Coded record and method of and system for interpreting the record

Claims

What is claimed and desired to be secured by Letters Patent of the United States is:

1. A coded record adapted for machine reading comprising

a record member,

and a series of segments of different first and second characteristics on said record member, the segments of first and second characteristics being alternated with each other in said series and the dimensions of the segments of both of said first and second characteristics being of more than two different values with the relative dimensions of sequentially-positioned pairs of segments providing a coded representation of a data value in which an increase in the relative widths of a sequentially-positioned pair of segments represents one binary value and a decrease in the relative widths of a sequentially-positioned pair of segments represents the opposite binary value, at least some of said segments forming a part of the coded representation of more than one data value.

2. A coded record comprising

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

a plurality of areas on said surface spaced from each other along said path and having a second light reflecting characteristic, said areas being of more than two different widths and being spaced from each other by more than two different distances to define areas of said surface of first light relecting characteristics having more than two different widths, the areas of first and second light reflecting characteristics being arranged in a sequence and the relative widths of sequentially-positioned pairs of areas providing a coded representation of a bit value in which an increase in the relative widths of a sequentially-positioned pair of segments represents one binary value and a decrease in the relative widths of a sequentially-positioned pair of segments represents the opposite binary value.

3. The coded record set forth in claim 2 in which

the width of a given area relative to the width of a preceding area in the sequence provides a coded representation of a bit value and the width of this same given area relative to the width of a following area in the sequence provides a coded representation of another bit value.

4. A coded record adapted for machine reading comprising

a record member,

and a series of segments of different first and second characteristics on said record member, the segments of first and second characteristics being alternated with each other in said series and the dimensions of the segments of both of said first and second characteristics being of more than two different values with the relative dimensions of different pairs of the segments providing coded representations of data values in which an increase in the relative widths of a sequentially-positioned pair of segments represents one binary value and a decrease in the relative widths of a sequentially-positioned pair of segments represents the opposite binary value.

5. A method of encoding a record which comprises the steps of

producing on a record a series of areas of different first and second characteristics alternating with each other,

assigning different pairs of said areas to represent different bit values to be encoded with at least some of the areas included in more than one pair,

and varying the relative sizes of the areas in said different pairs of areas in a range including more than two different sizes so that the relative sizes of the areas in each pair of areas represents a bit value to be encoded, an increase in the relative widths of a sequentially-positioned pair of areas representing one binary value and a decrease in the relative widths of a sequentially-positioned pair of areas representing the opposite binary value.

6. A method of translating records binary coded by a sequence of alternate areas of first and second light reflecting characteristics each of which can have one of more than two different widths using a light responsive reader, which method comprises the steps of

producing relative movement between the reader and the record so that the reader passes over all of the areas,

producing a sequence of digital reader-controlled signals in which each signal corresponds to the width of one of the areas, including at least a first signal, a second signal following the first signal in the sequence, and a third signal following the second signal in the sequence,

digitally comparing each two successive signals to determine the relative widths of successive areas, and in particular comparing the first signal to the second signal and comparing the second signal to the third signal,

and registering binary "1"s and "0"s in accordance with the relative widths of the successive areas.

7. A method of translating records binary coded by a sequence of alternate areas of first and second light reflecting characteristics each of which can have one of at least two different widths using a light responsive reader, which method comprises the steps of

producing relative movement between the reader and the record so that the reader passes over all of the areas,

producing a sequence of digital reader-controlled signals in which each signal is based on the width of one of the areas,

making a first digital comparison of a given signal in the sequence with a preceding signal in the sequence to determine the relative widths of the corresponding areas,

registering a digital value in dependence on the relative widths determined in the first comparison,

making a second digital comparison of said given signal with a subsequent signal in the sequence to determine the relative widths of the corresponding areas,

and registering a digital value in dependence on the relative widths determined in the second comparison.

8. A method of interpreting records encoded with a sequence of areas of alternating different characteristics in which each area can have at least two different widths using a reader responsive to the different characteristics which comprises the steps of

producing relative movement between the reader and the record so that the reader passes over all of the areas in sequence,

generating a sequence of reader-controlled signals based on the widths of the areas,

storing a pair of digital values under the control of the reader-controlled signals based on the widths of a given area and of a preceding area in the sequence,

comparing the stored digital values to determine the relative widths of said given and preceding areas,

producing a first digital weight indication in dependence on the determined relative widths of said given and preceding areas,

clearing the stored value based on the width of said preceding area,

storing a digital value under the control of the reader-controlled signals based on the width of an area subsequent to said given area in the sequence,

comparing the stored digital values to determine the relative widths of said given area and said subsequent area,

and producing a second digital weight indication in dependence on the determined relative width of said given and subsequent area.

9. A system for translating data from a record bearing alternate areas of different characteristics and different widths comprising

a reader controlled by the record and supplying a sequence of signals corresponding to the widths of the areas,

a pair of storage means controlled by the reader for storing representations of the widths of successive areas in accordance with the signals supplied by the reader,

comparing means controlled by the pair of storage means for determining the greater than and less than relations between the width representations stored in the storage means,

register means coupled to and controlled by the comparing means for storing different values in dependence on the greater than and less than relationships determined by the comparing means,

and control means operable after each comparison by the comparing means for clearing alternate ones of the two storage means to receive a representation of the next area width under the control of the reader.

10. A system for translating a binary coded record having alternate areas of different first and second light reflecting characteristics and at least two different widths comprising

a first storage means,

a second storage means,

light responsive means controlled by the record and responsive to the areas of first and second characteristics,

first control means controlled by the light responsive means and coupled to the first and second storage means for storing successive width representations of areas of the first characteristic in the first storage means and successive width representations of the areas of the second characteristic in the second storage means,

comparing means coupled to the first and second storage means for comparing the width representations stored therein, said comparing means making a comparison each time that a new representation is stored in one of the first and second storage means,

indicating means controlled by the comparing means for providing a "1" or "0" indication in accordance with the width comparison made by the comparing means,

and second control means controlled by the light responsive means and operable as successive areas are sensed for clearing alternate ones of the first and second storage means and for effecting in alternate sequence the comparison of the first and second storage means by the comparing means.

11. A system for translating records binary coded in "1"s and "0"s by pairs of areas of different relative width comprising

first and second storage means,

record reading means for reading the widths of the areas and supplying width representing signals,

gating means coupled to the record reading means and the storage means and controlled by the width representing signals for storing the values of the widths of different pairs of areas in the first and second storage means,

comparator means coupled to the first and second storage means and controlled by the values of the widths stored in the storage means to establish greater than and less than relations between the stored width values,

indicating means coupled to and controlled by the comparator means for selectively providing binary "0" and "1" indications in accordance with the established greater than and less than relationships,

and reset means controlled by the record reading means for clearing alternate ones of the first and second storage means as successive areas are read by the record reading means.

12. The system set forth in claim 11 including

a counter in each of the first and second storage means, each of said counters having an input,

a signal source supplying counter operating signals,

and the gating means renders the signal source effective to supply counter operating signals to the inputs of the counters in alternate ones of the first and second storage means.

13. A system for reading records wherein each N bit character is encoded with a sequence of at least N + 1 alternate areas of different first and second characteristics and wherein the areas have at least two different widths comprising

reader means for producing a sequence of alternate first and second signals representing the widths of the areas of first and second characteristics respectively,

first and second storage means,

a first control circuit coupled to the reader means and the first storage means and controlled by the first signals for storing values in the first storage means based on the widths of the areas of the first characteristic,

a second control circuit coupled to the reader means and the second storage means and controlled by the second signals for storing values in the second storage means based on the widths of the areas of the second characteristic,

comparing means for comparing the values in the first and second storage means to determine the relative widths of the second area using the first areas as a reference and of the first area using the second areas as a reference, said comparing means providing an output signal representing a binary "1" or "0" based on the results of the value comparison,

and resetting means controlled by the first and second signals for clearing values from alternate ones of the first and second storage means so that each area is used in two area width representations.

14. An apparatus for extracting information from a record encoded with a sequence of areas of alternate differing optical characteristics in which each area can have at least two different widths comprising

optical scanning means for scanning the record, including means for generating a binary signal whose state indicates the characteristics of the area scanned at any given moment,

timing means for generating a sequence of signals each corresponding to the amount of time which elapses between two successive reversals of said binary signal, said sequence of signals including at least a first signal, a second signal subsequent to said first signal in the sequence, and a third signal subsequent to said first and second signals in the sequence,

comparison means connecting to said timing means for comparing said first signal to said second signal and for comparing said second signal to said third signal, said comparison means including means for generating an output signal which indicates the comparison results,

and means for storing successive output signals supplied by said comparison means.

15. An apparatus for extracting information from a record encoded with a sequence of areas in which each area can have at least two different widths comprising

reader means controlled by the record for supplying a time-sequence of signals corresponding to the widths of the sequence of areas on the record, said time-sequence of signals including at least a first signal, a second signal subsequent to said first signal in said sequence of signals, and a third signal subsequent to said first and second signals in said sequence of signals,

first storage means for storing at least two of said signals,

means for feeding at least said first, second and third signals into said first storage means one after another in such a manner that as each new signal is fed into the first storage means the signal that has been stored within the first storage means for the longest time is removed from the storage means,

comparison means for comparing the signal most recently fed into said first storage means to the signal that has been stored within the first storage means for the longest time, including means for generating a digital output which indicates the result of the comparison,

second storage means for storing digital outputs,

and means for feeding the digital output of said comparison means into said second storage means each time that a new signal is fed into said first storage means by said means for feeding.

16. An apparatus in accordance with claim 15 wherein the reader means includes means for generating a first binary signal that reverses its state at the end of time intervals proportional to the width of areas, and wherein the means for feeding includes means for generating a second signal after each reversal of said binary signal and means responsive to said second signal for transferring digital data from the digital output of said comparison means into said second storage means.

17. An apparatus in accordance with claim 16 wherein the means for generating said second signal comprises first pulse generating means having said first binary signal as an input for generating a first pulse in response to a fluctuation of said first binary signal in a first direction, second pulse generating means having said first binary signal as an input for generating a second pulse in response to a fluctuation of said binary signal in a second, opposite direction, and pulse signal combining means having inputs to which said first and second pulses are applied and having an output at which said second signal appears for ORing together the pulses generated by said first and second pulse generating means to form said second signal.

18. In a system for interpreting records coded by areas of alternating characteristics and varying widths,

first and second storage means for storing representations of the widths of sequential areas,

first control means controlled by the storage means for determining the relative widths of the areas stored in the first and second storage means,

signal means providing a control signal representing the sequence of storing width representations in the first and second storage means,

and second control means coupled to and controlled by the first control means and the signal means for supplying an output signal representing code values in accordance with the determined relative widths and the sequence of stored widths.

19. A system for translating a binary coded record having alternate areas of different first and second light reflecting characteristics and at least two different widths comprising

means for optically scanning said record including means for generating a binary signal whose state indicates whether an area being scanned is of said first or said second light reflecting characteristic,

first and second storage means,

means for developing within alternate ones of said storage means signals indicating the length of time said binary signal remains in either of its states and thereby representing the widths of said alternate areas,

means for comparing the signals stored in said storage means including means for generating a digital signal indicating their relative sizes,

and means controlled by said binary signal and having said digital signal as an input for reversing the sense of the relative size data conveyed by said digital signal when said binary signal is in one of its two states.

20. A system in accordance with claim 14 wherein said means for reversing comprises an exclusive OR logic gate having said binary signal and said digital signal as input signals.

This invention relates to machine readable codes and records and, more particularly, to a new and improved record, method of making the record, and a method of and a system for translating or interpreting the record.

The need for acquiring data at, for example, a point of sale is well recognized, and many attempts have been made in the past to provide records, tags, or labels and reading and interpreting systems that are capable of being used in retail stores at the point of sale and for inventory. In this application, the records must be easily and economically made and must be such that, for example, handling by customers does not deface the coding or render the code incapable of accurate reading. Further, the record should be such that it can be read either by a portable manually manipulated reader or a stationary machine reader of low cost. Further, when the record or label is to be read by a manual reader, it should be such that the record interpretation is as independent of speed and direction of reading as is possible.

Prior approaches to this problem have used sequential areas or bars of different light reflecting characteristics in which bit value is determined by color. These records are inexpensive to produce and require somewhat more elaborate reading systems than desirable. Other techniques provide codes in bar or stylized character form with magnetic or light reflecting recordings in which absolute values in a dimension such as width are assigned to the different binary weights or values. These codes can be read serially or in parallel. The parallel codes require plural transducers which cannot be easily accommodated in a portable reader, and the magnetic recordings also are not easily read with manual or portable readers. The sequential bars of varying width are easily read using a single transducer in a portable unit but require either extensive level detection equipment or individual width timers in the interpreting system which are not easily compensated for variations in the manually controlled speed of relative movement between the reader and the record.

Accordingly, one object of the present invention is to provide a new and improved coded record.

Another object is to provide a coded record using width modulated areas in which the width of the area is not assigned an absolute binary value but provides a binary value only by comparison with the width of an adjacent area.

A further object is to provide a method of making binary coded records by varying the relative widths of consecutive areas of different characteristics in accordance with data to be encoded on the record.

Another object is to provide a method of interpreting or translating records coded in areas of varying width by comparing the widths of successive areas and establishing bit values in dependence on their relative widths.

A further object is to provide a system for reading records coded in areas of varying width including means for storing the widths of adjacent areas, means for comparing the stored widths, and means for assigning different bit weights or values in dependence on the determined relative widths.

In accordance with these and many other objects, an embodiment of the present invention comprises a record, tag, or label made, for example, of a member having a light reflective surface on which are recorded a plurality of nonreflecting bars. The widths of the nonreflecting bars and the reflecting bars disposed between and defined by the nonreflecting bars are modulated in width so that, for example, when the width of any one bar, either reflective or nonreflective, is greater than the width of the preceding bar, a binary "1" is encoded. A binary "0" is encoded whenever the width of any given bar, either reflective or nonreflective, is less than the width of the immediately preceding bar. These records can be easily produced using nothing more than conventional paper or card stock and simple coding elements either individual or in sequence for applying ink or other nonreflective material to the record. The record making apparatus can be such as to sequentially or concurrently record a plural character message, each character comprising a plurality of bits with the message preceded and followed by start and stop codes coded in the same manner as the characters of the message.

This record is interpreted by a manually held light pen including, for example, a light source for directing light onto the record and a light responsive element providing a varying output in dependence on the quantity of reflected light received from the record, although this reading assembly could as well be incorporated into a stationary record reading mechanism. The record is read by producing relative movement between the reader and the record in either a forward or backward direction requiring only that the reader pass across the entire coded message at some point along its length. The analog signal developed by the photoresponsive unit in the reader is digitized into a two-level signal representing white or black and, in dependence on the level and length of this signal, gates a free running clock into one of two counters so that at the end of two bars, either white or black, the two counters store representations of the widths of the two bars. The outputs of the counters are connected to a comparator circuit which determines the relative widths of the two bars and shifts a binary "1" or "0" into the first stage of a shift register in dependence thereon. The next transition from the reader clears one of the counters to read the next bar width into this counter, and the width of this bar is compared with the width of the previous bar which remained in storage to determine the relative widths of these two bars and to shift a binary "1" or "0" into the shift register. The other of the counters is then cleared, and the width of the next bar is stored. This continues until such time as a start code is recognized when the record is read in the forward direction or a stop code is recognized when the record is being read in a backwards or reverse direction.

More specifically, a signal source continuously reads out the contents of the shift register to a start-stop decoder as each bit is shifted into the shift register. This continues until such time as either a start or a stop code is recognized. At this time, the decoder set a storage element indicating whether the record is being read in the forward or reverse direction and shifts the mode of operation of the interpreting circuit from a scanning mode of operation to reading mode.

The next plural bit character is then read into the storage register in the manner described above using the counters and the comparator. When all of the bits of the first character of the message have been shifted into the shift register, the contents of the shift register are clocked or read out to a utilization device such as a lamp display or the input of a data processor, if the record is being read in a forward direction. If the data is being read in a reverse direction, the contents of the shift register are reversed in order, complemented, and then read out to the display or data processor. The remaining characters of the message are processed in this manner until such time as the start or stop code is detected, depending on the direction of reading. At this time, the decoding circuit returns the interpreting system from the read mode to the scan mode in preparation for reading the next message.

It should be noted that since the system is capable of correctly interpreting records read in either a forward or reverse direction, a record or label containing a plurality of messages can be scanned in any sequence or order, and the results are correctly interpreted and forwarded to display or the input to the data processor unit.

Many other objects and advantages of the present invention will become apparent from considering the following detailed description in conjunction with the drawings in which:

FIG. 1 is a schematic diagram illustrating a record embodying the present invention in conjunction with a reader and interpreting circuit therefor;

FIG. 2 is a schematic illustration of one set of codes for the digits "1-9", "0", start, and stop embodying the present invention;

FIG. 3 is a plan view of a label or record embodying the present invention;

FIG. 4 is a table illustrating timing and control signals used in the translating or interpreting circuit of the present invention;

FIG. 5 is a schematic diagram in block logic form illustrating the basic data flow in a record translating system embodying the present invention;

FIG. 6 is a logic block diagram of circuits included in the record translating system of the present invention providing forward and reverse detecting controls and error controls; and

FIG. 7 is a logical block diagram illustrating timing and display circuits provided in the record translating circuit.

Referring now more specifically to FIG. 1 of the drawings, therein is illustrated a record 10 embodying the present invention which is capable of being read or interpreted by a manual or portable reader 12, the output of which is coupled to a record translating or interpreting system 14 embodying the present invention. In the illustration of FIG. 1, an edge portion 10A of the record, tag, or label 10 is provided with a plural digit or character message preceded by a start code and followed by a stop code (not shown), all encoded in binary form in accordance with the present invention. As illustrated, the digit or character can be recorded in a character or visually recognizable form. As illustrated in FIG. 1, the message comprises five numerical digits "25672", although the message could include any variable number of digits recorded in any position on the record 10.

FIG. 2 of the drawings illustrates one set of codes embodying the present invention which provides a 3 of 6 code using four bars or areas 16A-16D defining three intervening areas or bars 18A-18C of a different characteristic. In a preferred embodiment, the bars 16A-16D are formed by printing a substantially nonreflective material, such as black ink, on the reflective surface of the record 10 so that the areas or bars 18A-18C comprise the light reflective surface of the record. The different characteristics of the bars 16A-16D and 18A-18C could also be defined by the use of different materials, such as the presence or absence of magnetic material or materials of sufficiently different light reflecting characteristics.

The widths of the bars 16 and 18 is selectively varied or modulated to encode binary "1" and "0" information. By using four bars in a 3 of 6 code, each of the bars 16 and 18 can have one of three different widths, and in a preferred embodiment, these widths can comprise 12, 18, and 27 units, respectively, which have been found to provide a more than adequate differentiation on interpretation using the reader 12 and the translating system 14. In general, the differentiation between widths on reading can be increased by increasing the difference between the narrow, middle, and wide widths with an accompanying loss of bit density or packing on the record. On the other hand, the difference in width between the narrowest width and the widest width can be reduced to increase bit density or packing with the result that differentiation between widths on interpreting becomes somewhat more difficult.

To illustrate the width coding embodying the present invention using the code for the digit one, the code assigned to this digit reading left to right is "100101", as illustrated immediately above the bars 16 and 18 in FIG. 2. Thus, the first nonreflective bar 16A is assigned a middle width, and the following reflective bar or area 18A is assigned the widest width. On interpretation, the width of the bar 18A is compared with the width of the bar 16A and found to be greater, and the system 14 recognizes this greater than relationship as denoting a binary "1" value. During record interpretation the width of the nonreflective or dark bar 16A is discarded and replaced by the width of the bar 16B as relative movement is produced by the record 10 and the reader 12. The bar 16B has a middle width which is less than the wide width of the bar 18A. The system 14 recognizes this less than relation as representing a binary "0". Since the next binary value in the code for the digit one is a binary "0", the next bar 18A is assigned the narrowest width so that when the width of this bar is compared with the middle width of the bar 16B, a less than relationship is again established to encode the binary "0". To encode the next binary "1" in the code for the digit one, the bar 16C is made of a middle width, and when compared with the narrow width of the bar 18B results in a binary "1". Similarly, the next reflective bar 18C is made of a narrow width and compared with the wider middle width of the bar 18C to result in a binary "0". The final nonreflective bar 16D is made of the middle width, which, compared with the narrow width of the bar 18C, results in a binary "1". Thus, the width modulation of the bars 16 and 18 when read in a forward direction results in the assigned 3 of 6 code "100101".

As set forth above, the message information on the record 10 provided by the code such as the code occupying the portion 10A of the record 10 can be read in either a forward or a backward direction. Obviously, when the code is read in a reverse or backward direction, the binary significance of the width modulated bars is changed, and a correct code for the digit may not be provided. This is illustrated in the coded representation of digit one in FIG. 2. The binary digits appearing adjacent the lower edges of the bars indicate that when this code is read in a reverse or backward direction as shown by the arrow, the input from the reader 12 to the system 14 considered in the direction of scanning is "010110". If this entry is reversed in order to "011010" and complemented, the code "100101" results. Thus, any width modulated code read in a backward or reverse direction can be converted to a true code by inverting and complementing the results obtained by reading the code in a reverse or backward direction.

FIG. 3 illustrates a record 20 embodying the present invention containing three separate messages 22, 24, and 26 printed in parallel, spaced relation on the record 20. Each of the messages 22, 24, 26 is preceded by a start code as shown in FIG. 2 followed by a plural digit message, each consisting of a plurality of bits encoded in accordance with the code illustrated in FIG. 2. Each of these messages is terminated by a stop code. The messages 22, 24, and 26 on the record 20 can be read all in a forward direction or all in a reverse direction, or in any intermixing of forward and reverse directions. The only requirement that must be met for correct interpretation of the record 20 and the messages 22, 24, and 26 thereof is that the relative movement between the record 20 and the reader 12 is such that each of the bars in the codes of the message passes by the reader 12.

Referring now more specifically to the logic block diagrams of FIGS. 5-7, these circuits comprise the record interpreting system 14 and are shown in simplified form in AND and OR logic. Although the system 14 is illustrated in FIGS. 5-7 in this simplified form to facilitate an understanding of the invention, an embodiment of the system 14 has been constructed in NAND and NOR logic using series 55/74 TTL logic elements manufactured and sold by Texas Instruments Incorporated of Dallas, Texas. The conversion of the illustrated AND and OR logic elements to TTL logic is well within the expected skill of a designer familar with digital logic.

Referring now more specifically to FIGS. 5-7 of the drawings, a data interpreting circuit 500 is illustrated in FIG. 5 and a sequence or status control circuit 600 which places the system 14 in either a scan mode to look for a start indication or a read mode to read message data is illustrated in FIG. 6. FIG. 6 also illustrates an error checking or detecting circuit 650 which provides an error indication whenever a received character is not provided in the desired 3 of 6 code or when the message includes more than a maximum number of characters or when the width of any area exceeds a given maximum limit. A timing circuit 700 (FIG. 7) provides certain basic timing signals used to control the operation of the system 14, and a data utilization means or display means 750 is also illustrated in FIG. 7.

When the system 14 is not actually engaged in translating a record 10, this system is in a scan mode searching for either a stop code read in a backwards or reverse direction or a start code read in a forward direction. On detection of one of these codes, the system 14 is set into its read mode to translate the data from the record 10. This status of the system 14 is basically established by a start flip-flop 610 which is set to its reset condition either by an error or the completion of the satisfactory reading of a message. In its reset condition, a start signal START is at a low or "0" level, and an inverted start signal START/ is at a high or "1" level. Throughout the drawings, an inverted signal is indicated by a "/" following the signal designation. The signal START/ is used among other purposes to reset a binary counter 668 which controls the production of an indication that an excess number o