Actuator apparatus, electronic device, and control method

Abstract

An actuator apparatus includes a pair of substrates facing each other; a plurality of bias actuators that each vary a gap dimension of a gap between the pair of substrates; a gap detection portion that detects the gap dimension; and a voltage control unit that controls driving of each of the bias actuators on the basis of the detected gap dimension. The bias actuators are located asymmetric relative to a driving central axis and are mutually independently driven; and the voltage control unit derives driving parameters for use in driving the bias actuators, on the basis of voltages and gap dimensions obtained by sequentially switching and driving the bias actuators on by one.

What is claimed is: 
     
         1 . An actuator apparatus comprising:
 a pair of substrates facing each other;   a plurality of electrostatic actuators that each vary a gap dimension of a gap between the pair of substrates;   a gap detection portion that detects the gap dimension; and   driving controller that controls driving of each of the plurality of electrostatic actuators,   
       wherein the plurality of electrostatic actuators are mutually independently driven, and the driving controller derives at least one driving parameter for use in driving each the plurality of electrostatic actuators on the basis of a voltage supplied to each of the plurality of electrostatic actuators and a gap dimension detected by the gap detection portion at a time of the supply of the voltage thereto. 
     
     
         2 . The actuator apparatus according to  claim 1 , wherein the driving controller derives a parallel control voltage for keeping the pair of substrates in a mutually parallel state, as a driving parameter of the at least one driving parameter for use in driving each the plurality of electrostatic actuators. 
     
     
         3 . The actuator apparatus according to  claim 2 , wherein, when supplying a voltage to each of the plurality of electrostatic actuators so that the each of the plurality of electrostatic actuators causes each of at least one of the pair of substrates to bend toward the other one of the pair of substrates and thereby vary the gap dimension, the driving controller derives a spring contact of the pair of substrates for the each of the plurality of electrostatic actuators and an initial gap dimension of a gap between electrodes constituting the each of the plurality of electrostatic actuators, as driving parameters of the at least one parameter for use in driving the each of the plurality of electrostatic actuators, and further, the driving controller drives the parallel control voltage as a driving parameter of the at least one driving parameter for use in driving the each of the plurality of electrostatic actuators, on the basis of the spring contact and the initial gap dimension. 
     
     
         4 . The actuator apparatus according to  claim 2 , further comprising a control electrostatic actuator,
 wherein the plurality of electrostatic actuators operate as bias electrostatic actuators each supplied with a bias voltage,   wherein the control electrostatic actuator is driven independently of the bias electrostatic actuators, and   wherein the driving controller supplies each of the bias electrostatic actuators with the parallel control voltage as the bias voltage, and supplies the control electrostatic actuator with a feedback voltage corresponding to a gap dimension detected by the gap detection portion.   
     
     
         5 . The actuator apparatus according to  claim 1 , wherein the gap detection portion detects a gap dimension of a gap between portions of the pair of substrates, the portions being located on a driving central axis in a plan view. 
     
     
         6 . The actuator apparatus according to  claim 1 , wherein a first reflecting film is provided on one of the pair of substrates and a second reflecting film is provided on the other one of the pair of substrates so as to face the first reflecting film. 
     
     
         7 . The actuator apparatus according to  claim 6 , wherein the first reflecting film and the second reflecting film are provided such that a center point of the first reflecting film as well as a center point of the second reflecting film is located on the driving central axis in a plan view. 
     
     
         8 . An electronic device comprising:
 the actuator apparatus according to  claim 1 ; and   a processing control unit that designates a target value of the gap dimension to thereby control the actuator apparatus,   wherein the driving controller derives the parameter for use in driving each of the plurality of electrostatic actuators on the basis of the voltage supplied to each of the plurality of electrostatic actuators, the gap dimension detected by the gap detection portion at a time of the supply of the voltage thereto, and the target value.   
     
     
         9 . A control method for an actuator apparatus, comprising:
 supplying each of a plurality of electrostatic actuators with a voltage;   detecting, by a gap detection portion, a gap dimension of a gap between a pair of substrates every time each of the plurality of electrostatic actuators is supplied with the voltage; and   deriving a driving parameter for driving each of the plurality of electrostatic actuators on the basis of the voltage supplied to each of the plurality of electrostatic actuators and the gap dimension at a time of the supply of the voltage thereto.