Optical medium reproduction apparatus and optical medium reproduction method

Patent metadata

Field	Value
Publication number	US-9672859-B2
Application number	US-201414911980-A
Country	US
Kind code	B2
Filing date	Jul 30, 2014
Priority date	Aug 14, 2013
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

The present disclosure relates to a reproduction apparatus. The reproduction apparatus may comprise an optical filter and electric filters. The optical filter may be configured to provide electrical signals corresponding to regions of an optical beam returning from an optical medium, the optical beam being incident on the optical filter, the regions of the optical beam corresponding to different bands in a line density direction and/or a track density direction. The electric filters may be configured to provide outputs based, at least in part, on the electrical signals provided by the optical filter, wherein the reproduction apparatus is configured to obtain a reproduced signal by combining the outputs of the electric filters.

First claim

The invention claimed is:

1. A reproduction apparatus comprising:
a detection unit configured to:
divide a section of a beam returning from an optical medium into at least first and second outer regions exclusive of a center of the section of the beam and corresponding, respectively, to first and second channels, wherein the first region includes an outer region in a radial direction of the beam, and wherein the second region includes an outer region in a tangential direction of the beam, and
form detected signals corresponding to the respective channels;

a multi-input equalizer component comprising equalizer units supplied with the respective detected signals corresponding to the channels, and configured to perform computing on outputs of the equalizer units and to output an equalized signal based on the computing; and
a binarization unit configured to perform binarization processing on the equalized signal to obtain binary data.

2. The reproduction apparatus according to claim 1 , wherein the multi-input equalizer component comprises a multi-input adaptive equalizer component configured to output the equalized signal, and wherein the apparatus further comprises an equalization error computing unit configured to:
obtain equalization error data based, at least in part, on an equalization target signal and on the equalized signal, wherein the equalization target signal is obtained based, at least in part, on the binary data, and supply the equalization error data to the adaptive equalizer unit to control adaptive equalization.

3. The reproduction apparatus according to claim 2 , wherein:
the multi-input adaptive equalizer component is configured to perform partial response equalization processing on the detected signals corresponding to the respective channels, the binarization processing by which the binary data is obtained comprises maximum likelihood decoding processing, the equalization target signal is obtained by performing convolution with the binary data, and the equalization error computing unit is configured to obtain the equalization error data by computing using the equalization target signal and the equalized signal.

4. The reproduction apparatus according to claim 1 , wherein the detection unit includes photodetectors divided to correspond to the regions and configured to obtain the detected signals.

5. The reproduction apparatus according to claim 4 , further comprising an optical path conversion element configured to separate the beam returning from the optical medium into the regions, wherein the optical path conversion element is disposed in an optical path through an object lens and to the detectors, and wherein the regions of the beam separated by the optical path conversion element are input to respective detectors.

6. The reproduction apparatus according to claim 1 , wherein the optical medium includes alternating lands and grooves, and wherein information is recorded on both the lands and grooves.

7. A method comprising:
dividing a section of a beam returning from an optical medium into at least first and second outer regions exclusive of a center of the section of the beam and corresponding, respectively, to first and second channels, wherein the first region includes an outer region in a radial direction of the beam, and wherein the second region includes an outer region in a tangential direction of the beam;
forming detected signals corresponding to the respective channels;
supplying the detected signals corresponding to the channels to respective equalizer units;
using a multi-input equalizer component comprising the equalizer units to perform computing on outputs of the equalizer units and to output an equalized signal based on the computing; and
performing binarization processing on the equalized signal to obtain binary data.

Assignees

• Sony Corp

Inventors

• Nishi Noriaki
• Saito Kimihiro
• Shiraishi Junya
• Tentaku Yutaka
• Ando Nobuhiko

Classifications

• G11B7/00718 Primary

  Groove and land recording, i.e. user data recorded both in the grooves and on the lands · CPC title

• G11B20/10037

  A/D conversion, D/A conversion, sampling, slicing and digital quantisation or adjusting parameters thereof · CPC title

• G11B20/10046 Primary

  filtering or equalising, e.g. setting the tap weights of an FIR filter · CPC title

• G11B7/1381

  Non-lens elements for altering the properties of the beam, e.g. knife edges, slits, filters or stops (G11B7/1353 - G11B7/1369 take precedence) · CPC title

• G11B7/133

  Shape of individual detector elements · CPC title