Magnetic recording apparatus
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMutsuhito Kaine, Hiroaki Kojima
Life of this patent
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Abstract
There is provided a magnetic recording apparatus which, even when crosstalk occurs between signals form three photosensitive parts of a photodetector, can detect a high-precision tracking error signal with stability. In a signal processing unit 61 which processes electrical signals outputted from photosensitive part of a photodetector 15 to detect a tracking error signal, an output signal from an I-V converting unit 354 is subjected to voltage division by voltage-dividing units 381 and 382, and the voltage-divided output signals and output signals from I-V converting units 353 and 355 are subjected to differential calculation by differential arithmetic units 376 and 377, respectively.
Claims6
A magnetic recording apparatus comprising:
- a disk-shaped information recording medium on which periodic physical changes providing changes of reflectivity are formed;
- a light source which outputs a light beam;
- a diffraction element which receives the beam outputted from the light source and generates three beams;
- a light-converging optical system which converges the beams generated by the diffraction element on the information recording medium as a microspot;
- a photodetection means having three photosensitive parts which receive beams reflected and diffracted by the information recording medium and again transmitted in the aperture of the light-converging optical system, and which output signals in accordance with the quantities of received light beams, respectively;
- a signal processing means which processes the signals outputted from the photodetection means to output a tracking error signal;
- a driving means which receives the tracking error signal outputted from the signal processing means, and determines a position of the beam on a desired track;
- a magnetic head which records information on the information recording medium, or reproduces or deletes information from the information recording medium;
- wherein the signal processing means includes a cancel means which cancels crosstalk that occurs between the signals outputted from three photosensitive parts of the photodetection means.
Dependencies are inferred from the claim text.