System and method for charging a barcode scanner

Patent metadata

Field	Value
Publication number	US-10804718-B2
Application number	US-201816004717-A
Country	US
Kind code	B2
Filing date	Jun 11, 2018
Priority date	Jan 8, 2015
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

Cordless indicia readers may use a rechargeable energy storage unit (RESU) for power. The RESU may include either at least one lithium-ion battery or at least one super capacitor. Problems may arise when an RESU containing a lithium-ion battery is charged using a super-capacitor charging-scheme. The present invention embraces a system and method for charging a barcode scanner that includes determining the RESU type and then charging the RESU with a charging process that is appropriate for the RESU type.

First claim

The invention claimed is:

1. A method for selecting a charging process, the method comprising:
connecting a rechargeable energy storage unit (RESU) to a charger, the RESU configured to supply electrical energy to a barcode scanner, and the charger configured to perform a first charging process for charging a supercapacitor and a second charging process for charging a battery, wherein the charger comprises a detection circuit configured to interface with a pin on the RESU and to output a digital signal indicative of a terminal resistance at the pin, wherein the detection circuit comprises a MOSFET that further comprises a gate terminal, a source terminal, and a drain terminal, wherein the source terminal is connected to a power source, and the drain terminal is connected to a first end of a current-limiting resistor, wherein a second end of the current-limiting resistor is connected to a digital to analog (A/D) convertor and to a ground through the terminal resistance at the pin of the RESU;
ascertaining with a processor whether the digital signal, received from the A/D convertor, indicates that the RESU comprises the supercapacitor or the battery, wherein the digital signal indicates a voltage drop across the terminal resistance (Rt), and wherein the voltage drop across the terminal resistance indicates a type of the RESU; and selecting the first charging process for charging the supercapacitor in response to the voltage drop indicating a short circuit between the drain terminal and the ground, wherein the short circuit indicates a first terminal resistance value of the terminal resistance as approximately zero ohms; or
selecting the second charging process for charging the battery in response to the voltage drop indicating a presence of the terminal resistance between the drain terminal and the ground, wherein a second terminal resistance value of the terminal resistance is greater than the first terminal resistance value.

2. The method according to claim 1 , wherein the method further comprises obtaining the terminal resistance from a thermistor pin at least when the RESU comprises a battery.

3. The method according to claim 1 , wherein the battery is a lithium-ion (Li-ion) battery.

4. The method according to claim 1 , wherein the charger comprises one interface configured to receive the supercapacitor or the battery, wherein the supercapacitor or the battery comprises a uniform mechanical shape/size and a uniform electrical interface, and wherein the uniform electrical interface comprises the pin.

5. The method according to claim 1 , wherein the digital signal is indicative of a voltage from the pin.

6. The method according to claim 1 , wherein the second terminal resistance value is approximately 10,000 ohms when the RESU comprises the battery.

7. The method according to claim 1 , wherein the method further comprises:
charging the RESU using the first charging process when the processor selects the first charging process; or
charging the RESU using the second charging process when the processor selects the second charging process.

8. The method according to claim 1 , wherein the charger comprises a cradle configured to hold and charge the RESU.

9. The method according to claim 1 , wherein the charger comprises a cradle configured to hold and charge the RESU while the RESU is connected to the barcode scanner.

10. A charging system for a barcode scanner, comprising:
a rechargeable energy storage unit (RESU) configured to supply electrical energy to a barcode scanner;
a charger configured to perform a first charging process for charging a supercapacitor and a second charging process for charging a battery, wherein the charger comprises a detection circuit configured to interface with a pin on the RESU and to output a digital signal corresponding to a terminal resistance at the pin, wherein the detection circuit comprises a MOSFET comprising a gate terminal, a source terminal, and a drain terminal, wherein the source terminal is connected to a power source and the drain terminal is connected to a first end of a current-limiting resistor, wherein a second end of the current-limiting resistor is connected to a digital to analog (A/D) convertor and to a ground through the terminal resistance at the pin of the RESU; and
a processor configured to:
ascertain whether the digital signal, received from the A/D convertor, indicates that the RESU comprises the supercapacitor or the battery, wherein the terminal resistance is approximated being sufficiently different such that the processor may ascertain whether the digital signal indicates that the RESU comprises the supercapacitor or whether the digital signal indicates that the RESU comprises the battery; and
select the first charging process for charging the supercapacitor in response to the voltage drop indicating a short circuit between the drain terminal and the ground, wherein the short circuit indicates a first terminal resistance value of the terminal resistance as approximately equal to zero ohms; or
select the second charging process for charging the battery in response to the voltage drop indicating a presence of the terminal resistance between the drain terminal and the ground, wherein a second terminal resistance value of the terminal resistance is greater than first terminal resistance value; and
wherein the charger is configured to:
charge the supercapacitor using the first charging process when the processor selects the first charging process; or
charge the battery using the second charging process when the processor selects the second charging process.

11. The charging system according to claim 10 , wherein the pin provides a terminal resistance of a circuit element in the RESU when the RESU comprises the supercapacitor.

12. The charging system according to claim 10 , wherein the battery comprises one or more lithium-ion batteries.

13. The charging system according to claim 10 , wherein the digital signal is indicative of a voltage from the pin.

14. The charging system according to claim 10 , wherein the terminal resistance at the pin corresponds to a resistance of a thermistor in the RESU.

15. The charging system according to claim 10 , wherein the first terminal resistance value at the pin when the RESU comprises the supercapacitor and the second terminal resistance value at the pin when the RESU comprises the battery differ by more than 1000 ohms.

16. The charging system according to claim 10 , wherein the digital signal corresponds to a voltage-level indicative of the terminal resistance at the pin.

17. The charging system according to claim 10 , wherein the charger comprises a cradle having a housing configured to mechanically and electrically mate with the RESU, and wherein the housing contains the detection circuit and the processor.

Assignees

• Hand Held Prod Inc

Inventors

• Allen Christopher
• Colavito Stephen J
• Haggerty Thomas

Classifications

• H02J7/443

  using passive battery identification means, e.g. resistors or capacitors (identification by mechanical connections H02J7/751) · CPC title

• H02J7/731 Primary

  specially adapted for holding portable devices containing batteries (H02J7/751 takes precedence) · CPC title

• H02J7/485

  with provisions for charging different types of batteries · CPC title

• H02J7/0044 Primary

  Electricity · mapped topic

• H02J7/00038

  Electricity · mapped topic