Patent ID: 9541752
Date: 2017-01-10
CPC Classifications: G01J,G02B

Claim:
1. An optical filter device comprising: a light interference filter having a first substrate, a second substrate facing the first substrate, a first reflection film provided on the first substrate, and a second reflection film provided on the second substrate and facing the first reflection film; and a casing having a base substrate that fixes the light interference filter, and a lid that is joined to the base substrate and forms an internal space capable of housing the light interference filter between the base substrate and the lid; wherein the second substrate has an annular recessed portion provided on a surface opposite to the first substrate, the annular recessed portion is disposed outside of a light interference region where the first reflection film and the second reflection film overlap with each other, as viewed in a plan view of the first substrate and the second substrate seen from a direction of substrate thickness, the base substrate has a first base substrate and a second base substrate, the first base substrate being disposed between the second base substrate and the second substrate, the base substrate has a light transmission hole corresponding to a light transmission region, the light transmission hole having a first light transmission hole of the first base substrate and a second light transmission hole of the second base substrate, a first outer peripheral edge of the first light transmission hole overlaps with the annular recessed portion in the plan view, a second outer peripheral edge of the second light transmission hole is disposed inboard from the first outer peripheral edge in the plan view, and the surface opposite to the first substrate of the second substrate is joined to the base substrate.