Device and method for optical distance measurement

• US 7,728,957 B2
• Filed: 07/01/2005
• Issued: 06/01/2010
• Est. Priority Date: 09/02/2004
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schulte, Clemens, Renz, Kai, Haase, Bjoern, Wolf, Peter, Stierle, Joerg, Pahud, Cedric
• Primary Examiner(s): ALSOMIRI, ISAM A
• Application Number:
  US10/593,595
• Publication Number:
  US 20070211329A1
• Time in Patent Office: 1,796 Days
• Field of Search: 356 301- 515, 356/614, 356/623
• US Class Current: 356/5.1
• CPC Class Codes: G01C 3/085 with electronic parallax measurement
• CPC Class Codes: G01S 17/36 with phase comparison between the received signal and the contemporaneously transmitted signal
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves

Abstract

The invention relates to a device for optical distance measurement, in particular a device functioning in accordance with the phase measurement principle, having at least one transmission unit (12) equipped with at least one light source (22, 24) for transmitting modulated optical measurement radiation (16) toward a target object (20), and having a reception unit (18) for receiving the optical measurement radiation (17) returning from the target object (20).

According to the present invention, the device has means (51, 55, 68) that enable a measurement of distances from a target object (20′) by means of a triangulation method.

The invention also relates to a method for optical distance measurement in which it is possible to switch back and forth between a phase measurement method for determining a distance of a distance measuring device from a target object (20, 20′) and a triangulation method for determining this distance.

Claims

1. A device for optical distance measurement functioning in accordance with the phase measurement principle, having at least one transmission unit (12) equipped with at least one light source (22, 24) for transmitting modulated optical measurement radiation (16) toward a target object (20), and having a reception unit (18) for receiving the optical measurement radiation (17) returning from the target object (20), wherein the device has means (51, 53, 55, 68) that enable a measurement of distances between the device and a target object (20′

) using a triangulation, wherein the means include the light source (22, 24) of the transmission unit (12).

2. The device as recited in claim 1, wherein the means include at least one position-sensitive sensor (55).

3. The device as recited in claim 2, wherein the position-sensitive sensor (55) is a planar detector.

4. The device as recited in claim 2, wherein the position-sensitive sensor (55) is a linear detector.

5. The device as recited in claim 2, wherein the position-sensitive sensor (55) also has the capacity to be used for time delay measurement of the modulated measurement signal (16, 17, 17′

) for a phase measurement of the returning measurement signal (17).

6. The device as recited in claim 1, wherein the means (51, 53, 55, 68) include at least one set of projection optics (51).

7. The device as recited in claim 1, wherein the means (51, 53, 55, 68) include at least one circular aperture (53).

8. The device as recited in claim 1, wherein the device has at least one control and evaluation unit (58) for determining a distance of the device (10) from the target object (20, 20′

) based on the phase shift of the optical measurement radiation (17) returning from the target object (20).

9. The device as recited in claim 1, wherein the device (10) has at least one mechanical, slidable measurement stop (72, 74).

10. A method for optical distance measurement in which it is possible to switch back and forth between a phase measurement method for determining a distance of a distance measuring device from a target object (20, 20′

) and a triangulation method for determining this distance, wherein the same light source (22, 24) is used for the phase measurement method and the triangulation method.

11. The method for optical distance measurement as recited in claim 10, wherein the same modulated transmission measurement beam (16) is used for the phase measurement method and the triangulation method.

12. The method for optical distance measurement as recited in claim 10, wherein the same detector element (55) is used for the phase measurement method and the triangulation method.