Imaging apparatus, control method, and program

Abstract

To contribute to an improvement in the performance of an imaging apparatus.SOLUTION: An imaging apparatus has: a first load; a second load; and a control unit that performs control to supply power from a first power supply to the first load and the second load. When the control unit can receive a power larger than the power from the first power supply from a second power supply different from the first power supply, it controls to supply the power from the first power supply to the first load and supply the power from the second power supply and larger than the power from the first power supply to the second load.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an imaging device and a method for controlling the imaging device.

Background Art

[0002] Patent Document 1 describes a method of supplying power from a sub-power source to a high-priority load when the output power of the main power source decreases.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The method described in Patent Document 1 can prevent the power supply to a high-priority load from being interrupted, but does not control the power supply so as to contribute to the performance improvement of the imaging device.

[0005] Therefore, an object of the present invention is to contribute to the performance improvement of an imaging device.

Means for Solving the Problems

[0006] In order to achieve the above object, an imaging device according to the present invention includes a first load, a second load, and a control unit that controls to supply power from a first power source to the first load and the second load. When the control unit can receive power greater than the power from the first power source from a second power source different from the first power source, the control unit supplies the power from the first power source to the first load and controls to supply the power greater than the power from the first power source from the second power source to the second load.

Effects of the Invention

[0007] According to the present invention, it is possible to contribute to improving the performance of imaging devices. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram illustrating the components related to the power supply operation of the imaging device 100 in Embodiment 1. [Figure 2] This is a block diagram illustrating the components related to the imaging operation of the imaging device 100 in Embodiment 1. [Figure 3] This is a circuit diagram illustrating the configuration of the strobe charging unit 231 and the strobe light emission control unit 232 of the imaging device 100 in Embodiment 1. [Figure 4] This is a flowchart illustrating an example of the imaging operation of the imaging device 100 in Embodiment 1. [Figure 5] This figure shows an example of the determination conditions for the strobe charging mode of the imaging device 100 in Embodiment 1. [Figure 6] This figure illustrates an example of the operation of the imaging device 100 in charging mode in Embodiment 1. [Figure 7] This is a sequence diagram illustrating an example of the shooting operation of the imaging device 100 in strobe charging mode in Embodiment 1. [Figure 8] This figure shows an example of the display screen of the imaging device 100 during strobe photography in Embodiment 1. [Figure 9] This figure shows an example of the operating state of the switch circuit of the imaging device 100 in Embodiment 1. [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention to the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, the same or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0010] [Embodiment 1] The imaging device 100 in Embodiment 1 will be described below.

[0011] Figure 1 is a block diagram illustrating the components related to the power supply operation of the imaging device 100 in Embodiment 1.

[0012] Embodiment 1 describes a case where the imaging device 100 is a digital camera capable of continuous shooting (burst shooting) using a strobe. However, the imaging device 100 is not limited to a digital camera, but may be a smartphone or tablet PC, etc., capable of continuous shooting (burst shooting) using a strobe.

[0013] The imaging device 100 is connected to the power supply device 500 via an external connection terminal 101. The power supply device 500 is connected to a commercial AC outlet and operates on AC power. The external connection terminal 101 is a terminal compliant with the USB (Universal Serial Bus) Type-C standard. The external connection terminal 101 includes a VBUS terminal for power supply, CC1 and CC2 terminals for detecting the connection of external devices and communicating with external devices, D+ and D- terminals for communication compliant with the USB 2.0 standard, a GND terminal, etc. The external connection terminal 101 is a terminal compliant with the PPS (Programmable Power Supply) function compliant with the USB PD (Power Delivery) standard. The power supply device 500 supplies voltage to the external connection terminal 101 according to the requirements of the imaging device 100. The imaging device 100 and the power supply device 500 are connected, for example, by a cable compliant with the USB Type-C standard.

[0014] The first switch circuit 102 is a circuit for switching between an ON state, which supplies power to the imaging device 100 via the external connection terminal 101, and an OFF state, which does not supply power to the imaging device 100. The first switch circuit 102 is composed of a switch element such as an FET (Field Effect Transistor), and is controlled to switch between the ON state and the OFF state by the PD communication control unit 103.

[0015] The PD communication control unit 103 can detect connections to external devices and communicate with external devices in accordance with the USB PD standard using the CC1 and CC2 terminals. The PD communication control unit 103 controls the first switch circuit 102 to an ON state or an OFF state according to the power supply status from the power supply device 500 connected to the external connection terminal 101 or a control command from the system control unit 104. The PD communication control unit 103 transmits and receives voltage and / or current information during power supply to and from the power supply device 500 using the CC1 or CC2 terminal according to a control command from the system control unit 104.

[0016] The system control unit 104 executes various processes (programs) according to instructions from the user received by the UI (user interface) unit to control each component of the imaging device 100 or to control data transfer between components. The system control unit 104 may be a microcomputer in which a CPU and a memory are configured as a hardware processor.

[0017] The second switch circuit 105 is a circuit for switching between an on state in which power is supplied to the first power supply unit 115 via the external connection terminal 101 and an off state in which power is not supplied to the first power supply unit 115 via the external connection terminal 101. The second switch circuit 105 is composed of elements such as FETs, for example. The on state or off state of the second switch circuit 105 is controlled by the charge control unit 107.

[0018] The charging power supply unit 106 converts the voltage supplied from the external connection terminal 101 into a predetermined voltage. The charging power supply unit 106 is, for example, a step-up / step-down operable buck-boost type DC / DC converter circuit composed of an inductor element, a capacitor element, and a switching element. By accumulating and releasing the energy of the inductor element by the on / off operation of the switching element, the voltage from the external connection terminal 101 can be converted into a predetermined voltage. The on state or off state of the switching element is controlled by the charge control unit 107.

[0019] The charge control unit 107 is a circuit that controls the charging power supply unit 106 based on the voltage and current detected by the current-voltage detection circuit 108. When charging the battery 110, the charge control unit 107 controls the output voltage of the charging power supply unit 106 so that the terminal voltage and charging current of the battery 110 reach predetermined values.

[0020] The current-voltage detection circuit 108 is a circuit that detects the terminal voltage of the battery 110 and the charging current to or discharging current from the battery 110. The detected values of the terminal voltage, charging current, and discharging current detected by the current-voltage detection circuit 108 are notified to the charge control unit 107.

[0021] The third switch circuit 109 is a circuit for switching between an ON state, which enables power supply by connecting the power supply path from the battery 110 to the imaging device 100, and an OFF state, which disables power supply by disconnecting the power supply path. The third switch circuit 109 is composed of elements such as FETs. The third switch circuit 109 is controlled to be either ON or OFF by the charge control unit 107.

[0022] The battery 110 can be easily attached to and detached from the imaging device 100 by an attachment / detachment mechanism (not shown). The battery 110 is a rechargeable power supply unit composed of, for example, two battery cells. The battery cells in the battery 110 are lithium-ion battery cells composed of, for example, lithium-ion polymer. The two battery cells in the battery 110 are connected in series, for example. The battery 110 supplies power to the imaging device 100 via a third switch circuit 109. The battery 110 is charged by the power converted by the charging power supply unit 106. For example, when the battery 110 is fully charged, the voltage of the battery 110 is, for example, about 8.4V. The cutoff voltage of the battery 110 is, for example, about 6.0V. Note that the number of battery cells in the battery 110 is not limited to two, but may be one or three or more.

[0023] The fourth switch circuit 111, the fifth switch circuit 112, the sixth switch circuit 113, and the seventh switch circuit 114 are circuits controlled by the system control unit 104 to be on or off, and are composed of switching elements such as FETs. The fourth switch circuit 111 is a circuit for switching the power supply source to the strobe charging unit 231, and is controlled by the system control unit 104 to be on or off.

[0024] The fifth switch circuit 112 is a circuit for switching the power supply source to the first power supply unit 115, and is controlled by the system control unit 104 to be either ON or OFF. The fifth switch circuit 112 and the second switch circuit 105 are controlled so that they are not ON at the same time.

[0025] The sixth switch circuit 113 and the seventh switch circuit 114 are circuits for switching the power supply source to the second power supply unit 116, and are controlled by the system control unit 104 to be either ON or OFF. The sixth switch circuit 113 and the seventh switch circuit 114 are controlled so that they are not ON at the same time.

[0026] The first power supply unit 115 has a plurality of voltage conversion circuits for boosting or bucking the input voltage. The first power supply unit 115 has voltage conversion circuits such as a boost-type DC / DC converter circuit or a buck-boost-type DC / DC converter circuit composed of an inductor element, a capacitor element and a switching element. In Embodiment 1, the first power supply unit 115 receives an input voltage in the range of 5V to 15V and supplies an output voltage of 3.3V to 25V to the high-voltage load unit 118.

[0027] The second power supply unit 116 has a plurality of voltage conversion circuits for stepping down the input voltage. The second power supply unit 116 has voltage conversion circuits such as a buck-type DC / DC converter circuit composed of an inductor element, a capacitor element, and a switching element. In Embodiment 1, the second power supply unit 116 receives a voltage of 3.3V and supplies an output voltage of 0.7V to 1.8V to the low-voltage load unit 119.

[0028] The strobe charging section 231 is a charging circuit for storing charge in the main capacitor 304, which will be described later.

[0029] The shutter drive unit 117 is a drive circuit that drives the shutter unit 203 in response to a control command from the system control unit 104.

[0030] The high-voltage load section 118 is a load circuit that is driven by a high voltage, similar to the backlight section 212 described later.

[0031] The low-voltage load unit 119 is a load circuit that is driven by a low voltage, such as the imaging unit 204 or the image processing unit 206, which will be described later.

[0032] The power supply device 500 transmits and receives information about the voltage and / or current to be supplied to the imaging device 100 with the PD communication control unit 103. The power supply device 500 supplies the voltage and / or current requested by the PD communication control unit 103 to the imaging device 100 via the external connection terminal 101.

[0033] Figure 2 is a block diagram illustrating the components related to the imaging operation of the imaging device 100 in Embodiment 1.

[0034] The lens group 201 is an optical system for focusing the subject image light onto the imaging unit 204, which will be described later. The lens group 201 has an aperture mechanism to reduce the amount of light, a zoom mechanism to change the focal length by changing the lens position, and a focusing mechanism to adjust the focus by changing the lens position.

[0035] The lens drive unit 202 is a drive circuit that controls the aperture mechanism, zoom mechanism, and focus mechanism of the lens group 201 in response to control commands from the system control unit 104.

[0036] The shutter unit 203 is a mechanism that controls the exposure time of the subject image light reaching the imaging surface of the imaging unit 204 by opening and closing the incident light path from the lens group 201 to the imaging unit 204. The shutter unit 203 includes a shutter curtain that blocks the incident light path, a curtain travel member that moves the shutter curtain, and a motor that drives the curtain travel member. Furthermore, the shutter unit 203 includes a biasing member that applies a biasing force to the curtain travel member, and a locking member that holds the curtain travel member in a state where the biasing force of the biasing member has been accumulated. One end of the biasing member is fixed and the other end is connected to the curtain travel member, and the biasing force is accumulated by moving the curtain travel member against the biasing force of the biasing member using the motor. The locking member is moved by the motor to a position that holds the curtain travel member in a state where the biasing force of the biasing member has been accumulated, and the locking member releases the hold on the curtain travel member, thereby allowing the curtain travel member to move.

[0037] The imaging unit 204 is an image sensor having an imaging surface in which photoelectric conversion elements such as CMOS (Complementary Metal Oxide Semiconductor) or CCD (Charge Coupled Device) are arranged in a two-dimensional manner. The subject image light incident through the lens group 201 of the imaging device 100 is formed on the imaging surface of the imaging unit 204.

[0038] The AD conversion unit 205 is a circuit that converts the analog signal output from the imaging unit 204 into a digital signal.

[0039] The image processing unit 206 is a processor such as a GPU (Graphics Processing Unit) that performs image processing on image data output from the AD conversion unit 205, such as resizing (including pixel interpolation and reduction) or color conversion. The image processing unit 206 also performs predetermined calculations using the captured image data, and the system control unit 104 performs exposure control and distance measurement control based on the calculation results. This enables TTL (Through-the-Lens) AF (Autofocus), AE (Automatic Exposure), and EF (Flash Pre-flash) processing. Furthermore, the image processing unit 206 performs predetermined calculations using the image data and also performs TTL AWB (Automatic White Balance) processing based on the calculation results. Additionally, the image processing unit 206 converts the processed image data into an image file in a predetermined format (e.g., JPEG) and records it on the recording medium 209. The image processing unit 206 also generates display data for displaying the image on the display unit 211. Image processing can be performed on the entire image data area or on only a portion of the image data area.

[0040] The memory control unit 207 controls the transmission and reception of data between the AD conversion unit 205, the image processing unit 206, the volatile memory 208, the recording medium 209, and the display unit 211. Data from the AD conversion unit 205 is written to the volatile memory 208 via the image processing unit 206 and the memory control unit 207, or directly via the memory control unit 207.

[0041] The volatile memory 208 is a semiconductor memory such as DRAM that enables high-speed reading and writing of data. The volatile memory 208 is used as a work area for the system control unit 104 to process constants, variables, and programs read from the non-volatile memory 210. The volatile memory 208 is also used as a buffer memory to temporarily hold image data captured by the imaging unit 204 and as image display memory for the display unit 211.

[0042] The recording medium 209 is a storage device that can write new image files or read already recorded image files. The recording medium 209 may be a memory card or hard disk that is removable from the imaging device 100, or a flash memory or hard disk built into the imaging device 100.

[0043] The non-volatile memory 210 is a semiconductor memory such as flash ROM or EEPROM that allows data to be read and written. The non-volatile memory 210 stores constants and programs for the operation of the system control unit 104, characteristic data for the display unit 211, image processing parameters for the image processing unit 206, and so on.

[0044] The display unit 211 displays the viewfinder image during shooting, displays the captured image, and displays text for interactive operation. The display unit 211 is, for example, a display device such as a liquid crystal display or an organic EL display. The display unit 211 may be integrated with the imaging device 100 or it may be an external device connected to the imaging device 100. The imaging device 100 only needs to be able to connect to the display unit 211 and have the function to control the display of the display unit 211.

[0045] The display unit 211 has a UI unit (e.g., a touch panel) that receives instructions from the user. The touch panel detects touch operations by the user's finger or stylus on the display surface of the display unit 211 and outputs an operation signal corresponding to the touch operation to the system control unit 104.

[0046] The display unit 211 can display a menu screen stored in the image display data area of ​​the non-volatile memory 210, or an image file stored in the recording medium 209, in response to a control command from the system control unit 104. In addition, the display unit 211 functions as an EVF (Electronic View Finder) that provides live view by sequentially displaying image data output from the imaging unit 204.

[0047] The backlight unit 212 illuminates the display unit 211 from behind. Since an LCD display is a display that cannot emit light on its own, visibility as a display is achieved by illuminating it from the back. The backlight unit 212 is composed of light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), or fluorescent tubes, etc. The backlight unit 212 can turn on or off the illumination in response to control commands from the system control unit 104.

[0048] In Embodiment 1, the backlight section 212 is configured by connecting five white LEDs with the following characteristics in series.

[0049] VF (Forward Voltage): 3.75[V], where IF (Forward Current) = 26.7mA The voltage required to drive the LED is 3.75 × 5 = 15 [V], and the backlight unit 212 is powered by the first power supply unit 115.

[0050] Timer 213 is a timing unit that measures the time used for various controls or the time of the built-in clock. The system control unit 104 controls each component of the imaging device 100 based on the time measured by Timer 213. In addition, Timer 213 measures the strobe charging times Ta and Tb in the strobe charging mode, which will be described later in Figure 6.

[0051] The shutter button 214 is an operating member for issuing a shooting instruction or a shooting preparation instruction. The shutter button 214 has a first shutter switch 215 and a second shutter switch 216.

[0052] The first shutter switch 215 turns on during the user's operation while shooting, specifically when it is half-pressed (instructing the user to prepare for shooting), generating the first shutter switch signal SW1. Upon receiving the first shutter switch signal SW1, the system control unit 104 controls the imaging unit 204 to start shooting preparation operations such as AF processing, AE processing, AWB processing, and EF (flash pre-flash) processing.

[0053] The second shutter switch 216 turns ON when the user completes the operation during shooting, so-called a full press (shooting start instruction), and generates the second shutter switch signal SW2. Upon receiving the ON state of the second shutter switch signal SW2, the system control unit 104 starts a series of shooting operations, from reading the signal from the imaging unit 204 to writing the image data to the recording medium 209. The shooting operation then ends when the second shutter switch signal SW2 turns OFF (shooting end instruction).

[0054] The strobe charging unit 231 is a circuit that controls the charging of the main capacitor 304 in order to emit light from the strobe in response to a control command from the system control unit 104.

[0055] The strobe light emission control unit 232 is a circuit that controls the amount of light emitted by the strobe or the timing of the light emission in response to a control command from the system control unit 104.

[0056] The strobe section of the imaging device 100 is comprised of the strobe charging unit 231 and the strobe light emission control unit 232.

[0057] Figure 3 is a circuit diagram illustrating the configuration of the strobe charging unit 231 and the strobe light emission control unit 232 of the imaging device 100 in Embodiment 1.

[0058] The strobe charging unit 231 includes a step-up transformer 301, a switching control switch 302 for the step-up transformer 301, a diode 303, and a main capacitor 304.

[0059] When the switching control switch 302 is turned ON, current flows to the primary side of the step-up transformer 301. When the peak value of the primary side current reaches a predetermined value, the switching control switch 302 is turned OFF. When the switching control switch 302 is turned OFF, current begins to flow to the secondary side of the step-up transformer 301, and the main capacitor 304 is charged. When the secondary side current stops, the switching control switch 302 is turned ON again, and current flows to the primary side of the step-up transformer 301. The charging voltage of the main capacitor 304 is monitored by the system control unit 104. The system control unit 104 repeatedly controls the switching control switch 302 to be ON or OFF until the charging voltage reaches a predetermined value.

[0060] The strobe light emission control unit 232 includes a trigger capacitor 305, a trigger coil 307, a xenon tube 308, and an IGBT (insulated gate bipolar transistor) 306. When the IGBT 306 is turned on, the charge stored in the trigger capacitor 305 is boosted to several thousand volts by the trigger coil 307. The xenon in the xenon tube 308 is ionized by the boosted voltage from the trigger coil 307, causing it to conduct. The charge stored in the main capacitor 304 flows into the xenon tube 308, which is now conducting, causing it to emit light. The system control unit 104 controls the timing and amount of light emitted by controlling the on and off states of the IGBT 306.

[0061] The user can change the shooting parameters of the imaging device 100 by operating the menu screen displayed by the UI section of the display unit 211. The user can also change the operating mode of the imaging device 100 by operating the switches on the imaging device 100. The operating modes of the imaging device 100 include a strobe flash mode and a strobe off mode.

[0062] An external strobe can be connected to the imaging device 100 via an accessory shoe (not shown). The imaging device 100 can also supply power to and control the external strobe connected via the accessory shoe. Furthermore, the voltage and / or current supplied by the imaging device 100 to the external strobe can be changed depending on the type of external strobe. For example, if the maximum flash output of the external strobe connected to the imaging device 100 is high, the imaging device 100 will supply power to the external strobe at a voltage of 6V. If the maximum flash output of the external strobe connected to the imaging device 100 is low, the imaging device 100 can supply power to the external strobe at a voltage of 3V.

[0063] Next, the imaging operation of the imaging device 100 in Embodiment 1 will be described with reference to the flowchart in Figure 4.

[0064] The process shown in Figure 4 is achieved by the system control unit 104 executing a program stored in the non-volatile memory 210 to control each component of the imaging device 100.

[0065] When the battery 110 is installed in the imaging device 100 and the user instructs to turn on the power of the imaging device 100, the process shown in Figure 4 begins.

[0066] In step S401, the system control unit 104 supplies power to each part of the imaging device 100 using power from the battery 110, performs the startup process for the imaging device 100, and transitions to the shooting standby state. In the shooting standby state, the imaging unit 204 takes a picture to acquire a live view image. The image taken by the imaging unit 204 is processed by the AD conversion unit 205 and the image processing unit 206. The image processed by the image processing unit 206 is sent to the volatile memory 208 via the memory control unit 207 and temporarily stored in the volatile memory 208. Then, the image is read from the volatile memory 208 at an appropriate timing and sent to the display unit 211, where it is displayed as a live view image. In addition, in the shooting standby state, the system control unit 104 can control the image processing unit 206 to superimpose various information onto the live view image and display it on the display unit 211.

[0067] In step S402, the system control unit 104 obtains the terminal voltage of the battery 110 using the current-voltage detection circuit 108 and proceeds to step S403 of the process 400.

[0068] In step S403, the system control unit 104 determines whether the power supply device 500 is connected to the imaging device 100 by monitoring the external connection terminal 101 or by information from the PD communication control unit 103. If it determines that the power supply device 500 is connected to the imaging device 100, the system control unit 104 proceeds to step S404 of process 400. If it determines that the power supply device 500 is not connected to the imaging device 100, the system control unit 104 proceeds to step S412 of process 400.

[0069] In step S404, the system control unit 104 determines the power supply capacity of the power supply device 500 connected to the imaging device 100. The power supply capacity is determined by measuring the terminal voltage of the external connection terminal 101 or by communicating with the power supply device 500 via the PD communication control unit 103.

[0070] In step S405, the system control unit 104 stores the power supply capacity of the power supply device 500, which was determined in step S404, in the volatile memory 208, and proceeds to step S406 of the process 400.

[0071] In step S406, the system control unit 104 acquires information about the strobe to be used during shooting and proceeds to step S407 of process 400. The system control unit 104 acquires information about at least the maximum voltage that the strobe charging unit 231 can input and the battery voltage when fully charged.

[0072] In step S407, the system control unit 104 determines whether the strobe charging time of the imaging device 100 can be shortened based on the battery voltage obtained in step S402 and the power supply capacity of the power supply device 500 obtained in step S405. The system control unit 104 determines the power supply capacity of the power supply device 500 according to the determination conditions shown in Figure 5 and determines whether the strobe charging mode of the imaging device 100 can be changed to the high-speed charging mode. Figure 5 is a diagram showing an example of the determination conditions for the strobe charging mode of the imaging device 100 in Embodiment 1. In Figure 5, if the power supply capacity of the power supply device 500 exceeds the power supply capacity of the battery 110 (the output voltage and output current of the power supply device 500 exceed the terminal voltage and discharge current of the battery 110), it is determined that the strobe charging mode of the imaging device 100 can be changed to the high-speed charging mode. Furthermore, if the power supply capacity of the power supply device 500 is less than or equal to the power supply capacity of the battery 110 (the output voltage and output current of the power supply device 500 are less than or equal to the terminal voltage and discharge current of the battery 110), it is determined that the strobe charging mode of the imaging device 100 cannot be changed to the fast charging mode. In Figure 5, the first charging mode is the strobe charging mode when the imaging device 100 is operating using the power of the battery 110 and the power supply device 500. The second charging mode is the strobe charging mode when the imaging device 100 is operating using only the power of the battery 110. If the power supply capacity of the power supply device 500 connected to the imaging device 100 exceeds the power supply capacity of the battery 110, the strobe charging mode of the imaging device 100 can be changed to the first charging mode, which has a faster strobe charging time than the second charging mode. For example, suppose the power supply capacity of the battery 110 of the imaging device 100 is a terminal voltage of 8.4V and a discharge current of 3A when fully charged. In this case, the first charging mode can be selected when the power supply capacity of the power supply device 500 exceeds an output voltage of 8.4V and an output current of 3A. Also, when the power supply capacity of the battery 110 of the imaging device 100 drops to a terminal voltage of 7.2V and a discharge current of 3A, the first charging mode can be selected when the power supply capacity of the power supply device 500 exceeds an output voltage of 7.2V and an output current of 3A. If it is determined that the strobe charging mode can be changed to the high-speed charging mode, the system control unit 104 proceeds to step S408 of the process 400.If the system control unit 104 determines that it cannot change the strobe charging mode to high-speed charging mode, it proceeds to step S412 of process 400. The operation of the strobe charging unit 231 in the first charging mode and the second charging mode will be described later.

[0073] In step S408, the system control unit 104 displays a screen on the display unit 211 to notify the user that the strobe charging mode can be changed, and proceeds to step S409 of the process 400. The screen displayed on the display unit 211 includes, for example, a dialog 801 and buttons 802 and 803 as shown in Figure 8(a). Figure 8(a) is a diagram showing an example of the display screen of the live view image of the imaging device 100 in Embodiment 1. 801 is a dialog that displays that the strobe charging mode can be changed and the details of the change to the strobe charging mode. Button 802 is an option to accept the change notified in dialog 801. Button 803 is an option to reject the change notified in dialog 801.

[0074] Figure 8(b) shows an example of the display screen when button 802 is selected in the screen shown in Figure 8(a). In the screen shown in Figure 8(b), the first charging mode is selected and icon 804 is displayed, indicating that the shooting speed (frame rate) will not decrease during continuous shooting using the flash.

[0075] Figure 8(c) shows an example of the display screen when button 803 is selected in the screen shown in Figure 8(a). In the screen shown in Figure 8(c), the second charging mode is selected and icon 805 is displayed, indicating that the frame rate will decrease when continuous shooting is performed using the flash.

[0076] In step S409, the system control unit 104 determines whether either button 802 or button 803 was selected on the screen displayed on the display unit 211 in step S408. If the user selects button 802 using the touch panel or the like, the system control unit 104 proceeds to step S410 of process 400. If button 803 is selected, the system control unit 104 proceeds to step S412 of process 400.

[0077] In step S410, the system control unit 104 reads parameters from the non-volatile memory 210 to set the strobe charging time Ta for the first charging mode (< strobe charging time Tb for the second charging mode) based on the strobe information acquired in step S406.

[0078] In step S411, based on the strobe information acquired in step S406, the PD communication control unit 103 requests voltage and current from the power supply device 500 and proceeds to step S413. The PD communication control unit 103 determines the voltage and current to request from the power supply device 500 based on the voltage and current that the strobe charging unit 231 can input. For example, when using the strobe built into the imaging device 100, it requests 8.4V, which is the maximum value of the terminal voltage when the battery 110 is fully charged. When using an external strobe, it determines the external strobe based on the strobe information acquired in step S406, and for example, supplies 6V to a strobe with a high maximum flash output and 3V to a strobe with a low maximum flash output.

[0079] In step S412, the system control unit 104 reads parameters from the non-volatile memory 210 to set the strobe charging mode time Tb for the second charging mode (> strobe charging time Ta for the first charging mode) based on the strobe information acquired in step S408.

[0080] In step S413, the system control unit 104 determines whether the first shutter switch signal SW1 is in the ON state. If it determines that the first shutter switch signal SW1 is in the ON state, the system control unit 104 proceeds to step S414 with process 400. If it determines that the first shutter switch signal SW1 is not in the ON state, the system control unit 104 repeats the process in step S413.

[0081] In step S414, the system control unit 104 switches the fourth switch circuit 111 to the ON state, thereby changing the power supply for the strobe charging unit 231 from the first power supply unit 115 to the power supply device 500. After that, the system control unit 104 proceeds to step S415 with process 400.

[0082] In step S415, the system control unit 104 determines whether the power supply capacity of the power supply device 500 exceeds the power supply capacity of the battery 110. In S415 as well, the system control unit 104 determines whether the power supply capacity of the power supply device 500 exceeds the power supply capacity of the battery 110 based on the determination conditions shown in Figure 5. In Figure 5, if it is determined that the power supply capacity of the power supply device 500 does not exceed the power supply capacity of the battery 110, the system control unit 104 proceeds to step S416 of process 400. If it is determined that the power supply capacity of the power supply device 500 does not exceed the power supply capacity of the battery 110, the system control unit 104 proceeds to step S420 of process 400.

[0083] In step S416, the system control unit 104 determines whether the second shutter switch signal SW2 is in the ON state. If it determines that the second shutter switch signal SW2 is in the ON state, the system control unit 104 proceeds to step S417 of process 400. If it determines that the second shutter switch signal SW2 is not in the ON state, the system control unit 104 proceeds to step S413 of process 400.

[0084] In step S417, the system control unit 104 controls the imaging device 100 to execute the imaging sequence and proceeds to step S418.

[0085] In step S418, the system control unit 104 determines whether or not the shooting of one frame has been completed. If it determines that the shooting of one frame has been completed, the system control unit 104 proceeds to step S419 of process 400. If it determines that the shooting of one frame has not been completed, the system control unit 104 proceeds to step S416 of process 400.

[0086] In step S419, the system control unit 104 determines whether the second shutter switch signal SW2 is in the ON state. If it determines that the second shutter switch signal SW2 is in the ON state, the system control unit 104 proceeds to step S415 of process 400. If it determines that the second shutter switch signal SW2 is not in the ON state, the system control unit 104 proceeds to step S401 of process 400.

[0087] In step S420, the system control unit 104 displays a notification on the display unit 211 to change the charging mode and proceeds to step S421 of process 400. In Embodiment 1, for example, the icon 804 indicating the first charging mode in Figure 8(b) is displayed blinking, and the display unit 211 switches from the screen in Figure 8(b) to the screen in Figure 8(c).

[0088] In step S421, the system control unit 104 switches the fourth switch circuit 111 to the off state, thereby stopping the power supply from the power supply device 500 to the strobe charging unit 231. Then, it changes the power supply to the strobe charging unit 231 to come from the first power supply unit 115. After that, the system control unit 104 proceeds to step S422 of process 400.

[0089] In step S422, the system control unit 104 reads parameters from the non-volatile memory 210 to set the strobe charging time Tb for the second charging mode (> strobe charging time Ta for the first charging mode) based on the strobe information acquired in step S408.

[0090] In step S423, the system control unit 104 determines whether the first shutter switch signal SW1 is in the ON state. If it determines that the first shutter switch signal SW1 is in the ON state, the system control unit 104 proceeds to step S424 with process 400. If it determines that the first shutter switch signal SW1 is not in the ON state, the system control unit 104 repeats the process in step S423.

[0091] In step S424, the system control unit 104 determines whether the second shutter switch signal SW2 is in the ON state. If it determines that the second shutter switch signal SW2 is in the ON state, the system control unit 104 proceeds to step S425 of process 400. If it determines that the second shutter switch signal SW2 is not in the ON state, the system control unit 104 proceeds to step S423 of process 400.

[0092] In step S425, the system control unit 104 controls the imaging device 100, executes the imaging sequence, and proceeds to step S426 for processing 400.

[0093] In step S426, the system control unit 104 determines whether or not the shooting of one frame has been completed. If it determines that the shooting of one frame has been completed, the system control unit 104 proceeds to step S427 of process 400. If it determines that the shooting of one frame has not been completed, the system control unit 104 proceeds to step S424 of process 400.

[0094] In step S427, the system control unit 104 determines whether the second shutter switch signal SW2 is in the ON state. If it determines that the second shutter switch signal SW2 is in the ON state, the system control unit 104 proceeds to step S423 of process 400. If it determines that the second shutter switch signal SW2 is not in the ON state, the system control unit 104 proceeds to step S401 of process 400.

[0095] Figure 6 is a diagram illustrating an example of the operation of the imaging device 100 during strobe charging in Embodiment 1. Figure 6(a) is an explanatory diagram of the first charging mode. Figure 6(b) is an explanatory diagram of the second charging mode.

[0096] First, the second charging mode will be explained with reference to Figure 6(b). When the first shutter switch signal SW1 is turned ON, the strobe charging unit 231 starts charging the main capacitor 304 in response to a control command from the system control unit 104. The system control unit 104 repeatedly turns the switch 302 ON and OFF for a period of energizing time T1. By repeatedly turning the switch 302 ON and OFF in this way, charge accumulates in the main capacitor 304, gradually approaching the full charge voltage. When the main capacitor 304 is fully charged, the system control unit 104 stops the charging operation to the main capacitor 304. In the second charging mode, power is supplied from the battery 110 to the first power supply unit 115, and power is supplied from the first power supply unit 115 to the strobe charging unit 231. That is, in the first charging mode, the strobe charging unit 231 is charged by power from the battery 110. Furthermore, the energizing time T1 is set based on the peak current and battery voltage that the strobe charging unit 231 can tolerate. In Embodiment 1, for example, it is set to the time when the peak current becomes 2.2A when the input voltage of the strobe charging unit 231 is 8.4V. In the second charging mode, the components of the imaging device 100 used by the strobe charging unit 231, which will be described later, are also powered by the battery 110. As power is consumed by each component of the imaging device 100, the terminal voltage of the battery 110 decreases. Therefore, the amount of charge to the main capacitor 304 during the energizing time T1 decreases, and the time until the main capacitor 304 is fully charged becomes longer.

[0097] Next, the first charging mode will be explained with reference to Figure 6(a). The operation from the ON state of the first shutter switch signal SW1 to charging the main capacitor 304 is the same as in Figure 6(b). In the first charging mode, power from the power supply device 500 is supplied to the strobe charging unit 231 via the fourth switch circuit 111. The power supplied from the power supply device 500 in the first charging mode is greater than or equal to the power used by the strobe charging unit 231. Therefore, even after time has elapsed since the start of charging by the strobe charging unit 231, the amount of charge accumulated in the main capacitor 304 during the energizing time T1 does not decrease. As a result, the time Ta for the main capacitor 304 to be fully charged in the first charging mode is shorter than the time Tb for the main capacitor 304 to be fully charged in the second charging mode.

[0098] Figure 7 is a sequence diagram showing the relationship between the operation of the shutter drive unit 117, imaging unit 204, image processing unit 206, and lens drive unit 202, and the power supply destination and supply period, in an example of the shooting operation of the imaging device 100 in the strobe charging mode in Embodiment 1. Figure 7(a) is an explanatory diagram of the shooting sequence in the first charging mode. The process in Figure 7(a) corresponds to the shooting sequence process at S417 in Figure 4. Figure 7(b) is an explanatory diagram of the shooting sequence in the second charging mode. The process in Figure 7(b) corresponds to the shooting sequence process at S425 in Figure 4. In Figure 7, the horizontal direction represents the elapsed time in the shooting sequence.

[0099] Furthermore, the power values ​​E11, E12, E21, and E22 of the shutter drive unit 117 are shown as vertical magnitudes because a large current flows when the motor starts up, and the current decreases as the rotational operation stabilizes. In contrast, the power values ​​E13 and E23 of the imaging unit 204, and E14 and E24 of the image processing unit 206 and system control unit 104 are approximately constant, so their vertical magnitudes are also shown as constant.

[0100] First, the shooting sequence (S425) in the second charging mode will be explained with reference to Figure 7(b). When it is detected that the first shutter switch signal SW1 is ON (YES in S423), the system control unit 104 drives the lens group 201 through the lens drive unit 202 to perform AF control (D21). When the system control unit 104 detects that the first shutter switch signal SW1 is ON and the second shutter switch signal SW2 is ON (YES in S424), it starts the shooting sequence. The system control unit 104 starts supplying power to the imaging unit 204 (E23). The system control unit 104 also controls the imaging unit 204 to accumulate subject image light (D22).

[0101] After a time TB1 following the second shutter switch signal SW2 being turned ON, the shutter drive unit 117 begins supplying power to the motor of the shutter unit 203, and the biasing force of the biasing member of the shutter unit 203 is accumulated (D23, E21). The power supplied to the motor by the shutter drive unit 117 is supplied from the battery 110.

[0102] Furthermore, the image captured by the imaging unit 204 is read out, processed by the image processing unit 206, and written to the volatile memory 208 (D24, E24). In addition, the aperture is opened (wide open) by the lens drive unit 202 (D25).

[0103] Then, after a further time TB2 has elapsed, the shutter drive unit 117 starts supplying power to the motor of the locking member of the shutter unit 203, and the locking member moves to a position where it holds the curtain travel member and stops (D26, E22). At the same time, the lens drive unit 202 drives (closes) the aperture (D27), and the unit enters a shooting standby state.

[0104] After another time TB3 has elapsed, the shutter drive unit 117 stops powering the motor of the locking member. At the same time, the strobe flash control unit 232 flashes the strobe, the locking member releases its hold on the curtain travel member, the shutter curtain moves, and the imaging unit 204 takes a picture. The power to charge the main capacitor 304 by the strobe charging unit 231 is supplied from the battery 110. The sum of times TB1, TB2, and TB3 is the time (frames / second) required to take one picture. For subsequent shots, the operations of times TB1, TB2, and TB3 are repeated.

[0105] Next, the shooting sequence in the first charging mode will be explained with reference to Figure 7(a). When it is detected that the first shutter switch signal SW1 is ON (YES in S413), the system control unit 104 drives the lens group 201 through the lens drive unit 202 to perform AF control (D11). When the system control unit 104 detects that the first shutter switch signal SW1 is ON and the second shutter switch signal SW2 is ON (YES in S416), it starts the shooting sequence. The system control unit 104 starts supplying power to the imaging unit 204 (E13). The system control unit 104 also controls the imaging unit 204 to accumulate subject image light (D12).

[0106] After a time TA1 following the second shutter switch signal SW2 being turned ON, the shutter drive unit 117 begins supplying power to the motor of the shutter unit 203, and the biasing force of the biasing member of the shutter unit 203 is accumulated (D13, E11). The power supplied to the motor by the shutter drive unit 117 is provided by the battery 110 and the power supply device 500.

[0107] Furthermore, the image captured by the imaging unit 204 is read out, processed by the image processing unit 206, and written to the volatile memory 208 (D14, E14). In addition, the aperture is opened (wide open) by the lens drive unit 202 (D15).

[0108] Then, after another time TA2 has elapsed, the shutter drive unit 117 starts supplying power to the motor of the locking member of the shutter unit 203, and the locking member moves to a position where it holds the curtain travel member and stops (D16, E12). At the same time, the lens drive unit 202 drives (closes) the aperture (D17), and the unit enters a shooting standby state.

[0109] After another time TA3 has elapsed, the shutter drive unit 117 stops powering the motor of the locking member. At the same time, the strobe flash control unit 232 flashes the strobe, the locking member releases its hold on the curtain travel member, the shutter curtain moves, and the imaging unit 204 takes a picture. Power to charge the main capacitor 304 by the strobe charging unit 231 is supplied from the power supply device 500. The sum of times TA1, TA2, and TA3 is the time required to take one picture. The operation of times TA1, TA2, and TA3 is repeated for the second and subsequent pictures. In the shooting sequence during the first charging mode, at least time TA2 of times TA1, TA2, and TA3 is shorter than time TB2.

[0110] Figure 9 shows an example of the operating state of the switch circuit of the imaging device 100 in Embodiment 1.

[0111] Figures 9(a) to 9(c) show examples of the ON and OFF states of the switch circuit in the process shown in Figure 4, with the ON state switch circuit shown in black and the OFF state switch circuit shown in white.

[0112] Figure 9(a) shows an example of the state of the switch circuit in step S413 of Figure 4. The first switch circuit 102, the third switch circuit 109, the fifth switch circuit 112, and the seventh switch circuit 114 are all in the ON state. The imaging device 100 uses power from the battery 110 as the power source for the first power supply unit 115 through the power supply path formed by the third switch circuit 109, the fifth switch circuit 112, and the seventh switch circuit 114. Power from the first power supply unit 115 is supplied to the shutter drive unit 117 and the high-voltage load unit 118. Power from the first power supply unit 115 is also supplied to the second power supply unit 116 via the seventh switch circuit 114, and the second power supply unit 116 steps down the voltage from the first power supply unit 115 and supplies it to the low-voltage load unit 119.

[0113] Figure 9(b) shows an example of the state of the switch circuits in step S414 of Figure 4. The first switch circuit 102, the third switch circuit 109, the fourth switch circuit 111, the fifth switch circuit 112, and the seventh switch circuit 114 are all in the ON state. The imaging device 100 uses power from the battery 110 as the power source for the first power supply unit 115 through the power supply path formed by the third switch circuit 109, the fifth switch circuit 112, and the seventh switch circuit 114. The imaging device 100 also supplies power from the power supply device 500 to the strobe charging unit 231 through the power supply path formed by the first switch circuit 102 and the fourth switch circuit 111. Therefore, the strobe charging unit 231 performs charging operations using power from the external device 500. On the other hand, power from the first power supply unit 115 is not supplied to the strobe charging unit 231. Power from the first power supply unit 115 is supplied to each load of the imaging device 100, except for the strobe charging unit 231.

[0114] Figure 9(c) shows an example of the switch circuit state in step S423 of Figure 4. The third switch circuit 109, the fifth switch circuit 112, and the seventh switch circuit 114 are in the ON state. Since it does not receive power from the power supply device 500, the imaging device 100 turns off the first switch circuit 102. Then, the power from the battery 110 is used as the power source for the first power supply unit 115 through the power supply path formed by the third switch circuit 109, the fifth switch circuit 112, and the seventh switch circuit 114. Similarly, in the second charging mode, the imaging device 100 uses the power from the battery 110 as the power source for the first power supply unit 115 through the power supply path formed by the third switch circuit 109, the fifth switch circuit 112, and the seventh switch circuit 114 shown in Figure 9(c).

[0115] According to Embodiment 1, the imaging device 100 can operate using power from the battery 110, or from both the battery 110 and the power supply device 500. Furthermore, the power supply device 500 has an adjustable output voltage, and the output voltage adjusted by the power supply device 500 can be supplied to the strobe charging unit 231, thereby enabling high-speed charging of the main capacitor 304. In this way, by using two power sources, the power from the battery 110 and the power from the power supply device 500, it is possible to reduce the decrease in frame rate due to the delay in strobe charging time in the imaging device 100, thereby contributing to improved performance of the imaging device 100.

[0116] [Embodiment 2] At least one of the various functions, processes, and methods described in the above embodiments can also be realized by a personal computer, microcomputer, CPU (Central Processing Unit), or microprocessor executing a program. Hereinafter in Embodiment 2, a personal computer, microcomputer, CPU, or microprocessor will be referred to as "Computer X". In Embodiment 2, a program for controlling Computer X that realizes at least one of the various functions, processes, and methods described in the above embodiments will be referred to as "Program Y".

[0117] At least one of the various functions, processes, and methods described in the above embodiments is realized by computer X executing program Y. In this case, program Y is supplied to computer X via a computer-readable storage medium. The computer-readable storage medium in Embodiment 2 includes at least one of a hard disk drive, magnetic storage device, optical storage device, magneto-optical storage device, memory card, volatile memory, non-volatile memory, etc. The computer-readable storage medium in Embodiment 2 is a non-transitory storage medium.

[0118] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of Symbols]

[0119] 100...Imaging device, 102...First switch circuit, 104...System control unit, 110...Battery, 102...First switch circuit, 109...Third switch circuit, 111...Fourth switch circuit, 117...Shutter drive unit, 231...Strobe charging unit, 500...Power supply equipment

Claims

1. a first load; and a second load; and a control unit that controls the supply of power from a first power source to the first load and the second load, an imaging device characterized in that, when it is possible to receive power from a second power source different from the first power source that is greater than the power from the first power source, the control unit controls so as to supply power from the first power source to the first load, and to supply power from the second power source that is greater than the power from the first power source to the second load.

2. The control unit determines whether it is possible to receive power from the second power source that is greater than the power from the first power source; 2. The imaging device according to claim 1, wherein, when it is determined that the second power source can receive greater power than the first power source, the imaging device controls the power from the first power source to be supplied to the first load but not to the second load, and the power from the second power source to be supplied to the second load but not to the first load.

3. 3. The imaging device according to claim 2, wherein the control unit controls the supply of power from the first power source to the first load and the second load when it determines that the second power source cannot receive power greater than that of the first power source.

4. The imaging device described in Claim 1, characterized in that when it is possible to receive greater power from the second power source than from the first power source, the control unit determines the voltage or current to be supplied from the second power source to the second load so that the time the second load operates on power from the second power source is shorter than the time the second load operates on power from the first power source.

5. 2. The imaging device according to claim 1, wherein the control unit requests a voltage higher than that of the first power supply from the second power supply and controls the imaging device to receive a voltage higher than that of the first power supply from the second power supply.

6. 6. The imaging device according to claim 5, wherein the control unit requests the second power supply to supply a maximum voltage that can be input to the second load.

7. 2. The imaging device according to claim 1, wherein the control unit determines a voltage and a current required of the second power supply in accordance with the second load.

8. A power supply device having a connection terminal to which an external power supply device is connected, the first power source is a battery attached to the imaging device, 2. The imaging device according to claim 1, wherein the second power source is the external power supply device connected to the connection terminal via a cable.

9. 9. The imaging device according to claim 8, wherein the second power supply is a power supply device conforming to the USB (Universal Serial Bus) PD (Power Delivery) standard.

10. The imaging device of claim 1, wherein the second load is a circuit for charging a strobe.

11. A control method for an imaging device having a first load and a second load, comprising: a control step of controlling power to be supplied from a first power source to the first load and the second load; a control step of supplying power from the first power source to the first load when it is possible to receive power from a second power source different from the first power source that is greater than the power from the first power source, and supplying power from the second power source that is greater than the power from the first power source to the second load, in the control step;

12. 12. A program for causing a computer of an image pickup apparatus having a first load and a second load to execute the image pickup apparatus control method according to claim 11.

Images