Electronic apparatus and method for controlling the same, program, and storage medium

Abstract

To provide an electronic apparatus that, when the electronic apparatus is used as a power source, can appropriately control the power consumption of the electronic apparatus itself and supply of power to the outside.SOLUTION: An electronic apparatus can supply power to an external device, and comprises: a power supply unit; and a control unit that, when supplying power from the power supply unit to the external device in a first state of the electronic apparatus, controls the power supply unit to supply, to the external device, a first supply power that is equal to or less than a power obtained by subtracting the power consumption of the electronic apparatus in a second state larger than the power consumption in the first state from the power that can be supplied by the power supply unit.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an electronic device capable of supplying power to an external device. [Background technology]

[0002] Conventionally, many information processing devices are equipped with a USB (registered trademark) (Universal Serial Bus) interface. A USB can transmit and receive various signals to and from a connected electronic device, and can also supply power to the electronic device.

[0003] The USB Power Delivery (PD) standard has been established as a standard for USB power supply, which allows for bidirectional supply of up to 100W of power. In addition to dedicated power supply devices such as mobile batteries, some electronic devices such as information processing devices and multifunction printers comply with the USB PD standard. If a cable and external device that comply with the USB PD standard are connected to such devices, the electronic device becomes a power source and can supply power to the external device at the current or voltage specified by the standard.

[0004] Patent Document 1 discloses a technique that enables power to be supplied to an external device connected to an information processing device via USB even after the information processing device is turned off or put into a power saving mode.

[0005] Patent Document 2 proposes that in a configuration in which a multifunction printer serves as a power source, a stable supply of power can be achieved by operating the multifunction printer in a low power consumption mode while supplying power to an external device. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-53748 A [Patent Document 2] JP 2017-27454 A Summary of the Invention [Problem to be solved by the invention]

[0007] When an electronic device is used as a power source, it is required to change the power supply depending on the operating state of the electronic device. For example, when the power source electronic device is turned off or in a power saving mode, it is required to increase the power supply.

[0008] In addition, when an electronic device has a built-in battery and uses the battery to supply power to an external device, the total power consumption of the electronic device itself and the power supplied to the external device must be within the maximum rated capacity of the battery. In order to supply power to an external device while using the electronic device, it becomes necessary to operate the electronic device in a low power consumption mode or reduce the power supply.

[0009] However, changing the power supply requires negotiation with the external device, which takes time according to the standard. While waiting for the negotiation to be completed, the electronic device may not be able to operate, which reduces the performance and usability of the electronic device.

[0010] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide an electronic device that can appropriately control the electronic device's own power consumption and power supply to the outside when the electronic device is used as a power source. [Means for solving the problem]

[0011] The electronic device of the present invention is an electronic device capable of supplying power to an external device, and is characterized in comprising a power supply unit and a control means for controlling the power supply unit so that, when supplying power to the external device from the power supply unit in a first state of the electronic device, a first supply power that is equal to or less than the power that the power supply unit can supply minus the power consumption of the electronic device in a second state that consumes more power than the first state is supplied to the external device. Effect of the Invention

[0012] According to the present invention, when an electronic device is used as a power source, it is possible to appropriately control the power consumption of the electronic device itself and the power supply to the outside. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram showing the appearance of a digital camera as an embodiment of an electronic device of the present invention. [Diagram 2] FIG. 1 is a block diagram showing the internal configuration of a digital camera. [Diagram 3] 6 is a flowchart showing the operation when the digital camera is turned off and the USB is not connected. [Figure 4] 6 is a flowchart showing the operation when the digital camera is turned off and a USB is connected. [Diagram 5] 5 is a flowchart showing the operation of the digital camera in a standby power supply state. [Figure 6] 4 is a flowchart showing the operation of the digital camera in an active state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0015] 1(a) and (b) are diagrams showing the external appearance of a digital camera 100, which is an embodiment of an electronic device of the present invention. Fig. 1(a) is a front perspective view of the digital camera 100, and Fig. 1(b) is a rear perspective view of the digital camera 100.

[0016] In Fig. 1, display unit 28 is a display unit provided on the back of the camera that displays images and various information. Outside-finder display unit 43 is a display unit provided on the top of the camera, and displays various camera settings such as shutter speed and aperture. Shutter button 61 is an operation unit for issuing shooting instructions. Mode change switch 60 is an operation unit for switching between various modes.

[0017] The terminal cover 40 is a cover that protects a connector (not shown) that connects a connection cable with an external device to the digital camera 100. The main electronic dial 71 is a rotary operation member included in the operation unit 70 (see FIG. 2), and by turning this main electronic dial 71, settings such as shutter speed and aperture can be changed. The power switch 72 is an operation member that switches the power of the digital camera 100 between ON and OFF. The sub electronic dial 73 is a rotary operation member included in the operation unit 70, and can move the selection frame, advance images, etc.

[0018] The cross key 74 is included in the operation unit 70 and is a four-way key that can be pressed up, down, left, or right. An operation can be performed according to which part of the cross key 74 is pressed. The SET button 75 is a push button included in the operation unit 70 and is mainly used for confirming selected items. The LV button 76 is included in the operation unit 70 and is a button that switches live view (hereinafter, LV) ON and OFF. In video capture mode, it is used to instruct the start and stop of video capture (recording).

[0019] The enlargement button 77 is included in the operation unit 70 and is an operation button for turning the enlargement mode ON and OFF and changing the magnification ratio during the enlargement mode in the live view display in the shooting mode. In the playback mode, it functions as an enlargement button for enlarging the playback image and increasing the magnification ratio. The reduction button 78 is included in the operation unit 70 and is a button for reducing the magnification ratio of the enlarged playback image and reducing the displayed image. The playback button 79 is included in the operation unit 70 and is an operation button for switching between the shooting mode and the playback mode. By pressing the playback button 79 during the shooting mode, the mode switches to the playback mode, and the latest image among the images recorded on the recording medium 200 can be displayed on the display unit 28.

[0020] The quick return mirror 12 is raised and lowered by an actuator (not shown) in response to an instruction from the system control unit 50 (see FIG. 2). The communication terminal 10 is a communication terminal that enables the digital camera 100 to communicate with the lens side (detachable). The eyepiece finder 16 is a peer-type finder that enables the user to check the focus and composition of the optical image of the subject obtained through the lens unit 150 by observing the focusing screen 13 (see FIG. 2). The lid 202 is a lid for a slot that stores the recording medium 200. The grip unit 90 is a holding unit shaped to be easily held in the user's right hand when holding the digital camera 100.

[0021] FIG. 2 is a block diagram showing the internal configuration of the digital camera 100. As shown in FIG.

[0022] In FIG. 2, lens unit 150 is equipped with a photographing lens and is replaceable with respect to digital camera 100 .

[0023] The lens 103 is usually composed of multiple lenses, but here, for simplification, only one lens is shown. The communication terminal 6 is a terminal through which the lens unit 150 communicates with the digital camera 100, and the communication terminal 10 is a terminal through which the digital camera 100 communicates with the lens unit 150. The lens unit 150 communicates with a system control unit 50 of the digital camera 100 via the communication terminals 6 and 10. A lens system control circuit 4 inside the lens unit controls the aperture 1 via an aperture drive circuit 2 based on instructions from the system control unit 50. Also, the lens 103 is focused by displacing its position via an AF drive circuit 3.

[0024] The AE sensor 17 measures the luminance of the subject through the lens unit 150 .

[0025] The focus detection unit 11 outputs defocus amount information to the system control unit 50. The system control unit 50 controls the lens unit 150 based on the defocus information to perform phase difference AF (autofocus).

[0026] The quick return mirror 12 (hereinafter, mirror 12) can be raised and lowered by an actuator (not shown). The mirror 12 has a function of switching the light beam incident from the lens 103 between the viewfinder 16 side and the imaging unit 22 side. The mirror 12 is normally arranged to reflect the light beam to guide it to the viewfinder 16, but when shooting or live view display is performed, the mirror 12 jumps up and retreats from the light beam to guide the light beam to the imaging unit 22 (mirror up). The mirror 12 is also a half mirror whose center portion is capable of transmitting part of the light, and transmits part of the light beam. The transmitted light beam is reflected by the sub-mirror 12a and enters the focus detection unit 11 for focus detection.

[0027] By observing the focusing screen 13 through the pentaprism 14 and the viewfinder 16, the photographer can check the focus and composition of the optical image of the subject obtained through the lens unit 150.

[0028] The shutter 101 is a focal plane shutter that can freely control the exposure time of the imaging unit 22 under the control of the system control unit 50 .

[0029] The imaging unit 22 has an imaging element 22a that converts an optical image into an electric signal and is composed of a CCD, a CMOS element, etc. The A / D converter 23 converts an analog signal output from the imaging unit 22 into a digital signal.

[0030] The image processing unit 24 performs predetermined pixel interpolation, resizing such as reduction, and color conversion processing on the data from the A / D converter 23 or the data from the memory control unit 15. The image processing unit 24 also performs predetermined arithmetic processing using the captured image data, and the system control unit 50 performs exposure control and distance measurement control based on the obtained arithmetic results. This allows TTL (through-the-lens) type AF (autofocus) processing, AE (autoexposure) processing, and EF (flash pre-flash) processing to be performed. The image processing unit 24 also performs predetermined arithmetic processing using the captured image data, and TTL type AWB (auto white balance) processing based on the obtained arithmetic results.

[0031] The output data from the A / D converter 23 is written into the memory 32 via the image processing unit 24 and the memory control unit 15, or directly via the memory control unit 15. The memory 32 stores image data obtained by the imaging unit 22 and converted into digital data by the A / D converter 23, and image data to be displayed on the display unit 28. The memory 32 has a storage capacity sufficient to store a predetermined number of still images and a predetermined period of moving images and audio.

[0032] The memory 32 also serves as a memory for image display (video memory). The D / A converter 19 converts the image display data stored in the memory 32 into an analog signal and supplies it to the display unit 28. In this way, the image data for display written in the memory 32 is displayed by the display unit 28 via the D / A converter 19. The display unit 28 performs display according to the analog signal from the D / A converter 19 on a display device such as an LCD. The digital signal once A / D converted by the A / D converter 23 and stored in the memory 32 is converted into an analog signal in the D / A converter 19, and the analog signal is sequentially transferred to the display unit 28 for display, thereby realizing an electronic viewfinder function. In other words, the display unit 28 can perform through image display (live view display).

[0033] A frame (AF frame) indicating the distance measuring point for which autofocus is currently being performed, icons indicating the camera setting state, and the like are displayed on the in-finder liquid crystal display 41 via an in-finder display drive circuit 42.

[0034] Various camera settings such as shutter speed and aperture are displayed on an outside viewfinder display section 43 such as an LCD via an outside viewfinder display section drive circuit 44 .

[0035] The non-volatile memory 56 is an electrically erasable and recordable memory, and may be, for example, an EEPROM. Constants, programs, and the like for operating the system control unit 50 are stored in the non-volatile memory 56. The programs referred to here are programs for executing various flowcharts described later in this embodiment.

[0036] The system control unit 50 is a control unit having at least one processor, and controls the entire digital camera 100. By executing the programs recorded in the nonvolatile memory 56 described above, each process of this embodiment, which will be described later, is realized. Reference numeral 52 denotes a system memory, which uses a RAM. Constants and variables for the operation of the system control unit 50, programs read from the nonvolatile memory 56, and the like are loaded into the system memory 52. ​​The system control unit 50 also performs display control by controlling the memory 32, the D / A converter 19, the display unit 28, and the like.

[0037] The system timer 53 is a timing unit that measures the time used for various controls and the time of a built-in clock.

[0038] The mode changeover switch 60 , the first shutter switch 62 , the second shutter switch 64 , and the operation unit 70 are operation means for inputting various operational instructions to the system control unit 50 .

[0039] The mode changeover switch 60 changes the operation mode of the system control unit 50 to one of a still image recording mode, a video shooting mode, a playback mode, etc. Modes included in the still image recording mode include an auto shooting mode, an auto scene determination mode, a manual mode, an aperture priority mode (Av mode), and a shutter speed priority mode (Tv mode). In addition, there are various scene modes, which are shooting settings according to shooting scenes, a program AE mode, a custom mode, etc. The mode changeover switch 60 can directly change to one of these modes. Alternatively, after switching once to a list screen of shooting modes with the mode changeover switch 60, one of the displayed multiple modes can be selected using another operating member. Similarly, the video shooting mode may also include multiple modes.

[0040] The first shutter switch 62 is turned on and generates a first shutter switch signal SW1 when the shutter button 61 provided on the digital camera 100 is pressed halfway (instruction to prepare for shooting) during operation. The system control unit 50 starts operations such as AF (autofocus) processing, AE (auto exposure) processing, AWB (auto white balance) processing, and EF (pre-flash) processing in response to the first shutter switch signal SW1.

[0041] The second shutter switch 64 is turned on when the shutter button 61 is fully pressed (photographing instruction) and generates a second shutter switch signal SW2. The system control unit 50 starts a series of photographing processing operations from reading a signal from the imaging unit 22 to writing image data to the recording medium 200 in response to the second shutter switch signal SW2.

[0042] Each operating member of the operating unit 70 is assigned a function appropriate for each situation by selecting and operating various functional icons displayed on the display unit 28, and acts as various functional buttons. The functional buttons include, for example, an end button, a back button, an image forward button, a jump button, a filter button, an attribute change button, and the like. For example, when the menu button is pressed, a menu screen in which various settings can be made is displayed on the display unit 28. The user can intuitively make various settings using the menu screen displayed on the display unit 28, the four directional buttons (up, down, left, right) and the SET button.

[0043] The operation unit 70 is a variety of operation members that serve as an input unit for receiving operations from the user. The operation unit 70 includes at least the following operation members: the shutter button 61, the main electronic dial 71, the power switch 72, the sub electronic dial 73, the cross key 74, the SET button 75, the LV button 76, the enlarge button 77, the reduce button 78, and the playback button 79.

[0044] The power supply control unit 80 is composed of a battery detection circuit, a DC-DC converter, a switch circuit for switching between blocks to be energized, and the like, and detects whether a battery is attached, the type of battery, and the remaining battery level. The power supply control unit 80 also controls the DC-DC converter based on the detection results and instructions from the system control unit 50, and supplies the required voltage for the required period to each unit including the recording medium 200. Furthermore, when the digital camera 100 is connected to an external device via a USB connector (USB terminal) 83, the power supply control unit 80 operates a power supply switch 81 based on instructions from the system control unit 50, and can supply power from the power supply unit 30 to the external device.

[0045] The power supply unit 30 is a battery that is built into the digital camera 100 or is detachably arranged therein, and is made up of a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, a NiMH battery or a Li-ion battery, an AC adapter, etc. The recording medium I / F 18 is an interface with a recording medium 200 such as a memory card or a hard disk. The recording medium 200 is a recording medium such as a memory card for recording captured images, and is made up of a semiconductor memory, a magnetic disk, etc.

[0046] The communication unit 54 is connected to an external device wirelessly or via a wired cable, and transmits and receives video and audio signals. The communication unit 54 can also be connected to a wireless LAN (Local Area Network) or the Internet. The communication unit 54 can transmit images (including through images) captured by the imaging unit 22 and images recorded on the recording medium 200, and can also receive image data and various other information from the external device.

[0047] The attitude detection unit 55 detects the attitude of the digital camera 100 with respect to the direction of gravity. Based on the attitude detected by the attitude detection unit 55, it is possible to determine whether the image captured by the imaging unit 22 was captured with the digital camera 100 held horizontally or vertically. The system control unit 50 can add orientation information corresponding to the attitude detected by the attitude detection unit 55 to the image file of the image captured by the imaging unit 22, or rotate and record the image. The attitude detection unit 55 can be an acceleration sensor, a gyro sensor, or the like.

[0048] The USB connector 83 is a receptacle-shaped USB connector. In this embodiment, the USB connector 83 is, for example, a USB Type-C connector.

[0049] The PD communication unit 82 is connected to a communication terminal of the USB connector 83, and can execute data communication based on the USB PD standard between an external device connected through the USB connector 83 and an IC built into the USB cable. The PD communication unit 82 also determines whether the connected external device and USB cable are compatible with the USB PD standard. The PD communication unit 82 performs negotiation communication based on the communication protocol of the USB PD standard, and negotiates the amount of power to be supplied to the external device.

[0050] The power supply switch 81 is a switch for turning on or off the power supply from the power supply unit 30 to the external device. By turning the power supply switch 81 on, the power supply unit 30 can supply power to the external device based on the USB standard, and by turning the power supply switch 81 off, the power supply to the external device can be stopped. In this embodiment, as an example, it is assumed that the PD communication unit 82 controls the power supply switch 81.

[0051] Next, the operation of the digital camera 100 in this embodiment will be described, but the premise for this will be described.

[0052] In this embodiment, an example will be described in which the digital camera 100 serves as a power source and is started up from a state in which the digital camera 100 is supplying power to an external device in a power-off state. More specifically, a method will be described in which the start-up (power ON) of the digital camera 100 can be started up immediately without delay even in a state in which power is being supplied to an external device.

[0053] It is assumed that digital camera 100 is capable of supplying two powers, A and B, which have different power values, to an external device. In this embodiment, it is assumed that power supply unit 30 of digital camera 100 can supply 45 W of power, power A is 5 V×3 A=15 W, and power B is 5 V×1.5 A=7.5 W.

[0054] Moreover, each state of the digital camera 100 is defined as follows.

[0055] The non-operating state of the digital camera 100 refers to a state in which the power supply of the digital camera 100 is OFF or in a power saving mode, and no power is supplied to external devices from the digital camera 100. The power consumption in this state is approximately 0 W.

[0056] The non-operating power supply state is a state in which the digital camera 100 is powered off or in a power saving mode, the digital camera 100 and an external device are connected via USB, and the digital camera 100 supplies power to the external device.

[0057] The standby state is a state in which the power of the digital camera 100 is ON, a live view image is displayed, or playback is being performed, and awaits a user operation. It is also a state in which power is not being supplied from the digital camera 100 to an external device. In this embodiment, the power consumption in this state is 15 W.

[0058] The standby power supply state is a state in which the power of the digital camera 100 is ON, a live view image is being displayed (standby state for shooting) or playback is being performed, and power is being supplied from the digital camera 100 to an external device.

[0059] The active state is a state in which the digital camera 100 is actually taking pictures, or is in a shooting standby state, but can take pictures immediately upon receiving a shooting instruction from the user. The power consumption in this state varies depending on the user's operation, but the maximum power consumption is 40 W when taking still pictures or continuous shots that involve driving the mechanical shutter.

[0060] Based on these states, power A and power B can be expressed as follows:

[0061] Power A supplied to the external device is the power that can be left in power supply unit 30 to enable immediate operation without waiting for power negotiation to be completed, even when digital camera 100 goes from a non-operating state to a standby state. Power consumption in the standby state is 15 W, so in order to leave this power in power supply unit 30, power A is set to be equal to or less than 30 W, which is obtained by subtracting 15 W from 45 W, which is the maximum power that power supply unit 30 can supply.

[0062] The USB PD standard prescribes combinations of voltage and current that can be supplied, with the voltages being 5V, 9V, 15V, and 20V, and the currents being 3A and 5A. From these, in this embodiment, 5V and 3A are selected as a combination of 30W or less. In other words, in this embodiment, power A is set to 15W.

[0063] Power B supplied to external devices is power that can be supplied to external devices even when digital camera 100 is in an active state. Since the maximum power consumption in the active state is 40 W, in order to leave this power in power supply unit 30, it is desirable to set power B to 5 W or less, which is calculated by subtracting 40 W from 45 W, which is the power supplied by the power supply unit.

[0064] However, as described above, the USB PD standard does not have a combination that results in a power supply of 5W or less. In contrast, the USB 3.0 standard specifies a combination of 5V and 1.5A. Therefore, in this embodiment, power B is set to 5V x 1.5A = 7.5W. However, since this value of 7.5W exceeds the above 5W, an operation that consumes the maximum power in the active state cannot be performed while power B is being supplied to an external device. In other words, while power B is being supplied to the outside, there are operations that can be performed in the active state and operations that cannot be performed, and when an operation that consumes the maximum power is to be performed, the supply of power B must be stopped.

[0065] Based on the above premise, the operation of the digital camera 100 will be described below with reference to Figures 3 to 6. Figures 3 to 6 are flow charts showing the operation of the digital camera 100 of this embodiment.

[0066] Each process in the flowchart is realized by the CPU included in the system control unit 50 expanding a program stored in the non-volatile memory 56 into the system memory 52 and executing it.

[0067] 3 is a flowchart showing the operation of the system control unit 50 when the digital camera 100 is in a non-operating state. As already explained, the non-operating state refers to a state in which the power supply of the digital camera 100 is OFF or in a power saving mode, and the digital camera 100 is not supplying power to external devices.

[0068] In step S101, the system control unit 50 determines whether or not an external device is connected via a USB cable to the USB connector 83. If the connection of an external device is detected and power can be supplied to the connected external device, the process proceeds to step S102, and if not, the process proceeds to step S107.

[0069] In step S102, the system control unit 50 instructs the PD communication unit 82 to start power negotiation in order to supply power A from the power supply unit 30 to the external device. In response to this, the PD communication unit 82 starts power negotiation with the external device. In the negotiation, the digital camera 100 notifies the external device that it is capable of supplying two types of power, the above-mentioned power A and power B (power A>power B). Here, a power list indicating the voltages and currents that the digital camera 100 can supply is entered with combinations of the voltages and currents of power A and power B, and transmitted to the external device. In the following explanation, unless otherwise specified, it is assumed that the external device has requested power A.

[0070] In step S103, the system control unit 50 determines whether or not the power negotiation for supplying power A to the external device has been completed. If the power negotiation has been completed, the process proceeds to step S104. If not, the process of step S103 is repeated. Note that the wait for the completion of the power negotiation here is assumed to be the wait for the completion of the power negotiation started in step S102.

[0071] In step S104, the system control unit 50 sets the power determined by the power negotiation as the supply power in the power supply control unit 80 in order to supply power A from the power supply unit 30 to the external device. Also, if the power supply switch 81 is OFF, it is changed to ON via the PD communication unit 82. When these settings are completed, power supply from the power supply unit 30 to the external device begins.

[0072] In step S105, the system control unit 50 determines whether or not power supply to the external device has started from the power supply unit 30. If power supply has started, the process proceeds to step S106; if not, the process of step S105 is repeated.

[0073] In step S106, the system control unit 50 transitions to a non-operating power supply state, and starts the operation of the flowchart in FIG.

[0074] In step S107, the system control unit 50 determines whether or not a start-up trigger for the digital camera 100 has been detected. When the power switch 72 of the digital camera 100 is OFF and the power source of the digital camera 100 is OFF, the start-up trigger means turning ON the power switch 72 of the digital camera 100. When the power switch 72 of the digital camera 100 is ON and the camera is in a power saving mode, the start-up trigger means pressing the shutter button 61, pressing the mode change switch 60, or pressing a button included in the operation unit 70. If the system control unit 50 detects a start-up trigger, it proceeds to step S108, and if not, it returns to step S101.

[0075] In step S108, the system controller 50 turns on the power of the digital camera 100.

[0076] In step S109, the system controller 50 causes the digital camera 100 to transition to an active state, and starts the operation of the flowchart in FIG.

[0077] 4 is a flowchart showing the operation of the system control unit 50 in the non-operating power supply state. As already described, the non-operating power supply state refers to a state in which the power supply of the digital camera 100 is OFF or in a power saving mode, the digital camera 100 and an external device are connected via a USB cable, and the digital camera 100 supplies power to the external device.

[0078] In step S201, the system control unit 50 determines whether or not a start-up cause of the digital camera 100 has been detected. The method for detecting the start-up cause is the same as the determination method in step S107. If a start-up cause has been detected, the process proceeds to step S202; if not, the process proceeds to step S207.

[0079] In step S202, the system control unit 50 reads the setting value of the power supply control unit 80 in order to obtain the setting value of the current supply power. Note that the current supply power may be stored in the system memory 52 as an operating variable and read out.

[0080] In step S203, the system control unit 50 determines whether the supply power obtained in step S202 is power B and whether power is being supplied to an external device. If the condition is met, the process proceeds to step S205, and if not, the process proceeds to step S204. Here, when power B is being supplied to the outside, power B is 7.5 W as already described, so the power supply unit 30 has a remaining power supply capacity of 45-7.5=37.5 W. Therefore, even if the power of the digital camera 100 is turned on in step S205, it can start up immediately.

[0081] In step S204, the system control unit 50 instructs the PD communication unit 82 to start power negotiation in order to change the power that can be supplied from the power supply unit 30 to the external device from power A to power B. In response to this, the PD communication unit 82 starts power negotiation with the external device. In the negotiation, the system control unit 50 notifies the external device via the PD communication unit 82 that power B can be supplied from the power supply unit 30. In the following description, unless otherwise specified, it is assumed that the external device has requested power B.

[0082] In step S205, even if the system control unit 50 performed the power negotiation in step S204, it controls the power control unit 80 to turn on the power of the digital camera 100 without waiting for the completion of the negotiation. Here, the power A is 15 W as already explained, so the power supply unit 30 has a remaining power supply capacity of 45-15=30 W. And, as mentioned above, the power consumption in the standby state when the camera is turned on is 15 W. Therefore, it is possible to turn on the power of the digital camera 100, start it up immediately, and transition to the standby power supply state without waiting for the completion of the negotiation to change the power supply to the external device from power A to power B.

[0083] In step S206, the system control unit 50 transitions to a standby power supply state and starts the operation of the flowchart in FIG.

[0084] In step S207, the system control unit 50 determines whether or not a request to stop power supply from the power supply unit 30 to the external device has been received from the external device via the PD communication unit 82, or from the mode changeover switch 60, the shutter button 61, or the operation unit 70. If a request has been received, the process proceeds to step S208;

[0085] In step S208, the system control unit 50 instructs the PD communication unit 82 to start power negotiation in order to stop the power supply to the external device. In response to this, the PD communication unit 82 starts power negotiation with the external device.

[0086] In step S209, the system control unit 50 determines whether or not the power negotiation for stopping the power supply to the external device has been completed. If the power negotiation has been completed, the process proceeds to step S210. If not, the process of step S209 is repeated. Note that the wait for the completion of the power negotiation here is assumed to be the wait for the completion of the power negotiation started in step S208.

[0087] In step S210, the system control unit 50 performs a setting to turn off the power supply switch 81 via the PD communication unit 82 in order to stop the power supply from the power supply unit 30 to the external device.

[0088] In step S211, the system control unit 50 determines whether or not the power supply to the external device has stopped from the power supply unit 30. If the power supply has stopped, the process proceeds to step S212; otherwise, the process of step S211 is repeated.

[0089] In step S212, the system controller 50 puts the digital camera 100 into a non-operating state, and starts the operation of the flowchart in FIG.

[0090] 5 is a flowchart showing the operation of digital camera 100 in a standby power supply state. As already explained, the standby power supply state refers to a state in which digital camera 100 is powered on, digital camera 100 and an external device are connected via a USB cable, and power A is being supplied from digital camera 100 to the external device.

[0091] In step S301, the system controller 50 determines whether or not an external device is connected via a USB cable to the USB connector 83. If connected, the process proceeds to step S302;

[0092] In step S302, the system control unit 50 creates display data such as a live view image, and sequentially transfers the data to the display unit 28 to update the display.

[0093] In step S303, the system control unit 50 determines whether or not the power negotiation for supplying power B from the power supply unit 30 to the external device has been completed. If the power negotiation has been completed, the process proceeds to step S304, and if not, the process proceeds to step S307. Note that the wait for the completion of the power negotiation here is assumed to be the wait for the completion of the power negotiation started in step S204.

[0094] In step S304, the system control unit 50 sets the power determined by the power negotiation as the supply power in the power supply control unit 80 in order to supply power B from the power supply unit 30 to the external device. Also, if the power supply switch 81 is OFF, it is changed to ON via the PD communication unit 82. When these settings are completed, power supply from the power supply unit 30 to the external device begins.

[0095] In step S305, the system control unit 50 determines whether the power supplied from the power supply unit 30 to the external device has been changed to power B. If the power change has been completed, the process proceeds to step S306; otherwise, step S305 is repeated.

[0096] In step S306, the system controller 50 causes the digital camera 100 to transition to the active state, and starts the operation of the flowchart in FIG.

[0097] In step S307, the system control unit 50 determines whether any of the following operations has been performed: pressing the mode change switch 60, pressing any of the various switches of the operation unit 70, pressing the shutter button 61, or turning off the power switch 72. If any of these operations has been performed, the process proceeds to step S308;

[0098] In step S308, the system control unit 50 determines whether or not the operation determined in step S307 was an operation to turn off the power switch 72. If it was an operation to turn off the power switch 72, the process proceeds to step S309, and if not, the process proceeds to step S311.

[0099] In step S309, the system control unit 50 controls the power supply control unit 80 to turn off the power supply of each unit of the digital camera 100.

[0100] In step S310, the system controller 50 switches the digital camera to a non-operating state and starts the operation of the flowchart in FIG.

[0101] In step S311, the system control unit 50 determines whether or not the operation determined in step S308 (step S307) can be executed in the standby state. Here, because power negotiation for reducing the power supply to the external device from power A to power B has not been completed, the power supply unit 30 supplies power A=15 W to the external device. Therefore, the digital camera 100 can only operate in the standby state. The system control unit 50 holds operations executable in the standby state in the non-volatile memory 56, and if the operation to be executed matches this, the process proceeds to step S312, and if not, the process proceeds to step S313.

[0102] Although this overlaps with the above explanation, as to whether or not a function can be executed in the standby state, it is determined that the function can be executed if the sum of the maximum power consumption of the function and the power supplied to the external device does not exceed the maximum output of the power supply unit 30. Specifically, when the digital camera 100 is supplying power A to the external device, the sum of the power A and the operation of pressing the mode selector switch 60 or various switches of the operation unit 70 does not exceed the maximum output of the power supply unit 30. Therefore, in the case of these operations, the process proceeds to step S312, and if not, the process proceeds to step S313.

[0103] Regarding the storage of operations that can be performed in the standby state, the maximum power consumption for each operation item to be executed is measured in advance and stored in the non-volatile memory 56, or a judgment threshold value is stored in the non-volatile memory 56. In this case, these are read and compared, and if the sum of the maximum power consumption of the operation item to be executed and the power supplied to the external device is smaller than the maximum output of the power supply unit 30, the process proceeds to step S312, and if they are the same or larger, the process proceeds to step S313.

[0104] In step S312, the system controller 50 executes the operation detected in step S307.

[0105] In step S313, the system controller 50 stores in the non-volatile memory 56 the operation detected in step S307.

[0106] 6 is a flowchart showing the operation of digital camera 100 in the active state. The active state refers to a state in which digital camera 100 is powered on and supplies power B to an external device from digital camera 100, or a state in which power is not being supplied from digital camera 100.

[0107] In step S401, the system control unit 50 creates display data such as a live view image, and sequentially transfers the data to the display unit 28 to update the display.

[0108] In step S402, the system control unit 50 determines whether or not the user has operated any of the mode changeover switch 60, the shutter button 61, the operation unit 70, and the power switch 72. If any operation has been performed, the process proceeds to step S403; otherwise, the process proceeds to step S406.

[0109] In step S403, the system control unit 50 checks whether or not the user operation in step S402 was a power-off operation for the power switch 72. If it was a power-off operation for the power switch 72, the process proceeds to step S404, and if not, the process proceeds to step S407.

[0110] In step S404, the system control unit 50 controls the power supply control unit 80 to turn off the power supply of each unit of the digital camera 100.

[0111] In step S405, the system controller 50 puts the digital camera 100 into a non-operating state and starts the operation of the flowchart in FIG.

[0112] In step S406, the system control unit 50 determines whether or not an operation to be executed is stored in the non-volatile memory 56. It is assumed that the operation to be executed is written to the non-volatile memory 56 in step S313. If an operation to be executed is stored, the process proceeds to step S407; if not, the process proceeds to step S416.

[0113] In step S407, the system control unit 50 acquires the process to be executed in response to the user operation detected in step S402 or the operation detected in step S406. Specifically, information that can identify the camera function to be executed, such as image playback, changing settings such as shutter speed and aperture, shooting, and enlargement in live view display, is acquired.

[0114] In step S408, the system control unit 50 determines whether or not to stop the supply of power B from the power supply unit 30 to the external device for the operation to be executed acquired in step S407. Since the power B is 7.5 W as described above, it is necessary to stop the supply of power B in order to perform an operation that consumes more than 37.5 W obtained by subtracting the power B from the power supply unit 30's available power of 45 W. The operation that needs to be stopped is stored in the non-volatile memory 56, and if the operation to be executed matches this, the process proceeds to step S409, and if not, the process proceeds to step S415.

[0115] Although this overlaps with the above explanation, it is determined that it is necessary to stop the supply when the sum of the maximum power consumption of the function and the power supplied to the external device exceeds the maximum output of the power supply unit 30. Specifically, when the digital camera 100 is supplying power B to the external device, the sum of the power consumption for driving the shutter during shooting and power B exceeds the maximum output of the power supply unit 30. Therefore, if it is a shooting operation, the process proceeds to step S409, and if not, the process proceeds to step S415.

[0116] Regarding the retention of operations that require the supply to be stopped, the maximum power consumption for each operation item to be executed is measured in advance and retained in non-volatile memory 56, or a judgment threshold value is retained in non-volatile memory 56. In this case, these are read and compared, and if the sum of the maximum power consumption of the operation item to be executed and the power supplied to the external device is greater than the maximum output of the power supply unit 30, the process proceeds to step S409, and if they are the same or smaller, the process proceeds to step S415.

[0117] In step S409, the system control unit 50 determines whether or not the power negotiation for supplying power B from the power supply unit 30 to the external device has been completed. If the power negotiation has been completed, the process proceeds to step S410, and if not, the process of step S409 is repeated. Note that the wait for the completion of the power negotiation here is assumed to be the wait for the completion of the power negotiation started in step S418.

[0118] In step S410, the system controller 50 instructs the PD communication unit 82 to start power negotiation in order to stop the power supply to the external device. In response to this, the PD communication unit 82 starts power negotiation with the external device.

[0119] In step S411, the system control unit 50 determines whether or not the power negotiation for stopping the supply of power from the power supply unit 30 to the external device has been completed. If the power negotiation has been completed, the process proceeds to step S412, and if not, the process of step S411 is repeated. Note that the wait for the completion of the power negotiation here is assumed to be the wait for the completion of the power negotiation started in step S410.

[0120] In step S412, the system control unit 50 performs a setting to turn off the power supply switch 81 via the PD communication unit 82 in order to stop the power supply to the external device.

[0121] In step S413, the system control unit 50 determines whether or not the power supply to the external device has stopped from the power supply unit 30. If the power supply has stopped, the process proceeds to step S414; otherwise, the process of step S413 is repeated.

[0122] In step S414, the system controller 50 executes a process corresponding to the user operation detected in step S402 or the operation detected in step S406. Specifically, as described in step S408, the system controller 50 executes a shooting operation and returns the process to step S401.

[0123] In step S415, the system controller 50 executes a process corresponding to the user operation detected in step S402 or the operation detected in step S406, and proceeds to step S416.

[0124] In step S416, the system control unit 50 reads the setting value of the power supply control unit 80 to obtain the setting value of the current power supply. Note that the current power supply may be stored in the system memory 52 as an operating variable and read out.

[0125] In step S417, the system control unit 50 determines whether the supply power obtained in step S416 is power B and whether power is being supplied to an external device. If the condition is met, the process returns to step S401, and if not, the process proceeds to step S418.

[0126] In step S418, system control unit 50 instructs PD communication unit 82 to start power negotiation in order to supply power B from power supply unit 30 to the external device. In response to this, PD communication unit 82 starts power negotiation with the external device. In the negotiation, digital camera 100 notifies the external device that it is capable of supplying power B. Once the negotiation has started, the process returns to step S401 without waiting for its completion.

[0127] As described above, in the above embodiment, when the digital camera supplies power to an external device, the power required to switch the power source from a non-operating state to a standby state is left in the power supply unit, and as much power as possible is supplied to the external device from the remaining power. This makes it possible to immediately switch the digital camera to a standby state with the power source turned on without spending time on power negotiation with the external device while a large amount of power is still being supplied to the external device.

[0128] The various controls described above as being performed by the system control unit 50 may be performed by a single piece of hardware, or the entire device may be controlled by multiple pieces of hardware (e.g., multiple processors or circuits) sharing the processing.

[0129] In the embodiment, the maximum power that the power supply unit 30 can supply is set to 45 W, but other powers are also possible. In this case, the power A and the power B are determined based on the maximum power that the power supply unit 30 can supply and the power consumption of the digital camera 100.

[0130] In the above-described embodiment, the present invention is applied to a digital camera, but the present invention is not limited to this and can be applied to any electronic device that can supply power to an external device. That is, the present invention can be applied to information processing terminals, portable information terminals, portable image viewers, multifunction devices, game consoles, tablets, etc.

[0131] The disclosure of this specification includes the following electronic device, its control method, program, and storage medium.

[0132] (Item 1) An electronic device capable of supplying power to an external device, A power supply unit; a control means for controlling the power supply unit so that, when supplying power from the power supply unit to the external device in a first state of the electronic device, the power supply unit supplies a first supply power to the external device that is equal to or less than a power obtained by subtracting a power consumption of the electronic device in a second state, the power consumption of which is greater than that of the first state, from a power that the power supply unit can supply; An electronic device comprising:

[0133] (Item 2) 2. The electronic device according to item 1, wherein the control means controls the power supply unit to supply a second supply power smaller than the first supply power to the external device in the second state.

[0134] (Item 3) The electronic device described in item 2, characterized in that the second supply power is a power close to the power that can be supplied by the power supply unit minus the power consumption in a third state of the electronic device, which consumes more power than the second state.

[0135] (Item 4) The electronic device described in item 2, characterized in that when an instruction is given to switch the state of the electronic device from the first state to the second state while the control means is in the first state, the control means negotiates with the external device to switch from the first supply power to the second supply power.

[0136] (Item 5) 5. The electronic device according to item 4, wherein the control means switches the state of the electronic device from the first state to the second state without waiting for the completion of the negotiation.

[0137] (Item 6) 6. The electronic device according to any one of items 1 to 5, further comprising a USB terminal, and supplying power to the external device via the USB terminal.

[0138] (Item 7) 7. The electronic device according to item 6, wherein the USB terminal supplies power to the external device based on the USB PD standard.

[0139] (Item 8) 8. The electronic device according to item 7, wherein the control means negotiates with the external device when changing the power supplied to the external device.

[0140] (Item 9) 9. The electronic device according to any one of items 1 to 8, wherein the first state is a state in which the power of the electronic device is OFF or a state in which the electronic device is in a power saving mode.

[0141] (Item 10) 10. The electronic device according to any one of items 1 to 9, wherein the second state is a standby state in which the power of the electronic device is turned on and awaits a user operation.

[0142] (Item 11) 11. The electronic device according to any one of items 1 to 10, wherein the power supply unit is a battery that is built into or detachably arranged in the electronic device.

[0143] (Item 12) 12. The electronic device according to any one of items 1 to 11, wherein the electronic device is an imaging device.

[0144] (Item 13) A method for controlling an electronic device having a power supply unit capable of supplying power to an external device, comprising: A control method for an electronic device, comprising: a control step of controlling the power supply unit so that, when supplying power to the external device from the power supply unit in a first state of the electronic device, a first supply power that is equal to or less than the power that can be supplied by the power supply unit minus the power consumption of the electronic device in a second state, which has greater power consumption than the first state, is supplied to the external device.

[0145] (Item 14) Item 14. A program for causing a computer to execute the control method according to item 13.

[0146] (Item 15) A computer-readable storage medium storing a program for causing a computer to execute the control method according to item 13.

[0147] (Other embodiments) The present invention can also be realized by a process in which a program for realizing one or more functions of the above-mentioned embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) for realizing one or more functions.

[0148] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0149] 22: imaging unit, 24: image processing unit, 30: power supply unit, 50: system control unit, 80: power supply control unit, 81: power supply switch, 83: USB connector, 100: digital camera, 150: lens unit

Claims

1. An electronic device capable of supplying power to an external device, A power supply unit; a control means for controlling the power supply unit so that, when supplying power from the power supply unit to the external device in a first state of the electronic device, the power supply unit supplies a first supply power to the external device that is equal to or less than a power obtained by subtracting a power consumption of the electronic device in a second state, the power consumption of which is greater than that in the first state, from a power that the power supply unit can supply; An electronic device comprising:

2. 2 . The electronic device according to claim 1 , wherein the control means controls the power supply unit so as to supply, in the second state, a second supply power smaller than the first supply power to the external device.

3. 3. The electronic device according to claim 2, wherein the second supply power is a power close to the power that can be supplied by the power supply unit minus the power consumption in a third state of the electronic device, which consumes more power than the second state.

4. 3. The electronic device according to claim 2, wherein the control means negotiates with the external device to switch from the first supply power to the second supply power when an instruction to switch the state of the electronic device from the first state to the second state is given while the electronic device is in the first state.

5. 5. The electronic device according to claim 4, wherein the control means switches the state of the electronic device from the first state to the second state without waiting for the completion of the negotiation.

6. 2. The electronic device according to claim 1, further comprising a USB terminal, and supplying power to the external device via the USB terminal.

7. 7. The electronic device according to claim 6, wherein the USB terminal supplies power to the external device in accordance with the USB PD standard.

8. 8. The electronic device according to claim 7, wherein the control means negotiates with the external device when changing the power supplied to the external device.

9. 2. The electronic device according to claim 1, wherein the first state is a state in which the power supply of the electronic device is OFF or a state in which the electronic device is in a power saving mode.

10. 2. The electronic device according to claim 1, wherein the second state is a standby state in which the power supply of the electronic device is turned on and the electronic device waits for a user operation.

11. 2. The electronic device according to claim 1, wherein the power supply unit is a battery that is built into the electronic device or that is detachably arranged therein.

12. 2. The electronic device according to claim 1, wherein the electronic device is an image pickup device.

13. A method for controlling an electronic device having a power supply unit capable of supplying power to an external device, comprising: A control method for an electronic device, comprising: a control step of controlling the power supply unit so that, when supplying power to the external device from the power supply unit in a first state of the electronic device, a first supply power that is equal to or less than the power that can be supplied by the power supply unit minus the power consumption of the electronic device in a second state, which has greater power consumption than the first state, is supplied to the external device.

14. A program for causing a computer to execute the control method according to claim 13.

15. A computer-readable storage medium storing a program for causing a computer to execute the control method according to claim 13.

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