System and method of reading bar code with two scanning beams

• US 6,619,548 B1
• Filed: 06/21/2000
• Issued: 09/16/2003
• Est. Priority Date: 12/12/1987
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Satoh, Shinichi, Watanabe, Mitsuo, Kawai, Hiroaki, Iwaguchi, Isao, Itoh, Motohiko
• Primary Examiner(s): Frech, Karl D.
• Assistant Examiner(s): Kim, Ahshik
• Application Number:
  US09/598,702
• Time in Patent Office: 1,182 Days
• Field of Search: 235/462.01, 235/462.08, 235/462.14, 235/462.22, 235/462.47, 235/462.48, 235/472.01, 235/472.03
• US Class Current: 235/462.16
• 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 of the invention reads a bar code based on bar-code data obtained by scanning the bar code with light. The method includes the steps of a) obtaining bar-code data, b) obtaining a sum of bar-data widths with respect to a predetermined number of bar data provided in at least one of a preceding portion and a following portion of the bar-code data, c) repeating the steps a) and b) once to obtain another sum, and d) making a comparison of the sum with another sum. The methods further includes a step of accepting the bar-code data as valid data when a result of the comparison satisfies a predetermined condition.

Claims

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

a scan unit selectively producing a first scan pattern of a scan beam for reading a bar code in a first mode and a second pattern of a scan beam for reading a bar code in a second mode, different from the first mode;

a switch, manually operated by an operator, causing the scan unit to selectively produce the second scan pattern for scanning a bar code; and

a controller, in response to a detected release of the switch and at a predetermined time period thereafter, terminating scanning of the bar code with the second scan pattern.

2. The device as recited in claim 1, wherein, after a predetermined time period following release of the switch, the controller causes the scan unit to produce the first scan pattern for resumed reading of a bar code.

3. The device as recited in claim 2, wherein the controller terminates further bar code reading using the second scan pattern during the predetermined time period.

4. The device as recited in claim 1, further comprising:

a detector detecting movement of the device 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.

5. The device as recited in claim 4, wherein the second scan pattern comprises one or more parallel scan beams.

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

7. The device as recited in claim 6, wherein the first scan pattern comprises a plurality of scan beams emitted in multiple directions.

8. The device as recited in claim 6, wherein the first scan pattern is suitable for use in a fixedly mounted scanning device.

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

10. The device as recited in claim 9, wherein the second scan pattern is suitable for use in a hand held scanning device.

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

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

12. The method as recited in claim 11, wherein:

the scanning position is a fixed position, unmovable relatively to the bar code being read.

13. The method as recited in claim 12, wherein:

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

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

selectively producing a first scan pattern of a scan beam for reading a bar code in a first mode and a second scan pattern of the scan beam for reading a bar code in a second mode;

selecting 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 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.

15. The device as recited in claim 14, wherein the first scan pattern employs a greater number of scanning beams than the second scan pattern.

16. The method as recited in claim 14, wherein the second pattern employs one or more parallel scanning beams.

17. The method as recited in claim 14, wherein the scan beam is proceeded by a scanning device, further comprising:

detecting movement of the scanning device relatively to a bar code being scanned with the second scan pattern; and

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

18. The method as recited in claim 17, wherein:

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

19. The method as recited in claim 18, wherein:

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

20. The method as recited in claim 19, wherein:

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

21. The method as recited in claim 14, further comprising:

terminating further bar code reading using the second scan pattern during the predetermined time period.

22. A medium storing a program readable by computer for controlling a computer to read a bar code by a scanning device, including responding to manual actuation of a switch on a scanning device, by:

selectively producing a first scan pattern of a scan beam for reading a bar code in a first mode and a second scan pattern of the scan beam for reading a bar code in a second mode;

selecting 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 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.

23. The memory medium storing a program as recited by claim 22, wherein the first scan pattern employs a greater number of scanning beams than the second scan pattern.

24. The memory medium storing a program as recited by claim 22, wherein the second pattern employs one or more parallel scanning beams.

25. The memory medium storing a program as recited by claim 22, wherein the scan beam is proceeded by a scanning device, further comprising:

detecting movement of the scanning device relatively to a bar code being scanned with the second scan pattern; and

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

26. The memory medium storing a program as recited by claim 25, wherein:

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

27. The memory medium storing a program as recited by claim 26, wherein:

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

28. The memory medium storing a program as recited by claim 27,

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

29. The memory medium storing a program as recited by claim 22, further comprising:

terminating further bar code reading using the second scan pattern during the predetermined time period.