Endoskop und Verfahren zur Ermittlung von Objektabstaenden
The description refers to a measuring process to determine the distance between the distal end of an endoscope and an object under examination by means of optical radar, and to an endoscope which contains a distance measuring device. To perform the measurement, a transmit optical fibre and a receive optical fibre are each connected in the endoscope to optic modules provided separately at the front end of the endoscope. A semiconductor laser injects high-frequency amplitude-modulated light into the transmit optical fibre, said light being projected through the transmit optic module onto the object in the form of a light spot. Light reflected by the object is received by the receive optic module and fed to a light detector of a control unit through the receive optical fibre in the endoscope. In the control unit, a phase measurement is performed and an evaluating device calculates a distance from the phase difference.
DE 1994-4439227 A: 19941103