Imaging apparatus, control method, and program

Abstract

To provide a technique for reducing the peak current of a main power supply for supplying electric power to an imaging sensor.SOLUTION: An imaging apparatus includes an imaging sensor, power feeding means, power storage means, charging means for charging the power storage means by using the electric power from the power feeding means, and control means for performing control so as to supply the electric power to the imaging sensor from the power feeding means, without supplying the electric power to the imaging sensor from the power storage means, in the first operation state of the imaging apparatus and for performing control so as to supply the electric power to the imaging sensor from the power feeding means and the power storage means, in the second operation state of the imaging apparatus in which the maximum electric power consumption of the imaging sensor is larger than that in the first operation state.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an imaging apparatus, a control method, and a program. [Background technology]

[0002] There is known a technique for assisting the power supply from a battery by using a capacitor to supply power to a load (for example, see Patent Document 1).

[0003] Also, there is known an imaging device that is equipped with an imaging sensor capable of simultaneously reading out data from a plurality of pixels, thereby enabling shooting with reduced rolling distortion without using a mechanical shutter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-166797 A Summary of the Invention [Problem to be solved by the invention]

[0005] When data of many pixels is read out simultaneously from an image sensor at high speed, the peak current of the image sensor increases. When the peak current increases, the current supplied from the battery of the image sensor exceeds the allowable value, which may cause the battery voltage to drop and the system to shut down. When the peak current becomes large, a voltage drop occurs due to line resistance, and the voltage drops below the minimum drive voltage of the image sensor, which may also cause the system to shut down. However, the technology of Patent Document 1 does not address the problem of the peak current of the image sensor exceeding the allowable value.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a technique for reducing the peak current of the main power supply that supplies power to an image sensor. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention provides an imaging device comprising an imaging sensor, a power supplying means, a power storage means, charging means for charging the power storage means using power from the power supplying means, and control means for controlling, in a first operating state of the imaging device, to supply power from the power supplying means to the imaging sensor without supplying power from the power storage means to the imaging sensor, and for controlling, in a second operating state of the imaging device in which the maximum power consumption of the imaging sensor is greater than in the first operating state, to supply power from the power supplying means and the power storage means to the imaging sensor. Effect of the Invention

[0008] According to the present invention, it is possible to reduce the peak current of the main power supply that supplies power to the image sensor.

[0009] Other features and advantages of the present invention will become apparent from the accompanying drawings and the following detailed description of the preferred embodiments of the present invention. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing the configuration of an imaging device 100. [Diagram 2] FIG. 2 is a block diagram showing a detailed configuration of an imaging power supply unit 1072. [Diagram 3] FIG. 2 is a diagram illustrating a hardware structure of the imaging device 100. [Figure 4A] FIG. 2 is a block diagram showing a detailed configuration of a supply source selection unit 203. [Figure 4B] FIG. 13 shows another example of the configuration of the supply source selection unit 203. [Figure 5A] 4 is a flowchart of a process executed by the imaging device 100. [Figure 5B] 4 is a flowchart of a process executed by the imaging device 100. [Figure 5C] 4 is a flowchart of a process executed by the imaging device 100. [Figure 6]4 is a switch setting table for the main power supply path switching unit 401 when switching the main power supply path in response to temperature. [Figure 7] 13 is a switch setting table for the main power supply path switching unit 401 when switching the main power supply path in accordance with the ESR of the power storage device unit 202. [Figure 8] 1A is a graph showing the temperature characteristics of the power storage device section 202, and FIGS. 1B and 1C are graphs showing the deterioration characteristics of the power storage device section 202. FIG. [Figure 9] 4 is a diagram showing regions for each degree of deterioration of the power storage device section 202. [Figure 10] 3A to 3C are diagrams illustrating examples of various notifications to a user by the imaging device 100. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0012] [First embodiment] FIG. 1 is a block diagram showing the configuration of the imaging device 100. The configuration and operation of the imaging device 100 will be described with reference to FIG. 1. An imaging drive control unit 1012 receives a command from a control unit 1011 in a CPU 101 that controls the entire imaging device 100, and controls the imaging sensor 102 based on the command. The imaging sensor 102 controlled in this manner performs photoelectric conversion (exposure) by capturing light from a subject into each pixel, and generates digital data by an A / D converter in the imaging sensor 102. Image data generated based on the digital data obtained from each pixel is captured in a temporary memory 1014 in the CPU 101. The imaging sensor 102 has at least 8K (7680 pixels horizontally by 4320 pixels vertically) pixels. The imaging sensor 102 is capable of outputting 8K image data at 60 frames per second.

[0013] In the case of a shooting standby state in which a through image is displayed, data is captured from the image sensor 102 in response to a thinning drive command for a through image from the control unit 1011. The captured data is expanded in a temporary memory 1014. The acquired image is corrected by an image correction unit 1015, and then converted into data for display by a display image conversion unit 1016, and displayed on the display unit 103.

[0014] When the user presses the release button, image data is captured from the image sensor 102, which is driven and controlled for actual shooting (shooting an image for recording) in accordance with instructions from the image capture drive control unit 1012. The image data expanded in the temporary memory 1014 is corrected by the image correction unit 1015, JPEG encoded by the image compression unit 1013, and recorded in the recording unit 104 as a still image.

[0015] When the user presses the video recording button, image data is continuously captured from the imaging sensor 102, which is driven and controlled for video by instructions from the imaging drive control unit 1012. The image data expanded in the temporary memory 1014 is corrected by the image correction unit 1015, undergoes video encoding processing by the image compression unit 1013, and is recorded as a video in the recording unit 104. Although not shown in FIG. 1 for simplification, the imaging device 100 also includes an operation unit for user operation input.

[0016] Representative operational modes of the imaging device 100 include a still image mode and a video mode. More specifically, the still image mode includes a single-shot mode in which one still image is shot each time the release button is pressed, and a continuous-shot mode in which still images are continuously captured while the release button is pressed. The continuous-shot mode includes a high-speed continuous-shot mode in which a greater number of images are shot per unit time, and a low-speed continuous-shot mode in which a relatively small number of images are shot per unit time.

[0017] In addition to the single shot mode and continuous shot mode, which are different in terms of the number of shots, there are also modes that are different in terms of the readout method. The readout method modes include a high-speed readout mode, which obtains still images with reduced distortion of moving subjects by simultaneously reading out a larger number of pixels from the image sensor 102, and a low-speed readout mode, which simultaneously reads out a smaller number of pixels. In particular, the high-speed readout modes include a global shutter mode, which reads out all pixels at once.

[0018] In the movie mode, the operation mode of the imaging device 100 is classified according to the movie format to be recorded, for example, 8K recording mode, 4K recording mode, FHD recording mode, etc. In the movie mode, the frame rate can also be changed, and the operation mode of the imaging device 100 is also classified according to the frame rate.

[0019] The above-mentioned operation modes of the imaging device 100 may be changed in response to a user's operation, or the control unit 1011 may automatically change the operation mode to the most suitable operation mode for the user.

[0020] The power supply unit 107 plays a role of converting power supplied from the battery 108 or the USB power supply unit 110 into a required voltage and current and supplying it to each unit of the imaging device 100. The battery 108 corresponds to a power supply source for the imaging device 100 and is, for example, a removable lithium ion battery. The battery monitoring unit 109 monitors the voltage and discharge current of the battery 108 and transmits the information to the control unit 1011. The battery monitoring unit 109 can also calculate the internal resistance of the battery 108 from the discharge current and voltage drop amount of the battery 108. Based on the battery information provided by the battery monitoring unit 109, when the remaining capacity of the battery 108 is low or the internal resistance is rising, the control unit 1011 performs control such as putting the imaging device 100 into a low power consumption state.

[0021] The imaging device 100 can also operate using power supplied from a USB power supply unit 110 instead of the battery 108. The USB power supply unit 110 is connected to a mobile battery, an AC adapter, or the like via a USB cable. In FIG. 1, the power supply unit 107 only includes a CPU power supply unit 1071 that supplies power to the CPU 101 and an imaging power supply unit 1072 that supplies power to the imaging sensor 102. However, the power supply unit 107 also includes power supply units that supply power to the display unit 103, the recording unit 104, and the like.

[0022] The power supply control unit 106 controls the power supply unit 107 based on instructions from the control unit 1011. For example, the power supply control unit 106 performs on / off control, changes in output voltage, and the like for each unit in the power supply unit 107. In FIG. 1, the power supply control unit 106 is depicted as a device separate from the CPU 101, but the power supply control unit 106 may be configured within the CPU 101. Alternatively, a configuration in which the control unit 1011 directly controls the power supply unit 107 may be adopted.

[0023] The temperature sensor 105 is disposed in the imaging device 100 and outputs temperature data in the vicinity of the temperature sensor 105. The control unit 1011 can estimate the temperature of any point of the imaging device 100 based on the output data of the temperature sensor 105. The number of temperature sensors 105 is not limited to one, and the control unit 1011 can estimate the temperature of the imaging device 100 in more detail based on the output data of two or more temperature sensors 105. The control unit 1011 can change the control of the imaging device 100 according to the temperature information. For example, when the estimated temperature of the imaging sensor 102 exceeds a predetermined temperature, the control unit 1011 sends a command to the imaging drive control unit 1012 to stop the imaging operation. At the same time, the control unit 1011 sends a command to the power control unit 106 to turn off the imaging power supply unit 1072. This makes it possible to safely stop the imaging operation when the imaging sensor 102 falls into a temperature state outside the usable range.

[0024] 2 is a block diagram showing a detailed configuration of the imaging power supply unit 1072. Power from the battery 108 or the USB power supply unit 110 is input to the imaging main power supply unit 201 and the power storage device charging / discharging unit 204. The imaging main power supply unit 201 converts the voltage of the battery 108 into an operating voltage for the imaging sensor 102 and outputs it. The imaging main power supply unit 201 includes, for example, a DC / DC converter or an LDO. The power storage device charging / discharging unit 204 performs a charging operation for the power storage device unit 202 using power from the battery 108 or the USB power supply unit 110.

[0025] The power storage device unit 202 is, for example, an electric double layer capacitor (EDLC), but is not limited to this. A power storage device such as an all-solid-state battery may be used as the power storage device unit 202 as long as it has a large capacity sufficient to cover the driving power of the image sensor 102 and an equivalent series resistance (ESR) sufficient to cover the response speed of the image sensor 102.

[0026] The power supply selection unit 203 selects the output of one or both of the main imaging power supply unit 201 and the power storage device unit 202 to supply power to the imaging sensor 102. The power supply selection unit 203 is controlled by the power supply control unit 106 so as to supply power from the battery 108 or the USB power supply unit 110 via the main imaging power supply unit 201 to the imaging sensor 102. However, the power of the battery 108 or the USB power supply unit 110 is also used as a power supply for other circuit blocks of the imaging device 100. Therefore, if the power of the battery 108 or the USB power supply unit 110 is used to cover all the power consumption of the imaging sensor 102, there is a risk that the allowable power of the battery 108 or the USB power supply unit 110 will be exceeded. For example, when the operation mode of the imaging device 100 is the global shutter mode, the imaging sensor 102 consumes a momentary large amount of power to simultaneously read out all pixels. Therefore, there is a high risk that the allowable output current of the battery 108 or the USB power supply unit 110 will be exceeded. For this reason, in operation modes of the imaging device 100 with high maximum power consumption, such as the global shutter mode, the supply source selection unit 203 is controlled to supply power from the power storage device unit 202 to the image sensor 102. In addition to the global shutter mode, operation modes of the imaging device 100 with high maximum power consumption also include a mode in which multiple pixels are read out simultaneously and a mode in which the readout speed is increased for the purpose of high-speed continuous shooting.

[0027] When the imaging sensor 102 consumes the power once stored in the power storage device unit 202, the current supplied from the battery 108 or the USB power supply unit 110 is reduced. When the power storage device unit 202 has the capacity to supply sufficient power, the supply source selection unit 203 may select only the power from the power storage device unit 202 and supply it to the imaging sensor 102.

[0028] When the power storage device charging / discharging unit 204 performs constant current charging on the power storage device unit 202, the power storage device charging / discharging unit 204 keeps the output current constant. The power storage device charging / discharging unit 204 changes the output voltage in accordance with the increase in voltage of the power storage device unit 202. When the voltage of the power storage device unit 202 reaches a charging completion voltage, the power storage device charging / discharging unit 204 stops the charging operation.

[0029] The output voltage, output current, and charge completion voltage of the power storage device charge / discharge unit 204 can be changed by the control of the power supply control unit 106. For example, by setting the output current of the power storage device charge / discharge unit 204 to a large value, it is possible to shorten the time until the power storage device unit 202 is fully charged. On the other hand, when the output current is set to a large value, the power taken out from the battery 108 or the USB power supply unit 110 increases. For this reason, in order to suppress the power taken out from the battery 108 or the USB power supply unit 110, the output current value of the power storage device charge / discharge unit 204 can be set to a small value. In addition, by setting the charge completion voltage of the power storage device charge / discharge unit 204 to a high value, more power can be supplied from the power storage device unit 202 to the image sensor 102. On the other hand, if the charge completion voltage is set to a high value, there is a concern that the deterioration of the power storage device unit 202 will progress due to a high voltage being applied to the power storage device unit 202 for a long time. For this reason, the charge completion voltage of the power storage device charge / discharge unit 204 can be set to a low value in order to prevent the deterioration. Although the above describes the case where the power storage device charging / discharging unit 204 performs constant current charging on the power storage device unit 202, constant voltage charging may also be performed, in which case the upper limit values ​​of the charging voltage and charging current, etc. can be set by the power supply control unit 106.

[0030] The power storage device charge / discharge unit 204 has a function of charging the power storage device unit 202, as well as a function of discharging the power storage device unit 202 to prevent the power storage device unit 202 from being overcharged.

[0031] Next, the hardware structure of the imaging device 100 will be described with reference to Fig. 3. A main board 301 and an imaging sensor board 302 are arranged inside the housing of the imaging device 100. The CPU 101 and the power supply unit 107 are mounted on the main board 301. The imaging sensor 102 is mounted on the imaging sensor board 302. In order for the imaging sensor 102 to efficiently capture light, the imaging sensor board 302 is arranged closer to the lens than the main board 301.

[0032] The imaging sensor board 302 is connected to the main board 301 by making full use of flexible printed circuits (FPC), connectors, etc. This makes it possible to supply control signals from the CPU 101 and power from the imaging power supply unit 1072 to the imaging sensor 102. The power storage device unit 202 may be mounted on the main board 301 or on the imaging sensor board 302. When the power storage device unit 202 is mounted on the imaging sensor board 302, the impedance between the imaging sensor 102 and the power storage device unit 202 becomes small, which has the advantage that power from the power storage device unit 202 can be easily supplied to the imaging sensor 102.

[0033] 3 shows temperature sensors 105a, 105b, and 105c as examples of the multiple temperature sensors 105. Temperature sensor 105a is a temperature sensor arranged on the imaging sensor board 302. Temperature sensor 105b is a temperature sensor arranged on the main board 301. Temperature sensor 105c is a temperature sensor attached to the housing. Based on the output data of these temperature sensors 105, control unit 1011 can estimate the temperature at any point of imaging device 100.

[0034] Since the power storage device unit 202 deteriorates when exposed to a high-temperature environment, it is important to manage the temperature of the power storage device unit 202. For example, when the power storage device unit 202 is mounted on the imaging sensor board 302, the temperature sensor 105a is not only used to monitor whether the temperature of the imaging sensor 102 is outside the usable range, but is also used to estimate the temperature of the power storage device unit 202. When the power storage device unit 202 is mounted on the main board 301, the temperature sensor 105b arranged near the power storage device unit 202 is used to estimate the temperature of the power storage device unit 202. When the temperature sensor 105b cannot be arranged near the power storage device unit 202, the control unit 1011 estimates the temperature of the power storage device unit 202 on the main board 301 using the output data of the temperature sensor 105b from the correlation between the output of the temperature sensor 105b and the power storage device unit 202.

[0035] Fig. 4A is a block diagram showing a detailed configuration of the power supply selection unit 203. In the example of Fig. 4A, the power supply selection unit 203 is configured to be able to switch the impedance of the power supply path (main power supply path) from the imaging main power supply unit 201 to the imaging sensor 102.

[0036] The power supply source selection unit 203 includes a main power supply path switching unit 401, a resistor 402, a power storage device path switching unit 403, and a main power supply current detection unit 404. Resistor 402 is a general term for resistors 402a to 402c shown in Fig. 4A. The main power supply path switching unit 401 and the power storage device path switching unit 403 can switch between on and off under the control of the power supply control unit 106.

[0037] During shooting operation in an operation mode (e.g., global shutter mode) in which the maximum power consumption of the imaging device 100 is relatively large, the power storage device path switching unit 403 turns on the power supply path (power storage device path) from the power storage device unit 202 to the imaging sensor 102. By charging the power storage device unit 202 to a voltage higher than the voltage of the imaging main power supply unit 201 before shooting operation, it is possible to supply power preferentially from the power storage device unit 202 to the imaging sensor 102 during shooting operation.

[0038] However, as power is supplied from the power storage device unit 202 to the imaging sensor 102, the voltage of the power storage device unit 202 drops. In addition, the equivalent series resistance (ESR) of the power storage device unit 202 causes the voltage of the power storage device unit 202 to drop in proportion to the amount of current drawn from the power storage device unit 202. In the example of FIG. 4A, a diode is arranged in the circuit constituting the power storage device path switching unit 403 so that no current flows from the imaging main power supply unit 201 to the power storage device unit when the power storage device path is turned on. This diode also causes the voltage on the power storage device path side to drop. When the voltage on the power storage device path side drops, the voltage of the main power supply path and the voltage of the power storage device path become the same potential at the junction of the paths. In this state, power is supplied to the imaging sensor 102 preferentially from the path with the smallest impedance.

[0039] When the main power supply path switching unit 401 is in a pass-through state and the line impedance of the main power supply path from the imaging main power supply unit 201 is sufficiently low, power is preferentially supplied from the imaging main power supply unit 201 to the imaging sensor 102 even if the power storage device path is on. To avoid this state, the main power supply path switching unit 401 switches so as to limit the current on the main power supply path side. Specifically, the main power supply path switching unit 401 performs a switching operation so that the resistor 402 is arranged in series with the main power supply path so that the impedance of the main power supply path is greater than the impedance of the power storage device path including the ESR of the power storage device unit 202. This allows power to be continuously supplied preferentially from the power storage device unit 202 to the imaging sensor 102 even if the voltage of the power storage device unit 202 drops.

[0040] Note that, when the power storage device path is turned on in a state in which the voltage of the power storage device section 202 is higher than the voltage of the imaging main power supply section 201, there is a risk of current flowing back to the output of the imaging main power supply section 201. To prevent backflow, a backflow prevention function may be provided in the imaging main power supply section 201 or in a switch arranged in series in the main power supply path.

[0041] The supply source selection unit 203 includes resistors 402a to 402c with different resistance values ​​as the resistor 402. The resistance value of resistor 402b is greater than that of resistor 402a, and the resistance value of resistor 402c is greater than that of resistor 402b. The supply source selection unit 203 selects an optimum resistor 402 depending on the situation. Although four paths with different impedances are shown in FIG. 4A, the number of paths is not limited to four. Also, the combined impedance of the paths may be changed by changing the combination of switches to be turned on.

[0042] Even when it is desired to give priority to the power supply from the power storage device unit 202, it is desirable that the resistance 402 is as small as possible in order to reduce unnecessary loss caused by the resistance 402. Therefore, at the initial stage of the operation of the imaging device 100, the supply source selection unit 203 turns on the path A having a relatively small resistance value. However, if the impedance of the power storage device path increases, the impedance of the main power supply path becomes relatively small, and as a result, the necessary power is not supplied from the power storage device unit 202. An example of an increase in the impedance of the power storage device path is when the power storage device unit 202 is at a low temperature. When the power storage device unit 202 is in a low temperature state, the ESR tends to increase. To address this problem, the control unit 1011 controls the main power supply path switching unit 401 via the power supply control unit 106 based on the output data of the temperature sensor 105 to change the impedance of the main power supply path. Specifically, the control unit 1011 estimates the temperature of the power storage device unit 202 based on the output of the temperature sensor 105. According to the impedance of the power storage device path expected at the estimated temperature, the control unit 1011 performs control to switch from path A to path B or path C. This allows the power storage device unit 202 to supply the necessary power even if the impedance of the power storage device path increases at a low temperature.

[0043] For example, a state in which path A is selected can be called a first supply mode. Also, a state in which path B or path C is selected can be called a second supply mode. In the second supply mode, the value of the current output by the main power supply path is controlled to be lower than in the first supply mode. Although FIG. 4A shows a configuration in which three paths (paths A to C) excluding the pass-through path can be switched, the number of paths is not particularly limited.

[0044] Other factors that increase the impedance of the power storage device path include the deterioration of the power storage device section 202, in addition to the temperature characteristics of the power storage device section 202. When the power storage device section 202 deteriorates, the ESR increases. Since the ESR is variable in this way, the control section 1011 measures the impedance of the power storage device path. The impedance measurement of the power storage device path can be calculated by detecting the current of the main power supply path. For this purpose, the supply source selection section 203 includes a main power supply current detection section 404.

[0045] The main power supply current detection unit 404 can calculate the current flowing through the main power supply path from the voltage difference between both ends of the resistor 402. For example, if it is known that the current during reading of the image sensor is 3 A and the current flowing through the main power supply path is 1 A, then 2 A flows through the power storage device path. This current ratio corresponds to the ratio of the impedance of the main power supply path to the impedance of the power storage device path. If the main power supply path at this time is path A, the control unit 1011 can calculate that the impedance of the power storage device path is 1 / 2 of the resistor 402a. The control unit 1011 controls the power supply control unit 106 to switch from path A to path B or path C according to the impedance of the power storage device path calculated in this manner. This allows the power storage device unit 202 to supply the necessary power to the image sensor 102 even if the power storage device unit 202 deteriorates and the impedance of the power storage device path increases.

[0046] A configuration may be adopted in which the impedance of the power storage device path is measured by a method other than the method of detecting the current of the main power path. For example, a configuration may be provided in which a switch in the power storage device path switching unit 403 calculates the impedance of the power storage device path. The impedance of the power storage device path can be measured from the current and voltage flowing through the power storage device path. In another example, a configuration may be provided in the power storage device charging / discharging unit 204 that calculates the impedance of the power storage device path. The impedance of the power storage device path can be measured from the amount of voltage drop in the power storage device unit 202 when discharging at a constant current.

[0047] Increasing the impedance of the main power path also has the disadvantage of increasing the loss in the main power path. Furthermore, when the power storage device path is on, power is supplied from the power storage device unit 202 to the image sensor 102 regardless of whether or not power needs to be supplied from the power storage device unit 202 to the image sensor 102. This causes unnecessary charging and discharging in the power storage device unit 202, resulting in a decrease in the battery life of the battery 108.

[0048] To solve this problem, in an operation mode in which the maximum power consumption of the imaging device 100 is relatively small and the imaging device 100 operates within the allowable power of the battery 108 or the USB power supply unit 110, the main power path switching unit 401 switches the path so that the impedance of the main power path is small. This makes it possible to minimize loss in the main power path. Also, when the impedance of the main power path is small and the voltage of the main power path and the voltage of the power storage device path become the same potential, power is supplied from the imaging main power supply unit 201 to the imaging sensor 102. As a result, unnecessary charging and discharging of the power storage device unit 202 is reduced, and the battery life of the battery 108 can be improved. In addition, the power storage device path switching unit 403 may turn off the power storage device path at the same time as switching the main power path. This makes it possible to operate the imaging sensor 102 without consuming the power charged in the power storage device unit 202, and prevents loss due to unnecessary charging and discharging of the power storage device unit 202.

[0049] The operation modes in which the imaging device 100 operates within the allowable power of the battery 108 or the USB power supply unit 110 include, for example, a moving image mode, a single shot mode and a low-speed continuous shooting mode in a still image mode, and a low-speed readout mode. Also, a live view state in an operation mode in which the maximum power consumption of the imaging device 100 is relatively high (for example, a global shutter mode, a high-speed continuous shooting mode, a high-speed readout mode, etc.) is included in the operation modes in which the imaging device 100 operates within the allowable power of the battery 108 or the USB power supply unit 110.

[0050] The main power path switching unit 401 may perform control to switch the main power path between a read operation of the image sensor 102 and other periods, regardless of the operation mode of the imaging device 100. For example, the main power path switching unit 401 controls to increase the impedance of the main power path in synchronization with a read operation of the image sensor 102, and to decrease the impedance of the main power path during periods other than read operation. By performing control in this manner, it becomes possible to reduce the current drawn from the battery 108 or the USB power supply unit 110 during a read operation, and to reduce unnecessary loss in the power storage device unit 202 during periods other than read operation.

[0051] Fig. 4B is a diagram showing another example of the configuration of the power supply source selection unit 203. In Fig. 4B, compared to Fig. 4A, the main power supply path switching unit 401 is replaced with a main power supply current limiting unit 406. The main power supply current limiting unit 406 performs current limiting, which is a process of limiting the current value output to the imaging sensor 102 by the main power supply path so that it does not exceed a current threshold value determined by the power supply control unit 106. Fig. 4B shows, as an example, a case in which the main power supply current limiting unit 406 is a component of the power supply source selection unit 203, but the imaging main power supply unit 201 may be provided with a function equivalent to that of the main power supply current limiting unit 406.

[0052] The main power supply current limiting unit 406 can change the current threshold based on information from a temperature sensor, similar to the main power supply path switching unit 401 shown in Fig. 4A. Furthermore, the main power supply current limiting unit 406 can also change the current threshold depending on the operation mode of the imaging device 100, similar to the main power supply path switching unit 401 shown in Fig. 4A.

[0053] The main power supply control unit 406 also has the first supply mode and the second supply mode as described above. In the second supply mode, the current value output from the main power supply path is controlled to be lower than that in the first supply mode. In this case, the control unit 1011 can perform control to switch between the first supply mode and the second supply mode according to the operation mode of the imaging device 100. Furthermore, the control unit 1011 can perform control to switch between the first supply mode and the second supply mode according to information from the temperature sensor 105. Furthermore, the control unit 1011 can perform control to switch between the first supply mode and the second supply mode according to the ESR. By such switching control, it is possible to suppress power loss in the imaging power supply unit 1072 while reducing the maximum current (peak current) of the battery 108 or the USB power supply unit 110.

[0054] The state in which the current of the main power path is not limited and the state in which the current is limited may be referred to as a first supply mode and a second supply mode, respectively. Alternatively, a configuration in which three or more supply modes with different degrees of current limiting are switched may be adopted. Here, the degree of current limiting can also be referred to as the magnitude of the current value output from the main power path to the image sensor 102. The greater the degree of current limiting, the smaller the current value output from the main power path to the image sensor 102 is controlled.

[0055] Also, a configuration may be adopted in which the supply mode is switched depending on the state of the battery 108 monitored by the battery monitoring unit 109 shown in FIG. 4B. For example, when the voltage of the battery 108 is lower than a predetermined voltage value, the control unit 1011 switches to the second supply mode. In another example, when the current of the battery 108 is greater than a predetermined current value, the control unit 1011 switches to the second supply mode. In another example, when the internal resistance of the battery 108 is greater than a predetermined resistance value, the control unit 1011 switches to the second supply mode. In this way, the output current of the imaging main power supply unit 201 is limited so as not to exceed the allowable current of the battery 108, and the imaging sensor 102 can be operated in combination with the power from the power storage device unit 202.

[0056] 4A and 4B, a configuration has been described above in which the impedance of the main power supply path is changed depending on the temperature or ESR of the power storage device unit 202. This makes it possible to supply the necessary power from the power storage device unit 202 to the imaging sensor 102. However, when the power storage device unit 202 is in an excessively low temperature state, even if the impedance of the main power supply path is set to the maximum, the impedance of the power storage device path becomes larger than the maximum. Therefore, power is preferentially supplied from the imaging main power supply unit 201 to the imaging sensor 102. At this time, there is a risk that the allowable power of the battery 108 or the USB power supply unit 110 will be exceeded, causing a system shutdown of the imaging device 100.

[0057] To solve this problem, the control unit 1011 predicts the power supplied from the imaging main power supply unit 201 to the imaging sensor 102 based on information from the temperature sensor 105, and if the power exceeds a predetermined value, controls the imaging device 100 to prohibit shooting operations.

[0058] Furthermore, if the impedance of each power supply path for the image sensor 102 becomes excessively large, there is a risk that the supply voltage will fall below the operating voltage of the image sensor 102 due to a voltage drop caused by the impedance.

[0059] To solve this problem, the control unit 1011 predicts a voltage drop in the power supply of the image sensor 102 based on information from the temperature sensor, and controls the image capturing device 100 to prohibit shooting operations if the voltage drop exceeds a predetermined value.

[0060] In the above example, the control unit 1011 prohibits the image capturing operation of the image capturing apparatus 100 based on information from the temperature sensor, but the control unit 1011 may predict the ESR of the power storage device unit 202 and prohibit the image capturing operation. In this case, the control unit 1011 predicts the power supplied from the image capturing main power supply unit 201 to the image capturing sensor 102 from the ESR of the power storage device unit 202, and performs control to prohibit the image capturing operation of the image capturing apparatus 100 if the power exceeds a predetermined power value. The control unit 1011 also predicts a voltage drop of the power supply of the image capturing sensor 102 from the ESR of the power storage device unit 202, and performs control to prohibit the image capturing operation of the image capturing apparatus 100 if the voltage drop exceeds a predetermined value.

[0061] For example, consider a case where the still image mode has a higher maximum power than the video mode and is premised on supplying power from the power storage device unit 202 to the image sensor 102. In this case, when the power storage device unit 202 falls into the above-mentioned state, the control unit 1011 prohibits image capture operations only in the still image mode. Alternatively, the control unit 1011 may prohibit image capture operations in the high-speed continuous shooting mode, high-speed readout mode, and global shutter mode, which are premised on supplying more power than in the still image mode from the power storage device unit 202 to the image sensor 102.

[0062] 5A to 5C are flowcharts of processing executed by the imaging device 100. Unless otherwise specified, the processing of each step of this flowchart is realized by the control unit 1011 executing a control program stored in a ROM (not shown) of the imaging device 100. Furthermore, the control unit 1011 controls the power supply unit 107 via the power supply control unit 106. When a user presses the power button of the imaging device 100 to turn on the power supply of the imaging device 100, the processing of this flowchart starts.

[0063] In S502, the control unit 1011 initializes the main power supply path. Specifically, the control unit 1011 controls the switch of the main power supply path switching unit 401 so that the main power supply path becomes a pass-through path. This prevents unnecessary loss from occurring in the resistor 402 in the live view state.

[0064] In S503, the control unit 1011 disables the power storage device path. Specifically, the control unit 1011 controls the power storage device path switching unit 403 to turn off the switch so that power is not supplied from the power storage device unit 202 to the image sensor 102. This prevents loss due to unnecessary charging and discharging of the power storage device unit 202 in the live view state.

[0065] In S504, the control unit 1011 performs imaging startup processing and starts operation in a live view state (LV state) of the imaging device 100. In this live view state, power is supplied from the imaging main power supply unit 201 to the imaging sensor 102 via a pass-through path.

[0066] In S505, the control unit 1011 predicts the ESR of the power storage device unit 202. Specifically, first, the control unit 1011 controls the main power path to be path B. Also, the control unit 1011 turns on the switch of the power storage device path switching unit 403 to enable the power storage device path. In addition, the control unit 1011 controls the power storage device charging / discharging unit 204 to charge the power storage device unit 202 so that the voltage of the power storage device unit 202 is higher than the output voltage of the imaging main power supply unit 201. Thereafter, the control unit 1011 causes the imaging sensor 102 to operate so that the current consumption is known and constant. At this time, the main power supply current detection unit 404 detects the current flowing in the main power supply path from the voltage difference between both ends of the resistor 402a. The detected main power supply path current is transmitted to the control unit 1011. The control unit 1011 calculates the current of the power storage device path by the following formula 1. Power storage device path current = Image sensor current consumption – Main power path current … (1)

[0067] Next, the control unit 1011 predicts the ESR of the power storage device unit 202 using the ratio between the power storage device path current and the main power supply path current according to the following formula 2. Power storage device ESR=resistance value of resistor 402a × (main power supply path current / power storage device path current) … (2)

[0068] In this way, it is possible to predict the ESR of the power storage device unit 202 by detecting the current of the main power supply path. Here, the current consumption of the image sensor 102 is used to predict the ESR of the power storage device unit 202, but other current consumption may be used. For example, a dedicated circuit that generates a load that consumes a current known to the control unit 1011 may be provided separately from the image sensor 102. Here, a method based on current detection of the main power supply path has been described as a method for predicting the ESR of the power storage device unit 202. However, the method for predicting the ESR of the power storage device unit 202 is not limited to the method described here and the above calculation formula, and the ESR of the power storage device unit 202 may be predicted using another method or calculation formula.

[0069] When the prediction of the ESR of the power storage device unit 202 is completed, the control unit 1011 controls the switch so that the main power path becomes a pass-through path and the power storage device path is disabled.

[0070] In S506 , the control unit 1011 estimates the temperature of the power storage device unit 202 based on the output data of the temperature sensor 105 .

[0071] In S507, the control unit 1011 performs a deterioration determination of the power storage device unit 202. The deterioration determination of the power storage device unit 202 will be described with reference to Figs.

[0072] FIG. 8(A) is a diagram showing the temperature characteristics of the power storage device unit 202. The power storage device unit 202 exhibits a characteristic in which the ESR increases as the temperature decreases. Also, FIGS. 8(B) and 8(C) show the deterioration characteristics of the power storage device unit 202. Even with the same applied voltage, the higher the temperature is, the more the deterioration progresses, and as a result of the deterioration, the ESR increases. Also, even with the same temperature, the higher the applied voltage is, the more the deterioration progresses, and as a result of the deterioration, the ESR increases. Therefore, simply by identifying the ESR, it is not possible to determine whether the identified ESR is due to the temperature characteristics of the power storage device unit 202 or is the result of the deterioration progressing.

[0073] FIG. 9 is a diagram showing regions for each degree of deterioration of the power storage device unit 202. The control unit 1011 performs a deterioration judgment of the power storage device unit 202 based on each region shown in FIG. 9. When the temperature is high, the ESR of the power storage device unit 202 tends to be small, but if the ESR is large despite this, this is because deterioration is progressing. Also, when the temperature is low, the ESR of the power storage device unit 202 tends to be high, so even if the ESR is somewhat large, it can be judged that this is due to temperature characteristics. The control unit 1011 uses the ESR and temperature information acquired in S504 and S505 to identify in which region of FIG. 9 the relationship between ESR and temperature is located, and judges the deterioration degree accordingly.

[0074] As another example, the control unit 1011 may determine the degree of deterioration using an ESR deterioration threshold value determined for each temperature. In this case, the control unit 1011 can determine the degree of deterioration by comparing the acquired ESR with the ESR deterioration threshold value corresponding to the acquired temperature.

[0075] In S508, the control unit 1011 determines whether the operation mode of the imaging device 100 is the still image mode. If the operation mode is the still image mode, the process proceeds to S509. If the operation mode is not the still image mode (i.e., if the operation mode is the video mode), the process proceeds to S528.

[0076] The still image mode determined in S508 is an example of an operation mode in which the current required for the battery 108 or the USB power supply unit 110 is likely to exceed the maximum allowable current. The moving image mode determined in S508 is an example of an operation mode in which the current required for the battery 108 or the USB power supply unit 110 is unlikely to exceed the maximum allowable current. Therefore, for example, in the case of a mode with relatively low power consumption among still image modes (e.g., a low-speed continuous shooting mode or a low-speed readout mode), a configuration may be employed in which the process proceeds to S528 instead of S509.

[0077] In S509, the control unit 1011 determines whether the power storage device unit 202 is usable. To make this determination, the control unit 1011 refers to the degree of deterioration of the power storage device unit 202 determined in S507. If the degree of deterioration of the power storage device unit 202 is large (for example, in the case of "Deterioration 3" in FIG. 9), the control unit 1011 determines that the power storage device unit 202 is not usable. If the degree of deterioration of the power storage device unit 202 is large, it is predicted that the system will not function even if the control unit 1011 controls the main power path switching unit 401 so that the impedance of the main power path is maximized. For example, this is a situation in which a large amount of power is supplied from the imaging main power supply unit 201 to the imaging sensor 102, exceeding the allowable power of the battery 108 or the USB power supply unit 110 and causing a system shutdown. In another case, the impedance of each path serving as the power supply path for the image sensor 102 is large, and the voltage drop due to the impedance is predicted to fall below the operating voltage of the image sensor 102. If the degree of deterioration is such that such a predicted situation actually occurs, the control unit 1011 determines that the power storage device unit 202 is not usable. If the power storage device unit 202 is usable, the process proceeds to S510, and if the power storage device unit 202 is not usable, the process proceeds to S529.

[0078] In S510, the control unit 1011 determines whether the temperature of the power storage device unit 202 is higher than a threshold value Ta. The control unit 1011 uses the temperature estimated in S506 as the temperature of the power storage device unit 202. The threshold value Ta is a temperature above which deterioration of the power storage device unit 202 progresses rapidly. When the estimated temperature of the power storage device unit 202 is equal to or lower than the threshold value Ta, there is a relatively low risk that deterioration of the power storage device unit 202 will progress even if a high voltage is applied to the power storage device unit 202. In this case, the process proceeds to S512. When the estimated temperature of the power storage device unit 202 is higher than the threshold value Ta, there is a high risk that continued application of a high voltage to the power storage device unit 202 will cause deterioration of the power storage device unit 202 to progress. In this case, the process proceeds to S511.

[0079] In S511, the control unit 1011 controls the power storage device charging / discharging unit 204 to set a charging voltage for the power storage device unit 202. When the power storage device charging / discharging unit 204 charges the power storage device unit 202 by constant current charging, the control unit 1011 sets the charging voltage low. This is because the temperature of the power storage device unit 202 is high, and there is a high risk that deterioration of the power storage device unit 202 will progress. By lowering the charging voltage for the power storage device unit 202 based on information from the temperature sensor 105 in this way, it is possible to suppress deterioration of the power storage device unit 202.

[0080] In S512, similarly to S511, the control unit 1011 controls the power storage device charge / discharge unit 204 to set the charging voltage of the power storage device unit 202. In the case of S512, since the temperature of the power storage device unit 202 is low and the risk of deterioration of the power storage device unit 202 progressing is low, the control unit 1011 sets the charging voltage high. If the operation mode of the imaging apparatus 100 is an operation mode that assumes that power is supplied from the power storage device unit 202 to the imaging sensor 102, the voltage of the power storage device unit 202 needs to reach at least a voltage higher than the output voltage of the imaging main power supply unit 201 at the time of shooting. Therefore, in a state where the temperature is low and there is little concern about deterioration, by keeping the charging voltage of the power storage device unit 202 high, it is possible to smoothly transition to the shooting operation without taking unnecessary charging time at the time of shooting.

[0081] In S513, the control unit 1011 controls the power storage device charging / discharging unit 204 to set the charging current of the power storage device unit 202. When the power storage device charging / discharging unit 204 charges the power storage device unit 202 by constant current charging, the control unit 1011 sets the output current of the power storage device charging / discharging unit 204. The power storage device charging / discharging unit 204 has a high output mode in which the output current is relatively large and a low output mode in which the output current is relatively small. In S513, the control unit 1011 sets the power storage device charging / discharging unit 204 to the high output mode. This makes it possible to charge the power storage device unit 202 at high speed up to the target charging voltage. Note that during this timing from when the operation mode is set to the still image mode until shooting is started, the current consumption of the imaging device 100 is relatively small, and there is a margin in the power supply of the battery 108 or the USB power supply unit 110. Therefore, there is no problem even if the power storage device charging / discharging unit 204 is in the high output mode at this timing.

[0082] In S514, the control unit 1011 determines whether SW1 has been pressed by the user. SW1 corresponds to the operation (shooting preparation instruction) immediately before the user's release operation, for example, equivalent to a half-press of the release button. When SW1 is pressed, the imaging device 100 is in a shooting preparation state in which it can immediately move to a shooting operation when SW2 is pressed. If SW1 is not pressed, the process proceeds to S515. If SW1 is pressed, the process proceeds to S516.

[0083] In S515, the control unit 1011 determines whether the operation mode of the imaging device 100 has been changed. If the operation mode has not been changed, the process returns to S514. If the operation mode has been changed, the process returns to S505. Also, if the user performs an operation to shut down the imaging device 100, such as turning off the main power switch, the process proceeds to S531.

[0084] In S516, the control unit 1011 sets the charging voltage of the power storage device unit 202 high (more specifically, to a voltage that enables power to be supplied from the power storage device unit 202 to the imaging sensor 102). If the charging voltage of the power storage device unit 202 is set in S512 to the same voltage as the charging voltage of the power storage device unit 202 set in S516, there is no need to reset the charging voltage of the power storage device unit 202 in S516. If the charging voltage of the power storage device unit 202 is set low in S511 to prevent deterioration, the control unit 1011 sets the charging voltage of the power storage device unit 202 in S516 to a voltage that enables power to be supplied from the power storage device unit 202 to the imaging sensor 102. This makes it possible to perform an image capturing operation while minimizing the time for which the voltage is increased and preventing deterioration, even when the temperature of the power storage device unit 202 is high.

[0085] In S517, the control unit 1011 determines whether charging of the power storage device unit 202 is complete. The control unit 1011 can determine whether charging is complete by comparing the voltage set in S516 with the current voltage of the power storage device unit 202. Alternatively, the control unit 1011 may monitor the charging current and determine whether charging of the power storage device unit 202 is complete based on whether the charging current has stopped. If charging of the power storage device unit 202 has not yet been completed, the process proceeds to S518. If charging of the power storage device unit 202 has been completed, the process proceeds to S519.

[0086] In S518, the control unit 1011 displays a busy message together with the live view display. The busy message here means that the imaging device 100 is unable to perform an image capturing operation. The user can know whether or not image capturing is possible by checking the busy message. After the busy message is displayed, the process returns to S517. The processes of S517 and S518 are repeated until charging of the power storage device unit 202 is complete. If it is determined in S517 that charging of the power storage device unit 202 is complete, the control unit 1011 erases the busy message.

[0087] In S519, the control unit 1011 determines whether SW2 has been pressed by the user. SW2 corresponds to the user's release operation, such as the full press of the release button. If SW2 has not been pressed, the process proceeds to S527. If SW2 has been pressed, the process proceeds to S520.

[0088] In S520, the control unit 1011 changes the charging current from the power storage device charging / discharging unit 204 to the power storage device unit 202. When the power storage device charging / discharging unit 204 charges the power storage device unit 202 with constant current charging, the control unit 1011 changes the output current of the power storage device charging / discharging unit 204. In S520, the control unit 1011 sets the power storage device charging / discharging unit 204 to a low output mode. This makes it possible to reduce the power taken out from the battery 108 or the USB power supply unit 110 during shooting operation. When the operation mode of the imaging device 100 is a high-speed continuous shooting mode state with a short shooting interval, in the low output mode, charging is performed with a charging current that is sufficient to complete recharging of the power storage device unit 202 that has been reduced during shooting within the time until the next shooting operation.

[0089] In S521, the control unit 1011 sets the main power path to a path other than the pass-through path. The control unit 1011 selects the path to be set according to the output data of the temperature sensor. The lower the temperature of the power storage device unit 202, the higher the ESR of the power storage device unit 202. Therefore, the control unit 1011 controls the impedance of the main power path to be higher as the temperature increases. This makes it possible to supply power from the power storage device unit 202 to the imaging sensor 102 regardless of the temperature of the imaging apparatus 100. Furthermore, the ESR increases due to deterioration of the power storage device unit 202. Therefore, the control unit 1011 may select the path to be set by referring to the ESR of the power storage device unit 202 predicted in S505. When the degree of deterioration of the ESR is within an allowable range, it is possible to supply power from the power storage device unit 202 to the imaging sensor 102 regardless of the value of the ESR.

[0090] In S522, the control unit 1011 enables the power storage device path. The control unit 1011 controls the power storage device path switching unit 403 to turn on the switch so that power is supplied from the power storage device unit 202 to the image sensor 102. This makes it possible to supply power from the power storage device unit 202 to the image sensor 102 during image capture.

[0091] In S523, the control unit 1011 performs an image capturing operation. First, since the voltage of the power storage device unit 202 is higher than the voltage of the imaging main power supply unit 201, power is supplied from the power storage device unit 202 to the imaging sensor 102. When the voltage of the power storage device unit 202 drops and becomes the same as the voltage of the imaging main power supply unit 201, more power is supplied to the imaging sensor 102 from the path with the smaller impedance of the main power supply path or the power storage device path. Since the impedance of the power storage device path is controlled to be smaller than that of the main power supply path in S521, even if the voltage of the power storage device unit 202 drops, power is preferentially supplied from the power storage device unit 202 to the imaging sensor 102. As a result, even when the imaging apparatus 100 is capturing images in an operation mode with a large maximum power such as a global shutter mode, it is possible to reduce the instantaneous power drawn from the battery 108 or the USB power supply unit 110.

[0092] In S524, the control unit 1011 determines whether SW2 has been released. If SW2 continues to be pressed, the process returns to S523, and the control unit 1011 performs the next shooting operation. If SW2 has been released, the shooting operation stops, and the process proceeds to S525.

[0093] In S525, the control unit 1011 performs the initialization process of the main power path switching unit 401 in the same manner as in S502.

[0094] In S526, the control unit 1011 invalidates the power storage device path in the same manner as in S503.

[0095] In S527, the control unit 1011 determines whether SW1 has been released. If SW1 continues to be pressed, the process returns to S519, and the control unit 1011 determines whether SW2 is pressed again. If SW1 is released and SW2 is released, the shooting preparation state stops, and the process returns to S510.

[0096] In S528, the control unit 1011 sets the charging voltage of the power storage device unit 202 low. For example, in an operation mode such as a video mode in which the power supplied by the battery 108 or the USB power supply unit 110 is sufficient to cover the maximum power of the image sensor 102, the control unit 1011 sets the charging voltage of the power storage device unit 202 low even during shooting. This makes it possible to prevent deterioration of the power storage device unit 202. In particular, when the operation mode of the imaging device 100 is a video mode, there are many use cases in which shooting continues for a long period of time, and therefore the internal temperature of the imaging device 100 rises, and the temperature of the power storage device unit 202 also rises. In an operation mode in which the temperature of the power storage device unit 202 is likely to rise, it is important to set the charging voltage of the power storage device unit 202 low to prevent deterioration. Furthermore, even if the charging voltage of the power storage device unit 202 is set low here, when the mode is later switched to still image mode, the charging current is increased in S513 to charge the power storage device unit 202 at high speed, so that it is possible to quickly transition to shooting operation.

[0097] In S529, the control unit 1011 displays on the display unit 103 that the current operation mode (i.e., the still image mode) cannot be used due to deterioration of the power storage device unit 202. This allows the user to know that in addition to not being able to use the still image mode, the power storage device unit 202 has deteriorated. For example, if the user who sees this display wants to continue using the still image mode, the user can take measures such as replacing the power storage device unit 202. Also, in S529, the control unit 1011 may display a guide to a usable alternative mode, which allows the user to continue shooting in the alternative mode.

[0098] In S530, the control unit 1011 determines whether the operation mode of the imaging device 100 has been changed, similarly to S515. If the operation mode has not been changed, the control unit 1011 repeats the determination of S530 while maintaining the live view state, and waits for a change in mode. If the operation mode has been changed, the process returns to S505. Also, if the user performs an operation to shut down the imaging device 100, such as turning off the main power switch, the process proceeds to S531.

[0099] In S531, the control unit 1011 sets the charging voltage of the power storage device unit 202 to 0 V. This makes it possible to suppress deterioration of the power storage device unit 202 when the power of the imaging device 100 is off. Thereafter, the control unit 1011 performs a shutdown process for the imaging device 100, and ends the process of this flowchart. In the shutdown process for the imaging device 100, in addition to the shutdown process for each device, a power-off operation for the power supply unit 107 is performed.

[0100] However, as a result of setting the charging voltage low in S511, S528, and S531, the target charging voltage may become lower than the current voltage of the power storage device unit 202. In this case, the control unit 1011 may stop the output of the power storage device charging / discharging unit 204 and wait for the power storage device unit 202 to reach the target voltage by natural discharge. In this case, the frequency of the power once stored in the power storage device unit 202 becoming invalid is reduced, which is advantageous for the battery life of the battery 108. On the other hand, since the time during which a voltage higher than the target is applied becomes longer, there is a concern that deterioration of the power storage device unit 202 will progress. For this reason, the power storage device charging / discharging unit 204 may be provided with a discharge function and discharged until the target voltage is reached. In this case, the voltage of the power storage device unit 202 quickly drops to the voltage of the power storage device unit 202, so that deterioration of the power storage device unit 202 can be suppressed.

[0101] Next, an example of switch settings of the main power supply path switching unit 401 will be described with reference to Figures 6(A) and 6(B). Here, in the still image mode, the maximum power consumption of the imaging device 100 is relatively large, and it is assumed that the imaging device 100 is operated by supplying power from the power storage device unit 202 to the imaging sensor 102. On the other hand, in the moving image mode, the maximum power consumption of the imaging device 100 is relatively small, and it is assumed that the imaging device 100 is operated without supplying power from the power storage device unit 202 to the imaging sensor 102. Furthermore, among the still image modes, the global shutter mode in particular is assumed to have an even larger maximum power consumption of the imaging device 100, and it is assumed that the imaging device 100 is operated by supplying more power from the power storage device unit 202 to the imaging device 100.

[0102] FIG. 6A is a switch setting table for the main power path switching unit 401 when switching the main power path in response to temperature.

[0103] When the temperature is 20° C. or higher, in the global shutter mode, the path B and the path C are turned on. At this time, the impedance of the main power supply path is a composite resistance of the resistor 402b and the resistor 402c arranged in parallel. In still image modes other than the global shutter mode, the path A and the path C are turned on. At this time, the impedance of the main power supply path is a composite resistance of the resistor 402a and the resistor 402c arranged in parallel. And, even in the moving image mode or the still image mode, in the live view state, the path is a pass-through path. In this way, the more power is supplied from the power storage device unit 202 to the image sensor 102 in the operation mode, the higher the current limit of the main power supply path is. In other words, in the operation mode in which the power supply from the power storage device unit 202 is not required much, the limit of the main power supply path is relaxed so that the power is not supplied from the power storage device unit 202 more than necessary, thereby making it possible to reduce the loss of the main power supply path. In addition, it is possible to reduce the loss due to the charging and discharging of the power storage device unit 202.

[0104] When the temperature is equal to or higher than 0° C. and lower than 20° C., the switch state is changed so as to increase the impedance of the main power supply path in each mode. This is because the ESR of the power storage device unit 202 increases in a low temperature state, and by increasing the impedance of the main power supply path, it is possible to supply power from the power storage device unit 202 to the image sensor 102. Conversely, when the temperature is sufficiently high, it is possible to reduce the loss in the main power supply path and the loss due to charging and discharging the power storage device unit 202 by relaxing the restrictions on the main power supply path. Furthermore, even in video mode or still image mode, it is assumed that the image sensor 102 will be operated without being supplied with power from the power storage device unit 202 in the live view state, so the pass-through path is fixed regardless of the temperature.

[0105] Similarly, when the temperature is below 0° C., the switch state is changed so as to further increase the impedance of the main power supply path in each mode.

[0106] FIG. 6B is a switch setting table for the main power supply path switching unit 401 when switching the main power supply path in accordance with the ESR of the power storage device unit 202.

[0107] When estimating the ESR of the power storage device section 202, path B is turned on regardless of the operating mode or other settings of the imaging apparatus 100. The control section 1011 can predict the ESR of the power storage device section 202 from the known resistance 402b and the operating power of the imaging sensor 102, as well as information from the main power supply current detection section 404 when the imaging sensor 102 is operated. During imaging, the control section 1011 switches the switch state of the main power supply path switching section 401 according to the predicted ESR.

[0108] When the ESR of the power storage device unit 202 is less than 100 mΩ, path B and path C are turned on in the global shutter mode. At this time, the impedance of the main power supply path is a composite resistance of resistors 402b and 402c arranged in parallel. Also, in still image modes other than the global shutter mode, path A and path C are turned on. At this time, the impedance of the main power supply path is a composite resistance of resistors 402a and 402c arranged in parallel. And, even in the video mode or still image mode, the path is a pass-through path in the live view state. In this way, the more power is supplied from the power storage device unit 202 to the image sensor 102 in the operation mode, the higher the current limit of the main power supply path is. Conversely, in an operation mode in which power supply from the power storage device unit 202 is not required much, the limit of the main power supply path is relaxed so that power is not supplied from the power storage device unit 202 more than necessary, thereby making it possible to reduce loss in the main power supply path. In addition, it is possible to reduce loss due to charging and discharging the power storage device unit 202.

[0109] When the ESR of the power storage device unit 202 is equal to or greater than 100 mΩ and less than 400 mΩ, the switch state is changed so as to increase the impedance of the main power supply path in each mode. Since the ESR of the power storage device unit 202 is increased, the impedance of the main power supply path is increased so that power can be supplied from the power storage device unit 202 to the image sensor 102. In other words, when the ESR of the power storage device unit 202 is sufficiently low, it is possible to reduce the loss in the main power supply path and the loss due to charging and discharging the power storage device unit 202 by relaxing the restrictions on the main power supply path. Furthermore, even in the video mode or still image mode, since it is assumed that the power storage device unit 202 will operate without supplying power to the image sensor 102 in the live view state, the pass-through path is fixed regardless of the ESR of the power storage device unit 202.

[0110] Similarly, when the ESR of the power storage device section 202 is equal to or greater than 400 mΩ and less than 600 mΩ, the switch state is changed so as to further increase the impedance of the main power supply path in each mode.

[0111] When the ESR of the power storage device unit 202 becomes 600 mΩ or more, shooting in the global shutter mode is prohibited. This is because it is predicted that the system will not function even if only the path C is turned on so that the impedance of the main power supply path is maximized. For example, this situation is a situation in which a large amount of power is supplied from the imaging main power supply unit 201 to the imaging sensor 102, exceeding the allowable power of the battery 108 or the USB power supply unit 110 and causing a system down. In another case, the impedance of each path that serves as the power supply path for the imaging sensor 102 is large, and the voltage drop due to the impedance is predicted to cause the voltage to fall below the operating voltage of the imaging sensor 102. It is possible to prohibit shooting operations according to the ESR before such a predicted situation actually occurs.

[0112] Next, the settings of the power storage device charge / discharge unit 204 in each operation mode will be described with reference to FIG. 6(C).

[0113] During shooting in the global shutter mode, the charging voltage of the power storage device unit 202 is set to 5.0V. For example, if the output voltage of the imaging main power supply unit 201 is 4.5V, the voltage of the power storage device path will be higher than that of the main power supply path, so that power is preferentially supplied from the power storage device unit 202 to the imaging sensor 102. Also, when the estimated temperature of the power storage device unit 202 is higher than Ta in the live view state, the charging voltage is lowered to 2.0V. This makes it possible to suppress deterioration of the power storage device. If the charging voltage is set to 0V here, if a user performs an operation to start shooting in this state, it will take time to charge from 0V to 5.0V, and the user will not be able to shoot for a long time. To solve this problem, even if the temperature is higher than Ta, charging is performed within a range where deterioration does not progress significantly. Also, when the estimated temperature of the power storage device unit 202 is equal to or lower than Ta, the voltage is lowered to about 4.5V in order to prevent deterioration. The time it takes to charge from 4.5V to 5.0V is short, thereby reducing the impact on the user.

[0114] During shooting in a still image mode other than the global shutter mode, the charging voltage of the power storage device unit 202 is set to 4.5 V. In a still image mode other than the global shutter mode, less power needs to be supplied from the power storage device unit 202 to the image sensor 102 than in the global shutter mode, so the charging voltage of the power storage device unit 202 is set lower than in the global shutter mode. In this way, it is important to optimize the charging voltage of the power storage device unit 202 according to the operation mode in order to suppress deterioration of the power storage device unit 202. Also, when the estimated temperature of the power storage device unit 202 is higher than Ta in the live view state, the charging voltage is lowered to 2.0 V, as in the global shutter mode.

[0115] In the case of video mode, regardless of whether the camera is in shooting mode or in live view mode, the charging voltage of the power storage device unit 202 is set to a uniform 2.0 V. In this manner, in a mode that is premised on operation without supplying power from the power storage device unit 202 to the image sensor 102, deterioration of the power storage device unit 202 can be suppressed by lowering the charging voltage of the power storage device unit 202. Here, the reason that the charging voltage of the power storage device unit 202 is not set to 0 V is to shorten the charging time of the power storage device unit 202 as much as possible when the user switches to still image mode and immediately attempts to start shooting.

[0116] Furthermore, when measuring the ESR, the charging voltage of the power storage device unit 202 is set to 4.5 V. Here, 4.5 V refers to a voltage setting that is approximately the same as the output voltage of the imaging main power supply unit 201, and this makes it possible to calculate the impedance ratio of each path from the current ratio of each path.

[0117] Furthermore, when the imaging device 100 is powered off, since there is a high possibility that this state will continue for a long time, the charging voltage of the power storage device unit 202 is set to 0.0 V. This makes it possible to suppress deterioration of the power storage device unit 202 while the imaging device 100 is powered off.

[0118] For example, when the operation mode is switched from the video mode to the global shutter mode, the charging voltage is changed from 2.0V to 5.0V. If the charging current is small at this time, it takes a long time from when the user switches the mode until shooting becomes possible. Therefore, in a live view state from when the operation mode is switched to when shooting starts, the power storage device charging / discharging unit 204 is in the high output mode, and the power storage device unit 202 is charged with a charging current of 300mA. If shooting starts while still in the high output mode, the power taken out from the battery 108 or the USB power supply unit 110 increases due to the charging current of the power storage device unit 202. For this reason, before shooting starts, the power storage device charging / discharging unit 204 is in the low output mode, and the power storage device unit 202 is charged with a charging current of 100mA. It is sufficient that the switching from the high output mode to the low output mode is executed before shooting starts, and for example, the switching to the low output mode may be performed at the stage where charging is completed using a means such as voltage monitoring. In another example, after the operation mode and the charging voltage of the power storage device unit 202 are changed, the mode may be switched to the low output mode after a predetermined time corresponding to the difference in the charging voltage of the power storage device unit 202 has elapsed.

[0119] Next, an example of the operation of the imaging device 100 will be described with reference to the timing chart of Fig. 7. This timing chart is an example of the operation, and it is assumed that the imaging device 100 operates in an appropriate mode in response to a user's operation.

[0120] In FIG. 7, from the top, an operation by a user operating the imaging device 100 is shown in 7A, and an operation of the imaging device 100 accompanying the user operation of 7A is shown in 7B.

[0121] 7C indicates the amount of current (current consumption) when the imaging sensor 102 operates. 7D indicates the change in temperature of the power storage device unit 202 calculated by the temperature sensor 105. 7E indicates the setting of the main power supply path switching unit 401 (setting as to whether power supply is to be prioritized from the imaging main power supply unit 201 or the power storage device unit 202). When the level of 7E is Low (pass-through), power is supplied to the imaging sensor 102 preferentially from the imaging main power supply unit 201. When the level of 7E is High (resistance ON), power is supplied to the imaging sensor 102 preferentially from the power storage device unit 202.

[0122] 7F indicates the amount of current supplied from the imaging main power supply unit 201. This amount of current must not exceed the maximum power of the battery 108 or the USB power supply unit 110. 7G indicates the amount of current supplied from the power storage device unit 202. 7H indicates the charging voltage of the power storage device unit 202. 7I indicates the maximum amount of current when charging the power storage device unit 202.

[0123] The operation of the imaging device 100 will be described below in accordance with the operation of the imaging device 100 by the user.

[0124] At T701, the user operates the power switch to start the imaging device 100. Initially, it is assumed that the imaging device 100 is set to operate in the global shutter mode. The imaging device 100 starts an initialization operation (see 7B), and the current of the imaging sensor 102 increases (see 7C). When the current of the imaging sensor 102 becomes stable, the main power path switching unit 401 is switched (see 7E). The imaging sensor 102 is operated with power from the power storage device unit 202, and a deterioration determination of the power storage device unit 202 is performed. In the following description, it is assumed that the power storage device unit 202 is not deteriorated. Once the deterioration determination is completed, the state transitions to a live view state. In the live view state, the charging voltage of the power storage device unit 202 is set to about 4.5V (see 7H). About 4.5V is a voltage that is unlikely to deteriorate when the temperature is not high, and does not take much time to charge. In the following description, it is assumed that the imaging device 100 is set to a still image mode and a global shutter mode by a user operation.

[0125] At T702, the user presses SW1 to perform an AF operation. At this time, the imaging apparatus 100 enters a shooting standby state, and the power storage device unit 202 is charged to a voltage (about 5.0 V) that can sufficiently supply power to the imaging sensor 102 (see 7H).

[0126] At T703, when the user presses SW2, the imaging device 100 starts the imaging operation. Since imaging is performed in the global shutter mode, the current consumption of the imaging sensor 102 momentarily increases (see 7C). At this time, the maximum charging current of the power storage device unit 202 is reduced (see 7I). Specifically, control is performed to reduce the maximum charging current from 300 mA to about 100 mA. Furthermore, the main power path switching unit 401 is switched (see 7E). Specifically, the path B is changed from the pass-through state to the on state. As a result, the main power path is changed to a path via the resistor 402b (about 200 mΩ). By performing the above operations, when the imaging sensor 102 requires a momentary large current, it becomes possible to supply a current from the power storage device unit 202. In addition, the current from the imaging main power supply unit 201 does not increase, and it becomes possible to operate while observing the rated current of the battery 108 or the USB power supply unit 110.

[0127] At T704, when the user releases SW1 and SW2, the imaging device 100 ends the shooting operation and returns to the live view state. Here, the maximum charging current of the power storage device unit 202 is increased (see 7I). Specifically, control is performed to increase the maximum charging current from 100 mA to approximately 300 mA. Furthermore, switching of the main power supply path switching unit 401 is performed (see 7E). Specifically, the main power supply path is changed from a path via resistor 402b (approximately 200 mΩ) to a pass-through path.

[0128] At T705, the user switches the mode from still image mode to video mode. The current consumption of the image sensor 102 in video mode is assumed to be high on average but not instantaneously higher than that in still image mode (see 7C). Therefore, there is no problem if the power of the power storage device unit 202 is not used. The charging voltage (about 2.0 V) of the power storage device unit 202 is lowered (see 7H), and the maximum charging current to the power storage device unit 202 is also lowered (see 7I). Specifically, control is performed to lower the maximum charging current from 300 mA to about 100 mA.

[0129] On the other hand, since the average current is large in the moving image mode, the internal temperature of the imaging device 100 rises, and so does the temperature of the built-in power storage device section 202. If moving images are captured continuously for a certain period of time, the temperature of the power storage device section 202 will exceed Ta (see 7D).

[0130] At T706, the user operates the camera to end video capture and switch the imaging device 100 to a still image mode. At this time, the temperature of the power storage device unit 202 exceeds Ta (see 7D). At this time, the charging voltage of the power storage device unit 202 is maintained at a low setting (approximately 2.0 V) in order to prevent deterioration of the power storage device unit 202 (see 7H).

[0131] At T707, it is assumed that the user simultaneously presses SW1 and SW2. The power storage device unit 202 is charged to a voltage (about 5.0 V) that can sufficiently support the power of the image sensor 102 (see 7H). However, since the temperature of the power storage device unit 202 is high, the charging voltage of the power storage device unit 202 at the start of charging is low, and the time required for charging is long. During this time, the imaging device 100 displays a busy message to notify the user that the global shutter mode cannot be used. When charging of the power storage device unit 202 is completed, the maximum charging current of the power storage device unit 202 is reduced (see 7I). Specifically, control is performed to reduce the maximum charging current from 300 mA to about 100 mA. The main power supply path switching unit 401 is switched (see 7E). Specifically, the path B is changed from the pass-through state to the on state. As a result, the main power supply path is changed to a path via the resistor 402b (about 200 mΩ). By performing the above operations, when the image capture sensor 102 requires a momentary large current, it becomes possible to supply current from the power storage device unit 202. Furthermore, the current from the image capture main power supply unit 201 does not become large, and operation can be performed while observing the rated current of the battery 108 or the USB power supply unit 110.

[0132] At T708, the user releases SW1 and SW2, causing the imaging device 100 to end the shooting operation and return to the live view state. The maximum charging current of the power storage device unit 202 is increased (see 7I). Specifically, the maximum charging current is changed from 100 mA to approximately 300 mA. Furthermore, the main power path switching unit 401 is switched (see 7E). Specifically, the main power path is changed from a path via resistor 402b (approximately 200 mΩ) to a pass-through path.

[0133] From this point on, if the temperature of the power storage device unit 202 drops sufficiently, the operations of T709 and T710 will be the same as those of T703 and T704.

[0134] After that, if there is no user operation for a certain period of time, the imaging device 100 enters a power saving mode at T711. At this time, the imaging sensor 102 is powered off, and the voltage of the power storage device unit 202 is reduced (see 7H).

[0135] At T712, when the user turns off the power switch of the imaging apparatus 100, the voltage of the power storage device section 202 is reduced to 0 V (see 7H).

[0136] Next, various examples of notifications to the user by the imaging device 100 will be described with reference to Fig. 10. The control unit 1011 notifies the user by displaying a GUI on the display unit 103. Here, the global shutter mode is an example of an operation mode of the imaging device 100 on the premise that power is supplied from the power storage device unit 202 to the imaging sensor 102.

[0137] A display 1001 is an example of a display that is displayed when the user sets the global shutter mode and it is determined that the power storage device unit 202 has deteriorated and therefore shooting cannot be performed in the global shutter mode.

[0138] As described with reference to FIG. 9, the degree of deterioration of the power storage device unit 202 is determined from the prediction of the ESR of the power storage device unit 202 and information from the temperature sensor 105. The display 1001 notifies the user that the power storage device unit 202 is deteriorated and that image capture is prohibited in the current operation mode. In addition, guidance to an alternative operation mode is also provided, and when the button 1003 is selected, the image capture device 100 transitions to the alternative operation mode. When the button 1002 is selected, the image capture device 100 enters a live view state while remaining in the current mode. The display 1001 allows the user to know that the deterioration of the power storage device unit 202 is progressing and that image capture is not possible in the current operation mode. In addition, the user can smoothly capture images in another mode. The display 1001 is displayed, for example, in S529.

[0139] Display 1004 is an example of a display when it is determined that the temperature of the power storage device unit 202 is extremely low when the user sets the global shutter mode and therefore image capturing cannot be performed in the global shutter mode. Display 1004 notifies the user that the power storage device unit 202 cannot be used due to its low temperature, and thus the user knows that image capturing will be possible in the global shutter mode once the temperature of the imaging device 100 rises. Similarly to display 1001, guidance to an alternative operation mode is also provided, and when button 1006 is selected, the imaging device 100 transitions to the alternative operation mode. When button 1005 is selected, the imaging device 100 remains in the current mode and enters a live view state. Display 1004 is displayed, for example, in S529.

[0140] Display 1007, like display 1001, is an example of a display that is displayed when the user sets the global shutter mode and it is determined that shooting cannot be performed in the global shutter mode because the power storage device unit 202 has deteriorated. Display 1007 notifies the user that replacement of the power storage device unit 202 is necessary. For example, if the power storage device unit 202 can be replaced by the user himself, this display can urge the user to replace the power storage device unit 202. Display 1007 is displayed, for example, in S529.

[0141] Like the display 1001 and the display 1007, the display 1008 is an example of a display when it is determined that the temperature of the power storage device unit 202 is extremely low and therefore shooting cannot be performed in the global shutter mode when the user sets the global shutter mode. The display 1008 notifies the user that an abnormality has occurred in the imaging device 100. For example, a user who has confirmed this display can request repair by bringing the imaging device 100 to the manufacturer's service desk. Also, by displaying an error number associated with deterioration of the power storage device unit 202, the user or a person in charge at the service desk can confirm the error number and know that there is an abnormality in the power storage device unit 202. The display 1008 is displayed, for example, in S529.

[0142] Display 1009 is an example of a live view display in a state where it is determined that shooting cannot be performed in global shutter mode due to deterioration of the power storage device unit 202. For example, display 1009 is displayed when the user selects button 1002 in display 1001, or when the user selects button 1005 in display 1004. By superimposing an icon indicating that shooting in global shutter mode is prohibited on the live view, the user can easily understand whether shooting is currently possible. Furthermore, if this display is displayed due to low temperature, the icon is erased when the temperature rises and it becomes possible to supply power from the power storage device unit 202 to the image sensor 102. This allows the user to know that shooting is now possible.

[0143] Displays 1001, 1004, 1007, 1008, and 1009 are all displayed when it is determined that shooting cannot be performed in the global shutter mode due to deterioration or low temperature of the power storage device unit 202. Furthermore, these displays are displayed when the user sets the imaging device 100 to the global shutter mode. As a result, for example, they are not displayed while the user is using the imaging device 100 in another mode, so that the user can concentrate on shooting even if the power storage device unit 202 is deteriorated or the temperature is low.

[0144] Display 1010 is an example of a live view display in a state in which shooting is not possible until charging of the power storage device unit 202 is complete. By superimposing an icon indicating that shooting needs to wait on the live view display, the user can easily understand whether shooting is currently possible. In addition, this icon is erased when charging is complete. This allows the user to know that shooting is now possible. Display 1010 is displayed in, for example, S518.

[0145] A display 1021 is an example of a setting screen of the imaging device 100. For example, when a user presses a menu button of the imaging device 100, the display unit 103 displays the display 1021. The display 1021 displays, for example, an item for checking information on the battery 108 and an item for checking the deterioration level of the power storage device unit 202. When a user operates the display 1021 to display the deterioration level of the power storage device unit 202, a display 1022 or a display 1023 is displayed according to the deterioration level of the power storage device unit 202. When the deterioration level of the power storage device unit 202 is within a range in which the power storage device unit 202 can be used in the global shutter mode, a display such as the display 1022 is displayed. The display 1022 displays the degree of deterioration of the power storage device unit 202. When the deterioration level of the power storage device unit 202 is such that the power storage device unit 202 cannot be used in the global shutter mode, the display 1023 is displayed. The display 1023 notifies the user of the necessity of replacement in addition to the information on the degree of deterioration of the power storage device unit 202. This display can prompt the user to replace the power storage device unit 202.

[0146] As described above, according to the first embodiment, the imaging device 100 charges the power storage device unit 202 using power from the imaging main power supply unit 201. In a first operating state (for example, an operating state in which an image for recording is being captured in S523), the imaging device 100 controls so that power is supplied from the imaging main power supply unit 201 to the imaging sensor 102 without supplying power from the power storage device unit 202 to the imaging sensor 102. Also, in a second operating state (for example, an operating state in which an image for recording is not being captured) in which the maximum power consumption of the imaging sensor 102 is higher than in the first operating state, the imaging device 100 controls so that power is supplied from the imaging main power supply unit 201 and the power storage device unit 202 to the imaging sensor 102. This makes it possible to reduce the peak current of the main power supply that supplies power to the imaging sensor.

[0147] [Other embodiments] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0148] [summary] The above-described embodiment discloses at least the inventions shown in the following items, but is not limited to these inventions.

[0149] [Item 1] 1. An imaging device, comprising: An imaging sensor; A power supply means; A storage means; a charging means for charging the power storage means using electric power from the power supply means; a control means for controlling, in a first operating state of the imaging device, to supply power from the power supply means to the imaging sensor without supplying power from the power storage means to the imaging sensor, and for controlling, in a second operating state of the imaging device in which a maximum power consumption of the imaging sensor is higher than in the first operating state, to supply power from the power supply means and the power storage means to the imaging sensor; An imaging device comprising:

[0150] [Item 2] the first operating state is an operating state in which the imaging device is not capturing an image for recording in a first operating mode, The second operating state is an operating state in which the imaging device is taking an image for recording in the first operating mode. 2. The imaging device according to item 1,

[0151] [Item 3] a maximum power consumption of the image sensor when the imaging device captures an image for recording in the first operation mode is greater than a maximum power consumption of the image sensor when the imaging device captures an image for recording in the second operation mode; In the second operation mode, the control means controls the power supply means to supply power to the image sensor without supplying power from the power storage means to the image sensor. 3. The imaging device according to item 2,

[0152] [Item 4] the first operating mode is a still image mode; The second operating mode is a video mode. 4. The imaging device according to item 3,

[0153] [Item 5] The control means when a shooting preparation instruction is not given in the first operating state, controlling the charging means to charge the storage means to a second voltage; When the instruction for preparing to take a photograph is given in the first operating state, the charging means is controlled so as to charge the power storage means to a third voltage that is equal to or higher than the second voltage. 5. The imaging device according to any one of items 2 to 4,

[0154] [Item 6] When the photographing preparation instruction is not given in the first operating state, if the temperature of the storage means is a first temperature, controlling the charging means to charge the storage means to the second voltage; If the temperature of the storage means is a second temperature higher than the first temperature, the charging means is controlled so as to charge the storage means to a first voltage lower than the second voltage. 6. The imaging device according to item 5,

[0155] [Item 7] When the image for recording in the second operating state is captured by a global shutter, the third voltage is higher than the second voltage. 7. The imaging device according to item 5 or 6,

[0156] [Item 8] The control means controlling the charging means to charge the storage means with a first current in the first operating state; In the second operating state, the charging means is controlled so as to charge the storage means with a second current smaller than the first current. 8. The imaging device according to any one of items 1 to 7,

[0157] [Item 9] The power supply device further includes a determination unit for determining whether the power storage unit is available or not, When the power storage means is not available, the control means controls the imaging device not to enter the second operating state. 9. The imaging device according to any one of items 1 to 8,

[0158] [Item 10] The determining means determines whether the power storage means is usable or not based on a temperature and an equivalent series resistance (ESR) of the power storage means. 10. The imaging device according to item 9,

[0159] [Item 11] The storage means includes an electric double layer capacitor (EDLC) or an all-solid-state battery. 11. The imaging device according to any one of items 1 to 10,

[0160] [Item 12] A control method for an imaging device, comprising: The imaging device includes: An imaging sensor; A power supply means; A storage means; a charging means for charging the power storage means using electric power from the power supply means; Equipped with The control method includes: a control step of controlling, in a first operating state of the imaging device, to supply power from the power supply means to the imaging sensor without supplying power from the power storage means to the imaging sensor, and controlling, in a second operating state of the imaging device in which a maximum power consumption of the imaging sensor is higher than that in the first operating state, to supply power from the power supply means and the power storage means to the imaging sensor. A control method comprising:

[0161] [Item 13] 12. A program for causing a computer to function as a control unit of the imaging device according to any one of items 1 to 11.

[0162] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0163] 100: imaging device, 101: CPU, 102: imaging sensor, 106: power supply control unit, 107: power supply unit, 108: battery, 201: imaging main power supply unit, 202: power storage device unit, 203: supply source selection unit, 204: power storage device charge / discharge unit, 1011: control unit

Claims

1. An imaging device, an imaging sensor; a power supply unit for supplying power from a battery that is a power source for the imaging device; A storage means; a charging means for charging the power storage means using electric power from the power supply means; a control means for controlling, in a first operating state of the imaging device, to supply power from the power supply means to the imaging sensor without supplying power from the power storage means to the imaging sensor, and for controlling, in a second operating state of the imaging device in which the maximum power consumption of the imaging sensor is higher than in the first operating state, to supply power from the power supply means and the power storage means to the imaging sensor; An imaging device comprising:

2. the first operating state is an operating state in which the imaging device is not capturing an image for recording in a first operating mode, The second operating state is an operating state in which the imaging device is taking an image for recording in the first operating mode.

2. The imaging device according to claim 1.

3. a maximum power consumption of the image sensor when the imaging device captures an image for recording in the first operation mode is greater than a maximum power consumption of the image sensor when the imaging device captures an image for recording in the second operation mode; In the second operation mode, the control means controls the power supply means to supply power to the image sensor without supplying power from the power storage means to the image sensor.

3. The imaging device according to claim 2.

4. the first operating mode is a still image mode; The second operating mode is a video mode.

4. The imaging device according to claim 3.

5. The control means when a shooting preparation instruction is not given in the first operating state, controlling the charging means to charge the storage means to a second voltage; When the instruction for preparing to take a photograph is given in the first operating state, the charging means is controlled to charge the power storage means to a third voltage that is equal to or higher than the second voltage.

3. The imaging device according to claim 2.

6. When the instruction for preparing for photography is not given in the first operating state, the control means If the temperature of the storage means is a first temperature, controlling the charging means to charge the storage means to the second voltage; If the temperature of the storage means is a second temperature higher than the first temperature, the charging means is controlled to charge the storage means to a first voltage lower than the second voltage.

6. The imaging device according to claim 5.

7. When the image for recording in the second operating state is captured by a global shutter, the third voltage is higher than the second voltage.

6. The imaging device according to claim 5.

8. The control means In the first operating state, the charging means is controlled to charge the storage means with a first current; In the second operating state, the charging means is controlled so as to charge the storage means with a second current smaller than the first current.

2. The imaging device according to claim 1.

9. further comprising a determination means for determining whether the power storage means is usable; When the determining means determines that the power storage means is not usable, the control means controls the imaging device so that it does not enter the second operating state.

2. The imaging device according to claim 1.

10. The determining means determines whether the power storage means is usable or not based on the temperature and equivalent series resistance (ESR) of the power storage means.

10. The imaging device according to claim 9.

11. The power storage means includes an electric double layer capacitor (EDLC) or an all-solid-state battery.

2. The imaging device according to claim 1.

12. The battery is removable from the imaging device; The charging means charges the power storage means using power from the battery.

2. The imaging device according to claim 1.

13. The imaging sensor having a plurality of readout modes including a global shutter mode and a slow readout mode; the first operating state is a standby state for photographing, and the second operating state is a photographing state in which the image sensor photographs an image for recording; The control means performs control so that, when the image sensor is set to the global shutter mode, in the first operating state, power is supplied to the image sensor from the power supply means without being supplied from the power storage means, and in the second operating state, power is supplied to the image sensor from the power supply means and the power storage means, and when the image sensor is set to the low-speed readout mode, power is supplied to the image sensor from the power supply means without being supplied from the power storage means, in both the first operating state and the second operating state.

2. The imaging device according to claim 1.

14. A control method for an imaging device, comprising: The imaging device is an imaging sensor; a power supply unit for supplying power from a battery that is a power source for the imaging device; A storage means; a charging means for charging the power storage means using electric power from the power supply means; Equipped with The control method includes: a control step of controlling, in a first operating state of the imaging device, to supply power from the power supply means to the imaging sensor without supplying power from the power storage means to the imaging sensor, and controlling, in a second operating state of the imaging device in which the maximum power consumption of the imaging sensor is higher than in the first operating state, to supply power from the power supply means and the power storage means to the imaging sensor. A control method comprising:

15. A program for causing a computer to function as a control unit of the imaging device according to any one of claims 1 to 13.

Images