Monolithic mirror structure for use in a multi-perspective optical code reader

• US 8,608,076 B2
• Filed: 12/23/2009
• Issued: 12/17/2013
• Est. Priority Date: 02/12/2008
• Status: Active Grant

• Current Assignee: Datalogic Adc, Inc. (Datalogic S.p.A.)
• Original Assignee: Datalogic Adc, Inc. (Datalogic S.p.A.)
• Inventors: Olmstead, Bryan L.
• Primary Examiner(s): Le, Thien M
• Assistant Examiner(s): LY, TOAN C
• Application Number:
  US12/646,794
• Publication Number:
  US 20100163622A1
• Time in Patent Office: 1,455 Days
• Field of Search: 235/462.41
• US Class Current: 235/462.41
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence
• 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 monolithic compound mirror structure is used in an optical code reader employing an imager that captures images of items bearing optical codes in a viewing volume of the optical code reader. The monolithic compound mirror structure comprises a plurality of highly reflective surfaces positioned on the structure so that the structure can be positioned in a field of view of the imager in the optical code reader and oriented so that two or more of the plurality of highly reflective surfaces appear in the field of view of the imager, to thereby split the field of view of the imager into two or more different views into the viewing volume. The different views into the viewing volume may be direct off of the monolithic compound mirror structure or indirect off of one or more intermediate mirrors.

Claims

1. An optical code reader comprising:

an imager that captures images of items bearing optical codes in a viewing volume of the optical code reader, the imager having a field of view;

a fixed mirror structure comprising a base and at least first and second highly reflective surfaces mounted or formed on the base, wherein the structure is positioned in the optical code reader in a field of view of the imager and oriented so that the at least first and second highly reflective surfaces appear in the field of view of the imager, to thereby split the field of view of the imager into at least first and second different fields of view, the first field of view being of a first region of the imager and the second field of view being of a different second region of the imager; and

a set of pattern mirrors disposed about the structure for reflecting the first and second different views from the highly reflective surfaces into the viewing volume, wherein each of the highly reflective surfaces of the structure reflects a respective view only once.

2. An optical code reader according to claim 1, the set of pattern mirrors comprising:

a first intermediate mirror positioned to reflect light from the viewing volume onto one or more of the highly reflective surfaces of the mirror structure.

3. An optical code reader according to claim 2, the set of pattern mirrors further comprising:

a second intermediate mirror positioned to reflect light from the viewing volume onto one or more of the reflective surfaces of the mirror structure.

4. An optical code reader according to claim 3, wherein the first and second intermediate mirrors are in the same optical path.

5. An optical code reader according to claim 3, wherein the first and second intermediate mirrors are in different optical paths.

6. An optical code reader according to claim 1, wherein the mirror structure is integral to at least part of the optical code reader.

7. An optical code reader according to claim 1, further comprising:

an illumination source that shines light into the viewing volume,

wherein the light from the illumination source reflects off the one or more of the highly reflective surfaces of the mirror structure to reach the viewing volume.

8. An optical code reader according to claim 1, wherein the imager is a CMOS imager.

9. An optical code reader according to claim 1, wherein at least one of the different views into the viewing volume has a field of view having a substantial nonoverlapping region with respect to other views in the viewing volume.

10. An optical code reader according to claim 1, wherein the optical code reader is a bioptic reader that captures at least one lower perspective and at least one upper perspective into the viewing volume.

11. An optical code reader according to claim 1, further comprising:

a first intermediate mirror and a second intermediate mirror, the second intermediate mirror positioned to reflect light from the viewing volume onto the first intermediate mirror which in turn reflects light from the second intermediate mirror onto one or more of the highly reflective surfaces of the mirror structure.

12. An optical code reader according to claim 1, wherein the base comprises a molded plastic piece, wherein the mirror structure comprises a monolithic compound mirror structure with the first and second highly reflective surfaces comprising reflective coatings on the molded plastic piece.

13. An optical code reader according to claim 1, wherein the first and second highly reflective surfaces being strip-shaped with respective lengthwise major axes, the field of view of the imager being split into first and second different parallel strip-shaped views.

14. A method of optical code reading, comprising the steps of:

capturing, at an imager of an optical code reader, images of items bearing optical codes in a viewing volume of the imager, the imager having a field of view;

positioning a fixed mirror structure in the field of view of the imager, the mirror structure comprising a base and at least first and second mirror surfaces mounted or formed on the base with the first and second mirror surfaces appearing in the field of view of the imager;

positioning a set of pattern mirrors about the mirror structure;

splitting the field of view of the imager into at least first and second different split views by reflecting the field of view of the imager off of the first and second mirror surfaces, the first split view being of a first region of the imager and the second split view being of a different second region of the imager, wherein each of the first and second mirror surfaces reflecting a respective split view only once; and

reflecting the respective first and second split views off of one or more of the pattern mirrors and into the viewing volume.

15. A method according to claim 14 wherein the base comprises a molded plastic piece, wherein the mirror structure comprises a monolithic compound mirror structure with the first and second mirror surfaces comprising reflective coatings on the molded plastic piece.

16. A method according to claim 14 wherein the step of splitting the field of view comprises splitting the field of view of the imager into at least first and second different parallel strip-shaped split views by reflecting the field of view of the imager off of the first and second mirror surfaces, the first and second mirror surfaces being strip-shaped with respective lengthwise major axes.