Dual illuminator as field of view identification and aiming

Patent metadata

Field	Value
Publication number	US-11928546-B2
Application number	US-202117534797-A
Country	US
Kind code	B2
Filing date	Nov 24, 2021
Priority date	Dec 30, 2020
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

A code reader comprises a first imager and a second imager configured to capture an image with different field of views, a first illuminator and a second illuminator configured to project a different illumination pattern, and a processor operably coupled to the imagers and the illuminators. The processor configured to activate the first imager and the first illuminator as a receiver pair responsive to detecting a first condition, activate the second imager and the second illuminator as a receiver pair responsive to detecting a second condition, and decode an optical code using an image captured by the selected receiver pair.

First claim

What is claimed:

1. A code reader, comprising:
a first imager and a second imager configured to capture an image with different field of views, wherein the first imager has a near FOV and the second imager has a far FOV;
a first illuminator and a second illuminator each configured to project a different illumination pattern visible to a user;
a processor operably coupled to the imagers and the illuminators, the processor configured to:
determine a target distance for an object from the code reader;
activate the first imager and the first illuminator as a receiver pair with the second illuminator not active, responsive to detecting the target distance being less than a first distance threshold indicative of the object being in a near field;
activate the second imager and the second illuminator as a receiver pair with the first illuminator not active, responsive to detecting the target distance being greater than a second distance threshold indicative of the object being in a far field, wherein the first illuminator and the second illuminator project a different pattern substantially matching dimensions of the corresponding field of view for its receiver pair such that the respective illumination pattern that is visually presented to the user changes its shape depending on which imager is selected as the active imager; and
decode an optical code using an image captured by the selected receiver pair.

2. The code reader of claim 1 , wherein selection of the first imager and first illuminator or the second imager and second illuminator as the receiver pair to be activated is further based, at least in part, on a determination of code size of an optical code on the object responsive to determining the target distance to be between the first distance threshold and the second distance threshold.

3. The code reader of claim 1 , wherein the target distance is determined based on at least one of a time of flight measurement, laser triangulation, or passive focus run with best contrast evaluation.

4. The code reader of claim 1 , wherein selection of the first imager and first illuminator or the second imager and second illuminator as the receiver pair to be activated is further based, at least in part, on a determination of a code resolution of an optical code of the object responsive to determining the target distance to be between the first distance threshold and the second distance threshold.

5. The code reader of claim 1 , wherein the code reader is incorporated within one of a handheld scanner, a presentation scanner, a scan engine, a fixed scanner, a top down reader associated with a fixed scanner, a mobile computer, a point of sale system, a vision system, a robotic system, an automated driving system, or a machine vision system.

6. The code reader of claim 1 , wherein the processor is configured to perform a switch operation from activating the first illuminator to activating the second illuminator or from activating the second illuminator to activating the first illuminator responsive to detecting a changing condition.

7. The code reader of claim 6 , wherein the switch operation occurs over a plurality of frames following detection of the changing condition.

8. The code reader of claim 6 , wherein the switch operation occurs over a next frame following detection of the changing condition.

9. The code reader of claim 6 , wherein the switch operation includes the processor gradually fading out one illuminator while fading in the other illuminator.

10. The code reader of claim 9 , wherein the processor gradually fades the illuminators by gradually mixing active illuminators with a changing duty cycle.

11. The code reader of claim 1 , wherein the patterns for each of the first illuminator and the second illuminator have a rectangular shape with sharp edges that are different in dimensions.

12. A method of operating a code reader, the method comprising:
determining a target distance of an object;
selecting and activating a first imager and a first illuminator as a receiver pair of an optical code reader with a second illuminator not active, responsive to the target distance being less than a first distance threshold indicative of the object being in a near field of the code reader;
selecting and activating a second imager and a second illuminator as a receiver pair of the optical code reader with the first illuminator not active, responsive to the target distance being greater than a second distance threshold indicative of the object being in a far field of the code reader, wherein the first imager has a near field of view and the second imager has a far field of view, wherein the first illuminator and the second illuminator project a different pattern visible to a user and that has substantially matching dimensions of the corresponding field of view for its receiver pair, such that the respective illumination pattern that is visually presented to the user changes its shape depending on which imager is selected as the active imager; and
decoding an optical code using an image captured by the selected receiver pair.

13. The method of claim 12 , wherein if the target distance is between the first distance threshold and the second distance threshold, the method further comprises:
capturing a first image with the first imager and determining a code resolution for the code identified in the first image;
capturing a second image with the second imager and determining a code size for the code identified in the second image; and
selecting either the first imager and the first illuminator pair or the second imager and the second illuminator pair for activation based, at least in part, on analysis of both the code resolution as determined from the first image and the code size as determined from the second image.

14. The method of claim 13 , wherein the code resolution is determined by calculating a pixel per module (PPM) value for the first image.

15. The method of claim 14 , wherein the code size is determined from determining a bounding box surrounding the code identified in the second image.

16. The method of claim 15 , wherein selecting includes:
selecting the first imager and the first illuminator pair responsive to the calculated PPM value being less than a maximum PPM threshold for the first imager and the code size being greater than a field of view size for the second imager; and
selecting the second imager and the second illuminator pair responsive to the calculated PPM value being greater than a maximum PPM threshold for the first imager and the code size being less than a field of view size for the second imager.

17. The method of claim 13 , further comprising:
comparing the target distance with a third distance threshold in between the first distance threshold and the second distance threshold;
selecting the first illuminator for activation with both the first imager and the second imager responsive to the target distance being less than the third distance threshold; and
selecting the second illuminator for activation with both the first imager and the second imager responsive to the target distance being greater than the third distance threshold.

18. The method of claim 17 ,
wherein comparing the target distance with the third distance threshold only occurs when insufficient code information is determined for at least one of the code resolution or the code size.

19. The method of claim 17 , further comprising sending images from each the first imager and the second imager to a decoder for decoding during a time in which t

Assignees

• Datalogic IP Tech Srl

Inventors

• Perugini Luca
• Vonmetz Kurt
• Bruni Davide

Classifications

• G06K7/10732 Primary

  Light sources · CPC title

• G06K7/10811

  Focalisation · CPC title

• G06K7/10881

  constructional details of hand-held scanners · CPC title

• G06K7/1452

  detecting bar code edges · CPC title