Phase error detector and optical disc device

Patent metadata

Field	Value
Publication number	US-9495999-B2
Application number	US-201514964614-A
Country	US
Kind code	B2
Filing date	Dec 10, 2015
Priority date	Dec 26, 2014
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A phase error detector includes a sine wave generation circuit that generates a sine wave signal, based on a first input signal of a first period, a cosine wave generation circuit that generates a cosine wave signal, based on the first input signal, a first calculator that calculates a phase difference between the sine wave signal and a second input signal of a second period, a second calculator that calculates a phase difference between the cosine wave signal and the second input signal, and a first selection unit that outputs the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is within a predetermined range, and outputs a predetermined value having a same sign as a sign of the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is out of the predetermined range.

First claim

What is claimed is:

1. A phase error detector comprising:
a sine wave generation circuit configured to generate a sine wave signal, based on a first input signal of a first period;
a cosine wave generation circuit configured to generate a cosine wave signal, based on the first input signal;
a first calculator configured to calculate a phase difference between the sine wave signal and a second input signal of a second period;
a second calculator configured to calculate a phase difference between the cosine wave signal and the second input signal; and
a first selection unit configured to output, as a phase error, the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is within a predetermined range, and outputs, as the phase error, a predetermined value having a same sign as a sign of the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is out of the predetermined range.

2. The phase error detector according to claim 1 , wherein the predetermined value is an absolute value of a maximum value or a minimum value of the phase difference calculated by the first calculator.

3. The phase error detector according to claim 1 , wherein the predetermined range is a range from −90 degrees to +90 degrees.

4. The phase error detector according to claim 1 , comprising:
a timing generation circuit configured to output a timing signal “1” when the phase error as the output of the first selection unit is substantially 0, and outputs a timing signal “0” when the phase error as the output of the first selection unit is not substantially 0;
a low-pass filter configured to output a value obtained by smoothing the phase error output by the first selection unit when the timing signal is “0”, and hold and output the value obtained by smoothing the phase error when the timing signal is “1”, and
a second selection unit configured to output input from the low-pass filter when the timing signal is “1”, and outputs the phase error output by the first selection unit when the timing signal is “0”.

5. An optical disc device comprising:
a sine wave generator configured to generate a sine wave signal, based on a first input signal of a first period;
a cosine wave generator configured to generate a cosine wave signal, based on the first input signal;
a first calculator configured to calculate a phase difference between the sine wave signal and a second input signal of a second period;
a second calculator configured to calculate a phase difference between the cosine wave signal and the second input signal;
a first selection unit configured to output, as a phase error, the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is within a predetermined range, and outputs, as the phase error, a predetermined value having a same sign as a sign of the phase difference calculated by the first calculator when the phase difference calculated by the second calculator is out of the predetermined range; and
a clock generator configured to generate a clock, using the phase error.

6. The optical disc device according to claim 5 , further comprising:
a timing generation circuit configured to output a timing signal “1” when the phase error as the output of the first selection unit is substantially 0, and outputs a timing signal “0” when the phase error as the output of the first selection unit is not substantially 0;
a low-pass filter configured to output a value obtained by smoothing the phase error output by the first selection unit when the timing signal is “0”, and hold and output the value obtained by smoothing the phase error when the timing signal is “1”; and
a second selection unit configured to output input from the low-pass filter when the timing signal is “1”, and outputs the phase error output by the first selection unit when the timing signal is “0”,
wherein the clock generator generates the clock, using the output of the second selection unit.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Minamino Junichi
• Nakata Kohei

Classifications

• G11B7/24082

  Meandering · CPC title

• G11B7/0053

  Reproducing non-user data, e.g. wobbled address, prepits, BCA · CPC title

• G11B20/1024 Primary

  wherein a phase-locked loop [PLL] is used · CPC title

• G11B7/0941

  Methods and circuits for servo gain or phase compensation during operation (for initialising servos G11B7/0945) · CPC title

• G11B2020/1268

  Address in pregroove [ADIP] information · CPC title