US 7,151,348 B1 · Motor driving apparatus

Abstract

A motor driving apparatus for driving a linear vibration motor having a spring member that supports a mover so as to form a spring vibration system including the mover. The motor driving apparatus employs an accurate spring constant of the spring member corresponding to an individual linear vibration motor at a position calculation for obtaining the position of the mover during the operation, thereby increasing the accuracy of the position calculation. The motor driving apparatus includes a mover force vibration unit for making the mover of the linear vibration motor freely vibrate, a relative position detection unit for detecting a timing when the freely vibrating mover passes through a fixed point (relative position), and a natural frequency detection unit for detecting a natural frequency of the mover based on output information from the relative position detection unit, thereby calculating the spring constant based on the detected natural frequency.

Claims50

Dependent claims

A motor driving apparatus for driving a linear vibration motor having a mover which is reciprocatably provided and a spring member which supports the mover, said motor driving apparatus including:

a mover force vibration unit for making the mover freely vibrate;
a vibration parameter obtaining unit for obtaining a natural vibration parameter that shows natural vibration of the mover on the basis of a free vibration state of the mover;
a spring constant decision unit for calculating a spring constant of the spring member by using the natural vibration parameter obtained by said vibration parameter obtaining unit;
and
a mover position calculation unit for calculating the position of the mover on the basis of a driving current and a driving voltage which are applied to the linear vibration motor, by using the spring constant calculated by said spring constant decision unit.

2 more elements

A motor driving apparatus for driving a linear vibration motor having a mover which is reciprocatably provided and a spring member which supports the mover, said motor driving apparatus including:

a motor driver for applying a driving current and a driving voltage to the linear vibration motor;
a current detection unit for detecting a current that is applied from the said motor driver to the linear vibration motor;
a voltage detection unit for detecting a voltage that is applied from said motor driver to the linear vibration motor;
a resonance frequency detection unit for detecting a resonance frequency of the linear vibration motor from the detected current and the detected voltage;
a spring constant decision unit for calculating a spring constant of the spring member by multiplying the resonance frequency detected by said resonance frequency detection unit by a twofold of the ratio of the circumference to the diameter, squaring the result of the multiplication, and multiplying the squared value by a mass of the mover;
and
a mover position calculation unit for calculating the position of the mover on the basis of the driving current and the driving voltage, by using the spring constant calculated by said spring constant decision unit.

4 more elements

A motor driving apparatus for driving a linear vibration motor having a mover which is reciprocatably provided and a spring member which supports the mover, said motor driving apparatus including:

a mover force vibration unit for making the mover freely vibrate;
a vibration parameter obtaining unit for obtaining a natural vibration parameter that shows natural vibration of the mover on the basis of a free vibration state of the mover;
a mass/spring ratio decision unit for deciding a mass/spring ratio that is a ratio between a mass of the mover and a spring constant of the spring member by using the natural vibration parameter obtained by said vibration parameter obtaining unit;
and
a mover position calculation unit for calculating the position of the mover on the basis of a driving current and a driving voltage which are applied to the linear vibration motor, by using the mass/spring ratio decided by said mass/spring ratio decision unit.

2 more elements

A motor driving apparatus for driving a linear vibration motor having a mover which is reciprocatably provided and a spring member which supports the mover, said motor driving apparatus including:

a motor driver for applying a driving current and a driving voltage to the linear vibration motor;
a current detection unit for detecting a current that is applied from said motor driver to the linear vibration motor;
a voltage detection unit for detecting a voltage that is applied from said motor driver to the linear vibration motor;
a resonance frequency detection unit for detecting a resonance frequency of the linear vibration motor from the detected current and the detected voltage;
a mass/spring ratio decision unit for deciding a mass/spring ratio by multiplying the resonance frequency detected by said resonance frequency detection unit by a twofold of the ratio of the circumference to the diameter, squaring the result of the multiplication, and calculating an inverse of the squared value;
and
a mover position calculation unit for calculating the position of the mover on the basis of the driving current and the driving voltage, by using the mass/spring ratio decided by said mass/spring ratio decision unit.

4 more elements

Dependencies are inferred from the claim text.

Motor driving apparatus

Life of this patent

Motor driving apparatus

Life of this patent

Abstract

Claims50