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 . An optical module comprising:
 a first reflective film that transmits a portion of incident light and reflects a portion thereof;   a second reflective film, disposed so as to face the first reflective film, which reflects a portion of incident light and transmits a portion thereof; and   a gap control unit that changes a size of a gap between the first reflective film and the second reflective film,   wherein the gap control unit controls the size of the gap corresponding to a wavelength to be measured, on the basis of an order of a transmission spectrum which is set with respect to each of two or more wavelength region group constituting a wavelength region to be measured.   
     
     
         2 . The optical module according to  claim 1 , further comprising a gap change portion that changes the size of the gap by applying a voltage,
 wherein the gap control unit includes a storage unit that stores V-λ data in which a voltage applied to the gap change portion with respect to a wavelength to be measured is recorded for each wavelength to be measured,   the V-λ data is data in which the wavelength to be measured is associated with a voltage corresponding to the gap for extracting light of the wavelength to be measured as a peak wavelength of the set order, and   the gap control unit applies the voltage, corresponding to the wavelength to be measured, from the V-λ data to the gap change portion.   
     
     
         3 . The optical module according to  claim 1 , further comprising a gap change portion that changes the size of the gap by applying a voltage,
 wherein the gap control unit includes a storage unit that stores V-λ data in which a voltage applied to the gap change portion with respect to a wavelength to be measured is recorded for each wavelength to be measured,   the V-λ data indicates a relationship between the wavelength to be measured and a voltage corresponding to the gap for extracting light of the wavelength to be measured as a peak wavelength of each order, and   the gap control unit selects an order corresponding to the wavelength to be measured, and applies the voltage corresponding to the selected order to the gap change portion.   
     
     
         4 . The optical module according to  claim 1 , wherein a measurement wavelength region includes a first wavelength region and a second wavelength region having a longer wavelength than that of the first wavelength region, and
 the order which is set with respect to the wavelength to be measured belonging to the first wavelength region is higher than the order which is set with respect to the wavelength to be measured belonging to the second wavelength region.   
     
     
         5 . The optical module according to  claim 4 , wherein the gap for extracting light of a longest wavelength in the second wavelength region is larger than the gap for extracting light of a shortest wavelength in the first wavelength region. 
     
     
         6 . The optical module according to  claim 4 , wherein the gap control unit acquires the gap with respect to each of a plurality of the wavelengths to be measured included in the measurement wavelength region, and performs a sequential change to the acquired gap from a maximum value of the gap in a direction in which the gap is reduced. 
     
     
         7 . An electronic device comprising:
 the optical module according to  claim 1 ; and   a processing control unit that performs a predetermined process on the basis of light extracted by the first reflective film and the second reflective film.   
     
     
         8 . An electronic device comprising:
 the optical module according to  claim 2 ; and   a processing control unit that performs a predetermined process on the basis of light extracted by the first reflective film and the second reflective film.   
     
     
         9 . An electronic device comprising:
 the optical module according to  claim 3 ; and   a processing control unit that performs a predetermined process on the basis of light extracted by the first reflective film and the second reflective film.   
     
     
         10 . An electronic device comprising:
 the optical module according to  claim 4 ; and   a processing control unit that performs a predetermined process on the basis of light extracted by the first reflective film and the second reflective film.   
     
     
         11 . An electronic device comprising:
 the optical module according to  claim 5 ; and   a processing control unit that performs a predetermined process on the basis of light extracted by the first reflective film and the second reflective film.   
     
     
         12 . An electronic device comprising:
 the optical module according to  claim 6 ; and   a processing control unit that performs a predetermined process on the basis of light extracted by the first reflective film and the second reflective film.   
     
     
         13 . The electronic device according to  claim 7 , further comprising a detection unit that detects the light extracted by the first reflective film and the second reflective film,
 wherein the processing control unit causes a transformation matrix for transforming a measurement spectrum into an optical spectrum to act on the measurement spectrum based on the amount of light of each wavelength to be measured which is detected by the detection unit, and estimates an optical spectrum of measurement light incident on the first reflective film and the second reflective film.   
     
     
         14 . A method of driving a wavelength variable interference filter including a first reflective film that transmits a portion of incident light and reflects a portion thereof, a second reflective film, disposed so as to face the first reflective film, which reflects a portion of incident light and transmits a portion thereof, and a gap change portion that changes a size of a gap between the first reflective film and the second reflective film, the driving method comprises:
 controlling the gap change portion on the basis of a wavelength to be measured and an order of a transmission spectrum which is set with respect to each of two or more wavelength region groups constituting a wavelength region to be measured.   
     
     
         15 . An optical module comprising:
 a first reflective film that transmits a portion of incident light and reflects a portion thereof;   a second reflective film, disposed so as to face the first reflective film, which reflects a portion of incident light and transmits a portion thereof; and   a gap change portion that changes a size of a gap between the first reflective film and the second reflective film,   wherein when m and n are set to different natural numbers, light of a first wavelength region is detected using an m-th peak wavelength, and light of a second wavelength region different from the first wavelength region is detected using an n-th peak wavelength.   
     
     
         16 . The optical module according to  claim 15 ,
 wherein the first wavelength region has a shorter wavelength than that of the second wavelength region, and   a relation of m=n+1 is satisfied.