Optical information recording apparatus including error checking circuit
AssigneeHitachi, Ltd.
InventorsToshimitsu Miyauchi, Yoshito Tsunoda
Life of this patent
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Abstract
In apparatus wherein a predetermined information signal is recorded on an optical disk by the use of a light beam; an information recording apparatus characterized by provision of a light detector for detecting reflected light caused by the reflection of the light beam by the optical disk, and a checking circuit for detecting the duration for which a maximum peak value of the output from the light detector exists, the recorded state of information on the optical disk being detected on the basis of the output from the detector by the checking circuit.
Claims14
In an information recording apparatus having a signal source for generating digital information, light beam generating means for generating a light beam modulated by the digital information, and optical means for focusing the light beam from the light beam generating means onto a predetermined recording medium having a reflectivity to said light beam which changes by a predetermined amount in a given time of irradiation;
- the improvement comprising first detection means for detecting said light beam after it is reflected from said recording medium, second detection means for detecting a change in the output of said first detection means resulting from a change by said predetermined amount in the quality of light reflected from said recording medium and for producing an output representative thereof, and error detecting means for checking the recorded state of the information as it is recorded on said medium solely on the basis of the output of said second detection means.
In an information recording apparatus having a signal source for generating digital information, light beam generating means for generating light beam modulated by the digital information, and optical means for focusing the light beam from the light beam generating means onto a predetermined recording medium having a reflectivity thereof to said light beam which lowers during the period of irradiation of said light beam as a result of the formation of a hole in said recording medium;
- the improvement comprising first detection means for detecting said light beam after it is reflected from said recording medium, second detection means for detecting a change of an output of said first detecting means in accordance with a change in the quantity of light of said reflected light beam corresponding to a change of the reflectivity of said recording medium;
- and error detecting means for checking the recorded state of the information recorded on said medium solely on the basis of the output of said second detection means.
In an information recording apparatus having a signal source for generating digitial information, light beam generating means for generating a light beam modulated by the digital information, and optical means for focusing the light beam from said light beam generating means onto selected areas of a recording medium having a reflectivity to said light beam which changes by a predetermined amount in a given time of irradiation to produce in said medium a plurality of areas of first or second reflectivity representing said digital information;
- the improvement comprising detection means for detecting said light beam after it is reflected from said recording medium;
- comparator means connected to said detection means for producing an output signal when the output of said detection means exceeds a reference level;
- delay means for delaying said output signal for at least said given time;
- and logic means responsive to the output of said delay means and said output signal of said comparator means for producing an error signal.
Dependencies are inferred from the claim text.