Image capture apparatus and control method

An image capture apparatus comprises a first load, a second load and a power receiving circuitry that receives power from a second power supply which is different from a first power supply, and performs control so as to supply power from the first power supply to the first load and the second load, and controls such that when the power receiving circuitry is capable of receiving power that is greater than the power from the first power supply from the second power supply, the power from the first power supply is supplied to the first load, and the power from the second power supply which is greater than the power from the first power supply is supplied to the second load.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an image capture apparatus and a method of controlling the image capture apparatus.

Description of the Related Art

Japanese Patent Laid open No. 2017-127112 discloses a method of supplying power of a sub power supply for a high priority load when an output power of a main power supply decreases.

The method described in Japanese Patent Laid open No. 2017-127112 can keep the power supply to the high priority load from being interrupted, but does not control the power supply so as to improve performance of an image capture apparatus.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the aforementioned problems, and realizes techniques that can contribute to the improvement of the performance of the image capture apparatus.

In order to solve the aforementioned problems, the present invention provides an image capture apparatus comprising: a first load; a second load; a power receiving circuitry that receives power from a second power supply which is different from a first power supply; a CPU; and a memory storing a program which, when executed by the CPU, causes the CPU to function as the following unit: a control unit that performs control so as to supply power from the first power supply to the first load and the second load, wherein the control unit controls such that when the power receiving circuitry is capable of receiving power that is greater than the power from the first power supply from the second power supply, the power from the first power supply is supplied to the first load, and the power from the second power supply which is greater than the power from the first power supply is supplied to the second load.

In order to solve the aforementioned problems, the present invention provides a method of controlling an image capture apparatus having a first load and a second load, the method comprising: supplying power from a first power supply to the first load and the second load; receiving power from a second power supply which is different from the first power supply; controlling such that when the receiving is capable of receiving power that is greater than the power from the first power supply from a second power supply, the power from the first power supply is supplied to the first load, and the power from the second power supply which is greater than the power from the first power supply is supplied to the second load.

In order to solve the aforementioned problems, the present invention provides a non-transitory computer-readable storage medium storing a program which causes an image capture apparatus having a first load, a second load and a power receiving circuitry that receives power from a second power supply which is different from a first power supply and a CPU to execute the following method, the method comprising: performing control so as to supply power from the first power supply to the first load and the second load, wherein in the control, when the power receiving circuitry is capable of receiving power that is greater than the power from the first power supply from the second power supply, the power from the first power supply is supplied to the first load, and the power from the second power supply which is greater than the power from the first power supply is supplied to the second load.

The present invention can contribute to the improvement of the performance of the image capture apparatus

DESCRIPTION OF THE EMBODIMENTS

First Embodiment

Hereinafter, the image capture apparatus100according to the first embodiment will be described.

FIG.1is a block diagram illustrating components according to a power supply operation of image capture apparatus100according to a first embodiment.

In the first embodiment, a case where the image capture apparatus100is a digital camera capable of continuous shooting (burst shooting) using a flash will be described. However, the image capture apparatus100is not limited to the digital camera, and may be a smart phone, a tablet PC, or the like capable of continuous shooting (burst shooting) using the flash.

The image capture apparatus100is connected to power supply device500via external connection terminal101. The power supply device500is, for example, connected to a commercial AC outlet to operate by an AC power source. The external connection terminal101is a terminal compliant with Universal Serial Bus (USB) Type-C standard. The external connection terminal101includes VBUS terminal for power supply, CC1terminal and CC2terminal for detecting a connection of an external device and for communicating with the external device, D+terminal and D-terminal for performing communication compliant with USB2.0 standard, and GND terminal or the like. The external connection terminal101is a terminal compliant with Programmable Power Supply (PPS) function compliant with USB Power Delivery (PD) standard. Voltages according to requests of the image capture apparatus100as a Device, is supplied from the power supply device500to the external connection terminal101. The image capture apparatus100is connected to the power supply device500, for example, by a cable compatible with the USB Type-C standard.

First switch circuitry102has circuitry for switching to ON state where the power supply to the image capture apparatus100is performed via the external connection terminal101or OFF state where the power supply to the image capture apparatus100is not performed via the external connection terminal101. The first switch circuitry102is comprised of, for example, a switching element such as Field Effect Transistor (FET), and is controlled to switch to ON state or OFF state by PD communication control unit103.

The PD communication control unit103can detect a connection with an external device and can perform communication with an external device compliant with USB PD standard by CC1terminal and CC2terminal. The PD communication control unit103controls the first switch circuitry102to ON state or OFF state in accordance with a control command from system control unit104or the state of the power supply from the power supply device500connected to the external connection terminal101. The PD communication control unit103transmits and receives information of voltage and/or current at the time of the power supply to the power supply device500using CC1terminal or CC2terminal in accordance with the control command of the system control unit104.

The system control unit104executes various processing (programs) in accordance with an instruction from the user received by a user interface (UI) unit to control each component of the image capture apparatus100or to control data transfer between the components. The system control unit104may be a microcomputer in which the CPU and memory are configured as a hardware processor.

Second switch circuitry105has circuitry for switching to either ON state where the power supply to the first power supply unit115is performed via the external connection terminal101or OFF state where the power supply to the first power supply unit115is not performed via the external connection terminal101. The second switch circuitry105, for example, is comprised of an element such as a FET. The second switch circuitry is controlled to ON state or OFF state by charge control unit107.

Charge power supply unit106converts a voltage supplied from the external connection terminal101to a predetermined voltage. The charge power supply unit106is, for example, a buck-boost type DC/DC converter circuitry comprised of an inductor element, a capacitor element and a switching element and capable of stepping-up and stepping-down operations of the voltage. It is possible to convert the voltage from the external connection terminal101can be converted to the predetermined voltage by performing operations of charging and discharging an energy of the inductor element by ON and OFF operations of the switching elements. The switching elements are controlled to ON state or OFF state by the charge control unit107.

The charge control unit107includes circuitry for controlling the charge power supply unit106based on the voltage and the current detected by current-voltage detection circuitry108. When the charging control unit107charges battery110, the charge control unit107controls the output voltage of the charge power supply unit106so that the terminal voltage and a charge current of the battery110comes to a predetermined value.

The current-voltage detection circuitry108has circuitry for detecting the terminal voltage of the battery110and the charge current to the battery110or the discharge current from the battery110. The detection values of the terminal voltage, the charge current and the discharge current detected by the current-voltage detection circuitry108are notified to the charge control unit107.

Third switch circuitry109has circuitry for switching to ON state to enable the power supply by connecting the power supply path from the battery110to the image capture apparatus100or OFF state to disable the power supply by disconnecting the power supply path from the battery110to the image capture apparatus100. The third switch circuitry109is comprised of an element such as a FET. The third switch circuitry109is controlled to ON state or OFF state by the charge control unit107.

The battery110can be easily attached to and removed from the image capture apparatus100by an attachment/ejection mechanism that is not shown. The battery110is, for example, a chargeable power supply unit comprised of two battery cells. The battery cells included in the battery110are, for example, lithium ion battery cells comprised of a lithium ion polymer or the like. The two battery cells of the battery110are connected in series, for example. The battery110supplies power to the image capture apparatus100via the third switch circuitry109. The battery110is charged by the power converted by the charge power supply unit106. For example, in a case where the battery110is fully charged, the voltage of the battery110is, for example, about 8.4V. The termination voltage of the battery110is, for example, about 6.0V. Note that the number of battery cells included in the battery110is not limited to two, and may be one or three or more.

Fourth switch circuitry111, fifth switch circuitry112, sixth switch circuitry113and seventh switch circuitry114have circuitry which are controlled to ON state or OFF state by the system control unit104, and comprised of, for example, a switch element such as a FET. The fourth switch circuitry111has circuitry for switching the power supply source to the flash charge unit231and controlled to ON state or OFF state by the system control unit104.

The fifth switch circuitry112has circuitry for switching the power supply source to first power supply unit115and controlled to ON state or OFF state by the system control unit104. The fifth switch circuitry112and the second switch circuitry105is controlled so as not to be in ON state simultaneously.

The sixth switch circuitry113and the seventh switch circuitry114have circuitry for switching the power supply source to second power supply unit116and controlled to ON state or OFF state by the system control unit104. The sixth switch circuitry113and the seventh switch circuitry114are controlled so as not to be in ON state simultaneously.

The first power supply unit115has a plurality of voltage conversion circuitry for stepping up and down the input voltage. The first power supply unit115includes a voltage conversion circuitry such as a boost-type DC/DC converter circuitry or a buck-boost type DC/DC converter circuitry comprised of, for example, an inductor element, a capacitor element and a switching element. The first power supply unit115receives the voltage of the input voltage range 5V to 15V in the first embodiment, and supplies the voltage of the output voltage 3.3V to 25V to the high-voltage load section118.

The second power supply unit116has a plurality of voltage conversion circuitry for stepping down the input voltage. The second power supply unit116includes a voltage conversion circuitry such as a buck-type DC/DC converter circuitry comprised of, for example, an inductor element, a capacitor element and a switching element. The second power supply unit116receives the voltage of 3.3V in the first embodiment, and supplies the voltage of the output voltage 0.7V to 1.8V to the low-voltage load section119.

The flash charge unit231includes charge circuitry for performing charge accumulation to the main capacitor304to be described later.

Shutter drive unit117includes drive circuitry for driving the shutter unit203in accordance with a control command from the system control unit104.

High-voltage load section118includes load circuitry driven at high voltage as a backlight unit212to be described later.

Low-voltage load section119includes load circuitry driven at a low voltage as an image capturing unit204or the image processing unit206to be described later.

The power supply device500transmits and receives information of the voltage and/or current to be supplied to the image capture apparatus100between the PD communication control unit103. The power supply device500supplies the voltage and/or current requested from the PD communication control unit103via the external connection terminal101to the image capture apparatus100.

FIG.2is a block diagram illustrating components according to the shooting operation of the image capture apparatus100according to the first embodiment.

Lens group201is an optical system for forming an optical image of a subject image to the image capturing unit204to be described later. The lens group201has an aperture mechanism for reducing the amount of light, a zoom mechanism for changing the focal length by changing the lens position, a focus mechanism for focusing by changing the lens position.

Lens drive unit202includes drive circuitry for controlling the aperture mechanism, the zoom mechanism and the focus mechanism of the lens group201in accordance with a control command from the system control unit104.

Shutter unit203is a mechanism for controlling the exposure time of the optical image of the subject reaching the image capturing surface of image capturing unit204by opening and closing the incident light path from the lens group201to the image capturing unit204. The shutter unit203includes a shutter curtain for shielding the incident light path, a curtain traveling member for causing the shutter curtain to travel, and a motor for driving the curtain traveling member. The shutter unit203further includes a biasing member for applying a biasing force to the curtain traveling member, and a latch member for latching the curtain traveling member in a state where the biasing force of the biasing member is accumulated. One end of the biasing member is fixed and another end of the biasing member is connected to the curtain traveling member. The biasing force is accumulated by moving the curtain traveling member against the biasing force of the biasing member by a motor. The latch member is moved by the motor to a position where the curtain traveling member is retained in the state that the biasing force of the biasing member is accumulated, and the curtain traveling member is caused to travel by releasing the retained state of the curtain traveling member.

The image capturing unit204is an image sensor having an image capturing surface in which photoelectric conversion elements such as Complementary Metal Oxide Semiconductor (CMOS) or Charge Coupled Device (CCD) are arranged two dimensionally. The optical image of the subject incident through the lens group201of the image capture apparatus100is formed on the image capturing surface of the image capturing unit204.

AD conversion unit205includes circuitry for converting analog signal output from the image capturing unit204into digital signal.

Image processing unit206is a processor such as a Graphics Processing Unit (GPU) that performs image processing such as resizing processing such as predetermined pixel interpolation and reduction or color conversion processing on the image data outputted from the AD conversion unit205. Further, in the image processing unit206, a predetermined calculation process is performed using the captured image data, the system control unit104performs exposure control and focusing control based on the obtained calculation result. In this way, Auto Focus (AF) processing, Auto Exposure (AE) processing, Flash pre-emission (EF) processing of Through-The Lens (TTL) method is performed. The image processing unit206further performs predetermined calculation processing using the image data, and performs Auto White Balance (AWB) processing of the TTL method based on the calculation result. Further, the image processing unit206converts the image data that has been processed into an image file of a predetermined format (e.g., JPEG) and records the image file on the recording medium209. The image processing unit206also generates display data for displaying an image on the display unit211, etc. The image processing can be performed on the entire area of the image data or on the partial area of the image data.

Memory control unit207controls transmission and reception of data between the AD conversion unit205, the image processing unit206, volatile memory208, recording medium209, and display unit211. The data of the AD conversion unit205is written into the volatile memory208through the image processing unit206and the memory control unit207, or the data of the AD conversion unit205is written into the volatile memory208directly through the memory control unit207.

The volatile memory208is a semiconductor memory such as a DRAM capable of reading and writing data at high speed. The volatile memory208is used as a working area for loading constants and variables for the operation of the system control unit104, and programs read from the nonvolatile memory210, and the like. The volatile memory208is used as a buffer memory for temporarily storing image data captured by the image capturing unit204or as an image display memory of the display unit211.

The recording medium209is a storage device capable of newly writing an image file or reading out an already recorded image file. The recording medium209is a memory card, a hard disk or the like detachable from the image capture apparatus100, or a flash memory, a hard disk or the like built in the image capture apparatus100.

The nonvolatile memory210is a semiconductor memory such as a flash ROM or an EEPROM capable of reading and writing data. The nonvolatile memory210stores constants, programs and the like for the operation of the system control unit104, characteristic data and the like of the display unit211, image processing parameters and the like of the image processing unit206.

The display unit211performs display of a viewfinder image at the time of shooting, display of a shot image, display of characters for interactive operation, and the like. The display unit211is, for example, a display device such as a liquid crystal display or an organic EL display. The display unit211may be integrated with the image capture apparatus100or may be an external device connected to the image capture apparatus100. It is sufficient that the image capture apparatus100is capable of connecting with the display unit211and has a function of controlling the display of the display unit211.

The display unit211includes a UI unit (e.g., a touch panel) that receives an instruction from a user. The touch panel detects a touch operation by a user's finger or a stylus with respect to a display surface of the display unit211, and outputs operation signal corresponding to the touch operation to the system control unit104.

The display unit211can display a menu screen stored in the image display data area of the nonvolatile memory210or an image file stored in the recording medium209in accordance with a control command from the system control unit104. The display unit211functions as an Electronic View Finder (EVF) that performs live view by sequentially displaying image data output from the image capturing unit204.

Backlight unit212illuminates the display unit211from the backside. Since LCD display is a display which cannot emit light by itself, visibility as a display device is realized by irradiating illumination light from the back side. The backlight unit212is comprised of a light emitting diode (LED), an organic light emitting diode (OLED), a fluorescent tube, or the like. The backlight unit212can turn on or off the illumination in accordance with a control command from the system control unit104.

In the first embodiment, the backlight unit212is configured by serially connecting five white LEDs having the following characteristics.

Voltage required to drive the LEDs is 3.75×5=15 [V], power is supplied from the first power supply unit115to the backlight unit212.

Timer213is a time measurement unit for measuring time used for various controls or time of a built-in clock. The system control unit104controls each component of the image capture apparatus100based on the time measured by the timer213. In addition, the timer213measures flash charging time Ta and Tb in a flash charge mode which will be described later inFIG.6.

Shutter-release button214is an operation member for performing a shooting start instruction or a shooting preparation instruction. The shutter button214has first shutter switch215and second shutter switch216.

While the shutter-release button214is being operated, that is, pressed halfway (the shooting preparation instruction) as an operation at the time of shooting by the user, the first shutter switch215is turned to ON state and generates first shutter switch signal SW1. In response to the first shutter switch signal SW1being turned to ON state, the system control unit104starts shooting preparation operations such as the AF processing, the AE processing, the AWB processing and the EF processing by controlling the image capturing unit204.

When the shutter-release button214is completed, that is, the shutter-release button214is pressed fully (the shooting start instruction) as an operation at the time of shooting by the user, the second shutter switch216is turned to ON state and generates second shutter switch signal SW2. In response to the second shutter switch signal SW2being turned to ON state, the system control unit104starts a series of shooting operations from reading out signal from the image capturing unit204to writing of image data to the recording medium209. Then, the system control unit104ends the shooting operations in response to the second shutter switch signal SW2being turned to OFF state (shooting end instruction).

The flash charge unit231includes circuitry for controlling charging of a main capacitor304for emitting flash light in accordance with a control command from the system control unit104.

The flash light emission control unit232includes circuitry for controlling a light emission amount or a light emission timing of the flash in accordance with a control command from the system control unit104. Note that a flash unit of the image capture apparatus100is configured by the flash charge unit231and the flash light emission control unit232.

FIG.3is a diagram illustrating circuitry of the flash charge unit231and the flash light emission control unit232of the image capture apparatus100according to the first embodiment.

Current flows to the primary side of the step-up transformer301when the switching control switch302is turned to ON state. The switching control switch302is turned to OFF state when the peak value of the primary current comes to a predetermined value. When the switching control switch302is turned to OFF state, the current starts to flow to the secondary side of the step-up transformer301and the main capacitor304is charged. When the secondary side current stops, the switching control switch302is turned to ON state again and the current flows to the primary side of the step-up transformer301. A charge voltage for the main capacitor304is monitored by the system controller104. The system control unit104repeats the control of ON state or OFF state of the switching control switch302until the charge voltage comes to a predetermined value.

The flash light emission control unit232includes trigger capacitor305, trigger coil307, xenon tube308and Insulated Gate Bipolar Transistor (IGBT)306. When the IGBT306is turned on, electric charge accumulated in the trigger capacitor305is stepped up by the trigger coil307to several thousand volts. Xenon of the xenon tube308is ionized by the stepped up voltage of the trigger coil307and is in a conductive state. Electric charge accumulated in the main capacitor304flows into the xenon tube308in the conductive state and the xenon tube308emits light. The system control unit104controls the light emission amount and the light emission timing of the flash by controlling the IGBT306to ON state and OFF state.

The user can change shooting parameters of the image capture apparatus100by operating a menu screen or the like displayed by the UI unit of the display unit211. The user can change an operation mode of the image capture apparatus100by operating a switch included in the image capture apparatus100. The operation mode of the image capture apparatus100includes a flash light emission enabled mode and a flash light emission disabled mode.

Note that an external flash can be connected to the image capture apparatus100via an accessory shoe (not shown). The image capture apparatus100can also supply power to the external flash connected via the accessory shoe and control the external flash. In addition, depending on the type of the external flash, the voltage and/or the current to be supplied to the external flash by the image capture apparatus100can be changed, for example, power can be supplied at 6V to the external flash in the case where the maximum light emission amount of the external flash connected to the image capture apparatus100is large, and power can be supplied at 3V to the external flash in the case where the maximum light emission amount of the external flash is small.

Next, shooting operations of the image capture apparatus100according to the first embodiment will be described with reference to the flowcharts ofFIGS.4A to4C.

The processing ofFIGS.4A to4Cis realized by the system control unit104executing the programs stored in nonvolatile memory210to control each component of the image capture apparatus100.

The processing ofFIG.4Ais started when the battery110is installed in the image capture apparatus100and the instruction is made by the user for turning on the power of the image capture apparatus100.

In step S401, the system control unit104uses the power from the battery110to supply the power to each component of the image capture apparatus100, performs activation processing of the image capture apparatus100, and transits to the shooting standby state. In the shooting standby state, the image capturing for acquiring a live view image is performed by the image capturing unit204. The image captured by the image capturing unit204is processed by the AD conversion unit205and the image processing unit206. The image processed by the image processing unit206is output to the volatile memory208via the memory control unit207, and first stored in the volatile memory208. The image is then read from the volatile memory208at the appropriate timing, output to the display unit211, and displayed on the display unit211as the live-view image. Furthermore, in the shooting standby state, the system control unit104controls the image processing unit206to superimpose various information on the live-view image and can display the superimposed image on the display unit211.

In step S402, the system control unit104acquires the terminal voltage of the battery110by the current-voltage detection circuitry108, and advances the processing400to step S403.

In step S403, the system control unit104determines whether or not the power supply device500is connected to the image capture apparatus100by monitoring the external connection terminal101or by information from the PD communication control unit103. When the system control unit104determines that the power supply device500is connected to the image capture apparatus100, the system control unit104advances the processing400to step S404. When the system control unit104determines that the power supply device500is not connected to the image capture apparatus100, the system control unit104advances the processing400to step S412.

In step S404, the system control unit104determines a power supply capability of the power supply device500connected to the image capture apparatus100. The determination of the power supply capability is implemented by measuring the terminal voltage of the external connection terminal101or by communicating with the power supply device500via the PD communication control unit103.

In step S405, the system control unit104holds the power supply capability of the power supply device500determined in step S404in the volatile memory208and advances the processing400to step S406.

In step S406, the system control unit104acquires the information of the flash to be used at the time of shooting, and advances the processing400to step S407. The system control unit104acquires at least information on the maximum voltage that can be input by the flash charge unit231and the voltage of the battery when fully charged.

In step S407, the system control unit104determines whether or not the flash charging time of the image capture apparatus100can be shortened from the battery voltage acquired in step S402and the power supply capacity of the power supply device500acquired in step S405. The system control unit104determines the power supply capability of the power supply device500according to a determination condition shown inFIG.5and determines whether or not the flash charge mode of the image capture apparatus100can be changed to a high-speed charge mode.FIG.5is a diagram illustrating an example of the determination condition of the flash charge mode of the image capture apparatus100according to the first embodiment. InFIG.5, when the power supply capacity of the power supply device500exceeds the power supply capacity of the battery110(the output voltage and the output current of the power supply device500exceeds the terminal voltage and a discharge current of the battery110), it is determined that the flash charge mode of the image capture apparatus100can be changed to the high-speed charge mode. In contrast, when the power supply capacity of the power supply device500is equal to or less than the power supply capacity of the battery110(the output voltage and the output current of the power supply device500is equal to or less than the terminal voltage and the discharge current of the battery110), it is determined that the flash charge mode of the image capture apparatus100cannot be changed to the high-speed charge mode. InFIG.5, a first charge mode is a flash charge mode in which the image capture apparatus100is operating by the power of the battery110and the power of the power supply device500. A second charge mode is a flash charge mode in which the image capture apparatus100is operating by only the power of the battery110. When the power supply capability of the power supply device500connected to the image capture apparatus100exceeds the power supply capability of the battery110, the flash charge mode of the image capture apparatus100can be changed to the first charge mode in which the flash charging time is faster than that in the second charge mode. For example, it is assumed that the power supply capacity of the battery110of the image capture apparatus100is the terminal voltage 8.4V and the discharge current3A when the battery110is fully charged. In this case, when the power supply capacity of the power supply device500exceeds the output voltage 8.4V and the output current3A, the first charge mode is selectable. In contrast, in a state where the power supply capacity of the battery110of the image capture apparatus100drops to the terminal voltage 7.2V and the discharge current3A, when the power supply capacity of the power supply device500exceeds the output voltage 7.2V and the output current3A, the first charge mode is selectable. When the system control unit104determines that the flash charge mode can be changed to the high-speed charge mode, the system control unit104advances the processing400to step S408. When the system control unit104determines that the flash charge mode cannot be changed to the high-speed charge mode, the system control unit104advances the processing400to step S412. The operations of the flash charge unit231in the first and second charge modes will be described later.

In step S408, the system control unit104displays a screen to notify the user that the flash charge mode can be changed on the display unit211, and advances the processing400to step S409. The screen displayed on the display unit211includes, for example, a dialogue801and buttons802and803shown inFIG.8A.FIG.8Ais a diagram illustrating an example of a display screen for a live-view image in the image capture apparatus100according to the first embodiment. The dialogue801indicates that the flash charge mode can be changed and contents to be changed in the flash charge mode. The button802is a selection item for permitting changes as notified in the dialog801. The button803is a selection item for rejecting changes as notified in the dialog801.

FIG.8Billustrates an example of a display screen when the button802is selected on the screen ofFIG.8A. In the screen shown inFIG.8B, icon804which indicates that the first charge mode is selected, and that shooting speed (frame speed) is not slowed at the time of continuous shooting using the flash, is displayed.

FIG.8Cillustrates an example of a display screen when the button803is selected on the screen ofFIG.8A. In the screen shown inFIG.8C, icon805which indicates that the second charge mode is selected, and that shooting speed (frame speed) is slowed at the time of continuous shooting using the flash.

In step S409, the system control unit104determines whether one of the buttons802and803is selected on the screen displayed on the display unit211in step S408. When the user selects the button802using a touch panel or the like, the system control unit104advances the processing400to step S410. When the user selects the button803, the system control unit104advances the processing400to step S412.

In step S410, the system control unit104reads out parameters from the nonvolatile memory210so as to set the flash charging time Ta (<the flash charging time Tb of the second charge mode) of the first charge mode according to the flash information acquired in step S406.

In step S411, the PD communication control unit103requests a voltage and a current to the power supply device500based on the flash information acquired in step S406, and advances the processing400to step S413. The PD communication control unit103determines the voltage and current to be requested to the power supply device500based on the voltage and the current that the flash charge unit231can input. For example, when a built-in flash in the image capture apparatus100is used, 8.4V that is the maximum value of the terminal voltage when the battery110is fully charged, is requested. When the external flash is used, the external flash is determined based on the flash information acquired in step S406, for example, 6V is supplied to the flash when the maximum light emission amount is large, and 3V is supplied to the flash when the maximum light emission amount is small.

In step S412, the system control unit104reads out parameter from the nonvolatile memory210so as to set the flash charging time Tb (>the flash charging time Ta of the first charge mode) of the second charge mode according to the flash information acquired in step S408.

In step S413, the system control unit104determines whether or not the first shutter switch signal SW1is in ON state. When the system control unit104determines that the first shutter switch signal SW1is in ON state, the system control unit104advances the processing400to step S414. When the system control unit104determines that the first shutter switch signal SW1is not ON state, the system control unit104repeats the processing of step S413.

In step S414, the system control unit104changes the power supply of the flash charge unit231from the first power supply unit115to the power supply device500by switching the fourth switch circuitry111to ON state. Thereafter, the system control unit104advances the processing400to step S415.

In step S415, the system control unit104determines whether the power supply capability of the power supply device500exceeds the power supply capability of the battery110. Also in step S415, it is determined whether the power supply capability of the power supply device500exceeds the power supply capability of the battery110based on the determination condition shown inFIG.5. When the system control unit104determines that the power supply capability of the power supply device500exceeds the power supply capability of the battery110according to the determination condition ofFIG.5, the system control unit104advances the processing400to step S416. When the system control unit104determines that the power supply capability of the power supply device500does not exceed the power supply capability of the battery110, the system control unit104advances the processing400to step S420.

In step S416, the system control unit104determines whether or not the second shutter switch signal SW2is in ON state. When the system control unit104determines that the second shutter switch signal SW2is in ON state, the system control unit104advances the processing400to step S417. When the system control unit104determines that the second shutter switch signal SW2is not ON state, the system control unit104advances the processing400to step S413.

In step S417, the system control unit104controls the image capture apparatus100and executes a shooting sequence, and advances the processing400to step S418.

In step S418, the system control unit104determines whether or not shooting for one frame has been completed. When the system control unit104determines that the shooting for one frame has been completed, the system control unit104advances the processing400to step S419. When the system control unit104determines that the shooting for one frame has not been completed, the system control unit104advances the processing400to step S416.

In step S419, the system control unit104determines whether or not the second shutter switch signal SW2is in ON state. When the system control unit104determines that the second shutter switch signal SW2is in ON state, the system control unit104advances the processing400to step S415. When the system control unit104determines that the second shutter switch signal SW2is not ON state, the system control unit104advances the processing400to step S402.

In step S420, the system control unit104displays a notification to change the charge mode on the display unit211, and advances the processing400to step S421. In the first embodiment, for example, the icon804indicating the first charge mode ofFIG.8Bis displayed and caused to blink, and the display unit211is switched from the screen ofFIG.8Bto the screen ofFIG.8C.

In step S421, the system control unit104stops the power supply from the power supply device500to the flash charge unit231by switching the fourth switch circuitry111to OFF state. The system control unit104changes the power supply to the flash charge unit231to be supplied from the first power supply unit115. Thereafter, the system control unit104advances the processing400to step S422.

In step S422, the system control unit104reads out parameter from the nonvolatile memory210so as to set the flash charging time Tb (>the flash charging time Ta of the first charge mode) of the second charge mode according to the flash information acquired in step S408.

In step S423, the system control unit104determines whether or not the first shutter switch signal SW1is in ON state. When the system control unit104determines that the first shutter switch signal SW1is in ON state, the system control unit104advances the processing400to step S424. When the system control unit104determines that the first shutter switch signal SW1is not ON state, the system control unit104repeats the processing of step S423.

In step S424, the system control unit104determines whether or not the second shutter switch signal SW2is in ON state. When the system control unit104determines that the second shutter switch signal SW2is in ON state, the system control unit104advances the processing400to step S425. When the system control unit104determines that the second shutter switch signal SW2is not ON state, the system control unit104advances the processing400to step S423.

In step S425, the system control unit104controls the image capture apparatus100and executes the shooting sequence, and advances the processing400to step S426.

In step S426, the system control unit104determines whether or not shooting for one frame has been completed. When the system control unit104determines that the shooting for one frame has been completed, the system control unit104advances the processing400to step S427. When the system control unit104determines that the shooting for one frame has not been completed, the system control unit104advances the processing400to step S424.

In step S427, the system control unit104determines whether or not the second shutter switch signal SW2is in ON state. When the system control unit104determines that the second shutter switch signal SW2is in ON state, the system control unit104advances the processing400to step S423. When the system control unit104determines that the second shutter switch signal SW2is not ON state, the system control unit104advances the processing400to step S402.

FIGS.6A and6Bare diagrams illustrating examples of operations at the time of charging the flash in the image capture apparatus100according to the first embodiment.FIG.6Ais a diagram illustrating the first charge mode.FIG.6Bis a diagram illustrating the second charge mode.

First, the second charge mode is described with reference toFIG.6B. When the first shutter switch signal SW1is turned to ON state, the flash charge unit231starts charging operation to the main capacitor304in accordance with a control command from the system control unit104. The system control unit104repeats control of the switch302to be ON and control of the switch302to be OFF for the time period of energization time T1. In this way, charge is accumulated in the main capacitor304and gradually comes close to the fully charged voltage by repeating ON and OFF of the switch302. The system control unit104stops the charging operation to the main capacitor304when the main capacitor304is fully charged. In the second charge mode, the power is supplied from the battery110to the first power supply unit115, and the power is supplied from the first power supply unit115to the flash charge unit231. In other words, in the first charge mode, the charging of the flash charge unit231is performed by the power from the battery110. Further, the energization time T1is a time set based on a peak current that is acceptable by the flash charge unit231and a battery voltage. In the first embodiment, for example, the energization time T1is set to a time in which the peak current is 2.2 A when the input voltage is 8.4V of the flash charge unit231. Note that in the second charge mode, components of the image capture apparatus100used in the flash charge unit231to be described later also operate with the power from the battery110. The terminal voltage of the battery110falls as the power is consumed in each components of the image capture apparatus100. That is why, since the charge amount to the main capacitor304during the energization time T1is decreased, the time until the main capacitor304has been fully charged is lengthened.

Next, the first charge mode is described with reference toFIG.6A. The operations from ON state of the first shutter switch signal SW1to the charging of the main capacitor304is the same as the operations inFIG.6B. In the first charge mode, the power form the power supply device500is supplied to the flash charge unit231via the fourth switch circuitry111. The power supplied from the power supply device500in the first charge mode is equal to or larger than the power used in the flash charge unit231. As a result, the charge amount that has been charged in the main capacitor304in the energization time T1is not decreased even after the time from the start of charging by the flash charge unit231has elapsed. That is why, the time Ta until the main capacitor304has been fully charged in the first charge mode is shortened than the time Tb until the main capacitor304has been fully charged in the second charge mode.

FIGS.7A and7Billustrate sequence diagrams indicating a relationship between the operations of the shutter drive unit117, the image capturing unit204, the image processing unit206and the lens drive unit202, and the power supply destination and the power supply period in an example of shooting operations in the flash charge mode of the image capture apparatus100according to the first embodiment.FIG.7Ais a diagram illustrating the shooting sequence in the first charge mode. The processing ofFIG.7Acorresponds to the processing of the shooting sequence in step S417ofFIG.4.FIG.7Bis a diagram illustrating the shooting sequence in the second charge mode. The processing ofFIG.7Bcorresponds to the processing of the shooting sequence in step S425ofFIG.4.

InFIGS.7A and7B, the horizontal direction corresponds to the elapsed time in the shooting sequence. Since a large current flows at the start of driving the motor and the current drops as the rotational operation of the motor stabilizes in the power E11, E12, E21, and E22of the shutter drive unit117, the vertical direction corresponds to the changes in the power amount. In contrast, since the power E13and E23of the image capturing unit204and the power E14and E24of the image processing unit206, the system control unit104and the like are substantially constant, the power amount corresponding to the vertical direction is also indicated to be constant.

First, the shooting sequence (S425) in the second charge mode will be described with reference toFIG.7B. When it is detected that the first shutter switch signal SW1is turned to ON state (YES in step S423), the system control unit104drives the lens group201by the lens drive unit202and performs AF control (D21). When it is detected that the second shutter switch signal SW2is turned to ON state (YES in step S424) while the first shutter switch signal SW1is in ON state, the system control unit104starts the shooting sequence. The system control unit104starts the power supply to the image capturing unit204(E23). The system control unit104also controls the image capturing unit204to accumulate the optical image of the subject (D22).

After time TB1has elapsed from when the second shutter switch signal SW2was turned to ON state, the energization to the motor of the shutter unit203is started by the shutter drive unit117and the biasing force of the biasing member of the shutter unit203is accumulated (D23, E21). The power for the energization to the motor of the shutter unit203by the shutter drive unit117is supplied from the battery110.

In addition, images shot by the image capturing unit204are read out, processed by the image processing unit206, and written in the volatile memory208(D24, E24). Furthermore, the driving (open) of the aperture is started by the lens drive unit202(D25).

Then, time TB2has further elapsed, the shutter drive unit117starts the energization to the motor of the latch member of the shutter unit203and then the latch member moves to the position where the latch member retains the curtain traveling member and is in a stopped state (D26, E22). In addition, the lens drive unit202drives (close) the aperture (D27), and the system is in the shooting standby state.

Subsequently, time TB3has further elapsed, the shutter drive unit117stops the energization for the motor of the latch member. In addition, the flash light emission control unit232causes the flash to emit flash light, and the retention of the curtain traveling member by the latch member is released and then the shutter curtain is caused to travel, and the shooting by the image capturing unit204is performed. The power for charging the main capacitor304by the flash charge unit231is supplied from the battery110. The sum of time TB1, TB2and TB3is the time (frames/second) required to shoot one frame. The operations in time TB1, TB2and TB3are repeatedly executed for shooting of the second and subsequent frames.

Next, the shooting sequence (S417) in the first charge mode will be described with reference toFIG.7A. When it is detected that the first shutter switch signal SW1is turned to ON state (YES in step S413), the system control unit104drives the lens group201by the lens drive unit202and performs AF control (D11). When it is detected that the second shutter switch signal SW2is turned to ON state (YES in step S416) while the first shutter switch signal SW1is in ON state, the system control unit104starts the shooting sequence. The system control unit104starts the power supply to the image capturing unit204(E13). The system control unit104also controls the image capturing unit204to accumulate the optical image of the subject (D12).

After time TA1has elapsed from when the second shutter switch signal SW2was turned to ON state, the energization to the motor of the shutter unit203is started by the shutter drive unit117and the biasing force of the biasing member of the shutter unit203is accumulated (D13, E11). The power for the energization to the motor of the shutter unit203by the shutter drive unit117is supplied from the battery110and the power supply device500.

In addition, images shot by the image capturing unit204are read out, processed by the image processing unit206, and written in the volatile memory208(D14, E14). Furthermore, the driving (open) of the aperture is started by the lens drive unit202(D15).

Then, time TA2has further elapsed, the shutter drive unit117starts the energization to the motor of the latch member of the shutter unit203and then the latch member moves to the position where the latch member retains the curtain traveling member and is in a stopped state (D16, E12). In addition, the lens drive unit202drives (close) the aperture (D17), and the system is in the shooting standby state.

Subsequently, when time TA3has further elapsed, the shutter drive unit117stops the energization for the motor of the latch member. The vertical direction, the flash light emission control unit232causes the flash to emit flash light, and the retention of the curtain traveling member by the latch member is released and then the shutter curtain is caused to travel, and the shooting by the image capturing unit204is performed. The power for charging the main capacitor304by the flash charge unit231is supplied from the power supply device500. The sum of time TA1, TA2and TA3is the time required to shoot one frame. The operations of time TA1, TA2and TA3are repeatedly executed for shooting of the second and subsequent frames. In the shooting sequence in the first charge mode, at least time TA2among time TA1, TA2and TA3is a time shorter than time TB2.

FIGS.9A to9Care diagrams illustrating examples of operation states of the switch circuitry of the image capture apparatus100according to the first embodiment.

FIGS.9A to9Cillustrate examples of ON state or OFF state of the switch circuitry in the processing ofFIGS.4A to4C, the switch circuitry in ON state is illustrated in black and the switch circuitry in OFF state is illustrated in white.

FIG.9Aillustrates an example of the state of the switch circuitry in step S413ofFIG.4B. The first switch circuitry102, the third switch circuitry109, the fifth switch circuitry112and the seventh switch circuitry114are ON states. The image capture apparatus100uses the power supplied from the battery110as the power source of the first power supply unit115by the power supply path formed by the fifth switch circuitry112and the seventh switch circuitry114. The power from the first power supply unit115is supplied to the shutter drive unit117and the high-voltage load section118. In addition, the power from the first power supply unit115is supplied to the second power supply unit116through the seventh switch circuit114, and the second power supply unit116steps down the voltage from the first power supply unit115and the stepped down voltage is supplied to the low-voltage load section119.

FIG.9Billustrates an example of the state of the switch circuitry in step S414ofFIG.4B. The first switch circuitry102, the third switch circuitry109, the fourth switch circuitry111, the fifth switch circuitry112and the seventh switch circuitry114are ON states. The image capture apparatus100uses the power supplied from the battery110as the power source of the first power supply unit115by the power supply path formed by the third switch circuitry109, the fifth switch circuitry112and the seventh switch circuitry114. In addition, the image capture apparatus100supplies the power supplied from the power supply device500to the flash charge unit231by the power supply path formed by the first switch circuitry102and the fourth switch circuitry111. As a result, the flash charge unit231performs the charging operation with the power from the external device500. On the other hand, the power from the power supply unit115is not supplied to the flash charge unit231. The power from the first power supply unit115is supplied to each load of the image capture apparatus100other than the flash charge unit231.

FIG.9Cillustrates an example of the state of the switch circuitry in step S423ofFIG.4C. The third switch circuitry109, the fifth switch circuitry112and the seventh switch circuitry114are ON states. Since the image capture apparatus100does not receive the power from the power supply device500, the image capture apparatus100set the first switch circuitry102to be OFF state. And then, the image capture apparatus100uses the power form the battery110as the power source of the first power supply unit115by the power supply path formed by the third switch circuitry109, the fifth switch circuitry112and the seventh switch circuitry114. In addition, also in the case of the second charge mode, the image capture apparatus100uses the power form the battery110as the power source of the first power supply unit115by the power supply path formed by the third switch circuitry109, the fifth switch circuitry112and the seventh switch circuitry114shown inFIG.9C.

According to the first embodiment, the image capture apparatus100can be operated by the power of the battery110or the power of the battery110and the power from the power supply device500. In addition, since the power supply device500can adjust the output voltage and can supply the output voltage adjusted by the power supply device500to the flash charge unit231, it is possible to charge the main capacitor304at high speed. As a result, it is possible to suppress the reduction of the frame speed due to a delay of a flash charging time in the image capture apparatus100by using two power sources including the power from the power of the battery110and the power of the power supply device500, and it is possible to contribute to the improvement of the performance of the image capture apparatus100.

Second Embodiment

At least one of various kinds of functions, processes, or methods described in the foregoing embodiments can also be realized by a personal computer, a microcomputer, a CPU (Central Processing Unit), or a microprocessor executing a program. In the second embodiment, a personal computer, a microcomputer, a CPU, or a microprocessor will be called a “computer X” below. Also, in the second embodiment, a program for controlling the computer X and realizing at least one of various kinds of functions, processes, or methods described in the foregoing embodiments will be called a “program Y”.

At least one of various kinds of functions, processes, or methods described in the foregoing embodiments are realized by the computer X executing the program Y. In this case, the program Y is supplied to the computer X via a computer-readable storage medium. The computer-readable storage medium according to the second embodiment includes at least one of a hard disk device, a magnetic storage device, an optical storage device, a magneto-optical storage device, a memory card, a volatile memory, a nonvolatile memory, or the like. The computer-readable storage medium according to the second embodiment is a non-transitory storage medium.

This application claims the benefit of Japanese Patent Application No. 2021-157234, filed Sep. 27, 2021, and Japanese Patent Application No. 2022-130124, filed Aug. 17, 2022, which are hereby incorporated by reference herein in their entirety.