Code reading device and code reader adjustment support system

Abstract

To provide a code reader apparatus which can be easily adjusted to reading conditions which allow stable reading.SOLUTION: A code reader apparatus has a camera, a reading unit for reading a coder from a code image captured by the camera, and an adjustment support unit for supporting adjustment of reading conditions by a user. The reading unit has an image generating unit for generating an image of a code, a decoder unit for decoding the code, and a calculating unit for calculating a score of the code image generated by the image generating unit. The adjustment support unit has an adjustment principle determining unit for determining a principle for adjustment of the reading conditions based on the calculated score, an output unit for outputting the adjustment principle, and an adjustment unit for adjusting the reading conditions based on an operation by the user.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a code reading device and a code reader adjustment support system. [Background technology]

[0002] In recent years, with the spread of traceability, codes are printed on a variety of parts. There is a demand for code reading devices (so-called "code readers") that can reliably read codes regardless of the code itself or the object (workpiece) on which the code is printed.

[0003] Japanese Patent No. 5956941 (Patent Document 1) discloses a technique for simultaneously displaying on a display an image of a code, the success or failure of the decode, and the reading margin. The reading margin is an index showing the stability or reliability of the reading, and the higher the value, the higher the stability or reliability of the reading. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5956941 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the technology disclosed in Japanese Patent No. 5956941, in order to stabilize code reading by a code reader, the user had to adjust the code reader's reading conditions (for example, the mounting position and installation angle of the code reader body, the position of the workpiece, the inclination of the printed surface, etc.) through trial and error while checking the reading margin shown on the display. Furthermore, when the reading margin is poor, the cause of the deterioration is not known, which increases the amount of trial and error. As a result, it takes time to adjust the code reader's reading conditions.

[0006] An object of the present disclosure is to provide a code reading device that can be easily adjusted to reading conditions that enable stable reading, and a code reader adjustment support system that can easily adjust a code reading device to reading conditions that enable stable reading. [Means for solving the problem]

[0007] The code reading device according to this disclosure is a code reading device that reads a code printed on a printing target. The code reading device includes a camera that captures an image of the code, a reading unit that reads the code from an image of the code captured by the camera, and an adjustment support unit that supports a user in adjusting reading conditions of the reading unit. The reading unit includes an image generation unit that generates an image of the code to be processed by the reading unit, a decoding unit that decodes the code from the image of the code generated by the image generation unit, and a calculation unit that calculates scores for each of a plurality of evaluation items that evaluate the printing state of the code for the image of the code generated by the image generation unit. The adjustment support unit includes an adjustment policy determination unit that determines an adjustment policy for the reading conditions by the user based on the scores for each of the plurality of evaluation items calculated by the calculation unit, an output unit that outputs the adjustment policy determined by the adjustment policy determination unit to the user, and an adjustment unit that adjusts the reading conditions based on a user operation.

[0008] According to the above disclosure, a user can easily adjust the code reading device to reading conditions that enable stable reading.

[0009] In the above disclosure, the image generation unit has an imaging condition setting unit that sets the imaging conditions of the camera, and a pre-processing unit that performs image processing on the image of the code, and the image of the code captured under the imaging conditions set by the imaging condition setting unit is subjected to image processing in the pre-processing unit to generate an image of the code to be processed by the reading unit.

[0010] According to the above disclosure, when the imaging conditions are adjusted, image processing is applied to the image of the code captured under the adjusted imaging conditions and a score is output, allowing the user to check the adjusted score.

[0011] In the above disclosure, the code reading device further includes an illumination unit connected to the reading unit and configured to illuminate the code when the camera captures an image of the code. The imaging condition setting unit further sets illumination conditions for the illumination unit.

[0012] According to the above disclosure, when the lighting conditions are adjusted, the adjusted lighting conditions can be set in the code reading device.

[0013] In the above disclosure, the adjustment policy determination unit switches between a plurality of evaluation items for calculating a score depending on the evaluation method selected by the user.

[0014] According to the above disclosure, by selecting an evaluation method, multiple evaluation items are set, thereby reducing the setting burden on the user.

[0015] In the above disclosure, the adjustment policy includes information on which evaluation item the score should be improved from.

[0016] According to the above disclosure, the user can recognize how to adjust the reading conditions of the reading unit.

[0017] In the above disclosure, the adjustment policy includes information suggesting how to adjust the reading conditions for each evaluation item to improve the score.

[0018] According to the above disclosure, the user can recognize how to adjust the reading conditions of the reading unit.

[0019] In the above disclosure, the suggested information includes at least one of a first policy regarding image processing for an image of a code captured by a camera and a second policy regarding capturing an image of the code.

[0020] According to the above disclosure, the user can recognize how to adjust the reading conditions of the reading unit.

[0021] In the above disclosure, the output unit further outputs to the user information indicating the scores for each of the multiple evaluation items calculated by the calculation unit.

[0022] According to the above disclosure, the user can recognize which evaluation items have poor scores.

[0023] In the above disclosure, the information indicating the score includes comparison information comparing the score with a threshold. The comparison information includes information distinguishing between evaluation items whose scores are below the threshold and evaluation items whose scores are equal to or greater than the threshold.

[0024] According to the above disclosure, a user can recognize evaluation items whose scores are below a threshold and evaluation items whose scores are equal to or above the threshold.

[0025] In the above disclosure, the comparison information further includes information indicating the deviation between the score and a threshold for each evaluation item.

[0026] According to the above disclosure, the user can recognize the deviation between the score and the threshold for each evaluation item.

[0027] In the above disclosure, the output unit stops outputting at least a part of the information indicating the scores for the evaluation items selected by the user as not being evaluated. The scores of the evaluation items not being evaluated are not taken into consideration when the adjustment policy is determined by the adjustment policy determination unit.

[0028] According to the above disclosure, since information that is not required by the user is not output, the user can focus only on the information that the user needs. In addition, since the scores of evaluation items that are not the evaluation targets selected by the user are not taken into consideration when deciding an adjustment policy, it is easy to decide an adjustment policy in the direction desired by the user.

[0029] In the above disclosure, the code is composed of a plurality of elements, and the output unit displays an image of the code by superimposing an image showing the positions of elements whose scores are below a threshold.

[0030] According to the above disclosure, a user can identify the location of elements whose scores are below a threshold.

[0031] The code reader adjustment support system according to the present disclosure includes a code reading device that reads a code printed on a printing object, and an adjustment support device that supports a user's adjustment of reading conditions of the code reading device. The code reading device includes a camera that captures an image of a code, and a reading unit that reads the code from the image of the code captured by the camera. The reading unit has an image generation unit that generates an image of the code to be processed by the reading unit, a decoding unit that decodes the code from the image of the code generated by the image generation unit, and a calculation unit that calculates scores for each of a plurality of evaluation items that evaluate the printing state of the code, for the image of the code generated by the image generation unit. The adjustment support device includes an adjustment policy determination unit that determines an adjustment policy for the reading conditions by a user based on the scores for each of the plurality of evaluation items calculated by the calculation unit, an output unit that outputs the adjustment policy determined by the adjustment policy determination unit to the user, and an adjustment unit that adjusts the reading conditions based on a user operation.

[0032] According to the above disclosure, a user can easily adjust the code reading device to reading conditions that enable stable reading. Effect of the Invention

[0033] According to the present disclosure, it is possible to provide a code reading device that can be easily adjusted to reading conditions that enable stable reading, and a code reader adjustment support system that can easily adjust a code reading device to reading conditions that enable stable reading. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is a diagram for explaining an outline of a code reading device. [Diagram 2] FIG. 2 is a block diagram showing a code reader and its peripherals. [Diagram 3] FIG. 13 is a diagram showing an example of evaluation items used in the code reading device. [Figure 4]10 is a flowchart illustrating an example of a process performed by a code reading device. [Diagram 5] FIG. 13 is a diagram showing an example of a screen for selecting an evaluation method. [Figure 6] FIG. 13 is a diagram showing an example of a screen displayed during a reading test. [Figure 7] FIG. 11 is a diagram showing an example of overhead view information. [Figure 8] FIG. 13 is a diagram showing an example of information indicating a score for a specific evaluation item, among the detailed information. [Figure 9] FIG. 13 is a diagram showing an example of detailed information other than the scores for specific evaluation items. [Figure 10] FIG. 13 is a diagram showing a modified example of the image of the code. [Figure 11] FIG. 13 is a diagram showing an example of an image used for adjusting reading conditions; [Figure 12] FIG. 2 is a block diagram showing a code reader adjustment support system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same or corresponding parts in the drawings are given the same reference numerals and the description thereof will not be repeated. The embodiments and modifications described below may be appropriately and selectively combined.

[0036] [Example of application] First, an example of a situation to which the present invention is applied will be described with reference to Figures 1 and 2. The situation to which the present invention is applied is a situation in which a user adjusts the reading conditions of a code reading device 100. The code reading device 100 has a reading function for reading a code 1 printed on a workpiece 2, and an adjustment support function for supporting the user in adjusting the conditions related to reading the code 1 (reading conditions of the reading unit 30).

[0037] Reading the code 1 by the code reading device 100 means capturing an image of the code 1 and applying image processing (filter processing) to the captured image to decode the code 1, and this is achieved by the reading unit 30. Therefore, to ensure stable reading by the code reading device 100, the user is required to appropriately adjust the reading conditions of the reading unit 30.

[0038] The reading conditions of the reading unit 30 can be classified into two: one is a condition related to the imaging of the code 1, and the other is a condition related to image processing of the image of the code 1 captured by the camera. The conditions related to the imaging of the code 1 include the imaging conditions of the camera (e.g., the exposure time of the camera, the gain of the camera, the aperture of the camera, the camera angle, etc.) and the lighting conditions of the lighting (e.g., the brightness of the lighting, the inclination of the lighting, whether one-sided lighting or full lighting is used, etc.). The conditions related to the image processing of the image of the code 1 captured by the camera include, for example, the type of filter to be used, the size of the filter, the number of times filtering is performed, etc.

[0039] As described above, since the reading conditions of the reading unit 30 include various conditions, it is not easy for a user to appropriately adjust these conditions. Therefore, the code reading device 100 of the present invention provides the user with an adjustment policy for the reading conditions of the reading unit 30. Specifically, the code reading device 100 captures an image of the code 1, and determines an adjustment policy required for stable reading based on the captured image of the code 1. Then, the code reading device 100 outputs the determined adjustment policy to the user. Furthermore, when the code reading device 100 receives an adjustment operation for the reading conditions by the user, it sets the reading conditions corresponding to the received operation.

[0040] Therefore, the user can stabilize reading by the code reading device 100 simply by adjusting the reading conditions of the reading unit 30 according to the output adjustment policy. This reduces the burden on the user of adjusting the reading conditions of the reading unit 30.

[0041] More specific application examples of the embodiment will be described below.

[0042] [Embodiment 1] (Outline of the code reader) 1 is a diagram for explaining an outline of a code reading device 100. The code reading device 100 captures an image of a code 1 printed on a workpiece 2, and decodes the code 1 by performing image processing on the captured image.

[0043] There are three types of Code 1: one-dimensional symbols, two-dimensional symbols, and composite symbols. One-dimensional symbols are symbols in which bars and spaces are arranged in a straight line, such as code39 and code128. Two-dimensional symbols include multi-row symbols in which one-dimensional symbols are stacked in multiple stages, and matrix symbols in which cells are arranged in the X / Y directions. Examples of matrix symbols include QR Code (registered trademark) and DataMatrix (registered trademark). Composite symbols are symbols that combine one-dimensional and two-dimensional symbols.

[0044] The workpiece 2 corresponds to the "printing target." The material of the workpiece 2 may be metal, resin, ceramic, wood, paper, glass, rubber, or the like.

[0045] Furthermore, the code reading device 100 supports the user in adjusting the conditions for reading the code 1 (the reading conditions of the reading unit 30 shown in FIG. 2). Specifically, the code reading device 100 captures an image of the code 1, and determines a policy of adjustment required to stabilize reading based on the captured image of the code 1. The code reading device 100 is connected to the output device 200, and causes the output device 200 to output the determined adjustment policy. In this example, the output device 200 is a display, but the output device 200 may be any device that is used to output information to the user, and may be, for example, a speaker.

[0046] The code reading device 100 is also connected to an input device 300. The input device 300 is used for input operations by a user. In this example, the input device 300 includes a keyboard 301 and a mouse 302, but may also include a touch panel display integrated with an output device in addition to or instead of these. When a user uses the input device 300 to perform an input operation for adjusting the reading conditions of the reading unit 30, the reading conditions corresponding to the input operation are set in the code reading device 100.

[0047] (Code reader configuration) The configuration of the code reading device 100 will be described with reference to Figures 1 and 2. Figure 2 is a block diagram showing the code reading device 100 and its peripheral devices. The code reading device 100 includes a camera 10, a light 20, a reading unit 30, and an adjustment support unit 40.

[0048] Camera 10 is connected to reading unit 30, specifically, to imaging condition setting unit 311 described later, and captures an image of code 1 printed on workpiece 2 according to imaging conditions (e.g., exposure time of camera 10, gain of camera 10, aperture of camera 10, angle of camera 10, etc.) set by imaging condition setting unit 311. Camera 10 is also connected to reading unit 30, specifically, to pre-processing unit 312 described later, and transmits data of the captured image of code 1 to pre-processing unit 312.

[0049] The lighting 20 is connected to the reading unit 30, specifically, to the image capturing condition setting unit 311 described below, and illuminates the code 1 when the camera 10 captures the image of the code 1 in accordance with the lighting conditions set by the image capturing condition setting unit 311 (e.g., the brightness of the lighting 20, the inclination of the lighting 20, whether one-sided lighting or full lighting is to be used, etc.).

[0050] The reading unit 30 reads (decodes) the code 1 from the image of the code 1 captured by the camera 10. The reading unit 30 includes an image generation unit 31, a decoding unit 32, and a calculation unit 33. The image generation unit 31 further includes an image capture condition setting unit 311 and a pre-processing unit 312. The adjustment support unit 40 supports the user in adjusting the reading conditions of the reading unit 30. The adjustment support unit 40 includes an adjustment policy determination unit 41, an output unit 42, and an adjustment unit 43.

[0051] The imaging condition setting unit 311 is connected to the camera 10, the lighting 20, and the adjustment unit 43. When the imaging condition setting unit 311 receives imaging conditions for the camera 10 from the adjustment unit 43, the imaging condition setting unit 311 sets the received imaging conditions for the camera 10, and when the imaging condition setting unit 311 receives illumination conditions for the lighting 20 from the adjustment unit 43, the imaging condition setting unit 311 sets the received illumination conditions for the lighting 20.

[0052] The pre-processing unit 312 is connected to the camera 10, the decoding unit 32, the calculation unit 33, and the adjustment unit 43. The pre-processing unit 312 receives conditions related to image processing (e.g., the type of filter to be used, the size of the filter, the number of times filter processing is performed, etc.) from the adjustment unit 43. The pre-processing unit 312 also receives an image of the code 1 from the camera 10. The pre-processing unit 312 performs image processing on the received image of the code 1 in accordance with the received conditions related to image processing, and generates an image of the code 1 to be processed by the reading unit 30. The pre-processing unit 312 transmits the generated image of the code 1 to the decoding unit 32.

[0053] The decoding unit 32 is connected to the pre-processing unit 312 and the calculation unit 33. The decoding unit 32 finds the code 1 in the image based on the data of the image of the code 1 received from the pre-processing unit 312, and decodes the code 1. At the stage of adjusting the reading conditions (stage of the reading test), the decoding unit 32 transmits the data of the image of the code 1 including the decoded result (e.g., the center coordinates of the cell) to the calculation unit 33. At the stage of reading the code 1 (actual reading), the decoding unit 32 may or may not transmit the data of the image of the code 1 including the decoded result to the calculation unit 33.

[0054] The calculation unit 33 is connected to the decoding unit 32, the adjustment policy determination unit 41, and the output unit 42. The calculation unit 33 calculates a score (0 to 100) for each of a plurality of evaluation items for the image of the code 1 received from the decoding unit 32 based on the result of the decoding, and transmits the calculated scores to the adjustment policy determination unit 41 and the output unit 42.

[0055] Depending on the evaluation method described below, there may be cases where no image processing is performed on the image of the code 1 captured by the camera 10. In such cases, the calculation unit 33 may calculate the scores for each of the multiple evaluation items based on the results of decoding the image of the code 1 captured by the camera 10 (i.e., an image that has not been subjected to image processing).

[0056] The evaluation items will be described in detail later, but the evaluation items are defined by ISO (International Organization for Standardization), IEC (International Electrotechnical Commission), JISC (Japanese Industrial Standards Committee), etc. as indices for evaluating the printing state of the code 1. The multiple evaluation items for which the scores are calculated by the calculation unit 33 are determined by the adjustment policy determination unit 41 according to an algorithm pre-stored in a storage device provided in the code reading device 100.

[0057] Here, an algorithm is a procedure for determining the evaluation items to be improved and the order in which they should be improved in order to stabilize reading, and for example, a procedure for determining the evaluation items to be improved and the order in which they should be improved along with the process of reading Code 1 with the code reader 100. There are three prerequisites for formulating an algorithm:

[0058] (1) Since one of a plurality of decryption processes is selected depending on the type of code 1 selected in a field 502 (see FIG. 5) described later, it is necessary to formulate an algorithm for each type of code 1. (2) The reading process according to the type of Code 1 is composed of multiple steps, and the order of these steps is fixed. For example, when reading a two-dimensional symbol, the process of reading Code 1 is performed in the order of "search," "grid estimation," "cell binarization," and "decoding." Note that "search" refers to detecting where Code 1 is located in the image captured by camera 10. "Grid estimation" refers to identifying the position of the cell. "Cell binarization" refers to classifying the identified cell position as either white or black. "Decoding" refers to decoding Code 1. (3) The evaluation items of the evaluation method selected in the field 503 (see FIG. 5) described later can be associated with each step of the reading process. For example, when performing a "search," attention is focused on the fixed pattern of Code 1, so there is a strong association with FPD (Fixed Pattern Damage).

[0059] In this way, in the reading process, each step is executed in a set order, so if a step fails, the process will not proceed to the next step and the reading will fail. On the other hand, if the evaluation items closely related to each step are improved in accordance with the execution order of each step, the processing in each step will be successful in sequence, and the reading process will be stable.

[0060] The algorithm used by the code reader 100 to determine the evaluation items to be improved and the order in which they should be improved is formulated based on these preconditions. Specifically, the code reader 100 uses an algorithm that determines the evaluation items to be improved and the order in which they should be improved based on the processing content in each step of the reading process and the execution order of the steps.

[0061] In the code reading device 100, the above-mentioned storage device stores the algorithm for each type of code 1, and the adjustment policy determination unit 41 determines the evaluation items to be improved and the order in which they should be improved according to the algorithm.

[0062] The adjustment policy determination unit 41 is connected to the calculation unit 33, the output unit 42, and the input device 300. The adjustment policy determination unit 41 determines an adjustment policy (hereinafter also referred to as an "adjustment policy") that the user should make in order to stabilize reading by the code reading device 100, and transmits the determined adjustment policy to the output unit 42. The adjustment policy includes at least one of information on which of a plurality of evaluation items the score should be improved from, and information suggesting how to adjust the reading conditions of the reading unit 30 for each evaluation item whose score should be improved. Furthermore, the suggested information includes at least one of a first policy regarding image processing for the image of the code 1 captured by the camera 10 and a second policy regarding the capture of the code 1.

[0063] The adjustment policy determination unit 41 determines the adjustment policy as follows: First, the adjustment policy determination unit 41 determines a plurality of evaluation items according to the above algorithm, and instructs the calculation unit 33 to calculate scores for the determined plurality of evaluation items.

[0064] Next, the adjustment policy determination unit 41 determines, in accordance with the above algorithm, from which evaluation item the score should be improved.

[0065] Next, the adjustment policy determination unit 41 receives the scores for the determined multiple evaluation items from the calculation unit 33, compares the received scores for each of the multiple evaluation items with a threshold value that is preset for each evaluation item, and determines evaluation items whose scores are below the threshold as evaluation items whose scores should be improved (hereinafter also referred to as ``evaluation items to be improved'').

[0066] Next, the adjustment policy determination unit 41 extracts adjustment items corresponding to the evaluation items to be improved from among the adjustment items stored in advance in the code reading device 100.

[0067] Items to be adjusted for each evaluation item ("adjustment items") are stored in advance in a storage device provided in the code reading device 100, and the adjustment policy decision unit 41 extracts an adjustment item corresponding to the evaluation item to be improved from the stored items. As an example of adjustment items stored for each evaluation item, a density correction filter, an exposure time of the camera 10, and an aperture of the camera 10 are stored in association with each other as adjustment items for an evaluation item called SC (Symbol Contrast) described later. Also, a smoothing filter and an expansion / contraction filter are stored in association with each other as adjustment items for an evaluation item called MOD (Modulation) described later. In addition to these, adjustment items related to the imaging conditions of the camera 10 (e.g., camera exposure time, camera gain, camera aperture, camera angle, etc.), adjustment items related to the lighting conditions of the lighting 20 (e.g., lighting brightness, lighting inclination, whether to use one-sided lighting or full lighting, etc.), and adjustment items related to image processing of the image of the code 1 captured by the camera 10 (e.g., type of filter to be used, filter size, number of times filtering is performed, etc.) are stored in correspondence with each evaluation item.

[0068] The adjustment items extracted for each evaluation item to be improved are an example of information suggesting how to adjust the reading conditions of the reading unit 30 for each evaluation item whose score should be improved. When the user makes adjustments for each of the extracted adjustment items, the adjusted conditions are set in the code reading device 100 as the reading conditions of the reading unit 30.

[0069] The adjustment items may be stored in the storage device by the degree of deviation between the score and the threshold value in addition to by evaluation item, and the adjustment policy decision unit 41 may extract the adjustment items corresponding to the evaluation items to be improved based on the evaluation items to be improved and the degree of deviation between the score of the evaluation items and the threshold value. In addition to the adjustment items, the storage device may store information on what values ​​the adjustment items should be adjusted to by evaluation item.

[0070] The adjustment policy determination unit 41 may determine the first policy and the second policy at once, or may determine the first policy and the second policy in stages. As an example of a staged determination, the adjustment policy determination unit 41 may first determine only the first policy, and then determine the content of the second policy when the score of the evaluation item to be improved is not improved despite adjustments based on the first policy being performed a predetermined number of times or more.

[0071] The adjustment policy determination unit 41 may also receive an input of an evaluation item that is not a target of evaluation from the input device 300. The evaluation item that is not a target of evaluation means an evaluation item whose score calculated by the calculation unit 33 is not taken into consideration when determining an adjustment policy. When the adjustment policy determination unit 41 receives an input of an evaluation item that is not a target of evaluation from the input device 300, the adjustment policy is determined after excluding the score of the evaluation item, and the adjustment policy is instructed to the output unit 42 to stop outputting information indicating the score of the evaluation item. This makes it easier to determine an adjustment policy with a direction desired by the user. In addition, since information that is not required by the user is not output, the user can be directed to only the information that the user requires.

[0072] When the adjustment policy decision unit 41 receives an input of an evaluation item that is not a target of evaluation from the input device 300, the adjustment policy decision unit 41 may stop outputting the comparison information among the information indicating the scores of the evaluation items, but may output the scores calculated by the calculation unit 33. The comparison information is information obtained by comparing the scores calculated by the calculation unit 33 with a threshold value that is preset for each evaluation item.

[0073] The output unit 42 is connected to the calculation unit 33, the adjustment policy determination unit 41, and the output device 200. The output unit 42 outputs information indicating the scores for each of the multiple evaluation items received from the calculation unit 33 and the adjustment policy received from the adjustment policy determination unit 41 to the user. More specifically, the output unit 42 outputs the evaluation items and the scores in a manner that allows the user to recognize the order of improvement determined by the adjustment policy determination unit 41. The output unit 42 also outputs the adjustment items extracted by the adjustment policy determination unit 41 in a manner that allows the user to recognize them by evaluation item. Note that, for an evaluation item for which the adjustment policy determination unit 41 has instructed the output to be stopped, the output unit 42 stops outputting information indicating the score of the evaluation item.

[0074] When the output device 200 is a display, the output unit 42 causes the display to display the score received from the calculation unit 33 and the adjustment policy received from the adjustment policy determination unit 41. When the output device 200 is a speaker, the output unit 42 causes the speaker to output the score received from the calculation unit 33 and the adjustment policy received from the adjustment policy determination unit 41 as audio.

[0075] The user can adjust the adjustment items corresponding to the evaluation items in the order in which the evaluation items are output, thereby adjusting the code reading device 100 to a reading condition that enables stable reading.

[0076] The adjustment unit 43 is connected to the imaging condition setting unit 311, the pre-processing unit 312, and the input device 300. The adjustment unit 43 adjusts the reading conditions of the reading unit 30 based on the user's operation. Specifically, when the user uses the input device 300 to perform an operation to adjust an adjustment item related to the imaging conditions of the camera 10 or an adjustment item related to the lighting conditions of the lighting 20, the adjustment unit 43 transmits the conditions corresponding to the operation to the imaging condition setting unit 311. Also, when the user uses the input device 300 to perform an operation to adjust an adjustment item related to image processing, the adjustment unit 43 transmits the conditions corresponding to the operation to the pre-processing unit 312. In the camera 10 and the lighting 20, the imaging condition setting unit 311 captures and lights up the code 1 according to the conditions received from the adjustment unit 43, and the pre-processing unit 312 performs image processing according to the conditions received from the adjustment unit 43.

[0077] In addition, the camera 10 and the lighting 20 may be provided in a housing different from the housing in which the reading unit 30 and the adjustment support unit 40 are provided, or may be provided in the same housing as the housing in which the reading unit 30 and the adjustment support unit 40 are provided.

[0078] In addition, the calculation unit 33 may be provided in the adjustment support unit 40 instead of in the reading unit 30.

[0079] (Evaluation items) 1 to 3, the evaluation items used in the code reading device 100 will be described. Fig. 3 is a diagram showing an example of evaluation items used in the code reading device 100. To evaluate the printing condition of the code 1, the code reading device 100 uses indices defined by ISO, IEC, JISC, etc. as evaluation items.

[0080] As an example, the code reading device 100 uses indices such as Symbol Contrast (SC), Cell Contrast (CC), Modulation (MOD), Cell Modulation (CM), Reflectance Margin (RM), Fixed Pattern Damage (FPD), Decode (DEC), Unused Error Correction (UEC), Grid Nonuniformity (GN), and Axial Nonuniformity (AN) as evaluation items.

[0081] Among these indices, SC, CC, MOD, CM, RM, and FPD are indices for evaluating the ease of binarization. More specifically, SC and CC are indices for evaluating contrast. MOD, RM, and CM are indices for evaluating the margin of binarization in an area where data is stored. FPD is an index for evaluating the margin of binarization in an area of ​​a fixed pattern. SC and CC have the same evaluation target, but different evaluation methods (calculation methods). Similarly, MOD and CM have the same evaluation target, but different evaluation methods (calculation methods).

[0082] DEC and UEC are indices for evaluating the validity of the binarization result. More specifically, DEC is an index for evaluating whether decoding is possible, and UEC is an index for evaluating whether binarization has been performed accurately.

[0083] GN and AN are indices for evaluating the lattice distortion. More specifically, GN is an index for evaluating the amount of lattice misalignment, and AN is an index for evaluating the aspect ratio in the X / Y directions.

[0084] SC, MOD, RM, FPD, DEC, UEC, GN, and AN are defined in ISO / IEC15415, while CC, CM, FPD, DEC, UEC, GN, and AN are defined in ISO / IEC TR29158. It is said that the evaluation items defined in ISO / IEC15415 are suitable for evaluating the printing condition of two-dimensional symbols printed on label paper, whereas the evaluation items defined in ISO / IEC TR29158 are suitable for evaluating the printing condition of two-dimensional symbols printed directly on metal parts, etc. If the evaluation items are not selected appropriately, the evaluation results may deviate from the actual printing condition of Code 1.

[0085] Therefore, the code reading device 100 provides the user with an interface for selecting an evaluation method, and switches between multiple evaluation items for calculating a score according to the evaluation method selected by the user. As an example, the output unit 42 causes the output device 200 to output a screen for selecting an evaluation method (see FIG. 5 described later). When the user selects ISO / IEC15415 as the evaluation method, the adjustment policy determination unit 41 sets multiple evaluation items for calculating a score from among SC, MOD, RM, FPD, DEC, UEC, GN, and AN according to the above-mentioned algorithm, and when the user selects ISO / IEC TR29158 as the evaluation method, the adjustment policy determination unit 41 sets multiple evaluation items for calculating a score from among CC, CM, FPD, DEC, UEC, GN, and AN according to the above-mentioned algorithm.

[0086] Note that the number of evaluation methods that a user can select may be any number of times, and is not limited to the evaluation methods shown in Fig. 3. A manufacturer may devise its own evaluation method using indicators defined by ISO, IEC, JISC, etc., and include the devised evaluation method in the evaluation methods that can be selected by the user. Also, it is sufficient to have any number of evaluation items, and the evaluation items may include indicators unique to the manufacturer in addition to indicators defined by ISO, IEC, JISC, etc.

[0087] (Processing performed by the code reader) The process performed in the code reading device 100 will be described with reference to Figures 1, 2 and 4. Figure 4 is a flow chart showing an example of the process performed in the code reading device 100. The process shown in Figure 4 is realized by a CPU (Central Processing Unit) executing a predetermined program. The predetermined program is stored in a storage device provided in the code reading device 100. The CPU selects a target program from among the programs stored in the storage device, and loads the selected program into a RAM (Random Access Memory) for execution.

[0088] In step S405, the CPU determines whether or not a command to start a read test has been issued. If a command to start a read test has been issued (YES in step S405), the CPU proceeds to step S410. If a command to start a read test has not been issued (NO in step S405), the CPU proceeds to step S475.

[0089] In step S410, the CPU sets the reading conditions of the reading unit 30 (imaging conditions of the camera 10, lighting conditions of the lighting 20, and conditions related to image processing by the pre-processing unit 312). Specifically, when the CPU receives input of reading conditions of the reading unit 30 from the user, the CPU sets the received conditions as the conditions for the initial imaging and image processing of the reading test, and when the CPU does not receive input of reading conditions from the user, the CPU sets initial values ​​registered in advance in the code reading device 100 as the conditions for the initial imaging and image processing of the reading test.

[0090] In step S415, the CPU determines a plurality of evaluation items. The process in step S415 is realized by the adjustment policy determination unit 41. Setting of the evaluation items will now be described with reference to FIG. 5. FIG. 5 is a diagram showing an example of a screen for selecting an evaluation method. Screen 501 is an example of a screen for selecting an evaluation method. Screen 501 is displayed on output device 200 by output unit 42. Screen 501 includes a field 502 for selecting the type of code 1, a field 503 for selecting the evaluation method, and a button 504 for instructing the start of measurement of the printing state of code 1 (score calculation).

[0091] When the user uses the input device 300 to select the type of code 1 in field 502, select an evaluation method in field 503, and press button 504, the adjustment policy determination unit 41 determines multiple evaluation items from among the evaluation items corresponding to the evaluation method selected in field 503, in accordance with the above-mentioned algorithm, and instructs the calculation unit 33 to calculate scores for the determined multiple evaluation items. As an example, when ISO / IEC15415 is selected as the evaluation method (see FIG. 3), the adjustment policy determination unit 41 determines SC, MOD, FPD, DEC, UEC, GN, and AN from among SC, MOD, RM, FPD, DEC, UEC, GN, and AN as the evaluation items for calculating scores, in accordance with the above-mentioned algorithm.

[0092] 4 again, in step S420, the CPU captures an image of code 1. Specifically, based on an instruction from the CPU, the illumination 20 illuminates code 1, and the camera 10 captures an image of code 1. For the imaging conditions of camera 10 and the illumination conditions of illumination 20, the conditions set in step S410 are used in the first imaging after an instruction to start a reading test is given, and for the second and subsequent imaging after an instruction to start a reading test, the conditions set based on an adjustment operation by the user are used.

[0093] In step S425, the CPU performs image processing on the image of Code 1 captured by camera 10 to generate an image of Code 1 to be processed by reading unit 30, and decodes Code 1 from the generated image of Code 1. Of the processes in step S425, the image processing is realized by pre-processing unit 312, and the decoding process is realized by decoding unit 32. Regarding the conditions for image processing, the conditions set in step S410 are used in the first image generation after an instruction to start a reading test is given, and the conditions set by an adjustment operation by the user are used in the second and subsequent image generation after an instruction to start a reading test is given.

[0094] In step S430, the CPU calculates the scores of each of the evaluation items determined in step S415 based on the result of decoding the image of Code 1 generated in step S425. The process in step S430 is realized by the calculation unit 33.

[0095] In step S435, the CPU determines a policy for adjusting the reading conditions by the user based on the scores for each of the evaluation items calculated in step S430. The process in step S435 is realized by the adjustment policy determination unit 41.

[0096] In step S440, the CPU outputs to the user information indicating the scores for the multiple evaluation items calculated in step S430 and the adjustment policy determined in step S435. If the output device 200 is a display, the CPU causes the display to display the information indicating the scores for the multiple evaluation items calculated in step S430 and the adjustment policy determined in step S435. If the output device 200 is a speaker, the CPU causes the speaker to output the information indicating the scores for the multiple evaluation items calculated in step S430 and the adjustment policy determined in step S435 as audio.

[0097] In step S445, the CPU determines whether or not an operation to adjust the conditions related to image processing among the reading conditions has been accepted. If an operation to adjust the conditions related to image processing has been accepted (YES in step S445), the CPU proceeds to step S450. If an operation to adjust the conditions related to image processing has not been accepted (NO in step S445), the CPU proceeds to step S460.

[0098] In step S450, the CPU adjusts the conditions related to image processing based on the accepted operation. Specifically, when the user performs an operation to adjust the conditions related to image processing using the input device 300, the CPU transmits the conditions corresponding to the operation to the preprocessing unit 312. The process in step S450 is realized by the adjustment unit 43. The conditions transmitted to the preprocessing unit 312 are stored by the preprocessing unit 312 as the adjusted conditions. Then, when an instruction to perform remeasurement, which will be described later, is given, the preprocessing unit 312 performs image processing under the adjusted conditions.

[0099] In step S455, the CPU determines whether or not remeasurement has been instructed. Remeasurement means that when the reading conditions of the reading unit 30 have been adjusted, the CPU calculates the score again under the adjusted conditions. If remeasurement has been instructed (YES in step S455), the CPU returns the process to step S425, and if remeasurement has not been instructed (NO in step S455), the CPU transitions the process to step S460. In this way, since the process returns to step S425 when remeasurement has been instructed, image processing is performed on the image of Code 1 already captured in step S420 under the adjusted conditions, and the score is calculated again.

[0100] In step S460, the CPU determines whether or not an operation to adjust the imaging conditions among the reading conditions has been accepted. If an operation to adjust the imaging conditions has been accepted (YES in step S460), the CPU proceeds to step S465, and if an operation to adjust the imaging conditions has not been accepted (NO in step S460), the CPU proceeds to step S470.

[0101] In step S465, the CPU adjusts the imaging conditions based on the received operation. Specifically, when the user performs an operation to adjust the imaging conditions using the input device 300, the CPU transmits the conditions corresponding to the operation to the imaging condition setting unit 311. The process in step S465 is realized by the adjustment unit 43. The conditions transmitted to the imaging condition setting unit 311 are stored by the imaging condition setting unit 311 as adjusted conditions. Then, when remeasurement is instructed, the adjusted conditions are transmitted by the imaging condition setting unit 311 to the camera 10 and the lighting 20, and the camera 10 and the lighting 20 capture the code 1 under the adjusted conditions.

[0102] In step S470, the CPU determines whether or not a remeasurement has been instructed. If a remeasurement has been instructed (YES in step S470), the CPU returns the process to step S420, and if a remeasurement has not been instructed (NO in step S470), the CPU transitions the process to step S475. In this way, if a remeasurement has been instructed, the process returns to step S420, so that the image of Code 1 is captured and processed under the adjusted conditions, and the score is calculated again. Note that if the image processing conditions among the reading conditions are not adjusted, and only the image capturing conditions are adjusted and a remeasurement is instructed (NO in step S445, YES in step S460, and YES in step S470), the image of Code 1 is captured under the adjusted conditions, the image processing is performed under the same conditions as those used in the most recent image processing, and the score is calculated again.

[0103] In step S475, the CPU determines whether or not it has been instructed to read (main) Code 1. If it has been instructed to read (main) Code 1 (YES in step S475), the CPU proceeds to step S480, and if it has not been instructed to read (main) Code 1 (NO in step S475), the CPU ends the series of processes shown in FIG.

[0104] In step S480, the CPU sets the reading conditions of the reading unit 30 (the imaging conditions of the camera 10, the illumination conditions of the illumination 20, and the conditions related to the image processing by the preprocessing unit 312). Specifically, when an instruction to read Code 1 (main) is given after the reading test, the CPU sets the adjusted conditions adjusted in the reading test as the reading conditions for the reading (main). On the other hand, when an instruction to read Code 1 (main) is given without going through the reading test and the input of the reading conditions for the reading unit 30 is accepted from the user, the CPU sets the accepted conditions as the reading conditions for the reading (main). When an instruction to read Code 1 (main) is given without going through the reading test and the input of the reading conditions for the reading unit 30 is not accepted from the user, the CPU sets the initial values ​​registered in advance in the code reading device 100 as the reading conditions for the reading (main).

[0105] In step S485, the CPU captures an image of the code 1 under the conditions set in step S480. Specifically, the lighting 20 illuminates the code 1, and the camera 10 captures an image of the code 1, based on an instruction from the CPU.

[0106] In step S490, the CPU performs image processing on the image of Code 1 captured by camera 10 under the conditions set in step S480 to generate an image of Code 1 to be processed by reading unit 30 (more specifically, decoding unit 32). The processing in step S490 is realized by pre-processing unit 312.

[0107] In step S495, the CPU decodes Code 1 from the image of Code 1 generated in step S490. The process in step S495 is realized by the decoding unit 32.

[0108] After step S495, the CPU ends the series of processes shown in FIG.

[0109] (Interface to assist user adjustment) An interface for assisting a user in making adjustments in the code reading device 100 will be described with reference to FIGS. 1 to 4 and 6 to 11.

[0110] 1 to 4 and 6, a description will be given of screens displayed during a reading test. FIG. 6 is a diagram showing an example of a screen displayed during a reading test. Screen 601 is an example of a screen displayed in step S440 during a reading test. Screen 601 is displayed on a display (output device 200) by output unit 42. Screen 601 includes columns 610, 620, 630, 640, 650, 660, tabs 673, 674, and various buttons 671, 672, 675, 676.

[0111] In the field 610, information indicating the score calculated in step S430 is displayed. The field 610 has two tabs (tab 611, tab 612), and the user can switch the information displayed in the field 610 by selecting a tab. Specifically, when the user selects the tab 611, information (overhead information) in which the print state of the code 1 imaged in step S420 is comprehensively evaluated based on the multiple evaluation items determined in step S415 is displayed in the field 610. On the other hand, when the user selects the tab 612, information (detailed information) in which the print state of the code 1 imaged in step S420 is evaluated for a specific evaluation item among the multiple evaluation items determined in step S415 is displayed in the field 610. The overhead information and the detailed information include information indicating the score for each of the multiple evaluation items calculated in step S430, and the information indicating the score includes comparison information obtained by comparing the score calculated in step S430 with a threshold value preset for each evaluation item.

[0112] In the columns 620 and 630, information is displayed that suggests how to adjust the reading conditions for each evaluation item whose score should be improved. The information is determined by the adjustment policy determination unit 41. In the column 620, all evaluation items whose scores should be improved are displayed in a pull-down menu. In the column 630, information is displayed that suggests adjustment of the adjustment items extracted by the adjustment policy determination unit 41. When the user selects one of the evaluation items to be improved in the column 620, the adjustment item corresponding to the selected evaluation item is displayed in the column 630. As an example, when "SC" is selected in the column 620, information is displayed in the column 630 that suggests the use of a density correction filter and information that suggests adjustment of the exposure time and aperture of the camera. The information that suggests the use of a density correction filter is an example of a "first policy". The information that suggests adjustment of the exposure time and aperture of the camera is an example of a "second policy". As another example, when "FPD" or "MOD" is selected in the column 620, information is displayed in the column 630 that suggests the use of a smoothing filter and an expansion / contraction filter. Information suggesting the use of a smoothing filter and a dilation / erosion filter is an example of a "first policy."

[0113] Column 640 displays image G of Code 1 generated in step S425. Image P showing the positions of elements with printing problems is displayed superimposed on image G of Code 1. As an example, image P shows the positions of elements whose scores are below a threshold. An element corresponds to a bar or space if Code 1 is a one-dimensional symbol, and corresponds to a cell if Code 1 is a two-dimensional symbol. Code 1 is made up of multiple elements.

[0114] Image P may show only the positions of elements with scores below the threshold for the evaluation item selected in field 620, or may show the positions of all elements with scores below the threshold. Image P may also show the positions of elements with scores below the threshold for each evaluation item. As an example, image P may show the positions of elements with scores below the threshold by using different colors for each evaluation item.

[0115] When the evaluation item is UEC, the image P may show the position of the misrecognized element. When the evaluation item is an evaluation item related to the brightness value (e.g., MOD, FPD, etc.), the image P may show the position (singular point) of an element whose brightness value is a unique value compared to other elements.

[0116] Image P allows the user to recognize the location of elements that have printing problems.

[0117] A flow of the reading test is displayed in field 650. Field 660 displays an image to be used for adjusting the reading conditions. When the user selects "Image Input" in field 650, an image to be used for adjusting the conditions related to imaging among the reading conditions is displayed in field 660. When the user selects "Preprocessing" in field 650, an image to be used for adjusting the conditions related to image processing among the reading conditions is displayed in field 660. When the user selects "Read" in field 650, screen 501 shown in FIG. 5 is displayed in field 660, and the user can set the conditions related to the reading process.

[0118] Note that the column 650 may have multiple "Read" columns for different types of code 1 or different sizes of code 1. As an example, a "Read 1" column for QR codes of 18×18 size and a "Read 2" column for QR codes of 20×20 size may be provided. This allows the user to set conditions for the reading process for different types of code 1 or different sizes of code 1.

[0119] Tabs 673 and 674 are tabs, and the user can switch between buttons displayed below tabs 673 and 674 by selecting tab 673 or 674 .

[0120] Tab 673 is selected by the user when the user wishes to adjust the reading conditions using an image of Code 1 stored in a device (e.g., a PC or a USB memory). When tab 673 is selected, buttons 671, 672, and 675 are displayed below tabs 673 and 674. An example of the user's operation of buttons 671, 672, and 675 is as follows.

[0121] First, the user clicks button 671 to select the target Code 1 image. Next, the user clicks button 675 to cause the code reading device 100 to measure (i.e., read and evaluate) the selected Code 1 image. Once measurement of the selected Code 1 image is complete, the displays in columns 610, 620, 630, and 640 are updated. Note that, if the images are saved in the same folder, the user can press button 672 "<<" to measure the previous Code 1 image, and press button 672 ">>" to measure the next Code 1 image.

[0122] When tab 673 is selected, the user can adjust not only the conditions related to image processing, but also the conditions related to capturing an image of code 1. However, even if the user adjusts the conditions related to capturing an image of code 1, an image of code 1 is not captured, and image processing is performed on the image of code 1 stored in a device (e.g., a PC or a USB memory) according to the set conditions.

[0123] Tab 674 is selected by the user when the user wishes to capture an image of Code 1 in real time using camera 10 and adjust the reading conditions using the image of Code 1 captured by camera 10. When tab 674 is selected, only a button labeled "Measure" is displayed under tabs 673 and 674, instead of buttons 671, 672, and 675. When the user clicks the button labeled "Measure", Code 1 is captured by camera 10 and the captured image of Code 1 is measured. In addition, the displays in columns 610, 620, 630, and 640 are updated. The image of the captured Code 1 is displayed in column 640.

[0124] Button 676 is selected by the user when the user wishes to end the reading test and move on to reading (actual).

[0125] Note that the columns 610, 620, 630, 640, 650, and 660 may be configured to be expandable and scalable in response to a user operation.

[0126] The bird's-eye view information displayed in the field 610 will be described with reference to Figs. 1 to 4, 6 and 7. Fig. 7 is a diagram showing an example of the bird's-eye view information. The bird's-eye view information is information obtained by comprehensively evaluating the print state of the code 1 imaged in step S420 based on a plurality of evaluation items determined in step S415. The bird's-eye view information is displayed in the field 610 when the user selects the tab 611. The bird's-eye view information is displayed in the field 610 in a format that satisfies the following six requirements.

[0127] The first requirement is that the user can recognize the multiple evaluation items determined in step S415. The second requirement is that the user can recognize the evaluation items with poor scores and the evaluation items with good scores among the multiple evaluation items determined in step S415. The third requirement is that the user can recognize which evaluation item the score should be improved from. The fourth requirement is that the user can recognize the deviation between the score and the threshold for each evaluation item. The fifth requirement is that the user can set and cancel evaluation items that are not subject to evaluation. The sixth requirement is that the user can recognize the adjustment phase.

[0128] 7 shows a radar chart as an example of a format that satisfies the above six requirements. In the radar chart, the multiple evaluation items (icons 701 to 707) determined in step S415 are arranged clockwise in the order in which the scores should be improved. The order in which the scores should be improved is determined by the adjustment policy determination unit 41 according to the above-mentioned algorithm. This allows the user to recognize the multiple evaluation items determined in step S415, and to recognize which evaluation item the score should be improved from (first requirement, third requirement).

[0129] Moreover, in the radar chart, the score calculated in step S430 is indicated by a solid line (solid line 708), and the threshold value preset for each evaluation item is indicated by a dotted line (dotted line 709). The information indicated by the solid line 708 is an example of information indicating the score for each of the multiple evaluation items calculated in step S430. Moreover, the information indicated by the solid line 708 and the dotted line 709 is an example of "comparison information", and more specifically, is an example of information indicating the deviation between the score and the threshold for each evaluation item. This allows the user to recognize evaluation items with poor scores and evaluation items with good scores among the multiple evaluation items determined in step S415 (second requirement). Moreover, the user can recognize the deviation between the score and the threshold for each evaluation item (fourth requirement).

[0130] Furthermore, the evaluation items arranged on the radar chart are displayed in different colors depending on whether their scores are below the threshold or not. Evaluation items with scores below the threshold and evaluation items with scores above the threshold, which are displayed in different colors, are an example of "comparison information," and more specifically, are an example of information that distinguishes between evaluation items with scores below the threshold and evaluation items with scores above the threshold. This allows the user to recognize which evaluation items have poor scores and which have good scores among the multiple evaluation items determined in step S415 (second requirement).

[0131] Moreover, the icons 701 to 707 can be operated by the user (clicked, touched, etc.) and are used to set and release the evaluation items corresponding to the icons to be excluded from evaluation. This allows the user to set and release the evaluation items to be excluded from evaluation (the fifth requirement). As an example, the evaluation items set to be evaluated are displayed in a state where the user can see them, whereas the evaluation items set to be excluded from evaluation are grayed out so that the user cannot see or cannot see them easily. When the user operates the icons 701 to 707 that are not grayed out, the evaluation items corresponding to the operated icons are set to be excluded from evaluation, and the information indicating the scores of the evaluation items is grayed out so that the information indicating the scores of the evaluation items is not visible or cannot see them easily. The scores of the evaluation items set to be excluded from evaluation are not taken into consideration when determining the adjustment policy. On the other hand, when the user operates the grayed out icons 701 to 707, the setting of the evaluation items corresponding to the operated icons to be excluded from evaluation is released, and the information indicating the scores of the evaluation items becomes visible. The scores of the evaluation items for which the setting of the evaluation items to be excluded from evaluation has been released are taken into consideration when determining the adjustment policy.

[0132] Note that, although the output of comparison information among the information indicating the scores of evaluation items set as non-evaluation targets is stopped, the scores calculated by the calculation unit 33 may be output. As an example, information comparing the scores calculated by the calculation unit 33 with thresholds set in advance for each evaluation item may be grayed out, and only the scores calculated by the calculation unit 33 may be displayed next to the icons 701 to 707.

[0133] Also, in the column 610, a message (display 710) is displayed so that the user can recognize the adjustment phase. More specifically, in a phase in which at least one of the evaluation items to be evaluated has a score below the threshold, a message (e.g., "Overall improvement is required") is displayed indicating that this is a phase in which the overall level of the score needs to be raised by improving the scores of the evaluation items displayed in the column 610 in a clockwise order, and in a phase in which all of the evaluation items to be evaluated are equal to or above the threshold, a message (e.g., "FPD / MOD can be further improved") is displayed indicating that this is a phase in which further improvement in the score of a specific evaluation item can be expected. This allows the user to recognize the adjustment phase (sixth requirement).

[0134] In the above, the bird's-eye view information is displayed in the form of a radar chart, but it may be displayed in the form of a bar graph. As an example, bar-shaped images showing the scores for each evaluation item may be arranged in the order of the evaluation items whose scores should be improved, and the thresholds for each evaluation item may be superimposed on the bar graph.

[0135] In addition, in the above, the multiple evaluation items (icons 701 to 707) determined in step S415 are arranged clockwise in the order in which the score should be improved, but the multiple evaluation items (icons 701 to 707) determined in step S415 may be arranged clockwise in the order in which they are most likely to affect the printing state of Code 1 (in order of importance).

[0136] In addition, in the above, the evaluation items to be placed are displayed in different colors depending on whether their scores are below the threshold or not. However, it is sufficient that the evaluation items to be placed are displayed in a manner that allows distinction between evaluation items with scores below the threshold and evaluation items with scores above the threshold. The size of the icons 701-707 may be changed, or the type of the icons 701-707 may be changed.

[0137] In the above, both the scores for each of the multiple evaluation items calculated in step S430 and the threshold value that is preset for each evaluation item are displayed, but it is also possible to display the scores for each of the multiple evaluation items calculated in step S430 and information that distinguishes between evaluation items whose scores are below the threshold value and evaluation items whose scores are equal to or above the threshold value without displaying the threshold value.

[0138] The detailed information displayed in the field 610 will be described with reference to Figs. 1 to 4, 6, 8, and 9. The detailed information is information on an evaluation of the print state of the code 1 imaged in step S420 for a specific evaluation item among the multiple evaluation items determined in step S415, and is information indicating the score for the specific evaluation item, or information other than the score for the specific evaluation item.

[0139] 8 is a diagram showing an example of information indicating a score for a specific evaluation item among the detailed information. The information indicating the score for a specific evaluation item is output to the user when multiple images of the code 1 are captured in step S420. When multiple images of the code 1 are captured in step S420, this refers to when multiple codes 1 are captured, when one code 1 is captured multiple times, etc.

[0140] As an example, information showing the score for a specific evaluation item is displayed in the form of a graph as shown in Fig. 8. The graph shown in Fig. 8 plots only the scores for a specific evaluation item out of the scores calculated for each image. In the graph shown in Fig. 8, the score for a specific evaluation item is shown on the vertical axis, and the number of Code 1 (count number) is shown on the horizontal axis.

[0141] Regarding the number of Code 1 (count number) shown on the horizontal axis, the older the image, the smaller the number assigned to the multiple images of Code 1, and the newer the image, the larger the number assigned to the multiple images, and these "numbers" are shown on the horizontal axis. Therefore, it can be said that the "number" indicates the number of Code 1 (count number). Note that the horizontal axis may also indicate the image capture time of Code 1.

[0142] The user can switch between specific evaluation items by operating field 620. The graph shown in Fig. 8 is an example of information showing the scores for each of the multiple evaluation items calculated in step S430. Such a graph allows the user to comprehensively recognize the scores calculated from multiple images for each evaluation item.

[0143] Furthermore, the graph may have a line (line 801) drawn on it indicating the threshold value of the evaluation item selected in the field 620. The graph shown in Fig. 8 with the line 801 drawn on it is an example of "comparison information", more specifically, an example of information indicating the deviation between the score and the threshold value for each evaluation item. With such a graph, the user can recognize the deviation between the score calculated from multiple images and the threshold value preset for each evaluation item across the board for each evaluation item.

[0144] Also, when the user clicks on a measurement point on the graph, the display in column 640 may be switched to image G of code 1 corresponding to the measurement point. This allows the user to display a desired image from among multiple images in column 640, and to grasp the positions of elements with poor scores in the desired image.

[0145] 6 has multiple "Read" columns, the graphs generated for Code 1 corresponding to each "Read" column may all be superimposed and displayed in column 610. As an example, if column 650 has a "Read 1" column for an 18×18 QR code and a "Read 2" column for a 20×20 QR code, the graph generated for the 18×18 QR code shown in FIG. 8 and the graph generated for the 20×20 QR code shown in FIG. 8 may be superimposed and displayed in column 610.

[0146] FIG. 9 is a diagram showing an example of information other than the score for a specific evaluation item among the detailed information. When the evaluation item is an evaluation item related to luminance (e.g., SC, FPD, MOD, etc.), information other than the score may be displayed. As an example, information showing the distribution of luminance values ​​is displayed in the form of a histogram as shown in FIG. 9. In the graph shown in FIG. 9, the horizontal axis shows the luminance value, and the vertical axis shows the frequency of the luminance value. The histogram of luminance values ​​may show the distribution of luminance values ​​in the entire symbol area of ​​Code 1, or may show the distribution of luminance values ​​only in the central coordinates of the cells of Code 1. Such a graph allows the user to recognize the printing state of Code 1 from information other than the score for a specific evaluation item. In particular, the histogram of luminance values ​​is useful when the user checks the effect of the adjustment (the effect of the applied filter) when the conditions related to image processing are adjusted.

[0147] 1, 3, 6, and 10, a modified example of the image G of the code 1 displayed in the field 640 will be described. FIG. 10 is a diagram showing a modified example of the image of the code 1.

[0148] 6, image G of code 1 was overlaid with only image P indicating the position of an element with a printing problem, but in the example shown in Fig. 10, image P and image Q indicating a grid are overlaid on image G of code 1 and displayed in field 640. Image Q may be displayed all the time image G of code 1 is displayed in field 640, or may be displayed only when the score for an evaluation item related to lattice distortion (e.g. GN, AN, etc.) is poor. Image Q enables the user to recognize the lattice distortion.

[0149] The method of adjusting the reading conditions will be described with reference to Fig. 1, Fig. 2, Fig. 6, and Fig. 11. Fig. 11 is a diagram showing an example of an image subjected to the adjustment of the reading conditions. Fig. 11(A) shows the state before the adjustment, and Fig. 11(B) shows the state after the adjustment.

[0150] Column 660 includes column 111 showing an item to be adjusted by the user, and column 112 displaying an image to be used for adjusting the adjustment item. The item to be adjusted by the user is the above-mentioned "adjustment item" determined by adjustment policy determination unit 41 and suggested for adjustment in column 630. Column 112 displays image 113 resembling a knob that can be slid left and right according to a user's operation. Column 112 further includes column 114 displaying a reading condition corresponding to the position of image 113.

[0151] The user can change the reading conditions by simply moving the image 113 so that the desired reading conditions are displayed in the field 114. When the user moves the image 113 of a certain adjustment item, the adjustment unit 43 transmits the reading conditions corresponding to the stop position of the image 113 to the reading unit 30. More specifically, if the adjustment item to which the user has moved the image 113 is an adjustment item related to the imaging conditions of the code 1, the adjustment unit 43 transmits the reading conditions corresponding to the stop position of the image 113 to the imaging condition setting unit 311. The imaging condition setting unit 311 sets the imaging conditions of the camera 10, among the received reading conditions, to the camera 10, and sets the illumination conditions of the illumination 20 to the illumination 20. On the other hand, if the item to which the user has moved the image 113 is an adjustment item related to image processing, the adjustment unit 43 transmits the reading conditions corresponding to the stop position of the image 113 to the pre-processing unit 312. The pre-processing unit 312 performs image processing under the received reading conditions.

[0152] In this way, the user can adjust the reading conditions simply by moving the image 113. Furthermore, the adjustment items to be adjusted are displayed in a field 630. Therefore, the user can adjust the reading conditions simply by sliding the image 113 left and right in accordance with the display in the field 630, thereby reducing the burden on the user in adjusting the reading conditions.

[0153] (Small summary) In this way, the code reading device 100 in the first embodiment has an adjustment support function that supports the user in adjusting the conditions related to reading the code 1 (reading conditions of the reading unit 30), and outputs to the user a guideline for adjusting the reading conditions of the reading unit 30. This allows the user to stabilize reading by the code reading device 100 simply by adjusting the reading conditions of the reading unit 30 according to the output adjustment guideline, thereby reducing the burden on the user in adjusting the reading conditions of the reading unit 30.

[0154] [Embodiment 2] The code reading device 100 in the first embodiment has an adjustment support function that supports a user in adjusting the conditions related to reading the code 1 (reading conditions of the reading unit 30). In contrast, the code reading device in the second embodiment does not have the adjustment support function. Instead, the code reading device in the second embodiment can be connected to an adjustment support device that has the adjustment support function, and forms a code reader adjustment support system together with the adjustment support device. The code reader adjustment support system will be described below. Note that the same configurations and processes as those in the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

[0155] (Configuration of the code reader adjustment support system) The configuration of a code reader adjustment support system 500 will be described with reference to Fig. 1, Fig. 2, and Fig. 12. Fig. 12 is a block diagram showing the code reader adjustment support system 500. The code reader adjustment support system 500 includes a code reading device 100A and an adjustment support device 40A. The code reading device 100A and the adjustment support device 40A are connected via a network 600.

[0156] The code reading device 100A differs from the code reading device 100 in embodiment 1 in that it includes a first communication unit 34A that communicates information with the adjustment support device 40A, but is similar to the code reading device 100 in other respects.

[0157] The adjustment support device 40A differs from the adjustment support unit 40 in the first embodiment in that it includes a second communication unit 44A that communicates information with the code reading device 100A, but is similar to the adjustment support unit 40 in other respects.

[0158] The first communication unit 34A receives the score from the calculation unit 33 and transmits the received score to the adjustment support device 40A. The second communication unit 44A receives the score from the code reading device 100A and transmits the received score to the adjustment policy determination unit 41 and the output unit 42. The adjustment policy determination unit 41 determines an adjustment policy based on the received score. The output unit 42 outputs information indicating the received score to the user.

[0159] The second communication unit 44A receives the reading conditions from the adjustment unit 43 and transmits the received reading conditions to the code reading device 100A. The first communication unit 34A receives the reading conditions sent from the adjustment support device 40A and transmits the received reading conditions to the image generating unit 31. Specifically, the first communication unit 34A receives the conditions related to imaging sent from the adjustment support device 40A and transmits the received conditions to the imaging condition setting unit 311. The first communication unit 34A also receives the conditions related to image processing sent from the adjustment support device 40A and transmits the received conditions to the pre-processing unit 312. The imaging condition setting unit 311 sets the imaging conditions of the camera 10 out of the received conditions to the camera 10 and sets the illumination conditions of the illumination 20 to the illumination 20. The pre-processing unit 312 performs image processing under the received conditions.

[0160] Camera 10 and lighting 20 may be provided in a housing different from the housing in which reading unit 30A is provided, or may be provided in the same housing as the housing in which reading unit 30A is provided.

[0161] Furthermore, the calculation unit 33 may be provided in the adjustment support device 40A, instead of in the code reading device 100A.

[0162] (Small summary) Thus, according to the second embodiment, it becomes possible to retrofit the code reading device with an adjustment support function. That is, the code reading device 100A in the second embodiment is connected to an adjustment support device 40A having an adjustment support function to form a code reader adjustment support system 500, which outputs a policy for adjusting the conditions related to reading the code 1 (reading conditions of the reading unit 30A) to the user. This allows the user to stabilize reading by the code reading device 100A simply by adjusting the reading conditions of the reading unit 30A according to the output adjustment policy, thereby reducing the burden on the user of adjusting the reading conditions of the reading unit 30A.

[0163] [Summary] The code reading device 100 and the code reader adjustment support system 500 in the embodiment output to the user a policy for adjusting the conditions (reading conditions of the reading units 30, 30A) related to reading the code 1. This allows the user to stabilize reading by the code reading device 100, 100A simply by adjusting the reading conditions of the reading units 30, 30A according to the output adjustment policy, thereby reducing the burden on the user of adjusting the reading conditions of the reading units 30, 30A.

[0164] [Note] The above-described embodiment includes the following technical ideas.

[0165] [Configuration 1] A code reader (100) for reading a code (1) printed on a printing object (2), comprising: a camera (10) for capturing an image of the code (1); a reading unit (30) that reads the code (1) from an image of the code (1) captured by the camera (10); an adjustment support unit (40) that supports a user in adjusting the reading conditions of the reading unit (30); The reading unit (30) an image generating unit (31) that generates an image of the code (1) to be processed by the reading unit (30); a decoding unit (32) that decodes the code (1) from the image of the code (1) generated by the image generating unit (31); a calculation unit (33) that calculates a score for each of a plurality of evaluation items for evaluating a printing state of the code (1) for the image of the code (1) generated by the image generation unit (31), The adjustment support unit (40) an adjustment policy determination unit (41) that determines an adjustment policy for the reading conditions by the user based on the scores for each of the evaluation items calculated by the calculation unit (33); an output unit (42) that outputs the adjustment policy determined by the adjustment policy determination unit (41) to the user; and an adjustment unit (43) that adjusts the reading conditions based on the user's operation.

[0166] [Configuration 2] The image generating unit (31) an imaging condition setting unit (311) that sets imaging conditions for the camera (10); A pre-processing unit (312) that performs image processing on the image of the code (1), The code reading device according to configuration 1, wherein the pre-processing unit (312) performs image processing on the image of the code (1) captured under the imaging conditions set by the imaging condition setting unit (311) to generate an image of the code to be processed by the reading unit (30).

[0167] [Configuration 3] The device further includes a light (20) connected to the reading unit (30) and configured to illuminate the code (1) when the camera (10) captures an image of the code (1), 3. The code reading device according to configuration 2, wherein the imaging condition setting unit (311) further sets an illumination condition for the illumination (20).

[0168] [Configuration 4] The code reading device according to any one of configurations 1 to 3, wherein the adjustment policy determination unit (41) switches between the plurality of evaluation items for calculating the score depending on an evaluation method selected by a user.

[0169] [Configuration 5] 5. The code reading device according to any one of configurations 1 to 4, wherein the adjustment policy includes information on which of the evaluation items the score should be improved from.

[0170] [Configuration 6] The code reading device according to any one of configurations 1 to 5, wherein the adjustment policy includes information suggesting how to adjust the reading conditions for each evaluation item for which the score is to be improved.

[0171] [Configuration 7] The code reading device of configuration 6, wherein the suggested information includes at least one of a first policy regarding image processing of the image of the code (1) captured by the camera (10) and a second policy regarding imaging of the code (1).

[0172] [Configuration 8] The code reading device according to any one of configurations 1 to 7, wherein the output unit (42) further outputs information indicating the scores for each of the evaluation items calculated by the calculation unit (33) to the user.

[0173] [Configuration 9] the information indicating the score includes comparison information obtained by comparing the score with a threshold value, 9. The code reading device according to claim 8, wherein the comparison information includes information distinguishing between the evaluation items whose scores are below a threshold and the evaluation items whose scores are equal to or greater than a threshold.

[0174] [Configuration 10] 10. The code reading device according to claim 9, wherein the comparison information further includes information indicating a deviation between the score and a threshold for each of the evaluation items.

[0175] [Configuration 11] The output unit (42) stops outputting at least a part of the information indicating the scores for the evaluation items selected by the user as non-evaluation targets, 11. The code reading device according to any one of configurations 8 to 10, wherein the adjustment policy determination unit (41) does not take into consideration the scores of the evaluation items that are not evaluation targets when determining the adjustment policy.

[0176] [Configuration 12] The code (1) is composed of a plurality of elements, 12. The code reading device according to any one of configurations 1 to 11, wherein the output unit (42) displays an image of the code (1) by superimposing an image showing the positions of the elements whose scores are less than the threshold value.

[0177] [Configuration 13] A code reader (100A) for reading a code (1) printed on a printing object (2); an adjustment support device (40A) that supports a user in adjusting reading conditions of the code reading device (100A), The code reader (100A) a camera (10) for capturing an image of the code (1); a reading unit (30A) that reads the code (1) from an image of the code (1) captured by the camera (10); The reading unit (30A) an image generating unit (31) that generates an image of the code (1) to be processed by the reading unit (30A); a decoding unit (32) that decodes the code (1) from the image of the code (1) generated by the image generating unit (31); a calculation unit (33) that calculates a score for each of a plurality of evaluation items for evaluating a printing state of the code (1) for the image of the code (1) generated by the image generation unit (31), The adjustment support device (40A) includes: an adjustment policy determination unit (41) that determines an adjustment policy for the reading conditions by the user based on the scores for each of the evaluation items calculated by the calculation unit (33); an output unit (42) that outputs the adjustment policy determined by the adjustment policy determination unit (41) to the user; and an adjustment unit (43) that adjusts the reading conditions based on the user's operation.

[0178] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0179] 1 code, 2 work, 10 camera, 20 lighting, 30, 30A reading unit, 31 image generation unit, 32 decoding unit, 33 calculation unit, 34A first communication unit, 40 adjustment support unit, 40A adjustment support device, 41 adjustment policy determination unit, 42 output unit, 43 adjustment unit, 44A second communication unit, 100, 100A code reading device, 111, 112, 114, 502, 503, 610, 620, 630, 640, 650, 660 column, 113, G, P, Q image, 200 output device, 300 input device, 301 keyboard, 302 mouse, 311 imaging condition setting unit, 312 preprocessing unit, 500 code reader adjustment support system, 501, 601 screen, 504, 671 to 675 Buttons, 600 Network, 611,612 Tabs, 701-707 Icons, 708 Solid lines, 709 Dotted lines, 710 Display, 801 Lines.

Claims

1. A code reading device for reading a code printed on a printing object, comprising: A camera for capturing an image of the code; a reading unit that reads the code from an image of the code captured by the camera; an adjustment support unit that supports a user in adjusting the reading conditions of the reading unit; The reading unit is an image generating unit that generates an image of the code to be processed by the reading unit from the image of the code captured by the camera; a decoding unit that decodes the code from the image of the code generated by the image generating unit; a calculation unit that calculates a score for each of a plurality of evaluation items for evaluating a printing state of the code for the image of the code generated by the image generation unit, The adjustment support unit includes: an adjustment policy determination unit that determines an adjustment policy for the reading conditions by the user based on the scores for each of the evaluation items calculated by the calculation unit; an output unit that outputs the adjustment policy determined by the adjustment policy determination unit to the user; an adjustment unit that adjusts the reading conditions based on an operation of the user, The process of reading the code by the reader includes a plurality of steps, The steps vary depending on the type of the code, a code reading device, wherein the adjustment policy determination unit determines the order in which the scores should be improved for two or more evaluation items based on the processing content in each of the plurality of steps corresponding to the type of code and the execution order of the plurality of steps corresponding to the type of code.

2. The image generating unit includes: an imaging condition setting unit that sets imaging conditions of the camera; A pre-processing unit that performs image processing on the image of the code, 2. The code reading device according to claim 1, wherein the preprocessing unit performs the image processing on the image of the code captured under the imaging conditions set by the imaging condition setting unit to generate an image of the code to be processed by the reading unit.

3. a light connected to the reading unit and configured to illuminate the code when the camera captures the code; The code reading device according to claim 2 , wherein the imaging condition setting unit further sets an illumination condition for the illumination.

4. The code reading device according to claim 1, wherein the adjustment policy determination unit switches between the evaluation items for calculating the score depending on an evaluation method selected by the user.

5. The code reading device according to claim 1 , wherein the adjustment policy includes information suggesting how the reading conditions should be adjusted for each of the evaluation items for which the score should be improved.

6. The adjustment policy includes information suggesting how to adjust the reading conditions for each of the evaluation items for which the score should be improved, 4. The code reading device according to claim 2, wherein the suggested information includes at least one of a first policy regarding the image processing of the image of the code captured by the camera and a second policy regarding the imaging of the code.

7. The code reading device according to any one of claims 1 to 6, wherein the output unit further outputs to the user information indicating the scores for each of the evaluation items calculated by the calculation unit.

8. the information indicating the score includes comparison information obtained by comparing the score with a threshold value, The code reading device according to claim 7 , wherein the comparison information includes information distinguishing between the evaluation items whose scores are below the threshold and the evaluation items whose scores are equal to or greater than the threshold.

9. The code reading device according to claim 8 , wherein the comparison information further includes information indicating a deviation between the score and the threshold for each of the evaluation items.

10. The output unit stops outputting at least a part of information indicating the scores for the evaluation items selected by the user that are not to be evaluated, The code reading device according to claim 8 or 9, wherein the adjustment policy determination unit determines the adjustment policy without taking into consideration the scores of the evaluation items that are not evaluation targets.

11. The code is composed of a plurality of elements, The code reading device according to any one of claims 8 to 10, wherein the output section displays an image indicating the positions of the elements whose scores are less than the threshold value superimposed on the image of the code.

12. A code reader that reads a code printed on an object to be printed; an adjustment support device that supports a user in adjusting a reading condition of the code reading device, The code reader comprises: A camera for capturing an image of the code; a reading unit that reads the code from an image of the code captured by the camera, The reading unit is an image generating unit that generates an image of the code to be processed by the reading unit from the image of the code captured by the camera; a decoding unit that decodes the code from the image of the code generated by the image generating unit; a calculation unit that calculates a score for each of a plurality of evaluation items for evaluating a printing state of the code for the image of the code generated by the image generation unit, The adjustment support device includes: an adjustment policy determination unit that determines an adjustment policy for the reading conditions by the user based on the scores for each of the evaluation items calculated by the calculation unit; an output unit that outputs the adjustment policy determined by the adjustment policy determination unit to the user; an adjustment unit that adjusts the reading conditions based on an operation of the user, The process of reading the code by the reader includes a plurality of steps, The steps vary depending on the type of the code, the adjustment policy determination unit determines the order in which the scores should be improved for two or more evaluation items for which the scores should be improved, based on the processing content in each of the plurality of steps corresponding to the code type and the execution order of the plurality of steps corresponding to the code type.

Images