Shopping cart system

Abstract

To provide a shopping cart system that can ensure durability of a power supply device that supplies a charging current to a shopping cart.SOLUTION: A shopping cart system comprises: a shopping cart that is provided with a cart terminal (terminal device) that registers a commodity to purchase; and a power supply device that supplies power for charging the cart terminal. The shopping cart includes an input connector that receives charging power for a battery from the power supply device, a charging circuit (charging current supply unit) that supplies part of the power received by the input connector to a battery, and an output connector that outputs part of the power received by the input connector to an input connector included in another shopping cart connected to the subsequent stage of the shopping cart. The power supply device includes an output connector that supplies the charging current for a battery to the input connector of the shopping cart, a current measurement unit that measures the magnitude of a current output from the current measurement unit, and a current limiting unit that limits the magnitude of the current measured by the current measurement unit to be equal to or less than the rated current of the current limiting unit.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to a shopping cart system. [Background technology]

[0002] Conventionally, a shopping cart has been proposed that is equipped with a product registration device, allowing customers to register the products they want to purchase while shopping in a store. Such shopping carts are moved to a fixed position and the battery that operates the product registration device is charged (for example, Patent Document 1).

[0003] These shopping carts are designed to charge their own batteries when stacked together. To do this, each shopping cart is connected to the other via electrical contacts. Power is supplied from a power supply to the upstream contact, but as the number of connected shopping carts increases, the current supplied from the power supply may exceed its rated current. Continued use of the power supply with a current exceeding the rated current may impair the durability of the power supply. Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a shopping cart system that can ensure the durability of a power supply device that supplies charging current to the shopping cart. [Means for solving the problem]

[0005] A shopping cart system according to an embodiment includes a shopping cart equipped with a terminal device for registering products to be purchased, and a power supply device that supplies power for charging the terminal device. The shopping cart includes an input connector that receives power from the power supply device for charging a battery that operates the terminal device, a charging current supply unit that supplies a portion of the power received by the input connector to the battery, and an output connector that outputs a portion of the power received by the input connector to an input connector of another shopping cart connected downstream of the shopping cart. The power supply device includes an output connector that supplies power for charging the battery to the input connector of the shopping cart, a current measurement unit that measures the magnitude of the current output by the power supply device, and a current limiting unit that limits the magnitude of the current measured by the current measurement unit to less than or equal to the rated current of the power supply device. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is an external view illustrating an example of a shopping cart system according to an embodiment. [Figure 2] FIG. 2 is a first perspective view of a shopping cart. [Figure 3] FIG. 3 is a second perspective view of the shopping cart. [Figure 4] FIG. 4 is a perspective view showing an example of a power supply device. [Figure 5] FIG. 5 is a hardware block diagram illustrating an example of a hardware configuration of a shopping cart system according to an embodiment. [Figure 6] FIG. 6 is a first diagram showing an example of the configuration of the main parts of the power supply device and the output connector provided in the shopping cart. [Figure 7] FIG. 7 is a second diagram illustrating an example of the configuration of the main part of the output connector. [Figure 8] FIG. 8 is a first diagram showing the configuration of the main part of an input connector provided in a shopping cart. [Figure 9] FIG. 9 is a second diagram illustrating an example of the configuration of the main part of the input connector. [Figure 10] FIG. 10 is a block diagram showing an example of the functional configuration of the current control circuit included in the power supply device. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments described below.

[0008] A shopping cart 10 according to an embodiment of the present disclosure will now be described with reference to the drawings.

[0009] (Shopping cart system overview) A schematic configuration of a shopping cart system 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is an external view showing an example of a shopping cart system according to an embodiment.

[0010] The shopping cart system 1 includes a power supply device 50 and a plurality of shopping carts 10.

[0011] The power supply device 50 supplies power to the shopping cart 10 connected to it for charging the battery 29 that drives the cart terminal 20 provided in the shopping cart 10. The power supply device 50 is, for example, an AC adapter or an AC / DC converter. The power supply device 50 converts a commercial AC voltage of 100V into a predetermined DC voltage E (for example, +24V) and supplies it to the shopping cart 10 connected to it.

[0012] The battery 29 of the shopping cart 10 is charged by power (current) supplied from the power supply device 50. Specifically, the output connector 53 (see FIG. 4) of the power supply device 50 is connected to the input connector 31 (see FIG. 3) of the shopping cart 10, thereby supplying power for charging to the shopping cart 10. When multiple shopping carts 10 are stacked as shown in FIG. 1, the output connector 34 (see FIG. 2) of the preceding shopping cart 10, i.e., the shopping cart 10 closest to the power supply device 50, is connected to the input connector 31 (see FIG. 3) of the succeeding shopping cart 10, thereby supplying power for charging to the succeeding shopping cart 10. In terms of electrical circuitry, the batteries 29 of each shopping cart 10 are connected in parallel from the perspective of the power supply device 50. The structures of the input connector 31 and the output connectors 53 and 34 will be described in detail below (see FIGS. 6 to 9).

[0013] The number of connectable shopping carts 10 is determined by the current value that the power supply device 50 can output and the charging current of the battery 29. For example, ignoring losses due to harnesses, connectors, various elements, ICs, etc., if the rated current that the power supply device 50 can output is 10A and the charging current required to charge the battery 29 is 1A, the number of shopping carts 10 that can be charged simultaneously is 10. However, if the batteries 29 of some of the 10 connected shopping carts 10 have already been charged, charging current will not be supplied to the shopping carts 10 that have already been charged, so the 11th and subsequent shopping carts 10 can also be charged. In other words, the upper limit of the number of shopping carts 10 that can be currently being charged among the shopping carts 10 connected to the power supply device 50 is 10.

[0014] Generally, a power supply device 50 can output a current exceeding its rated value. For example, a power supply device with a rated current of 10A can output a current of up to approximately 12A. However, if the power supply device 50 is continuously used at a current exceeding the rated current, the durability of the power supply device 50 may be impaired, so it is desirable to use the power supply device 50 in a range below the rated current. For this reason, in the shopping cart system 1 of this embodiment, the power supply device 50 has a function to limit the output current to below the rated current. This will be described in more detail later (see FIG. 10).

[0015] (Shopping cart outline) The general configuration of the shopping cart 10 will be described with reference to Figures 2 and 3. Figure 2 is a first perspective view of the shopping cart, and Figure 3 is a second perspective view of the shopping cart.

[0016] As a customer walks through a store pushing the shopping cart 10, the shopping cart 10 reads product information about products they wish to purchase and registers those products. The customer places the registered products in a shopping basket or the like placed on the shopping cart 10 and continues shopping. After finishing their shopping, the customer goes to a cash register (not shown) and has the cash register process the payment for the registered products. The shopping cart 10 may also have a function to process the payment itself.

[0017] For convenience, an XYZ coordinate system including an X-axis, a Y-axis, and a Z-axis is defined in this specification. The XYZ coordinate system is established for the shopping cart 10. The X-axis, Y-axis, and Z-axis are perpendicular to one another. The X-axis is established along the front-to-rear direction of the shopping cart 10. The Y-axis is established along the width direction (left-to-right direction) of the shopping cart 10. The Z-axis is established along the up-down direction of the shopping cart 10.

[0018] Furthermore, in this specification, the X direction, Y direction, and Z direction are defined. The X direction is a direction along the X axis, and includes the +X direction indicated by the X axis arrow and the -X direction opposite the X axis arrow. The Y direction is a direction along the Y axis, and includes the +Y direction indicated by the Y axis arrow and the -Y direction opposite the Y axis arrow. The Z direction is a direction along the Z axis, and includes the +Z direction indicated by the Z axis arrow and the -Z direction opposite the Z axis arrow. Furthermore, the +Z direction is the same as the upward vertical direction, and the -Z direction is the same as the downward vertical direction.

[0019] The shopping cart 10 includes a frame 60, a pair of front wheels 70 (see FIG. 3), and a pair of rear wheels 71. The frame 60 includes a pair of left and right bottom frames 61, a lower frame 62, and an upper frame 63. The pair of left and right bottom frames 61, the lower frame 62, and the upper frame 63 are connected to one another. The distance between the pair of front wheels 70 is narrower than the distance between the pair of rear wheels 71. The front wheels 70 and the rear wheels 71 are installed in the fore-and-aft direction (X direction) of the shopping cart 10. The front wheels 70 and the rear wheels 71 are attached to the bottom frame 61 by mounting members (not shown). The front wheels 70 and the rear wheels 71 can turn left and right around their attachment positions to the bottom frame 61. Therefore, the direction of travel of the shopping cart 10 can be changed left and right depending on the force applied to the handle 72 installed above the shopping cart 10. In other words, the shopping cart 10 is rotatable. The customer holds the handle 72 and pushes the shopping cart 10 while turning it from side to side.

[0020] A charging unit 30 is attached between the pair of left and right bottom frames 61. The charging unit 30 has a built-in charging circuit 32 (see FIG. 5), which charges the battery 29. The charging unit 30 also has an input connector 31 (see FIG. 3), an output connector 34, and an indicator 35. The charging unit 30 also serves as a strength member connecting the left and right bottom frames 61.

[0021] The input connector 31 is a charging connector that connects to the output connector 53 (see FIG. 4) of the power supply device 50. The input connector 31 receives power from the power supply device 50 to charge the battery 29 that powers the cart terminal 20. The input connector 31 is also a charging connector that connects to the output connector 34 of the preceding shopping cart 10. The input connector 31 receives power from the output connector 34 of the preceding shopping cart 10 to charge its own battery 29. The input connector 31 is attached to the housing 38 of the charging unit 30 with its exterior covered by an input connector cover 311. The input connector 31 and the output connector 34 are installed at the same height from the floor. The detailed structure of the input connector 31 will be described later (see FIGS. 8 and 9).

[0022] The output connector 34 is a charging connector that connects to the input connector 31 of the subsequent shopping cart 10. The output connector 34 transfers a portion of the power supplied to the preceding shopping cart 10 for charging the battery 29 to the subsequent shopping cart 10. The output connector 34 is attached to the housing 38 of the charging unit 30 with its exterior covered by an output connector cover 341. The detailed structure of the output connector 34 will be described later in detail (see Figures 6 and 7).

[0023] The indicator 35 is composed of a light-emitting element such as an LED, and indicates the charging status of the battery 29 by the charging circuit 32 (see FIG. 5 ). The indicator 35, for example, can be turned off, on, or flashing to indicate at least that the battery 29 is fully charged, that the battery 29 is being charged, and that the output current of the power supply device 50 exceeds a rated value. The indicator 35 may be composed of multiple LEDs, and each status may be indicated by the number of LEDs that are lit or the combination of the LEDs that are lit. The indicator 35 may also be composed of multiple LEDs with different light emission colors, and each status may be indicated by the different colors of the LEDs that are lit. The installation location of the indicator 35 is not limited to the charging unit 30, and it may be installed at a higher position on the shopping cart 10, for example, near the display unit 22. The indicator 35 is an example of a notification unit in the present disclosure.

[0024] A lower frame 62 is attached to the front side (+X direction) of the bottom frame 61, rising upward (+Z direction) and then extending diagonally upward toward the front (-X direction). The lower frame 62 holds the battery 29. The battery 29 is a rechargeable secondary battery that supplies power to the various electronic devices included in the shopping cart 10. The battery 29 may be, for example, a lithium-ion battery, a nickel-cadmium battery, a nickel-metal hydride battery, or a lead-acid battery.

[0025] A pair of upper frames 63 are attached to the upper ends of the lower frames 62, facing upward (in the +Z direction). A rod-shaped handle 72 is attached to the pair of upper frames 63, extending along the left-right direction (Y direction) of the shopping cart 10. Various electronic devices provided on the shopping cart 10 are attached to the upper frames 63 and the handle 72.

[0026] A lower basket support frame 64 is attached to the bottom frame 61 and the lower frame 62. A shopping basket (not shown) for storing merchandise is placed on the lower basket support frame 64 when a customer goes shopping. The lower basket support frame 64 also has a pair of left and right guide surfaces 641. When a subsequent shopping cart 10 enters between them, the pair of guide surfaces 641 come into contact with a guided portion 621 provided below the lower frame 62 of the subsequent shopping cart 10, thereby guiding (leading) the subsequent shopping cart 10 so that the input connector 31 of the subsequent shopping cart 10 is directed toward its own output connector 34.

[0027] An upper basket support frame 65 is attached to the upper frame 63. A shopping basket (not shown) for containing merchandise is placed on the upper basket support frame 65 when a customer goes shopping.

[0028] Additionally, a weight sensor 28 is installed on the upper frame 63 at a position extending toward the front (-X direction). The weight sensor 28 is located below the upper basket support frame 65 and measures the weight of an item placed in a shopping basket placed on the upper basket support frame 65.

[0029] The cart terminal 20, hand scanner 25, card reader 26, and camera 27 (see FIG. 3) are mounted on the upper part of the upper frame 63. In addition, the fixed scanner 24 is mounted on the handle 72. These electronic devices are powered by the battery 29.

[0030] The cart terminal 20 registers products to be purchased by customers. The cart terminal 20 includes a display unit 22 and an operation unit 23. The cart terminal 20 may further include a function for making payments for registered products. The cart terminal 20 is an example of a terminal device in the present disclosure.

[0031] The display unit 22 displays various information related to product registration. The display unit 22 is, for example, a liquid crystal monitor or an organic EL monitor.

[0032] The operation unit 23 detects operations on various buttons displayed on the display unit 22. The operation unit 23 is, for example, a touch panel laminated on the display unit 22.

[0033] The fixed scanner 24 reads a code symbol, such as a barcode, attached to a product for sale that is held up to a reading window on the front. A product code that uniquely identifies the product is registered in the code symbol. The fixed scanner 24 obtains the product code by decoding the code symbol reading result.

[0034] The hand scanner 25, like the fixed scanner 24, reads the code symbol attached to the product to obtain the product code. In particular, the hand scanner 25 is used to read the code symbol of a product that is difficult to read with the fixed scanner 24, such as a heavy or large product.

[0035] Card reader 26 reads information registered on an IC card or magnetic card held by a customer. Card reader 26 may read information stored on an electronic chip of an inserted IC card, or may read information stored on a magnetic stripe by scanning the card. Card reader 26 may also read information stored on the card by performing short-range wireless communication.

[0036] The card reader 26 reads, for example, membership information registered on the customer's membership card. The cart terminal 20 may display, on the display unit 22, bargain information on products that suit the customer's preferences, service information, etc., based on the membership information read by the card reader 26, for example, by referencing the customer's purchase history. If the shopping cart 10 also has a payment processing function, the card reader 26 may also read the registration information of the credit card used by the customer for payment, the charge amount of an electronic money card, prepaid card, etc.

[0037] The camera 27 captures an image of the area including the shopping basket placed on the upper basket support frame 65. The cart terminal 20 associates identification information for identifying itself, the image captured by the camera 27, the weight of the shopping basket measured by the weight sensor 28, and the product registration information at that time, and transmits the associated information to a store server (not shown).

[0038] The store server analyzes the information sent from the shopping cart 10 and monitors whether an unregistered item has been added to the shopping cart. Specifically, if the weight of the shopping cart increases even though an item has not been registered, it determines that the customer may have added an unregistered item to the shopping cart. In such a case, the store server sends a signal to the cart terminal 20 to alert the customer. The cart terminal 20 then displays a message on the display unit 22 to alert the customer. The cart terminal 20 may also output a warning sound from a speaker (not shown). Furthermore, the store server may notify a mobile device carried by a store clerk of the identification number of the corresponding shopping cart 10. The clerk, upon receiving the notification, goes to the corresponding shopping cart 10 and checks the product registration information and the items added to the shopping cart. Note that such monitoring processing may be performed by the cart terminal 20 itself.

[0039] Although Figures 2 and 3 only show the camera 27 and weight sensor 28 that monitor the shopping basket placed on the upper basket support frame 65, by installing the camera and weight sensor on the side of the lower basket support frame 64 as well, it is possible to monitor the shopping basket placed on the lower basket support frame 64 as well.

[0040] (Outline of power supply configuration) The general configuration of the power supply device 50 will be described with reference to Fig. 4. Fig. 4 is a perspective view showing an example of a power supply device.

[0041] 4, the power supply device 50 includes a housing 501, an output connector 53, an output connector cover 531, and a guide portion 54. The power supply device 50 is installed (fixed) on, for example, a floor surface 100 of a store (see FIG. 1).

[0042] The housing 501 is formed in a rectangular parallelepiped shape and houses a power transmission circuit 51 (see FIG. 5) and a current control circuit 52 (see FIG. 5) therein.

[0043] The power transmission circuit 51 is a power source that supplies the power required to charge the battery 29. The power transmission circuit 51 is composed of, for example, an inverter circuit that converts a commercial AC voltage of 100 V into a DC voltage, and a rectifier circuit that rectifies the output of the inverter circuit and converts it into a DC voltage.

[0044] When the shopping cart 10 is connected to the output connector 53 and the output current of the power supply device 50 is equal to or less than the rated current, the power supply control circuit 52 supplies power to the shopping cart 10 connected to the output connector 53. The function of the power supply control circuit 52 will be described in detail later (see FIG. 10).

[0045] Output connector 53 has the same size and shape as output connector 34 (see FIG. 2) provided on shopping cart 10. Output connector 53 is attached to housing 501 of power supply device 50 with its exterior covered by output connector cover 531. The detailed structure of output connector 53 will be described in detail later (see FIGS. 6 and 7).

[0046] The guide portions 54 are a pair of protrusions provided along the Y axis with the output connector 53 sandwiched between them. The pair of guide portions 54 are installed at a distance slightly greater than the width of the guided portion 621 (see FIG. 3) of the shopping cart 10. The guided portion 621 of the shopping cart 10 is guided between the pair of guide portions 54, thereby connecting the input connector 31 of the shopping cart 10 and the output connector 53 of the power supply device 50.

[0047] (Hardware configuration of shopping cart system) The hardware configuration of the shopping cart system 1 will be described with reference to Fig. 5. Fig. 5 is a hardware block diagram showing an example of the hardware configuration of the shopping cart system according to the embodiment.

[0048] The power supply device 50 provided in the shopping cart system 1 includes a power transmission circuit 51, a current control circuit 52, and an output connector 53. The functions of each of these components are as described above.

[0049] The shopping cart 10 included in the shopping cart system 1 includes a cart terminal 20, a charging unit 30, a battery 29, and peripheral devices such as a fixed scanner 24, a hand scanner 25, a card reader 26, a camera 27, and a weight sensor 28.

[0050] The cart terminal 20 performs various processes related to product registration. The cart terminal 20 includes a control unit 21, a display unit 22, and an operation unit .

[0051] The control unit 21 controls various processes related to product registration performed by the cart terminal 20 itself. The control unit 21 also controls the operation of various peripheral devices connected to the control unit 21. The control unit 21 includes a CPU, RAM, ROM, and a storage unit. The CPU loads a control program stored in the storage unit into the RAM and executes it, causing the cart terminal 20 to perform predetermined processes related to product registration, etc. The functions of the display unit 22 and operation unit 23 provided in the cart terminal 20 are as described above.

[0052] The functions of the fixed scanner 24, hand scanner 25, card reader 26, camera 27, and weight sensor 28, which are peripheral devices connected to the control unit 21, are as described above.

[0053] The charging unit 30 charges the battery 29. The charging unit 30 includes an input connector 31, a charging circuit 32, a current control circuit 33, an output connector 34, and an indicator 35. The charging unit 30 is housed in a housing 38 (see FIGS. 2 and 3) and fixed to a frame 60. The input connector 31 and the output connector 34 are supported by the housing 38 and exposed to the outside of the housing 38.

[0054] The input connector 31 inputs a current (voltage signal) from the power supply device 50 by connecting to the output connector 53 of the power supply device 50. The input connector 31 also inputs a current (voltage signal) from the preceding shopping cart 10 by connecting to the output connector 34 of the charging unit 30 of the preceding shopping cart 10. The voltage signal is transmitted via two signal lines: a signal line that transmits the voltage signal, and a ground line that transmits the ground (GND) level, which is the reference potential. In other words, the input connector 31 has two terminals. In this embodiment, the input connector 31 is configured as a plug.

[0055] The output connector 34 outputs a current (voltage signal) to the subsequent shopping cart 10 by connecting to the input connector 31 provided on the charging unit 30 of the subsequent shopping cart 10. Two signal lines are connected to the output connector 34: one signal line that outputs a voltage signal, and the other signal line that outputs a ground level. In this embodiment, the output connector 34 is configured as a socket.

[0056] The charging circuit 32 supplies a portion of the power from the power supply device 50 to charge the battery 29 that operates the cart terminal 20. The charging circuit 32 is an example of a charging current supply unit in the present disclosure.

[0057] The power supply control circuit 33 supplies power to the shopping cart 10 in the subsequent stage only when a shopping cart 10 is connected in the subsequent stage to itself. On the other hand, when a shopping cart 10 is not connected in the subsequent stage to itself, the power supply control circuit 33 does not output power (current) from the output connector 34. This prevents electric shock even if a person accidentally touches the output connector 34.

[0058] The function of the indicator 35 is as described above.

[0059] The function of the battery 29 is as described above.

[0060] (Output connector structure) The structures of output connector 53 and output connector 34 will be explained using Figures 6 and 7. Figure 6 is a diagram showing the main configuration of the output connectors provided on the power supply device and shopping cart. Figure 7 is a perspective view showing the detailed structure of the output connectors provided on the power supply device and shopping cart. Note that the output connector 53 provided on power supply device 50 and the output connector 34 provided on shopping cart 10 have the same structure, so the output connector 53 provided on power supply device 50 will be explained here as an example.

[0061] The output connector 53 is installed facing the -X direction in the housing 501 (see FIG. 4) of the power supply device 50. The output connector 53 includes a socket 41, a socket 42, and a socket housing 43.

[0062] The socket 42 is formed of a conductive material and outputs a DC voltage E (for example, +24 V) from the power supply device 50. The socket 42 is also called a female terminal.

[0063] Socket 41 is formed of a conductive material and is a ground (GND) terminal of power supply device 50. Socket 41 is also called a female terminal. Note that socket 41 may be an output connector for a voltage signal, and socket 42 may be an output connector for a ground potential.

[0064] The socket housing 43 is formed to surround the outer peripheries of the sockets 41 and 42, and supports the sockets 41 and 42 in parallel at a predetermined distance. That is, the socket housing 43 has an outer periphery surface 431 that surrounds the outer peripheries of the sockets 41 and 42. The socket housing 43 is also referred to as a shell.

[0065] A switch 44 is embedded in the base of the outer peripheral surface 431 of the socket housing 43. The switch 44 includes a switch housing 441 and a switch button 442.

[0066] The switch housing 441 protects the internal structure of the switch 44 and supports the switch button 442 .

[0067] The switch button 442 is supported by a spring or other elastic member relative to the switch housing 441 so as to be able to move back and forth along the extension direction (+X direction, −X direction) of the sockets 41, 42. When the input connector 31 is inserted into the output connector 53, the switch button 442 is pressed in the +X direction by a tip portion 314 (see FIG. 9 ) of a plug housing 47 of the input connector 31, which will be described later. The switch 44 performs a momentary operation, being turned on when the switch button 442 is pressed a predetermined amount and being turned off when the amount of pressing is less than the predetermined amount. The current control circuit 52 of the power supply device 50 outputs a voltage signal from the output connector 53 when the switch 44 is on, and stops outputting the voltage signal when the switch 44 is off. In other words, the switch 44 functions as a so-called interlock switch.

[0068] An output connector cover 531 is attached to the outside of the socket housing 43. The output connector cover 531 has an opening 532 that exposes the outer peripheral surface 431 of the socket housing 43 to the outside. The opening 532 is sized so that even if a finger is inserted from the outside, the finger will not reach the switch button 442. This prevents the switch button 442 from being accidentally touched and causing a voltage signal to be output from the output connector 53.

[0069] In this embodiment, the switch 44 is configured as a push switch, but the form of the switch 44 is not limited to this. For example, the switch 44 may be configured as a photosensor consisting of a pair of a light-emitting element and a light-receiving element. The switch 44 may also be configured as a magnetic sensor or a capacitance sensor.

[0070] The structure of the output connector 34 provided on the shopping cart 10 is the same as that of the output connector 53. That is, the output connector 34 is installed on the shopping cart 10 with the outer circumferential surface 431 of the socket housing 43 exposed to the outside through an opening 342 formed in the output connector cover 341. The switch 44 provided on the output connector 34 causes the output connector 34 to output a voltage signal when the input connector 31 of the subsequent shopping cart 10 is connected.

[0071] (Input connector structure) The structure of the input connector 31 provided in the shopping cart 10 will be described using Figures 8 and 9. Figure 8 is a first diagram showing the configuration of the main parts of the input connector provided in the shopping cart. Figure 9 is a second diagram showing an example of the configuration of the main parts of the input connector.

[0072] The input connector 31 is installed on the positive side of the X-axis of the charging unit 30, i.e., on the front side of the shopping cart 10, facing forward with respect to the shopping cart 10. The input connector 31 includes a plug 45, a plug 46, and a plug housing 47.

[0073] The plug 46 is formed of a conductive material and is removably connected to the socket 42. The plug 46 inputs a voltage signal (e.g., +24 V) from the socket 42 to the charging unit 30 (see FIG. 5) in which the plug 46 is installed. The plug 46 is also referred to as a male terminal.

[0074] The plug 45 is made of a conductive material and is removably connected to the socket 41. The plug 45 equalizes its own potential with the ground potential of the socket 41. The plug 45 is also referred to as a male terminal. Note that the plug 45 may be an input connector for a voltage signal, and the plug 46 may be an input connector for a ground potential.

[0075] The plug housing 47 is formed to surround the plugs 45 and 46 with gaps between it and the plugs 45 and 46, and supports the plugs 45 and 46 in parallel at the same distance as the sockets 41 and 42. The plug housing 47 has an inner circumferential surface 313 that is shaped like an elongated cylinder, and the depth of the inner circumferential surface 313 is greater than the length of the plugs 45 and 46, and a tip portion 314 is formed at the tip of the inner circumferential surface 313.

[0076] The plug housing 47 is fixed to the charging unit 30 by screwing or the like.

[0077] An input connector cover 311 is attached to the outside of the plug housing 47. The input connector cover 311 has an opening 312 through which the plugs 45, 46 and an inner peripheral surface 313 that protects them pass.

[0078] When connecting the input connector 31 to the output connector 53 or the output connector 34, the inner surface 313 of the plug housing 47 is inserted along the outer surface 431 of the socket housing 43, thereby connecting the plug 45 and the socket 41, and connecting the plug 46 and the socket 42.

[0079] In this embodiment, the input connector 31 is configured to include plugs 45 and 46, and the output connectors 34 and 53 are configured to include sockets 41 and 42, but this is not limiting. For example, the input connector 31 may be configured as a pogo pin, and the output connectors 34 and 53 may be configured as flat terminals.

[0080] (Functional configuration of the power supply control circuit) The functional configuration of the energization control circuit 52 included in the power supply device 50 will be described with reference to Fig. 10. Fig. 10 is a block diagram showing an example of the functional configuration of the energization control circuit included in the power supply device.

[0081] The power supply device 50 includes a current control circuit 52 that includes a current measurement unit 521 , a current limiting unit 522 , a contact determination unit 523 , and a current control unit 524 .

[0082] The current measuring unit 521 measures the magnitude of the current flowing through the current control circuit 52 by amplifying the minute potential difference generated across both ends of a resistive element (e.g., a shunt resistor) inserted in series in the current control circuit 52 using an operational amplifier.

[0083] The current limiting unit 522 compares the output of the operational amplifier included in the current measuring unit 521 with a reference voltage using, for example, a comparator. When the operational amplifier included in the current measuring unit 521 forms an inverting amplifier circuit and the input of the comparator is greater than the reference voltage, the current limiting unit 522 inputs the current flowing through the energization control circuit 52 (e.g., a current less than 10 amperes, which is the rated current of the power supply device 50) to the input connector 31 of the shopping cart 10 via the energization control unit 524 (described later) and the output connector 53. On the other hand, when the input of the comparator is equal to or less than the reference voltage, the current limiting unit 522 stops the outflow of current from the energization control circuit 52. That is, the current inflow to the shopping cart 10 is stopped. Then, after a predetermined time, the current is resumed, and the comparator repeats its determination. By repeating this operation, the current limiting unit 522 limits the input current to the shopping cart 10 to a predetermined value (e.g., 10 amperes, which is the rated current of the power supply device 50) or less. The magnitude of the predetermined value is set by the magnitude of the reference voltage applied to the comparator. More specifically, the magnitude of the reference voltage is set to a voltage value obtained by amplifying, by an operational amplifier, a potential difference generated across a resistor inserted in the current measuring unit 521 when the rated current (e.g., 10 amperes) of the power supply device 50 is passed through the energization control circuit 52.

[0084] Furthermore, when the operational amplifier included in the current measurement unit 521 forms a non-inverting amplifier circuit, and the input to the comparator is greater than the reference voltage, the current limiting unit 522 stops the outflow of current from the energization control circuit 52. That is, it stops the inflow of current to the shopping cart 10. Then, after a predetermined time, it resumes energization and repeats the determination by the comparator. On the other hand, when the input to the comparator is equal to or less than the reference voltage, it inputs the current flowing through the energization control circuit 52 (e.g., a current less than 10 amperes, which is the rated current of the power supply device 50) to the input connector 31 of the shopping cart 10 via the energization control unit 524 and the output connector 53, which will be described later. By repeating this operation, the current limiting unit 522 limits the input current to the shopping cart 10 to a predetermined value or less (e.g., 10 amperes, which is the rated current of the power supply device 50).

[0085] Although an example in which the current is measured on the line on the +E(V) side in FIG. 10 has been shown here, the current may also be measured on the line on the GND side in FIG.

[0086] The indicator 35 provided on the shopping cart 10 lights up in response to the input current to the shopping cart 10. Therefore, if a current less than the rated current of the power supply device 50 continues to be supplied, the indicator 35 remains lit. In other words, if the indicator 35 remains lit, it indicates that a current less than the rated current of the power supply device 50 is being supplied to the shopping cart 10.

[0087] On the other hand, if a current exceeding the rated current flows through the power supply device 50, the current limiting unit 522 temporarily cuts off the current, and the current flow resumes after a predetermined time. This operation is repeated. That is, a pulsed current is supplied to the shopping cart 10. In this case, the indicator 35 provided on the shopping cart 10 starts flashing. When the indicator 35 starts flashing, this indicates that a current exceeding the rated current of the power supply device 50 is being supplied to the shopping cart 10. In this case, since the number of shopping carts 10 connected to the power supply device 50 exceeds the specified number, a store employee who notices the flashing of the indicator 35 takes action, such as removing a shopping cart 10, so that the indicator 35 stays lit.

[0088] The contact determination unit 523 detects whether the sockets 41, 42 and the plugs 45, 46 are in contact with each other. The contact determination unit 523 is configured, for example, by a circuit that becomes conductive when the switch 44 is turned on, or that outputs a predetermined voltage when the switch 44 is turned on. The specific circuit configuration is not important. The contact determination unit 523 may also be configured by a circuit that becomes non-conductive when the switch 44 is turned off.

[0089] The energization control unit 524 is configured with a switching circuit that causes the output of the current limiting unit 522 to be output from the socket 42 when triggered by the output of the contact determination unit 523. The energization control unit 524 is, for example, a load switch. The specific circuit configuration of the switching circuit is not important, and it may be, for example, a switching circuit using a MOSFET, or a mechanical or electrical relay. Note that the energization control unit 524 only needs to control the energization state of at least the side of the sockets 41, 42 that outputs a voltage signal from the power supply device 50 (socket 42 side in the case of FIG. 10).

[0090] The energization control circuit 33 (see FIG. 5) provided in the shopping cart 10 has a configuration similar to that of the energization control circuit 52, but excluding the current measurement unit 521 and the current limiting unit 522. In other words, the energization control circuit 33 includes only the contact determination unit 523 and the energization control unit 524. The functions of the contact determination unit 523 and the energization control unit 524 have been described above, and therefore will not be described again.

[0091] (Effects of the embodiment) As described above, the shopping cart system 1 of the embodiment includes a shopping cart 10 equipped with a cart terminal 20 (terminal device) for registering products to be purchased, and a power supply device 50 for supplying power for charging the terminal device. The shopping cart 10 includes an input connector 31 that receives power from the power supply device 50 for charging a battery 29 that operates the cart terminal 20, a charging circuit 32 (charging current supply unit) that supplies a portion of the power received by the input connector 31 to the battery 29, and an output connector 34 that outputs a portion of the power received by the input connector 31 to an input connector 31 of another shopping cart 10 connected downstream of the shopping cart 10. The power supply device 50 includes an output connector 53 that supplies power for charging the battery 29 to the input connector 31 of the shopping cart 10, a current measurement unit 521 that measures the magnitude of the current output by the power supply device 50, and a current limiting unit 522 that limits the magnitude of the current measured by the current measurement unit 521 to less than or equal to the rated current of the power supply device 50. Therefore, even when multiple shopping carts 10 are connected to a power supply device 50 that supplies charging current, the power supply device 50 can be used within the rated current range, thereby ensuring the durability of the power supply device 50.

[0092] In addition, in the shopping cart system 1 of the embodiment, the current limiting unit 522 stops the current flow when a current exceeding the rated current is detected, and then resumes the current flow after a predetermined time has elapsed. This allows the magnitude of the current output by the power supply device 50 to be kept below the rated current of the power supply device 50. The predetermined time until the current flow is resumed is determined appropriately.

[0093] In the shopping cart system 1 of the embodiment, the shopping cart 10 further includes an indicator 35 (alert unit) that receives the current output by the current limiting unit 522 and alerts the user that a current exceeding the rated current has been detected. This allows the user to immediately recognize that a current exceeding the rated current is flowing from the power supply device 50. When a store clerk notices that a current exceeding the rated current is flowing from the power supply device 50, the store clerk disconnects the stacked shopping cart 10, thereby canceling the alert from the indicator 35.

[0094] In addition, in the shopping cart system 1 of the embodiment, the indicator 35 (notification unit) includes a light-emitting element that lights up or flashes in response to the current output by the current limiting unit 522. Therefore, it is possible to immediately recognize that a current exceeding the rated current is flowing from the power supply device 50.

[0095] Although the embodiments of the present invention have been described above, these embodiments are merely examples and are not intended to limit the scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0096] 1. Shopping Cart System 10 Shopping Cart 100 floor 20 Cart terminal (terminal device) 21 Control Unit 22 Display section 23 Control section 24 Fixed Scanner 25 Hand Scanner 26 Card Reader 27 Camera 28 Weight Sensor 29 Battery 30 Charging Unit 31 Input Connector 311 Input connector cover 312 Opening 313 Inner surface 314 Tip 32 Charging circuit 33 Power control circuit 34 output connector 341 Output connector cover 342 Opening 35 Indicator (alarm unit) 38 Case 41,42 Socket 43 Socket housing 431 Outer surface 44 Switch 441 Switch Housing 442 Switch Button 45,46 Plug 47 Plug housing 50 Power supply 501 Case 51 Power transmission circuit 52 Power supply control circuit 521 Current measurement unit 522 Current limiter 523 Contact determination section 524 Power supply control unit 53 Output Connector 531 Output connector cover 532 Opening 54 Information Department 60 frames 61 Bottom frame 62 Lower frame 621 Guided part 63 Upper Frame 64 Lower cage support frame 641 Guideway 65 Upper basket support frame 70 front wheel 71 rear wheel 72 Handle [Prior art documents] [Patent documents]

[0097] [Patent Document 1] Japanese Patent Application Publication No. 2023-102931

Claims

1. A shopping cart system comprising: a shopping cart having a terminal device for registering products to be purchased; and a power supply device for supplying power for charging the terminal device, The shopping cart is an input connector that receives power from the power supply device for charging a battery that operates the terminal device; a charging current supply unit that supplies a portion of the power received by the input connector to the battery; an output connector that outputs a portion of the power received by the input connector to an input connector of another shopping cart connected downstream of the shopping cart, The power supply device an output connector for supplying power to the input connector of the shopping cart for charging the battery; a current measurement unit that measures the magnitude of the current output by itself; a current limiting unit that limits the magnitude of the current measured by the current measuring unit to a rated current or less. Shopping cart system.

2. the current limiting unit repeats an operation of stopping current flow when a current exceeding the rated current is detected and restarting current flow after a predetermined time has elapsed.

10. The shopping cart system of claim 1.

3. The shopping cart is a notification unit that receives the current output from the current limiting unit and notifies that a current exceeding the rated current has been detected, 3. The shopping cart system of claim 2.

4. The notification unit a light emitting member that lights up or blinks in response to the current output from the current limiting unit; 4. The shopping cart system of claim 3.

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