Device for optically measuring the distance from a reflective target object

Patent metadata

Field	Value
Publication number	US-10816645-B2
Application number	US-201615575237-A
Country	US
Kind code	B2
Filing date	May 11, 2016
Priority date	May 18, 2015
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A device for optically measuring the distance from a reflective target object is disclosed. The device includes a beam source, a detector, a beam shaping system having an optical transmission system and an optical receiving system, and a laser beam shaping element that can be arranged in the path of the laser beam. The laser beam shaping element is designed as a transmission aperture array with a first array of transmission pixels, where the transmission pixels are switchable by a first control unit between a transmission state impermeable to the laser beam and a transmission state at least partially permeable to the laser beam.

First claim

The invention claimed is:

1. A device for optically measuring a distance from a reflective target object, which is embodied as an individual retroreflector, and for optically measuring a distance from a reflective target object, which is embodied as a surface retroreflector, comprising:
a beam source, wherein the beam source is a first electro-optical component and wherein the beam source emits a laser beam;
a detector, wherein the detector is a second electro-optical component and wherein the detector receives a reception beam reflected or scattered at the reflective target object;
a beam shaping system with a transmission optical system that shapes the laser beam and a reception optical system that shapes the reception beam; and
a laser beam shaping element, wherein the laser beam shaping element is disposable in a path of the laser beam, wherein the laser beam shaping element is a transmission aperture array with a first array of transmission pixels, and wherein the transmission pixels are switchable by a first control unit between a transmission state impermeable to the laser beam having a transmission degree less than 10%, a transmission state partially permeable to the laser beam having a transmission degree between 10% and 90%, and a transmission state fully permeable to the laser beam having a transmission degree greater than 90%;
wherein in the first control unit at least one preset first transmission pixel array and at least one preset second transmission pixel array are provided;
wherein in the at least one preset first transmission pixel array at least 50% of the transmission pixels of the first array disposed in the path of the laser beam are impermeable to the laser beam;
wherein in the at least one preset second transmission pixel array at least 50% of the transmission pixels of the first array disposed in the path of the laser beam are partially permeable or fully permeable to the laser beam.

2. The device according to claim 1 , wherein one transmission pixel or multiple adjacent transmission pixels of the first array form a transmission aperture for the laser beam wherein the transmission aperture creates a partial beam and the partial beam expands to one or more opening angles that are not smaller than a minimum critical angle of 1.0 mrad.

3. The device according to claim 2 , wherein the first array has multiple transmission apertures, wherein the multiple transmission apertures create multiple partial beams, and wherein the multiple partial beams each expand to one or more opening angles that are not smaller than the minimum critical angle of 1.0 mrad.

4. The device according to claim 1 , wherein the partially permeable or the fully permeable transmission pixels of the first array form a shaping aperture, wherein the shaping aperture converts the laser beam to a shaped laser beam with one or more opening angles and the one or more opening angles are smaller than a maximum critical angle of 0.3 mrad.

5. The device according to claim 1 further comprising a reception beam shaping element, wherein the reception beam shaping element is disposable in a path of the reception beam, wherein the reception beam shaping element is a reception aperture array with a second array of reception pixels, and wherein the reception pixels are switchable by a second control unit between a reception state impermeable to the reception beam and a reception state at least partially permeable to the reception beam.

6. The device according to claim 5 , wherein the reception pixels are switchable between a reception state partially permeable to the reception beam and a reception state fully permeable to the reception beam.

7. The device according to claim 5 , wherein in the second control unit at least one preset reception pixel array of the second array is provided and wherein in the at least one preset reception pixel array one reception pixel or multiple adjacent reception pixels of the second array form a reception aperture for the reception beam.

8. The device according to claim 7 , wherein the second array has multiple reception apertures spaced apart from each other.

9. The device according to claim 7 , wherein in the second control unit multiple preset reception pixel arrays of the second array are provided that differ from each other at least partially in a transmission degree of the reception pixels.

10. The device according to claim 5 , wherein the first array of transmission pixels and the second array of reception pixels are arranged in a shared light modulator.

Assignees

• Hilti Ag

Inventors

• Gogolla Torsten
• Winter Andreas

Classifications

• G01S7/4814 Primary

  of transmitters alone · CPC title

• G01S17/08 Primary

  for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) · CPC title