Self-service POS terminal device

A self-service POS terminal device comprises a first antenna and a second antenna, and reads, via each of the first antenna and the second antenna, commodity-related information stored in IC tags of commodities. The first antenna is positioned at a position for reading the IC tags of the commodities loaded in a shopping basket at a prescribed position, and forms a first reading area. The second antenna is positioned at a position for reading the IC tags of the commodities taken out from the shopping basket at the prescribed position and put into a shopping bag, and forms a second reading area.

This application is a National Stage Entry of PCT/JP2019/004962 filed on Feb. 13, 2019, which claims priority from Japanese Patent Application 2018-034804 filed on Feb. 28, 2018, the contents of all of which are incorporated herein by reference, in their entirety.

TECHNICAL FIELD

This invention relates to a self-service POS terminal device.

BACKGROUND ART

As a POS (Point of Sales) terminal device installed in a shop, such as a supermarket, to register commodities to be purchased by a customer and to perform checkout, a so-called self-service POS terminal device is known. In the self-service POS terminal device, the customer him/herself performs commodity registration of the commodities to be purchased and performs checkout.

Patent Document 1 discloses a wireless tag reading and processing device as one example of the self-service POS terminal device. With the wireless tag reading and processing device, it is possible for a customer to perform commodity registration and make settlement while commodities are kept loaded in a shopping cart.

PRIOR ART LITERATURE(S)

Patent Literature 1: JP 2010-267010 A

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

However, in the wireless tag reading and processing device, the commodity registration is performed while the commodities to be purchased are kept loaded in the shopping cart. Therefore, if a plurality of commodities overlap one another, wireless tags (IC tags) of some commodities may not be read depending on a state of overlapping. When the wireless tags (IC tags) of those commodities cannot be read, the commodity registration is not performed therefor. This results in a trouble that settlement (checkout) is completed although there are unregistered commodities.

It is an object of this invention to provide a self-service POS terminal device for reading an IC tag of a commodity, which is free from risk of causing a trouble that checkout is completed although there is an unregistered commodity.

Means to Solve the Problem

According to one aspect of this invention, there is provided a self-service POS terminal device having a first antenna and a second antenna and configured to read, through each of the first antenna and the second antenna, commodity-related information stored in an IC tag of a commodity, wherein the first antenna is disposed at a position to read the IC tag of the commodity loaded in a shopping basket at a predetermined position and forms a first reading area whereas the second antenna is disposed at a position to read the IC tag of the commodity taken out from the shopping basket at the predetermined position and put into a shopping bag and forms a second reading area.

Effect of the Invention

According to this invention, it is possible to provide a self-service POS terminal device for reading an IC tag of a commodity, which is free from risk of causing a trouble that checkout is completed although there is an unregistered commodity.

MODE FOR EMBODYING THE INVENTION

Referring toFIGS. 1 to 11, an embodiment of this invention will be described.

FIG. 1is a perspective view of a self-service POS terminal device according to the embodiment of this invention.FIG. 2Ais a front view of the self-service POS terminal device,FIG. 2Bis a top view,FIG. 2Cis a left side view,FIG. 2Dis a right side view, andFIG. 2Eis a rear view.FIG. 3Ais a front view of an upper part of the self-service POS terminal device, andFIG. 3Bis a sectional view taken along a line A-A inFIG. 3A.FIG. 4is a top view of the self-service POS terminal device with a first reading area and a second reading area shown by long-dashed double-dotted lines.FIG. 5Ais a perspective view of a shopping cart (hereinafter abbreviated to “cart”) with a shopping basket mounted thereon,FIG. 5Bis a right side view, andFIG. 5Cis a rear view.FIG. 6Ais a right side view of another example of the cart andFIG. 6Bis a rear view.FIG. 7Ais a perspective view of the self-service POS terminal device when the cart, on which the shopping basket loaded with commodities (not shown) is mounted, is advanced to a position to perform commodity registration and checkout,FIG. 7Bis a front view, andFIG. 7Cis a right side view.FIG. 8Ais a perspective view of the self-service POS terminal device when the shopping basket loaded with the commodities (not shown) is placed on a shopping basket placing portion,FIG. 8Bis a front view, andFIG. 8Cis a right side view.FIG. 9is a perspective view for illustrating a state where a customer performs commodity registration and checkout at the self-service POS terminal device.

In the following description, putting the commodities into the shopping basket will be called “loading”, putting the shopping basket on the cart will be called “mounting”, and putting the shopping basket on the shopping basket placing portion of the self-service POS terminal device will be called “placing” so as to discriminate one from another. A front side of the self-service POS terminal device may be called a “customer side” and an opposite side thereto may be called a rear side.

As shown inFIGS. 1 and 2A to 2E, the self-service POS terminal device100comprises a main body portion110of the device, a left side plate portion120, a right side plate portion130, a bottom plate portion140, a frame portion150, and the shopping basket placing portion160. The self-service POS terminal device100is constructed by plates and frames made of metal (iron, aluminum, or the like) except a part thereof.

A dotted line in the right side viewFIG. 2Drepresents a first antenna ANT1built in the right side plate portion130whereas a dotted line in the front view ofFIG. 2Arepresents a second antenna ANT2built in the main body portion110. As the first antenna ANT1and the second antenna ANT2, for example, a RFID (Radio Frequency Identification) antenna may be used. To a surface of the main body portion110which faces the left side plate portion120and the right side plate portion130, an outside surface of the left side plate portion120, and an outside surface of the right side plate portion130, plastic plates111,121, and131are attached, respectively.

A printer PRT for outputting a receipt and a noncontact IC card reader/writer (CRW) for reading and writing a noncontact IC card are built in an upper part of the main body portion110. As illustrated inFIGS. 3A and 3B, an AI (Aerial Imaging) plate AIP for forming an image of a built-in LCD (Liquid Crystal Display) (display device)112in the air is attached to the upper part of the main body portion110. The AI plate AIP is a glass plate or a resin plate. To a front surface of the AI plate AIP, a plastic transparent panel113is attached for the purpose of protection.

Herein, the AI plate AIP is attached so as to have an inclination angle of 85 degrees with respect to a horizontal plane. The image of the LCD112is formed in the air through the AI plate AIP as depicted by a symbol IMG inFIGS. 3A and 3B. The AI plate AIP and the LCD112are arranged so as to form an angle of 45 degrees. The AI plate AIP and the aerial image IMG forms an angle of 45 degrees. The aerial image IMG has an inclination angle of 40 degrees with respect to the horizontal plane. Below the AI plate AIP, a camera as an image pickup device is disposed towards the aerial image IMG in order to detect a position of a fingertip of the customer in the aerial image IMG. The customer can perform input to the self-service POS terminal device by positioning his/her finger at an operation key displayed on an operation screen of the aerial image IMG. The operation screen is displayed as the aerial image IMG and, therefore, causes no obstacle to customer's operations associated with the commodity registration and the checkout. Since the operation screen alone is displayed as the aerial image IMG, a visual field of the customer is prevented from being blocked by a frame formed around the operation screen as in a conventional display device.

A mode of arrangement of a plurality of components and a mode of display illustrated inFIGS. 3A and 3Bare merely one example. It is needless to say that this invention is not limited to the mode of arrangement and the mode of display being illustrated.

As illustrated inFIGS. 2A to 2E and 4, an IC tag reader (not shown) having the first antenna ANT1and the second antenna ANT2is built in the main body portion110. The IC tag reader can read, through each of the first antenna ANT1and the second antenna ANT2, data (commodity-related information) stored in an IC tag (not shown) attached to each commodity.

The left side plate portion120extends from a left end of the main body portion110towards the customer side whereas the right side plate portion130extends from a right end of the main body portion110towards the customer side. Each of the left side plate portion120and the right side plate portion130has a shape of a rectangle with its one corner cut away, and is supported by the frame portion150. Nothing is built in the left side plate portion120whereas the first antenna ANT1is built in the right side plate portion130. As illustrated in an enlarged view on a lower side ofFIG. 4, a first shielding plate SP1for shielding an electric wave is disposed on a rear surface of the first antenna ANT1. A surface of the right side plate portion130on the side of the shopping basket placing portion160is covered with the plastic plate131(FIG. 2D) so as to pass the electric wave from the first antenna ANT1.

As illustrated inFIGS. 1 and 2A to 2E, the shopping basket placing portion160is horizontally fixed through a shelf rest161to the frame portion150at a height position near a bottom of the right side plate portion130. As illustrated inFIG. 4, the first reading area RA1to read a commodity code stored in the IC tag attached to the commodity is defined in an area on the shopping basket placing portion160. The commodity code is commodity identification information for identifying the commodity and one of the commodity-related information.

The second antenna ANT2is built in the main body portion110at a height position corresponding to the left side plate portion120and the right side plate portion130. On a rear surface of the second antenna ANT2, a second shielding plate SP2for shielding the electric wave is disposed. The surface of the main body portion110which faces the left side plate portion120and the right side plate portion130is covered with the plastic plate111(FIG. 2A) so as to pass the electric wave from the second antenna ANT2. As illustrated inFIG. 4, in an area surrounded by the left side plate portion120, the right side plate portion130, the main body portion110corresponding to the left side plate portion120and the right side plate portion130, and the bottom plate portion140, the second reading area RA2to read the commodity code stored in the IC tag attached to the commodity is formed.

In the top view of the self-service POS terminal device inFIG. 4, the first reading area RA1and the second reading area RA2are shown by the long-dashed double-dotted lines. Dotted lines inFIG. 4indicate the first antenna ANT1, the first shielding plate SP1, the second antenna ANT2, and the second shielding plate SP2.

As shown inFIG. 1, the bottom plate portion140is disposed between a bottom of the left side plate portion120and the bottom of the right side plate portion130by using the frame portion150also. On the bottom plate portion140, a shopping bag reserving holding portion141is provided. In the shopping bag reserving holding portion141, a plurality of shopping bags (checkout bags) are reserved. The customer standing in front of the self-service POS terminal device pulls out, among the plurality of shopping bags being reserved, one shopping bag at the front and brings the shopping bag into an opened state. In the shopping bag reserving holding portion141, the shopping bag is held in the opened state so that the customer can put the commodity into the shopping bag. InFIGS. 1, 2A to 2E, and 4, the plurality of shopping bags being reserved and the shopping bag in the opened state are not illustrated.

The shopping basket placing portion160may be a wooden plate member and is formed at the height position near the bottom of the right side plate portion130. The shopping basket placing portion160is provided at its front end with a recessed portion160a(seeFIG. 1,FIGS. 2A to 2E) for guiding a narrow portion201of a cart200(seeFIGS. 5A to 5C) when the customer advances the cart200, on which the shopping basket loaded with the commodities is mounted, to a position (predetermined position) to perform the commodity registration and the checkout. By providing the shopping basket placing portion160with the recessed portion160aof a generally V shape narrowed in width towards the rear side, the narrow portion201is guided by the recessed portion160a. Thus, the customer can certainly and easily advances the cart200, on which the shopping basket loaded with the commodities is mounted, to the position to perform the commodity registration and the checkout.

FIGS. 5A, 5B, and 5Care the perspective view, the right side view, and the rear view of the cart200with the shopping basket250mounted thereto. As illustrated inFIGS. 5A to 5C, the cart200has the narrow portion201, a shopping basket mounting portion202for mounting the shopping basket250, a handle portion203, and a plurality of (herein, three) wheels204and wheel fixing portions (leg portions)205. The narrow portion201is formed between the shopping basket mounting portion202and the wheel fixing portions205and has a planar occupied area which is narrow as compared with the shopping basket mounting portion202and the wheel fixing portions205.

In the meanwhile, the cart may be a cart having a shape illustrated inFIGS. 6A and 6B. The cart300illustrated inFIGS. 6A and 6Bhas a narrow portion301, a shopping basket mounting portion302for mounting the shopping basket250, a handle portion303, a plurality of (herein, three) wheels304, and a wheel fixing portion305. The narrow portion301is formed between the shopping basket mounting portion302and the wheel fixing portion305and has a cylindrical shape.

The cart is not limited to those illustrated inFIGS. 5A to 5CandFIGS. 6A and 6B. It is sufficient that the cart has the shopping basket mounting portion, the wheels, and the wheel fixing portion(s) and has the narrow portion formed therebetween and adapted to be guided by the recessed portion160aof the shopping basket placing portion160.

FIGS. 7A, 7B, and 7Care the perspective view, the front view, and the right side view of the self-service POS terminal device100, respectively, when the cart200, on which the shopping basket250loaded with the commodities (not shown) is mounted, is advanced to the position (predetermined position) to perform the commodity registration and the checkout. The self-service POS terminal device100can read, through the first antenna ANT1(FIG. 4) built in the right side plate portion130, the IC tags of the commodities in the shopping basket250mounted on the cart200at the predetermined position.

FIGS. 8A, 8B, and 8Care the perspective view, the front view, and the right side view of the self-service POS terminal device100, respectively, when the shopping basket250loaded with the commodities (not shown) is placed on the shopping basket placing portion160. As illustrated inFIG. 8, the shopping basket250loaded with the commodities can be placed on the shopping basket placing portion160. Even in a state where the shopping basket250loaded with the commodities is placed on the shopping basket placing portion160, the self-service POS terminal device100can read, through the first antenna ANT1(FIG. 4) built in the right side plate portion130, the IC tags of the commodities in the shopping basket250.

InFIGS. 7A to 7CandFIG. 8,FIGS. 8A to 8C, the commodities loaded in the shopping basket250are not illustrated. InFIGS. 7A to 7CandFIGS. 8A to 8Cthe plurality of shopping bags being reserved and the shopping bag in the opened state are not illustrated.

FIG. 9is the perspective view for illustrating a state where the customer performs the commodity registration and the checkout at the self-service POS terminal device100after advancing, to the predetermined position, the cart200on which the shopping basket250loaded with the commodities is mounted. InFIG. 9, the commodities loaded in the shopping basket are not illustrated.

The customer advances the cart200, on which the shopping basket250loaded with the commodities (not shown) is mounted, to the predetermined position to perform the commodity registration and the checkout, which has been described with reference toFIGS. 7A to 7C. Thereafter, as illustrated inFIG. 9, the customer takes out the commodities one by one or several commodities from the shopping basket250in the first reading area RA1(FIG. 4) and put the commodities into the shopping bag350in the second reading area RA2(FIG. 4), while visually confirming the aerial image IMG, i.e., the operation screen on which messages prompting the operations and the keys for the operations are displayed. Thus, the commodity registration is performed. After completion of the commodity registration, the noncontact IC card (not shown) is passed over the noncontact IC card reader/writer CRW to perform the checkout using an electronic money loaded on the noncontact IC card.

FIG. 10is a view for illustrating one example of an electric configuration of the self-service POS terminal device. The self-service POS terminal device100comprises a control unit10having a storage unit MM, a data input unit11implemented by the operation screen or the like, a data printing unit12implemented by a printer or the like, an output unit13, a display unit14, a card reader/writer unit15, an IC tag reader unit16, and a communicating unit17.

The control unit10controls the respective units of the self-service POS terminal device. The input unit11enters data, for example, by pressing down the keys on the operation screen. In the above-mentioned self-service POS terminal device100, data input by the key operation is performed by pointing, with the fingertip of the customer, a desired position on the operation screen of the aerial image IMG, and picking up an image thereof by the camera CM to recognize at which position the fingertip is. The output unit13produces a sound or a speech sound for confirmation of operation, guiding, alert, and so on. In the self-service POS terminal device100described above, the sound and the speech sound are produced from a loudspeaker not illustrated in the figure. The display unit14displays the messages required for the operations and the keys to perform the operations. In the above-mentioned self-service POS terminal device100, the screen displayed on the built-in LCD112is displayed as the aerial image IMG through the AI plate AIP, as described with reference toFIG. 4. Herein, functions of the input unit11and the display unit14are implemented by the LCD112which forms the aerial image IMG, the AI plate AIP, and the camera CM.

The card reader/writer unit15carries out reading and writing of the noncontact IC card. In the above-mentioned self-service POS terminal device100, the built-in noncontact IC card reader/writer CRW carries out reading and writing of the noncontact IC card. The IC tag reader unit16reads the data stored in the IC tag. In the above-mentioned self-service POS terminal device100, the IC tag reader having the first antenna ANT1and the second antenna ANT2reads, through each of the first antenna ANT1and the second antenna ANT2, the data memorized in the IC tag attached to each commodity. The communicating portion17communicates with another device, such as a shop server, via wire or wirelessly

FIG. 11is a flowchart of processing to be executed by the control unit10of the self-service POS terminal device100. Hereinafter, referring toFIGS. 9 and 10also, description will be made of the flow of processing, including the commodity registration and the checkout, executed by the control unit10of the self-service POS terminal device100.

1. When the customer positions the shopping basket250loaded with the commodities in the first reading area RA1, the IC tag reader unit16detects the commodity code of each commodity. That is, in the first reading area RA1, the first antenna ANT1emits the electric wave at predetermined time intervals (for example, one second) t1to detect the commodity code. In a step S1, the control unit10determines whether or not the commodity code is detected in the first reading area RA1through the IC tag reader unit16. When the commodity code is detected in the first reading area RA1(Yin the step S1), operation proceeds to a step S2. When the commodity code is not detected in the first reading area RA1(N in the step S1), the step S1is repeated.

2. The control unit10stores, in the storage unit MM, commodity codes of all commodities detected in the first reading area RA1as a commodity code list (the step S2) and operation proceeds to a step S3. In the step S2, the first antenna ANT1emits the electric wave in the first reading area RA1at the predetermined time intervals to detect the commodity codes. Thereafter, until the checkout is completed, detection of the commodity codes is carried out in the first reading area RA1at the predetermined time intervals. Every time when the commodity code is detected, the commodity code list is updated.

3. The control unit10starts the commodity registration and operation proceeds to a step S4(the step S3).

4. In the step S4, the control unit10determines whether or not the commodity code is detected in the second reading area RA2through the IC tag reader unit16. When the commodity code is detected in the second reading area RA2(Y in the step S4), the operation proceeds to a step S5. When the commodity code is not detected in the second reading area RA2(N in the step S4), the step S4is repeated. Herein, when the customer takes out each commodity from the shopping basket250and puts the commodity into the shopping bag350in the second reading area RA2, the commodity code of the commodity is detected through the IC tag reader unit16. In the second reading area RA2also, the second antenna ANT2emits the electric wave at predetermined time intervals (for example, one second) t2to detect the commodity codes.

5. In the step S5, the control unit10registers the commodity having the commodity code detected in the second reading area RA2. Upon the commodity registration, the control unit10refers to a PLU (Price Look Up) file stored in the storage unit MM and registers the commodity. The PLU file stores the commodity code and the commodity-related information (commodity names and unit prices, etc.) in association therewith. Without storing the PLU file in the storage unit MM, the commodity code may be transmitted through the communicating unit17to the shop server or the like which stores the PLU file, to acquire the commodity-related information.

6. In a step S6, the control unit10determines whether or not the commodity registration is completed. When the commodity registration is completed (Y in the step S6), operation proceeds to a step S7. When the commodity registration is not completed (N in the step S6), operation returns to the step S4. The commodity registration is completed when the customer operates, on the operation screen, a key for entering the completion of the commodity registration.

7. In the step S7, the control unit10again determines whether or not the commodity code is detected in the first reading area RA1through the IC tag reader unit16. When the commodity code is detected in the first reading area RA1(Y in the step S7), operation is shifted to a step S9. When the commodity code is not detected in the first reading area RA1(N in the step S7), the operation is shifted to a step S8. The commodity code being detected in the first reading area RA1in the step S7means that an unregistered commodity remains in the shopping basket250because the customer overlooks the commodity although the input operation of the completion of the commodity registration is carried out.

8. In the step S8, the control unit10determines whether or not the checkout is completed. When the checkout is completed (Y in the step S8), operation is shifted to a step S10. When the checkout is not completed (N in the step S8), the step S8is repeated. The checkout being completed is a case where processing associated with payment of a total price of all commodities already registered is completed and a receipt is printed and discharged from the printer PRT. In the above-mentioned self-service POS terminal device100, the noncontact IC card is passed over the noncontact IC card reader/writer CRW to perform the checkout using the electronic money loaded on the noncontact IC card.

9. In the step S9, the control unit10produces an alarm through the output unit13. For example, an alarm sound or a voice message that the unregistered commodities remain in the shopping basket is sent through a loudspeaker. In this event, the control unit10grasps the commodity code of the unregistered, i.e., remaining commodity through the IC tag reader unit16and, therefore, may send the voice message with the commodity name of the remaining commodity included therein. The customer having confirmed the alarm takes out the commodity from the shopping basket250and puts the commodity into the shopping bag350. As a result, the commodity code is detected in the step S4and the commodity is registered.

10. In the step S10, the control unit10determines whether or not a predetermined time interval t3has lapsed from a time instant when the completion of the checkout is determined, i.e., a time instant when the receipt is printed and discharged from the printer PRT. When the predetermined time interval t3has lapsed (Yin the step S10), operation is shifted to a step S11. When the predetermined time interval t3has not lapsed (N in the step S10), the step S10is repeated. The predetermined time interval t3is a sufficient time as a time required for the customer to take out, from the shopping bag reserving holding portion141, the shopping bag350with the commodities put therein and to leave there, for example, 10 seconds. Instead of counting the predetermined time interval t3, the self-service POS terminal device100may be provided with a human sensor so as to determine whether or not the human sensor detects a human being. In this case, the flow is as follows. When the human sensor does not detect the human being (Yin the step S10), operation is shifted to the step S11. When the human sensor detects the human being (N in the step S10), the step S10is repeated.

11. In the step S11, the control unit10again determines whether or not the commodity code is detected in the second reading area RA2through the IC tag reader unit16. When the commodity code is detected in the second reading area RA2(Yin the step S11), operation is shifted to a step S12. When the commodity code is not detected in the second reading area RA2(N in the step S11), operation returns to the step S1. Herein, the commodity code being detected in the second reading area RA2is a case where the customer is going to leave without taking out, from the shopping bag reserving holding portion141, the shopping bag350with the commodities put therein.

12. In the step S12, the control unit10produces an alarm through the output unit13. For example, an alarm sound or a message that the shopping bag with the commodities put therein remains in the self-service POS terminal device is sent through a loudspeaker. The customer having confirmed the alarm takes out the shopping bag350from the shopping bag reserving holding portion141and leaves there. Operation is shifted to the step S10.

The self-service POS terminal device according to the above-mentioned embodiment exhibits the following effects.

(1) When the customer takes out the commodities from the shopping basket and put the commodities into the shopping bag, the commodity registration is carried out. Accordingly, there is no risk of causing a trouble that the checkout is performed although the unregistered commodities exist.

(2) Because the commodities are put into the shopping bag during the commodity registration, it is not necessary to bag the commodities after the checkout.

(3) The alarm is produced if the commodities remain in the shopping basket after the input operation of the completion of the commodity registration. Accordingly, there is no risk that the commodities remain in the shopping basket because the customer overlooks the commodities.

Although this invention has been described in conjunction with the preferred embodiment thereof, this invention is not limited to the foregoing embodiment.

For example, in the foregoing embodiment, the first antenna ANT1is built in the right side plate portion130and the shopping basket placing portion160is disposed outside the right side plate portion130at the height position near the bottom thereof. Alternatively, the first antenna ANT1may be built in the left side plate portion120and the shopping basket placing portion160may be disposed outside the left side plate portion120at the height position near the bottom thereof. In this case, it is desirable that the printer PRT and the noncontact IC card reader/writer CRW are arranged on the left side of the upper part of the main body portion110whereas the LCD112, the AI plate AIP, and the camera CM are arranged on the right side of the upper part of the main body portion110.

In the foregoing embodiment, the IC tag reader having the first antenna ANT1and the second antenna ANT2is used. Alternatively, two IC tag readers each of which has one antenna may be used.

In the foregoing embodiment, the commodity registration is carried out by acquiring the commodity code from the IC tag of each commodity and referring to the PLU file to obtain the commodity-related information required for the commodity registration. Alternatively, the commodity-related information required for the commodity registration may be stored in the IC tag of the commodity so as to carry out the commodity registration by directly acquiring, from the IC tag of the commodity, the commodity-related information required for the commodity registration without referring to the PLU file.

In the foregoing embodiment, only the noncontact IC card reader/writer CRW is provided for the purpose of the checkout. However, in case where the checkout is performed by cash, a bill handling device and a coin handling device may be provided. In case where the checkout is performed by a contact IC card, a contact IC card reader/writer may be provided. Furthermore, in case where the checkout is performed by a magnetic card, a magnetic card reader/writer may be provided.

In the foregoing embodiment, the display unit14and the input unit11are implemented by the build-in LCD112, the AI plate AIP, and the camera CM. Instead, a touch panel display may be used.

INDUSTRIAL APPLICABILITY

This invention is applicable to all self-service POS terminal devices having a self-checkout function.

This application is based upon and claims the benefit of priority from Japanese patent application No. 2018-034804, filed on Feb. 28, 2018, the disclosure of which is incorporated herein in its entirety by reference.

EXPLANATION OF REFERENCE SYMBOLS