Bar code and method and apparatus for interpreting the same

• US 4,074,114 A
• Filed: 03/12/1976
• Issued: 02/14/1978
• Est. Priority Date: 03/12/1976
• Status: Expired due to Term

• Current Assignee: Monarch Marking Systems, Inc. (Avery Dennison Corporation)
• Original Assignee: Monarch Marking Systems, Inc. (Avery Dennison Corporation)
• Inventors: Dobras, Bruce W.
• Primary Examiner(s): Cook, Daryl W.
• Application Number:
  US05/666,569
• Time in Patent Office: 704 Days
• Field of Search: 235/61.11 E, 235/61.12 N, 250/555, 250/566, 250/567, 250/568, 250/569, 340/146.3 Z, 340/146.3 F
• US Class Current: 235/462.07
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners

Abstract

A bar code is constructed from individual characters that are laid out along a first straight line. Each character is formed by a series of bars and spaces that are parallel to the first straight line and that are laid out along a second straight line which is perpendicular to the first straight line and which passes through the center of the character. The resulting bar code is scanned manually by an operator who propels a hand-held scanner across the bar code in a direction parallel to the first straight line. The hand-held scanner contains a linear photodetector array mounted opposite optical elements in such a manner that a line image of a bar code character roughly perpendicular to the first straight line is projected upon the linear array as the stylus passes over a character. As the bar code is manually scanned, the linear array scans through each bar-coded character at numerous points and thereby generates numerous sets of digital data each representing the width of the successive bar and space regions which comprise each character. The resultant digital data is filtered, decoded and error-checked. When a series of consecutive scans over a given character result in the detection of identical error-free data, that data is accepted as a proper representation of the given character and is forwarded to a data capturing device. The scanning then commences to look for bar space patterns indicating that the scanning has progressed to the region which separates adjoining characters from each other. Then the scanning for data recommences. In this manner, a single pass of the hand-held scanner over the bar code results in the accurate capture of the data represented by the code without the necessity of multiple passes over the ticket.

Claims

1. An apparatus for reading and interpreting a bar-encoded record bearing a group of substantially parallel, scannable bars having distinctive light reflective characteristics and whose widths represent encoded data, said apparatus comprising:

light responsive means including a linear series of photodetectors arranged along a single straight line for generating a signal whose amplitude fluctuations reflect the spatial variations of the incident light intensity along said series of photodetectors;

means for simultaneously projecting an image of the record onto said series of photodetectors, said record image being along a line generally perpendicular to said group of bars; and

decoding means attached to said light responsive means for decoding the amplitude fluctuations of said signal into data.

2. An apparatus in accordance with claim 1 wherein said light responsive means includes an analog charge-transport shift register connecting said series of photodetectors to said decoding means, and means for periodically causing said shift register to convey charges from said series of photodetectors to said decoding means in sequence to thereby form said signal whose amplitude fluctuations with time reflect the spatial variations of the incident light intensity along said series of photodetectors.

3. An apparatus as set forth in claim 1, wherein said decoding means includes means for identifying that group of photodetectors within said series of photodetectors which are responsive to light reflected from said group of bars, and area control means for thereafter causing said decoding means to respond only to the output of said group of photodetectors within said series of photodetectors.

4. An apparatus for extracting information from a scannable, bar-encoded record having predetermined characteristics whereon groups of plural bars are spaced apart in a first direction, leaving a space between adjacent groups, and whereon the plural bars within each such group are spaced out in a second direction substantially perpendicular to said first direction, the bars within each such group also being adjacent, parallel, variable-width bars arranged so that adjoining bars have predetermined characteristics, said apparatus comprising:

scanning means for scanning said record in a direction generally parallel to said second direction with successive scans passing over said record at locations spaced apart in said first direction such that each group of bars is scanned a plurality of times and the space between each group of bars is scanned at least once, said scanning means generating a signal whose fluctuations with time represent the width variations of the bars and spaces scanned;

decoding means attached to said scanning means for decoding the fluctuations of said signal resulting from scans across the full width of each bar in a group of bars into a data set;

a data utilization device;

error check means accepting data sets from said decoding means for comparing successive data sets produced by said decoding means and for supplying a single data set to said data utilization device after receiving identically the same data set from said decoding means a predetermined number of times; and

means placed in operation by said error check means after said error check means has supplied a data set to said data utilization device for preventing additional data sets from reaching said data utilization device from said error check means until after a predetermined duration fluctuation of the signal generated by said scanning means occurs, said predetermined duration fluctuation signal indicating that the scanning means is scanning the space separating two groups of characters from each other.

5. An apparatus for extracting information from an optically-scannable, bar-encoded record wherein groups of plural bars are spaced apart in a first direction and are separated by at least two optically dissimilar regions, said two optically dissimilar regions being separated from each other by a border substantially perpendicular to said first direction, and whereon the plural bars within each such group are spaced out in a second direction substantially perpendicular to said first direction, the bars in each such group also being adjacent, parallel, variable-width bars arranged so that adjoining bars are optically dissimilar, said apparatus comprising:

scanning means for optically scanning said record in a direction roughly parallel to said second direction with successive scans passing over said record at locations spaced apart in said first direction such that each group of bars is scanned a plurality of times and the regions separating groups of bars are each scanned at least once over a predetermined portion of their lengths, said scanning means generating a signal whose fluctuations with time represent the width of the bars and regions scanned;

decoding means attached to said scanning means for decoding the fluctuations of said signal resulting from scans across the full width of each bar in a group of bars into a data set;

a data utilization device;

error check means for accepting data sets from said decoding means for comparing successive data sets produced by said decoding means and for supplying a single data set to said data utilization device after receiving identically the same data set from decoding means a predetermined number of times greater than once; and

means placed in operation by said error check means after said error check means has supplied a data set to said data utilization device for preventing additional data sets from reaching said data utilization device from said error check means until after a predetermined duration fluctuation of the signal generated by said scanning means occur corresponding to each of the optically dissimilar regions between groups of plural bars, said predetermined duration fluctuation signal being longer in duration than any of said signals representing a bar scan and indicating that the scanning has progressed from one group of bars to the next.

6. An apparatus for extracting information from a bar-encoded record having distinctive scannable characteristics and wherein groups of plural bars are spaced apart in a first direction, leaving a space between groups, and wherein the plural bars within each such group are spaced out in a second direction substantially perpendicular to said first direction, the bars within each such group also being adjacent, parallel, variable-width bars arranged so that adjoining bars are of two distinct scannable characteristics, and wherein the spaces between groups of bars contain identical scannable patterns having characteristics different from those of the bars in any of said groups, said apparatus comprising:

scanning means for scanning said record in a direction generally parallel to said second direction with successive scans passing over said record at locations spaced apart in said first direction such that each group of bars is scanned a plurality of times and the patterns between each group of bars are also scanned, said scanning means generating a signal whose fluctuations with time represent the width variations of the bars and patterns scanned;

decoding means attached to said scanning means for decoding the fluctuations of said signal resulting from scans across the full width of each bar in a group of bars into a data set;

error check means accepting data sets from said decoding means for comparing successive data sets produced by said decoding means and for supplying a single data set to said data utilization device after receiving identically the same data set from said decoding means a predetermined number of times greater than once; and

means placed in operation by said error check means after said error check means has supplied a data set to said data utilization means for preventing additional data sets from reaching said data utilization device from said error check means until the signal generated by said scanning means fluctuates in a manner indicative that a pattern of the type found between groups of data bars is being scanned.

7. Apparatus for extracting information from a scannable, bar-encoded record whereon groups of plural bars are spaced apart in a first direction and are separated by a pair of separation bars having first and second predetermined characteristics respectively and oriented substantially perpendicular to said first direction, and whereon the plural bars within each such group are spaced out in a second direction substantially perpendicular to said first direction, the bars in each such group being adjacent and having the same alternating first and second characteristics as the separation bars between the groups of bars, each group including a fixed number of bars whose width variations represent data, said data including data values to be conveyed and redundant data for error checking, said apparatus comprising:

scanning means for scanning said record in a direction generally parallel to said second direction with successive scans of said record occurring at locations spaced apart in said first direction such that each group of bars is scanned a plurality of times and the separation bars between the groups are also scanned, said scanning means generating a signal whose fluctuations with time represent the width variations of the bars or portions thereof scanned;

decoding means attached to said scanning means for decoding the fluctuations of said signal resulting from scans across the full width of each bar in a group of bars into a data set, said decoding means sensing improper redundant data in other scans and not responding to such other scans;

error check means accepting data sets from said decoding means for comparing successive data sets produced by said decoding means and for supplying a single data set to said data utilization device after receiving identically the same set from said decoding means a predetermined number of times; and

means placed in operation by said error check means after said error check means has supplied a data set to said data utilization means for preventing additional data sets from reaching said data utilization device until a signal generated by said scanning means generates fluctuations of predetermined durations of a first predetermined state followed by a second predetermined state representing the scanning of the separation bars.

8. A method for extracting information from a scannable, bar-encoded record whereon groups of plural bars having predetermined distinctive characteristics are spaced apart in a first direction and are separated by identical scannable patterns having predetermined characteristics distinguishable from those of the bars in any of said groups, and whereon the plural bars within each such group are spaced out in a second direction substantially perpendicular to said first direction, the bars within each such group also being adjacent, parallel, variable-width bars arranged so that adjoining bars are of two distinct predetermined characteristics, said method comprising the steps of:

scanning said record in a direction generally parallel to said second direction with successive scans of said record occurring at locations spaced apart in said first direction such that each group of bars is scanned several times and such that the patterns separating groups of bars are also scanned for recognition, and generating a signal whose fluctuations with time represent the fluctuations with distance of the characteristics of the bars and other patterns scanned;

converting the signal fluctuations with time into digital code values by assigning a code value to each predetermined signal fluctuation pattern encountered during a scan, said conversion into digital code values being performed only when a signal fluctuation pattern is determined to have been caused by the complete scanning of all the bars in a group;

accepting that digital code value as a valid representation of data encoded into a single group of bars after the same digital code value has been obtained by the above conversion step a predetermined number of times in succession; and

discontinuing the above signal conversion process after accepting a digital code value until the signal fluctuations with time are fluctuations recognizable as the scanning of the pattern that separates two groups of bars whereupon the above signal conversion process is reinitiated until all the groups of bars on the record have been scanned.

9. A method for scanning and decoding information from a coded record having a series of areas positioned along a scanning path, each area comprising two groups of segments having different characteristics which are alternated in a first direction, said groups of segments in each area are spaced out in a second direction substantially perpendicular to said first direction, the segments within each of said areas being adjacent parallel, variable-width bars, said method comprising the steps of:

scanning said record in a direction generally parallel to said second direction such that a representation of the record along a line generally perpendicular to said scanning direction is simultaneously presented of the entire variable-width bar pattern of the area being scanned;

generating a signal whose transitions with respect to time are representations of the characteristics of the bars of the area being scanned;

and converting said signal into a digital code representation of data encoded into the area of bars being scanned.

10. A coded record for reading by relative movement between the record and a reader along a path comprising,

a record member with a surface of a first light reflecting characteristic,

a series of fields representing different characters in a character set and extending along said path,

each of said fields including a plurality of areas on said surface spaced from one another along a line perpendicular to said path and having a second light reflecting characteristic, said areas being of predetermined widths and being spaced from each other by predetermined distances to define areas on said surface of said first light reflecting characteristic which have predetermined widths to provide a coded representation of a character, each of said fields including an additional area on said surface of said second light reflecting characteristic extending along said line perpendicular to said path and of a length equal to the combined widths of all of said areas of first and second light reflecting characteristics, said additional area in each of said fields being connected to said plurality of areas in the same field.

11. A hand held scanner for reading a coded record having a series of areas corresponding to different characters, said areas being positioned along a scanning path and each comprising two groups of segments having different characteristics which are alternated with one another in a direction perpendicular to said path, comprising a housing, a series of photosensitive devices arranged in a single line within said housing which is generally perpendicular to said path as said scanner is moved along said path, light source means within said housing and arranged to illuminate a coded record, and means for directing light reflected from the record along a line perpendicular to said path onto said linear array of photosensitive devices in such manner that said devices are simultaneously responsive to light reflected from different points on the record along said line.

12. The combination of claim 11, wherein said housing has a generally V-shaped cross sectional profile in a plane perpendicular to said line of photosensitive devices, whereby said housing may be tilted a substantial amount on either side of a vertical plane passing through the apex of said V so that said scanner may be used for either right hand or left hand operation.

13. The combination of claim 12, wherein said housing is provided with a narrow elongated slot along the bottom edge of said V-shaped profile for illuminating the record along a line perpendicular to said path, said linear array of photosensitive devices is positioned in a plane perpendicular to said slot, and optical means for directing light reflected from the record in the vicinity of said slot onto all of said photosensitive devices simultaneously.

14. The combination of claim 11, which includes optical means for focusing an image of the surface of the coded record along said perpendicular line onto said linear array of photosensitive devices.

15. The combination of claim 11, wherein said light source means comprises a plurality of light emitting diodes arranged to provide substantially uniform illumination of the record surface along said perpendicular line said plurality of diodes being substantially fewer in number than said series of photosensitive devices.

16. A system for interpreting a record encoded with a series of areas corresponding to different characters, said areas being positioned along a scanning path and each comprising two groups of segments having different characteristics which are alternated with one another in a direction perpendicular to said path, the segments in at least one of said groups having predetermined widths in said perpendicular direction to provide a coded representation of a character, a linear series of photosensitive devices, means for mounting said series of devices in a single line so that they may be moved as a unit along said path while said line is generally perpendicular to said path, said devices being simultaneously sensitive to light from different points on a record along said line during movement along said path, means for developing a series of electrical signals corresponding to the light received by each of said series of devices, and means responsive to said electrical signals for developing digital signals corresponding to the width of said segments.

17. The combination of claim 16, wherein said series of electrical signals are repetitively produced a number of times during relative movement over a single one of said areas, whereby successive groups of said digital signals corresponding to a single one of said characters are developed.

18. A system for interpreting a record encoded with a series of areas corresponding to encoded data positioned along a scanning path, each area comprising at least two groups of segments having different predetermined characteristics which are alternated with one another in a direction generally perpendicular to said path, the segments in at least one of said groups having variable predetermined widths in said perpendicular direction to provide a coded representation of data,

means for scanning said record in a direction generally parallel to said scanning path such that a representation of the record along said direction perpendicular to said scanning path is simultaneously presented of the entire variable width pattern of the area being scanned, and

means responsive to said scanning means for interpreting said variable width pattern record representation and for generating an electrical signal representing the pattern of variable width segments along said perpendicular direction.

19. The combination of claim 18, wherein said interpreting means comprises a linear series of photosensitive devices and said scanning means comprises means for mounting said linear array to be movable as a unit along said scanning path.

20. The combination of claim 18 wherein said scanning means further scans said record in said perpendicular direction with successive scans of said record occurring at locations spaced apart along said scanning path such that each area of segments is scanned a plurality of times.

21. The combination of claim 18 further comprising decoding means responsive to said generated electrical signal representing the pattern of said area being scanned for developing digital signals corresponding to the width of said segments whereby successive digital signals correspond to the information encoded in said area being scanned.

22. An apparatus for reading and interpreting a bar-encoded record bearing a series of substantially parallel, adjacent, scannable bars having distinctive light reflective characteristics and whose widths represent encoded data, said apparatus comprising:

light responsive means including a linear array of photodetectors for generating a signal whose amplitude fluctuations reflect the spatial variations of the incident light intensity along said array;

means for simultaneously projecting an image of the record into said array, said record image being along a line generally perpendicular to said series of bars; and

decoding means attached to said light responsive means for decoding the amplitude fluctuations of said signal into data; and

error check means for comparing successive sets of data produced by said decoding means, said error check means rejecting any data which is not successively produced by said decoding means a predetermined number of times without alteration.

23. An apparatus for reading and interpreting a bar-encoded record bearing a series of substantially parallel, adjacent, scannable bars having distinctive light reflective characteristics and whose widths represent encoded data, said apparatus comprising:

light responsive means including a linear array of photodetectors for generating a signal whose amplitude fluctuations reflect the spatial variations of the incident light intensity along said array;

means for simultaneously projecting an image of the record onto said array, said record image being along a line generally perpendicular to said series of bars; and

decoding means attached to said light responsive means for decoding the amplitude fluctuations of said signal into data; and

spot and void filter means interposed between said light responsive means and said decoding means for cancelling any fluctuation of said signal whose time duration is shorterthan a predetermined minimum value, thereby preventing small defects in the scanned record from being interpreted as encoded data.

24. A method for scanning and decoding information from a coded record having a series of areas positioned along a scanning path, each area comprising two groups of segments having different characteristics which are alternated in a first direction, said groups of segments in each area are spaced out in a second direction substantially perpendicular to said first direction, the segments within each of said areas being adjacent parallel, variable-width bars, said areas being separated by identical scannable patterns having predetermined characteristics distinguishable from the segments in any of said areas, said method comprising the steps of:

scanning said record in a direction generally parallel to said second direction such that a representation of the record along a line generally perpendicular to said scanning direction is simultaneously presented of the entire variable-width bar pattern of the area being scanned;

generating a signal whose transitions with respect to time are representations of the characteristics of the bars of the area being scanned;

converting said signal into a digital code representation of data encoded into the area of bars being scanned;

scanning and recognizing said patterns separating said areas; and

generating a signal indicating the end of an area and the beginning of the next successive area in the direction of scanning.

25. A system for interpreting a record encoded with a series of areas corresponding to encoded data positioned along a scanning path, each area comprising at least two groups of segments having different predetermined characteristics which are alternated with one another in a direction generally perpendicular to said path, the segments in at least one of said groups having variable predetermined widths in said perpendicular direction to provide a coded representation of data, said areas of said coded record being separated by identical scannable patterns having first predetermined characteristics distinguishable from those of said segments in any of said areas and having second distinguishable characteristics which are the same as those of said segments,

means for scanning said record in a direction generally parallel to said scanning path such that a representation of the record along said direction perpendicular to said scanning path is simultaneously presented of the entire variable width pattern of the area being scanned,

means responsive to said scanning means for interpreting said variable width pattern record representation and for generating an electrical signal representing the pattern of variable width segments along said perpendicular direction;

decoding means responsive to said generated electrical signal representing the pattern of said area being scanned for developing digital signals corresponding to the width of said segments whereby successive digital signals correspond to the information encoded in said area being scanned;

means for generating signals representative of said separating patterns, and

means responsive to said last named generated electrical signals for detecting the scanning of said separating patterns indicating the end of one area and the beginning of the next successive adjacent area in the scanning direction.

26. The combination of claim 25 wherein said separating pattern associated with each area includes a first separation bar connecting each of said variable width segments and extending along said direction perpendicular to said scanning path and a second separation bar having characteristics of said second type distinguishable from said first separating bar and immediately following said first separation bar and extending along said direction perpendicular to said scanning path, said detecting means further comprising:

means for generating a first separation signal upon the detection of said first separation bar of the area being scanned, said characteristic of said first type being the length or width along said perpendicular direction, said detection of said first separation bar determined by the detection of the length of said first separation bar as being greater than the width of any of the segments;

means for generating a second separation signal after the occurrence of said first separation signal and upon the detection of said second separation bar, said detection of said second separation bar determined by the detection of the length of said second separation bar as being greater than the width of any of the segments and by said second separation bar being distinghishable from said first bar, according to said characteristic of said second type, and

means responsive to said first separation signal generating means and said second separation signal generating means for generating an end of area signal to control said decoding means to initiate the scan for the next successive area of segments immediately adjacent said area previously scanned along said scanning path.

27. The combination of claim 26, wherein said decoding means further comprises means for generating an area border signal to control said detecting means to operate only within the boundaries of said areas scanned as defined by the overall width of said segments within said areas, said area border signal being generated only after at least one complete decoding of the data encoded within said variable width segment has been verified.

28. A coded record for reading by relative movement between the record and a reader along a path comprising,

a record member with a surface of a first light reflecting characteristic,

a series of fields representing different characters in a character set and extending along said path,

each of said fields including a plurality of areas on said surface spaced from one another along a line perpendicular to said path and having a second light reflecting characteristic, said areas being of predetermined widths and being spaced from each other by predetermined distances to define areas on said surface of said first light reflecting characteristic which have predetermined widths to provide a coded representation of a character, each of said fields including an additional area on said surface of said second light reflecting characteristic extending along said line perpendicular to said path and of a length equal to the combined widths of all of said areas of first and second light reflecting characteristics.

29. An apparatus for extracting information from a scannable, bar-encoded record having predetermined characteristics whereon groups of plural bars are spaced apart in a first direction, leaving a space between adjacent groups, and whereon the plural bars within each group are spaced out in a second direction substantially perpendicular to said first direction, the bars within each such group also being adjacent, parallel, variable-width bars, said apparatus comprising:

scanning means for scanning said record in a direction generally parallel to said second direction with successive scans passing over said record at locations spaced apart in said first direction such that each group of bars is scanned a plurality of times and the space between each group of bars is scanned at least once, said scanning means generating a signal whose fluctuations with time represent the width variations of the bars and spaces scanned;

decoding means attached to said scanning means for decoding the fluctuations of said signal resulting from scans across the full width of each bar in a group of bars into a data set;

a data utilization device; and

error check means accepting data sets from said decoding means for comparing successive data sets produced by said decoding means and for supplying a single data set to said data utilization device after receiving identically the same data set from said decoding means a predetermined number of times.