Flexure-type suspension system providing for three degrees of freedom and flexure-type positioning assembly based thereon
View Patent ↗Suspension system comprising a flat spring member having four legs. The legs are symmetrically arranged with respect to the center position of the spring member and each of the legs has a longitudinal axis and an end portion. A suspension frame is provided to support the spring member (by fixing the end portion of two legs. Two preload elements are arranged close to the end portions of two of the legs in a manner to apply a preloading force at those legs. The preloading force essentially points in the direction of the longitudinal axis.
1. Suspension system comprising
a flat spring member, and
a suspension supporting the spring member by fixing the spring member,
characterized in that
a suspension frame serves as the suspension that supports the spring member by fixing the spring member at m positions with respect to the suspension frame, with m≧1,
said flat spring member serves as a membrane for carrying an optical element,
k preload elements, with k≧1, being arranged with respect to the suspension frame and the spring member in order to locally apply a preload force to the spring member so as to provide for positive stress in an active area of the spring member,
wherein m+k≧3,
wherein the k preload elements comprise one or more spring elements being attached to or being an integral part of the suspension frame, and
wherein said flat spring member comprises three or more in plane oriented leg-shaped flexible members.
2. The suspension system of claim 1 , wherein the spring member is a cross-like spring member having n=3 or n=4 legs and wherein the suspension frame comprises k=1 or k=2 preload elements.
3. The suspension system of claim 2 , wherein the cross-like spring member is a membrane with cut outs.
4. The suspension system of claim 1 , wherein the suspension frame and/or the spring member comprises plastic, silicon or metal.
5. Positioning or alignment assembly having a suspension system, the suspension system comprising
a flat spring member, and
a suspension supporting the spring member by fixing the spring member,
characterized in that
a suspension frame serves as the suspension that supports the spring member by fixing the spring member at m positions with respect to the suspension frame, with m≧2,
said flat spring member serves as a membrane for carrying an optical element,
k preload elements, with k≧2, being arranged with respect to the suspension frame and the spring member in order to locally apply a preload force to the spring member so as to provide for positive stress in an active area of the spring member,
wherein m+k≧3,
wherein the k preload elements comprise one or more spring elements being attached to or being an integral part of the suspension frame, and
wherein said flat spring member comprises three or more in plane oriented leg-shaped flexible members.