JP3618405B2 - Bar code information reader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information reading apparatus that reads information written on a two-dimensional barcode or the like.
[0002]
[Prior art]
Conventionally, in the field of distributing goods, there has been a demand for rationalization by various methods such as speeding up of the distribution and reduction of labor involved in work. As one of the techniques, there is an adoption of a bar code in which information such as an article name, a classification number, and a price regarding the article is pattern-coded with bars and spaces.
[0003]
A conventional barcode is called a one-dimensional barcode represented by a JAN code, and can store information of 10 to 20 digits. On the other hand, two-dimensional barcodes capable of storing information of 1,000 digits or more are now being put into practical use. One of them is a barcode system called PDF-417.
[0004]
Regarding this PDF-417 bar code, Japanese Patent Laid-Open No. 3-204793 “Nonvolatile Electro-Optical Read-Only Memory with High-Density Two-dimensional Symbol Display Method” and Japanese Patent Laid-Open No. 5-290204 “Data can be read mechanically” An apparatus and method for encoding and decoding a simple graphic shape "is known as a known technique.
[0005]
According to these publications, PDF-417 is characterized by a two-dimensional barcode as shown in FIG. 11, having a specific pattern called start / stop (start / stop) on the left and right sides of the barcode, and the above start A left / right row indicator (left / right low indicator) is located on the right / left side of each of the / stop (start / stop) patterns. However, the bar code excluding the start / stop pattern is composed of columns and rows, and is composed of a minimum block called a code word. The bar code size excluding the start / stop pattern is the above-mentioned codeword unit, with a minimum of 1 column and a maximum of 30 columns (start to stop pattern direction), a minimum of 3 rows, and a maximum of 90 rows (start and stop). Direction along the stop pattern).
[0006]
The left / right row indicator includes a row number indicating the number of rows of the row indicator, a number of rows indicating the total number of rows of the barcode, a number of columns indicating the total number of columns of the barcode, and an error correction level. Is stored repeatedly every three rows. This is shown below.
[0007]
Assuming that the number of rows of the row indicator is N, “N mod 3” represents a remainder obtained by dividing N by 3.
The left row indicator on the (N mod3 = 0) line has a line number and the number of lines.
The right row indicator on the (N mod3 = 0) line has a row number and the number of columns.
(N mod3 = 1) The left row indicator on the line has the line number and information on the security level.
The right row indicator on the (N mod3 = 1) line has a line number and the number of lines.
(N mod3 = 2) The left row indicator of the row has a row number and the number of columns.
(N mod3 = 2) The right row indicator on the line shows the line number and safety level information.
Further, in the left / right low indicator, the data code word area, and the error correction area excluding the start / stop pattern from the entire barcode, each row has clusters 0, 3, 6 in order from the top as shown in FIG. Is partitioned into three mutually exclusive subsets, each of which uses only one of the three clusters to encode the data for bar code representation. Thereby, since arbitrary adjacent rows belong to different clusters, they can be clearly distinguished.
[0008]
Furthermore, as shown in FIG. 13, even if an error correction code according to each security protection level is stored in the error correction area and information is lost due to dirt on the bar code label, an error corresponding to the safety protection level is obtained. If it is within the number of correction code words, errors can be corrected.
[0009]
Each start pattern, stop pattern, left / right row indicator, data code word / error correction code word is composed of 4 bars and 4 spaces, and is expressed by an 8-digit number such as “31111136”, for example. . Each number indicates the width of a bar (usually black) or a space (usually the base), and the “3111136” represents the barcode pattern shown in FIG. The sum of the numbers is “17”. According to this, the start pattern is expressed as “81111113” and the stop pattern is expressed as “71131112”.
[0010]
PDF-417 barcode analysis is performed as follows.
In each scan, processing for detecting a start or stop pattern is performed from a combination of bars and spaces. In the detection of the start / stop pattern, it is checked whether or not it coincides with “81111113” or “71131112” shown in FIGS.
[0011]
Thereafter, the low indicator and the code word are detected. Each row indicator stores the line number indicating the corresponding line as described above, and the line number of the adjacent code word can be known. Even if the code word of the adjacent row is read due to the deviation between the barcode and the imaging unit, the cluster is different for each row as shown above, so when reading the code word continuously from each scan, You can recognize the line correctly. Each column can correctly recognize the number of columns of the data code word from the width of the start and stop patterns.
[0012]
As described above, the column and row of each data code word can be recognized.
According to the above-mentioned Japanese Patent Application Laid-Open No. 5-290204 “Device and Method for Encoding and Decoding Data into Machine-Readable Graphical Shape”, the number of codewords read is stored in the left / right row indicator. When reading more than the number of code words that can be corrected based on the security protection level of the barcode, error correction processing is performed immediately. If the correction fails, the code word is continuously read and finally read. Read the barcode.
4). Problems to be solved by the invention (object of the present invention)
[0013]
[Problems to be solved by the invention]
However, according to the above-mentioned publication, the code word recognition and error correction processing is programmed by the CPU, but the error correction processing takes time compared to the code word recognition processing, and the number of code words read. The less it takes, the more time it takes.
[0014]
Therefore, if error correction is performed immediately after the number of read code words exceeds the number that can be corrected, there is a high possibility that error correction cannot be performed and that code word reading and error correction processing are repeated. Therefore, a great deal of time is required for the barcode reading process.
[0015]
Therefore, the present invention reads bar code information from an image including a bar code that has been taken in, and if the reading is impossible, the bar code information that speeds up bar code reading by aborting the reading process after a certain period of time. An object is to provide a reader.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an image capturing unit that captures an image including a barcode by PDF-417, a storage unit that stores an image signal captured by the image capturing unit, and an image signal read from the storage unit. In a processing apparatus having a barcode decoding unit for reading a barcode code word from the barcode and performing error correction, the total number of code words constituting the barcode to be read is compared with the number of code words successfully read, and the error Based on the accuracy of the information restored by correction, error correction is performed when the number of code words equal to or higher than a preset ratio is read, and when the number of code words successfully read is equal to or lower than the ratio, a new value is acquired from the imaging unit. Bar code information reading having reading and comparing means that picks up and reads an image and repeats until a code word exceeding the above ratio can be read To provide a location.
[0017]
In addition, an error correction is performed by reading a code word from an image signal captured by the imaging system, an imaging unit that captures an image including a barcode by PDF-417, a conveyance system that conveys a medium on which a barcode is described, and the like. In a processing apparatus having a barcode decoding unit to be applied, the total number of code words constituting the barcode to be read is compared with the number of code words that have been successfully read, and based on the accuracy of information restored by the error correction in advance. When a codeword exceeding the set ratio is read, error correction is performed. When the number of codewords successfully read is equal to or less than the ratio, the transport system is driven and a barcode on the medium is read by the imaging unit. And a reading comparison means that reads the code word and repeats until a code word exceeding the above ratio is read. Providing code information reading device.
[0018]
With the barcode information reader as described above, the code word is read as much as possible instead of error correction immediately after the number of code words read exceeds the number that can be corrected as in the prior art. Error correction processing is performed, and the time required for barcode reading is shortened. If the reading is impossible, the reading process is terminated when a preset time is exceeded.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an outline of a barcode information reading apparatus as a first embodiment. The barcode information reading apparatus includes a two-dimensional imaging unit 1 that reads a barcode 2 such as PDF-417, a data processing unit 3 that analyzes (decodes) the read barcode, and the data processing unit 3 The host device 5 is composed of a personal computer or the like that is connected via the communication line 4 and processes information decoded by analysis.
[0020]
The barcode 2 is read two-dimensionally by the two-dimensional imaging unit 1 and generated as an image signal, which is sent to the data processing unit 3 where the barcode is analyzed. The information decoded by the above analysis is sent to the host device 5 through the communication line 4. However, the description of the illumination means of the barcode 2 that may be necessary when reading is omitted.
[0021]
Next, the configuration of the data processing unit 3 will be described.
A frame memory 6 for temporarily storing image signals picked up by the two-dimensional image pickup unit 1; a CPU 7 for reading out and decoding from the frame memory; a RAM 8 for storing decoded information and data necessary for decoding; It comprises a program memory 9 for storing a program for processing performed by the CPU 7, a switch 10 for instructing the end of reading, and a timer incorporated in the CPU 7.
[0022]
With such a configuration, the image signal sequentially captured by the two-dimensional imaging unit 1 is stored in the frame memory 6 without changing the signal content, and when the image signal is read from the frame memory 6, the CPU 7 It can be read out randomly by control.
[0023]
Next, an example of the barcode by PDF-417 in this embodiment is shown in FIGS. The bar code includes a start pattern 11 and a stop pattern 12 which are continuous in the vertical direction of the bar code, a left row indicator 13 and a right row indicator 14 which are blocked in units of code words, and a data code word / error correction code word. The unit 15 is configured.
[0024]
As described in the prior art, each start pattern, stop pattern, left / right low indicator, data code word / error correction code word is composed of 4 bars and 4 spaces, such as “3111136”. Expressed with 8-digit numbers. Each number indicates the width of a bar (usually black) or a space (usually the base), and the “3111136” represents the barcode pattern shown in FIG. The sum of the numbers is “17”. According to this, the start pattern is represented as “81111113” and the stop pattern is represented as “71131112”, and the patterns are as shown in FIGS. An image picked up by the two-dimensional image pickup unit 1 is as shown in FIG. 2, but each scan is performed from left to right and from top to bottom to form a screen. Here, a scan position at a certain moment is indicated as a scan 100.
[0025]
Then, the barcode analysis of the read PDF-417 is decoded as follows. In each scan, processing for detecting a start or stop pattern from a combination of bars and spaces is performed.
[0026]
In the detection of the start / stop pattern, for example, in the case of the start pattern, it is assumed that the bar appearing on the scan is the first 8 of the above “81111113”, and the subsequent “11111113” is determined according to the width estimated from the width of 8. This is accomplished by checking whether the pattern matches. If the subsequent patterns do not match, the above-described pattern check is repeated assuming that the sequentially appearing bar is 8.
[0027]
In the case of the stop pattern, it is checked whether or not it matches “71131112” as described above. Thereafter, both the low indicator and the data code word are detected from the minimum module size of the barcode (corresponding to the number 1 representing the barcode) obtained by dividing the width of the start / stop pattern into 17 equal parts, for example. Shall.
[0028]
Hereinafter, the barcode reading operation will be described in detail with reference to the flowchart shown in FIG.
First, the image 1 imaged by the two-dimensional imaging device 1 is stored in the frame memory 6 (step S1), and then the image 2 imaged similarly is stored in the frame memory 6 (step S2). However, these images 1 and 2 are stored in different areas of the frame memory 6. In the present embodiment, the two images 1 and 2 are captured. Of course, two or more images may be captured.
[0029]
Next, when the above-described image capture is completed, start and stop patterns are detected from image 1 (steps S3 and S4), and left / right low indicators are further detected (steps S5 and S6). By this detection, it is recognized that the PDF-417 barcode is surely captured in the captured image, and the process proceeds to the next process. If even one of the processes in steps S3 to S6 cannot be detected, the process returns to step S1 and the process starts again from the capture of the image 1.
[0030]
Next, when the presence of the four patterns is recognized, the code word included in the image 1 is taken in (step S7), and the code word is stored in the matrix row as shown in FIG. Each row indicator stores the line number indicating the corresponding line as described above, and the line number of the adjacent code word can be known. Even if the data code of the adjacent row is read due to the deviation between the barcode and the imaging unit, the cluster is different for each row as shown above, so when reading the code word continuously from each scan, You can recognize the line correctly. Each column can correctly recognize the number of columns of the data code word from the width of the start and stop patterns.
[0031]
Next, when the reading of the code word is completed (step S8), the number of code words read is determined (step S9), and the number of code words is more than a certain percentage of the total number of code words originally included in the barcode. For example, if it is 90% or more, error correction processing is performed (step S12). However, if it does not reach 90% (NO), the code word is read from the image 2 (step S10), and then the same processing as that for the image 1 is performed (steps S11, S15 to S17), and the above step S12. Error correction.
[0032]
In the present embodiment, the image 2 is captured in advance before the processing of the image 1, but may be captured after the processing of the image 1 in step S9. At this time, the same barcode confirmation processing as in steps S3 to S6 may be performed.
[0033]
In step S9, 90% is set as a fixed ratio as a reference, but it is not limited and may be set to a value that is in a situation other than 90%. In addition, there is no restriction on reading codewords from image 2, but error correction may be performed when the total number of codewords read from images 1 and 2 exceeds 90%, for example. It doesn't matter.
[0034]
Next, in the determination of step S8, when reading is not finished (NO), when a reading end instruction is instructed by the switch 10, this signal is sent to the CPU 7, and the CPU 7 aborts the barcode reading process ( Steps S13 and S15).
[0035]
However, in steps S13 and S15, there is no instruction to end reading (NO), and if the reading is not completed, reading of the code word is continued for a predetermined time (steps S14 and S16). As described above, for example, if the code word cannot be read more than a certain percentage of the total number of code words even after continuing for 10 seconds or more (YES), the reading operation is terminated.
[0036]
Through the above process, barcode reading is achieved.
Next, FIG. 6 shows and describes an outline of a barcode reading apparatus as a second embodiment according to the present invention.
[0037]
This bar code information reading device is composed of an information reading device main body 21 and a host device 5 which is connected via a communication line 4 and is composed of a personal computer or the like for processing information decoded by analysis. The information reader main body 21 includes a one-dimensional imaging unit 22 that reads a barcode 2 such as PDF-417, and a conveyance system that conveys in front of the one-dimensional imaging unit 22 to read a label or the like on which the barcode 2 is written. 23, an insertion detection sensor (upstream side) 24 provided before and after (upstream and downstream) of the conveyance system 23 across the one-dimensional imaging unit 22, and a termination detection sensor (downstream side) for detecting the end of the barcode 2 25, input of detection values of the sensors 24 and 25, drive control of the one-dimensional imaging unit 22 and decoding of the read data, a switch 32 for instructing the end of reading, and the CPU 27 It consists of a built-in timer.
[0038]
The data processing unit 26 includes a CPU 27 that reads and decodes an image signal picked up by the one-dimensional image pickup unit 22, a RAM 28 that records the decoded information and data necessary for the decoding, and a program for processing performed by the CPU 27. And a program memory 29 to be stored.
[0039]
The barcode 2 is read one-dimensionally by the one-dimensional imaging unit 22 and generated as an image signal, which is sent to the data processing unit 22 where the barcode is analyzed. The information decoded by the above analysis is sent to the host device 5 through the communication line 4. However, the description of the illumination means of the barcode 2 that may be necessary when reading is omitted.
[0040]
The reading operation of the barcode reader configured in this way will be described. The image signal including the barcode 2 imaged by the one-dimensional imaging unit 22 is sent to the data processing unit 26. The sent image signal is basically not stored in the recording unit such as the RAM 28, but is processed in the order of generation of the image signal. When a new image signal is generated, the information about the previous image signal is lost. Shall be broken. Of course, depending on the processing method, an image signal captured in a recording unit such as the RAM 28 may be stored.
[0041]
The barcode 2 in the present embodiment is a barcode based on PDF-417, and is equivalent to the first embodiment. The image captured and read by the one-dimensional imaging unit 22 is virtually in the form shown in FIG. 2, but each scan is performed from left to right.
[0042]
Hereinafter, the reading operation will be described in detail with reference to the flowcharts shown in FIGS.
First, when a medium (article or the like) in which the barcode 2 is described is inserted from the insertion port 30 of the barcode reader main body 21, the insertion detection sensor 24 detects it and sends a signal to that effect to the CPU 27 (step). S21). The CPPU 27 drives the medium transport motor 31 of the transport system 23 to pass the barcode 2 through the reading position (imaging position) of the one-dimensional imaging unit 22 (step S22).
[0043]
While the barcode 2 is being transported, the start and stop patterns are detected by the one-dimensional imaging unit 22 (steps S23 and S24). Next, the left / right low indicator is detected (steps S25 and S26).
[0044]
By the above steps, it is recognized that the PDF-417 barcode is surely captured in the captured image (YES), and the process proceeds to the next process. However, if even one of the above four cannot be confirmed (NO), the medium is discharged in step S32 described later.
[0045]
Then, after the presence of the four patterns is confirmed, the code word is taken in (step S27), and the code word is stored in the column row in the matrix shown in FIG. 5 as in the first embodiment.
[0046]
When the reading of the code word is completed, the number of code words read is compared (step S28). If the number of code words is more than a certain percentage of the total number of code words originally included in the barcode, for example, 90% or more (YES), error correction processing is performed (step S33), and if it does not reach 90% (NO), the code word is read and is read until it reaches 90% or more.
[0047]
Next, when the number of code words does not reach 90% even after reading again, the bar code 2 reaches the end of the transport path 94 by the end detection sensor 25 while transporting the medium (bar code). If the end is detected (YES), the signal is sent from the end detection sensor 25 to the CPU 27, and the CPU 27 reverses the medium transport motor 31 (step S34). The process proceeds to S ″ ′ to continue reading the code word. Next, when the inverted barcode 2 reaches the end in the direction of the insertion slot 30, it is detected by the insertion detection sensor 21, and again in the same manner as described above. Invert and continue reading.
[0048]
In step S29, if the reading end instruction is instructed by the switch 32 before the barcode 2 reaches the end (step S30), this signal is sent to the CPU 27, and the CPU 27 ejects the medium and reads the barcode. Abort the reading operation.
[0049]
However, if there is no instruction to end reading in step S30 (NO) and reading is not completed, the code word reading is continued for a predetermined time (step S31), for a predetermined time or longer, for example, 10 seconds or longer. If reading continues beyond a certain percentage of the total number of code words (YES), the barcode is discharged and the reading process is terminated. Through the above process, barcode reading is achieved.
[0050]
Next, FIG. 9 shows an outline of a barcode information reading apparatus according to a third embodiment of the present invention. This bar code information reading apparatus reads a bar code by manually moving the apparatus main body that houses the imaging unit.
[0051]
The barcode information reading device main body 39 includes a one-dimensional imaging unit 33 that reads a barcode 2 such as PDF-417, a data processing unit 34 that analyzes and decodes the read barcode, and a communication with the data processing unit 34. A host apparatus 5 made of a personal computer or the like that is connected via the line 4 and processes information decoded by analysis is accommodated and integrated so as to be handheld.
[0052]
The data processing unit 34 stores a CPU 35 that decodes an image signal captured by the one-dimensional imaging unit 33, a RAM 36 that stores decoded information, data necessary for decoding, and the like, and a program for processing performed by the CPU 35. Program memory 37, a switch 38 for instructing the end of reading, and a timer incorporated in the CPU 35.
[0053]
The barcode 2 read as an image signal by the one-dimensional imaging unit a is decoded by the data processing unit 35 and the result is sent to the host device 5 through the communication line 4. Here, description of illumination means that may be necessary when reading a barcode is omitted.
[0054]
The reading operation of the barcode information reading apparatus configured as described above will be described.
The image signal captured by the one-dimensional imaging unit 33 is sent to the data processing unit 34. The sent image signal is basically stored in a memory such as the RAM 36 and processed in the order of generation of the read image signal. When a new image signal is input, information on the previous image signal, Shall be lost. Here, it is assumed that the barcode 2 is the same as that in the first embodiment.
[0055]
The barcode reading operation will be described below with reference to the flowchart shown in FIG. Here, in the present embodiment, the emission of the reading light is always performed.
[0056]
First, the one-dimensional imaging unit 33 is brought close to the barcode 2 to start reading, and start and stop patterns are detected (steps S41 and S42). Further, the left / right low indicator is detected (steps S43 and S44). If there is a pattern and a low indicator in the above step (YES), it is recognized that the barcode 2 is reliably captured in the captured image, and the process proceeds to the next process. When even one of the above four cannot be confirmed (NO), the process is continued until all four are detected.
[0057]
When the presence of the four patterns is confirmed, the code word is fetched (step S45), and the code word is stored in the column row in the matrix shown in FIG. 5 as in the first embodiment. Next, when the reading of the code word is completed, the number of code words read is determined (step S46). If the number of code words read is more than a certain percentage of the total number of code words originally included in the barcode, for example, 90% or more (YES), error correction processing is performed (step S49). However, if it does not reach 90% (NO), reading is performed until it reaches 90% or more.
[0058]
If the reading end instruction is instructed by the switch 95 without the number of code words read reaching 90% (step S47), this instruction signal is sent to the CPU 35, and the CPU 35 interrupts the reading of the bar code.
[0059]
If the number of code words does not reach 90% in step S47 and there is no instruction to end reading (NO), in step S48, the reading is continued until a predetermined time is set. If reading is not possible (NO), or if reading of the same code word occurs continuously in step S50 (NO), reading of the bar code is terminated. Bar code reading is achieved by the above process.
[0060]
Although described based on the above embodiments, the present invention includes the following inventions.
(1) In a processing apparatus comprising an imaging unit that reads a barcode by PDF-417, a storage unit that stores an image signal read by the imaging unit, and a barcode decoding unit that reads a code word from the signal and corrects an error.
Compare the total number of codewords that make up the barcode to be read with the number of successfully read codewords, compare the number of codewords with a predetermined ratio or more, and select the codeword with a predetermined ratio or more. A bar code characterized by providing means for performing error correction at the time of reading and repeating the process of reading a new image from the imaging unit and reading the code word when the number of code words read is less than a predetermined ratio Information reader.
(2) The bar according to (1) above, characterized in that when reading a new image from the imaging unit and reading a code word, a means for aborting the barcode reading process is provided when a predetermined time has elapsed. Code information reader.
(3) The barcode information reader according to (1) above, characterized in that means for aborting the barcode reading process is provided when there is a reading termination instruction.
(4) The barcode information reader according to (2) above, characterized in that means for aborting the barcode reading process is provided when there is a reading termination instruction.
(5) A bar for carrying out error correction by reading a code word from the above signal and a storage part for storing an image signal read by an image pickup part for reading a barcode by PDF-417, a conveying part for conveying a medium on which a barcode is written In a processing device comprising a code decoding unit,
Comparing the total number of code words constituting the barcode to be read with the number of successfully read code words, error correction is performed when code words exceeding a predetermined ratio are read. A bar code information reading apparatus comprising means for repeating a process of reading a new image from an imaging unit and reading a code word when the ratio is equal to or less than a predetermined ratio.
(6) The bar described in (5) above, characterized in that when reading a code word by reading a new image from the image pickup unit, means for stopping the barcode reading process when a predetermined time has elapsed is provided. Code information reader.
(7) The barcode information reader according to (5) above, characterized in that means for aborting the barcode reading process is provided when there is a reading termination instruction.
(8) Reading censored bar code information reading device.
The bar code information reading device according to the above item (6), characterized in that means for canceling the bar code reading process when provided is provided.
(9) When reading a new image from the image pickup unit and reading a code word, there is provided means for aborting the barcode reading process when a valid code word cannot be read during a predetermined time. The barcode information reading device according to (5) above.
(10) It is characterized in that when reading a code word by reading a new image from the imaging unit, a means for aborting the barcode reading process is provided when a valid code word cannot be read during a predetermined time. The barcode information reading device according to the above item (6).
(11) The present invention is characterized in that when reading a code word by reading a new image from the image pickup unit, a means for aborting the barcode reading process is provided when a valid code word cannot be read during a predetermined time. The barcode information reading device according to item (7).
(12) When reading a new image from the imaging unit and reading a code word, there is provided means for aborting the barcode reading process when a valid code word cannot be read during a predetermined time. The barcode information reading device according to the above item (8).
[0061]
【The invention's effect】
As described above in detail, according to the present invention, the time required for barcode reading can be shortened, and when reading processing is continued for a certain period of time, reading is aborted and waste can be omitted. Furthermore, the operability can be improved by providing means for aborting the reading process.
[0062]
According to the present invention, if a code word is read from an image including a captured bar code and cannot be read, the reading process is terminated when a predetermined time is exceeded, and the bar code reading speed is increased. A bar code information reading device can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a barcode information reading apparatus as a first embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of a barcode by PDF-417.
FIG. 3 is a diagram illustrating an example of a barcode pattern.
FIG. 4 is a flowchart for explaining a barcode reading operation by the barcode information reading apparatus according to the first embodiment;
FIG. 5 is a diagram illustrating a matrix for storing codewords.
FIG. 6 is a diagram showing an outline of a barcode information reading apparatus as a second embodiment according to the present invention.
FIG. 7 is a first half of a flowchart for explaining a barcode reading operation by the barcode information reading apparatus according to the second embodiment;
FIG. 8 is a second half of a flowchart for explaining a barcode reading operation by the barcode information reading apparatus according to the second embodiment;
FIG. 9 is a diagram showing an outline of a barcode information reading apparatus as a third embodiment according to the present invention.
FIG. 10 is a flowchart for explaining a barcode reading operation by the barcode information reading apparatus according to the third embodiment.
FIG. 11 is a diagram illustrating an example of a two-dimensional barcode by PDF-417.
FIG. 12 is a diagram illustrating an arrangement example of a left / right low indicator, a data codeword area, and an error correction area in a barcode.
FIG. 13 is a diagram showing the relationship of the number of error correction codewords corresponding to each safety level.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Two-dimensional imaging part, 2 ... Bar code, 3 ... Data processing part, 4 ... Communication line, 5 ... Host apparatus, 6 ... Frame memory, 7 ... CPU, 8 ... RAM, 9 ... Program memory, 10 ... Switch.

Claims (3)

An image capturing unit that captures an image including a barcode by PDF-417, a storage unit that stores an image signal captured by the image capturing unit, a barcode code word is read from the image signal read from the storage unit, and error correction is performed. In a processing apparatus having a barcode decoding unit for performing
The total number of code words constituting the barcode to be read was compared with the number of code words that were successfully read, and based on the accuracy of the information restored by the error correction, the number of code words greater than a preset ratio was read. Sometimes error correction is performed, and when the number of code words that have been successfully read is less than or equal to the ratio, a reading comparison unit that captures and reads a new image from the imaging unit and repeats until a code word greater than or equal to the ratio can be read,
A barcode information reading device further comprising: In the reading comparison means,
When the number of code words that have been successfully read is less than or equal to the above ratio, the time taken to capture a new image and to compare the read code word with the set ratio becomes a new value after a preset time has elapsed. Means for canceling the image capture and comparison process,
The barcode information reader according to claim 1, further comprising: A conveyance system that conveys a medium on which a barcode is described, an imaging unit that captures an image including a barcode by PDF-417, and a bar that performs error correction by reading a code word from an image signal captured by the imaging unit. In a processing apparatus having a code decoding unit,
Comparing the total number of code words constituting the barcode to be read with the number of code words that have been successfully read, and when reading a code word that exceeds a preset ratio based on the accuracy of information restored by the error correction, When error correction is performed and the number of code words that have been successfully read is less than or equal to the above ratio, the transport system is driven and the barcode of the medium is captured as a new image by the imaging unit, and the code word is read and the ratio is A bar code information reading apparatus, further comprising reading comparison means for repeatedly performing the above code word reading.

Images