Optical reading system

Abstract

To provide a technique capable of improving user convenience in situations where character recognition is performed repeatedly.SOLUTION: The optical reading system includes: an image sensor; a registration medium that registers a piece of relative location information that indicates the relative position of the character for the information code for a display media that displays information codes and characters in a predetermined format; a setting unit that sets a character recognition reading range to the location indicated by the relative location information within the registration medium using the image in the information code as a reference in a first captured image, which is the image of the display medium captured by the image sensor; and a character recognition execution unit that performs character recognition for the set reading range.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed herein relates to an optical reading system that optically reads information from an object. [Background technology]

[0002] Patent Document 1 discloses a form reading system that performs character recognition on characters that are present at a desired position in a form image that is specified by a tap operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-90623 Summary of the Invention [Problem to be solved by the invention]

[0004] In a situation where character recognition is repeatedly performed, a user may find it annoying to repeatedly tap characters. This specification provides a technique for improving user convenience in a situation where character recognition is repeatedly performed. [Means for solving the problem]

[0005] The optical reading system disclosed in this specification includes an image sensor, a registration medium for registering relative position information indicating the relative position of characters with respect to an information code displayed on a display medium in a predetermined format, a setting unit for setting a reading range for character recognition at a position in the registration medium indicated by the relative position information using an image of the information code as a reference in a first captured image of the display medium captured by the image sensor, and a character recognition execution unit for executing the character recognition for the set reading range. Here, the display medium is, for example, a label, a package, etc.

[0006] Display media such as labels have a predetermined format, and in recent years, information codes have increasingly been included in the predetermined format. According to the above configuration, relative position information indicating the relative position of characters with respect to the information code is stored in advance in the registration medium based on the predetermined format. The optical reading system then automatically sets the reading range to the position indicated by the relative position information in the registration medium. In situations where character recognition is performed repeatedly, the user does not need to specify the reading range each time. This improves user convenience.

[0007] The relative position information may be a value in a coordinate system defined using the size of an element that constitutes the information code.

[0008] The size of the elements that make up the information code is standardized. By defining a coordinate system using standardized, unchanging sizes, relative position information can be determined with high precision.

[0009] The information code may be a two-dimensional code, and the size may be a width of a cell of the two-dimensional code.

[0010] The information code may be a barcode, and the size may be at least one of a module width and a bar height in the barcode.

[0011] The display medium displays at least two information codes including a first information code and a second information code, and the character, and the relative position information may be a value of a coordinate system defined using at least two of the size of an element constituting the first information code and the size of an element constituting the second information code.

[0012] The size of one element can be complemented by the size of the other element, and the read range can be set more accurately than when the read range is set from relative position information that uses only the size of one element.

[0013] The optical reading system may further include a registration unit that executes a registration process to register the relative position information on the registration medium, and the registration process may include a process of calculating the relative position information indicating the relative position of a specific point with respect to the image of the information code in a second captured image, which is an image of the display medium captured by the image sensor.

[0014] According to the above configuration, it is possible to calculate relative position information using an image on the display medium and register the relative position information on the registration medium.

[0015] The optical reading system may further include a marker irradiation unit that irradiates an indication marker, and the registration process may further include a process of irradiating the indication marker with the marker irradiation unit, and the specific location may be a location where an image of the indication marker is located within the second captured image.

[0016] According to the above configuration, the character to be read can be specified using the pointing marker.

[0017] The optical reading system may further include an operation unit and a display unit, and the registration process may further include a process of displaying the second captured image on the display unit, and the specific location may be a location selected by the operation unit from the second captured image displayed on the display unit.

[0018] According to the above configuration, it is possible to intuitively specify a specific location within the second captured image displayed on the display unit.

[0019] The registration medium may register, for each of the multiple types of display media, the code information recorded in the information code in the display medium in association with the relative position information, and the optical reading system may further include a reading unit that reads the code information from the image of the information code in the first captured image, and an acquisition unit that acquires the relative position information registered in association with the code information read from the image of the information code in the first captured image from the registration medium that registers the multiple pieces of relative position information.

[0020] According to the above configuration, it is possible to improve user convenience when performing character recognition on a plurality of types of display media. In particular, appropriate relative position information is obtained from code information read from an information code on the display medium.

[0021] The registration medium registers the code information, the relative position information, and the character recognition setting information in association with each other for each of the multiple types of display media, and the acquisition unit further acquires the setting information registered in association with the code information read from the image of the information code in the first captured image from the registration medium that registers the multiple pieces of setting information, and the character recognition execution unit may perform the character recognition for the reading range with the settings indicated by the acquired setting information.

[0022] According to the above configuration, it is possible to change the character recognition settings in accordance with the characteristics of each of a plurality of types of display media. In particular, appropriate setting information is obtained from code information read from an information code in the display medium.

[0023] The optical reading system may further include a display unit, and a display control unit that causes the display unit to display a first image indicating the position of the reading range in the first captured image.

[0024] According to the above configuration, the user can know the read range of character recognition.

[0025] The optical reading system may further include a display unit and a display control unit that causes the display unit to display a second image indicating the position of the information code in the first captured image.

[0026] According to the above configuration, the user can know the information code that is the reference for the read range.

[0027] The optical reading system may further include a first notification unit that outputs a first notification when at least a part of the reading range is set outside the first captured image.

[0028] According to the above configuration, the first notification lets the user know that the position of the image sensor relative to the display medium should be adjusted.

[0029] The first notification unit may further output a movement direction for adjusting a relative position of the image sensor with respect to the display medium so that the entire reading range is included in the first captured image.

[0030] According to the above configuration, the user can know the direction in which to move the image sensor or the display medium.

[0031] The optical reading system may further include a second notification unit that outputs a second notification when a size of the image of the information code in the first captured image is larger than a predetermined size.

[0032] For example, if the image sensor is too close to the display medium, the characters to be read may not fit within the field of view. According to the above configuration, it is possible to determine whether the image sensor is too close to the display medium by using the size of the information code image. The second notification then informs the user that they should increase the distance between the image sensor and the display medium. [Brief explanation of the drawings]

[0033] [Figure 1]FIG. 2 is a schematic diagram of an optical reading terminal and a label. [Figure 2] FIG. 2 is a block diagram of an optical reading terminal. [Figure 3] FIG. 4 is a flowchart of a registration process according to the first embodiment. [Figure 4] FIG. 10 is a diagram illustrating a specific case of the registration process. [Figure 5] FIG. 10 is a diagram illustrating a specific case of the registration process. [Figure 6] FIG. 10 is a flowchart of a reading process. [Figure 7] FIG. 10 is a diagram illustrating a specific case of the reading process. [Figure 8] FIG. 10 is a diagram illustrating a specific case of the reading process. [Figure 9] FIG. 10 is a flowchart of a registration process according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0034] (First Example) (Configuration of optical reading terminal 10; Figure 1) The optical reading terminal 10 is a portable terminal device that optically reads information from a display medium on which the information is displayed. Hereinafter, the optical reading terminal 10 will be abbreviated to "terminal 10." The external appearance of the terminal 10 shown in FIG. 1 is merely an example. The display medium is a label 100 or the like. Note that the display medium is not limited to the label 100 or the like, and may be, for example, packaging.

[0035] Label 100 displays a character field 102 for displaying a character string, and a two-dimensional code 104. In character field 102, for example, product information about the product to which label 100 is affixed is written as text. Product information may be, for example, a model, an order number, a date, etc. In two-dimensional code 104, for example, part of the product information (for example, an order number) or identification information other than the product information is recorded.

[0036] The label 100 is created in a predetermined format, and in this format, the positional relationship between the character field 102 and the two-dimensional code 104 is fixed. There are various formats, and for example, the label 110 displays a barcode 106 in addition to the character field 102 and the two-dimensional code 104. The barcode 106 also records part of the product information and identification information other than the product information. In this format, the positional relationship between the character field 102, the two-dimensional code 104, and the barcode 106 is also fixed. Another label 120 displays the barcode 106 instead of the two-dimensional code 104. Note that the labels 100, 110, and 120 shown in FIG. 1 are merely examples.

[0037] The terminal 10 captures an image of an information code (e.g., a two-dimensional code 104 or a barcode 106) on the label 100 or the like, decodes the information code, and acquires information recorded in the information code. The terminal 10 also captures an image of characters in a character field 102 on the label 100 or the like, performs character recognition processing on the image of the characters, and acquires information indicating the characters. The terminal 10 can simultaneously read information from both the information code and the characters.

[0038] (Configuration of terminal 10; Figure 2) The terminal 10 includes an operation unit 12, a display unit 14, an image sensor 20, a marker projection unit 22, and a control unit 30. The operation unit 12 includes a plurality of keys. A user can input various instructions to the terminal 10 by operating the operation unit 12. The display unit 14 is a display for displaying various information, and is, for example, a liquid crystal display or an organic EL display. The display unit 14 may also function as a touch screen (i.e., the operation unit 12) that can accept user operations. The image sensor 20 is a sensor that captures an image of an object, and is, for example, a CCD image sensor. The marker projection unit 22 emits a beam that projects an indication marker. The shape of the image of the indication marker is, for example, a circle, a polygon, a cross, etc.

[0039] The control unit 30 includes a CPU 32 and a memory 34 configured from a non-volatile memory, a volatile memory, etc. The CPU 32 executes various processes in accordance with a program 40 stored in the memory 34.

[0040] The memory 34 also stores a registration table 42. Information used in the reading process (see FIG. 6 ) for reading information from the label 100 or the like is registered in the registration table 42. The registration table 42 stores, in association with each other, the label name, reference information, code information, relative position information, and setting information for each of a plurality of types of labels. The label name is the name of the label, for example, the name of the business partner that uses the label 100. The reference information is information related to an information code (hereinafter referred to as a “reference code”) that serves as the reference for the reading range of character recognition. For example, in this embodiment, the two-dimensional code 104 is used as the reference code on the label 100. In this case, “two-dimensional code” is stored as the reference information. For example, both the two-dimensional code 104 and the barcode 106 are used as reference codes on the label 110. In this case, “two-dimensional code” and “barcode” are stored as the reference information. The reference information also includes the size of the captured image of the reference code.

[0041] The code information is all or part of the information read from the information code (e.g., two-dimensional code 104, barcode 106) displayed on the label. For example, the information code in the label of Company A records information indicating Company A (e.g., company name, number, etc.). The code information is, for example, information indicating Company A.

[0042] The relative position information indicates the relative position of the reading range of character recognition with respect to the reference code. The relative position information is, for example, a coordinate system value. The setting information indicates various settings for character recognition. For example, the setting information includes the type of filter used for preprocessing of character recognition, the number of characters in the string to be recognized, the type of characters used in the string (e.g., numbers, English, kana, etc.), the display mode of the string, etc. The display mode is, for example, a printing method such as dots.

[0043] (Registration process: Figures 3 to 5) 3 to 5, a registration process for registering information in the registration table 42 will be described. The CPU 32 executes the process of FIG. 3 in accordance with the program 40. The process of FIG.

[0044] In S10, the CPU 32 monitors whether a predetermined registration instruction has been received by the operation unit 12. If the operation unit 12 has received the registration instruction (YES in S10), the CPU 32 proceeds to S12.

[0045] In S12, the CPU 32 displays a registration screen SC1 for inputting information to be registered. FIG. 5 illustrates the registration screen SC1 in case C1 for registering information about the label 100 of FIG. 1. On the registration screen SC1, a reference code that serves as a reference for the relative position information is first selected. The registration screen SC1 includes a captured image IM1 of the label 100 and a "Next" button B1. The captured image IM1 is an image captured by the image sensor 20 in accordance with a predetermined capture instruction from the user. The capture instruction is input, for example, by pressing a predetermined button (not shown) on the registration screen SC1. In a modified example, the captured image IM1 may be captured in advance before the processing of FIG. 3. The user may select the captured image IM1 from multiple images in a folder.

[0046] The user can specify various locations within the captured image IM1 displayed on the registration screen SC1 using the operation unit 12. For example, the user specifies the image of the reference code within the captured image IM1 by tapping. The reference code can be specified through an intuitive operation. For example, in case C1 of FIG. 5, the user specifies the image of the two-dimensional code 104 within the captured image IM1. When the image of the reference code is specified by tapping, a mark M1 is displayed at the location specified by tapping.

[0047] In S14, the CPU 32 monitors whether the "Next" button B1 is selected while the mark M1 is displayed. If the "Next" button B1 is selected (YES in S14), the CPU 32 proceeds to S20. In S20, the CPU 32 analyzes the image of the reference code and determines reference information related to the reference code. If the image of the reference code includes a feature of the two-dimensional code 104 (e.g., a symbol mark), the CPU 32 determines the reference information as "two-dimensional code." Furthermore, if the image in the mark M1 includes a feature of the barcode 106 (e.g., a bar), the CPU 32 determines the reference information as "barcode 1." Furthermore, the CPU 32 calculates the size of the image of the reference code specified by the user and determines this size as the reference information.

[0048] In S22, the CPU 32 reads code information from the reference code. In S24, the CPU 32 changes the content of the registration screen SC1. Specifically, a "Register" button B2 is displayed in the registration screen SC1 instead of the "Next" button B1. In the changed registration screen SC1, a character string to be subjected to character recognition is selected. The character string is also specified by the user in the same manner as the reference code. The target character string can be specified by an intuitive operation. When the target character string is specified by tapping, a mark M2 is displayed at the location specified by tapping.

[0049] In S30, the CPU 32 monitors whether the "Register" button B2 is selected while the mark M2 is displayed. If the "Register" button B2 is selected (YES in S30), the CPU 32 proceeds to S32. In S32, the CPU 32 analyzes the characteristics of the target character string. For example, the CPU 32 performs character recognition on the character string within the mark M2, and analyzes the number of characters, the type of characters, and the display mode of the characters in the target character string. Based on the analysis result of the target character string, the CPU 32 determines the type of filter to be used for pre-processing of character recognition. Then, the CPU 32 determines setting information including the analysis result of the target character string, the type of filter, etc. Note that in a modified example, part of the setting information, such as the number of characters, may be specified by the user.

[0050] In S34, the CPU 32 calculates relative position information indicating the relative position of the target character string with respect to the reference code. For example, if the reference code is a two-dimensional code 104, the CPU 32 defines a coordinate system (hereinafter referred to as a "cell coordinate system") in which the width of a cell constituting the two-dimensional code 104 is one unit. The origin of the cell coordinate system is, for example, one of the four corners of the two-dimensional code 104. Note that the origin of the cell coordinate system may be the center of the two-dimensional code 104 or one of the four corners of the field of view. The CPU 32 calculates relative position information (x1, y1) as the difference between the coordinate point indicating the center of the reference code in the cell coordinate system and the coordinate point indicating the center of the target character string in the cell coordinate system. As shown in FIG. 4, the value x1 is the distance along the left-right direction on the paper, and the value y1 is the distance along the up-down direction on the paper.

[0051] Furthermore, for example, when the reference code is a barcode 106 (e.g., when registering the label 120 in FIG. 1), the CPU 32 defines a coordinate system (hereinafter referred to as a "bar coordinate system") in which the size of the elements constituting the barcode 106 is one unit. Here, the elements constituting the barcode 106 are modules and bars, and the size of the elements is at least one of the module width and the bar height. The size of the elements of the information code (e.g., cell width, module width) is standardized. By defining a coordinate system in which a standardized, unchanging size is one unit, it is possible to accurately calculate the relative position of the target character string with respect to the reference code. In particular, whether the distance to the label, which is the subject, is close or far, the relative position of the target character string with respect to the reference code can be calculated using the standardized, unchanging size as one unit.

[0052] In S36, the CPU 32 associates the reference information determined in S20, the code information read in S22, the setting information determined in S32, and the relative position information calculated in S34, and registers them in the registration table 42. Here, the label name may be entered by the user, or part of the code information may be used. When S36 ends, the CPU 32 ends the processing of FIG. 3.

[0053] In this embodiment, two reference codes can be specified on the registration screen SC1 of FIG. 3. For example, FIG. 6 illustrates the registration screen SC1 in case C2 for registering information on the label 110 of FIG. 1. The user specifies an image of the two-dimensional code 104 and an image of the barcode 106 from the captured image IM1. A mark M1 is displayed on the image of the two-dimensional code 104, and a mark M3 is displayed on the image of the barcode 106. In case C2, the CPU 32 calculates two pieces of relative position information in S34 of FIG. 3. As in case C1, one piece of relative position information is a difference value (x1, y1) on the cell coordinate system. The other piece of relative position information is a difference (x2, y2) between a coordinate point indicating the center of the barcode 106 in the bar coordinate system and a coordinate point indicating the center of the target character string in the bar coordinate system. In this case, the CPU 32 registers two values ​​(x1, y1) and (x2, y2) as the relative position information in the registration table 42. As a result, the position of the read range set using one value (x1, y1) can be complemented using the other value (x2, y2). The position of the read range can be set more accurately than when a single reference code is used. In a modified example, the CPU 32 may define a coordinate system in which the average value of the size of the elements constituting the two-dimensional code 104 and the size of the elements constituting the barcode 106 is used as one unit. The CPU 32 may then calculate, for either of the two reference codes, one piece of relative position information as the difference between the coordinate point indicating the center of the reference code and the coordinate point indicating the center of the target character string in the cell coordinate system. In another modified example, the number of reference codes is not limited to two, but may be three or more, and relative position information may be calculated for each of the three or more reference codes.

[0054] 3, a captured image IM1 of an actual image of the label 100 or the like is used to register each piece of information in the registration table 42 (FIG. 3). In particular, the target character string can be specified by an intuitive operation such as tapping, which improves user convenience.

[0055] (Reading process: Figure 6) The reading process for reading information from the label 100 etc. will be described with reference to Fig. 6. The CPU 32 executes the process of Fig. 6 in accordance with the program 40. The process of Fig. 6 is started when the program 40 is started.

[0056] In S40, the CPU 32 monitors whether the operation unit 12 has received a predetermined reading instruction. If the operation unit 12 has received the reading instruction (YES in S40), the CPU 32 proceeds to S50. In S50, the CPU 32 captures an image of a label (e.g., 100) with the image sensor 20. Here, if the label is captured from an oblique direction, the CPU 32 performs keystone correction on the captured image IM2 captured by the image sensor 20. For example, the outline of the image of the information code included in the captured image IM2 is used as the shape that serves as the basis for the keystone correction. This is because the outline of the information code is standardized, and for example, the outline is a rectangular parallelepiped. By performing keystone correction, the accuracy of character recognition is improved.

[0057] In S52, the CPU 32 displays on the display unit 14 an image screen SC2 including a captured image IM2 captured by the image sensor 20. For example, case C3 in Fig. 7 is an example of the captured screen SC2.

[0058] In S54, the CPU 32 decodes the image of the information code in the captured image IM2 and reads the information recorded in the information code. In S56, the CPU 32 obtains, from the registration table 42, each piece of information stored in association with the code information included in the information read in S54. With this configuration, in a situation where multiple types of labels exist, it is possible to obtain relative position information appropriate for the label from which information is to be read. The registration table 42 makes it possible to perform character recognition on multiple types of labels.

[0059] In S60, the CPU 32 defines a coordinate system in which the elements constituting the image of the information code in the captured image IM2 are defined as units. The CPU 32 sets a reading range at the coordinate point indicated by the relative position information acquired in S54 in the defined coordinate system. Here, the size of the reading range is determined using the setting information acquired in S54.

[0060] In S62, the CPU 32 determines whether the entire reading range set in S60 is included in the captured image IM2. If the CPU 32 determines that the entire reading range is included in the captured image IM2 (YES in S62), the process proceeds to S70. In S70, the CPU 32 displays an OK message N1 on the captured screen SC2, indicating that character recognition can be performed. Case C3 in FIG. 7 is an example of the OK message N1. When the OK message N1 is displayed, the entire frame M4 indicating the reading range is displayed on the captured screen SC2. The frame M4 is displayed superimposed on the captured image IM2. The frame M4 allows the user to know the reading range for character recognition.

[0061] In S72, the CPU 32 performs character recognition on the image of the character string within the reading range, using the settings indicated by the setting information obtained in S56 from the registration table 42. According to the configuration of this embodiment, the character recognition settings can be changed to suit the characteristics of each of multiple types of labels.

[0062] In S74, the CPU 32 outputs a reading result including the information acquired from the information code in S54 and the information acquired by the character recognition in S72. The reading result is displayed, for example, on the display unit 14. In a modified example, the reading result may be transmitted to an external device (for example, a server) capable of communicating with the terminal 10. When S74 ends, the CPU 32 ends the processing of FIG. 6.

[0063] Furthermore, if the CPU 32 determines that the entire reading range is not included in the captured image IM2 (NO in S62), the CPU 32 proceeds to S64. In S64, the CPU 32 determines whether the distance to the label, which is the subject, is appropriate. An appropriate distance to the label means that the distance to the label in the reading process of FIG. 6 is substantially the same as or farther from the distance to the label in the registration process of FIG. 3. If the distance to the label is appropriate, both the reading range and the reference code can be included in the captured image IM2. However, for example, if the center of the label is significantly deviated from the center of the angle of view of the image sensor 20, the entire reading range may not be included in the captured image IM2 even if the distance to the label is appropriate.

[0064] Whether the distance to the label is appropriate is determined using the size of the image of the reference code included in the reference information acquired in S56. For example, if the size of the image of the reference code captured in the reading process of FIG. 6 is equal to or smaller than the size in the reference information, the CPU 32 determines that the distance to the label is appropriate. On the other hand, if the size of the image of the quasi-code is larger than the size in the reference information, the CPU 32 determines that the distance to the label is inappropriate. With this configuration, even without a separate sensor for measuring the distance to the label, it is possible to determine whether the terminal 10 is too close to the label by using the size of the image of the reference code.

[0065] If the CPU 32 determines that the distance to the label is appropriate (YES in S64), the process proceeds to S80. In S80, the CPU 32 displays a message N2 on the captured screen SC2, instructing the user to move the terminal 10 horizontally along the label, and a direction image N3 indicating the direction of movement. Looking at the message N2 and the direction image N3, the user moves the terminal 10 horizontally along the label. The position of the terminal 10 relative to the label can be adjusted so that the entire reading range is included in the captured image IM2. Note that the user may move the label, rather than the terminal 10, horizontally.

[0066] Case C4 in FIG. 7 is an example of the captured screen SC2 when YES is determined in S64. In this case, the top of the frame M4 indicating the reading range is located outside the captured image IM2. In this case, the directional image N3 indicates the direction in which the terminal 10 is moved upward along the label. For example, when the top of the frame M4 is located outside the captured image IM2, the CPU 32 determines the orientation of the directional image N3 to be upward, and when the left side of the frame M4 is located outside the captured image IM2, the CPU 32 determines the orientation of the directional image N3 to be leftward.

[0067] Furthermore, if the CPU 32 determines that the distance to the label is not appropriate (NO in S64), the process proceeds to S82. In S82, the CPU 32 displays a message N4 on the captured screen SC2, instructing the user to move the terminal 10 in a direction perpendicular to the label. Case C5 in FIG. 8 is an example of the captured screen SC2 when the determination in S64 is NO. In this case, the terminal 10 is too close to the label, so the image of the information code is larger than the size of the reference information. Furthermore, the entire frame M4 indicating the reading range is located outside the captured image IM2. Seeing the message N4, the user moves the terminal 10 away from the label so that the distance to the label is appropriate. Note that the user may also move the label away from the terminal 10. When S80 or S82 ends, the CPU 32 returns to S60.

[0068] In this embodiment, the direction image N3 or the message N4 informs the user of the direction of movement for adjusting the relative position of the terminal 10 with respect to the label. The user can know the direction in which to move the terminal 10 or the label.

[0069] In this embodiment, a mark M5 indicating the position of the reference code is displayed on the captured image SC2. By looking at the mark M5, the user can know the information code that is the reference for the reading range.

[0070] (Effects of this embodiment) Labels such as the label 100 have a predetermined format, and in recent years, information codes (e.g., 104 and 106) have increasingly been included in the predetermined format. According to the configuration of this embodiment, relative position information indicating the relative position of characters with respect to the information code is pre-stored in the registration table 42 based on the predetermined format. The terminal 10 then automatically sets the read range to the position indicated by the relative position information in the registration table 42 (S60 in FIG. 6). In situations where character recognition is repeatedly performed, the user does not need to specify the read range each time. This improves user convenience. For example, a comparative example may be envisioned in which a simple symbol is used as the reference for the relative position. Standardized information codes are expected to provide more stable recognition than simple symbols. By using a stably recognizable information code as the reference, the read range can be set stably. As a result, the accuracy of character recognition can also be improved.

[0071] (Correspondence) The terminal 10 is an example of an "optical reading system." The operation unit 12, the display unit 14, and the image sensor 20 are examples of an "operation unit," a "display unit," and an "image sensor," respectively. The label 100, the two-dimensional code 104, and the characters in the character field 102 are examples of a "display medium," an "information code," and a "character," respectively. The memory 34 is an example of a "registration medium." The relative position information and setting information stored in the registration table 42 are examples of "relative position information" and "setting information," respectively. The two-dimensional code 104 and the barcode 106 on the label 110 are examples of a "first information code" and a "second information code," respectively. The captured image IM2 in FIG. 7 is an example of a "first captured image." The frame M4 and the mark M5 are examples of a "first image" and a "second image," respectively. The OK message N1, the direction image N3, and the message N4 are examples of a "first notification," a "movement direction," and a "second notification," respectively. The process and the captured image IM1 in FIG. 3 are examples of the "registration process" and the "second captured image", respectively.

[0072] S60 and S72 in FIG. 6 are examples of the processes implemented by the "setting unit" and the "character recognition execution unit", respectively.

[0073] (Second Example) (Registration process; Figure 9) This embodiment is similar to the first embodiment except for the difference in the content of the registration process. S100 and S102 are similar to S10 and S12 in FIG. 3. In S110, the CPU 32 causes the marker projection unit 22 to project an indication marker. The user adjusts the position of the terminal 10 so that the image of the indication marker overlaps the character string to be recognized in the character field 102 of the label. As a result, the registration screen SC1 includes a captured image IM4 including an image IM3 of the indication marker. The CPU 32 automatically designates the image of the captured image IM4, displayed at a location overlapping the image IM3 of the indication marker, as the image of the character string to be recognized.

[0074] In S120, the CPU 32 automatically designates the image of the information code included in the captured image IM4 as the image of the reference code. S122 and S124 are similar to S20 and S22 in FIG. 3. In S140, the CPU 32 monitors whether the "Register" button B2 in the registration screen SC1 is selected. If the "Register" button B2 is selected (YES in S140), the CPU 32 proceeds to S142. S142, S144, and S146 are similar to S32, S34, and S36 in FIG. 3.

[0075] According to the configuration of this embodiment, the pointing marker can be used to specify the location on the label where the target character string is displayed. The user simply adjusts the position of the terminal 10 so that the image of the pointing marker overlaps the target character string. This improves user convenience. The marker projection unit 22 is an example of a "marker projection unit." The location where the image IM3 overlaps is an example of a "specific location."

[0076] Although specific examples of the technology disclosed in this specification have been described above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. For example, the following modifications may be adopted.

[0077] (Variation 1) The registration table 42 is not limited to being stored in the memory 34 of the terminal 10, but may also be stored in an external memory (for example, a server, a USB memory, or an SD card) that can communicate with the terminal 10. Furthermore, the registration table 42 is not limited to being stored in a storage medium, but may also be recorded in an information code. In these variations, the external memory and the information code are examples of a "registration medium," and a system including the external memory or the like and the terminal 10 is an example of an "optical reading system."

[0078] (Variation 2) In S72 of Fig. 6, the CPU 32 may transmit the image within the reading range to an external server. Then, the external server may perform character recognition on the image within the reading range. In this variation, the external server is an example of a "character recognition execution unit," and a system including the terminal 10 and the external server is an example of an "optical reading system."

[0079] (Variation 3) The relative position information may be calculated using a coordinate system in which a pixel of the captured image is used as a unit. In this variation, the "coordinate system defined using the size of the elements that make up the information code" can be omitted.

[0080] (Modification 4) The process shown in case C2 in Fig. 5 does not have to be executed. In this modification, the "first information code" and the "second information code" can be omitted.

[0081] (Modification 5) The relative position information may be registered by manual input, or may be downloaded from an external server to the terminal 10. In this modification, the "imaging process" and the "calculation process" can be omitted.

[0082] (Variation 6) One piece of relative position information for one label may be registered in the memory 34. In this variation, the "plural types of display media" can be omitted.

[0083] (Variation 7) Setting information does not have to be registered in the registration table 42. In this variation, the "setting information" can be omitted.

[0084] (Modification 8) The frame M4 in Fig. 7 does not have to be displayed. In this modification, the "first image" can be omitted.

[0085] (Modification 9) The mark M5 in Fig. 7 does not have to be displayed. In this modification, the "second image" can be omitted.

[0086] (Modification 10) The "first notification" is not limited to displaying the messages in S80 and S82 in FIG. 6, but may also be outputting a predetermined sound, generating a predetermined vibration, or turning on a light.

[0087] (Modification 11) The processes of S80 and S82 in Fig. 6 do not have to be executed. In this modification, the "first notification" can be omitted.

[0088] (Modification 12) The direction image N3 does not have to be displayed. In this modification, the "movement direction" can be omitted.

[0089] (Modification 13) The "second notification" is not limited to displaying the message in S82 of FIG. 6, but may also be outputting a predetermined sound, generating a predetermined vibration, or turning on a light.

[0090] (Modification 14) The process of S82 in Fig. 6 does not have to be executed. In this modification, the "second notification" can be omitted.

[0091] The technical elements described in this specification or drawings exhibit technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings simultaneously achieve multiple objectives, and achieving one of those objectives is itself technically useful. [Explanation of symbols]

[0092] 1: Barcode 10: Optical reading terminal 12:Operation section 14: Display section 20: Image sensor 22: Marker irradiation unit 30: Control section 32 :CPU 34: Memory 40: Program 42: Registration table 100, 110, 120: Label 102: Text field 104: 2D code 106: Barcode B1: Button B2: Button IM1, IM2, IM4: Captured images IM3: Image of the indicator marker M1, M2, M3, M5: Marks M4: Frame N1: OK message N2: Message N3: Direction image N4: Message SC1: Registration screen SC2: Imaging screen

Claims

1. 1. An optical reading system, comprising: An image sensor; a registration medium for registering relative position information indicating the relative position of the characters with respect to the information code, for a display medium on which an information code and characters are displayed in a predetermined format; a setting unit that sets a read range for character recognition at a position within the registration medium indicated by the relative position information, using the image of the information code as a reference, in a first captured image that is an image of the display medium captured by the image sensor; a character recognition execution unit that executes the character recognition for the set reading range; An optical reading system comprising:

2. 2. The optical reading system according to claim 1, wherein the relative position information is a value in a coordinate system defined using the size of an element that constitutes the information code.

3. the information code is a two-dimensional code, The optical reading system according to claim 2 , wherein the size is a width of a cell of the two-dimensional code.

4. the information code is a barcode, The optical reading system according to claim 2 , wherein the size is at least one of a module width and a bar height in the barcode.

5. At least two information codes including a first information code and a second information code and the character are displayed on the display medium, 2. The optical reading system according to claim 1, wherein the relative position information is a value of a coordinate system defined using at least two of the size of an element constituting the first information code and the size of an element constituting the second information code.

6. The optical reading system further comprises: a registration unit that executes a registration process to register the relative position information in the registration medium; An optical reading system as described in any one of claims 1 to 5, wherein the registration process includes a process of calculating relative position information indicating the relative position of a specific point with respect to the image of the information code in a second captured image, which is an image of the display medium captured by the image sensor.

7. the optical reading system further includes a marker illuminating unit that illuminates an indication marker; the registration process further includes a process of causing the marker projection unit to project the instruction marker; The optical reading system according to claim 6 , wherein the specific location is a location where an image of the indication marker is located in the second captured image.

8. the optical reading system further comprises an operation unit and a display unit; the registration process further includes a process of displaying the second captured image on the display unit, The optical reading system according to claim 6 , wherein the specific portion is a portion selected by the operation unit from the second captured image displayed on the display unit.

9. the registration medium registers, for each of the plurality of types of display media, code information recorded in the information code in the display medium and the relative position information in association with each other; The optical reading system further comprises: a reading unit that reads the code information from an image of the information code in the first captured image; an acquisition unit that acquires, from the registration medium that registers a plurality of pieces of the relative position information, the relative position information registered in association with the code information read from the image of the information code in the first captured image; 6. An optical reading system according to claim 1, comprising:

10. the registration medium registers the code information, the relative position information, and the character recognition setting information in association with each other for each of the plurality of types of display media; the acquiring unit further acquires, from the registration medium that registers a plurality of pieces of the setting information, the setting information registered in association with the code information read from the image of the information code in the first captured image; The optical reading system according to claim 9 , wherein the character recognition execution unit executes the character recognition for the reading range with settings indicated by the acquired setting information.

11. The optical reading system further comprises: A display unit; The optical reading system according to claim 1 , further comprising a display control unit that causes the display unit to display a first image indicating a position of the reading range in the first captured image.

12. The optical reading system further comprises: A display unit; The optical reading system according to claim 1 , further comprising a display control unit that causes the display unit to display a second image indicating a position of the information code in the first captured image.

13. The optical reading system further comprises: The optical reading system according to claim 1 , further comprising a first notification unit that outputs a first notification when at least a part of the reading range is set outside the first captured image.

14. 14. The optical reading system according to claim 13, wherein the first notification unit further outputs a movement direction for adjusting a relative position of the image sensor with respect to the display medium so that the entire reading range is included in the first captured image.

15. The optical reading system further comprises: The optical reading system according to claim 1 , further comprising a second notification unit that outputs a second notification when a size of the image of the information code in the first captured image is larger than a predetermined size.

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