Display control program, display control device, and display control method

Abstract

This program causes a display control device (10) to function as: a display control unit (102) that causes a display unit (15) of the display control device (10) to display a code screen including a code; and an optical information acquisition unit (103) that, when the code screen is displayed on the display unit (15), acquires optical information relating to light incident on the display control device (10). The display control unit (102) changes display of the code screen on the basis of the optical information.

Description

Display control program, display control device, and display control method

[0001] The present disclosure relates to a program, a display control device, and a display control method.

[0002] Conventionally, there is known a technology for displaying a code screen including a code such as a barcode or a two-dimensional code on a display unit of a display control device. For example, Patent Document 1 describes an information code reading system in which, when a display change instruction is acquired from a payment device by decoding an instruction code captured by an imaging unit in a mobile terminal, the display unit is controlled by a control unit to change the display state of a payment code in accordance with the display change instruction.

[0003] Publication No. 2019-061427

[0004] However, with the technology of Patent Document 1, in order for the mobile terminal to change the display state of the payment code, the reading device must issue a display change instruction, which does not sufficiently improve user convenience. This point is not limited to payment codes as in Patent Document 1. The same applies when the code screen is used for purposes other than payment. Conventional technologies have not been able to sufficiently improve user convenience when the code screen is displayed.

[0005] One of the objectives of the present disclosure is to improve user convenience.

[0006] The program of the present disclosure causes the display control device to function as a display control unit that displays a code screen including a code on the display unit of the display control device, and as a light information acquisition unit that acquires light information regarding light to the display control device when the code screen is displayed on the display unit, and the display control unit changes the display of the code screen based on the light information.

[0007] According to the present disclosure, convenience for users is improved.

[0008] 1 is a diagram illustrating an example of the hardware configuration of a display control system. FIG. 1 is a diagram illustrating an example of how a user uses a payment service. FIG. 2 is a diagram illustrating an example of how the attitude of the display control device changes when a code is read. FIG. 3 is a diagram illustrating an example of a code screen in which the size of the code is dynamically changed based on the attitude of the display control device. FIG. 4 is a diagram illustrating an example of a function implemented in the first embodiment. FIG. 5 is a diagram illustrating an example of attitude information. FIG. 6 is a diagram illustrating an example of a process executed in the first embodiment. FIG. 7 is a diagram illustrating an example of a function implemented in a modified example of the first embodiment. FIG. 8 is a diagram illustrating an example of a change in the attitude of the display control device when a code is read. FIG. 9 is a diagram illustrating an example of a reference attitude. FIG. 10 is a diagram illustrating an example of upper content and lower content. FIG. 11 is a diagram illustrating an example of a code screen in which the brightness changes depending on the attitude of the display control device. FIG. 12 is a diagram illustrating an example of how the size of the code is repeatedly changed. FIG. 13 is a diagram illustrating an example of a function implemented in a modified example of the second embodiment.

[0009] [1. First Embodiment] A first embodiment, which is an example of an embodiment of a program, a display control device, and a display control method according to the present disclosure, will be described. In the first embodiment, a display control system including a display control device and another device will be exemplified.

[0010] [1-1. Hardware Configuration of Display Control System] Fig. 1 is a diagram showing an example of the hardware configuration of a display control system. For example, the display control system 1 includes a display control device 10, a reading device 20, and a server 30. Each of the display control device 10, the reading device 20, and the server 30 is connected to a network N such as the Internet or a LAN. Although Fig. 1 shows one each of the display control device 10, the reading device 20, and the server 30, there may be multiple units of at least one of the display control device 10, the reading device 20, and the server 30.

[0011] The display control device 10 is a device that controls the display of a code screen, which will be described later. For example, the display control device 10 is a smartphone, a mobile phone not classified as a smartphone, a tablet, a wearable terminal, a handheld terminal, or a personal computer. The display control device 10 may be a portable device not classified as any of these. The display control device 10 may also be a non-portable device. In the first embodiment, the display control device 10 may be a device whose posture can be changed.

[0012] For example, the display control device 10 includes a control unit 11, a storage unit 12, a communication unit 13, an operation unit 14, a display unit 15, a sensor unit 16, and an imaging unit 17. The control unit 11 includes at least one processor. The storage unit 12 includes at least one of a volatile memory such as a RAM and a non-volatile memory such as a flash memory. The communication unit 13 includes at least one of a communication interface for wired communication and a communication interface for wireless communication. The operation unit 14 is an input device such as a touch panel or a mouse. The display unit 15 is a display such as a liquid crystal display or an organic electroluminescence display.

[0013] For example, the sensor unit 16 includes at least one sensor. In the first embodiment, the sensor unit 16 includes a sensor used to detect the attitude of the display control device 10. The sensor used to detect the attitude of the display control device 10 may be a known sensor. For example, the sensor unit 16 may include an acceleration sensor, a gyro sensor, a geomagnetic sensor, an angle sensor, or a combination of these. The sensor unit 16 may include a sensor called a motion sensor that includes multiple sensors. The sensor unit 16 may also include other sensors that are not used to detect the attitude of the display control device 10.

[0014] For example, the photographing unit 17 includes at least one camera. The photographing unit 17 may include at least one of an in-camera and an out-camera. The in-camera is a camera arranged on the same surface of the display control device 10 as the surface on which the display unit 15 is arranged. The out-camera is a camera arranged on the surface of the display control device 10 opposite the surface on which the display unit 15 is arranged. In the first embodiment, an example is given in which the photographing unit 17 has a different configuration from the sensor unit 16, but because the optical element included in the photographing unit 17 is also a type of sensor, the photographing unit 17 may be part of the sensor unit 16.

[0015] The reading device 20 is a device that reads the code described below. For example, the reading device 20 is a POS terminal, a self-checkout terminal, a smartphone, a mobile phone not classified as a smartphone, a tablet, a wearable terminal, a handheld terminal, an ATM, an automatic ticket gate, or a personal computer. For example, the reading device 20 includes a control unit 21, a memory unit 22, a communication unit 23, an operation unit 24, a display unit 25, and a reading unit 26. The hardware configurations of the control unit 21, the memory unit 22, the communication unit 23, the operation unit 24, and the display unit 25 may be similar to those of the control unit 11, the memory unit 12, the communication unit 13, the operation unit 14, and the display unit 15, respectively.

[0016] For example, the reading unit 26 includes at least one code reader. The reading unit 26 may include a known code reader. For example, the reading unit 26 may include a barcode reader, a two-dimensional code reader, a camera, a scanner, or a combination thereof. In the first embodiment, an example is given in which the reading unit 26 is included in the reading device 20, but the reading unit 26 may be connected to the outside of the reading device 20. The reading device 20 may include only the reading unit 26, without including the control unit 21, the memory unit 22, the communication unit 23, the operation unit 24, and the display unit 25.

[0017] The server 30 is a server computer. For example, the server 30 includes a control unit 31, a storage unit 32, and a communication unit 33. The hardware configurations of the control unit 31, the storage unit 32, and the communication unit 33 may be similar to those of the control unit 11, the storage unit 12, and the communication unit 13, respectively.

[0018] The programs stored in the storage units 12, 22, and 32 may be supplied to the display control device 10, the reading device 20, or the server 30 via the network N. Also, at least one of a reading unit (e.g., a memory card slot) that reads a computer-readable information storage medium and an input / output unit (e.g., a USB port) that inputs and outputs data to and from an external device may be included in the display control device 10, the reading device 20, or the server 30. For example, a program stored in an information storage medium may be supplied to the display control device 10, the reading device 20, or the server 30 via at least one of the reading unit and the input / output unit.

[0019] Furthermore, the display control system 1 only needs to include at least one computer. The computers included in the display control system 1 are not limited to the example of FIG. 1. For example, the display control system 1 may include only the display control device 10 and the reading device 20. In this case, the server 30 exists outside the display control system 1. The display control system 1 may include only the display control device 10 and the server 30. In this case, the reading device 20 exists outside the display control system 1. The display control system 1 may include only the display control device 10. In this case, the reading device 20 and the server 30 exist outside the display control system 1. For example, the display control system 1 may include the display control device 10 and another computer not shown in FIG. 1.

[0020] [1-2. Overview of the First Embodiment] In the first embodiment, an example is given in which the display control system 1 is used for a payment service. A payment service is a service that provides electronic payments (cashless payments) to users. The display control system 1 may be used for services other than payment services. Services in which the display control system 1 is used are not limited to payment services. The display control system 1 may be used for services in which codes are used in some form. For example, the display control system 1 may be used for an electronic ticket service, a coupon distribution service, an entrance / exit management service, a check-in service, a communication service, a financial service, a travel reservation service, an e-commerce service, a public transportation service, an administrative service, or other services.

[0021] In the first embodiment, a case is taken as an example in which a smartphone of a user who uses a payment service corresponds to the display control device 10. For example, a payment app, which is an application for the payment service, is pre-installed on the display control device 10. The payment app is an example of a program related to the present disclosure. The display control device 10 controls the display of various screens in the payment service based on the payment app. The display control device 10 may control the display of various screens based on another program, such as a browser (for example, a script embedded in HTML, an application other than the payment service, or an operating system), rather than the payment app.

[0022] 2 is a diagram showing an example of how a user uses a payment service. For example, when a user launches a payment app installed on the display control device 10, the display control device 10 communicates with the server 30 and executes a login process for the user to log in to the payment service. If the login process is successful, the display control device 10 communicates with the server 30 and causes the display unit 15 to display a code screen SC including a code C generated based on information required for payment (e.g., a code ID that can temporarily identify the user).

[0023] In the first embodiment, an example is given in which code C includes both a barcode and a two-dimensional code, but code C may be only a barcode, or only a two-dimensional code. That is, the code screen SC may include both a barcode and a two-dimensional code, or may include only either a barcode or a two-dimensional code. Code C may be a known code. When a code that is not classified as a barcode or a two-dimensional code (for example, a code whose appearance changes over time) is used, code C may be another code.

[0024] It should be noted that code C can be used for any purpose. In the example of FIG. 2 , code C is used for payment based on a payment source designated by a user, but code C may also be used for other purposes. For example, code C may be used as a points card, for charging electronic money, for identifying coupons, for a user to check in at a predetermined location, or as identification such as a membership card. When the display control device 10 is used for a service other than a payment service, code C may be used for any purpose in the other service.

[0025] FIG. 3 is a diagram showing an example of the change in the attitude of the display control device 10 when reading the code C. Details of the code screen SC are omitted from FIG. 3 . In the first embodiment, an example is given of a case where a user uses a payment service to pay for goods or services at a store affiliated with the payment service. In the example of FIG. 3 , the user is positioned to the left of the display control device 10. A store clerk is positioned to the right of the display control device 10. As shown in the upper part of FIG. 3 , the user holds the display control device 10 in an attitude such that the display unit 15 of the display control device 10 faces the user. While maintaining the attitude of the display control device 10, the user starts the payment app and confirms that the code screen SC is displayed on the display unit 15.

[0026] For example, when the user confirms that the code screen SC is displayed on the display unit 15, the user changes the orientation of the display control device 10 so that the display unit 15 of the display control device 10 faces the store clerk, as shown in the lower part of Fig. 3, and presents the code screen SC to the store clerk. The store clerk reads the code C on the code screen SC displayed on the display unit 15 facing toward them with the reading unit 26. Once the code C is read, the reading device 20 communicates with the server 30 and executes the payment. The payment flow using the code C may be similar to that of known payment services.

[0027] For example, as shown in the upper part of Fig. 3, when the user launches the payment app and checks the display of the code screen SC, if the code C is too large, visibility may be reduced. On the other hand, as shown in the lower part of Fig. 3, when the user presents the code screen SC to a store clerk, the larger the code C, the easier it may be for the reading unit 26 to read the code C. Therefore, in the first embodiment, the display control device 10 dynamically changes the size of the code C based on its own posture.

[0028] 4 is a diagram showing an example of a code screen SC in which the size of the code C is dynamically changed based on the orientation of the display control device 10. The code screen SC on the left side of FIG. 4 is an example of the code screen SC when the display control device 10 is in the orientation shown in the upper part of FIG. 3. As shown on the left side of FIG. 4, the display control device 10 displays the code C so that a certain amount of white space is left, rather than displaying the code C to the full width of the display unit 15. This improves user visibility. For example, it becomes easier for the user to check not only the code C but also other parts of the code screen SC.

[0029] The code screen SC on the right side of Fig. 4 is an example of the code screen SC when the display control device 10 is in the lower position of Fig. 3. As shown on the right side of Fig. 4, the display control device 10 changes the size of the code C so that the code C is displayed across the entire width of the display unit 15. In the example on the right side of Fig. 4, the barcode of the code C fills the entire width of the display unit 15, but the two-dimensional code of the code C may also fill the entire width of the display unit 15. In the state on the right side of Fig. 4, the user's visibility is slightly reduced, but because this is the stage at which the user presents the code C, readability of the code C is prioritized. Because the code C is displayed large, the reading unit 26 can more easily read the code C.

[0030] When reading of code C is completed, the display control device 10 may return code C to its original size (the size on the left side of FIG. 4). If reading of code C is not completed and the user returns the orientation of the display control device 10 to the upper orientation of FIG. 3, the display control device 10 may return code C to its original size (the size on the left side of FIG. 4). If the user subsequently returns the orientation of the display control device 10 to the lower orientation of FIG. 3 again, the display control device 10 may enlarge code C again.

[0031] As described above, the display control device 10 of the first embodiment controls the display of the code screen SC so that the size of the code C changes based on its own posture. For example, when the display control device 10 is in a posture in which the display unit 15 faces the user, the display control device 10 does not display the code C as large, thereby improving the visibility of the code screen SC. When the display control device 10 is in a posture in which the user is presenting the code C, the display control device 10 enlarges the code C in preparation for reading. This allows the display control device 10 to improve user convenience. Details of the display control system 1 of the first embodiment will be described below.

[0032] [1-3. Functions Realized in the First Embodiment] FIG. 5 is a diagram showing an example of functions realized in the first embodiment.

[0033] [1-3-1. Functions Realized by the Display Control Device] For example, the display control device 10 includes a data storage unit 100, a posture information acquisition unit 101, and a display control unit 102. The data storage unit 100 is realized by the storage unit 12. The posture information acquisition unit 101 and the display control unit 102 are each realized by the control unit 11.

[0034] [Data Storage Unit] The data storage unit 100 stores data necessary for displaying the code screen SC. For example, the data storage unit 100 stores a payment app. The payment app causes the display control device 10 to function as the posture information acquisition unit 101 and the display control unit 102. When a user uses a payment service from another program, such as a browser, rather than the payment app, the data storage unit 100 stores the other program. The other program causes the display control device 10 to function as the posture information acquisition unit 101 and the display control unit 102.

[0035] [Orientation Information Acquisition Unit] The orientation information acquisition unit 101 acquires orientation information related to the orientation of the display control device 10 when the code screen SC is displayed on the display unit 15. The orientation of the display control device 10 is at least one of the tilt and orientation of the display control device 10. Both the tilt and orientation of the display control device 10 may correspond to the orientation of the display control device 10, or only one of the tilt or orientation of the display control device 10 may correspond to the orientation of the display control device 10. Note that the orientation information acquisition unit 101 may acquire orientation information before the code screen SC is displayed on the display unit 15.

[0036] For example, when the display control device 10 is integrated with the display unit 15, the attitude of the display control device 10 can also be said to be the attitude of the display unit 15. When the display control device 10 is not integrated with the display unit 15 (for example, when the main body of the display control device 10 and the display unit 15 are connected by a cable), the attitude of the display control device 10 is the attitude of the display unit 15, which is one of the components of the display control device 10.

[0037] In the first embodiment, an example is given in which the orientation information acquisition unit 101 acquires, as orientation information, tilt information related to the tilt of the display control device 10. The tilt of the display control device 10 is the difference between a reference axis (e.g., vertical or horizontal direction) or plane (e.g., vertical plane or horizontal plane) in space and a reference axis (e.g., longitudinal or lateral direction) or plane (e.g., the surface of the display unit 15) in the display control device 10. For example, the tilt of the display control device 10 is the angle formed between these.

[0038] The orientation information acquisition unit 101 may acquire, as the orientation information, orientation information regarding the orientation of the display control device 10. The orientation of the display control device 10 is the direction in which the surface of the display control device 10 faces (for example, the direction of a perpendicular line with an arbitrary position on the surface as the foot of the perpendicular line). For example, the direction of a perpendicular line with an arbitrary position on the surface of the display unit 15 (for example, the position of the center of the display unit 15) as the foot of the perpendicular line is the orientation of the display control device 10. The orientation information acquisition unit 101 may acquire both tilt information and orientation information as the orientation information.

[0039] FIG. 6 is a diagram illustrating an example of attitude information. In the first embodiment, an example is given in which attitude information is expressed by Euler angles. Euler angles are angles that indicate the tilt of the display control device 10. For example, the attitude information indicates a roll angle θX (a rotation angle around the X axis), a pitch angle θY (a rotation angle around the Y axis), and a yaw angle θZ (a rotation angle around the Z axis). The X axis, the Y axis, and the Z axis are sometimes called the roll axis, the pitch axis, and the yaw axis, respectively. For example, when attitude information is expressed by Euler angles, tilt information is expressed by the roll angle θX and the pitch angle θY. Orientation information is expressed by the yaw angle θZ.

[0040] The method for acquiring the orientation information may be a known method. The orientation information acquisition unit 101 may acquire the orientation information based on a known algorithm. When tilt information is acquired as the orientation information, the method for acquiring the tilt information may be a known method. The orientation information acquisition unit 101 may acquire the tilt information based on a known algorithm. For example, the orientation information acquisition unit 101 may acquire the orientation information based on a detection signal from the sensor unit 16. The orientation information acquisition unit 101 may calculate a gravity vector of the display control device 10 based on an acceleration sensor included in the sensor unit 16, and acquire the orientation information based on the gravity vector. The orientation information acquisition unit 101 may calculate an angular velocity of the display control device 10 based on a gyro sensor included in the sensor unit 16, and acquire the orientation information based on the angular velocity. The orientation information acquisition unit 101 may acquire the orientation information by integrating information obtained from multiple sensors included in the sensor unit 16.

[0041] For example, the posture information acquisition unit 101 may acquire posture information at each of a plurality of time points. The posture information acquisition unit 101 acquires the latest posture information at predetermined time intervals based on the latest detection signal of the sensor unit 16. In other words, the posture information acquisition unit 101 periodically acquires the latest posture information. The posture information acquisition unit 101 may record a history of posture information in the data storage unit 100. The posture information acquisition unit 101 may acquire the latest posture information irregularly rather than periodically. The posture information acquisition unit 101 may acquire posture information at least when the code screen SC is displayed. The posture information acquisition unit 101 may also acquire posture information when the code screen SC is not displayed.

[0042] Note that the attitude information does not need to indicate all of the roll angle θX, pitch angle θY, and yaw angle θZ, and may indicate only one or two of the roll angle θX, pitch angle θY, and yaw angle θZ. For example, when the attitude information acquisition unit 101 acquires only tilt information as attitude information, it may calculate only the roll angle θX and pitch angle θY, but not the yaw angle θZ. When the attitude information acquisition unit 101 acquires only orientation information as attitude information without acquiring tilt information as attitude information, it may calculate only the yaw angle θZ, but not at least one of the roll angle θX and the pitch angle θY.

[0043] Furthermore, the attitude information may be publicly known information. The attitude information is not limited to Euler angles. For example, the attitude information may be expressed in a quaternion in which the attitude is expressed by four real numbers, a rotation matrix in which the attitude is expressed by a 3×3 matrix, an axis-angle representation in which a rotation angle is expressed by a unit vector in three-dimensional space, a direction cosine matrix in which the rotation of a coordinate system in three-dimensional space is expressed, a direction angle in which the attitude is expressed by the angle between two vectors, or another format. The attitude information acquisition unit 101 may acquire the attitude information using an acquisition method according to the format used as the attitude information.

[0044] [Display control unit] The display control unit 102 displays a code screen SC including a code C on the display unit 15 of the display control device 10. For example, when the payment app is launched, the display control device 10 communicates with the server 30 and acquires information (e.g., a code ID) necessary for displaying the code C. The information necessary for displaying the code C is information to be coded. The display control unit 102 generates the code C based on the information necessary for displaying the code C. If the information necessary for displaying the code C is stored in the data storage unit 100 in advance, the display control device 10 does not particularly communicate with the server 30, and the display control unit 102 generates the code C.

[0045] The method for generating the code C may be a method defined by a known standard. The type of the code C may also be a known type. For example, the display control unit 102 executes a series of processes required to display the code screen SC by executing a payment app. The series of processes is indicated in the program code of the payment app. When a program other than the payment app is used, the series of processes is indicated in the program code of the other program.

[0046] In the first embodiment, the display control unit 102 changes the display of the code screen SC based on the posture information. Changing the display of the code screen SC by the display control unit 102 means that the display control unit 102 changes the display of at least a part of the code screen SC. In other words, performing control by the display control unit 102 to change the content that is visually recognizable by humans corresponds to changing the display of the code screen SC by the display control unit 102.

[0047] For example, changing the size, brightness, color, pattern, blinking or other effects, display position, orientation, image type, or a combination thereof of the components of the code screen SC corresponds to a change in display. The components of the code screen SC are objects displayed on the code screen SC. For example, the components of the code screen SC may be code C, images other than code C, text, user interface parts, or other elements. As in the modified example described below, changing the brightness of the code screen SC itself also corresponds to a change in display.

[0048] In the first embodiment, the display control unit 102 changes the display of the code screen SC by changing the size of the code C on the code screen SC, but the display control unit 102 may also change the display of the code screen SC by changing the brightness of the code screen SC, the color of the code C, the background color of the code screen SC, the pattern of the code screen SC, the effect of the code C, the orientation of the code C, the type of code C, or a combination of these.

[0049] For example, the display control unit 102 determines whether the posture indicated by the posture information is a predetermined posture, and changes the display of the code screen SC based on the result of the determination. The predetermined posture is a posture that serves as a reference for determining whether the display of the code screen SC is changed. If the display control unit 102 determines that the posture indicated by the posture information is not the predetermined posture, it does not change the display of the code screen SC, and if it determines that the posture indicated by the posture information is the predetermined posture, it changes the display of the code screen SC. In other words, the display control unit 102 changes the display of the code screen SC on the condition (trigger) that the posture indicated by the posture information is determined to be the predetermined posture.

[0050] For example, when the posture information indicates a first posture, the display control unit 102 displays the code screen SC in a first display method. The display control unit 102 determines whether the display control device 10 has changed from the first posture to a second posture based on the posture information. When it is determined that the display control device 10 has changed from the first posture to the second posture, the display control unit 102 displays the code screen SC in the second display method. When it is determined that the display control device 10 has returned from the second posture to the first posture, the display control unit 102 may return the code screen SC to the first display method.

[0051] The first and second orientations may be defined in the payment app or in setting data referenced by the payment app. The setting data is assumed to be stored in the data storage unit 100. The display control unit 102 determines whether the display control device 10 is in the first orientation or the second orientation based on at least one of the payment app and the setting data. Similarly, the first and second display methods may be defined in the payment app or in setting data referenced by the payment app. The display control unit 102 may control the display method of the code screen SC based on at least one of the payment app and the setting data.

[0052] In the examples of Figures 3 and 4, the orientation at the top of Figure 3 corresponds to the first orientation. The orientation at the bottom of Figure 3 corresponds to the second orientation. For example, when tilt information is acquired as orientation information, the display control unit 102 changes the display of the code screen SC based on the tilt information. As shown in Figure 6, the display control unit 102 calculates the angle θXY between the horizontal plane (X-Y plane) and the longitudinal direction of the display control device 10 based on the roll angle θX and pitch angle θY indicated by the tilt information. The angle θXY is an example of tilt. Therefore, any reference to the angle θXY can be interpreted as tilt. Any tilt other than the angle θXY may be used as the tilt. The tilt may be represented in a form other than an angle (for example, a vector or coordinates).

[0053] For example, if the angle θXY is positive, the display control unit 102 determines that the display control device 10 is in the first orientation. When it is determined that the display control device 10 is in the first orientation, the display control unit 102 causes the display unit 15 to display a code screen SC including a code C of a first size, as shown on the left side of Fig. 4. When the angle θXY is negative, the display control unit 102 determines that the display control device 10 is in the second orientation. When it is determined that the display control device 10 is in the second orientation, the display control unit 102 causes the display unit 15 to display a code screen SC including a code C of a second size that is larger than the first size, as shown on the right side of Fig. 4.

[0054] The threshold value for determining the first attitude and the second attitude may be any value. In the above example, the threshold value is 0, but the threshold value may be a positive or negative value. The threshold value is assumed to be stored in the data storage unit 100. For example, if the threshold value is -10 degrees, the display control unit 102 may determine that the display control device 10 has assumed the second attitude when the angle θXY in FIG. 6 becomes less than -10 degrees. The threshold value is assumed to be stored in the data storage unit 100.

[0055] Furthermore, the method by which the display control unit 102 changes the size of the code C may be a known method. For example, the display control unit 102 may change the size of the code C by executing image processing to stretch the image. If a parameter indicating the size of the code C is stored in the data storage unit 100, the display control unit 102 may change the size of the code C by changing the parameter. The extent to which the display control unit 102 increases the size of the code C is assumed to be indicated in the payment app or the setting data described above. If codes C of multiple sizes are prepared in advance as separate images, the display control unit 102 may change the size of the code C by switching the code C to be displayed. Furthermore, the display control unit 102 may reduce the size of the code C, rather than increasing the size, based on posture information.

[0056] [1-3-2. Functions Realized by the Reading Device] For example, the reading device 20 includes a data storage unit 200 and a processing execution unit 201. The data storage unit 200 is realized by the storage unit 22. The processing execution unit 201 is realized by the control unit 21.

[0057] [Data Storage Unit] The data storage unit 200 stores data necessary for reading the code C. For example, the data storage unit 200 stores a store app, which is a program for stores that are members of a payment service. The store app causes the reading device 20 to function as the processing execution unit 201. When a store uses the payment service from another program, such as a browser, rather than the store app, the data storage unit 200 stores the other program. The other program causes the reading device 20 to function as the processing execution unit 201.

[0058] [Processing Execution Unit] The processing execution unit 201 executes a predetermined process when the code C is read. The predetermined process is a process that is executed based on information extracted from the code C. In the first embodiment, the display control system 1 is used for a payment service, so the predetermined process is a process for payment. For example, the processing execution unit 201 executes the predetermined process by extracting a code ID from the code C and sending a payment request including the code ID to the server 30. The payment request is a request for payment. The payment request may be in the same format as data used in known payment services. For example, the payment request may include the payment amount, the store ID, or other information.

[0059] The predetermined process is not limited to a process for payment. The predetermined process may be a process corresponding to the service for which the display control system 1 is used. For example, when the display control system 1 is used for an electronic ticket service, the process execution unit 201 acquires, from the code C, an electronic ticket ID for a user to enter a facility using an electronic ticket. The process execution unit 201 may execute the predetermined process by sending an authentication request including the electronic ticket ID to the server 30. The authentication request is a request for verifying the validity of the electronic ticket ID. When the process execution unit 201 receives information indicating the authentication result of the electronic ticket ID from the server 30, the process execution unit 201 displays the authentication result on the display unit 25.

[0060] For example, when the display control system 1 is used for a coupon distribution service, the processing execution unit 201 obtains the coupon ID of a coupon held by the user from the code C. The processing execution unit 201 may execute predetermined processing by transmitting a usage request including the coupon ID to the server 30. The usage request is a request for coupon usage. When the processing execution unit 201 receives information from the server 30 indicating that coupon usage is permitted, the processing execution unit 201 applies the coupon to a product or service for which the user pays. When the display control system 1 is used for another service, the processing execution unit 201 may execute predetermined processing according to the other service.

[0061] [1-3-3. Functions Realized by the Server] For example, the server 30 includes a data storage unit 300 and a process execution unit 301. The data storage unit 300 is realized by the storage unit 32. The process execution unit 301 is realized by the control unit 31.

[0062] [Data Storage Unit] The data storage unit 300 stores data necessary for a predetermined process. For example, the data storage unit 300 stores a user database that stores various information about users who use payment services. For example, the user database stores user IDs, passwords, code IDs, payment method information about the payment methods used by the user in the payment service, and usage history information about the user's usage history of the payment service. The server 30 issues a code ID based on predetermined issuance rules so that the code ID does not overlap with other code IDs. If a process other than payment is executed as the predetermined process, the data storage unit 300 only needs to store data necessary for the other process. For example, the data storage unit 300 may store data for electronic tickets or coupons.

[0063] [Processing Execution Unit] The processing execution unit 301 executes a predetermined process when the code C is read. The processing execution unit 301 differs in that the predetermined process executed by the processing execution unit 201 is a process on the reading device 20 side, while the processing executed by the processing execution unit 301 is a process on the server 30 side; however, other aspects may be the same as the process described for the processing execution unit 201. For example, upon receiving a payment request from the reading device 20, the processing execution unit 301 executes the predetermined process by executing payment based on information such as a code ID included in the payment request. The processing execution unit 301 may execute authentication in an electronic ticket service, permission to use a coupon in a coupon distribution service, or other processing as the predetermined process. The processing execution unit 301 may execute processing according to the service for which the display control system 1 is used as the predetermined process.

[0064] [1-4. Processing Executed in First Embodiment] Fig. 7 is a diagram showing an example of processing executed in the first embodiment. Fig. 7 shows processing of the display control device 10 among the processing executed in the display control system 1. The processing of Fig. 7 is executed by the control unit 11 executing a program (e.g., a payment application) stored in the storage unit 12. Each step of Fig. 7 is an example of a step included in the display control method according to the present disclosure.

[0065] 7 , when the user selects a payment app, the display control device 10 launches the payment app (S10). The display control device 10 communicates with the server 30 and executes a login process (S11). If the login process is successful, the display control device 10 acquires a code ID from the server 30 (S12). The display control device 10 generates a code C based on the code ID acquired in S12 and displays a code screen SC on the display unit 15 (S13).

[0066] The display control device 10 acquires the orientation information based on the detection signal of the sensor unit 16 (S14). Details of the process of S14 are as described above in relation to the processing content of the orientation information acquisition unit 101. The display control unit 102 changes the display of the code screen SC based on the orientation information (S15), and this process ends. Details of the process of S15 are as described above in relation to the processing content of the display control unit 102.

[0067] [1-5. Summary of the First Embodiment] The display control device 10 of the first embodiment acquires posture information when a code screen SC is displayed on the display unit 15. The display control device 10 changes the display of the code screen SC based on the posture information. This allows the display control device 10 to flexibly display the code screen SC on the display unit 15 in accordance with the posture information, thereby improving user convenience. For example, when the display control device 10 is in a posture where it is not necessary to prepare for reading the code C, the display control device 10 can prioritize user visibility by not displaying the code C as large. When the display control device 10 is in a posture where it is necessary to prepare for reading the code C, the display control device 10 enlarges the code C to make it easier to read, thereby preventing it from taking a long time to read the code C. Because the user does not need to perform a special operation (e.g., tapping the code screen SC) to change the display of the code screen SC, the display control device 10 can reduce the operational burden on the user.

[0068] The display control device 10 also acquires tilt information related to the tilt of the display control device 10 as posture information. The display control device 10 changes the display of the code screen SC based on the tilt information. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in accordance with the tilt information, thereby improving user convenience. For example, in the case of an tilt that does not require preparation for reading the code C (e.g., an upper tilt in FIG. 3 ), the display control device 10 can prioritize user visibility by not displaying the code C as large. In the case of an tilt that requires preparation for reading the code C (e.g., a lower tilt in FIG. 3 ), the display control device 10 can increase the size of the code C to make it easier to read, thereby preventing the code C from taking a long time to read. For example, as shown in Fig. 3, when a user presents code C, the display control device 10 changes the display of the code screen SC based on the angle (e.g., 30 degrees from horizontal) at which the head of the display control device 10 (the top of the code screen SC) is lowered, thereby changing the display of the code screen SC when code C is about to be read, thereby improving user convenience. As shown in Fig. 11 described below, when a user changes the orientation of the display control device 10 so that it is in an orientation corresponding to the angle (e.g., horizontal or vertical) of the reading unit 26 and holds up code C, the display control device 10 changes the display of the code screen SC based on the orientation, thereby changing the display of the code screen SC when code C is about to be read, thereby improving user convenience.

[0069] Furthermore, the display control device 10 changes the display of the code screen SC by changing the size of the code C on the code screen SC. This allows the display control device 10 to display the code C at a flexible size according to the posture information. For example, when the posture does not require preparation for reading the code C, the code C is not displayed so large, and user visibility can be prioritized. When the posture requires preparation for reading the code C, the display control device 10 enlarges the code C to make it easier to read, thereby preventing it from taking a long time to read the code C. Because the user does not need to perform a special operation (for example, tapping the code screen SC) to change the size of the code C, the display control device 10 can reduce the operational burden on the user.

[0070] [2. Second Embodiment] Next, a second embodiment, which is different from the first embodiment, will be described. In the second embodiment, the description of the same points as in the first embodiment will be omitted. For example, the hardware configuration of the display control system 1 may be the same as in the first embodiment.

[0071] In the second embodiment, the sensor unit 16 includes a sensor capable of detecting light. For example, the sensor unit 16 includes at least one of an ambient light sensor and an optical sensor other than the ambient light sensor (e.g., a photodiode or a phototransistor). The sensor unit 16 may be an optical sensor capable of detecting the presence or absence of light having a certain brightness or higher, rather than an optical sensor capable of detecting the brightness of light. The sensor unit 16 of the second embodiment does not need to include a sensor for detecting the attitude (e.g., an acceleration sensor or a gyro sensor) described in the first embodiment.

[0072] [2-1. Overview of the Second Embodiment] In the second embodiment, as in the first embodiment, an example is taken of a case where the display control system 1 is used for a payment service. For example, as shown in the lower part of FIG. 3 , when code C is read by the reading unit 26, the shadow of the reading unit 26 may make it dark around the user's hand. The store visited by the user may itself be dark. Depending on the time of day or weather, the inside of the store may be darker than usual. In this way, the brightness around the display control device 10 differs depending on the environment when code C is read. If the light on the display control device 10 is dim (for example, if the area around the display control device 10 is dark), reading of code C may fail.

[0073] Therefore, the display control device 10 of the second embodiment improves user convenience by changing the display of the code screen SC depending on the light incident on the display control device 10 so as to reduce the likelihood of failure in reading the code C. Details of the display control system 1 of the second embodiment will be described below.

[0074] 2-2. Functions Realized in the Second Embodiment FIG. 8 is a diagram showing an example of functions realized in the second embodiment. In the second embodiment, the functions of the reading device 20 and the server 30 are the same as those in the first embodiment. Some functions of the display control device 10 are the same as those in the first embodiment. In the second embodiment, functions of the display control device 10 that are different from those in the first embodiment will be described. For example, the display control device 10 includes a data storage unit 100, a display control unit 102, and an optical information acquisition unit 103. The data storage unit 100 may be the same as that in the first embodiment.

[0075] In the second embodiment, the display control device 10 may not include the orientation information acquisition unit 101 and at least some of the functions of the display control unit 102 described in the first embodiment. The display control unit 102 of the second embodiment may not include a function for changing the display of the code screen SC based on orientation information. The display control device 10 may not even acquire orientation information. A configuration in which the display control device 10 does not include a function for changing the display of the code screen SC based on orientation information is also within the scope of the present disclosure. The display control device 10 of the second embodiment may be a device whose orientation does not change in principle. For example, the display control device 10 may be a device whose orientation is fixed.

[0076] [Light Information Acquisition Unit] The light information acquisition unit 103 acquires light information related to light to the display control device 10 when the code screen SC is displayed on the display unit 15. The light to the display control device 10 is light in the surroundings of the display control device 10. The light to the display control device 10 may include not only direct light to the display control device 10 but also light reflected by other objects such as walls. The light to the display control device 10 may include not only natural light but also light output from a light. For example, the light to the display control device 10 may be light in the environment surrounding the display control device 10. Note that the light information acquisition unit 103 may acquire light information before the code screen SC is displayed on the display unit 15.

[0077] In the second embodiment, a case where light information indicates the degree of brightness of light is taken as an example. The degree of brightness of light can also be referred to as light intensity. The degree of brightness of light is also referred to as luminance, luminous intensity, or brightness. The unit indicating the degree of brightness of light may be a known unit. For example, the degree of brightness of light may be expressed in lux, candela, nits, or other units. The degree of brightness of light may be expressed in a unique unit such as dark, normal, or bright instead of a common unit. In the second embodiment, a case where the degree of brightness of light is expressed numerically is taken as an example, but the degree of brightness of light may also be expressed in other forms such as letters or symbols.

[0078] Note that the light information may not be the degree of brightness of light, but may simply indicate whether the light is brighter than a reference value. That is, the light information may not be information that can express the degree of brightness of light in three or more levels, but may be binary information indicating whether the light is brighter than a reference value. When the light information is binary, the light information may also be information indicating whether light brighter than a reference value has been detected. For example, the light information acquisition unit 103 acquires the light information based on a detection signal from the sensor unit 16. When the sensor unit 16 includes an ambient light sensor, the light information acquisition unit 103 detects the degree of brightness of light in the environment surrounding the display control device 10 based on the ambient light sensor, and acquires light information indicating the degree of brightness of the light.

[0079] For example, the light information acquisition unit 103 may acquire light information at each of a plurality of time points. The light information acquisition unit 103 acquires the latest light information at predetermined time intervals based on the latest detection signal of the sensor unit 16. In other words, the light information acquisition unit 103 periodically acquires the latest light information. The light information acquisition unit 103 may record the history of the light information in the data storage unit 100. The light information acquisition unit 103 may acquire the latest light information irregularly rather than periodically. The light information acquisition unit 103 may acquire the light information at least when the code screen SC is displayed. The light information acquisition unit 103 may also acquire the light information when the code screen SC is not displayed.

[0080] [Display Control Unit] The display control unit 102 changes the display of the code screen SC based on the light information. In the second embodiment, as in the first embodiment, an example is given in which the display control unit 102 changes the display of the code screen SC by changing the size of the code C on the code screen SC. In the second embodiment, as in the first embodiment, the display control unit 102 may change the display of the code screen SC by changing the brightness of the code screen SC, the color of the code C, the background color of the code screen SC, the pattern of the code screen SC, the effect of the code C, the orientation of the code C, the type of code C, or a combination thereof.

[0081] For example, the display control unit 102 determines whether the light indicated by the light information is predetermined light, and changes the display of the code screen SC based on the result of the determination. The predetermined light is light that serves as a criterion for determining whether the display of the code screen SC is changed. If the display control unit 102 determines that the light indicated by the light information is not predetermined light, it does not change the display of the code screen SC, but if it determines that the light indicated by the light information is predetermined light, it changes the display of the code screen SC. In other words, the display control unit 102 changes the display of the code screen SC when the light indicated by the light information is determined to be predetermined light.

[0082] For example, when the light information indicates a first light, the display control unit 102 displays the code screen SC in the first display method. The display control unit 102 determines whether the display control device 10 has changed from the first light to the second light based on the light information. When it is determined that the display control device 10 has changed from the first light to the second light, the display control unit 102 displays the code screen SC in the second display method. When it is determined that the display control device 10 has returned from the second light to the first light, the display control unit 102 may return the code screen SC to the first display method.

[0083] The types of light that the first light and the second light are may be defined in the payment app or may be defined in setting data referenced by the payment app. The setting data is assumed to be stored in the data storage unit 100. The display control unit 102 determines whether the display control device 10 is using the first light or the second light based on at least one of the payment app and the setting data. Similarly, the types of light that the first display method and the second display method are may be defined in the payment app or may be defined in setting data referenced by the payment app. The display control unit 102 may control the display method of the code screen SC based on at least one of the payment app and the setting data.

[0084] In the examples of Figures 3 and 4, the light input to the display control device 10 in the state shown in the upper part of Figure 3 corresponds to the first light. The light input to the display control device 10 in the state shown in the lower part of Figure 3 corresponds to the second light. For example, the display control unit 102 detects a change in light based on light information at each of multiple time points and changes the display of the code screen SC based on the change in light. The display control unit 102 detects a change in light such as a darkening of the light and changes the display of the code screen SC based on the darkening of the light. When the state changes from the upper part of Figure 3 to the lower part of Figure 3, the light indicated by the light information may become darker due to the shadow of the reading unit 26. Therefore, when the display control unit 102 detects such a change in light, it changes the display of the code screen SC. In the example of Figure 4, when the light information indicates the first light, the display control unit 102 causes the display unit 15 to display the code screen SC including the code C of a first size, as shown on the left side of Figure 4. When the light information indicates the second light, the display control unit 102 causes the display unit 15 to display a code screen SC including a code C of a second size larger than the first size, as shown on the right side of Figure 4.

[0085] For example, the display control unit 102 calculates the amount of change in the degree of brightness of light based on the light information at each of multiple time points and determines whether the amount of change is equal to or greater than a threshold. If the display control unit 102 determines that the amount of change is less than the threshold, it does not change the display of the code screen SC. If the display control unit 102 determines that the amount of change is equal to or greater than the threshold, it changes the display of the code screen SC. In the example of FIG. 3 , the amount of change is the amount of decrease in the degree of brightness of light. If the brightness of light is expressed in lux, the display control unit 102 does not change the display of the code screen SC if it determines that the amount of decrease in lux is less than the threshold, but changes the display of the code screen SC if it determines that the amount of decrease in lux is equal to or greater than the threshold. In the example of FIG. 4 , if it determines that the amount of decrease in lux is less than the threshold, the display control unit 102 does not change the size of the code C, keeping it at a first size, as shown on the left side of FIG. 4 . If it determines that the amount of decrease in lux is equal to or greater than the threshold, the display control unit 102 changes the size of the code C to a second size larger than the first size, as shown on the right side of FIG. 4 . Note that the amount of change may refer to the amount of increase in the degree of brightness of light.

[0086] The display control unit 102 may determine whether the brightness of light at a certain point in time is equal to or greater than a threshold value based on light information at that point in time, rather than on the amount of change in the degree of brightness of light. The display control unit 102 may not change the display of the code screen SC when it is determined that the brightness of light at that point in time is equal to or greater than the threshold value, and may change the display of the code screen SC when it is determined that the brightness of light at that point in time is less than the threshold value. In the case where the light information is a binary value indicating whether or not light is detected, rather than the degree of brightness of light, the display control unit 102 may determine whether or not light is detected based on light information in a certain one dimension. The display control unit 102 may not change the display of the code screen SC when it is determined that light is detected, and may change the display of the code screen SC when it is determined that light is no longer detected. The display control unit 102 may change the display of the code screen SC when a state changes from one in which it is determined that light is detected to one in which it is determined that light is no longer detected.

[0087] 2-3. Processing Executed in the Second Embodiment Fig. 9 is a diagram showing an example of processing executed in the second embodiment. Fig. 9 shows processing of the display control device 10 among the processing executed in the display control system 1. The processing of Fig. 9 is executed by the control unit 11 executing a program (e.g., a payment application) stored in the storage unit 12. Each step of Fig. 9 is an example of a step included in the display control method according to the present disclosure.

[0088] 9, S20 to S23 are the same as S10 to S13, respectively. The display control device 10 acquires light information based on the detection signal of the sensor unit 16 (S24). Details of the process of S24 are as described above as the processing content of the light information acquisition unit 103. The display control unit 102 changes the display of the code screen SC based on the light information (S25), and this process ends. Details of the process of S25 are as described above as the processing content of the display control unit 102.

[0089] [2-4. Summary of the Second Embodiment] The display control device 10 of the second embodiment acquires light information when a code screen SC is displayed on the display unit 15. The display control device 10 changes the display of the code screen SC based on the light information. This allows the display control device 10 to flexibly display a code screen SC on the display unit 15 in accordance with the light information, thereby improving user convenience. For example, when the light does not need to be prepared for reading the code C, the display control device 10 can prioritize user visibility by not displaying the code C so large. As shown in FIG. 3 , when a user holds up the code C, the shadow of the reading unit 26 obscures the area around the user's hand. Therefore, when the light needs to be prepared for reading the code C, the display control device 10 enlarges the code C to make it easier to read, thereby preventing the code C from taking a long time to read. Because the user does not need to perform a special operation (e.g., tapping the code screen SC) to change the display of the code screen SC, the display control device 10 can reduce the user's operational burden.

[0090] Furthermore, the display control device 10 acquires light information at each of a plurality of time points. The display control device 10 detects changes in light based on the light information at each of the plurality of time points and changes the display of the code screen SC based on the changes in light. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in response to changes in light, thereby improving user convenience. For example, in the case of a change in light that does not require preparation for reading the code C, the display control device 10 can prioritize user visibility by not displaying the code C as large. In the case of a change in light that requires preparation for reading the code C, the display control device 10 can increase the size of the code C to make it easier to read, thereby preventing it from taking a long time to read the code C.

[0091] Furthermore, the display control device 10 detects a change in light such as a dimmer, and changes the display of the code screen SC based on the dimmer change. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in response to dimmer light, thereby improving user convenience. For example, the display control device 10 can prevent the code C from taking a long time to read by increasing the size of the code C so that it is easy to read even in dimmer light.

[0092] Furthermore, the display control device 10 changes the display of the code screen SC by changing the size of the code C on the code screen SC. This allows the display control device 10 to display the code C at a flexible size according to the light information. For example, in the case of light that does not require preparation for reading the code C, the code C is not displayed so large, and user visibility can be prioritized. In the case of light that does require preparation for reading the code C, the display control device 10 increases the size of the code C to make it easier to read, thereby preventing the code C from taking a long time to read. Because the user does not need to perform a special operation (for example, tapping the code screen SC) to change the size of the code C, the display control device 10 can reduce the operational burden on the user.

[0093] [3. Third Embodiment] Next, a third embodiment, which is different from the first and second embodiments, will be described. In the third embodiment, a description of the same points as at least one of the first and second embodiments will be omitted. For example, the hardware configuration of the display control system 1 may be the same as at least one of the first and second embodiments.

[0094] The first embodiment exemplifies a case in which the display control unit 102 changes the display of the code screen SC based on posture information. The second embodiment exemplifies a case in which the display control unit 102 changes the display of the code screen SC based on light information. The third embodiment exemplifies a case in which the display control unit 102 determines, based on a predetermined determination method, whether or not the code C is about to be read by the reading unit 26, and changes the display of the code screen SC based on the result of the determination.

[0095] The predetermined determination method is a method for determining whether or not the code C is about to be read by the reading unit 26. The predetermined determination method can also be said to be a method for determining whether or not to change the display of the code screen SC. The determination method based on posture information described in the first embodiment is an example of a predetermined determination method. The determination method based on light information described in the second embodiment is an example of a predetermined determination method. The predetermined determination method may be a determination method other than the determination methods described in each of the first and second embodiments.

[0096] For example, the predetermined determination method may be a determination method based on a captured image generated by the image capturing unit 17. When the code screen SC is displayed, the display control device 10 acquires a captured image generated by the in-camera of the image capturing unit 17. The display control unit 102 performs image analysis on the captured image and determines whether the reading unit 26 has approached. The approach of the reading unit 26 may be determined based on a known object detection algorithm. For example, the object detection algorithm may be a template matching method, an edge detection method, a method using a machine learning model, or another method.

[0097] For example, when the template matching method is used, the data storage unit 100 stores a template image in which the reading unit 26 is shown as a template. The display control unit 102 determines whether the code C is about to be read by the reading unit 26 based on the template image and a known algorithm in the template matching method, by determining whether the reading unit 26 is shown in the captured image. The reading unit 26 being shown in the captured image corresponds to the code C being about to be read by the reading unit 26. The absence of the reading unit 26 being shown in the captured image corresponds to the code C not being about to be read by the reading unit 26. Even when an object detection algorithm other than the template matching method is used, the display control unit 102 may make a determination based on the other object detection algorithm.

[0098] The display control unit 102 may determine, based on the captured image, whether or not an object other than the reading unit 26 has approached the code screen SC. An object approaching the code screen SC can also be said to mean that an object is approaching the code C, the in-camera of the photographing unit 17, or the display control device 10. The display control unit 102 may determine, from the captured image, that an object corresponding to the foreground has approached the code screen SC, rather than using an object detection algorithm for detecting a specific object. An object approaching the code screen SC corresponds to the code C being about to be read by the reading unit 26. Whether or not an object is approaching the code screen SC corresponds to the code C not being about to be read by the reading unit 26.

[0099] For example, if the sensor unit 16 includes an object detection sensor or a proximity sensor, the predetermined determination method may be a determination method based on the object detection sensor or proximity sensor of the sensor unit 16. The object detection sensor or proximity sensor may be a known sensor. The display control device 10 acquires object information regarding the object detection result based on the detection signal of the object detection sensor or proximity sensor of the sensor unit 16. The object information indicates the detection result of the object detection sensor or proximity sensor of the sensor unit 16. The display control unit 102 may determine whether the code C is about to be read by the reading unit 26 based on the object information. The object information indicating the detection of an object or the proximity of an object corresponds to the code C being about to be read by the reading unit 26. The object information not indicating the detection of an object or the proximity of an object corresponds to the code C not being about to be read by the reading unit 26.

[0100] The predetermined determination method is not limited to the above example. For example, the predetermined determination method may be whether or not the user has checked in at a store, whether or not the display control device 10 has detected a beacon emitted by the reading device 20, a method in which the sensor unit 16 includes a depth sensor and uses the depth of an object detected by the depth sensor, or another determination method. The display control unit 102 may make a determination using these other determination methods.

[0101] The display control unit 102 of the third embodiment does not change the display of the code screen SC when it is determined that the code C is not about to be read by the reading unit 26, and changes the display of the code screen SC when it is determined that the code C is about to be read by the reading unit 26. That is, the display control unit 102 changes the display of the code screen SC on the condition (trigger) that the code C is about to be read by the reading unit 26. The process for changing the display of the code screen SC may be similar to at least one of the first and second embodiments.

[0102] The display control device 10 of the third embodiment determines whether the code C is about to be read by the reading unit 26 based on a predetermined determination method, and changes the display of the code screen SC based on the result of the determination. This allows the display control device 10 to obtain the same effect as that described in at least one of the summary of the first embodiment and the summary of the second embodiment. For example, even if the display control device 10 does not detect the attitude and light, as long as it has a function that can realize another determination method, it can obtain the same effect as that described in at least one of the summary of the first embodiment and the summary of the second embodiment by using the other determination method.

[0103] [4. Modifications] The present disclosure is not limited to the first, second, and third embodiments described above. The present disclosure can be modified as appropriate without departing from the spirit of the present disclosure. Modifications of the first, second, and third embodiments will be described below.

[0104] 10 is a diagram showing an example of functions realized in a modification of the first embodiment. For example, in the display control device 10 of the modification of the first embodiment, a reference attitude setting unit 104 and an execution determination unit 105 are realized. Each of the reference attitude setting unit 104 and the execution determination unit 105 is realized by the control unit 11.

[0105] [Variation 1-1] For example, the orientation information acquisition unit 101 may acquire tilt information, such as information relating to the tilt of the display control device 10 and the orientation V1 of the code screen SC. The tilt information indicates not only the tilt of the display control device 10 but also the orientation V1 of the code screen SC. The orientation V1 of the code screen SC can also be referred to as the orientation V1 of the display control device 10 or the display unit 15. The orientation V1 of the code screen SC can also be referred to as the orientation V1 of the surface of the housing of the display control device 10 on which the display unit 15 is exposed.

[0106] In Modification 1-1, an example is given in which the tilt information indicates the roll angle θX, pitch angle θY, and yaw angle θZ described in FIG. 6 . While the attitude information and tilt information described in the first embodiment may indicate only some of these three angles, rather than all of them, the tilt information in Modification 1-1 indicates all of these three angles. The tilt information may indicate a direction V1, but because the direction V1 can be calculated from these three angles, the tilt information does not need to indicate the direction V1. For example, the display control unit 102 identifies the tilt of the display control device 10 based on the roll angle θX and pitch angle θY of the tilt information, rather than the yaw angle θZ. This is as described in the first embodiment.

[0107] For example, in Modification 1-1, the display control unit 102 determines the orientation V1 of the code screen SC based on the roll angle θX, pitch angle θY, and yaw angle θZ indicated by the information on tilt, etc. In the example of FIG. 6 , the display control unit 102 determines the direction of a perpendicular line to the display unit 15 displaying the code screen SC as the orientation V1 of the code screen SC based on the information on tilt, etc. The display control unit 102 may determine the orientation V1 of the code screen SC based on at least the yaw angle θZ of the information on tilt, etc. For example, the display control unit 102 may determine the orientation V1 of the code screen SC without based on at least one of the roll angle θX and the pitch angle θY of the information on tilt, etc.

[0108] The tilt information may be represented by information other than Euler angles, such as the roll angle θX, the pitch angle θY, and the yaw angle θZ. For example, the tilt information may be expressed in the quaternion, rotation matrix, axis angle representation, direction cosine matrix, pointing angle, or other formats described in the first embodiment. The tilt information may be acquired by a known method. The attitude information acquisition unit 101 may acquire the tilt information based on a known algorithm.

[0109] FIG. 11 is a diagram showing an example of a change in the posture of the display control device 10 when reading a code C. In the first embodiment, a reading method in which the user presents the code C is given as an example. Hereinafter, a reading method in which the user presents the code C is referred to as the presentation type. In variant example 1-1, the code C may also be read using the presentation type, but variant example 1-1 uses a different type of reading method as an example. As shown in FIG. 11 , the user holds the code C over the reading unit 26 placed in a predetermined position (for example, on a table in a store). Hereinafter, a reading method in which the user holds the code C over the reading unit 26 is referred to as the holding type.

[0110] The reading unit 26 used in the wave-type reading method may be a known device. In the example of FIG. 11 , the reading unit 26 includes at least one light (e.g., an LED light). The light may be constantly emitting light, or may be emitting light only when a predetermined condition is met. The predetermined condition may be any condition. For example, the predetermined condition may be that a transaction operation is performed from the operation unit 24 of the reading device 20, that a proximity sensor provided in the reading unit 26 detects the proximity of an object, or another condition.

[0111] For example, at least a portion of the surface of the reading unit 26 is a surface for reading the code C. Hereinafter, this surface will be referred to as the reading surface. The reading surface can also be referred to as the surface of the reading unit 26 over which the user must hold the code C. In the example of FIG. 11 , the reading unit 26 is positioned so that its reading surface faces upward. For example, the reading surface may be made of a transparent or translucent material (e.g., glass or acrylic). The reading unit 26 reads the external code C via the reading surface using an internal sensor (e.g., a camera or scanner).

[0112] For example, the user changes the orientation of the display control device 10 so that the code screen SC faces the reading surface of the reading unit 26. The code screen SC facing the reading surface of the reading unit 26 means that the angle between the orientation V1 of the code screen SC and the orientation V2 of the reading surface of the reading unit 26 is 180 degrees or approximately 180 degrees. Approximately 180 degrees is an angle close to 180 degrees. For example, approximately 180 degrees may be 150 degrees to 210 degrees. In the example of FIG. 11 , since the reading surface of the reading unit 26 faces upward, the user changes the orientation of the display control device 10 so that the code screen SC faces downward. In Modification Example 1-1, the user's changing the tilt of the display control device 10 and the orientation of the code screen SC corresponds to changing the orientation of the display control device 10.

[0113] The reading surface of the reading unit 26 can face in any direction. The direction in which the reading surface of the reading unit 26 faces is not limited to the upward direction. For example, the reading surface of the reading unit 26 may face diagonally upward, horizontally, diagonally downward, downward, or in another direction. Regardless of the direction in which the reading surface of the reading unit 26 faces, the user simply changes the orientation of the display control device 10 so that the code screen SC faces the reading surface of the reading unit 26.

[0114] 12 is a diagram showing an example of a change in the attitude of the display control device 10 when reading a code C. In the example of FIG. 12, the reading surface of the reading unit 26 faces horizontally. In this case, the user changes the attitude of the display control device 10 so that the code screen SC faces horizontally, opposite the reading surface of the reading unit 26. By changing the attitude of the display control device 10 in this way, the user can hold the code C over the reading unit 26.

[0115] The display control unit 102 in Modification Example 1-1 changes the display of the code screen SC based on the tilt information, etc. For example, when the tilt information, etc. indicates a first tilt and orientation, the display control unit 102 displays the code screen SC in a first display method. The first tilt and orientation are tilt and orientation in which the code screen SC does not face the reading surface of the reading unit 26. In the example of FIG. 11, the first tilt and orientation are tilt and orientation in which the code screen SC does not face downward. In the example of FIG. 12, the first tilt and orientation are tilt and orientation in which the code screen SC does not face the horizontal direction.

[0116] For example, the display control unit 102 determines, based on the tilt information, whether the display control device 10 has changed from a first tilt and orientation to a second tilt and orientation. The second tilt and orientation is a tilt and orientation in which the code screen SC faces the reading surface of the reading unit 26. In the example of Fig. 11, the second tilt and orientation is a tilt and orientation in which the code screen SC faces downward. In the example of Fig. 12, the second tilt and orientation is a tilt and orientation in which the code screen SC faces horizontally.

[0117] For example, when it is determined that the display control device 10 has changed from a first tilt and orientation to a second tilt and orientation, the display control unit 102 displays the code screen SC in the second display method. When it is determined that the display control device 10 has returned from the second tilt and orientation to the first tilt and orientation, the display control unit 102 may return the code screen SC to the first display method.

[0118] Although the holding-type reading method has been exemplified in Modification 1-1, even in the case of a presentation-type reading method, the display control unit 102 may change the display of the code screen SC based on information such as tilt. In the example of Fig. 3, the display control unit 102 may determine not only the tilt described in the first embodiment but also whether the code screen SC is facing upward or diagonally upward, and may change the display of the code screen SC when it is determined that the code screen SC is facing upward or diagonally upward.

[0119] The display control device 10 of Modification 1-1 acquires tilt information, such as tilt information relating to the tilt of the display control device 10 and the orientation of the code screen SC. The display control device 10 changes the display of the code screen SC based on the tilt information. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in accordance with the tilt information, thereby improving user convenience. For example, when the code C is read using the hold-up method as shown in FIGS. 11 and 12 , the display control device 10 can determine whether the user is attempting to hold up the code C based on the tilt information.

[0120] [Variation 1-2] For example, the posture information acquisition unit 101 may acquire posture information at each of a plurality of time points. This is as described in the first embodiment. The display control unit 102 may detect a change in posture of the display control device 10 based on the posture information at each of the plurality of time points, and change the display of the code screen SC based on the change in posture of the display control device 10. For example, the display control unit 102 detects, as the change in posture, a difference between the posture indicated by the posture information at a first time point among the plurality of time points and the posture indicated by the posture information at a second time point among the plurality of time points.

[0121] The second time point is a time point among the multiple time points that is different from the first time point. In Modification 1-2, an example is given in which the second time point is a time point later than the first time point, but the second time point may be a time point earlier than the first time point. The time interval between the first time point and the second time point may be any interval. For example, the second time point may be a time point immediately after the first time point among the multiple time points, or may be a time point two or more times later. The posture information acquisition unit 101 may repeatedly detect changes in the posture of the display control device 10 based on the latest posture information.

[0122] For example, the display control unit 102 determines whether a change in the attitude of the display control device 10 is a predetermined change. The predetermined change is a change that serves as a criterion for determining whether to change the display of the code screen SC. For example, the predetermined change may be the amount of change in attitude being equal to or greater than a threshold, a change from a first attitude to a second attitude, or some other change. Modification 1-2 takes as an example a case where the amount of change in attitude being equal to or greater than a threshold as the predetermined change. When Euler angles are used as attitude information as in the first embodiment, the display control unit 102 may determine whether a change in attitude of the display control device 10 is a predetermined change by determining whether the amount of change in the Euler angles is equal to or greater than a threshold.

[0123] For example, the display control unit 102 does not change the display of the code screen SC if it is determined that the change in the attitude of the display control device 10 is not a predetermined change, but changes the display of the code screen SC if it is determined that the change in the attitude of the display control device 10 is a predetermined change. That is, the display control unit 102 changes the display of the code screen SC when it is determined that the change in the attitude of the display control device 10 is a predetermined change, as a condition (trigger). The method of changing the display of the code screen SC may be the same as in the first embodiment. For example, as shown in FIG. 4 , the display control unit 102 may change the display of the code screen SC by enlarging the code C.

[0124] In the example of Fig. 3, a change in the attitude of the display control device 10 from the upper attitude of Fig. 3 to the lower attitude of Fig. 3 may correspond to the predetermined change in the attitude of the display control device 10. In the example of Fig. 11, a change from the upper attitude of Fig. 11 to the lower attitude of Fig. 11 may correspond to the predetermined change in the attitude of the display control device 10. In the example of Fig. 12, a change from the upper attitude of Fig. 12 to the lower attitude of Fig. 12 may correspond to the predetermined change in the attitude of the display control device 10. The display control unit 102 may change the display of the code screen SC when detecting at least one of the attitude changes shown in Fig. 3, Fig. 11, and Fig. 12.

[0125] The display control device 10 in Modification Example 1-2 acquires posture information at each of a plurality of time points. The display control device 10 detects a change in posture of the display control device 10 based on the posture information at each of the plurality of time points, and changes the display of the code screen SC based on the change in posture of the display control device 10. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in accordance with changes in posture of the display control device 10, thereby improving user convenience. For example, if the amount of change in posture of the display control device 10 is equal to or greater than a threshold, it is estimated that code C is about to be read. In such a case, the display control device 10 can change the display of the code screen SC to make code C easier to read.

[0126] [Modification 1-3] For example, in Modification 1-2, the display control unit 102 may detect the rotation of the display control device 10 as a change in the attitude of the display control device 10, and change the display of the code screen SC based on the rotation of the display control device 10. The display control unit 102 can detect rotation about any rotation axis, but Modification 1-3 takes as an example a case where the display control unit 102 detects rotation about a rotation axis in a direction other than the Z-axis direction in FIG. 6. The other direction is a direction different from the Z-axis direction. For example, the other direction may be a direction whose angle with the Z-axis is equal to or greater than a threshold value (e.g., 30 degrees).

[0127] For example, the display control unit 102 determines whether the rotation of the display control device 10 is a predetermined rotation. The predetermined rotation is a rotation that serves as a reference for determining whether to change the display of the code screen SC. For example, the predetermined rotation may be a rotation amount in a direction other than the Z-axis direction that is equal to or greater than a threshold, or another rotation. Modification 1-3 cites an example in which the rotation amount in a direction other than the Z-axis direction that is equal to or greater than a threshold corresponds to the predetermined rotation. When Euler angles are used as posture information as in the first embodiment, the display control unit 102 detects the amount of rotation in a direction other than the Z-axis direction based on the roll angle θX and the pitch angle θY.

[0128] For example, the display control unit 102 does not change the display of the code screen SC when it is determined that the rotation of the display control device 10 is not a predetermined rotation, but changes the display of the code screen SC when it is determined that the rotation of the display control device 10 is a predetermined rotation. That is, the display control unit 102 changes the display of the code screen SC when it is determined that the rotation of the display control device 10 is a predetermined rotation. The method of changing the display of the code screen SC may be the same as in the first embodiment. For example, as shown in FIG. 4 , the display control unit 102 may change the display of the code screen SC by increasing the code C. The predetermined rotation may be a rotation in which the amount of rotation (rotation angle or rotation angular velocity) is equal to or greater than a threshold.

[0129] In the example of Fig. 3, the rotation of the display control device 10 from the upper state of Fig. 3 to the lower state of Fig. 3 may correspond to the predetermined rotation of the display control device 10. In the example of Fig. 11, the rotation of the display control device 10 from the upper state of Fig. 11 to the lower state of Fig. 11 may correspond to the predetermined rotation of the display control device 10. In the example of Fig. 12, the rotation of the display control device 10 from the upper state of Fig. 12 to the lower state of Fig. 12 may correspond to the predetermined rotation of the display control device 10. The display control unit 102 may change the display of the code screen SC when detecting at least one of the rotations shown in Figs. 3, 11, and 12.

[0130] The display control device 10 of Modification 1-3 detects the rotation of the display control device 10 as a change in the attitude of the display control device 10, and changes the display of the code screen SC based on the rotation of the display control device 10. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in accordance with the rotation of the display control device 10, thereby improving user convenience. For example, when the amount of rotation of the display control device 10 is equal to or greater than a threshold, it is estimated that the code C is about to be read, and in such a case the display control device 10 can change the display of the code screen SC to make the code C easier to read.

[0131] [Modification 1-4] For example, in Modification 1-2, the change in the attitude of the display control device 10 may be a change from a reference attitude that serves as a reference. The reference attitude is an attitude that serves as a judgment criterion. The attitude indicated by the attitude information at the first time point in Modification 1-2 is an example of a reference attitude. In Modification 1-3, the rotation of the display control device 10 may be a rotation from the reference attitude. In Modification 1-4, other examples of the reference attitude will be described.

[0132] FIG. 13 is a diagram showing an example of a reference attitude. In the example of FIG. 13, the reference attitude is indicated by a roll angle θX1, a pitch angle θY1, and a yaw angle θZ1 at a certain point in time. The display control device 10 of Modification Example 1-4 includes a reference attitude setting unit 104. For example, a payment app causes the display control device 10 to further function as the reference attitude setting unit 104. The reference attitude setting unit 104 sets a reference attitude related to a reference attitude. Reference attitude data indicating the reference attitude may be stored in advance in the data storage unit 100, but Modification Example 1-4 illustrates an example in which the reference attitude setting unit 104 dynamically sets the reference attitude depending on the situation of the display control device 10. The reference attitude setting unit 104 sets the reference attitude by recording the reference attitude data in the data storage unit 100.

[0133] For example, the reference attitude setting unit 104 sets the attitude indicated by the attitude information acquired at a predetermined time point as the reference attitude. The predetermined time point is the time point at which the reference attitude setting unit 104 should set the reference attitude. Data indicating the predetermined time point is assumed to be stored in advance in the data storage unit 100. The reference attitude setting unit 104 determines whether the predetermined time point has arrived based on the data. The reference attitude setting unit 104 sets the attitude indicated by the attitude information acquired when it is determined that the predetermined time point has arrived as the reference attitude. The attitude information acquisition unit 101 may continuously acquire attitude information from before the predetermined time point arrives, or may acquire attitude information when it is determined that the predetermined time point has arrived.

[0134] The predetermined time point may be any time point. For example, if the time point when the payment app is launched corresponds to the predetermined time point, the reference posture setting unit 104 sets the posture indicated by the posture information acquired when the payment app is launched as the reference posture. If the time point when the login process to the payment service is successful corresponds to the predetermined time point, the reference posture setting unit 104 sets the posture indicated by the posture information acquired when the login process is successful as the reference posture. If the time point when the user performs a predetermined operation corresponds to the predetermined time point, the reference posture setting unit 104 sets the posture indicated by the posture information acquired when the user performs the predetermined operation as the reference posture.

[0135] In Modification Example 1-4, the display control unit 102 detects a change in attitude from the reference attitude and changes the display of the code screen SC based on the change in attitude from the reference attitude. For example, the display control unit 102 detects the difference between the reference attitude and the attitude indicated by the latest attitude information as the change in attitude from the reference attitude. In the example of FIG. 13 , the attitude indicated by the latest attitude information is indicated by a roll angle θX2, a pitch angle θY2, and a yaw angle θZ2. The display control unit 102 determines whether the change in attitude from the reference attitude is a predetermined change (for example, the amount of change in attitude is equal to or greater than a threshold). If the display control unit 102 does not determine that the change in attitude from the reference attitude is a predetermined change, it does not change the display of the code screen SC. However, if the change in attitude from the reference attitude is determined to be a predetermined change, it changes the display of the code screen SC. In other words, the display control unit 102 changes the display of the code screen SC when the change in attitude from the reference attitude is determined to be a predetermined change, which is a condition (trigger).

[0136] Note that this differs from Modification Example 1-2 in that the change in posture for changing the display of the code screen SC is a change from a reference posture, but other points may be the same as Modification Example 1-2. When rotation is used as the change in posture, this differs from Modification Example 1-3 in that the rotation for changing the display of the code screen SC is a rotation from a reference posture, but other points may be the same as Modification Example 1-3.

[0137] The display control device 10 in Modification Example 1-4 sets a reference attitude related to a reference attitude. The display control device 10 detects a change in attitude from the reference attitude and changes the display of the code screen SC based on the change in attitude from the reference attitude. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in accordance with changes in attitude from the reference attitude, thereby improving user convenience. For example, if the amount of change in attitude from the reference attitude that serves as a reference for estimating whether code C is about to be read is equal to or greater than a threshold, it is estimated that code C is about to be read. In such cases, the display control device 10 can make code C easier to read by changing the display of the code screen SC.

[0138] [Variation 1-5] For example, in Variation 1-4, the reference orientation setting unit 104 may set the reference orientation based on orientation information acquired when the code screen SC is displayed on the display unit 15. The reference orientation setting unit 104 sets the reference orientation based on orientation information acquired after program code that displays the code screen SC, among program codes included in the payment app, is executed. The processing of the display control unit 102 after the reference orientation is set may be the same as in Variation 1-4.

[0139] If code C is not displayed when the code screen SC is displayed, the reference attitude setting unit 104 may set the reference attitude based on attitude information acquired when code C is subsequently displayed. If code C is not displayed when the code screen SC is displayed, code C may be displayed by a user operation, or may be displayed after a predetermined time has elapsed. The reference attitude setting unit 104 may set the reference attitude based on attitude information acquired when code C is displayed.

[0140] The display control device 10 in Modification Example 1-5 sets the reference orientation based on the orientation information acquired when the code screen SC is displayed on the display unit 15. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in accordance with changes in the orientation after the code screen SC is displayed on the display unit 15, thereby improving user convenience. For example, the orientation of the display control device 10 when the code screen SC is displayed on the display unit 15 is the orientation for the user to check the display of the code screen SC, so it is considered that reading of the code C will not yet occur in this orientation. Therefore, if this orientation is set as the reference orientation and the orientation subsequently changes significantly from the reference orientation, it is estimated that the code C is about to be read, and the display control device 10 can make the code C easier to read in such cases by changing the display of the code screen SC.

[0141] [Variation 1-6] For example, as shown in Fig. 4, the display control unit 102 may change the display of the code screen SC by changing the display position of the lower content displayed below the code C on the code screen SC without changing the display position of the upper content displayed above the code C on the code screen SC. Content is a component of the code screen SC (a part serving as a user interface). For example, content may be text, a link, an input form such as a button or a check box, or an image such as an icon. Code C is also a type of content.

[0142] Fig. 14 is a diagram showing an example of upper content and lower content. In Fig. 14, content other than the code C is omitted from the code screen SC. As shown in Fig. 14, the content displayed in the display area A1 above the code C on the code screen SC is the upper content. In the example of the code screen SC in Figs. 2 and 4, the "AAA Pay" text, the hamburger icon, the text indicating the number of points, and the text indicating the balance of electronic money each correspond to the upper content.

[0143] 14, the content displayed in the display area A2 below the code C on the code screen SC is the lower content. In the example of the code screen SC in FIGS. 2 and 4, the lower content corresponds to the text indicating the payment source set by the user, the button for setting the payment source, the button for selecting another payment method such as self-payment or code scanning, and the icon of a mini-appli such as an invoice.

[0144] For example, the data storage unit 100 stores display position data indicating the display position of each content on the code screen SC. The display position data indicates the display position of each of the upper content, the code C, and the lower content. The display control unit 102 does not change the display position of the upper content indicated by the display position data. The display control unit 102 changes the display positions of the code C and the lower content indicated by the display position data so that the resized code C does not overlap with the upper content and the lower content.

[0145] Note that the display control unit 102 does not have to change the display position as in Modification Example 1-6. For example, the present disclosure also includes a display control unit 102 that changes the display position of the upper content, a display control unit 102 that changes the display position of the lower content, a display control unit 102 that does not display any content above the code C (upper content does not exist in the first place), a display control unit 102 that does not display any content below the code C (lower content does not exist in the first place), or a display control unit 102 that combines these.

[0146] The display control device 10 of Modification Example 1-6 changes the display of the code screen SC by changing the display position of the lower content displayed below the code C on the code screen SC without changing the display position of the upper content displayed above the code C on the code screen SC. This allows the display control device 10 to prevent a decrease in the visibility of the code screen SC. For example, the display control device 10 can prevent the code C from going outside the code screen SC and becoming unreadable.

[0147] [Variation 1-7] For example, the display control unit 102 may change the display of the code screen SC by changing the brightness of the code screen SC. Variation 1-7 takes as an example a case in which the display control unit 102 changes the size of the code C and also changes the brightness of the code screen SC in the same manner as in the first embodiment, but the display control unit 102 may change the brightness of the code screen SC without changing the size of the code C. In other words, the display control unit 102 may change the display of the code screen SC by changing only the brightness of the code screen SC.

[0148] FIG. 15 is a diagram showing an example of a code screen SC whose brightness changes depending on the attitude of the display control device 10. In FIG. 15, the brightness of the code screen SC is schematically represented by halftone dots. The higher the halftone dot density, the darker the code screen SC. In other words, the lower the halftone dot density, the brighter the code screen SC. A code screen SC with no halftone dots is the brightest. For example, when code C is read in the presentation type, if the attitude of the display control device 10 changes as shown in FIG. 3, the display control unit 102 changes the brightness of the code screen SC from left to right in FIG. 15, thereby brightening the code screen SC. The change in the presentation type attitude may be detected in the same manner as in the first embodiment.

[0149] For example, when the code C is read by holding it over the screen, if the orientation of the display control device 10 changes as shown in Fig. 10 or 11, the display control unit 102 changes the brightness of the code screen SC from left to right in Fig. 15, thereby brightening the code screen SC. The change in orientation of the holding it over the screen may be detected in the same manner as in Modification 1-1. The orientation changes such as those in Modifications 1-2 to 1-6 can also be applied to Modification 1-7.

[0150] The method by which the display control unit 102 changes the brightness of the code screen SC may be the same as a known method. For example, if the screen brightness setting is stored in the data storage unit 100 as a setting of the operating system installed in the display control device 10, the display control unit 102 may change the brightness of the code screen SC by changing the screen brightness setting.

[0151] The display control device 10 of Modification Example 1-7 changes the display of the code screen SC by changing the brightness of the code screen SC. This allows the display control device 10 to display the code screen SC at a flexible brightness that corresponds to the posture information. For example, when the posture does not require preparation for reading the code C, the display control device 10 does not display the code screen SC so brightly, thereby prioritizing user visibility and reducing power consumption. When the posture requires preparation for reading the code C, the display control device 10 brightens the code screen SC to make the code C easier to read, thereby preventing the code C from taking a long time to read. Because the user does not need to perform a special operation (for example, tapping the code screen SC) to change the brightness of the code screen SC, the display control device 10 can reduce the operational burden on the user.

[0152] [Variation 1-8] For example, the display control unit 102 may determine the degree of change in the display of the code screen SC based on the posture information, and change the display of the code screen SC based on that degree. The degree of change in the display is the amount of change in the display. For example, at least one of the size of the code C and the brightness of the code screen SC corresponds to the degree of change in the display. Variation 1-8 exemplified a case in which both of these correspond to the degree of change in the display, but only one of the size of the code C or the brightness of the code screen SC may correspond to the degree of change in the display.

[0153] In Variation Example 1-8, the relationship between the posture indicated by the posture information and the degree of display change is defined in the payment app. However, these relationships may be defined in data separate from the payment app as settings referenced by the payment app. The display control unit 102 determines the degree of display change based on the posture information and the relationship. For example, the display control unit 102 determines the degree of display change so that the greater the amount of change in posture indicated by the posture information, the greater the degree of display change, and changes the display of the code screen SC based on that degree.

[0154] In the example of the first embodiment, the display control unit 102 determines the size of the code C as a degree of change in display such that the size of the code C increases as the tilt of the display control device 10 increases, and displays the code C of that size on the code screen SC. In the example of Modification 1-1, the display control unit 102 determines the size of the code C as a degree of change in display such that the size of the code C increases as the orientation of the code screen SC changes, and displays the code C of that size on the code screen SC. In the example of Modification 1-3, the display control unit 102 determines the size of the code C as a degree of change in display such that the size of the code C increases as the amount of rotation of the display control device 10 increases, and displays the code C of that size on the code screen SC.

[0155] When the brightness of the code screen SC is changed as in variant example 1-7, the display control unit 102 determines the degree of brightness of the code screen SC as a degree related to the change in display so that the code screen SC becomes brighter the greater the tilt of the display control device 10, and displays the code screen SC at that degree of brightness. The display control unit 102 determines the degree of brightness of the code screen SC as a degree related to the change in display so that the code screen SC becomes brighter the greater the orientation of the code screen SC changes, and displays the code screen SC at that degree of brightness. The display control unit 102 determines the degree of brightness of the code screen SC as a degree related to the change in display so that the code screen SC becomes brighter the greater the amount of rotation of the display control device 10, and displays the code screen SC at that degree of brightness.

[0156] The display control device 10 in Modification Example 1-8 determines the degree of change to the display of the code screen SC and changes the display of the code screen SC based on that degree. This allows the display control device 10 to display the code screen SC on the display unit 15 more flexibly according to the posture information, thereby improving user convenience. For example, the display control device 10 can gradually change at least one of the size of the code C and the brightness of the code screen SC according to the posture indicated by the posture information, thereby further increasing the flexibility of the display of the code screen SC during reading.

[0157] [Variation 1-9] For example, depending on the circumstances under which the code C is read, a standard-sized code C (the initial size when the code screen SC is displayed) may be more appropriate than a large code C, or a code C smaller than the standard size may be more appropriate. When the brightness of the code screen SC is changed as in Variation 1-7, a standard-brightness code screen SC may be more appropriate, or a code screen SC darker than the standard brightness may be more appropriate. Therefore, the display control unit 102 may repeatedly change the display of the code screen SC. Variation 1-9 takes as an example a case in which the size of the code C is changed, as in the first embodiment.

[0158] FIG. 16 is a diagram showing an example of how the size of the code C is repeatedly changed. As shown in FIG. 16 , the display control unit 102 switches the display of the code C between three sizes: small (standard size) as shown in the upper left of FIG. 16 , medium as shown in the upper right of FIG. 16 , and large as shown in the lower right of FIG. 16 . For example, the display control unit 102 changes the size of the code C when a predetermined time has elapsed since the code C was displayed. The display control unit 102 may determine whether the predetermined time has elapsed using a known timing process. The display control unit 102 changes the size of the code C each time the predetermined time has elapsed. Instead of the size of the code C, the display control unit 102 may switch the brightness of the code screen SC between three brightness levels: dark, standard, and bright.

[0159] The display control unit 102 may switch the display of the code screen SC between two or four or more stages, instead of three stages as shown in Fig. 16. After switching the size between small, medium, and large as shown in Fig. 16, the display control unit 102 may return the code C to the small size again and repeat the size switching. Similarly, the display control unit 102 may switch the brightness between dark, normal, and bright, and then return the code screen SC to dark and repeat the brightness switching.

[0160] The display control device 10 in Modification Example 1-9 repeatedly changes the display of the code screen SC. This allows the display control device 10 to increase the probability that the code C will be read accurately. For example, in a situation where a standard-sized code C is more appropriate than a large code C, the code C is read at the timing when the display control device 10 changes the size of the code C from the large code C back to the standard code C, thereby increasing the probability that the code C will be read accurately. The display control device 10 can display the code screen SC in a way that can accommodate various situations.

[0161] [Variation 1-10] For example, in Variation 1-9, the display of the code screen SC may be changed until payment is executed. The display control device 10 in Variation 1-10 includes an execution determination unit 105. For example, the payment app causes the display control device 10 to function as the execution determination unit 105. The execution determination unit 105 determines whether or not a predetermined process that is executed when the code C is read by the reading device 20 has been executed. The predetermined process is as described in the first embodiment for the process execution unit 201 and the process execution unit 301.

[0162] For example, when a predetermined process is executed, the process execution unit 301 of the server 30 transmits an execution notification indicating that the predetermined process has been executed to the display control device 10. The execution determination unit 105 determines whether the predetermined process has been executed by determining whether an execution notification has been received from the server 30. The execution notification may be transmitted from a device other than the server 30 (e.g., the reading device 20). In this case, the execution determination unit 105 may determine whether the predetermined process has been executed by determining whether an execution notification has been received from the other device. When the display control device 10 executes a predetermined process, the process execution unit 301 may determine whether the predetermined process has been executed based on the processing result of a program (e.g., a payment app) that executes the predetermined process.

[0163] The display control unit 102 in Modification Example 1-10 repeatedly changes the display of the code screen SC while it is determined that a predetermined process is not being executed. The display control unit 102 stops changing the display of the code screen SC when it is determined that a predetermined process has been executed. The display control unit 102 repeatedly changes the display of the code screen SC until it is determined that a predetermined process has been executed. The display control unit 102 stops changing the display of the code screen SC when a predetermined process has been executed. The display control unit 102 may transition to a screen other than the code screen SC when a predetermined process has been executed.

[0164] The display control device 10 of Modification Example 1-10 determines whether or not a predetermined process that is executed when the code C is read by the reading device 20 has been executed. The display control device 10 repeatedly changes the display of the code screen SC while it is determined that the predetermined process has not been executed. This allows the display control device 10 to repeatedly change the display of the code screen SC so that the code screen SC is appropriate for the predetermined process until the predetermined process is executed. As a result, the predetermined process is executed accurately.

[0165] 17 is a diagram showing an example of functions realized in a modification of the second embodiment. For example, the display control device 10 of the modification of the second embodiment realizes an execution determination unit 105 and a reference degree setting unit 106. The execution determination unit 105 and the reference degree setting unit 106 are each realized by the control unit 11.

[0166] [Variation 2-1] For example, in the second embodiment, the code C may also be read by a holding-up type reading method, as shown in Figures 11 and 12. In this case, when the display control device 10 approaches the reading surface of the reading unit 26, the display control device 10 is brightly illuminated by light from the light. Therefore, the display control unit 102 may detect a change in the light, such as an increase in the brightness of the light, and change the display of the code screen SC based on this change in the brightness of the light.

[0167] When the state changes from the upper state of Fig. 11 to the lower state of Fig. 11, or when the state changes from the upper state of Fig. 12 to the lower state of Fig. 12, the light indicated by the light information becomes brighter due to the light from the light inside the reading unit 26. When the light indicated by the light information becomes brighter, the display control unit 102 changes the display of the code screen SC. For example, when the light indicated by the light information becomes brighter, the display control unit 102 changes the display of the code screen SC so that the code C becomes larger, as shown in Fig. 4.

[0168] In Modification 2-1, the display control unit 102 calculates the increase in the brightness of light as the change in the brightness of light. As in the second embodiment, when the brightness of light is expressed in lux, the display control unit 102 does not change the display of the code screen SC if it determines that the increase in lux is less than a threshold, and changes the display of the code screen SC if it determines that the increase in lux is equal to or greater than the threshold. In the second embodiment, an example was given in which the display control unit 102 uses the decrease in lux, but the display control unit 102 may change the display of the code screen SC based on at least one of the increase and decrease in lux. This also applies when an index other than lux is used.

[0169] The display control device 10 of modification 2-1 detects a change in light, such as an increase in light brightness, and changes the display of the code screen SC based on the change in light brightness. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in response to the increase in light brightness, thereby improving user convenience. For example, as shown in FIG. 11 , when the display control device 10 is brightly illuminated by light from a lamp, the display control device 10 determines that the surroundings are bright and that preparations should be made to read the code C, and increases the size of the code C, thereby preventing the code C from taking a long time to read.

[0170] [Modification 2-2] For example, in the second embodiment and Modification 2-1, the change in light to the display control device 10 may be a change from a reference degree that serves as a reference. The reference degree is light that serves as a judgment criterion. For example, when the display control unit 102 detects, as a change in light, the difference between the light indicated by the light information at a first time point among the multiple time points and the light indicated by the light information at a second time point among the multiple time points, the light indicated by the light information at the first time point is an example of the reference degree. In Modification 2-2, another example of the reference degree will be described.

[0171] FIG. 18 is a diagram showing an example of a reference degree. In the example of FIG. 18, the reference degree is 100 lux, which is the degree of brightness of light at a certain point in time. The display control device 10 of Modification 2-2 includes a reference degree setting unit 106. For example, a payment application causes the display control device 10 to further function as the reference degree setting unit 106. The reference degree setting unit 106 sets a reference degree related to the degree of brightness of light that serves as a reference. Although reference degree data indicating the reference degree may be stored in advance in the data storage unit 100, Modification 2-2 illustrates an example in which the reference degree setting unit 106 dynamically sets the reference degree depending on the status of the display control device 10. The reference degree setting unit 106 sets the reference degree by recording the reference degree data in the data storage unit 100.

[0172] For example, the reference degree setting unit 106 sets the degree of brightness indicated by the light information acquired at a predetermined time point as the reference degree. The predetermined time point is the time point at which the reference degree setting unit 106 should set the reference degree. Data indicating the predetermined time point is assumed to be stored in advance in the data storage unit 100. The reference degree setting unit 106 determines whether the predetermined time point has arrived based on the data. The reference degree setting unit 106 sets the degree of brightness indicated by the light information acquired when it is determined that the predetermined time point has arrived as the reference degree. The light information acquisition unit 103 may continuously acquire light information from before the predetermined time point arrives, or may acquire light information when it is determined that the predetermined time point has arrived.

[0173] The predetermined time point may be any time point. For example, if the predetermined time point corresponds to the time point when the payment app is launched, the reference degree setting unit 106 sets the brightness level indicated by the light information acquired when the payment app is launched as the reference degree. If the predetermined time point corresponds to the time point when a login process to a payment service is successful, the reference degree setting unit 106 sets the brightness level indicated by the light information acquired when the login process is successful as the reference degree. If the predetermined time point corresponds to the time point when a user performs a predetermined operation, the reference degree setting unit 106 sets the brightness level indicated by the light information acquired when the user performs the predetermined operation as the reference degree.

[0174] The display control unit 102 in Modification Example 2-2 changes the display of the code screen SC based on a change in light from the reference level. For example, the display control unit 102 detects the difference between the reference level and the brightness level indicated by the latest light information as a change in light from the reference level. In the example of FIG. 18 , the brightness level indicated by the latest light information is 50 lux. The display control unit 102 determines whether the change in light from the reference level is a predetermined change (e.g., the amount of change in brightness is equal to or greater than a threshold). If the display control unit 102 does not determine that the change in light from the reference level is a predetermined change, it does not change the display of the code screen SC. However, if the display control unit 102 determines that the change in light from the reference level is a predetermined change, it changes the display of the code screen SC. In other words, the display control unit 102 changes the display of the code screen SC when the change in light from the reference level is determined to be a predetermined change as a condition (trigger).

[0175] Note that this embodiment differs from the second embodiment in that the change in light required to change the display of the code screen SC is a change from a reference degree, but other points may be the same as those of the second embodiment. For example, the display control unit 102 determines whether the amount of change in the degree of brightness from the reference degree is equal to or greater than a threshold. If the display control unit 102 determines that the amount of change in the degree of brightness from the reference degree is not equal to or greater than the threshold, it does not change the display of the code screen SC, but if it determines that the amount of change in the degree of brightness from the reference degree is equal to or greater than the threshold, it changes the display of the code screen SC.

[0176] The display control device 10 of Modification 2-2 sets a reference degree related to the reference degree of light brightness. The display control device 10 changes the display of the code screen SC based on changes in light from the reference degree. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 in accordance with changes in the degree of brightness from the reference degree, thereby improving user convenience. For example, if the amount of change in the degree of brightness from the reference degree that serves as a reference for estimating whether code C is about to be read is equal to or greater than a threshold, it is estimated that code C is about to be read. In such cases, the display control device 10 can make code C easier to read by changing the display of the code screen SC.

[0177] [Variation 2-3] For example, in Variation 2-2, the reference degree setting unit 106 may set the reference degree based on light information acquired when the code screen SC is displayed on the display unit 15. The reference degree setting unit 106 sets the reference degree based on light information acquired after program code included in the payment app, which program code indicates the display of the code screen SC, is executed. The processing of the display control unit 102 after the reference degree is set may be the same as in Variation 2-2.

[0178] If code C is not displayed when the code screen SC is displayed, the reference degree setting unit 106 may set the reference degree based on light information acquired when code C is displayed on the code screen SC. If code C is not displayed when the code screen SC is displayed, code C may be displayed by a user operation, or may be displayed after a predetermined time has elapsed. The reference degree setting unit 106 may set the reference degree based on light information acquired when code C is displayed.

[0179] The display control device 10 of Modification 2-3 sets the reference degree based on light information acquired when the code screen SC is displayed on the display unit 15. This allows the display control device 10 to display the code screen SC on the display unit 15 flexibly in response to changes in light after the code screen SC is displayed on the display unit 15, thereby improving user convenience. For example, when the code screen SC is displayed on the display unit 15, the user checks the display of the code screen SC, so it is considered that reading of the code C has not yet occurred. For this reason, the brightness degree of the light at this time is set as the reference degree, and if the brightness degree subsequently changes significantly from the reference degree, it is estimated that the code C is about to be read. Therefore, the display control device 10 can change the display of the code screen SC in such a case to make the code C easier to read.

[0180] [Variation 2-4] For example, the light information acquisition unit 103 may acquire color information related to the color of light as light information, instead of the brightness of light. In the example of Fig. 3, the reading unit 26 may read the code C using light from a light including a red LED or the like. In this case, the light to the display control device 10 is red. In the examples of Figs. 11 and 12, the reading unit 26 may read the code C by illuminating the display control device 10 with light from a light including a white LED or the like. In this case, the light to the display control device 10 is white.

[0181] In variant 2-4, the sensor unit 16 includes a light color sensor capable of detecting the color of light. For example, the light color sensor may be an RGB sensor, a color sensor, a spectral sensor, or another sensor. The light information acquisition unit 103 acquires light information indicating the color of light based on the detection signal of the sensor unit 16. The color of light indicated by the light information may be any color. For example, the light information may indicate only the presence or absence of a specific color, or may indicate each of multiple colors. The light information may also indicate the degree of brightness of each color.

[0182] The display control unit 102 in Modification Example 2-4 changes the display of the code screen SC based on the color information. For example, if the color information does not indicate a specific color of light, the display control unit 102 does not change the display of the code screen SC, and if the color information indicates a specific color of light, the display control unit 102 changes the display of the code screen SC. The specific color is a color that serves as a criterion for determining whether or not to change the display of the code screen SC. The specific color may be a predetermined color. In the example of FIG. 3, the specific color may be red. If the color information does not indicate red light, the display control unit 102 does not change the display of the code screen SC, and if the color information indicates red light, the display control unit 102 changes the display of the code screen SC. In the examples of FIGS. 11 and 12, the specific color may be white. If the color information does not indicate white light, the display control unit 102 does not change the display of the code screen SC, and if the color information indicates white light, the display control unit 102 changes the display of the code screen SC.

[0183] The display control device 10 in Variation 2-4 acquires color information regarding the color of light as light information. The display control device 10 changes the display of the code screen SC based on the color information. This allows the display control device 10 to flexibly display the code screen SC on the display unit 15 according to the color of light indicated by the light information, thereby improving user convenience. For example, the display control device 10 estimates, based on the color information, that a reading unit 26 including a red LED or the like is nearby. In a situation where a presentation-type reading should be prepared, the display control device 10 changes the display of the code screen SC to make the code C easier to read and prevent a time-consuming reading of the code C. For example, when the reading unit 26 uses light of a color that is not commonly found around the user, such as a red LED, the display control device 10 can reduce the possibility of erroneous detection. The display control device 10 estimates, based on the color information, that a reading unit 26 including a white LED or the like is nearby. In a situation where a hold-up-type reading should be prepared, the display control device 10 changes the display of the code screen SC to make the code C easier to read and prevent a time-consuming reading of the code C. Even if there is white light around the user, as a general rule in everyday life, the display control device 10 is not surrounded by strong white light, as occurs when reading by holding it over the device, so in such cases the display control device 10 can estimate that the reading unit 26 is nearby.

[0184] [Modification 2-5] For example, in Modification 2-4, the light information acquisition unit 103 may acquire color information based on the in-camera of the display control device 10. That is, the light information acquisition unit 103 may acquire color information by performing image analysis on the captured image generated by the in-camera of the display control device 10, rather than the detection signal of the sensor unit 16. The light information acquisition unit 103 may acquire color information by comprehensively analyzing both the detection signal of the sensor unit 16 and the captured image.

[0185] 19 is a diagram showing an example of a captured image. As shown in the upper part of FIG. 19, the in-camera of the image capturing unit 17 captures an image in the direction perpendicular to the surface of the display control device 10 on which the display unit 15 is arranged, and generates a captured image I. The in-camera may repeatedly generate the captured image I based on a predetermined frame rate. The light information acquiring unit 103 determines whether or not there is a locally bright area based on the captured image I. If the light information acquiring unit 103 determines that there is a locally bright area in the captured image I, it acquires color information indicating the color of the image.

[0186] In addition, when the color of light emitted by the reading unit 26 is known in advance, the light information acquisition unit 103 may determine whether a color that is the same as or similar to the color of light emitted by the reading unit 26 is locally displayed in the captured image I. A color similar to the color of light emitted by the reading unit 26 is a color whose difference from the pixel value of the light emitted by the reading unit 26 is less than a threshold value. When a specific light color is displayed in the captured image I, the light information acquisition unit 103 acquires light information indicating that the specific light color is displayed in the captured image I. In the example of FIG. 3, when red light is displayed in the captured image I, the light information acquisition unit 103 acquires light information indicating that red light is displayed in the captured image I. In the examples of FIGS. 11 and 12, when red or white light is displayed in the captured image I, the light information acquisition unit 103 acquires light information indicating that white light is displayed in the captured image I.

[0187] The display control device 10 of Variation 2-5 acquires color information based on the in-camera of the display control device 10. This allows the display control device 10 to acquire light information without using a special sensor for detecting light. For example, if the display control device 10 is a smartphone, the display control device 10 can acquire light information using the in-camera to which the reading unit 26 inevitably approaches when reading code C (the in-camera to which the reading unit 26 inevitably falls within the shooting range when reading code C).

[0188] [Modification 2-6] For example, in the second embodiment, as in Modification 1-6, the display control unit 102 may change the display of the code screen SC by changing the display position of the lower content that is displayed below the code C on the code screen SC, without changing the display position of the upper content that is displayed above the code C on the code screen SC. This is different in that this processing is performed based on optical information, but the details of this processing are as described in Modification 1-6.

[0189] The display control device 10 of Modification 2-6 can prevent a decrease in the visibility of the code on the code screen SC, similar to Modification 1-6. For example, the display control device 10 can prevent the code C from going outside the code screen SC and becoming unreadable.

[0190] [Variation 2-7] For example, in the second embodiment, as in Variation 1-7, the display control unit 102 may change the display of the code screen SC by changing the brightness of the code screen SC. Variation 2-7 takes as an example a case in which the display control unit 102 changes the size of the code C and also changes the brightness of the code screen SC in the same manner as in the second embodiment, but the display control unit 102 may change the brightness of the code screen SC without changing the size of the code C. In other words, the display control unit 102 may change the display of the code screen SC by changing only the brightness of the code screen SC.

[0191] For example, the display control unit 102 may change the display of the code screen SC so that the brighter the light indicated by the light information, the brighter the code screen SC. That is, the display control unit 102 may change the display of the code screen SC so that the dimmer the light indicated by the light information, the darker the code screen SC. Conversely, the display control unit 102 may change the display of the code screen SC so that the brighter the light indicated by the light information, the darker the code screen SC. That is, the display control unit 102 may change the display of the code screen SC so that the dimmer the light indicated by the light information, the brighter the code screen SC.

[0192] The display control device 10 of Modification 2-7 changes the display of the code screen SC by changing the brightness of the code screen SC. This allows the display control device 10 to display the code screen SC at a flexible brightness that corresponds to the light information. For example, in a situation where it is not necessary to prepare for reading the code C, the display control device 10 can prioritize user visibility and reduce power consumption by not displaying the code screen SC so brightly. In a situation where it is necessary to prepare for reading the code C, the display control device 10 brightens the code screen SC to make the code C easier to read, thereby preventing the code C from taking a long time to read. Because the user does not need to perform a special operation (for example, tapping the code screen SC) to change the brightness of the code screen SC, the display control device 10 can reduce the operational burden on the user.

[0193] [Variation 2-8] For example, the display control unit 102 may determine the degree of change in the display of the code screen SC based on the light information, and change the display of the code screen SC based on that degree. The meaning of the degree of change in the display is as explained in Variation 1-8. Variation 2-8 gives an example in which both of these correspond to the degree of change in the display, but only one of the size of the code C or the brightness of the code screen SC may correspond to the degree of change in the display.

[0194] In Variation Example 2-8, the relationship between the light indicated by the light information and the degree of display change is defined in the payment app. However, this relationship may be defined in data separate from the payment app as settings referenced by the payment app. The display control unit 102 determines the degree of display change based on the light information and the relationship. For example, the display control unit 102 determines the degree of display change so that the greater the change in light indicated by the light information, the greater the degree of display change, and changes the display of the code screen SC based on that degree.

[0195] In the example of the second embodiment, the display control unit 102 determines the size of the code C as a degree of change in display such that the larger the amount of change in light indicated by the optical information, the larger the size of the code C, and displays the code C of that size on the code screen SC. In the example of Modification 2-7, the display control unit 102 determines the degree of brightness of the code screen SC as a degree of change in display such that the larger the amount of change in light indicated by the optical information, the brighter the code screen SC, and displays the code screen SC with that degree of brightness.

[0196] The display control device 10 of Modification 2-8 determines the degree of change in the display of the code screen SC based on the light information, and changes the display of the code screen SC based on that degree. This allows the display control device 10 to display the code screen SC on the display unit 15 more flexibly in accordance with the light information, thereby improving user convenience. For example, if the code screen SC is at maximum brightness in a darker-than-usual location, such as a movie theater or an event venue, the code screen SC may stand out. However, the display control device 10 can prevent the code screen SC from standing out by reducing the degree of brightness of the code screen SC in such cases.

[0197] [Variation 2-9] For example, in the second embodiment, as in Variation 1-9, the display control unit 102 may repeatedly change the display of the code screen SC. As in Variation 1-9, the display control unit 102 may switch the size of the code C or the brightness of the code screen SC. This is different in that this processing is performed based on light information, but the processing of repeatedly changing the display of the code screen SC is the same as in Variation 1-9.

[0198] The display control device 10 in modification 2-9 repeatedly changes the display of the code screen SC. This allows the display control device 10 to increase the probability that the code C will be accurately read. For example, in a situation where a standard-sized code C is more appropriate than a large code C, the code C is read at the timing when the display control device 10 switches back from the large code C to the standard-sized code C, thereby increasing the probability that the code C will be accurately read.

[0199] [Modification 2-10] For example, in the second embodiment, as in Modification 1-10, the display control device 10 may include an execution determination unit 105. The display control unit 102 may repeatedly change the display of the code screen SC while it is determined that a predetermined process is not to be executed. These processes are as described in Modification 1-10.

[0200] The display control device 10 of modification 2-10 determines whether or not a predetermined process that is executed when the code C is read by the reading device 20 has been executed. The display control device 10 repeatedly changes the display of the code screen SC while it is determined that the predetermined process is not being executed. This allows the display control device 10 to repeatedly change the display of the code screen SC so that the code screen SC is appropriate for the predetermined process until the predetermined process is executed. As a result, the predetermined process is accurately executed.

[0201] [Variation 2-11] For example, the display control unit 102 may estimate the distance between the display control device 10 and the reading device 20 that reads the code C based on the light information, and change the display of the code screen SC based on this distance. In Variation 2-11, the display control unit 102 estimates the distance based on the brightness level indicated by the light information. For example, in a holding-type reading method, the brightness level increases as the display control device 10 gets closer to the reading unit 26, so the display control unit 102 estimates the distance so that the higher the brightness level, the closer the distance. In other words, the display control unit 102 estimates the distance so that the lower the brightness level, the farther the distance. The display control unit 102 may not change the display of the code screen SC when the distance is equal to or greater than a threshold, and may change the display of the code screen SC when the distance is less than the threshold.

[0202] The display control device 10 of Modification 2-11 estimates the distance between the display control device 10 and the reading device 20 that reads the code C based on the optical information, and changes the display of the code screen SC based on the distance. This allows the display control device 10 to display a flexible code screen SC on the display unit 15 according to the distance, thereby improving user convenience. For example, when the distance becomes short and it becomes necessary to prepare for reading the code C, the display control device 10 increases the size of the code C, thereby preventing the code C from taking a long time to be read.

[0203] [4-3. Modification of the Third Embodiment] For example, the modification of the first embodiment may be applied to the display control device 10 of the third embodiment. The modification of the second embodiment may be applied to the display control device 10 of the third embodiment. For example, the display control unit 102 may determine, based on a predetermined determination method, whether or not the code C is about to be read by the reading unit 26, and may brighten the code screen SC based on the result of the determination.

[0204] [4-4. Other Modifications] For example, two or three of the modifications of the first embodiment, the second embodiment, and the third embodiment may be combined.

[0205] For example, the display control device 10 is not limited to a device operated by a user. The display control device 10 may also be a device not operated by a user. The display control device 10 may also be a device in a store. For example, the display control device 10 may cause the display unit 15 to display a code screen SC including a code C generated based on a store ID that can identify the store. In this case, a terminal such as a smartphone of the user may correspond to the reading device 20. A store clerk points the display control device 10, which is a tablet or the like in the store, toward the user and prompts the user to read the code C. In such a case, the display control device 10, which is a tablet or the like in the store, may change the display of the code screen SC based on at least one of posture information and light information.

[0206] For example, a function described as being realized by the display control device 10 may be realized by the reading device 20, the server 30, or another computer. A process described as being realized by the display control device 10 may be shared among multiple computers. A function described as being realized by the reading device 20 may be realized by the display control device 10, the server 30, or another computer. A function described as being realized by the server 30 may be realized by the display control device 10, the reading device 20, or another computer.

[0207] [5. Supplementary Note] For example, the program according to the present disclosure may also be configured as follows.

[0208] [5-1. Supplementary notes on the first embodiment] For example, the program according to the first embodiment may also be configured as follows. (1-1) A program that causes a display control device to function as a display control unit that causes a code screen including code to be displayed on a display unit of a display control device, and an attitude information acquisition unit that acquires attitude information related to the attitude of the display control device when the code screen is displayed on the display unit, wherein the display control unit changes the display of the code screen based on the attitude information. (1-2) The program described in (1-1) in which the attitude information acquisition unit acquires tilt information related to the tilt of the display control device as the attitude information, and the display control unit changes the display of the code screen based on the tilt information. (1-3) The program described in (1-2) in which the attitude information acquisition unit acquires tilt information etc. related to the tilt of the display control device and the orientation of the code screen as the tilt information, and the display control unit changes the display of the code screen based on the tilt information etc. (1-4) The program according to any one of (1-1) to (1-3), wherein the attitude information acquisition unit acquires the attitude information at each of a plurality of time points, and the display control unit detects a change in attitude based on the attitude information at each of the plurality of time points, and changes the display of the code screen based on the change in attitude. (1-5) The program according to (1-4), wherein the display control unit detects a rotation of the display control device as the change in attitude, and changes the display of the code screen based on the rotation of the display control device. (1-6) The program according to (1-4) or (1-5), wherein the program further causes the display control device to function as a reference attitude setting unit that sets a reference attitude related to the attitude that serves as a reference, and the display control unit detects a change in attitude from the reference attitude, and changes the display of the code screen based on the change in attitude from the reference attitude. (1-7) The program according to (1-6), wherein the reference attitude setting unit sets the reference attitude based on the attitude information acquired when the code screen is displayed on the display unit.(1-8) The program according to any of (1-1) to (1-7), wherein the display control unit changes the display of the code screen by changing the size of the code on the code screen. (1-9) The program according to (1-8), wherein the display control unit changes the display of the code screen by changing the display position of lower content displayed below the code on the code screen without changing the display position of upper content displayed above the code on the code screen. (1-10) The program according to any of (1-1) to (1-9), wherein the display control unit changes the display of the code screen by changing the brightness of the code screen. (1-11) The program according to any of (1-1) to (1-10), wherein the display control unit determines a degree of change in the display of the code screen based on the posture information, and changes the display of the code screen based on the degree. (1-12) The program according to any one of (1-1) to (1-11), wherein the display control unit repeatedly changes the display of the code screen. (1-13) The program according to (1-12), wherein the program further causes the display control device to function as an execution determination unit that determines whether a predetermined process that is executed when the code is read by a reading device has been executed, and the display control unit repeatedly changes the display of the code screen while it is determined that the predetermined process has not been executed.

[0209] [5-2. Supplementary notes on the second embodiment] For example, the program according to the second embodiment can also be configured as follows. (2-1) A program that causes the display control device to function as a display control unit that causes a display unit of the display control device to display a code screen including a code, and a light information acquisition unit that acquires light information related to light to the display control device when the code screen is displayed on the display unit, and the display control unit changes the display of the code screen based on the light information. (2-2) The program described in (2-1), in which the light information acquisition unit acquires the light information at each of a plurality of time points, and the display control unit detects a change in the light based on the light information at each of the plurality of time points, and changes the display of the code screen based on the change in light. (2-3) The program described in (2-2), in which the display control unit detects a change in the light such that the light becomes darker, and changes the display of the code screen based on the change in the light. (2-4) The program according to (2-2) or (2-3), wherein the display control unit detects, as the change in the light, a change in the light becoming brighter, and changes the display of the code screen based on the change in the light becoming brighter. (2-5) The program according to any of (2-2) to (2-4), wherein the program further causes the display control device to function as a reference degree setting unit that sets a reference degree related to a reference degree of brightness of the light, and the display control unit changes the display of the code screen based on the change in the light from the reference degree. (2-6) The program according to (2-5), wherein the reference degree setting unit sets the reference degree based on the light information acquired when the code screen is displayed on the display unit. (2-7) The program according to any of (2-1) to (2-6), wherein the light information acquisition unit acquires color information related to a color of the light as the light information, and the display control unit changes the display of the code screen based on the color information. (2-8) The program according to (2-7), wherein the light information acquisition unit acquires the color information based on an in-camera of the display control device.(2-9) The program according to any one of (2-1) to (2-8), wherein the display control unit changes the display of the code screen by changing the size of the code on the code screen. (2-10) The program according to (2-9), wherein the display control unit changes the display of the code screen by changing the display position of lower content displayed below the code on the code screen without changing the display position of upper content displayed above the code on the code screen. (2-11) The program according to any one of (2-1) to (2-10), wherein the display control unit changes the display of the code screen by changing the brightness of the code screen. (2-12) The program according to any one of (2-1) to (2-11), wherein the display control unit determines a degree of change in the display of the code screen based on the light information, and changes the display of the code screen based on the degree. (2-13) The program according to any one of (2-1) to (2-12), wherein the display control unit repeatedly changes the display of the code screen. (2-14) The program according to (2-13), wherein the program further causes the display control device to function as an execution determination unit that determines whether a predetermined process that is to be executed when the code is read by a reading device has been executed, and the display control unit repeatedly changes the display of the code screen while it is determined that the predetermined process has not been executed. (2-15) The program according to any one of (2-1) to (2-14), wherein the display control unit estimates a distance between the display control device and a reading device that reads the code based on the light information, and changes the display of the code screen based on the distance.

[0210] [5-3. Supplementary notes on the third embodiment] For example, the program according to the third embodiment may also be configured as follows. (3-1) A program that causes a display control device to function as a display control unit that displays a code screen including a code on a display unit of the display control device, wherein the display control unit determines, based on a predetermined determination method, whether the code is about to be read by a reading device, and changes the display of the code screen based on the result of the determination. (3-2) The program according to (3-1), wherein the predetermined determination method is a determination method based on the posture information described in any of (1-1) to (1-13), and has a function of any of (1-1) to (1-13). (3-3) The program according to (3-1) or (3-2), wherein the predetermined determination method is a determination method based on the light information described in any of (2-1) to (2-15), and has a function of any of (2-1) to (2-15).

Claims

1. A program that causes a display control device to function as: a display control unit that displays a code screen including a code on a display unit of a display control device; and an optical information acquisition unit that acquires optical information regarding light to the display control device when the code screen is displayed on the display unit; and the display control unit changes the display of the code screen based on the optical information.

2. The program described in claim 1, wherein the light information acquisition unit acquires the light information at each of a plurality of points in time, and the display control unit detects changes in the light based on the light information at each of the plurality of points in time, and changes the display of the code screen based on the changes in the light.

3. The program according to claim 2, wherein the display control unit detects a change in the light such that the light becomes darker, and changes the display of the code screen based on the change in the light becoming darker.

4. The program according to claim 2 or 3, wherein the display control unit detects a change in the light such that the light becomes brighter, and changes the display of the code screen based on the change in the light such that the light becomes brighter.

5. The program according to claim 2 or 3, further causing the display control device to function as a reference degree setting unit that sets a reference degree regarding the reference degree of brightness of the light, and the display control unit changes the display of the code screen based on a change in the light from the reference degree.

6. The program according to claim 5, wherein the reference degree setting unit sets the reference degree based on the light information acquired when the code screen is displayed on the display unit.

7. The program according to any one of claims 1 to 3, wherein the light information acquisition unit acquires color information relating to the color of the light as the light information, and the display control unit changes the display of the code screen based on the color information.

8. The program according to claim 7, wherein the light information acquisition unit acquires the color information based on an in-camera of the display control device.

9. The program according to any one of claims 1 to 3, wherein the display control unit changes the display of the code screen by changing the size of the code on the code screen.

10. The program described in claim 9, wherein the display control unit changes the display of the code screen by changing the display position of lower content displayed below the code on the code screen without changing the display position of upper content displayed above the code on the code screen.

11. The program according to any one of claims 1 to 3, wherein the display control unit changes the display of the code screen by changing the brightness of the code screen.

12. The program according to any one of claims 1 to 3, wherein the display control unit determines the degree of change to the display of the code screen based on the light information, and changes the display of the code screen based on that degree.

13. The program according to any one of claims 1 to 3, wherein the display control unit repeatedly changes the display of the code screen.

14. The program according to claim 13, further causing the display control device to function as an execution determination unit that determines whether a predetermined process that is to be executed when the code is read by a reading device has been executed, and the display control unit repeatedly changes the display of the code screen while it is determined that the predetermined process has not been executed.

15. The program according to any one of claims 1 to 3, wherein the display control unit estimates the distance between the display control device and a reading device that reads the code based on the optical information, and changes the display of the code screen based on the distance.

16. A display control device comprising: a display control unit that displays a code screen including a code on a display unit of a display control device; and an optical information acquisition unit that acquires optical information regarding light to the display control device when the code screen is displayed on the display unit, wherein the display control unit changes the display of the code screen based on the optical information.

17. A display control method comprising: a display control step of displaying a code screen including a code on a display unit of a display control device; and an optical information acquisition step of acquiring optical information regarding light to the display control device when the code screen is displayed on the display unit, wherein the display control step changes the display of the code screen based on the optical information.

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