Disk drive apparatus and motor

• US 6,566,827 B2
• Filed: 11/08/2001
• Issued: 05/20/2003
• Est. Priority Date: 11/09/2000
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Mori, Hideaki, Yamamoto, Susumu, Gotou, Makoto, Ochi, Masaaki, Fukamizu, Shingo
• Primary Examiner(s): Leykin, Rita
• Application Number:
  US10/005,955
• Publication Number:
  US 20020053890A1
• Time in Patent Office: 558 Days
• Field of Search: 318/254, 318/293, 318/599, 318/439
• US Class Current: 318/400.07
• CPC Class Codes: G11B 19/20 Driving; Starting; Stopping; Control thereof
• CPC Class Codes: H02P 6/085 in a bridge configuration

Abstract

In a disk drive apparatus of the present invention, power transistors of a power supplying part execute high-frequency switching operation and form current paths to three-phase windings so as to rotate a disk, a position detecting part produces a position signal which responds with terminal voltages of the three-phase windings, an activation operation part controls active periods of the power transistors in response to an output signal of the position detecting part, a commanding part produces a command signal in response to an output pulse signal of the position detecting part, and a switching operation block produces a switching pulse signal in response to a comparison result of a current detection signal with the command signal. The activation operation part produces a slew-rate switching signal which responds with the switching pulse signal, and causes at least a power transistor of the power supplying part to follow the slew-rate switching signal, thereby executing high-frequency switching of the power transistor in response to the slew-rate switching signal.

Claims

1. A disk drive apparatus comprising:

head means for reproducing a signal from a disk;

processing means for processing an output signal from said head means and outputting a processed signal;

a rotor, having a field part which generates field fluxes, for driving said disk;

Q-phase windings (Q is an integer of 3 or more);

voltage supplying means, including two output terminals, for supplying a DC voltage;

power supplying means having Q first power transistors and Q second power transistors, each of said Q first power transistors forming a current path between one output terminal side of said voltage supplying means and one of said Q-phase windings, and each of said Q second power transistors forming a current path between the other output terminal side of said voltage supplying means and one of said Q-phase windings;

position detecting means for producing a position signal which responds with the rotation of said rotor;

activation operation means for controlling active periods of said Q first power transistors and said Q second power transistors responding with an output signal of said position detecting means, each of said active periods being larger than the period of 360/Q electrical degrees;

commanding means for producing a command signal which responds with a rotational speed of said disk; and

switching operation means for causing at least one of said Q first power transistors and said Q second power transistors to perform high-frequency switching responding with said command signal; and

that

said switching operation means includes;

current detecting means for producing a current detection signal which responds with or corresponds to a composed current to said Q-phase windings from said voltage supplying means, and

switching control means for producing a switching pulse signal which responds with said current detection signal and said command signal, and

said activation operation means produces at least a slew-rate switching signal which responds with said switching pulse signal at a control terminal side of at least one power transistor among said Q first power transistors and said Q second power transistors, said at least a slew-rate switching signal having a smoothed voltage slope in at least one of rising and falling slopes, and causes said at least one power transistor to follow said at least a slew-rate switching signal, thereby supplying a high-frequency switching drive voltage signal to one terminal of said Q-phase windings, said high-frequency switching drive voltage signal having smoothed voltage slopes and responding with said current detection signal and said command signal.

2. The disk drive apparatus in accordance with claim 1, wherein

said activation operation means produces two slew-rate switching signals which responds with said switching pulse signal at control terminal sides of two of said Q first power transistors and causes said two of said Q first power transistors to perform high-frequency switching substantially simultaneously responding with said switching pulse signal, when said two of said Q first power transistors alter current paths to said Q-phase windings.

3. The disk drive apparatus in accordance with claim 1, wherein

said activation operation means causes two of said Q first power transistors to perform high-frequency switching substantially simultaneously responding with said switching pulse signal when said two of said Q first power transistors alter current paths to said Q-phase windings.

4. The disk drive apparatus in accordance with claim 1, wherein

said switching operation means produces a noise eliminating signal which responds with said switching pulse signal, and

said position detecting means executes or stops detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal, thereby producing said position signal which responds with the terminal voltages of said Q-phase windings.

5. The disk drive apparatus in accordance with claim 4, wherein

said position detecting means stops the detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal in at least slope periods of said at least a slew-rate switching signal.

6. The disk drive apparatus in accordance with claim 1, wherein

said activation operation means causes at least one of said Q first power transistors to perform ON-OFF high-frequency switching responding with said at least a slew-rate switching signal, produces at least an auxiliary switching pulse signal which responds with said switching pulse signal, and causes at least one of said Q second power transistors to perform auxiliary OFF-ON high-frequency switching responding with said at least an auxiliary switching pulse signal, said at least an auxiliary switching pulse signal being substantially complementary to said at least a slew-rate switching signal.

7. The disk drive apparatus in accordance with claim 6, wherein

said switching operation means provides an off period between an effective period of said at least a slew-rate switching signal and an effective period of said at least an auxiliary switching pulse signal.

8. The disk drive apparatus in accordance with claim 1, wherein

said activation operation means includes:

capacitor means, and

charge-discharge means for charging or discharging said capacitor means responding with said switching pulse signal, thereby producing said at least a slew-rate switching signal.

9. A disk drive apparatus comprising:

head means for reproducing a signal from a disk;

processing means for processing an output signal from said head means and outputting a processed signal;

a rotor, having a field part which generates field fluxes, for driving said disk;

Q-phase windings (Q is an integer of 3 or more);

voltage supplying means, including two output terminals, for supplying a DC voltage;

power supplying means having Q first power transistors and Q second power transistors, each of said Q first power transistors forming a current path between one output terminal side of said voltage supplying means and one of said Q-phase windings, and each of said Q second power transistors forming a current path between the other output terminal side of said voltage supplying means and one of said Q-phase windings;

position detecting means for producing a position signal which responds with the rotation of said rotor;

activation operation means for controlling active periods of said Q first power transistors and said Q second power transistors responding with an output signal of said position detecting means, each of said active periods being larger than the period of 360/Q electrical degrees;

commanding means for producing a command signal which responds with a rotational speed of said disk; and

switching operation means for causing at least one of said Q first power transistors and said Q second power transistors to perform high-frequency switching responding with said command signal; and

that

each of said Q first power transistors is a first NMOS-FET power transistor for forming a current path from the positive terminal side of said voltage supplying means to one of said Q-phase windings,

each of said Q second power transistors is a second NMOS-FET power transistor for forming a current path from the negative terminal side of said voltage supplying means to one of said Q-phase windings,

said switching operation means includes;

current detecting means for producing a current detection signal which responds with or corresponds to a composed current to said Q-phase windings from said voltage supplying means, and

switching control means for producing a switching pulse signal which responds with said current detection signal and said command signal, and

said activation operation means produces at least a slew-rate switching signal at a control terminal side of at least one power transistor among said first NMOS-FET power transistors responding with said switching pulse signal, said at least a slew-rate switching signal having a smoothed voltage slope in at least one of rising and falling slopes, and causes said at least one power transistor to follow said at least a slew-rate switching signal, thereby supplying a high-frequency switching drive voltage signal to one terminal of said Q-phase windings, said high-frequency switching drive voltage signal having smoothed voltage slopes and responding with said current detection signal and said command signal.

10. The disk drive apparatus in accordance with claim 9, wherein

said activation operation means produces two slew-rate switching signals which responds with said switching pulse signal at control terminal sides of two of said first NMOS-FET power transistors and causes said two of said first NMOS-FET power transistors to perform high-frequency switching substantially simultaneously responding with said switching pulse signal, when said two of said first NMOS-FET power transistors alter current paths to said Q-phase windings.

11. The disk drive apparatus in accordance with claim 9, wherein

said activation operation means causes two of said first NMOS-FET power transistors to perform high-frequency switching substantially simultaneously responding with said switching pulse signal when said two of said first NMOS-FET power transistors alter current paths to said Q-phase windings.

12. The disk drive apparatus in accordance with claim 9, wherein

said switching operation means produces a noise eliminating signal which responds with said switching pulse signal, and

said position detecting means executes or stops detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal, thereby producing said position signal which responds with the terminal voltages of said Q-phase windings.

13. The disk drive apparatus in accordance with claim 12, wherein

said position detecting means stops the detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal in at least slope periods of said at least a slew-rate switching signal.

14. The disk drive apparatus in accordance with claim 9, wherein

said activation operation means causes at least one of said Q first power transistors to perform ON-OFF high-frequency switching responding with said at least a slew-rate switching signal, produces at least an auxiliary switching pulse signal which responds with said switching pulse signal, and causes at least one of said Q second power transistors to perform auxiliary OFF-ON high-frequency switching responding with said at least an auxiliary switching pulse signal, said at least an auxiliary switching pulse signal being substantially complementary to said at least a slew-rate switching signal.

15. The disk drive apparatus in accordance with claim 14, wherein

said switching operation means provides an off period between an effective period of said at least a slew-rate switching signal and an effective period of said at least an auxiliary switching pulse signal.

16. The disk drive apparatus in accordance with claim 9, wherein

said activation operation means includes:

capacitor means, and

charge-discharge means for charging or discharging said capacitor means responding with said switching pulse signal, thereby producing said at least a slew-rate switching signal.

17. A disk drive apparatus comprising:

head means for reproducing a signal from a disk;

processing means for processing an output signal from said head means and outputting a processed signal;

a rotor, having a field part which generates field fluxes, for driving said disk;

Q-phase windings (Q is an integer of 3 or more);

voltage supplying means, including two output terminals, for supplying a DC voltage;

power supplying means having Q first power transistors and Q second power transistors, each of said Q first power transistors forming a current path between one output terminal side of said voltage supplying means and one of said Q-phase windings, and each of said Q second power transistors forming a current path between the other output terminal side of said voltage supplying means and one of said Q-phase windings;

position detecting means for producing a position signal which responds with the rotation of said rotor;

activation operation means for controlling active periods of said Q first power transistors and said Q second power transistors responding with an output signal of said position detecting means, each of said active periods being larger than the period of 360/Q electrical degrees;

commanding means for producing a command signal which responds with a rotational speed of said disk; and

switching operation means for causing at least one of said Q first power transistors and said Q second power transistors to perform high-frequency switching responding with said command signal; and

that

said switching operation means includes;

current detecting means for producing a current detection signal which responds with or corresponds to a composed current to said Q-phase windings from said voltage supplying means, and

switching control means for producing a switching pulse signal which responds with said current detection signal and said command signal, and

said activation operation means produces two slew-rate switching signals which responds with said switching pulse signal at control terminal sides of two of said Q first power transistors, each of said two slew-rate switching signals having a smoothed voltage slope in at least one of rising and falling slopes, and causes said two of said Q first power transistors to perform high-frequency switching substantially simultaneously responding with said two slew-rate switching signals, when said two of said Q first power transistors alter current paths to said Q-phase windings while at least one of said Q second power transistors remains ON without ON-OFF switching.

18. The disk drive apparatus in accordance with claim 17, wherein

said activation operation means supplies two high-frequency switching drive voltage signals to two terminals of said Q-phase windings when said two of said Q first power transistors alter current paths to said Q-phase windings while said at least one of said Q second power transistors remains ON without ON-OFF switching, each of said two high-frequency switching drive voltage signals having smoothed voltage slopes and responding with said current detection signal and said command signal.

19. The disk drive apparatus in accordance with claim 17, wherein

said switching operation means produces a noise eliminating signal which responds with said switching pulse signal, and

said position detecting means executes or stops detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal, thereby producing said position signal which responds with the terminal voltages of said Q-phase windings.

20. The disk drive apparatus in accordance with claim 19, wherein

said position detecting means stops the detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal in at least slope periods of said at least a slew-rate switching signal.

21. A motor comprising:

a rotor having a field part which generates field fluxes;

Q-phase windings (Q is an integer of 3 or more);

voltage supplying means, including two output terminals, for supplying a DC voltage;

power supplying means having Q first power transistors and Q second power transistors, each of said Q first power transistors forming a current path between one output terminal side of said voltage supplying means and one of said Q-phase windings, and each of said Q second power transistors forming a current path between the other output terminal side of said voltage supplying means and one of said Q-phase windings;

position detecting means for producing a position signal which responds with the rotation of said rotor;

activation operation means for controlling active periods of said Q first power transistors and said Q second power transistors responding with an output signal of said position detecting means, each of said active periods being larger than the period of 360/Q electrical degrees;

commanding means for producing a command signal which responds with a rotational speed of said rotor; and

switching operation means for causing at least one of said Q first power transistors and said Q second power transistors to perform high-frequency switching responding with said command signal; and

that

said switching operation means includes;

current detecting means for producing a current detection signal which responds with or corresponds to a composed current to said Q-phase windings from said voltage supplying means, and

switching control means for producing a switching pulse signal which responds with said current detection signal and said command signal, and

said activation operation means produces at least a slew-rate switching signal which responds with said switching pulse signal at a control terminal side of at least one power transistor among said Q first power transistors and said Q second power transistors, said at least a slew-rate switching signal having a smoothed voltage slope in at least one of rising and falling slopes, and causes said at least one power transistor to follow said at least a slew-rate switching signal, thereby supplying a high-frequency switching drive voltage signal to one terminal of said Q-phase windings, said high-frequency switching drive voltage signal having smoothed voltage slopes and responding with said current detection signal and said command signal.

22. The motor in accordance with claim 21, wherein

said activation operation means produces two slew-rate switching signals which responds with said switching pulse signal at control terminal sides of two of said Q first power transistors and causes said two of said Q first power transistors to perform high-frequency switching substantially simultaneously responding with said switching pulse signal, when said two of said Q first power transistors alter current paths to said Q-phase windings.

23. The motor in accordance with claim 21, wherein

said activation operation means causes two of said Q first power transistors to perform high-frequency switching substantially simultaneously responding with said switching pulse signal when said two of said Q first power transistors alter current paths to said Q-phase windings.

24. The motor in accordance with claim 21, wherein

said switching operation means produces a noise eliminating signal which responds with said switching pulse signal, and

said position detecting means executes or stops detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal, thereby producing said position signal which responds with the terminal voltages of said Q-phase windings.

25. The motor in accordance with claim 24, wherein

said position detecting means stops the detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal in at least slope periods of said at least a slew-rate switching signal.

26. The motor in accordance with claim 21, wherein

said activation operation means causes at least one of said Q first power transistors to perform ON-OFF high-frequency switching responding with said at least a slew-rate switching signal, produces at least an auxiliary switching pulse signal which responds with said switching pulse signal, and causes at least one of said Q second power transistors to perform auxiliary OFF-ON high-frequency switching responding with said at least an auxiliary switching pulse signal, said at least an auxiliary switching pulse signal being substantially complementary to said at least a slew-rate switching signal.

27. The motor in accordance with claim 26, wherein

said switching operation means provides an off period between an effective period of said at least a slew-rate switching signal and an effective period of said at least an auxiliary switching pulse signal.

28. The motor in accordance with claim 21, wherein

said activation operation means includes:

capacitor means, and

charge-discharge means for charging or discharging said capacitor means responding with said switching pulse signal, thereby producing said at least a slew-rate switching signal.

29. A motor comprising:

a rotor having a field part which generates field fluxes;

Q-phase windings (Q is an integer of 3 or more);

voltage supplying means, including two output terminals, for supplying a DC voltage;

power supplying means having Q first power transistors and Q second power transistors, each of said Q first power transistors forming a current path between one output terminal side of said voltage supplying means and one of said Q-phase windings, and each of said Q second power transistors forming a current path between the other output terminal side of said voltage supplying means and one of said Q-phase windings;

position detecting means for producing a position signal which responds with the rotation of said rotor;

activation operation means for controlling active periods of said Q first power transistors and said Q second power transistors responding with an output signal of said position detecting means, each of said active periods being larger than the period of 360/Q electrical degrees;

commanding means for producing a command signal which responds with a rotational speed of said rotor; and

switching operation means for causing at least one of said Q first power transistors and said Q second power transistors to perform high-frequency switching responding with said command signal; and

that

each of said Q first power transistors is a first NMOS-FET power transistor for forming a current path from the positive terminal side of said voltage supplying means to one of said Q-phase windings,

each of said Q second power transistors is a second NMOS-FET power transistor for forming a current path from the negative terminal side of said voltage supplying means to one of said Q-phase windings,

said switching operation means includes;

current detecting means for producing a current detection signal which responds with or corresponds to a composed current to said Q-phase windings from said voltage supplying means, and

switching control means for producing a switching pulse signal which responds with said current detection signal and said command signal, and

said activation operation means produces at least a slew-rate switching signal at a control terminal side of at least one power transistor among said first NMOS-FET power transistors responding with said switching pulse signal, said at least a slew-rate switching signal having a smoothed voltage slope in at least one of rising and falling slopes, and causes said at least one power transistor to follow said at least a slew-rate switching signal, thereby supplying a high-frequency switching drive voltage signal to one terminal of said Q-phase windings, said high-frequency switching drive voltage signal having smoothed voltage slopes and responding with said current detection signal and said command signal.

30. The motor in accordance with claim 29, wherein

said activation operation means produces two slew-rate switching signals which responds with said switching pulse signal at control terminal sides of two of said first NMOS-FET power transistors and causes said two of said first NMOS-FET power transistors to perform high-frequency switching substantially simultaneously responding with said switching pulse signal, when said two of said first NMOS-FET power transistors alter current paths to said Q-phase windings.

31. The motor in accordance with claim 29, wherein

said activation operation means causes two of said first NMOS-FET power transistors to perform high-frequency switching substantially simultaneously responding with said switching pulse signal when said two of said first NMOS-FET power transistors alter current paths to said Q-phase windings.

32. The motor in accordance with claim 29, wherein

said switching operation means produces a noise eliminating signal which responds with said switching pulse signal, and

said position detecting means executes or stops detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal, thereby producing said position signal which responds with the terminal voltages of said Q-phase windings.

33. The motor in accordance with claim 32, wherein

said position detecting means stops the detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal in at least slope periods of said at least a slew-rate switching signal.

34. The motor in accordance with claim 29, wherein

said activation operation means causes at least one of said Q first power transistors to perform ON-OFF high-frequency switching responding with said at least a slew-rate switching signal, produces at least an auxiliary switching pulse signal which responds with said switching pulse signal, and causes at least one of said Q second power transistors to perform auxiliary OFF-ON high-frequency switching responding with said at least an auxiliary switching pulse signal, said at least an auxiliary switching pulse signal being substantially complementary to said at least a slew-rate switching signal.

35. The motor in accordance with claim 34, wherein

said switching operation means provides an off period between an effective period of said at least a slew-rate switching signal and an effective period of said at least an auxiliary switching pulse signal.

36. The motor in accordance with claim 29, wherein

said activation operation means includes:

capacitor means, and

charge-discharge means for charging or discharging said capacitor means responding with said switching pulse signal, thereby producing said at least a slew-rate switching signal.

37. A motor comprising:

a rotor having a field part which generates field fluxes;

Q-phase windings (Q is an integer of 3 or more);

voltage supplying means, including two output terminals, for supplying a DC voltage;

power supplying means having Q first power transistors and Q second power transistors, each of said Q first power transistors forming a current path between one output terminal side of said voltage supplying means and one of said Q-phase windings, and each of said Q second power transistors forming a current path between the other output terminal side of said voltage supplying means and one of said Q-phase windings;

position detecting means for producing a position signal which responds with the rotation of said rotor,

activation operation means for controlling active periods of said Q first power transistors and said Q second power transistors responding with an output signal of said position detecting means, each of said active periods being larger than the period of 360/Q electrical degrees;

commanding means for producing a command signal which responds with a rotational speed of said rotor; and

switching operation means for causing at least one of said Q first power transistors and said Q second power transistors to perform high-frequency switching responding with said command signal; and

that

said switching operation means includes;

current detecting means for producing a current detection signal which responds with or corresponds to a composed current to said Q-phase windings from said voltage supplying means, and

switching control means for producing a switching pulse signal which responds with said current detection signal and said command signal, and

said activation operation means produces two slew-rate switching signals which responds with said switching pulse signal at control terminal sides of two of said Q first power transistors, each of said two slew-rate switching signals having a smoothed voltage slope in at least one of rising and falling slopes, and causes said two of said Q first power transistors to perform high-frequency switching substantially simultaneously responding with said two slew-rate switching signals, when said two of said Q first power transistors alter current paths to said Q-phase windings while at least one of said Q second power transistors remains ON without ON-OFF switching.

38. The motor in accordance with claim 37, wherein

said activation operation means supplies two high-frequency switching drive voltage signals to two terminals of said Q-phase windings when said two of said Q first power transistors alter current paths to said Q-phase windings while said at least one of said Q second power transistors remains ON without ON-OFF switching, each of said two high-frequency switching drive voltage signals having smoothed voltage slopes and responding with said current detection signal and said command signal.

39. The motor in accordance with claim 37, wherein

said switching operation means produces a noise eliminating signal which responds with said switching pulse signal, and

said position detecting means executes or stops detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal, thereby producing said position signal which responds with the terminal voltages of said Q-phase windings.

40. The motor in accordance with claim 39, wherein

said position detecting means stops the detection of terminal voltages of said Q-phase windings responding with said noise eliminating signal in at least slope periods of said at least a slew-rate switching signal.