The invention relates to a measuring device and a method based on a
confocal microscopy principle. The inventive device comprises a
light source (1), a diaphragm unit (3) for limiting a beam, an imagine optical
system (4) for focusing the light (5) which is irradiated by said source on a measurable object (6) and passes through said diaphragm unit. Said device also comprises an optical
system (10) for receiving the light (5) reflected from the object and passing through said optical
system or another diaphragm unit disposed in an observation beam (7) and an image
receiver (10) which is provided with at least two
radiation-sensitive sensor elements (13, 14) (pixel). Said invention is characterized in that, in order to obtain the image of an altitude information-containing measurement, the device is also provided with means (11) for modifying the beam
optical path length disposed between the
light source (1) and / or the image
receiver (10), on one side, and the object (6) on the other and the optical distance (d) of a focal point is modifiable in a predetermined manner. In addition, said intention makes it possible to influence the dependence of an accumulation of charges (Q13, Q14) in at least two sensor elements (13, 14) on the
light intensity of the observation beam (7) during the
exposure time in such a way that a correlation associated with the optical distance (d) of an
image plane can be carried out by the imagine optical system (4), thereby making it possible to reconstitute the altitude co-ordinate (zs) of the object by distributing the intensity values obtained during the
exposure time from at least two sensor elements (13, 14).