Optical module, electronic device, and driving method

Abstract

An optical module includes a wavelength variable interference filter having a fixed reflective film, a movable reflective film which faces the fixed reflective film with a gap between reflective films interposed therebetween, and an electrostatic actuator that changes the gap between reflective films, and a gap control unit that controls the electrostatic actuator. The gap control unit controls the electrostatic actuator on the basis of an order which is set in accordance with a wavelength to be measured, and changes the gap between the reflective films.

What is claimed is: 
     
         1 . A driving method of wavelength variable interference filter, the wavelength variable interference filter including an actuator that controls wavelength of measurement light and a voltage controller that applies a plurality of voltages to the actuator, the method comprising:
 applying a first voltage among the plurality of voltages to the actuator, the first voltage corresponding to a first wavelength of m+1-th light in a first wavelength range;   acquiring a first detection signal that corresponds to a first light amount of a first measurement light;   after the acquiring the first detection signal, applying a second voltage among the plurality of voltages to the actuator, the second voltage corresponding to a second wavelength of m-th light in a second wavelength range; and   acquiring a second detection signal that corresponds to a second light amount of a second measurement light,   the first voltage being smaller than the second voltage.   
     
     
         2 . The driving method of wavelength variable interference filter according to  claim 1 ,
 the voltage controller applies the plurality of voltages including the first voltage and the second voltage in ascending order.   
     
     
         3 . The driving method of wavelength variable interference filter according to  claim 1 , the wavelength variable interference filter including a first mirror and a second mirror, a gap between the first mirror and the second mirror corresponding to the wavelength of measurement light,
 a first gap that is the gap when the first voltage is applied to the actuator being larger than a second gap that is the gap when the second voltage is applied to the actuator.   
     
     
         4 . The driving method of wavelength variable interference filter according to  claim 1 , further comprising:
 reading a plurality of voltage values by the controller, one of the plurality of voltage values corresponding to one of the plurality of voltages; and   sorting the plurality of voltage values in ascending order.   
     
     
         5 . The driving method of wavelength variable interference filter according to  claim 1 , further comprising:
 selecting an order of the light corresponding to the first wavelength range by an order selector;   reading a first voltage value that corresponds the first wavelength from storage by the voltage controller;   applying the first voltage to the actuator by the voltage controller.   
     
     
         6 . A method of spectroscopy comprising:
 the driving method of wavelength variable interference filter according to  claim 1 ,   estimating an optical spectrum of the measurement light by operating a transformation matrix to a measurement spectrum based on the first detection signal and the second detection signal.   
     
     
         7 . A driving method of wavelength variable interference filter, the wavelength variable interference filter including an actuator that controls wavelength of measurement light and a voltage controller that applies a plurality of voltages to the actuator, the method comprising:
 applying a first voltage among the plurality of voltages to the actuator, the first voltage corresponding to a first wavelength of a first number order light in a first wavelength range;   acquiring a first detection signal that corresponds to a first light amount of a first measurement light;   after the acquiring the first detection signal, applying a second voltage among the plurality of voltages to the actuator, the second voltage corresponding to a second wavelength of a second number order light in a second wavelength range; and   acquiring a second detection signal that corresponds to a second light amount of a second measurement light,   the first voltage being smaller than the second voltage.