Apparatuses, methods, and computer program products for flicker reduction in a multi-sensor environment

Patent metadata

Field	Value
Publication number	US-11736811-B2
Application number	US-202217934794-A
Country	US
Kind code	B2
Filing date	Sep 23, 2022
Priority date	Feb 28, 2020
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

Embodiments of the disclosure relate generally to flicker reduction in a multi-imager environment. Embodiments include methods, computer program products, and apparatuses configured for producing a near-field illumination using a near-field illuminator, the near-field illumination produced at a defined pulse train. A near-field image sensor may be exposed near the start of a near-field illumination pulse, and a far-field image sensor may be exposed between pulses of the near-field illumination. Some embodiments, additionally or alternatively, are configured for detecting an illuminator switch event, deactivating the near-field illuminator source, and producing, using a far-field illuminator source, a far-field illumination. Upon switching the illuminator source, some such embodiments are configured for exposing a far-field illuminator near the start of the far-field illumination pulse, and exposing a near-field image sensor near the start of the next available far-field illumination pulse. Such image capture may repeat until an image processing task such as barcode reading is successful.

First claim

What is claimed is:

1. A method for flicker reduction in a multi-imager environment, the method comprising:
producing, using a first illuminator source of a plurality of illuminator sources, a first illumination, wherein the plurality of illuminator sources comprises more than two illuminator sources, and wherein the first illuminator source produces the broadest illumination among the plurality of illuminator sources;
exposing a near-field image sensor during the first illumination;
generating at least one near-field image based on the exposure of the near-field image sensor;
exposing a far-field image sensor such that the exposure of the far-field image sensor is not during any pulse associated with the first illumination;
generating a far-field image based on the exposure of the far-field image sensor;
detecting an illuminator switch event; and
in response to the detection of the illuminator switch event:
deactivating the first illuminator source; and
producing, using a second illuminator source of the plurality of illuminator sources, a second illumination associated with at least one second illumination pulse, wherein a field of view illuminated by the second illuminator source is different than a field of view illuminated by the first illuminator source, and wherein the second illuminator source produces the narrowest illumination among the plurality of illuminator sources.

2. The method of claim 1 , further comprising:
exposing the near-field image sensor during the second illumination;
generating a second near-field image based on the exposure of the near-field image sensor during the second illumination;
exposing the far-field image sensor such that the exposure of the far-field image sensor is not during any pulse associated with the second illumination; and
generating the second far-field image based on the exposure of the far-field image sensor during the second illumination.

3. The method of claim 1 , further comprising:
in response to generating the near-field image, determine a timing offset until a next near-field pulse start time associated with a next near-field illumination pulse of the at least one near-field illumination pulse,
wherein the exposing the far-field image sensor occurs after delaying for a length of time represented by the timing offset combined with a difference between the next near-field pulse start time associated with the next near-field illumination pulse and a next near-field pulse end time associated with the next near-field illumination pulse.

4. The method of claim 1 , wherein the field of view illuminated by the second illuminator source is narrower than the field of view illuminated by the first illuminator source.

5. The method of claim 1 , the method further comprising, prior to exposing the near-field image sensor during the first illumination:
determining that the near-field image sensor was last utilized for capturing an image that was successfully processed.

6. The method of claim 1 , wherein a first pulse associated with the first illumination is produced at same rate and for a same length as a second pulse associated with the second illumination.

7. The method of claim 1 , wherein each illuminator source of the plurality of illuminator sources is configured to produce illumination pulses based on a respective defined pulse frequency and a respective defined pulse phase.

8. The method of claim 1 , wherein detecting the illuminator switch event comprises:
determining each captured image of a captured image set is associated with an image property that does not satisfy an image property threshold, wherein the captured image set comprises at least the near-field image and the far-field image,
wherein the captured image set comprises a number of captured images, wherein the number of captured images satisfies a near-illuminator capture threshold, and wherein the image property comprises an image white level value, and wherein the image property threshold comprises a minimum white level threshold.

9. The method of claim 1 , wherein the near-field imaging sensor is utilized to capture a plurality of near-field images prior to exposing the far-field image sensor.

10. The method of claim 1 , wherein the beginning of the exposure of the far-field image sensor is near-aligned with a first pulse end time of a first pulse associated with the near-field illumination.

11. The method of claim 1 , the method further comprising:
processing the first far-field image to determine an image property associated with the far-field image does not satisfy an image property threshold associated with the image property; and
altering at least one of an exposure time value for the far-field image sensor or a gain value for the far-field image sensor.

12. An apparatus for flicker reduction in a multi-imager environment, the apparatus comprising:
a multi-sensor imaging engine comprising a plurality of illuminator sources, a near-field image sensor, and a far-field image sensor; and
a processor that configures the apparatus to:
produce, using a first illuminator source of the plurality of illuminator sources, a first illumination, wherein the plurality of illuminator sources comprises more than two illuminator sources, and wherein the first illuminator source produces the broadest illumination among the plurality of illuminator sources;
expose the near-field image sensor during the first illumination;
generate at least one near-field image based on the exposure of the near-field image sensor;
expose the far-field image sensor such that the exposure of the far-field image sensor is not during any pulse associated with the first illumination;
generate a first far-field image based on the exposure of the far-field image sensor;
detect an illuminator switch event; and
in response to the detection of the illuminator switch event:
deactivate the first illuminator source; and
produce, using a second illuminator source of the plurality of illuminator sources, a second illumination associated with at least one second illumination pulse, wherein a second field of view illuminated by the second illuminator source is different than a first field of view illuminated by the first illuminator source, and wherein the second illuminator source produces the narrowest illumination among the plurality of illuminator sources.

13. The apparatus of claim 12 , wherein the apparatus is further configured to:
expose the near-field image sensor during the second illumination;
generate a second near-field image based on the exposure of the near-field image sensor during the second illumination;
expose the far-field image sensor such that the exposure of the far-field image sensor is not during any pulse associated with the second illumination; and
generate the far-field image based on the exposure of the far-field image sensor during the second illumination.

14. The apparatus of claim 12 , wherein the apparatus is further configured to:
in response to generating the near-field image, determine a timing offset until a next near-field pulse start time associated with a next near-field illumination pulse of the at least one near-field illumination pulse,
wherein the exposing the far-field image sensor occurs after delaying for a length of time represented by the timing offset combined with a difference between the next near-field pulse start time associated with the next near-field illumination pulse and a next near-field pulse end time associated with the next near-field illumination pulse.

15. The apparatus of claim 12 , wherein the field of view illuminated by the second

Assignees

• Hand Held Prod Inc

Inventors

• Hejl Benjamin
• Au Ka Man
• Van Horn Erik
• Wilz David M
• Miraglia Michael V
• Giordano Patrick

Classifications

• H04N23/745 Primary

  Detection of flicker frequency or suppression of flicker wherein the flicker is caused by illumination, e.g. due to fluorescent tube illumination or pulsed LED illumination · CPC title

• H04N23/73

  by influencing the exposure time · CPC title

• H04N23/74

  by influencing the scene brightness using illuminating means · CPC title

• G06K7/1095

  the scanner comprising adaptations for scanning a record carrier that is displayed on a display-screen or the like · CPC title

• G06K7/10881

  constructional details of hand-held scanners · CPC title