Spindle motor controlling method and optical disk drive using the same

An optical disk drive includes a spindle motor, a power source, a microprocessor, and a comparator. The spindle motor is for supporting a disk. The power source supplies a first voltage to drive the spindle motor to rotate. The microprocessor signals the power source to supply a second voltage to slow down rotational speed of the spindle motor when receiving a power-off signal. The comparator compares the rotational speed with a predetermined value. The microprocessor signals the power source to stop supplying power to the spindle motor when the rotational speed is smaller than the predetermined value. A controlling method for controlling the spindle motor in the optical disk driver is also provided.

BACKGROUND

1. Field of the Invention

The present invention generally relates to optical disk drives, and more particularly relates to an optical disk drive using a controlling method for controlling operation of a spindle motor of the optical disk drive.

2. Description of related art

Currently, controlling operation of a spindle motor in an optical disk drive always includes the following steps: rotating a disk by the spindle motor; receiving controlling signals via an input unit; controlling the operation of the spindle motor according to the controlling signals by a control unit.

When one needs to insert and/or remove (or swap) a disk from an optical disk drive the following events may occur: receiving a power-off signal via the input unit; signaling a power source to discontinue supplying power to the spindle motor. When the spindle motor is powered off, the spindle motor slowly decelerates and comes to a complete stop after a period of time. Only after the spindle motor comes to a complete stop that the disk can be safely inserted/removed from disk drive without risking damage. However, the period of time for the motor to come to a complete stop is time consuming, and, as a result, one wastes too much time waiting for the motor to come to a complete stop before swapping or removing the disk with or without another one.

Therefore, controlling method for a spindle motor is needed in the industry to address the aforementioned deficiency.

DETAILED DESCRIPTION

Referring toFIG. 1, an optical disk drive100in accordance with an exemplary embodiment includes a spindle motor20, a power source30, an input device40, a microprocessor50, a detector60, and a comparator70. The spindle motor20, the power source30, the microprocessor50, the detector60, and the comparator70are electrically connected together. The input device40is electrically connected to the microprocessor50.

The spindle motor20supports a disk (not shown) and rotates the disk in order for other components to write or read information from the disk. The power source30supplies a first voltage to drive the spindle motor20to rotate. The input device40responds to operations and generates input signals. The microprocessor50scans the input signals for a power-off signal. If the power-off signal is not detected, the microprocessor50will continue to scan another group of input signals.

If the power-off signal is detected, the microprocessor50generates a slowing signal to the power source30. In response to the slowing signal, the power source30supplies a second voltage that slows down a rotational speed of the spindle motor20. The second voltage starts from zero volts and the voltage is gradually increased with a polarity opposite to that of the first voltage, thus no abrupt change in speed of the spindle is realized and the spindle is allowed to slow down smoothly. The detector60detects the rotational speed of the spindle motor20. The comparator70compares the rotational speed with a predetermined value stored in the optical disk drive100. If the rotational speed is larger than or equal to the predetermined value, the power source30continues supplying the second voltage to slow down the rotational speed.

If the rotational speed of the spindle motor20is smaller than the predetermined value, the microprocessor50signals the power source30to stop supplying power to the spindle motor20. If the predetermined value is set quite small, the spindle motor20rotates at a very low speed when the spindle motor20is powered off. Therefore, operators don't need to wait too long.

In the embodiment, the input device40includes an input unit42and a receiver44. The input unit42generates the input signals in response to an operators' input, and then sends the input signals to the receiver44wirelessly. In other embodiment, the input device40may be directly assembled on the optical disk drive100as a button.

Referring toFIG. 2, a procedure of a controlling method in accordance with an exemplary embodiment is used for controlling the spindle motor20. The procedure includes the following steps.

In step S802, a first voltage is supplied to rotate the spindle motor20.

In step S804, input signals are generated by the input device40.

In step S806, the input signals are scanned for a power-off signal by the microprocessor50. If the power-off signal is not found, the procedure goes to step S804. If the power-off signal is found, the procedure goes to step S808.

In step S808, a second voltage is supplied to slow down rotational speed of the spindle motor20.

In step S810, the rotational speed of the spindle motor20is detected by the detector60.

In step S812, the rotational speed is compared with a predetermined value by the comparator70. If the rotational speed is larger than or equal to the predetermined value, the procedure goes to step S808. If the rotational speed is smaller than the predetermined value, the procedure goes to step S814.

In step S814, the spindle motor20is powered off.

It is to be understood that the above description and the following claims drawn to a method may include some indication in reference to certain steps. However, the indication used is only to be viewed for identification purposes and not as a suggestion as to an order for the steps.