Apparatus and record carrier for optically writing information

Claim 1

An apparatus comprising: a record carrier having a circular disc-shaped substrate provided thereon with a recording layer capable of optically writing information therein and in which a plurality of circumferential reference tracks extending in a rotating direction of said record carrier are disposed at radial intervals, each of said reference tracks being constructed into an optically detectable structure so as to function as an optical guide for enabling recording of information at least between adjacent reference tracks; an objective lens for condensing first and second light beans and for focusing said first and second light beams on said recording layer of said record carrier respectively; optical detection means for detecting an intensity of said first light beam from said recording layer; means for deriving from the output of said optical detection means a tracking signal for controlling impingement positions of both said first and second light beams in a direction traversing the track direction; tracking means for causing said first light beam to follow one of said reference tracks in response to the tracking signal; light diffraction means for moving said second light beam on said recording layer of said record carrier in the radial direction thereof, said light diffraction means including an acousto-optic diffracter, first oscillation means for generating an output signal corresponding to a first frequency which varies by a predetermined frequency corresponding to a predetermined pitch each time said record carrier performs one revolution, and driving means for supplying the output signal of said first oscillation means to said acousto-optic diffracter so that said acousto-optic diffracter moves said second light beam to vary the interval between said first and second light beams on said recording layer by said predetermined pitch each time said record carrier performs one revolution while said first light beam follows one of said reference tracks; and means to modulate the intensity of said second light beam in response to information to be recorded so that said second light beam writes information as information tracks between said reference tracks while one of said reference tracks is followed by said first light beam, said information tracks having radial intervals of said predetermined pitch therebetween.

Claim 2

An apparatus comprising: a record carrier having a circular disc-shaped substrate provided thereon with a recording layer capable of optically writing information therein and in which a plurality of circumferential reference tracks extending in a rotating direction of said record carrier are disposed at radial intervals, each of said reference tracks being constructed into an optically detectable structure so as to function as an optical guide for enabling recording of information at least between adjacent reference tracks; an objective lens for condensing first and second light beans and for focusing said first and second light beams on said recording layer of said record carrier respectively; optical detection means for detecting an intensity of said first light beam from said recording layer; means for deriving from the output of said optical detection means a tracking signal for controlling impingement positions of both said first and second light beams in a direction traversing the track direction; tracking means for causing said first light beam to follow one of said reference tracks in response to the tracking signal; light diffraction means for moving said second light beam on said recording layer of said record carrier in the radial direction thereof, said light diffraction means including an acousto-optic diffracter, first oscillation means for generating an output signal corresponding to a first frequency which varies by a predetermined frequency corresponding to a predetermined pitch each time said record carrier performs one revolution, and driving means for supplying the output signal of said first oscillation means to said acousto-optic diffracter so that said acousto-optic diffracter moves said second light beam to vary the interval between said first and second light beams on said recording layer by said predetermined pitch each time said record carrier performs one revolution while said first light beam follows one of said reference tracks; and means to modulate the intensity of said second light beam in response to information to be recorded so that said second light beam writes information as information tracks between said reference tracks while one of said reference tracks is followed by said first light beam, said information tracks having radial intervals of said predetermined pitch therebetween.

Claim 4

An apparatus comprising: a record carrier having a circular disc-shaped substrate provided thereon with a recording layer capable of optically writing information therein and in which a plurality of circumferential reference tracks extending in a rotating direction of said record carrier are disposed at radial intervals, each of said reference tracks being constructed into an optically detectable structure so as to function as an optical guide for enabling recording of information at least between adjacent reference tracks; an objective lens for condensing first and second light beams and for focusing said first and second light beams on said recording layer of said record carrier respectively; optical detection means for detecting an intensity of said first light beam from said recording layer; means for deriving from the output of said optical detection means a tracking signal for controlling impingement positions of both said first and second light beams in a direction traversing the track direction; tracking means for causing said first light beam to follow one of said reference tracks in response to the tracking signal; light diffraction mens for moving said second light beam on said recording layer of said record carrier in the radial direction thereof, said light diffraction means including an acousto-optic diffracter, first oscillation means for generating an output signal corresponding to a first frequency which varies by a predetermined frequency corresponding to a predetermined pitch each time said record carrier performs one revolution, and driving means for supplying the output signal of said first oscillation means to said acousto-optic diffracter so that said acousto-optic diffracter moves said second light beam to vary the interval between said first and second light beams on said recording layer by said predetermined pitch each time said record carrier performs one revolution while said first light beam follows one of said reference tracks, said first oscillation means including a quartz oscillator, a first scaler for dividing an output frequency of said quartz oscillator, a phase locked loop, and a control circuit for controlling said first scaler and a third scaler of said phase locked loop, said phase locked loop including a voltage-controlled oscillator for generating an output signal of a frequency corresponding to a control voltage, a second scaler for dividing the output frequency of said voltage-controlled oscillator, said third scaler for dividing a frequency of an output of said second scaler, a phase detector for detecting a phase difference between an output of said first scaler and an output of said third scaler and for generating the control voltage corresponding to the phase difference, and a low-pass filter for applying the output of said phase detector to said voltage-controlled oscillator after removing high frequency components thereof, the output of said voltage-controlled oscillator being utilized as the output of said first oscillation means; and means to modulate the intensity of said second light beam in response to information to be recorded so that said second light beam writes information as information tracks between said reference tracks while one of said reference tracks is followed by said first light beam, said information tracks having radial intervals of said predetermined pitch therebetween.

Claim 5

An apparatus comprising: a record carrier having a circular disc-shaped substrate provided thereon with a recording layer capable of optically writing information therein and in which a plurality of circumferential reference tracks extending in a rotating direction of said record carrier are disposed at radial intervals, each of said reference tracks being constructed into an optically detectable structure so as to function as an optical guide for enabling recording of information at least between adjacent reference tracks; an objective lens for condensing first and second light beams and for focusing said first and second light beams on said recording layer of said record carrier respectively; optical detection means for detecting an intensity of said first light beam from said recording layer; means for deriving from the output of said optical detection means a tracking signal for controlling impingement positions of both said first and second light beams in a direction traversing the track direction; tracking means for causing said first light beam to follow one of said reference tracks in response to the tracking signal; light diffraction mens for moving said second light beam on said recording layer of said record carrier in the radial direction thereof, said light diffraction means including an acousto-optic diffracter, first oscillation means for generating an output signal corresponding to a first frequency which varies by a predetermined frequency corresponding to a predetermined pitch each time said record carrier performs one revolution, and driving means for supplying the output signal of said first oscillation means to said acousto-optic diffracter so that said acousto-optic diffracter moves said second light beam to vary the interval between said first and second light beams on said recording layer by said predetermined pitch each time said record carrier performs one revolution while said first light beam follows one of said reference tracks, said first oscillation means including a quartz oscillator, a first scaler for dividing an output frequency of said quartz oscillator, a phase locked loop, and a control circuit for controlling said first scaler and a third scaler of said phase locked loop, said phase locked loop including a voltage-controlled oscillator for generating an output signal of a frequency corresponding to a control voltage, a second scaler for dividing the output frequency of said voltage-controlled oscillator, said third scaler for dividing a frequency of an output of said second scaler, a phase detector for detecting a phase difference between an output of said first scaler and an output of said third scaler and for generating the control voltage corresponding to the phase difference, and a low-pass filter for applying the output of said phase detector to said voltage-controlled oscillator after removing high frequency components thereof, the output of said voltage-controlled oscillator being utilized as the output of said first oscillation means; and means to modulate the intensity of said second light beam in response to information to be recorded so that said second light beam writes information as information tracks between said reference tracks while one of said reference tracks is followed by said first light beam, said information tracks having radial intervals of said predetermined pitch therebetween.

Claim 14

An apparatus comprising: a record carrier having a circular disc-shaped substrate provided thereon with a recording layer capable of optically writing information therein and in which a plurality of circumferential reference tracks extending in a rotating direction of said record carrier are disposed at radial intervals, each of said reference tracks being constructed into an optically detectable structure so as to function as an optical guide for enabling recording of information at least between adjacent reference tracks; an objective lens for condensing first and second light beams and for focusing said first and second light beams on said recording layer of said record carrier respectively; optical detection means for detecting an intensity of said first light beam from said recording layer; means for deriving from the output of said optical detection means a tracking signal for controlling impingement positions of both said first and second light beams in a direction traversing the track direction; tracking means for causing said first light beam to folIow one of said reference tracks in response to the tracking signal; light diffraction means for moving said second light beam on said recording layer of said second carrier in the radial direction thereof, said light diffraction means including an acousto-optic diffracter, first oscillation means for generating an output signal corresponding to a first frequency which varies by a predetermined frequency corresponding to a predetermined pitch each time said record carrier performs one revolution, and driving means or supplying the output signal of said first oscillation eans to said acousto-optic diffracter so that said cousto-optic diffracter moves said second light beam to vary the interval between said first and second light beams on said recording layer by said predetermined pitch each time said record carrier performs one revolution while said first light beam follows one of said reference tracks, said first oscillation means including a quartz oscillator, a first scaler for dividing an output frequency of said quartz oscillator, a frequency synthesizer for producing a signal of a desired frequency on the basis of an output of said first scaler, a phase locked loop, a mixer for mixing an output of a voltage-controlled oscillator and the output of said quartz oscillator, and a band-pass filter for deriving a side band component of an output of said mixer, said phase locked loop including the voltage-controlled oscillator for generating a signal of a frequency corresponding to a control voltage, a second scaler for dividing the output frequency of said voltage-controlled oscillator, a phase detector for detecting a phase difference between the output of said frequency synthesizer and an output of said second scaler and for generating the control voltage corresponding to the phase difference, and a low-pass filter for applying the output of said phase detector to said voltage-controlled oscillator after removing high frequency components thereof, the output of said band-pass filter being utilized as the output of said first oscillation means; and means to modulate the intensity of said second light beam in response to information to be recorded so that said second light beam writes information as information tracks between said reference tracks while one of said reference tracks is followed by said first light beam, said information tracks having radial intervals of said predetermined pitch therebetween.

Claim 15

An apparatus comprising: a record carrier having a circular disc-shaped substrate provided thereon with a recording layer capable of optically writing information therein and in which a plurality of circumferential reference tracks extending in a rotating direction of said record carrier are disposed at radial intervals, each of said reference tracks being constructed into an optically detectable structure so as to function as an optical guide for enabling recording of information at least between adjacent reference tracks; an objective lens for condensing first and second light beams and for focusing said first and second light beams on said recording layer of said record carrier respectively; optical detection means for detecting an intensity of said first light beam from said recording layer; means for deriving from the output of said optical detection means a tracking signal for controlling impingement positions of both said first and second light beams in a direction traversing the track direction; tracking means for causing said first light beam to folIow one of said reference tracks in response to the tracking signal; light diffraction means for moving said second light beam on said recording layer of said second carrier in the radial direction thereof, said light diffraction means including an acousto-optic diffracter, first oscillation means for generating an output signal corresponding to a first frequency which varies by a predetermined frequency corresponding to a predetermined pitch each time said record carrier performs one revolution, and driving means or supplying the output signal of said first oscillation eans to said acousto-optic diffracter so that said cousto-optic diffracter moves said second light beam to vary the interval between said first and second light beams on said recording layer by said predetermined pitch each time said record carrier performs one revolution while said first light beam follows one of said reference tracks, said first oscillation means including a quartz oscillator, a first scaler for dividing an output frequency of said quartz oscillator, a frequency synthesizer for producing a signal of a desired frequency on the basis of an output of said first scaler, a phase locked loop, a mixer for mixing an output of a voltage-controlled oscillator and the output of said quartz oscillator, and a band-pass filter for deriving a side band component of an output of said mixer, said phase locked loop including the voltage-controlled oscillator for generating a signal of a frequency corresponding to a control voltage, a second scaler for dividing the output frequency of said voltage-controlled oscillator, a phase detector for detecting a phase difference between the output of said frequency synthesizer and an output of said second scaler and for generating the control voltage corresponding to the phase difference, and a low-pass filter for applying the output of said phase detector to said voltage-controlled oscillator after removing high frequency components thereof, the output of said band-pass filter being utilized as the output of said first oscillation means; and means to modulate the intensity of said second light beam in response to information to be recorded so that said second light beam writes information as information tracks between said reference tracks while one of said reference tracks is followed by said first light beam, said information tracks having radial intervals of said predetermined pitch therebetween.