JP7534152B2 - Charging device and charging system - Google Patents

Description

Embodiments of the present invention relate to a charging device and a charging system.

In recent years, some shopping carts are equipped with electronic devices, such as tablet terminals with built-in batteries. Such shopping carts are equipped with an external battery that supplies power to the attached electronic devices, allowing them to operate continuously for long periods of time. The electronic devices installed in the shopping cart operate while charging their built-in batteries (internal batteries) with power supplied from the external battery.

However, mobile batteries used as external batteries are generally designed not to output power while charging. External batteries with such specifications cannot supply power to electronic devices such as tablet terminals while charging. Electronic devices with built-in batteries (internal batteries) consume power stored in the internal battery even while the external battery is charging. For this reason, in the case of a shopping cart, the internal battery of the electronic device may become empty while the external battery is being charged. When the internal battery becomes empty, the electronic device such as the tablet terminal will shut down, and will need to be restarted before it can be used again.

JP 2019-151219 A

The problem that this invention aims to solve is to provide a charging device and charging system that can prevent the operation of electronic devices powered by an internal battery from being stopped even when an external battery is being charged.

According to an embodiment, a charging device has a first connector, a second connector, a switch circuit, a power detection circuit, and a control circuit. The first connector receives power from an external device. The second connector is connected to an electronic device having an internal battery. The switch circuit is provided between an output section of an external battery having an input section connected to the first connector and the second connector. The power detection circuit detects the amount of power output from the first connector. The control circuit controls the switch circuit to connect the output section of the external battery to the second connector when power is input from the outside to the first connector, and then controls the switch circuit to connect the first connector to the second connector when the power detected by the power detection circuit falls below a threshold value .

FIG. 1 is a perspective view showing a configuration example of a shopping cart equipped with a charging system according to an embodiment. FIG. 2 is a diagram showing a configuration example (first configuration example) of a charging system including a charging device according to an embodiment. FIG. 3 is a diagram illustrating an example of the configuration of an external battery in the charging system according to the embodiment. FIG. 4 is a diagram illustrating an example of a configuration in which a charging system including a charging device according to an embodiment is connected to an AC adapter. FIG. 5 is a diagram illustrating a configuration example of a charging system including a charging device according to an embodiment when receiving power in a wireless manner. FIG. 6 is a diagram showing a modified example (second configuration example) of a charging system including a charging device according to the embodiment. FIG. 7 is a flowchart for explaining an example of operation of a modified example of the charging system according to the embodiment.

Hereinafter, a charging device and a charging system according to an embodiment will be described with reference to the drawings.
FIG. 1 is a perspective view showing a shopping cart 1 equipped with a charging system 2 according to an embodiment.
A shopping cart (hereinafter, also simply referred to as a cart) 1 is an example of a mobile object equipped with a charging system 2. The shopping cart 1 is used, for example, for shopping in a store or the like.

The charging system 2 has a charging circuit (charging device) 21 and an external battery 22. The charging system 2 receives power supplied from the outside through the charging circuit 21. In the charging system 2, the charging circuit 21 charges the external battery 22 with the power received from the outside. The charging circuit 21 also has a function of supplying the power received from the outside to the electronic device 3 mounted on the cart 1.

The electronic devices 3 mounted on the cart 1 include electronic devices 31 with a built-in battery (internal battery). The electronic devices 31 operate using electricity stored in the internal battery as a power source. The electronic devices 31 charge the internal battery with electricity supplied from the charging system 2. For example, when the charging system 2 is not receiving electricity from the outside, such as when the shopping cart 1 is moving, the electronic devices 31 operate while charging the internal battery with electricity supplied from the external battery 22. Also, when the charging system 2 is receiving electricity from the outside, the electronic devices 31 charge the internal battery when electricity is supplied from the outside by the charging circuit 21.

1, the cart 1 includes a movable cart body 11 that can store products therein. The cart body 11 is configured to store products therein and move according to an operation by a user.
The cart body 11 has a storage basket 12 for storing products. The storage basket 12 is supported by a frame 14 having four casters 15 (15Fr, 15Fl, 15Rr, 15Rl). The four casters 15 are provided at the four corners of the lower part of the frame 14. Each caster 15 (15Fr, 15Fl, 15Rr, 15Rl) has front wheels 13Fr and 13Fl and rear wheels 13Rr and 13Rl that rotate in the moving direction. The cart body 11 moves when the wheels 13 of each caster 15 rotate on the floor surface. In addition, each caster 15 is configured so that the rotation direction of the wheels 13 can freely rotate. This allows the cart body 11 to freely change the moving direction.

A handle 16 is provided on the frame 14 at the front side of the storage basket 12. The handle 16 is held by a user. For example, the user holds the handle 16 to move the cart body 11. In this embodiment, the direction in which the user pushes the storage basket 12 from the handle 16 held by the user is considered to be the forward direction.

The lower part of the frame 14, where the four casters 15 are provided at the four corners, is narrower at the front and wider at the rear in the forward direction. Therefore, the casters 15Fr and 15Fl that support the front wheels are narrower in width from side to side than the casters 15Rr and 15Rl that support the rear wheels. As a result, when multiple carts are stored lined up one behind the other, the frames of the rear carts are stored so that they overlap along the frame of the front cart.

In the embodiment, the handle 16 side of the storage basket 12 is referred to as the near side, and the opposite side, the front of the cart, is referred to as the tip side. The near side of the storage basket 12 has an opening and closing surface 12a that can be opened and closed with the lower end as the free end. The front side of the storage basket 12 is also formed so that the surface on the tip side is smaller than the near side surface that serves as the opening and closing surface 12a. As a result, when multiple carts are stored lined up in front of each other, the rear cart pushes up the opening and closing surface 12a of the front cart, so that the storage baskets 12 of the front and rear carts overlap.

Electronic devices 3 (31, 32, 33) including electronic device 31 equipped with an internal battery are attached to cart body 11. Electronic device 3 is a device for providing information and services to users. For example, electronic device 3 is an information terminal such as a tablet terminal for providing information to users, a product reader for acquiring information on a product selected by a user, or a card reader for reading credit cards, membership cards, etc. However, electronic devices 3 mounted on the cart according to this embodiment include electronic device 31 equipped with an internal battery.

In the configuration example shown in FIG. 1, the electronic device 3 is attached to the handle 16 of the storage basket 12. FIG. 1 illustrates a tablet terminal 31, a product reader 32, and a card reader 33 as examples of the electronic device 3. The tablet terminal 31 is an example of an electronic device equipped with an internal battery. The tablet terminal 31 is a computer that operates using power stored in the internal battery and has a display unit with a touch panel. The tablet terminal 31 is installed with the display unit facing the user located on the handle 16 side. For example, the tablet terminal 31 displays information about a product read by the product reader 32. The tablet terminal 31 may also have a function of performing a payment process for the product read by the product reader 32.

The product reader 32 as the electronic device 3 is a device that reads product information. The product reader 32 may have a display unit that displays the read product information. For example, the product reader 32 is a scanner that reads product identification information such as a barcode attached to a product to be put into or taken out of the storage basket 12. The product reader 32 may also be an RFID tag reader that reads an RFID tag or the like attached to a product. The card reader 33 as the electronic device 3 is a card reader for reading a credit card, membership card, or the like owned by a user.

A box containing a charging circuit 21 (charging device) and an external battery 22 that constitute the charging system 2 is attached to the cart body 11. The charging circuit 21 includes a circuit for receiving power transmitted from an external device and outputting the received power to the external battery 22 or the electronic device 31. The external battery 22 serves as a power source device for operating each electronic device 3, including the electronic device 31. The external battery 22 is charged by power supplied via the charging circuit 21.

Next, the configuration of the charging system 2 according to the embodiment will be described.
FIG. 2 is a diagram showing a configuration example (first configuration example) of a charging system 2 according to an embodiment.
2, the charging system 2 has a charging circuit 21 as a charging device and an external battery 22. The charging circuit 21 has a first connector 41, a control circuit 42, a switch circuit 43, and a second connector 44. The charging circuit 21 is connected to an input section and an output section of the external battery 22.

The first connector 41 is an interface for inputting power from an external power source. In the configuration example shown in FIG. 1, the first connector 41 is connected to an input section for power input in the external battery 22, a control circuit 42, and a switch circuit 43. The first connector 41 supplies power received from the outside to the external battery 22. When the first connector 41 is connected to the second connector 44 by the switch circuit 43, it also supplies power received from the outside to the second connector 44.

The control circuit 42 controls the switch circuit 43. The control circuit 42 may be configured with a logic circuit, a microcomputer having a processor and memory, or a combination of a microcomputer and a circuit. The control circuit 42 has a function of detecting that the first connector 41 is receiving power to be supplied to the external battery 22. When the first connector 41 is not receiving power from the outside, the control circuit 42 connects the external battery 22 and the second connector 44 by the switch circuit 43. When the first connector 41 is receiving power from the outside, the control circuit 42 connects the first connector 41 and the second connector 44 without going through the external battery 22.

The second connector 44 is an interface for outputting electric power from the charging system 2. The second connector 44 is connected to the electronic device 3. In other words, the second connector 44 is an interface for the charging system 2 to output electric power to each electronic device 3, including the electronic device 31.

The switch circuit 43 is a switch that switches the connection destination of the second connector 44. The switch circuit 43 switches the switch in response to a control signal from the control circuit 42. The switch circuit 43 switches between connecting the second connector 44 to the external battery 22 or connecting the second connector 44 to the first connector 41.

2, the switch circuit 43 connects one end of the switch, which is connected to the o terminal, to either the a terminal or the b terminal in accordance with a control signal from the control circuit 42. For example, when connecting the external battery 22 to the second connector 44, the control circuit 42 connects the o terminal to point a using the switch circuit 43. When connecting the first connector 41 to the second connector 44, the control circuit 42 connects the o terminal to terminal b using the switch circuit 43.

Next, the configuration of the external battery 22 in the charging system 2 according to the embodiment will be described.
FIG. 3 is a diagram showing an example of the configuration of the external battery 22 in the charging system 2 according to the embodiment.
As shown in FIG. 3 , the external battery 22 of the charging system 2 has an input unit 50 , a battery cell 51 , a charging circuit 52 , a control circuit 53 , a switch 54 , and an output unit 55 .
The input unit 50 is an interface for inputting power for charging. Power is input to the input unit 50 from a charging circuit 21 serving as a charging device in the charging system 2. The input unit 50 is connected to a charging circuit 52. The input unit 50 supplies the power supplied from the charging system 2 to the charging circuit 52.

The battery cell 51 stores the power supplied from the charging circuit 52. The battery cell 51 outputs the stored power in response to switching of the switch 54.
The charging circuit 52 stores the power input to the input unit 50 in the battery cell 51 under the control of the control circuit 53 .

The control circuit 53 controls the charging circuit 52 and the switch 54. When the control circuit 53 is to charge the battery cell 51 with the input power, it outputs a control signal to the charging circuit 52 to instruct the charging of the battery cell 51. When the control circuit 53 is to output the power stored in the battery cell 51, it outputs a control signal to switch the switch 54 so that the power stored in the battery cell 51 is output.

The switch 54 is connected to the battery cell 51. The switch 54 operates according to control from the control circuit 53. The switch 54 is set to either a state in which the power stored in the battery cell 51 is output or a state in which the power is not output. In other words, the switch 54 switches whether or not the power stored in the battery cell 51 is output according to control from the control circuit 53.

The output unit 55 is an interface for outputting the power stored in the battery cell 51. When the switch 54 is set to output power from the battery cell 51, the output unit 55 outputs the power stored in the battery cell 51.

For example, the control circuit 53 performs control so as not to output power while the battery cell 51 is being charged. When power is input to the input unit 50, the control circuit 53 instructs the charging circuit 52 to charge the battery cell 51 and switches the switch 54 so as not to output the power stored in the battery cell 51. Furthermore, when there is no power input to the input unit 50, the control circuit 53 switches the switch 54 so as to output the power stored in the battery cell 51 from the output unit 55.
In order to output a predetermined voltage from the output section, a step-down circuit or a step-up circuit for stepping down/stepping up the output voltage of the battery cell is provided between the battery cell and the switch, or between the switch and the output section.

Next, a configuration for the charging system 2 according to the embodiment to receive electric power from an external source will be described.
FIG. 4 is a diagram showing a first example in which the charging system 2 according to the embodiment receives electric power from an external source.
4, the charging circuit 21 of the charging system 2 has a first connector 41 that receives power from an external source. The first connector 41 is configured as an interface for connecting an AC adapter 61.

The AC adapter 61 is connected to a commercial AC power source as an external power source. The AC adapter 61 converts AC power from the external power source into DC power of a predetermined value. For example, the AC adapter 61 converts AC power from the external power source into DC power of a voltage suitable for the operation of the charging circuit 21 in the charging system 2.

The first connector 41 of the charging circuit 21 is connected to the output of the AC adapter 61. A predetermined value of DC power generated by the AC adapter 61 from an external AC power source is input to the first connector 41.

As shown in FIG. 1, the charging system 2 including the charging circuit 21 is mounted on the cart 1. In the configuration shown in FIG. 4, when charging the external battery 22, an AC adapter 61 is connected to the first connector 41 of the charging system 2 mounted on the cart 1. The first connector 41 of the charging circuit 21 receives power from the connected AC adapter 61. When the AC adapter 61 is connected to the first connector 41, the charging circuit 21 supplies the power received by the first connector 41 to the external battery 22 and the electronic device 31 connected to the second connector 44.

FIG. 5 is a diagram showing a second example in which the charging system 2 according to the embodiment receives electric power from the outside in a wireless manner.
5 , the cart 1 includes a power receiver 23 that receives power in a non-contact manner from a power transmitter 62 that transmits power in a non-contact manner. The output of the power receiver 23 is connected to the first connector 41.

The power transmitter 62 is connected to an external power source such as a commercial AC power source via an AC adapter 61. The power transmitter 62 converts power from the external power source into power that can be received by the power receiver 23 in a non-contact manner and outputs the converted power. For example, the power transmitter 62 is composed of a power transmission circuit and a power transmission coil.

The power transmission circuit converts the DC power supplied from the AC adapter 61 into AC power for transmission from the power transmission coil. The power transmission circuit supplies the generated AC power to the power transmission coil. For example, the power transmission circuit generates AC power as transmission power by switching the DC power supplied from the AC adapter 61 based on the control of the control circuit.

The power transmission coil outputs power that can be received by the power receiver in accordance with the transmission power supplied from the power transmission circuit. The power transmission coil has a planar power transmission surface that transmits power. The power transmission surface of the power transmission coil is arranged to face the power receiving surface of the power receiving coil of the power receiver at the charging position. For example, the power transmission surface of the power transmission coil is arranged to face the power receiving surface of the power receiving coil of the power receiver, parallel to the floor surface.

The power transmission coil may be connected in series or parallel with a resonant capacitor to form a resonant circuit (power transmission resonant circuit). When AC power is supplied from the power transmission circuit, the power transmission coil as a power transmission resonant circuit generates a magnetic field according to the supplied AC power. The power transmission coil may be configured as a winding structure in which an insulated electric wire is wound, or may be configured by forming a coil pattern on a printed circuit board.

The power transmitter 62 may be provided with a wireless communication circuit for wireless communication. For example, the wireless communication circuit is a circuit that performs wireless communication at a frequency different from the frequency of power transmission. The control circuit may control each part by wirelessly communicating with the power receiver via the wireless communication circuit.

The power receiver 23 receives the power output from the power transmitter in a wireless manner. For example, the power receiver 23 includes a power receiving coil and a power receiving circuit.
The receiving coil receives the transmitted power from the transmitting coil of the power transmitter 62. The receiving coil supplies the received power to a receiving circuit. For example, the receiving coil has a flat receiving surface that receives power. The receiving surface of the receiving coil may be installed so as to face the transmitting coil. For example, when the transmitting coil is installed on the floor surface, the receiving coil is installed on the bottom surface of the cart body 11 in a state parallel to the floor surface.

The receiving coil may be connected in series or parallel with a resonant capacitor for receiving power to form a resonant circuit (receiving resonant circuit). When the receiving coil as a receiving resonant circuit approaches the transmitting coil of the power transmitter 62, it is electromagnetically coupled to the transmitting coil. The receiving coil generates an induced current due to the magnetic field output from the transmitting coil of the power transmitter. The receiving coil as a receiving resonant circuit supplies the received AC power to the receiving circuit. In other words, the receiving coil functions as an AC power source while receiving AC power from the power transmitter. In addition, when using a magnetic field resonance method for power transmission, the self-resonant frequency of the receiving resonant circuit as the receiving coil is configured to be approximately the same as the frequency at which the power transmitter transmits power. This improves the power transmission efficiency when the receiving coil and the transmitting coil are electromagnetically coupled.

In the power receiver 23, the power receiving circuit converts the received power supplied from the power receiving coil into power that can be supplied to the external battery 22 and the electronic device 31 connected to the second connector 44. For example, the power receiving circuit rectifies the received power supplied from the power receiving coil and converts it into direct current. Such a power receiving circuit may be realized by a circuit including a rectifier bridge composed of multiple diodes. In this case, a pair of input terminals of the rectifier bridge are connected to a power receiving resonant circuit composed of a power receiving coil and a resonant capacitor. The power receiving circuit outputs direct current power from a pair of output terminals by full-wave rectifying the received power supplied from the power receiving coil.

The power receiver 23 may be provided with a wireless communication circuit for wireless communication with the corresponding power transmitter. For example, the wireless communication circuit is a circuit that performs wireless communication at a frequency different from the frequency of power transmission. The wireless communication circuit may also use load modulation to perform wireless communication at the same frequency as the frequency of power transmission. The control circuit 42 as a control circuit or a control unit provided in the power receiver may control each unit based on information received from the power transmitter via the wireless communication circuit.

As described above, the charging system according to the embodiment includes a charging device that charges an external battery that supplies power to an electronic device equipped with an internal battery attached to a mobile object such as a cart. When the first connector receives power from the outside, the charging system according to the first configuration example controls the power from the first connector to be supplied to both the external battery and the electronic device equipped with an internal battery connected to the second connector. This allows the charging system to supply power to the electronic device even while the external battery is being charged. As a result, it is possible to prevent the internal battery equipped in the electronic device from running out of power while the external battery is being charged.

Next, a charging system 2' as a modification (second configuration example) of the embodiment will be described.
FIG. 6 is a diagram showing a configuration example of a charging system 2 ′ according to a modified example (second configuration example) of the embodiment.
6, the charging system 2' has a charging circuit 21' as a charging device and an external battery 22. The charging circuit 21' has a first connector 41, a control circuit 42', a switch circuit 43, a second connector 44, a current detection circuit 71, and a resistor 71R. The charging circuit 21' is connected to an input unit 50 and an output unit 55 of the external battery 22.

The first connector 41, the switch circuit 43 and the second connector 44 may be realized with the same configuration as shown in FIG.
For example, the first connector 41 is an interface that receives power from the outside. In the configuration example shown in Fig. 6, the first connector 41 is connected to an input unit 50 for inputting power from the external battery 22 and to a terminal b of the switch circuit 43 via a resistor 71R for current detection. The first connector 41 may be connected to an AC adapter 61 as shown in Fig. 4 or to a power receiver that receives power in a non-contact manner as shown in Fig. 5.

The second connector 44 is an interface for outputting electric power. The second connector 44 is connected to each of the electronic devices 3 including the electronic device 31.
2, the switch circuit 43 is a switch that switches a path for outputting power to the second connector 44. The switch circuit 43 switches the switch according to a control signal from the control circuit 42'. The switch circuit 43 connects one end of the switch, the other end of which is connected to the o-terminal, to either the a-terminal or the b-terminal according to the control signal from the control circuit 42'. For example, when connecting the external battery 22 and the second connector 44, the control circuit 42' connects the o-terminal and the a-terminal by the switch circuit 43. When connecting the first connector 41 and the second connector 44, the control circuit 42' connects the o-terminal and the b-terminal by the switch circuit 43.

The current detection circuit 71 is an example of a power detection circuit that detects the amount of power supplied from the first connector 41. The current detection circuit 71 is a circuit that detects the current value of the current flowing between the first connector 41 and the external battery 22. The resistor 71R is a current detection resistor that allows the current detection circuit 71 to detect the current. The current detection circuit 71 outputs a signal indicating the detected current value to the control circuit 42'.

The control circuit 42' controls the switch circuit 43. The control circuit 42 may be configured with a microcomputer having a processor and memory, or may be configured by combining a microcomputer with a circuit such as a comparison circuit. The control circuit 42' acquires the current value detected by the current detection circuit 71. The control circuit 42' controls the switch circuit 43 according to the current value detected by the current detection circuit 71. The control circuit 42' controls the path for supplying power from the first connector 41 according to the amount of power input from the outside through the first connector 41.

For example, the control circuit 42' controls the supply of power to the electronic device 31 connected to the second connector 44 while giving priority to charging the external battery 22. Specifically, when the maximum output current (power) value X of the AC adapter 61 or the power receiver 23 connected to the first connector is equal to or greater than the sum of the maximum input value A of the external battery 22 and the maximum input value B of the electronic device 31 (X≧A+B), the control circuit 42' connects the b terminal and the o terminal by the switch circuit 43. In other words, if X≧A+B, the control circuit 42' directly connects the first connector 41 and the second connector 44. As a result, the control circuit 42' controls the switch circuit 43 to supply the power input to the first connector 41 to both the external battery 22 and the electronic device 31 connected to the second connector 44 during charging of the external battery 22.

In addition, when the maximum output current value X is less than the sum of the maximum input value A of the external battery 22 and the maximum input value B of the electronic device 31 (when X<A+B), the control circuit 42' connects the a terminal and the o terminal via the switch circuit 43. In other words, when X<A+B, the control circuit 42' connects the external battery 22 and the second connector 44. As a result, the control circuit 42' controls the switch circuit 43 to supply the power input to the first connector 41 to the external battery 22.

However, even if X<A+B, when the control circuit 42' detects that the external battery 22 is nearly fully charged, the amount of charging power has decreased, and the current (power) value has fallen below a predetermined value, the control circuit 42' connects the a terminal and the o terminal with the switch circuit 43. In other words, even if X<A+B, the control circuit 42' connects the first connector 41 and the second connector 44 within a range in which the current (power) value actually charged to the external battery and the input current (power) value of the electronic device 31 do not exceed X. As a result, the control circuit 42' can effectively charge the external battery 22 and drive the electronic device 31 within a range in which the maximum output current (power) value X of the AC adapter 61 and the power receiver 23 is not exceeded.

The control circuit 42' may first connect b and o of the switch circuit 43 so as to prioritize charging of the internal battery of the electronic device 31. The control circuit 42' may then supply power to the external battery 22 when the charge level of the internal battery of the electronic device 31 exceeds a predetermined value. This allows the external battery 22 to be charged while the charge level of the internal battery of the electronic device 31 is ensured.

Next, an example of the operation of the charging system 2' including the charging circuit 21' according to the second configuration example will be described.
FIG. 7 is a flowchart for explaining an example of the operation of a charging system 2' including a charging circuit 21' according to the second configuration example.
When power is input from the outside to the first connector 41, the control circuit 42 connects the external battery 22 and the second connector 44 with the switch circuit 43 (ACT 11). This corresponds to the control circuit 42' connecting the a-terminal and the o-terminal with the switch circuit 43 in the configuration shown in Fig. 6 .

Here, the external battery 22 is configured to charge the battery cell 51 with power input to the input unit 50, and not to output power from the output unit 55 during charging. Therefore, if power is supplied to the external battery 22 from the first connector 41 while the output unit 55 of the external battery 22 is connected to the second connector 44, no power will be supplied to the second connector 44.

In addition, in the charging system 2', the control circuit 42' acquires the current value detected by the current detection circuit 71 constantly or at a predetermined cycle. The control circuit 42' monitors whether the current value detected by the current detection circuit 71 falls below a predetermined threshold (ACT 12). The predetermined threshold is a value for determining whether the sum of the current (power) value charged to the external battery and the input current (power) value of the electronic device 31 exceeds the maximum output value X of the AC adapter 61 connected to the first connector 41. Here, the external battery 22 is generally designed to reduce the input current value when the charging power amount approaches full charge, and the control circuit 42' can also determine that the external battery 22 is close to full charge when the current value detected by the current detection circuit 71 falls below the predetermined threshold.

When the current value falls below a predetermined threshold, the control circuit 42' connects the first connector 41 and the second connector 44 with the switch circuit 43 (ACT 13). This corresponds to the control circuit 42' connecting the b terminal and the o terminal with the switch circuit 43 in the configuration shown in FIG. 6. When the b terminal and the o terminal are connected with the switch circuit 43, the second connector 44 is supplied with power received by the first connector 41 from the first connector 41 without passing through the external battery 22. As a result, power is supplied to the electronic device 31 connected to the second connector 44, and the internal battery of the electronic device 31 is charged.

The control circuit 42' also monitors whether the current value detected by the current detection circuit 71 becomes 0 after the current value falls below the threshold value (ACT 14). When the current value detected by the current detection circuit 71 becomes 0 (ACT 14, YES), the control circuit 42' connects the external battery 22 and the second connector 44 via the switch circuit 43 (ACT 15). This corresponds to the control circuit 42' connecting the a terminal and the o terminal via the switch circuit 43 in the configuration shown in FIG. 6.

When the current value detected by the current detection circuit 71 is 0, power is not being supplied to the external battery 22. If there is no power supply to the input section 50, the external battery 22 outputs the power stored in the battery cell 51 from the output section 55. Therefore, when the external battery 22 and the second connector 44 are connected due to the current value becoming 0, the second connector 44 is supplied with power output from the external battery 22. As a result, the electronic device 31 connected to the second connector 44 is supplied with power from the external battery 22.

ACT14 in FIG. 7 may detect that the power input to the first connector 41 is zero. In this case, the control circuit 42' may connect the a-terminal and the o-terminal of the switch circuit 43 when the power input to the first connector 41 becomes zero. For example, the switch circuit 43 may be configured to connect the a-terminal and the o-terminal when the power supply from the first connector 41 to the control circuit 42' is stopped.

5, a power receiver 23 that receives power in a non-contact manner may be connected to the first connector 41 in the second configuration example. In this case, the control circuit 42′ may acquire a value indicating the power that the power receiver 23 receives through wireless power transmission.
If the received power X of the power receiver 23 is equal to or greater than the sum of the maximum input value A of the external battery 22 and the maximum input value B of the electronic device 31, the control circuit 42' connects the b terminal and the o terminal of the switch circuit 43. As a result, if X≧A+B (except for X=0), the control circuit 42' supplies the received power of the power receiver 23 to both the external battery 22 and the electronic device 31 connected to the second connector 44.

The control circuit 42' also performs the operational control as described in FIG. 7 if the received power X of the power receiver 23 is less than the sum of the maximum input value A of the external battery and the maximum input value B of the electronic device 31. That is, the control circuit 42' connects the b terminal and the o terminal of the switch circuit 43 when the current value detected by the current detection circuit 71 is equal to or greater than a predetermined threshold or is zero. The control circuit 42' also connects the a terminal and the o terminal of the switch circuit 43 when the current value detected by the current detection circuit 71 is less than a predetermined threshold and is not zero.

As described above, the charging system according to the embodiment includes an external battery and an electronic device having an internal battery, such as a tablet terminal, that operates on power supplied from the external battery. The charging system provides a switch circuit between the external battery and the electronic device having an internal battery. When the external battery is being charged with power from an external source, the charging system switches the switch so that the internal battery of the electronic device is also charged.

As a result, the charging system according to the embodiment can charge the internal battery built into the electronic device even while the external battery is being charged. As a result, the charging system according to the embodiment can prevent the charge level of the internal battery of the electronic device from reaching zero while the external battery is being charged.

In addition, in the charging system according to the embodiment, when the power supplied from the outside is not enough to charge both the external battery and the internal battery of the electronic device, the control circuit controls the switch according to the power (or current) supplied to the external battery. When the power (or current) supplied to the external battery is smaller than a predetermined threshold, the control circuit switches the switch to charge the internal battery of the electronic device.
As a result, in the charging system according to the embodiment, it is possible to charge the internal battery built into the electronic device while giving priority to charging the external battery.

In the above-described embodiment, an example was described in which a charging device that charges an external battery and an internal battery of an electronic device with power received from the outside was mounted on a shopping cart. However, the charging device is not limited to being mounted on a shopping cart. For example, the charging device may be mounted on a cart such as a picking cart used in a warehouse, or on a moving object other than a cart.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented 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 in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims.
The following is a summary of the contents of the claims as originally filed in this application.
[1]
a first connector to which external power is input;
a second connector for connecting to an electronic device having an internal battery;
a switch circuit provided between an output portion of an external battery having an input portion connected to the first connector and the second connector;
a control circuit that controls the switch circuit so that, when power is input from an external source to the first connector, the power is supplied from the first connector to both the external battery and the second connector;
A charging device having the same.
[2]
the control circuit controls the switch circuit to connect the first connector and the second connector when power is input from the outside to the first connector, and controls the switch circuit to connect the output portion of the external battery and the second connector when power is not input from the outside to the first connector.
The charging device according to [1].
[3]
Further, a power detection circuit is provided for detecting an amount of power output from the first connector.
the control circuit controls the switch circuit to connect an output section of the external battery and the second connector when power is input from the outside to the first connector, and then controls the switch circuit to connect the first connector and the second connector when the power detected by the power detection circuit falls below a threshold.
A charging device according to any one of [1] and [2].
[4]
The first connector receives power from an external source in a non-contact manner.
A charging device according to any one of [1] to [3].
[5]
An electronic device having an internal battery installed in a mobile object;
an external battery mounted on the moving object and connected to the electronic device;
a first connector to which external power is input;
a switch circuit provided between an output portion of an external battery having an input portion connected to the first connector and the electronic device;
a control circuit that controls the switch circuit so that, when power is input from the outside to the first connector, the power is supplied from the first connector to both the external battery and the electronic device;
A charging system having

1...Shopping cart (mobile object), 2, 2'...Charging system, 21, 21'...Charging circuit (charging device), 22...External battery, 23...Power receiver, 31...Electronic device (tablet terminal), 41...First connector, 42...Control circuit, 43...Switch circuit, 44...Second connector (connector), 71...Current detection circuit (power detection circuit).

Claims (4)

a first connector to which external power is input;
a second connector for connecting to an electronic device having an internal battery;
a switch circuit provided between an output portion of an external battery having an input portion connected to the first connector and the second connector;
a power detection circuit for detecting an amount of power output from the first connector;
a control circuit that controls the switch circuit to connect an output unit of the external battery and the second connector when power is input from the outside to the first connector, and then controls the switch circuit to connect the first connector and the second connector when the power detected by the power detection circuit falls below a threshold;
A charging device having the same. the control circuit controls the switch circuit to connect the first connector and the second connector when power is input from the outside to the first connector, and controls the switch circuit to connect the output portion of the external battery and the second connector when power is not input from the outside to the first connector.
The charging device according to claim 1 . The first connector receives power from an external source in a non-contact manner.
3. The charging device according to claim 1 or 2 . An electronic device having an internal battery installed in a mobile object;
an external battery mounted on the moving object and connected to the electronic device;
a first connector to which external power is input;
a switch circuit provided between an output portion of an external battery having an input portion connected to the first connector and the electronic device;
a power detection circuit for detecting an amount of power output from the first connector;
a control circuit that controls the switch circuit to connect an output unit of the external battery and the electronic device when power is input from the outside to the first connector, and then controls the switch circuit to connect the first connector and the electronic device when the power detected by the power detection circuit falls below a threshold;
A charging system having