JP7084799B2 - Image pickup device and its control method - Google Patents

Description

The present invention relates to an image pickup apparatus and a control method thereof.

Various auxiliary devices (accessories) such as interchangeable lenses, mount adapters, teleconverters, and flashes can be attached to the image pickup device. In general, auxiliary devices do not have an independent power source and operate on the power supplied by the image pickup device. A large-capacity capacitor may be provided in the power supply line of the auxiliary device for the purpose of reducing power supply noise and stabilizing the voltage.

When power is started to be supplied from the image pickup device to such an auxiliary device, a large current (inrush current) flows to charge the capacitor of the auxiliary device, and the supply voltage from the image pickup device fluctuates greatly to normalize the auxiliary device. It may not work. Therefore, in Patent Document 1, inrush current is suppressed by providing a circuit that temporarily becomes high impedance at the start of power supply in the power supply line that supplies power from the power supply circuit of the image pickup device to the auxiliary device.

Japanese Unexamined Patent Publication No. 10-10602

However, since a circuit having high impedance is provided in the power supply line even temporarily, the time required for charging the capacitor of the auxiliary device becomes long. This problem is exacerbated when a plurality of auxiliary devices are mounted on the image pickup device, for example, when the interchangeable lens is mounted on the image pickup device via a teleconverter.

The present invention has been made in view of the problems of the prior art, and is an image pickup device capable of quickly supplying electric power to an auxiliary device mounted on the image pickup device while suppressing a load on a power supply unit of the image pickup device. The purpose is to provide the control method.

The above-mentioned object is an image pickup device to which an auxiliary device can be attached, and the operation of the power supply means for supplying power to the auxiliary device through the first power supply line and the second power supply line and the image pickup device. It has a control means for controlling, and the control means has power based on information acquired from each of the auxiliary devices mounted on the image pickup device in a state where power is not supplied by the second power supply line. It is achieved by an image pickup apparatus characterized in that the power supply characteristic is changed through a second power supply line by the supply means.

According to the present invention, it is possible to provide an image pickup device capable of quickly supplying electric power to an auxiliary device mounted on the image pickup device and a control method thereof while suppressing a load on a power supply unit of the image pickup device.

Block diagram showing a functional configuration example of the camera system according to the embodiment Flow chart regarding power supply operation at startup in the first embodiment Flow chart regarding power supply operation at startup in the second embodiment Block diagram showing a functional configuration example of the camera system according to the third embodiment Flow chart regarding power supply operation at startup in the third embodiment

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, based on its exemplary embodiments. In the following, an embodiment in which the present invention is applied to a configuration in which an interchangeable lens is attached to an image pickup device via one or more intermediate accessories will be described. However, the present invention is applicable to any configuration in which one or more auxiliary devices are mounted on the imaging device. The auxiliary device includes, but is not limited to, accessories such as a mount adapter, a teleconverter, a flash, a GPS receiver, a wireless communication adapter, an electronic viewfinder, and an assistant grip. Further, an embodiment in which the present invention is applied to an interchangeable lens digital camera as an example of an image pickup apparatus will be described below. However, the present invention is applicable to any electronic device having an imaging function to which an auxiliary device can be attached and detached. Examples of such electronic devices include, but are not limited to, video cameras, computer devices (personal computers, tablet computers, PDA, etc.), mobile phones, smartphones, game consoles, robots, drones, and drive recorders.

● (First embodiment)
FIG. 1 is a block diagram showing a configuration example of a camera system as an example of the image pickup apparatus according to the present embodiment. The camera system includes a main body (camera main body) 100 of an interchangeable lens type digital camera and an auxiliary device that can be attached to and detached from the camera main body 100. FIG. 1 shows a combination of a mount portion of the camera body 100, which is an example of a mounting portion of an auxiliary device, an interchangeable lens 400 as an example of an auxiliary device that can be mounted on the mount portion, and two intermediate accessories 200 and 300. Shows. However, the mount portion is an example of a mounting portion of the auxiliary device provided in the camera body 100, and may be another mounting portion such as a hot shoe or an external I / F. Further, the auxiliary device may be another auxiliary device according to the mounting site.

In FIG. 1, an interchangeable lens 400 is attached to the camera body 100 via an intermediate accessory 200 and an intermediate accessory 300. The intermediate accessories 200 and 300 have mount portions on both end faces, and the interchangeable lens 400 has mount portions on one end face according to the same standard (having corresponding shapes). Then, the auxiliary device is attached to the camera body 100 or the auxiliary device by relatively rotating the two auxiliary devices (or one auxiliary device and the camera body) with the opposing mount portions abutted at a specific relative position. Can be removed or removed. For example, each mount portion has a plurality of claw portions, and by rotating the mount portions relative to each other from a state where they are butted at a specific relative position, so-called bayonet coupling in which the claw portions of the opposing mount portions engage with each other. It is removable from each other by the method. That is, the mount mechanically and electrically connects the two auxiliary devices. In FIG. 1, the mount mechanisms 113, 205, and 301 collectively represent the opposite mount portions. Theoretically, there is no limit to the number of auxiliary devices that can be connected in series to the camera body 100, and one or more arbitrary number of auxiliary devices can be mounted in series on the camera body 100.

The interchangeable lens 400 has a lens group 401. The lens group 401 includes a movable lens such as a focus lens. Of the luminous flux passing through the lens group 401, the luminous flux emitted from the mount portion of the interchangeable lens 400 through the opening of the aperture 402 is incident from the mount portion of the camera body 100 through the intermediate accessories 200 and 300. The luminous flux incident on the camera body 100 passes through the opening of the shutter 103 and forms an optical image on the image pickup device 101.

The image sensor 101 is, for example, a CMOS image sensor. Pixels provided with a photoelectric conversion unit are arranged in a matrix on the image pickup element 101, the optical image formed by the lens group 401 of the interchangeable lens 400 is photoelectrically converted by the pixels, and an analog electric signal group corresponding to the optical image is output.

The system control unit 102 is a programmable processor such as a CPU, and for example, reads a program stored in the ROM 121 into the RAM 104 and executes it to control the operation of the camera body 100 and the attached auxiliary device, and functions the camera system. Realize. For example, when the system control unit 102 detects the operation of the operation unit 120, the system control unit 102 executes a process according to the detected operation such as a still image or moving image shooting process.

The system control unit 102 applies various image processes to the RAW image data output by the image pickup device 101, and generates image data according to the application. The system control unit 102 generates, for example, image data for display on the rear monitor 108 and image data for recording on the recording medium 119. Further, the system control unit 102 executes processing according to the purpose of the image data, such as superimposition processing of OSD and GUI data, coding processing, and data file generation processing. The system control unit 102 also executes a process (decoding process, etc.) for reproducing the image data read from the recording medium 119.

Further, the system control unit 102 generates evaluation values for automatic exposure control (AE) and automatic focus detection (AF) using the RAW image data or the generated image data, and also executes AF processing and AE processing. In the AF process and the AE process, the system control unit 102 controls the operation of the auxiliary device by communicating with the auxiliary device through the mount mechanism 113. For example, the system control unit 102 controls the drive of the focus lens and the aperture 402 of the interchangeable lens 400 by communicating with the control unit 405 of the interchangeable lens 400. The communication path and the power supply line between the system control unit 102 and each auxiliary device are formed through the contacts of the mount mechanisms 113, 205, and 301.

In the present embodiment, each of the auxiliary devices mounted on the camera body 100 has a control unit, and can communicate with the system control unit 102 separately. In the present embodiment, communication between the system control unit 102 and the control units 405 and 203 of the auxiliary device is exclusive, and at the same time, only one auxiliary device can communicate with the system control unit 102. Although the configuration of the intermediate accessory 300 is not shown for convenience, it is assumed that the control unit exists.

The rear monitor 108 is, for example, a liquid crystal display, and displays information on the camera system, an image captured or reproduced, a GUI, and the like. The recording medium 119 is, for example, a semiconductor memory card, and is used for recording image data, audio data, and the like obtained by photographing.

The RAM 104 is used as a buffer memory for the system control unit 102 to temporarily store image data. The RAM 104 is also used as a system memory for reading a program executed by the system control unit 102 and storing variables and the like for executing the program.

The ROM 121 stores a program executed by the system control unit 102, various setting values of the camera body 100, GUI data, and the like. The ROM 121 may be electrically rewritable.

The operation unit 120 is a general term for a group of input devices for a user to input an instruction to the camera body 100. For example, the operation unit 120 includes a power switch 105, a shutter button, a moving image recording button, a menu button, a direction key, a determination key, a shooting mode / playback mode switching switch, and the like. It should be noted that these are merely examples, and may include buttons, switches, and the like to which other functions are assigned.

The power switch 105 is a switch for switching the power on / off of the camera body 100. When the power is turned on by operating the power switch 105, the power supply unit 107 composed of a DCDC converter or the like converts, for example, the voltage of the power supply 106, which is a secondary battery, into an appropriate voltage in the camera body 100. Power is supplied to each part. The power supply unit 107 also supplies power to the attached auxiliary device. However, as shown in FIG. 1, the first power supply line 1071 to the control units 203 and 405, and the drive units 202, 403 and 404 having the motors and actuators for driving the moving parts and the drive circuit thereof. Power is supplied separately from the power supply line 1072 of 2. The load fluctuation of the second power supply line 1072 is larger than that of the first power supply line 1071. In particular, the load fluctuation at the start of power supply is significantly larger in the second power supply line 1072.

It is sufficient that the first power supply line 1071 common to the control unit of the auxiliary device can be supplied with enough power to drive the logic circuit. Therefore, a large-capacity smoothing capacitor is not connected to the first power supply line 1071, and it is not necessary to consider the inrush current. On the other hand, a large-capacity smoothing capacitor is connected to the second power supply line 1072 common to the drive units 202, 403, and 404 that drive the moving parts in each auxiliary device. Therefore, it is necessary to consider suppressing the inrush current for the power supply at the time of starting to the second power supply line 1072.

The power supply unit 107 also controls the start of power supply, sets the power supply start-up time, monitors the power supply voltage, and the like in accordance with the control of the system control unit 102.

The finder display unit 109, the eyepiece 110, and the proximity detection unit 111 constitute an electronic viewfinder (EVF). The system control unit 102 causes, for example, a finder 109, which is a liquid crystal display, to display a moving image taken during a shooting standby state or a moving image recording in real time. When the proximity detection unit 111 detects an object close to the eyepiece 110 while the system control unit 102 is displaying the moving image shot during the shooting standby state or the moving image recording on the rear monitor 108, the system control unit 102 displays the moving image on the rear monitor 108. To switch to the finder display unit 109. Conversely, if an object is no longer detected by the proximity detection unit 111 while the video recorded during the shooting standby state or video recording is being displayed on the finder display unit 109, the video recording destination is set from the finder display unit 109. Switch to the rear monitor 108. The display destination of the moving image may be switched according to a user instruction through the operation unit 120.

Next, the configuration of the intermediate accessory 200 will be described. In the present embodiment, as the intermediate accessory 200, an accessory for inserting an ND filter 201 having a variable density, which is arranged in the optical path from the interchangeable lens 400 to the image sensor 101, is shown.

The intermediate accessory 200 includes an ND filter 201 having a variable density, an ND control circuit 202 for driving the ND filter 201, a control unit 203, and a memory 204. The control unit 203 is a programmable processor such as a CPU, and controls the operation of the intermediate accessory 200 by, for example, reading a program stored in the ROM portion of the memory 204 into the RAM portion of the memory 204 and executing the program. In addition to the program, the ROM portion of the memory 204 stores unique information of the intermediate accessory 200 such as identification information.

The intermediate accessory 300 is mechanically and electrically connected to the intermediate accessory 200 by a mounting mechanism 205. Here, for ease of explanation and understanding, it is assumed that the intermediate accessory 300 has the same configuration as the intermediate accessory 200. However, it may be any intermediate accessory that provides functionality other than the variable ND filter.

The interchangeable lens 400 is mechanically and electrically connected to the intermediate accessory 300 by a mounting mechanism 301. As described above, the present embodiment has a photographing optical system in which three auxiliary devices (interchangeable lens 400, intermediate accessory 300, and intermediate accessory 200) are connected.

The interchangeable lens 400 includes a lens group 401, a diaphragm 402, a lens drive circuit 403, a diaphragm drive circuit 404, a control unit 405, and a memory 406. In FIG. 1, the lens group 401 is illustrated with a single lens for the sake of simplification, but it is actually composed of a large number of photographing lenses.

The control unit 405 is a programmable processor such as a CPU, and controls the operation of the interchangeable lens 400 by, for example, reading a program stored in the ROM portion of the memory 406 into the RAM portion of the memory 406 and executing the program. In addition to the program, the ROM portion of the memory 406 stores unique information of the interchangeable lens 400 such as maximum / minimum aperture values, focal lengths, and identification information.

The system control unit 102 of the camera body 100 generates evaluation values for automatic exposure control (AE) and automatic focus detection (AF) using RAW image data or generated image data, and also executes AF processing and AE processing. do. For example, when generating a contrast evaluation value as an AF evaluation value, the system control unit 102 generates a contrast evaluation value of images taken sequentially while changing the position of the focus lens included in the lens group 401. Then, the system control unit 102 moves the focus lens to the position of the focus lens that maximizes the contrast evaluation value. The movement of the focus lens can be realized by operating the lens drive circuit 403 by communication between the system control unit 102 and the lens control unit 405. Further, when the defocus amount is generated as the AF evaluation value, the system control unit 102 moves the focus lens to a position corresponding to the generated defocus amount.

Further, the system control unit 102 generates an evaluation value regarding the brightness value of the image using the RAW image data or the generated image data, and determines the exposure condition by referring to the program diagram stored in the ROM 121. .. The exposure condition may be, for example, a combination of an aperture value, a shutter speed, and a shooting sensitivity. Then, in order to control the aperture 402 to the determined aperture value, the system control unit 102 controls the operation of the aperture drive circuit 404 by communicating with the lens control unit 405.

Since the operation of the camera system during recording of still images and moving images is not directly related to the present invention, the description thereof will be omitted.

When the function of the intermediate accessory 200 is controlled from the camera body 100, the system control unit 102 functions of the intermediate accessory 200 through communication with the control unit 203 based on the content set by the user through, for example, the menu screen displayed on the rear monitor 108. To control. For example, the system control unit 102 transmits the set ND value to the control unit 203. Then, the control unit 203 determines the rotation amount and the rotation direction of the ND filter from the relationship between the current ND value and the received ND value. Then, the control unit 203 can control the concentration of the ND filter to the specified ND value by rotating the variable ND filter in the determined direction through the ND drive circuit 202 by the determined amount. The same applies to the intermediate accessory 300. Further, although the target for controlling the operation differs depending on the function provided by the intermediate accessory, the drive of the movable member to be controlled and the operation of the circuit can be controlled from the system control unit 102 through the control unit of the intermediate accessory.

Next, the power supply operation at startup in the camera system of the present embodiment will be described with reference to the flowchart shown in FIG.
In S501, the power supply unit 107 waits for an instruction to turn on the power through the power switch 105. When the power is turned on, the power supply unit 107 advances the process to S502.

In S502, the power supply unit 107 starts supplying power to the system control unit 102.
In S503, the power supply unit 107 powers the first power supply line 1071 connected to the control unit of the auxiliary device among the power supply lines to the auxiliary device mounted on the mount mechanism 113 of the camera body 100. Start supplying. Here, since it is sufficient to supply the low voltage required for the operation of the CPU, it is not necessary to consider the suppression of the inrush current.

In S504, the system control unit 102 communicates with the control unit of each of the auxiliary devices mounted on the camera body 100, and detects the number of auxiliary devices mounted in series. Here, the system control unit 102 detects the number of auxiliary devices mounted in series with the mount mechanism 113. In this way, the control unit of the auxiliary device is operated by the first power supply line 1071 in a state where power is not supplied by the second power supply line 1072, and communication with the system control unit 102 is possible. It is possible to detect the number of auxiliary devices installed. It should be noted that the communication procedure for recognizing the auxiliary device to which the system control unit 102 is mounted and the operation of the control unit of the auxiliary device are described in advance when the power is turned on or when the mounting of the auxiliary device to the mount mechanism 113 is detected. It can be performed by any specified procedure.

In S505, the system control unit 102 determines whether or not the number of auxiliary devices mounted in series is a predetermined number or more, and if the number is a predetermined number (here, 3) or more, the system control unit 102 goes to S507, if the number is less than the predetermined number. If so, proceed to S506. The process of S505 corresponds to the process of determining whether or not the load of the second power supply line 1072 commonly connected to the drive unit is equal to or greater than the threshold value.

In S506, the system control unit 102 starts up the power to the second power supply line 1072 that supplies power to the drive units 202, 403, and 404 that drive the moving parts of the auxiliary device mounted on the mount mechanism 113. Determine the time as 2 ms. Then, the system control unit 102 sets the determined power start-up time in the power supply unit 107, and advances the processing to S508.

In S507, the system control unit 102 starts up the power to the second power supply line 1072 that supplies power to the drive units 202, 403, and 404 that drive the moving parts of the auxiliary device mounted on the mount mechanism 113. The time is determined to be 8 ms. Then, the system control unit 102 sets the determined power start-up time in the power supply unit 107, and advances the processing to S508. The start-up time is the time required to reach the specified voltage value V supplied to the power supply line. Further, instead of the start-up time, the start-up speed (V / start-up time) may be controlled.

In this way, the system control unit 102 controls the power supply characteristic of the power supply unit 107 based on the number of auxiliary devices mounted on the camera body. Further, as a power supply characteristic, the voltage rise time or speed is controlled. Specifically, the voltage supplied to the drive unit of the auxiliary device when the number of auxiliary devices mounted in series is a second number larger than the first number than when the number is the first number. Set a long start-up time (small slew rate). If the number of auxiliary devices mounted in series is large, the number of capacitors connected to the second power supply line 1072 commonly connected to the drive unit is also large, so that the inrush current becomes large. Therefore, the inrush current is suppressed by slowing the rise of the voltage at the start of power supply. The relationship between the number of auxiliary devices mounted in series and the voltage rise time can be experimentally determined in advance. Although an example of switching the rising slew rate of the voltage in two ways has been described here, it may be configured to switch in three or more ways.

In S508, the power supply unit 107 starts supplying power to the second power supply line 1072 commonly connected to the drive unit of the auxiliary device according to the power supply start-up time set in S506 or S507.

In S509, the power supply unit 107 monitors the voltage of the second power supply line 1072 and notifies the system control unit 102 when the voltage exceeds 90% of the set voltage. Upon receiving the notification, the system control unit 102 transmits an operation command to each control unit of the auxiliary device. As a result, each auxiliary device starts operation.

As described above, according to the present embodiment, the power supply characteristic of the power supply unit 107 is controlled based on the number of auxiliary devices connected to the second power supply line 1072. Further, as a power supply characteristic, the voltage rise time or speed is controlled. Specifically, when the number of auxiliary devices mounted in series is a second number larger than the first number than when the number is the first number, the electric power supplied to the drive unit of the auxiliary device. The startup time of is set longer (slew rate is smaller). This makes it possible to make the appropriate start-up time different depending on the number of auxiliary devices installed in series, which may take longer than necessary to start up, or the operation of the camera body may become unstable due to the inrush current. Can be prevented from doing so.

● (Second embodiment)
Next, a second embodiment of the present invention will be described. The camera system in this embodiment has a different power supply operation at startup from the first embodiment. Therefore, in the following, the power supply operation at startup according to the present embodiment in the camera system shown in FIG. 1 will be described with reference to the flowchart of FIG. In FIG. 3, the same reference numbers as those in FIG. 2 are added to the steps for performing the same operation as in the first embodiment, and the description thereof will be omitted.

S501 to S503 are the same as those in the first embodiment.
In S604, the system control unit 102 resets the load parameter, which is a variable stored in the RAM 104, to 0, for example. Here, the load parameter is information about the magnitude of the load of the drive unit of the auxiliary device in the second power supply line 1072, which is stored as unique information in the memory of each auxiliary device. In the present embodiment, as a load parameter, it is assumed that a value representing the total capacity [μF] of the bypass capacitor connected in parallel to the second power supply line 1072 is held in the memory. The load parameter may be an actual capacitance value or a code representing the capacitance value.

In S605, the system control unit 102 acquires a load parameter from one control unit of the mounted auxiliary device through communication. For example, the system control unit 102 acquires load parameters in order from the auxiliary device closest to the mount mechanism 113.

In S606, the system control unit 102 adds the load parameter acquired in S605 to the acquired load parameter. When S606 is executed for the first time, the load parameter is reset to 0 in S604, so that the acquired load parameter may be stored as the addition result as it is. When the load parameter is a code, the system control unit 102 converts the load parameter into a capacity value by referring to a table stored in the ROM 121, and then adds the load parameter.

If there is an auxiliary device that cannot acquire the load parameter, the system control unit 102 may add the load parameter based on the model information included in the unique information acquired from the auxiliary device or the information indicating the type of the auxiliary device, for example. can. For example, the model name, the type of auxiliary device, and the representative value of the load parameter are stored in the ROM 121 in advance in association with each other. Then, for the auxiliary device for which the load parameter cannot be acquired, the system control unit 102 can acquire the load parameter for the auxiliary device by referring to the ROM 121 based on the unique information of the auxiliary device.

In S607, the system control unit 102 determines whether or not the load parameters have been acquired from all the mounted auxiliary devices, and if it is determined that the load parameters have been acquired, the process proceeds to S608, and if not, the process returns to S605. Get the remaining load parameters.

In the auxiliary device that provided the load parameter to the system control unit 102, the control unit stores, for example, a flag for which the load parameter has been acquired in the memory, and waits until the system control unit 102 finishes acquiring the load parameter from all the auxiliary devices.

In S608, the system control unit 102 determines whether or not the total of the acquired load parameters is a predetermined value (here, 100 [μF]) or more, and if it is determined to be a predetermined value or more, it is determined to S507. Proceed with processing to S506. It is assumed that the predetermined value used as the threshold value here is determined in advance according to the capabilities of the power supply 106 of the camera body 100 and the power supply unit 107, and is stored in the ROM 121, for example. The process of S608 corresponds to the process of determining whether or not the load of the second power supply line 1072 commonly connected to the drive unit is equal to or greater than the threshold value.

Since the subsequent processing is the same as that of the first embodiment, the description thereof will be omitted. When each auxiliary device receives an operation command from the system control unit 102 in S509, each auxiliary device deletes the flag for which the load parameter has been acquired and starts the operation.

As described above, in this embodiment, instead of the number of auxiliary devices mounted in series, the power supply unit is based on the total load of each auxiliary device (drive unit) connected to the second power supply line 1072. It controls the power supply characteristics of 107. Further, as a power supply characteristic, the voltage rise time or speed is controlled. Specifically, when the total load is a second value larger than the first value than the first value, the second power supply line to which the drive unit of the auxiliary device is commonly connected is connected. The start-up time of the electric power supplied to the 1072 is set to be long (slew rate is small). The same effect as that of the first embodiment can be realized in this embodiment as well. Further, it is possible to control the rise of the voltage at the time of starting more accurately than in the first embodiment. Also in this embodiment, the start-up speed may be controlled instead of the start-up time. In this embodiment, a configuration in which load parameters are acquired from all mounted auxiliary devices and the total value is compared with a predetermined value has been described, but the present invention is not limited to this. For example, if it is an auxiliary device that does not have a control unit or a drive unit and simply conducts conduction between directly connected devices at any position between the auxiliary device and the camera body 100, the auxiliary device is concerned. The load parameter of S608 may be replaced with a fixed value, and the processing of S608 may be executed.

● (Third embodiment)
Next, a third embodiment of the present invention will be described. FIG. 4 is a block diagram showing a configuration example of the camera system according to the present embodiment, and the same reference figures as those in FIG. 1 are attached to the same components as those in the first embodiment. In the present embodiment, of the first and second power supply lines 1071 and 1072, the second power supply line 1072 commonly connected to the drive unit is shared with the power supply line to the system control unit 102. , The fact that the load switch 114 is provided is different from the first embodiment. The load switch 114 is a switch for controlling whether or not the second power supply line 1072 is connected to the auxiliary device.

Further, it is assumed that the DCDC converter included in the power supply unit 107 of the present embodiment has a PWM (pulse width modulation) mode and a PFM (pulse frequency modulation) mode as a switching control method. Then, as the power supply characteristic of the power supply unit 107, the switching control method of the DCDC converter possessed by the power supply unit 107 is controlled.

The power supply operation at startup according to this embodiment will be described with reference to the flowchart of FIG. In FIG. 5, the same reference number as in FIG. 2 is attached to the step that performs the same operation as that of the first embodiment, and the same reference number as that of FIG. 3 is attached to the step that performs the same operation as the second embodiment. Omit. The load switch 114 is turned off in the initial state.

When the power is turned on in S501, the power supply unit 107 sets the switching control method of its DCDC converter to the PFM mode in S702, and proceeds to the process in S502. If the default mode of the DCDC converter is set to the PFM mode, no explicit setting operation is required. As a result, in S502 and S503, power supply to the system control unit 102 and each control unit of the auxiliary device is started in the PFM mode.

After that, the processes of S604 to S608 are executed in the same manner as in the second embodiment. In S608, the system control unit 102 determines whether or not the total of the acquired load parameters is equal to or greater than a predetermined value (for example, 100 [μF]). Proceed with processing.

In S710, the system control unit 102 sets the DCDC converter of the power supply unit 107 to the PWM mode, and advances the process to S711. In this way, when it is determined that the load is equal to or higher than the predetermined value, the switching control method of the DCDC converter is switched from the PFM mode to the PWM mode.

Then, in S711, the system control unit 102 turns on the load switch 114 to connect the second power supply line 1072, which is commonly connected from the power supply unit 107 to the drive unit of the auxiliary device, and the power supply unit 107. .. As a result, the supply of electric power to the drive unit of the auxiliary device is started.

The PFM mode is more efficient than the PWM mode because the number of switchings is reduced when the load is low, but it is more vulnerable to load fluctuations (lower responsiveness) than the PWM mode. In a configuration in which the system control unit and the drive unit of the auxiliary device are connected to the same second power supply line 1072 as in the present embodiment, load fluctuation occurs when the load switch 114 is turned on. When the load of the auxiliary device is large, the load fluctuation when the load switch 114 is turned on is large, so that the supply voltage may drop significantly and the operation of the system control unit may become unstable in the PFM mode. .. Therefore, the PWM mode is switched to before the load switch 114 is turned on. On the other hand, when the load of the auxiliary device is not large, the PFM mode having excellent efficiency at the time of low load is maintained.

As described above, in the present embodiment, as in the second embodiment, the power supply characteristic of the power supply unit 107 is controlled based on the total load of each auxiliary device (drive unit). However, as a power supply characteristic, the switching control method of the DCDC converter possessed by the power supply unit 107 is controlled. Specifically, when the total load is the first value, the switching control method is set to the PFM mode, and when the total load is a second value larger than the first value, the switching control method is set to the PWM mode. I made it. In the present embodiment, even when power is supplied to the control unit of the camera body and the drive unit of the auxiliary device mounted on the camera body by the same power supply line, the control unit of the camera body is controlled while the auxiliary device is quickly activated. The stable operation of the part can be realized.

The control of the switching control method described in the present embodiment is the second embodiment in which the power supply line of the control unit of the camera body and the power supply line of the drive unit of the auxiliary device mounted on the camera body are independent. It can also be applied to the configuration of forms.

The present invention has been described in detail above based on an exemplary embodiment. However, the present invention is not limited to the described embodiments, and various modifications and changes can be made within the scope of the claims.

(Other embodiments)
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

100 ... Camera body, 102 ... System control unit, 107 ... Power supply unit, 113, 205, 301 ... Mount mechanism, 200, 300 ... Accessories, 204, 406 ... Memory, 400 ... Interchangeable lens, 203, 405 ... Control unit

Claims (14)

It is an image pickup device that can be equipped with an auxiliary device.
A power supply means for supplying power to the auxiliary device through the first power supply line and the second power supply line, and
It has a control means for controlling the operation of the image pickup apparatus, and has.
The control means is the second by the power supply means based on the information acquired from each of the auxiliary devices mounted on the image pickup device in a state where the power is not supplied by the second power supply line. To change the power supply characteristics through the power supply line of
An imaging device characterized by this. The information is the number of auxiliary devices attached to the image pickup device.
The supply characteristic is the voltage rise time or the voltage rise rate.
The image pickup apparatus according to claim 1. The control means has a voltage rise time when the number of auxiliary devices mounted on the image pickup apparatus is a second number larger than the first number than when the number of auxiliary devices is the first number. To lengthen or reduce the rise speed of the voltage.
The image pickup apparatus according to claim 2. The information is a parameter relating to the load of the auxiliary device mounted on the image pickup device.
The supply characteristic is the voltage rise time or speed.
The image pickup apparatus according to claim 1. The imaging device according to claim 4, wherein the parameter represents the total capacity of a capacitor connected to the second power supply line in the auxiliary device. The control means obtains the total load of the auxiliary device mounted on the image pickup device on the second power supply line based on the information acquired from each of the auxiliary devices mounted on the image pickup device. When the total of the loads is a second value larger than the first value, the voltage rise time is lengthened or the voltage rise speed is reduced. ,
The image pickup apparatus according to claim 4 or 5. The information is a parameter relating to the load of the auxiliary device mounted on the image pickup device.
The supply characteristic is a switching control method for a DCDC converter included in the power supply means.
The imaging apparatus according to any one of claims 1 and 4 to 6. The imaging device according to claim 7, wherein the parameter represents the total capacity of a capacitor connected to the second power supply line in the auxiliary device. The control means obtains the total load of the auxiliary device mounted on the image pickup device on the second power supply line based on the information acquired from each of the auxiliary devices mounted on the image pickup device. When the total of the loads is the first value, the switching control method is set to the PFM mode, and when the total of the loads is a second value larger than the first value, the switching control method is set to the PWM mode.
The image pickup apparatus according to claim 7 or 8. The control means of the image pickup device is connected to the second power supply line, and the control means is connected to the second power supply line.
The imaging device further comprises a switch for controlling whether or not the second power supply line is connected to the auxiliary device.
The control means acquires the information from the auxiliary device in a state where the switch is off, and when the total of the loads is the second value, the switching control method is set to the PWM mode and then the switch is turned on. turn on,
The image pickup apparatus according to claim 9. One of claims 1 to 10, wherein the auxiliary device has a mount portion having a shape corresponding to the mount portion of the image pickup device, and can be attached to and detached from the image pickup device by the mount portion. The image pickup apparatus according to the above. The imaging device according to any one of claims 1 to 11, wherein the auxiliary device includes an interchangeable lens or an adapter or an accessory that can be attached between the interchangeable lens and the main body of the imaging device. It is a control method of an image pickup device that can be equipped with an auxiliary device.
The image pickup apparatus has a power supply means for supplying power to the auxiliary device through a first power supply line and a second power supply line.
In the control method, the power supply means is based on information acquired by the control means from each of the auxiliary devices mounted on the image pickup device in a state where power is not supplied by the second power supply line. It has a control step of changing the power supply characteristic through the second power supply line according to the above.
A control method for an image pickup apparatus, characterized in that. A program for causing a computer to function as the control means of the image pickup apparatus according to any one of claims 1 to 12.

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