Optical distance measuring device

• US 8,773,642 B2
• Filed: 07/21/2010
• Issued: 07/08/2014
• Est. Priority Date: 09/11/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Eisele, Andreas, Wolst, Oliver, Schmidtke, Bernd
• Primary Examiner(s): RATCLIFFE, LUKE D
• Application Number:
  US13/395,265
• Publication Number:
  US 20120262696A1
• Time in Patent Office: 1,448 Days
• Field of Search: 356 301- 315, 356 401- 41, 356 501- 515, 356 6- 22, 356/28, 356/28.5, 35613901-1391
• US Class Current: 356/4.01
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 7/4816 of receivers alone
• CPC Class Codes: G01S 7/4863 Detector arrays, e.g. charge-transfer gates

Abstract

A measuring device for optically measuring a distance to a target object including an emitter device for emitting an optical measuring beam to the target object, a capturing device comprising a detection surface for detecting an optical beam returned by the target object, and an evaluation device. The detection surface has a plurality of pixels, each pixel having at least one light-sensitive element and each of the plurality of pixels is connected to the evaluation device. The emitting device and the capturing device are configured in such a manner that the optical measurement beam returned by the target object simultaneously illuminates a plurality of pixels. The evaluation device is configured in such a manner that detection signals of a plurality of pixels are guided to at least one of the plurality of distance determining devices.

Claims

1. A measuring device for optical distance measurement, in particular a handheld measuring device, comprising:

a transmitting unit for emitting optical measurement radiation toward a target object;

a receiving unit having a detection area for detecting optical measurement radiation returning from the target object; and

an evaluation unit having a plurality of distance determining units,

wherein the detection area has a multiplicity of pixels,

wherein each pixel has at least one light-sensitive element,

wherein the evaluation unit is designed in such a way that detection signals of a plurality of pixels are forwarded to at least one of the plurality of distance determining units, on the basis of which the respective distance determining unit determines distance data which correlate with the distance between the measuring device and the target object, and

wherein the evaluation unit is designed to determine a distance between the measuring device and the target object on the basis of an evaluation of distance data that were determined by the plurality of distance determining units.

2. The measuring device as claimed in claim 1, wherein the distance determining devices are in each case designed to determine a time of flight of measurement radiation between emission by the transmitting unit until detection of measurement radiation returning from the target object and to determine a distance therefrom.

3. The measuring device as claimed in claim 1, further comprising:

at least one multiplexer in order to forward detection signals of individual pixels sequentially to a distance determining unit.

4. The measuring device as claimed in claim 2, wherein the evaluation unit is designed to determine the distance between the measuring device and the target object on the basis of the distances determined by the distance determining units.

5. The measuring device as claimed in claim 1, wherein at least some pixels each contain a plurality of light-sensitive elements.

6. The measuring device as claimed in claim 5, furthermore comprising:

at least one combiner designed to combine detection signals of light-sensitive elements which are contained in an individual pixel.

7. The measuring device as claimed in claim 5, furthermore comprising:

at least one pulse shortener in order to temporally shorten a digital signal generated by an SPAD.

8. The measuring device as claimed in claim 5, wherein the number of light-sensitive elements contained in a pixel varies depending on the location of the pixel within the detection area of the receiving unit.

9. The measuring device as claimed in claim 5, wherein an area of light-sensitive elements contained in a pixel varies depending on the location of the pixel within the detection area of the receiving unit.

10. The measuring device as claimed in claim 8, wherein:

the transmitting unit and the receiving unit are arranged alongside one another along a parallax axis, and

the number of light-sensitive elements contained in a pixel varies depending on the location along the parallax axis.

11. The measuring device as claimed in claim 8, wherein the number of light-sensitive elements contained in a pixel is smaller in pixels near the transmitting unit than in pixels remote from the transmitting unit.

12. The measuring device as claimed in claim 8, wherein the number of light-sensitive elements contained in a pixel is smaller in pixels near the center of the detection area than in pixels remote from the center of the detection area.

13. The measuring device as claimed in claim 1, wherein the transmitting unit and the receiving unit are designed in such a way that a number of pixels which are illuminated simultaneously by optical measurement radiation returning from the target object varies in a manner dependent on a distance between the target object and the measuring device.

14. The measuring device as claimed in claim 1, furthermore comprising:

a non-automatically focusing optical unit for directing optical measurement radiation returning from the target object onto the detection area.

15. The measuring device as claimed in claim 1, wherein the receiving unit and the evaluation unit are designed for the purpose that detection signals of individual pixels can be evaluated independently of detection signals of other pixels by the evaluation unit.

16. The measuring device as claimed in claim 1, wherein the receiving unit and the evaluation unit are designed to determine a distance between the measuring device and the target object on the basis of an evaluation of detection signals exclusively of pixels within an effective detection area, onto which light from that area of the target object which is illuminated by the transmitting unit is radiated back.

17. The measuring device as claimed in claim 1, furthermore comprising:

at least one multiplexer designed to forward detection signals of a plurality of pixels selectively to the evaluation unit.