Multiple camera imaging-based bar code reader

• US 8,662,397 B2
• Filed: 09/27/2007
• Issued: 03/04/2014
• Est. Priority Date: 09/27/2007
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Carlson, Bradley S., Joseph, Eugene
• Primary Examiner(s): STANFORD, CHRISTOPHER J
• Application Number:
  US11/862,568
• Publication Number:
  US 20090084854A1
• Time in Patent Office: 2,350 Days
• Field of Search: 235/454, 235/462.01, 235/462.41, 235/462.43, 235/462.44
• US Class Current: 235/462.32
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48

Abstract

A multicamera imaging-based bar code reader for imaging a target bar code on a target object features: a housing supporting a plurality of transparent windows and defining an interior region, a target object being presented to the plurality of windows for imaging a target bar code; an imaging system including a plurality of camera assemblies coupled to an image processing system, each camera assembly of the plurality of camera assemblies being positioned within the housing interior position. Each camera assembly includes a sensor array and an imaging lens assembly for focusing a field of view of the camera assembly onto the sensor array and wherein the sensor array is read out at a predetermined frame rate. The predetermined frame rate of at least one camera assembly is less than the predetermined frame rates of the other camera assemblies.

Claims

1. A multicamera imaging-based bar code reader for imaging a target bar code on a target object, the bar code reader comprising:

a housing supporting a plurality of transparent windows and defining an interior region, a target object being presented to the plurality of windows for imaging a target bar code;

an imaging system including a plurality of camera assemblies coupled to an image processing system, each camera assembly of the plurality of camera assemblies being positioned within the housing interior position and defining a field of view which is different than a field of view of each other camera assembly of the plurality of camera assemblies, each camera assembly including a sensor array and an imaging lens assembly for focusing the field of view of the camera assembly onto the sensor array; and

for each camera assembly of the plurality of camera assemblies, the sensor array being read out at a predetermined frame rate to generate image frames of the field of view of the camera assembly at periodic intervals, the image frames being transmitted to the image processing system, a predetermined frame rate of at least one camera assembly of the plurality of camera assemblies being less than respective predetermined frame rates of others of the plurality of camera assemblies; and

wherein the predetermined frame rates are determined based on positions of each camera assembly of the plurality of camera assemblies with respect to the plurality of windows such that those camera assemblies of the plurality of windows determined to be less likely to image a target bar code on a target object presented to the plurality of windows for imaging being assigned a lower predetermined frame rate.

2. The bar code reader of claim 1 wherein the image processing system determines the predetermined frame rate for each camera assembly based on a determination of a relative probability of each camera assembly of the plurality of camera assemblies imaging a decodable image of a target bar code on a target object presented to the plurality of windows for imaging, wherein a camera assembly with a lower relative probability is assigned a lower predetermined frame rate.

3. The bar code reader of claim 1 wherein a number of data lines utilized for transmitting image frames from each camera assembly of the plurality of camera assemblies is proportional to a predetermined frame rate of the camera assembly.

4. The bar code reader of claim 1 wherein the housing is integrated into a point of sale counter.

5. The bar code reader of claim 1 wherein the plurality of windows includes at least one vertically oriented window and one horizontally oriented window.

6. A method of operating a multicamera imaging-based bar code reader for imaging a target bar code on a target object, the steps of the method comprising:

providing a multicamera imaging-based bar code reader including;

a housing supporting a plurality of transparent windows and defining an interior region, a target object being presented to the plurality of windows for imaging a target bar code;

an imaging system including a plurality of camera assemblies coupled to an image processing system, each camera assembly of the plurality of camera assemblies being positioned within the housing interior position and defining a field of view which is different than a field of view of each other camera assembly of the plurality of camera assemblies, each camera assembly including a sensor array and an imaging lens assembly for focusing the field of view of the camera assembly onto the sensor array;

operating the reader to image a target bar code on a target object, for each camera assembly of the plurality of camera assemblies , the sensor array being read out at a predetermined frame rate to generate image frames of the field of view of the camera assembly at periodic intervals , the image frames being transmitted to the image processing system, a predetermined frame rate of at least one camera assembly of the plurality of camera assemblies being less than respective predetermined frame rates of others of the plurality of camera assemblies; and

wherein the predetermined frame rates are determined based on positions of each camera assembly of the plurality of camera assemblies with respect to the plurality of windows such that those camera assemblies of the plurality of windows determined to be less likely to image a target bar code on a target object presented to the plurality of windows for imaging being assigned a lower predetermined frame rate.

7. The method of claim 6 wherein the image processing system determines the predetermined frame rate for each camera assembly based on a determination of a relative probability of each camera assembly of the plurality of camera assemblies imaging a decodable image of a target bar code when a target object is presented to the plurality of windows for imaging and wherein a camera assembly with a lower relative probability is assigned a lower predetermined frame rate.

8. The method of claim 6 wherein a number of data lines utilized for transmitting image frames from each camera assembly of the plurality of camera assemblies is proportional to a predetermined frame rate of the camera assembly.

9. An imaging system for use in multicamera imaging-based bar code reader having a housing supporting a plurality of transparent windows and defining an interior region, a target object being presented to the plurality of windows for imaging a target bar code on a target object, the imaging system comprising:

a plurality of camera assemblies coupled to an image processing system, each camera assembly of the plurality of camera assemblies being positioned within the housing interior position and defining a field of view which is different than a field of view of each other camera assembly of the plurality of camera assemblies, each camera assembly including a sensor array and an imaging lens assembly for focusing the field of view of the camera assembly onto the sensor array; and

for each camera assembly of the plurality of camera assemblies, the sensor array being read out at a predetermined frame rate to generate image frames of the field of view of the camera assembly at periodic intervals, the image frames being transmitted to the image processing system, a predetermined frame rate of at least one camera assembly of the plurality of camera assemblies being less than respective predetermined frame rates of others of the plurality of camera assemblies; and

wherein the predetermined frame rates are determined based on positions of each camera assembly of the plurality of camera assemblies with respect to the plurality of windows such that those camera assemblies of the plurality of windows determined to be less likely to image a target bar code on a target object presented to the plurality of windows for imaging being assigned a lower predetermined frame rate.

10. The imaging system of claim 9 wherein the image processing system determines the predetermined frame rate for each camera assembly based on a determination of a relative probability of each camera assembly of the plurality of camera assemblies imaging a decodable image of a target bar code on a target object presented to the plurality of windows for imaging, wherein a camera assembly with a lower relative probability is assigned a lower predetermined frame rate.

11. The imaging system of claim 9 wherein a number of data lines utilized for transmitting image frames from each camera assembly of the plurality of camera assemblies is proportional to a predetermined frame rate of the camera assembly.

12. A multicamera imaging-based bar code reader for imaging a target bar code on a target object, the bar code reader comprising:

a housing means supporting a plurality of transparent windows and defining an interior region, a target object being presented to the plurality of windows for imaging a target bar code;

an imaging system means including a plurality of camera assembly means coupled to an image processing system means, each camera assembly means of the plurality of camera assembly means being positioned within the housing interior position and defining a field of view which is different than a field of view of each other camera assembly means of the plurality of camera assembly means, each camera assembly means including a sensor array and an imaging lens assembly for focusing the field of view of the camera assembly means onto the sensor array; and

for each camera assembly means of the plurality of camera assembly means, the sensor array being read out at a predetermined frame rate to generate image frames of the field of view of the camera assembly means at periodic intervals, the image frames being transmitted to the image processing system means, a predetermined frame rate of at least one camera assembly means of the plurality of camera assembly means being less than respective predetermined frame rates of others of the plurality of camera assembly means; and

wherein the predetermined frame rates are determined based on positions of each camera assembly of the plurality of camera assemblies with respect to the plurality of windows such that those camera assemblies of the plurality of windows determined to be less likely to image a target bar code on a target object presented to the plurality of windows for imaging being assigned a lower predetermined frame rate.

13. The bar code reader of claim 12 wherein the image processing system means determines the predetermined frame rate for each camera assembly means based on a determination of a relative probability of each camera assembly means of the plurality of camera assembly means imaging a decodable image of a target bar code on a target object presented to the plurality of windows for imaging, wherein a camera assembly means with a lower relative probability is assigned a lower predetermined frame rate.

14. The bar code reader of claim 12 wherein a number of data lines utilized for transmitting image frames from each camera assembly means of the plurality of camera assembly means is proportional to the predetermined frame rate of the camera assembly means.