Method and system for determining the quality of a storage system

• US 8,958,274 B2
• Filed: 09/06/2011
• Issued: 02/17/2015
• Est. Priority Date: 09/08/2010
• Status: Expired due to Fees

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Hepper, Dietmar, Theis, Oliver, Chen, Xiaoming, Hoelzemann, Herbert, Pilard, Gael
• Primary Examiner(s): BERNARDI, BRENDA C
• Application Number:
  US13/820,543
• Publication Number:
  US 20130155827A1
• Time in Patent Office: 1,260 Days
• Field of Search: 369/47.27, 369/47.5, 369/53.2, 369/53.22, 369/53.26, 369/53.44, 369/59.11, 369/116, 360/53, 714/719
• US Class Current: 369/47.5
• CPC Class Codes: G11B 20/10481 optimisation methods
• CPC Class Codes: G11B 20/1816 Testing
• CPC Class Codes: G11B 20/182 using test patterns
• CPC Class Codes: G11B 20/20 for correction of skew for multitrack recording
• CPC Class Codes: G11B 2220/2537 Optical discs
• CPC Class Codes: G11B 7/1267 Power calibration
• CPC Class Codes: G11B 7/24 Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the arrangement of information on the carrier G11B7/007

Abstract

In accordance with an exemplary embodiment of the present invention, a method for measuring a quality parameter of an optical storage system comprising a non-diffraction-limited optical storage medium and a readout device, the method comprising the process of deriving an impulse response of the optical storage system, and the process of analyzing the impulse response to determine at least one of a width of the impulse response and a skewness of the impulse response as the quality parameter.

Claims

1. A readout-device-implemented method for measuring a quality parameter of an optical storage system, the storage system comprising the readout device and a non-diffraction-limited optical storage medium carrying predefined data, the method comprising:

deriving, by the readout device, based on a readout of the predefined data, an impulse response of the optical storage system as a sequence of impulse response samples; and

analyzing, by the readout device, the impulse response to determine as the quality parameter a width of the impulse response by evaluating a second-order central moment of squares of the impulse response samples.

2. A method according to claim 1, wherein the optical storage medium contains one of predefined sync data, predefined test data, and predefined user data, and the impulse response is derived at least in part by evaluating a readout signal of the predefined data from the storage medium.

3. A readout-device-implemented method for determining an optimum readout laser power for a non-diffraction-limited optical storage medium, the method comprising:

setting, by the readout device, the laser power to a start laser power;

determining, by the readout device, a width of an impulse response at the set laser power by deriving the impulse response as a sequence of impulse response samples based on a readout of predefined data and analyzing the impulse response to determine as the quality parameter the width of the impulse response by evaluating a second-order central moment of squares of the impulse response samples; and

modifying, by the readout device, the laser power until the width of the impulse response has reached its minimum.

4. A readout-device-implemented method for measuring a quality parameter of an optical storage system, the storage system comprising the readout device and a non-diffraction-limited optical storage medium carrying predefined data, the method comprising:

deriving, by the readout device, based on a readout of the predefined data, an impulse response of the optical storage system as a sequence of impulse response samples; and

analyzing, by the readout device, the impulse response to determine as the quality parameter a skewness of the impulse response.

5. A method according to claim 4, wherein the optical storage medium contains one of predefined sync data, predefined test data, and predefined user data, and the impulse response is derived at least in part by evaluating a readout signal of the predefined data from the storage medium.

6. A method according to claim 4, wherein the skewness of the impulse response is determined by evaluating a third-order central moment of squares of the impulse response samples.

7. A system for measuring a quality parameter of an optical storage channel, comprising:

a non-diffraction-limited optical storage medium carrying predefined data; and

a readout device that derives an impulse response of the optical storage channel as a sequence of impulse response samples based on a readout of the predefined data and analyzes the impulse response to determine as the quality parameter a width of the impulse response by evaluating a second-order central moment of squares of the impulse response samples.

8. The system according to claim 7, wherein the optical storage medium contains one of predefined sync data, predefined test data, and predefined user data, and the readout device derives the impulse response at least in part by evaluating a readout signal of the predefined data from the storage medium.

9. A system for determining an optimum readout laser power, comprising:

a non-diffraction-limited optical storage medium carrying predefined data; and

a readout device that sets the laser power to a start laser power and determines a width of an impulse response at the set laser power and modifies the laser power until the width of the impulse response has reached its minimum,

wherein the readout device determines the width of the impulse response by deriving the impulse response as a sequence of impulse response samples based on a readout of the predefined data and analyzing the impulse response to determine as the quality parameter the width of the impulse response by evaluating a second-order central moment of squares of the impulse response samples.

10. A system for measuring a quality parameter of an optical storage channel, the system comprising:

a non-diffraction-limited optical storage medium caffying predefined data; and

a readout device that derives an impulse response of the optical storage channel as a sequence of impulse response samples based on a readout of the predefined data and analyzes the impulse response to determine as the quality parameter a skewness of the impulse response.

11. The system according to claim 10, wherein the optical storage medium contains one of predefined sync data, predefined test data, and predefined user data, and the readout device derives the impulse response at least in part by evaluating a readout signal of the predefined data from the storage medium.

12. The system according to claim 10, wherein the readout device determines the skewness of the impulse response by evaluating a third-order central moment of squares of the impulse response samples.