Patent ID: 11960074
Assignee: SEIKO EPSON CORPORATION
Field: nan (nan)
Classification: CPC nan | IPC G

Claim 0:
1. An optical filter comprising:
a pair of reflection films facing each other via a gap; and
an actuator that changes a distance between the pair of reflection films,
wherein each of the reflection films are formed of a plurality of layered structures,
the plurality of layered structures of each reflective film are respectively formed by sandwiching a low-refractive layer with a pair of high-refractive layers, wherein the low-refractive layer has a smaller refractive index than the pair of high-refractive layers,
in each of the respective layered structures of each reflective film, optical film thicknesses of the high-refractive layers and optical film thicknesses of the low-refractive layers are film thicknesses are based on a predetermined design center wavelength that is set with respect to that particular layered structure,
the design center wavelengths in each of the layered structures of a respective reflective film are different,
the plurality of layered structures are coupled by light-transmissive coupling layers, and
optical film thicknesses of the coupling layers are film thicknesses based on averages of the design center wavelengths of pairs of the layered structures with the coupling layers in between.