System and method of reading bar code with two scanning beams

• US 6,189,796 B1
• Filed: 07/16/1999
• Issued: 02/20/2001
• Est. Priority Date: 01/31/1997
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Watanabe, Mitsuo, Kawai, Hiroaki, Iwaguchi, Isao, Satoh, Shinichi, Itoh, Motohiko
• Primary Examiner(s): LEE, MICHAEL GUNYOUNG
• Application Number:
  US09/356,024
• Time in Patent Office: 585 Days
• Field of Search: 235/462.01, 235/462.06, 235/462.2, 235/462.22, 235/462.23, 235/462.25, 235/462.45, 235/454, 235/472.01, 235/462.48, 235/462.42
• US Class Current: 235/462.48
• CPC Class Codes: G06K 7/10574 Multiple sources
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1486 Setting the threshold-width for bar codes to be decoded

Abstract

A method and apparatus for selectively reading a bar code in accordance with first and second scan patterns emitted by a scan unit. A button is manually operable by an operator for switching from the first scan pattern to a second scan pattern. A controller controls the scanning unit to switch from the first scan pattern to the second scan pattern, responsive to operation of the button by the operator and, a predetermined time after relative of the button, to switch from the second scan pattern to the first scan pattern.

Claims

1. A device for reading a bar code, comprising:

a scan unit, containing a light source, selectively emitting a first scan pattern and a second scan pattern for reading a bar code respectively in first and second modes;

a switch, manually operatable by an operator, for switching from the first and to the second scan pattern; and

a controller controlling the scan unit to switch from the first scan pattern to the second scan pattern, responsive to operation of the switch, and to switch from the second scan pattern to the first scan pattern when a predetermined period has passed after the switch is released.

2. The device as claimed in claim 1, wherein said first scan pattern includes a plurality of valid scan beams and said second scan pattern includes only one valid scan beam.

3. The device as recited in claim 1, wherein the first scan pattern employs a greater number of scanning beams than the second scan pattern.

4. The device as recited in claim 1, wherein the second pattern employs a single scanning beam.

5. The device as recited in claim 1, wherein the controller terminates further bar code reading using the second scan pattern during the predetermined time period.

6. The method as recited in claim 1, where:

the device is a hand-held device, moveable by an operator to the scanning position.

7. The method as recited in claim 6, wherein:

the scanning position is fixed relatively to the bar code being scanned.

8. The method as recited in claim 7, wherein:

upon detection of movement of the device relatively to the scanning position, discarding the bar code data derived when scanning the bar code with the second scan pattern.

9. The device for reading a bar code comprising:

a scan unit providing a first scan pattern of a scan beam for reading a bar code in a first mode when the device is stationary and producing a second pattern of a scan beam for reading a bar code in a second mode when the device is movable from a remote position to a scanning position relatively to the bar code;

a switch operated by selective, manual operation of an operator, for scanning a bar code with the second scan pattern while the device maintained at the scanning position;

a detector detecting completion of demodulation of scanned bar code and, upon such completion whether the switch is released; and

a controller, after a predetermined time period following the detected release of the switch, selecting the first scan pattern for reading a bar code.

10. The device as recited in claim 9, wherein the first scan pattern employs a greater number of scanning beams than the second scan pattern.

11. The method as recited in claim 9, wherein the second scan pattern employs a single scanning beam.

12. A device as recited in claim 9, wherein:

the detector, further, detects movement of the source of the scanning beam relatively to the bar code while scanning the bar code with the second scan pattern; and

the controller, in response to detection of the relative movement, discards bar code data derived when scanning the bar code with the second scan pattern during the relative movement.

13. The device as recited in claim 9, wherein the controller terminates further bar code reading using the second scan pattern during the predetermined time period.

14. The method as recited in claim 9, further comprising terminating further bar code reading using the second scan pattern during the predetermined time period.

15. The method as recited in claim 14, wherein:

the scanning position is fixed relatively to the bar code being scanned.

16. The method as recited in claim 15, wherein:

upon detection of movement of the device relatively to the scanning position, discarding the bar code derived when scanning the bar code with the second scan pattern.

17. A method for reading a bar code, comprising the steps of:

emitting a first scan pattern of a scan beam for reading a bar code in a first mode;

switching to a second scan pattern of the scan beam for reading a bar code in a second mode, different from the first mode, when an operator selects the second mode;

determining if a predetermined period has passed after the operator releases the selection of the second mode; and

switching from the second scan pattern of the scan beam to the first scan pattern of the scan beam when the predetermined period has passed.

18. The device as recited in claim 17, wherein the first and second scan patterns respectively employ relatively greater and lesser numbers of scanning beams.

19. The method as recited in claim 17, wherein the second pattern employs a single scanning beam.

20. The method as recited in claim 17, further comprising terminating further bar code reading using the second scan pattern during the predetermined time period.

21. A method for reading a bar code, comprising the steps of:

providing a device producing a first scan pattern of a scan beam for reading a bar code in a first mode when the device is stationary and producing a second pattern of a scan beam for reading a bar code in a second mode when the device is moved from a remote position to a scanning position relatively to the bar code;

under operator control, switching from the first scan pattern to the second scan pattern by manual actuation of a switch and, while the switch is actuated, scanning a bar code with the second scan pattern;

determining when demodulation of scanned bar code data is completed and determining, upon such completion, whether the switch is released; and

after a predetermined time period following release of the switch, selecting the first scan pattern for reading a bar code.

22. The device as recited in claim 21, wherein the first scan pattern employs a greater number of scanning beams than the second scan pattern.

23. The method as recited in claim 21, wherein the second pattern employs a single scanning beam.

24. The method as recited in claim 21, wherein:

the step of determining whether the bar code demodulation is complete further comprises detecting movement of the device relatively to the bar code while scanning the bar code with the second scan pattern; and

upon detection of the movement of the device relative to the scanning position, discarding bar code data derived when scanning the bar code with the second scan pattern.

25. The method as recited in claim 21, further comprising terminating further bar code reading using the second scan pattern during the predetermined time period.

26. The method as recited in claim 21, further comprising terminating further bar code reading using the second scan pattern during the predetermined time period.

27. The method as recited in claim 26, wherein:

the scanning position is fixed relatively to the bar code being scanned.

28. The method as recited in claim 27, wherein:

upon detection of movement of the device relatively to the scanning position, discarding the bar code derived when scanning the bar code with the second scan pattern.