Optoelectronic sensor and method for detecting objects

1. An optoelectronic sensor for detecting objects in a monitored zone, the optoelectronic sensor comprising:

at least one light transmitter for transmitting a plurality of mutually separated light beams starting from a respective one transmission point;

a transmission optics for the transmitted light beams;

at least one light receiver for generating a respective received signal from the remitted light beams reflected from the objects and incident at a respective reception point;

a reception optics for the remitted light beams; and

an evaluation unit for acquiring information on the objects from the received signals,

wherein at least one of the reception optics and the transmission optics is a two-lens objective for an annular image field with an image field angle α that has a first lens and a second lens, with the first lens being configured such that light beams of every single transmission point and/or reception point with an image field angle α only impinge on half of the second lens.

2. The optoelectronic sensor in accordance with claim 1 ,

wherein the inequality d≥(D 1 *f 1 )/(D 1 +2*f 1 *tan α) is satisfied for the two-lens objective, with a focal length f 1 and a diameter D 1 of the first lens and a distance d between the first lens and the second lens.

3. The optoelectronic sensor in accordance with claim 2 ,

wherein d=(D 1 *f 1 )/(D 1 +2*f 1 *tan α) applies at least approximately.

4. The optoelectronic sensor in accordance with claim 1 ,

wherein the focal length f 2 of the second lens corresponds to the distance between the first lens and the second lens.

5. The optoelectronic sensor in accordance with claim 1 ,

wherein the first lens has a small f-number k 1 .

6. The optoelectronic sensor in accordance with claim 5 ,

wherein the first lens has an f-number k 1 =1.

7. The optoelectronic sensor in accordance with claim 1 ,

wherein the transmission points are arranged on a first circular line.

8. The optoelectronic sensor in accordance with claim 1 ,

wherein the reception points are arranged on a second circular line.

9. The optoelectronic sensor in accordance with claim 1 ,

that has a plurality of light transmitters.

10. The optoelectronic sensor in accordance with claim 9 ,

wherein the optoelectronic sensor has one light transmitter per transmission point.

11. The optoelectronic sensor in accordance with claim 1 ,

that has a plurality of light receivers.

12. The optoelectronic sensor in accordance with claim 11 ,

wherein the optoelectronic sensor has one light receiver per reception point.

13. The optoelectronic sensor in accordance with claim 1 ,

wherein the light transmitter and the light receiver form a coaxial arrangement and the transmission optics and the reception optics are combined in a common optics.

14. The optoelectronic sensor in accordance with claim 1 ,

that is configured as a laser scanner and has a movable deflection unit with whose aid the transmitted light beams are periodically conducted through the monitored zone.

15. The optoelectronic sensor in accordance with claim 14 ,

wherein the deflection unit is configured in the form of a rotatable scanning unit in which at least one of the light transmitter and the light receiver is accommodated.

16. The optoelectronic sensor in accordance with claim 1 ,

wherein the evaluation unit is configured to determine a distance of the objects from a time of flight between the transmission of the light beams and the reception of the remitted light beams.

17. A method of detecting objects in a monitored zone in which a plurality of mutually separated light beams are transmitted from a transmission optics starting from a respective transmission point; in which a respective received signal is generated from the remitted light beams reflected from the objects and incident at a respective reception point after passing through a reception optics; and in which the received signals are evaluated to acquire information on the objects,

wherein at least one of the reception optics and the transmission optics is a two-lens objective for an annular image field with an image field angle α that has a first lens and a second lens; and wherein due to the design of the first lens, bundles of rays of every single transmission point and/or reception point with an image field angle α only impinge on half of the second lens.