The invention concerns an assembly comprising an optical element and a mount.
Assemblies of this type, in particular lens systems as the optical element, in which the connection of the lenses to a mount surrounding them takes place by means of elastic connecting elements, are generally known.
U.S. Pat. No. 5,248,482 relates to the isolation of an optical element from a mount by means of elastic bar-like connecting elements between the optical element and the mount.
EP 0 230 277 A2 concerns a precision lens mounting with elastic bending elements in the form of bars between the optical element and the mount likewise being provided. The elastic bending elements are intended to make radial compliance possible to compensate for thermal stresses.
Something similar applies to EP 0 243 893 B1, in which a lens mounting for positioning lenses is described, with a multiplicity of bending devices designed in the manner of leaf springs holding a lens as an optical element on a mount.
The present invention is based on the object of providing a connecting technique between an optical element and a mount holding the latter, the optical element being connected to the mount via elastic links in such a way as to provide, at least to a great dextent, freedom from stress or low stress and consequently a reduction in the surface deformation of the optical element, along with a geometrically simple design.
This object is achieved according to the invention by the features.
The connection by means of the membrane-like joining element via a rigid, moment-transferring connection allows differences in stress to be reduced or no longer to occur during installation. This also means that deformations or tolerance inaccuracies of the flange do not affect the optical element, for example a lens.
The membrane-like joining element according to the invention has the effect during installation of achieving great elasticity of compliance in the z direction, i.e., in the direction of the optical axis. In this way, the optical element can be aligned exactly on the joining element in a low-stress manner. If, subsequently, a secure connection is established between the joining element and the optical element, to be precise a rigid, moment-transferring connection according to the invention, the bending angle thereby obtained between the joining element and the optical element is virtually fixed, whereby further bending may bot readily take place when loading occurs, i.e. angular changes are no longer possible. By establishing a secure connection, the degrees of freedom for moments at the connecting point are blocked. Consequently, when external forces and moments occur, there is a buckling stress, the inflexibility of which is significantly greater than that of pure bending, as a result of which the required natural frequency and stability are ensured.
A simple structural design for achieving the object set may be that the joining element comprises a membrane ring or a plurality of ring segments which are put together to form a closed membrane ring. In this way a clear reduction in surface deformations of the optical element is achieved.