Remote indicia reading system

• US 20020134835A1
• Filed: 03/26/2001
• Published: 09/26/2002
• Est. Priority Date: 03/26/2001
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: PIPS Technology Incorporated (3M Company)
• Inventors: Kennedy, James M.
• Granted Patent: US 6,832,728 B2
• Time in Patent Office: Days
• US Class Current: 235/384
• CPC Class Codes: G06K 19/06028 using bar codes
• CPC Class Codes: G06K 7/10732 Light sources

Abstract

An apparatus is provided for reading indicia, such as a bar code, from a remote location. The apparatus includes a light source for illuminating the indicia, preferably with infrared illumination. The indicia is incorporated in a reflective medium, disposed remotely from the light source, which reflects the illumination provided by the light source. The apparatus includes a light sensing device also disposed remotely from the reflective medium. The light sensing device receives the reflected image of the indicia and generates an indicia image signal based thereon. An indicia processing system receives and operates on the indicia image signal to extract indicia information therefrom. The light source and the light sensing device may be located up to 75 feet or more away from the reflective medium, and the reflective medium may be moving at speeds of up to 85 miles per hour or more relative to the light source and the light sensing device. To prevent blurring of the reflected indicia image, the infrared illumination is preferably provided in pulses, and the light sensing device is shuttered in synchronism with the pulses. The indicia and reflective medium may be attached to a motor vehicle, a trailer portion of a tractor/trailer rig, a railroad box car or container, or any other type of vehicle, package, or cargo container.

Claims

1. An apparatus for reading indicia from a remote location, comprising:

a light source for providing illumination;

a reflective medium disposed remotely from the light source, the reflective medium including indicia operable to reflect the illumination provided by the light source, where portions of the illumination reflected from the indicia comprise a reflected indicia image;

a light sensing device disposed remotely from the reflective medium, the light sensing device for receiving the reflected indicia image and for generating an indicia image signal based thereon; and

an indicia processing system for receiving the indicia image signal and for operating on the indicia image signal to extract indicia information therefrom.

2. The apparatus of claim 1 wherein the light source provides infrared illumination within a wavelength range of about 770 to 1100 nanometers.

3. The apparatus of claim 2 wherein the light source provides the infrared illumination in a pulse having a pulse width ranging from about 0.1 to 1.5 milliseconds.

4. The apparatus of claim 3 wherein the light sensing device is sensitive to the infrared illumination provided by the light source and is electronically shuttered in synchronism with the pulse of infrared illumination provided by the light source.

5. The apparatus of claim 2 further comprising an optical filter disposed between the light sensing device and the reflective medium, the optical filter for attenuating optical radiation outside of a desired range of infrared wavelengths.

6. The apparatus of claim 2 wherein the light source further comprises an array of infrared light emitting diodes.

7. The apparatus of claim 6 wherein the light source further comprises a driving circuit for driving the array of infrared light emitting diodes with current pulses having pulse amplitudes of about 1000 milliamperes.

8. The apparatus of claim 2 wherein the light source further comprises an infrared laser light source.

9. The apparatus of claim 2 further comprising a cover over the reflective medium which is transmissive to infrared light and non-transmissive to visible light, such that the indicia on the reflective medium beneath the cover are substantially undetectable to human eyesight.

10. The apparatus of claim 2 further comprising graphic components over the reflective medium which are transmissive to infrared light and non-transmissive to visible light, such that the indicia on the reflective medium beneath the graphic components are substantially undetectable to human eyesight.

11. The apparatus of claim 10 wherein the graphic components comprise alphanumeric characters.

12. The apparatus of claim 10 wherein the graphic components comprise a decoy bar code.

13. The apparatus of claim 1 wherein the light sensing device further comprises a camera incorporating charge-coupled devices.

14. The apparatus of claim 1 wherein the reflective medium is disposed at least 5 feet away from the light source and the light sensing device.

15. The apparatus of claim 1 further comprising a protective housing in which the light source and the light sensing device are disposed.

16. The apparatus of claim 1 wherein the light source provides the illumination along an illumination path, the light sensing device receives the reflected indicia image along a reflected image path, and wherein an included angle between the illumination path and the reflected image path is no greater than about two degrees.

17. The apparatus of claim 1 further comprising:

the light sensing device for generating the indicia image signal as a bit-mapped image of the indicia; and

the indicia processing system for receiving the bit-mapped image and for operating on the bit-mapped image to extract the indicia information therefrom.

18. The apparatus of claim 1 wherein the indicia further comprise a bar-code.

19. The apparatus of claim 1 wherein the reflective medium further comprises a retro-reflective material.

20. The apparatus of claim 1 wherein the light sensing device is operable to receive the reflected indicia image and generate the indicia image signal, and the indicia processing system is operable to operate on the indicia image signal to extract the indicia information as the reflective medium is moving relative to the light source and the light sensing device.

21. The apparatus of claim 20 wherein the reflective medium is operable to be disposed on a motor vehicle, a railroad car, or a cargo container.

22. An apparatus for reading indicia from a remote location, comprising:

an infrared light source for providing pulses of infrared illumination;

a reflective medium disposed remotely from the light source, the reflective medium including indicia operable to reflect the pulses of infrared illumination provided by the light source, where portions of the illumination reflected from the indicia comprise a reflected indicia image;

a camera incorporating charge-coupled devices which is

disposed remotely from the reflective medium,

sensitive to the infrared illumination reflected from the indicia,

electronically shuttered in synchronism with the pulses of infrared illumination provided by the light source,

for receiving the reflected indicia image and for generating a bit-mapped indicia image based on the reflected indicia image; and

an indicia processing system for receiving the bit-mapped indicia image and for operating on the bit-mapped indicia image to extract indicia information therefrom.

23. An apparatus for reading a bar code from a remote location, comprising:

a light source for providing illumination from a fixed location;

a retro-reflective medium operable to be disposed on a vehicle or container which is remote from the light source and which is moveable relative to the light source, the retro-reflective medium including the bar code which is operable to reflect the illumination provided by the light source, where portions of the illumination reflected from the bar code comprise a reflected bar code image;

a light sensing device disposed at the fixed location for receiving the reflected bar code image and for generating a bar code image signal based thereon; and

a bar code processing system for receiving the bar code image signal and for operating on the bar code image signal to extract bar code information therefrom as the retro-reflective medium is moving relative to the light source and the light sensing device.