Drive system of actuator having piezoelectric device for use in motor vehicle

Patent 5013955 Issued on May 7, 1991. Estimated Expiration Date:

June 7, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3573781

3819961

3828773

Driving apparatus for ultrasonic motor
Patent #: 4888514
Issued on: 12/19/1989
Inventor: Takahashi, et al.

Process and circuit for exciting an ultrasonic generator and its use for atomizing a liquid Patent #: 4901034
Issued on: 02/13/1990
Inventor: Frank-Peter

Inventors

Assignee

Application

No. 535194 filed on 06/07/1990

US Classes:

310/323.21, Detector (e.g., sensor)310/328With mechanical energy coupling means

Examiners

Primary: Budd, Mark O.

Attorney, Agent or Firm

Cushman, Darby & Cushman

Foreign Patent References

6185210 JP. 04/13/1986
61230507 JP. 10/13/1986
6412880 JP. 01/13/1989
1202177 JP. 08/13/1989
1208213 JP. 08/13/1989

International Class

H01L 041/08

Foreign Application Priority Data

1989-06-07 JP

Abstract

A drive system of a piezo-type actuator for use in a motor vehicle, which piezo-type actuator is constructed with a piezoelectric device which is expandable and contractible in accordance with application of a voltage thereto. The drive system includes a voltage-increasing section for increasing an output voltage of a power source mounted on the motor vehicle so as to develop a drive voltage for the piezo-type actuator and a voltage-application section for applying to the piezoelectric device of the piezo-type actuator the drive voltage. Also included in the drive system is an abnormality detection section which is arranged so as to an abnormality of the drive voltage developed by the voltage-increasing section. A safety controller is responsive to an abnormality signal from the abnormality detection section for prohibiting the application of the drive voltage to the piezoelectric device thereof and further discharging charges accumulated in the piezoelectric device thereof when the abnormality detection section detects the abnormality of the developed drive voltage. With this arrangement, it is possible to prevent troubles due to the abnormality of the drive voltage to be applied to the piezoelectric device of the piezo-type actuator.