Installable pinhole

1. An adjustable pinhole for the illumination beam path and/or detection beam path of a laser scanning microscope, comprising that the pinhole is defined by foil edges which are adjustable relative to one another,

the foils have solid-state joints and the solid-state joints which are driven by motor are provided for adjusting the foil edges,

a referencing of a stepping motor drive is carried out by means of a path measuring system and/or an optical detector for detecting the amount of light passing through the pinhole,

wherein the pinhole can be closed in such a way that the foils overlap and at least one of the foils has an offset to prevent collision

wherein an adjustment is carried out by a stepping motor which drives, by two spindles running in the same direction, a plurality of plates which are displaceable at different pitches, the foils being fastened to the plates.

2. The adjustable pinhole according to claim 1 , wherein at least two foils, each with at least one straight edge, are arranged relative to one another and/or connected to one another in such a way that their edges describe an L-shape and the L-shaped connection pieces are arranged on one another in such a way that they define a rhombic or square light passage and are moved relative to one another for adjusting the pinhole.

3. The adjustable pinhole according to claim 2 , wherein the movement direction is the direction of the bisecting line of the angle defined by the L-shape or of another angle lying within the defined angle.