Electronic apparatus, control method, and program

Abstract

To achieve a technique that can supply a large amount of power to an external device, while reducing heat generation.SOLUTION: An electronic apparatus has: first connection means to which a first power supply device is connected; second connection means to which an external device can be connected and which can supply power to the external device; third connection means to which a second power supply device is connected; and control means which switches between a first path for converting at least one of voltage received from the first power supply device through the first connection means and voltage received from the second power supply device through the third connection means and supplying the resulting voltage to the external device through the second connection means, and a second path for supplying the voltage received from the first power supply device through the first connection means to the external device through the second connection means without converting the voltage. When the voltage to be supplied to the external device is higher than the voltage which can be supplied from the first path, the control means performs control to supply power to the external device from the second path.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a technique for supplying power to an external device. [Background technology]

[0002] Some electronic devices, such as digital cameras, can be fitted with external devices, such as a strobe, a microphone, etc. The external devices are driven by power supplied from a power source of the external devices or from the electronic device, but as the performance of the external devices increases, a large amount of power may be required to drive the external devices.

[0003] When an electronic device supplies power to an external device connected to the electronic device, the electronic device may supply the external device with power from its own battery, or the electronic device may supply power received from an external power supply device to the external device.

[0004] Patent Document 1 describes a method for supplying power to a load by switching between a path for supplying battery power to the load after voltage conversion and a path for supplying battery power to the load without voltage conversion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6999713 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when power is voltage-converted and supplied to a load as in Patent Document 1, if the power supplied to the load is large, measures must be taken to reduce heat generated by losses that occur during the voltage conversion.

[0007] The present invention has been made in view of the above problems, and has an object to realize a technology that can supply a large amount of power to an external device while suppressing heat generation. [Means for solving the problem]

[0008] In order to solve the above problems and achieve the object, the electronic device of the present invention has a first connection means to which a first power supply device is connected, a second connection means to which an external device can be connected and capable of supplying power to the external device, a third connection means to which a second power supply device is connected, and a control means for switching between a first path that converts at least one of a voltage received from the first power supply device via the first connection means and a voltage received from the second power supply device via the third connection means and supplies the converted voltage to the external device via the second connection means, and a second path that supplies the voltage received from the first power supply device via the first connection means to the external device via the second connection means without voltage conversion, and the control means controls so that power is supplied to the external device from the second path when the voltage to be supplied to the external device is higher than the voltage that can be supplied from the first path. Effect of the Invention

[0009] According to the present invention, it is possible to supply a large amount of power to an external device while suppressing heat generation. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a system configuration diagram of the present embodiment. [Diagram 2] FIG. 1 is a block diagram showing a configuration of an electronic device according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a block diagram showing the configuration of an accessory device according to the embodiment. [Figure 4A] 5 is a flowchart showing a control process of the electronic device of the first embodiment. [Figure 4B] 5 is a flowchart showing a control process of the electronic device of the first embodiment. [Diagram 5] 5 is a flowchart showing a control process of the accessory device according to the first embodiment. [Figure 6] FIG. [Figure 7] 4 is a timing chart showing the operation of the first embodiment. [Figure 8A] 10 is a flowchart showing a control process of the electronic device of the second embodiment. [Figure 8B] 10 is a flowchart showing a control process of the electronic device of the second embodiment. [Figure 9] 6 is a timing chart showing the operation of the second embodiment. [Figure 10] FIG. 11 is an explanatory diagram of the operation of the second embodiment. [Figure 11] FIG. 4 is a diagram illustrating a UI of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the embodiment described below is an example for realizing the present invention, and should be appropriately modified or changed depending on the configuration of the device to which the present invention is applied and various conditions, and the present invention is not limited to the following embodiment. In addition, the present invention may be configured by appropriately combining parts of each embodiment described below.

[0012] In the following embodiment, the electronic device of the present invention will be described as an imaging device such as a digital camera. Note that the electronic device of the present invention is not limited to a digital camera, and can also be applied to a personal computer (notebook PC or tablet PC), a smartphone, etc.

[0013] <System configuration> First, the system configuration of this embodiment will be described with reference to FIG.

[0014] To the digital camera 100 of this embodiment, a first power supply device 200, a second power supply device 300, and a third power supply device 301 that can supply power to the digital camera 100, as well as an accessory device 400 that assists the functions of the digital camera 100 can be connected.

[0015] The first power supply device 200 is a power adapter that can be connected to a household power source and can supply power received from the household power source to the digital camera 100. When the first connection unit 201 is connected to the external power supply connection unit 120 of the digital camera 100, the first power supply device 200 can supply power to the digital camera 100 from the household power source.

[0016] The second power supply device 300 is a primary battery such as an alkaline battery or a lithium battery, or a rechargeable secondary battery such as a NiCd battery, a NiMH battery, a lithium ion battery, etc. When the second power supply device 300 is attached to the battery connector 130 of the digital camera 100, the second power supply device 300 can supply power to the digital camera 100.

[0017] The third power supply device 301 is a DC coupler that can be connected to a household power source via an AC adapter 302 and a DC cable 303. When the third power supply device 301 is attached to the battery connection unit 130 of the digital camera 100, the third power supply device 301 can supply power to the digital camera 100. The digital camera 100 has a battery box for mounting the battery 300. The DC coupler 301 has a shape that allows it to be mounted in the battery box. A user can use the digital camera 100 by mounting either the battery 300 or the DC coupler 301 in the battery box of the digital camera 100.

[0018] In the following description, the first power device 200 will be referred to as a power adapter, the second power device 300 as a battery, and the third power device 301 as a DC coupler.

[0019] The accessory device 400 is a main accessory having a predetermined function by itself. The accessory device 400 is a strobe in the example of Fig. 1. When the camera connector 4001 is connected to the accessory connector 140 of the digital camera 100, the accessory device 400 is mechanically and electrically connected to the digital camera 100.

[0020] Sub-accessories 410, 420 can also be connected to the accessory connection unit 140 of the digital camera 100. When the sub-accessories 410, 420 are connected to the accessory connection unit 140, the accessory device 400 can also be connected to the digital camera 100 via the sub-accessories 410, 420. The sub-accessories 410, 420 only have a function of assisting the connection between the accessory device 400 and the digital camera 100, and are interposed between the camera connection unit 4001 of the accessory device 400 and the accessory connection unit 140 of the digital camera 100.

[0021] 1, the sub-accessory is an off-camera adapter 410 or an accessory distributor 420. The off-camera adapter 410 is an off-camera shoe cord, and enables the accessory device 400 to be used at a location away from the digital camera 100. The accessory distributor 420 enables multiple accessory devices 400 to be connected to the accessory connection unit 140 of the digital camera 100.

[0022] The camera connection section 4101 of the off-camera adapter 410 or the camera connection section 4201 of the accessory distributor 420 can be connected to the accessory connection section 140 of the digital camera 100. In addition, the accessory connection section 4102 of the off-camera adapter 410 or the first accessory connection section 4202 and the second accessory connection section 4203 of the accessory distributor 420 can be connected to the camera connection section 4001 of the accessory device 400.

[0023] <Configuration of Digital Camera 100> Next, the configuration and functions of the digital camera 100 will be described with reference to FIG.

[0024] The main control unit 101 is a central processing unit (CPU) that controls the entire camera 100, and executes programs stored in a non-volatile memory 103, which will be described later, to realize communication processing and control processing, which will be described later. Note that instead of the main control unit 101 controlling the entire device, the entire device may be controlled by multiple hardware devices sharing the processing. The main control unit 101 may also be configured as a microcontroller including a processor such as a CPU, memories such as a ROM and a RAM, a controller, and peripheral circuits.

[0025] The imaging unit 102 includes a group of lenses including a zoom lens and a focus lens, and a shutter with an aperture function. The imaging unit 102 also includes an imaging element configured with a CCD or CMOS element or the like that converts a subject image into an electric signal, and an A / D converter that converts an analog image signal output from the imaging element into a digital signal. Under the control of the main control unit 101, the imaging unit 102 converts the subject image light formed by the lens included in the imaging unit 102 into an electric signal using the imaging element, performs noise reduction processing, and outputs image data consisting of a digital signal.

[0026] The main control unit 101 performs resizing processes such as pixel interpolation and reduction, and color conversion processes on image data captured by the imaging unit 102. The main control unit 101 also compresses and encodes the processed still image data using JPEG or the like, and encodes moving image data using a moving image compression format such as MPEG2 or H.264 to create an image file, which is then recorded on the recording medium 107. The main control unit 101 also performs predetermined calculation processes using the captured image data, and performs AF (autofocus) processing and AE (autoexposure) processing by controlling the focus lens, aperture, and shutter of the imaging unit 102 based on the calculation results.

[0027] The non-volatile memory 103 is an electrically erasable and recordable memory, and for example, an EEPROM is used. Constants, programs, etc. for the operation of the main control unit 101 are recorded in the non-volatile memory 103. The program here refers to a program for executing a control process described later in this embodiment.

[0028] The working memory 104 is used as a working area for expanding constants and variables for the operation of the main control unit 101, programs read from the non-volatile memory 103, etc. The working memory 104 is also used as a buffer memory for temporarily storing image data captured by the imaging unit 102, and an image display memory for the display unit 106.

[0029] The operation unit 105 is an operation member such as various switches, buttons, and dials that accept various operations from the user, and outputs information input by user operations to the main control unit 101 and the sub-control unit 108. The operation unit 105 includes, for example, a power button for turning the power on or off, a capture button for issuing an instruction to start or end still image capture or video capture, a playback button for issuing an instruction to play back an image, and a mode switching button for changing the operation mode of the camera. The operation unit 105 also includes a zoom lever for issuing a zoom instruction, etc. Furthermore, the operation unit 105 includes a touch panel that is integrally configured with the display unit 106 described later.

[0030] The shooting button operation unit 105 outputs information input by a user operation to the main control unit 101 and the sub control unit 108 .

[0031] In still image shooting mode, the main control unit 101 starts AE control and AF control when the shooting button is half-pressed, and executes still image shooting processing to record image data captured by the imaging unit 102 on the recording medium 107 when the shooting button is fully pressed.

[0032] In addition, in the video shooting mode, when the shooting button is pressed for the first time, the main control unit 101 performs AE control and AF control on the image data (frames) captured by the imaging unit 102, continues the video shooting process to record a video of a predetermined length of time on the recording medium 107, and stops the video shooting process when the shooting button is pressed again.

[0033] Display unit 106 displays live view images, captured images, and text for interactive operations. Display unit 106 is, for example, a display device such as a liquid crystal display or an organic EL display. Display unit 106 may be integrated with digital camera 100 or may be an external device connected to digital camera 100. Digital camera 100 only needs to be able to connect to display unit 106 and control the display on display unit 106.

[0034] Image files created by the main control unit 101 are recorded on the recording medium 107, and image files already recorded on the recording medium 107 are read out by the main control unit 101. The recording medium 107 may be a memory card or a hard disk drive that is attached to the digital camera 100, or may be a flash memory or a hard disk drive built into the digital camera 100. It is sufficient that the digital camera 100 is at least capable of accessing the recording medium 107.

[0035] The sub-controller 108 is configured as a microcontroller including a processor such as a CPU, memories such as a ROM and a RAM, a controller, and peripheral circuits, and controls part of the camera 100. The sub-controller 108 executes a program stored in the ROM to realize control processing, which will be described later. The sub-controller 108 can operate with lower power than the main control unit 101, and is connected to the main control unit 101 so as to be able to send and receive data. The sub-controller 108 controls a power supply control unit 109 and a power receiving control unit 110, which will be described later.

[0036] The sub-control unit 108 includes a battery determination unit 1081 and an accessory determination unit 1082 .

[0037] The battery determination unit 1081 communicates with a power supply device such as the battery 300 or DC coupler 301 connected to the battery connection unit 130, and acquires power supply device information, which is information related to the power supply device. The power supply device information includes, for example, information indicating the type of device (information for identifying the battery 300 and the DC coupler 301), the power that the power supply device can supply, the model name of the power supply device (for example, the product name of the battery 300 that can be attached to the battery connection unit 130), etc. The power supply device information also includes, for example, information indicating the remaining capacity and degradation level of the battery 300 (for example, a value indicating the amount of decrease in battery capacity since the time of shipment).

[0038] The accessory determination unit 1082 communicates with the accessory device 400, the off-camera adapter 410, the accessory distributor 420, and the like connected to the accessory connection unit 140, and acquires accessory device information related to the accessory device. The accessory device information includes, for example, the type of the accessory device (information for identifying the main accessory, information for identifying the sub-accessory), the model name of the accessory device (for example, the product name of the accessory device 400), and function information. In addition, when the accessory device 400 has a plurality of operation modes, the accessory device information includes information on the power required for the accessory device to operate in each mode. In addition, the accessory device information includes, for example, information indicating the rated voltage, rated current, the presence or absence of a built-in battery, the presence or absence of a charging function, power supply specifications when the power is off or in sleep mode, a start-up method, a communication method, and the like of the accessory device. In addition, the accessory device information includes, for example, information indicating the operation specifications when another device is connected to the accessory device, the connection state of the other device, and the like.

[0039] The power supply control unit 109 controls a first path that converts the voltage from the external power supply connection unit 120 or the battery connection unit 130 into a predetermined voltage by the power receiving control unit 110 and supplies the voltage to the accessory connection unit 140. The power supply control unit 109 switches between an ON state in which the first path is open, and an OFF state in which the first path is not open.

[0040] The power supply control unit 109 includes a voltage conversion unit 1091 and a first power supply control unit 1092 .

[0041] The voltage conversion unit 1091 has a voltage conversion circuit that converts the voltage of the power supplied from the power reception control unit 110 into a voltage required for the operation of each component of the digital camera 100. The voltage conversion circuit includes, for example, a switching circuit such as a DC-DC converter. The voltage supplied from the voltage conversion unit 1091 is converted into a voltage (for example, 3.3 V) that can be used as a power source for each component of the digital camera 100.

[0042] Based on a control signal from the main control unit 101 or the sub-control unit 108, the first power supply control unit 1092 switches between an on state in which the power output from the voltage conversion unit 1091 is supplied to the accessory connection unit 140, and an off state in which the power is not supplied.

[0043] The power receiving control unit 110 receives power from the external power supply connection unit 120 and charges the battery 300 using the power received from the external power supply connection unit 120. The power receiving control unit 110 also supplies the power received from the battery connection unit 130 to the power supply control unit 109.

[0044] The power receiving control unit 110 includes a device information acquisition unit 1101 , an input control unit 1102 , a power receiving voltage conversion unit 1103 , a charge / discharge control unit 1104 , a power receiving voltage monitoring unit 1105 , and a temperature monitoring unit 1106 .

[0045] Device information acquisition unit 1101 communicates with power adapter 200 via external power connection unit 120 , and sends power device information acquired from power adapter 200 to input control unit 1102 .

[0046] Input control unit 1102 receives power from power adapter 200 via external power supply connection unit 120. Based on power supply device information acquired from device information acquisition unit 1101, input control unit 1102 controls whether the power received from power adapter 200 is supplied to receiving voltage conversion unit 1103 or to second power supply control unit 111.

[0047] The receiving voltage conversion unit 1103 converts the voltage output from the input control unit 1102 as necessary, and supplies the converted voltage to the charge / discharge control unit 1104 or the power supply control unit 109. The receiving voltage conversion unit 1103 includes, for example, a charge control IC and a DC / DC converter.

[0048] The charge / discharge control unit 1104 supplies the power received from the power receiving voltage conversion unit 1103 to the battery via the battery connection unit 130, thereby charging the battery 300. The charge / discharge control unit 1104 also receives power from the battery 300 and the DC coupler 301 via the battery connection unit 130, and supplies the power to the power supply control unit 109.

[0049] The receiving voltage monitoring unit 1105 detects the voltage supplied from the input control unit 1102 to the receiving voltage conversion unit 1103 or the second power supply control unit 111, and notifies the sub-control unit 108 of the detection result.

[0050] The temperature monitoring unit 1106 detects the temperature of the power receiving control unit 110 based on a control signal from the sub-control unit 108, and notifies the sub-control unit 108 of the detection result.

[0051] For example, when the sub-control unit 108 determines that the temperature information received from the temperature monitoring unit 1106 is higher or lower than a predetermined temperature, it limits or stops the power reception control unit 110 from receiving power and the power supply to the subsequent stages. This makes it possible to reduce the impact of heat generation from the digital camera 100 on the user and parts.

[0052] The second power supply control unit 111 controls a second path through which the power receiving control unit 110 receives power from the external power supply connection unit 120 and supplies the power output from the input control unit 1102 to the accessory connection unit 140. The second power supply control unit 111 switches between an ON state in which the second path is opened, and an OFF state in which the second path is not opened. The second power supply control unit 111 also supplies the voltage of the power received from the external power supply connection unit 120 (for example, a VBUS voltage) to the accessory connection unit 140 without voltage conversion. The second power supply control unit 111 controls whether or not to supply power to the accessory connection unit 140 based on a control signal from the sub-control unit 108.

[0053] The external power supply connection unit 120 is an interface that exchanges power supply device information with the power adapter 200 and can receive power from the power adapter 200. In this embodiment, the external power supply connection unit 120 is, for example, an adapter having a connector that complies with the USB (Universal Serial Bus) Type-C standard, and can be connected to a USB connector that is the first connection unit 201 of the power adapter 200. The power adapter 200 is a power supply device that complies with the USB PD (Power Delivery) standard.

[0054] The main control unit 101 and the sub-control unit 108 control the external power supply connection unit 120 to perform communication and power reception with the power adapter 200 in accordance with the USBPD standard.

[0055] A battery 300 or a DC coupler 301 is connected to the battery connection unit 130. The battery connection unit 130 communicates with the battery 300 or the DC coupler 301 and receives power supply device information. The battery connection unit 130 is also an interface capable of receiving power from the battery 300 or the DC coupler 301 and supplying power to the battery 300. The battery connection unit 130 is a battery attachment unit to which the battery 300 or the DC coupler 301 can be attached.

[0056] The accessory connection unit 140 is an accessory shoe to which the accessory device 400, the off-camera adapter 410, or the accessory distributor 420 can be connected. When the accessory device 400 is connected to the accessory connection unit 140, the accessory connection unit 140 communicates with the accessory device 400 and receives accessory device information. The accessory connection unit 140 is also an interface capable of supplying power to the accessory device 400.

[0057] Digital camera 100 of this embodiment has a first path and a second path as paths for supplying power to accessory connector 140. Digital camera 100 can switch between power supply via the first path and power supply via the second path.

[0058] The first path can supply power from the power supply control unit 109 to the accessory connection unit 140. The power supplied through the first path is power that has been converted to a first voltage by a voltage conversion unit 1091 of the power supply control unit 109. The power that has been converted to the first voltage by the voltage conversion unit 1091 is supplied to the accessory connection unit 140 and each component of the digital camera 100.

[0059] The second path can supply power from the second power supply control unit 111 to the accessory connection unit 140. The power supplied through the second path is not converted to the first voltage by the voltage conversion unit 1091 of the power supply control unit 109. The power supplied through the second path is power of a second voltage higher than the first voltage, and is equivalent to the voltage of the power received from the external power supply connection unit 120.

[0060] The digital camera 100 can detect that the accessory connector 140 and the camera connector 4001 are electrically connected by being in physical contact with each other.

[0061] For example, the terminals of the accessory connection unit 140 include a terminal that outputs a positive voltage and a terminal that is grounded to the digital camera 100, and the terminals of the camera connection unit 4001 include two terminals that are connected via a predetermined resistance.

[0062] When the camera connection unit 4001 is connected to the accessory connection unit 140, the two terminals of the accessory connection unit 140 are connected to the two terminals of the camera connection unit 4001 via a predetermined resistance, and the voltage of the terminal that outputs a positive voltage changes.

[0063] The accessory determination unit 1082 of the sub-control unit 108 detects a change in the terminal voltage of the accessory connection unit 140, thereby determining whether or not the camera connection unit 4001 is connected to the accessory connection unit 140.

[0064] Note that the above-mentioned connection detection based on a change in terminal voltage is a method based on physical contact, and the connection detection of the accessory device 400 by the accessory determination unit 1082 does not require communication with the accessory communication control unit 4004, which will be described later. Therefore, before power is supplied from the accessory connection unit 140 to the camera connection unit 4001, the connection of the accessory device 400 can be detected.

[0065] As described above, the digital camera 100 of this embodiment has a first connection part, a second connection part, and a third connection part as connection parts for connecting to an external device. The first connection part is the external power supply connection part 120. The second connection part and the third connection part are the battery connection part 130.

[0066] Moreover, the digital camera 100 of this embodiment has a first path and a second path for supplying power to the accessory connection unit 140. The first path supplies power to the accessory connection unit 140 via a voltage conversion unit 1091 of the power supply control unit 109. The second path supplies power to the accessory connection unit 140 without passing through the voltage conversion unit 1091 of the power supply control unit 109.

[0067] <Configuration of power adapter 200> Next, the configuration of power adapter 200 will be described.

[0068] The power adapter 200 supplies power to the digital camera 100 from the first connection unit 201 via the external power supply connection unit 120. The power adapter 200 is, for example, a power supply device such as a charger that complies with the USBPD standard. The first connection unit 201 is a USB Type-C plug of a USB connector. The external power supply connection unit 120 is a USB Type-C receptacle of a USB connector.

[0069] In this embodiment, in terms of the input / output direction of the VBUS voltage of the USB connector, the power adapter 200 is a source device and the digital camera 100 is a sink device.

[0070] In addition, the power adapter 200 is not limited to a power supply device that complies with the USB standard, but may be any device that can supply power to the electronic device 100, such as a mobile battery or other device that can supply power without being connected to a household power source.

[0071] <Configuration of Battery 300 and DC Coupler 301> Next, the configurations of the battery 300 and the DC coupler 301 will be described.

[0072] Battery 300 and DC coupler 301 supply power from battery connection unit 130 to power receiving control unit 110 of digital camera 100. Battery 300 is configured as a battery pack in which two lithium ion battery cells are connected in series. Note that battery 300 is not limited to a lithium ion battery pack, and the number and connection configuration of battery cells are not limited to this example, and may be, for example, a battery pack configured with primary batteries.

[0073] The battery 300 includes a microcontroller including a processor such as a CPU, memories such as a ROM and a RAM, a controller, and peripheral circuits, and controls charging / discharging and communication. The battery 300 exchanges power supply device information with the main control unit 101 or the sub-control unit 108 of the digital camera 100. The power supply device information includes, for example, the type of device, available power, model name, remaining capacity, and degree of deterioration.

[0074] The DC coupler 301 can be connected to the battery connector 130 in the same manner as the battery 300, and is, for example, a power supply device that complies with the USBPD standard.

[0075] The AC adapter 302 converts household power into DC power, and supplies power from the DC coupler 301 via the battery connector 130 to the power receiving control unit 110 of the digital camera 100 .

[0076] The DC coupler 301 includes a microcontroller including a processor such as a CPU, memories such as a ROM and a RAM, a controller, and peripheral circuits, and controls power supply and communication. The DC coupler 301 exchanges power supply device information with the main control unit 101 or the sub-control unit 108 of the digital camera 100. The power supply device information includes, for example, the type of device, the available power, and the model name.

[0077] The AC adapter 302 is, for example, a power supply device that complies with the USBPD standard, and can be connected to the DC coupler 301 via a USB Type-C connector. The maximum power that the AC adapter 302 can supply from the DC coupler 301 to the digital camera 100 depends on the power profile of the AC adapter 302 based on the USBPD standard and the rated voltage or rated current of the DC coupler 301.

[0078] The DC coupler 301 is not limited to a form connected to a household power source via the AC adapter 302, but may be in any form as long as it can supply power from the battery connector 130 to the digital camera 100.

[0079] <Configuration of the accessory device 400, the off-camera adapter 410, and the accessory distributor 420> Next, configurations of the accessory device 400, the off-camera adapter 410, and the accessory distributor 420 will be described with reference to FIG.

[0080] FIG. 3A is a block diagram illustrating the configuration of an accessory device 400, an off-camera adapter 410, and an accessory distributor 420 of this embodiment.

[0081] In this embodiment, an example will be described in which the accessory device 400 is a strobe, but the accessory device 400 is not limited to this and may be a sound collecting device such as a microphone, or a display device such as a display monitor. The accessory device 400 is not limited to a device that assists the functions of the digital camera 100, and may be, for example, a device that exchanges power and information with the digital camera 100 or a device that is fixed to the digital camera 100.

[0082] The camera connection section 4001 is an interface that is connected to the accessory connection section 140 of the digital camera 100 and can exchange power and information with the digital camera 100 .

[0083] The light emitting unit 4002 is composed of, for example, a xenon tube, and is a light source capable of emitting concentrated light for a short period of time.

[0084] The accessory control unit 4003 includes a microcontroller including a processor such as a CPU, memories such as a ROM and a RAM, a controller, and peripheral circuits. The accessory control unit 4003 controls each component of the accessory device 400 by executing a program stored in the memory. Note that instead of the accessory control unit 4003 controlling the entire device, the entire device may be controlled by multiple hardware devices sharing the processing.

[0085] An accessory communication control unit 4004 communicates with the digital camera 100 connected to the camera connection unit 4001, and exchanges accessory device information.

[0086] The accessory power receiving control unit 4005 supplies the power received from the camera connecting unit 4001 to the accessory charging / discharging control unit 4008 and the accessory voltage conversion unit 4006. The accessory charging / discharging control unit 4008 charges the accessory battery 4009 using the power received from the camera connecting unit 4001, and supplies the power supplied from the accessory battery 4009 to the accessory voltage conversion unit 4006.

[0087] The accessory voltage conversion unit 4006 converts into a predetermined voltage the power received from the accessory power reception control unit 4005 or the accessory charge / discharge control unit 4008. The accessory voltage conversion unit 4006 is configured by, for example, a DC-DC converter or an LDO (Low Drop Out) regulator.

[0088] The accessory voltage conversion unit 4006 supplies the voltage-converted power to the light emission circuit 4007 or the accessory control unit 4003.

[0089] The light emitting circuit 4007 controls the light emitting unit 4002 based on a control signal from the accessory control unit 4003 .

[0090] The light emitting circuit 4007 includes, for example, a charging circuit that charges the light emitting unit 4002 with power for applying a high voltage thereto, and a switch element that controls light emission.

[0091] The accessory charge / discharge control unit 4008 controls charging / discharging of the accessory battery 4009 based on a control signal from the accessory control unit 4003 or a control signal from an AND circuit 4011 .

[0092] The accessory battery 4009 performs charging or power supply under the control of the accessory charge / discharge control unit 4008 .

[0093] The accessory battery 4009 is configured as a battery pack in which two lithium ion battery cells are connected in series. The accessory battery 4009 is not limited to a battery pack of lithium ion batteries, and the number and connection configuration of the battery cells are not limited to this, and may be, for example, a battery pack configured of primary batteries. The accessory battery 4009 may be built into the accessory device 400, or may be detachable.

[0094] Furthermore, if the accessory device 400 is configured to receive power from the digital camera 100, the accessory battery 4009 may not be required.

[0095] The first voltage monitoring unit 4010 detects the voltage of the power received from the camera connection unit 4001 .

[0096] The first voltage monitoring unit 4010 determines whether or not the received voltage is equal to or higher than a third voltage, and sends a control signal according to the determination result to the accessory control unit 4003 and the AND circuit 4011.

[0097] For example, when the voltage from the camera connection unit 4001 is equal to or higher than the third voltage, the first voltage monitoring unit 4010 sends a control signal that permits the accessory device 400 to operate in the high load mode. Also, for example, when the voltage from the camera connection unit 4001 is lower than the third voltage, the first voltage monitoring unit 4010 sends a control signal that restricts the accessory device 400 from operating in the high load mode.

[0098] The AND circuit 4011 sends a control signal to the accessory charge / discharge control unit 4008 when both the control signal from the accessory control unit 4003 and the control signal from the first voltage monitoring unit 4010 are predetermined signals (for example, HIGH).

[0099] For example, assume that the voltage received from camera connection unit 4001 changes so as to exceed or fall below the third voltage.

[0100] In this case, a signal sent from the first voltage monitoring unit 4010 is sent to the AND circuit 4011 without passing through the accessory control unit 4003, and a control signal is sent from the AND circuit 4011 to the accessory charging / discharging control unit 4008. This makes it possible to shorten the delay time when changing the control of the accessory charging / discharging control unit 4008 depending on the voltage of the power received from the camera connection unit 4001.

[0101] The second voltage monitoring unit 4012 detects the voltage of the power received from the camera connection unit 4001 .

[0102] The second voltage monitoring unit 4012 judges whether the voltage from the camera connection unit 4001 is equal to or higher than the fourth voltage, and sends a control signal according to the judgment result to the accessory control unit 4003. Note that the fourth voltage of the second voltage monitoring unit 4012 is lower than the third voltage of the first voltage monitoring unit 4010.

[0103] FIG. 3B is a block diagram illustrating the configuration of the off-camera adapter 410 of this embodiment.

[0104] The off-camera adapter 410 and the accessory distributor 420 connect the digital camera 100 to the accessory device 400 and other accessory devices.

[0105] In this embodiment, an example will be described in which the sub-accessories are the off-camera adaptor 410 and the accessory distributor 420, but the sub-accessories are not limited to these examples and may be devices having other functions.

[0106] The off-camera adapter 410 includes a camera connection portion 4101 and an accessory connection portion 4102 .

[0107] The off-camera adapter 410 allows the accessory device 400 to be moved to a location away from the accessory connector 140 while still connected to the digital camera 100, improving the freedom of photography.

[0108] The camera connection unit 4101 is an interface that is connected to the accessory connection unit 140 of the digital camera 100 and can exchange power and information with the digital camera 100 .

[0109] The accessory connection unit 4102 is connected to the camera connection unit 4001 of the accessory device 400 , and is an interface capable of transmitting and receiving power and information to and from the accessory device 400 .

[0110] The off-camera adapter control unit 4103 includes a microcontroller including a processor such as a CPU, memories such as a ROM and a RAM, a controller, and peripheral circuits. The off-camera adapter control unit 4103 controls each component of the off-camera adapter 410 by executing a program stored in the memory. Note that instead of the off-camera adapter control unit 4103 controlling the entire device, the entire device may be controlled by multiple hardware devices sharing the processing. Note that the off-camera adapter control unit 4103 may be configured only with a memory that stores information. In this case, the main control unit 101 or the sub control unit 108 of the digital camera 100, or the accessory control unit 4003 of the accessory device 400 acquires accessory device information from the off-camera adapter 410.

[0111] FIG. 3C is a block diagram illustrating the configuration of the accessory distributor 420 of this embodiment.

[0112] The accessory distributor 420 comprises a camera connection section 4201 , a first accessory connection section 4202 and a second accessory connection section 4203 .

[0113] The accessory distributor 420 of this embodiment allows a plurality of (eg, two) accessory devices to be connected to a single accessory connection unit 140.

[0114] The camera connection unit 4201 is an interface that is connected to the accessory connection unit 140 of the digital camera 100 and can exchange power and information with the digital camera 100 .

[0115] The first accessory connection unit 4202 and the second accessory connection unit 4203 are connected to the camera connection unit 4001 of the accessory device 400, and are interfaces capable of exchanging power and information with the accessory device 400.

[0116] The distributor control unit 4204 includes a microcontroller including a processor such as a CPU, memories such as a ROM and a RAM, a controller, and peripheral circuits. The distributor control unit 4204 controls each component of the accessory distributor 420 by executing a program stored in the memory. Note that instead of the distributor control unit 4204 controlling the entire device, the entire device may be controlled by multiple hardware devices sharing the processing. Note that the distributor control unit 4204 may be configured only with a memory that stores information. In this case, the main control unit 101 or the sub control unit 108 of the digital camera 100, or the accessory control unit 4003 of the accessory device 400 acquires accessory device information from the accessory distributor 420.

[0117] [Embodiment 1] The control processes of the digital camera 100 and the accessory device 400 in the first embodiment will be described below with reference to FIGS. 4A, 4B, 5, 6 and 11.

[0118] In the first embodiment, a process will be described in the case where a power adapter 200 or an accessory device 400 is attached or detached while a battery 300 is connected to a digital camera 100.

[0119] 4A and 4B are flowcharts showing the control process of the digital camera 100 of the first embodiment.

[0120] The processing in Figures 4A and 4B is realized by main control unit 101 of digital camera 100 loading a program stored in non-volatile memory 103 into working memory 104, executing it, and controlling each component of digital camera 100. The same applies to Figures 8A and 8B described below. The processing in Figures 4A and 4B is started when digital camera 100 is powered on with battery 300 connected to battery connection unit 130 of digital camera 100.

[0121] First, the power supply state at the start of the process in FIG. 4A will be described with reference to FIG. 6(a).

[0122] Digital camera 100 has a first power source, a second power source, and a third power source. The first power source is a power adapter 200 connected via an external power source connector 120. The second power source is a battery 300 connected via a battery connector 130. The third power source is a DC coupler 301 connected via the battery connector 130.

[0123] 4A, the digital camera 100 is supplied with power from the battery 300 via the battery connector 130. The power adapter 200 is not connected to the external power connector 120, and the input control unit 1102 is in an off state.

[0124] Digital camera 100 has a first path that passes through power supply control unit 109 and a second path that does not pass through power supply control unit 109 but passes through second power supply control unit 111 as paths for supplying power to accessory connection unit 140.

[0125] 4A, the accessory device 400 is not connected to the accessory connection unit 140, and therefore the digital camera 100 is not supplying power to the accessory device 400. Therefore, both the first power supply control unit 1092 and the second power supply control unit 111 are in the off state.

[0126] In the following description, it is assumed that an external power supply device conforming to the USBPD standard is connected to the external power supply connection unit 120.

[0127] In step S401, device information acquisition unit 1101 determines whether or not power adapter 200 is connected to external power connection unit 120.

[0128] When the user connects first connection unit 201 of power adapter 200 to external power connection unit 120, device information acquisition unit 1101 determines that power adapter 200 is connected to external power connection unit 120, and proceeds to step S402. When device information acquisition unit 1101 determines that power adapter 200 is not connected to external power connection unit 120, it proceeds to step S405.

[0129] In step S402, device information acquisition unit 1101 determines the function of power adapter 200 connected to external power connection unit 120, and proceeds to step S403. Device information acquisition unit 1101 determines, for example, which version of the USBPD standard power adapter 200 complies with.

[0130] In step S403, device information acquisition unit 1101 requests power from power adapter 200, and proceeds to step S404. For example, device information acquisition unit 1101 performs CC communication with power adapter 200 based on the USBPD standard, and selects one of a plurality of power profiles of power adapter 200 based on the USBPD standard.

[0131] In this process, the sub-control unit 108 communicates with the device information acquisition unit 1101 and selects an efficient voltage / current profile that is necessary for the steady operation of the digital camera 100. For example, the required voltage for the power adapter 200 (hereinafter also referred to as the VBUS voltage) is 9 V, which is close to the voltage of the battery 300.

[0132] In step S404, the device information acquisition unit 1101 turns on the input control unit 1102 and starts receiving power from the external power supply connection unit 120. When the receiving voltage monitoring unit 1105 monitors the voltage and confirms the reception of power from the external power supply connection unit 120, the sub-control unit 108 advances the process to step S405.

[0133] When this process is complete, the digital camera 100 is ready to operate using the power received by the external power connection unit 120 from the power adapter 200 .

[0134] In step S405, the accessory determination unit 1082 determines whether or not the accessory device 400 is connected to the accessory connection unit 140. Due to the configurations of the accessory connection unit 140 and the camera connection unit 4001, the digital camera 100 and the accessory device 400 can determine the connection without communicating with each other.

[0135] The accessory device 400 can also be connected to the accessory connection section 140 via a sub-accessory such as an off-camera adapter 410 or an accessory splitter 420 .

[0136] If the accessory determination unit 1082 determines that the accessory device 400 is connected to the accessory connection unit 140, the process proceeds to step S406, and if it determines that the accessory device 400 is not connected, the process returns to step S401.

[0137] In step S406, the main control unit 101 or the sub control unit 108 turns on the first power supply control unit 1092 and starts supplying power to the accessory connection unit 140 via the first path. Since the first path passes through the voltage conversion unit 1091, the voltage of the power supplied to the accessory connection unit 140 is equivalent to the voltage of the power supply required by each component of the digital camera 100. In this embodiment, the voltage of the power supplied from the first path to the accessory connection unit 140 is 3.3V.

[0138] Note that the voltage of the power received from power adapter 200 (VBUS voltage) is close to the voltage of battery 300 (9 V), so the amount of heat generated due to loss in voltage conversion in power receiving voltage converter 1103 of power receiving control unit 110 is small. Therefore, the heat generated by digital camera 100 is dominated by heat generated due to loss in voltage conversion in voltage converter 1091.

[0139] At the completion of this process, as shown in FIG. 6(b), the input control section 1102 is in the ON state, the first power supply control section 1092 is in the ON state, and the second power supply control section 111 is in the OFF state.

[0140] The power source for supplying power to accessory connection unit 140 is at least one of power adapter 200 and battery 300. If it is determined in step S401 that power adapter 200 is connected to external power connection unit 120, input control unit 1102 is in the on state.

[0141] When the main control unit 101 or the sub-control unit 108 turns on the first path passing through the power supply control unit 109, the process proceeds to step S407.

[0142] In step S407, the accessory determination unit 1082 communicates with the accessory communication control unit 4004 and determines whether the accessory device 400 is activated. If the accessory determination unit 1082 determines that the accessory device 400 is activated, the process proceeds to step S408. If the accessory determination unit 1082 determines that the accessory device 400 is not activated, the process of step S407 is repeated. However, if the accessory determination unit 1082 continues to be unable to communicate with the accessory communication control unit 4004 for a certain period of time, a timeout process may be performed. As the timeout process, for example, the main control unit 101 may notify the user via the display unit 106 that the accessory device 400 is not activated and prompt the user to reattach the accessory device 400.

[0143] Moreover, it is preferable that the main control unit 101 or the sub-control unit 108 turn off the first power supply control unit 1092 and return the process to step S401.

[0144] In step S408, the accessory determination unit 1082 communicates with the accessory communication control unit 4004 and acquires type information of all connected devices. The accessory determination unit 1082 determines whether the connected device is a main accessory such as the accessory device 400 or a sub-accessory such as the off-camera adapter 410 based on the type information. In step S408, the accessory determination unit 1082 acquires device information of the main accessory.

[0145] The communication method in this embodiment is I2C communication in which the digital camera 100 serves as the host and the accessory device 400 serves as the slave.

[0146] The accessory device 400 has a register that stores connected device information. The correspondence between the storage locations of this register and the information items stored in each storage location is determined in advance. Therefore, in communication with the accessory device 400, the digital camera 100 can acquire necessary information from the accessory device 400 by specifying the storage location of the register in which the necessary information is stored.

[0147] In this process, if a sound collection device such as a microphone other than the accessory device 400 is connected to the digital camera 100 by the accessory distributor 420, information is also acquired from that sound collection device.

[0148] When the accessory determination unit 1082 acquires the information on the accessory device 400, the process proceeds to step S409.

[0149] In step S409, the accessory determination unit 1082 acquires device information of the sub-accessory determined to be the sub-accessory. In step S409, the accessory determination unit 1082 communicates with the off-camera adapter control unit 4103 or the distributor control unit 4204 to acquire device information of the off-camera adapter 410 or the accessory distributor 420.

[0150] If a sub-accessory such as the off-camera adapter 410 or the accessory distributor 420 is not connected to the accessory connection unit 140, the process in step S409 is not performed.

[0151] The communication method in this embodiment is I2C communication in which the digital camera 100 serves as the host and the off-camera adapter 410 or the accessory distributor 420 serves as the slave.

[0152] The off-camera adapter 410 or the accessory distributor 420 has a register for storing device information. The correspondence between the storage locations of this register and the information items stored in each storage location is determined in advance. Therefore, in communication with the accessory device 400, the digital camera 100 can acquire necessary information by specifying the storage location of the register in which the necessary information is stored.

[0153] When multiple sub-accessories such as the off-camera adapter 410 or the accessory distributor 420 are connected, information is also obtained from the other sub-accessories.

[0154] When accessory determination unit 1082 acquires the device information of off-camera adapter 410 or accessory distributor 420, the process proceeds to step S410.

[0155] Note that the order of obtaining device information by the accessory determination unit 1082 in steps S409 and S410 is not limited to that shown in the figure, and for example, the order of steps S409 and S410 may be reversed.

[0156] Furthermore, the accessory determination unit 1082 may acquire device information about devices connected to the accessory connection unit 140 in ascending order of distance from the digital camera 100, regardless of the type information of the accessory device.

[0157] In step S410, the main control unit 101 or the sub-control unit 108 determines a voltage (required voltage, hereinafter also referred to as ACC voltage) to be supplied to the accessory device 400 connected to the accessory connection unit 140 based on the connected device information acquired in steps S408 and S409. Here, the ACC voltage is set so as not to exceed the rated voltages of all devices connected to the accessory connection unit 140. For example, when one accessory device 400 is connected to the accessory connection unit 140, the main control unit 101 or the sub-control unit 108 sets the rated voltage of the accessory device 400 to the ACC voltage based on the accessory information.

[0158] Here, an example in which the accessory device 400 is connected via the off-camera adapter 410 will be described.

[0159] In this case, since the same voltage is applied to the power supply path from the digital camera 100, the ACC voltage is determined so as not to exceed the rated voltage of any of the devices connected to the digital camera 100.

[0160] In this embodiment, for the sake of simplicity, the rated currents of the first path, the second path, the accessory device 400, etc. are assumed to be the same. Also, when the digital camera 100 sets the power to be supplied or received, it is assumed that the voltage can be changed, and the magnitude relationship of the power is assumed to be the same as the magnitude relationship of the voltage.

[0161] When the rated current differs for each connected device, the current supplied to the accessory device is determined by the rated current for each connected device and the connection state of the sub-accessory, as with the rated voltage. For example, when the accessory distributor 420 is connected, the power supply path from the digital camera 100 is split into multiple paths. The current supplied to the accessory device is set so as not to exceed the rated current of all devices connected to each of the multiple split power supply paths.

[0162] When determining the voltage to be supplied to the accessory device 400, the voltage may be determined based on the model name, functions, etc. of the accessory device in addition to the rated voltage. For example, assume that the accessory device 400 is connected to the digital camera 100 via an off-camera adapter 410. In this case, when the rated voltage of the off-camera adapter 410 is low relative to the power consumption in an operation mode that requires the greatest power among a plurality of operation modes of the accessory device 400, the rated voltage of the off-camera adapter 410 is determined as the ACC voltage.

[0163] In this way, when a voltage corresponding to some of the operation modes of the accessory device 400 is determined as the ACC voltage, a notification may be given to the user via the display unit 106 to urge the user to remove the off-camera adapter 410. Alternatively, a notification may be given that some of the functions of the accessory device 400 are restricted by the off-camera adapter 410.

[0164] Consider a case where multiple devices with different rated voltages are connected by the accessory distributor 420. In this case, the operation mode or use of one of the connected devices may be restricted. In such a case, a notification may be given to the user via the display unit 106 to urge the user to remove the accessory distributor 420. Alternatively, a notification may be given that some of the functions of the devices connected via the accessory distributor 420 will be restricted.

[0165] In this way, even if a single accessory device 400 or multiple accessory devices 400 with different rated voltages are connected to the digital camera 100, it is possible to supply power within a range that does not exceed the rated voltage of the accessory device 400.

[0166] When the main control unit 101 or the sub control unit 108 determines the ACC voltage, the process proceeds to step S411.

[0167] In step S411, the main control unit 101 or the sub-control unit 108 determines whether or not the ACC voltage determined in step S410 is higher than a predetermined voltage (3.3 V).

[0168] The predetermined voltage of 3.3 V is equivalent to the voltage required for the operation of each component of digital camera 100. This predetermined voltage of 3.3 V is converted by voltage conversion unit 1091 and is supplied from first power supply control unit 1092 to accessory connection unit 140.

[0169] If the main control unit 101 or the sub-control unit 108 determines that the ACC voltage is higher than the predetermined voltage (3.3 V), it proceeds to step S412; if it determines that the ACC voltage is lower than or equal to the predetermined voltage (3.3 V), it proceeds to step S424.

[0170] In step S412, the power receiving control unit 110 determines whether or not the digital camera 100 is receiving power from the power adapter 200 via the external power connection unit 120. If the power receiving control unit 110 determines that the digital camera 100 is receiving power from the power adapter 200 via the external power connection unit 120, the process proceeds to step S413, and if the power receiving control unit 110 determines that the digital camera 100 is not receiving power, the process proceeds to step S429.

[0171] In step S413, the main control unit 101 or the sub-control unit 108 compares the VBUS voltage with the ACC voltage. If the main control unit 101 or the sub-control unit 108 determines that the VBUS voltage and the ACC voltage are equivalent, the process proceeds to step S422. If the main control unit 101 or the sub-control unit 108 determines that the VBUS voltage and the ACC voltage are not equivalent, the process proceeds to step S414.

[0172] In step S414, the main control unit 101 or the sub-control unit 108 compares the VBUS voltage with the ACC voltage. If the main control unit 101 or the sub-control unit 108 determines that the ACC voltage is higher than the VBUS voltage (for example, the VBUS voltage is 9 V and the ACC voltage is 15 V), the process proceeds to step S415. If the main control unit 101 or the sub-control unit 108 determines that the ACC voltage is equal to or lower than the VBUS voltage (for example, the VBUS voltage is 9 V and the ACC voltage is 5 V), the process proceeds to step S420.

[0173] In step S415, device information acquisition unit 1101 determines whether the voltage (VBUS voltage) requested of power adapter 200 in step S403 can be changed to the ACC voltage.

[0174] Device information acquisition unit 1101 communicates with power adapter 200 via external power connection unit 120 and checks the power profile based on the USBPD standard. If device information acquisition unit 1101 determines that the power profile indicating the voltage and current that power adapter 200 can supply includes a voltage that is the same as the ACC voltage, it proceeds to step S416. If device information acquisition unit 1101 determines that the power profile of power adapter 200 does not include a voltage that is the same as the ACC voltage, it proceeds to step S417.

[0175] In step S416, device information acquisition section 1101 selects a voltage equivalent to the ACC voltage from the power profile of power adapter 200 and requests power adapter 200 to supply the voltage.

[0176] This process is performed when the voltage that the digital camera 100 receives from the power adapter 200 is lower than the voltage to be supplied to the accessory device 400. Therefore, the digital camera 100 performs a process to request the power adapter 200 to supply a voltage equivalent to the ACC voltage, which is higher than the current receiving voltage. The device information acquisition unit 1101 requests the power adapter 200 to change the power. For example, if the voltage to be supplied to the accessory device 400 is 15V, the device information acquisition unit 1101 requests 15V from the power adapter 200. When the power adapter 200 receives the request to change the power from the digital camera 100, it performs a process to change the voltage to be output to the digital camera 100 to the voltage requested by the digital camera 100. When the receiving voltage monitoring unit 1105 detects that the VBUS voltage is the voltage requested to be changed, it notifies the sub-control unit 108 of the fact and proceeds to step S422.

[0177] In step S417, the accessory determination unit 1082 determines, based on the accessory device information acquired in step S409, whether or not the accessory device 400 has a function for charging the accessory battery 4009. In this embodiment, since the accessory device 400 includes the accessory battery 4009, it is determined whether or not the accessory device 400 has a function for charging the accessory battery 4009.

[0178] When the accessory device 400 has a function of charging the accessory battery 4009, the accessory control unit 4003 stops charging the accessory battery 4009 by the accessory charging / discharging control unit 4008, thereby reducing power consumption of the accessory device 400.

[0179] In this embodiment, the accessory device 400 becomes operable at the VBUS voltage (9V) by stopping charging of the accessory battery 4009. In this way, when the accessory device 400 can stop charging of the accessory battery 4009, it becomes possible to operate at the VBUS voltage (9V) supplied from the power adapter 200 to the digital camera 100.

[0180] If the accessory device 400 does not have a function for stopping charging of the accessory battery 4009, it can be determined that the power required to operate the accessory device 400 is insufficient with the VBUS voltage.

[0181] In a broader sense, this process determines whether or not the accessory device has a low-load mode in which power consumption is reduced by restricting some functions, in addition to a mode in which all functions are permitted.

[0182] When the low load mode is provided, even if the ACC voltage cannot be supplied to the accessory device 400, the accessory device 400 can use some of its functions by supplying a voltage lower than the ACC voltage.

[0183] If the accessory determination unit 1082 determines that the accessory device 400 has a function for charging the accessory battery 4009, the process proceeds to step S418. If the accessory determination unit 1082 determines that the accessory device 400 does not have a function for charging the accessory battery 4009, the process proceeds to step S429.

[0184] In this way, even if the power that can be supplied from the digital camera 100 to the accessory device 400 is less than the maximum power required by the accessory device 400, the digital camera 100 can supply as much power as it can, as necessary.

[0185] In step S418, the main control unit 101 or the sub-control unit 108 communicates with the accessory communication control unit 4004 and performs charging prohibition processing to prevent charging of the accessory battery 4009.

[0186] In the accessory device 400 , the accessory control unit 4003 sends a control signal to the accessory charge / discharge control unit 4008 to stop the charging function of the accessory battery 4009 .

[0187] When the charging inhibition process for the accessory battery 4009 of the accessory device 400 is completed, the accessory communication control unit 4004 sends a notification to the main control unit 101 or the sub-control unit 108 that the charging inhibition process for the accessory battery 4009 has been completed.

[0188] When the accessory determination unit receives a notification from the accessory device 400 that the charging inhibition process for the accessory battery 4009 has been completed, the main control unit 101 or the sub-control unit 108 advances the process to step S419.

[0189] In step S419, the main control unit 101 notifies the user via the display unit 106 that the accessory battery 4009 cannot be charged, and proceeds to step S422. The main control unit 101 performs a notification such as a screen 1131 in FIG. 11(a) via the display unit 106, for example.

[0190] In step S420, the main control unit 101 notifies the user via the display unit 106 to select whether or not to permit the accessory device 400 to use the high load mode, and proceeds to step S422. In this case, for example, the accessory device 400 has a charging function and requires 5V for the charging function, but may not be able to receive 9V due to the rated voltage of the accessory device 400.

[0191] In this case, it is possible to either not use the charging function of the accessory device 400 or to change the power supply to 5 V in order to use the charging function. If 5 V is supplied to the accessory device 140 via the second path in order to use the charging function, the voltage received from the external power supply connector 120 needs to be 5 V.

[0192] In such a case, for example, the digital camera 100 may operate in such a way that the power used by the digital camera 100 is supplied by taking power from the battery 300. As a result, even if the power adapter 200 is connected to the digital camera 100, the remaining capacity of the battery 300 may be consumed unintentionally. In this way, in order to prevent the remaining capacity of the battery 300 from being consumed against the user's intention, the main control unit 101 issues a notification such as a screen 1132 in FIG. 11(b) via the display unit 106. Then, if the user selects the "Yes" button 1132a on the screen 1132 in FIG. 11(b), the main control unit 101 advances the process to step S421, and if the user selects the "No" button 1132b, the main control unit 101 advances the process to step S424.

[0193] In step S421, device information acquiring section 1101 requests a voltage equivalent to the ACC voltage from the power profile of power adapter 200. Here, since the ACC voltage is 5V, 5V is requested from power adapter 200.

[0194] This process is performed when the voltage that the digital camera 100 receives from the power adapter 200 is higher than the voltage that it supplies to the accessory device 400. In this case, if the digital camera 100 supplies the voltage that it receives from the power adapter 200 to the accessory device 400 through the second path without voltage conversion, the rated voltage of the accessory device 400 will be exceeded. Therefore, the digital camera 100 performs a process of requesting the power adapter 200 to provide a voltage equivalent to the ACC voltage, which is lower than the current receiving voltage. The device information acquisition unit 1101 requests the power adapter 200 to change the power. When the power adapter 200 receives the request for power change from the digital camera 100, it performs a process of changing the voltage that it outputs to the digital camera 100 to the voltage requested by the digital camera 100. When the receiving voltage monitoring unit 1105 detects that the VBUS voltage is the voltage requested to be changed, it notifies the sub-control unit 108 of the fact and the process proceeds to step S422.

[0195] In step S422, the sub-control unit 108 turns on the second power supply control unit 111 to start supplying power to the accessory connection unit 140 via a second path that does not pass through the power supply control unit 109, and proceeds to step S423.

[0196] Since the second path does not pass through voltage conversion unit 1091 of power supply control unit 109, the voltage of the power supplied to accessory connection unit 140 is equivalent to the voltage of the power received from external power supply connection unit 120. As described above, the voltage received from power adapter 200 is an optimal voltage for accessory device 140 through the processes of steps S414 to S421.

[0197] The second path can minimize loss due to voltage conversion since it does not pass through the voltage conversion unit 1091. Therefore, the amount of heat generated when power is supplied from the digital camera 100 to the accessory device 400 can be reduced.

[0198] At the completion of this process, as shown in FIG. 6(c), the input control section 1102 is in the ON state, the first power supply control section 1092 is in the ON state, and the second power supply control section 111 is in the ON state.

[0199] The power source for the electric power supplied by the digital camera 100 to the accessory connector 140 is at least one of a power adapter 200 and a battery 300.

[0200] Since the voltage (5V, 9V, 12V) of the power supplied from the second path to accessory connection unit 140 is higher than the voltage (3.3V) of the power supplied from the first path, the power from the second path is prioritized over the power from the first path. Furthermore, the remaining power, which is obtained by subtracting the power supplied from the second path to accessory connection unit 140, from the power supplied from power adapter 200, is supplied to power control unit 109 of the first path, where it is voltage converted in voltage conversion unit 1091 and supplied to each component of digital camera 100. In this case, the power supplied to power control unit 109 is sufficiently smaller than the power supplied from the second path, so that the amount of heat generated due to loss in voltage conversion in voltage conversion unit 1091 is small enough not to affect the heat generation of digital camera 100.

[0201] In step S423, the sub-control unit 108 notifies the accessory communication control unit 4004 that the process of changing the voltage to be output to the accessory device 400 to the ACC voltage has been completed, and the process proceeds to step S424.

[0202] In step S424, the accessory communication control unit 4004 determines whether or not the accessory device 400 is connected to the accessory connection unit 140. In this process, if the accessory device 400 is removed from the digital camera 100 while power is being supplied from the digital camera 100 to the accessory device 400, the accessory determination unit 1082 determines that the accessory device 400 is not connected to the accessory connection unit 140. If the accessory communication control unit 4004 determines that the accessory device 400 is not connected to the accessory connection unit 140, it advances the process to step S425. If the accessory communication control unit 4004 determines that the accessory device 400 is connected to the accessory connection unit 140, it advances the process to step S427.

[0203] In step S425, the sub-control unit 108 turns off the second power supply control unit 111, stops the power supply to the accessory connection unit 140 via the second path that does not pass through the power supply control unit 109, and proceeds to step S424.

[0204] In step S426, the main control unit 101 or the sub-control unit 108 turns off the first power supply control unit 1092, stops the power supply to the accessory connection unit 140 via the first path via the power supply control unit 109, and returns the process to step S401.

[0205] In step S427, device information acquisition unit 1101 determines whether power adapter 200 has been changed from a connected state to a disconnected state, that is, whether power adapter 200 is connected to external power connection unit 120 or not.

[0206] Here, if it is determined in step S401 that power adapter 200 is not connected, power adapter 200 remains in a disconnected state, so it is not determined that the state has changed from connected to disconnected, and processing proceeds to step S424.

[0207] Furthermore, if it is determined in step S401 that the power adapter 200 is connected, when the processing of step S423 is completed, the digital camera 100 is supplying power to the accessory device 400 based on the power received from the power adapter 200.

[0208] In this state, if the power adapter 200 is removed from the digital camera 100, it may become impossible to supply sufficient power to the accessory device 400. Therefore, when the power adapter 200 is removed from the digital camera 100, the power supply to the accessory device 400 needs to be stopped.

[0209] If device information acquisition unit 1101 determines that power adapter 200 has been changed from a connected state to a disconnected state, it proceeds to processing step S428, and if it determines that it has not been changed, it returns the process to step S424.

[0210] In step S428, the sub-control unit 108 turns off the second power supply control unit 111 to stop the power supply to the accessory connection unit 140 through the second path, and advances the process to step S429.

[0211] In step S429, the main control unit 101 notifies the user via the display unit 106 to prompt the user to connect an appropriate power adapter 200 to the digital camera 100, and returns the process to step S401. The main control unit 101 notifies the user via the display unit 106, for example, as shown on a screen 1133 in FIG. 11(c).

[0212] FIG. 5 is a flowchart showing the control process of the accessory device 400 according to the first embodiment.

[0213] 5 is realized by the accessory control unit 4003 of the accessory device 400 executing a program stored in the memory and controlling each component of the accessory device 400. The process of FIG. 5 is started when the accessory device 400 is connected to the digital camera 100.

[0214] In step S501, the second voltage monitoring unit 4012 monitors the voltage of the power supplied from the digital camera 100 to the camera connection unit 4001. The second voltage monitoring unit 4012 waits until it determines that the voltage of the power supplied from the digital camera 100 to the camera connection unit 4001 has become equal to or higher than a fourth voltage, and if it determines that the voltage has become equal to or higher than the fourth voltage, the process proceeds to step S502. The fourth voltage is, for example, 2.7V.

[0215] The second voltage monitoring unit 4012 determines whether or not the accessory device 400 is receiving enough power to activate the accessory control unit 4003. For example, when step S406 in Fig. 4A is completed, the camera connection unit 4001 receives 3.3V, and therefore the accessory control unit 4003 is in a state where it can be activated.

[0216] In step S502, the accessory communication control unit 4004 notifies the digital camera 100 that the accessory device 400 has started up, and the process proceeds to step S503. This process corresponds to step S407 in FIG. 4A.

[0217] In step S503, the accessory communication control unit 4004 communicates with the accessory determination unit 1082, sends information about the accessory device 400, and the process proceeds to step S504. This process corresponds to step S408 in Fig. 4A.

[0218] In step S504, the accessory control unit 4003 determines whether or not it is possible to increase the power supplied from the digital camera 100 via the camera connection unit 4001. For example, as in step S423 in Fig. 4B, when the accessory communication control unit 4004 receives a power change completion notification from the digital camera 100, it can determine that it is possible to increase the power.

[0219] If the accessory control unit 4003 determines that the power supplied from the digital camera 100 can be increased, the process proceeds to step S506; if it determines that the power cannot be increased, the process proceeds to step S505.

[0220] In step S505, the accessory control unit 4003 operates the accessory device 400 in the low-load mode, and the process proceeds to step S511. The accessory control unit 4003 prohibits the accessory device 400 from operating while charging the accessory battery 4009, for example, by instructing the accessory charging / discharging control unit 4008 to stop charging control.

[0221] In step S506, the first voltage monitoring unit 4010 monitors the voltage of the power supplied from the digital camera 100 to the camera connection unit 4001. If the first voltage monitoring unit 4010 determines that the voltage of the power supplied from the digital camera 100 is equal to or higher than the third voltage, the process proceeds to step S507. The third voltage is, for example, 3.3V to 15V.

[0222] In this process, the accessory control unit 4003 determines whether the accessory device 400 receives enough power to use the high load mode. For example, when step S422 in FIG. 4B is completed, the camera connection unit 4001 may receive a voltage higher than 3.3V.

[0223] In step S507, the accessory control unit 4003 permits the high load mode of the accessory device 400, and the process proceeds to step S508. For example, by instructing the accessory charge / discharge control unit 4008 to permit charging control, it becomes possible for the accessory device 400 to operate while charging the accessory battery 4009. Other examples of the high load mode include permission to use an accessory type with high power consumption characteristics, permission to use multiple accessories in the accessory distributor 420, and the like, and are not limited to permission to the charging function.

[0224] In step S508, the first voltage monitoring unit 4010 monitors the voltage of the power supplied from the digital camera 100 to the camera connection unit 4001. If the first voltage monitoring unit 4010 determines that the voltage of the power supplied from the digital camera 100 has become less than the third voltage, the process proceeds to step S509.

[0225] For simplicity of explanation, in this embodiment, the thresholds in steps S506 and S508 are the same value as the third voltage, but in practice, it is desirable to provide a hysteresis voltage (for example, about 0.2 V) to prevent chattering.

[0226] In step S509, the accessory control unit 4003 stops the high load mode of the accessory device 400, and proceeds to step S510. The accessory control unit 4003 stops the operation of the accessory device 400 while charging the accessory battery 4009, for example, by instructing the accessory charging / discharging control unit 4008 to stop charging control.

[0227] In this way, even if the power supply required for the high load mode from the digital camera 100 is stopped, the accessory device 400 can be used continuously by switching to the low load mode.

[0228] In step S510, the accessory communication control unit 4004 notifies the digital camera 100 that the high load mode has been stopped, and the process proceeds to step S511.

[0229] In step S 511 , the second voltage monitoring unit 4012 monitors the voltage of the power supplied from the digital camera 100 to the camera connection unit 4001 .

[0230] If the second voltage monitoring unit 4012 determines that the voltage of the power supplied from the digital camera 100 is less than the fourth voltage, the accessory communication control unit 4004 advances the process to step S512. If the second voltage monitoring unit 4012 determines that the voltage of the power supplied from the digital camera 100 is equal to or greater than the fourth voltage, the accessory communication control unit 4004 returns the process to step S505.

[0231] In step S512, the accessory control unit 4003 stops the operation of the accessory device 400, and ends the process.

[0232] Next, an example of the operation of the digital camera 100 and the accessory device 400 in the first embodiment will be described with reference to FIG.

[0233] Note that the operation shown in FIG. 7 is just an example, and the digital camera 100 and the accessory device 400 can operate appropriately in response to user operations.

[0234] In T701, first connector 201 of power adapter 200 is connected to digital camera 100. Here, the voltage supplied from power adapter 200 to digital camera 100 is, for example, 5 V. The operation of T701 corresponds to step S401 in FIG. 4A.

[0235] In T702, the digital camera 100 communicates with the power adapter 200 and requests a voltage from the power adapter 200. Here, for example, 9 V is requested from the power adapter 200 and 9 V is received from the power adapter 200. The operation of T702 corresponds to steps S403 and S404 in FIG. 4A.

[0236] In T703, the accessory device 400 is connected to the digital camera 100. The operation of T703 corresponds to step S405 in Fig. 4A.

[0237] The digital camera 100 detects the connection of the accessory device 400 , turns on the first power supply control unit 1092 , and power is supplied from the digital camera 100 to the accessory device 400 .

[0238] At T704, when the power supply voltage of the accessory device 400 becomes equal to or higher than a fourth voltage (for example, 2.6 V), the accessory device 400 becomes able to communicate with the digital camera 100. The operation at T704 corresponds to step S501 in Fig. 5. The accessory device 400 operates in the low-load mode.

[0239] The voltage of the power supplied from the digital camera 100 to the accessory device 400 is, for example, 3.3 V. This is a voltage that can be commonly supplied to each component of the digital camera 100.

[0240] When a predetermined voltage is supplied to the accessory device 400, the accessory device 400 notifies the digital camera 100 that it has started up.

[0241] Next, digital camera 100 communicates with accessory device 400 and determines the voltage (ACC voltage) to be supplied to accessory device 140. Then, digital camera 100 communicates with power adapter 200 and requests (req) power adapter 200 to change the voltage. Power adapter 200 transmits to digital camera 100 that it has accepted the request (accept), and changes the voltage of the power to be supplied to digital camera 100.

[0242] In T705, when the change to the requested voltage is completed, power adapter 200 transmits a completion notification (PS_RDY) to digital camera 100. In T706, digital camera 100 waits for a voltage change completion notification (PS_RDY) from power adapter 200, and turns on second power supply control unit 111. The above operations from T704 to T706 correspond to step S416 in FIG. 4B. Also, the operation of T706 corresponds to step S422 in FIG. 4B.

[0243] Here, the voltage that the digital camera 100 receives from the power adapter 200 and the voltage supplied from the second power supply control unit 111 to the accessory device 400 are equal, for example 15 V. This is the voltage that the power adapter 200 that complies with the USBPD standard can output. Note that this voltage is a voltage that can be supplied to the accessory device 400 and the digital camera 100, and is a voltage that allows all operations of the accessory device 400 even if the current to the accessory connection unit 140 is limited.

[0244] Thereafter, the digital camera 100 sends a notification to the accessory device 400 that the voltage change has been completed.

[0245] In T707, the accessory device 400 receives a notification of completion of the voltage change from the digital camera 100, and when the voltage received by the accessory device 400 becomes equal to or higher than the third voltage, the accessory device 400 transitions to the high load mode. The operation of T707 corresponds to step S507 in FIG.

[0246] In T708, the power adapter 200 is removed from the digital camera 100 while the accessory device 400 is operating in the high load mode, and power supply from the power adapter 200 to the accessory device 400 is stopped. The operation of T708 corresponds to step S427 in FIG. 4B.

[0247] In T709, when the voltage received from the digital camera 100 falls below the third voltage, the accessory device 400 stops the high load mode and transitions to the low load mode. The operation of T709 corresponds to step S509 in FIG.

[0248] After switching to the low-load mode, the accessory device 400 notifies the digital camera 100 that it has stopped the high-load mode.

[0249] At T710, the digital camera 100 turns off the second power supply control unit 111. The operation at T710 corresponds to step S428 in FIG. 4B.

[0250] In T711, the accessory device 400 is removed from the digital camera 100. The operation of T711 corresponds to step S424 in Fig. 4B.

[0251] When the digital camera 100 detects that the accessory device 400 has been removed, it turns off the first power supply control unit 1092 .

[0252] At T712, the accessory device 400 stops operating when the voltage received from the digital camera 100 falls below the fourth voltage. The operation at T712 corresponds to steps S511 and S512 in FIG.

[0253] As described above, according to the first embodiment, the power adapter 200 and the accessory device 400 are connected to the digital camera 100, and power supplied from the power adapter 200 is supplied to the accessory device 400 at a first voltage via a first path that passes through the voltage conversion unit 1091. Then, when the voltage supplied from the power adapter 200 is changed to a second voltage higher than the first voltage, power supplied from the power adapter 200 is supplied to the accessory device 400 at the second voltage via a second path that does not pass through the voltage conversion unit 1091. This makes it possible to supply a large amount of power to the accessory device 400 while reducing the amount of heat generated when power is supplied from the digital camera 100 to the accessory device 400.

[0254] [Embodiment 2] Next, control processing of the digital camera 100 and the accessory device 400 in the second embodiment will be described with reference to FIGS. 8A, 8B, 9, 10 and 11. FIG.

[0255] In the second embodiment, a process will be described in the case where an accessory device 400 is attached to or detached from the digital camera 100 when a DC coupler 301 is connected to the battery connector 130 of the digital camera 100.

[0256] The second embodiment assumes that a DC coupler 301 is attached to the digital camera 100 instead of a battery 300, and the power adapter 200 is not connected. In the second embodiment, when an accessory device 400 is connected to the digital camera 100, the power source for supplying power from the digital camera 100 to the accessory device 400 is the DC coupler 301.

[0257] The configurations of the digital camera 100 and the accessory device 400 of the second embodiment are the same as those in Fig. 1 to Fig. 3. The operation of the accessory device 400 of the second embodiment is the same as that in Fig. 5.

[0258] The receiving voltage conversion unit 1103 has a function of switching the output direction of the power supplied from the battery 300 or DC coupler 301 via the battery connection unit 130. This is a function called an OTG (ON THE GO) function or a reverse function that directly connects devices conforming to the USB standard to each other. The receiving voltage conversion unit 1103 switches the output direction of the power supplied from the battery 300 or DC coupler 301 to a first direction that is a first path or a second direction that is a second path, based on the control of the sub-control unit 108.

[0259] 8A and 8B are flowcharts showing the processing of the digital camera 100 of the second embodiment.

[0260] First, the power supply state at the start of the process in FIG. 8A will be described with reference to FIG. 9(a).

[0261] The digital camera 100 has a third power supply. The third power supply is a DC coupler 301 connected via the battery connector 130.

[0262] 8A starts, power is supplied to the digital camera 100 from the DC coupler 301 via the battery connection unit 130. The power adapter 200 is not connected to the external power connection unit 120, and the input control unit 1102 is in the off state.

[0263] The digital camera 100 has a first path that passes through the power supply control unit 109 and a second path that does not pass through the power supply control unit 109 but passes through a second power supply control unit 111 as paths for supplying power to the accessory connection unit 140.

[0264] 8A, the accessory device 400 is not connected to the accessory connection unit 140, and therefore the digital camera 100 is not supplying power to the accessory device 400. Therefore, both the first power supply control unit 1092 and the second power supply control unit 111 are in the off state. Also, the output direction of the power from the receiving voltage conversion unit 1103 is the first direction, which is the first path.

[0265] In step S801, the battery determination unit 1081 acquires power supply device information from the battery 300 or DC coupler 301 connected to the battery connection unit 130, and the process proceeds to step S802.

[0266] Steps S802 to S808 are similar to steps S405 to S411 in FIG. 4A and FIG. 4B.

[0267] In step S809, the battery determination unit 1081 determines whether the device connected to the battery connection unit 130 is the battery 300 or the DC coupler 301, based on the power supply device information acquired in step S801.

[0268] In this embodiment, it is assumed that the power supply capacity of the DC coupler 301 that can supply power from a household power source is higher than that of the battery 300. Also, it is assumed that the battery 300 cannot supply the power required to operate the accessory device 400 in the high load mode.

[0269] If the battery determination unit 1081 determines that the DC coupler 301 is connected to the battery connection unit 130, the process proceeds to step S810. If the battery determination unit 1081 determines that the battery 300 is connected, the process proceeds to step S822.

[0270] In step S810, the battery determination unit 1081 determines whether the power that the DC coupler 301 can supply is equal to or greater than a predetermined power based on the power supply device information acquired in step S801. The predetermined power is, for example, the power required to operate the accessory device 400 in high load mode. The voltage of the predetermined power is, for example, 3.3V or greater. The DC coupler 301 can supply different power depending on the type and the AC adapter 302.

[0271] If the battery determination unit 1081 determines that the power that the DC coupler 301 can supply is equal to or greater than the predetermined power, the process proceeds to step S811. If the battery determination unit 1081 determines that the power that the DC coupler 301 can supply is less than the predetermined power, the process proceeds to step S822.

[0272] In step S811, the sub-control unit 108 turns off the input control unit 1102. This is to prevent power from being supplied from the power adapter 200 to the digital camera 100 via the external power connection unit 120.

[0273] It should be noted that since the digital camera 100 can receive a predetermined amount of power from the DC coupler 301 , it does not need to receive power from the external power supply connector 120 .

[0274] In step S812, the sub-control unit 108 changes the power output setting of the power receiving voltage conversion unit 1103 to the second direction, which is the second path, and proceeds to step S813.

[0275] In step S813, the sub-control unit 108 starts outputting electric power from the receiving power voltage conversion unit 1103 in the second direction, which is the second route.

[0276] When the sub-control unit 108 confirms via the receiving voltage monitoring unit 1105 that a predetermined voltage is being output from the receiving voltage conversion unit 1103, the sub-control unit 108 advances the process to step S814.

[0277] Steps S814 and S815 are similar to steps S422 and S423 in FIG. 4B.

[0278] 9B, when the processing of step S815 is completed, the input control unit 1102 is in the OFF state, the first power supply control unit 1092 is in the ON state, and the second power supply control unit 111 is in the ON state. The power source for the power that the digital camera 100 supplies to the accessory connection unit 140 is the DC coupler 301.

[0279] In this way, the digital camera 100 can supply a large amount of power to the accessory device 400 while maintaining the rated power of the DC coupler 301 .

[0280] Steps S816 and S817 are similar to steps S424 and S425 in FIG. 4B.

[0281] In step S818, the sub-control unit 108 stops the output of power from the receiving power voltage conversion unit 1103, and proceeds to step S819.

[0282] In step S819, the sub-control unit 108 changes the power output setting of the power receiving voltage conversion unit 1103 to the first direction, which is the first path, and proceeds to step S820.

[0283] In step S820, the sub-control unit 108 turns on the input control unit 1102, and the process proceeds to step S821. Note that this process does not need to be performed if it is determined in step S802 that nothing is connected to the external power connection unit 120.

[0284] Step S821 is similar to step S426 in FIG. 4B.

[0285] In step S822, the main control unit 101 notifies the user via the display unit 106 to prompt the user to connect a predetermined power supply device to the digital camera 100 or the DC coupler 301, and returns the process to step S802. The main control unit 101 notifies the user via the display unit 106, for example, as shown on a screen 1133 in FIG. 11(c).

[0286] In order to increase the power that digital camera 100 receives from battery connector 130, it is possible to consider, for example, changing DC coupler 301 to one with a higher rating, or changing AC adapter 302 to one that can output more power.

[0287] Next, an example of the operation of the digital camera 100 and the accessory device 400 in the second embodiment will be described with reference to FIG.

[0288] Note that the operation shown in FIG. 10 is just an example, and the digital camera 100 and the accessory device 400 can operate appropriately in response to user operations.

[0289] In T1001, the DC coupler 301 is connected to the digital camera 100. Here, the voltage supplied from the DC coupler 301 to the digital camera 100 is, for example, 15V.

[0290] In T1002, the digital camera 100 communicates with the DC coupler 301 and acquires power supply device information of the DC coupler 301. The operation of T1002 corresponds to step S801 in Fig. 8A.

[0291] In T1003, the accessory device 400 is connected to the digital camera 100. The operation of T1003 corresponds to step S802 in Fig. 8A.

[0292] When the digital camera 100 detects the connection of the accessory device 400 , it turns on the first power supply control unit 1092 , and power is supplied from the digital camera 100 to the accessory device 400 .

[0293] In T1004, when the power supply voltage of the accessory device 400 becomes equal to or higher than the fourth voltage threshold, communication is enabled for the accessory device 400. The operation of T1004 corresponds to step S804 in Fig. 8A.

[0294] In this case, the accessory device 400 operates in a low-load mode. The voltage of the power supplied from the digital camera 100 to the accessory device 400 is, for example, 3.3V.

[0295] After that, the accessory device 400 notifies the digital camera 100 that it has started up.

[0296] The digital camera 100 communicates with the accessory device 400 and acquires information about the accessory device 400. Then, the digital camera 100 determines the power to be supplied to the accessory device 400 based on the information about the accessory device 400. In this embodiment, the power to be supplied to the accessory device 400 is set to 15V / 1A, which is higher than the currently supplied power of 3.3V / 0.5A.

[0297] The digital camera 100 determines whether or not the device connected to the battery connection unit 130 is the DC coupler 301. Furthermore, the battery determination unit 1081 determines whether or not the available power supply of the DC coupler 301 is equal to or greater than a predetermined power.

[0298] In this embodiment, the DC coupler 301 is capable of supplying 15 V / 6 A. The digital camera 100 determines that it is capable of supplying 15 V / 1 A to the accessory device 400, taking into account the power consumption of the digital camera 100.

[0299] In T1005, the digital camera 100 turns off the input control unit 1102, preventing power from being supplied from the power adapter 200 to the digital camera 100 via the external power connection unit 120. The operation of T1005 corresponds to step S811 in FIG. 8B.

[0300] At T1006, the digital camera 100 changes the power output setting of the power receiving voltage converter 1103 from the first direction which is the first path to the second direction which is the second path. The operation of T1006 corresponds to steps S812 and S813 in FIG. 8B.

[0301] In T1007, the digital camera 100 turns on the second power supply control unit 111. The operation of T1007 corresponds to step S814 in FIG. 8B.

[0302] Through the above operations, the voltage (15V / 1A) requested by the accessory device 400 at T1004 can be supplied from the digital camera 100 to the accessory device 400 via the second power supply control unit 111.

[0303] In T1008, the digital camera 100 transmits a notification of completion of the voltage change to the accessory device 400. Upon receiving the notification of completion of the voltage change, when the voltage of the received power becomes equal to or higher than the third voltage, the accessory device 400 transitions to the high load mode.

[0304] The operation of T1008 corresponds to between steps S815 and S816 in FIG. 8B.

[0305] In T1009, the accessory device 400 is removed from the digital camera 100. The operation of T1009 corresponds to step S816 in Fig. 8B.

[0306] At T1010, the accessory device 400 stops operating when the voltage received from the digital camera 100 falls below the fourth voltage. The timing of T1010 may be T1011 or later depending on the degree of voltage drop at the camera connection unit 4001 of the accessory device 400.

[0307] At T1011, the digital camera 100 turns off the second power supply control unit 111. The operation of T1011 corresponds to step S817 in FIG. 8B.

[0308] At T1012, the digital camera 100 changes the power output setting of the power receiving voltage converter 1103 from the second direction which is the second path to the first direction which is the first path. The operation of T1012 corresponds to steps S818 and S819 in FIG. 8B.

[0309] In T1013, the digital camera 100 turns on the input control unit 1102 so that power is supplied to the digital camera 100 from the power adapter 200 via the external power connection unit 120. The operation of T1013 corresponds to step S820 in Fig. 8B.

[0310] In T1014, the accessory device 400 turns off the first power supply control unit 1092. The operation of T1014 corresponds to step S821 in FIG. 8B.

[0311] As described above, according to the second embodiment, the accessory device 400 is connected to the digital camera 100, and power supplied from the DC coupler 301 is supplied to the accessory device 400 at a first voltage via a first path passing through the voltage conversion unit 1091. Then, when the voltage supplied to the adapter device 400 changes to a second voltage higher than the first voltage, power supplied from the DC coupler 301 is supplied to the accessory device 400 at the second voltage via a second path not passing through the voltage conversion unit 1091. This makes it possible to supply large power to the accessory device 400 while reducing the amount of heat generated when power is supplied from the digital camera 100 to the accessory device 400.

[0312] [Other embodiments] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described 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) that implements one or more of the functions.

[0313] 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.

[0314] The disclosure of this specification includes the following electronic device, control method, and program. [Configuration 1] An electronic device, a first connection means to which a first power supply device is connected; A second connection means to which an external device can be connected and which can supply power to the external device; a third connection means to which a second power supply device is connected; a control means for switching between a first path for converting at least one of a voltage received from the first power supply device via the first connection means and a voltage received from the second power supply device via the third connection means and supplying the converted voltage to the external device via the second connection means, and a second path for supplying the voltage received from the first power supply device via the first connection means to the external device via the second connection means without converting the voltage, The electronic device, characterized in that the control means controls the supply of power to the external device through the second path when the voltage supplied to the external device is higher than the voltage that can be supplied through the first path. [Configuration 2] a voltage conversion means for converting a voltage received via at least one of the first connection means and the third connection means; the first path converts a voltage received via at least one of the first connection means and the third connection means into a predetermined voltage by the voltage conversion means and supplies the voltage to the external device via the second connection means; The electronic device described in configuration 1, characterized in that the second path supplies a voltage higher than the specified voltage received from the first power supply device via the first connection means to the external device via the second connection means without converting the voltage by the voltage conversion means. [Configuration 3] 3. The electronic device according to configuration 2, wherein the voltage output from the voltage conversion means is supplied to components in the electronic device. [Configuration 4] The electronic device described in any one of configurations 1 to 3, characterized in that when the voltage received from the first power supply device is equivalent to the voltage supplied to the external device, the control means controls the voltage received via the first connection means to be supplied to the external device from the second path via the second connection means. [Configuration 5] The electronic device described in any one of configurations 1 to 4, characterized in that when connection of the external device to the second connection means is detected and the voltage received from the first power supply device is lower than the voltage supplied to the external device, the control means changes the voltage requested of the first power supply device via the first connection means to the voltage supplied to the external device, and controls the supply of power to the external device from the second path. [Configuration 6] The electronic device described in configuration 5, characterized in that when the voltage received from the first power supply device via the first connection means cannot be changed to the voltage supplied to the external device, the control means performs control to reduce the power consumption of the external device and controls to supply power to the external device from the second path. [Configuration 7] 7. The electronic device according to configuration 6, wherein the control means reduces the power consumption by restricting a predetermined function of the external device. [Configuration 8] 8. The electronic device according to configuration 7, wherein the predetermined function is a function of charging a battery of the external device. [Configuration 9] The electronic device described in any one of configurations 1 to 4, characterized in that when connection of the external device to the second connection means is detected and the voltage received from the first power supply device is higher than the voltage supplied to the external device, the control means changes the voltage requested of the first power supply device via the first connection means to the voltage supplied to the external device, and controls the supply of power to the external device from the first path. [Configuration 10] When a predetermined function of the external device connected to the second connection means is not restricted, the control means changes a voltage requested of the first power supply device via the first connection means to a voltage to be supplied to the external device, and controls so as to supply power to the external device from the second path; The electronic device described in configuration 9, characterized in that when the specified function of the external device connected to the second connection means is restricted, the electronic device is controlled to supply power to the external device from the first path. [Configuration 11] 11. The electronic device according to configuration 10, wherein the predetermined function is a function of charging a battery of the external device. [Configuration 12] 12. The electronic device according to claim 10, wherein the control means notifies the user via a display means to allow the user to select whether or not to restrict the predetermined function of the external device. [Configuration 13] The electronic device described in any one of configurations 1 to 12, characterized in that the control means receives a voltage higher than a voltage that can be supplied from the first power supply device via the first connection means, and when the voltage to be supplied to the external device is higher than the voltage that can be supplied from the first path, controls the supply of power to the external device from the second path. [Configuration 14] The electronic device described in any one of configurations 1 to 13, characterized in that the control means determines a voltage to be supplied to the external device based on a rated voltage of the external device, and controls switching between the first path and the second path depending on the voltage to be supplied to the external device. [Configuration 15] The electronic device described in any one of configurations 1 to 14, characterized in that the control means determines a voltage to be supplied to the external device based on information about the external device received from the external device via the second connection means, and controls switching between the first path and the second path depending on the voltage to be supplied to the external device. [Configuration 16] the external device is a device that assists a function of the electronic device, 16. The electronic device according to any one of configurations 1 to 15, wherein the first power supply device is a power supply device conforming to the Universal Serial Bus (USB) Power Delivery (PD) standard. [Configuration 17] The electronic device described in any one of configurations 1 to 16, characterized in that the second power supply device is a battery that can be attached to a battery box of the electronic device, or a DC coupler that is connected to a household power source and can be attached to the battery box of the electronic device. [Configuration 18] An electronic device, a third connection means to which a third power supply device is connected; A second connection means to which an external device can be connected and which can supply power to the external device; a control means for switching between a first path for converting a voltage received from the third power supply device via the third connection means and supplying the converted voltage to the external device via the second connection means, and a second path for supplying the voltage received from the third power supply device via the third connection means to the external device via the second connection means without converting the voltage, The electronic device, characterized in that the control means controls the supply of power to the external device through the second path when the voltage supplied to the external device is higher than the voltage that can be supplied through the first path. [Configuration 19] the control means supplies power to the external device through the first path when a voltage received from the third power supply device via the third connection means is less than a predetermined voltage; The electronic device described in configuration 18, characterized in that when the voltage received from the third power supply device via the third connection means is equal to or higher than the specified voltage, the electronic device is controlled to supply power to the external device from the second path. [Configuration 20] 20. The electronic device described in configuration 19, further comprising a setting means for setting the path for outputting power received from the third power supply device via the third connection means to the first path or the second path. [Configuration 21] a first connection means to which a first power supply device is connected; The electronic device described in configuration 20, characterized in that when the voltage received from the third power supply device via the third connection means is equal to or higher than the specified voltage, the control means stops receiving power from the first power supply device via the first connection means, and sets the path for outputting the power received from the third power supply device to the second path. [Configuration 22] The electronic device described in configuration 21, characterized in that when the first power supply device is not connected via the first connection means, the voltage received from the third power supply device via the third connection means is less than the specified voltage, and a specified function of the external device is to be used, the control means issues a notification urging the user to connect the first power supply device. [Configuration 23] The electronic device described in any one of configurations 18 to 22, characterized in that the control means stops supplying power to the external device via the third connection means when the external device is disconnected from the electronic device. [Configuration 24] The electronic device described in any one of configurations 18 to 23, characterized in that the control means determines a voltage to be supplied to the external device based on information about the external device received from the external device via the second connection means, and controls switching between the first path and the second path depending on the voltage to be supplied to the external device. [Configuration 25] the external device is a device that assists a function of the electronic device, 25. The electronic device of any one of configurations 18 to 24, wherein the third power supply device is a DC coupler that is connected to a household power supply and can be attached to a battery box of the electronic device. [Configuration 26] A method for controlling an electronic device, comprising: The electronic device includes: a first connection means to which a first power supply device is connected; A second connection means to which an external device can be connected and which can supply power to the external device; and a third connection means to which a second power device is connected, The control method includes: a step of switching between a first path for converting at least one of a voltage received from the first power supply device via the first connection means and a voltage received from the second power supply device via the third connection means and supplying the converted voltage to the external device via the second connection means, and a second path for converting the voltage received from the first power supply device via the first connection means and supplying the voltage to the external device via the second connection means, A control method characterized in that, in the step, when the voltage to be supplied to the external device is higher than the voltage that can be supplied from the first path, control is performed so that power is supplied to the external device from the second path. [Configuration 27] A method for controlling an electronic device, comprising: The electronic device includes: a third connection means to which a third power supply device is connected; A second connection means to which an external device can be connected and which can supply power to the external device, The control method includes: a step of switching between a first path for converting a voltage received from the third power supply device via the third connection means and supplying the converted voltage to the external device via the second connection means and a second path for supplying a voltage received from the third power supply device via the third connection means to the external device via the second connection means without converting the voltage, A control method characterized in that, in the step, when the voltage to be supplied to the external device is higher than the voltage that can be supplied from the first path, control is performed so that power is supplied to the external device from the second path. [Configuration 28] A program for causing a computer to function as an electronic device according to any one of claims 1 to 25. [Explanation of symbols]

[0315] 100... digital camera, 101... main control unit, 108... sub control unit, 1091... voltage conversion unit, 1092... first power supply control unit, 111... second power supply control unit, 120... external power supply connection unit, 130... battery connection unit, 140... accessory connection unit

Claims

1. An electronic device, a first connection means to which a first power supply device is connected; A second connection means to which an external device can be connected and which can supply power to the external device; a third connection means to which a second power supply device is connected; a control means for switching between a first path for converting at least one of a voltage received from the first power supply device via the first connection means and a voltage received from the second power supply device via the third connection means and supplying the converted voltage to the external device via the second connection means, and a second path for supplying the voltage received from the first power supply device via the first connection means to the external device via the second connection means without converting the voltage, The electronic device according to claim 1, wherein the control means controls the supply of power to the external device through the second path when the voltage supplied to the external device is higher than the voltage that can be supplied through the first path.

2. a voltage conversion means for converting a voltage received via at least one of the first connection means and the third connection means; the first path converts a voltage received via at least one of the first connection means and the third connection means into a predetermined voltage by the voltage conversion means and supplies the voltage to the external device via the second connection means; 2. The electronic device according to claim 1, wherein the second path supplies a voltage higher than the specified voltage to the external device via the second connection means without converting the voltage received from the first power supply device via the first connection means by the voltage conversion means.

3. 3. The electronic device according to claim 2, wherein the voltage output from the voltage conversion means is supplied to components in the electronic device.

4. The electronic device according to claim 1, characterized in that when the voltage received from the first power supply device is equivalent to the voltage supplied to the external device, the control means controls the voltage received via the first connection means to be supplied to the external device from the second path via the second connection means.

5. The electronic device according to claim 1, characterized in that when connection of the external device to the second connection means is detected and the voltage received from the first power supply device is lower than the voltage supplied to the external device, the control means changes the voltage requested of the first power supply device via the first connection means to the voltage supplied to the external device, and controls the supply of power to the external device from the second path.

6. The electronic device described in claim 5, characterized in that when the voltage received from the first power supply device via the first connection means cannot be changed to the voltage supplied to the external device, the control means performs control to reduce the power consumption of the external device and controls to supply power to the external device from the second path.

7. 7. The electronic device according to claim 6, wherein the control means reduces the power consumption by restricting a predetermined function of the external device.

8. 8. The electronic device according to claim 7, wherein the predetermined function is a function of charging a battery of the external device.

9. The electronic device according to claim 1, characterized in that when connection of the external device to the second connection means is detected and the voltage received from the first power supply device is higher than the voltage supplied to the external device, the control means changes the voltage requested of the first power supply device via the first connection means to the voltage supplied to the external device, and controls the supply of power to the external device from the first path.

10. When a predetermined function of the external device connected to the second connection means is not restricted, the control means changes a voltage requested of the first power supply device via the first connection means to a voltage to be supplied to the external device, and controls so as to supply power to the external device from the second path; 10. The electronic device according to claim 9, further comprising a control unit configured to supply power to the external device from the first path when the predetermined function of the external device connected to the second connection means is restricted.

11. 11. The electronic device according to claim 10, wherein the predetermined function is a function of charging a battery of the external device.

12. 11. The electronic device according to claim 10, wherein the control means notifies the user via a display means to allow the user to select whether or not to restrict the predetermined function of the external device.

13. The electronic device according to claim 1, characterized in that the control means receives a voltage higher than the voltage that can be supplied from the first path from the first power supply device via the first connection means, and when the voltage to be supplied to the external device is higher than the voltage that can be supplied from the first path, controls the supply of power to the external device from the second path.

14. 2. The electronic device according to claim 1, wherein the control means determines a voltage to be supplied to the external device based on a rated voltage of the external device, and performs control to switch between the first path and the second path depending on the voltage to be supplied to the external device.

15. The electronic device according to claim 1, characterized in that the control means determines a voltage to be supplied to the external device based on information regarding the external device received from the external device via the second connection means, and controls switching between the first path and the second path depending on the voltage to be supplied to the external device.

16. the external device is a device that assists a function of the electronic device, 2. The electronic device according to claim 1, wherein the first power supply device is a power supply device conforming to the Universal Serial Bus (USB) Power Delivery (PD) standard.

17. 2. The electronic device according to claim 1, wherein the second power supply device is a battery that can be attached to a battery box of the electronic device, or a DC coupler that is connected to a household power source and can be attached to the battery box of the electronic device.

18. An electronic device, a third connection means to which a third power supply device is connected; A second connection means to which an external device can be connected and which can supply power to the external device; a control means for switching between a first path for converting a voltage received from the third power supply device via the third connection means and supplying the converted voltage to the external device via the second connection means, and a second path for supplying the voltage received from the third power supply device via the third connection means to the external device via the second connection means without converting the voltage, The electronic device according to claim 1, wherein the control means controls the supply of power to the external device through the second path when the voltage supplied to the external device is higher than the voltage that can be supplied through the first path.

19. the control means supplies power to the external device through the first path when a voltage received from the third power supply device via the third connection means is less than a predetermined voltage; 19. The electronic device according to claim 18, characterized in that when the voltage received from the third power supply device via the third connection means is equal to or higher than the specified voltage, the electronic device is controlled to supply power to the external device from the second path.

20. 20. The electronic device according to claim 19, further comprising a setting means for setting a path for outputting power received from the third power supply device via the third connection means to the first path or the second path.

21. a first connection means to which a first power supply device is connected; The electronic device according to claim 20, characterized in that, when the voltage received from the third power supply device via the third connection means is equal to or higher than the specified voltage, the control means stops receiving power from the first power supply device via the first connection means, and sets the path for outputting the power received from the third power supply device to the second path.

22. The electronic device described in claim 21, characterized in that the control means issues a notification urging a user to connect the first power device when the first power device is not connected via the first connection means, the voltage received from the third power device via the third connection means is less than the specified voltage, and a specified function of the external device is to be used.

23. 20. The electronic device according to claim 18, wherein the control unit stops the power supply to the external device via the third connection unit when the external device is disconnected from the electronic device.

24. The electronic device according to claim 18, characterized in that the control means determines a voltage to be supplied to the external device based on information regarding the external device received from the external device via the second connection means, and performs control to switch between the first path and the second path depending on the voltage to be supplied to the external device.

25. the external device is a device that assists a function of the electronic device, 20. The electronic device according to claim 18, wherein the third power supply device is a DC coupler that is connected to a household power supply and can be attached to a battery box of the electronic device.

26. A method for controlling an electronic device, comprising: The electronic device includes: a first connection means to which a first power supply device is connected; A second connection means to which an external device can be connected and which can supply power to the external device; and a third connection means to which a second power supply device is connected, The control method includes: a step of switching between a first path for converting at least one of a voltage received from the first power supply device via the first connection means and a voltage received from the second power supply device via the third connection means and supplying the converted voltage to the external device via the second connection means, and a second path for supplying the voltage received from the first power supply device via the first connection means to the external device via the second connection means without converting the voltage, A control method characterized in that, in the step, when the voltage to be supplied to the external device is higher than the voltage that can be supplied from the first path, control is performed so that power is supplied to the external device from the second path.

27. A method for controlling an electronic device, comprising: The electronic device includes: a third connection means to which a third power supply device is connected; a second connection means to which an external device can be connected and which can supply power to the external device; The control method includes: a step of switching between a first path for converting a voltage received from the third power supply device via the third connection means and supplying the converted voltage to the external device via the second connection means and a second path for supplying a voltage received from the third power supply device via the third connection means to the external device via the second connection means without converting the voltage, A control method characterized in that, in the step, when the voltage to be supplied to the external device is higher than the voltage that can be supplied from the first path, control is performed so that power is supplied to the external device from the second path.

28. A program for causing a computer to function as the electronic device according to any one of claims 1 to 25.

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