Optical recording device, and method of determining optimum focus offset value for the device

An optical recording device that is equipped with a focus control system for performing a focus control operation to focus light emitted from a light source onto a recording face of an optical recording medium, and reproduces information from the optical recording medium,

• said device comprising:
• a focus offset value setting unit for sequentially setting a plurality of offset values;
• an adder unit for using the focus offset values set by the focus offset value setting unit to adjust the focus control system;
• a light quantity setting unit for sequentially setting a quantity of reproducing light which is emitted from the light source, at each of a plurality of predetermined values indicating the quantity of recording light for each of the focus offset values set by the focus offset value setting unit;
• a reproducing unit for reproducing information from the optical recording medium, using the quantity of reproducing light set by the light quantity setting unit;
• an error rate measuring unit for measuring an error rate in the information reproduced from the optical recording medium;
• and
• an optimum focus offset value determining unit for determining an optimum focus offset value based on the error rate measured by the error rate measuring unit.

A method of determining an optimum focus offset value for a focus control system that performs a focus control operation to focus light emitted from a light source onto a recording face of an optical recording medium,

• said method comprising the steps of:
• sequentially setting a focus offset value from a plurality of offset values for the focus control system;
• using each focus offset value set in the focus offset value setting step to adjust the focus control system;
• sequentially setting a quantity of recording light which is emitted from the light source, at each of a plurality of predetermined values indicating the quantity of recording light for each of the focus offset values set in the focus offset value setting step;
• recording information on the optical recording medium using the quantity of recording light set in the light quantity setting step with the focus offset value set in the focus offset value setting step;
• reproducing the information recorded in the recording step;
• measuring an error rate in the reproduced information;
• and
• determining an optimum focus offset value based on the error rate measured in the error rate measuring step.

A method of determining an optimum focus offset value for a focus control system that performs a focus control operation to focus light emitted from a light source onto a recording face of an optical recording medium,

• said method comprising the steps of:
• sequentially setting a plurality of offset values for the focus control system;
• using each focus offset value set in the focus offset value setting step to adjust the focus control system;
• sequentially setting a quantity of reproducing light which is emitted from the light source, at each of a plurality of predetermined values indicating the quantity of reproducing light for each of the focus offset values set in the focus offset value setting step;
• reproducing information from the optical recording medium, using the quantity of reproducing light set in the light quantity setting step;
• measuring an error rate in the information reproduced from the optical recording medium;
• and
• determining an optimum focus offset value based on the error rate measured in the error rate measuring step.