Microtome

摘要

A microtome (1) has a specimen arm (18) which can be displaced in the axial direction and on whose front end there is mounted a specimen holder (19) which is assigned an optical position (displacement) sensor operating using the reflection method. The position sensor consists of a light-emitting diode (89), which projects focused light obliquely onto a high-gloss plane cut surface (86) on the end face of the specimen (84). The reflected light is imaged on an optoelectronic potentiometer (61). If the position of the cut surface (85, 86, 87) changes, the light spot (92, 93) migrates correspondingly on the surface of the optoelectronic potentiometer (61), with the result that it is therefore possible to detect the exact position of the specimen (84). <IMAGE>