RECEIVING UNIT FOR A LIDAR DEVICE

Abstract

A receiving unit, in particular for a LIDAR device, for receiving rays reflected and/or backscattered from an object. The receiving unit includes receiving optics and at least one detector, wherein arranged in a ray path of the rays between the receiving optics and the detector are a directional filter and a wavelength-selective unit. A LIDAR device and a method for evaluating measurement data of a detector are described.

Claims

1-13. (canceled)

14. A receiving unit for a LIDAR device for receiving rays reflected and/or backscattered from a sampling region, the receiving unit comprising: receiving optics; at least one detector; and a directional filter and a wavelength-selective unit arranged in a ray path of the rays between the receiving optics and the detector.

15. The receiving unit according to claim 14, wherein the directional filter is a diaphragm or a slit diaphragm.

16. The receiving unit according to claim 14, wherein the wavelength-selective unit includes transmitting or reflecting wavelength-selectivity.

17. The receiving unit according to claim 14, wherein the wavelength-selective unit is configured to adjust a wavelength-dependent angle of refraction or wavelength-dependent angle of reflection for incoming rays.

18. The receiving unit according to claim 17, wherein the rays affected by the wavelength-selective unit are guided onto the detector at a wavelength-dependent angle of refraction or at a wavelength-dependent angle of reflection, wherein measurement values ascertained by the detector from received rays are used for an evaluation as a function of their detection location on the detector.

19. The receiving unit according to claim 14, wherein the wavelength-selective unit is a diffractive optical element.

20. The receiving unit according to claim 14, further comprising: at least one first optical arrangement arranged in a ray path between the directional filter and the wavelength-selective unit, wherein the at least one first optical element includes a lens or a cylindrical lens or a lens array, configured to collimate rays which pass the directional filter.

21. The receiving unit according to claim 20, further comprising: at least one second optical unit arranged in a ray path between the wavelength-selective unit and the detector.

22. The receiving unit according to claim 21, wherein the second optical element is a microlens array.

23. The receiving unit according to claim 21, wherein the directional filter, the first optical element, the wavelength-selective unit, the second optical element, and the detector are implemented together in one piece or are connected integrally with one another.

24. A LIDAR device for sampling of sampling regions, comprising: at least one transmitting unit configured to generate and radiate generated rays into a sampling region; and at least one receiving unit for receiving rays reflected and/or backscattered from the sampling region, the receiving unit including: receiving optics, at least one detector, and a directional filter and a wavelength-selective unit arranged in a ray path of the rays between the receiving optics and the detector.

25. A method for evaluating measurement data of a detector of a receiving unit, the method comprising the following steps: receiving, by the receiving unit, rays from a sampling region; filtering, by a directional filter of the receiving unit, the receiving rays, the filtered rays being guided directly or via at least one first optical element, onto a wavelength-selective unit; splitting up, by the wavelength-selective unit, the filtered rays wavelength-dependently and radiating them wavelength-dependently onto different light-sensitive regions of the detector.

26. The method according to claim 25, wherein by radiating the light-sensitive regions of the detector, measurement data are generated and received by an evaluation unit, wherein at least one of the light-sensitive regions of the detector is selected in an automated or predefined manner for receiving measurement data for evaluation by the evaluation unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 shows a schematic depiction of a LIDAR device according to an example embodiment of the present invention,

[0032] FIG. 2 shows a schematic depiction of a receiving unit according to a first example embodiment of the present invention.

[0033] FIG. 3 shows a schematic depiction of a receiving unit according to a second example embodiment of the present invention.

[0034] FIG. 4 shows a schematic depiction of a receiving unit according to a third example embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0035] FIG. 1 shows a schematic depiction of a LIDAR device 1 according to an example embodiment of the present invention. The LIDAR device 1 includes a transmitting unit 2 and a receiving unit 4.

[0036] The transmitting unit 2 serves for generating and emitting rays 6 along a sampling region A. For example, the generated rays 6 may be configured as laser beams. For this purpose the transmitting unit 2 includes one or several laser emitters 3. The transmitting unit 2 may generate and emit the rays 6 at a defined pulse frequency. This may be coordinated and initiated by a control unit 8.

[0037] The receiving unit 4 includes a detector 10 and receiving optics 12. The rays 14, 15 reflected or backscattered from the sampling region A in the direction of the receiving unit 4 are received by the receiving optics 12 and guided into the receiving unit 4. The rays 14, 15 reflected or backscattered in the sampling region A consist here of reflected or backscattered rays 14 which were generated by the transmitting unit 2 and of rays 15 originating from spurious sources.

[0038] The detector 10 may be implemented as a planar detector, such as for example a CCD or CMOS. The detector 10 includes a light-sensitive region 11, which is able to generate electric signals in the form of measurement data from the incoming rays. The detector 10 is coupled with the control unit 8 in such a way that a location-dependent evaluation of the measurement data of the detector 10 is possible. In particular, the measurement data may be assigned to the light-sensitive regions 11 in which the respective measurement data were generated by incident rays.

[0039] The control unit 8 may preferably be implemented as an evaluation unit for evaluating the measurement data of the detector 10.

[0040] FIG. 2 shows a schematic depiction of the receiving unit 4 according to a first example embodiment. The construction of the receiving unit 4 is visualized in detail.

[0041] The receiving unit 4 includes receiving optics 12 implemented as a planoconvex lens. The receiving optics 12 is followed in the ray path of the reflected rays 14 by a directional filter 16. The directional filter 16 is configured as a diaphragm or slit diaphragm. According to the example embodiment, directional filtering of the reflected or backscattered rays 14, 15 is produced by a combination of the receiving optics 12 and the directional filter 16, since only rays 14 from a defined direction are able to pass through the directional filter 16. Rays 15 from other directions are not focused by the receiving optics 12 on the slit of the directional filter 16 and consequently are blocked.

[0042] The receiving optics 12 and the directional filter 16 form a first region B1 of the receiving unit 4. The rays 18 filtered by the directional filter 16 are subsequently directed into a second region B2 of the receiving unit 4. In the second region B2, the rays 18 are formed by a first optical unit 20. According to the example embodiment, the first optical unit 20 is configured as a planoconvex lens and focuses the filtered rays 18 onto a wavelength-selective unit 22. In particular, the filtered rays 18 are collimated by the first optical unit 20 such that they exhibit the same angle of incidence on the wavelength-selective unit 22.

[0043] The wavelength-selective unit 22 is configured as a holographic grating and exhibits a reflectivity which depends on a wavelength of the filtered rays 18. For example, rays having a short wavelength may be deflected more strongly than rays having a longer wavelength.

[0044] The rays 24 deflected by the wavelength-selective unit 22 are subsequently concentrated by a second optical unit 26 onto the detector 10. Through this step, with the help of the wavelength-dependent element 22, incident rays 18 having different wavelengths are deflected to different extents. The consequence is that after the renewed focusing with the help of the second optical unit 26, the rays 24 arrive at different places on the detector 10, depending on their wavelength.

[0045] Now by selecting the correct region 11 of the detector 10, spurious background light can be separated from the useful signal. If the wavelength of the rays 6 emitted by the transmitting unit 2 changes, this region 11 may be changed accordingly.

[0046] FIG. 3 shows a schematic depiction of the receiving unit 4 according to a second example embodiment. Unlike the first example embodiment, the wavelength-selective unit 22 acts on the filtered rays 18 in the passage direction. In this process, a refraction or diffraction of the filtered rays 18 takes place when transmitted through the wavelength-selective unit 22.

[0047] FIG. 4 illustrates a schematic depiction of the receiving unit 4 according to a third example embodiment. Unlike the above-described example embodiments, the directional filter 16, the first optical unit 20, the wavelength-selective unit 22, the second optical unit 26, and the detector 10 are implemented in one piece. For example, the components 10, 16, 20, 22, 26 are cemented with one another. The first optical unit 20 is arranged between the directional filter 16 and the wavelength-selective unit 22. The second optical unit 26 is positioned between the wavelength-selective unit 22 and the detector 10. According to the example embodiment the first optical unit 20 and the second optical unit 26 are configured as microlens arrays.