Charging and discharging control device and cart-type product registration device

Abstract

A highly convenient charge and discharge control device and a handcart type commodity registration device are provided. The charge and discharge control device according to one embodiment includes a power receiving device and a switch circuit. The power receiving device includes: a power receiving coil that is electromagnetically coupled to a power transmission coil of a power supply device; and a power receiving circuit that rectifies the voltage generated in the power receiving coil and supplies charging power to a secondary battery. During the period when the charging power is supplied from the power receiving device to the secondary battery, the switch circuit disconnects the secondary battery and the load, and during the period when the charging power is not supplied from the power receiving device to the secondary battery, the switch circuit connects the secondary battery and the load.

Description

Technical Field

[0001] Embodiments of the present invention relate to a charge and discharge control device and a cart-type commodity registration device. Background Art

[0002] A contactless power supply system consisting of a power supply device having a power supply coil and a power receiving device having a power receiving coil electromagnetically coupled to the power supply coil has been put into practical use. The power supply device causes a change in magnetic flux in the power supply coil by passing an alternating current through the power supply coil. The power receiving device can charge a secondary battery (storage battery) by the induced current generated in the power receiving coil due to the change in magnetic flux generated by the power supply coil. In addition, in order to suppress power consumption, the following power supply device has been put into practical use: it detects the presence of a power receiving device and energizes the power supply coil only when the power receiving device is detected.

[0003] In addition, a handcart-type commodity registration device that has a commodity registration device (flat plate) for registering the commodities purchased by users and a shopping basket (storage portion) for inserting commodities has been put into practical use in stores, etc. In addition, the handcart-type commodity registration device has a secondary battery that supplies power to the commodity registration device and a power receiving circuit that charges the secondary battery. However, in such a structure, there is the following technical problem: in the case where the secondary battery does not automatically start to discharge after charging, power is not supplied from the secondary battery to the commodity registration device as a load. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a charging and discharging control device and a cart-type commodity registration device with high convenience.

[0005] A charge and discharge control device according to one embodiment includes a power receiving device and a switch circuit. The power receiving device includes: a power receiving coil that is electromagnetically coupled to a power transmission coil of a power supply device; and a power receiving circuit that rectifies a voltage generated in the power receiving coil and supplies charging power to a secondary battery. The switch circuit disconnects the secondary battery and a load during a period in which the charging power is supplied from the power receiving device to the secondary battery, and connects the secondary battery and the load during a period in which the charging power is not supplied from the power receiving device to the secondary battery.

[0006] A cart-type commodity registration device according to one embodiment comprises a commodity registration device, a secondary battery, a charge and discharge control circuit and a cart body, wherein the cart body is used to indicate the commodity registration device, the secondary battery and the charge and discharge control circuit, and the charge and discharge control circuit comprises a power receiving device and a switch circuit, wherein the power receiving device comprises: a power receiving coil, which is electromagnetically coupled to a power transmitting coil of a power supply device; and a power receiving circuit, which rectifies a voltage generated in the power receiving coil and supplies charging power to the secondary battery, wherein the switch circuit disconnects the secondary battery and the load during a period in which the charging power is supplied from the power receiving device to the secondary battery, and connects the secondary battery and the load during a period in which the charging power is not supplied from the power receiving device to the secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a diagram for explaining an example of the configuration of a contactless power supply system according to an embodiment.

[0008] Figure 2 This is a diagram for explaining a configuration example of a cart-type commodity registration device according to one embodiment.

[0009] Figure 3 This is a diagram for explaining a configuration example of a cart power supply device according to one embodiment.

[0010] Figure 4 It is a diagram for explaining a configuration example of the charge and discharge control device according to the first embodiment.

[0011] Figure 5 This is a diagram for explaining an example of the operation of the charge and discharge control device according to one embodiment.

[0012] Figure 6 It is a diagram for explaining a configuration example of a charge and discharge control device according to the second embodiment.

[0013] Description of Reference Numerals

[0014] 1…contactless power supply system; 2…trolley type commodity registration device; 3…trolley power supply device; 11…trolley body; 12…commodity reader; 13…commodity registration device; 14…charge and discharge control device; 14A…charge and discharge control device; 21…shopping basket; 22…frame; 23…castors; 24…handle; 31…battery storage box; 32…power receiving device; 33…secondary battery; 34…switch circuit; 34A…switch circuit; 35…power receiving coil; 36…power receiving circuit; 41…power supply base; 42… Guide groove; 43…stopper; 44…power supply surface; 45…power supply coil; 46…power supply circuit; 51…power supply resonance circuit; 52…AC adapter; 53…power receiving resonance circuit; 61…switching circuit; 61A…switching circuit; 62…RC delay circuit; 71…optical coupler; 91…loss suppression circuit; C1…resonance capacitor; C2…resonance capacitor; 92…first optocoupler MOSFET; 93…second optocoupler MOSFET; 94…third optocoupler MOSFET; 95…fourth optocoupler MOSFET. DETAILED DESCRIPTION

[0015] Hereinafter, embodiments will be described with reference to the drawings.

[0016] Figure 1 It is an explanatory diagram for explaining a configuration example of a contactless power supply system 1 according to an embodiment.

[0017] The contactless power supply system 1 transmits power from a power supply device to a power receiving device through electromagnetic coupling such as electromagnetic induction or magnetic field resonance (resonance). The power supply device includes a power supply coil, and the power receiving device includes a power receiving coil that is electromagnetically coupled to the power supply coil. Figure 1 In the example of FIG. 1 , the contactless power supply system 1 includes a cart-type commodity registration device 2 as a power receiving device, and includes a cart power supply device 3 as a power supply device.

[0018] First, a configuration example of the cart-type commodity registration device 2 will be described.

[0019] Figure 2 This is an explanatory diagram for explaining a configuration example of the cart-type commodity registration device 2.

[0020] The cart-type commodity registration device 2 is a device that registers commodities placed in a shopping basket (storage portion) by a user in a store, etc., and uses the registration information for checkout. The cart-type commodity registration device 2 includes a cart body 11, a commodity reader 12, a commodity registration device 13, and a charge and discharge control device 14.

[0021] The cart body 11 supports the commodity reader 12, the commodity registration device 13, and the charge and discharge control device 14. The cart body 11 includes a storage shopping basket 21, a frame 22, and a plurality of casters 23.

[0022] The storage shopping basket 21 is a storage portion for storing commodities and is supported by a frame 22 .

[0023] The frame 22 is a member that supports the shopping basket 21, the commodity reader 12, the commodity registration device 13, and the charge and discharge control device 14. For example, a portion of the frame 22 is configured as a handle 24 for the user to hold. The handle 24 is provided on the front side of the frame 22 where the shopping basket 21 is stored.

[0024] The multiple casters 23 are components for facilitating the movement of the cart body 11. The multiple casters 23 are respectively provided at the four corners of the lower part of the frame 22. The multiple casters 23 each have a wheel that rotates in the moving direction. The cart body 11 moves by the wheels of the multiple casters 23 rotating on the ground. In the present embodiment, the direction in which the shopping basket 21 is pressed from the handle 24 for the user to hold is set as the forward direction of the cart body 11. In addition, the pair of casters in front of the forward direction of the cart body 11 among the multiple casters 23 is called the front wheels, and the pair of casters in the rear of the forward direction of the cart body 11 is called the rear wheels.

[0025] The commodity reader 12 is a device for reading commodity information. The commodity reader 12 is provided on the frame 22 of the cart body 11. The commodity reader 12 transfers the read commodity information to the commodity registration device 13. The commodity reader 12 is configured as a scanner for reading a code (e.g., a barcode, a QR code, etc.) attached to a commodity and acquiring commodity information. In addition, the commodity reader 12 may also be configured as an RFID tag reader (wireless tag reader) for reading, for example, an RFID tag (wireless tag) attached to a commodity put into the storage shopping basket 21.

[0026] The commodity registration device 13 is a device for generating a commodity catalog. The commodity registration device 13 is provided on the frame 22 of the cart body 11. The commodity registration device 13 is composed of, for example, an information terminal such as a tablet terminal installed with a program for commodity registration. The commodity registration device 13 displays the catalog of commodities that the user has put into the storage shopping basket 21 based on the commodity information transferred from the commodity reader 12. The commodity registration device 13 can also settle the payment for commodities in the commodity catalog according to the operation input. The commodity registration device 13 has, for example, a communication interface, a processor, a memory, a touch panel, and a secondary battery, etc., which are not shown in the figure.

[0027] The communication interface is an interface for communicating with other devices. The commodity registration device 13 obtains commodity information from the commodity reader 12 via the communication interface. In addition, the communication interface sends the generated commodity catalog to the store server.

[0028] The processor is a computing element that performs arithmetic processing. The processor is configured as a CPU, for example. The processor performs various processes based on the program stored in the memory.

[0029] The memory is a storage device that stores programs and data. The memory includes, for example, one or more of a ROM that is a read-only nonvolatile memory, a RAM that temporarily stores data, and a memory that stores data.

[0030] A touch panel is a device that displays a screen and generates an operation signal based on an operation. The touch panel includes a display and a touch sensor. The display displays a screen based on display data (screen data) supplied from a processor or a graphics controller (not shown). The touch sensor generates an operation signal indicating the position touched by the user on the screen displayed on the display.

[0031] The charge and discharge control device 14 is configured to supply DC power for operation to the commodity reader 12 and the commodity registration device 13. The charge and discharge control device 14 includes a battery storage box 31, a power receiving device 32, a secondary battery 33, and a switch circuit 34.

[0032] The battery storage box 31 accommodates the secondary battery 33 and the switch circuit 34. The battery storage box 31 is attached to the frame 22 of the cart body 11.

[0033] The power receiving device 32 receives the power supplied from the cart power supply device 3 by electromagnetic coupling such as electromagnetic induction or magnetic field resonance (resonance). That is, the power receiving device 32 receives power in a non-contact state without electrical connection. The power receiving device 32 supplies DC power (charging power) to the secondary battery 33 through the received power. The power receiving device 32 is mounted on the frame 22 of the cart body 11. The power receiving device 32 includes a power receiving coil 35 and a power receiving circuit 36.

[0034] The power receiving coil 35 is an element that generates induced power by a change in magnetic flux. For example, the power receiving coil 35 is formed as a coil pattern on a printed circuit board. In addition, for example, the power receiving coil 35 may also be a winding structure formed by winding an insulated wire in a plane. The power receiving coil 35 is attached to the frame 22 of the cart body 11 in a manner that a conductive wire is arranged parallel to the ground.

[0035] The power receiving coil 35 is connected in series or in parallel with a resonant capacitor to form a resonant circuit (power receiving resonant circuit). The power receiving coil 35 generates an induced current by interlinking with a magnetic flux generated in a power supply coil described later.

[0036] The power receiving circuit 36 ​​is a circuit for supplying charging power to the secondary battery 33 using the induced current generated in the power receiving coil 35. The details of the power receiving circuit 36 ​​will be described later.

[0037] The secondary battery 33 is configured as, for example, a lithium ion secondary battery including an electrode group in which a positive electrode and a negative electrode are stacked with a separator interposed therebetween. The secondary battery 33 includes an input terminal and an output terminal.

[0038] The input terminal of the secondary battery 33 is connected to the output terminal of the power receiving circuit 36 ​​of the power receiving device 32. The secondary battery 33 is charged when DC power of a predetermined voltage is input to the input terminal. That is, the secondary battery 33 is charged by the charging power supplied from the power receiving device 32. The output terminal of the secondary battery 33 is connected to the switch circuit 34. The secondary battery 33 outputs DC power of a predetermined voltage from the output terminal.

[0039] In addition, the secondary battery 33 outputs DC power from the output terminal to the load when the load is connected to the output terminal. That is, the secondary battery 33 starts discharging by using the connection between the load and the output terminal as a trigger. In addition, the secondary battery 33 ends discharging when charging power is supplied to the input terminal. That is, the secondary battery 33 ends discharging when charging starts. Furthermore, the case where the secondary battery 33 is configured so that discharging does not restart even if charging ends is described.

[0040] The switch circuit 34 is a circuit for switching the connection between the secondary battery 33 and the commodity reader 12 and the commodity registration device 13 as loads. The switch circuit 34 switches the connection between the secondary battery 33 and the loads according to the state of the output of the charging power from the power receiving device 32. In addition, the detailed structure and operation of the switch circuit 34 will be described later.

[0041] Next, an example of the configuration of the cart power supply device 3 will be described.

[0042] Figure 3 This is an explanatory diagram for explaining a configuration example of the cart power supply device 3.

[0043] The cart power supply device 3 supplies power to the cart type commodity registration device 2 in a wireless manner. The cart power supply device 3 includes a power supply base 41, a guide groove 42, a stopper 43, a power supply surface 44, a power supply coil 45, and a power supply circuit 46. In addition, the cart power supply device 3 may also include, for example, a plurality of power supply coils 45 and a power supply circuit 46. Figure 3 In the example of FIG. 4 , the cart power supply device 3 includes, for example, four combinations of power supply coils 45 and power supply circuits 46. In addition, since the plurality of power supply coils 45 and power supply circuits 46 are respectively of the same configuration, one will be described as a representative.

[0044] The power supply base 41 is a housing provided with a guide groove 42, a stopper 43, a power supply surface 44, a power supply coil 45, etc. The power supply base 41 is installed on the ground.

[0045] The guide groove 42 guides the cart-type commodity registration device 2 in the direction of entering the power supply base 41. The guide groove 42 is configured as a groove for guiding the wheel of the caster 23 of the cart-type commodity registration device 2, for example. Figure 2 In the example of FIG. 1 , the guide groove 42 is configured as a pair of grooves for guiding the front wheels of the cart-type commodity registration device 2 .

[0046] The stopper 43 guides the stop position of the cart type commodity registration device 2. The stopper 43 is configured as a component that abuts against the front wheel of the cart type commodity registration device 2 that enters along the guide groove 42. The stopper 43 stops the cart type commodity registration device 2 by abutting against the front wheel of the cart type commodity registration device 2.

[0047] The power supply surface 44 is a surface provided with the power supply coil 45. The power supply surface 44 is formed, for example, parallel to the ground between a pair of grooves of the guide groove 42. The position where the power supply surface 44 is provided may be appropriately changed according to the position of the power receiving coil of the cart type commodity registration device 2.

[0048] The power supply coil 45 is an element that changes the magnetic flux according to the AC current flowing therethrough. For example, the power supply coil 45 is formed as a coil pattern on a printed circuit board. In addition, for example, the power supply coil 45 may also be an insulated wire wound in a plane to form a winding structure. The power supply coil 45 is embedded in the power supply surface 44 in a manner such that a conductive wire is arranged in parallel with the power supply surface 44. The power supply coil 45 is arranged so that when it is opposite to the power receiving coil 35, the magnetic flux generated in the power supply coil 45 interlinks with the power receiving coil 35. The power supply coil 45 is configured to be larger than the power receiving coil 35. In addition, the power supply coil 45 may also be provided on the upper part of the magnetic body.

[0049] The power supply coil 45 is connected in series or in parallel with a resonant capacitor to form a resonant circuit (power supply resonant circuit). When an alternating current flows through the power supply coil 45, the magnetic flux generated in the power supply coil 45 interlinks with the power receiving coil 35 to generate an induced current. That is, the power supply coil 45 transmits power to the power receiving coil by a magnetic field resonance method. In addition, when a magnetic field resonance method is used for power transmission, the self-resonant frequency of the power supply resonant circuit and the self-resonant frequency of the power receiving resonant circuit are configured to be the same or approximately the same. As a result, the power transmission efficiency when the power supply coil and the power receiving coil are electromagnetically coupled is improved.

[0050] Furthermore, when the front wheel of the cart type commodity registration device 2 is in contact with the stopper 43, at least one of the plurality of power supply coils 45 is disposed at a position opposite to the power receiving coil 35 of the cart type commodity registration device 2. Furthermore, when a plurality of cart type commodity registration devices 2 are stored in an overlapping and nested manner, the other power supply coils 45 are disposed at positions opposite to the power receiving coils 35 of the respective cart type commodity registration devices 2.

[0051] The power supply circuit 46 controls the supply of current to the power supply coil 45 .

[0052] Next, the circuits of the cart power supply device 3 and the charge and discharge control device 14 will be described in detail.

[0053] Figure 4 It is an explanatory diagram for explaining a configuration example of a circuit of the cart power supply device 3 and the charge and discharge control device 14 .

[0054] First, the cart power supply device 3 will be described. The power supply coil 45 of the cart power supply device 3 is connected in series with the resonant capacitor C1 to form a power supply resonant circuit 51. The power supply circuit 46 is provided for each power supply resonant circuit 51.

[0055] The power supply circuit 46 uses a DC power supply from the commercial power supply AC to the AC adapter 52 or the like to operate the power supply coil 45. In addition, a power conversion circuit that converts AC power from the commercial power supply AC into DC power may be provided in the housing of the cart power supply device 3. In addition, the power supply circuit 46 includes a semiconductor switch and a control circuit (not shown).

[0056] The semiconductor switch is a switching element that is switched by a control circuit. The semiconductor switch is, for example, a FET (Field Effect Transistor) composed of a wide-bandgap semiconductor such as silicon semiconductor, SiC, GaN, gallium oxide, or diamond. The semiconductor switch has a drain terminal, a gate terminal, and a source terminal. The semiconductor switch is connected to the power supply coil 45 via the resonant capacitor C1 of the resonant circuit 51.

[0057] A drive signal is input from a control circuit to a gate terminal of the semiconductor switch. The drive signal is configured as a pulse signal, for example. The semiconductor switch switches between a state where the drain terminal and the source terminal are conductive and a state where they are not conductive according to the drive signal.

[0058] The control circuit generates a drive signal and outputs the drive signal to a gate terminal of the semiconductor switch, thereby controlling the switching of the semiconductor switch (switching control).

[0059] By switching control of the semiconductor switch, an alternating current flows through the power supply coil 45 via the resonant capacitor C1. As a result, the magnetic flux generated in the power supply coil 45 changes periodically.

[0060] Next, the charge and discharge control device 14 will be described.

[0061] The power receiving coil 35 of the power receiving device 32 is connected in series with the resonance capacitor C2 to form a power receiving resonance circuit 53. The power receiving coil 35 is connected to an input terminal of the power receiving circuit 36 ​​via the resonance capacitor C2.

[0062] The power receiving circuit 36 ​​includes a rectifying and smoothing circuit and a voltage conversion circuit.

[0063] The rectifying and smoothing circuit constitutes an input side circuit of the power receiving circuit 36. The rectifying and smoothing circuit rectifies, smoothes, and outputs the induced current flowing from the power receiving coil 35. The rectifying and smoothing circuit includes a rectifying bridge composed of a diode or a plurality of diodes connected in series to the power receiving coil 35 and a smoothing capacitor. The rectifying and smoothing circuit outputs the voltage between the two terminals of the smoothing capacitor.

[0064] The voltage conversion circuit is a DC / DC converter that converts the output voltage of the rectification and smoothing circuit into a DC power of a voltage corresponding to the load and outputs it. The voltage conversion circuit is connected to the two terminals of the smoothing capacitor of the rectification and smoothing circuit. For example, the voltage conversion circuit converts the voltage between the two terminals of the smoothing capacitor of the rectification and smoothing circuit into a voltage corresponding to the specification of the secondary battery 33, and outputs the charging power for charging the secondary battery 33 to the secondary battery 33. In addition, when the output voltage of the rectification and smoothing circuit corresponds to the specification of the secondary battery 33, the voltage conversion circuit can also be omitted.

[0065] According to the above configuration, the magnetic flux interlinked with the power receiving coil 35 of the power receiving device 32 of the cart type commodity registration device 2 changes through the power supply coil 45 of the cart power supply device 3, and an induced current is generated in the power receiving coil 35. The power receiving device 32 rectifies and smoothes the induced current and performs voltage conversion corresponding to the rated voltage of the secondary battery 33, thereby supplying charging power to the secondary battery 33. As a result, the power receiving device 32 can wirelessly charge the secondary battery 33 using the power transmitted in a non-contact manner.

[0066] (First Embodiment)

[0067] Next, the switch circuit 34 according to the first embodiment will be described.

[0068] As described above, the switch circuit 34 switches the connection between the secondary battery 33 and the commodity registration device 13 or the commodity reader 12 as a load according to the state of the output of the charging power from the power receiving device 32. Here, the commodity reader 12 may be connected in parallel with the commodity registration device 13, and may be driven by the power output from the commodity registration device 13.

[0069] The switch circuit 34 includes a switching circuit 61 and an RC delay circuit 62. In addition, the switch circuit 34 includes an input terminal, an output terminal, and a control terminal.

[0070] An input terminal of the switch circuit 34 is connected to an output terminal of the secondary battery 33 .

[0071] The output terminal of the switch circuit 34 is connected to the commodity registration device 13 or the commodity reader 12 or the like as a load.

[0072] The control terminal of the switch circuit 34 is connected to the input terminal of the secondary battery 33, that is, the output terminal of the power receiving device 32. For example, the control terminal of the switch circuit 34 is connected to the output circuit of the power receiving device 32 via a high resistor.

[0073] The switching circuit 61 includes a resistor R and a photocoupler 71. Here, the resistor R is an operating resistor of a semiconductor relay device (photocoupler 71).

[0074] The photocoupler 71 is a normally closed semiconductor relay device. The emitter terminal of the photocoupler 71 is connected to the output terminal of the secondary battery 33. The collector terminal of the photocoupler 71 is connected to the commodity registration device 13 or the commodity reader 12 as a load. That is, the transistor of the photocoupler 71 constitutes the input terminal and the output terminal of the switch circuit 34.

[0075] In addition, an anode terminal of the photocoupler 71 is connected to the control terminal of the switch circuit 34 via the RC delay circuit 62. A cathode terminal of the photocoupler 71 is grounded.

[0076] That is, when the optocoupler 71 applies a voltage to the control terminal of the switch circuit 34 and current flows through the light-emitting diode via the RC delay circuit 62, the collector-emitter becomes closed (non-conducting state), and when no current flows through the light-emitting diode, the collector-emitter becomes open (conducting state).

[0077] The RC delay circuit 62 is a circuit composed of a resistor and a capacitor. The RC delay circuit 62 delays the rise and fall of the signal by a time corresponding to the RC time constant determined by the resistor value and the capacitance of the capacitor. As described above, the RC delay circuit 62 is connected between the control terminal of the switch circuit 34 and the anode terminal of the photocoupler 71. That is, the RC delay circuit 62 delays the rise and fall of the output terminal voltage of the power receiving device 32 by a time corresponding to the RC time constant, and inputs it to the anode of the photocoupler 71.

[0078] Next, the operation of the switch circuit 34 in the above-described configuration will be described.

[0079] Figure 5 This is an explanatory diagram for explaining the voltage in each part of the switch circuit 34 when the secondary battery 33 is switched from charging to discharging, that is, the charging and discharging state of the secondary battery 33 .

[0080] Figure 5 The first graph 81 represents the voltage of the control terminal of the switch circuit 34 (hereinafter referred to as the control signal). Figure 5 The second graph 82 represents the voltage at the input terminal of the switching circuit 34 . Figure 5 The third graph 83 represents the voltage of the output terminal of the switch circuit 34 .

[0081] exist Figure 5 In the example of , at timing t0, charging power is supplied from the power receiving device 32 to the secondary battery 33. In this case, the control signal input to the control terminal of the switch circuit 34 is raised to a high level according to the charging power (voltage) output from the power receiving device 32. That is, a predetermined voltage is applied to the control terminal of the switch circuit 34, and current flows through the light-emitting diode of the photocoupler 71. As a result, the collector-emitter of the photocoupler 71 becomes closed. That is, the switch circuit 34 disconnects the secondary battery 33 and the load during the period when charging power is supplied from the power receiving device 32 to the secondary battery 33.

[0082] Next, it is assumed that at timing t1, the supply of charging power from the power receiving device 32 to the secondary battery 33 ends. For example, when the cart type commodity registration device 2 moves and becomes a state where it does not receive power from the cart power supply device 3, the supply of charging power ends. In this case, since the charging power is not supplied from the power receiving device 32 to the secondary battery 33, the control signal input to the control terminal of the switch circuit 34 changes from a high level to a low level.

[0083] When the control signal input to the control terminal of the switch circuit 34 changes from a high level to a low level, the light emitting diode of the photocoupler 71 turns off after a time corresponding to the RC time constant of the RC delay circuit 62 has passed. The timing at which the light emitting diode of the photocoupler 71 turns off is set to timing t2. That is, the interval between timing t1 and timing t2 is a time corresponding to the RC time constant of the RC delay circuit 62.

[0084] At timing t2, the collector-emitter connection of the photocoupler 71 is turned on. That is, the input terminal and the output terminal of the switch circuit 34 are turned on. As a result, the secondary battery 33 is connected to the load such as the commodity registration device 13 or the commodity reader 12, and discharge from the secondary battery 33 to the load begins. That is, after the supply of charging power from the power receiving device 32 to the secondary battery 33 ends and a time corresponding to the RC time constant has passed, the switch circuit 34 connects the secondary battery 33 to the load, and discharge from the secondary battery 33 to the load begins.

[0085] As described above, the charge and discharge control device 14 of the handcart type commodity registration device 2 includes a secondary battery 33, a power receiving device 32, and a switch circuit 34. When charging power is supplied from the power receiving device 32 to the secondary battery 33, the switch circuit 34 disconnects the secondary battery 33 from the load. In addition, when the supply of charging power from the power receiving device 32 to the secondary battery 33 is terminated, the switch circuit 34 connects the secondary battery 33 to the load. Thus, even if the secondary battery 33 does not start to discharge automatically after charging is completed, by switching the state of the output terminal of the secondary battery 33, the switch circuit 34 also forms the same state as when the output terminal is connected to the load after charging is completed. As a result, when the charging of the secondary battery 33 is completed, the switch circuit 34 can start discharging from the secondary battery 33 to the commodity registration device 13 as a load.

[0086] In addition, the switch circuit 34 can delay the timing from the completion of charging to the connection of the load to the secondary battery 33 through the RC delay circuit 62. That is, from the timing t1 when the state of being supplied with charging power changes to the state of not being supplied, the switch circuit 34 connects the secondary battery 33 to the load by delaying the time corresponding to the RC time constant of the RC delay circuit 62. Thus, the switch circuit 34 can be controlled so as not to start discharging from the secondary battery 33 until the operation of the control circuit that depends on the secondary battery 33 (for example, the discharge of the internal capacitor of the secondary battery 33) is completed. As a result, since it can be separated from the operation of the secondary battery 33, safety can be improved.

[0087] In the above embodiment, the switch circuit 34 includes the photocoupler 71 that connects the input terminal and the output terminal according to the voltage applied to the control terminal, but the present invention is not limited to this configuration. The switch circuit 34 may be configured to perform the same operation using a mechanical relay or the like instead of a semiconductor relay device.

[0088] (Second Embodiment)

[0089] Next, the cart-type commodity registration device 2 involved in the second embodiment is described. The cart-type commodity registration device 2 of the second embodiment is different from the first embodiment in that it has a charge and discharge control device 14A, and the charge and discharge control device 14A has a switch circuit 34A that uses an optocoupler MOSFET (metal oxide semiconductor field effect transistor) as a semiconductor relay device instead of the optocoupler 71. In addition, for the same structure as the first embodiment, the same reference figure mark is marked, and the detailed description is omitted.

[0090] Figure 6 This is an explanatory diagram for explaining a configuration example of a charge and discharge control device 14A according to the second embodiment. The charge and discharge control device 14A includes a battery storage box 31 , a power receiving device 32 , a secondary battery 33 , and a switch circuit 34A.

[0091] The switch circuit 34A is a circuit for switching the connection between the secondary battery 33 and the commodity reader 12 and the commodity registration device 13 as loads. The switch circuit 34A switches the connection between the secondary battery 33 and the loads according to the state of the charging power output from the power receiving device 32.

[0092] The switch circuit 34A includes a switching circuit 61A, an RC delay circuit 62, and a loss suppression circuit 91. The switch circuit 34A also includes an input terminal, an output terminal, and a control terminal.

[0093] An input terminal of the switch circuit 34A is connected to an output terminal of the secondary battery 33 .

[0094] The output terminal of the switch circuit 34A is connected to the commodity registration device 13 or the commodity reader 12 or the like as a load.

[0095] The control terminal of the switch circuit 34A is connected to the input terminal of the secondary battery 33, that is, the output terminal of the power receiving device 32. For example, the control terminal of the switch circuit 34A is connected to the output terminal of the power receiving device 32 via a high resistor.

[0096] The switching circuit 61A includes a resistor R, a first photocoupler MOSFET 92 , and a second photocoupler MOSFET 93 . The resistor R serves as an operating resistor (on-resistance loss) of the first photocoupler MOSFET 92 and the second photocoupler MOSFET 93 .

[0097] The first photocoupler MOSFET 92 and the second photocoupler MOSFET 93 are normally closed semiconductor relay devices.

[0098] The source terminal of the first photocoupler MOSFET 92 is connected to the output terminal of the secondary battery 33. That is, the source terminal of the first photocoupler MOSFET 92 serves as an input terminal of the switch circuit 34A.

[0099] The drain terminal of the first photocoupler MOSFET 92 is connected to the drain terminal of the second photocoupler MOSFET 93. That is, the first photocoupler MOSFET 92 and the second photocoupler MOSFET 93 are connected in series so that their body diodes are opposite to each other.

[0100] The source terminal of the second photocoupler MOSFET 93 is connected to the commodity registration device 13 or the commodity reader 12 as a load. That is, the source terminal of the second photocoupler MOSFET 93 serves as an output terminal of the switch circuit 34A.

[0101] In addition, the anode terminal of the first photocoupler MOSFET 92 is connected to the control terminal of the switch circuit 34A via the RC delay circuit 62 .

[0102] The cathode terminal of the first photocoupler MOSFET 92 is connected to the anode terminal of the second photocoupler MOSFET 93 .

[0103] The cathode terminal of the second photocoupler MOSFET 93 is grounded.

[0104] That is, in the first optocoupler MOSFET 92 and the second optocoupler MOSFET 93, when a voltage is applied to the control terminal of the switch circuit 34A and a current flows through the light-emitting diode, the source-drain of the first optocoupler MOSFET 92 and the drain-source of the second optocoupler MOSFET 93 become closed (non-conductive state). In addition, in the first optocoupler MOSFET 92 and the second optocoupler MOSFET 93, during the period when no current flows through the light-emitting diode, the source-drain of the first optocoupler MOSFET 92 and the drain-source of the second optocoupler MOSFET 93 become open (conductive state).

[0105] In the secondary battery 33, the output terminal voltage becomes negative when charging. For example, when the output terminal voltage of the secondary battery 33 becomes negative and there is only one optocoupler MOSFET in the switch circuit 34A, a current (reverse current) flows from the load to the secondary battery 33 in the body diode of the optocoupler MOSFET. However, in the switch circuit 34A, the first optocoupler MOSFET 92 and the second optocoupler MOSFET 93 are connected in series in a manner that the body diodes are reversed to each other. Thus, the switch circuit 34A can prevent the generation of reverse current.

[0106] Furthermore, as described above, when normally closed devices are connected in series, there is a possibility that the operation loss will increase. Therefore, the switch circuit 34A includes a loss suppression circuit 91 that is connected in parallel with the switching circuit 61A and constitutes a bypass path.

[0107] The loss suppression circuit 91 includes a third photocoupler MOSFET 94 and a fourth photocoupler MOSFET 95 .

[0108] The third photocoupler MOSFET 94 and the fourth photocoupler MOSFET 95 are normally-open semiconductor relay devices, and have smaller operating resistance than the first photocoupler MOSFET 92 and the second photocoupler MOSFET 93 .

[0109] A drain terminal of the third photocoupler MOSFET 94 is connected to the output terminal of the secondary battery 33 .

[0110] The source terminal of the third photocoupler MOSFET 94 is connected to the source terminal of the fourth photocoupler MOSFET 95. That is, the third photocoupler MOSFET 94 and the fourth photocoupler MOSFET 95 are connected in series so that their body diodes are opposite to each other.

[0111] The drain terminal of the fourth photocoupler MOSFET 95 is connected to the commodity registration device 13 or the commodity reader 12 as a load. That is, the drain terminal of the fourth photocoupler MOSFET 95 constitutes an output terminal of the switch circuit 34A.

[0112] In addition, an anode terminal of the third photocoupler MOSFET 94 is connected to the output terminal of the secondary battery 33 .

[0113] The cathode terminal of the third photocoupler MOSFET 94 is connected to the anode terminal of the fourth photocoupler MOSFET 95 .

[0114] The cathode terminal of the fourth photocoupler MOSFET 95 is grounded.

[0115] In the above-mentioned structure, when the secondary battery 33 and the load are connected through the switching circuit 61A, a current flows from the secondary battery 33 to the switching circuit 34A. When the current flows from the secondary battery 33 to the switching circuit 34A, the current also flows through the light-emitting diodes of the third optocoupler MOSFET 94 and the fourth optocoupler MOSFET 95. As a result, the drain-source of the third optocoupler MOSFET 94 and the source-drain of the fourth optocoupler MOSFET 95 are turned on and connected in parallel with the switching circuit 61A, and a bypass path with a small operating resistance is formed. As a result, the switching circuit 34A can suppress losses and effectively utilize the power charged to the secondary battery 33.

[0116] In addition, the third optocoupler MOSFET 94 may be used in accordance with the control state (voltage) of the output terminal of the secondary battery 33 during charging and discharging. That is, the loss suppression circuit 91 may be configured to omit the third optocoupler MOSFET 94 and include the fourth optocoupler MOSFET 95. When the third optocoupler MOSFET 94 is omitted from the loss suppression circuit 91, the effect of suppressing loss can be further improved.

[0117] In the above embodiment, the description is given of the commodity registration device 13 being provided on the cart body 11 of the cart type commodity registration device 2, but the present invention is not limited to this configuration. The commodity registration device 13 of the cart type commodity registration device 2 may also be replaced with an information terminal (e.g., a smart phone, a tablet terminal, a digital camera, etc.) held by a user. That is, the charge and discharge control device 14 of the cart type commodity registration device 2 may also be a configuration that supplies power to the information terminal held by the user.

[0118] Furthermore, the functions described in the above embodiments are not limited to being configured using hardware, and can also be implemented by reading a program describing each function into a computer using software. In addition, each function can be configured by appropriately selecting either software or hardware.

[0119] Although several embodiments are described, these embodiments are only presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the purpose of the invention. These embodiments and their variations are included in the scope and purpose of the invention, and are also included in the invention described in the claims and their equivalents.

Claims

1. A charge and discharge control device, comprising: The secondary battery has an input terminal and an output terminal and supplies power to a load. The power receiving coil is electromagnetically coupled to the power transmitting coil of the power supply device; a power receiving circuit having an input terminal connected to the power receiving coil and an output terminal connected to the input terminal of the secondary battery, the power receiving circuit rectifying a voltage generated in the power receiving coil and supplying charging power to the secondary battery; and a switch circuit having an input terminal connected to the output terminal of the secondary battery, an output terminal connectable to the load, and a control terminal connected to both the input terminal of the secondary battery and the output terminal of the power receiving circuit, The switching circuit has an optocoupler or an optocoupler MOSFET, and the optocoupler or optocoupler MOSFET has a light-emitting diode whose anode is connected to the input terminal of the secondary battery. During the period when the charging power is supplied to the secondary battery, the switching circuit disconnects the secondary battery and the load according to the voltage applied to the control terminal. When the charging power is not supplied to the secondary battery, the switching circuit connects the secondary battery and the load.

2. The charge and discharge control device according to claim 1, wherein: The switch circuit connects the secondary battery to the load with a predetermined time delay from a timing when a state in which the charging power is supplied is changed to a state in which the charging power is not supplied.

3. The charge and discharge control device according to claim 1 or 2, wherein: The switch circuit includes the photocoupler of a normally closed type.

4. The charge and discharge control device according to claim 1 or 2, wherein: The switch circuit includes at least two normally-off photocoupler MOSFETs connected in series with their body diodes being in opposite directions to each other.

5. The charge and discharge control device according to claim 4, wherein: The switch circuit includes a loss suppression circuit that is turned on when the secondary battery and the load are connected via the photocoupler MOSFET.

6. A trolley type commodity registration device, wherein: The cart-type commodity registration device comprises a commodity registration device, a secondary battery having an input terminal and an output terminal and supplying power to the commodity registration device, a charge and discharge control circuit, and a cart body, wherein the cart body is used to support the commodity registration device, the secondary battery, and the charge and discharge control circuit. The charge and discharge control circuit comprises: The power receiving coil is electromagnetically coupled to the power transmitting coil of the power supply device; a power receiving circuit having an input terminal connected to the power receiving coil and an output terminal connected to the input terminal of the secondary battery, the power receiving circuit rectifying a voltage generated in the power receiving coil to supply charging power to the secondary battery; as well as a switch circuit having an input terminal connected to the output terminal of the secondary battery, an output terminal connectable to the commodity registration device, and a control terminal connected to both the input terminal of the secondary battery and the output terminal of the power receiving circuit, The switching circuit has an optocoupler or an optocoupler MOSFET, and the optocoupler or optocoupler MOSFET has a light-emitting diode whose anode is connected to the input terminal of the secondary battery. During the period when the charging power is supplied to the secondary battery, the switching circuit disconnects the secondary battery and the commodity registration device according to the voltage applied to the control terminal. During the period when the charging power is not supplied to the secondary battery, the switching circuit connects the secondary battery and the commodity registration device.

7. The cart-type commodity registration device according to claim 6, wherein: The switch circuit connects the secondary battery to the commodity registration device with a predetermined time delay from a timing when the state in which the charging power is supplied is changed to a state in which the charging power is not supplied.

8. The cart-type commodity registration device according to claim 6 or 7, wherein: The switch circuit includes the photocoupler of a normally closed type.

9. The cart-type commodity registration device according to claim 6 or 7, wherein: The switch circuit includes at least two normally-off photocoupler MOSFETs connected in series with their body diodes being in opposite directions to each other.

10. The cart-type commodity registration device according to claim 9, wherein: The switch circuit includes a loss suppression circuit that is turned on when the secondary battery and the commodity registration device are connected via the photocoupler MOSFET.

Images