Pulsed wireless directional object counter

• US 7,448,548 B1
• Filed: 01/13/2006
• Issued: 11/11/2008
• Est. Priority Date: 01/13/2006
• Status: Active Grant

• Current Assignee: Mesa Laboratories Inc.
• Original Assignee: Point Six Wireless LLC (Mesa Laboratories Inc.)
• Inventors: Compton, John I.
• Primary Examiner(s): Lee; Michael G.
• Assistant Examiner(s): Haupt; Kristy A
• Application Number:
  US11/331,603
• Time in Patent Office: 1,033 Days
• Field of Search: 235/440, 235/385, 235/454, 235/382, 235/384
• US Class Current: 235/440
• CPC Class Codes: G06M 1/101 by electro-optical means
• CPC Class Codes: G06M 7/02 wherein objects ahead of the sensing element are separated to produce a distinct gap between successive objects
• CPC Class Codes: G07C 9/00 Individual registration on entry or exit

Abstract

A directional object counter uses two or more light sources to generate pulses of light, which travel on two light paths across a passageway. Light from both sources illuminates two sensors, after the light has traversed the passageway, and a processor connected to the sensors determines, based on the pulsed nature of the sources, which source(s) is/are illuminating which sensor(s), and counts movement of objects through the light paths in an identified direction. The pulsed nature of the light permits low-power operation of the directional object counter with a battery. Furthermore, the independence of the pulse discrimination from the pulse generation, enables the light sources and light sensors to be positioned on opposite sides of a passageway without wiring connecting them across the passageway.

Claims

1. A directional object counter, comprising:

first and second light sources generating first and second light paths,

at least a first light sensor for detecting light from said light sources after traversing a passageway,

said light sensor detecting light from both said first and second light sources and generating a responsive signal, and

a processor connected to said light sensor for receiving said responsive signal, determining whether said first source is or is not illuminating said light sensor without the use of a timing reference synchronized to the pulse transmission, and counting the movement of an object through said light paths in an identified direction based upon said determination.

2. The object counter of claim 1 further comprising a second light sensor, wherein said processor determines whether said first light source is illuminating said first light sensor and whether said second light source is illuminating said second light sensor, and counting the movement of an object through said light paths based upon said determination.

3. The object counter of claim 2 wherein said processor counts movement of an object through said light paths upon detecting blockage of said first light path, followed by blockage of said second light path, followed by restoration of said light paths.

4. The object counter of claim 1 wherein said light sources generate light pulses, and said processor detects whether at least one of said light sources is illuminating said light sensor based upon the reception, or lack thereof, of said pulses.

5. The object counter of claim 4 wherein said light pulses comprise a pulse generated by said first light source, followed by a pulse generated by said second light source, followed by a pulse generated by said first light source.

6. The object counter of claim 5 wherein said processor detects that light generated by said first light source is illuminating said light sensor based upon the receipt by said sensor of a light pulse followed by a light pulse two pulse widths later.

7. The object counter of claim 5 wherein said processor detects that light generated by said second light source is illuminating said light sensor based upon the receipt by said sensor of a light pulse followed by a light pulse one pulse width later, or based upon the receipt by said sensor of a light pulse not followed by a light pulse two pulse widths later.

8. The object counter of claim 4 wherein said light pulses comprise a long pulse generated by said first light source, and a short pulse generated by said second light source, wherein said processor determines that said first light source is illuminating said sensor based upon the receipt of a light pulse that continues for a time longer than said short pulse, and said processor determines that said second light source is illuminating said sensor based upon the receipt of a light pulse that continues longer than said long pulse, or a light pulse that continues for a time longer than said short pulse but shorter than said long pulse.

9. The object counter of claim 1 wherein said light is infrared light.

10. The object counter of claim 1 further comprising a battery, wherein said light sources, light sensor and processor are powered by said battery.

14. The object counter of claim 1 wherein said processor counts movement of an object through said light paths upon detecting blockage of said first light path, followed by blockage of said second light path, followed by restoration of said light paths.

11. A directional object counter, comprising:

a battery,

first and second light sources generating first and second light paths using battery power,

at least a first light sensor, using battery power for detecting light from at least one of said light sources after traversing a passageway, said light sensor generating a responsive signal, and

a processor connected to said light sensor for receiving said responsive signal, and using battery power, determining whether said at least one light source is or is not illuminating said light sensor solely from the signal from the light sensor, and counting the movement of an object in an identified direction through said light paths based upon said determination.

12. The object counter of claim 11 further comprising a second battery, wherein the first and second light sources use battery power from said first battery, and said first light sensor and said processor use battery power from said second battery.

13. The object counter of claim 11 further comprising a second light sensor, wherein said processor determines whether said first light source is illuminating said first light sensor and whether said second light source is illuminating said second light sensor, and counts the movement of an object through said light paths based upon said determination.

15. The object counter of claim 11 wherein said light sources generate light pulses, and said processor detects whether at least one of said light sources is illuminating said light sensor based upon the reception, or lack thereof, of said pulses.

16. The object counter of claim 15 wherein said light pulses comprise a pulse generated by said first light source, followed by a pulse generated by said second light source, followed by a pulse generated by said first light source.

17. The object counter of claim 16 wherein said processor detects that light generated by said first light source is illuminating said light sensor based upon the receipt by said sensor of a light pulse followed by a light pulse two pulse widths later.

18. The object counter of claim 16 wherein said processor detects that light generated by said second light source is illuminating said light sensor based upon the receipt by said sensor of a light pulse followed by a light pulse one pulse width later, or based upon the receipt by said sensor of a light pulse not followed by a light pulse two pulse widths later.

19. The object counter of claim 15 wherein said light pulses comprise a long pulse generated by said first light source, and a short pulse generated by said second light source, wherein said processor determines that said first light source is illuminating said sensor based upon the receipt of a light pulse that continues for a time longer than said short pulse, and said processor determines that said second light source is illuminating said sensor based upon the receipt of a light pulse that continues longer than said long pulse, or a light pulse that continues for a time longer than said short pulse but shorter than said long pulse.

20. The object counter of claim 11 wherein said light is infrared light.

21. A directional object counter for detecting the movement of objects through a passageway, comprising:

first and second light sources generating first and second light paths carrying different transmitted signals, positioned on a first side of a passageway,

at least a first light sensor positioned on a second side of said passageway opposite to said first side, detecting light from at least one of said light sources after traversing said passageway, said light sensor generating a responsive signal, and

a processor connected to said light sensor for receiving said responsive signal, and no other signal input relating to said light sources, and determining from the differences in the transmitted signals as received by the light sensor whether said at least one light source is or is not illuminating said light sensor, and counting the movement of an object in an identified direction through said light paths based upon said determination.

22. The object counter of claim 21 further comprising a second light sensor, wherein said processor determines whether said first light source is illuminating said first light sensor and whether said second light source is illuminating said second light sensor, and counts the movement of an object through said light paths based upon said determination.

23. The object counter of claim 21 wherein said processor counts movement of an object through said light paths upon detecting blockage of said first light path, followed by blockage of said second light path, followed by restoration of said light paths.

24. The object counter of claim 21 wherein said light sources generate light pulses, and said processor detects whether at least one of said light sources is illuminating said light sensor based upon the reception, or lack thereof, of said pulses.

25. The object counter of claim 24 wherein said light pulses comprise a pulse generated by said first light source, followed by a pulse generated by said second light source, followed by a pulse generated by said first light source.

26. The object counter of claim 25 wherein said processor detects that light generated by said first light source is illuminating said light sensor based upon the receipt by said sensor of a light pulse followed by a light pulse two pulse widths later.

27. The object counter of claim 25 wherein said processor detects that light generated by said second light source is illuminating said light sensor based upon the receipt by said sensor of a light pulse followed by a light pulse one pulse width later, or based upon the receipt by said sensor of a light pulse not followed by a light pulse two pulse widths later.

28. The object counter of claim 24 wherein said light pulses comprise a long pulse generated by said first light source, and a short pulse generated by said second light source wherein said processor determines that said first light source is illuminating said sensor based upon the receipt of a light pulse that continues for a time longer than said short pulse, and said processor determines that said second light source is illuminating said sensor based upon the receipt of a light pulse that continues longer than said long pulse, or a light pulse that continues for a time longer than said short pulse but shorter than said long pulse.

29. The object counter of claim 21 wherein said light is infrared light.