Information processing system, information processing device, operation device, and power supply method

An example information processing system includes a main device, and an operation device attachable to the main device. The operation device includes a first control circuit, a first battery, and a first power supply circuit. The main device includes a second control circuit, a second battery, and a second power supply circuit. The second power supply circuit supplies power from the second battery to the operation device in response to satisfaction of a condition about the amount of remaining charge indicated by the remaining charge amount information transmitted from the operation device. When power is supplied from the main device to the operation device, the first power supply circuit supplies power supplied from the main device to the first control circuit, instead of power from the first battery.

CROSS REFERENCE TO RELATED APPLICATIONS

The disclosure of Japanese Patent Application No. 2016-220726, filed Nov. 11, 2016, is incorporated herein by reference.

FIELD

The technology disclosed herein relates to an information processing system which includes an information processing device and an operation device attachable to the information processing device.

BACKGROUND AND SUMMARY

An information processing system including a main device and an operation device is known. In such an information processing system, when the main device and the operation device are connected together via a wire, the operation device is driven by power supplied from the main device. When the main device and the operation device wirelessly communicate with each other, the operation device is driven by power from its own built-in battery.

When the operation device is connected with the main device via a wire, the range within which the operation device can be used is limited, which is inconvenient. When the operation device and the main device are wirelessly communicating with each other, then if the battery in the operation device becomes dead, the operation device can no longer be used. Therefore, it is desirable to maintain the power of the battery in the operation device as long as possible.

With the above in mind, the present application discloses an information processing system, information processing device, operation device, and power supply method which can improve the convenience of an operation device.

(1) An example non-limiting information processing system described herein includes a main device, and an operation device attachable to the main device.

The operation device includes a first control circuit, a first battery, a first power supply circuit, and a remaining charge amount information transmission circuit. The first control circuit controls at least a portion of the operation device. The first battery supplies power to the first control circuit. The first power supply circuit allows power supply from the first battery to the first control circuit. The remaining charge amount information transmission circuit transmits, to the main device, remaining charge amount information indicating the amount of charge remaining in the first battery.

The main device includes a second control circuit, a second battery, and a second power supply circuit. The second control circuit controls at least a portion of the main device. The second battery supplies power to the second control circuit. The second power supply circuit allows power supply from the second battery to the second control circuit.

The second power supply circuit supplies power from the second battery to the operation device in response to satisfaction of a condition about the amount of remaining charge indicated by the remaining charge amount information transmitted from the remaining charge amount information transmission circuit. When power is supplied from the main device to the operation device, the first power supply circuit supplies power supplied from the main device to the first control circuit, instead of power from the first battery.

According to the configuration (1), power is supplied from the main device to the operation device in response to satisfaction of the condition about the amount of charge remaining in the first battery. Therefore, the occurrence of the situation where the amount of charge remaining in the first battery of the operation device becomes zero, so that the operation device can no longer be used, can be reduced. Thus, the convenience of the operation device can be improved. In addition, the main device does not always supply power to the operation device when the operation device is in the connected state, and supplies power in response to satisfaction of the condition about the amount of charge remaining in the first battery. Therefore, the power of the second battery of the main device can be efficiently used. As a result, the duration in which the information processing system can be used can be extended. Thus, the convenience of the operation device and the information processing system can be improved.

(2) The operation device may further include an operation unit. The remaining charge amount information transmission circuit may include a first communication interface configured to perform wired communication with the main device. The main device may further include a second communication interface configured to perform wired communication with the operation device. The remaining charge amount information transmission circuit may transmit operation information indicating an operation performed on the operation unit, and the remaining charge amount information, to the main device by the wired communication through the first communication interface. The second power supply circuit, when determining to supply power to the operation device, may supply power from the second battery to the operation device through the second communication interface.

According to the configuration (2), power supply is performed through the communication interfaces which perform wired communication between the main device and the operation device, and the remaining charge amount information is transmitted through the communication interfaces. As a result, the main device can acquire the remaining charge amount information from the operation device without using wireless communication.

(3) The second control circuit may performs a predetermined information process on the basis of the operation information transmitted from the remaining charge amount information transmission circuit.

(4) The operation device may further include an operation unit. The remaining charge amount information transmission circuit may further include a third communication interface configured to perform wireless communication with the main device. The main device may further include a fourth communication interface configured to perform wireless communication with the operation device. The remaining charge amount information transmission circuit may transmit operation information indicating an operation performed on the operation unit, and the remaining charge amount information, to the main device by the wireless communication through the third communication interface.

According to the configuration (4), the operation device can transmit information to the main device by the wireless communication. The user can use the operation device in the detached state. Therefore, the configuration (4) can further improve the convenience of the operation device.

(5) The second control circuit may performs a predetermined information process on the basis of the operation information transmitted from the remaining charge amount information transmission circuit.

(6) When the operation device is performing the wireless communication with the main device, the first power supply circuit may supply power from the first battery to the first control circuit.

According to the configuration (6), the operation device, when performing the wireless communication, can be driven by power from its own built-in battery, i.e. the first battery.

(7) When the operation device is performing the wireless communication with the main device, even if the condition about the amount of remaining charge is satisfied, the first power supply circuit may supply power from the first battery to the first control circuit.

(8) The main device may further include a power terminal configured to acquire of power supplied from a power source external to the main device. When the second power supply circuit is supplied with power from the power source device through the power terminal, the second power supply circuit may supply power supplied from the power source to the second control circuit, and supply power supplied from the power source to the operation device.

According to the configuration (8), when external power is supplied to the main device, the information processing system can be driven without consumption of power of the second battery of the main device.

(9) When the first power supply circuit is supplying power from the first battery to the first control circuit, then if power is supplied from the main device to the operation device, the first power supply circuit may stop supplying power from the first battery to the first control circuit, and start supplying power supplied from the main device to the first control circuit.

According to the configuration (9), the operation device, when supplied with power from the main device, can reduce power consumption of its own built-in battery, i.e. the first battery.

(10) When power is supplied from the main device to the operation device, the first power supply circuit may supply power supplied from the main device to the first control circuit, and charge the first battery using power supplied from the main device.

According to the configuration (10), when power is supplied from the main device to the operation device, the operation device can charge its own built-in battery, i.e. the first battery. As a result, the user can use the operation device while the operation device is being charged, and therefore, the convenience of the operation device can be improved.

(11) When the second power supply circuit is supplying power to the operation device, then if the amount of remaining charge indicated by the remaining charge amount information transmitted from the remaining charge amount information transmission circuit is greater than or equal to a first value, the second power supply circuit may stop supplying power to the operation device. When the second power supply circuit is not supplying power to the operation device, then if the amount of remaining charge indicated by the remaining charge amount information transmitted from the remaining charge amount information transmission circuit is smaller than a second value which is smaller than the first value, the second power supply circuit may start supplying power to the operation device.

According to the configuration (11), the main device determines whether or not to supply power from the main device to the operation device, using different values depending on whether or not power is being supplied from the main device to the operation device. Thus, by using such different values, the frequency of repetition of the starting and stopping of power supply can be reduced.

(12) In the information processing system, there may be a plurality of the operation devices attachable to the main device. The second power supply circuit may supply power from the second battery to any operation device that has transmitted the remaining charge amount information satisfying the condition, of the plurality of operation devices attached to the main device.

According to the configuration (12), a plurality of operation devices can be simultaneously attached to the main device. Therefore, the convenience of the operation device can be improved. In addition, according to the configuration (12), the main device determines whether or not to supply power to operation devices separately. Therefore, the main device can control power supply to operation devices separately, resulting in efficient power supply to the operation devices.

(13) The operation device may further include an operation unit. The second control circuit may execute a game process on the basis of an operation performed on the operation unit.

According to the configuration (13), in the information processing system capable of executing a game process, the convenience of the operation device (and the information processing system) can be improved.

(14) When the amount of charge remaining in the second battery is smaller than or equal to a predetermined value, the second power supply circuit may stop supplying power from the second battery to the operation device, regardless of the amount of remaining charge indicated by the remaining charge amount information transmitted from the remaining charge amount information transmission circuit.

According to the configuration (14), when the amount of charge remaining in the second battery of the main device becomes small, the main device stops supplying power to the operation device. Therefore, the rate of decrease of the amount of charge remaining in the second battery of the main device can be reduced, and therefore, the duration in which the main device can be used can be extended.

(15) Another example non-limiting information processing system described herein includes a portable main device, and two operation devices simultaneously attachable to the main device.

Each of the operation devices includes a first control circuit, a first battery, a first power supply circuit, a first communication interface, and a second communication interface. The first control circuit controls at least a portion of the operation device. The first battery supplies power to the first control circuit. The first power supply circuit allows power supply from the first battery to the first control circuit. The first communication interface is configured to perform wired communication with the main device. The second communication interface is configured to perform wireless communication with the main device.

The main device includes a second battery, a second battery, a second power supply circuit, a third and a fourth communication interface, and a fifth communication interface. The second control circuit controls at least a portion of the main device. The second battery supplies power to the second control circuit. The second power supply circuit supplies power from the second battery to the second control circuit. The third and fourth communication interfaces are configured to perform wired communication with the respective operation devices. The fifth communication interface is configured to perform wireless communication with the operation devices.

For any of the operation devices that is connected with the main device by the wired communication, the second power supply circuit supplies power from the second battery to said operation device in response to satisfaction of a condition that the main device is connected with said operation device by the wired communication. In each of the operation devices, the first power supply circuit supplies power from the first battery to the first control circuit when said operation device is not connected with the main device by the wired communication.

According to the configuration (15), the user can use the two operation devices both with and without the wired communication, resulting in an improvement in the convenience of the operation devices. Furthermore, according to the configuration (15), when the wired communication is performed, power is supplied from the main device to an operation device, and therefore, the occurrence of the situation where the amount of charge remaining in the first battery becomes zero, so that the operation device can no longer be used, can be reduced. As a result, the convenience of the operation devices can be further improved.

Note that disclosed herein are a non-limiting example of the main device (in other words, the information processing device) included in the information processing system as set forth in (1)-(15), and a non-limiting example of the operation device included in the information processing system. In addition, disclosed herein is a non-limiting example of a power supply method executed in the information processing system as set forth in (1)-(15).

According to the above information processing system, information processing device, operation device, and power supply method, the convenience of the operation device can be improved.

These and other objects, features, aspects and advantages of the present exemplary embodiment will become more apparent from the following detailed description of the present exemplary embodiment when taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF NON-LIMITING EXAMPLE EMBODIMENTS

[1. Overview of Information Processing System]

FIG. 1is a diagram showing an example non-limiting external appearance of an information processing system according to a non-limiting example embodiment. As shown inFIG. 1, the information processing system1includes a main device2, a left controller3, and a right controller4.

The main device2is an information processing device which executes various processes in the information processing system1. The main device2has a display5. The main device2has information processing units such as a CPU, a memory, and the like (including a main-device control circuit described below). In this embodiment, the main device2can execute a game process by executing a game program which is stored in its own built-in storage unit or in a storage medium removably attached to the main device2.

The left controller3and the right controller4are an example non-limiting operation device (also referred to as an “input device”) for allowing the use to perform inputting to the information processing system1. In this embodiment, the controllers3and4each have an operation unit (specifically, a button and a stick). Note that the left controller3and the right controller4may hereinafter be collectively referred to as “the controllers.”

In this embodiment, the controllers may be attached (also referred to as “connected”) to the main device2. The left controller3may be attached to the left side of the main device2(i.e., in the positive direction of an x-axis shown inFIG. 1from the center of the main device2). The right controller4may be attached to the right side of the main device2(i.e., in the negative direction of the x-axis shown inFIG. 1from the center of the main device2).

As shown inFIG. 1, in a state where the controllers are attached to the main device2(hereinafter referred to as “the attached state”), the main device2and the controllers have a fixed positional relationship therebetween. Therefore, the user can hold the information processing system1(i.e., the main device2and the controllers) in the attached state as an integrated structure. Therefore, the information processing system1can be said to be a portable information processing device (or a game device).

FIG. 2is a diagram showing an example non-limiting external appearance of the information processing system when the controllers are removed from the main device. As shown inFIGS. 1 and 2, the controllers are removably attached to the main device2. In this embodiment, the controllers can be used in a state where the controllers are removed from the main device2(hereinafter referred to as “the detached state”). Thus, in the information processing system1of this embodiment, when the controllers3and4are attached to the main device2, the user can hold and use the entire information processing system1, and in addition, when the controllers3and4are removed from the main device2, the user can hold and use the controllers alone.

Note that the main device2can be coupled to a display device not shown (e.g., a television), and can transmit an image to the display device, which then displays the image. Therefore, the user can use the information processing system1in such a manner that the user operates the controllers removed from the main device2while viewing an image displayed on a display device coupled to the main device2.

The controllers may be removably attached to the main device2by any suitable means. For example, in this embodiment, a rail member is provided on each of side faces (i.e., side faces in the x-axis direction) of the main device2, while a slider which is engaged with the rail member so that the slider can be slid with respect to the rail member is provided on a side face of each controller. The user can attach the controllers to the main device2by engaging the sliders of the controllers with the respective rail members of the main device2.

In this embodiment, the two controllers3and4can be simultaneously attached to the main device2(seeFIG. 1). Note that, in another non-limiting example embodiment, any suitable number of controllers may be simultaneously attached to the main device2. In this embodiment, the controllers are attached to the side faces of the main device2. Alternatively, in another non-limiting example embodiment, the controllers may be attached to other portions of the main device.

[2. Configuration of Each Device in Information Processing System]

FIG. 3is a block diagram showing an example non-limiting internal configuration of each device (i.e., the main device or the controllers) in the information processing system. Specific example non-limiting internal configurations of the main device2and each of the controllers3and4will now be described with reference toFIG. 3.

(2-1. Configuration of Main Device)

As shown inFIG. 3, the main device2has a main-device battery21for supplying power to predetermined elements to be supplied with power. Here, the elements to be supplied with power are electronic members which are included in the main device2and are driven by power (specifically, including various control circuits, a CPU, etc.). Here, main-device power-driven elements25described below correspond to the elements to be supplied with power.

The main device2has a main-device power supply unit22which supplies power from the main-device battery21to the above elements to be supplied with power. The main-device battery21is coupled to the main-device power supply unit22. The main-device power supply unit22is coupled to the above predetermined elements to be supplied with power (i.e., the main-device power-driven elements25described below). In this embodiment, the main-device power supply unit22supplies power to each of the controllers3and4under a predetermined condition, in addition to the main-device power-driven elements25, as described in detail below. Therefore, the main-device power supply unit22has a booster circuit for increasing the voltage of power supplied to the controllers to a predetermined voltage (i.e., a voltage which allows charging of a battery in each of the controllers).

The main device2has a main-device control circuit23which controls at least a portion of the main device2. The main-device control circuit23includes various circuits for controlling the main device2, such as a CPU and a memory. The main-device control circuit23also includes a control circuit for controlling a sensor, an input/output unit, and/or a wireless communication unit which are included in the main device2. The main device2also has a main-device wireless communication unit24. The main-device wireless communication unit24includes an antenna for wireless communication with each of the controllers3and4. The main-device wireless communication unit24is coupled to the main-device control circuit23.

Note that, in this embodiment, the main-device control circuit23and the main-device wireless communication unit24are included in the main-device power-driven elements25. In other words, the main-device power supply unit22supplies power to at least the main-device control circuit23and the main-device wireless communication unit24. Note that the main-device power-driven elements25include any electronic members such as a sensor (e.g., an acceleration sensor or a gyroscopic sensor) and an input/output unit (e.g., a touchscreen or a display) which are included in the main device2.

The main device2has a main-device left connection/communication unit26which can communicate with the left controller3via a wire, and a main-device right connection/communication unit27which can communicate with the right controller4via a wire. The connection/communication units26and27are each coupled to the main-device power supply unit22and the main-device control circuit23. The connection/communication units26and27each have a plurality of terminals. In this embodiment, the connection/communication units26and27each include a communication terminal for transmitting and receiving information, and a power terminal for exchanging power.

When the main device2and the left controller3are in the attached state, the main-device left connection/communication unit26is connected with a communication unit (a left wired communication unit37described below) of the left controller3. Specifically, in the attached state, the terminals of the main-device left connection/communication unit26are in contact with the respective corresponding terminals of the left wired communication unit37of the left controller3. As a result, the main device2is electrically connected with the left controller3. In this regard, the right controller4is similar to the left controller3. When the main device2and the right controller4are in the attached state, the main-device right connection/communication unit27is connected with the communication unit (a right wired communication unit47described below) of the right controller4, so that the main device2is electrically connected with the right controller4.

The terminals of the communication units in the main device2and the controllers may specifically take any suitable structure. For example, each terminal is provided at a position where that terminal is in contact with a respective corresponding terminal when the main device2and the controllers are in the attached state.

The main device2has a power terminal unit28which can acquire power supplied from a power source external to the main device2. The power terminal unit28is a member (e.g., a connector) for electrically connecting a charger not shown (e.g., an AC adaptor, etc.) to the main device2. For example, the power terminal unit28may be a USB connector (more specifically, a female connector). In this embodiment, an AC adaptor can be connected to the power terminal unit28, and the main device2can acquire commercial power supply through the AC adaptor.

(2-2. Configuration of Each Controller)

As shown inFIG. 3, the left controller3has a left battery31for supplying power to predetermined elements to be supplied with power. In this embodiment, left power-driven elements36described below correspond to the predetermined elements to be supplied with power. Note that, in this embodiment, the capacity of the left battery31is smaller than that of the main-device battery21.

The left controller3has a left power supply unit32for supplying power from the left battery31to the above elements to be supplied with power. The left battery31is coupled to the left power supply unit32. The left power supply unit32is coupled to the left power-driven elements36. The left power supply unit32supplies power (the power of the battery31or power supplied from the main device2) to the above elements to be supplied with power. The left power supply unit32also charges the left battery31with power supplied from the main device2.

The left controller3has a left control circuit33, a left wireless communication unit34, and a left operation unit35. The left control circuit33controls at least a portion of the left controller3, and includes a control circuit for controlling, for example, a sensor (e.g., an acceleration sensor or a gyroscopic sensor) which is included in the left controller3, the left wireless communication unit34, and/or the left operation unit35. The left wireless communication unit34includes an antenna for wireless communication with the main device2. The left operation unit35includes a button and a stick provided on the left controller3.

In this embodiment, the left control circuit33, the left wireless communication unit34, and the left operation unit35are included in the left power-driven elements36. Specifically, the left power supply unit32supplies power to at least the left control circuit33, the left wireless communication unit34, and the left operation unit35. Note that the left power-driven elements36may include any electronic members such as a sensor included in the left controller3and the like.

The left controller3has the left wired communication unit37which can communicate with the main device2via a wire. The left wired communication unit37is coupled to the left power supply unit32and the left control circuit33. In this embodiment, the left wired communication unit37has as many terminals as there are terminals included in the main-device left connection/communication unit26of the main device2. More specifically, the terminals include a communication terminal for transmitting and receiving information, and a power terminal for exchanging power.

As shown inFIG. 3, the right controller4has constituent elements41-47similar to the constituent elements31-37of the left controller3. Specifically, the right battery41corresponds to the left battery31. The right power supply unit42corresponds to the left power supply unit32. The right control circuit43corresponds to the left control circuit33. The right wireless communication unit44corresponds to the left wireless communication unit34. The right operation unit45corresponds to the left operation unit35. The right wired communication unit47corresponds to the left wired communication unit37. The constituent elements41-47of the right controller4each have a function similar to that of the respective corresponding one of the constituent elements31-37of the left controller3, and can operate in a similar manner.

Note that the left controller3and the right controller4may not have exactly the same configuration and may have different configurations. For example, only one of the left controller3and the right controller4may have a specific operation unit and/or sensor. The left controller3and the right controller4may have different external appearances, or different arrangements of the constituent elements (e.g., a button and a stick).

[3. Overview of Operations in Information Processing System]

Next, an overview of operations in the information processing system1will be described. In the description that follows, operations involved with communication between the main device2and the controllers, and operations involved with power supply from the main device2to the controllers, will be mainly described. Note that, in the description that follows, operations between the main device2and the left controller3will be mainly described. Operations between the main device2and the right controller4are similar to those between the main device2and the left controller3, and therefore, will not be described in detail.

(3-1. Operations Involved with Communication)

In this embodiment, the left controller3transmits controller information to the main device2at a rate of once per predetermined period of time. The controller information includes operation information indicating an operation performed on an operation unit (i.e., the left operation unit35), and remaining charge amount information indicating the amount of charge remaining in the left battery31. Here, remaining charge amount information about a battery is any information that can be used to estimate (or calculate) or determine the amount of charge remaining in the battery. Specifically, the remaining charge amount information about a battery may be voltage information indicating the voltage of the battery, or information indicating the value of a proportion (e.g., a percentage or a fraction) indicating the amount of charge remaining in the battery, which is calculated from the voltage information.

In this embodiment, the left power supply unit32repeatedly acquires the remaining charge amount information about the left battery31, and outputs the acquired remaining charge amount information to the left control circuit33. The left control circuit33repeatedly transmits the controller information including the operation information and the remaining charge amount information to the main device2.

The main device2transmits instruction information to the left controller3. In this embodiment, the instruction information, which indicates an instruction to the left controller3, includes information indicating whether or not the left battery31is to be charged. Note that the instruction information may be transmitted from the main device2to the left controller3with any suitable timing. For example, the instruction information is transmitted at the same intervals at which the controller information is transmitted (i.e., once per the above predetermined period of time), or at intervals different from those of the controller information.

In this embodiment, the main device2and the left controller3can perform wired communication through the above terminals, or wireless communication using the wireless communication units. Specifically, in the attached state, the main device2and the left controller3perform wired communication. Here, in the attached state, the main-device left connection/communication unit26of the main device2is electrically connected with the left wired communication unit37of the left controller3so that wired communication can be performed therebetween. Therefore, the left control circuit33transmits the controller information (in other words, the remaining charge amount information included in the controller information) to the main device2by wired communication through the left wired communication unit37. The main-device control circuit23transmits the instruction information to the left controller3through the main-device left connection/communication unit26. Thus, in the attached state, one of the main device2and the left controller3can transmit information to the other by wired communication (i.e., without using wireless communication).

In the detached state, the main device2and the left controller3perform wireless communication. Specifically, the left control circuit33transmits the controller information to the main device2by wireless communication through the left wireless communication unit34(in other words, the left control circuit33causes the left wireless communication unit34to transmit the controller information). The main-device control circuit23transmits the instruction information to the left controller3through the main-device wireless communication unit24(in other words, the main-device control circuit23causes the main-device wireless communication unit24to transmit the instruction information). Thus, in the detached state, one of the main device2and the left controller3can transmit information to the other by wireless communication.

Note that, in another non-limiting example embodiment, the main device2and the controllers may perform communication wirelessly no matter whether they are in the attached state or in the detached state. In other words, the main device2and the controllers may perform wireless communication at least in the detached state, and may also perform wireless communication in the attached state. In still another non-limiting example embodiment, the controllers may be used only in the attached state. In other words, the controllers may not have the function of wirelessly communicating with the main device2.

The main device2notifies the user of the amount of charge remaining in each of the batteries31and41of the controllers3and4. For example, the main device2may display, on the display5, information indicating the amount of charge remaining in each of the batteries31and41. In this embodiment, the main device2can acquire the remaining charge amount information in both the attached state and the detached state, and therefore, in both of the two states, can notify the user of the amount of remaining charge.

(3-2. Operations Involved with Power Supply)

As described above, in this embodiment, the main device2and the controllers are each provided with a battery. Therefore, the main device2and the controllers can each be driven by power from their own built-in batteries. Here, in this embodiment, the main device2supplies power to the controllers under a predetermined condition so that the duration in which the information processing system1can be used is extended. As a result, the duration in which the controllers can be used can be extended, and therefore, the duration in which the information processing system1can be used can be extended. An overview of operations involved with power supply will now be described.

FIG. 4is a diagram showing example non-limiting ways of supplying power to the left-controller power-driven elements. In this embodiment, the information processing system1determines the way of supplying power to the left power-driven elements36, depending on which of modes (a)-(d) shown inFIG. 4the information processing system1is in. The way of supplying power in each of modes (a)-(d) shown inFIG. 4will be described.

In mode (a) shown inFIG. 4, the main device2and the left controller3are in the attached state, the main device2is not supplied with power from an external power source, and the amount of charge remaining in the left battery31is sufficient. Here, it is determined whether or not the amount of charge remaining in the left battery31is sufficient, by a determination step of determining whether or not the amount of charge remaining in the left battery31is greater than or equal to a predetermined threshold value. Note that the main device2can determine the amount of charge remaining in the left battery31on the basis of the remaining charge amount information transmitted from the left controller3. In this embodiment, as the predetermined threshold value used in the determination step, one of two different threshold values is used, depending on whether or not the left controller3is being supplied with power, as described in detail below.

In mode (a) shown inFIG. 4, the main-device power supply unit22does not supply power to the left controller3. In this case, the left power supply unit32supplies power from the left battery31to the left power-driven elements36(indicated by a dashed arrow shown in a portion corresponding mode (a) ofFIG. 4).

Note that, in all modes (a)-(d), the main-device power supply unit22supplies power to the main-device power-driven elements25, although not shown inFIG. 4. In other words, in this embodiment, when the main-device power supply unit22is supplying power to the left controller3, the main-device power supply unit22is supplying power to the main-device power-driven elements25as well as the left controller3. Note that, in mode (a) shown inFIG. 4, the main-device power supply unit22supplies power from the main-device battery21to the main-device power-driven elements25.

In mode (b) shown inFIG. 4, the main device2and the left controller3are in the attached state, the main device2is not supplied with power from an external power source, and the amount of charge remaining in the left battery31is not sufficient. Specifically, when the main device2and the left controller3are in the attached state, and the main device2is not supplied with power from an external power source, the main-device power supply unit22supplies power in mode (a) shown inFIG. 4if the amount of charge remaining in the left battery31is sufficient, or in mode (b) shown inFIG. 4if the amount of charge remaining in the left battery31is not sufficient.

In mode (b) shown inFIG. 4, the main-device power supply unit22supplies power from the main-device battery21to the left controller3(specifically, the left power-driven elements36) (indicated by a dashed arrow shown in a portion corresponding mode (b) ofFIG. 4). In other words, the left power supply unit32supplies power supplied from the main device2to the left power-driven elements36. In addition, in mode (b) shown inFIG. 4, the main device2charges the left controller3. Specifically, the left power supply unit32charges the left battery31with power supplied from the main device2(indicated by a dashed arrow shown in a portion corresponding to mode (b) ofFIG. 4).

Note that, in mode (b) shown inFIG. 4, the main-device power supply unit22supplies power from the main-device battery21to the main-device power-driven elements25, as in mode (a) ofFIG. 4.

In mode (b) shown inFIG. 4, when the left battery31is charged, so that the amount of charge remaining in the left battery31is greater than or equal to a predetermined value, the main device2determines that the amount of charge remaining in the left battery31is sufficient, as described in detail below. As a result, the information processing system1is changed from mode (b) to mode (a) shown inFIG. 4, in which the charging of the left battery31is stopped.

As described above in relation to modes (a) and (b) shown inFIG. 4, in this embodiment, the main-device power supply unit22supplies power from the main-device battery21to the left controller3under a predetermined condition about the amount of remaining charge which is indicated by the remaining charge amount information received from the left controller3(specifically, the amount of remaining charge is smaller than the predetermined threshold value). When the main device2supplies power to the left controller3, the left power supply unit32supplies power supplied from the main device2to the left power-driven elements36(including the left control circuit33) instead of power from the left battery31.

As described above, the main device2does not always supply power to the left controller3when the left controller3is in the attached state, and supplies power under a predetermined condition about the amount of charge remaining in the left battery31. Therefore, the power of the main-device battery21can be efficiently used. As a result, the duration in which the information processing system1can be used can be extended. When the predetermined condition is satisfied, the main device2supplies power to the left controller3. Therefore, the occurrence of the situation where the battery of the left controller3is dead can be reduced. In addition, when the amount of charge remaining in the left battery31is zero, the user can charge the left battery31by attaching the left controller3to the main device2. In other words, even when the amount of charge remaining in the left battery31is zero, the user can use the left controller3to operate the main device2by attaching the left controller3to the main device2.

In mode (c) shown inFIG. 4, the main device2and the left controller3are in attached state, and the main device2is being supplied with power from an external power source. In mode (c) shown inFIG. 4, the main device2is being supplied with power from an external power source, i.e. external power is being supplied to the main device2through the power terminal unit28.

In mode (c) shown inFIG. 4, the main-device power supply unit22supplies external power from the power terminal unit28to the left controller3(indicated by a dashed arrow shown in a portion corresponding to mode (c) ofFIG. 4). In this case, as in mode (b) shown inFIG. 4, the left power supply unit32supplies power supplied from the main device2to the left power-driven elements36, and at the same time, charges the left battery31with power supplied from the main device2(indicated by dashed arrows shown in the portion corresponding to mode (b) ofFIG. 4).

Also, in this case, the main-device power supply unit22supplies external power from the power terminal unit28to the main-device power-driven elements25(not shown), and at the same time, charges the main-device battery21with external power from the power terminal unit28(indicated by a dashed arrow shown in the portion corresponding to mode (c) ofFIG. 4). Note that, in another non-limiting example embodiment, the main-device power supply unit22may not charge the main-device battery21when the amount of charge remaining in the main-device battery21is greater than or equal to a predetermined value.

Note that, in mode (c) shown inFIG. 4, the main-device power supply unit22charges the main-device battery21until the main-device battery21reaches a full charge (i.e., the amount of remaining charge is 100%). The left power supply unit32charges the left battery31until the amount of charge remaining in the left battery31is 100%. Therefore, in mode (c) shown inFIG. 4, the information processing system1can sufficiently charge the batteries21and31.

As described above in relation to mode (c) shown inFIG. 4, in this embodiment, the main-device power supply unit22, when supplied with power from a power source external to the main device2through the power terminal unit28, supplies power supplied from the power source external to the main device2to the main-device power-driven elements25. As a result, when external power is being supplied, the information processing system1can operate without consuming the power of the batteries. Alternatively, the main-device power supply unit22may supply power supplied from a power source external to the main device2to the left controller3, regardless of the amount of remaining charge indicated by the remaining charge amount information.

As described above in relation to modes (a)-(c) and the like, in the attached state, the left controller3transmits the remaining charge amount information to the main device2through the left wired communication unit37. In the attached state, when the main-device power supply unit22determines to supply power to the left controller3, the main-device power supply unit22supplies power from the main-device battery21to the left controller3through the main-device left connection/communication unit26(mode (a) shown inFIG. 4). As a result, the remaining charge amount information can be exchanged between the main device2and the left controller3by wired communication through terminals, and in addition, power can be exchanged therebetween through the terminals.

In mode (d) shown inFIG. 4, the main device2and the left controller3are in the detached state (i.e., the left controller3wirelessly communicates with the main device2). In the detached state, the main device2is not connected with the left controller3via a wire, and therefore, the main-device power supply unit22does not supply power to the left controller3(see a portion corresponding to mode (d) ofFIG. 4). Therefore, when the left controller3is wirelessly communicating with the main device2, the left power supply unit32supplies power from the left battery31to the left power-driven elements36(indicated by a dashed arrow shown in the portion corresponding to mode (d) ofFIG. 4). As a result, the left controller3can operate even in the detached state.

Next, a step of determining whether or not the main device2is to supply power to the left controller3(i.e., whether or not the amount of charge remaining in the left battery31is sufficient, or in other words, whether to perform the operation of mode (a) shown inFIG. 4or the operation of mode (b) shown inFIG. 4) will be described with reference toFIG. 5.

In this embodiment, if the amount of charge remaining in the left battery31is greater than or equal to a threshold value, the main device2determines not to supply power to the left controller3. Meanwhile, if the amount of charge remaining in the left battery31is smaller than the threshold value, the main device2determines to supply power to the left controller3. Here, in this embodiment, the determination of whether or not to supply to the left controller3is based on a first threshold value and a second threshold value smaller than the first threshold value. The determination step will now be described in greater detail with reference toFIG. 5, which shows a non-limiting example.

FIG. 5is a diagram showing example non-limiting changes with time in the amount of charge remaining in the left battery31coupled to the main device2. The main device2initially performs the determination using the first threshold value at a time point T0when the left controller3is attached to the main device2(referred to as “the attachment time point”). Specifically, the main-device control circuit23, when detecting the attachment of the left controller3to the main device2, determines whether or not the amount of remaining charge indicated by the remaining charge amount information from the left controller3is greater than or equal to the first threshold value. If the amount of remaining charge indicated by the remaining charge amount information from the left controller3is greater than or equal to the first threshold value, the main-device control circuit23determines not to supply power to the left controller3. If the amount of remaining charge indicated by the remaining charge amount information from the left controller3is smaller than the first threshold value, the main-device control circuit23determines to supply power to the left controller3. Note that it is here assumed that the amount of charge remaining in the battery is expressed in percentage terms, and the first threshold value is 50%.

Note that, in another non-limiting example embodiment, in the determination step at the time of the attachment, the second threshold value, or a threshold value which is different from the first and second threshold values (e.g., a value which is smaller than the first threshold value and greater than the second threshold value), may be used.

In the example ofFIG. 5, at the attachment time point T0, the amount of charge remaining in the left battery31is greater than or equal to the first threshold value (i.e., 50%), and therefore, the main-device control circuit23determines not to supply power. In this case, the main-device control circuit23causes the main-device power supply unit22to operate in mode (a) shown inFIG. 4. In this case, the left power-driven elements36are driven by power from the left battery31, and therefore, the amount of charge remaining in the left battery31decreases with time (seeFIG. 5). Meanwhile, if the amount of charge remaining in the left battery31is smaller than the first threshold value at the attachment time point T0, the main-device control circuit23determines to supply power, although not shown. In this case, the main-device control circuit23causes the main-device power supply unit22to operate in mode (b) shown inFIG. 4.

After the determination step at the attachment time point T0, if the main device2is in the attached state and is not supplied with power from an external power source, the determination step is performed at a rate of once per predetermined period of time. The determination step is, for example, performed each time the controller information is acquired from the left controller3. Here, after the attachment time point T0, the main-device control circuit23performs the determination step using the first threshold value when power is being supplied to the left controller3, and the second threshold value when power is not being supplied to the left controller3. In the example ofFIG. 5, since power supply is not being performed at the attachment time point T0, the determination step is performed using the second threshold value immediately after the attachment time point T0. Note that it is here assumed that the second threshold value is 25%, which is smaller than the first threshold value. Therefore, as in the example shown inFIG. 5, when power is not being supplied, then if the amount of charge remaining in the left battery31is smaller than the first threshold value, but greater than or equal to the second threshold value, power is not supplied to the left controller3.

When the amount of charge remaining in the left battery31becomes smaller than the second threshold value at a time point T1shown inFIG. 5, the main-device control circuit23determines to supply power to the left controller3. As a result, power starts to be supplied from the main device2to the left controller3, so that the left battery31is charged (see the portion corresponding to mode (b) ofFIG. 4). Therefore, after the time point T1, the amount of charge remaining in the left battery31increases with time (seeFIG. 5).

As described above, when power is being supplied to the left controller3, the main-device control circuit23performs the determination step using the first threshold value. Therefore, after the time point T1, even when the amount of charge remaining in the left battery31is greater than or equal to the second threshold value, but smaller than the first threshold value, the main-device control circuit23determines to supply power to the left controller3. As a result, the main-device power supply unit22continues to supply power to the left controller3, and therefore, the amount of charge remaining in the left battery31increases (seeFIG. 5).

When the amount of charge remaining in the left battery31becomes greater than or equal to the first threshold value at a time point T2, the main-device control circuit23determines not to supply power to the left controller3. As a result, the main device2stops supplying power to the left controller3. Therefore, after the time point T2, the amount of charge remaining in the left battery31decreases with time (seeFIG. 5).

In the example ofFIG. 5, after the time point T2, the main device2repeatedly performs an operation of starting supplying power to the left controller3when the amount of charge remaining in the left battery31becomes smaller than the second threshold value, and an operation of stopping supplying power to the left controller3when the amount of charge remaining in the left battery31becomes greater than or equal to the first threshold value. Therefore, in this embodiment, in the attached state, the amount of charge remaining in the left battery31is maintained greater than or equal to the second threshold value (here 25%).

As described above, in this embodiment, when power is being supplied from the left battery31to the left control circuit33, then if the main device2starts supplying power to the left controller3(the time point T1shown inFIG. 5), the left power supply unit32stops supplying power from the left battery31to the left control circuit33, and starts supplying power supplied from the main device2to the left control circuit33. Therefore, in this embodiment, the left controller3can inhibit power consumption of its own left battery31when power is supplied from the main device2.

As described above, in this embodiment, when the main-device power supply unit22is supplying power to the left controller3, then if the amount of remaining charge indicated by the remaining charge amount information transmitted from the left controller3becomes greater than or equal to the first threshold value, the main-device power supply unit22stops supplying power to the left controller3(the time point T2shown inFIG. 5). When the main-device power supply unit22is not supplying power to the left controller3, then if the amount of remaining charge indicated by the remaining charge amount information transmitted from the left controller3becomes smaller than the second threshold value, the main-device power supply unit22starts supplying power to the left controller3(the time point T1shown inFIG. 5).

Note that if only one threshold value is used in the determination step, power supply is started when the amount of charge remaining in the left battery31becomes smaller than the threshold value, and power supply is stopped when the amount of charge remaining in the left battery31becomes greater than or equal to the threshold value. Therefore, the starting and stopping of power supply are frequently repeated. In contrast to this, in this embodiment, the two threshold values are used, and therefore, the frequency of repetition of the starting and stopping of power supply can be reduced. Note that, in another non-limiting example embodiment, the main device2may use only one threshold value in the determination step.

In this embodiment, the main device2determines whether or not to supply power to the left controller3on the basis of the determination step, regardless of the amount of charge remaining in the main-device battery21. In other words, in this embodiment, even when the amount of charge remaining in the main-device battery21is small, the main device2may supply power to the left controller3. In this embodiment, when the information processing system1continues to be used in the attached state, the amount of charge remaining in the main-device battery21reaches zero earlier than does the amount of charge remaining in each controller.

Here, if the amount of charge remaining in a controller reaches zero earlier than does the amount of charge remaining in the main-device battery21, the controller can no longer be used in the detached state. In this case, while the main device2can operate, the controller cannot be used, and therefore, the user cannot use the information processing system1. In contrast to this, when the amount of charge remaining in the main-device battery21reaches zero earlier than does the amount of charge remaining in the battery of each controller, the user can use the controllers in the detached state while the main device2is being charged (e.g., the main device2may be coupled to a display device, which is used to display an image, as described above). Thus, in this embodiment, the possibility that the amount of charge remaining in the battery of a controller reaches zero earlier is reduced, and therefore, even after the amount of charge remaining in the main-device battery21reaches zero, the controllers can be used, leading to an improvement in the convenience of the information processing system1.

Note that, in the foregoing, a case where the main device2supplies power to the left controller3has been described by way of example. The main device2supplies power to the right controller4in a manner similar to that described above. Here, in this embodiment, the main device2controls power supply to the controllers3and4separately. In other words, the main device2determines whether or not to supply power to the right controller4no matter what state the left battery31is in (e.g., the attached state, or the state of charge of the left battery31). Therefore, the main device2may not supply power to the right controller4while supplying power to the left controller3.

Here, in this embodiment, the main-device power supply unit22supplies power from the main-device battery21to one or more of a plurality of controllers (two in this embodiment) attached to the main device2that have transmitted the remaining charge amount information satisfying a condition (i.e., the remaining charge amount information indicating that the amount of remaining charge is smaller than a threshold value). As a result, the main device2can control power supply to controllers separately, and therefore, each controller can be efficiently supplied with power.

[4. Specific Non-Limiting Example of Process in each Device]

(4-1. Specific Non-Limiting Example of Process in Main Device2)

FIG. 6is a flowchart showing an example non-limiting flow of a process executed in the main device2. Note that a series of steps shown inFIG. 6is continually executed when the main device2is active. Specifically, the series of steps shown inFIG. 6is started during activation of the main device2. In this embodiment, the main device2operates in either an on mode or a sleep mode when it is active. In the on mode, for example, the main device2performs a normal operation. In the sleep mode, for example, the display may be off, or no application may be executed. In this embodiment, the series of steps is executed in each of the two modes. Note that, in another non-limiting example embodiment, the series of steps may not be executed in the sleep mode.

In this embodiment, a CPU included in the main-device control circuit23of the main device2executes each step shown inFIG. 6. Specifically, in this embodiment, the CPU executes each step shown inFIG. 6by executing an information processing program stored in the main device2. Note that, in another non-limiting example embodiment, a portion of the steps in the flowchart may be executed by a processor or a dedicated circuit (e.g., a circuit included in the main-device power supply unit22) other than the CPU.

The steps in the flowchart shown inFIG. 6are merely for illustrative purposes (the same is true of a flowchart shown inFIG. 7described below). As long as a similar effect is achieved, the order in which the steps are executed may be changed, or another step may be executed in addition to (or instead of) each step.

In the flowchart shown inFIG. 6, shown is a process which is performed by the main device2with respect to the left controller3. In this embodiment, the main device2executes a series of steps similar to those shown inFIG. 6with respect to the right controller4. Note that the series of steps (steps S1-S9) with respect to the left controller3, and the series of steps with respect to the right controller4, are executed in parallel.

The main device2stores, in a memory, various pieces of information (in other words, data) which are used in the series of steps shown inFIG. 6. For example, the memory stores the remaining charge amount information, the first threshold value information, the second threshold value information, and the power supply flag information. The first threshold value information indicates the first threshold value. The second threshold value information indicates the second threshold value. The power supply flag information indicates a flag which indicates whether or not the main device is supplying power to a controller. In this embodiment, the power supply flag information about the left controller3and the power supply flag information about the right controller4are stored in a memory. The main-device control circuit23(specifically, a CPU) executes each step shown inFIG. 6using the memory. Specifically, the main-device control circuit23stores information obtained in each step into the memory, and reads and uses the information from the memory in a subsequent step if necessary.

In step S1shown inFIG. 6, the main-device control circuit23acquires the remaining charge amount information from the left controller3. Specifically, the main-device control circuit23receives the controller information from the left controller3through the main-device wireless communication unit24or the main-device left connection/communication unit26. The main-device control circuit23stores, into the memory, the remaining charge amount information included in the controller information. Note that, in this embodiment, step S1is repeatedly executed at a rate of once per predetermined period of time. The predetermined period of time may be the same as or different from time intervals at which the left controller3transmits the controller information. Following step S1, step S2is executed.

In step S2, the main-device control circuit23determines whether or not the main device2and the left controller3are in the attached state. The determination in step S2may be specifically achieved in any suitable manner. For example, the main-device control circuit23performs the determination on the basis of a signal state (e.g., a voltage state) at a predetermined terminal included in the main-device left connection/communication unit26. If the determination result in step S2is positive, step S3is executed. Meanwhile, if the determination result in step S2is negative, step S9is executed.

In step S3, the main-device control circuit23determines whether or not the main device2is being supplied with power from an external power source. Specifically, the main-device control circuit23determines whether or not power is being supplied from an external power source through the power terminal unit28. If the determination result in step S3is positive, step S4is executed. Meanwhile, if the determination result in step S3is negative, step S5is executed.

In step S4, the main-device control circuit23supplies external power to the left controller3. Specifically, the main-device control circuit23outputs a control instruction to the main-device power supply unit22to supply external power from the power terminal unit28to the left controller3. Note that if external power has already been being supplied to the left controller3at step S4, the main-device control circuit23may not output the control instruction again. The main-device control circuit23also transmits instruction information indicating an instruction to charge the left battery31, to the left controller3through the main-device left connection/communication unit26.

Furthermore, in step S4, the main-device control circuit23supplies external power from the power terminal unit28to the main-device power-driven elements25, and controls the main-device power supply unit22so that the main-device battery21is charged using external power from the power terminal unit28. Thus, the operation of mode (c) shown inFIG. 4is performed by step S4. Following step S4, step S1is executed again.

In step S5, the main-device control circuit23determines whether or not either “the left controller3has been just attached to the main device2(in other words, it is immediately after the attachment)” or “the left controller3is being supplied with power.” Here, it can be determined whether or not the left controller3has been just attached to the main device2, by determining whether or not the determination result in step S2has just changed from negative to positive, for example. It can be determined whether or not the left controller3is being supplied with power, by referring to the power supply flag information stored in the memory. If the determination result in step S5is positive, step S6is executed. Meanwhile, if the determination result in step S5is negative, step S7is executed.

In step S6, the main-device control circuit23determines whether or not the amount of charge remaining in the left battery31is sufficient, using the first threshold value. Specifically, the main-device control circuit23determines whether or not the amount of charge remaining in the left battery31which is indicated by the remaining charge amount information acquired in step S1is greater than or equal to 50%. If the determination result in step S6is positive, step S9is executed. Meanwhile, if the determination result in step S6is negative, step S8is executed.

Meanwhile, in step S7, it is determined whether or not the amount of charge remaining in the left battery31is sufficient, using the second threshold value. Specifically, the main-device control circuit23determines whether or not the amount of charge remaining in the left battery31which is indicated by the remaining charge amount information acquired in step S1is greater than or equal to 25%. If the determination result in step S7is positive, step S9is executed. Meanwhile, if the determination result in step S7is negative, step S8is executed.

In step S8, the main-device control circuit23supplies power from the main-device battery21to the left controller3. Specifically, the main-device control circuit23outputs a control instruction to the main-device power supply unit22to supply power from the main-device battery21to the left controller3. The main-device control circuit23also stores, into the memory, the power supply flag information indicating that power is being supplied to the left controller3. Note that, at the time of step S8, if power is being supplied from the main-device battery21to the left controller3, the main-device control circuit23may not output the control instruction again, and may not store the power supply flag information into the memory again. The main-device control circuit23also transmits instruction information indicating an instruction to charge the left battery31, to the left controller3through the main-device left connection/communication unit26.

Furthermore, in step S8, the main-device control circuit23controls the main-device power supply unit22so that power is supplied from the main-device battery21to the main-device power-driven elements25. By step S8, the operation of mode (b) shown inFIG. 4is performed. Following step S8, step S1is executed again.

Meanwhile, in step S9, the main-device control circuit23supplies power to the main-device power-driven elements25, but not to the left controller3. Specifically, the main-device control circuit23controls the main-device power supply unit22so that power is supplied from the main-device battery21to the main-device power-driven elements25. The main-device control circuit23also stores, into the memory, the power supply flag information indicating that power is not being supplied to the left controller3. Note that, at the time of step S9, if power is not being supplied from the main-device battery21to the left controller3, the main-device control circuit23may not store the power supply flag information into the memory. The main-device control circuit23also transmits instruction information indicating an instruction not to charge the left battery31, to the left controller3through the main-device left connection/communication unit26. By step S9, the operation of mode (a) or (d) shown inFIG. 4is performed. Following step S9, step S1is executed again.

(4-2. Specific Example Non-Limiting Process of Left Controller3)

FIG. 7is a flowchart showing an example non-limiting flow of a process executed in the left controller3. Note that a series of steps shown inFIG. 7is continually executed when the left controller3is active (specifically, when power is being supplied to the left power-driven elements36, or when the left controller3is on).

In this embodiment, the left control circuit33of the left controller3executes each step shown inFIG. 7. Note that, in another non-limiting example embodiment, a portion of the steps in the flowchart may be executed by another processing circuit (e.g., a circuit included in the left power supply unit32) instead of the left control circuit33.

In the flowchart shown inFIG. 7, a series of steps executed by the left controller3is shown. Note that, in this embodiment, the right controller4executes a series of steps similar to those shown inFIG. 7.

The left controller3stores, in its own built-in memory, various pieces of information (in other words, data) for use in the series of steps shown inFIG. 7. The left control circuit33executes each step shown inFIG. 7using the memory. Specifically, the left control circuit33stores information obtained in each step into the memory, and reads and uses the information from the memory in a subsequent step if necessary.

In step S11shown inFIG. 7, the left control circuit33communicates with the main device2. Specifically, the left control circuit33transmits the controller information to the main device2through the left wireless communication unit34or the left wired communication unit37. The left control circuit33receives the instruction information from the main device2through the left wireless communication unit34or the left wired communication unit37. Note that, in this embodiment, step S11is repeatedly executed at a rate of once per predetermined period of time. Following step S11, step S12is executed.

In step S12, the left control circuit33determines whether or not the main device2and the left controller3are in the attached state. The determination in step S12may be specifically achieved in any suitable manner. For example, the left control circuit33performs the determination on the basis of a signal state (e.g., a voltage state) at a predetermined terminal included in the left wired communication unit37. If the determination result in step S12is positive, step S13is executed. Meanwhile, if the determination result in step S12is negative, step S15is executed.

In step S13, the left control circuit33determines whether or not power is being supplied from the main device2through the left wired communication unit37. The determination in step S13may be specifically achieved in any suitable manner. For example, the left control circuit33may perform the determination on the basis of whether or not the instruction information transmitted from the main device2indicates an instruction to charge the left battery31, or on the basis of the voltage state of the power terminal included in the left wired communication unit37. If the determination result in step S13is positive, step S14is executed. Meanwhile, if the determination result in step S13is negative, step S15is executed.

In step S14, the left control circuit33supplies power from the main device2to the left power-driven elements36, and charges the left battery31with power from the main device2. Specifically, the left control circuit33controls the left power supply unit32so that power is supplied from the main device2to the left power-driven elements36, and at the same time, the left battery31is charged with power from the main device2(modes (b) and (c) shown inFIG. 4). Following step S14, step S11is executed again.

Meanwhile, in step S15, the left control circuit33supplies power from the left battery31to the left power-driven elements36. Specifically, the left control circuit33controls the left power supply unit32so that power is supplied from the left battery31to the left power-driven elements36(modes (a) or (d) shown inFIG. 4). Following step S15, step S11is executed again.

(Non-Limiting Example Variation of Charging of Battery of Controller)

In the above embodiments, the power supply unit (specifically, the left power supply unit32or the right power supply unit42) of each of the controllers3and4, when the controller is supplied with power from the main device2, supplies power supplied from the main device2to the control circuit (specifically, the left control circuit33or the right control circuit43), and at the same time, charges the battery (specifically, the left battery31or the right battery41) with power supplied from the main device2.

Here, in another non-limiting example embodiment, the power supply unit of each of the controllers3and4, when the controller is supplied with power from the main device2, may supply the supplied power to the control circuit, and at the same time, may not charge the battery. In other words, the main device2, when supplying power to a controller, may supply power to elements of the controller which are to be supplied with power, and at the same time, may not charge the battery of the controller. Note that, in this embodiment, the main device2, when supplying power to a controller, can supply power only to elements to be supplied with power by transmitting, to the controller, the instruction information indicating an instruction not to charge the battery of the controller.

For example, in a non-limiting example variation of this embodiment, when power is not being supplied to a controller, then if the amount of charge remaining in the controller is smaller than a predetermined threshold value, the main device2may supply power only to elements of the controller which are to be supplied with power (i.e., may not charge the battery). As a result, the rate of decrease of the amount of charge remaining in the main-device battery21of the main device2can be reduced, and therefore, the duration in which the main device2can be used can be extended. Note that the predetermined threshold value in this variation may be, for example, the first threshold value or the second threshold value. The main device2may use a single threshold value.

In this variation, for example, when a controller is attached to the main device2, then if the amount of charge remaining in the battery of the controller is smaller than the predetermined threshold value, power may be supplied to elements of the controller which are to be supplied with power, and the battery of the controller may be charged. Thus, when a predetermined first condition is satisfied, the main device2may supply power to elements of the controller which are to be supplied with power, and charge the battery of the controller. When a predetermined second condition is satisfied, the main device2may only supply power to elements of the controller which are to be supplied with power. Note that the first and second conditions are, for example, a condition about the amount of charge remaining in a controller, a condition about the state of power supply from the main device2to a controller (e.g., whether or not power is being supplied), and/or the attached state of the main device2and a controller (e.g., whether or not the main device2and the controller have been just attached together).

(Non-Limiting Example Variation of Power Supply to Controller)

In a non-limiting example variation of this embodiment, when the amount of charge remaining in the main-device battery21becomes small, the main device2may stop supplying power to the controllers. Specifically, when the amount of charge remaining in the main-device battery21becomes smaller than or equal to a predetermined value (e.g., 25% or less), the main-device power supply unit22may stop supplying power from the main-device battery21to the controllers, regardless of the amount of remaining charge indicated by the remaining charge amount information transmitted from the controllers. As a result, a decrease in the amount of charge remaining in the main-device battery21of the main device2can be reduced, and therefore, the duration in which the main device2can be used can be extended.

In another non-limiting example embodiment, a variation in which power is supplied only to elements of a controller which are to be supplied with power (see the above section “(Non-Limiting Example Variation of Charging of Battery of Controller)”), and a variation in which power supply to the controllers is stopped when the amount of charge remaining in the main-device battery21is small (see the above section “(Non-Limiting Example Variation of Power Supply to Controller)”), may be combined together.

In a non-limiting example variation of this embodiment, the main device2may start supplying power to a controller in response to the attachment of the controller to the main device2. In this case, after the attachment time point, the main device2may stop supplying power to the controller under a predetermined condition (e.g., when the amount of charge remaining in the controller is greater than or equal to a predetermined value), or may continue to supply power to the controller as long as the controller is in the attached state. In this variation, the controller may only supply power supplied from the main device2to elements of the controller which are to be supplied with power, or may supply power to elements of the controller which are to be supplied with power, and charge the battery.

Thus, in the above embodiments and variations, if at least a condition that the main device2is allowed to perform wired communication with a controller (in other words, the main device2is connected with the controller by wired communication, or are in the attached state) is satisfied, the main-device power supply unit22supplies power from the main-device battery21to the controller which is allowed to perform wired communication with the main device2(in other words, the controller is connected with the main device2by wired communication). When the main device2and a controller are not allowed to perform wired communication with each other (in other words, the main device2and the controller are not connected together by wired communication, or are in the detached state), the power supply units32and42of the controllers3and4supply power from the batteries31and41of the controllers3and4to the control circuits33and43, respectively. Thus, the controllers can be used in the detached state from the main device2, and the batteries of the controllers can be charged by being attached to the main device2, and therefore, the user can use the controller while the controllers are being charged. As a result, the convenience of the controllers can be improved.

In the above embodiments, the main-device control circuit23executes a game process on the basis of operations performed on the operation unit (the left operation unit35and/or the right operation unit45). In other words, in the above embodiments, the information processing system1functions as a game device (or a game system). Here, in another non-limiting example embodiment, the information processing system1may be, for example, any information processing devices such as a tablet terminal, smartphone, mobile telephone, and the like, in addition to a game device.

In another non-limiting example embodiment, when the main device2can communicate with a server via a network, such as the Internet or the like, the process operations of the main device2and/or the controllers may be changed by the main device2receiving an update instruction from the server. For example, according to an update instruction from the server, the main device2may change (a) the threshold value, (b) whether or not the battery of a controller is to be charged when power is supplied to the controller, or (c) whether or not power is to be supplied to a controller when the amount of charge remaining in the main-device battery21is small.

A portion of the steps which are executed in the main device2in the above embodiments may be executed in the controllers. A portion of the steps which are executed in the controllers in the above embodiments may be executed in the main device2. For example, in another non-limiting example embodiment, the controllers may execute the determination steps using the threshold values (i.e., the determination steps in steps S6and S7), and transmit the determination results to the main device2. For example, when power is supplied from the main device2to a controller, the controller may determine whether or not the battery of the controller is to be charged.

The above embodiments may be applied to a mobile information processing device (or information processing system), game device (or game system), and the like, in order to improve the convenience of an operation device, for example.