JP2007221470A - Imaging device and power supply method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch a power supply source to an AC power supply adapter, without making a fully charged battery consumed, when the AC power supply adapter is connected to a camera body. <P>SOLUTION: When it is detected that the AC power supply adapter is connected to the camera body, power supplied from the battery is interrupted, and power is supplied to each part of the digital camera body from the AC power supply adapter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging apparatus that quickly realizes mutual switching between an internal power supply and an external power supply without wastefully consuming the internal power supply, and a power supply method thereof.

  Conventionally, two types of power sources, an external power source and an internal power source, have been prepared as power sources for driving the digital camera body. The external power supply is generally assumed to be a household AC power supply, and functions as a DC power supply when connected to the digital camera body via an AC power adapter. In addition, a detachable battery (secondary battery) is used as the internal power source.

  In general, power required to drive the digital camera body is preferentially supplied from the AC power adapter when the AC power adapter is connected to the digital camera, and is not supplied from the battery. On the other hand, when the AC power adapter is not connected to the digital camera, it is supplied from the battery.

  This is because the voltage value supplied from the AC power adapter is generally larger than the voltage value supplied from the battery due to battery consumption, and the digital camera body includes the AC power adapter and the battery. This is because power is supplied from the power supply having the larger voltage value.

  Here, with reference to FIG. 10, a mechanism in which electric power is supplied to each part of the digital camera body from the power source having the larger voltage value of the AC power adapter and the battery will be described. Since the diode 105 and the diode 106 are connected so that both ends in the forward direction face each other, the potential between them is the same. Further, diodes 105 and 106 having the same voltage threshold are used. Accordingly, since the power source having the smaller voltage value of the AC power adapter 101 and the battery 102 cannot supply a voltage equal to or higher than the threshold value of the diode, power is supplied from the power source having the larger voltage value.

  Further, in the conventional digital camera, when the power supply from the AC power adapter to the digital camera body is interrupted, the voltage supplied from the AC power adapter is finally 0 V through a transient state that gradually attenuates. However, in the transition period, when the voltage value supplied from the battery becomes larger than the voltage value supplied from the AC power adapter, power is supplied so that power is supplied from the battery to the digital camera body. The source is switched.

  On the other hand, there is a computer control device that has a function of detecting power-off of a computer and storing processing data being operated by a backup power source (see Patent Document 1), but the computer body is driven by the backup power source. It is not a thing.

JP 2000-29578 A

  By the way, in the above-described conventional digital camera, if the battery is in a fully charged state or near a fully charged state, the voltage value supplied from the battery is higher than the voltage value supplied from the AC power adapter. Also grows. In such a case, even if the AC power adapter is connected to the digital camera, since the power to the digital camera body is supplied from the battery, a battery in a fully charged state or a state close to full charge is contrary to the user's intention. It was exhausted.

  In the above-described conventional digital camera, when power supply from the AC power adapter to the digital camera body is cut off, it is detected that the AC power adapter is cut off, and the power supply source is connected from the AC power adapter to the battery. In the case where the function of switching to is provided, if the timing for detecting that the AC power adapter is shut off is delayed, the digital camera may be momentarily interrupted, and image data or the like may be damaged.

  The present invention has been made in view of such circumstances. When the AC power adapter is connected to the digital camera body, the battery in a fully charged state or a state close to full charge is consumed against the user's intention. In addition, when the power is supplied to the digital camera from the AC power adapter and the connection between the AC power adapter and the digital camera body is interrupted, the digital camera is instantly switched to battery drive without instantaneous interruption. An object is to provide an imaging apparatus and a power supply method thereof.

  In order to solve the above-described problems, an imaging apparatus according to the present invention includes a power selection unit that supplies power to each part of the imaging apparatus main body from a power supply having a larger voltage value of an external power supply and an internal power supply, and the external power supply. An external power supply voltage detecting means for detecting a voltage supplied from the internal power supply, an internal power supply voltage detecting means for detecting a voltage supplied from the internal power supply, and supply and cut-off of power from the internal power supply to each part of the imaging apparatus main body. An internal power switch that can be switched between and the power supply to each part of the imaging apparatus main body from the internal power supply, and the external power supply detects the imaging based on the detection output by the external power supply voltage detection means When it is detected that it is connected to the apparatus body, the voltage value detected by the external power supply detection means is smaller than the voltage value detected by the internal power supply voltage detection means. In such a case, the internal power switch cuts off the power supplied from the internal power supply so that the external power supply is selected by the power supply selection means, and supplies the power from the external power supply to each part of the imaging apparatus main body. And a control means.

  In order to solve the above problems, the power supply method of the imaging apparatus according to the present invention is a power supply selection method for supplying power to each part of the imaging apparatus main body from a power supply having a larger voltage value of an external power supply and an internal power supply. An external power supply voltage detection step for detecting a voltage supplied from the external power supply, and an internal power supply voltage detection step for detecting a voltage supplied from the internal power supply. When power is supplied from the power source to each part of the imaging device body, and when it is detected that the external power source is connected to the imaging device body based on the detection output of the external power supply voltage detection step In addition, when the voltage value detected by the external power supply detection step is smaller than the voltage value detected by the internal power supply voltage detection step, the external power supply is selected as a power supply source. To block the power supplied from the internal power supply, and supplying power to the imaging apparatus main body each unit from the external power source.

  According to the present invention, when the AC power adapter is connected to the digital camera body, the power from the AC power adapter to the digital camera can be consumed without draining the battery in a fully charged state or a state close to full charging against the user's intention. Can be supplied.

  Further, according to the present invention, when the connection between the AC power adapter and the digital camera body is cut off, the digital camera can be instantaneously switched to battery driving without instantaneously interrupting the digital camera.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The present invention is applied to, for example, a digital camera 10 configured as shown in FIG.

  On the front surface of the digital camera 10 (see FIG. 1A), a lens 19 for forming a subject image, a strobe 11 that emits light to irradiate the subject as necessary during photographing, and a subject to be photographed. A finder 12 used for determining the composition is provided.

  On the top surface of the digital camera 10 (see FIG. 1B), there are provided a release button (shutter) 14 that is pressed when performing photographing, and a power switch 13. It should be noted that the release button 14 of the digital camera 13 according to the present embodiment is pressed to the intermediate position (hereinafter referred to as “half-pressed state”) and pressed to the final pressed position beyond the intermediate position. (Hereinafter, referred to as “fully pressed state”) can be performed in two stages.

  In the digital camera 10, the release button 14 is pressed halfway to activate the AE (Automatic Exposure) function and set the exposure state (shutter speed, aperture state), then AF (Auto Focus) Focusing function is activated and focusing control is performed, and then exposure (photographing) is performed when the button is fully pressed.

  On the back surface of the digital camera 10 (see FIG. 1C), a liquid crystal display (hereinafter referred to as “LCD”) for displaying the eyepiece portion of the finder 12 and a photographed subject image, a menu screen, and the like. 15), a mode changeover switch 16 that is slid to set any one of a shooting mode that is a mode for performing shooting and a playback mode that is a mode for playing back a subject image on the LCD 15, and a cursor key 17 are provided. The cursor key 17 functions as a determination key when it is tilted in four directions of up, down, left, and right to determine a moving direction with respect to the display on the LCD 15 and pressed. A function at the time of shooting or playback can be selected by the cursor key 17.

  A DC IN connector 18 for connecting the AC power adapter 20 is provided on the bottom surface of the digital camera 10 (see FIG. 1D).

  Next, the configuration of the AC power adapter 20 connected to the digital camera 10 will be described with reference to FIG. The AC power adapter 20 includes a power plug 21 that is inserted into a household power outlet and takes out the power, and a voltage converter that converts a household voltage (AC100V in Japan) into an operating voltage of the digital camera 10 (in this case, DC4.2V). 22 and a DC IN plug 23 connected to supply the converted voltage to the digital camera 10.

  Here, the configuration of the electrical system of the digital camera 10 according to the present embodiment will be described with reference to FIG. The digital camera 10 includes an optical unit 30 including the lens 19 described above, a charge coupled device (hereinafter referred to as “CCD”) 31 disposed behind the optical axis of the lens 19, and an input analog. And an analog signal processing unit 32 that performs various analog signal processing on the signal.

  The digital camera 10 also performs an analog / digital converter (hereinafter referred to as “ADC”) 33 that converts an input analog signal into digital data, and performs various digital signal processing on the input digital data. And a digital signal processing unit 34. The digital signal processing unit 34 has a built-in line buffer having a predetermined capacity, and also performs control to directly store the input digital data in a predetermined area of the memory 48 described later.

  The output end of the CCD 31 is connected to the input end of the analog signal processing unit 32, the output end of the analog signal processing unit 32 is connected to the input end of the ADC 33, and the output end of the ADC 33 is connected to the input end of the digital signal processing unit 34. ing. Therefore, the analog signal indicating the subject image output from the CCD 31 is subjected to predetermined analog signal processing by the analog signal processing unit 32, converted into digital image data by the ADC 33, and then input to the digital signal processing unit 34.

  In addition, the digital camera 10 generates an LCD interface (I / F) 49 that generates a signal for displaying an object image, a menu screen, and the like on the LCD 15 and supplies the signal to the LCD 15, and a CPU (center) that controls the operation of the entire digital camera 10. And a memory interface (I / F) 47 for controlling access to the memory 48. The processing device 39), a memory 48 for storing digital image data obtained by photographing, and the like.

  The digital camera 10 also has an external memory interface (I / F) 45 for making the portable memory card 44 accessible by the digital camera 10, and compression / decompression processing for performing compression processing and decompression processing on the digital image data. And a circuit 46.

  The digital signal processing unit 34, the LCD interface 49, the CPU 39, the memory interface 47, the external memory interface 45, and the compression / decompression processing circuit 46 are connected to each other via the system bus BUS. Therefore, the CPU 39 controls the operation of the digital signal processing unit 34 and the compression / decompression processing circuit 46, displays various information via the LCD interface 49 to the LCD 15, the memory interface 47 to the memory 48 and the memory card 44, and the external memory. Each access via the interface 45 can be made.

  The digital camera 10 includes a timing generator 36 that mainly generates a timing signal for driving the CCD 31 and supplies the timing signal to the CCD 31. The driving of the CCD 31 is controlled by the CPU 39 via the timing generator 36.

  Further, the digital camera 10 is provided with a motor drive unit 35, and the driving of a focus adjustment motor, a zoom motor and an aperture drive motor (not shown) provided in the optical unit 30 is also controlled by the CPU 39 via the motor drive unit 35. The

  The release button 14, the power switch 13, the mode change switch 16, and the cursor key 17 described above are connected to the CPU 39, and the CPU 39 always keeps track of the operation state of these operation units. In addition, the digital camera 10 includes a charging unit 38 that is interposed between the strobe 11 and the CPU 39 and charges power for causing the strobe 11 to emit light under the control of the CPU 39. Further, the strobe 11 is also connected to the CPU 39, and the light emission of the strobe 11 is controlled by the CPU 39.

  The digital camera 10 can be loaded with a battery 43 such as a battery, and includes a power supply circuit 41 for supplying power from the loaded battery 43 to the above-described units. The power supply circuit 41 can also be connected to the AC power adapter 20, and the power from the AC power adapter 20 can also be supplied to each load in the same manner as the battery. The power supply circuit 41 can also charge the battery 43 with power from the AC power adapter 20 under the control of the CPU 39.

  Here, the configuration of the power supply circuit 41 of the digital camera 10 will be described with reference to FIG. The power supply circuit 41 includes a DC IN connector 18 for connecting the AC power adapter 20, a connection terminal 55 for connecting the battery 43, a battery charge control FET 52, and a diode for causing the current from the AC power adapter 20 to flow in the forward direction. 50, a diode 51 for causing the current from the battery 43 to flow in the forward direction, an FET 53 for controlling the power from the battery 43, and a power output circuit 54 for outputting the power to each part of the electrical system constituting the digital camera 10. , Is composed of.

  In the power supply circuit 41, power is output from the battery 43 or the AC power adapter 20 to each part of the electrical system of the digital camera 10.

  The power supply circuit 41 is controlled by the CPU 39 described above. The CPU 39 includes an A / D port that reads a voltage from the AC power adapter 20 and also includes an output port that controls the FET 52 and the FET 53.

  The FET 52 constituting the power supply circuit 41 is controlled by the CPU 39 so as to be turned on at the time of charging. The operation of the FET 53 will be described later.

  For these FET 52 and FET 53, MOS FETs having a small ON resistance are used, and for the diode 50 and the diode 51, those having a small forward voltage (VF) are used. FIG. 5 shows IF-VF characteristics of the diode 50 and the diode 51 mentioned as examples.

  Next, characteristics of the AC power adapter 20 connected to the digital camera 10 will be described with reference to FIG. FIG. 6 shows a general load characteristic with respect to the load current of the output voltage of the AC power adapter 20 connected to the digital camera 10. There is a difference. In the embodiment, the value about 1.2% lower than the reference value is the minimum specification value. The output voltage of the AC power adapter 20 varies even when the load current is constant as indicated by the reference value and the minimum specification value. For example, even if the rated voltage of the AC power adapter is referred to as 4.2 V, the actual output voltage may be low within the range of the reference value and the minimum specification value. Further, as indicated by the load characteristics, the output voltage decreases as the load current increases. For example, the reference value of the output voltage at a load current of 500 mA is 4.15 V. However, when the load current is set to 1000 mA, the reference value of the output voltage decreases to around 4.00 V.

  Here, the operation of the power supply circuit 41 when the FET 53 is in the ON state will be described with reference to FIG. First, power is supplied to the power supply circuit 41 by either the AC power adapter 20 or the battery 43. The battery 43 is a general lithium ion rechargeable battery having a rated voltage of 3.6V. When the battery 43 is fully charged, the output voltage is 4.2 V or higher. Further, the AC power adapter 20 has the load characteristics shown in FIG. 6 as described above. By connecting the AC power adapter 20 to the DC IN connector 18, power is supplied from the AC power adapter 20 to the power circuit 41.

  Since the diode 50 and the diode 51 are connected so that both ends in the forward direction face each other, the potential between them is the same. The diode 50 and the diode 51 have the IF-VF characteristics shown in FIG. 5 and have the same voltage threshold. If the voltage from the AC power adapter 20 is Vac, the voltage from the battery 43 is Vbat, and the forward voltage of the diode 50 and the diode 51 is Vf, then if Vac−Vf> Vbat−Vf holds, Even when both batteries 43 are connected, the power from the AC power adapter 20 is preferentially supplied to the power output circuit 53.

  Here, a case where both a fully charged battery and an AC power adapter are connected to the digital camera 10 and the load current of the digital camera 10 is 500 mA will be described as an example. The voltage Vac from the AC power adapter 20 is 4.15V as a reference value with reference to FIG. On the other hand, the voltage Vbat from the fully charged battery 43 is 4.2 V or more as described above. Since Vf of the diode 50 and the diode 51 are equal, 4.15−Vf <4.2−Vf, and the voltage from the battery 43 is higher than the voltage from the AC power adapter, and the power from the battery 43 is Is supplied.

  Next, the operation of the power supply circuit 41 when the FET 53 is in the OFF state will be described with reference to FIG. When the FET 53 is turned off, the power from the battery 43 is cut off. Therefore, even when the battery is in a fully charged state, power is supplied to the power supply circuit 41 from the AC power adapter 20.

  With reference to FIG. 7, the control of the CPU 39 when the AC power adapter 20 is connected to the digital camera 10 to which only the battery 43 is connected will be described.

  First, in step S <b> 1, the CPU 39 detects the voltage of the DC IN connector 18 regardless of the standby state of the digital camera 10 or the operation state by a user operation.

  In step S <b> 2, the CPU 39 determines whether the AC power adapter 20 is connected to the DC IN connector 18. When the user connects the AC power adapter 20 to the DC IN connector 18, a predetermined voltage is applied to the DC IN connector 18. Therefore, when the CPU 39 detects the predetermined voltage, the AC power adapter 20 is connected. On the other hand, if it is not detected, it is determined that the AC power adapter 20 is not connected. The CPU 39 proceeds to the next step when determining that the AC power adapter 20 is connected, and ends the process when determining that the AC power adapter 20 is not connected.

  In step S3, the CPU 39 detects the voltage from the battery.

  In step S4, the CPU 39 determines the magnitude of the voltage value supplied from the AC power adapter 20 and the voltage value supplied from the battery. If the voltage value supplied from the AC power adapter 20 is larger, the power supply is performed. Since the source does not switch to the battery, the process is terminated to maintain the current state. On the other hand, if the voltage value supplied from the battery is larger, the process proceeds to the next step of switching the power supply source to the AC power adapter 20 in order to avoid wasteful consumption of the battery.

  In step S5, the CPU 39 controls the FET 53 to be in an OFF state. When the FET 53 is turned off, the power from the battery 43 is cut off as described above, and power is supplied from the AC power adapter 20 to the power supply circuit 41.

  As described above, according to the present invention, even when the battery 43 is fully charged or the output voltage is unstable due to the load characteristics of the AC power adapter 20, the power supply source is connected from the battery 43 to the AC. Switching to the power adapter 20 is possible.

  Furthermore, with reference to FIG. 8, the control of the CPU 39 when the AC power adapter 20 is removed while both the battery 43 and the AC power adapter 20 are connected to the digital camera 10 will be described. When the AC power adapter 20 is already connected, the power supply source is the AC power adapter 20 as described above, and the voltage value supplied from the AC power adapter 20 and the voltage supplied from the battery are as follows. Depending on the magnitude of the value, the FET 53 can be in two states, an ON state and an OFF state. If the FET 53 is in the ON state, the power supply source having a large voltage value is given priority as before, so that the battery becomes the power supply source after the decay transition period. On the other hand, if the FET 53 is in the OFF state, the power supply source is not automatically switched to the battery, so that it is necessary to switch the power supply source to the battery under the control of the CPU 39. Here, the control of the CPU 39 when the FET 53 is in the OFF state will be described.

  Here, the digital camera 10 is provided with various operation modes, and the load current differs depending on the operation mode. When the load current changes, the voltage at the end of the AC power adapter 20 having the load characteristics shown in FIG. 6 also changes. In the table of FIG. 9, an example of the AC power adapter 20 terminal voltage with respect to various operation modes is shown.

  First, in step S11, the CPU 39 initially turns off the power supply of the digital camera 10 and then the user turns on the power supply in an arbitrary operation mode, or the power supply of the digital camera 10 turns on. It is ON, and then it is determined whether or not the digital camera 10 has started to operate in an arbitrary operation mode by detecting that the user has switched the operation mode to an arbitrary operation mode. If the digital camera 10 has already been operated in an arbitrary operation mode, the process proceeds to step S14.

  In step S12, the voltage (Va) at the end of the AC power adapter 20 is detected under the control of the CPU 39.

  In step S13, the reference voltage value Va is recorded in the RAM in the CPU 39 for each operation mode under the control of the CPU 39. For example, the voltage Va at the AC power adapter 20 end in the “release half-press” operation mode is 4.0 V, the voltage Va at the AC power adapter 20 end in the “zoom” operation mode is 3.5 V, and so on. Record in RAM.

  Each time step S13 is executed, the reference voltage value Va in the operation mode is rewritten on the RAM.

  In step S14, the voltage (Vb) at the end of the AC power adapter 20 is detected under the control of the CPU 39. If it is determined in step S11 that the digital camera 10 has already been operated in an arbitrary operation mode, this step is executed.

  In step S15, the CPU 39 determines the magnitude of Va and Vb. What is important here is to match the operation mode of the reference voltage value Va with the operation mode of the current voltage value Vb. If Vb is equal to or greater than Va, it can be determined that the AC power adapter 20 is still connected to the digital camera 10, and the process is terminated so that the current state is maintained.

  In step S16, the CPU 39 determines that the supply of power from the AC power adapter 20 is interrupted because Va> Vb, and proceeds to step S17.

  In step S17, the CPU 39 controls the FET 53 to be turned on. As a result, the power supply source is switched from the AC power adapter 20 to the battery 43.

  The above-described steps are periodically executed by the CPU 39.

  Here, in the conventional digital camera, the power supply source is switched to the battery when the voltage supplied from the AC power adapter becomes lower than the voltage supplied from the battery after the decay transition period. . In the present invention, if the voltage drops below the reference voltage value for each operation mode without passing through the decay transition period, it can be determined that the connection has been cut off. There is no delay.

  As described above, according to the present invention, when the connection between the AC power adapter and the digital camera body is interrupted, the digital camera can be instantaneously switched to battery driving without instantaneously interrupting the digital camera.

  In addition, this invention is not limited to the above example. In particular, the internal power supply of the imaging apparatus according to the present invention is not limited to a lithium ion rechargeable battery, and may be another battery such as a fuel cell.

(A) is a front view of the digital camera, (B) is a plan view of the digital camera, (C) is a rear view of the digital camera, and (D) is a bottom view of the digital camera. It is the figure which showed the structure of AC power adapter. It is the block diagram which showed the structure of the electric system of a digital camera. It is the block diagram which showed the structure of the power supply circuit of a digital camera. It is a figure showing IF-VF characteristic of a diode. It is a figure showing the characteristic of the output voltage with respect to the load current of AC power adapter. It is the flowchart which showed the control process when detecting that the AC power adapter was connected. It is the flowchart which showed the control process when it detects that the connection of AC power adapter was cut | disconnected. It is the table which showed an example of the AC power adapter terminal voltage with respect to various operation modes. It is the block diagram which showed the structure of the power supply circuit of the conventional digital camera.

Explanation of symbols

  10 Digital Camera, 11 Strobe, 12 Finder, 13 Power Switch, 14 Release Button, 15 LCD, 16 Mode Change Switch, 17 Cursor Key, 18 DC IN Connector, 20 AC Power Adapter, 21 Power Plug, 22 Voltage Converter, 23 DC IN plug, 30 optical unit, 31 CCD, 32 analog signal processing unit, 33 ADC, 34 digital signal processing unit, 35 motor drive unit, 36 timing generator, 38 charging unit, 39 CPU, 40 operation unit, 41 power supply circuit, 43 battery, 44 memory card, 45 external memory I / F, 46 compression / extension processing function unit, 47 memory I / F, 48 memory, 49 LCD I / F, 50 diode, 51 diode, 52 FET, 53 FET, 4 power supply output circuit, 55 a connection terminal, 100 a power supply circuit, 101 AC power adapter, 102 battery, 103 DC IN connector 104 connecting terminal, 105 a diode, 106 a diode, 107 FET, 108 power supply output circuit, 109 CPU

Claims (4)

A power source selecting means for supplying power to each part of the imaging apparatus main body from a power source having a larger voltage value of the external power source and the internal power source;
An external power supply voltage detecting means for detecting a voltage supplied from the external power supply;
Internal power supply voltage detecting means for detecting a voltage supplied from the internal power supply;
An internal power switch capable of switching between power supply and cutoff from the internal power supply to each part of the imaging apparatus main body;
When power is supplied from the internal power supply to each part of the imaging apparatus body, it is detected that the external power supply is connected to the imaging apparatus body based on a detection output from the external power supply voltage detection means. The internal power supply so that the external power supply is selected by the power supply selection means when the voltage value detected by the external power supply detection means is smaller than the voltage value detected by the internal power supply voltage detection means. Control means for cutting off power supplied from the internal power supply by a switch and supplying power from the external power supply to each part of the imaging apparatus body;
An imaging apparatus comprising: The voltage value detected by the external power supply voltage detection means when the imaging apparatus body is activated in an arbitrary operation mode or when the imaging apparatus body in the activated state is switched to an arbitrary operation mode. External power supply voltage recording means for recording as a reference voltage value in the operation mode,
The control means is configured such that when power is supplied from the external power source to each part of the imaging apparatus body, the voltage value detected by the external power supply voltage detection means in any operation mode of the imaging apparatus body is the external power supply. When it is smaller than the reference voltage value in the operation mode recorded by the voltage recording means, it is detected that the connection between the external power source and the imaging device body is cut off, and the internal power source is selected by the power source selecting means. The imaging apparatus according to claim 1, wherein the internal power switch is energized and power is supplied from the internal power supply to each part of the imaging apparatus main body. A power supply selection process for supplying power to each part of the imaging apparatus main body from the power supply having the larger voltage value of the external power supply and the internal power supply,
An external power supply voltage detection step for detecting a voltage supplied from the external power supply;
An internal power supply voltage detection step for detecting a voltage supplied from the internal power supply,
The power source selection step is a case where power is supplied from the internal power source to each part of the imaging device body, and the external power source is connected to the imaging device body based on a detection output in the external power source voltage detection step. If the voltage value detected by the external power source detection step is smaller than the voltage value detected by the internal power source voltage detection step, the external power source is selected as a power supply source. A method of supplying power to the imaging apparatus, wherein the power supplied from the internal power supply is cut off and power is supplied from the external power supply to each part of the imaging apparatus main body. The voltage value detected by the external power supply voltage detection step when the imaging apparatus body is activated in an arbitrary operation mode or when the imaging apparatus body in the activated state is switched to an arbitrary operation mode An external power supply voltage recording step for recording as a reference voltage value in the operation mode;
In the power source selection step, when power is supplied from the external power source to each part of the imaging device main body, the voltage value detected by the external power source voltage detection step in any operation mode of the imaging device main body is When it is smaller than the reference voltage value in the operation mode recorded in the power supply voltage recording step, it is detected that the connection between the external power supply and the imaging device body is cut off, and the internal power supply is selected as a power supply source. The power supply of the imaging apparatus according to claim 3, wherein the power supply from the internal power supply is released from a cutoff state, and power is supplied from the internal power supply to each part of the imaging apparatus main body. Method.

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