Dual laser article detection system

1. A method of detecting an article on a conveyor, the method comprising:

directing a first laser trace laterally across a surface of the conveyor from an acute angle;

directing a second laser trace laterally across the surface of the conveyor, in spaced apart alignment with the first laser trace, from an acute angle;

imaging from above a field of view that encompasses at least a portion of the first and second laser traces;

detecting a presence or absence of portions of the first and second laser traces; and

determining a feature of the article on the conveyor based upon the detecting of the presence or absence.

2. The method of claim 1 , further comprising:

filtering the imaging for a frequency band of the first and second laser traces.

3. The method of claim 1 , wherein the conveyor system comprises a loop sorter.

4. The method of claim 3 , further comprising a determining feature of a carrier of the loop sorter based upon the detecting of the presence or absence.

5. The method of claim 4 , wherein determining the feature of the carrier further comprises:

determining a space between a first carrier and a second carrier based upon detecting an absence of at least one of the first and second laser traces.

6. The method of claim 4 , wherein determining the feature of the carrier further comprises:

determining an attachment detail of the carrier based upon detecting a gap in at least one of the first and second laser traces at a pre-set lateral position.

7. The method of claim 4 , wherein determining the feature of the carrier further comprises:

determining a leading edge of the carrier based upon detecting a truncation in at least one of the first and second laser traces.

8. The method of claim 1 , wherein determining the feature of the article further comprises:

determining lateral edges of the article based upon detecting a first gap in the first laser trace and a second gap in the second laser trace.

9. The method of claim 8 , wherein the first gap is closer to a second lateral side than a first lateral side and the second gap is closer to the first lateral side than the second lateral side.

10. The method of claim 1 , wherein the first laser trace and the second laser trace are directed in opposite directions across the surface of the conveyor.

11. A detection system, comprising:

a first laser configured to direct a first laser trace laterally across a surface of a conveyor from an acute angle;

a second laser configured to direct a second laser trace laterally across the surface of the conveyor, in spaced apart alignment with the first laser trace, from an acute angle;

a camera configured to image from above a field of view that encompasses at least a portion of the first and second laser traces; and

an image processing system configured to detect a presence or absence of portions of the first and second laser traces and wherein the image processing system is operable to determine a feature of one of the conveyor and an article on the conveyor based upon the detecting of the presence or absence.

12. The detection system of claim 11 , further comprising:

an optical filter configured to filter the imaging for a frequency band of the first and second laser traces.

13. The detection system of claim 11 , wherein the conveyor comprises a loop sorter, wherein the image processing system is further operable to determine a feature of a carrier of the loop sorter by determining a space between carriers based upon detecting an absence of at least one of the first and second laser traces.

14. The detection system of claim 11 , wherein the conveyor comprises a loop sorter, wherein the image processing system is further operable to determine a feature of a carrier of the loop sorter by determining an attachment detail of the carrier based upon detecting a gap in at least one of the first and second laser traces at a pre-set lateral position.

15. The detection system of claim 11 , wherein the image processing system is further operable to determine the feature by determining lateral edges of the article based upon detecting a first gap in the first laser trace and a second gap in the second laser trace.

16. The detection system of claim 11 , wherein the conveyor comprises a loop sorter, wherein the image processing system is further operable to determine a leading edge of a carrier of the loop sorter based upon detecting a truncation in at least one of the first and second laser traces.

17. A conveyor system, comprising:

a conveyor; and

a detection system, comprising:

a first laser configured to direct a first laser trace laterally across a surface of a conveyor from an acute angle;

a second laser configured to direct a second laser trace laterally across the surface of the conveyor, in spaced apart alignment with the first laser trace, from an acute angle;

a camera configured to image from above a field of view that encompasses at least a portion of the first and second laser traces; and

an image processing system configured to detect a presence or absence of portions of the first and second laser traces and wherein the image processing system is operable to determine a feature of one of the conveyor and an article on the conveyor based upon the detecting of the presence or absence.

18. The conveyor system of claim 17 , wherein the detection system comprises a network interface to report the feature.

19. The conveyor system of claim 18 further comprising a sortation controller in communication with the network interface to discharge the conveyor based at least in part upon the feature.