Information code reading device, information code reading method, and information code reading program

Abstract

To provide an information code reading device capable of reading a transparent information code that cannot be recognized with visible light, an information code reading method, and an information code reading program.SOLUTION: A portable terminal device 14 is a QR code (R) reading device that reads, by illuminating with light of a predetermined wavelength other than visible light, a transparent QR code 10 that is printed on a printed matter 12 and cannot be visually recognized by visible light. A guide unit guides image-capturing operation of an operator to capture an image so as to mitigate the influence of infrared light. The portable terminal device uses a camera 22 to image the transparent QR code 10, to read the transparent QR code 10 irradiated with infrared light by an infrared light irradiation unit 24.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an information code reading device, an information code reading method, and an information code reading program. [Background technology]

[0002] Currently, various information codes are in widespread use, including two-dimensional codes such as QR codes (registered trademark) and one-dimensional codes such as bar codes.

[0003] Among such information codes, transparent two-dimensional codes that are invisible to humans are also being developed. There are various reasons for using transparent two-dimensional codes. For example, printing multiple two-dimensional codes on a product is undesirable from a design perspective, and transparent two-dimensional codes can store information about distribution that consumers do not need to know.

[0004] Patent Document 1 describes printing a transparent two-dimensional code on paper using a toner that does not absorb visible light but does absorb infrared light. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-89840 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in reality, it has been difficult to read information codes that are not visible with visible light even when photographed with a camera.

[0007] In view of the above, an object of the present invention is to provide an information code reading device, an information code reading method, and an information code reading program capable of reading a transparent information code that cannot be recognized by visible light. [Means for solving the problem]

[0008] The present invention employs the following technical means to solve the above problems. The reference characters in the claims and in this section are merely examples showing the corresponding relationship with the specific means described in the embodiments below as one aspect, and do not limit the technical scope of the present invention.

[0009] An information code reading device according to one embodiment of the present invention is an information code reading device (14) that reads an information code (10) that cannot be seen with visible light by illuminating it with light of a predetermined wavelength other than visible light, and is equipped with an imaging unit (22) that images a subject, an irradiation unit (24) that irradiates light of the predetermined wavelength, and a guidance unit (38) that guides an operator in performing an imaging operation to perform imaging that reduces the effects of light of the predetermined wavelength when imaging the information code with the imaging unit.

[0010] Transparent information codes, which are information codes that cannot be seen with visible light, can be read by illuminating them with light of a specific wavelength other than visible light, such as infrared light or ultraviolet light. However, it is difficult to read such transparent information codes, and the reason why it is difficult to read them has not been clear. The inventor has newly discovered that this is due to the light of a specific wavelength that illuminates the transparent information code, and that when photographing a transparent information code, it is necessary to reduce the influence of the light of the specific wavelength.

[0011] Therefore, when photographing a transparent information code, the information code reader of the present configuration guides the operator to photograph the transparent information code in a manner that reduces the influence of light of a predetermined wavelength. When the operator photographs the transparent information code according to the guidance, the information code reader of the present configuration can read the transparent information code.

[0012] In the above-mentioned information code reading device, the guidance unit may guide the operator's photographing operation so that the photographing position of the information code by the photographing unit is a predetermined position based on a positional relationship between the photographing unit and the irradiation unit.

[0013] The inventors have newly discovered that one of the reasons why it is difficult to read a transparent information code is the effect of reflection of light of a specific wavelength irradiated from an irradiating unit. In other words, even if an operator photographs a transparent information code with a photographing unit, if the image photographed by the photographing unit is strongly affected by the reflection of light from the irradiating unit, the transparent information code cannot be read. According to this configuration, the operator's photographing operation is guided so that the photographing position of the transparent information code is a specific position that is less affected by light of a specific wavelength based on the positional relationship between the photographing unit and the irradiating unit, so that the transparent information code can be read more reliably.

[0014] In the above-mentioned information code reading device, a display unit (20) is provided that displays the image captured by the photographing unit, and the guidance unit may cause a partial area of ​​the image captured by the photographing unit to be enlarged and displayed on the display unit so that the photographing position of the information code by the photographing unit becomes the specified position.

[0015] According to this configuration, the operator moves the information code reader so that the transparent information code is displayed in the central area of ​​the enlarged display. Therefore, according to this configuration, the photographing position of the transparent information code is an appropriate position that is less susceptible to the influence of reflected light, and the transparent information code can be read more reliably.

[0016] In the above-mentioned information code reading device, a location determination unit (36) is provided that determines whether the location where the information code was photographed is indoors or outdoors, and the guidance unit may guide the operator in the photographing operation based on the determination result by the location determination unit.

[0017] The inventors have newly discovered that one of the reasons why it is difficult to read transparent information codes is the effect of sunlight that contains certain wavelengths such as infrared rays and ultraviolet rays. With this configuration, the operator's shooting operation is guided based on whether the shooting location is indoors or outdoors, so that transparent information codes can be read more reliably.

[0018] In the above information code reading device, the guiding unit may guide an operator's photographing operation so that the photographing position of the information code by the photographing unit is a predetermined position based on a result of the determination by the location determination unit.

[0019] According to this configuration, the positional relationship between the transparent information code and the photographing unit is set to an appropriate positional relationship based on whether it is indoors or outdoors, and the transparent information code is photographed, so that the transparent information code can be read more reliably.

[0020] In the above information code reading device, the guiding unit may guide the operator in the photographing operation so that the distance between the information code and the photographing unit becomes a distance based on a result of determination by the location determination unit.

[0021] According to this configuration, the transparent information code is photographed at an appropriate distance where the influence of light of a specific wavelength is mitigated, so that the transparent information code can be read more reliably.

[0022] In the above information code reading device, the distance may be shorter when the information code is photographed outdoors than when the information code is photographed indoors.

[0023] According to this configuration, the influence of light of a specific wavelength is mitigated during outdoor photography, so that the transparent information code can be read more reliably.

[0024] In the above information code reading device, the guiding unit may guide the operator in a photographing operation so as to adjust an angle between the photographing unit and the information code.

[0025] According to this configuration, the imaging angle is optimized, so that the transparent information code can be read more reliably.

[0026] In the above-mentioned information code reading device, the guidance unit may guide the operator's photographing operation so as to increase the angle when the distortion of the information code photographed by the photographing unit is relatively small, and to decrease the angle when the distortion is relatively large.

[0027] According to this configuration, distortion of the photographed transparent information code is reduced, so that the transparent information code can be read more reliably.

[0028] In the above-mentioned information code reading device, when the information code is photographed outdoors and the information code is photographed but not recognized, the guidance unit may guide the photographer's shooting direction so that sunlight does not illuminate the information code.

[0029] According to this configuration, the influence of light of a specific wavelength is mitigated during outdoor photography, so that the transparent information code can be read more reliably.

[0030] An information code reading method according to one embodiment of the present invention is a method for reading an information code that cannot be seen with visible light by illuminating it with light of a predetermined wavelength other than visible light, in which a guidance unit guides an operator in performing a photographing operation to perform a photograph that reduces the influence of light of the predetermined wavelength, and an illumination unit irradiates light of the predetermined wavelength while an imaging unit photographs the information code, thereby reading the information code.

[0031] An information code reading program according to one embodiment of the present invention is an information code reading program possessed by an information code reading device that reads an information code that cannot be seen with visible light by shining light of a predetermined wavelength other than visible light, and causes a computer to function as a guidance unit that guides an operator in performing a photographing operation so as to perform a photographing operation that reduces the effects of light of the predetermined wavelength when photographing the information code with a photographing unit that photographs a subject. Effect of the Invention

[0032] According to the present invention, it is possible to read a transparent information code that cannot be recognized by visible light. [Brief description of the drawings]

[0033] [Figure 1]1 is a schematic configuration diagram of a transparent QR code and a mobile terminal device according to an embodiment. [Diagram 2] 4 is a functional block diagram relating to reading of a transparent QR code in the mobile terminal device of the embodiment. FIG. [Diagram 3] 1A and 1B are external views of an enlarged screen display of a mobile terminal device according to an embodiment, in which (A) shows the screen display before enlargement, and (B) shows the screen display after enlargement. [Figure 4] 1 is an external view showing an angle at which a transparent QR code is photographed by the mobile terminal device of this embodiment. [Diagram 5] 10 is a flowchart showing a flow of a transparent QR code reading process according to an embodiment. [Figure 6] 10 is a flowchart showing a flow of a process for changing the shooting direction of an operator according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below shows an example of a case where the present invention is implemented, and the present invention is not limited to the specific configuration described below. In implementing the present invention, a specific configuration according to the embodiment may be appropriately adopted.

[0035] FIG. 1 is a schematic diagram of a printed matter 12 on which a transparent QR code 10 of this embodiment is printed, and a mobile terminal device 14. As shown in FIG.

[0036] The transparent QR code 10 is an information code that cannot be seen with visible light and can be read by illuminating it with light of a specific wavelength other than visible light. In other words, the transparent QR code 10 printed on the printed matter 12 becomes visible when illuminated with light of a specific wavelength other than visible light.

[0037] The predetermined wavelength is, for example, a wavelength in the infrared region (hereinafter referred to as "infrared light"). That is, the transparent QR code 10 of this embodiment is read by photographing it while illuminated with infrared light. For this reason, the transparent QR code 10 of this embodiment is printed on the printed matter 12 with ink that does not absorb visible light but absorbs infrared light. Also, although the information code that is made transparent in this embodiment is a QR code, this is merely an example, and other two-dimensional codes or one-dimensional codes such as barcodes may also be used.

[0038] There are no limitations on the printed matter 12 as long as it is an object capable of printing the transparent QR code 10. The transparent QR code 10 may be printed on a sticker or the like, and the sticker may be attached to another object.

[0039] The mobile terminal device 14 is, for example, a portable information processing device such as a smartphone or a tablet terminal, and has a function of reading a QR code. Note that the mobile terminal device 14 may be a dedicated reader for reading the transparent QR code 10 without having a calling function.

[0040] The mobile terminal device 14 includes a computing device such as a CPU (Central Processing Unit) capable of executing a program, a storage device such as an SSD (Solid State Drive), a communication device for connecting to the Internet or an intranet, and various connectors. The mobile terminal device 14 also includes a touch panel display 20 that displays images and accepts operations for the mobile terminal device 14, a camera 22 that captures an image of a subject, an infrared light emitting unit 24 that irradiates infrared light, and an operation unit 26 that accepts operations for the mobile terminal device 14.

[0041] The mobile terminal device 14 is provided with a touch panel display 20 on one side, that is, the front side, and with a camera 22 and an infrared light emitting unit 24 on the other side, that is, the back side. In the mobile terminal device 14 of the present embodiment, as an example, the camera 22 is provided at the upper right when viewed from the front, and the infrared light emitting unit 24 is provided at the upper left on the back side.

[0042] In this embodiment, the operator of the mobile terminal device 14 reads out the information recorded in the transparent QR code 10 by shining infrared light from the infrared light emitting unit 24 onto the transparent QR code 10 and photographing the transparent QR code 10 with the camera 22. At this time, the transparent QR code 10 is displayed on the touch panel display 20 so that it can be seen by the operator.

[0043] However, it is difficult to read the transparent QR code 10, and the reason for this difficulty was unclear. The inventors have newly discovered that this is due to the light of a specific wavelength (infrared light in this embodiment) illuminating the transparent QR code 10, and that when photographing the transparent QR code 10, it is necessary to mitigate the effect of the light of the specific wavelength.

[0044] Therefore, the mobile terminal device 14 of this embodiment performs a guidance process that guides the operator in the shooting operation to perform shooting that reduces the influence of infrared light when shooting the transparent QR code 10 with the camera 22. When the operator follows this guidance to shoot the transparent QR code 10, the mobile terminal device 14 can read the transparent QR code 10.

[0045] FIG. 2 is a functional block diagram of the mobile terminal device 14 with respect to the transparent QR code reading function.

[0046] The mobile terminal device 14 includes a touch panel display 20, a camera 22, an infrared light emitting unit 24, a communication unit 30, a memory unit 32, a QR code recognition unit 34, a photography location determination unit 36, and a guidance unit 38.

[0047] The communication unit 30 transmits and receives information to and from other information processing devices via the Internet or the like.

[0048] The storage unit 32 stores a program and various data related to reading the transparent QR code 10.

[0049] The QR code recognition unit 34 recognizes the transparent QR code 10 from the image data captured by the camera 22. The QR code recognition unit 34 performs a decoding process to decode the information recorded in the recognized transparent QR code 10.

[0050] The photography location determination unit 36 ​​determines whether the photography location of the transparent QR code 10 is indoors or outdoors. The photography location is determined based on the illuminance detected by the camera 22.

[0051] When the transparent QR code 10 is photographed by the camera 22, the guiding unit 38 performs a guiding process for guiding the operator in the photographing operation so as to perform photographing in a manner that reduces the influence of infrared light.

[0052] Here, the guiding process executed by the guiding unit 38 of this embodiment will be described. Note that the guiding process of this embodiment includes a plurality of processes. The guiding unit 38 may execute at least one of the plurality of guiding processes described below.

[0053] First, the inventors have newly discovered that one of the reasons why it is difficult to read the transparent QR code 10 is the influence of the reflection of the infrared light irradiated from the infrared light irradiator 24. In other words, even if an operator photographs the transparent QR code 10 with the camera 22, if the image photographed by the camera 22 is strongly influenced by the reflection of the irradiated infrared light, the transparent QR code 10 cannot be read. For example, an operator generally adjusts the positional relationship between the camera 22 and the transparent QR code 10 so that the transparent QR code 10 is displayed in the central area of ​​the touch panel display 20. However, with this positional relationship, there are cases where the transparent QR code 10 cannot be read due to the influence of the reflection of the infrared light irradiated from the infrared light irradiator 24.

[0054] Therefore, the guidance process of this embodiment guides the operator's photographing operation so that the photographing position of the transparent QR code 10 by the camera 22 is a predetermined position based on the positional relationship between the camera 22 and the infrared light irradiating unit 24. That is, the guidance process guides the operator's photographing operation so that the transparent QR code 10 is located at an appropriate photographing position that is unlikely to be affected by the infrared light irradiated by the infrared light irradiating unit 24, in other words, at a position that avoids reflection of the infrared light from the infrared light irradiating unit 24.

[0055] The optimal photographing position of the transparent QR code 10 differs depending on the positional relationship between the camera 22 and the infrared light emitting unit 24. Therefore, the mobile terminal device 14 stores an appropriate photographing position of the transparent QR code 10 based on the positional relationship between the camera 22 and the infrared light emitting unit 24. The guidance process then guides the operator's photographing operation based on the positional relationship between the camera 22 and the infrared light emitting unit 24 so that the transparent QR code 10 is positioned in a position that avoids reflection of infrared light, such as the upper right or lower left on the touch panel display 20.

[0056] In the guidance process of the present embodiment, a partial area of ​​the image captured by the camera 22 is enlarged and displayed on the touch panel display 20 so that the position where the transparent QR code 10 is captured by the camera 22 coincides with a predetermined position.

[0057] Fig. 3 is an external view of an enlarged screen display of the mobile terminal device 14 of this embodiment. Fig. 3(A) shows the screen display before enlargement, and Fig. 3(B) shows the screen display after enlargement. Note that the arrows A and B in Fig. 3 do not have to be actually displayed on the touch panel display 20.

[0058] 3, the infrared light irradiator 24 is provided at the upper left when viewed from the front of the mobile terminal device 14, so that the reflected infrared light is strongest at the upper left side of the touch panel display 20 and weakest at the lower right side of the touch panel display 20. For this reason, as shown by arrow A in FIG. 3(A), it is preferable that the transparent QR code 10 is displayed and read at a position on the lower right side of the touch panel display 20.

[0059] Therefore, the mobile terminal device 14 of this embodiment virtually divides the touch panel display 20 into four parts, vertically, horizontally, and enlarges the lower right area where reflected infrared light is weakest, as shown in Fig. 3(B). As the lower right area of ​​the touch panel display 20 is enlarged, the operator moves the mobile terminal device 14 in the direction of arrow B so that the transparent QR code 10 is displayed in the center area of ​​the enlarged display. As a result, the photographing position of the transparent QR code 10 becomes an appropriate position that is less affected by reflected light, and the transparent QR code 10 can be read more reliably.

[0060] The guidance process for setting the photographing position of the transparent QR code 10 by the camera 22 to an appropriate predetermined position is not limited to the enlarged display. For example, the guidance process may guide the display position of the transparent QR code 10 by displaying an arrow on the touch panel display 20. The guidance process may also guide the operator by outputting a voice from the mobile terminal device 14, such as "Please display the transparent QR code in the lower right corner of the touch panel display."

[0061] Furthermore, the inventors have newly discovered that sunlight containing infrared light, ultraviolet light, etc., has an effect on the difficulty in reading the transparent QR code 10. Therefore, the guidance process of this embodiment guides the operator in the shooting operation based on whether the operator is indoors or outdoors.

[0062] That is, since the strength of sunlight differs indoors and outdoors, the effect of sunlight on reading the transparent QR code 10 differs. For this reason, the guidance process guides the operator in the photographing operation based on whether the operator is indoors or outdoors. This makes it possible for the portable terminal device 14 of this embodiment to read the transparent QR code 10 more reliably.

[0063] For example, the guidance process guides the operator in the photographing operation so that the photographing position of the transparent QR code 10 by the camera 22 becomes a predetermined position based on the determination result by the photographing location determination unit 36. Specifically, as described above, the guidance process guides the operator in the photographing operation so that the display position of the transparent QR code 10 on the touch panel display 20 becomes an appropriate position (within a predetermined area). As a result, the positional relationship between the transparent QR code 10 and the camera 22 is set to an appropriate positional relationship based on whether it is indoors or outdoors, and the transparent QR code 10 is photographed, so that the transparent QR code 10 can be read more reliably.

[0064] As described above, the appropriate display position of the transparent QR code 10 also differs depending on the positional relationship between the camera 22 and the infrared light emitting unit 24. Therefore, the mobile terminal device 14 stores an appropriate display position of the transparent QR code 10 based on the combination of the positional relationship between the camera 22 and the infrared light emitting unit 24 and the shooting location (indoors or outdoors).

[0065] For example, in the mobile terminal device 14 of this embodiment, when the transparent QR code 10 is photographed indoors, the appropriate display position for the transparent QR code 10 is the bottom right of the touch panel display 20. On the other hand, when the transparent QR code 10 is photographed outdoors, the appropriate display position for the transparent QR code 10 is the top left of the touch panel display 20.

[0066] If the transparent QR code 10 is photographed outdoors, an appropriate display position for the transparent QR code 10 may be determined taking into account the position of the sun at the photographing location. The position of the sun at the photographing location can be found, for example, from the photographing date and time and the latitude and longitude of the photographing location. The photographing date and time is obtained from the calendar function and clock function of the mobile terminal device 14. The latitude and longitude of the photographing location are obtained from the GPS of the mobile terminal device 14.

[0067] The guidance process also guides the operator in the photographing operation so that the photographing distance, which is the distance between the transparent QR code 10 and the camera 22, becomes the optimal photographing distance based on the determination result by the photographing location determination unit 36. This guidance process allows the transparent QR code 10 to be photographed at an appropriate distance where the effects of infrared light are mitigated, so that the mobile terminal device 14 can read the transparent QR code 10 more reliably.

[0068] In addition, the influence of sunlight is greater outdoors than indoors, and it tends to be difficult to read the transparent QR code 10 if the shooting distance is long when shooting outdoors. This is because the longer the shooting distance outdoors, the stronger the sunlight illuminating the transparent QR code 10 becomes. Therefore, the optimal shooting distance is shorter when shooting a transparent QR code outdoors than when shooting indoors. For example, the optimal shooting distance indoors is 11 cm, whereas the optimal shooting distance outdoors is 8 cm. This reduces the influence of infrared light when shooting outdoors, allowing the mobile terminal device 14 to read the transparent QR code 10 more reliably.

[0069] The optimum shooting distances for indoors and outdoors are stored in the mobile terminal device 14. The guidance process guides the operator in his / her shooting operation by displaying the optimum shooting distance based on the result of the determination by the shooting location determination unit 36 ​​on the touch panel display 20 and / or by outputting the optimum shooting distance by voice, etc.

[0070] The guidance process also guides the operator in the photographing operation to adjust the photographing angle between the camera 22 and the transparent QR code 10. When the photographing angle changes, the recognition state of the transparent QR code 10 by the reflected infrared light also changes. Therefore, by optimizing the photographing angle, the mobile terminal device 14 can more reliably read the transparent QR code 10.

[0071] 4 is a schematic diagram showing the shooting angle of the transparent QR code 10. The shooting angle is set to 0° when the mobile terminal device 14 is parallel to the transparent QR code 10. When there is no reflected infrared light, the shooting angle of 0° is preferable. On the other hand, when there is reflected light, it is preferable to increase the shooting angle. Thus, the inventors have newly discovered that the greater the influence of reflected light, the more preferable it is to shoot the transparent QR code 10 at a larger shooting angle. For this reason, the guidance process may guide the operator to adjust the shooting angle by displaying an image or outputting a sound when shooting the transparent QR code 10.

[0072] On the other hand, the larger the shooting angle, the more distorted the transparent QR code 10 will be when photographed, and the worse the recognition performance of the transparent QR code 10 will be. For this reason, the shooting angle may be adjusted to an optimal angle, taking into consideration the distortion of the photographed transparent QR code 10.

[0073] Therefore, the guidance process guides the operator in the photographing operation so that the photographing angle is increased when the distortion of the transparent QR code 10 photographed by the camera 22 is relatively small, and the photographing angle is decreased when the distortion is relatively large. This reduces the distortion of the photographed transparent QR code 10, allowing the mobile terminal device 14 to more reliably read the transparent QR code 10. The magnitude of distortion of the photographed transparent QR code 10 is determined based on a predetermined criterion by performing image analysis of the transparent QR code 10.

[0074] 5 is a flowchart showing the flow of the transparent QR code reading process of this embodiment. The transparent QR code reading process is executed by a program (transparent QR code reading application) stored in a recording medium such as the storage unit 32 included in the mobile terminal device 14. Note that the execution of this program results in the execution of a method corresponding to the program. Furthermore, when the transparent QR code reading process is performed, the infrared light emitting unit 24 is in a state of emitting infrared light.

[0075] First, in step S100, the trial number n is set. The trial number n is the number of times to attempt to recognize the transparent QR code 10. That is, when the camera 22 starts capturing an image of the transparent QR code 10, the QR code recognition unit 34 performs a recognition process of the transparent QR code 10, and if the transparent QR code 10 cannot be recognized even after the recognition process has been performed more than N times, the recognition fails.

[0076] In addition to setting the number of trials N, various settings may be made, for example, suitable for recognizing the transparent QR code 10. Here, the various settings are, for example, settings of the resolution and the zoom magnification of the camera 22.

[0077] In the next step 102, the function of the camera 22 is used to measure the environment in which the transparent QR code 10 is read, in other words, the illuminance around the mobile terminal device 14.

[0078] In the next step 104, the photography location determination unit 36 ​​determines whether the transparent QR code 10 was photographed indoors or outdoors, based on the illuminance measured in step 102. Note that even if the photograph is actually outdoors, it may be determined to be indoors in step 104 if the illuminance is low. Even in such a case, there is little effect of sunlight on the reading of the transparent QR code 10, so there is no problem if it is determined to be indoors. If the photography location is determined to be indoors in step 104, the process proceeds to step 106, and if the photography location is determined to be outdoors, the process proceeds to step 110.

[0079] In step 106, the guiding unit 38 performs settings for indoor image display. Indoor image display is, for example, processing for enlarging and displaying the bottom right corner of the touch panel display 20.

[0080] In the next step 108, the guiding unit 38 guides the operator to adjust the shooting distance for indoor use, and the process proceeds to step 114. The shooting distance for indoor use is, for example, 11 cm. The shooting distance for indoor use is stored in advance in the storage unit 32, and the guiding unit 38 causes the touch panel display 20 to display these values, for example.

[0081] In step 110, which is performed if it is determined in step 104 that the shooting location is outdoors, the guiding unit 38 sets the image display for outdoors. The image display for indoors is, for example, a process of enlarging and displaying the upper left corner of the touch panel display 20.

[0082] In the next step 116, the guiding unit 38 guides the operator to adjust the shooting distance for outdoor use, and the process proceeds to step 114. The shooting distance for outdoor use is, for example, 6 cm. The shooting distance for outdoor use is stored in advance in the storage unit 32, and the guiding unit 38 causes these values ​​to be displayed on the touch panel display 20, for example.

[0083] In step 114, the QR code recognition unit 34 sets the trial number n to one.

[0084] In the next step 116 , the QR code recognition unit 34 performs recognition processing of the transparent QR code 10 from the image captured by the camera 22 .

[0085] In the next step 118, the QR code recognition unit 34 judges whether or not the recognition process of the transparent QR code 10 has been successful. If the judgment is affirmative, the transparent QR code reading process ends. If the judgment is negative, the process proceeds to step 120.

[0086] In step 120, the QR code recognition unit 34 determines whether the trial number n is less than the number of trials N or not, and if the determination is affirmative, the process proceeds to step 124. On the other hand, if the determination is negative, the process proceeds to step 122.

[0087] In step 122, the QR code recognition unit 34 increments the trial number n by one, and then the process proceeds to step 116, where the QR code recognition unit 34 repeats the recognition process.

[0088] In step 124, the QR code recognition unit 34 determines the distortion of the transparent QR code 10 photographed by the camera 22. If the distortion is small, the process proceeds to step 126. On the other hand, if the distortion is large, the process proceeds to step 128.

[0089] In step 126, the guiding unit 38 guides the operator to increase the shooting angle, and the process returns to step 114. The guiding unit 38, for example, displays a message on the touch panel display 20 to prompt the operator to increase the shooting angle, or outputs the message by voice.

[0090] In step 128, the guiding unit 38 guides the operator to reduce the imaging angle, and the process returns to step 114. For example, the guiding unit 38 causes the touch panel display 20 to display a message for prompting the operator to reduce the imaging angle, or outputs the message by voice.

[0091] When the recognition of the transparent QR code 10 fails, the guiding unit 38 may guide the operator to make other adjustments, such as adjusting the shooting distance, in addition to adjusting the shooting angle.

[0092] As another example of adjustment, the guidance process executed by the guidance unit 38 guides the photographer's shooting direction so that the transparent QR code 10 is not illuminated by sunlight when the transparent QR code 10 is photographed outdoors and the transparent QR code 10 is not recognized even though it is photographed. When the transparent QR code 10 is photographed outdoors, it is affected by the infrared rays contained in the sunlight, as described above. For this reason, when the transparent QR code 10 is not recognized during photography outdoors, the influence of the sunlight may be large. Therefore, the operator's shooting direction is guided to reduce the influence of the infrared light contained in the sunlight.

[0093] 6 shows the flow of the above-mentioned guidance process. First, after step 120 shown in FIG.

[0094] In the next step 200, the photography location determination unit 36 ​​determines whether the photography location of the transparent QR code 10 is indoors or outdoors, based on the illuminance measured in step 102. If the photography location is determined to be indoors in step 200, the process returns to step 114, and if the photography location is determined to be outdoors, the process proceeds to step 202.

[0095] In step 202, the guiding unit 38 guides the photographer to change the shooting orientation, and the process returns to step 114. The guiding unit 38, for example, causes the touch panel display 20 to display a message for the operator to change the orientation with respect to the sun, or outputs it as voice. For this orientation, for example, an appropriate body orientation of the photographer to reduce the effect of sunlight is calculated based on GPS information, latitude and longitude information, and time information, and is displayed on the touch panel display 20. Furthermore, without being limited to this, a message such as "Please change the orientation of your body with respect to the sun" may be displayed or output as voice, without calculating an appropriate body orientation of the photographer.

[0096] As described above, the mobile terminal device 14 of this embodiment is a QR code reader that reads the transparent QR code 10, which cannot be seen with visible light, by illuminating it with light of a predetermined wavelength other than visible light. In the mobile terminal device 14, the guidance unit 38 guides the operator in performing a photographing operation to perform photographing that reduces the effects of infrared light, and the camera 22 photographs the transparent QR code 10 while the infrared light irradiating unit 24 irradiates infrared light, thereby reading the transparent QR code 10. In this way, the mobile terminal device 14 of this embodiment can read the transparent QR code 10.

[0097] Although the present invention has been described above using the above embodiment, the technical scope of the present invention is not limited to the scope described in the above embodiment. Various modifications or improvements can be made to the above embodiment without departing from the gist of the invention, and the forms with such modifications or improvements are also included in the technical scope of the present invention.

[0098] In the above embodiment, the portable terminal device 14 is provided with the infrared light emitting unit 24 that emits infrared light, but the present invention is not limited to this. The infrared light emitting unit 24 may not be directly provided in the portable terminal device 14, and may have a different configuration from the portable terminal device 14.

[0099] In the above embodiment, the transparent QR code 10 is read by infrared light, but the present invention is not limited to this. If the transparent QR code 10 can be read by light with a wavelength other than visible light, it may be read by light other than infrared light, for example, light with a wavelength in the ultraviolet region (ultraviolet light). Ultraviolet light is also contained in sunlight, and has the same problems as infrared light. [Explanation of symbols]

[0100] 10···Transparent QR code, 14···Mobile terminal device, 20···Touch panel display, 22 camera, 24 infrared irradiation unit, 36 shooting location determination unit, 38 guidance unit

Claims

1. An information code reader (14) for reading an information code (10) that cannot be seen with visible light by illuminating it with light of a predetermined wavelength other than visible light, comprising: An imaging unit (22) for imaging a subject; an irradiation unit (24) that irradiates light of the predetermined wavelength; a guidance unit (38) that guides an operator in performing a photographing operation so as to perform photographing that reduces the influence of light of the predetermined wavelength when photographing the information code by the photographing unit; An information code reading device comprising:

2. 2 . The information code reading device according to claim 1 , wherein the guiding unit guides an operator in a photographing operation so that a photographing position of the information code by the photographing unit is a predetermined position based on a positional relationship between the photographing unit and the irradiating unit.

3. A display unit (20) is provided for displaying an image captured by the imaging unit, the guiding unit causes the display unit to enlarge and display a partial area of ​​the image captured by the photographing unit so that the photographing position of the information code by the photographing unit coincides with the predetermined position.

3. An information code reader according to claim 2.

4. A location determination unit (36) is provided for determining whether the location where the information code was photographed is indoors or outdoors, The guidance unit guides the operator in a photographing operation based on a result of the determination by the location determination unit.

3. An information code reading device according to claim 1 or 2.

5. 5. The information code reading device according to claim 4, wherein the guiding unit guides the operator in a photographing operation so that the photographing position of the information code by the photographing unit is a predetermined position based on a result of the determination by the location determining unit.

6. 5. The information code reading device according to claim 4, wherein the guiding unit guides the operator in the photographing operation so that the distance between the information code and the photographing unit is a distance based on a result of the determination by the location determining unit.

7. 7. The information code reader according to claim 6, wherein the distance is shorter when the image of the information code is captured outdoors than when the image is captured indoors.

8. 3. The information code reading device according to claim 1, wherein the guiding section guides an operator in a photographing operation so as to adjust an angle between the photographing section and the information code.

9. 9. The information code reading device according to claim 8, wherein the guidance unit guides an operator in a photographing operation so as to increase the angle when a distortion of the information code photographed by the photographing unit is relatively small, and to decrease the angle when the distortion is relatively large.

10. The information code reading device according to claim 2, wherein the guidance unit guides the photographer in a photographing direction so that sunlight does not illuminate the information code when the photographing location of the information code is outdoors and the information code is not recognized despite being photographed.

11. An information code reading method for reading an information code that cannot be seen by visible light by illuminating the code with light of a predetermined wavelength other than visible light, comprising the steps of: a guidance unit guides an operator in a photographing operation so as to perform photographing that reduces the influence of the light of the predetermined wavelength; an imaging unit captures an image of the information code while an irradiation unit irradiates the information code with light of the predetermined wavelength, thereby reading the information code;

12. An information code reading program included in an information code reading device that reads an information code that cannot be seen by visible light by illuminating the information code with light of a predetermined wavelength other than visible light, comprising: Computer, a guidance unit that guides an operator in performing a photographing operation so as to perform photographing that reduces the influence of light of the predetermined wavelength when photographing the information code by an imaging unit that photographs a subject; An information code reading program to function as a

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