DISPLAY DEVICE AND DISPLAY METHOD

A display device includes a display, an acquirer, and a controller. The display is configured to display a display image containing identification information of a purchase item to a reader of a cash register. The acquirer is configured to acquire external output information from the cash register. The controller is configured to control a display operation of the display on the basis of the external output information. When the controller determines, on the basis of external output information of a first purchase item from the cash register, that the cash register has identified the first purchase item, the controller causes the display to display a display image containing identification information of a second purchase item.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2021-007244 (filed on Jan. 20, 2021), the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a display device and a display method.

BACKGROUND OF INVENTION

For example, Patent Literature 1 discloses a self-service cash register system that allows customers to make payment at a retail store or the like without staff intervention.

CITATION LIST

Patent Literature

SUMMARY

In an aspect of the present disclosure, a display device includes a display, an acquirer, and a controller. The display is configured to display a display image containing identification information of a purchase item to a reader of a cash register. The acquirer is configured to acquire external output information from the cash register. The controller is configured to control a display operation of the display on the basis of the external output information. When the controller determines, on the basis of external output information of a first purchase item from the cash register, that the cash register has identified the first purchase item, the controller causes the display to display a display image containing identification information of a second purchase item.

In another aspect of the present disclosure, a display method includes displaying a display image containing identification information of a first purchase item to a reader of a cash register; acquiring external output information from the cash register; and displaying a display image containing identification information of a second purchase item when determining, on the basis of external output information of the first purchase item from the cash register, that the cash register has identified the first purchase item.

DESCRIPTION OF EMBODIMENTS

Introducing a self-service cash register system, such as that described in Patent Literature 1, often involves replacing an existing cash register system. In view of the cost of equipment, it is preferable to introduce a self-service cash register system without replacing an existing cash register system. The present disclosure enables construction of a self-service cash register system capable of connecting to an existing cash register system.

Embodiments of a display device and a display method to which the present disclosure is applied will now be described with reference to the drawings.

First Embodiment

FIG.1andFIG.2are a functional block diagram and an external view, respectively, of a payment processing system according to a first embodiment.

In the first embodiment of the present disclosure, as illustrated inFIG.1, the payment processing system includes an imaging device1, a display device2, and a cash register3.

In the drawings described below, each solid arrow connecting functional blocks represents a control signal or a flow of communicated information. Communication indicated by the solid arrow may be wire communication, wireless communication, or a combination of both. For wireless communication, the imaging device1, the display device2, or the cash register3may include a communication module for communication compliant with various wire/wireless communication standards including, for example, Bluetooth (registered trademark) IEEE 802.3 or IEEE 802.11. The wireless communication may be optical communication.

In the drawings described below, each broken arrow connecting functional blocks represents, for example, a flow of information sent from the functional block at the start point of the arrow and acquired by the functional block at the end point of the arrow.

As illustrated inFIG.1, the imaging device1includes an imager11, an extractor12, and an output unit13.

The imager11captures an image of an imaging object and generates a captured image of the imaging object.

The imager11includes a camera. The camera includes an imaging optical system and an imaging element. The imaging optical system includes, for example, optical members, such as one or more lenses and an aperture stop. The lens may be a lens of any focal length. For example, the lens may be a commonly used lens, a wide-angle lens such as a fisheye lens, or a zoom lens with a variable focal length. The imaging optical system forms a subject image on a light receiving surface of the imaging element. The imaging element is, for example, a charge coupled device (CCD) image sensor or a complementary metal-oxide semiconductor (CMOS) image sensor. The imaging element captures the subject image formed on the light receiving surface and generates a captured image. The imager11may continuously capture still images at any frame rate. Continuously capturing still images may mean capturing a moving image.

From the captured image captured by the imager11, the extractor12extracts identification information for identifying the type of the imaging object.

The identification information may be, for example, a one-dimensional barcode, such as a Japan Article Number (JAN) code, or a two-dimensional barcode, such as a QR code (registered trademark). Generally, using identification information makes it possible to identify the item name or the price of the imaging object, and perform payment processing, sales management, and inventory and purchase management.

To extract identification information, the extractor12may use an object recognition technique based on, for example, pattern matching or machine learning. As the object recognition technique for extracting identification information, the extractor12may use a known technique, such as a detection network or sliding window detection.

For the extractor12to extract identification information, for example, the extractor12may trim the first image to include identification information and generate a new image.

The extractor12includes a processor and a memory. The processor may be a central processing unit (CPU), a graphics processing unit (GPU), or a field-programmable gate array (FPGA). The memory may be a semiconductor memory, a magnetic memory, or an optical memory. The semiconductor memory may be a volatile memory or a non-volatile memory. The magnetic memory may be, for example, a hard disk or a magnetic tape. The optical memory may be, for example, a compact disc (CD), a digital versatile disc (DVD), or a Blu-ray (registered trademark) disc (BD).

The memory included in the extractor12may store various types of information or parameters related to the operation of the imaging device1. The memory may store programs executed by the extractor12. The memory may function as a working memory for the extractor12. The memory may store the first image or identification information.

The output unit13outputs identification information acquired by the extractor12to an input unit21of the display device2.

FIG.2illustrates an example in which the output unit13is connected to the input unit21wirelessly, not by a wire. As described in paragraph (0012), however, the output unit13may be connected by a wire to the input unit21.

FIG.3is a functional block diagram of the display device2included in the first embodiment of the payment processing system.

The display device2includes the input unit21, a controller22, a display23, and an acquirer24.

The input unit21accepts an input of identification information output from the output unit13included in the imaging device1. The input unit21then transmits the accepted identification information to the controller22.

As illustrated inFIG.3, the controller22includes a determiner221and a memory222.

The determiner221performs various types of determination processing described below.

The determiner221includes a processor. The processor may be a central processing unit (CPU), a graphics processing unit (GPU), or a field-programmable gate array (FPGA).

The memory222stores, for example, various types of information or parameters related to the operation of the display device2. That is, data related to the functions of the display device2and various types of information received by and output from the controller22are all processed through the memory222. The memory222may store programs executed by the determiner221. The memory222may function as a working memory for the determiner221. The memory222may store a captured image, identification information, or a display image (described below).

The memory222may be a semiconductor memory, a magnetic memory, or an optical memory. The semiconductor memory may be a volatile memory or a non-volatile memory. The magnetic memory may be a hard disk or a magnetic tape. The optical memory may be a compact disc (CD), a digital versatile disc (DVD), or a Blu-ray (registered trademark) disc (BD).

On the basis of external output information from the cash register3received by the acquirer24, the determiner221generates a display image containing identification information transmitted from the input unit21, and determines whether to update and display the display image on the display23. The term “update and display” means to update a display image already displayed on the display23. That is, when two or more pieces of identification information are transmitted to the determiner221, the “update and display” may mean display processing which involves displaying a display image containing first identification information on the display23, displaying identification information containing second identification information on the display23, and then displaying identification information containing third identification information on the display23. Details of the external output information will be described later on, along with the description of the acquirer24.

The display image may be generated after correction processing, such as trimming or rearrangement of identification information, for a reader31of the cash register3to easily read the identification information.

For the determiner221to update and display a display image on the display23, the cash register3is required to detect identification information and identify/register an imaging object. That is, the determiner221determines, on the basis of external output information, whether the cash register3has detected identification information and has identified/registered an imaging object.

When the determiner221determines that the cash register3has detected identification information contained in the display image and has identified an imaging object, the determiner221updates and displays the display image on the display23.

The “update and display” may mean, for example, to display a whiteout that occurs by stopping a pre-update display image before displaying a post-update display image, or to display an image not containing identification information.

The controller22causes the display23to display a display image to the reader31.

The display23includes a display device, such as a liquid crystal display, an organic EL (or emitting diode) display, or an inorganic EL display.

The acquirer24acquires external output information from the cash register3and transmits the acquired external output information to the determiner221. Details of the acquirer24will be described later on.

As illustrated inFIG.1, the cash register3includes the reader31, an identifier32, a computer processor33, an operation screen34, and a speaker35. The operation screen34or the speaker35may be optional.

The reader31reads and analyzes identification information displayed on the display23included in the display device2, and acquires a management code used to identify the type of an imaging object. The management code is associated with the item name of the imaging object. For example, the management code may be a JAN code. The reader31transmits the acquired management code to the identifier32.

The reader31may be, for example, an optical reader. The optical reader may be, for example, a pen reader, a CCD touch reader, a laser scanner, a two-dimensional barcode reader, or a stationary barcode reader.

The identifier32identifies an imaging object on the basis of the management code acquired by the reader31. Identifying an imaging object involves identifying the item name or the price of the imaging object.

The computer processor33performs registration/payment processing on the basis of, for example, the item name or the price of the imaging object identified by the identifier32. The registration processing may be, for example, calculating the price of one imaging object identified by the identifier32and registering the imaging object and the price on a list. The computer processor33may calculate the sum of the prices of imaging objects registered on the list. The payment processing may mean making payment on the basis of the sum of the prices of one or more imaging objects registered on the list during execution of the payment processing.

The identifier32and the computer processor33include a processor and a memory. The processor may be a central processing unit (CPU), a graphics processing unit (GPU), or a field-programmable gate array (FPGA). The memory may be a semiconductor memory, a magnetic memory, or an optical memory. The semiconductor memory may be a volatile memory or a non-volatile memory. The magnetic memory may be, for example, a hard disk or a magnetic tape. The optical memory may be, for example, a compact disc (CD), a digital versatile disc (DVD), or a Blu-ray (registered trademark) disc (BD).

The memory included in the identifier32and the computer processor33may store various types of information or parameters related to the operation of the cash register3. The memory may store programs executed by the identifier32and the computer processor33. The memory may function as a working memory for the identifier32and the computer processor33.

The identifier32and the computer processor33may share part of or the entire processor and memory, or may each include a processor and a memory.

The operation screen34displays data related to imaging objects identified, registered, or subjected to payment processing by the identifier32and the computer processor33. The operation screen34thus functions as an interface for the user to operate the cash register3. Examples of the user operation performed on the cash register3through the operation screen34include correcting the result of registration/payment processing performed by the computer processor33, and confirming the result of payment processing.

The operation screen34includes a display device, such as a liquid crystal display, an organic EL (or emitting diode) display, or an inorganic EL display. An operation on the operation screen34may be a touch operation, a keyboard operation, a mouse operation, or a trackball operation. When the operation on the operation screen34is a touch operation, the operation screen34may be a pressure-sensitive or electrostatic touch panel. When the operation on the operation screen34is a keyboard operation, a mouse operation, or a trackball operation, the operation screen34may be provided with an input keyboard, a mouse, or a trackball.

The speaker35outputs a read sound when the computer processor33identifies and registers an imaging object.

The speaker35includes, for example, a piezoelectric speaker. A read sound output by the speaker35may be, for example, a beep or voice. The read sound may vary depending on, for example, whether the computer processor33has succeeded in registration processing.

External output information acquired by the acquirer24and a method of determination processing performed by the determiner221, according to the first embodiment, will now be described by usingFIGS.4to6.

FIG.4is a diagram illustrating an image of how the acquirer24acquires external output information. As illustrated inFIG.4, the acquirer24captures an image in an imaging range IR including the operation screen34as external output information from the cash register3. The acquirer24transmits the acquired captured image to the determiner221. The determiner221makes a determination on the basis of the acquired captured image.

In the first embodiment, the acquirer24includes a camera. The camera includes an imaging optical system and an imaging element. The imaging optical system includes, for example, optical members, such as one or more lenses and an aperture stop. The lens may be a lens of any focal length. For example, the lens may be a commonly used lens, a wide-angle lens such as a fisheye lens, or a zoom lens with a variable focal length. The imaging optical system forms a subject image on a light receiving surface of the imaging element. The imaging element is, for example, a charge coupled device (CCD) image sensor or a complementary metal-oxide semiconductor (CMOS) image sensor. The imaging element captures the subject image formed on the light receiving surface and generates a captured image. The imager11may continuously capture still images at any frame rate. Continuously capturing still images may mean capturing a moving image.

FIG.5andFIG.6are diagrams illustrating pre-update and post-update images, respectively, of external output information on the operation screen, acquired by the display device. Differences betweenFIG.5andFIG.6are surrounded by frames inFIG.6. As indicated, an item EEE is added and the total amount is updated inFIG.6.

The determiner221detects changes in the operation screen34, such as those illustrated inFIG.5andFIG.6, through a captured image acquired by the acquirer24.

When the acquirer24continuously captures still images to generate a captured image, a registered imaging object may be added and the total amount may be updated, as illustrated inFIG.6. In this case, the determiner221may determine, on the basis of the occurrence of changes in the generated captured image, that the cash register3has detected identification information and has identified/registered the imaging object.

By usingFIG.7, an update and display processing flow in the display device2, according to the first embodiment, will be described while referring to processing in the imaging device1and the cash register3. The description herein assumes that there are two imaging objects, a first purchase item and a second purchase item. The processing flow may be constructed in such a way that the same and/or similar processing can be performed on three or more imaging objects on the basis of the description herein. This also applies to the description of update and display processing flows in second and third embodiments.

The imaging device1causes the imager11to capture an image of a first purchase item to generate a captured image, and causes the extractor12to extract identification information of the first purchase item from the captured image. Then, the process proceeds to <S002>.

After the extractor12extracts the identification information of the first purchase item, the imaging device1causes the output unit13to transmit the identification information of the first purchase item to the display device2. Then, the process proceeds to <S003>.

After the output unit13transmits the identification information of the first purchase item to the display device2, the display device2stores, in the memory222, the identification information of the first purchase item transmitted from the imaging device1to the input unit21. Then, the process proceeds to <S004>.

After the memory222stores therein the identification information of the first purchase item, the display device2confirms that no image is displayed on the display23at this point. The display device2then causes the determiner221to generate a display image containing the identification information of the first purchase item, and causes the display23to display the display image containing the identification information of the first purchase item. Then, the process proceeds to <S005>.

After the display23displays the display image containing the identification information of the first purchase item, the imaging device1causes the imager11to capture an image of a second purchase item to generate a captured image, and causes the extractor12to extract identification information of the second purchase item from the captured image. Then, the process proceeds to <S006>.

After the extractor12extracts the identification information of the second purchase item, the imaging device1causes the output unit13to transmit the identification information of the second purchase item to the display device2. Then, the process proceeds to <S007>.

After the output unit13transmits the identification information of the second purchase item to the display device2, the display device2stores, in the memory222, the identification information of the second purchase item transmitted from the imaging device1to the input unit21. Then, the process proceeds to <S008>.

After the memory222stores therein the identification information of the second purchase item, the display device2causes the acquirer24to start acquisition of a captured image of the operation screen34included in the cash register3. The acquired captured image of the operation screen34is sequentially transmitted to the determiner221. Then, the process proceeds to <S009>.

After the acquirer24starts acquisition of a captured image of the operation screen34included in the cash register3, the cash register3causes the reader31to read the identification information contained in the display image of the first purchase item, and causes the identifier32and the computer processor33to identify/register the first purchase item. Then, the process proceeds to <S010>.

After the identifier32and the computer processor33identify/register the first purchase item, the cash register3reflects the update on the identified/registered first purchase item on the operation screen34. Then, the process proceeds to <S011>.

After the update on the registered first purchase item is reflected on the operation screen34, or if the determiner221determines in <S012> that there has been no update on the first purchase item on the operation screen34, the display device2causes the acquirer24to acquire the latest captured image of the operation screen34included in the cash register3. Since the acquisition of a captured image has started in <S008>, the display device2is assumed to have at least two captured images at this point. Then, the process proceeds to <S012>. The acquired captured images may be deleted after being stored in the memory222for a given period of time.

After the acquirer24acquires the latest captured image of the operation screen34included in the cash register3, the display device2causes the determiner221to determine, from the captured image of the operation screen34acquired by the acquirer24, whether there has been any update on the registered first purchase item on the operation screen34. In other words, on the basis of the captured image of the operation screen34acquired by the acquirer24, the determiner221determines whether the cash register3has detected the identification information of the first purchase item and has identified/registered the first purchase item. If the determiner221determines that there has been an update on the first purchase item, the process proceeds to <S013>. If the determiner221determines that there has been no update on the first purchase item, the process returns to <S011>.

If the determiner221determines that there has been an update on the first purchase item on the operation screen34, the display device2causes the determiner221to determine that the cash register3has detected the identification information of the first purchase item and has identified/registered the first purchase item. Then, the process proceeds to <S014>.

If the determiner221determines that the cash register3has detected the identification information of the first purchase item and has identified/registered the first purchase item, the display device2causes the determiner221to generate a display image containing identification information of a second purchase item, and causes the display23to display the generated display image, in place of the display image containing the identification information of the first purchase item.

Second Embodiment

In the first embodiment, a display image on the display23is updated on the basis of changes in the operation screen34of the cash register3. In a second embodiment, a display image on the display23is updated on the basis of an output sound from the speaker35of the cash register3.

The second embodiment will be described, with a focus on differences from the first embodiment.

By usingFIG.8andFIG.9, external output information acquired by the acquirer24and a determination processing method performed by the determiner221, according to the second embodiment, will be described.

FIG.8is a diagram illustrating an image of how the acquirer24acquires external output information. As illustrated inFIG.8, the acquirer24collects an output sound from the cash register3, in a collectable state, as external output information of the cash register3, and transmits the acquired sound to the determiner221. The output sound may be, for example, a read sound output from the speaker35. The determiner221makes a determination on the basis of the acquired sound.

In the second embodiment, the acquirer24includes one or more microphones. The microphone may be, for example, a capacitor microphone or a dynamic microphone. The microphone may have directivity that enables precise collection of a read sound output from the speaker35.

The determiner221learns a sound waveform corresponding to the read sound in advance, and attempts to detect a sound waveform corresponding to the read sound from the sound acquired by the acquirer24. To detect a sound waveform, the determiner221may use, for example, a pattern matching technique, such as dynamic programming (DP) matching, or other known sound recognition/matching techniques.

The determiner221may determine, when determining that a sound waveform corresponding to the read sound has been detected, that the cash register3has detected identification information and has identified/registered an imaging object.

By usingFIG.9, an update and display processing flow in the display device2, according to the second embodiment, will be described while referring to processing in the imaging device1and the cash register3.

The description of steps <S101> to <S107>, which are equivalent to <S001> to <S007> in the first embodiment, is omitted here. After the memory222stores the identification information of the second purchase item in <S107>, the process proceeds to <S108>.

After the memory222stores therein the identification information of the second purchase item, the display device2causes the acquirer24to start acquisition of a sound. The sound acquired here is sequentially transmitted to the determiner221, which analyzes the sound waveform. Then, the process proceeds to <S109>.

After the acquirer24starts acquisition of a sound and the determiner221starts analysis of a sound waveform, the cash register3causes the reader31to read the identification information of the first purchase item, contained in the display image, and causes the identifier32and the computer processor33to identify/register the first purchase item. Then, the process proceeds to <S110>.

After the identifier32and the computer processor33identify/register the first purchase item, the cash register3outputs, from the speaker35, a read sound indicating that the first purchase item has been identified/registered. Then, the process proceeds to <S111>.

After the read sound is output from the speaker35, or if the determiner221determines in <S112> that the sound waveform corresponding to the read sound has not been detected, the display device2causes the acquirer24to acquire the latest sound and transmit it to the determiner221, which analyzes the sound waveform. Then, the process proceeds to <S112>.

After the acquirer24acquires the latest sound and the determiner221analyzes the sound waveform, the display device2causes the determiner221to determine whether a sound waveform corresponding to the read sound has been detected. In other words, on the basis of the sound acquired by the acquirer24, the determiner221determines whether the cash register3has detected the identification information of the first purchase item and has identified/registered the first purchase item. If the determiner221determines that the sound waveform corresponding to the read sound has been detected, the process proceeds to <S113>. If the determiner221determines that the sound waveform corresponding to the read sound has not been detected, the process returns to <S111>.

If the determiner221determines that the sound waveform corresponding to the read sound has been detected, the display device2causes the determiner221to determine whether the cash register3has detected the identification information of the first purchase item and has identified/registered the first purchase item. Then, the process proceeds to <S114>.

If the determiner221determines that the cash register3has identified the identification information of the first purchase item and has identified/registered the first purchase item, the display device2causes the determiner221to generate a display image containing identification information of a second purchase item, and causes the display23to display the generated display image, in place of the display image containing the identification information of the first purchase item.

Third Embodiment

In the second embodiment, a display image on the display23is updated on the basis of an output sound from the speaker35of the cash register3. In a third embodiment, a display image on the display23is updated on the basis of changes in the operation screen34of the cash register3and an output sound of the speaker35. In other words, the third embodiment is a combination of the first and second embodiments.

In the third embodiment, the acquirer24includes a camera and a microphone. The configurations of the camera and the microphone are the same as those described in the first and second embodiments.

The determiner221determines whether the acquirer24has detected a change in the operation screen34and the output sound of the speaker35at substantially the same time. The term “substantially the same time” means that the outputs from the cash register3in registering the same imaging object take place within an allowable range of time. That is, the determiner221may appropriately adjust the allowable range of “substantially the same time” in accordance with the specifications of the cash register3to be used.

The determiner221may determine, when determining that acquirer24has detected a change in the operation screen34and the output sound of the speaker35at substantially the same time, that the cash register3has detected the identification information and has identified/registered an imaging object.

By usingFIG.10, an update and display processing flow in the display device2, according to the second embodiment, will be described while referring to processing in the imaging device1and the cash register3.

The description of steps <S201> to <S207>, which are equivalent to <S001> to <S007> in the first embodiment, is omitted here. After the memory222stores the identification information of the second purchase item in <S207>, the process proceeds to <S208>.

After the memory222stores therein the identification information of the second purchase item, the display device2causes the acquirer24to start acquisition of a sound. The sound acquired here is sequentially transmitted to the determiner221, which analyzes the sound waveform. Then, the process proceeds to <S209>.

After the acquirer24starts acquisition of a sound and the determiner221starts analysis of a sound waveform, the display device2causes the acquirer24to start acquisition of a captured image of the operation screen34included in the cash register3. Then, the process proceeds to <S210>.

After the acquirer24starts acquisition of a captured image of the operation screen34included in the cash register3, the cash register3causes the reader31to read the identification information contained in the display image of the first purchase item, and causes the identifier32and the computer processor33to identify/register the first purchase item. Then, the process proceeds to <S211>.

After the identifier32and the computer processor33identify/register the first purchase item, the cash register3outputs, from the speaker35, a read sound indicating that the first purchase item has been registered. Then, the process proceeds to <S212>.

After the read sound is output from the speaker35, the cash register3reflects the update on the registered first purchase item on the operation screen34. Then, the process proceeds to <S213>.

After the read sound is output from the speaker35, or if the determiner221determines in <S214> that the sound waveform corresponding to the read sound has not been detected, determines in <S216> that there has been no update on the first purchase item on the operation screen34, or determines in <S217> that the operation screen34has not been updated at substantially the same time as the output of the read sound, the display device2causes the acquirer24to acquire the latest sound and transmit it to the determiner221, which analyzes the sound waveform. Then, the process proceeds to <S214>.

After the acquirer24acquires the latest sound and the determiner221analyzes the sound waveform, the display device2causes the determiner221to determine whether a sound waveform corresponding to the read sound has been detected. In other words, on the basis of the sound acquired by the acquirer24, the determiner221determines whether the cash register3has detected the identification information of the first purchase item and has identified/registered the first purchase item. If the determiner221determines that the sound waveform corresponding to the read sound has been detected, the process proceeds to <S215>. If the determiner221determines that the sound waveform corresponding to the read sound has not been detected, the process returns to <S213>.

If the determiner221determines that the sound waveform corresponding to the read sound has been detected, the display device2causes the acquirer24to acquire the latest captured image of the operation screen34included in the cash register3. Since the acquisition of a captured image has started in <S209>, the display device2is assumed to have at least two captured images at this point. Then, the process proceeds to <S216>. The acquired captured images may be deleted after being stored in the memory222for a given period of time.

After the acquirer24acquires the latest captured image of the operation screen34included in the cash register3, the display device2causes the determiner221to determine, from the captured image of the operation screen34acquired by the acquirer24, whether there has been any update on the registered first purchase item on the operation screen34. In other words, on the basis of the captured image of the operation screen34acquired by the acquirer24, the determiner221determines whether the cash register3has detected the identification information of the first purchase item and has identified/registered the first purchase item. If the determiner221determines that there has been an update on the first purchase item, the process proceeds to <S217>. If the determiner221determines that there has been no update on the first purchase item, the process returns to <S213>.

If the determiner221determines that there has been an update on the first purchase item on the operation screen34, the display device2causes the determiner221to determine, from the captured image of the operation screen34acquired by the acquirer24, whether the registered first purchase item has been updated on the operation screen34within the range of substantially the same time as the detection of the sound waveform corresponding to the read sound. If the determiner221determines that the first purchase item has been updated within the range of substantially the same time as the detection of the sound waveform corresponding to the read sound, the process proceeds to <S218>. If the determiner221determines that there has been no update on the first purchase item within the range of substantially the same time as the detection of the sound waveform corresponding to the read sound, the process returns to <S213>.

If the determiner221determines that the sound waveform corresponding to the read sound has been detected within the range of substantially the same time as the detection of the sound waveform corresponding to the read sound, the display device2causes the determiner221to determine that the cash register3has detected the identification information of the first purchase item and has identified/registered the first purchase item. Then, the process proceeds to <S219>.

If the determiner221determines that the cash register3has detected the identification information of the first purchase item and has identified/registered the first purchase item, the display device2causes the determiner221to generate a display image containing identification information of a second purchase item, and causes the display23to display the generated display image, in place of the display image containing the identification information of the first purchase item.

Although the display device and the display method of the present disclosure have been described on the basis of the drawings and embodiments, it is to be noted that any person skilled in the art can easily make various alternative embodiments and amendments on the basis of the present disclosure.

For example, functions, means, and steps described in embodiments can be rearranged in a logically non-contradictory way. A plurality of means or steps may be combined into a single one, or may each be divided.

For the update and display on the display23included in the display device2described, for example, in paragraph (0037), if the first purchase item and the second purchase item are the same items, the display images containing the same identification information are displayed in succession. This may cause a problem in updating and displaying, depending on the specifications of the cash register3. Therefore, for example, the determiner221may determine whether the first purchase item and the second purchase item are the same items. Then, if the first purchase item and the second purchase item are the same items, the determiner221may set a standby time of a predetermined length before a post-update display image is displayed in updating and displaying on the display23. During the standby time, the display23may display a whiteout display image or a display image not containing identification information.

Although the display device and the display method have been described as a solution in the present disclosure, the present disclosure may be implemented as an embodiment including the display device and the display method, or may be implemented as a system, a program, and a storage medium recording the program that are substantially equivalent to the display device and the display method. It is to be understood, therefore, that such a system, a program, and a storage medium are also included in the scope of the present disclosure.

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