Wobble signal detection circuit and optical disk device

A wobble signal detection circuit for detecting a wobble signal based on signals provided from first and second light receiving elements that are divided from each other in a direction tangential to a spiral or concentric recording region of an optical recording medium in which the first and second light receiving elements receive light that is reflected from a surface of the optical recording medium, the wobble signal detection circuit comprising:

• a first sample circuit for, in sync with a specific control signal, sampling a first voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the first light receiving element, wherein the specific control signal is specific to a period for forming a space region when recording information on the optical recording medium;
• a first amplifying circuit for amplifying an amplitude of the sampled first voltage signal output from the first sample circuit, and outputting the amplified first voltage signal;
• a second sample circuit for, in sync with the specific control signal, sampling a second voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the second light receiving element;
• a second amplifying circuit for amplifying the sampled second voltage signal output from the second sample circuit, and outputting the amplified second voltage signal;
• and
• an arithmetic processing circuit for receiving the amplified first voltage signal output by the first amplifying circuit, the amplified second voltage signal output by the second amplifying circuit, the first voltage signal output by the first light receiving element, and the second voltage signal output by the second light receiving circuit, and for performing an arithmetic process on the received signals so as to output the wobble signal.

A wobble signal detection circuit for detecting a wobble signal based on signals provided from first and second light receiving elements that are divided from each other in a direction tangential to a spiral or concentric recording region of an optical recording medium in which the first and second light receiving elements receive light that is reflected from a surface of the optical recording medium, the wobble signal detection circuit comprising:

• a first amplitude adjustment circuit for adjusting an amplitude of a first voltage signal so that the amplitude of the first voltage signal can be equal to a target amplitude, wherein the first voltage signal corresponds to an electric signal converted from a light signal being based on the reflected light received by the first light receiving element, and outputting the adjusted first voltage signal;
• a second amplitude adjustment circuit for adjusting an amplitude of a second voltage signal so that the amplitude of the second voltage signal can be equal to the target amplitude, wherein the second voltage signal corresponds to an electric signal converted from a light signal being based on the reflected light received by the second light receiving element, and outputting the adjusted second voltage signal;
• a target amplitude setting circuit for setting the target amplitude achieved by the first amplitude adjustment circuit, and the target amplitude achieved by the second amplitude adjustment circuit;
• and
• a subtracting circuit for outputting the wobble signal that is a difference in level between the adjusted first voltage signal output by the first amplitude adjustment circuit and the adjusted second voltage signal output by the second amplitude adjustment circuit.

A wobble signal detection circuit for detecting a wobble signal based on signals provided from first and second light receiving elements that are divided from each other in a direction tangential to a spiral or concentric recording region of an optical recording medium in which the first and second light receiving elements receive light that is reflected from a surface of the optical recording medium, the wobble signal detection circuit comprising:

• a first amplitude adjustment circuit for adjusting an amplitude of a first voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the first light receiving element, and outputting the adjusted first voltage signal;
• a second amplitude adjustment circuit for adjusting an amplitude of a second voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the second light receiving element, and outputting the adjusted second voltage signal;
• and
• a speed setting circuit for setting first and second response speeds of the first amplitude adjustment circuit to the first voltage signal input thereto, and the first and second response speeds of the second amplitude adjustment circuit to the second voltage signal input thereto so that the first response speed set for immediately after switching between a recording operation and a reproducing operation is performed is larger than the second response speed set for during the recording operation.

A wobble signal detection unit for detecting a wobble signal based on signals provided from first and second light receiving elements that are divided from each other in a direction tangential to a spiral or concentric recording region of an optical recording medium in which the first and second light receiving elements receive light that is reflected from a surface of the optical recording medium, the wobble signal detection unit comprising a first wobble signal detection circuit and a second wobble signal detection circuit,

• wherein the first wobble signal detection circuit includes:
• a first sample circuit for, in sync with a specific control signal, sampling a first voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the first light receiving element, wherein the specific control signal is specific to a period for forming a space region when recording information on the optical recording medium;
• a first voltage adjustment circuit for adjusting a signal level of the sampled first voltage signal so that an average voltage of the adjusted first voltage signal output from the first sample circuit can be equal to a first target voltage;
• a second sample circuit for, in sync with the specific control signal, sampling a second voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the second light receiving element;
• a second voltage adjustment circuit for adjusting a signal level of the sampled second voltage signal so that an average voltage of the adjusted second voltage signal output from the second sample circuit can be equal to the first target voltage;
• and
• a subtracting circuit for outputting a wobble signal that is a difference in level between the first voltage signal adjusted and output by the first voltage adjustment circuit and the second voltage signal adjusted and output by the second voltage adjustment circuit,
• wherein the second wobble signal detection circuit includes:
• a first sample circuit for, in sync with a specific control signal, sampling the first voltage signal corresponding to the electric signal converted from the light signal being based on the reflected light received by the first light receiving element, wherein the specific control signal is specific to the period for forming a space region when recording information on the optical recording medium;
• a first amplifying circuit for amplifying an amplitude of the sampled first voltage signal output from the first sample circuit, and outputting the amplified first voltage signal;
• a second sample circuit for, in sync with the specific control signal, sampling the second voltage signal corresponding to the electric signal converted from the light signal being based on the reflected light received by the second light receiving element;
• a second amplifying circuit for amplifying the sampled second voltage signal output from the second sample circuit, and outputting the amplified second voltage signal;
• and
• an arithmetic processing circuit for receiving the amplified first voltage signal output by the first amplifying circuit, the amplified second voltage signal output by the second amplifying circuit, the first voltage signal output by the first light receiving element, and the second voltage signal output by the second light receiving circuit, and for performing an arithmetic process on the received signals so as to output the wobble signal,
• and wherein the wobble signal detection unit further comprises a selecting circuit for selecting either the first wobble signal detection circuit or the second wobble signal detection circuit, based on a signal indicating a type of the optical recording medium.

A wobble signal detection unit for detecting a wobble signal based on signals provided from first and second light receiving elements that are divided from each other in a direction tangential to a spiral or concentric recording region of an optical recording medium in which the first and second light receiving elements receive light that is reflected from a surface of the optical recording medium, the wobble signal detection unit comprising a first wobble signal detection circuit and a second wobble signal detection circuit,

• wherein the first wobble signal detection circuit includes:
• a first sample circuit for, in sync with a specific control signal, sampling a first voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the first light receiving element, wherein the specific control signal is specific to a period for forming a space region when recording information on the optical recording medium;
• a first voltage adjustment circuit for adjusting a signal level of the sampled first voltage signal so that an average voltage of the adjusted first voltage signal output from the first sample circuit can be equal to a first target voltage;
• a second sample circuit for, in sync with the specific control signal, sampling a second voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the second light receiving element;
• a second voltage adjustment circuit for adjusting a signal level of the sampled second voltage signal so that an average voltage of the adjusted second voltage signal output from the second sample circuit can be equal to the first target voltage;
• and
• a subtracting circuit for outputting a wobble signal that is a difference in level between the first voltage signal adjusted and output by the first voltage adjustment circuit and the second voltage signal adjusted and output by the second voltage adjustment circuit,
• wherein the second wobble signal detection circuit includes:
• a first amplitude adjustment circuit for adjusting an amplitude of the first voltage signal so that the amplitude of the first voltage signal can be equal to a target amplitude, wherein the first voltage signal corresponds to the electric signal converted from the light signal being based on the reflected light received by the first light receiving element, and outputting the adjusted first voltage signal;
• a second amplitude adjustment circuit for adjusting an amplitude of the second voltage signal so that the amplitude of the second voltage signal can be equal to the target amplitude, wherein the second voltage signal corresponds to the electric signal converted from the light signal being based on the reflected light received by the second light receiving element, and outputting the adjusted second voltage signal;
• a target amplitude setting circuit for setting the target amplitude achieved by the first amplitude adjustment circuit, and the target amplitude achieved by the second amplitude adjustment circuit;
• and
• a subtracting circuit for outputting the wobble signal that is a difference in level between the adjusted first voltage signal output by the first amplitude adjustment circuit and the adjusted second voltage signal output by the second amplitude adjustment circuit,
• and wherein the wobble signal detection unit further comprises a selecting circuit for selecting either the first wobble signal detection circuit or the second wobble signal detection circuit, based on a signal indicating a type of the optical recording medium.

An optical disk device that records information on the optical recording medium, comprising:

• a wobble signal detection circuit for detecting a wobble signal based on signals provided from first and second light receiving elements that are divided from each other in a direction tangential to a spiral or concentric recording region of an optical recording medium in which the first and second light receiving elements receive light that is reflected from a surface of the optical recording medium;
• and
• a processing unit for performing a recording operation by using the wobble signal detected by the wobble signal detection circuit,
• wherein the wobble signal detection circuit comprising:
• a first sample circuit for, in sync with a specific control signal, sampling a first voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the first light receiving element, wherein the specific control signal is specific to a period for forming a space region when recording information on the optical recording medium;
• a first voltage adjustment circuit for adjusting a signal level of the sampled first voltage signal so that an average voltage of the adjusted first voltage signal output from the first sample circuit can be equal to a first target voltage;
• a second sample circuit for, in sync with the specific control signal, sampling a second voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the second light receiving element;
• a second voltage adjustment circuit for adjusting a signal level of the sampled second voltage signal so that an average voltage of the adjusted second voltage signal output from the second sample circuit can be equal to the first target voltage;
• and
• a subtracting circuit for outputting a wobble signal that is a difference in level between the first voltage signal adjusted and output by the first voltage adjustment circuit and the second voltage signal adjusted and output by the second voltage adjustment circuit.

An optical disk device that records information on the optical recording medium, comprising:

• a wobble signal detection circuit for detecting a wobble signal based on signals provided from first and second light receiving elements that are divided from each other in a direction tangential to a spiral or concentric recording region of an optical recording medium in which the first and second light receiving elements receive light that is reflected from a surface of the optical recording medium;
• and
• a processing unit for performing a recording operation by using the wobble signal detected by the wobble signal detection circuit,
• wherein the wobble signal detection circuit comprises:
• a first sample circuit for, in sync with a specific control signal, sampling a first voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the first light receiving element, wherein the specific control signal is specific to a period for forming a space region when recording information on the optical recording medium;
• a first amplifying circuit for amplifying an amplitude of the sampled first voltage signal output from the first sample circuit, and outputting the amplified first voltage signal;
• a second sample circuit for, in sync with the specific control signal, sampling a second voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the second light receiving element;
• a second amplifying circuit for amplifying the sampled second voltage signal output from the second sample circuit, and outputting the amplified second voltage signal;
• and
• an arithmetic processing circuit for receiving the amplified first voltage signal output by the first amplifying circuit, the amplified second voltage signal output by the second amplifying circuit, the first voltage signal output by the first light receiving element, and the second voltage signal output by the second light receiving circuit, and for performing an arithmetic process on the received signals so as to output the wobble signal.

An optical disk device that records information on the optical recording medium, comprising:

• a wobble signal detection circuit for detecting a wobble signal based on signals provided from first and second light receiving elements that are divided from each other in a direction tangential to a spiral or concentric recording region of an optical recording medium in which the first and second light receiving elements receive light that is reflected from a surface of the optical recording medium;
• and
• a processing unit for performing a recording operation by using the wobble signal detected by the wobble signal detection circuit,
• wherein the wobble signal detection circuit comprises:
• a first amplitude adjustment circuit for adjusting an amplitude of a first voltage signal so that the amplitude of the first voltage signal can be equal to a target amplitude, wherein the first voltage signal corresponds to an electric signal converted from a light signal being based on the reflected light received by the first light receiving element, and outputting the adjusted first voltage signal;
• a second amplitude adjustment circuit for adjusting an amplitude of a second voltage signal so that the amplitude of the second voltage signal can be equal to the target amplitude, wherein the second voltage signal corresponds to an electric signal converted from a light signal being based on the reflected light received by the second light receiving element, and outputting the adjusted second voltage signal;
• a target amplitude setting circuit for setting the target amplitude achieved by the first amplitude adjustment circuit, and the target amplitude achieved by the second amplitude adjustment circuit;
• and
• a subtracting circuit for outputting the wobble signal that is a difference in level between the adjusted first voltage signal output by the first amplitude adjustment circuit and the adjusted second voltage signal output by the second amplitude adjustment circuit.

An optical disk device that records information on the optical recording medium, comprising:

• a wobble signal detection circuit for detecting a wobble signal based on signals provided from first and second light receiving elements that are divided from each other in a direction tangential to a spiral or concentric recording region of an optical recording medium in which the first and second light receiving elements receive light that is reflected from a surface of the optical recording medium;
• and
• a processing unit for performing a recording operation by using the wobble signal detected by the wobble signal detection circuit,
• wherein the wobble signal detection circuit comprises:
• a first amplitude adjustment circuit for adjusting an amplitude of a first voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the first light receiving element, and outputting the adjusted first voltage signal;
• a second amplitude adjustment circuit for adjusting an amplitude of a second voltage signal corresponding to an electric signal converted from a light signal being based on the reflected light received by the second light receiving element;
• a speed setting circuit for setting first and second response speeds of the first amplitude adjustment circuit to the first voltage signal input thereto, and the first and second response speeds of the second amplitude adjustment circuit to the second voltage signal input thereto so that the first response speed set for immediately after switching between a recording operation and a reproducing operation is performed is larger than the second response speed set for during the recording operation;
• and
• a subtracting circuit for outputting the wobble signal that is a difference in level between the adjusted first voltage signal output by the first amplitude adjustment circuit and the adjusted second voltage signal output by the second amplitude adjustment circuit.