JPH06266881A - Bar code symbol reader - Google Patents

Abstract

PURPOSE:To provide a bar code symbol reader capable of executing high speed processing even by using an one-dimensional(1-D) image pickup device. CONSTITUTION:A pulse width counting circuit 310 counts up the width of bars and spaces on a bar code symbol 100 from an image pickup signal outputted from a 1-D CCD array 302 and a pulse data counter 318B counts up the numbers of bars and spaces whose width is counted by the circuit 310. A comparator 318D compares the number counted by the counter 318B with a threshold stored in a threshold register 318C, and only when the number counted by the counter 318B is larger than the threshold stored in the register 318C as the result of the comparison, a high speed arithmetic circuit 318A executes decoding processing by using the width of bars and spaces counted by the circuit 310.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code symbol reading device for reading a bar code symbol,
In particular, it relates to a data processing method in such a bar code symbol reader.

[0002]

2. Description of the Related Art At present, bar code symbols are used in many countries, and the types thereof are very large. Typical bar code symbols are JAN / UPC / EAN code, ITF (Interleaved 2 of 5) code, CODE
39, NW-7 code, CODE128, etc. In addition, recently, two-dimensional bar code symbols having a large amount of information and a high recording density have begun to be proposed due to demands for expressing more information, sticking in a narrower space, and the like. As such a two-dimensional barcode symbol,
CODE16K, CODE49, PDF417, DAT
A CODE, VERI CODE, OFSTR
There are P, etc.

On the other hand, JAN / UPC / EAN code, I
TF (Interleaved 2 of 5) code, CODE39, N
There are many types of devices for reading W-7 code, CODE128, etc. (called one-dimensional barcode symbol for two-dimensional barcode symbol), and typical types are pen type, touch type, laser type. There is. On the other hand, there are few types of devices for reading the two-dimensional bar code symbol, and the reading technique is not yet established.

However, the basic method of reading a barcode symbol is almost the same as in the case of a conventional one-dimensional barcode even in the case of a two-dimensional barcode symbol. That is, the barcode symbol is irradiated with light from the light source, and the light reflected by the barcode symbol is focused on the light receiving element inside the reading device. Then, the condensed signal is decoded by an electric circuit configured by a microcomputer or the like to read the bar code symbol.

FIG. 12 is an external view of a two-dimensional bar code symbol reader. This barcode symbol reading device is composed of a camera stand 900 and a decoder box 902. The camera stand 900 includes a video camera 904 and a column 9 that supports the video camera 904.
06, and a base plate 910 on which a sheet or a product on which the barcode symbol 908 is recorded is placed. Further, the decoder box 902 receives the output of the video camera 904, detects the position of the bar code symbol 908 from the output signal, decodes the recorded contents, and outputs the bar code symbol 908 to the host computer 912 or a terminal device (not shown). The recorded contents of are transferred. The camera stand 900 and the decoder box 902 are connected by the camera cable 914. The monitor 916 also displays the barcode symbol 9
08 is for checking the image pickup state, and is connected to the decoder box 902.

However, in such a two-dimensional bar code symbol reader, the sheet on which the bar code symbol 908 is recorded is placed on the base plate 910 and the video camera 9 is used.
At 04, the image including the barcode symbol 908 is captured, and at the decoder box 902, the barcode symbol 90 is read.
8 is to read the contents, the device is very large,
It is expensive. Further, the sheet on which the bar code symbol 908 is recorded has poor portability and is difficult to operate with the reading device.

Recently, magnetic cards, IC cards,
Optical cards and the like in which a bar code is printed or pasted on a card-shaped medium are also beginning to be used. This barcode card has good portability and is expected to spread rapidly in the future.

Generally, a reading device such as a magnetic card is of a type in which an operator manually slides the card in a slit to read the recorded contents, and is generally called a swipe type card reader. There is also a so-called time card system in which the operator inserts / ejects the card into / from the insertion slot of the card reader to read the contents, and this is generally called a dip type card reader. These swipe-type card readers and dip-type card readers are both small and inexpensive, and of course, a device for reading a card on which a two-dimensional barcode symbol is printed or attached is also required to be a small and inexpensive device. It seems to be done.

[0009]

The use of the video camera 904 as shown in FIG. 12 causes an increase in the size and cost of the apparatus, and therefore an apparatus for reading a card on which a two-dimensional bar code symbol is printed or attached is used. In order to make the device small and inexpensive, it is conceivable to use a one-dimensional imaging device to read the two-dimensional bar code symbol line by line.

However, when the one-dimensional image pickup device is used, it is impossible to distinguish the bar code symbol from other than the bar code symbol such as characters and figures. Therefore, if a character or the like is imaged before the barcode symbol, the black-and-white pattern of the character is decoded as the barcode symbol before the actual decoding of the barcode symbol, resulting in unnecessary decoding time, and as a result, This means that it takes a lot of time to finish decoding the barcode symbol.

The present invention has been made in view of the above points, and an object of the present invention is to provide a bar code symbol reading device capable of reading a bar code symbol in a short time even when using a one-dimensional image pickup device. To do.

[0012]

In order to achieve the above object, a bar code symbol reading apparatus according to the present invention comprises an image pickup means for picking up an image of a bar code symbol by a one-dimensional image pickup apparatus and an image pickup signal from the image pickup means. The width counting means for counting the widths of the bars and spaces of the barcode symbol, the number counting means for counting the number of bars and spaces whose widths have been counted by the width counting means, and the number counted by the number counting means are It is characterized by comprising control means for permitting use of the width of the bar and space counted by the width counting means in the subsequent processing only when the width is larger than a predetermined value.

[0013]

That is, in the bar code symbol reading apparatus of the present invention, the width of the bar and space is counted by the width counting means from the image signal of the bar code symbol by the one-dimensional image pickup apparatus, and the counted bar and The number of spaces is counted. Then, the control means compares the number of bars and spaces with a predetermined value, and when the number is larger than a predetermined value, the width of the bar and space by the width counting means is set to the following bar code. Allowed for processing to read the contents of the symbol.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. (First embodiment)

FIG. 1A shows a bar code symbol reading apparatus of this embodiment (hereinafter referred to as a card reader).
2 is an external view of a system using the card reader of the present embodiment, and FIG.
It is a symbol structure figure of PDF417 as an example of a two-dimensional barcode symbol.

A system using a card reader is shown in FIG.
As shown in FIG. 2, a card 200 on which a barcode symbol 100 is printed or pasted, a card reader 30
0, host computer 400, and card reader 30
0 to connect the host computer 400 to the cable 50
It is composed of 0s.

Here, the card reader 300 uses the card 2
00 is slid on the slit 300S in the direction of the arrow, the content of the barcode symbol 100 is read, and the recorded content of the barcode symbol 100 is transferred to the host computer 400 or a terminal device (not shown). The card reader 300 incorporates an electric circuit as shown in FIG. In addition, this card reader 30
Various LEDs 300L indicating the operating state of the card reader 300 are incorporated in the LED 0.

Note that a card reader of the type in which the operator manually slides the card through the slit to read the recorded contents is often found in magnetic card readers and the like, and is generally called a swipe type card reader. Has been. Next, the configuration of the card reader 300 will be described with reference to FIG.

The card reader 300 includes a linear sensor (1
Barcode symbol 1 using DCCD array 302
The contents of 00 are read. That is, the card reader 300 includes a 1D CCD array 302, a CCD driver 304, a CCD amplifier 306, a binarization circuit 308, a pulse width counting circuit 310, a first-in-first-out (FIFO) memory 312, and a width memory 31.
4, initialization scan data memory 316, data processing circuit 318, host interface circuit 320, counter 322, marker write circuit “S” 324, insertion detection sensor 326, ejection detection sensor 328, marker write circuit “O” 330, and various types. It is composed of an LED 300L.

Here, the CCD driver 304 is a 1D
A clock signal is supplied to the CCD array 302, and the CCD amplifier 306 amplifies the output of the 1DCCD array 33. The binarization circuit 308 binarizes the output of the CCD amplifier 306, and the pulse width counting circuit 310 counts bars and spaces in the output signal of the binarization circuit 308 with a certain clock. The FIFO memory 312 stores the width information counted by the pulse width counting circuit 310.

The width memory 314 is the FIFO memory 3 described above.
The width data string for one scan read from 12 is stored. Further, the initialization scan data memory 316 stores the width data string of each scan until the size in the row direction and the column direction of the PDF417 barcode symbol described later and the security level are determined.

The data processing circuit 318 is used by the card reader 3
00, which controls the entire processing, and as shown in FIG. 1B, a high-speed arithmetic circuit 318A for performing various kinds of processing described later, width data for counting the number of width data columns of each scan. A number counter 318B, a threshold register 318C for storing a threshold value of the number of width data strings, and a number of width data strings of the width data number counter 318B and a threshold stored in the threshold register 318C. It is composed of a comparison circuit 318D for comparing with a value.

The host interface circuit 320 is for transferring the contents of the bar code symbol 100 to the host computer 400 of FIG. 2 or a terminal device (not shown).

The counter 322 is a 1DCCD supplied from the 1DCCD array 302 to the CCD amplifier 306.
The number of pixel data in the array 306 is counted, and the marker write circuit “S” 324 receives the output of the counter 322 and outputs a special marker for each scan to the FIFO memory 31.
Store in 2.

The insertion detection sensor 326 is used for the card 2
00 is for detecting that it has reached the image pickup position of the 1D CCD array 302, and is composed of a photo interrupter or the like. The discharge detection sensor 328 has only one card 200.
This is for detecting that the image pickup position of the DCCD array 302 has been removed, and is composed of a photo interrupter or the like. The marker write circuit “O” 330 receives the output of the discharge detection sensor 328 and stores a special marker in the FIFO memory 312. The LED 300L is for indicating the operating state of the card reader 300.

Next, the symbol structure of the bar code symbol 100 will be briefly described. Here, a two-dimensional barcode symbol PDF417 is used as the barcode symbol 100.
Is used. FIG. 3 shows the label structure of the PDF417.

The bar code symbol 100 is a label portion 1 which is an area of an information component to be decoded which is composed of a bar code character group consisting of a combination of a bar and a space.
02 and start code 104 and stop code 1 which are start / stop characters arranged before and after the character 02.
06 and. And one code is composed of four bars and a space except for the stop code 106. The stop code 106 consists of 5 bars and 4 spaces. Also, the start and stop codes 104 and 106 start from large bars 104A and 106A called "big bars".

The label portion 102 has a start code 104.
And a label matrix 102C consisting of a code called a row indicator 102A existing next to the stop code 106 and at least one data column 102B in which actual data sandwiched between them is described.
Composed of and. 4 in this data column 102B
A character consisting of two bars and a space is called a data character. Here, the row indicator 102A existing next to the stop code 106 can be omitted, and the stop code 106 can be replaced by only one bar. Row indicator 10
2A includes a label row size, a column size, a security level, and the row indicator 102.
The address indicating that A is the row number is described. The security level is a level of error correction capability of the PDF417, and has nine levels. There are 9 levels from security level 0 where error correction is not possible to security level 8 where error correction is possible even if 510 data characters cannot be read normally. Therefore, if the information of the row indicator 102A is decoded, the barcode symbol 1
The information size of 00 can be determined. In addition, this FIG.
It shows a bar code symbol with a 4x2 label matrix (i.e. 4x2 = 8 data characters).

Here, regarding the relationship between the bar code symbol 100 and the 1DCCD array 302 of FIG. 1A, the start code 104 and the stop code 106 of the bar code symbol 100 are included in the data string obtained by one scan.
To include. Next, the operation of each unit of the card reader 300 will be described with reference to FIG. 1A again, and then the operation of the data processing circuit 318 will be described with reference to FIGS. 3 to 8.

First, regarding the operation of each part of the card reader 300, when the insertion detection sensor 326 arranged near the image pickup position of the 1DCCD array 302 detects the card 200 (position P1 in FIG. 1A), Data processing circuit 31
8 (high-speed arithmetic circuit 318A) recognizes this, and the card 200 including the barcode symbol 100 is illuminated by an illuminating device (not shown) according to an instruction from the data processing circuit 318, and the reflected light thereof is an optical system including a lens (not shown). The light is incident on the 1D CCD array 302 via.

The 1DCCD array 302 converts an optical signal into an electric signal, and outputs the data for the total number of images of the 1DCCD array 302 to the CCD amplifier 306 together with a synchronizing signal.
It is amplified by the CCD amplifier 306 and converted to 2 by the binarization circuit 308.
The digitized scan data is output to the pulse width counting circuit 3
At 10, the widths of bars and spaces are counted in synchronization with the operation clock of the 1D CCD array 302, and the FIFO is further added.
The data is sequentially stored in the memory 312.

Further, the counter 322 counts the number of pixel data output from the 1DCCD array 302 to the CCD amplifier 306, and when the number of pixels of the 1DCCD array 302 has been counted, the marker write circuit “S” 324. Is "00" at the end of the width data string of each scan.
A value "H (H means hexadecimal number)" is stored in the FIFO memory 312. The value "00H" is a value that cannot be included in the width information of the bar and space, and thus the data processing circuit 318 is executed. (High-speed arithmetic circuit 318A)
Can determine the end of each scan (the end of the width data string by one scan).

FIG. 4A shows the contents of the FIFO memory 312. That is, a bar (or space) with a width of "64"
Starting from "10", "6", "10", "6",
"10", "6", "26" (up to here is the start pattern corresponding to the start code 104), "3"
5 "...," 25 "followed by the width data string, and then" 00H "(marker 312) indicating the end of the width data string of this scan.
M) is stored. After "00H", the width data string of the next scan is stored.

Here, it is not known how many pieces of width information the width data string of each scan has. Therefore, the maximum number of width information of the width data string of the scan is determined in advance, and the number is stored each time (when the width information is small, the rest is filled with specific data) or each scan is stored in a separate memory. Although there is a method of storing the number of width information of each scan, the method of preparing the number of width information in advance considering the maximum number of width information increases the memory capacity unnecessarily and stores each scan in another memory. The method of storing the number of width information is also a waste of memory.
Therefore, in this embodiment, the marker 312M of "00H" is stored at the end of the width data string of each scan. By doing so, the width data string of each scan having a variable length can be efficiently stored in the memory, and the FIFO memory 312 having a small capacity is sufficient.

In the data processing circuit 318, first, "00"
The width data string up to H ″ is taken out from the FIFO memory 312 and stored in the width memory 314.
The contents of 14 are read. The data processing circuit 318 sequentially repeats this operation to initialize the scan data memory 316.
The contents of the bar code symbol 100 on the card 200 are read while detecting the size and security level in the row and column directions by using, and when the bar code symbol 100 can be decoded correctly, the host interface circuit 320 is controlled. , Its contents are transferred to the host computer 400 of FIG. 2 or a terminal device (not shown).

Here, once storing from the FIFO memory 312 to the width memory 314 may be performed from the beginning of the width data string and then stored in the data matrix described later, or from the end of the width data string. This is because it may be stored in the data matrix described later. For example,
When the start code 104 at the beginning of the width data string cannot be detected and the stop code 106 at the end of the width data string is detected, processing is performed from the end of the width data string back to the beginning. .

Further, the discharge detection sensor 328 arranged near the image pickup position of the 1D CCD array 302 is mounted on the card 200.
When the passage of the data is detected (position P2 in FIG. 1A), the sensor 328 notifies the data processing circuit 318 of the fact and also notifies the marker write circuit “O” 330 of it. The signal is output.

The marker write circuit "O" 330 stores a special mark in the FIFO memory 312 when the card is ejected. The data processing circuit 318 makes this special mark F
It can be confirmed from the IFO memory 312 that the card 200 has been ejected. Of course, the discharge detection sensor 3
28, the data processing circuit 318 can confirm the ejection of the card 200. However, when the data processing circuit 318 cannot process the width data string of the FIFO memory 312 in real time, that is, the output of the ejection detection sensor 328 indicates the card 20.
If there is still an unprocessed width data string in the FIFO memory 312 when the discharge of 0 is confirmed, the data processing circuit 318 does not know how much to process, so the discharge timing is indicated. Special mark is prepared. The special mark that indicates the timing of this discharge is
A value that cannot be included in the information obtained by counting the widths of bars and spaces (for example, if the number of pixels of the 1DCCD array 302 is 20
If it is set to 48, the value “2100” may be used as a special mark indicating the discharge timing. The value "2100" does not exist. However, in this case, the FIFO memory 312 needs to be configured to have 12 bits or more).
No. 8 can judge the card ejection timing.

The data processing circuit 318 also controls each LED 300L indicating the operating state of the card reader 300. The LED 300L shown in FIG. 2 is a POW indicating that the card reader 300 is powered on.
ER LED, barcode symbol 1 on card 200
00 is a SCAN LED indicating that the 1D CCD array 302 is scanning, and DECODE indicating that the contents of the barcode symbol 100 have been correctly decoded.
It is composed of an LED and an ERROR LED indicating that the contents of the barcode symbol 100 could not be decoded.

Here, the data processing circuit 318 decodes the contents of the bar code symbol 100 on the basis of an algorithm as described below and transfers it to the host computer 400 of FIG. 2 or a terminal device (not shown). .

That is, FIG. 5 is a flow chart showing an outline of an algorithm for decoding the contents of the bar code symbol 100 in the data processing circuit 318 in the swipe type card reader 300.

First, the POWER LED is turned on (step S1), and it is confirmed whether or not the card 200 is inserted (step S2). If the card 200 is not inserted, step S2 is repeated.

When the card 200 is inserted, S
The CAN LED and the lighting device (not shown) are turned on, and the mark 0 counter (not shown) configured in the data processing circuit 318 for counting the number of "00H" indicating the division of the width data string of each scan is cleared (step S3).

Thereafter, a row number and column number determination routine which will be described in detail later is called (step S
4) Read the row indicator 102A of the barcode symbol 100 to determine the label size, security level and the like.

Then, it is judged whether or not the label size, the security level and the like have been decided in the row number and column number decision routine of step S4 (step S5), and if they have not been decided, ERROR
The LED is turned on (step S6), and the POWER L
The LEDs other than the ED are extinguished (step S7), and the control is moved to the above step S2 to wait for the card insertion.

On the other hand, if it is determined in step S5 that the label size, the security level, etc. have been determined, a scan routine to be described later is called (step S8), and the bar code symbol 100 is placed on the 1DCCD array 302. Scan sequentially, and barcode symbol 10
Read 0.

Then, it is judged whether or not the decoding is completed in the scan routine of the step S8 (step S9). If the decoding is not completed, the error is determined.
The LED is turned on (step S6), the other LEDs are turned off (step S7), and the control is transferred to the step S2 to wait for the card insertion.

On the other hand, when it is determined in step S9 that the decoding is completed, the DECODE LED is turned on (step SA) and the host interface circuit 32 is turned on.
By controlling 0, the contents of the barcode symbol 100 are displayed in FIG.
To the host computer 400 or a terminal device not shown (step SB). After that, POWER LE
The LEDs other than D are extinguished (step S7), and the control is moved to the step S2 to wait for the card insertion. Next, the operation of the row number and column number determination routine called in step S4 will be described in detail with reference to FIG.

First, the initialization scan number counter formed in the initialization scan data memory 316 for indicating how many scans the row number and the column number are determined is cleared (step S41). next,
A GETSCAN routine, which will be described later, is called (step S42), and a width data string obtained by one scan from the 1DCCD array 302 is stored in the width memory 314. next,
The width data string is sequentially fetched from the width memory 314, and it is confirmed whether the start code 104 or the stop code 106 is included in the width data string (step S43). If the start code 104 and the stop code 106 are not included in the width data string (step S44), it is further confirmed whether or not the card ejection mark is present in the width data string (step S45). Although the row number and column number determination routine ends, if there is no such control, the control is returned to the GETSCAN routine of step S42.

When the start code 104 or the stop code 106 is confirmed in step S44, the width data string is stored in the initialization scan data memory 316 (step S46), and each width data string called a pointer is stored. The start address of the initialization scan data memory 316 for storing the next width data string is written in the area indicating the start address (step S47), and the initialization scan number counter is incremented (step S48).

The structure of the initialization scan data memory 316 is shown in FIG. 4B. A width data string in which the start code 104 or the stop code 106 is detected is sequentially stored in the initialization scan data memory 316, and a pointer indicating the beginning of the width data string of each scan and an initialization scan number counter are separately prepared. Has been done. The pointer and the initialization scan number counter may not be prepared in the initialization scan data memory 316 but may be configured in another memory.

Thereafter, the detected start code 104
(Or, the row indicator 102A located next to the stop code 106) is read, the row number, column number, and security level of the barcode symbol 100 are confirmed (step S49), and the confirmed values are sequentially stored in variables not shown. I will do it. The row number, the column number, and the security level cannot be confirmed only by the row indicator 102A of one row, and the row indicator 102A of at least three rows is required. Here, it is determined whether or not the row number, column number, and security level have been determined (step S4A), and if so, this row number and column number determination routine ends. If not determined, the process proceeds to step S45 to further confirm whether or not the card ejection mark is present in the width data string, and if present, terminates this row number and column number determination routine, but if not present. Is the GETSCAN of step S42 above.
Return control to the routine. Next, the operation of the scan routine called in step S8 will be described in detail with reference to FIG.

First, the number of initialization scans obtained in the row number and column number determination routine called in step S4 is decremented (step S).
81). Next, a width data string for one scan is taken out from the initialization scan data memory 316 pointed to by the pointer at this initialization scan count position (step S8).
2). Here, the end of the width data string can be determined from the pointer immediately before.

After that, the start code 104 and the stop code 106 are confirmed from the width data string (step S8).
3). In this case, the start code 10 is used in the row number and column number determination routine (step S4) described above.
It has been confirmed that 4 and the stop code 106 are included in the width data string. Next, the row indicator 102A located next to the detected start code 104 (or stop code 106) is read, and the row number of the scanned width data string is confirmed (step S84). The row indicator 102A describes an address indicating which row the scan data is.

Next, in the data matrix to be described later, the row indicator 10 is displayed from the confirmed row number position.
Data characters after 2A are sequentially stored (step S85). If the start code 104 can be detected first, the first data character immediately after the row indicator 102A is stored at the left end of the data matrix,
Sequentially processed width data string is stored to the right,
This is repeated until the end of the width data string in one scan. If the stop code 106 is detected first, the first data character is stored at the right end of the data matrix, and the sequentially processed width data string is stored toward the left.

Here, it is determined whether or not the number of initialization scans is "0" (step S86), and if it is not "0", the width data string that has to be processed still remains in the initialization scan data memory 316. , The above step S8
Return control to 1.

If it is "0", a GETSCAN routine, which will be described in detail later, is called in order to newly fetch the width data string (step S87), and the start code 104 and the stop code 106 are fetched from the fetched width data string.
Is confirmed (step S88). If the start code 104 and the stop code 106 are not included in the width data string (step S89), it is determined whether or not there is a special mark indicating card ejection in the width data string taken in (step S8A). ), If the special mark exists, the scan routine is ended, but if the special mark does not exist, the control is returned to the step S87.

If it is determined in step S89 that the start code 104 or the stop code 106 is included in the width data string, it is next to the detected start code 104 (or stop code 106). The row indicator 102A located at is read and the row number of the scanned width data string is confirmed (step S8B). Next, in the data matrix described later,
Row indicator 1 from the confirmed row number position
Data characters after 02A are sequentially stored (step S8C).

Then, it is judged whether or not the information read so far can be decoded (step S8D). If the information can be decoded, the control is shifted to the decoding processing of the next step S8E. Here, "decodable" means that when error correction is involved, the number of data characters not stored in the data matrix described later is smaller than the number of error-correctable data characters, and error correction is not involved. In this case, it means the time when all data characters are stored in the data matrix.

If it is determined in step S8D that decoding is impossible, the process proceeds to step S8A to determine whether or not there is a special mark indicating card ejection in the width data string that has been further taken in. If the special mark does not exist, the control is returned to the step S87.
Here, "undecodeable" means, for example, when error correction is involved, when the number of data characters not stored in the data matrix described later is larger than the number of error-correctable data characters, and error correction is involved. When there is no data character, it means that there is a data character that has not been stored in the data matrix described later.

As described above, the entire surface of the card 200 is scanned and then it is not judged whether decoding is possible.
Determining whether or not decoding is possible for each scan is very important in order to shorten the decoding time.

In the decoding process in the next step S8E, the information read in the scan routine so far is checked. This check is performed on the characters stored in the data matrix described later, and in the case of merely confirming the decoding result (JAN / UPC / EAN code, ITF (Interleave).
d 2 of 5) Code, CODE39, NW-7 code, C
There are also conventional one-dimensional barcodes such as ODE128, but with error correction (PDF417, DATA
There are also two-dimensional bar code symbols such as CODE). After executing the decoding process in step S8E, the scan routine is ended.

Here, the data matrix will be described. The data matrix is a matrix for storing the data characters whose values are obtained from the scanned width data string, and the values of “0” to “9” are stored in the JAN / UPC / EAN code, and “0” to “in the PDF417”. The value of “928” is stored. PDF417
In this case, the size of the data matrix is the label matrix 10 of the barcode symbol 100 on the card 200.
It is the same size as 2C. A method for obtaining a data character from a width data string is, for example, JAN / UPC /
In the EAN code, the width data of a total of four black bars and two white spaces is converted into a value of "0" to "9". This conversion is generally performed by referring to a table. In PDF417, the black bar 4
The width data of a total of 8 books and 4 spaces is converted into a value of "0" to "928". This conversion is also generally performed by referring to a table. Next, the GE called in step S42 and step S87 described above.
The operation of the TSCAN routine will be described in detail with reference to FIG.

FIG. 8 is a flowchart of the GETSCAN routine. First, the high speed operation circuit 318A clears the width data number counter 318B which counts the number of width data columns of each scan (step S421). next,
The width data is fetched from the FIFO memory 312 storing the width data from the 1DCCD array 302 (step S422). Here, it is judged whether or not the taken-in width data is a special mark indicating card ejection (step S423), and if it is a special mark, this GETSCAN routine is ended, but if it is not a special mark, width data of one more scan It is determined whether it is "00H" indicating the end of the row (step S424). "0" indicating the end
In the case of "0H", first, the mark 0 counter for counting the number of "00H" indicating the division of the width data string of each scan is incremented (step S425).

Then, the comparison circuit 318 checks whether the value of the width data number counter 318B is larger than a certain threshold value, which will be described later, stored in the threshold value register 318C.
A determination is made using D (step S426). If it is larger than the certain threshold value, the GETSCAN routine is ended, but if it is smaller than or equal to the threshold value, the control is returned to the step S421.

If it is determined in step S424 that it is not "00H" indicating the end, the width data number counter 318B is incremented (step S427), and the width data taken in is stored in the width memory 314.
(Step S428). Then, the control is returned to step S422.

Next, the threshold value to be compared with the value of the width data number counter 318B will be described. Stop code 1
The row indicator 102A existing next to 06 can be omitted, and since the stop code 106 can be substituted by only one bar, PD
The minimum elements that make up the F417 barcode symbol are:
Start code 104, row indicator 102A,
One data column 102B, a simplified stop code (only a bar with a width of 1). That is, as the number of width information, 8 pieces of the start code 104 (4 bars, 4 spaces), 8 pieces of the row indicator 102A (4 bars, 4 spaces), and one data column 102B. 8 (4 bars, 4 spaces) and 1 simple stop code (1 bar) for a total of 25. Therefore, when 24 or less pieces of width information are obtained, the scan data string may be ignored. Therefore, the threshold value may be set to "24".

As described above, if the scanning of the width data number less than a certain threshold value is ignored, the start code 104 and the stop code are extracted from the width data string obtained by scanning the characters, photographs, illustrations and spaces on the card. 10
No need to search for 6, and there is no waste of searching for the start code 104 and the stop code 106 from the width data string that does not have the row indicator 102A and the data column 102B (which could not be scanned normally due to a defect, etc.). Get faster. Further, it is not necessary to configure the data processing circuit 318 with an expensive electric element capable of high-speed processing. That is, it is possible to provide a barcode symbol reading device that can process at high speed, and since an extra memory is not required, it is possible to provide an inexpensive barcode symbol reading device. (Second embodiment)

FIG. 9A is an external view of a system using the card reader 600 of the second embodiment. The difference between the second embodiment and the first embodiment is the method of decoding the card 200 on which the barcode symbol 100 is printed or pasted.

That is, in the present embodiment, the card 200 is not inserted into the slit of the card reader 300 to read the contents of the bar code symbol 100 as in the first embodiment, but the card 200 is inserted into the insertion slot of the card reader 600. 600
Bar code symbol 10 when the operator inserts / ejects it into I
It reads the contents of 0, which is a so-called time card system, and is generally called a dip type card reader. The operator of the dip-type card reader uses the barcode symbol 10 of the card 200.
Area where 0 is not printed (Handling area 200
H) by hand, and insert slot 600I of the card reader 300
The card 200 is inserted into the card reader 600, the operator judges that the card 200 has reached the abutting position inside the card reader 600, and this time the card 200 is removed from the card reader 600. The determination that the card 200 has reached the abutting position is made by the card 200 abutting a mechanical stopper inside the card reader 600.

The card reader 600 incorporates an electric circuit having a block diagram as shown in FIG. In the figure, the same components as those in FIG. 1A are designated by the same reference numerals.

The card reader 600 of this embodiment also uses the linear sensor 1D CCD array 302 to read the contents of the bar code symbol 100. Here, only the configuration different from that of the first embodiment will be described. That is, in the insertion / ejection detection sensor 602, the card 200 has the 1DCCD array 302.
It is for detecting that the image pickup position has been reached and that the card 200 has been removed, and is configured by a photo interrupter or the like. In addition, the hit detection sensor 60
Reference numeral 4 is for detecting that the card 200 has reached the abutting position inside the card reader 600, and is composed of a photo interrupter or the like. Marker light circuit "O"
The 330 receives the ejection detection output of the insertion / ejection detection sensor 602 and outputs a special ejection marker to the FIFO memory 31.
Store in 2. The marker write circuit “B” 606 receives the output of the hit detection sensor 604 and stores a special hit marker in the FIFO memory 312. of course,
The special discharge marker and the special butting marker need to be values that cannot be included in the width information of the bar and space.

Next, an algorithm for the data processing circuit 318 in the DIP type card reader 600 having such a configuration to decode the contents of the bar code symbol 100 will be described. The entire algorithm, the row number and column number determination routine, and the scan routine are the same as those in the first embodiment, and only the GETSCAN routine will be described here. FIG. 11 shows a flowchart of the GETSCAN routine. Basically, it is the same as the first embodiment.

In this embodiment, step S423 for confirming whether the width data is the card ejection mark and the width data is "00H".
Between step S424 for confirming whether or not there is inserted step S429 for confirming whether or not a card abutting mark is present in the width data string. And this step S4
When the card abutting mark is confirmed at 29,
It is recorded that the card abutting mark is confirmed (step S42A).

Further, instead of step S425 of incrementing the 0 counter which counts the number of "00H" indicating the division of the width data string of each scan, the insertion is made while the card abutting mark is not present in the width data string. After the 0 counter is incremented and the card abutment mark is present in the width data string, step S42B for incrementing the discharge 0 counter is inserted. Of course, these insertion 0 counter and ejection 0 counter are shown in FIG.
It is cleared in step S3 of the entire flowchart shown in FIG.

Even in the dip type card reader 600 as in the second embodiment, as in the first embodiment described above,
It is possible to provide a barcode symbol reading device capable of processing various barcodes at high speed. Further, as shown in FIG. 9B, the dip type card reader can be configured by inserting / ejecting the card 200 from the side.

As described in the first and second embodiments above, in the present invention, the scan of the width data number equal to or less than a certain threshold is ignored.
There is no need to search for the start code 104 and the stop code 106 from the width data string obtained by scanning the photograph, the illustration and the space portion, and the row indicator 10
Since there is no waste of searching for the start code 104 and the stop code 106 from the width data string having no 2A or the data column 102B (which could not be normally scanned due to a defect, etc.), the processing speed is increased. In addition, the data processing circuit 3
There is no need to configure 18 by an expensive electric element capable of high-speed processing. That is, it is possible to provide a barcode symbol reading device that can process at high speed, and since an extra memory is not required, it is possible to provide an inexpensive barcode symbol reading device.

Further, according to the present invention, at the end of each scan, the special marker which does not exist in the width of the normal bar and space is stored in the FIFO memory 312. Therefore, the width data of each scan having a variable length is stored. The columns can be efficiently stored in the memory, the FIFO memory 312 having a small capacity is sufficient, and it becomes possible to provide an inexpensive bar code symbol reading apparatus with a reduced memory capacity.

Further, by storing the width data string of each scan until the size of the bar code symbol is fixed in the initialization scan data memory 316, the bar code can be restarted from the beginning after the size of the bar code symbol is fixed. Since there is no need to reread the symbols, it is possible to provide a barcode symbol reader that can be read at high speed.

In the first and second embodiments, the scan data binarized by the binarization circuit 308 is divided into bars and spaces in synchronization with the operation clock of the 1DCCD array 302 by the pulse width counting circuit 310. Although it has been described that the width is counted, the width of the bar and the space may be counted with a clock faster than the operation clock of the 1DCCD array 302. Further, although it has been described that the value “00H” is stored in the FIFO memory 312 at the end of the width data string of each scan, “00H” is stored at the beginning of the width data string of each scan.
Storing H ″ in the FIFO memory 312 is also effective.
Further, in the marker write circuit “O” 330, a special mark “2100” is added to the FIFO memory 31 when the card is ejected.
It was explained that the barcode symbol 100 is stored in
If it is known in advance that there is no value of 200 or more when the width of the card is counted, by adopting, for example, “255” as a special mark for card ejection,
It is possible to configure the O memory 312 with normal 8 bits. Also, the data processing circuit 318 can be configured by a digital signal processor (DSP).

Up to this point, the description has been centered on the PDF417, which is a two-dimensional bar code symbol having a large amount of information and a high recording density. JAN / UPC / EAN code, ITF
One-dimensional barcode symbol such as (Interleaved 2 of 5) code, and other two-dimensional barcode symbol CO
DE16K, CODE49, DATA CODE, VE
Needless to say, by applying the present invention to the RI COOE, SOFT STRIP, etc., it is possible to configure a barcode symbol reading device capable of reading barcode symbol information in a short time.

Also, in the conventional system as shown in FIG. 12, instead of the video camera 904, 1DCC is used.
The present invention is applied by incorporating the D array 302 and the moving mechanism for moving the D array 302 in the row direction of the barcode symbol, and the device can be made inexpensive even if it cannot be downsized.

[0083]

As described in detail above, according to the present invention,
The width of the bar and space is counted from the read signal of the bar code symbol, the number of counted bars and spaces is compared with a predetermined value, and the number of counted bars and spaces is larger than the predetermined value. Since the contents of the bar code symbol are read using only the read signal at this time, it is possible to provide a bar code symbol reading device capable of high-speed processing even with a one-dimensional image pickup device.

[Brief description of drawings]

FIG. 1A is a block configuration diagram of a barcode symbol reading device according to a first embodiment of the present invention, and FIG.
It is a block block diagram of the inside data processing circuit.

FIG. 2 is an external view of a system using the barcode symbol reading apparatus according to the first embodiment.

FIG. 3 is a symbol structure diagram of PDF417 as an example of a two-dimensional barcode symbol to be read.

4A is a diagram showing the contents of the FIFO memory in FIG. 1A, and FIG. 4B is for explaining the storage structure of the initialization scan data memory in FIG. 1A. FIG.

5 is a flowchart showing an outline of an algorithm for decoding the contents of a barcode symbol in the data processing circuit in FIG. 1 (A).

FIG. 6 is a flowchart of a row number and column number determination routine in FIG.

FIG. 7 is a flowchart of a scan routine in FIG.

8 is a flowchart of a GETSCAN routine shown in FIG.

FIG. 9A is an external view of a system using the barcode symbol reading device according to the second embodiment of the present invention,
FIG. 7B is an external view of another barcode symbol reader to which the second embodiment is applied.

FIG. 10 is a block configuration diagram of a barcode symbol reading device according to a second embodiment.

FIG. 11 is a flowchart of a GETSCAN routine in the case of the second embodiment.

FIG. 12 is an external view of a system using a conventional barcode symbol reading device.

[Explanation of symbols]

100 ... Bar code symbol, 102 ... Label part, 10
2A ... Row indicator, 102B ... Data column,
102C ... Label matrix, 104 ... Start code, 104A, 106A ... Big bar, 106 ... Stop code, 200 ... Card, 200H ... Handling area, 300, 600 ... Card reader, 300S ... Slit, 300L ... LED, 302 ... Linear sensor (1D
CCD) array, 304 ... CCD driver, 306 ... C
CD amplifier, 308 ... Binarization circuit, 310 ... Pulse width counting circuit, 312 ... First-in-first-circuit
Out (FIFO) memory, 314 ... Width memory, 316
Initialization scan data memory, 318 ... Data processing circuit, 318A ... High speed operation circuit, 318B ... Width data number counter, 318C ... Threshold register, 318D ... Comparison circuit, 320 ... Host interface circuit, 322 ... Counter, 324 ... Marker light circuit "S", 326 ... Insertion detection sensor, 328 ... Ejection detection sensor, 330 ... Marker light circuit "O", 400 ... Host computer, 5
00 ... Cable, 600I ... Insertion port, 602 ... Insertion / ejection detection sensor, 604 ... Butting detection sensor, 606 ...
Marker write circuit "B".

Claims (1)

[Claims] 1. An image pickup means for picking up an image of a barcode symbol by a one-dimensional image pickup device, a width counting means for counting the widths of the bar and space of the barcode symbol from an image pickup signal from the image pickup means, and the width counting means. A number counting means for counting the number of bars and spaces whose width is counted by the number of bars, and a bar counted by the width counting means only when the number counted by the number counting means is larger than a predetermined value. And a control means for permitting the width of the space to be used in the subsequent processing, and a bar code symbol reading device.