Retainer plate switching mechanism for optical component

In a night vision device having an infrared LED port out of which radiation is emitted, a mechanism for switching a lens assembly between a spot position where it covers the LED port and a flood position where it does not cover the LED port, comprising,

• a housing including the LED port, which has a relatively large slot, the lens assembly including a cylindrical member which extends from a flange having a relatively larger diameter than that of the cylindrical member, the lens assembly being positioned so that the flange is in the relatively large slot of the housing and the slot and flange being dimesioned so that the flange is slidable in the slot, and a retainer plate positioned over the flange and secured to the housing so as to retain the lens assembly in the housing, the retainer plate having a relatively small slot through which the cylindrical member passes, the slot being bounded by a slot wall which has curved end portions at respective ends, the slot wall including two scallops between the end portions for defining the spot and flood positions for the lens assembly, each scallop exerting a force on the cylindrical member when it is disposed in that scallop, and a mechanical interference portion between the two scallops which contacts and resists the cylindrical member when it is moved between the spot and flood positions.

In an optical apparatus, a switching device for switching an optical component between defined positions, comprising,

• a housing in which the optical component is slidably mounted for sliding between the defined positions, and
• a retainer plate in front of the housing for capturing the optical component in the housing, wherein the retainer plate has a slot defined by a slot wall through which the optical component passes and wherein there are detents in the form of scallops in the slot wall for defining the defined positions and for maintaining the optical component in a selected one of the defined positions.