Colpitts type oscillator having reduced ringing and improved optical disc system utilizing same

An improved Colpitts oscillator electrical circuit, comprising:

• a transistor having an emitter, a base, and a collector;
• an electrical voltage supply;
• a capacitance connected in series between said collector and ground, and in parallel between said emitter and said collector;
• and
• a load resistance connected in series between said collector and said voltage supply to mitigate oscillator ringing when write pulses are supplied to the oscillator.

An improved Colpitts type oscillator circuit, comprising:

• a transistor having an emitter, a base, and a collector;
• a split capacitor tank connected in series between said collector and ground, and in parallel across said emitter and said collector of said transistor;
• a voltage supply;
• and
• a load inductance and load resistor in series between said collector and said voltage supply to mitigate oscillator ringing when write pulses are supplied to a junction between said load resistance and said load inductance.

An assembly for use in a disc drive system, said assembly comprising:

• a laser;
• a source of write pulses;
• a voltage supply;
• a Colpitts type oscillator having a transistor with an emitter, a base, and a collector;
• and
• a load resistance connected in series between said collector and said voltage supply to mitigate oscillator ringing when write pulses are supplied to the oscillator, said write pulses being combined with an output of said oscillator to produce an input signal to said laser.

An assembly for use in a disc drive system, said assembly comprising:

• a laser;
• a source of write pulses;
• a Colpitts type oscillator including a transistor having an emitter, a base, and a collector, and a split capacitor tank connected between said collector and ground, across said emitter and said collector;
• a voltage supply;
• and
• a load inductance and load resistance in series between said collector and said voltage supply to thereby mitigate oscillator ringing when write pulses are supplied to a junction between said load resistance and said load inductance, said write pulses being combined with an output of said oscillator to produce an input signal to said laser.

An optical disc system of the type having a focusing mechanism and a tracking mechanism controlled by a feedback loop, said system comprising:

• an electronic circuit for generating a servo error signal for effecting corrections of said focusing mechanism and said tracking mechanism;
• a laser;
• a source of write pulses;
• a Colpitts type oscillator including a transistor having an emitter, a base, and a collector, and a split capacitor tank connected in series between said collector and ground, and in parallel across said emitter and said collector;
• a voltage supply;
• and
• a load inductance and load resistor in series between said collector and said voltage supply to thereby mitigate oscillator ringing when write pulses are supplied to a junction between said load resistance and said load inductance.

An optical disc system, comprising:

• an optical assembly;
• a laser light source capable of transmitting light through said optical assembly;
• an objective lens subassembly for directing light from said laser light source between said optical assembly and a respective information storage medium;
• an objective lens disposed in said objective lens subassembly;
• an actuator assembly suspending said objective lens subassembly for relative motion thereof with respect to said actuator assembly;
• a photodetector disposed in a path of light returning from the respective medium, said photodetector for measuring return light received from the respective medium;
• a first servomotor for moving said objective lens subassembly in a tracking direction relative to said actuator assembly;
• a second servomotor for moving said objective lens subassembly in a focusing direction relative to said actuator assembly;
• a source of write pulses;
• first electronic means for controlling said first and second servomotors;
• a motor for moving the respective medium relative to said objective lens subassembly, said motor having a support assembly for supporting the respective medium;
• second electronic means responsive to an output signal of said photodetector for decoding information carried in said light returning from the respective medium;
• third electronic means for enabling said laser light source to emit light at a first intensity to encode information on the respective medium and at a second intensity to read information encoded thereon;
• a voltage supply;
• data receiving means for accepting data that is storable on the respective medium;
• data encoding means being responsive to said data receiving means for representing said data to be stored in a predetermined format, said data encoding means also for directing data to said third electronic means;
• a magnetic field generator for producing a magnetic field on a portion of the respective medium and for coacting with said third electronic means and said laser light source to write and erase information on the respective medium;
• a cartridge loading assembly for removably positioning the respective medium on said support assembly of said motor;
• servo error detecting means including said photodetector, said servo error detecting means being coupled to said first electronic means for determining when said return light exceeds a predetermined value;
• a Colpitts type oscillator having a transistor with an emitter, a base, and a collector;
• and
• a load resistance connected in series between said collector and said voltage supply to mitigate oscillator ringing when write pulses are supplied to the oscillator, said write pulses being combined with an output of said oscillator to produce an input signal to said laser light source.

An optical disc system, comprising:

• an optical assembly;
• a laser light source capable of transmitting light through said optical assembly;
• an objective lens subassembly for directing light from said laser light source between said optical assembly and a respective information storage medium;
• an objective lens disposed in said objective lens subassembly;
• an actuator assembly which suspends said objective lens subassembly for relative motion thereof with respect to said actuator assembly;
• light detection means disposed in a path of light returning from the respective medium, said light detection means for measuring return light received from the respective medium;
• a first servomotor for moving said objective lens subassembly in a tracking direction relative to said actuator assembly;
• a second servomotor for moving said objective lens subassembly in a focusing direction relative to said actuator assembly;
• first electronic means for controlling said first and second servomotors;
• a motor for moving the respective medium relative to said objective lens subassembly, said motor having a support assembly for supporting the respective medium;
• second electronic means responsive to an output signal of said light detection means, said second electronic means for decoding information carried in said return light returned from the respective medium;
• third electronic means for enabling said laser light source to emit light at a first intensity to encode information on the respective medium and at a second intensity to read information encoded thereon;
• a voltage supply;
• data receiving means for accepting data that is storable on the respective medium;
• data encoding means being responsive to said data receiving means for representing said data to be stored in a predetermined format, said data encoding means also for directing data to said third electronic means;
• write means coacting with said third electronic means to provide a source of write pulses for writing information on the respective medium;
• a cartridge loading assembly for removably positioning the respective medium on said support assembly of said motor;
• servo error detecting means coupled to said first electronic means and said light detection means for determining when said return light exceeds a predetermined value;
• a Colpitts type oscillator having a transistor with an emitter, a base, and a collector;
• and
• a load resistance connected in series between said collector and said voltage supply to mitigate oscillator ringing when write pulses are supplied to the oscillator, said write pulses being combined with an output of said oscillator to produce an input signal to said laser light source.

An optical disc system, comprising:

• an optical assembly;
• a laser light source capable of transmitting light through said optical assembly;
• an objective lens subassembly for directing light from said laser light source between said optical assembly and a respective information storage medium;
• an objective lens disposed in said objective lens subassembly;
• light detection means disposed in a path of light returning from the respective medium for measuring return light reflected from the respective medium, a total of said return light having a peak value associated therewith;
• an actuator assembly suspending said objective lens subassembly for relative motion thereof with respect to said actuator assembly;
• a first servomotor for moving said objective lens subassembly in a tracking direction relative to said actuator assembly;
• a second servomotor for moving said objective lens subassembly in a focusing direction relative to said actuator assembly;
• a third servomotor for moving said actuator assembly in said tracking direction relative to the respective medium;
• first electronic means for controlling said first, second, and third servomotors;
• a motor for moving the respective medium relative to said objective lens subassembly, said motor having a surface for supporting the respective medium;
• second electronic means responsive to an output signal of said light detection means for decoding information carried in said return light returning from the respective medium;
• third electronic means for enabling said light source to emit light at a first intensity to encode information on the respective medium and at a second intensity to read information encoded thereon;
• a voltage supply;
• data receiving means for accepting data that is storable on the respective medium;
• data encoding means being responsive to said data receiving means for representing said data to be stored in a predetermined format, said data encoding means also for directing data to said third electronic means;
• write means coacting with said third electronic means to provide a source of write pulses for writing information on the respective medium;
• a cartridge loading assembly for removably positioning the respective medium on said surface of said motor;
• servo error detecting means coupled to said first electronic means and said light detection means for determining when said return light exceeds one-half said peak value;
• a Colpitts type oscillator having a transistor with an emitter, a base, and a collector;
• a load resistance connected in series between said collector and said voltage supply to mitigate oscillator ringing when write pulses are supplied to the oscillator, said write pulses being combined with an output of said oscillator to produce an input signal to said laser light source;
• and
• a housing structure for positioning components of the optical disc system with respect to one another.

An optical disc system, comprising:

• an optical assembly;
• a laser light source capable of transmitting light through said optical assembly;
• an objective lens subassembly for directing light from said laser light source between said optical assembly and a respective information storage medium;
• an objective lens disposed in said objective lens subassembly;
• an actuator assembly which suspends said objective lens subassembly for relative motion thereof with respect to said actuator assembly;
• a photodetector disposed in a path of light returning from the respective medium, said photodetector for measuring return light received from the respective medium;
• a first servomotor for moving said objective lens subassembly in a tracking direction relative to said actuator assembly;
• a second servomotor for moving said objective lens subassembly in a focusing direction relative to said actuator assembly;
• a source of write pulses;
• a first electronic circuit employed to control said first and second servomotors;
• a motor for moving the respective medium relative to said objective lens subassembly, said motor having a support assembly for supporting the respective medium;
• a second electronic circuit responsive to an output signal of said photodetector to decode information carried in said light returning from the respective medium;
• a third electronic circuit implemented to enable said laser light source to emit light at a first intensity to encode information on the respective storage medium and at a second intensity to read information encoded thereon;
• a voltage supply;
• a data receiver positioned to accept data that is storable on the respective medium;
• a data encoder linked to said data receiver to represent said data to be stored in a predetermined format, said data encoder also positioned to direct data to said third electronic circuit;
• a magnetic field generator located to produce a magnetic field on a portion of the respective medium and to coact with said third electronic circuit and said laser light source to write and erase information on the respective medium;
• a cartridge loading assembly to removably position the respective medium on said support assembly of said motor;
• a servo error circuit coupled to said first electronic circuit and said photodetector to determine when said return light exceeds a predetermined value;
• a Colpitts type oscillator having a transistor with an emitter, a base, and a collector;
• and
• a load resistance connected in series between said collector and said voltage supply to mitigate oscillator ringing when write pulses are supplied to the oscillator, said write pulses being combined with an output of said oscillator to produce an input signal to said laser light source.

An optical disc system, comprising:

• an optical assembly;
• a laser light source capable of transmitting light through said optical assembly;
• an objective lens subassembly for directing light from said laser light source between said optical assembly and a respective information storage medium;
• an objective lens disposed in said objective lens subassembly;
• an actuator assembly which suspends said objective lens subassembly for relative motion thereof with respect to said actuator assembly;
• a photodetector disposed in a path of light returning from the respective medium, said photodetector for measuring return light received from the respective medium;
• a first servomotor for moving said objective lens subassembly in a tracking direction relative to said actuator assembly;
• a second servomotor for moving said objective lens subassembly in a focusing direction relative to said actuator assembly;
• a first electronic circuit employed to control said first and second servomotors;
• a motor for moving the respective medium relative to said objective lens subassembly, said motor having a support assembly for supporting the respective medium;
• a second electronic circuit responsive to an output signal of said photodetector, said second electronic circuit employed to decode information carried in said light returning from the respective medium;
• a third electronic circuit implemented to enable said laser light source to emit light at a first intensity to encode information on the respective storage medium and at a second intensity to read information encoded thereon;
• a voltage supply;
• a data receiver positioned to accept data that is storable on the respective medium;
• a data encoder linked to said data receiver to represent said data to be stored in a predetermined format, said data encoder also positioned to direct data to said third electronic circuit;
• a write member connected to said third electronic circuit to provide a source of write pulses, said write member thereby capable of writing information onto the respective medium;
• a cartridge loading assembly to removably position the respective medium on said support assembly of said motor;
• a servo error circuit connected to said first electronic circuit and said photodetector to determine when said return light exceeds a predetermined value;
• a Colpitts type oscillator having a transistor with an emitter, a base, and a collector;
• and
• a load resistance connected in series between said collector and said voltage supply to mitigate oscillator ringing when write pulses are supplied to the oscillator, said write pulses being combined with an output of said oscillator to produce an input signal to said laser light source.

An optical disc system, comprising:

• an optical assembly;
• a laser light source capable of transmitting light through said optical assembly;
• an objective lens subassembly for directing light from said laser light source between said optical assembly and a respective information storage medium;
• an objective lens disposed in said objective lens subassembly;
• a photodetector disposed in a path of light returning from the respective medium for measuring return light reflected from the respective medium, a total of said return light having a peak value associated therewith;
• an actuator assembly which suspends said objective lens subassembly for relative motion thereof with respect to said actuator assembly;
• a first servomotor for moving said objective lens subassembly in a tracking direction relative to said actuator assembly;
• a second servomotor for moving said objective lens subassembly in a focusing direction relative to said actuator assembly;
• a third servomotor for moving said actuator assembly in said tracking direction relative to the respective medium;
• a first electronic circuit employed to control said first, second, and third servomotors;
• a motor for moving the respective medium relative to said objective lens subassembly, said motor having a surface for supporting the respective medium;
• a second electronic circuit responsive to an output signal of said photodetector employed to decode information carried in said return light returning from the respective medium;
• a third electronic circuit implemented to enable said laser light source to emit light at a first intensity to encode information on the respective storage medium and at a second intensity to read information encoded thereon;
• a voltage supply;
• a data receiver positioned to accept data that is storable on the respective medium;
• a data encoder linked to said data receiver to represent said data to be stored in a predetermined format, said data encoder also positioned to direct data to said third electronic circuit;
• a write member connected to said third electronic means to provide a source of write pulses, said write member thereby enabled to write information onto the respective medium;
• a cartridge loading assembly to removably position the respective medium on said surface of said motor;
• a servo error circuit connected to said first electronic circuit and said photodetector to determine when said return light exceeds a predetermined value;
• a Colpitts type oscillator having a transistor with an emitter, a base, and a collector;
• a load resistance connected in series between said collector and said voltage supply to mitigate oscillator ringing when write pulses are supplied to the oscillator, said write pulses being combined with an output of said oscillator to produce an input signal to said laser light source;
• and
• a housing structure for positioning components of the optical disc system with respect to one another.