Device for distance measurement

Filing Information

• Patent Number: US5815251
• Application Number: US8537852
• Filing date: 11/15/1995
• PCT 371 date: 11/15/1995
• Issue date: 09/29/1998
• Predicted expiration date: 11/15/2015

• U.S. Classifications: 356/501  · 356/51  ·
• International Classifications: G01C 308 ·
• International Classifications: 3565.01-5.15;4.01 ·
• PCT Application Number: PCTEP9401412 - 05/04/1994
• PCT Publication Number: WO199427164 - 11/24/1994
• Foreign Priority: DE4316348.3 - 05/15/1993 ·

Patent Family

Abstract

A device for measuring distance with a visible measuring beam (11) generated by a semiconductor laser (10), a collimator object lens (12) to collimate the measuring beam towards the optical axis (13) of the collimator object lens (12), a radiation arrangement to modulate the measuring radiation, a reception object lens (15) to receive and image the measuring beam reflected from a distant object (16) on a receiver, a switchable beam deflection device (28) to generate an internal reference path between the semiconductor laser (10) and the receiver and an electronic evaluation device (25) to find and display the distance measured from the object. According to the invention, the receiver contains a light guide (17') with a downstream opto-electronic transducer (24), in which the light guide inlet surface (17) is arranged in the imaging plane of the reception object lens (15) for long distances from the object and can be controllably moved (18') from this position (18) transversely to the optical axis (14). In an alternative embodiment, the light inlet surface (17) is fixed and there are optical means (36) outside the optical axis (14) of the reception object lens (15) which, for short object distances, deflect the imaging position of the measuring beam to the optical axis (14) of the reception object lens (15). The measuring radiation is pulse modulated with excitation pulses with a pulse width of less than two nanoseconds.

Independent Claims | See all claims (35)

1. 1. A device for distance measurement, comprising:a visible measuring beam (11) generated by a semiconductor laser (10),a collimator objective lens (12) for collimating the measuring beam (11) along an optical axis (13) of the collimator objective lens (12),a circuit arrangement for modulating the measuring beam,a receiving objective lens (15) for receiving and imaging the measuring beam (11) reflected at a distant object (16) onto a receiving device,a switchable beam deflection device (28) for generating an internal reference path between the semiconductor laser (10) and the receiving device, andan electronic evaluation device (25) for determining and displaying a distance to the object (16),wherein the receiving device includes a light guide (17') with an optoelectronic converter (24) connected downstream thereof, an entry surface (17) of the light guide (17') being arranged in an image plane of the receiving objective lens (15) for large distances to the object and being controllably displaceable from this position transversely to an optical axis (14) of the receiving objective lens (15).
2. 2. A device for distance measurement, comprising:a visible measuring beam (11) generated by a semiconductor laser (10),a collimator objective lens (12) for collimating the measuring beam (11) along an optical axis (13) of the collimator objective lens (12),a circuit arrangement for modulating the measuring beam,a receiving objective lens (15) for receiving and imaging the measuring beam (11) reflected at a distant object (16) onto a receiving device,a switchable beam deflection device (28) for generating an internal reference path between the semiconductor laser (10) and the receiving device, andan electronic evaluation device (25) for determining and displaying a distance to the object (16),wherein the receiving device includes a light guide (17') with an optoelectronic converter (24) connected downstream thereof, an entry surface (17) of the light guide (17') being arranged along an optical axis (14) of the receiving objective lens (15) in an image plane of the receiving objective lens (15) for large distances to the object, and optical means (36; 37; 38) being provided between the receiving objective lens (15) and the light guide entry surface (17), outside the optical axis (14) of the receiving objective lens (15) for short distances to the object, such that the image position of the measuring beam (11) is deflected by the optical means towards the optical axis (14) of the receiving objective lens (15).
3. 19. A device for distance measurement, comprising:a visible measuring beam (11) generated by a semiconductor laser (10),a collimator objective lens (12) for collimating the measuring beam (11) along an optical axis (13) of the collimator objective lens (12),a circuit arrangement for modulating the measuring beam,a receiving objective lens (15) for receiving and imaging the measuring beam (11) reflected at a distant object (16) onto a receiving device,a switchable beam deflection device (28) for generating an internal reference path between the semiconductor laser (10) and the receiving device,an electronic evaluation device (25) for determining and displaying the distance measured to the object (16), andan electronic inclinometer (34) for measuring an inclination of the optical axis (13) of the collimator objective lens (12),wherein the measuring beam is pulse modulated with excitation pulses each having a pulse width below two nanoseconds, andwherein output signals of the inclinometer (34) are fed to an actuator for leveling the collimated measuring beam (11).
4. 25. A device for distance measurement, comprising:a semiconductor laser for generating a laser beam;a collimator objective lens for collimating the laser beam along an optical axis of the collimator objective lens and guiding the laser beam toward a distant object;a receiving objective lens for receiving and imaging the laser beam reflected from the distant object along an optical axis of the receiving objective lens, the optical axis of the receiving objective lens being parallel to the optical axis of the collimator objective lens;a light guide having an entry surface at which the laser beam imaged by the receiving objective lens is received, a position of the entry surface being adjustable in a direction transverse to the optical axis of the receiving objective lens;a switchable beam deflection device for generating an internal reference path between the semiconductor laser and the entry surface;an optoelectronic converter connected to the light guide for converting the laser beam received at the entry surface of the light guide to electrical signals; andan electronic evaluation device for determining the distance measured to the distant object based on the converted electrical signals.