System and method for illuminating a target of a barcode reader

Patent metadata

Field	Value
Publication number	US-12499337-B2
Application number	US-202318447298-A
Country	US
Kind code	B2
Filing date	Aug 9, 2023
Priority date	Sep 28, 2017
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

A code reader may include a light source configured to illuminate a target area in which items are to be located for reading machine-readable indicia associated with the items, an image sensor configured to capture an image of the target area, an illumination drive circuit in electrical communication with the light source, and an image capture circuit. The image capture circuit may be configured to (i) enable and disable the image sensor to capture an image of the target area during the high illumination and a portion(s) of the low illumination of the target area, and (ii) read an image captured by the image sensor. The illumination drive signals may cause the illumination drive circuit to generate a high illumination drive signal to cause the light source to produce a high illumination, and generate a low illumination drive current to cause said light source to produce a low illumination.

First claim

What is claimed:

1 . A code reader, comprising:
a light source configured to illuminate a target area; an image sensor configured to capture an image of the target area; an illumination drive circuit in electrical communication with the light source and configured to generate a continuous single, dual-intensity drive signal to the light source to cause the light source to operate in a high illumination time period or a low illumination time period, wherein a high current pulse is generated to cause the light source to produce a light strobe during the high illumination time period; and an image capture circuit configured to control the image sensor and the illumination drive circuit for image capture to occur during at least one of the high illumination time period or the low illumination time period for the light source.

2 . The code reader of claim 1 , wherein the high illumination time period has a shorter duration than the low illumination time period.

3 . The code reader of claim 1 , wherein the illumination drive circuit comprises:
a power supply controller electrically coupled to an external power source; an energy storage component electrically coupled to the power supply controller, and configured to store electrical energy; a current sink in electrical communication with the light source; and a driving circuit in electrical communication with the current sink and the power supply controller to drive the light source to output light.

4 . The code reader of claim 3 , wherein the current sink includes a field-effect transistor.

5 . The code reader of claim 3 , wherein the energy storage component includes at least one of a capacitor or a supercapacitor.

6 . The code reader of claim 3 , wherein the current sink is configured to constantly drain a variable amount of current.

7 . The code reader of claim 3 , wherein the power supply controller is configured to control parameters of the generation of the dual intensity drive signal to have high current pulses or low current signals responsive to a power enable signal.

8 . The code reader of claim 7 , wherein the high current pulses are above a threshold capable of being reached by the external power source.

9 . The code reader of claim 3 , wherein the driving circuit is further configured to provide different power consumption modes by regulating discharge resistance to current used to drive the light source.

10 . The code reader of claim 1 , wherein the driving circuit is configured to receive one or more control signals from an external controller to control operation thereof.

11 . The code reader of claim 10 , wherein the external controller is the image capture circuit.

12 . The code reader of claim 10 , the one or more control signals includes an illumination enable signal.

13 . The code reader of claim 10 , the one or more control signals includes a strobe signal for turning the light source on or off.

14 . The code reader of claim 10 , the one or more control signals includes an illumination synchronize select signal for synchronizing illumination over an exposure time period of the image sensor.

15 . The code reader of claim 10 , the one or more control signals includes an illumination current intensity signal for controlling illumination current intensity drained by the current sink.

16 . A method of operating a code reader, the method comprising:
illuminating a target area via a light source of the code reader; capturing an image of the target area via an image sensor of the code reader; generating, via an illumination drive circuit of the code reader, a continuous single, dual-intensity drive signal to the light source to cause the light source to operate in a high illumination time period or a low illumination time period, including generating a high current pulse to cause the light source to produce a light strobe during the high illumination time period; and controlling the image sensor and the illumination drive circuit for image capture to occur during at least one of the high illumination time period or the low illumination time period for the light source.

17 . The method of claim 16 , wherein generating the continuous single, dual-intensity drive signal includes:
charging an energy storage component; discharging the energy storage component to generate the high current pulse to cause the light source to produce the light strobe during the high illumination time period; and limiting current to a low level current threshold to the light source during low level emission periods defined by times outside the high current pulse.

18 . The method of claim 17 , wherein limiting current during low level emission periods occurs over a duration longer than that of discharging the energy storage component to generate the high current pulse.

19 . The method of claim 17 , wherein discharging the energy storage component to produce a light strobe includes discharging the energy storage component at a substantially constant rate and for substantially the same duration.

20 . The method of claim 17 , wherein generating the continuous single, dual-intensity drive signal further includes:
limiting the high current pulse to a high level threshold for a time duration to cause the light source to produce a light strobe; and wherein limiting current with the high level current threshold to generate the high current pulse and limiting current with the low level current threshold during low level emission periods alternates seamlessly to continuously illuminate a target area by the light source.

Assignees

• Datalogic IP Tech Srl

Inventors

• Bruni Davide
• Canini Federico
• Fabbri Mattia
• Fracassi Stefano
• Gavioli Davide
• Perugini Luca
• Spolzino Simone

Classifications

• G06K7/1413

  1D bar codes · CPC title

• G06K7/10851

  Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device (basic electronic circuitry H03) · CPC title

• G06K7/10752

  Exposure time control · CPC title

• G06K7/10732 Primary

  Light sources · CPC title

• G06K7/10722 Primary

  Photodetector array or CCD scanning · CPC title