Power supply device and imaging apparatus

Abstract

To provide a technique for making it possible to supply high power to an imaging apparatus as necessary in a power supply device having a protection circuit.SOLUTION: The power supply device for supplying power supplied from an external power source to an imaging apparatus includes a protection circuit configured to temporarily maintain the supply of power to the imaging apparatus when the supply of power from the external power source is cut off and control means that performs control for switching between a first mode in which the protection circuit is disabled and a second mode in which the protection circuit is enabled.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power supply device for connecting an external power source and an imaging device.

Background Art

[0002] Among imaging devices, there are products with a function (so-called external power source drive) that can perform shooting while directly supplying power from an external power source instead of using a built-in battery. The external power source drive is used, for example, when performing long-time video shooting. At this time, a configuration in which an external power source such as an AC adapter and an imaging device are connected via a power supply device called a DC coupler is common.

[0003] In a power supply device for an imaging device, a protection circuit may be provided to temporarily maintain power supply to the imaging device even after a sudden interruption of the input from an external power source. FIG. 8 of Patent Document 1 discloses a protection circuit composed of a diode (25) and a capacitor (26). For example, even if the input from an external power source is cut off due to, for example, a power outlet plug or cable coming out, the charge accumulated in the capacitor is supplied to the imaging device, so that a time for safely shutting down without damaging the imaging data can be ensured.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] For data protection in the event of an abnormal power failure, a protection circuit as described above is extremely useful. However, on the other hand, there is a drawback in that the power consumption within the power supply device increases due to the voltage drop caused by the protection circuit. If the power supply device consumes a part of the power of the external power supply, the power that can be supplied to the imaging device decreases accordingly. As a result, there is a possibility that sufficient power cannot be stably supplied during an operation in which the imaging device requires high power (for example, when continuously shooting a video), which is not preferable.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a technique for enabling a high power supply to an imaging device as needed in a power supply device having a protection circuit.

Means for Solving the Problems

[0007] The present disclosure is a power supply device for supplying power supplied from an external power supply to an imaging device, including a protection circuit configured to temporarily maintain power supply to the imaging device when the supply of power from the external power supply is cut off, and control means for performing control to switch between a first mode in which the protection circuit is disabled and a second mode in which the protection circuit is enabled.

[0008] The present disclosure is an imaging device in which power of an external power supply is supplied via a power supply device, the power supply device having a protection circuit configured to temporarily maintain power supply to the imaging device when the supply of power from the external power supply is cut off, and a function of switching the protection circuit between enabled and disabled, and the imaging device including instruction means for transmitting an instruction to switch the protection circuit between enabled and disabled to the power supply device.

Advantages of the Invention

[0009] According to the present invention, in a power supply device having a protection circuit, it is possible to supply high power to an imaging device as needed.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0012] The power supply device according to the present embodiment is a device for supplying power supplied from an external power source to an imaging device. As the power supply device, a DC coupler will be described as an example. The DC coupler in this specification mainly refers to a device that is used in combination with an AC adapter as an external power source and supplies the DC output of the AC adapter to the imaging device. By using such a DC coupler, it is possible to drive the imaging device while supplying power from a household outlet via the AC adapter instead of using the built-in battery (so-called external power source drive). External power source drive is advantageous, for example, when performing long-time continuous operation such as video shooting or video distribution.

[0013] FIG. 1 is a block diagram showing a configuration according to an embodiment of the present invention. In this figure, the imaging device 101 is connected to a DC coupler 102, and the DC coupler 102 is connected to an AC adapter 104 via a connector 103. The imaging device 101 receives power supply from the DC coupler 102 via a + terminal 105 and a - terminal 106. The imaging device 101 includes a battery (not shown) or a battery box which is a mounting portion where the DC coupler 102 can be mounted. When the imaging device 101 uses the battery as a power source, the battery (not shown) is mounted in the battery box. The + terminal 105 and the - terminal 106 are arranged in the battery box. When the battery is mounted, the + terminal and the - terminal, and the communication terminal of the battery are connected to the + terminal 105, the - terminal 106, and the communication terminal 108, respectively. Also, the DC coupler 102 has the same shape as the battery. When the DC coupler 102 is used as the power source of the imaging device 101, the DC coupler 102 is mounted in the battery box instead of the battery. The imaging device 101 is a portable imaging device corresponding to battery driving by a built-in battery and external power supply driving by the AC adapter 104 and the DC coupler 102, and is, for example, a digital camera, a digital camcorder, or the like. The AC adapter 104 is a device that converts AC (alternating current) of a commercial power supply into DC (direct current).

[0014] The microcomputer 107 in the imaging device 101 is connected to the microcomputer 109 in the DC coupler 102 via the communication terminal 108. The imaging device 101 and the DC coupler 102 communicate with each other by this communication means. The microcomputer 107 in the imaging device 101 receives power supply from the DC coupler 102 via the + terminal 105 and the - terminal 106.

[0015] The DC coupler 102 has a protection circuit for temporarily maintaining the power supply to the imaging device 101 when the input from the AC adapter 104 is disconnected. Specifically, the protection circuit is constituted by a capacitor 111 that holds electric charge and a diode 110 disposed in the path between the AC adapter 104 and the imaging device 101. Also, the DC coupler 102 has control means for switching between a mode (first mode) for disabling this protection circuit and a mode (second mode) for enabling the protection circuit. Specifically, the control means is constituted by an FET 112 which is a switch for opening and closing a path 113 that bypasses the diode 110 and a microcomputer 109 which is a control circuit for controlling the FET 112. Note that the FET 112 is a Field Effect Transistor.

[0016] The microcomputer 107 of the imaging device 101 communicates with the microcomputer 109 of the DC coupler 102 via the communication terminal 108 according to the operating state of the imaging device 101, and switches the ON / OFF of the FET 112.

[0017] When the FET 112 is OFF (second mode in which the protection circuit is enabled), power is supplied from the AC adapter 104 to the imaging device 101 through the diode 110. In this state, assume that an abnormality such as the connector 103 becoming disconnected or the plug of the AC adapter 104 being pulled out occurs, and the power supply from the AC adapter 104 to the DC coupler 102 suddenly stops. Even when such a power failure occurs, in the second mode, the charge accumulated by the diode 110 and the capacitor 111 can hold the power supply to the imaging device 101 for a while. By slowing down the discharge of the charge in the circuit in this way, for example, it is possible to save the data captured by the imaging device 101 and secure the power for performing the process for appropriately shutting down.

[0018] When FET112 is ON (the first mode where the protection circuit is ineffective), power is supplied from the AC adapter 104 to the imaging device 101 bypassing the diode 110 and passing through FET112. In the state where the diode 110 is shorted by FET112 in this way, it is not affected by the voltage drop of the diode 110. Therefore, in the first mode, power consumption by the protection circuit can be reduced, and more power can be supplied to the imaging device 101 compared to when FET112 is OFF (the second mode). The first mode with high power supply capacity can be preferably used, for example, when shooting videos that require a large amount of power. When a power failure occurs while shooting a video in the first mode, temporary power supply by the protection circuit is not performed, and the video recording of the imaging device 101 may end abnormally. Therefore, it is preferable to provide the imaging device 101 with a video data repair function for repairing video data that was not properly recorded so as to be able to handle such a situation.

[0019] When power is not supplied to the DC coupler 102 and the microcomputer 109 is powered off, it is preferable that FET112 is in the OFF state. That is, it is preferable that the state where the protection circuit of the DC coupler 102 is effective is the default. Also, when the DC coupler 102 is not connected to the imaging device 101 (that is, when the DC coupler 102 is not in use), it is preferable that FET112 is in the OFF state so that it can operate with priority given to handling power-off when connected to the imaging device 101 next. Also, when the DC coupler 102 is connected to an imaging device that does not support switching between the effective and ineffective states of the protection circuit, it is preferable that FET112 is in the OFF state so that it can also handle power-off.

[0020] Next, with reference to FIG. 2, an example of the processing executed in the configuration of FIG. 1 will be described. FIG. 2 is a flowchart showing the flow of the startup processing of the imaging device 101 and the DC coupler 102.

[0021] In step S201, the microcomputer 109 of the DC coupler 102 turns off the FET 112 to activate the protection circuit. That is, in the initial state at startup, the protection circuit is active.

[0022] In step S101, the microcomputer 107 of the imaging device 101 transmits data for baud rate adjustment to the DC coupler 102. In step S202, the micro computer 109 of the DC coupler 102 determines the baud rate based on the data received from the imaging device 101. In step S102, the microcomputer 107 of the imaging device 101 transmits a mounting identification command to the DC coupler 102. In step S203, the microcomputer 109 of the DC coupler 102 replies with the identification of the DC coupler 102 in response to the mounting identification command. In step S103, the microcomputer 107 of the imaging device 101 transmits a model name reading command to the DC coupler 102. In step S204, the microcomputer 109 of the DC coupler 102 replies with the model name of the DC coupler 102 in response to the model name reading command.

[0023] In step S104, the microcomputer 107 of the imaging device 101 determines whether the connected DC coupler 102 has a function to switch the enable / disable of the protection circuit based on the model name of the DC coupler 102. If a list in which the model name of the DC coupler and the switchability of the protection circuit are associated is stored in the non-volatile memory built into the imaging device 101, the microcomputer 107 may refer to this list to make the determination in step S104. If the imaging device 101 is connected to a network, the microcomputer 107 may make the determination in step S104 by querying a server on the network. If the DC coupler 102 supports switching the enable / disable of the protection circuit (YES in step S104), the process proceeds to step S105.

[0024] When the DC coupler 102 does not support switching the protection circuit between enabled and disabled states (NO in step S104), steps S105 to S107 are skipped, and the startup process ends. This prevents an inappropriate switching command from being sent to a DC coupler that does not have the function of switching the protection circuit between enabled and disabled states, and can avoid errors and failures of the DC coupler. As an assumed case, there is also a possibility that the DC coupler 102 having the function of switching the protection circuit between enabled and disabled states is connected to an imaging device that does not support the switching control of the protection circuit. In such a case, only the processes of steps S104 to S107 and steps S205 to S208 in FIG. 2 are not executed, but the DC coupler 102 operates as a DC coupler having a protection circuit, so there is no problem with the operations of the imaging device and the DC coupler 102.

[0025] In step S105, the microcomputer 107 of the imaging device 101 checks the operation mode of the imaging device 101. In step S106, the microcomputer 107 determines whether to enable or disable the protection circuit of the DC coupler 102 according to the operation mode of the imaging device 101, and sends a switching command for the protection circuit to the DC coupler 102.

[0026] FIG. 3 shows a specific example of the processes of steps S105 to S106. In step S301, the microcomputer 107 of the imaging device 101 checks whether the operation mode of the imaging device 101 is the video shooting mode or the still image shooting mode. During video shooting, since processes such as continuous capture of images at a certain frame rate, encoding of video and audio, and recording of video data on a storage medium are continuously executed, a larger amount of power is required compared to the still image shooting mode. Therefore, when the imaging device 101 is in the video shooting mode, priority is given to enhancing the power supply capacity of the DC coupler 102, and in step S302, the microcomputer 107 sends a command to disable the protection circuit to the DC coupler 102. On the other hand, when the imaging device 101 is in the still image shooting mode, priority is given to data protection when the power is turned off, and in step S303, the microcomputer 107 sends a command to enable the protection circuit to the DC coupler 102.

[0027] Returning to FIG. 2 again. When the microcomputer 109 of the DC coupler 102 receives a switching command for the protection circuit from the imaging device 101, in step S205, it determines whether the received command is a deactivation command or an activation command for the protection circuit. If a deactivation command for the protection circuit is received (YES in step S205), the process proceeds to step S206. If an activation command is received (NO in step S205), the process proceeds to step S207.

[0028] In step S206, the microcomputer 109 of the DC coupler 102 turns on (closes) the FET 112. As a result, a bypass path 113 that bypasses the diode 110 is formed, so that the DC output of the AC adapter 104 is supplied to the imaging device 101 without passing through the diode 110. This state is the first mode.

[0029] On the other hand, in step S207, the microcomputer 109 of the DC coupler 102 turns off (releases) the FET 112. As a result, the AC adapter 104 and the imaging device 101 are electrically connected via the diode 110, and the protection circuit becomes effective. This state is the second mode.

[0030] In step S208, the microcomputer 109 of the DC coupler 102 replays to the imaging device 101 that the switching of the protection circuit has been completed. In step S107, the microcomputer 107 of the imaging device 101 confirms the completion of the switching of the protection circuit of the DC coupler 102 upon receiving the replay from the DC coupler 102. Thus, the startup process ends.

[0031] By the above processing, the DC coupler 102 as a power supply device can select a power supply method according to the state of the imaging device 101 (whether it is in a state where a large amount of power is required). In FIG. 2, the startup time was taken as an example for explanation. However, for example, even when the operation mode changes during the use of the imaging device 101, the enable / disable of the protection circuit of the DC coupler 102 may be switched according to the changed operation mode. In that case, the microcomputer 107 of the imaging device 101 may execute the same processing as steps S105 to S107 in FIG. 2, and the microcomputer 109 of the DC coupler 102 may execute the same processing as steps S205 to S208 in FIG. 2.

[0032] FIG. 4 is a flowchart showing the flow of connection detection between the imaging device 101 and the DC coupler 102. In step S401, the microcomputer 109 of the DC coupler 102 determines whether it is communicating with the imaging device 101. If it is communicating, it returns to connection detection. If it is not communicating (that is, when the DC coupler 102 is not connected to the imaging device 101), it proceeds to step S402. In step S402, the microcomputer 109 of the DC coupler 102 turns off (releases) the FET 112 and switches to the second mode in which the protection circuit is enabled (note that if it was originally in the second mode, the second mode is maintained). By this connection detection process, when the DC coupler 102 is not connected to the imaging device 101, the protection circuit is in an enabled state. By executing such a connection detection process, when the DC coupler 102 is in an unused state (not connected to the imaging device 101), the protection circuit is automatically reset to an enabled state. Thereby, it is possible to guarantee that the initial state of the protection circuit is "enabled" when connecting the DC coupler 102 to the imaging device 101, and it is possible to prevent a situation where the DC coupler 102 with the protection circuit disabled is inadvertently connected to the imaging device 101.

[0033] <Configuration example of imaging device 101> FIG. 5 is a block diagram showing a configuration example of the imaging device 101. The lens unit 51 is a lens unit equipped with an interchangeable photographing lens. The lens 511 is usually composed of a plurality of lenses, but in FIG. 5, it is simply shown as a single lens. The communication terminal 515 is a communication terminal for the lens unit 51 to communicate with the imaging device 101 side, and the communication terminal 520 is a communication terminal for the imaging device 101 to communicate with the lens unit 51 side. The lens unit 51 communicates with the system control unit 530 via these communication terminals 515 and 520. Then, the lens unit 51 controls the aperture 510 via the aperture drive circuit 512 by the internal lens system control circuit 514. Also, the lens unit 51 focuses by displacing the position of the lens 511 via the AF drive circuit 513 by the lens system control circuit 514.

[0034] The shutter 521 is a focal plane shutter that can freely control the exposure time of the imaging unit 522 under the control of the system control unit 530.

[0035] The imaging unit 522 is an image sensor (image sensor) composed of a CCD, a CMOS element, etc. that converts an optical image into an electrical signal. The imaging unit 522 may have an imaging surface phase difference sensor that outputs defocus amount information to the system control unit 530. The A / D converter 523 converts the analog signal output from the imaging unit 522 into a digital signal.

[0036] The image processing unit 524 performs predetermined processing (such as pixel interpolation, resizing processing such as reduction, color conversion processing, etc.) on the data from the A / D converter 523 or the data from the memory control unit 525. Further, the image processing unit 524 performs predetermined arithmetic processing using the captured image data, and the system control unit 530 performs exposure control and distance measurement control based on the arithmetic result obtained by the image processing unit 524. As a result, TTL (through-the-lens) type AF (auto focus) processing, AE (automatic exposure) processing, EF (flash pre-emission) processing, etc. are performed. The image processing unit 524 further performs predetermined arithmetic processing using the captured image data, and performs TTL type AWB (auto white balance) processing based on the obtained arithmetic result.

[0037] The output data from the A / D converter 523 is written into the memory 531 via the image processing unit 524 and the memory control unit 525. Alternatively, the output data from the A / D converter 523 is written into the memory 531 via the memory control unit 525 without passing through the image processing unit 524. The memory 531 stores the image data obtained by the imaging unit 522 and converted into digital data by the A / D converter 523, the image data for display on the display unit 529 and the EVF 527, and the audio data. The memory 531 has a storage capacity sufficient to store a predetermined number of still images, a moving image for a predetermined time, and audio.

[0038] Further, the memory 531 also serves as an image display memory (video memory). The D / A converter 526 converts the image display data stored in the memory 531 into an analog signal and supplies it to the display unit 529 and the EVF 527. In this way, the image data for display written in the memory 531 is displayed by the display unit 529 and the EVF 527 via the D / A converter 526. Each of the display unit 529 and the EVF 527 is a display such as an LCD or an organic EL, and performs a display according to the analog signal from the D / A converter 526. The digital signal A / D-converted by the A / D converter 523 and stored in the memory 531 is converted into an analog signal by the D / A converter 526 and sequentially transferred to the display unit 529 or the EVF 527 for display, thereby enabling live view display (LV). Hereinafter, the image displayed in the live view display is referred to as a live view image (LV image).

[0039] The system control unit 530 is a control unit composed of at least one processor and / or at least one circuit, and controls the entire imaging device 101. The system control unit 530 is a processor and also a circuit. The system control unit 530 realizes each process by executing a program recorded in the non-volatile memory 556. Further, the system control unit 530 also performs display control by controlling the memory 531, the D / A converter 526, the display unit 529, the EVF 527, etc. Further, the system control unit 530 also performs a process of performing video encoding based on the video data obtained from the imaging unit 522 and the audio data obtained from the audio input unit, and generating a video file in a predetermined format. The system control unit 530 corresponds to the microcomputer 107 in FIG. 1.

[0040] The system memory 552 is, for example, a RAM. The system control unit 530 expands constants, variables for the operation of the system control unit 530, programs read from the non-volatile memory 556, etc. into the system memory 552.

[0041] The non-volatile memory 556 is an electrically erasable and recordable memory, such as an EEPROM or the like. Constants for the operation of the system control unit 530, programs, etc. are recorded in the non-volatile memory 556. The program mentioned here includes a program for executing the flowcharts shown in FIGS. 2 and 3.

[0042] The communication unit 554 transmits and receives video signals and audio signals to and from an external device connected by a wireless or wired cable. The communication unit 554 can also be connected to a wireless LAN (Local Area Network) or the Internet. In addition, the communication unit 554 can communicate with an external device via Bluetooth or Bluetooth Low Energy (Bluetooth is a registered trademark). The communication unit 554 can transmit an image (including the LV image) captured by the imaging unit 522 or an image recorded on the recording medium 534, and can receive various information such as image data and a video recording start instruction from the external device.

[0043] The power control unit 571 is composed of a battery detection circuit, a DC-DC converter, a switch circuit for switching the energized block, etc., and detects the presence or absence of a battery, the type of battery, the remaining battery level, etc. Further, the power control unit 571 controls the DC-DC converter based on the detection result and the instruction of the system control unit 530, and supplies a necessary voltage to each unit including the recording medium 534 for a necessary period. The power supply unit 570 consists of a primary battery such as an alkaline battery or a lithium battery, or a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery. Note that the DC coupler 102 in FIG. 1 is connected to the power control unit 571.

[0044] The recording medium I / F 532 is an interface with a recording medium 534 such as a memory card or a hard disk. The recording medium 534 is a recording medium such as a memory card for recording the captured image, and is composed of a semiconductor memory, a magnetic disk, or the like.

[0045] The operation unit 560 is an input unit that receives operations from the user (user operations) and is used to input various operation instructions to the system control unit 530. As shown in FIG. 5, the operation unit 560 includes a shutter button 561, a mode switch 564, a power switch 565, a touch panel 567, a video button 568, and the like.

[0046] The shutter button 561 includes a first shutter switch 562 and a second shutter switch 563. The first shutter switch 562 turns on during the operation of the shutter button 561, that is, a so-called half-press (shooting preparation instruction), and generates a first shutter switch signal SW1. The system control unit 530 starts shooting preparation operations such as AF (auto focus) processing, AE (auto exposure) processing, AWB (auto white balance) processing, and EF (flash pre-emission) processing according to the first shutter switch signal SW1.

[0047] The second shutter switch 563 turns on when the operation of the shutter button 561 is completed, that is, a so-called full-press (shooting instruction), and generates a second shutter switch signal SW2. The system control unit 530 starts a series of shooting processing operations from reading the signal from the imaging unit 522 to writing the captured image to the recording medium 534 as an image file according to the second shutter switch signal SW2.

[0048] The mode switch 564 switches the operation mode of the system control unit 530 to any one of a still image shooting mode, a video shooting mode, a playback mode, etc. Modes included in the still image shooting mode include an auto shooting mode, an auto scene discrimination mode, a manual mode, an aperture priority mode (Av mode), a shutter speed priority mode (Tv mode), and a program AE mode (P mode). There are also various scene modes and custom modes that are shooting settings according to the shooting scene. From the mode switch 564, the user can select any of these modes. It can be directly switched to either one. Alternatively, after once switching to the list screen of the shooting modes using the mode switching switch 564, it may be selectively switched to any one of the plurality of displayed modes using other operation members. Similarly, the video shooting mode may also include a plurality of modes.

[0049] The touch panel 567 is a touch sensor that detects various touch operations on the display surface of the display unit 529 (the operation surface of the touch panel 567). The touch panel 567 and the display unit 529 can be integrally configured. For example, the touch panel 567 is configured such that the light transmittance does not interfere with the display of the display unit 529 and is attached to the upper layer of the display surface of the display unit 529. Then, the input coordinates on the touch panel 567 and the display coordinates on the display surface of the display unit 529 are associated with each other. Thereby, a GUI (Graphical User Interface) can be provided as if the user can directly operate the screen displayed on the display unit 529. The display unit 529 having the touch panel 567 is called a touch panel display, and the touch-operable screen provided by the touch panel display is called a touch screen.

[0050] <Others> As described above, the preferred embodiments of the present invention have been explained, but the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

[0051] For example, a power supply device that combines the roles of the AC adapter and the DC coupler in the above embodiment may be configured. The power supply device with such a configuration converts the AC input from the commercial power supply as an external power source into DC and supplies it to the imaging device.

[0052] In the above embodiment, the protection circuit is switched between enabled and disabled according to whether the imaging device is in the still image shooting mode or the moving image shooting mode. However, the criteria for switching the protection circuit are not limited to this. For example, when there is a difference in power consumption during moving image shooting due to differences in the resolution, encoding, or image processing of the moving image, the protection circuit may be disabled only in the moving image shooting mode with high power consumption, and the protection circuit may be enabled in the moving image shooting mode with low power consumption. Alternatively, when the imaging device performs an operation with high power consumption other than moving image shooting, the protection circuit may be disabled.

[0053] The disclosure of this specification includes the following configurations.

[0054] (Configuration 1) A power supply device for supplying power from an external power source to an imaging device, A protection circuit configured to temporarily maintain power supply to the imaging device when the supply of power from the external power source is cut off, Control means for performing control to switch between a first mode in which the protection circuit is disabled and a second mode in which the protection circuit is enabled, A power supply device having the above.

[0055] (Configuration 2) The first mode is a mode in which power consumption by the protection circuit is reduced by disabling the protection circuit The power supply device according to Configuration 1.

[0056] (Configuration 3) The first mode is a mode in which, by reducing power consumption by the protection circuit, more power can be supplied to the imaging device than in the second mode The power supply device according to Configuration 2.

[0057] (Configuration 4) The control means switches between the first mode and the second mode in response to an instruction from the imaging device The power supply device according to any one of Configurations 1 to 3.

[0058] (Configuration 5) When the imaging device performs video shooting, the control means switches to the first mode, and when the imaging device performs still image shooting, the control means switches to the second mode. The power supply device according to any one of Configurations 1 to 4.

[0059] (Configuration 6) When the control means detects that the power supply device is not connected to the imaging device, the control means switches to the second mode. The power supply device according to any one of Configurations 1 to 5.

[0060] (Configuration 7) The protection circuit includes a capacitor that holds electric charge and a diode disposed between the external power supply and the imaging device. The control means includes a switch that opens and closes a path for bypassing the diode and a control circuit that controls the switch. In the first mode, the control circuit closes the switch, thereby electrically connecting the external power supply and the imaging device without passing through the diode. In the second mode, the control circuit opens the switch, thereby electrically connecting the external power supply and the imaging device via the diode. The power supply device according to any one of Configurations 1 to 6.

[0061] (Configuration 8) The external power supply is an AC adapter that converts AC to DC. The power supply device is a DC coupler for supplying the DC output of the AC adapter to the imaging device. The power supply device according to any one of Configurations 1 to 7.

[0062] (Configuration 9) An imaging device to which power from an external power supply is supplied via a power supply device. The power supply device has a protection circuit configured to temporarily maintain power supply to the imaging device when power supply from the external power source is cut off, and a function of switching the protection circuit between enabled and disabled. The imaging device has an instruction means for transmitting an instruction to switch the protection circuit between enabled and disabled to the power supply device. Imaging device.

[0063] (Configuration 10) The instruction means transmits an instruction to disable the protection circuit when the imaging device performs video shooting, and transmits an instruction to enable the protection circuit when the imaging device performs still image shooting. The imaging device according to Configuration 9.

[0064] (Configuration 11) The imaging device has a determination means for determining whether the connected power supply device has a function of switching the protection circuit between enabled and disabled. When it is determined that the connected power supply device does not have a function of switching the protection circuit between enabled and disabled, the instruction means does not transmit an instruction to switch the protection circuit between enabled and disabled. The imaging device according to Configuration 9 or Configuration 10.

Explanation of reference numerals

[0065] 101: Imaging device 102: DC coupler (power supply device) 104: AC adapter (external power source) 109: Microcomputer 110: Diode 111: Capacitor 112: FET​

Claims

1. A power supply device for supplying power from an external power source to an imaging device, comprising: a protection circuit configured to temporarily maintain power supply to the imaging device when power supply from the external power source is cut off; control means for performing control to switch between a first mode in which the protection circuit is disabled and a second mode in which the protection circuit is enabled; A power supply device having the above.

2. The first mode is a mode in which power consumption by the protection circuit is reduced by disabling the protection circuit. The power supply device according to claim 1.

3. The first mode is a mode in which, by reducing power consumption by the protection circuit, more power can be supplied to the imaging device than in the second mode. The power supply device according to claim 2.

4. The control means switches between the first mode and the second mode in response to an instruction from the imaging device. The power supply device according to claim 1.

5. The control means switches to the first mode when the imaging device performs video shooting, and switches to the second mode when the imaging device performs still image shooting. The power supply device according to claim 1.

6. When the control means detects that the power supply device is not connected to the imaging device, it switches to the second mode. The power supply device according to claim 1.

7. The protection circuit includes a capacitor for holding charge and a diode disposed between the external power source and the imaging device. The control means includes a switch for opening and closing a path for bypassing the diode and a control circuit for controlling the switch. In the first mode, the control circuit closes the switch to electrically connect the external power source and the imaging device without passing through the diode. In the second mode, the control circuit opens the switch to electrically connect the external power source and the imaging device via the diode. The power supply device according to claim 1.

8. The external power source is an AC adapter for converting AC to DC. The power supply device is a DC coupler for supplying the DC output of the AC adapter to the imaging device. The power supply device according to any one of claims 1 to 7.

9. An imaging device to which power from an external power source is supplied via a power supply device. The power supply device has a protection circuit configured to temporarily maintain power supply to the imaging device when power supply from the external power source is cut off, and a function of switching the protection circuit between enabled and disabled states. The imaging device has an instruction means for transmitting an instruction to the power supply device to switch the protection circuit between enabled and disabled states. Imaging device. **Claim 10** The instruction means transmits an instruction to disable the protection circuit when the imaging device performs video shooting, and transmits an instruction to enable the protection circuit when the imaging device performs still image shooting. The imaging device according to claim 9. **Claim 11** The imaging device has a determination means for determining whether the connected power supply device has a function of switching the protection circuit between enabled and disabled states. When it is determined that the connected power supply device does not have a function of switching the protection circuit between enabled and disabled states, the instruction means does not transmit an instruction to switch the protection circuit between enabled and disabled states. The imaging device according to claim 9 or 10.

Images