Speed detection apparatus, speed control motor, and track jump control circuit

• US 5,521,891 A
• Filed: 10/17/1994
• Issued: 05/28/1996
• Est. Priority Date: 03/31/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nakane, Hiroshi
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): Truong, Khoi
• Application Number:
  US08/323,577
• Time in Patent Office: 589 Days
• Field of Search: 369/43, 369/32, 369/58, 369/44.11, 369/44.25, 369/44.27, 369/44.28, 369/44.29, 369/44.35, 360/78.01, 360/78.04-78.12, 360/77.02, 318/560
• US Class Current: 369/44.28
• CPC Class Codes: G11B 19/247 using electrical means
• CPC Class Codes: G11B 21/083 on discs
• CPC Class Codes: G11B 5/5526 Control therefor; circuits, track configurations or relative disposition of servo-information transducers and servo-information tracks for control thereof G11B5/556 takes precedence
• CPC Class Codes: G11B 7/08529 Methods and circuits to control the velocity of the head as it traverses the tracks
• CPC Class Codes: G11B 7/08588 with position sensing by means of an auxiliary system using an external scale

Abstract

A track jump control circuit comprises: a head; a rotary motor which drives the head and is controlled in accordance with an input signal; a unit for detecting a speed of rotation corresponding to the rotation of the rotary motor; distance detection unit for producing a signal corresponding to a distance which the head should move with using no data read by the head when the head is moved to a desired position; speed setting unit for setting a speed of movement of the head based on the signal produced by the distance detection unit; and a unit for comparing a speed detected by the speed detection unit with a speed set by the speed setting unit to produce an output as the input signal to the rotary motor.

Claims

1. A track jump control circuit for controlling the movement of a head over a rotary disk, comprising:

a head for reproducing an information signal from said rotary disk;

a rotary motor which drives said head and whose drive force is controlled is accordance with an input signal;

distance detecting means for detecting a distance along which said head moves by an electrical signal, the electrical signal produced corresponding to a mechanical movement, the mechanical movement performed corresponding to the rotation of said rotary motor means for detecting a speed of rotation of said rotary motor responsive to an output signal of said distance detecting means;

means for setting a speed of movement of said head in accordance with a signal output from said distance detection means; and

means for comparing a speed detected by said speed detection means with a speed set by said speed setting means to produce an output signal as said input signal to said rotary motor.

2. A track jump control circuit according to claim 1, wherein said distance detection means includes a counter for counting a pulse corresponding to a distance along which said head moves.

3. A track jump control circuit according to claim 1, wherein said distance detection means detects a distance along which said head moves in accordance with a position of said head.

4. A track jump control circuit according to claim 1, wherein said distance detection means comprises,

means for detecting a speed of movement of said head;

and

means for integrating a detected head movement speed.

5. A track jump control circuit according to claim 1, wherein said speed detection means is not in contact with said motor.

6. A track jump control circuit according to claim 1, wherein said speed detection means comprises;

a magnet which rotates in association with said rotary motor;

a plurality of fixed coils, each of which generates an electromagnetic force as said magnet rotates;

means for detecting a rotational position of said magnet to produce a position signal;

means provided correspondingly to each of said plurality of coils for inverting an electromagnetic force generated by each of said plurality of coils;

noninverting means provided correspondingly to each of said plurality of coils for outputting an electromagnetic force generated by each of said plurality of coils without inverting it;

a plurality of means provided correspondingly to each of said plurality of coils for producing an output by switching the output signals of said inverting means and said noninverting means in accordance with said position signal; and

means for producing an output to said comparing means by adding the outputs of said plurality of switching means.

7. A track jump control circuit according to claim 1, wherein said speed detection means comprises:

a plurality of fixed coils, each of which generates an electromagnetic force as a magnet of said rotary motor is rotated;

means for detecting a rotational position of said magnet to produce a position signal;

means provided correspondingly to each of said plurality of coils for inverting an electromagnetic force generated by each of said plurality of coils;

noninverting means provided correspondingly to each of said plurality of coils for outputting an electromagnetic force generated by each of said plurality of coils without inverting it;

a plurality of means provided correspondingly to each of said plurality of coils for producing an output by switching the output signals of said inverting means and said noninverting means in accordance with said position signal; and

means for producing an output to said comparing means by adding the outputs of said plurality of switching means.

8. A track jump control circuit for controlling the movement of a head over a rotary disk, comprising:

a head for reproducing an information signal from said rotary disk;

a rotary motor which drives said head and whose drive force is controlled in accordance with an input signal;

distance detecting means for detecting a distance along which said head moves by an electrical signal, the electrical signal produced corresponding to a mechanical movement, the mechanical movement performed corresponding to the rotation of said rotary motor;

means for detecting a speed of rotation of said rotary motor, said speed detection means is electrically isolated from said rotary motor responsive to an output signal of said distance detecting means;

means for setting a speed of movement of said head in accordance with a signal output from said distance detection means; and

means for comparing a speed detected by said speed detection means with a speed set by said speed setting means to produce an output signal as said input signal to said rotary motor.

9. A track jump control circuit according to claim 8, wherein said distance detection means includes a counter for counting a pulse count corresponding to a distance along which said head moves.

10. A track jump control circuit according to claim 8, wherein said distance detection means detects a distance along which said head moves in accordance with a position of said head.

11. A track jump control circuit according to claim 8, wherein said distance detection means comprises,

means for detecting a speed of movement of said head;

and

means for integrating a detected head movement speed.

12. A track jump control circuit according to claim 8, wherein said speed detection means comprises;

a magnet which rotates in association with said rotary motor;

a plurality of fixed coils, each of which generates an electromagnetic force as said magnet rotates;

means for detecting a rotational position of said magnet to produce a position signal;

means provided correspondingly to each of said plurality of coils for inverting an electromagnetic force generated by each of said plurality of coils;

noninverting means provided correspondingly to each of said plurality of coils for outputting an electromagnetic force generated by each of said plurality of coils without inverting it;

a plurality of means provided correspondingly to each of said plurality of coils for producing an output by switching the output signals of said inverting means and said noninverting means in accordance with said position signal; and

means for producing an output to said comparing means by adding the outputs of said plurality of switching means.

13. A track jump control circuit according to claim 8, wherein said speed detection means comprises:

a plurality of fixed coils, each of which generates an electromagnetic force as a magnet of said rotary motor is rotated;

means for detecting a rotational position of said magnet to produce a position signal;

means provided correspondingly to each of said plurality of coils for inverting an electromagnetic force generated by each of said plurality of coils;

noninverting means provided correspondingly to each of said plurality of coils for outputting an electromagnetic force generated by each of said plurality of coils without inverting it;

a plurality of means provided correspondingly to each of said plurality of coils for producing an output by switching the output signals of said inverting means and said noninverting means in accordance with said position signal; and

means for producing an output to said comparing means by adding the outputs of said plurality of switching means.

14. A speed control motor comprising:

a motor whose drive force is controlled in accordance with an input signal;

rotating speed detection means for detecting a speed of rotation of said motor by an electrical signal, the electrical signal produced corresponding to a mechanical movement, the mechanical movement performed corresponding to the rotation of said motor; and

means for comparing a speed signal detected by said rotation speed detection means with a reference signal to produce an error signal as said input signal to said motor;

wherein said rotation speed detection means comprises;

a magnet which rotates in association with said rotary motor;

a plurality of fixed coils, each of which generates an electromagnetic force as said magnet rotates;

means for detecting a rotational position of said magnet to produce a position signal;

inverting means provided correspondingly to each of said plurality of coils for inverting said electromagnetic force generated by each of said plurality of coils;

noninverting means provided correspondingly to each of said plurality of coils for outputting an electromagnetic force generated by each of said plurality of coils without inverting means;

a plurality of means provided correspondingly to each of said plurality of coils for producing an output by switching the output signals of said inverting means and said noninverting means in accordance with said position signal; and

means for producing an output to said comparing means by adding the outputs of said plurality of switching means.

15. A speed control motor comprising:

a motor whose drive force is controlled in accordance with an input signal;

rotating speed detection means for detecting a speed of rotation of said motor by an electrical signal, the electrical signal produced corresponding to a mechanical movement, the mechanical movement performed corresponding to the rotation of said motor; and

means for comparing a speed signal detected by said rotation speed detection means with a reference signal to produce an error signal as said input signal to said motor;

wherein said rotation speed detection means comprises;

a plurality of fixed coils, each of which generates an electromagnetic force as a magnet of said motor is rotated;

means for detecting a rotational position of said magnet to produce a position signal;

inverting means provided correspondingly to each of said plurality of coils for inverting said electromagnetic force generated by each of said plurality of coils;

noninverting means provided correspondingly to each of said plurality of coils for outputting an electromagnetic force generated by each of said plurality of coils without inverting means;

a plurality of means provided correspondingly to each of said plurality of coils for producing an output by switching the output signals of said inverting means and said noninverting means in accordance with said position signal; and

means for producing an output to said comparing means by adding the outputs of said plurality of switching means.