JP5708357B2 - Information code verifier - Google Patents

Description

  The present invention relates to an information code verifier that verifies the display state of an information code displayed on a display surface to be verified.

  2. Description of the Related Art Conventionally, a two-dimensional code reading device disclosed in Patent Document 1 is known as a technique related to an information code verifier that verifies the display state of an information code displayed on a display surface to be verified. In this two-dimensional code reader, the two-dimensional code reading operation is normally performed by repeating the operation of acquiring the image data in the imaging unit and performing the decoding process in the decoding unit a plurality of times with the two-dimensional code set. Reading test mode for confirming whether or not it is being performed, and acquiring the image data in the imaging unit in a state where the illumination unit illuminates the two-dimensional code, thereby confirming the illuminance distribution in the visual field range of the imaging unit Therefore, there are two modes, namely, an illuminance distribution confirmation mode. Then, the two-dimensional code reader uses both modes to set the desired reading condition by repeating feedback that sets the two-dimensional code reading condition to a more preferable condition based on the result of the reading attempt. It is possible.

JP 2004-048771 A

  By the way, in the information code verifier adopting the reading condition setting disclosed in Patent Document 1, the display surface to be verified is displayed on the display surface by performing processing such as shaving / melting / burning. The following problem arises when verifying an information code generated, for example, an information code generated by direct marking.

  In other words, the information code generated by direct marking is made brighter than the surroundings by coloring the processed part like laser processing or by making holes like dot impact processing and illuminating the processed part. Thus, by adding a contrast difference between the processed portion and the non-processed portion, the captured information code can be decoded. For this reason, when the processing shape gradually changes due to the wear of the processing tool gradually, the information code display state gradually changes from the original display state.

  Then, since the information code as described above has greatly changed from the original print state (display state), the recognition rate of the information code is reduced by, for example, reducing the depth of surface cutting due to wear of the processing tool. And a decoding failure is detected. Since the processing tool is gradually worn as described above, the information code generated before the information code in which the decoding failure is detected is also greatly changed from the original display state, and the contrast difference is not easily generated. That is, there is a problem that many information codes (defect codes) whose decoding success rate is less than the allowable lower limit value are generated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an information code verifier capable of suppressing the generation of a defective code whose decoding success rate is less than an allowable lower limit value. It is to provide.

In order to achieve the above object, an information code verifier according to claim 1 is provided with a plurality of light-colored cells (Cw) and dark-colored cells (Cb) by processing the display surface (R) to be verified. An information code verifier (10) for verifying the display state of the information code (C, C1, C2) displayed so as to have an image pickup means for imaging the information code displayed on the display surface ( 28) and an image adjusting means capable of adjusting the brightness levels of a plurality of bright color areas and dark color areas constituting the code image with respect to the code image occupied by the information code in the captured image captured by the imaging means (40), and by performing a decoding process on the adjusted image whose brightness is adjusted so as to improve the decoding success rate (S) by the image adjusting means, the information code included in the adjusted image is decoded. A decoding means (40) that performs decoding, and a first threshold (So) that is set to be greater than an allowable lower limit value when the decoding means decodes one adjusted image a plurality of times. And a notification means (46) for notifying that an information code having a decoding success rate close to the lower limit value has been decoded , wherein the notification means has a decoding success rate by the decoding means of the first value. When the image is adjusted below the threshold value, the decoding success rate when the image that has been further adjusted so as to improve the decoding success rate by the image adjusting means is decoded a plurality of times. When the threshold value is exceeded, information on the further adjustment is information for suppressing the generation of a defective code whose decoding success rate is less than the lower limit value. And said that you informed Te.

The invention according to claim 2 is an information code verifier for verifying a display state of an information code displayed so as to have a plurality of light-colored cells and dark-colored cells by performing processing on a display surface to be verified. An imaging unit that images the information code displayed on the display surface, and a code image that the information code occupies among the captured images captured by the imaging unit constitutes the code image. Image adjustment means capable of adjusting the lightness and darkness of a plurality of light color areas and dark color areas, and performing a decoding process on the adjusted image whose lightness and darkness has been adjusted so as to improve the decoding success rate by the image adjustment means And a decoding means for decoding the information code included in the adjusted image, and a decoding when a single adjusted image is decoded a plurality of times by the decoding means. When the success rate falls below a first threshold value set larger than the allowable lower limit value, notification means for notifying that an information code having a decoding success rate close to the lower limit value has been decoded, and the code image An extraction unit capable of extracting any one of a light color region corresponding to at least one light color cell and a dark color region corresponding to at least one dark color cell, and the extraction unit extracts the cell region. Determination means for determining whether or not an occupation ratio of an area occupied more widely among the light color area and the dark color area with respect to the cell area is equal to or less than a second threshold, and the notification means includes the decoding when decoding success rate by means falls below the first threshold value, when the occupancy rate is determined to be equal to or less than the second threshold value by the determination means, this Display information obtained by enlarging the cell area, characterized in that broadcast as information for inhibiting the formation of bad code decoding success rate is less than the lower limit.

According to a third aspect of the present invention, there is provided an information code verifier for verifying a display state of an information code displayed so as to have a plurality of bright color cells and dark color cells by processing a display surface to be verified. An imaging unit that images the information code displayed on the display surface, and a code image that the information code occupies among the captured images captured by the imaging unit constitutes the code image. Image adjustment means capable of adjusting the lightness and darkness of a plurality of light color areas and dark color areas, and performing a decoding process on the adjusted image whose lightness and darkness has been adjusted so as to improve the decoding success rate by the image adjustment means And a decoding means for decoding the information code included in the adjusted image, and a decoding when a single adjusted image is decoded a plurality of times by the decoding means. Informing means for notifying that an information code having a decoding success rate close to the lower limit value is decoded when the success rate falls below a first threshold value set larger than an allowable lower limit value, and When the decoding success rate by the decoding unit falls below a third threshold value set larger than the first threshold value, the notification unit may decode an information code having a decoding success rate close to the lower limit value. It characterized that you inform the high.

  A fourth aspect of the present invention is the information code verifier according to any one of the first to third aspects, further comprising threshold setting means (40) capable of setting the first threshold to a desired value. It is characterized by.

Na us, the code in each parenthesis shows the correspondence with specific means described in the embodiments to be described later.

  According to the first aspect of the present invention, for the code image occupied by the information code in the captured image picked up by the image pickup means, image adjustment capable of adjusting the lightness and darkness of a plurality of light color regions and dark color regions constituting the code image Information is included in the adjusted image by performing decoding processing on the adjusted image whose brightness is adjusted so as to improve the decoding success rate by the image adjusting unit. The code is decoded. When the decoding success rate when the adjusted image is decoded a plurality of times by the decoding unit is reduced below the first threshold value, the notification unit notifies that the information code having the decoding success rate close to the lower limit value has been decoded. Informed.

  As a result, when the decoding success rate falls below the first threshold because the display state of the information code has gradually changed, the notifying means notifies that the information code having the decoding success rate close to the lower limit has been decoded. Therefore, the user can recognize that the display state of the information code is gradually changing from the original display state before the defective code is verified. In other words, since the user is prompted to perform maintenance of the processing equipment for processing the display surface, for example, replacement of the processing tool, before the defective code is generated, the decoding success rate is low. Code generation can be suppressed.

In particular , when the decoding success rate by the decoding means falls below the first threshold, the image that has been further adjusted so as to improve the decoding success rate by the image adjustment means for the brightness of the adjusted image is decoded a plurality of times. When the decoding success rate at this time exceeds the first threshold value, information related to the further adjustment is notified as information for suppressing generation of a defective code by the notification means.

  If further adjustment improves the decoding success rate to exceed the first threshold, this further adjustment corresponds to a specific method for improving the display state of the information code. For example, as a further adjustment, when the degree of success of the decoding is improved so as to exceed the first threshold by adjusting the lightness and darkness so as to expand the dark color region, the display corresponding to the dark color region is expanded. Changing the processing on the surface is a method for improving the display state of the information code.

  For this reason, when the decoding success rate falls below the first threshold, the information on the further adjustment (for example, information on the improvement of the decoding success rate due to the expansion of the dark area) is suppressed from generating a defective code. By notifying as information for the user, the user can use a specific method for improving the display state of the information code (for example, a method of increasing the processing force at the time of processing to expand the portion corresponding to the dark color region) ) Can be recognized.

In the invention of claim 2, and any at least one extractable extractor cell areas of bright regions and dark regions of the code image, the cell area extracted by the extraction means bright areas and dark areas Determining means for determining whether or not the occupation ratio of the more widely occupied area is equal to or less than the second threshold value. And when the decoding success rate by the decoding means falls below the first threshold value, and the determining means determines that the occupancy rate is below the second threshold value, the notification means enlarges the display of this cell area. Information is reported as information for suppressing the generation of defective codes.

  As a result, when the information code display state gradually changes and the occupation ratio becomes lower than the second threshold value and the decoding success rate falls below the first threshold value, the information code with the decoding success rate close to the lower limit value. Since the display information in which the cell area is expanded is notified as information for suppressing the generation of the defective code, the user is required to provide information before the defective code is decoded. It can be easily recognized that the display state of the code gradually changes from the original display state.

In particular, when the occupancy is equal to or less than the second threshold value, that is, when it is unclear that the cell area is a light cell or a dark cell, it is not clear. Display information in which the area is enlarged is notified. For this reason, since the user visually recognizes the ambiguity of the cell area by looking at the display information, a specific method for improving the display state, for example, the cell area is a dark cell. Accordingly, it is possible to recognize a method for increasing the processing force during processing in order to expand the portion corresponding to the dark color region.
In the invention according to claim 3, when the decoding success rate by the decoding means falls below a third threshold value set larger than the first threshold value, the notification means generates an information code having a decoding success rate close to the lower limit value. It is notified that the possibility of decoding is high.
Thus, before the information code having a decoding success rate close to the lower limit value is decoded, the notification means notifies that fact, so that the generation of a defective code having a low decoding success rate can be reliably suppressed.

  In the invention of claim 4, since the threshold setting means capable of setting the first threshold to a desired value is provided, an appropriate threshold can be easily set according to the use environment or the like.

1 is a block diagram schematically showing an electrical configuration of an information code verifier according to a first embodiment. FIG. 2A is an explanatory diagram showing a QR code displayed on the display surface to be verified by performing laser processing. FIGS. 2B to 2G are black cells in FIG. It is an enlarged view which expands and illustrates. It is explanatory drawing which shows QR code displayed on the display surface of verification object by performing a dot impact process. It is a part of flowchart which illustrates the flow of the verification process in 1st Embodiment. It is a part of flowchart which illustrates the flow of the verification process in 1st Embodiment. It is explanatory drawing for demonstrating the occupation rate in each cell area | region. It is explanatory drawing for demonstrating the smoothing filter process. It is explanatory drawing for demonstrating an expansion | swelling filter process. It is explanatory drawing for demonstrating a contraction filter process. It is explanatory drawing for demonstrating the filter process in the modification of 1st Embodiment. It is a flowchart which illustrates the flow of the verification process in 2nd Embodiment. It is a flowchart which illustrates the flow of the verification process in the modification of 2nd Embodiment.

[First Embodiment]
Hereinafter, a first embodiment of an information code verifier according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram schematically showing an electrical configuration of the information code verifier 10 according to the first embodiment. FIG. 2A is an explanatory diagram showing a QR code Q1 displayed on the display surface R to be verified by performing laser processing, and FIGS. 2B to 2G are views of FIG. It is an enlarged view which expands and illustrates black cell Cb. FIG. 3 is an explanatory diagram showing the QR code Q2 displayed on the display surface R to be verified by performing dot impact processing.

  The information code verifier 10 shown in FIG. 1 displays a display state (printing state) of a one-dimensional code such as a barcode displayed on the display surface R to be verified or a two-dimensional code such as a QR code (registered trademark). ). Here, the verification in the present embodiment is to confirm whether or not the decoding success rate when a predetermined decoding process is performed a plurality of times on the captured code image of the information code C is equal to or higher than an allowable lower limit value. That means.

  In the present embodiment, an information code that is displayed so as to have a plurality of light-colored cells and dark-colored cells by performing predetermined processing directly on the display surface R to be verified, that is, generated (printed) by direct marking. Information code C is verified. As a specific information code C to be verified, for example, there is a QR code C1 illustrated in FIG. This QR code C1 is exemplified by each black cell (Cb in FIG. 2A) among a plurality of white cells (light color cells) and black cells (dark color cells) constituting the QR code C1. ), For example, by performing laser processing such as cutting the display surface R as illustrated in any of FIGS. 2B to 2E.

  As another information code C to be verified, for example, there is a QR code C2 illustrated in FIG. The QR code C2 is formed by performing dot impact processing so as to crush the display surface R into a concave shape with respect to each region corresponding to each black cell. Here, in FIG. 3, the symbol Lb indicates the size of the black cell, the symbol Lw indicates the size of the white cell, and the engraving depth, that is, the Lb / Lw ratio varies depending on the pressure during processing (printing). The engraving is deeper and it is easier to read if the black cell is processed so as to be connected to other black cells.

  The information code C configured in this manner causes a contrast difference between the processed portion and the non-processed portion that can be distinguished from the bright color cell and the dark color cell by being irradiated with illumination light. Can be decoded to read the information code C.

Next, the electrical configuration of the circuit 20 of the information code verifier 10 will be described.
As shown in FIG. 1, the circuit 20 mainly includes an optical system such as an illumination light source 21, a light receiving sensor 28, and an imaging lens 27, and a microcomputer (hereinafter referred to as "microcomputer") system such as a memory 35 and a control circuit 40. And is composed of.

  The optical system is divided into a light projecting optical system and a light receiving optical system. The illumination light source 21 constituting the light projecting optical system functions as an illumination light source capable of emitting the illumination light Lf, and includes, for example, a red LED and a lens provided on the emission side of the LED. FIG. 1 conceptually shows an example in which the information code C is irradiated with the illumination light Lf toward the verification target displayed on the display surface R.

  The light receiving optical system includes a light receiving sensor 28, an imaging lens 27, a reflecting mirror (not shown), and the like. The light receiving sensor 28 is configured as a CCD area sensor, and is configured to receive the reflected light Lr irradiated and reflected on the information code C or the display surface R. The light receiving sensor 28 is mounted on a printed wiring board (not shown) so as to be able to receive incident light incident through the imaging lens 27. The light receiving sensor 28 may correspond to an example of an “imaging unit” recited in the claims.

  The imaging lens 27 functions as an imaging optical system capable of condensing incident light incident from the outside through the reading window 13 and forming an image on the light receiving surface 28a of the light receiving sensor 28. In the present embodiment, after the illumination light Lf emitted from the illumination light source 21 is reflected by the information code C, the reflected light Lr is condensed by the imaging lens 27, and the information code C is applied to the light receiving surface 28 a of the light receiving sensor 28. This image is formed.

  The microcomputer system includes an amplification circuit 31, an A / D conversion circuit 33, a memory 35, an address generation circuit 36, a synchronization signal generation circuit 38, a control circuit 40, a display unit 46, an operation unit 47, and the like. This microcomputer system is configured around a control circuit 40 and a memory 35 that can function as a microcomputer (information processing apparatus), and the image signal of the information code C imaged by the optical system described above is signaled in hardware and software. It can be processed.

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

  The memory 35 is a semiconductor memory device, and corresponds to, for example, a RAM (DRAM, SRAM, etc.) or a ROM (EPROM, EEPROM, etc.). In addition to the above-described image data storage area, the RAM of the memory 35 is configured to be able to secure a work area and a reading condition table used by the control circuit 40 in each processing such as arithmetic operation and logical operation. . The ROM stores in advance a predetermined program that can execute verification processing, analysis processing, and the like, which will be described later, and a system program that can control each piece of hardware such as the illumination light source 21 and the light receiving sensor 28.

  The control circuit 40 is a microcomputer that can control the entire information code verifier 10 and includes a CPU, a system bus, an input / output interface, and the like. The control circuit 40 can constitute an information processing apparatus together with the memory 35 and has an information processing function. The control circuit 40 is configured to be connectable to various input / output devices via a built-in input / output interface. In the case of this embodiment, the display unit 46 including a liquid crystal display, various operation keys, and the like. An operation unit 47 and the like are connected to be controllable.

Next, verification processing for the information code C performed in the present embodiment will be described.
When sequentially verifying the information codes C generated (printed) on the display surfaces R to be verified one after another by direct marking as exemplified in FIG. 2 or FIG. 3, a processing tool for forming each information code C is provided. When the machining shape gradually changes due to gradual wear or the like, the display state of each information code C gradually changes from the original display state. Then, since the information code C as described above has changed greatly from the original printing state (display state), when the recognition rate of the information code C decreases and decoding failure is detected, this decoding failure is detected. The information code generated before the information code C may be greatly changed from the original display state. In this case, a large number of information codes (defective codes) are generated in which the contrast difference is difficult to occur, that is, the decoding success rate is less than the allowable lower limit value.

Therefore, in the present embodiment, by performing the verification process described below, the display state of the information code C is gradually changed from the original display state before the defective code due to the change in the machining shape described above is verified. By notifying that there is a change, generation (printing) of defective codes is suppressed.
Hereinafter, verification processing by the control circuit 40 of the information code verifier 10 according to the present embodiment will be described with reference to FIGS. 4 and 5. 4 and 5 are flowcharts illustrating the flow of verification processing in the first embodiment.

  First, after the power is turned on and a predetermined initial setting is made, a verification target in which the information code C is printed (displayed) on the display surface R is sent to the information code verifier 10 to a predetermined position. The code image processing shown in step S101 of FIG. 4 is performed. In this process, the reflected light Lr reflected by the information code C in response to the illumination light Lf emitted from the illumination light source 21 is received by the light receiving sensor 28, so that it corresponds to the light reception signal output from the light receiving sensor 28. A code image is obtained.

  Next, the decoding process shown in step S103 is performed. In this process, a predetermined decoding process is performed a plurality of times on the code image, and a success rate (hereinafter referred to as a decoding success rate S) of successful decoding is calculated. Then, in the determination process shown in step S105, it is determined whether or not the decoding success rate S is equal to or less than the first threshold value So. Here, the first threshold value So is a threshold value set larger than the allowable lower limit value, and is set to 97%, for example. The first threshold value So may correspond to an example of a “first threshold value” recited in the claims.

  And since the processing tool at the time of direct marking does not wear out and the display state of the information code C does not change from the original display state, the state where the decoding success rate S exceeds the first threshold value So is maintained. (No in S105), the cell analysis process shown in step S135 of FIG. 5 is performed. In this process, for each cell area obtained from the mapping process for dividing the code image performed at the time of the decoding process for each cell area, the white area (bright area) and the black area (dark area) are wider. The occupation ratio P of the occupied area is calculated.

FIG. 6 is an explanatory diagram for explaining the occupation ratio P in each cell region.
As shown in FIG. 6A, by performing a mapping process, each cell area is extracted after the code image is divided for each cell area. If the extracted cell region is a black region Cb, for example, it is extracted as illustrated in FIGS. 6B to 6E, and if it is a white region Cw, for example, FIGS. ). When each cell area is extracted in this way, if it is a black area, the occupation ratio P occupied by the black part of the cell area is calculated. If it is a white area, the white part of the cell area is calculated. The occupation rate P occupied by is calculated.

  Then, the display process shown in step S137 is performed. In this process, when each filter process to be described later is not performed, the print state of each cell area analyzed by the cell analysis process and the occupation ratio P are displayed on the display unit 46. Thereby, the user (verifier) who uses the information code verifier 10 can grasp the print state of the information code C by looking at the print state of each cell area displayed on the display unit 46. it can. Note that the print state of each cell area displayed on the display unit 46 may be displayed only in a cell area where the occupation rate P is small, for example. Further, when each filtering process described later is not performed, the display unit 46 may display only that the verification result is good without displaying the printing state of each cell area.

  When the display process is performed in this manner, it is determined whether or not the readable condition is set in the determination process shown in step S139, and the readable condition such as the type of filter processing and the filter level is set. If yes, it is determined as Yes. Subsequently, in the determination process shown in step S141, it is determined whether or not an improvement request is necessary. If at least each filter process described later is not performed, it is determined No, and a setting condition notification described later is determined. Processing is done.

  On the other hand, if the processing tool gradually changes due to the wear of the processing tool at the time of direct marking and the display state of the information code C is gradually changed from the original display state, the decoding success rate S Gradually decreases. Then, when the change in the display state of the information code C becomes large and the decoding success rate S becomes equal to or less than the first threshold value So, it is determined Yes in step S105 described above. In this case, the smoothing filter process shown in step S107 is performed. The smoothing filter process will be described in detail with reference to FIG. FIG. 7 is an explanatory diagram for explaining the smoothing filter processing, FIG. 7A is a code image before the smoothing filter processing, and FIG. 7B is a code image of FIG. 7A. 7 shows a state where level 1 smoothing filter processing has been performed, and FIG. 7C shows a state where level 3 smoothing filter processing has been performed on the code image of FIG. 7A. (D) shows a state in which the level 5 smoothing filter processing is applied to the code image of FIG.

  The smoothing filter process is an image process in which the degree of contrast is adjusted so as to blur the entire code image. As can be seen from FIGS. Is processed as follows. For this reason, as illustrated in FIG. 7A, when a code image in which a part of the cell region is cut is acquired, FIGS. 7B to 7D are applied to the code image. By applying the smoothing filter processing at a predetermined level as exemplified in (2), image processing is performed so that each cell region is moderately blurred and connected in an image, and the decoding success rate S is improved.

  In this smoothing filter process, first, the decoding process shown in step S109 is performed on the code image that has been subjected to the level 1 smoothing filter process (hereinafter also referred to as an adjusted image). If the decoding success rate S is equal to or lower than the first threshold value So (Yes in S111), a decoding process is performed on the code image that has been subjected to the level 2 smoothing filter process as a further adjustment of the brightness level, It is determined No in step S113 until all levels of smoothing filter processing are performed, and the processing from the smoothing filter processing is repeated. The control circuit 40 that executes the smoothing filter process corresponds to an example of the “image adjustment unit” recited in the claims, and the code image that has been subjected to the smoothing filter process is recited in the claims. It can correspond to an example of “adjusted image”. Further, the control circuit 40 that executes the decoding process may correspond to an example of a “decoding unit” recited in the claims.

  If the decoding success rate S exceeds the first threshold value So for a code image that has undergone a certain level of smoothing filter processing during such repetitive processing, it is determined No in step S111. Then, when the occupancy P of each cell area is calculated in the cell analysis process shown in step S135, the display process shown in step S137 is performed. In this process, the information code having the decoding success rate S less than the first threshold value So is decoded, the level of the smoothing filter processing when the decoding success rate S is equal to or higher than the first threshold value So, and the cell analysis described above. The print state of each cell area analyzed by the processing and its occupation rate P are displayed on the display unit 46. Accordingly, the user can recognize that the information code having the decoding success rate S close to the lower limit value has been decoded.

  When the display process is performed in this manner, it is determined whether or not the readable condition is set in the determination process shown in step S139, and the readable condition such as the type of filter processing and the filter level is set. If yes, it is determined as Yes. Subsequently, in the determination process shown in step S141, it is determined whether or not an improvement request is necessary, and a smoothing filter process that requires an improvement request, for example, a level 5 smoothing filter process is performed. In this case, it is determined as Yes.

  Next, the notification process shown in step S149 is performed. In this process, information for suppressing the generation of a defective code, that is, information on a specific method for improving the display state of the information code is notified by being displayed on the display unit 46. This notification information will be described below.

  As described above, when the decoding success rate S is improved to exceed the first threshold value So by further adjustment, this further adjustment corresponds to a specific method for improving the display state of the information code. For example, as a further adjustment, when the decoding success rate S is improved so as to exceed the first threshold value So by adjusting the degree of contrast so as to blur the entire code image as described above, the missing portion of the cell is determined. Changing the processing on the display surface R so as to reduce it, for example, increasing the power at the time of printing or changing the tact time is a method for improving the display state of the information code.

  For this reason, when the decoding success rate S falls below the first threshold value So, the user can display the information code by notifying the information regarding the further adjustment as information for suppressing the generation of the defective code. Recognize specific ways to improve the situation. The control circuit 40 that executes the notification process in step S149 may correspond to an example of “notification means” described in the claims.

  On the other hand, in the determination process shown in step S141, when smoothing filter processing that does not require an improvement request, for example, level 1 smoothing filter processing is performed, it is determined No and the setting condition shown in step S143 Notification processing is performed. In this process, information for determining whether to change the setting condition to this filter level is displayed on the display unit 46 together with the filter level when the decoding success rate S exceeds the first threshold value So in the filter process. The

  Subsequently, in the determination process shown in step S145, it is determined whether or not an instruction to change the setting condition has been given. Since the user who has seen the information displayed on the display unit 46 in the setting condition notification process desires to change the setting condition to the filter level, the operation unit 47 is instructed to instruct the change. If it operates, it will determine with Yes in step S145. Then, the condition setting process shown in step S147 is performed, the setting condition is changed to the filter level according to the instruction, and the verification process for the captured code image is completed. Since the user does not desire to change the setting condition to the filter level, if the operation for instructing the change is not performed on the operation unit 47 (No in S145), the condition setting process is performed. The verification process for the captured code image ends without being made.

  In the determination process shown in step S113 described above, when the decoding success rate S does not exceed the first threshold value So even if smoothing filter processes of all levels are performed (Yes in S113), the expansion filter process shown in step S115 Is made. This expansion filter process will be described in detail with reference to FIG. FIG. 8 is an explanatory diagram for explaining the expansion filter process, FIG. 8A is a code image before the expansion filter process, and FIG. 8B is a code image of FIG. 8A. 8C shows a state where level 1 expansion filter processing has been performed, FIG. 8C shows a state where level 3 expansion filter processing has been performed on the code image of FIG. 8A, and FIG. FIG. 9 shows a state in which the level 5 expansion filter processing is performed on the code image of FIG.

  The expansion filter process is an image process in which the degree of contrast is adjusted so that each black area of each cell area constituting the code image is expanded. As can be seen from FIGS. The higher the level, the higher the degree of expansion of each black area. For this reason, as illustrated in FIG. 8A, a code image obtained by capturing an information code (see FIG. 3) in which each black cell is printed with one dot and an information code in which black cells are printed thinly is acquired. When this code image is subjected to a predetermined level of expansion filter processing illustrated in FIGS. 8B to 8D, image processing is performed so that each black region is appropriately thickened. Therefore, the decoding success rate S is improved.

  In this expansion filter process, first, a decoding process shown in step S117 is performed on a code image that has been subjected to the level 1 expansion filter process (hereinafter also referred to as an adjusted image). When the decoding success rate S is equal to or lower than the first threshold value So (Yes in S119), the decoding process is performed on the code image that has been subjected to the level 2 expansion filter process as a further adjustment of the brightness level. It is determined as No in step S121 until the level of expansion filter processing is performed, and the processing from the expansion filter processing is repeated. The control circuit 40 that executes the expansion filter processing corresponds to an example of the “image adjustment unit” recited in the claims, and the code image that has been subjected to the expansion filter processing is described in “ It may correspond to an example of “adjusted image”. Further, the control circuit 40 that executes the decoding process may correspond to an example of a “decoding unit” recited in the claims.

  If the decoding success rate S exceeds the first threshold value So for a code image that has undergone a certain level of expansion filter processing during such repeated processing, it is determined No in step S119. Then, when the occupancy P of each cell area is calculated in the cell analysis process shown in step S135, the display process shown in step S137 is performed. In this process, an information code having a decoding success rate S less than the first threshold value So is decoded, a level of expansion filter processing when the decoding success rate S is equal to or higher than the first threshold value So, and the cell analysis process The print state of each cell area analyzed and the occupancy rate P thereof are displayed on the display unit 46. Accordingly, the user can recognize that the information code having the decoding success rate S close to the lower limit value has been decoded.

  When the display process is performed in this manner, it is determined whether or not the readable condition is set in the determination process shown in step S139, and the readable condition such as the type of filter processing and the filter level is set. If yes, it is determined as Yes. Subsequently, in the determination process shown in step S141, it is determined whether or not an improvement request is necessary. When an expansion filter process that requires an improvement request, for example, an expansion filter process of level 5, is performed. Is determined as Yes.

  Next, a notification process shown in step S149 is performed, and information for suppressing the generation of a defective code is notified by being displayed on the display unit 46. As a further adjustment, the decoding success rate S is improved so as to exceed the first threshold value So by adjusting the degree of contrast so that each black area of each cell area constituting the code image is expanded as described above. Changing the processing on the display surface R so as to expand the portion corresponding to each black area is a method for improving the display state of the information code. Examples of such processing changes include increasing the processing force (printing power) applied to the processing tool during processing and shortening the processing time (tact time). By notifying information regarding such further adjustment as information for suppressing the generation of defective codes, the user can recognize a specific method for improving the display state of the information codes. .

  On the other hand, in the determination process shown in step S141, if an expansion filter process that does not require an improvement request, for example, a level 1 expansion filter process, is determined No, the setting condition notification process shown in step S143 Is made. In this process, information for determining whether to change the setting condition to this filter level is displayed on the display unit 46 together with the filter level when the decoding success rate S exceeds the first threshold value So in the filter process. The

  Subsequently, in the determination process shown in step S145, it is determined whether or not an instruction to change the setting condition has been given. Since the user who has seen the information displayed on the display unit 46 in the setting condition notification process desires to change the setting condition to the filter level, the operation unit 47 is instructed to instruct the change. If it operates, it will determine with Yes in step S145. Then, the condition setting process shown in step S147 is performed, the setting condition is changed to the filter level according to the instruction, and the verification process for the captured code image is completed.

  In the determination process shown in step S121 described above, if the decoding success rate S does not exceed the first threshold value So even after performing all levels of expansion filter processing (Yes in S121), the contraction shown in step S123 of FIG. Filter processing is performed. The contraction filter process will be described in detail with reference to FIG. FIG. 9 is an explanatory diagram for explaining the contraction filter processing. FIG. 9A shows a code image before the contraction filter processing, and FIG. 9B shows a code image of FIG. 9A. 9 (C) shows a state where level 1 contraction filter processing has been performed, FIG. 9 (C) shows a state where level 3 contraction filter processing has been performed on the code image of FIG. 9 (A), and FIG. FIG. 9A shows a state in which the level 5 contraction filter processing is applied to the code image of FIG.

  Shrinkage filter processing is image processing in which the degree of contrast is adjusted so that each black region of each cell region constituting the code image is shrunk. As can be seen from FIGS. The higher the value, the higher the degree of contraction of each black area. For this reason, as illustrated in FIG. 9A, when a code image composed of a fat black region is acquired, this code image is illustrated in FIGS. 9B to 9D. By applying the contraction filter processing at a predetermined level, image processing is performed so that each black region is appropriately thinned, and the decoding success rate S is improved.

  In this contraction filter process, first, a decoding process shown in step S125 is performed on a code image that has been subjected to level 1 contraction filter process (hereinafter also referred to as an adjusted image). When the decoding success rate S is equal to or less than the first threshold value So (Yes in S127), the decoding process is performed on the code image that has been subjected to the level 2 shrinkage filter process as a further adjustment of the brightness level. In step S129, it is determined No until the level of contraction filter processing is performed, and the processing from the contraction filter processing is repeated. The control circuit 40 that executes the contraction filter processing corresponds to an example of the “image adjustment unit” recited in the claims, and the code image that has undergone the contraction filter processing is described in the claims “ It may correspond to an example of “adjusted image”. Further, the control circuit 40 that executes the decoding process may correspond to an example of a “decoding unit” recited in the claims.

  If the decoding success rate S exceeds the first threshold value So for a code image that has undergone a certain level of shrinkage filter processing during such repeated processing, it is determined No in step S127. Then, when the occupancy P of each cell area is calculated in the cell analysis process shown in step S135, the display process shown in step S137 is performed. In this process, an information code having a decoding success rate S less than the first threshold value So is decoded, a level of contraction filter processing when the decoding success rate S is equal to or higher than the first threshold value So, and the cell analysis process The print state of each cell area analyzed and the occupancy rate P thereof are displayed on the display unit 46. Accordingly, the user can recognize that the information code having the decoding success rate S close to the lower limit value has been decoded.

  When the display process is performed in this manner, it is determined whether or not the readable condition is set in the determination process shown in step S139, and the readable condition such as the type of filter processing and the filter level is set. If yes, it is determined as Yes. Subsequently, in the determination process shown in step S141, it is determined whether or not an improvement request is necessary. When contraction filter processing that requires improvement is performed, for example, level 5 contraction filter processing is performed. Is determined as Yes.

  Next, a notification process shown in step S149 is performed, and information for suppressing the generation of a defective code is notified by being displayed on the display unit 46. As a further adjustment, the decoding success rate S is improved so as to exceed the first threshold value So by adjusting the degree of contrast so that each black region of each cell region constituting the code image is contracted as described above. In this case, changing the processing on the display surface R so as to contract the portion corresponding to each black region is a method for improving the display state of the information code. Examples of such processing changes include decreasing the processing force (printing power) applied to the processing tool during processing and increasing the processing time (tact time). By notifying information regarding such further adjustment as information for suppressing the generation of defective codes, the user can recognize a specific method for improving the display state of the information codes. .

  On the other hand, in the determination process shown in step S141, it is determined No when the contraction filter process that does not require an improvement request, for example, the level 1 contraction filter process is performed, and the setting condition notification process shown in step S143. Is made. In this process, information for determining whether to change the setting condition to this filter level is displayed on the display unit 46 together with the filter level when the decoding success rate S exceeds the first threshold value So in the filter process. The

  Subsequently, in the determination process shown in step S145, it is determined whether or not an instruction to change the setting condition has been given. Since the user who has seen the information displayed on the display unit 46 in the setting condition notification process desires to change the setting condition to the filter level, the operation unit 47 is instructed to instruct the change. If it operates, it will determine with Yes in step S145. Then, the condition setting process shown in step S147 is performed, the setting condition is changed to the filter level according to the instruction, and the verification process for the captured code image is completed.

  In the determination process shown in step S129 described above, if the decoding success rate S does not exceed the first threshold value So even if all levels of contraction filter processing are performed (Yes in S129), the code outline acquisition process shown in step S131. Is made. In this process, the image data obtained by imaging the information code is displayed on the display unit 46, and the user is caused to input information indicating the four corners of the code image via the operation unit 47 or the like. Thereby, the outer shape of the code image viewed from the user can be acquired.

  Then, the mapping process shown in step S133 is performed. In this process, the code image in which the code outline is clarified is divided for each cell region. Specifically, for example, when mapping a QR code, each finder pattern that is a QR code position specifying pattern is detected based on the code outline, and the code image is obtained using each finder pattern. Divide each cell area. Then, the processing after the cell analysis processing shown in step S135 is performed.

  As described above, in the information code verifier 10 according to the present embodiment, with respect to the code image occupied by the information code in the captured image captured by the code image acquisition process, a plurality of white regions constituting the code image (Bright color area) and Black area (Dark color area) The degree of lightness and darkness is adjusted by each filter process, and the decoding process is performed on the adjusted image whose lightness and darkness degree is adjusted so as to improve the decoding success rate S by each filter process. As a result, the information code included in the adjusted image is decoded. When the decoding success rate S when the adjusted image is decoded a plurality of times by the decoding process falls below the first threshold value So, the information code of the decoding success rate S close to the allowable lower limit value has been decoded. Is displayed on the display unit 46.

  As a result, when the decoding success rate S falls below the first threshold value So because the display state of the information code has gradually changed, it is displayed that the information code having the decoding success rate S close to the allowable lower limit value has been decoded. Since it is informed by being displayed at 46, the user can recognize that the display state of the information code is gradually changing from the original display state before the defective code is verified. . That is, since the user is prompted to maintain the processing equipment for processing the display surface R, for example, to replace the processing tool, before the defective code is generated, the decoding success rate is low. Generation of defective codes can be suppressed.

  Further, when the decoding success rate S by the decoding process falls below the first threshold value So, the degree of contrast of the code image that has been subjected to the filtering process is further improved so that the decoding success rate S is improved by each filtering process (image adjusting means). If the decoding success rate S when the image subjected to the adjustment is decoded more than once exceeds the first threshold value So, the information regarding the further adjustment is displayed as information for suppressing the generation of the defective code by the notification process. It is notified by being displayed at 46.

  As described above, when the decoding success rate S falls below the first threshold value So, information on the further adjustment (for example, information on improvement in the decoding success rate S due to expansion of the black region) is generated as a defective code. Informing the user of a specific method for improving the display state of the information code (for example, the processing force during processing to expand the portion corresponding to the black region) Can be recognized.

FIG. 10 is an explanatory diagram for describing filter processing in a modification of the first embodiment.
As a modification of the first embodiment, each of the filter processes of the smoothing filter process, the expansion filter process, and the contraction filter process is not limited to being used alone, and may be used in combination of two or more filter processes. Good.

  Specifically, as illustrated in FIG. 10, after the contraction filter process is sequentially performed as illustrated in FIGS. 10B to 10E on the image illustrated in FIG. 10A before the filter process. As shown in FIGS. 10F to 10I, the expansion filter process can be sequentially performed. As described above, by performing a combination of two or more filter processes, it is possible to perform a filter process corresponding to the code image.

  Further, when the filter process is performed on the code image, a predetermined filter process may be performed on a part of the code image and a different filter process may be performed on another area.

[Second Embodiment]
Next, an information code verifier 10 according to a second embodiment of the present invention will be described with reference to FIG. FIG. 11 is a flowchart illustrating the flow of verification processing in the second embodiment.
In the information code verifier 10 according to the second embodiment, the verification process described above is performed based on the flowchart shown in FIG. 11 instead of the flowcharts shown in FIGS. 4 and 5. Mainly different from the information code verifier according to the form. Accordingly, components that are substantially the same as those of the information code verifier of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

Hereinafter, the verification process in the second embodiment will be described with reference to the flowchart of FIG.
Similar to the verification process in the first embodiment, the decoding process shown in step S103 shown in FIG. 11 is performed, and the decoding success rate S is equal to or lower than the first threshold value So. If determined, the extraction process shown in step S201 is performed. In this process, each cell area is extracted according to a mapping process for dividing the code image performed at the time of the decoding process into each cell area. Then, the occupation ratio calculation process shown in step S203 is performed, and the occupation ratio P in each cell area is calculated (see FIG. 6).

  Next, in the determination process shown in step S205, it is determined whether the minimum occupancy ratio (hereinafter referred to as the minimum occupancy ratio Ps) among the calculated occupancy ratios P is equal to or less than the second threshold value Po. . Note that the second threshold Po is set to 80% in the present embodiment, but is not limited thereto, and may be appropriately set according to the use environment or the like.

  If the minimum occupancy Ps is not equal to or less than the second threshold Po (No in S205), the verification process for the code image captured without performing the notification process described later is completed. On the other hand, when the minimum occupancy Ps becomes equal to or smaller than the second threshold Po (Yes in S205), a notification process shown in Step S207 is performed, and the display information obtained by enlarging the cell area corresponding to the minimum occupancy Ps generates a defective code. As information for suppression, it is notified by being displayed on the display unit 46. The control circuit 40 that executes the occupancy rate calculation process in step S203 corresponds to an example of the “extracting means” described in the claims, and the control circuit 40 that executes the determination process in step S205 includes This can correspond to an example of “determination means” described in the range. Further, the second threshold Po may correspond to an example of a “second threshold” recited in the claims.

  As described above, in the information code verifier 10 according to the present embodiment, the extraction process for extracting the white area and the black area from the code image, and the minimum occupancy Ps for the cell area extracted by this extraction process are the first. And a determination process for determining whether or not it is equal to or less than 2 threshold value Po. When the decoding success rate S by the decoding process decreases to the first threshold value So or less, if the determination process determines that the minimum occupancy Ps is the second threshold value Po or less, the notification process increases the cell area. The displayed information is notified as information for suppressing the generation of a defective code.

  As a result, when the display state of the information code gradually changes and the minimum occupancy Ps falls below the second threshold Po and the decoding success rate S falls below the first threshold So, the decoding succeeds near the allowable lower limit. It is notified that the information code of rate S has been decoded, and the display information in which the cell area is enlarged is notified as information for suppressing the generation of the defective code, so that the user can decode the defective code. It is possible to easily visually recognize that the display state of the information code is gradually changing from the original display state.

  In particular, when the minimum occupancy Ps is equal to or less than the second threshold value Po, that is, when it is unclear enough to easily determine whether the cell area is a white cell or a black cell, the cell area is The enlarged display information is notified. For this reason, since the user visually recognizes the ambiguity of the cell area by looking at the display information, a specific method for improving the display state, for example, the cell area is a black cell. From this, it is possible to recognize a method for increasing the processing force during processing in order to expand the portion corresponding to the black region.

  In the determination process in step S205, not only the minimum occupancy Ps and the second threshold Po are compared, but also the occupancy P and the second threshold Po in all cell regions are compared. May be displayed in an enlarged manner in at least a part of the cell areas in which the threshold value Po is equal to or less than the second threshold value Po, or the occupancy ratio is compared with the occupancy ratio P in the partial cell area and the second threshold value Po. At least a part of the cell regions in which P is equal to or less than the second threshold value Po may be displayed in an enlarged manner.

FIG. 12 is a flowchart illustrating the flow of verification processing in the modification of the second embodiment.
As a modification of the second embodiment, verification processing may be performed based on the flowchart shown in FIG.
Specifically, as in the second embodiment, when the decoding process shown in step S103 of FIG. 12 is performed, the decoding success rate S by the decoding process of step S103 is set to the first threshold value in the determination process shown in step S104. It is determined whether or not it is equal to or smaller than a third threshold value St set larger than So.

  Here, the third threshold value St is set to 99%, for example, and if the decoding success rate S is not less than or equal to the third threshold value St, it is determined No in step S104, and after the determination processing in step S105. Processing is done. On the other hand, when the decoding success rate S is less than or equal to the third threshold value St (Yes in S104), that is, the decoding success rate S is not less than or equal to the first threshold value So, but is later decoded close to the allowable lower limit value described above. When there is a high possibility that the information code of the success rate S is decoded, the advance notification process shown in step S104a is performed. In this process, it is displayed on the display unit 46 and notified that there is a high possibility that an information code having a decoding success rate S close to the above-described allowable lower limit will be decoded.

Thereby, before the information code having the decoding success rate S close to the lower limit value is decoded, the fact is displayed and notified on the display unit 46, so that it is possible to reliably generate a defective code having a low decoding success rate S. Can be suppressed.
Note that the determination process shown in step S104 and the prior notification process shown in step s104a may be performed after the decoding process shown in step S103 in the first embodiment.

In addition, this invention is not limited to said each embodiment and modification, You may actualize as follows.
(1) In each of the above embodiments, a QR code composed of a plurality of black cells and white cells is verified. However, the present invention is not limited to this, and a QR code composed of a plurality of dark cells and light cells and other codes. Information codes of types, for example, bar codes, data matrix codes, maxi codes, etc. may be verified.

(2) In the verification process described above, a setting process for setting each of the threshold values (first threshold value So, second threshold value Po, third threshold value St) to a desired value may be performed. Thereby, an appropriate threshold value can be easily set as each threshold value according to the use environment or the like. The control circuit 40 that executes this setting process may correspond to an example of a “threshold setting unit” recited in the claims.

10: Information code verifier 28: Light receiving sensor (imaging means)
40... Control circuit (image adjusting means, decoding means, extracting means, determining means, threshold setting means)
46 ... Display section (notification means)
C ... Information code C1, C2 ... QR code (Information code)
Cb ... Black cell (dark cell)
Cw ... White cell (light cell)
R ... Display surface P ... Occupancy rate Ps ... Minimum occupancy rate Po ... 2nd threshold value (2nd threshold value)
S: Decoding success rate So: First threshold (first threshold)
St ... third threshold (third threshold)

Claims (4)

An information code verifier that verifies a display state of an information code displayed so as to have a plurality of light-colored cells and dark-colored cells by performing processing on a display surface to be verified,
Imaging means for imaging the information code displayed on the display surface;
Image adjustment means capable of adjusting the brightness levels of a plurality of bright color areas and dark color areas constituting the code image with respect to a code image occupied by the information code in a captured image captured by the imaging means;
Decoding means for decoding an information code included in the adjusted image by performing a decoding process on the adjusted image whose brightness is adjusted so as to improve the decoding success rate by the image adjusting means;
When the decoding success rate when the adjusted image is decoded a plurality of times for one adjusted image falls below a first threshold value set larger than an allowable lower limit value, the decoding success rate close to the lower limit value is reached. An informing means for informing that the information code has been decoded;
Equipped with a,
The notification means includes
When the decoding success rate by the decoding means falls below the first threshold value, the adjusted image is subjected to multiple adjustments for an image that has been further adjusted to improve the decoding success rate by the image adjustment means. when decoding success rate when decoding exceeds the first threshold value, Rukoto to notify information relating to the further adjustment, as information for inhibiting the formation of bad code decoding success rate is less than the lower limit value An information code verifier characterized by An information code verifier that verifies a display state of an information code displayed so as to have a plurality of light-colored cells and dark-colored cells by performing processing on a display surface to be verified,
Imaging means for imaging the information code displayed on the display surface;
Image adjustment means capable of adjusting the brightness levels of a plurality of bright color areas and dark color areas constituting the code image with respect to a code image occupied by the information code in a captured image captured by the imaging means;
Decoding means for decoding an information code included in the adjusted image by performing a decoding process on the adjusted image whose brightness is adjusted so as to improve the decoding success rate by the image adjusting means;
When the decoding success rate when the adjusted image is decoded a plurality of times for one adjusted image falls below a first threshold value set larger than an allowable lower limit value, the decoding success rate close to the lower limit value is reached. An informing means for informing that the information code has been decoded;
Extraction means capable of extracting any one of a light color region corresponding to at least one light color cell and a dark color region corresponding to at least one dark color cell in the code image;
Determination means for determining whether or not an occupancy ratio of an area occupied more widely among the light color area and the dark color area in the cell area extracted by the extraction means is equal to or less than a second threshold;
With
The notification means includes
When the decoding success rate by the decoding unit decreases to the first threshold value or less, if the determination unit determines that the occupation rate is equal to or less than the second threshold value, display information obtained by enlarging the cell area is displayed . , information code verifiers you characterized by notifying the information for suppressing the generation of defects code decoding success rate is less than the lower limit. An information code verifier that verifies a display state of an information code displayed so as to have a plurality of light-colored cells and dark-colored cells by performing processing on a display surface to be verified,
Imaging means for imaging the information code displayed on the display surface;
Image adjustment means capable of adjusting the brightness levels of a plurality of bright color areas and dark color areas constituting the code image with respect to a code image occupied by the information code in a captured image captured by the imaging means;
Decoding means for decoding an information code included in the adjusted image by performing a decoding process on the adjusted image whose brightness is adjusted so as to improve the decoding success rate by the image adjusting means;
When the decoding success rate when the adjusted image is decoded a plurality of times for one adjusted image falls below a first threshold value set larger than an allowable lower limit value, the decoding success rate close to the lower limit value is reached. An informing means for informing that the information code has been decoded;
With
The informing means may decode an information code having a decoding success rate close to the lower limit value when the decoding success rate by the decoding means falls below a third threshold value set larger than the first threshold value. information code verification machine shall be the features that you notify that is high.   The information code verifier according to claim 1, further comprising a threshold setting unit capable of setting the first threshold to a desired value.

Images