JPH02269492A - Spindle motor drive controller - Google Patents

Abstract

PURPOSE:To reduce consumption of a driving current and to improve rotatably driving efficiency by supplying a starting current of a lower level than a steady driving current to the coil of a motor at the time of starting, determining the driving direction of a magnet rotor, and rotatably driving the rotor in response to the steady driving current at the time of steady driving. CONSTITUTION:A rotation controller 12 outputs a control signal C at the time of initial starting so start a motor 10 by a low starting current. Thus, the magnet rotor of the motor 10 starts a rotary motion. The controller 12 shifts it to a control mode based on the detected rotating position of a agent rotor 13. In this case, the controller 12 supplies a steady driving current of a high level to drive the motor 10. A driving circuit 11 selectively electrifies coils 10a-10c to rotatably move the rotor in a predetermined rotating direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] [Field of Industrial Application] The present invention relates to a spindle motor drive control device used, for example, in a magnetic disk device.

[Prior Art] Conventionally, for example, a magnetic disk device is provided with a spindle mechanism for rotating a recording medium, and a spindle motor consisting of a DC brushless motor is used as a drive source for this spindle mechanism. This motor can be roughly divided into multiple coils (for example, 3-phase coils) that generate rotational torque by energization, and a magnet rotor that is driven to rotate by electromagnetic interaction with the coils and transmits the rotational torque to the outside. .

The motor is rotated in a predetermined direction by phase switching by selectively energizing each coil. At this time,
By detecting the rotational position of the magnet rotor and energizing a predetermined coil, the magnet rotor is rotationally driven in a designated direction.

Here, the method for detecting the rotational position of the magnet rotor is to detect the induced voltage in the coil when the magnet rotor is rotated during initial startup, without using a detector such as a Hall element. There is a method of detecting the rotational position of the magnet rotor from the position. In this method, since the rotational position of the magnet rotor cannot be detected during initial startup, it is necessary to energize any coil in order to drive the magnet rotor to rotate in a specified direction. Therefore, depending on the position of the energized coil, it may take a relatively long time to detect the rotational position of the magnet rotor and drive the magnet rotor to rotate in a designated direction.

Problem to be solved by the invention C] Conventionally, in a spindle motor, in a method of detecting the rotational position of a magnet rotor using the induced voltage of a coil, it takes a relatively long time to rotate the magnet rotor in a specified direction. It may take time. This results in an increase in drive current consumption at the time of initial startup, and also has the disadvantage that the rotational drive efficiency decreases until the rotational drive is performed in a designated direction.

An object of the present invention is to reduce the consumption of drive current during initial startup until the magnet rotor is rotated in a specified direction in a method of detecting the rotational position of the magnet rotor using the induced voltage of the coil. An object of the present invention is to provide a spindle motor drive control device that can improve rotational drive efficiency until rotationally driven in a designated direction.

[Structure of the Invention] [Means and Effects for Solving the Problems] The present invention provides a drive control device for a spindle motor, which is a brushless motor that detects the rotational position of a magnetic rotor using the induced voltage of a coil. At startup, a starting current at a lower level than the steady drive current is selectively supplied to each coil of the motor to determine the rotational drive direction of the magnet rotor according to the specified rotational direction, and during steady state, the rotational drive direction of the magnet rotor is determined according to the specified rotational direction. This device includes a drive control means that controls the magnet rotor to rotate.

With such a configuration, it is possible to prevent an increase in drive current consumption at the time of initial startup.

Furthermore, the present invention selectively supplies a starting current to each coil of the motor for a set period at startup, and determines the rotation drive direction of the magnet rotor according to the specified rotation direction,
This device includes a drive control means that controls the magnet rotor to rotate in accordance with a steady drive current during steady state. With such a configuration, it is possible to shorten the time required at initial startup.

〔Example〕

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a spindle motor drive control device according to a first embodiment.

In this embodiment, the motor 1o to be controlled is, for example, a motor for rotationally driving a recording medium used in a magnetic disk device, and is a brushless motor that detects the rotational position of a magnetic rotor using the induced voltage of a coil. It is. The motor 10 includes, for example, three-phase coils 1Oa-10c, and is configured such that a magnet rotor (rotor 13 in FIG. 4) rotates depending on the energization state of each coil 1Oa-10c.

The drive circuit 11 is a circuit for selectively supplying a drive current to each of the coils loa to 10c of the motor 1O in accordance with the control of the rotation control circuit 12 to rotate the magnet rotor I3. The rotation control circuit 12 is a circuit that is activated in response to a control signal A transferred from the outside and controls the drive circuit 11 so as to rotate the magnet rotor 13 of the motor IO in a designated rotation direction. .

Next, the operation of this embodiment will be explained. First, the drive circuit 11
As shown in FIG. 4, the transistors 14a to 14c
It is equipped with an energization logic circuit having a phase switching signal φl~ according to the control signal B from the rotation control circuit 12.
φ3 is generated to selectively energize each coil 10a-10c. Thereby, the phase of each coil 10a-10c is switched, and the magnet rotor 13 rotates in a predetermined rotational direction.

By the way, at the time of initial startup, the rotation control circuit 12 executes a control mode for detecting the rotational position of the magnet rotor 13. At this initial startup, in the same embodiment, the second
As shown in step S2 in the figure, the rotation control circuit 12 outputs a control signal C to start the motor 10 with a low starting current through the drive circuit 11. That is, in response to the control signal C from the rotation control circuit 12, the drive circuit 11 applies a drive current at a level lower than the steady drive current to each coil 10a-10.
Supplied to any coil in c. As a result, the magnet rotor 13 of the motor lO starts rotating, and the rotation control circuit 12 uses the induced voltage in the coil due to the electromagnetic action between the magnet rotor I3 and each of the coils 10a to lOc to control the rotational position of the magnet rotor. Detect.

Based on the detected rotational position of the magnet rotor 13, the rotation control circuit 12 shifts to a control mode (determining the phase switching operation of each coil 10a-10c) in which the magnet rotor 13 is rotated in an externally designated rotation direction. (Step 33). At this time, the rotation control circuit 12 controls the drive circuit 11 using the control signal C to supply a steady drive current at a higher level than the low starting current to drive the motor IO (step S4). The drive circuit 11 selectively energizes each coil LOa to LOe with a steady drive current,
The magnet rotor 13 rotates in a predetermined rotation direction.

In this way, at the time of initial startup, control is performed to rotate the magnet rotor 13 in a predetermined rotational direction by supplying a drive current at a lower level than the steady drive current to any coil among the coils 10a-foe. Run mode. Therefore, at initial startup, the motor l is lower than during steady drive.
The current consumption due to o is reduced. Therefore, motor 1o
Current consumption during initial startup can be minimized.

Note that at the initial startup, the purpose is to start the magnet rotor 13 in a predetermined rotational direction, and since rotational torque during steady drive is not required, a low starting current lower than the steady drive current may be used.

FIG. 3 is a flowchart for explaining the operation of the rotation control circuit 12 according to the second embodiment.

In the second embodiment, as shown in step Sll in FIG. 3, at the time of initial startup, the rotation control circuit I2 starts the motor IO through the drive circuit 11 for a preset period using the control signal C. In this case, the drive circuit 11 supplies a steady drive current to any one of the coils 1Oa-10c to rotate the magnet rotor 13 for a set period of time. The rotation control circuit 12 detects the rotational position of the magnet rotor 13 using the induced voltage in the coil caused by the activation of the magnet rotor 13 . In this case, if the rotation control circuit (2) cannot detect the rotational position of the magnet rotor 13 only by starting for the set period, it will execute the starting for the set period again (step 512).

Note that the other operations are the same as in the first embodiment.

In the second embodiment, at the time of initial startup, a control mode is set in which a drive current is supplied to any coil among the coils LOa-10c for a set period to rotate the magnet rotor 13 in a predetermined rotation direction. Execute. The set period is, for example, the average value of the activation time required for detecting the rotational position of the magnet rotor 13 according to its position. Thereby, the rotational drive of the magnet rotor 13 at the time of initial startup can be minimized, so that the transition to the steady drive mode can be performed efficiently. However, restarts may occur again during the set period, but by setting the set period to an appropriate value based on the characteristics of the motor 10 and, for example, the spindle mechanism of the magnetic disk device, the occurrence of restarts can be greatly reduced. It is possible to reduce the

[Effects of the Invention] As detailed above, according to the present invention, firstly, at the initial startup, the control uses a starting current lower than the steady driving current until the magnet rotor is driven to rotate in a specified direction. It is possible to reduce the consumption of drive current at the time of initial startup.

As a result, the overall power consumption for driving the motor can be reduced.

Second, by minimizing the rotational drive of the magnet rotor during initial startup, it is possible to efficiently transition to the steady drive mode.

As a result, the motor can be rotated efficiently.

[Brief explanation of drawings]

FIG. 1 is a block diagram relating to the first embodiment of the present invention, FIG. 2 is a flowchart for explaining the operation of the embodiment, and FIG. 3 is a flowchart for explaining the second operation. FIG. 4 is a conceptual diagram showing the configuration of the brushless morph according to the first embodiment. IO...Motor, 11...Drive circuit, 12...Rotation control circuit, 10a-10c...Coil, 13...
magnet rotor. Applicant's agent Patent attorney Takehiko Suzue Figure 4

Claims (2)

[Claims] (1) Motor drive means for selectively supplying a drive current to each coil of a brushless motor, which is a spindle motor, to rotationally drive the magnetic rotor of the brushless motor in a specified rotation direction; A low-level starting current is selectively supplied to each of the coils to determine a rotation drive direction of the magnet rotor according to a specified rotation direction, and the magnet rotor is rotated according to the steady drive current during steady state. A spindle motor drive control device comprising: drive control means for controlling the motor drive means to drive the motor. (2) A motor drive means for selectively supplying a drive current to each coil of a brushless motor, which is a spindle motor, to rotationally drive a magnetic rotor of the brushless motor in a specified rotation direction, and setting a starting current at startup. selectively supplying the current to each of the coils for a period of time to determine a rotational drive direction of the magnet rotor according to a specified rotational direction, and drive the magnet rotor to rotation according to a steady drive current during a steady state. 1. A spindle motor drive control device comprising: drive control means for controlling a motor drive means.