Device for scanning a disc-shaped information carrier with controlled changes in angular and linear velocities
AssigneeKoninklijke Philips Electronics N.V.
InventorsGheorghe S. Stan, Johannus L. Bakx
Life of this patent
Estimating the term…
Abstract
For scanning a disc-shaped information carrier at a high average information rate with minimum access time, the angular velocity is decreased substantially as the radial distance to the scan location increases, while at the same time the linear velocity of track scanning increases substantially. The track may be divided into zones which are scanned with constant angular velocity. With respect to the inner tracks of at least two adjacent zones, or the innermost and the outermost tracks, the angular velocity decreases less than inversely with increase of radial distance, while the linear velocity increases less than proportionally with increase of radial distance.
Claims193
A device for scanning an information track on a disc-shaped information carrier, comprising:
- scanning means for scanning a location on the information track,
- drive means for causing relative rotation between the location and the information carrier, at an angular velocity about a point of rotation, the location thereby having a linear velocity of relative movement along the track,
- means for varying a distance (r) between said location and the point of rotation, and
- control means for controlling the drive means,
- characterized in that said control means is arranged to control the drive means so as to cause the relative angular velocity to decrease substantially with increasing distance (r), and to cause the linear velocity to increase substantially with increasing distance (r).
A device for scanning an information track on a disc-shaped information carrier, where said track includes an innermost track, an outermost track, and a multiplicity of tracks therebetween, comprising:
- scanning means for scanning a location on the information track,
- drive means for causing relative rotation between the location and the information carrier, at an angular velocity about a point of rotation, the location thereby having a linear velocity of relative movement along the track,
- means for varying a distance (r) between said location and the point of rotation, and
- control means for controlling the drive means,
- characterized in that said control means is arranged to control the drive means so as to cause the relative angular velocity to decrease substantially, but less than inversely with the increase of distance (r), as said location is moved from said increment track to said outermost track;
- and to cause the linear velocity to increase substantially, but less than proportionally with the increase of distance (r), at said location is moved from said innermost track to said outermost track.
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a scan head drive that moves the scan head in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and a rotational axis;
- and,
- a carrier drive that imparts rotational movement of the carrier about the rotational axis at an angular velocity that decreases as the radial distance (r) increases, wherein the angular velocity is not inversely proportional to the radial distance (r).
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a carrier drive that imparts rotational movement of the carrier about a rotational axis at an angular velocity that decreases as a radial distance (r) between the scanning beam and the rotational axis increases, wherein the angular velocity is not inversely proportional to the radial distance (r);
- and,
- a scan head drive that moves the scan head in a radial direction relative to the information tracks, to thereby vary the radial distance (r) between the scanning beam and the rotational axis, wherein a linear velocity of the scanning beam relative to an information track being scanned increases as the radial distance (r) increases, and wherein further, the linear velocity is not proportional to the radial distance (r).
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a carrier drive that imparts rotational movement of the carrier about a rotational axis;
- and,
- a scan head drive that moves the scan head in a radial direction relative to the information tracks, so thereby vary a radial distance (r) between the scanning beam and the rotational axis, wherein a linear velocity of the scanning beam relative to an information track being scanned increases as the radial distance (r) increases, and wherein further, the linear velocity is not proportional to the radial distance (r).
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a drive system that imparts relative radial movement between the scanning beam and the carrier, to thereby vary a radial distance (r) between the scanning beam and a central axis of the carrier;
- and,
- a servo controller that controls the drive system to increase a linear velocity of the scanning beam relative to an information track being scanned as the radial distance (r) increases, wherein the linear velocity is not proportional to the radial distance (r).
A device for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier having a plurality of CAV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the device comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a carrier drive that imparts rotational movement of the carrier about a rotational axis, at an angular velocity;
- a scan head drive that moves the scan head in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- a servo controller that controls the carrier drive in such a manner as to cause the angular velocity to decrease in successive CAV zones located successively further from the rotational axis, and that control the carrier drive to maintain a substantially constant angular velocity within each CAV zone, wherein an average angular velocity decreases as the radial distance (r) increases, and wherein further, the average angular velocity is not inversely proportional to the radial distance (r).
A device for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier in a plurality of CLV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the device comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a drive system that imparts relative linear movement between the scanning beam and an information track being scanned, at a linear velocity;
- and,
- a servo controller that controls the drive system to increase the linear velocity in successive CLV zones located successively further from a central axis of the carrier, and that controls the drive system to maintain a substantially constant linear velocity within each CLV zone, wherein an average linear velocity of the scanning beam relative to an information track being scanned increases as a radial distance (r) between the scanning beam and the central axis increases, and wherein further, the average linear velocity is not proportional to the radial distance (r).
A method comprising recording information in a plurality of recording zones on a disc-shaped information carrier, each recording zone being comprised of a plurality of information tracks spanning a radial distance, wherein an information density decreases in successive recording zones located at a successively greater radial distance from a center of the carrier, but the information density within each zone is substantially constant.
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a scan head drive that moves the scan head in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and a rotational axis;
- a carrier drive that imparts rotational movement of the carrier about the rotational axis, at an angular velocity;
- and,
- a servo controller that controls the carrier drive in such a manner as to cause the angular velocity to decrease as the radial distance (r) increases, wherein the angular velocity is not inversely proportional to the radial distance (r).
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a carrier drive that imparts rotational movement of the carrier about a rotational axis, at an angular velocity;
- a scan head drive that moves the scan head in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- a first servo controller that controls the carrier drive in such a manner as to cause the angular velocity to decrease as the radial distance (r) increases, wherein the angular velocity is not inversely proportional to the radial distance (r);
- and,
- a second servo controller that controls the scan head drive in such a manner as to cause a linear velocity of the scanning beam to increase as the radial distance (r) increases, wherein the linear velocity is not proportional to the radial distance (r).
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a carrier drive that imparts rotational movement of the carrier about a rotational axis;
- a scan head drive that moves the scan head in a radial direction relative to the information tracks, to thereby vary the distance (r) between the scanning beam and a rotational axis;
- and,
- a servo controller that controls the scan head drive and the carrier device in such a manner as to cause a linear velocity of the scanning beam relative to an information track being scanned to increase as the radial distance (r) increases, wherein the linear velocity is not proportional to the radial distance (r).
A method for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- scanning the information tracks with a scanning beam;
- moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and a rotational axis;
- and,
- rotating the carrier about the rotational axis at an angular velocity that decreases as the radial distance (r) increases, wherein the angular velocity is not inversely proportional to the radial distance (r).
A method for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- scanning the information tracks with a scanning beam;
- rotating the carrier about a rotational axis at an angular velocity that decreases as a radial distance (r) between the scanning beam and the rotational axis increases, but at a rate that is not inversely proportional to the radial distance (r), wherein the angular velocity is not inversely proportional to the radial distance (r);
- and,
- moving the scanning beam in a radial direction relative to the information tracks, to thereby vary the radial distance (r) between the scanning beam and the rotational axis, wherein a linear velocity of the scanning beam relative to an information track being scanned increases as the radial distance (r) increases, and wherein further, the linear velocity is not proportional to the radial distance (r).
A method for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- scanning the information tracks with a scanning beam;
- rotating the carrier about a rotational axis;
- and,
- moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis, wherein a linear velocity of the scanning beam relative to an information track being scanned increases as the radial distance (r) increases, and wherein further, the linear velocity is not proportional to the radial distance (r).
A method for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- scanning the information tracks with a scanning beam;
- imparting relative radial movement between the scanning beam and the carrier, to thereby vary a radial distance (r) between the scanning beam and a central axis of the carrier;
- and,
- controlling the imparting in such a manner as to increase a linear velocity of the scanning beam relative to an information track being scanned as the radial distance (r) increases, wherein the linear velocity is not proportional to the radial distance (r).
A method for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier having a plurality of CAV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the method comprising:
- scanning the information tracks with a scanning beam;
- rotating the carrier about a rotational axis, at an angular velocity;
- moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- controlling the rotating in such a manner as to cause the angular velocity to decrease in successive CAV zones located successively further from the rotational axis, while maintaining a substantially constant angular velocity within each CAV zone, wherein an average angular velocity increases as the radial distance (r) increases, and wherein further, the average angular velocity is not inversely proportional to the radial distance (r).
A method for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier in a plurality of CLV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the method comprising:
- scanning the information tracks with a scanning beam;
- imparting relative linear movement between the scanning beam and an information track being scanned, at a linear velocity;
- and,
- controlling the imparting in such a manner as to increase the linear velocity in successive CLV zones located successively further from a central axis of the carrier, while maintaining a substantially constant linear velocity within each CLV zone, wherein the controlling is performed in such a manner as to cause an average linear velocity of the scanning beam relative to an information track being scanned to increase as the radial distance (r) increases, and wherein further, the average linear velocity is not proportional to the radial distance (r).
A device for recording information on a disc-shaped information carrier, comprising:
- means for recording information in a plurality of recording zones on the carrier, each recording zone being compared of a plurality of information tracks spanning a radial distance;
- and,
- means for controlling the means for recording in such a manner as to decrease an information density in successive recording zones located at a successively greater radial distance from a center of the carrier, while maintaining the information density within each zone substantially constant.
A method for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- scanning the information tracks with a scanning beam;
- rotating the carrier about a rotational axis, at an angular velocity;
- moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- controlling the rotating in such a manner as to cause the angular velocity to decrease as the radial distance (r) increases, wherein the angular velocity is not inversely proportional to the radial distance (r).
A method for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- scanning the information tracks with a scanning beam;
- rotating the carrier about a rotational axis, at an angular velocity;
- moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- controlling the rotating in such a manner as to cause the angular velocity to decrease as the radial distance (r) increases, wherein the angular velocity is not inversely proportional to the radial distance (r);
- and,
- controlling the moving in such a manner as to cause a linear velocity of the scanning beam relative to an information track being scanned to increase as the radial distance (r) increases, wherein the linear velocity is not proportional to the radial distance (r).
A method for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- scanning the information tracks with a scanning beam;
- rotating the carrier about a rotational axis;
- moving the scanning beam in a radial direction relative to the information tracks, to thereby vary the distance (r) between the scanning beam and the rotational axis;
- and
- controlling the rotating and moving in such a manner as to cause a linear velocity of the scanning beam relative to an information track being scanned to increase as the radial distance (r) increases, wherein the linear velocity is not proportional to the radial distance (r).
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- means for scanning the information tracks with a scanning beam;
- means for moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and a rotational axis;
- and,
- means for rotating the carrier about the rotational axis at an angular velocity that decreases as the radial distance (r) increases, wherein the angular velocity is not inversely proportional to the radial distance (r).
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- means for scanning the information tracks with a scanning beam;
- means for rotating the carrier about a rotational axis at an angular velocity that decreases as a radial distance (r) between the scanning beam and the rotational axis increases, but at a rate that i snot inversely proportional to the radial distance (r), wherein the angular velocity is not inversely proportional to the radial distance (r);
- and,
- means for moving the scanning beam in a radial direction relative to the information tracks, to thereby vary the radial distance (r) between the scanning beam and the rotational axis, wherein a linear velocity of the scanning beam relative to an information track being scanned increases as the radial distance (r) increases, wherein the linear velocity is not proportional to the radial distance (r).
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- means for scanning the information tracks with a scanning beam;
- means for rotating the carrier about a rotational axis;
- and,
- means for moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis, wherein a linear velocity of the scanning beam relative to an information track being scanned increases as the radial distance (r) increases, wherein the linear velocity is not proportional to the radial distance (r).
A device for scanning a plurality of information tracks recorded on a disc-shaped information carrier, comprising:
- means for scanning the information tracks with a scanning beam;
- means for imparting relative radial movement between the scanning beam and the carrier, to thereby vary a radial distance (r) between the scanning beam and a central axis of the carrier;
- and,
- means for controlling the means for imparting in such a manner as to increase a linear velocity of the scanning beam relative to an information track being scanned as the radial distance (r) increases, wherein the linear velocity is not proportional to the radial distance (r).
A device for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier having a plurality of CAV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the device comprising:
- means for scanning the information tracks with a scanning beam;
- means for rotating the carrier about a rotational axis, at an angular velocity;
- means for moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- means for controlling the means for rotating in such a manner as to cause the angular velocity to decrease in successive CAV zones located successively further from the rotational axis, while maintaining a substantially constant angular velocity within each CAV zone, wherein an average angular velocity increases as the radial distance (r) increases, and wherein further, the average angular velocity is not inversely proportional to the radial distance (r).
A device for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier in a plurality of CLV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the device comprising:
- means for scanning the information tracks with a scanning beam;
- means for imparting relative linear movement between the scanning beam and an information track being scanned, at a linear velocity;
- and,
- means for controlling the means for imparting in such a manner as to increase the linear velocity in successive CLV zones located successively further from a central axis of the carrier, while maintaining a substantially constant linear velocity within each CLV zone, wherein the means for controlling causes an average linear velocity of the scanning beam relative to an information track being scanned to increase as the radial distance (r) increases, and wherein further, the average linear velocity is not proportional to the radial distance (r).
A device for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier in a plurality of CLV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the device comprising:
- scanning means for generating a scanning beam for scanning the information tracks;
- rotating means for rotating the carrier about a rotational axis, at an angular velocity;
- moving means for moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- control means for controlling the rotating means and the moving means in such a manner as to substantially increase a linear velocity of the scanning beam relative to an information track being scanned as the scanning beam is moved from an innermost track towards an outermost track, the control means being arranged to set the linear velocity at a substantially constant linear velocity determined by the CLV zone of the information track being scanned,
- wherein the control means causes the angular velocity of the scanning beam relative to an information track being scanned to change as the radial distance (r) increases.
A device for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier in a plurality of CLV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the device comprising:
- scanning means for generating a scanning beam for scanning the information tracks;
- rotating means for rotating the carrier about a rotational axis, at an angular velocity;
- moving means for moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- control means for controlling the rotating means and the moving means in such a manner as to substantially increase a linear velocity of the scanning beam relative to an information track being scanned as the scanning beam is moved from an innermost track towards an outermost track, the control means being arranged to set the linear velocity at a substantially constant linear velocity determined by the CLV zone of the information track being scanned,
- wherein the radial portion spanned by an outermost one of the CLV zones is greater than the radial portion spanned by an innermost one of the CLV zone;
- and,
- wherein the angular velocity decreases substantially at least within the outermost one of the CLV zones.
A device for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier in a plurality of CLV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the device comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a carrier drive that rotates the carrier about a rotational axis, at an angular velocity;
- a scan head drive that moves the scan head in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- a servo controller that controls the carrier drive and the scan head drive in such a manner as to substantially increase a linear velocity of the scanning beam relative to an information track being scanned as the scanning beam is moved from an innermost track towards an outermost track, the servo controller being arranged to set the linear velocity at a substantially constant linear velocity determined by the CLV zone of the information track being scanned, wherein the servo controller causes the angular velocity of the scanning beam relative to an information track being scanned to change substantially as the radial distance (r) increases.
A device for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier in a plurality of CLV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the device comprising:
- a scan head that generates a scanning beam that scans the information tracks;
- a carrier drive that rotates the carrier about a rotational axis, at an angular velocity;
- a scan head drive that moves the scan head in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- a servo controller that controls the carrier drive and the scan head drive in such a manner as to substantially increase the linear velocity of the scanning beam relative to an information track being scanned as the scanning beam is moved from an innermost track towards an outermost track, the servo controller being arranged to set the linear velocity at a substantially constant linear velocity determined by the CLV zone of the information track being scanned,
- wherein the radial portion spanned by an outermost one of the CLV zones is greater than the radial portion spanned by an innermost one of the CLV zones;
- and,
- wherein the angular velocity decreases substantially at least within the outermost one of the CLV zones.
A method for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier in a plurality of CLV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the method comprising:
- generating a scanning beam for scanning the information tracks;
- rotating the carrier about a rotational axis, at an angular velocity;
- moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- controlling the rotating and the moving to substantially increase a linear velocity of the scanning beam relative to an information track being scanned as the scanning beam is moved from an innermost track towards an outermost track;
- to set the linear velocity at a substantially constant linear velocity determined by the CLV zone of the information track being scanned;
- and, to cause the angular velocity of the scanning beam relative to an information track being scanned to change substantially as the radial distance (r) increases.
A method for scanning a multiplicity of information tracks recorded on a disc-shaped information carrier in a plurality of CLV zones each comprised of a plurality of information tracks spanning a radial portion of a surface of the carrier, the method comprising:
- generating a scanning beam for scanning the information tracks;
- rotating the carrier about a rotational axis, at an angular velocity;
- moving the scanning beam in a radial direction relative to the information tracks, to thereby vary a radial distance (r) between the scanning beam and the rotational axis;
- and,
- controlling the rotating and the moving to substantially increase a linear velocity of the scanning beam relative to an information track being scanned as the scanning beam is moved from an innermost track towards an outermost track, and to set the linear velocity at a substantially constant linear velocity determined by the CLV zone of the information track being scanned,
- wherein the radial portion spanned by an outermost one of the CLV zones is greater than the radial portion spanned by an innermost one of the CLV zones;
- and,
- wherein the angular velocity decreases substantially at least within the outermost one of the CLV zones.
Dependencies are inferred from the claim text.