JP2008140255A - Bar code reader and bar code reading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bar code reader and a bar code reading method capable of accurately reading a bar code symbol even if unable to generate a bar code signal wherein the element width of a bar code symbol end is accurately expressed. <P>SOLUTION: In this bar code reader 1, when failing in decoding to a first bar code signal corresponding to a first processing direction caused by an end element positioned at the end of the bar code symbol, a decoding processing part 10 replaces a signal corresponding to the end element in the first bar code signal with a signal corresponding to an end element in a second bar code signal corresponding to a second processing direction to perform complementary processing complementing the first bar code signal, and newly performs the decoding by the use of the complemented first bar code signal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a barcode reading apparatus and a barcode reading method for reading information recorded on a barcode.

  A barcode reader that scans a barcode symbol with a laser beam or the like and reads information recorded in the barcode symbol is widely used. In such a barcode reader, a barcode signal representing the width of each element constituting the barcode symbol is generated by detecting a change in the optical characteristics of the reflected light from the barcode symbol. The information recorded in the bar code symbol is read by performing a decoding process based on the above. By the way, conventionally, the reflected light from the element at the end scanned first tends to include the influence of the surrounding situation where the bar code symbol is printed, such as print quality, paper quality and background. In some cases, it was not possible to generate a bar code signal accurately representing the element width. As a result, in the conventional barcode reader, the barcode signal corresponding to the element at the end is deformed, and barcode reading failure or reading failure occurs.

  For this reason, there has been proposed a barcode reader that estimates the start character and stop character in the barcode symbol and continues the reading process when the barcode signal corresponding to the end element is deformed ( For example, see Patent Document 1).

JP-A-3-166675

  However, in the conventional barcode reader, there may be a case where a start character or stop character different from the actual start character or stop character corresponding to the barcode symbol may be estimated, so that the barcode symbol may be misread. There was a problem.

  The present invention has been made in view of the above, and accurately reads a bar code symbol even when a bar code signal that accurately represents the element width at the end of the bar code symbol cannot be generated. An object of the present invention is to provide a barcode reading apparatus and a barcode reading method that can be used.

  In order to solve the above-described problems and achieve the object, the barcode reader according to the present invention is a barcode that represents each element width of a barcode symbol in which each element is displayed with a width corresponding to the recorded information. Barcode reading comprising signal processing means for generating a signal, and decoding processing means for decoding information recorded in the barcode symbol using measurement information obtained by measuring each element width represented by the barcode signal In the apparatus, the signal processing means generates the first barcode signal in a first processing direction and the second barcode signal in a second processing direction that is different from the first processing direction. The decoding processing means is caused by the end element located at the end of the bar code symbol being decoded for the first bar code signal. If unsuccessful, the signal corresponding to the end element in the first barcode signal is replaced with the signal corresponding to the end element in the second barcode signal to complement the first barcode signal. The complementary processing is performed, and decoding is performed again using the supplemented first bar code signal.

  In the barcode reading apparatus according to the present invention, the decoding processing means uses the measurement value of the end element in the first measurement information of the first barcode signal as the second processing as the complementary processing. Replacing the second measurement information of the barcode signal with the measurement value of the end element to complement the first measurement information, and decoding again using the complemented first measurement information. To do.

  In the barcode reading apparatus according to the present invention, the decode processing means may measure the measurement value of the first measurement information and the measurement value of the second measurement information for an element in a predetermined comparison area of the barcode symbol. When the difference between the two is within a predetermined range, the complementing process is performed.

  The bar code reader according to the present invention is characterized in that the predetermined range can be changed.

  In the barcode reading apparatus according to the present invention, the decode processing means may measure the measurement value of the first measurement information and the measurement value of the second measurement information for an element in a predetermined comparison area of the barcode symbol. Based on the above, a first threshold value in the first measurement information and a second threshold value in the second measurement information are set, and the first threshold value in the first measurement information in the comparison area is set. The first arrangement state of the measurement values exceeding and the measurement values below the first threshold, and the measurement values exceeding the second threshold and the second threshold in the second measurement information in the comparison region are below The complementing process is performed when the second array state of the measurement values matches.

  The bar code reader according to the present invention is characterized in that the number of the first threshold and the number of the second threshold can be changed.

  In the barcode reader according to the present invention, the barcode symbol is irradiated with scanning light according to the first processing direction or the second processing direction, and reflected sequentially from each region in the barcode symbol. Light receiving means for receiving light is further provided, wherein the signal processing means generates the first barcode signal based on a light reception result corresponding to the first processing direction by the light receiving means, and the light receiving means The second barcode signal is generated based on a light reception result corresponding to the second processing direction.

  In the barcode reading apparatus according to the present invention, the decoding processing means may be configured such that when the scanning speed in the first processing direction and the scanning speed in the second processing direction in the light receiving means are different, The complementary processing is performed after correcting either one of the measurement information or the second measurement information in accordance with the scanning speed in the other measurement information.

  In the barcode reader according to the present invention, the light receiving means emits light on the barcode symbol in accordance with the first processing direction or the second processing direction. Scanning means for scanning the light, condensing means for condensing the reflected light, detection means for sequentially receiving the light collected by the condensing means, converting it into an electrical signal, and outputting it to the signal processing means, The signal processing means controls a scanning process in the scanning means.

  The bar code reading device according to the present invention is a light receiving means for irradiating the entire bar code symbol with light and receiving reflected light from the entire bar code symbol to generate a light receiving signal corresponding to the entire bar code symbol. The signal processing means generates the first barcode signal by converting the light reception signal in accordance with the first processing direction, and converts the light reception signal in accordance with the second processing direction. By doing so, the second bar code signal is generated.

  In addition, the barcode reader according to the present invention is further characterized by further comprising storage means for storing the first measurement information and the second measurement information.

  In the barcode reader according to the present invention, the storage means stores the light reception signal, and the signal processing means acquires the light reception signal stored in the storage means to obtain the first barcode. Generating a signal and / or the second barcode signal.

  The bar code reader according to the present invention is characterized in that the comparison area can be changed.

  In addition, the barcode reading method according to the present invention includes a signal processing step for generating a barcode signal representing each element width in a barcode symbol in which each element is displayed with a width corresponding to recorded information, and the barcode And a decoding process step for decoding information recorded in the barcode symbol using measurement information obtained by measuring each element width represented in the signal. The signal processing step includes a first process. A first signal processing step for generating the first barcode signal in a direction, and a second for generating the second barcode signal in a second processing direction that is different from the first processing direction. Signal processing step, wherein the decoding processing step includes the first barcode signal generated in the first signal processing step. A first decoding process step for the first barcode processing step, and in the first decoding processing step, when the decoding of the first barcode signal fails due to an end element located at an end portion of the barcode symbol, A complementing step of complementing the first barcode signal by replacing a signal corresponding to the end element in one barcode signal with a signal corresponding to the end element in the second barcode signal; And a second decoding process step of decoding again using the first barcode signal supplemented in the complementing step.

  Further, in the barcode reading method according to the present invention, in the complementing step, the measurement value of the end element in the first measurement information of the first barcode signal is calculated using the second barcode signal. 2 is replaced with the measurement value of the end element in the measurement information, and the first measurement information is supplemented, and the second decoding processing step uses the first measurement information supplemented in the complementing step. And decoding again.

  In the barcode reading method according to the present invention, in the decoding step, the measurement value of the first measurement information and the measurement value of the second measurement information for an element in a predetermined comparison area of the barcode symbol. And a step of determining whether or not the difference between the first measurement information and the second value is within a predetermined range, and the complementing step includes the measurement value of the first measurement information for the element in the comparison region and the second value in the determination step. This is performed when it is determined that the difference between the measured information and the measured value is within a predetermined range.

  The barcode reading method according to the present invention is characterized in that the predetermined range can be changed.

  In the barcode reading method according to the present invention, in the decoding step, the measurement value of the first measurement information and the measurement value of the second measurement information for an element in a predetermined comparison area of the barcode symbol. And a threshold setting step for setting a first threshold in the first measurement information and a second threshold in the second measurement information, and the first measurement information in the comparison area. An array state of measurement values exceeding one threshold value and measurement values falling below the first threshold value, and a measurement value exceeding the second threshold value and the second threshold value in the second measurement information in the comparison region. An array state obtaining step for obtaining a second array state having a measured value below, an array state determining step for determining whether or not the first array state and the second array state match; If the said first array state the second arrangement state is determined to match in the state determination step, and carrying out the complementation step.

  The barcode reading method according to the present invention is characterized in that the number of the first threshold and the number of the second threshold can be changed.

  In the barcode reading method according to the present invention, the barcode symbol is irradiated with scanning light according to the first processing direction or the second processing direction, and reflected sequentially from each region in the barcode symbol. A light receiving step for receiving light, wherein the first signal processing step generates the first barcode signal based on a light reception result corresponding to the first processing direction by the light receiving step; In the second signal processing step, the second bar code signal is generated based on a light reception result corresponding to the second processing direction by the light receiving means.

  In the barcode reading method according to the present invention, when the decoding processing step is different from the scanning speed in the first processing direction and the scanning speed in the second processing direction in the light receiving step, The method further includes a correction step of correcting either one of the measurement information or the second measurement information in accordance with a scanning speed in the other measurement information, and the complementing step is performed after the correction step. .

  Further, the barcode reading method according to the present invention includes a light receiving step of irradiating the entire barcode symbol with light, receiving reflected light from the entire barcode symbol, and generating a received light signal corresponding to the entire barcode symbol. The first signal processing step generates the first barcode signal by converting the light reception signal generated in the light reception step according to the first processing direction, and generates the second barcode signal. In the signal processing step, the second barcode signal is generated by converting the light reception signal generated in the light reception step according to the second processing direction.

  The barcode reading method according to the present invention further includes a storing step of storing the first measurement information and the second measurement information.

  The barcode reading method according to the present invention is characterized in that the comparison area can be changed.

  In the present invention, when decoding fails due to an end element located at the end of a bar code symbol, an end in the bar code signal obtained by processing a signal corresponding to the end element in the bar code signal in a different processing direction. Even if it is not possible to generate a bar code signal that accurately represents the element at the end of the bar code symbol by replacing the signal corresponding to the sub element and supplementing the bar code signal and decoding again, the bar code The symbol can be read accurately.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments. In the description of the drawings, the same parts are denoted by the same reference numerals.

(Embodiment 1)
First, the first embodiment will be described. FIG. 1 is a schematic diagram illustrating a configuration of the barcode reading apparatus according to the first embodiment. As shown in FIG. 1, the barcode reading apparatus 1 according to the first embodiment reads information recorded on a barcode symbol 20 in which each element is displayed with a width corresponding to the recorded information.

  The barcode reader 1 includes a light source 2, a reflection mirror 3, a scanning mirror 4, a condenser mirror 5, an optical filter 6, a sensor 7, a shield 8, a signal processing unit 9, a decoding processing unit 10, and a storage unit 11.

  The light source 2 emits light such as laser light. The reflection mirror 3 is fixedly arranged and polarizes the light emitted from the light source 2 in the direction of the scanning mirror 4. The scanning mirror 4 can be rotated by a motor or the like, and scans the light polarized by the reflecting mirror 3 on the bar code symbol 20 according to the S1 direction or the S2 direction shown in FIG. Further, the scanning mirror 4 polarizes the reflected light sequentially reflected from each region in the bar code symbol 20 to the condenser mirror 5. The condensing mirror 5 condenses the reflected light from the bar code symbol 20 reflected by the scanning mirror 4 on the sensor 7. The optical filter 6 is provided on the front surface of the sensor 7 and transmits only the wavelength required for barcode reading. The sensor 7 sequentially receives the light collected by the condenser mirror 5 and transmitted through the optical filter 6, converts it into an electrical signal, and outputs it to the signal processing unit 9. The shield 8 has a function of excluding the influence of electromagnetic noise from the sensor 7.

  In the barcode reader 1, the scanning mirror 4 applies the light emitted from the light source 2 to the barcode symbol 20 in accordance with a predetermined first processing direction or a second processing direction that is different from the first processing direction. Let it scan. Specifically, the scanning mirror 4 scans the light emitted from the light source 2 as the forward scanning light in the S1 direction shown in FIGS. 1 and 2, and the light emitted from the light source 2 in S2 shown in FIGS. Scan in the direction as backward scanning light. The light source 2, the reflection mirror 3, the scanning mirror 4, the condensing mirror 5, the optical filter 6, the sensor 7 and the shield 8 scan the barcode symbol in the claims according to the first processing direction or the second processing direction. Light receiving means for receiving the reflected light that is irradiated with light and sequentially reflected from each region in the bar code symbol.

  The signal processing unit 9 amplifies, filters, and binarizes an electrical signal corresponding to the reflected light of the barcode symbol 20 output from the sensor 7, thereby converting a barcode signal representing each element width of the barcode symbol 20. Generate. Further, the signal processing unit 9 controls the scanning process in the scanning mirror 4 by driving a motor in the scanning mirror 4 and controlling the rotation operation of the scanning mirror 4.

  The signal processing unit 9 can generate a first barcode signal in the first processing direction for the barcode symbol 20 and a second barcode signal in the second processing direction. The signal processing unit 9 generates a first barcode signal based on the light reception result corresponding to the first processing direction by the light receiving means in the claims, and receives the light corresponding to the second processing direction by the light receiving means. Based on the result, a second barcode signal is generated. Specifically, when the scanning mirror 4 irradiates the barcode symbol 20 with the forward scanning light in the S1 direction shown in FIGS. 1 and 2, the signal processing unit 9 is based on the light reception result of the sensor 7. A forward bar code signal is generated. In addition, when the scanning mirror 4 irradiates the bar code symbol 20 with the backward scanning light in the S2 direction shown in FIGS. 1 and 2, the signal processing unit 9 detects the backward bar based on the light reception result of the sensor 7. Generate a code signal.

  The decode processing unit 10 decodes the information recorded in the barcode symbol 20 using the count data obtained by counting the element widths represented in the barcode signal generated by the signal processing unit 9, and sends it to an external device (not shown). Output. The storage unit 11 stores count data from the decoding processing unit 10.

  When the decoding for the first barcode signal fails due to the end element located at the end of the barcode symbol, the decode processing unit 10 outputs a signal corresponding to the end element in the first barcode signal. Then, a complementary process for complementing the first barcode signal by replacing with a signal corresponding to the end element in the second barcode signal is performed, and decoding is performed again using the complemented first barcode signal. When the decoding for the first barcode signal fails due to the end element located at the end of the bar code symbol, the decode processing unit 10 uses the end element in the count data of the first bar code signal. Is replaced with the measurement value of the end element in the count data of the second barcode signal to perform the complement processing for complementing the first measurement information, and is decoded again using the supplemented first measurement information. .

  Specifically, the decoding processing unit 10 decodes the backward scanning light after the decoding failure in the forward scanning light and further fails, the measured value of the end element in the count data of the backward barcode signal Is replaced with the measured value of the end element at the same position in the count data of the forward bar code signal stored in the storage unit 11 to complement the reverse direction count data. Then, the decode processing unit 11 performs the decoding process again using the complemented reverse count data. The storage unit 11 stores count data of the forward barcode signal and count data of the backward barcode signal.

  By the way, in the barcode reader 1, when the barcode symbol 20 is printed in a good state not affected by the surrounding situation, the barcode corresponding to the forward scanning light in the S1 direction shown in FIG. Since the signal is generated accurately, decoding is successful in one scan. However, as shown in FIG. 2, when the margin regions Gs and Ge at the end of the barcode symbol 20 have a background color other than a picture, character, or white, the element width at the end of the barcode symbol in the barcode signal Cannot be reproduced accurately. For this reason, in the barcode reader 1, decoding in the forward scanning light that is the first scanning light may fail. In this case, the barcode reader 1 irradiates the barcode symbol 20 with the backward scanning light as the second scanning light for re-decoding. However, even when reverse scanning light is used, the element width at the end of the bar code symbol cannot be generated accurately due to the influence of the margin regions Gs and Ge, and the second decoding may fail. In this case, the barcode reading apparatus 1 according to the first embodiment performs a complementing process.

  This will be specifically described with reference to FIGS. FIG. 3 is a diagram illustrating a light reception signal of the sensor 7 and a reverse barcode signal of the signal processing unit 9 when the backward scanning light is irradiated according to the S2 direction. FIG. 4 is a diagram illustrating a light reception signal of the sensor 7 and a forward barcode signal of the signal processing unit 9 when the forward scanning light is irradiated according to the S1 direction. FIG. 5 is a diagram for explaining the complementing process in the decoding processing unit 10. 3 and 4, an area including the right end portion of the bar code symbol 20 is shown.

  First, the case where decoding fails due to the end element of the barcode symbol 20 will be described in detail with reference to FIG. As shown in FIG. 3, when scanning the barcode symbol 20 according to the S2 direction, the reflected light to the element Ee located at the right end of the barcode symbol 20 is first received by the sensor 7. Next, the signal processing unit 9 first-order differentiates the light reception signal W2 sequentially output according to the S2 direction, whereby a differential signal E2 in which an increase / decrease edge of the light reception amount of the light reception signal W2 is represented by a peak signal in the vertical direction. Is generated.

  Here, when the margin area Ge of the element Ee has a background color other than a picture, a character, or white, the reflectance is lower than that of the white background color. For this reason, as shown in the light reception signal W2, the amount of light received in the region Sg corresponding to the margin region Ge is lower than the amount of light received in the region Sw corresponding to the white background region. Furthermore, since the element Ee is black, the amount of light received in the region Se corresponding to the element Ee is further lower than the amount of light received in the region Sg. Therefore, the signal processing unit 9 generates a downward peak signal Pg2 corresponding to the boundary between the margin region Ge and the white background region, and then generates the margin region Ge and the element as shown in the differential signal E2 of FIG. Corresponding to the boundary with Ee, the same downward peak signal Pe2 as the peak signal Pg2 is generated.

  Next, the signal processing unit 9 processes the differential signal E2 in accordance with the S2 direction. If there is a downward peak signal, the signal processing unit 9 lowers the barcode signal, and the upward peak next to the downward peak. When there is a signal, the barcode signal is raised to generate a barcode signal B2 representing a time width corresponding to each element width of the barcode symbol 20. Further, when there is a peak signal in the same direction in the received light signal, the signal processing unit 9 determines the vertical direction of the barcode signal according to the peak signal first, and then the peak signal in the same direction Even if it is, the vertical direction of the barcode signal is not changed, and the vertical direction of the barcode signal is changed when there is a peak signal in a different direction.

  Therefore, when the signal processing unit 9 generates the barcode signal B2 from the light reception signal W2 according to the S2 direction, the barcode signal B2 at the position P1 according to the peak signal Pg2 corresponding to the margin region Ge of the differential signal E2. Lower. The signal processing unit 9 maintains the barcode signal B2 as it is at the position P2 even when there is a peak signal Pe2 corresponding to the right end of the element Ee that is the original reading target. Then, the signal processing unit 9 raises the direction of the barcode signal B2 upward at the position P3 according to the peak signal detected at the left end of the element Ee.

  As described above, when the margin area Ge of the element Ee has a background color other than a picture, a character, or white, the signal processing unit 9 does not use the element Ee end of the barcode end that is the original reading target but the margin area Ge. The direction of the barcode signal is determined at the end. As a result, the first portion of the barcode signal B2 includes not only the width Dl of the element Ee that is the original reading target but also the width Dg of the margin region Ge. The barcode signal B2 Unlikely, the width of the end element Ee cannot be accurately reproduced. Therefore, the signal processing unit 9 cannot accurately measure the width of the end element Ee when the barcode signal B2 is used, and thus the decoding process fails.

  Here, in the barcode reading apparatus 1, before the backward scanning in which the scanning is performed in the S2 direction, the forward scanning in which the scanning is performed in the S1 direction is performed. In the forward scanning along the S1 direction, as shown in FIG. 4, the scanning direction is opposite to the backward scanning. In other words, since the barcode reader 1 irradiates the same barcode symbol 20 with scanning light in different directions, the received light signal W1 representing the barcode symbol 20 is output in the reverse order to the received light signal W2 in the backward scanning. The same waveform signal. Further, in the forward scanning, the received light signal is processed and a barcode signal is generated according to the reverse direction to the backward scanning. For this reason, in the forward scanning, the first element Ee that could not generate the barcode signal accurately in the backward scanning is scanned last to form the last part of the barcode signal. Since the last part of the barcode signal is hardly affected by the margin region Ge, the width of the element Ee at the end is often accurately reproduced.

  Specifically, as shown in FIG. 4, the signal processing unit 9 generates a barcode signal B1 from the differential signal E1 obtained by processing the light reception signal W1 obtained by the forward scanning according to the S1 direction. In the region corresponding to the end element Ee, the signal processing unit 9 lowers the barcode signal B1 downward at the position P3 according to the peak signal corresponding to the left end of the element Ee in the differential signal E1. Next, the signal processing unit 9 raises the barcode signal B1 upward at the position P2 in accordance with the peak signal Pe1 corresponding to the right end of the element Ee. The signal processing unit 9 maintains the barcode signal as it is even when there is a peak signal Pg1 corresponding to the right end of the margin region Ge. As a result, since the last part of the barcode signal B1 represents only the width Dl of the element Ee that is the original reading object, the barcode signal B1 accurately reproduces the width of the end element Ee. It will be a thing. In this way, the signal processing unit 9 uses the barcode B2 that first generates the signal of the end element Ee in the S2 direction in the barcode signal B1 that finally generates the signal of the element Ee in the S1 direction. Unlikely, the element Ee width can be expressed accurately.

  Therefore, as shown by an arrow Y1 in FIG. 5, the decode processing unit 10 sequentially outputs a signal in the region B2t including the width Dg of the margin region Ge together with the width Dl of the end element Ee in the barcode signal B2 in the backward scanning. This is complemented by replacing with the signal of the region B1l representing only the width Dl of the end element Ee in the bar code signal B1 of direction scanning. As a result, the decode processing unit 10 does not include the width Dg of the margin region Ge and does not include the width Dg of the margin region Ge, as shown by an arrow Y2 in FIG. Can be generated. The decode processing unit 10 can obtain the width of the end element Ee accurately by performing the decode process again using the complemented barcode signal B2a, and can successfully perform the decode process. In actual processing, the decoding processing unit 10 performs a complementary process using count data obtained by counting the width of each element of the barcode signal B2 and count data obtained by counting the width of each element of the barcode signal B1. To do. Specifically, the decode processing unit 10 replaces the count value corresponding to the area B2t in the count data of the barcode signal B2 with the count value corresponding to the area B1l in the count data of the barcode signal B1, thereby The count data corresponding to the signal B2 is complemented, and the decoding process is performed again using the complemented count data.

  Next, the barcode reading process of the barcode reading apparatus 1 will be described with reference to FIG. FIG. 6 is a flowchart showing the processing procedure of the barcode reading process in the barcode reading apparatus 1 shown in FIG.

  First, as shown in FIG. 6, the barcode reader 1 performs forward decoding processing on the barcode signal generated in the S1 direction of FIG. 2, for example (step S2). The decoding processing unit 10 determines whether the forward decoding process in step S2 has succeeded or failed (step S4). When the decoding processing unit 10 determines that the forward decoding process has been successful (step S4: success), the decoding processing unit 10 outputs the read barcode symbol 20 information to an external device (not shown) and uses the count used in the forward decoding process. The data is erased and the barcode reading process is terminated.

  On the other hand, when the decoding processing unit 10 determines that the forward decoding process has failed (step S4: failure), after holding the count data used in the forward decoding process in the storage unit 11 (step S6), for example, A backward decoding process is performed on the barcode signal generated in the S2 direction of FIG. 2 (step S8). Then, the decoding processing unit 10 determines whether the backward decoding process in step S8 has succeeded or failed (step S10). When the decoding processing unit 10 determines that the backward decoding process is successful (step S10: success), the decoding processing unit 10 outputs the read barcode symbol 20 information to an external device (not shown) and forward decoding processing and backward decoding processing. The count data used in is erased and the barcode reading process is terminated.

  On the other hand, when the decoding processing unit 10 determines that the backward decoding process has failed (step S10: failure), the first character of the barcode symbol 20 is caused by the element processed first in the backward decoding process. It is determined whether or not the decoding process has failed because the pattern does not match the decoding table (step S12). When the decoding processing unit 10 determines that the decoding process has not failed because the first character pattern of the bar code symbol 20 does not match the decoding table (step S12: No), the decoding processing unit 10 returns to step S2 and forwards again. Perform decoding processing.

  On the other hand, when the decoding processing unit 10 determines that the decoding process has failed because the first character pattern of the barcode symbol 20 does not match the decoding table (step S12: Yes), it is used in the backward decoding process. The counted data is held in the storage unit 11 (step S14).

  Then, the decoding processing unit 10 performs a complementing process for complementing the count data in the backward decoding process with the count data in the forward decoding process (step S16). Next, the decoding processing unit 10 performs the decoding process again using the count data supplemented in the complementing process (step S18), and determines whether the decoding process has succeeded or failed (step S20). When the decoding processing unit 10 determines that the decoding process is successful (step S20: success), the decoding processing unit 10 outputs the read barcode symbol 20 information to an external device (not shown) and performs forward decoding processing and backward decoding processing. The used count data is deleted and the barcode reading process is terminated. On the other hand, when it is determined that the decoding process has failed (step S20: failure), the decoding processing unit 10 returns to step S2 and performs the forward decoding process again. In step S6 and step S14, the decoding processing unit 10 holds the entire count data in the forward decoding process and the backward decoding process in the storage unit 11 and only a part of the count data used in the complementing process. It may be held.

  Next, the forward decoding process shown in FIG. 6 will be described. FIG. 7 is a flowchart showing a processing procedure of the forward decoding process shown in FIG. As shown in FIG. 7, in the forward decoding process, the light source 2 and the scanning mirror 4 are driven to irradiate the barcode symbol 20 with scanning light in the forward direction according to the S1 direction (step S21). Next, the sensor 7 sequentially receives the reflected light, converts it into an electrical signal, and outputs it to the signal processing unit 9. The signal processing unit 9 receives the electrical signal output from the sensor 7, and as illustrated in the light reception signal W1 in FIG. 4, the light reception signal corresponding to the barcode symbol 20 is reflected light with respect to the forward scanning light. Is detected (step S22).

  Next, the signal processing unit 9 generates a bar code signal in the forward direction by performing processing such as primary differentiation on the detected light reception signal (step S23), and generates the bar code generated in the decoding processing unit 10. Output a signal. The decode processing unit 10 counts each element width in the barcode signal generated by the signal processing unit 9 (step S24), generates forward count data, and stores the forward count data in the storage unit 11 ( Step S25). Then, the decode processing unit 10 refers to the decode table and performs a decoding process for obtaining a character pattern corresponding to each count value in the count data (step S26).

  Next, the backward decoding process shown in FIG. 6 will be described. FIG. 8 is a flowchart showing a processing procedure of the backward decoding process shown in FIG. As shown in FIG. 8, in the reverse decoding process, the light source 2 and the scanning mirror 4 are driven to irradiate the barcode symbol 20 with scanning light in the reverse direction according to the S2 direction (step S31). Next, the sensor 7 sequentially receives the reflected light, converts it into an electrical signal, and outputs it to the signal processing unit 9. The signal processing unit 9 receives the electrical signal output from the sensor 7 and, as exemplified by the light reception signal W2 in FIG. 3, the light reception signal corresponding to the barcode symbol 20 that is reflected light with respect to the backward scanning light. Is detected (step S32).

  Next, the signal processing unit 9 generates a barcode signal in the reverse direction by performing a process such as a primary differentiation process on the detected light reception signal (step S33), and generates the barcode generated in the decoding processing unit 10. Output a signal. The decode processing unit 10 counts each element width in the barcode signal generated by the signal processing unit 9 (step S34), generates reverse count data, and stores the reverse count data in the storage unit 11 ( Step S35). Then, the decode processing unit 10 refers to the decode table and performs a decoding process for obtaining a character pattern corresponding to each count value in the count data (step S36).

  Next, the complementing process shown in FIG. 6 will be described. FIG. 9 is a flowchart showing a processing procedure of the complement processing shown in FIG. As shown in FIG. 9, the decode processing unit 10 acquires count data corresponding to the barcode signal in the forward decoding process and count data corresponding to the barcode signal in the backward decoding process from the storage unit 11 (step S41). ). Next, the decoding processing unit 10 replaces the count value of the first part in the count data of the backward decoding process with the count value of the last part in the count data of the forward decoding process (step S42), and the replaced backward decoding process Is stored in the storage unit 11 as complementary count data (step S43), and the complementary processing is terminated.

  Thus, according to the first embodiment, when decoding fails due to the end element located at the end of the bar code symbol, the signal corresponding to the end element in the bar code signal is processed in a different processing direction. It is not possible to generate a barcode signal that accurately represents the element at the end of the bar code symbol by replacing the bar code signal with the signal corresponding to the end element in the bar code signal processed in step 2 Even in this case, the bar code symbol can be read accurately.

(Embodiment 2)
Next, a second embodiment will be described. FIG. 10 is a schematic diagram illustrating a configuration of the barcode reading apparatus according to the second embodiment. As shown in FIG. 10, the barcode reading apparatus 201 according to the second embodiment has a configuration including a decoding processing unit 210 instead of the decoding processing unit 10 in the barcode reading apparatus 1 shown in FIG. 1. When the count value of the forward scan count data matches the count value of the reverse scan count data for the element in the predetermined comparison area of the bar code symbol, or the predetermined value of the bar code symbol When the difference between the count value of the forward scan count data and the count value of the reverse scan count data for the elements in the comparison region is within a predetermined range, the same processing as that of the decoding processing unit 10 shown in FIG. Complement processing is performed in the processing procedure.

  Next, the barcode reading process of the barcode reading apparatus 201 shown in FIG. 10 will be described. FIG. 11 is a flowchart showing the processing procedure of the barcode reading process in the barcode reading apparatus 201 shown in FIG.

  As shown in FIG. 11, the bar code reader 201 performs the forward decoding process (step S202), the decoding success determination process (step S204), and the forward data holding process (step S204) as in steps S2 to S12 of FIG. Step S206), backward decoding processing (step S208), decoding success determination processing (step S210), and first character pattern mismatch determination processing (step S212) are performed.

  When the decoding processing unit 210 determines that the decoding process has failed because the first character pattern of the bar code symbol 20 does not match the decoding table (step S212: Yes), the count data of the forward scan in the predetermined comparison region It is determined whether or not the count value of the counter value coincides with the count value of the count data of the backward scanning (step S213). In step S213, it may be determined whether or not the difference between the count value of the forward scan count data and the count value of the reverse scan count data in the predetermined comparison area is within a predetermined range. . The scanning speed in the forward scanning and the scanning speed in the backward scanning do not always coincide completely. Therefore, if there is a difference in the scanning speed in each direction, even if the scanning in each direction in the predetermined comparison area is performed normally, the count value of the forward scan count data is in the reverse direction. There may be a difference in the count value of the scan count data. Therefore, a range corresponding to the scanning speed deviation between the forward scanning and the backward scanning is set, and the difference between the count value of the forward scanning count data and the count data of the backward scanning count data in a predetermined comparison area is determined. If the predetermined range is set, it can be determined that scanning in each direction is normally performed.

  Specifically, as shown in FIG. 12, the decode processing unit 210, for example, next to the end element Ee in the barcode signal B1 corresponding to forward scanning and the barcode signal B2 corresponding to backward scanning. The element widths of the regions including a predetermined number of elements from the elements positioned at are respectively compared. As indicated by an arrow Y21 in FIG. 12, the decoding processing unit 210 has a width of each element in the region Bc1 of the barcode signal B1 and each element in the region Bc2 of the barcode signal B2 corresponding to the region Bc1 of the barcode signal B1. Compare the width of. Then, the decoding processing unit 210 determines whether or not the width of each element in the region Bc1 of the barcode signal B1 matches the width of each element in the region Bc2 of the barcode signal B2. In step S213, when it is determined whether or not the difference between the count value of the forward scan count data and the count value of the reverse scan count data in the predetermined comparison area is within a predetermined range, the decoding is performed. The processing unit 210 may determine whether the difference between the width of each element in the area Bc1 of the barcode signal B1 and the width of each element in the area Bc2 of the barcode signal B2 is within a predetermined range. In addition, the comparison area and the predetermined range in which the element widths are compared in step S213 can be changed according to instruction information input from an external device (not shown). For this reason, the region compared in step S213 is not limited to the region including the element adjacent to the end element Ee illustrated in FIG. 12, but the barcode symbol 20 in which the barcode signal is expressed more stably and accurately. It may be the central part. Further, the number of elements included in the comparison region may be greater than or equal to the number shown in FIG. 12, or may be singular. By changing the comparison area, it is possible to change the number of elements to be compared, the area, and the like.

  When the decode processing unit 210 determines that the count value of the forward scan count data in the predetermined comparison region does not match the count value of the reverse scan count data, or the forward scan in the predetermined comparison region When it is determined that the difference between the count value of the count data and the count value of the count data of the backward scanning is not within the predetermined range (step S213: No), the barcode signal is accurately generated even in the elements other than the end elements. Therefore, the process returns to step S202, and the forward decoding process is performed again.

  On the other hand, when the decode processing unit 210 determines that the count value of the forward scan count data in the predetermined comparison area matches the count value of the reverse scan count data, the forward processing in the predetermined comparison area. When it is determined that the difference between the count value of the scan count data and the count value of the reverse scan count data is within a predetermined range (step S213: Yes), an accurate bar code other than the end element is used. Since it is considered that a signal is generated, a complementary process is performed by performing the same processing procedure as in step S16 shown in FIG. 6 (step S216). As a result, the decoding processing unit 210 can acquire a barcode signal that is considered to be accurately reproduced as a whole barcode signal including the end elements. Then, similarly to step S18 and step S20 shown in FIG. 6, a decoding process (step S218) and a decoding success determination process (step S220) are performed. Note that in steps S206 and S214, the decoding processing unit 10 holds the entire count data in the forward decoding process and the backward decoding process in the storage unit 11, and among the count data, in the determination process in step S213 and in step S216. Only a part used in the complementing process may be retained.

  As described above, in the second embodiment, before the complementing process, the count data in the predetermined comparison region of the count data in the forward decoding process and the count data in the backward decoding process used in the complementing process match. Or whether or not the difference between the count value of the forward scan count data and the count value of the reverse scan count data in the predetermined comparison area is within a predetermined range. It is verified whether or not an accurate barcode signal is generated in a region other than the region corresponding to the end element. Therefore, according to the second embodiment, it is possible to further improve the accuracy in the count data complementing process as compared with the first embodiment.

  In the second embodiment, the case where the count values of the count data in the predetermined comparison area are compared has been described. However, the information recorded in the bar code symbol 20 based on the arrangement state of the thin elements and the thick elements is described. In the case of reading, complementation processing may be performed after comparing the arrangement state of elements of each thickness in a predetermined comparison region. A specific description will be given with reference to FIGS.

  FIG. 13 is a schematic diagram illustrating another configuration of the barcode reading apparatus according to the second embodiment. A barcode reader 201a shown in FIG. 13 has a configuration including a decode processor 210a instead of the decode processor 210 in the barcode reader 201 shown in FIG. The decode processing unit 210a performs forward bar code based on the count value of the count data of the forward bar code signal and the count value of the count data of the reverse bar code signal for the elements in the predetermined comparison area of the bar code symbol 20. A first threshold value in the count data of the code signal and a second threshold value in the count data of the backward barcode signal are set. Then, the decoding processing unit 210a has a first arrangement indicating a first arrangement state of a count value exceeding the first threshold and a count value falling below the first threshold in the count data of the forward barcode signal in the comparison area. Get the pattern. Then, the decode processing unit 210a has a second arrangement indicating a second arrangement state of the count value exceeding the second threshold and the count value falling below the second threshold in the count data of the backward barcode signal in the comparison area. Get the pattern. Next, the decoding processing unit 210a determines whether or not the first array pattern and the second array pattern corresponding to each comparison region match each other, and the first array pattern and the second array pattern are determined. Complement processing is performed when it is determined that they match.

  Next, the barcode reading process of the barcode reading apparatus 201a shown in FIG. 13 will be described. FIG. 14 is a flowchart showing a processing procedure of barcode reading processing in the barcode reading apparatus 201a shown in FIG. As shown in FIG. 14, the barcode reader 201a obtains count data for the forward barcode signal and obtains an array pattern, a forward decoding process (step S222), a decoding success determination process (step S224), Direction data holding process (step S226), reverse decoding process (step S228) for obtaining count data for the backward barcode signal and obtaining an array pattern, decoding success judgment process (step S230), and first character pattern mismatch judgment Processing (step S232) is performed.

  When the decoding processing unit 210a determines that the decoding process has failed because the first character pattern of the barcode symbol 20 does not match the decoding table (step S232: Yes), the forward scanning array pattern in the predetermined comparison region It is determined whether or not the array pattern of the reverse scanning matches (step S233).

  When the decoding processing unit 210 determines that the forward scanning array pattern and the backward scanning array pattern in the predetermined comparison area do not match (step S233: No), the barcode signal is also output from elements other than the end elements. Since it is considered that the data has not been generated correctly, the process returns to step S222 and the forward decoding process is performed again.

  On the other hand, when the decoding processing unit 210a determines that the forward scanning array pattern and the backward scanning array pattern in the predetermined comparison region match (step S233: Yes), except for the end element, Since it is considered that an accurate barcode signal has been generated, a complementary process is performed by performing the same processing procedure as step S16 shown in FIG. 6 (step S236). As a result, the decoding processing unit 210a can acquire a barcode signal that is considered to be accurately reproduced as a whole barcode signal including the end element. Then, similarly to step S18 and step S20 shown in FIG. 6, a decoding process (step S238) and a decoding success determination process (step S240) are performed. In step S226 and step S234, the decode processing unit 10 holds the entire count data in the forward decoding process and the backward decoding process in the storage unit 11, and among the count data, in the determination process in step S233 and in step S236. Only a part used in the complementing process may be retained.

  Next, the forward decoding process shown in FIG. 14 will be described with reference to FIG. As shown in FIG. 15, as the forward decoding process, the decoding processing unit 210 a performs a forward scanning light irradiation process (step S <b> 241), a forward processing by performing a processing procedure similar to steps S <b> 21 to S <b> 24 shown in FIG. 7. Direction scanning light reception processing (step S242), forward barcode signal generation processing (step S243), and element width count processing (step S244) are performed.

  Then, the decode processing unit 210a performs a threshold setting process for setting a threshold based on the count value in a predetermined comparison area in the count data for the barcode signal in the forward scanning (step S245). For example, as shown in FIG. 17, when the barcode signal 20 is arranged with either an element larger than the predetermined width or an element thinner than the predetermined width, the decoding processing unit 210a performs the barcode signal B1 in the forward scanning. Based on the count data obtained by counting the element widths in the comparison area BC11, an element width threshold value is set that can classify the narrow and wide elements in the barcode signal B1. In this case, the value T1 corresponding to the width of the signal Bc1th in FIG. 17 that can classify the narrow-width element and the thick-width element is set as the first threshold value in the forward decoding process. A signal having a narrower width than the signal Bc1th, that is, a count value having a count value smaller than the threshold value T1, can be determined to correspond to an element having a narrow width. A signal having a wider width than the signal Bc1th, that is, a count value having a count value larger than the threshold value T1, can be determined to correspond to an element having a thick width.

  Then, the decoding processing unit 210a has a first arrangement indicating a first arrangement state of a count value exceeding the first threshold and a count value falling below the first threshold in the count data of the forward barcode signal in the comparison area. An array pattern acquisition process for acquiring a pattern is performed (step S246). Specifically, as shown in FIG. 17, when the count value in the count data of the forward barcode signal is lower than the threshold value T1, it can be determined that the element corresponds to an element having a width smaller than the threshold value T1, and the count value is When it exceeds the threshold value T1, it can be determined that it corresponds to an element having a width narrower than the threshold value T1. As a result, the decoding processing unit 210a can acquire an arrangement pattern indicating in what order the thin elements and the thick elements are arranged as in the signal Bs1 of FIG.

  Then, the decoding processing unit 210a stores the array pattern as forward data together with the acquired count data in the storage unit 11 (step S247), and performs a decoding process using the acquired count data and the array pattern (step S248). When using the arrangement pattern, the decoding processing unit 210a acquires information recorded in the barcode signal 20 based on the arrangement state of the thin elements and the thick elements.

  Next, the backward decoding process shown in FIG. 14 will be described with reference to FIG. As shown in FIG. 16, as the backward decoding process, the decoding processing unit 210 a performs the backward scanning light irradiation process (step S <b> 251), the reverse by performing the same processing procedure as step S <b> 31 to step S <b> 34 shown in FIG. 8. Direction scanning light reception processing (step S252), reverse barcode signal generation processing (step S253), and element width count processing (step S254) are performed.

  Then, the decode processing unit 210a performs a threshold setting process for setting a threshold based on the count value in a predetermined comparison area in the count data for the barcode signal in the backward scanning (step S255). For example, as shown in FIG. 17, the decoding processing unit 210a classifies the narrow width element and the wide width element from the count data obtained by counting the width of each element in the comparison area BC21 of the barcode signal B2 in the backward scanning. Set a threshold of element width that can be done. In this case, a value T2 corresponding to the width of the signal Bc2th in FIG. 17 that can classify the narrow-width element and the thick-width element in the barcode signal B2 is set as the second threshold value in the backward decoding process. A signal having a narrower width than the signal Bc2th, that is, a count value having a count value smaller than the threshold value T2, can be determined to correspond to an element having a narrow width. A signal having a wider width than the signal Bc2th, that is, a count value having a count value larger than the threshold value T2, can be determined to correspond to an element having a thick width.

  Then, the decode processing unit 210a has a second array indicating the first array state of the count value exceeding the second threshold and the count value falling below the second threshold in the count data of the backward barcode signal in the comparison area. An array pattern acquisition process for acquiring a pattern is performed (step S256). Specifically, as shown in FIG. 17, when the count value in the count data of the reverse barcode signal is lower than the threshold value T2, it can be determined that it corresponds to an element having a width narrower than the threshold value T2, and the count value is When it exceeds the threshold value T2, it can be determined that it corresponds to an element having a width narrower than the threshold value T2. As a result, the decoding processing unit 210a can acquire an arrangement pattern indicating in what order the thin elements and the thick elements are arranged as in the signal Bs2 of FIG.

  Then, the decoding processing unit 210a stores the array pattern as reverse data together with the acquired count data in the storage unit 11 (step S257), and performs a decoding process using the acquired count data and the array pattern (step S258).

  In step S233 shown in FIG. 14, the decoding processing unit 210a compares the signal Bs1 indicating the arrangement pattern corresponding to the barcode signal B1 with the signal Bs2 indicating the arrangement pattern corresponding to the barcode signal B2, and outputs the signal Bs1. And whether the arrangement state of the narrow-width element and the thick-width element in the signal Bs2 matches. Specifically, as shown by an arrow Y22 in FIG. 18, the decoding processing unit 210a performs the arrangement state of the narrow and wide elements of the signal Bs1, and the narrow and thick elements of the signal Bs2. When it is determined that the arrangement state of the barcode signal B1 matches that of the barcode signal B1 (step S233: Yes), an accurate arrangement pattern in the barcode signal B1 and the barcode signal B2 is obtained in a region other than the region corresponding to the end element to be complemented. Can be judged. For this reason, the decoding processing unit 210a proceeds to step S234 and step S246, and performs a complementing process. If the decoding processing unit 210a determines in step S233 shown in FIG. 14 that the arrangement state of the narrow-width elements and the thick-width elements in the signal Bs1 and the signal Bs2 does not match (step S233: No), the complement target It is determined that the accurate arrangement pattern in the barcode signal B1 and the barcode signal B2 is not obtained in the region other than the region corresponding to the end element, and the process proceeds to step S222, and the forward decoding process is performed again. To do.

  As shown in FIGS. 13 to 18, even when the information of the barcode symbol 20 is read based on the arrangement state of the elements of each thickness, the elements of each thickness in the predetermined comparison area in the predetermined comparison area are read. By performing the complement processing after comparing the array states, it is possible to further improve the accuracy in the count data complement processing.

  In FIGS. 17 and 18, the case where the barcode symbol 20 is formed by two types of thin elements and thick elements and a single threshold value is set has been described, but the present invention is not limited to this. When there are three or more types of element widths constituting the barcode symbol 20, the decode processing unit 210a may set each threshold value corresponding to the width of each type of element and acquire each array pattern. . For example, if the element thickness of the barcode symbol 20 is divided into three types: thick, medium, and thin, the threshold value that allows the element thickness to be classified as thick and medium, and the element thickness Two types of threshold values, a threshold value that can classify medium and thin items, are set in each of the forward decoding process and the backward decoding process, and thick, medium, and thin elements are set based on the two types of threshold values. Can be classified. Further, the number of each threshold can be changed according to instruction information input from an external device (not shown) according to the thickness of each element constituting the barcode symbol 20 to be read.

(Embodiment 3)
Next, a third embodiment will be described. FIG. 19 is a schematic diagram illustrating a configuration of the barcode reading apparatus according to the third embodiment. As illustrated in FIG. 19, the barcode reading apparatus 301 according to the third embodiment includes a decoding processing unit 310 instead of the decoding processing unit 210 in the barcode reading apparatus 201 illustrated in FIG. 10. When the reverse scanning speed and the forward scanning speed in the light receiving unit are different, the decoding processing unit 310 converts either the count data corresponding to the backward scanning or the count data corresponding to the forward scanning in the other count data. Complement processing is performed after correction corresponding to the scanning speed.

  Next, the barcode reading process of the barcode reading device 301 shown in FIG. 19 will be described. FIG. 20 is a flowchart showing a processing procedure of barcode reading processing in the barcode reading apparatus 301 shown in FIG.

  As shown in FIG. 20, the bar code reader 301 performs forward decoding processing (step S302), decoding success determination processing (step S304), and forward data holding processing (step S304) as in steps S202 to S212 of FIG. Step S306), backward decoding processing (step S308), decoding success determination processing (step S310), and first character pattern mismatch determination processing (step S311) are performed.

  Then, the decode processing unit 310 performs a correction process for correcting either one of the count data corresponding to the backward scanning and the count data corresponding to the forward scanning in accordance with the scanning speed of the other count data (step S312). ). For example, as shown in FIG. 21, the decoding processing unit 310 has a scanning speed in the backward scanning slower than the scanning speed in the forward scanning, and each element width of the barcode signal B2b has a barcode signal B1 in the forward scanning. As shown by an arrow Y31, the barcode signal B2c is generated by correcting the barcode signal in the backward scanning in accordance with the scanning speed in the forward scanning. Then, the decode processing unit 310 uses the barcode B1 and the corrected barcode signal B2c, similarly to steps S213 to S220 shown in FIG. 11, to determine the comparison value of the comparison area count value (step S313), Reverse data holding processing (step S314), complement processing (step S316), decoding processing (step S318), and decoding success determination processing (step S320) are performed.

  Thus, according to the third embodiment, even if the scanning speeds in the forward scanning and the backward scanning are different, the accuracy of the decoding process is improved by performing the complementing process after the correction process. Can do.

(Embodiment 4)
Next, a fourth embodiment will be described. FIG. 22 is a schematic diagram illustrating a configuration of the barcode reading apparatus according to the fourth embodiment. As shown in FIG. 22, the barcode reader 401 according to the fourth embodiment includes a reflection mirror 3, a scanning mirror 4, a condensing mirror 5, an optical filter 6, a sensor 7, and a sensor 7 in the barcode reader 1 shown in FIG. Instead of the shield 8, an imaging unit 407 and a transfer processing unit 408 are provided. Further, the barcode reading apparatus 401 includes a signal processing unit 409 instead of the signal processing unit 9 in the barcode reading apparatus 1 shown in FIG. The light source 2 irradiates the entire barcode symbol 20 with light.

  The imaging unit 407 is configured by a CCD (Charge Coupled Diode) or the like, and receives the reflected light reflected from the entire barcode symbol 20 out of the light irradiated to the entire barcode symbol 20 by the light source 2, and this barcode. A light reception signal corresponding to the entire symbol 20 is generated. As illustrated in FIG. 23, the imaging unit 407 generates a light reception signal Wc having a waveform indicating the amount of reflected light reflected from the entire barcode symbol 20. The transfer processing unit 408 includes a memory 408 a that stores the light reception signal output from the imaging unit 407, and transfers the light reception signal to the signal processing unit 409.

  The signal processing unit 409 includes a memory 409 a that stores the light reception signal transferred from the transfer processing unit 409. The signal processing unit 409 acquires the received light signal stored in the memory 409a, generates a first barcode signal by converting the waveform signal according to the first processing direction, and follows the second processing direction. A second barcode signal is generated by converting the waveform signal. Specifically, as shown in FIG. 23, the signal processing unit 409 first differentiates the received light signal Wc according to the C1 direction which is the forward direction and then detects each peak signal to generate a forward barcode signal. . When the decoding process on the forward barcode signal in the decoding processor 10 fails, the signal processing unit 409 processes the light reception signal Wc according to the C2 direction which is the reverse direction to generate a reverse barcode signal. Also in this case, as in the first embodiment, when a background color other than a picture, character, or white is in the margin area, it is affected by the margin area, and the first part of the barcode signal is the end element. The width of may not be accurately reproduced. For this reason, as in the first embodiment, the decoding processing unit 10 realizes accurate decoding processing by generating count data obtained by accurately counting the element width of the end portion in the complementing processing.

  Next, the barcode reading process of the barcode reading device 401 will be described with reference to FIG. FIG. 24 is a flowchart showing the processing procedure of the barcode reading process in the barcode reading device 401 shown in FIG.

  First, as illustrated in FIG. 24, the imaging unit 407 performs imaging processing that receives reflected light from the entire barcode symbol 20, generates a received light signal corresponding to the entire barcode symbol 20, and outputs the received light signal to the transfer processing unit 408. This is performed (step S402). The transfer processing unit 408 performs a transfer process of transferring the light reception signal output from the imaging unit 407 to the signal processing unit 409 (step S404). Next, the signal processing unit 409 stores the received light signal transferred from the transfer processing unit 408 in the memory 409a (step S406). Then, the signal processing unit 409 and the decoding processing unit 10 perform forward decoding processing for processing the received light signal in the C1 direction of FIG. 23 and performing decoding processing (step S408). Next, it is determined whether the forward decoding process in step S408 has succeeded or failed (step S410). When the decoding processing unit 10 determines that the forward decoding process is successful (step S410: success), the decoding processing unit 10 outputs the read barcode symbol 20 information to an external device (not shown) and counts used in the forward decoding process. The data is erased and the barcode reading process is terminated.

  On the other hand, when the decoding processing unit 10 determines that the forward decoding process has failed (step S410: failure), after holding the count data used in the forward decoding process in the storage unit 11 (step S412), for example, A reverse decoding process is performed in which the received light signal is processed in the C2 direction of FIG. 23 to perform a decoding process (step S414). Then, the decoding processing unit 10 determines whether the backward decoding process in step S414 has succeeded or failed (step S416). When the decoding processing unit 10 determines that the backward decoding process has been successful (step S416: success), the decoding processing unit 10 outputs the read barcode symbol 20 information to an external device (not shown), and forward decoding processing and backward decoding processing. The count data used in is erased and the barcode reading process is terminated.

  On the other hand, when the decoding processing unit 10 determines that the backward decoding process has failed (step S416: failure), the first character pattern mismatch determination process (step S418) is performed in the same manner as in steps S12 to S20 illustrated in FIG. The backward data holding process (step S420), the complementing process (step S422), the decoding process (step S424), and the decoding success determination process (step S426) are performed.

  Next, the forward decoding process shown in FIG. 24 will be described. FIG. 25 is a flowchart of a process procedure of the forward decoding process shown in FIG. As shown in FIG. 25, first, the signal processing unit 409 acquires the received light signal stored in the memory 409a (step S431). Then, for example, the signal processing unit 409 converts the received light signal Wc into a barcode signal in accordance with the C1 direction which is the forward direction in FIG. 23 to generate a forward barcode signal (step S433), and outputs it to the decode processing unit 10 To do. The decode processing unit 10 performs an element width count process (step S434), a forward data storage process (step S435), and a decode process (step S436), similarly to steps S24 to S26 of FIG.

  Next, the backward decoding process shown in FIG. 24 will be described. FIG. 26 is a flowchart of a process procedure of the backward decoding process shown in FIG. As shown in FIG. 26, the signal processing unit 409 acquires the received light signal stored in the memory 409a (step S441). Then, for example, the signal processing unit 409 converts the received light signal Wc into a barcode signal in accordance with the C2 direction that is the reverse direction of FIG. 23 to generate a backward barcode signal (step S443), and outputs the barcode signal to the decoding processor 10 To do. The decode processing unit 10 performs an element width count process (step S444), a reverse data storage process (step S445), and a decode process (step S446) in the same manner as steps S34 to S36 of FIG.

  As described above, in the fourth embodiment, even in a barcode reading apparatus having an image sensor such as a CCD, complementary processing is performed by using barcode signals generated by changing the processing direction of the received light signal. Yes. As a result, according to the fourth embodiment, as in the first embodiment, when the decoding fails due to the end element located at the end of the barcode symbol, the measurement value of the end element is different. When a barcode signal that accurately represents the element at the end of the bar code symbol cannot be generated by substituting with the measured value of the end element in the bar code signal processed in the processing direction, complementing it, and decoding again. Even so, the bar code symbol can be read accurately.

  In the fourth embodiment, the processing direction for the received light signal may be changed by changing the transfer direction of the received light signal in the transfer processing unit 408. Specifically, this will be described with reference to FIG. FIG. 27 is a flowchart showing another processing procedure of the barcode reading process in the barcode reader 401 shown in FIG.

  As illustrated in FIG. 27, the imaging unit 407 performs an imaging process in the same manner as in step S402 in FIG. 24 (step S502). The transfer processing unit 408 stores the light reception signal output from the imaging unit 407 in the memory 408a (step S504). Then, the transfer processing unit 408 performs forward transfer processing for transferring the received light signal stored in the memory 408a to the signal processing unit 409, for example, according to the C1 direction shown in FIG. 23 (step S506). The signal processing unit 409 and the decoding processing unit 10 perform the forward decoding process by performing the same processing procedure as step S408 shown in FIG. 24 using the received light signal transferred in the forward direction (step S508). Specifically, the signal processing unit 409 converts the received light signal transferred in the forward direction into a barcode signal according to the transfer order, and the decoding processing unit 10 performs a decoding process based on the count data in the barcode signal. Do.

  Then, similarly to step S410 shown in FIG. 24, the decoding processing unit 10 performs the decoding success determination process (step S510), and determines that the decoding process for the forward barcode signal has failed (step S510: failure). Similarly to step S412 shown in FIG. 24, forward data holding processing is performed (step S512).

  Next, the transfer processing unit 408 performs a reverse transfer process of transferring the received light signal stored in the memory 408a to the signal processing unit 410 in accordance with the C2 direction which is the reverse direction shown in FIG. 23, for example (step S513). . The signal processing unit 409 and the decoding processing unit 409 use the received light signal transferred in the reverse direction to perform the same decoding procedure as that in step S414 shown in FIG. 24 and perform the reverse decoding process (step S514). Specifically, the signal processing unit 409 converts the received light signal transferred in the reverse direction into a barcode signal according to the transfer order, and the decoding processing unit 10 performs the decoding process based on the count data in the barcode signal. Do.

  Then, the decoding processing unit 10 performs the decoding success determination processing (step S516), the first character pattern mismatch determination processing (step S518), and the backward data holding processing (step S520), similarly to steps S416 to S426 shown in FIG. ), Complement processing (step S522), decoding processing (step S524), and decoding success determination processing (step S526). As described above, by changing the transfer direction of the received light signal in the transfer processing unit 408, the complementary processing can be performed by changing the processing direction for the received light signal, so that the barcode symbol can be read accurately.

  In the first to fourth embodiments, the case where the backward barcode signal is complemented for the element Ee at the right end of the barcode symbol 20 has been described. However, the present invention is not limited to this, and as shown in FIG. The forward barcode signal may be supplemented with respect to the count value of the element Es at the left end of the symbol 20. For example, as indicated by an arrow Y41 in FIG. 28, the first count value of the region B1t corresponding to the element Es in the forward barcode signal in the S1 direction is the element in the backward barcode signal in the S2 direction. The count data of the forward barcode signal may be supplemented by replacing with the last count of the area B2l corresponding to Es. The decode processing units 10, 210, and 310 use the count data of the complemented forward bar code signal, step S18 shown in FIG. 6, step S218 shown in FIG. 11, step S318 shown in FIG. 20, and step shown in FIG. What is necessary is just to perform the decoding process again in S424 and step S524 shown in FIG. In the second embodiment, in step S213 shown in FIG. 11, for example, as indicated by an arrow Y42 in FIG. 28, each element width of the region Bd1 in the forward barcode signal and the backward barcode signal You may compare each element width in area | region Bd2. Further, in step S213 shown in FIG. 14, for example, as shown by an arrow Y42 in FIG. 28, the array pattern of elements of each width in the area Bd1 in the forward barcode signal and the area Bd2 in the backward barcode signal You may compare with the arrangement pattern of the elements of each width.

  In the first to third embodiments, the barcode readers 1, 201, and 301 including scanning mirrors capable of bidirectional scanning have been described. The present invention can also be applied to a pen-type barcode reader scanned by an operator.

1 is a schematic diagram illustrating a configuration of a barcode reading apparatus according to a first embodiment. It is a figure explaining the direction of the scanning light of the barcode reader shown in FIG. It is a figure which shows a reverse direction barcode signal when reverse direction scanning light is irradiated according to the S2 direction shown in FIG. It is a figure which shows a forward barcode signal in case the forward scanning light is irradiated according to the S1 direction shown in FIG. It is a figure explaining the complementation process in the decoding process part shown in FIG. FIG. 6 is a flowchart showing the processing procedure of the barcode reading process in the barcode reading apparatus shown in FIG. It is a flowchart which shows the process sequence of the forward direction decoding process shown in FIG. It is a flowchart which shows the process sequence of the reverse direction decoding process shown in FIG. It is a flowchart which shows the process sequence of the complementation process shown in FIG. FIG. 3 is a schematic diagram illustrating a configuration of a barcode reading apparatus according to a second embodiment. It is a flowchart which shows the process sequence of the barcode reading process in the barcode reading apparatus shown in FIG. It is a figure explaining the processing operation of the decoding process part shown in FIG. FIG. 10 is a schematic diagram illustrating another configuration of the barcode reading apparatus according to the second embodiment. It is a flowchart which shows the process sequence of the barcode reading process in the barcode reading apparatus shown in FIG. It is a flowchart which shows the process sequence of the forward direction decoding process shown in FIG. It is a flowchart which shows the process sequence of the reverse direction decoding process shown in FIG. It is a figure explaining the processing content of the decoding process part shown in FIG. It is a figure explaining the processing content of the decoding process part shown in FIG. FIG. 6 is a schematic diagram illustrating a configuration of a barcode reading apparatus according to a third embodiment. It is a flowchart which shows the process sequence of the barcode reading process in the barcode reading apparatus shown in FIG. It is a figure explaining the correction process shown in FIG. FIG. 6 is a schematic diagram illustrating a configuration of a barcode reading apparatus according to a fourth embodiment. It is a figure explaining the process direction of the received light signal in the barcode reading process shown in FIG. It is a flowchart which shows the process sequence of the barcode reading process in the barcode reading apparatus shown in FIG. It is a flowchart which shows the process sequence of the forward direction decoding process shown in FIG. It is a flowchart which shows the process sequence of the reverse direction decoding process shown in FIG. It is a flowchart which shows the other process sequence of the barcode reading process in the barcode reading apparatus shown in FIG. It is a figure explaining the complementation process shown in FIG.

Explanation of symbols

1, 201, 201a, 301, 401 Barcode reader 2 Light source 3 Reflecting mirror 4 Scanning mirror 5 Condensing mirror 6 Optical filter 7 Sensor 8 Shield 9 Signal processing unit 10, 210, 210a, 310 Decoding processing unit 11 Storage unit 20 Bar code symbol 407 Imaging unit 408 Transfer processing unit 409 Signal processing unit 408a, 409a Memory

Claims (24)

Signal processing means for generating a barcode signal representing each element width of the barcode symbol in which each element is displayed with a width corresponding to the recorded information, and measurement by measuring each element width represented by the barcode signal In a barcode reading apparatus comprising decoding processing means for decoding information recorded in the barcode symbol using information,
The signal processing means is capable of generating the first barcode signal in a first processing direction and generating the second barcode signal in a second processing direction that is different from the first processing direction. ,
When the decoding for the first barcode signal fails due to the end element located at the end of the barcode symbol, the decoding processing means applies the end element in the first barcode signal to the end element. A corresponding signal is replaced with a signal corresponding to the end element in the second barcode signal to perform a complementing process for complementing the first barcode signal, and the complemented first barcode signal is used. And a bar code reader for decoding again.   The decoding processing means uses the measurement value of the end element in the first measurement information of the first barcode signal as the complement processing, and the second measurement information of the second barcode signal in the second measurement information. The barcode reading apparatus according to claim 1, wherein the barcode is replaced with a measurement value of the end element to complement the first measurement information, and is decoded again using the complemented first measurement information.   When the difference between the measurement value of the first measurement information and the measurement value of the second measurement information for an element in a predetermined comparison area of the barcode symbol is within a predetermined range, the decoding processing means The barcode reading apparatus according to claim 2, wherein the complementing process is performed.   The barcode reading apparatus according to claim 3, wherein the predetermined range is changeable.   In the first measurement information, the decoding processing means is configured to use the measurement value of the first measurement information and the measurement value of the second measurement information for the element in the predetermined comparison area of the barcode symbol. A first threshold value and a second threshold value in the second measurement information are set, and a measurement value that exceeds the first threshold value in the first measurement information in the comparison region and a measurement that is less than the first threshold value. The first arrangement state of the values coincides with the second arrangement state of the measurement values exceeding the second threshold and the measurement values less than the second threshold in the second measurement information in the comparison region 3. The barcode reader according to claim 2, wherein the complementary processing is performed.   6. The barcode reader according to claim 5, wherein the number of the first threshold and the number of the second threshold can be changed. Further comprising light receiving means for irradiating the barcode symbol with scanning light according to the first processing direction or the second processing direction and receiving reflected light sequentially reflected from each region in the barcode symbol;
The signal processing unit generates the first barcode signal based on a light reception result corresponding to the first processing direction by the light receiving unit, and receives light corresponding to the second processing direction by the light receiving unit. 7. The bar code reader according to claim 1, wherein the second bar code signal is generated based on a result.   When the scanning speed in the first processing direction and the scanning speed in the second processing direction in the light receiving means are different from each other, the decoding processing means is either the first measurement information or the second measurement information. 8. The barcode reading apparatus according to claim 7, wherein the complementary processing is performed after correcting one in correspondence with the scanning speed in the other measurement information. The light receiving means is
A light source that emits light;
Scanning means for causing the light emitted from the light source to scan on the barcode symbol in accordance with the first processing direction or the second processing direction;
Condensing means for condensing the reflected light;
Detecting means for sequentially receiving the light collected by the light collecting means, converting it into an electrical signal, and outputting it to the signal processing means;
With
9. The bar code reading apparatus according to claim 7, wherein the signal processing unit controls a scanning process in the scanning unit. Further comprising light receiving means for irradiating the entire barcode symbol with light and receiving reflected light from the entire barcode symbol to generate a received light signal corresponding to the entire barcode symbol;
The signal processing means generates the first barcode signal by converting the received light signal according to the first processing direction, and converts the received light signal according to the second processing direction. The bar code reader according to claim 1, wherein the bar code signal is generated.   The barcode reader according to any one of claims 2 to 10, further comprising storage means for storing the first measurement information and the second measurement information. The storage means stores the light reception signal,
12. The signal processing means acquires the received light signal stored in the storage means and generates the first barcode signal and / or the second barcode signal. Bar code reader.   The bar code reader according to claim 3, wherein the comparison area is changeable. A signal processing step for generating a barcode signal representing each element width in the barcode symbol in which each element is displayed with a width corresponding to the recorded information, and measurement by measuring each element width represented by the barcode signal A barcode reading method comprising: a decoding process step for decoding information recorded in the barcode symbol using information;
The signal processing step includes
A first signal processing step of generating a first barcode signal in a first processing direction;
A second signal processing step of generating a second barcode signal in a second processing direction that is different from the first processing direction;
Including
The decoding step includes
A first decoding step for the first barcode signal generated in the first signal processing step;
If the decoding for the first barcode signal fails in the first decoding processing step due to an end element located at the end of the barcode symbol, the end of the first barcode signal A complementing step of complementing the first barcode signal by replacing a signal corresponding to an element with a signal corresponding to the end element in the second barcode signal;
A second decoding process step for decoding again using the first barcode signal supplemented in the complementing step;
A barcode reading method comprising: The complementing step includes measuring the end element in the first measurement information of the first barcode signal, and measuring the end element in the second measurement information of the second barcode signal. Replace with the value to complement the first measurement information,
15. The barcode reading method according to claim 14, wherein the second decoding processing step performs decoding again using the first measurement information supplemented in the complementing step. The decoding step includes
A determination step of determining whether or not a difference between a measurement value of the first measurement information and a measurement value of the second measurement information with respect to an element in a predetermined comparison area of the barcode symbol is within a predetermined range. Including
The complementing step is performed when it is determined in the determination step that a difference between the measurement value of the first measurement information and the measurement value of the second measurement information for the element in the comparison region is within a predetermined range. The barcode reading method according to claim 15, wherein the barcode reading method is performed.   The barcode reading method according to claim 16, wherein the predetermined range is changeable. The decoding step includes
A first threshold value in the first measurement information based on a measurement value of the first measurement information and a measurement value of the second measurement information for an element in a predetermined comparison area of the barcode symbol; A threshold setting step for setting a second threshold in the second measurement information;
An arrangement state of measurement values exceeding the first threshold value and measurement values falling below the first threshold value in the first measurement information in the comparison area, and the second measurement information in the comparison area in the second measurement information An array state obtaining step for obtaining a measured value exceeding a threshold value of 2 and a second array state of measured values falling below the second threshold value;
An array state determining step for determining whether or not the first array state and the second array state match;
16. The barcode reading method according to claim 15, wherein the complementing step is performed when it is determined in the arrangement state determining step that the first arrangement state and the second arrangement state coincide with each other.   19. The barcode reading method according to claim 18, wherein the number of the first threshold value and the number of the second threshold value are changeable. A light receiving step of irradiating the bar code symbol with scanning light according to the first processing direction or the second processing direction and receiving reflected light sequentially reflected from each region in the bar code symbol;
The first signal processing step generates the first barcode signal based on a light reception result corresponding to the first processing direction by the light reception step,
20. The second signal processing step generates the second barcode signal based on a light reception result corresponding to the second processing direction by the light receiving means. The barcode reading method according to claim 1. The decoding step includes
When the scanning speed in the first processing direction and the scanning speed in the second processing direction are different in the light receiving step, either the first measurement information or the second measurement information is used as the other measurement information. And a correction step of correcting in accordance with the scanning speed in
The barcode reading method according to claim 20, wherein the complementing step is performed after the correcting step. A light receiving step of irradiating the entire barcode symbol with light and receiving reflected light from the entire barcode symbol to generate a received light signal corresponding to the entire barcode symbol;
The first signal processing step generates the first barcode signal by converting the light reception signal generated in the light reception step according to the first processing direction,
15. The second signal processing step generates the second barcode signal by converting the light reception signal generated in the light reception step according to the second processing direction. The barcode reading method according to any one of -19.   The barcode reading method according to any one of claims 15 to 22, further comprising a storing step of storing the first measurement information and the second measurement information.   24. The barcode reading method according to claim 16, wherein the comparison area is changeable.

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