Optical disc device and focus jump method
AssigneeFunai Electric Co., Ltd.
InventorKazuki Kajikawa
Life of this patent
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Abstract
The optical disc device includes an optical pickup, a focus-error-signal generation section for generating a focus error signal of the differential astigmatic method by using a parameter and an electric signal outputted from a photodetector in the optical pickup, a control section for controlling the optical pickup to make a focus jump operation, and a parameter value changing section for temporarily changing a value of the parameter to be used to generate a focus error signal of the differential astigmatic method by the focus-error-signal generation section when the focus jump operation is performed by using the focus error signal of the differential astigmatic method.
Claims8
An optical disc device compatible with multilayer optical discs having a plurality of recording layers on one side, comprising:
- an optical pickup for applying light to an optical disc to detect return light from the optical disc by a photodetector;
- a focus-error-signal generation section for generating a focus error signal of a differential astigmatic method by using a parameter and an electric signal outputted from the photodetector;
- a control section for controlling the optical pickup to make a focus jump operation such that a focus position of the light is moved from a first recording layer to a second recording layer of the optical disc;
- and
- a parameter value changing section for temporarily changing a value of the parameter to be used to generate the focus error signal of the differential astigmatic method by the focus-error-signal generation section while the focus jump operation is performed by using the focus error signal of the differential astigmatic method, wherein
- the parameter value changing section temporarily changes a value of a multiplication coefficient by which a sub-beam component of the return light detected by the photodetector is multiplied.
A focus jump method for multilayer optical discs having a plurality of recording layers on one side, comprising:
- a first step of generating a focus error signal of a differential astigmatic method by using a parameter and an electric signal outputted from a photodetector of an optical pickup;
- and
- a second step of temporarily changing the value of the parameter to be used to generate the focus error signal of the differential astigmatic method while a focus jump operation for moving a focus position of applied light of the optical pickup from a first recording layer to a second recording layer of the multilayer optical disc is performed by using the focus error signal of the differential astigmatic method, wherein
- the second step is a step of temporarily changing a value of a multiplication coefficient by which a sub-beam component of return light detected by the photodetector is multiplied.
Dependencies are inferred from the claim text.