Recording apparatus using magneto-optical effect including control means for inhibiting energizing of the light beam generating means in responsive to coded data
AssigneeSony Corporation
InventorsTetsu Watanabe, Tamotsu Yamagami
Life of this patent
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Abstract
In a recording apparatus employing a magneto-optical effect, and in which a light beam irradiates a region of a magneto-optical disc while a magnetic field acts on the disc at such region and is modulated by coded data in accordance with a predetermined modulation system; the light beam is intermittently energized by drive pulses, and the energizing of the light beam is inhibited at times corresponding to transitions in the coded data when the ratio Tmin/Tw is greater than 1, in which Tmin is the minimum length between transitions in the coded data and Tw is a window margin for the modulation system employed for modulating the magnetic field.
Claims7
A magneto-optical recording apparatus, comprising:
- means for generating a light beam for irradiating a region of a magneto-optical disc;
- means for producing a magnetic field acting on said region of the magneto-optical disc;
- means for providing input data to be recorded;
- modulating means for modulating said input data in accordance with a predetermined modulation system so as to provide coded data having a minimum length (Tmin) between transitions thereof and a window margin (Tw) determined by said modulation system;
- means for transmitting and supplying said coded data to said magnetic field producing means so that said magnetic field is modulated in accordance with said coded data;
- means for generating reference clocks;
- light beam driving means operative in response to said reference clocks to provide drive pulses for energizing said means for generating said light beam to intermittently irradiate said region of the disc;
- and
- control means responsive to said coded data for inhibiting said energizing of said means for generating the light beam at times corresponding to all of said transitions in said coded data when the ratio Tmin/Tw is greater than 1.
A magneto-optical recording apparatus, comprising:
- means for generating a light beam for irradiating a region of a magneto-optical disc;
- means for producing a magnetic field acting on said region of the magneto-optical disc;
- means for supplying input data to be recorded;
- modulating means for modulating said input data in accordance with a predetermined modulation system so as to provide coded data having a minimum length (Tmin) between transitions thereof and a window margin (Tw) determined by said modulation system;
- means for transmitting and supplying said coded data to said magnetic field producing means so that said magnetic field is modulated in accordance with said coded data;
- means for generating reference clocks;
- light beam driving means operative in response to said reference clocks to provide drive pulses for energizing said means for generating said light beam to intermittently irradiate said region of the disc, said drive pulses having a frequency which is m times the frequency of said reference clocks, m being an integer;
- and
- control means responsive to said coded data for inhibiting said energizing of said means for generating the light beam by thinning out said drive pulses at times corresponding to all of said transitions in said coded data when the ratio Tmin/Tw is greater than 1.
Dependencies are inferred from the claim text.