MXPA96001809A - Simplified decoding method of codigode ba - Google Patents

Abstract

The present invention relates to a method of decoding a 2-D bar code in a bar code reader, comprising the steps of: (a) loading into said bar code reader, before the step of (b) ), a loadable correlation list that correlates decoded values of bar / space patterns for corresponding data characters, (b) selects, before step (h), between said loadable correlation list and a default correlation list available in said bar code reader; (c) reading a plurality of bar / space patterns of said 2-D bar code and deriving the corresponding sequence data; (d) processing said corresponding sequence data for a bar pattern / space to provide a representative numerical value thereof; (e) use said numerical value of step (d) as the decoded value of the bar / space pattern, if said numerical value does not exceed a predetermined number; rtir the numerical value of (d) to a corresponding number, if said numerical value exceeds the predetermined number, and use the corresponding number as the decoded value of said bar / space pattern; (g) repeat steps (d) m ( e) and (f) for other bar / space patterns of said 2-D bar code to provide the decoded values thereof, (h) use the correlation list selected in step (b) to correlate each of the plurality of decoded values as provided in steps (e), (f) and (g) for a corresponding data character, and (i) providing a decoded bar code signal representative of the corresponding data characters of the step (

Description

SIMPLIFIED BARCODE DISCQDIFICATION METHOD This invention relates to the decoding of bar code and, more particularly, to coding methods that allow for simplified processing during decoding and dynamic loading of data character sets, or both.

BACKGROUND OF THE INVENTION The use and decoding of one-dimensional bar codes is well known and such decoding can be achieved relatively simply. Various forms of two-dimensional (2-D) bar codes are also known. A 2-D bar code form designated PDF417 is described in detail in the "PDF417 Specification" authorized by the inventor herein, which was published in 1991.

[0005] Formats such as PDF417 are referenced in US Patent No. 5,264,655, issued to the present inventor on September 7, 1993. As a result of the availability of These and other documents, people with experience in this field have a relatively high level of information with respect to both coding and decoding of 2-D bar code. An improved form of 2-D bar decoding, packaged bar code, and encoding and decoding thereof is described in the North American Patent Application,. indent of the inventor of the present disclosure of Serial No. 06 / 260,490, filed on July 26, 1994, the content of which is incorporated herein by reference thereto. Typically, a 2-D bar code includes, in one form or another, a plurality of bar / space patterns, each of which represents a coded value or data character. For example, in the aforementioned Request each bar / space pattern comprises a pack consisting of a bar code 16, 4, 5. That form of identification is representative of a group of four bars and four spaces, starting with a bar , that is, a total width of 16 modules, with each bar and space without exceeding a width of 5 modules. Figure 1 shows an example of a bar code that includes 4 bars respectively of module width 4, 2, 1 and 2 and 4 spaces respectively of module width 3, 2, 1 and -? For this purpose, a "module" is a minimum unit of width. The bar / space pattern in Figure 1 can be considered for the use of different approaches. For example, an X-sequence approach considers the sequence of bar and space widths, resulting in a sequence 4, 3, 2, 2, 1, 1, 2, 1 for the pattern in Figure 1. A different approach is to consider widths based on similar edge-to-edge, which has been found more reliable in some circumstances. This approach provides a T-sequence based on pattern widths -from similar edges (that is, from the beginning of a bar to the start of the next bar and from the start of a space to the start of the next space) . On this basis, the sequence T for the bar / space pattern of Figure 1 is 7, 5, 4, 3, 2, 3, 3. The bar code coding is desirably arranged so that the T sequence is unique for each pattern of 4 bars and 4 spaces used. Figure 2 shows a table that could be used to decode a bar / space pattern. However, a code such as the packaged code referred to above uses different bar / space patterns providing 1024 different T-sequences to represent a similar number of decoded values (for example, decoded values from 0 to 1023). A decoder using the chart in Figure 2 would therefore have to make comparisons of up to 1024 table positions in order to either identify a pair that identifies the decoded value or a particular T sequence or determine that the sequence T particular is not valid due to an error, etc. As a way to decrease the time and processing that would be required with a simple match approach, a "Hashing function" has been used as a device to simplify the decoding of bar code. A Hashing function is a mathematical relationship that is used to combine all the components of a sequence T with relative weights to provide, as an output, a simple number of one or more wigits. The mathematical relationship can typically be determined on a trial-and-error basis, with the aim of selecting a relationship that has the characteristic of converting each T-sequence to a unique output number. The results of the weight of the Hashing function are illustrated in Figure 3. Thus, with reference to the first row in Figure 3, it is assumed that the sequence T shown, when each integer is multiplied by a particular weight factor, The results are summarized, and the aggregate is divided by a constant (as provided by a hypothetical Hashing function) by providing an output number "1" shown in the first column. The frame of figure 3 then cross-references the output number 1 for the first decoded value "0", shown in the last column. In this way, a specific T sequence is processed by using the Hashing function to provide the Rimero of exit 1 and the sequence T shown in the column «The board of the first row is then compared with the sequence T specified. If the sequence T q? E generates the output number is the same as the sequence T for the frame, the corresponding decoded value (0 in this example) is identified as the decoded value of the sequence T. In this case, a Unique decoded value for a specific bar / space pattern is identified by a unique output number that is reached by using the Hashing function to process the T sequence of the bar / space pattern. However, as a practical matter, a Hashing function can typically provide a unique output number for only about 60 percent of the unique bar / space patterns of a bar code coding set. For the remaining cases the same output number is duplicated for two or more different T sequences, when processed by the Hashing function. The table in Figure 3 provides the function of a Hashing table to allow the identification of the decoded value that is actually intended to correspond to each of the two or more T sequences that provide the same output number. The output number in the first column is derived from a sequence T that does not coincide with the sequence T immediately to the right of the output number. A mating is not performed and instead of the value of the column of - «. A designer in that row identifies a different row to be used for a coupling attempt. In this way, the row where the number in the first column is the output number "15", the pointer column identifies row 3. If the particular sequence T results in the output number 5 that is not identical to the sequence T included in the second column of this row, then that particular sequence T is compared to the sequence T in column 2 of row 3. If the sequence T is identical, the appropriate decoded value of the sequence T is "2" , otherwise, the sequence T is compared to identify with the sequence T shown in column 2 of row 2027 as identified in the pointer column. If it is identical, the output value for this sequence T (and its bar / space pattern) is "1021", if a coupling is not found again, then the sequence T is invalid. The invalidity can result from errors in the reading of the bar code, damage in the bar code, a defective printing of the bar code, etc. In this example the conclusion as a disability is reached because it is predetermined that only three valid T sequences result in a Hashing function output number of "5" and only the corresponding number of relevant pointers is provided. While not really shown in Figure 3, it must be understood that a different T sequence is accessed in the second column in each row of the table in Figure 3. - It should be noted that the Hashing function approach, insofar as it is More efficient than a direct comparison approach, it still requires a significant level of processing activity and time in order to identify the decoded values. As a separate consideration, in previous bar code decoding arrangements (as modeled in bar code reader units) the decoded values of bar / space patterns are converted directly into alphanumeric characters, for example, the codes are representative of the original information decoded in the bar code. In this way, the decoded value of the bar / space pattern can be "15" and this can correspond to the letter "C", for example. In a base which is predetermined and physically or by programming construction in the bar code decoder, the bar / space pattern resulting in the decoded value "15" always results in a decoder output signal ^ representative of the letter " C ". Yes, for a particular application, it may be desired subsequently to provide decoder output signals representing characters of Russian, Chinese or Greek characters, or words, phrases or symbols, for example, there is no way to change from an Arabic character set to a set of different output character, a significant level of modification of the bar code reader being absent. The objects of the present invention, therefore, are to provide bar code decoding methods characterized by one or more of the following: Decode simplified bar pattern / barcode space; -Direct the correspondence of a numerical value of a bar / space pattern of the decoded value, for most of the bar / space patterns; -Change of dynamic replacement of character game e > of output data without modification of the decoder; and -Replacement or supply of output data character set based on instructions encoded in a bar code readable by a bar code reader.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the invention, a 2-D bar code decoding method in a bar code reader comprises the following steps: (a) Loading into the bar code reader, before step (b), a loadable correlation listing that correlates the decoded values of bar / space patterns for corresponding data characters; (b) Select, before step (h), between the loadable correlation list and? n default correlation list available in the bar code reader; (c) Read a plurality of bar / space patterns of the 2-D bar code and derive the corresponding sequence data; (d) Process the sequence data corresponding to a bar / space pattern to provide a representative numerical value thereof; (e) Use the numerical value of step (d) as the decoded value of the bar / space pattern, if the numerical value does not exceed a predetermined number; (f) Converting the numerical value of step (d) to a corresponding number, if the numerical value exceeds said predetermined number, and using the corresponding number as the decoded value of the bar / space pattern; (g) Repeat steps (d), (e) and (f) for the other bar / space patterns of the 2-D bar code to provide the decoded values thereof; (h) Using the correlation list selected in step (b) to correlate one of a plurality of the decoded -'alores as provided in steps (e), (f) and (g) for a corresponding data character; (i) Providing a decoded bar code signal representative of the corresponding data characters of step (h).

BRIEF DESCRIPTION OF THE DRAWINGS - Figure 1 shows a bar / space pattern that can be one of many similar patterns included in a 2-D bar code. Figure 2 is a cross-reference frame of sequences T to decoded values of bar / space patterns. Figure 3 is a cross-reference frame of the prior art of Haßhing function values of T-sequences for corresponding T-sequences, to pointer information for resolving duplicated Hashing function values, and for decoded-bar pattern / space values. represented by the sequences T. Figure 4 is a flowchart useful for describing a method of decoding 2-D bar code according to the invention. Figure 5 is a simplified block diagram of a bar code reader arranged for use with the invention. , Figure 6 is a cross-reference frame useful for describing methods in accordance with the invention. Figure 7 is a table useful for describing default and chargeable correlation lists provided in accordance with the invention.

DESCRIPTION OF THE INVENTION - Figure 4 is a flowchart useful for describing a decoding method of a 2-D bar code according to the invention. In step 110 a chargeable correlation listing, which correlates decoded values of bar / space patterns of a bar code to corresponding data characters represented by such bar / space patterns, is loaded into a bar code reader . Figure 5 is a simplified block diagram of a bar code reader 60, which includes a scanner portion 62, a processor portion 64, a memory unit 66, and an output port 66 to make the representative signals available of data characters. The scanner portion 62 may comprise any suitable arrangement for providing signals representative of the bar / space patterns of a bar code, such as a laser scanner or other available device. The processor portion 64 is typically a microprocessor or other appropriate device designed to implement processing of representative bar / space signals utilizing bar code signal processing and known decoding techniques that are supplied or re-used as appropriate. to implement the present invention as will be described. The people working in the field are highly trained in the implementation of bar code reading and decoding and, once they have an understanding of the invention, they will be able to physically implement it in appropriate forms for various applications. The data character signals, representative of the information encoded in the bar / space patterns of a bar code, may be available at the output port 66 for coupling to a printer, further processing within a bar code reader , cable transmission, facsimile or computer interconnection network, etc. The processor 64 is desirably provided with an available default mapping list which may be stored in the memory unit 66. As previously described in the context of existing systems, after reading a bar / sparse pattern the corresponding sequence data are developed and processed to provide a numerical value which is then converted to a unique decoded value. In a typical decoder, the decoded values can take the form of a set of alphanumeric characters including numbers from 0 to 9, letters -from A to Z, and a number of additional characters. Although the current methods are different than the previously used methods, a default correlation listing can be set to correlate bar pattern / encoded space values to a similar data set to the anumeric data character. This allows the bar code reader of Figure 5 to scan a bar code 92 encoded with letters and numbers (for example "ABC123") and provides signals representative of the letters and numbers encoded in the output port 66. Referring back to step 110 in accordance with the present invention, a chargeable mapping list is loaded into a bar code reader. As a result, both a default correlation listing (e.g., correlating decoded bar / space patterns to alphanumeric characters) and a loadable correlation list will be available within the bar code reader. Depending on the particular application, the loadable mapping list may be configured to correlate decoded bar / space patterns for Russian, Chinese or Greek characters for English words or phrases, for numeric symbols, for diagram symbols or other types of characters. As used herein, (data character) is defined to encompass a wide range of letters, numbers, words and other data, texts and symbolic items as may be desired - for communication. It will be appreciated therefore that in the coding process a given bar / space pattern representative of the word "electron", for example, can be included in a bar code. Then, during decoding, by using a chargeable correlation list that correlates the given bar / space pattern, as read, with the "electron" character, the output signal provided by the bar code reader will be representative "" "" A ", and perceptible in further processing, such as the word" electron. "A variety of arrangements for loading a loadable correlation list into a bar code reader are available in the prior art. of the invention, a currently preferred charging method comprises encoding the loadable correlation state within a bar code, with proper identification and application instructions also encoded within the bar code.The bar code reader has the ability to read and decoding this bar code and the processor unit is arranged to recognize and store the loadable correlation list for future use, said load may be use of the default correlation list that is already available within the memory unit. bar code can be arranged to automatically use a loadable correlation list, when one is available, or it may be arranged to allow user selection between the loadable and default correlation lists. It will also be appreciated that a loadable mapping list may be configured to provide data characters corresponding only to some of the total complement of usable bar / space patterns, so that the default mapping list is used for the remaining patterns. For example, a loadable mapping list may include foreign language characters correlated to the bar / space patterns used for the alphabetical portion of the default correlation list, but not correlated characters in the bar / space patterns used for the portion number of the default correlation list The default correlation list will continue to be used for numeric characters, although a loadable correlation list is available for use for language characters, in this example. a loadable correlation listing loaded in step 110 and a default correlation list available in the bar code reader As noted, the bar code reader can automatically use a loadable correlation listing, if available in the reader, or the provn can be made for user selection. step 130, the bar code reader is activated to read a plurality of bar / space patterns of a bar code to be decoded and derive sequence data i Corresponding (eg T sequences as previously described). In step 140 the sequence data for bar / space pattern is processed to provide a numerical value representative thereof; according to the invention, however, instead of the approach of the Hashing function previously used, a different form of processing of sequence data T is used. As noted before, * * * Hashing references are derived to cover the goal of converting as many unique T sequences as possible into unique output numbers, in order to minimize the sequence number T that are converted into duplicate output numbers. In this way, the previous objective was to avoid the additional processing necessary to resolve ambiguities where the different T sequences result in the same output number. In the previous use of the Hashing functions, the output number of the Hashing function for each sequence T was converted to a decoded value as shown in the column to the right of the table in figure 3. In comparison, in the application of the present invention a processing function is derived to provide the data processing characteristic of sequence T to derive representative numerical values without duplicate numerical values at or below a predetermined number (for example, there are no ambiguities of numerical value at or below the number 1023 for the package bar code described (internally). The source code for the application of an appropriate processing function for decoding in accordance with the invention is provided below under the heading "PROCESSING FUNCTION". The results of the decoding with the use of this processing function are illustrated in Figure 6. Figure 6 illustrates a cross-reference frame between numerical values of (a) shown in the first column, which are provided by the use of ~ processing function to process sequence data of bar / space pattern T, and (b) correlate decoded values of bar / space patterns, as represented in the second column. As indicated, for numerical values that do not exceed the predetermined number 1023, the numerical value is simply used as the decoded value, so that cross-reference or conversion is not really required. In this way, the need for further processing of the prior art to go from a Hashing function output number in the first column of Figure 3 to a decoded value in the last column of Figure 3 is avoided. With reference to the Figure 6 it will be appreciated that the current processing function is not effective to process each T sequence directly into a final decoded value, so that no T sequence will be converted directly into a decoded value of 1022, for example. The processing function used in the source code as listed is, however, effective for processing the unique 1024 sequences T for the packet bar code to provide 999 numerical values directly usable as decoded values in the range from 0 to 1023 , as shown in the upper portion "A" of the table in figure 6. This leaves only 25 numerical values of sequence T that exceed the predetermined number of 1023. As indicated in the lower portion "B" of the figure box 6, those 25 T sequences were processed by using the processing function to provide a scale of numerical values that exceed the predetermined maximum number 1023 and which can therefore be converted to a corresponding number that is one of the missing decoded values in the A portion of the table (for example, the decoded value 1022, for example). The table in figure 6 is provided by way of example and does not correspond to the specific results obtained by using the source code of the listed processing function 16 It is effective to directly process 999 of the 1024 unique T sequences into the appropriate decoded values. Referring to Figure 4, in step 150 the method proceeds as described above. If the numerical value provided by the processing of a sequence T does not exceed the predetermined number 1023, in this example, in step 160 the numerical value is used as the decoded value of the bar / space pattern. In step 170, if the numerical value exceeds the predetermined number 1023 it is converted to a corresponding number (for example one of the missing numbers in the portion A of figure 6) and that the corresponding number is used as the decoded value of the pattern of bar / space. In step 160, if additional bar / space patterns remain to be decoded steps 140 to 170 ß repeat to provide the decoded values for each such additional pattern. In step 190, a correlation listing is used to correlate each decoded value to a corresponding data character. As described, a bar code reader may have both a default correlation listing and a loadable correlation list available. The default mapping list can be stored desirably in the bar code reader's memory before the reader leaves the factory. In accordance with a currently preferred embodiment, a loadable correlation listing can be accessed in the field or anywhere by the use of a properly encoded 2-D bar code to provide a character set of data more efficiently adapted for a use particular or type of application of a specific bar code reader. As shown in Figure 7, the decoded values of the 1024 unique bar / space patterns are listed in column A and the corresponding data characters of a default correlation list are listed in column B.? Loadable mapping list, one example of which is shown in column C, the bar code reader has the ability to respond directly to appropriately encoded 2-D bar codes to provide output signals representative of data characters such as letters Greek words and complete words, for example. As shown, column C does not include data characters in the initial rows, so data characters would be used / enter default 0, 1, 2, 3, etc. Alternatively, the loadable correlation list in column C can repeat the characters 0, 1, 2, 3 or substitute other characters. As noted, the bar code reader may be configured to automatically use the characters of a loadable correlation list, when present, or the selection between the default correlation listing and the chargeable one may be determined by the user. In step 200, a decoded bar code signal representative of the data characters is viewed (at the output port 66 in Figure 5, for example), for printing, transmission or other use. Through the adequate provision of a loadable correlation list of data characters directly usable by a computer placed to execute specialized data processing, complex or specialized data can be communicated in a very efficient manner to such a computer. The present invention provides flexibility to refer to specialized applications by enabling sets of data character accommodated to be loaded dynamically in the field. With reference to Figure 5, bar code scanner 60 can thus be used to read a bar code 90 encoded to use a normal form of alphanumeric data character set by means of a default correlation listing available on a normal base within the bar code reader. The bar code 7 may comprise coded alphanumeric data intended for normal decoding for later use, or may comprise a loadable correlation listing, with identification and appropriate instructions, to be read by the reader and stored for use. In the latter case, bar code 92 may comprise encoded data compatible with a set of accommodated data character represented by the loadable correlation listing. The invention thus provides improved capabilities and efficiencies for the use of data character sets which may be designed to include characters in the form of symbols, mathematical relationships, words, phrases, etc., selected for particular applications, and which may be dynamically loaded inside the bar code reader without the need for modifications of the installed factory. The invention as described is applicable for use with a variety of forms of 2-D bar codes, which includes the package bar code referred to above. ^ package bar code as described in the pending pending application uses individual packages including each two bar / space patterns. Each bar / space pattern can be of the type shown in Figure 1, with one bar / space pattern representing one piece of data and the other representing instructions (such as the address of the data portion in a data stream) in relation to the data portion. In the context of decoding a packet bar, steps 130 to 160 of FIG. 4 are typically executed for each instruction of the bar / space pattern independently in parallel or in series with the processing of bar patterns / data space representative of the data characters in the manner previously described with reference to Figure 4. Therefore, while the bar / space patterns represent data and are correlated with the data characters according to the present invention, the patterns Bar / space instruction provide information used to perform the placement of the bar / data code patterns or for other purposes. In a pack bar code application, for example, the initial packets will typically include information and instructions regarding the parameters of the bar code (such as the total number of packets and the error correction protocol) and may also include information regarding the particular correlation listing that is used in step 190. In the application of the invention, it will therefore be understood that steps 110 and 120 of the flow chart of figure 4 can actually be implemented at a point before the step 190. For example, it is assumed that a particular user of a bar code reader is prepared to execute a series of bar code readings as part of an inventory of a store of articles each having a bar code 2 -D. The user can simply set the Ví tor in step 120 to select a loadable correlation listing, previously loaded. The selected correlation listing may include data characters accommodated to provide instructions on how the data in each type of inventory will be accessed in the inventory database. Alternatively, as noted with reference to the package bar code, the bar code itself may include instructions for the selection of several pre-loaded, loadable correlation lists, which will be implemented without requiring any action on the part of the user. , therefore, step 110 may be executed before step 120 (unless the loadable correlation listing is provided, so that in step 120 the bar code reader only selects the default mapping list) . However, step 120 can be set to be implemented at any time before step 190. With an understanding of the invention, many variations and combinations, which may involve other known things (such as storage of decoded values before the correlation of data characters) will become apparent for people experienced in different applications., in the method illustrated in Figure 4 the processing of the additional T sequences to provide decoded values, in steps 140-170 can be carried out in series as indicated, or one or more of the T sequences can be processed in parallel.

PROCESSING NCI0N / * Metanetics Corporation (C) 1994 * / / # SuperCode tseq decoder: t_decode * / / return value C0..10231 for valid codeword return value -1 for invalid codeword. odd parity check required before callipg this routine. * / int t_tableC263 = < 22, 115, 140, 146, 179, 166, 196, 206, 226, 366, 395, 469, 562, 573, 707, 706, 755, 605, 624, 676, 665, 920, 951, -1,971, 97ß >; int t_ decode (char * t) • C / * map the t-seq into 0..1023 * / í int i, valué; valué = tC03; for (i = l; i < 6; i ++). { valué = valué < < 3; value + = tCil; if (value > = 1069) -Cvalue% = 1069; > J if (value> = 1024K if (I value <1050) valué = t_tableEvalue - 10243; else value = -1;> return value> > Metanetics Corp. 1994.

While the presently preferred embodiments of the invention have been described, those skilled in the art The technique will recognize that further modifications may be made without departing from the invention and it is intended to claim all modifications and variations as they fall within the scope of the invention.

Claims (7)

NOVELTY OF THE INVENTION CLAIMS

1. - A method of decoding a 2-D bar code in a bar code reader, comprising the steps of: (a) loading into said bar code reader, before step (b), a list of Loadable correlation that correlates decoded values of? arra / space patterns for corresponding data characters; (b) selecting, before step (h), between said loadable correlation list and a default correlation list available in said bar code reader; (c) reading a plurality of bar / space patterns of said 2-D bar code and deriving the corresponding sequence data; (d) processing said corresponding sequence data for a bar / space pattern to provide a numerical value (> present thereof) (e) use said numerical value of step (d) as the decoded value of the bar / space pattern, if said numerical value does not exceed a predetermined number; (f) convert the numerical value of the < d) to a corresponding number, if said numerical value exceeds the predetermined number, and use the corresponding number as the decoded value of said bar / space pattern; (g) repeating steps (d), (e) and (f) for other bar / space patterns of said 2-D bar code to provide the decoded values thereof, (h) using the selected correlation list in step (b) for correlating each of the plurality of decoded values as provided in steps (e), (f) and (g) for a corresponding data character; and (i) providing a decoded bar code signal representative of the corresponding data characters of step (h). 2.- A decoding method of a 2-D bar code according to claim 1, characterized < emás because step (a) comprises loading said loadable correlation list by reading a 2-D bar code containing said loadable correlation list in encoded form. 3. A decoding method of a 2-D bar code according to claim 1, further characterized in that step (a) comprises loading a plurality of said loadable correlation lists and step (b) d *. select between said loadable correlation lists and the default correlation list. 4. A decoding method of a 2-D bar code according to claim 1, further characterized in that step (c) comprises deriving T sequences corresponding to said bar / space patterns. 5. A method of decoding a 2-D bar code according to claim 1, further characterized in that said bar code 2-D is a bar code width of 16 modules, which includes 4 bars and 4 spaces _. * gives one of up to 5 modules in width, and said predetermined number in steps (e) and (f) is 1023. 6.- A method of decoding a 2-D bar code according to claim 1. , further characterized in that said bar code comprises bar / data space patterns representative of data characters and bar patterns / instruction space representative of information related to said bar / table space patterns, and steps (h ) and (i) are executed only with respect to a plurality of decoded values provided from said bar / data space patterns. 7. A decoding method of a 2-D bar code according to claim 6, further characterized in that it includes the next step between steps (g) and (h): (x) using decoded values of said patterns bar / instruction space to provide information used • control the processing of said bar / data space patterns in the bar code reader. 6. A method of decoding a 2-D bar code in a bar code reader, further characterized in that it comprises the steps of: (a) loading in the bar code reader, before step (f), a chargeable correlation list that correlates the decoded values of bar / space patterns for corresponding data characters; (b> read a plurality of patterns of 26 bar / space of said 2-D bar code and derive the corresponding sequence data; (c) processing said sequence data corresponding to a bar / space pattern to provide a representative numerical value thereof; (d > use said numerical value of the step (c> to provide a decoded value for said bar / space pattern; (e) repeat steps (c) and (d) for other bar / space patterns of said code bar to provide decoded values thereof, and (f) using said correlation list to correlate each of the pluralities of said decoded values as provided in steps (d) and (e) for a corresponding data character. .- A method according to claim 6, further characterized in that step (f) comprises: (f) selectively using one of said loadable correlation lists and one by default in said bar code reader, to correlate each of a plurality of encoded values as provided in steps (d) and (e) for a corresponding data character 10. A decoding method of a 2-D bar code according to claim f, character Furthermore, step (a) comprises loading said loadable correlation list by reading a 2-D bar code containing said loadable correlation list in coded form. 11. A decoding method of a 2-D bar code according to claim 6, characterized in that step (b) comprises deriving T sequences corresponding to said bar / space patterns. 1

2. A decoding method of a 2-D bar code according to claim 6, further characterized in that said 2-D bar code is a bar code of 16 modules width, which includes 4 bars and 4 spaces each of up to 5 modules wide. 13.- A method of decoding a code of *** ^ rr 2-D according to claim 6, further characterized in that said bar code comprises bar / data space patterns representative of data characters and bar patterns / instruction space representative of the related information of said bar / data space patterns, and step (f) is executed only with respect to a plurality of decoded values provided from said bar / data space patterns. 14. A decoding method of a 2-D bar code according to claim 13, further characterized in that it includes the next step between steps (e) and (f): (x) using decoded values of said patterns of bar / instruction space to provide information used to control the processing of said bar / data space patterns in the bar code reader. 15. A method of decoding a 2-D bar code in a bar code reader, comprising the? Dso5 of: (a) reading a plurality of bar / space patterns of a bar code and deriving the corresponding sequence data; (b) processing said sequence data corresponding to a bar / space pattern to provide a representative numerical value thereof; (c) using said numerical value of step (d) as the decoded value of said bar / space pattern, if said numerical value does not exceed a predetermined number; (d) converting the value of step (b) to a corresponding number, if said numerical value exceeds said predetermined number, and using the corresponding number as the decoded value of said bar / space pattern; and (e) repeating steps (b), (c) and (d) for other bar / space patterns of said bar code to provide the decoded values thereof. 16. A method of decoding a 2-D bar code according to claim 15, characterized in that it comprises the following steps: (f) using a correlation list available in said bar code reader to correlate One of the decoded values as given in steps (c), (d) and (e) for a corresponding data character; and (g) providing a decoded bar code signal representative of the corresponding data characters from step (f). 17. A decoding method of a 2-D bar code according to claim 15, further characterized in that step (a) comprises deriving T sequences corresponding to said bar / space patterns. 16. A decoding method of a 2-D bar code according to claim 15, further characterized in that said 2-D bar code is a bar code of 16 modules width, which includes 4 bars and 4 spaces each of up to 5 modules wide, and said predetermined number in steps (c) and (d) is 102

3. __ 19.- A decoding method of a 2-D bar code according to claim 16, characterized furthermore because said bar code comprises bar / data space patterns representative of data characters and bar patterns / instruction space representative of the information relating to bar / data space patterns, and steps (f) and (g) are executed only with respect to a plurality of valued / ized values provided from said bar / data space patterns. 20. A decoding method of a 2-D bar code according to claim 19, further characterized in that it includes the next step between steps (e) and (f): (x) using decoded values of said patterns of bar / instruction space for providing information used to control the processing of said bar / data space patterns in said bar code reader. 21. A method of decoding a 2-D bar code in a bar code reader comprising the steps of: (a) loading into said bar code reader, before step < g), a chargeable correlation list that correlates the decoded values of bar / space patterns for corresponding data characters; (b) reading a plurality of bar / space patterns of said 2-D bar code and deriving Corresponding sequence data; (c) processing said corresponding sequence data for a bar / space pattern to provide a numerical value representing it; (d> using said numerical value of step (c) as the decoded value of said bar / space pattern, if said numerical value does not exceed a predetermined number, (e) converting said numerical value from step (c) to a corresponding number, if said numerical value e? yields the value of the predeter- mined number, and .fiize the corresponding number as the decoded value of the bar / space pattern; (f) repeat steps (c), (d) and (e) for other bar / space patterns of said bar code to provide decoded values thereof, and <g> to use the correlation listing to correlate each of the decoded values as provided in steps (d) , (e) and (f) for a corresponding data character 22. A decoding method of a 2-D bar code according to claim 21, further characterized in that step < a) comprises loading the list of chargeable correlation by reading of a 2-D bar code that contains the loadable correlation list in coded form. 23. A decoding method of a 2-D bar code according to claim 21, further characterized in that step (b) comprises deriving T sequences corresponding to the bar / space patterns. 2

4. A method of decoding a 2-D bar code according to claim 21, further characterized in that said 2-D bar code is a bar code of 16 modules in width, which includes 4 bars and 4 spaces each of up to 5 modules wide, and said predetermined number in steps (d) and (e) is 1023. 25.- A method of decoding a 2-D bar code in accordance with claim 21, further characterized in that the bar code comprises i bar tones / data space representative of the data characters and bar patterns / instruction space representative of the information that relates to the bar / data space patterns and the step (g) is executed only with respect to a plurality of decoded values provided from said bar / data space patterns. 26. A decoding method of a 2-D bar code according to claim 25, further characterized by including the next step between the p «? Sos (f) and (g): (x) using the decoded values of said bar patterns / instruction space to provide information used to control the processing of bar patterns / data space in said bar code reader. SIMPLIFIED BARCODE DISCQDIFICATION METHOD SUMMARY OF THE INVENTION The reading and decoding of 2-dimensional bar codes in a bar code reader is simplified and the loading in the field of different data character sets is allowed; the decoding of bar / space patterns of a bar code is simplified by deriving the sequence numbers T representative of the bar / space pattern and then processing a majority of the T sequences directly into decoded values representative of the bar / space pattern; Dynamic loading of new data character sets partially or fully evicts an installed factory with default character set mapping status and is allowed throthe use of loadable correlation lists typed for characters. foreign language, symbols, words or phrases relevant to particular applications; the loadable correlation listings can be encoded in a 2-dimensional bar code and loaded by means of a bar code reading by the bar code reader. RM / cpm * crm *