Motor drive apparatus and method

• US 6,150,779 A
• Filed: 08/26/1999
• Issued: 11/21/2000
• Est. Priority Date: 08/26/1998
• Status: Expired due to Term

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Itami, Yukio, Suzuki, Mitsuo
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US09/384,291
• Time in Patent Office: 453 Days
• Field of Search: 318/138, 318/254, 318/430, 318/431, 318/439, 318/445, 318/484, 318/700, 318/720, 318/721, 318/722, 318/724
• US Class Current: 318/400.11
• CPC Class Codes: H02P 6/20 Arrangements for starting H02P6/08 takes precedence
• CPC Class Codes: H02P 6/24 Arrangements for stopping

Abstract

A motor drive apparatus for driving a motor with power derived from a main power source, including a signal input device configured to input a start signal and a stop signal to initiate starting and stopping of the motor; a voltage regulator configured to output regulated electric power to the motor; and a semiconductor switching device disposed between the main power source and the voltage regulator, coupled to the signal input device, and configured to switch electric power from the main power source to the voltage regulator in accordance with the start signal input from the signal input device, and to shut off the electric power to the voltage regulator in accordance with the stop signal input from the signal input device.

Claims

1. A motor drive apparatus for driving a motor with power derived from a main power source, comprising:

a signal input device configured to input a start signal and a stop signal to initiate starting and stopping of the motor;

a voltage regulator configured to output regulated electric power to the motor; and

a semiconductor switching device disposed between the main power source and the voltage regulator, coupled to the signal input device, and configured to switch electric power from the main power source to the voltage regulator in accordance with the start signal input from the signal input device, and to shut off the electric power to the voltage regulator in accordance with the stop signal input from the signal input device.

2. The motor drive apparatus according to claim 1, wherein the motor is a direct current brushless motor, comprising:

a position sensor configured to detect a rotating position of the motor and to receive the secondary electric power from the voltage regulator or the semiconductor switching device.

3. A motor drive apparatus for driving a motor with power derived from a main power source, comprising:

a signal input device configured to input a start signal and a stop signal to initiate starting and stopping of the motor;

a voltage regulator configured to output regulated electric power to the motor;

a first semiconductor switching device disposed between the main power source and the voltage regulator and coupled to the signal input device, said first semiconductor switching device including a control input and configured to switch electric power from the main power source to the voltage regulator; and

a second semiconductor switching device, connected to the control input of the first semiconductor switching device, and configured to generate a turn-on signal in accordance with the start signal input from the signal input device and to generate a turn-off signal in accordance with the stop signal input from the signal input device;

wherein the first semiconductor switching device is configured to switch the electric power to the voltage regulator in accordance with the turn-on signal input from the second semiconductor switching device and to shut off the electric power to the voltage regulator in accordance with the turn-off signal input from the second semiconductor switching device.

4. The motor drive apparatus according to claim 3, wherein the motor is a direct current brushless motor, comprising:

a position sensor configured to detect a rotating position of the motor and to receive the secondary electric power from the voltage regulator or the first semiconductor switching device.

5. A motor drive apparatus for driving a motor with power derived from a main power source, comprising:

a signal input device configured to input a start signal and a stop signal to initiate starting and stopping of the motor;

a voltage regulator configured to output regulated electric power to the motor;

a first semiconductor switching device disposed between the main power source and the voltage regulator and coupled to the signal input device, said first semiconductor switching device including a control input and configured to switch electric power from the main power source to the voltage regulator;

a second semiconductor switching device connected to the control input of the first semiconductor switching device; and

a timer device configured to generate a first timer signal at a first predetermined time after receiving the start signal input from the signal input device and to generate a second timer signal at a second predetermined time after receiving the stop signal input from the signal input device, the second predetermined time being longer than the first predetermined time;

wherein the second semiconductor switching device is configured to generate a turn-on signal in accordance with the first timer signal and to generate a turn-off signal in accordance with the second timer signal, and the first semiconductor switching device is configured to switch the electric power to the voltage regulator in accordance with the turn-on signal input from the second semiconductor switching device and to shut off the electric power to the voltage regulator in accordance with the turn-off signal input from the second semiconductor switching device.

6. The motor drive apparatus according to claim 5, wherein the motor is a direct current brushless motor, comprising:

a position sensor configured to detect a rotating position of the motor and to receive the secondary electric power from the voltage regulator or the first semiconductor switching device.

7. The motor drive apparatus according to claim 5, further comprising:

a slowdown circuit configured to decrease rotation of the motor in response to the stop signal.

8. The motor drive apparatus according to claim 7, wherein the motor includes a dynamic air pressure bearing and the slow down circuit is configured to decrease the rotation of the motor to a speed at which it can be determined whether the dynamic air pressure bearing is damaged.

9. The motor drive apparatus according to claim 5, wherein the timer device comprises:

a third semiconductor switching device configured to transmit the first timer signal and the second timer signal to the second semiconductor switching device;

a capacitor;

a discharging circuit configured to discharge the capacitor after the signal input device inputs the start signal; and

a charging circuit configured to charge the capacitor after the signal input device inputs the stop signal.

10. A motor drive apparatus of a direct current motor having a main power source, comprising:

a position sensor configured to detect a rotating position of the direct current motor;

a motor control device configured to control the rotation of the direct current motor;

a signal input device configured to input a start signal and a stop signal to initiate starting and stopping of the direct current motor;

a voltage regulator configured to output regulated electric power to the motor control device and the position sensor; and

a switching device disposed between the main power source and the voltage regulator, coupled to the signal input device, and configured to switch electric power from the main power source to the voltage regulator in accordance with the start signal input from the signal input device, and to shut off the electric power to the voltage regulator in accordance with the stop signal input from the signal input device.

11. The motor drive apparatus according to claim 10, wherein the motor control device is integrally structured inside the motor.

12. The motor drive apparatus according to claim 10, further comprising:

a slowdown circuit configured to stop rotation of the motor in response to the stop signal.

13. The motor drive apparatus according to claim 12, wherein the direct current motor includes a dynamic air pressure bearing and the slow down circuit is configured to decrease the rotation of the motor to a speed at which it can be determined whether the dynamic air pressure bearing is damaged.

14. A method for driving a motor with power derived from a main power source, comprising:

inputting start signals and stop signals to initiate starting and stopping of the motor;

supplying electric power input from the main power source to a voltage regulator configured to apply regulated power to the motor in accordance with a respective start signal input from the signal input device; and

shutting off the electric power from the main power source to the voltage regulator in accordance with a respective stop signal input from the signal input device.

15. A method for driving a motor from power derived from a main power source, comprising:

inputting start signals and stop signals to initiate starting and stopping of the motor;

supplying electric power input from the main power source to a voltage regulator configured to apply regulated power to the motor in accordance with a respective start signal input from the signal input device;

shutting off the electric power input from the main power source to the voltage regulator a predetermined time after receiving a respective stop signal; and

stopping rotation of the motor when the respective stop signal is received.