US 9,000,691 B2 · Method of controlling vibration motor

Abstract

Provided is a method of controlling a vibration motor, in which there are provided: a unit that generates a drive signal for generating elliptic motion; a unit that switches the drive signal with a voltage from a power supply, and changes a pulse width of the drive signal; a unit that detects a current flowing in an electromechanical energy conversion element through the switching unit; a unit that detects a position and a velocity of an object to be driven; and a control unit that controls the respective units, and sets the velocity of the object to be driven. The control unit controls a frequency and the pulse width of the drive signal so as to exercise a maximum output characteristic with respect to a target velocity within a range in which the current detected by the current detection unit does not exceed a given limit value.

Claims20

Dependent claims

A method of controlling a vibration motor comprising an electromechanical energy conversion element joined to an elastic body, the method comprising:

generating a drive signal in accordance with a signal from a control unit;
switching, using a switching unit, a voltage from a power supply in accordance with the drive signal;
detecting a current flowing to the switching unit;
detecting at least one of a position and a velocity of an object in contact with the elastic body of the vibration motor;
determining whether a frequency of the drive signal is in a first frequency domain or in a second frequency domain;
and
performing at least one of narrowing of a pulse width of the drive signal and decreasing the frequency of the drive signal when the frequency of the drive signal is in the first frequency domain;
and
performing narrowing of the pulse width of the drive signal when the frequency of the drive signal is in the second frequency domain,
wherein, in the first frequency domain, the current decreases when the frequency of the drive signal decreases, and
wherein, in the second frequency domain, the current increases when the frequency of the drive signal decreases.

8 more elements

A method of controlling a vibration motor comprising an electromechanical energy conversion element joined to an elastic body, the method comprising:

generating a drive signal in accordance with a signal from a control unit;
switching, using a switching unit, a voltage from a power supply in accordance with the drive signal;
acquiring an electric power between the power supply and the switching unit;
detecting at least one of a position and a velocity of an object in contact with the elastic body of the vibration motor;
determining whether a frequency of the drive signal is in a first frequency domain or in a second frequency domain;
and
performing at least one of narrowing of a pulse width of the drive signal and decreasing a frequency of the drive signal when the frequency of the drive signal is in the first frequency domain;
and
performing narrowing of the pulse width of the drive signal when the frequency of the drive signal is in the second frequency domain,
wherein, in the first frequency domain, the electric power decreases when the frequency of the drive signal decreases, and
wherein, in the second frequency domain, the electric power increases when the frequency of the drive signal decreases.

8 more elements

A driver for a vibration motor comprising an electromechanical energy conversion element and an elastic body joined with the electromechanical energy conversion element, the driver comprising:

a drive signal generation unit configured to generate a drive signal;
a switching unit configured to switch a voltage from a power supply;
a current detection unit between the power supply and the switching unit;
a detection unit configured to detect at least one of a position and a velocity of an object which is in contact with the elastic body;
and
a control unit comprising a determination unit configured to determine whether a frequency of the drive signal is in a first frequency domain or in a second frequency domain,
wherein the control unit is configured to output a first signal when the frequency of the drive signal is in the first frequency domain, and to output a second signal when the frequency of the drive signal is in the second frequency domain,
wherein, in the first frequency domain, the current decreases when the frequency of the drive signal decreases,
wherein, in the second frequency domain, the current increases when the frequency of the drive signal decreases,
wherein the first signal includes at least one of information to narrow a pulse width of the drive signal and information to decrease the frequency of the drive signal, and
wherein the second signal includes information to narrow the pulse width of the drive signal.

8 more elements

A driver for a vibration motor comprising an electromechanical energy conversion element and an elastic body joined with the electromechanical energy conversion element, the driver comprising:

a drive signal generation unit configured to generate a drive signal;
a switching unit configured to switch a voltage from the power supply;
an electric power acquisition unit provided between the power supply and the switching unit;
a detection unit configured to detect at least one of a position and a velocity of an object which is in contact with the elastic body;
and
a control unit comprising a determination unit configured to determine whether a frequency of the drive signal is in a first frequency domain or in a second frequency domain,
wherein the control unit is configured to output a first signal when the frequency of the drive signal is in the first frequency domain, and to output a second signal when the frequency of the drive signal is in the second frequency domain,
wherein, in the first frequency domain, the current decreases when the frequency of the drive signal decreases,
wherein, in the second frequency domain, the current increases when the frequency of the drive signal decreases,
wherein the first signal includes at least one of information to narrow a pulse width of the drive signal and information to decrease the frequency of the drive signal, and
wherein the second signal includes information to narrow the pulse width of the drive signal.

8 more elements

Dependencies are inferred from the claim text.

Method of controlling vibration motor

Life of this patent

Method of controlling vibration motor

Life of this patent

Abstract

Claims20