Barcode reader having multiple illumination systems and multiple sets of imaging optics

• US 9,082,034 B2
• Filed: 12/13/2013
• Issued: 07/14/2015
• Est. Priority Date: 07/19/2013
• Status: Expired due to Fees

• Current Assignee: The Code Corporation (Brady Corporation)
• Original Assignee: The Code Corporation (Brady Corporation)
• Inventors: Lei, Ming, Powell, George
• Primary Examiner(s): LEE, SEUNG H
• Application Number:
  US14/105,390
• Publication Number:
  US 20150021400A1
• Time in Patent Office: 578 Days
• Field of Search: 235/454, 235/462.14, 235/462.42, 235/462.43, 235/459
• US Class Current: 1/1
• CPC Class Codes: G06K 2007/10485 Arrangement of optical elements
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10742 including a diffuser for diffusing the light from the light source to create substantially uniform illumination of the target record carrier
• CPC Class Codes: G06K 7/1404 Methods for optical code recognition
• CPC Class Codes: G06K 7/1465 using several successive scans of the optical code

Abstract

A barcode reader comprises a first lens assembly with a first field of view and a first optical path for first illumination from the first field of view to project to a first image sensor section. The barcode reader further comprises a second lens assembly with a second field of view and a second optical path for second illumination from the second field of view to project to a second image sensor section. The barcode reader further comprises a first illumination system positioned outside of the first field of view projecting the first illumination into the first field of view at a first angle from the first optical path. The barcode reader further comprises a second illumination system positioned between the second lens assembly and a point from which the first illumination system projects the first illumination into the first field of view.

Claims

1. A barcode reader, comprising:

a first lens assembly with a first field of view and a first optical path for first illumination from the first field of view to project to a first image sensor section;

a second lens assembly with a second field of view and a second optical path for second illumination from the second field of view to project to a second image sensor section;

a first illumination system positioned outside of the first field of view projecting the first illumination into the first field of view at a first angle from the first optical path; and

a second illumination system positioned between the second lens assembly and a point from which the first illumination system projects the first illumination into the first field of view, the second illumination system being outside of the second field of view and projecting the second illumination into the second field of view at a second angle from the second optical path, the second angle being different than the first angle;

wherein the first optical path and the second optical path are substantially parallel.

2. The barcode reader of claim 1, wherein the first angle is less than 45 degrees from a plane that is perpendicular to the first optical path.

3. The barcode reader of claim 1, wherein the second angle is substantially parallel to the second optical path.

4. A barcode reader, comprising:

a first lens assembly with a first field of view and a first optical path for first illumination from the first field of view to project to a first image sensor section;

a second lens assembly with a second field of view and a second optical path for second illumination from the second field of view to project to a second image sensor section;

a first illumination system positioned outside of the first field of view projecting the first illumination into the first field of view at a first angle from the first optical path; and

a second illumination system positioned between the second lens assembly and a point from which the first illumination system projects the first illumination into the first field of view, the second illumination system being outside of the second field of view and projecting the second illumination into the second field of view at a second angle from the second optical path, the second angle being different than the first angle, wherein the first illumination system comprises a first set of illumination sources that are positioned to a left side of the first and second lens assemblies and a second set of illumination sources that are positioned to a right side of the first and second lens assemblies.

5. The barcode reader of claim 4, further comprising control circuitry that independently controls intensity of the first set of illumination sources and the second set of illumination sources.

6. The barcode reader of claim 4, wherein the first illumination system comprises a back lit illumination diffusor projecting the first illumination into the first field of view at the first angle, the first angle being less than 45 degrees from a plane that is perpendicular to the first optical path.

7. The barcode reader of claim 4, wherein the first illumination system comprises a refracting diffusor through which illumination enters at an entry angle that is different than the first angle and exits towards the first field of view at the first angle, the first angle being less than 45 degrees from a plane that is perpendicular to the first optical path.

8. The barcode reader of claim 7, wherein the entry angle is substantially parallel to the first optical path.

9. The barcode reader of claim 7, wherein the entry angle is substantially perpendicular to the first angle.

10. A barcode reader, comprising:

a first lens assembly with a first field of view and a first optical path for first illumination from the first field of view to project to a first image sensor section;

a second lens assembly with a second field of view and a second optical path for second illumination from the second field of view to project to a second image sensor section;

a first illumination system positioned outside of the first field of view projecting the first illumination into the first field of view at a first angle from the first optical path; and

a second illumination system positioned between the second lens assembly and a point from which the first illumination system projects the first illumination into the first field of view, the second illumination system being outside of the second field of view and projecting the second illumination into the second field of view at a second angle from the second optical path, the second angle being different than the first angle;

wherein the second illumination system is a diffuse bright field illumination system comprising;

an optical substrate with a front major surface and a back major surface, each of which is substantially perpendicular to the first and second optical paths, the front major surface facing the first and second fields of view;

at least one illumination source propagating illumination between the front major surface and the back major surface; and

extraction features causing the second illumination to exit the front major surface into the second field of view.

11. A barcode reader, comprising:

a first lens assembly with a first field of view and a first optical path for first illumination from the first field of view to project to a first image sensor section;

a second lens assembly with a second field of view and a second optical path for second illumination from the second field of view to project to a second image sensor section;

a first illumination system positioned outside of the first field of view projecting the first illumination into the first field of view at a first angle from the first optical path; and

a second illumination system positioned between the second lens assembly and a point from which the first illumination system projects the first illumination into the first field of view, the second illumination system being outside of the second field of view and projecting the second illumination into the second field of view at a second angle from the second optical path, the second angle being different than the first angle;

wherein the second illumination system is a direct bright field illumination system comprising two refracting diffusors, through each of which illumination enters at an entry angle that is substantially parallel to the second optical path and exits towards the second field of view at a converging angle.

12. A barcode reader, comprising:

an image sensor configured to capture an image of a barcode within a field of view of the barcode reader;

a first set of imaging optics and a second set of imaging optics, each providing a corresponding image of the barcode on the image sensor;

the first set of imaging optics comprising a first lens assembly with a first optical path from the field of view through the first lens assembly to a first portion of the image sensor;

the second set of imaging optics comprising a second lens assembly with a second optical path from the field of view through the second lens assembly to a second portion of the image sensor;

a first illumination system positioned outside of the field of view projecting first illumination into the field of view at a first angle from the first optical path; and

a second illumination system positioned between the second lens assembly and a point from which the first illumination system projects the first illumination into the field of view, the second illumination system being outside of the field of view and projecting second illumination into the field of view at a second angle from the second optical path, the second angle being different than the first angle.

13. The barcode reader of claim 12, wherein the first optical path and the second optical path are substantially parallel.

14. The barcode reader of claim 13, wherein the first angle is less than 45 degrees from a plane that is perpendicular to the first optical path.

15. The barcode reader of claim 13, wherein the second angle is substantially parallel to the second optical path.

16. The barcode reader of claim 12, wherein the first illumination system comprises a first set of illumination sources that are positioned to a left side of the field of view and a second set of illumination sources that are positioned to a right side of the field of view.

17. The barcode reader of claim 16, further comprising control circuitry that independently controls intensity of the first set of illumination sources and the second set of illumination sources.

18. The barcode reader of claim 16, wherein the first illumination system comprises a back lit illumination diffusor projecting illumination into the field of view at the first angle, the first angle being less than 45 degrees from a plane that is perpendicular to the first optical path.

19. The barcode reader of claim 16, wherein the first illumination system comprises a refracting diffusor through which illumination enters at an entry angle that is different than the first angle and exits towards the field of view at the first angle, the first angle being less than 45 degrees from a plane that is perpendicular to the first optical path.

20. The barcode reader of claim 19, wherein the entry angle is substantially parallel to the first optical path.

21. The barcode reader of claim 19, wherein the entry angle is substantially perpendicular to the first angle.

22. The barcode reader of claim 12, wherein the second illumination system is a diffuse bright field illumination system comprising:

an optical substrate with a front major surface and a back major surface, each of which is substantially perpendicular to an optical path of the barcode reader, the front major surface facing the field of view;

at least one illumination source propagating illumination between the front major surface and the back major surface; and

extraction features causing the second illumination to exit the front major surface into the field of view.

23. The barcode reader of claim 12, wherein the second illumination system is a direct bright field illumination system comprising two refracting diffusors, through each of which illumination enters at an entry angle substantially parallel to the second optical path and exits towards the field of view at a converging angle.

24. A barcode reader, comprising:

an image sensor configured to capture an image of a barcode within a field of view of the barcode reader;

a first illumination system positioned outside of the field of view projecting first illumination into the field of view at a first angle from a first optical path;

a second illumination system positioned between a second lens assembly and a point from which the first illumination system projects the first illumination into the field of view, the second illumination system being outside of the field of view and projecting second illumination into the field of view at a second angle from a second optical path, the second angle being different than the first angle; and

a first set of imaging optics and a second set of imaging optics, each providing a corresponding image of the barcode on the image sensor;

wherein the first set of imaging optics is configured to focus an image of the barcode, when illuminated by the first illumination system, with a superior contrast profile than when illuminated by the second illumination system;

wherein the second set of imaging optics is configured to focus an image of the barcode, when illuminated by the second illumination system, with a superior contrast profile than when illuminated by the first illumination system; and

wherein superior contrast profile means at least one of;

(i) greater maximum amplitude between the portions of the image that are dark marks of the barcode and the portions of the image that are light marks of the barcode; and

(ii) more distinct transitions between portions of the image that are dark marks of the barcode and the portions of the image that are light marks of the barcode.

25. The barcode reader of claim 24, wherein the first illumination system is a dark field illumination system, the dark field illumination system emitting the illumination of a first illumination spectrum into the field of view at an emission angle that is less than 45 degrees from a plane that is perpendicular to an optical path from the image sensor through the first set of imaging optics into a center of the field of view of the first set of imaging optics.

26. The barcode reader of claim 25, wherein the dark field illumination system comprises a first set of illumination sources positioned to a right side of a first lens assembly and the second lens assembly and a second set of illumination sources positioned to a left side of the first and second lens assemblies.

27. The barcode reader of claim 26, further comprising control circuitry that independently controls intensity of the first set of illumination sources and the second set of illumination sources.

28. The barcode reader of claim 25, wherein the dark field illumination system comprises a back lit illumination diffusor emitting the first illumination towards the first optical path at the emission angle.

29. The barcode reader of claim 25, wherein:

the dark field illumination system comprises a refracting diffusor through which the first illumination is emitted towards the first optical path at the emission angle; and

illumination enters the refracting diffusor at an entry angle that is different than the emission angle.

30. The barcode reader of claim 29, wherein the entry angle is substantially parallel to the first optical path.

31. The barcode reader of claim 29, wherein the entry angle is substantially perpendicular to the emission angle.

32. The barcode reader of claim 24, wherein the second illumination system is a diffuse bright field illumination system comprising:

an optical substrate with a front major surface and a back major surface, each of which is substantially perpendicular to an optical path of the barcode reader, the front major surface facing a field of view of a first lens assembly and the second lens assembly;

at least one illumination source propagating illumination between the front major surface and the back major surface; and

extraction features causing the second illumination to exit the front major surface into the fields of view of the first and second lens assemblies.