JP5152086B2 - Bar code reading method and bar code reading apparatus - Google Patents

Description

  The present invention relates to a barcode reading method and a barcode reading apparatus that optically read barcodes created based on a plurality of types of standards.

  Conventionally, many types of standards for bar codes have been developed and actually used. For this reason, there is a case where a part of a predetermined type of barcode constitutes another type of barcode. Therefore, in order to enable reading of a plurality of types of barcodes, it is necessary to clearly distinguish the types of barcodes even in the above case. Therefore, for example, as a barcode reading method for optically reading a barcode created based on a plurality of types of standards, a barcode reading method shown in Patent Document 1 below is known.

  In this barcode reading method, it is determined whether or not the barcode specified as a reading target is RSS_Limited, one of the space-saving RSS (Reduce Space Symbol) codes. When the possibility that the barcode is RSS_Limited is recognized, it is determined whether or not the character code of UPC-A / EAN-13 exists in at least one of both ends of the code pattern. When the character code does not exist, it is determined that the barcode is RSS_Limited. When the character code exists, it is determined that the character code is not RSS_Limited.

Japanese Patent Laying-Open No. 2006-227796 (paragraphs 34 and 35, FIG. 4)

  By the way, since RSS_Limited is developed as a space-saving type, a margin is not required on both outer sides of the barcode, so that a barcode-like pattern or the like may be arranged in the vicinity of the barcode. In this case, in the barcode reading method shown in Patent Document 1, even if the reading target is RSS_Limited, the character code of UPC-A / EAN-13 is placed on at least one of both ends of the code pattern read for the pattern. If it is assumed that the barcode is present, it is determined that the barcode is not RSS_Limited, and there is a problem that reading accuracy related to RSS_Limited is lowered.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide barcode reading that can improve reading accuracy even when barcodes of similar patterns of a plurality of types of standards coexist. It is to provide a method and a barcode reader.

  In order to achieve the above object, in the barcode reading method according to claim 1, a barcode created based on a plurality of kinds of standards is optically read and recorded in the barcode. In the barcode reading method for decoding data, among the plurality of types, a part of the code pattern of the first barcode based on the first standard is set to have a smaller number of bars than the first standard. When there is a possibility of being read as a second bar code based on the standard, the second bar code is read by applying the read algorithm of the second standard to the light and dark pattern string obtained by binarizing the read bar code. The first barcode may be present at least in the vicinity of both ends of the bright and dark pattern row read by the first step and the first step. A second step for determining whether or not a character pattern exists; and when the character pattern is determined to exist by the second step, the light and dark pattern sequence is assumed to be a part of the first barcode code pattern. A third step of estimating a margin position corresponding to the first barcode, and when no margin is detected at the margin position estimated by the third step, the light / dark pattern string is represented by the second barcode. And a fourth step of confirming as read data.

  According to a second aspect of the present invention, in the barcode reading method according to the first aspect, the third step estimates a margin position corresponding to the first barcode based on a center bar of the first barcode. It is characterized by.

  According to a third aspect of the present invention, in the barcode reading method according to the first or second aspect, when the fourth step detects a margin at the margin position estimated by the third step, the first step The bar code read in the step is invalidated.

  According to a fourth aspect of the present invention, in the barcode reading method according to the third aspect, when the barcode read in the first step is invalidated in the fourth step, a fifth step for notifying the fact is provided. It is characterized by providing.

  According to a fifth aspect of the present invention, in the barcode reading method according to any one of the first to fourth aspects, the first barcode is an EAN (European Article Number) code and a UPC (Universal Product Code) code. And the second bar code is an RSS (Reduced Space Symbol) code.

  The barcode reading device according to claim 6, wherein the barcode reading device optically reads a barcode created based on a plurality of types of standards and decodes data recorded in the barcode. In the apparatus, among the plurality of types, the second barcode based on the second standard in which a part of the code pattern of the first barcode based on the first standard is set to have a smaller number of bars than the first standard. Read by applying the reading algorithm of the second standard to the light and dark pattern string obtained by binarizing the read barcode, and the reading means Whether or not there is a character pattern that can exist in the first bar code in at least one of the vicinity of both ends of the read light / dark pattern row And a determination means for determining whether the character pattern is present by the determination means, the light and dark pattern string is assumed to be a partial code pattern of the first barcode and corresponds to the first barcode. Margin position estimating means for estimating a margin position, and confirmation means for determining the bright / dark pattern string as read data of the second barcode when no margin is detected at the margin position estimated by the margin position estimating means And.

  According to a seventh aspect of the present invention, in the barcode reading apparatus according to the sixth aspect, the margin position estimating means estimates a margin position corresponding to the first barcode based on a center bar of the first barcode. It is characterized by that.

  According to an eighth aspect of the present invention, in the barcode reading apparatus according to the sixth or seventh aspect, when the determining unit detects a margin at the margin position estimated by the margin position estimating unit, the reading unit The bar code read in the above is invalidated.

  A ninth aspect of the invention is the barcode reading apparatus according to the eighth aspect, further comprising notifying means for notifying the barcode read by the reading means when the barcode is invalidated by the determining means. It is characterized by.

  According to a tenth aspect of the present invention, in the bar code reading device according to any one of the sixth to ninth aspects, the first bar code includes an EAN (European Article Number) code and a UPC (Universal Product Code) code. And the second bar code is an RSS (Reduced Space Symbol) code.

  In the first and sixth aspects of the invention, the second barcode based on the second standard in which a part of the code pattern of the first barcode based on the first standard is set to have a smaller number of bars than the first standard. In the case where there is a possibility of reading, the reading is performed by applying the reading algorithm of the second standard to the light and dark pattern sequence obtained by binarizing the read barcode. If it is determined that there is a character pattern that can exist in the first barcode in at least one of the vicinity of both ends of the light / dark pattern row, the light / dark pattern row is assumed to be a partial code pattern of the first barcode. A margin position corresponding to one barcode is estimated. When a predetermined margin is not detected at the estimated margin position, the light / dark pattern sequence is determined as read data of the second barcode.

  Since it is assumed that a part of the code pattern of the first barcode can be read as the second barcode, when the light and dark pattern sequence is a partial code pattern of the first barcode, both ends of the light and dark pattern sequence A character pattern that may exist in the first barcode exists in at least one of the neighborhoods, and a margin exists at a predetermined margin position.

Therefore, when there is a possibility that the light and dark pattern string can be read as the second bar code, there is a character pattern that can exist in the first bar code at least near the both ends of the light and dark pattern line and a margin at a predetermined margin position. If the character pattern does not exist, the character pattern is a pattern different from a part of the barcode, so that the light / dark pattern row can be determined as the read data of the second barcode.
Therefore, even when bar codes with similar patterns of a plurality of types of standards are mixed, the reading accuracy of the second bar code as described above can be improved.

  In the inventions of claims 2 and 7, the margin position corresponding to the first barcode is estimated based on the center bar of the first barcode. Since the center bar is generally composed of five narrow bars, for example, the margin position is compared with the case where the margin position is estimated based on a guard bar composed of three narrow bars provided at both ends of the barcode. The estimation accuracy of can be improved.

  According to the third and eighth aspects of the present invention, when a margin is detected at the estimated margin position, the read barcode is invalidated.

  Originally, if a code pattern including a part of the light / dark pattern sequence can be read as the first barcode, the necessity of determining whether or not the light / dark pattern sequence can be read as the second barcode is reduced. For this reason, since it cannot be read as the first barcode due to a lack of a region different from the light and dark pattern row, it is determined whether or not the light and dark pattern row can be read as the second barcode and cannot be read as the second barcode. In other words, if a margin is detected at the estimated margin position, it is very unlikely that the code pattern including the light and dark pattern sequence will be read. Can do.

  In the inventions of claims 4 and 9, when the read barcode is invalidated, the fact is notified, so the read barcode cannot be read as the second barcode, but the barcode to be read is newly added. When reading, it is possible to make the user recognize that there is a high possibility of being read as the first barcode.

  In the inventions of claims 5 and 10, the first barcode is one of an EAN (European Article Number) code and a UPC (Universal Product Code) code, and the second barcode is an RSS (Reduced Space). (Symbolology) code.

  The RSS code is a space-saving type as compared with the EAN code and the UPC code, and part of the EAN code and the UPC code may actually match the RSS code. Even in such a case, as described above, when there is a character pattern that can exist in the first bar code in at least one of the vicinity of both ends of the light and dark pattern row and there is no margin at a predetermined margin position, the light and dark pattern row is displayed. Since the RSS code can be determined, the RSS code reading accuracy can be improved even when the RSS code, the EAN code, and the UPC code are mixed.

It is a block diagram which shows the electric constitution of the barcode reader 10 which concerns on this embodiment. A first portion of the bar code B ₁ is an explanatory view showing a state that matches the second barcode B _2. 6 is a part of a flowchart illustrating a flow of a reading process in the present embodiment. 6 is a part of a flowchart illustrating a flow of a reading process in the present embodiment. FIG. 5A is an explanatory diagram showing a state where the margin Bd does not exist on one end side of the light / dark pattern row Ba, and FIG. 5B shows a state where the margin Bd exists on one end side of the light / dark pattern row Ba. It is explanatory drawing shown.

  A barcode reader according to an embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the barcode reader 10 is configured as a device that reads a barcode (based on the barcode B attached to the article R in FIG. 1) created based on a plurality of types of standards. . The bar code means a one-dimensional code such as an RSS code, an EAN code, and a UPC code.

  The bar code reader 10 is configured such that a circuit unit 20 is accommodated in a case (not shown). The circuit unit 20 mainly includes an optical system such as an illumination light source 21, a light receiving sensor 28, and an imaging lens 27. And a microcomputer (hereinafter referred to as “microcomputer”) system such as a memory 35, a control circuit 40, and a trigger switch 42.

  The optical system is divided into a light projecting optical system and a light receiving optical system. The illumination light source 21 constituting the light projecting optical system functions as an illumination light source capable of emitting the illumination light Lf, and includes, for example, a red LED and a lens provided on the emission side of the LED. In addition, in FIG. 1, the example which irradiates the illumination light Lf toward the articles | goods R to which barcode B was attached | subjected is shown notionally.

  The light receiving optical system includes a light receiving sensor 28, an imaging lens 27, a reflecting mirror (not shown), and the like. The light receiving sensor 28 is configured as a CCD area sensor, and is configured to be able to receive the reflected light Lr irradiated and reflected on the barcode B. The light receiving sensor 28 is mounted on a printed wiring board (not shown) so as to be able to receive incident light incident through the imaging lens 27.

  The imaging lens 27 functions as an imaging optical system capable of condensing incident light incident from the outside via a reading port (not shown) and forming an image on the light receiving surface 28a of the light receiving sensor 28. . In the present embodiment, after the illumination light Lf emitted from the illumination light source 21 is reflected by the barcode B, the reflected light Lr is condensed by the imaging lens 27 and a code image is formed on the light receiving surface 28 a of the light receiving sensor 28. The image is formed.

  The microcomputer system includes an amplification circuit 31, an A / D conversion circuit 33, a memory 35, an address generation circuit 36, a synchronization signal generation circuit 38, a control circuit 40, a trigger switch 42, a light emitting unit 43, a buzzer 44, a vibrator 45, and a liquid crystal display. 46, a communication interface 48, and the like.

  The image signal (analog signal) output from the light receiving sensor 28 of the optical system is amplified by a predetermined gain by being input to the amplifier circuit 31, and then input from the analog signal when input to the A / D conversion circuit 33. Converted into a digital signal. When the digitized image signal, that is, image data (image information) is generated and input to the memory 35, it is stored in a predetermined code image information storage area. The synchronization signal generation circuit 38 is configured to generate a synchronization signal for the light receiving sensor 28 and the address generation circuit 36, and the address generation circuit 36 is based on the synchronization signal supplied from the synchronization signal generation circuit 38. Thus, the storage address of the image data stored in the memory 35 can be generated.

  The control circuit 40 is configured by a microcomputer capable of controlling the entire barcode reader 10 and has a CPU, a system bus, an input / output interface, and the like, and has an information processing function. It is composed. In the present embodiment, a trigger switch 42, a light emitting unit 43, a buzzer 44, a vibrator 45, a liquid crystal display 46, a communication interface 48, and the like are connected to the control circuit 40.

  Thereby, for example, the control circuit 40 can turn on / off the light emitting unit 43 that functions as an indicator for notifying information related to monitoring and management of the trigger switch 42 and reading of the barcode B, and a buzzer that can generate a beep sound and an alarm sound. Communication interface enabling ON / OFF of ringing 44, drive control of vibrator 45 capable of generating vibration that can be transmitted to the user of the barcode reader 10, display control of liquid crystal display 46, and serial communication with an external device 48 communication control and the like are possible.

Hereinafter, the reading process of the barcode reader 10 according to the present embodiment will be described in detail with reference to the drawings.
When reading a barcode based on a plurality of types of standards, the code pattern of a part of the first barcode based on the first standard is set to the second standard in which the number of bars is set to be smaller than that of the first standard. There is a possibility of being read as the second barcode. As the second bar code based on the second standard, for example, a space-saving RSS code is assumed, and as the first bar code based on the first standard, for example, an EAN code or a UPC code is assumed. .

Specifically, as shown in FIG. 2, an RSS code in which a part of the code pattern of the EAN code that is the first barcode B ₁ based on the first standard is the second barcode B ₂ based on the second standard One of them is assumed to match RSS_Limited.

In the present embodiment, in order first portion of the bar code B ₁ is to improve the second reading accuracy of the barcode B ₂ even if it matches the second barcode B ₂ as described above, read the following process To implement.

  First, in step S101 of FIG. 3, a minimum bar number setting process is performed. In this process, the minimum bar number X that can be read is set from a plurality of types of barcodes designated as reading targets by the user.

  Next, in step S103, a light / dark pattern string acquisition process is performed. In this process, when the bar code B code information is read by the light receiving sensor 28 in response to the user's operation of the trigger switch 42, the light receiving signal from the light receiving sensor 28 is applied by applying the reading algorithm of the second standard. Is compared with a predetermined threshold value, and based on the comparison, the signal waveform is binarized into a light color region and a dark color region, and a light / dark pattern sequence Ba corresponding to the arrangement data of the dark color region and the light color region is obtained. Is acquired. The processing in step S103 corresponds to an example of “first step” or “reading unit” in the claims.

  In step S105, the number n of bars is detected from the light / dark pattern row Ba, and in step S107, the bar width W is detected from the light / dark pattern row Ba.

  Next, in step S109, it is determined whether or not the number n of bars is equal to or greater than the minimum number X of bars. If n ≧ X (Yes in S109), barcode determination processing is performed in step S111, and a barcode to be decoded is determined according to the number of bars n. If the number of bars n is less than the minimum number of bars X in step S109 (No in S109), a reading invalidation process is performed in step S139 in FIG. 4, and the barcode read as the above reading fails is invalid. It is said.

  When the barcode is determined, it is determined in step S113 whether or not a one-side margin exists. In this determination processing, depending on the type of bar code between the first white bar (usually corresponding to the margin area) of the light / dark pattern row Ba and the black bar positioned next (inside) or from the first character pattern. Margin check is executed.

  Here, if the one-side margin exists in the light / dark pattern row Ba (Yes in S113), in step S115, a reading algorithm corresponding to the type of barcode is applied to the light / dark pattern row Ba, and the decoding process is performed. On the other hand, if there is no one-side margin in the light / dark pattern row Ba (No in S113), the bars at both ends of the light / dark pattern row Ba are reduced one by one (n = n−2) in step S117, and the above steps are performed. Processing from S109 is performed.

  When the decoding process is performed in step S115, it is determined in step S119 whether or not the decoding process is successful. If the decoding process is successful (Yes in S119), the process proceeds to step S121. A determination is made as to whether the other side margin exists. In this determination process, a margin check is executed in accordance with the type of barcode from the last black bar or character pattern in the light / dark pattern row Ba.

  Here, if the decoding process fails (No in S119) or the other side margin does not exist in the light / dark pattern row Ba (No in S121), it is evaluated as a decoding target in the decoding process described above in step S123. The number of bars m is subtracted from the number n of bars (n = n−m), and the processing from step S109 is performed.

  If the other side margin exists in the light / dark pattern row Ba (Yes in S121), it is determined in step S125 of FIG. 4 whether or not the barcode can be recognized as RSS_Limited, which is one of the RSS codes, and cannot be recognized as RSS_Limited. In this case (No in S125), the reading process is terminated.

On the other hand, if the barcode can be recognized as RSS_Limited (Yes in S125), in step S127, the determination character Bb is located outside the light / dark pattern row Ba in the vicinity of both ends of the light / dark pattern row Ba. It is determined whether or not it exists. Here, the determination character Bb is one of character patterns which may be present in the first bar code B _1, in the absence of determination character Bb in both regions near both ends of the light-dark pattern sequence Ba is (no in S127), since the light-dark pattern sequence Ba is not assumed to conform to a portion of the code pattern of the first bar code _{B 1,} at step S135, the barcode is determined to be RSS_Limited.

On the other hand, when it is determined that the determination character Bb exists because there is an area that matches a part of the code pattern of the first barcode B _{1 in} any area near both ends of the light / dark pattern row Ba (S127). In step S129, it is determined whether or not the center bar Bc is present in the light and dark pattern row Ba. In the present embodiment, it is assumed that the center bar Bc is composed of five narrow bars, and when the center bar Bc does not exist in the light / dark pattern row Ba (No in S129), the barcode is RSS_Limited in step S135. It is determined that

  On the other hand, as shown in FIG. 5, when the determination character Bb exists in the region near one end of the light / dark pattern row Ba and the center bar Bc exists in the light / dark pattern row Ba (Yes in S129), step S131. Margin position estimation processing is performed at. In this process, based on the first standard, the margin position where the determination character Bb is present is estimated based on the position of the center bar Bc with respect to the light and dark pattern row Ba.

  The reason for estimating the margin position based on the center bar Bc composed of five narrow bars in this way is, for example, based on the guard position composed of three narrow bars provided at both ends of the barcode. This is because the margin position estimation accuracy can be improved as compared with the case of estimating.

In step S133, it is determined whether or not the margin Bd based on the first standard exists at the margin position estimated as described above. Said Here, since the determined region and determination character Bb is actually the first bar code B ₁ is different pattern or the like in step S127, to the margin position as shown in FIG. 5 (A) If it is determined that the margin Bd based on the first standard does not exist (No in S133), it is determined in step S135 that the barcode is RSS_Limited.

  Thus, since it is determined that the determination character Bb is present due to the pattern or the like existing near both ends of the light / dark pattern row Ba, even if it is conventionally regarded as not RSS_Limited, the margin Bd is in the estimated margin position. When it is determined that there is no existing, it is possible to improve the reading accuracy regarding RSS_Limited by determining RSS_Limited.

On the other hand, since it is determined as the determination character Bb region is indeed a first portion of the bar code B ₁ at step S127, to the first standard to the margin position as shown in FIG. 5 (B) When the margin Bd based is present (Yes in S133), a notification process is performed in Step S137, and the light emitting unit 43 is lit in a predetermined warning color under the control of the control circuit 40.

  Then, invalidation processing is performed in step S139, and the above-mentioned reading fails and the read barcode is invalidated.

Here, the reason why the bar code is invalidated in step S139 because the margin Bd does not exist at the margin position will be described below. Originally, if the code pattern including a part of the light / dark pattern row Ba can be read as an EAN code or UPC code as the first barcode B ₁ , the light / dark pattern row Ba is originally the second barcode B ₂ . The necessity to determine whether or not it can be read as RSS_Limited is reduced. Therefore, it is determined whether the light-dark pattern array Ba different regions the dark pattern string Ba from the inability to read first as a bar code B ₁ by a deficiency or the like can be read as a second bar code B _2, the If you can not read as a 2 bar code B _2, namely, if the margin Bd is detected the estimated margin position disables the bar code read. In such a case, since the possibility of reading the code pattern including the light and dark pattern row Ba is very low, unnecessary data can be surely excluded by invalidating the read barcode.

In addition, since the margin Bd does not exist at the margin position and the barcode is invalidated in step S139, the light emitting unit 43 is lit in a predetermined warning color by the notification process, so the read barcode is 2 If is not be read as a bar code B ₂ to read a new bar code to be read is that there is likely to read the first bar code B _1, it can be recognized by the user.

As described above, in the barcode reader 10 according to the present embodiment, a part of the code pattern of the first barcode B ₁ based on the first standard is set to have a smaller number of bars than the first standard. If there is a possibility that read as the second bar code B ₂ based on the second standard being, the step S103 or the like (first step, reading means) by, obtained by binarizing the read bar code dark Reading is performed by applying the reading algorithm of the second standard to the pattern row Ba. If it is determined by step S127 (second step, determination means) that the determination character Bb is present at least near both ends of the light and dark pattern row Ba, step S131 (third step, margin position estimation means). ), the margin position corresponding to the first bar code B ₁ assumes a dark pattern columns Ba first bar code portion of the code pattern of B ₁ is being estimated. When detecting no margin Bd to the estimated margin position, the step S135 (the fourth step, determining means), the above-described light-dark pattern sequence Ba is determined as RSS_Limited a second barcode _{B 2} .

Thereby, when there is a possibility that the light / dark pattern row Ba can be read as RSS_Limited, the determination character Bb exists in at least one of the ends of the light / dark pattern row Ba and the margin Bd does not exist at a predetermined margin position. Since the character pattern is different from a part of the barcode, the light / dark pattern row Ba can be determined as RSS_Limited read data.
Therefore, even when barcodes with similar patterns of a plurality of types of standards coexist, the RSS_Limited reading accuracy can be improved.

  In the barcode reader 10 according to the present embodiment, since the margin position corresponding to the first barcode is estimated based on the center bar Bc of the first barcode, the margin position is estimated based on the guard bar or the like. The margin position estimation accuracy can be improved as compared with the case of doing so.

  Furthermore, in the barcode reader 10 according to the present embodiment, when the margin Bd is detected at the estimated margin position, the read barcode is invalidated. As described above, when the margin Bd is detected at the estimated margin position, the possibility of reading the code pattern including the light and dark pattern row Ba is very low, and by invalidating the read barcode, Unnecessary data can be surely excluded.

Further, in the barcode reader 10 according to the present embodiment, when the read barcode is invalidated, the light emitting unit 43 is lit in a predetermined warning color so that the user is informed so. and if it barcode not be read as a second bar code B ₂ to read a new bar code to be read is that there is likely to read the first bar code B _1, can be recognized by the user.

In addition, this invention is not limited to the said embodiment, You may actualize as follows, and even in that case, an effect | action and effect equivalent to the said embodiment are acquired.
(1) In the notification process in step S137, not only to inform the readability to the user as the first bar code B ₁ by turning on the light emitting portion 43, for example, by driving the buzzer 44 and a vibrator 45 The user may be notified of the readability as the first barcode B ₁ .

(2) The present invention is not limited to being applied when a partial code pattern of the EAN code matches RSS_Limited, but is applied when a partial code pattern of the UPC code matches RSS_Limited. Also good. Further, according to the present invention, a part of the code pattern of the first barcode based on the first standard is read as a second barcode based on the second standard in which the number of bars is set to be smaller than that of the first standard. It can be applied when there is a possibility that

10 ... barcode reader B ... Barcode B 1 _... first bar code B 2 _... second barcode Ba ... dark pattern string Bb ... determination character Bc ... center bar Bd ... margin

Claims (10)

In a barcode reading method for optically reading a barcode created based on multiple types of standards and decoding the data recorded in the barcode,
Among the plurality of types, a part of the code pattern of the first barcode based on the first standard can be read as a second barcode based on the second standard in which the number of bars is set to be smaller than that of the first standard. If you have sex
A first step of performing reading by applying the reading algorithm of the second standard to a light and dark pattern sequence obtained by binarizing the read barcode;
A second step of determining whether or not a character pattern that can exist in the first barcode exists in at least one of the vicinity of both ends of the light and dark pattern sequence read in the first step;
When it is determined in the second step that the character pattern exists, a margin position corresponding to the first barcode is estimated assuming that the light / dark pattern string is a partial code pattern of the first barcode. 3 steps,
A fourth step of determining the bright and dark pattern string as read data of the second barcode when a margin is not detected at the margin position estimated in the third step;
A bar code reading method comprising:   The barcode reading method according to claim 1, wherein the third step estimates a margin position corresponding to the first barcode based on a center bar of the first barcode.   The said 4th step makes invalid the said barcode read by the said 1st step, when a margin is detected in the said margin position estimated by the said 3rd step. The barcode reading method described in 1.   4. The barcode reading method according to claim 3, further comprising: a fifth step of notifying that the barcode read in the first step is invalidated in the fourth step. The first barcode is any one of an EAN (European Article Number) code and a UPC (Universal Product Code) code.
The barcode reading method according to any one of claims 1 to 4, wherein the second barcode is an RSS (Reduced Space Symbol) code. In a barcode reader that optically reads barcodes created based on multiple types of standards and decodes data recorded in the barcodes,
Among the plurality of types, a part of the code pattern of the first barcode based on the first standard can be read as a second barcode based on the second standard in which the number of bars is set to be smaller than that of the first standard. If you have sex
Reading means for applying a reading algorithm of the second standard to a light and dark pattern string obtained by binarizing the read barcode;
Determining means for determining whether or not a character pattern that may exist in the first barcode exists in at least one of the vicinity of both ends of the light and dark pattern row read by the reading means;
A margin position for estimating a margin position corresponding to the first barcode assuming that the light / dark pattern string is a partial code pattern of the first barcode when the determination unit determines that the character pattern exists. An estimation means;
A determination means for determining the bright and dark pattern string as read data of the second barcode when a margin is not detected at the margin position estimated by the margin position estimation means;
A bar code reader characterized by comprising:   7. The barcode reader according to claim 6, wherein the margin position estimation means estimates a margin position corresponding to the first barcode based on a center bar of the first barcode.   8. The method according to claim 6, wherein the determining unit invalidates the barcode read by the reading unit when detecting a margin at the margin position estimated by the margin position estimating unit. The barcode reader according to the description.   The barcode reading apparatus according to claim 8, further comprising a notifying unit that notifies that the barcode read by the reading unit is invalidated by the determining unit. The first barcode is any one of an EAN (European Article Number) code and a UPC (Universal Product Code) code.
10. The barcode reader according to claim 6, wherein the second barcode is an RSS (Reduced Space Symbol) code. 11.

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