differentiated signal and said first comparative voltage to release first digital data so that said first digital data can be used in an NRZ method;
and
a peak detecting circuit for releasing a second comparative voltage, and comparing said first order differentiated signal and said second digital data,
wherein said peak detecting circuit comprises:
a second comparator for comparing said first order differentiated signal and said second comparative voltage to release a second digital output signal;
and
two three-state inverters wherein an output signal released from said second comparator is fed to and that respectively release said second comparative voltage,
wherein only one of said three-state inverters is opened in response to control signal respectively fed into each of said three-state inverters.

7 more elements

Dependencies are inferred from the claim text.

Data reproduction circuit for converting a read analog signal

Life of this patent

Data reproduction circuit for converting a read analog signal

Life of this patent

Abstract

Claims14