Spatially resolving range-finding system

• US 6,636,300 B2
• Filed: 08/31/2001
• Issued: 10/21/2003
• Est. Priority Date: 03/18/1999
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Mengel, Peter, Doemens, Guenter
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US09/944,496
• Publication Number:
  US 20020003617A1
• Time in Patent Office: 781 Days
• Field of Search: 356/5-1-, 356/141.1, 180/169
• US Class Current: 356/141.1
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements
• CPC Class Codes: G01S 7/4814 of transmitters alone

Abstract

In a spatially resolving range-finding system, an object is illuminated in a pixelwise fashion by illuminating beams emanating from an array of light sources with returned imaging beams striking a corresponding array of solid state receiving elements. The particular arrangement of the light sources and the receiving elements may be varied. The laser light sources and receiving elements may be selectively operated such that one light source may illuminate one or more receiving elements or several light sources may illuminate a single receiving element. The light sources are driven serially, allowing limits of laser protection regulations to be reliably complied with. An advantage is a substantially better signal quality at the receiving elements.

Claims

1. A spatially resolving range-finding system for carrying out measurement of the travel-time of light to an object in pixelwise fashion, comprising a mechanically fixed array of individually modulable light sources for generating light beams for illuminating said object;

a mechanically fixed solid state image converter comprising a plurality of solid state light receiving elements arranged in an array corresponding to said array of light sources, and a mechanically fixed optical system for guiding light beams emanating from said sources to said object and for guiding light beams reflected from said object to said receiving elements, said optical system guiding each light beam reflected from the object to a selected receiving element corresponding to the light source from which the light beam emanated, wherein the light sources are driven by random access and the corresponding receiving elements are read-out by random access.

2. The spatially resolving range-finding system according to claim 1, wherein a divider mirror directs said reflected light beams to said receiving elements.

3. The spatially resolving range-finding system according to claim 1, wherein the arrangement of the light sources and the receiving elements are positioned immediately next to one another and facing in the direction of the object.

4. The spatially resolving range-finding system according to claim 1, wherein, the solid state light receiving elements are arranged in an array using CMOS technology.

5. The spatially resolving range-finding system according to claim 1, wherein said optical system may be selectively configured to provide that either one light source corresponds to one receiving element, several light sources correspond to one receiving element, or one light source corresponds to several receiving elements.

6. The spatially resolving range-finding system according to claim 1, wherein division is the same within the arrangements of the light sources and the receiving elements.

7. The spatially resolving range-finding system according to claim 1, wherein the array of the light sources and the array of receiving elements are both in the form of a rectangular matrix.

8. The spatially resolving range-finding system according to claim 1, wherein the array of light sources and the array of receiving elements are in a form appropriate to a specific measurement task.

9. The spatially resolving range-finding system according to claim 1, wherein both the array of the light sources and the array of the receiving elements are in a form selected from the group consisting of a line, a circle, a semicircle and a cross.

10. The spatially resolving range-finding system according to claim 1, in which a sectional view or a three-dimensional image of an object is generated.

11. The spatially resolving range-finding system according to claim 1, in which the light sources are represented by rapidly modulable laser diodes or light-emitting diodes.

12. The spatially resolving range-finding system according to claim 1, in which the light travel time measurement is a pulse travel time measurement or a phase measurement.

13. The spatially resolving range-finding system according to claim 1, for the purpose of intelligent building entrance safeguarding, railroad platform surveillance, railroad grid crossing surveillance or vehicle surveillance.

14. The spatially resolving range-finding system according to claim 1, for the purpose of surveillance of interiors of buildings or vehicles.