Electronic device and control method

Abstract

To extend the available time of an electronic apparatus.SOLUTION: An electronic apparatus having a plurality of power modes has: acquisition means that acquires any one of residual time that is the remaining available time of the electronic apparatus, the remaining amount of a battery that supplies power to the electronic apparatus, and the voltage of the battery; determination means that determines whether a switching condition is satisfied for switching from a first power mode to a second power mode with a lower power consumption than the first power mode; and notification means that, when the current power mode is the first power mode, the residual time, the remaining amount of the battery, or the voltage of the battery acquired by the acquisition means is less than a threshold, and the switching condition is satisfied, performs notification to encourage switching from the first power mode to the second power mode.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to an electronic device and a control method.

Background Art

[0002] Patent Document 1 describes a method of calculating the amount of used power according to the use of an electronic device and displaying the number of possible shots based on the total capacity of the battery and the amount of used power. Patent Document 2 describes a method in which the function to be executed is changed to a function with lower power consumption according to the priority of each function and the battery state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a user continues to use an electronic device even though the available usage time of the electronic device has decreased, the user may want to extend the usage time. The user can extend the available usage time by switching to a power mode in which the available functions are disabled. However, even if the electronic device can continue to operate by switching the power mode, if the power mode cannot be switched, the available usage time may not be extended and the operation may end.

[0005] The present invention has been made in view of the above problems, and an object thereof is to extend the available usage time when the available usage time of an electronic device has decreased.

Means for Solving the Problems

[0006] The first aspect of the present invention is, electricity A sub-device, a remaining time which is the remaining available time of the electronic device between An acquisition means for acquiring, a first power mode and A second power mode with lower power consumption than the first power mode of the electronic device And a means for to perform control for switching to any one of a plurality of power modes including When the current power mode is the first power mode, the remaining time acquired by the acquisition means having control means, the control means being Is less than a threshold value, and the switching condition is satisfied, a notification for prompting a switch from the first power mode to the second power mode is performed This is an electronic device that performs the above. between for switching from the first power mode to the second power mode characterized by performing control for

[0007] , electricity between obtaining A second aspect of the present invention , electricity A control method for a sub-device, a remaining time which is the remaining available time of the electronic device between An acquisition step obtaining A first power mode and A second power mode with lower power consumption than the first power mode of the electronic device And a step to perform control for switching to any one of a plurality of power modes including When the current power mode is the first power mode, the remaining time acquired in the step including control for Is less than a threshold value, and the switching condition is satisfied, a notification for prompting a switch from the first power mode to the second power mode is performed obtained This is a control method that performs the above. between for switching from the first power mode to the second power mode characterized by performing control for

[0008] , electricity a program to be executed, between A third aspect of the present invention , electricity On a computer of a sub-device a program to be executed, An acquisition step for acquiring a remaining time which is the remaining available time of the electronic device between And an acquisition step obtaining A first power mode and A second power mode with lower power consumption than the first power mode of the electronic device And a step to perform control for switching to any one of a plurality of power modes including When the current power mode is the first power mode, the remaining time acquired in the step causing to execute control, and in the control step, Is less than a threshold value, and the switching condition is satisfied, a notification for prompting a switch from the first power mode to the second power mode is performed obtained The remaining time obtained in the step between is less than the threshold value, and when the for switching from the first power mode to the second power mode switching condition is satisfied, a notification for prompting the switching from the first power mode to the second power mode is performed characterized by causing control for is a program.

Advantages of the Invention

[0009] According to the present invention, the available time of the electronic device can be extended.

Brief Description of the Drawings

[0010] [Figure 1] It is a block diagram for explaining the configurations of the battery 100 and the electronic device 200 in Embodiment 1. [Figure 2] It is a block diagram for explaining a part of the configuration of the electronic device 200 in Embodiment 1. [Figure 3] It is a diagram for explaining the adverse effects when the reference voltage is increased. [Figure 4] It is a diagram for explaining the switching method of the calculation formula for the remaining amount display of the electronic device 200 in Embodiment 1. [Figure 5] It is a block diagram for explaining a part of the configuration of the electronic device 200a in Embodiment 3. [Figure 6] It is a flowchart for explaining the display switching process 600 of the power mode. [Figure 7] It is a diagram for explaining the determination of the power mode switching condition when there are two power modes. [Figure 8] It is a diagram for explaining the determination of the power mode switching condition when there are three power modes. [Figure 9] It is a flowchart for explaining the power saving control process 900 in Embodiment 1. [Figure 10] It is a diagram for explaining an example of the notification screen. [Figure 11] It is a diagram for explaining an example of the notification screen. [Figure 12] It is a flowchart for explaining the power saving control process 1200 in Embodiment 2.

Mode for Carrying Out the Invention

[0011] <Embodiment 1> Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The electronic device of the present invention may be an electronic device that operates using a battery (hereinafter referred to as a battery), such as a digital video camera, a digital still camera, a smartphone, a personal computer, or the like.

[0012] The power consumption of electronic devices such as cameras has a tendency to increase due to the influence of the addition of new functions and the like. On the other hand, since the battery of the camera is required to be smaller and lighter and the development cost is optimized, the battery of a newly developed product is not necessarily optimal, and it has become common to use conventional products. When using a conventional battery, the situation may occur where the maximum supply power of the battery is lower than the maximum power consumption of the camera. In order to prevent the maximum supply power of the battery from falling below the maximum power consumption of the camera, the minimum operating voltage (reference voltage) of the battery is raised. By raising the reference voltage of the battery, the maximum supply power of the battery increases, and the battery can cover the maximum power consumption of the electronic device.

[0013] Using FIG. 3, the adverse effects when the reference voltage of the battery that supplies power to the camera is increased will be described. The graph 301 in FIG. 3 is a graph showing the change in the battery voltage with respect to the actual operating time (real time) of the camera. The vertical axis represents the battery voltage, and the horizontal axis represents the real time. The remaining available time (hereinafter also referred to as the remaining time) of the camera is calculated so as to be 0 when the battery voltage drops to the reference voltage. When the remaining time of the camera becomes 0, the drive of the camera ends (shuts down).

[0014] When the reference voltage is raised from reference voltage B (12V) to reference voltage A (13.5V) to cover the maximum power consumption, the camera shuts down at time ta when the battery voltage drops to reference voltage A. Since the camera shuts down at time tb at reference voltage B, when the reference voltage is raised to reference voltage A, the available operating time of the camera is shortened by tb - ta.

[0015] Graph 302 in FIG. 3 is a graph showing the remaining available operating time (remaining time) of the camera with respect to the actual operating time (actual time) of the camera. The vertical axis represents the remaining time of the camera, and the horizontal axis represents the actual time. When the reference voltage of the battery is raised from reference voltage B to reference voltage A, the remaining time of the camera is calculated to be 0 at time ta.

[0016] Graph 303 in FIG. 3 is a graph showing the remaining battery level display with respect to the actual operating time (actual time) of the camera. The vertical axis represents the remaining battery level display, and the horizontal axis represents the actual time. The remaining battery level may be displayed on a display unit provided in the battery itself. The remaining battery level is displayed, for example, by marks, lamps, LED displays, etc. In the example of graph 303, the remaining battery level display is shown in four levels from 1 to 4.

[0017] Even when the reference voltage of the camera is raised to reference voltage A, the remaining battery level display is set based on the time tb until the battery voltage reaches reference voltage B. On the other hand, when the reference voltage of the camera is raised to reference voltage A, the remaining time of the camera is calculated based on reference voltage A. Therefore, the remaining battery level display and the remaining level display shown on the camera (remaining level display corresponding to the remaining time of the camera) do not match.

[0018] As described with reference to FIG. 3, when the reference voltage of an electronic device such as a camera is raised, there can be drawbacks such as a shortening of the available operating time of the electronic device and a mismatch between the remaining battery level display and the remaining level display of the electronic device. In Embodiment 1, the electronic device can reduce the shortening of the available operating time and the mismatch between the remaining battery level display and the remaining level display of the electronic device by switching the calculation method of the remaining time according to the power consumption.

[0019] FIG. 1 is a block diagram showing a configuration example of the battery 100 and the electronic device 200 in Embodiment 1. The battery 100 and the electronic device 200 are interconnected by connecting contacts 7a to 7d of the battery 100 to contacts 8a to 8d of the electronic device 200, respectively. The battery 100 supplies power to the electronic device 200 via the contact 7a, the contact 8a, the contact 7d, and the contact 8d.

[0020] The configuration of the battery 100 will be described. The battery cell 1 is a rechargeable battery cell that generates an electromotive force. The protection IC (Integrated Circuit) 2 is a circuit that controls the protection function during charging and discharging of the battery cell 1. The voltage detection unit 3 detects the voltage between the terminals of the battery cell 1 (battery voltage). The detection resistor 4 detects the discharge current (battery current). The temperature sensor 5 detects the battery temperature. The temperature sensor 5 is, for example, a thermistor or a thermocouple.

[0021] The information processing unit 6a in the control unit 6 performs A / D conversion on the information detected by the voltage detection unit 3, the detection resistor 4, and the temperature sensor 5 and performs current integration. The battery 100 may be equipped with an LED display unit (not shown) indicating the remaining amount of the battery. The remaining amount display of the battery 100 is controlled by the control unit 6. The battery 100 can display the remaining amount of the battery 100 on the LED display unit separately from the remaining amount display in the electronic device 200. 0's remaining amount can be displayed on the LED display unit.

[0022] The configuration of the electronic device 200 will be described. The power supply control unit 9 generates a use voltage from the power supply supplied from the battery 100 and supplies power to the components of the electronic device 200. The power supply control unit 9 is, for example, a DC / DC converter or a linear regulator.

[0023] Processor 10 controls each component of the electronic device 200. Processor 10 transmits a request command to the control unit 6 of the battery 100 via contact point 8b and contact point 7b. Processor 10 receives, as response data, the remaining amount information of the battery 100 including the remaining battery amount (remaining capacity), battery voltage, battery current, etc. via contact point 7b and contact point 8b. Processor 10 obtains the remaining available time of the electronic device 200 using the remaining amount information from the battery 100. Further, Processor 10 receives information on the battery temperature of the battery 100 from the temperature sensor 5 via contact point 7c and contact point 8c.

[0024] The display unit 11 displays information regarding the electronic device 200 such as the remaining time and moving image data, etc. The display unit 11 is, for example, a liquid crystal display. The operation unit 12 receives operations from the user. The operation unit 12 is, for example, a switch or a button, and may be a touch panel configured integrally with the display unit 11. Processor 10 controls the components of the electronic device 200 according to the input information from the operation unit 12.

[0025] FIG. 2 is a block diagram showing a configuration example of the electronic device 200 in Embodiment 1. FIG. 2 will explain in detail the processor 10 among the respective configurations of the electronic device 200 described in FIG. 1. The CPU 26 included in the processor 10 controls each block of the processor 10 via a bus (not shown). The ROM 27 stores programs executed by the CPU 26. A part of the area of the ROM 27 is used to hold the state of the electronic device 200 and the like for backup. The RAM 28 is a volatile memory used as a temporary storage of the CPU 26.

[0026] The CPU 26 realizes the functions of the communication unit 20, remaining time acquisition unit 21, calculation method change unit 22, power consumption determination unit 23, and power mode switching unit 25 by executing a program read from the ROM 27 or a recording medium that is a non-volatile memory into the RAM 28. Also, when the remaining time of the electronic device 200 reaches 0, the CPU 26 controls to end the drive of the electronic device. The communication unit 20 receives remaining amount information of the battery 100 including the remaining battery amount and battery current through communication with the battery 100.

[0027] The remaining time acquisition unit 21 acquires the remaining time of the electronic device 200 based on the remaining battery amount and battery current acquired from the battery 100. The calculation method of the remaining time is changed based on a change signal from the calculation method change unit 22. The acquired remaining time of the electronic device 200 is output to the display unit 11 via a signal line and displayed.

[0028] The calculation method change unit 22 changes the calculation method of the remaining time based on the determination result of the power consumption of the electronic device 200 output from the power consumption determination unit 23. The calculation method change unit 22 outputs a change signal regarding the changed calculation method of the remaining time to the remaining time acquisition unit 21.

[0029] The power consumption determination unit 23 determines the power consumption of the electronic device 200. The power consumption determination unit 23 can determine the power consumption based on the power mode information from the power mode switching unit 25. The electronic device 200 has a plurality of power modes with different maximum power consumptions. Since the available functions are different in each power mode, the maximum power consumption in each power mode is acquired based on the functions available in each mode. The power consumption determination unit 23 outputs the determination result of the power consumption of the electronic device 200 to the calculation method change unit 22.

[0030] Note that the power consumption determination unit 23 may calculate the power consumption of the electronic device 200 from the product of the battery voltage and the battery current acquired via the communication unit 20, and determine the current power mode by comparing it with the power consumption table stored in advance in the ROM 27. The power consumption table is a table that defines the correspondence between the power consumption of the electronic device 200 and the power mode.

[0031] The power mode switching unit 25 receives a signal indicating the operation content for switching the power mode from the operation unit 12, and switches the power mode based on the received signal. For example, the display unit 11 displays the names of the respective power modes of the electronic device 200, and when the user selects a desired power mode via the operation unit 12, the operation content is transmitted to the power mode switching unit 25. The power mode switching unit 25 switches the power mode based on the user's operation, and outputs information on the switched power mode to the power consumption determination unit 23.

[0032] Note that the display unit 11 may display a user interface for selecting ON or OFF of the power saving mode instead of the names of the respective power modes. When the power saving mode is set from OFF to ON by the user, the power mode switching unit 25 outputs information indicating that the switched power mode is the power saving mode to the power consumption determination unit 23.

[0033] With reference to FIG. 4, a change in the method for calculating the remaining time of the electronic device 200 will be described. The graph 401 in FIG. 4 is a graph showing the change in the battery voltage with respect to the actual operation time (real time) of the electronic device 200. The vertical axis represents the battery voltage, and the horizontal axis represents the real time.

[0034] When the reference voltage is raised to the reference voltage A (13.5V) as the power consumption increases, as described with reference to FIG. 3, the real time of the electronic device 200 is shortened to ta. The electronic device 200 can reduce the power consumption and lower the reference voltage by switching to the power saving mode and restricting the available functions. The electronic device 200 can delay the shutdown until the real time becomes tb by lowering the reference voltage to the reference voltage B (12V).

[0035] The electronic device 200 has a plurality of power modes with different maximum power consumptions, and can change the reference voltage according to the power consumption in each power mode. The maximum power consumption of each power mode is different according to the functions available in each power mode. The power modes of the electronic device 200 include, for example, a normal mode and a power-saving mode with a lower maximum power consumption than the normal mode. The power-saving mode is an operating state in which the maximum power consumption of the electronic device 200 is reduced by restricting the available functions. When the user wants to extend the available time of the battery, the user can turn on the power-saving mode. The normal mode corresponds to the "first power mode", and the power-saving mode corresponds to the "second power mode".

[0036] In the power-saving mode, some functions of the electronic device 200 are disabled. In the power-saving mode, at least one of the functions available in the normal mode may be disabled. For example, in the power-saving mode, the electronic device 200 disables functions such as the high-brightness setting of the backlight of the display unit and the network function. Also, in the power-saving mode, the processing content of each function of the electronic device 200 may be changed so that the processing load of the processor 10 is reduced. When the electronic device 200 is operating in the normal mode, the user can switch to the power-saving mode to extend the remaining time of the electronic device 200.

[0037] With reference to the graph 402 in FIG. 4, a method for calculating the remaining available time (remaining time) displayed on the electronic device 200 will be described. The graph 402 is a graph showing the remaining time of the electronic device 200 with respect to the actual operating time (actual time) of the electronic device 200. The vertical axis represents the remaining time of the electronic device 200, and the horizontal axis represents the actual time. The electronic device 200 calculates the remaining time of the electronic device 200 by changing the calculation method according to the current power mode.

[0038] The power consumption determination unit 23 determines the maximum power consumption in the current power mode of the electronic device 200 based on the power mode information from the power mode switching unit 25. The calculation method change unit 22 changes the calculation method of the remaining time of the electronic device 200 based on the determination result of the power consumption determination unit 23.

[0039] The calculation method change unit 22 changes the calculation method by determining a coefficient (hereinafter referred to as a correction coefficient) used in the calculation of the remaining time of the electronic device 200 according to the power consumption in the current power mode. The correction coefficient is a coefficient for correcting the reference voltage at which the remaining time of the electronic device 200 is set to 0. The reference voltage at which the remaining time is set to 0 is obtained based on the power consumption in the current power mode of the electronic device 200. The calculation method change unit 22 can output, for example, the changed correction coefficient to the remaining time acquisition unit 21 as a change signal.

[0040] When the correction coefficient in the normal mode is k1 and the correction coefficient in the power saving mode is k2, the remaining time acquisition unit 21 can calculate the remaining time of the electronic device 200 by the following calculation formulas (Equation 1) and (Equation 2), respectively. T = {C × k1 / I} × 60 ··· (Equation 1) T = {C × k2 / I} × 60 ··· (Equation 2) T is the remaining time [minutes] of the electronic device 200. C is the remaining battery capacity [mAh]. I is the battery current [mA]. The remaining battery capacity and the battery current are acquired from the battery 100 as remaining amount information.

[0041] The graph 402a shown by the dotted line in the graph 402 is a graph of the remaining time when the correction coefficient k1 is used, and the remaining time becomes 0 at the actual time ta. The graph 402b shown by the solid line is a graph of the remaining time when the correction coefficient k2 is used, and the remaining time becomes 0 at the actual time tb.

[0042] The graph 403 in FIG. 4 is the graph in FIG. 3 3Similar to 03, it is a graph showing the remaining battery level display with respect to the actual operating time (real time) of the electronic device 200. The vertical axis represents the remaining battery level display, and the horizontal axis represents the real time. In the power saving mode, since the calculation method of the electronic device 200 is changed to (Equation 2), the remaining time becomes 0 at the real time tb as shown in the graph 402b. Therefore, the discrepancy between the remaining battery level display and Remaining amount display of the electronic device 200 and is eliminated.

[0043] By switching the correction coefficient used for calculating the remaining time according to the power mode, the electronic device 200 can extend the available time of the battery 100. Also, the remaining time display shown on the electronic device 200 can be made to match the remaining level display of the battery 100.

[0044] Note that the power mode of the electronic device 200 is not limited to two, and may be three or more. When there are three or more power modes, the electronic device 200 can obtain the remaining time according to the power consumption by changing the correction coefficient for each mode. Also, the values of the reference voltages in each power mode are just examples, and they may be set based on the functions used in each power mode. Also, the power consumption in each power mode can be set as the maximum power consumption in that power mode. Also, the correction coefficient is not limited to being changed based on the current power mode, and may be changed based on the current power consumption of the electronic device 200.

[0045] By changing the calculation method of the remaining time of the electronic device 200 according to the power mode or power consumption, the electronic device 200 can suppress the shortening of the available time. Also, the discrepancy between the remaining battery level display and the remaining level display of the electronic device can be reduced.

[0046] Even when the electronic device 200 can continue to be driven by switching the power mode, If the power mode cannot be switched, the remaining available time may not be extended and the drive may end. Therefore, in Embodiment 1, when the available time decreases, the electronic device 200 issues a notification prompting a switch to a power mode that can extend the available time. The user can extend the available time by switching to the power mode in response to the notification.

[0047] With reference to FIGS. 9 to 11, a notification prompting the user to switch the power mode from the normal mode (first power mode) to the power-saving mode (second power mode) that can extend the remaining time will be described. FIG. 9 is a flowchart for explaining the power-saving control process 900 performed by the electronic device 200. By performing the power-saving control process 900, the electronic device 200 can allow the user to select whether the power-saving mode is valid or not. The power-saving control process 900 starts when the power of the electronic device 200 is turned on.

[0048] In step S901, the CPU 26 determines whether to notify the user to switch to the power-saving mode. The CPU 26 determines to notify the user when any of the following conditions are met: the power-saving mode is invalid, the switching condition for switching from the normal mode to the power-saving mode is satisfied, and the remaining time is less than the threshold value. When the CPU 26 determines to notify the user to switch to the power-saving mode, it proceeds to step S902. When the CPU 26 determines not to notify, it continues to make the determination in step S901 until the notification condition is met.

[0049] The CPU 26 can determine whether the power-saving mode is invalid based on the current power mode setting. Also, the CPU 26 may determine whether the power-saving mode is invalid based on the power consumption determined by the power consumption determination unit 23. For example, the CPU 26 can determine that the power-saving mode is invalid when the power consumption is higher than the maximum power consumption of the power-saving mode. The CPU 26 can determine that the power-saving mode is valid when the power consumption is less than or equal to the maximum power consumption of the power-saving mode.

[0050] The CPU 26 determines whether or not the switching condition is satisfied based on whether or not a function exclusive to the power saving mode (not available in the power saving mode) is in a stopped state. The switching condition is a condition for determining whether or not switching to the power saving mode is possible. For example, when a function such as a network function or a high brightness setting function of the display unit 11 such as an LCD is exclusive to the power saving mode, if either the network function or the LCD high brightness setting function is valid, the CPU 26 determines that the switching condition is not satisfied. On the other hand, if the network function and the LCD high brightness setting function are invalid, the CPU 26 determines that the switching condition is satisfied.

[0051] In the first embodiment, the functions exclusive to the power saving mode are described as a network function or a high brightness setting function of an LCD. However, other functions such as functions related to image processing may be used. The exclusive functions may be registered in advance in the ROM 27 or the like, or may be set by the user.

[0052] The CPU 26 determines whether or not the remaining time is less than the threshold value based on the remaining time acquired by the remaining time acquisition unit 21. The threshold value of the remaining time can be set to, for example, 1 minute. In this case, if the remaining time acquired by the remaining time acquisition unit 21 is less than 1 minute, the CPU 26 determines that the remaining time is less than the threshold value. Note that the threshold value of the remaining time is not limited to 1 minute and may be set to a time longer or shorter than 1 minute. The threshold value of the remaining time may be a value registered in advance in the ROM 27 or the like, or may be a value set by the user.

[0053] In step S902, the CPU 26 displays a notification screen (area) prompting switching to the power saving mode, and issues a notification prompting the user to make a setting change to enable the power saving mode. Here, with reference to FIG. 10, the notification to the user in the first embodiment will be described. FIG. 10(a) is a diagram showing an example of a screen displayed on the display unit 11 at the time of shooting.

[0054] The shooting screen 1000 in Fig. 10(a) displays the subject 1001, the subject 1002, and the subject 1003. The CPU 26 expands the image data including the subjects 1001 to 1003 captured by the imaging unit of the electronic device 200 in the RAM 28 and displays it on the display unit 11.

[0055] The shooting screen 1000 displays the remaining time 1011, the recording state 1012, the shooting time code 1013, the recordable time of the SD card 1014, the camera mode icon 1015, and the shooting parameters 1016 on the OSD (On-Screen Display). The data displayed on the OSD is expanded in the RAM 28. The CPU 26 superimposes the OSD data on the image data acquired from the imaging unit and thereby displays the shooting screen 1000 on the display unit 11.

[0056] The display unit 11 is, for example, a liquid crystal display. The operation unit 12 is, for example, a switch, a button, or a cross key, and may be a touch panel configured integrally with the display unit 11. In Embodiment 1, an example of the screen display when the electronic device 200 is a video camera is shown, but the electronic device 200 is not limited to a video camera and may be a playback device or other electronic device.

[0057] Fig. 10(b) is an example of the display of a notification screen for prompting the user to make a setting change to enable the power-saving mode. In the notification screen of Fig. 10(b), the confirmation message 1050 prompting the activation of the power-saving mode is displayed on the OSD superimposed on the shooting screen 1000 shown in Fig. 10(a). By displaying the notification screen in step S902, the user can select whether to enable / disable the power-saving mode.

[0058] In step S903, the CPU 26 determines the selection operation received from the user. If the received selection operation is "OK", the CPU 26 proceeds to the process of step S904; otherwise, it proceeds to the process of step S905. Note that the received selection operation refers to the operation performed by the user via the operation unit 12. For example, when the operation unit 12 is a cross key, the user can select "OK" or "Cancel" by operating in the left - right direction. When the CPU 26 is operated in the left - right direction, it displays a cursor on the screen indicating which of "OK" or "Cancel" is valid. The confirmation message 1050 in Fig. 10(b) shows a state where the cursor is displayed on "OK". When the user presses the center of the cross key in the state where the cursor is displayed on "OK", the CPU 26 determines that "OK" has been selected. Note that in Embodiment 1, the case where the operation unit 12 is a cross key has been described, but the operation unit 12 only needs to be able to select "OK" or "Cancel", and it may be a touch panel or an operation button.

[0059] In step S904, the CPU 26 enables the power - saving mode. Also, the CPU 26 makes the confirmation message 1050 non - visible and displays the shooting screen 1000.

[0060] In step S905, the CPU 26 determines whether the selection operation received from the user is a selection of "Cancel". If the received operation is a selection of "Cancel", the CPU 26 proceeds to the process of step S906; otherwise, it proceeds to the process of step S903.

[0061] In step S906, the CPU 26 maintains the power - saving mode as invalid. Also, the CPU 26 makes the confirmation message 1050 non - visible and displays the shooting screen 1000. While the electronic device 200 is being driven, the CPU 26 repeats the processes from step S901 to step S9 06 at a predetermined interval.

[0062] Note that the conditions for determining whether to issue the notification in step S901 described above are merely examples, and different conditions may be adopted. For example, the CPU 26 may notify the user when two conditions are met: the power-saving mode is invalid and the remaining time is less than the threshold value. When these two conditions are met and an exclusive function (not meeting the switching conditions from the normal mode to the power-saving mode) is being executed, if the user performs an operation to enable the power-saving mode, the CPU 26 may stop the currently executing exclusive function. Also, the CPU 26 may notify the user to prompt the change to the power-saving mode while informing that the exclusive function will be stopped when switching to the power-saving mode. In this way, even when the power-saving mode cannot be set, by prompting the user to change the setting, the user can extend the remaining time of the electronic device 200.

[0063] Also, in the above description, an example where the notification screen displayed in step S902 displays the confirmation message 1050 has been shown, but the information to be displayed is not limited to this. For example, as shown in FIG. 11, the CPU 26 may also display information regarding the remaining time before and after the power mode switch on the notification screen. In the example of FIG. 11, the CPU 26 displays the current remaining time 1101 acquired by the remaining time acquisition unit 21 and the remaining time 1102 after the power-saving mode switch on the confirmation message 1100 of the power-saving mode. The remaining time before and after the power-saving mode switch can be calculated using the above-described calculation formula. Also, the remaining time before and after the power-saving mode switch may be calculated from the remaining battery level or battery voltage acquired from the battery 100. By displaying the remaining time before and after the switch to the power-saving mode, the user can more clearly confirm the effect of enabling the power-saving mode. Note that the CPU 26 may display both the remaining time and the battery icon on the notification screen as shown in FIG. 11, or may display only the remaining time. Also, the CPU 26 may display the time extended by switching to the power-saving mode on the notification screen.

[0064] In Embodiment 1, when the remaining time of the electronic device 200 becomes less than the threshold value, the CPU 26 displays a notification screen. The user can extend the remaining time by switching the electronic device 200 to the power saving mode by performing an operation to enable the power saving mode. Also, in the method of Embodiment 1, the user can switch to the power saving mode without displaying the power mode setting screen and performing the switching operation. Therefore, the method of Embodiment 1 is highly convenient for users who find it troublesome to change settings such as switching the power mode. Also, in the method of Embodiment 1, the user can extend the remaining time by switching to the power saving mode in response to the displayed notification screen without previously knowing the existence of the power saving mode function.

[0065] Note that if the electronic device 200 determines in step S901 that it is necessary to notify the user to switch to the power saving mode, it may automatically switch to the power saving mode without notifying the user. The user can extend the remaining time without switching the power mode by himself / herself.

[0066] <Embodiment 2> In Embodiment 2, the device configuration of the electronic device 200 is the same as that in Embodiment 1, but the content and timing of the notification prompting the switch to the power saving mode are different from those in Embodiment 1 in that the process of changing according to the imaging state is performed. By changing the control content according to the imaging state, the electronic device 200 can provide a more convenient setting means. Hereinafter, with reference to FIG. 12, the flowchart of the power saving control process will be described together with the differences from Embodiment 1.

[0067] FIG. 12 is a flowchart for explaining the power saving control process 1200 performed by the electronic device 200. The power saving control process 1200 starts when the power of the electronic device 200 is turned on.

[0068] In step S1201, the CPU 26 determines the imaging state of the electronic device 200. The imaging state of the electronic device 200 includes the REC state (recording state) and the state where it is not in the REC process. The REC state is a state where the electronic device 200 captures an object and records the captured data. The state where it is not in the REC process is, for example, the standby state where the electronic device 200 is in a state capable of capturing images, or the state where the power is turned on. If it is in the REC state, the CPU 26 proceeds to the process of step S1202, and if it is not in the REC state, the CPU 26 proceeds to the process of step S1203.

[0069] In step S1202, the CPU 26 sets the threshold value of the remaining time used for determining whether to issue a notification to 2 minutes (the first threshold value), and proceeds to the process of step S1204.

[0070] In step S1203, the CPU 26 sets the threshold value of the remaining time used for determining whether to issue a notification to 5 minutes (the second threshold value), and proceeds to the process of step S1204. Note that the values of the threshold values of the remaining time set in steps S1202 and S1203 are merely examples and are not limited thereto.

[0071] In Embodiment 2, unlike Embodiment 1, the CPU 26 sets different values for the remaining time threshold according to the determination of the imaging state in step S1201. For example, when in the REC state, the CPU 26 may set the threshold to 2 minutes, which is a shorter time compared to the threshold of 5 minutes when not in the REC state. When in the REC state, a part of the shooting screen 1000 may be blocked by the display of the confirmation message 1050 or the confirmation message 1100 on the notification screen, resulting in a decrease in visibility. Also, switching to the power-saving mode and stopping the high-brightness setting function may also reduce visibility. Therefore, when in the REC state, in order to shoot for a longer time with good visibility, the CPU 26 controls to display the notification screen when the remaining time is shorter than when not in the REC state. Since the notification screen is not displayed until the battery remaining time is almost exhausted, the user can use the device while maintaining visibility for a longer time. On the other hand, when not in the REC state, the CPU 26 controls to display the notification screen at an earlier time than when in the REC state. By displaying the notification screen at a certain timing when the remaining time has decreased to a certain extent, the user can switch to the power-saving mode with a margin.

[0072] Note that the remaining time threshold is not limited to 2 minutes or 5 minutes, and other values may be set. Also, for example, if the user wants to shoot for a longer time even when visibility decreases, the threshold for the REC state may be set longer than the threshold for the non-REC state.

[0073] In step S1204, the CPU 26 determines whether to notify the user to switch to the power-saving mode. The CPU 26 determines to notify the user when any of the following conditions are met: the power-saving mode is invalid, the switching conditions for switching from the normal mode to the power-saving mode are satisfied, and the remaining time is less than the threshold value. When the CPU 26 determines to notify the user to switch to the power-saving mode, it proceeds to step S1205. When it determines not to notify, it returns to step S1201 and repeats the processing from step S1201 to step S1204. For the threshold value of the remaining time used in the determination in step S1204, the CPU 26 makes the determination using different values set according to the imaging state of the electronic device 200.

[0074] Note that the determination of whether to notify the user to switch to the power-saving mode is not limited to the above, and different conditions may be used for the determination. For example, as long as it can be determined that the available time of the electronic device 200 is decreasing, the CPU 26 may use the condition that the battery voltage or the remaining battery level is less than the threshold value instead of the condition that the remaining time is less than the threshold value. Further, the CPU 26 may obtain the remaining time based on the battery voltage or the remaining battery level.

[0075] Furthermore, in addition to satisfying the switching conditions for switching from the normal mode to the power-saving mode and the remaining time being less than the threshold value, the CPU 26 may determine whether to notify the user to switch to the power-saving mode based on the imaging state. When the switching conditions are satisfied and the remaining time is less than the threshold value, if the imaging state is the REC state, the CPU 26 may display a notification screen, and if it is not in the REC state, it may not display the notification screen.

[0076] After step S1204, the CPU 26 performs the same processing as steps S902 and later in Embodiment 1. Note that, similar to Embodiment 1, the CPU 26 may also display the remaining time after the power mode switch on the notification screen displayed in step S902.

[0077] In the description of the power saving control process 1200 in FIG. 12, the CPU 26 has been described as an example of changing the threshold value of the remaining time according to the imaging state of the electronic device 200, but the display mode of the notification screen may be changed. For example, the CPU 26 may change the display area (display position, size) of the notification screen according to the imaging state of the electronic device 200. For example, when the CPU 26 is in the REC state, in order to make the captured image easier to view, the notification screen may be displayed small in a part of the display unit 11 . Also, for example, when the CPU 26 is in the REC state, the notification screen may be displayed as a pop-up. On the other hand, when the CPU 26 is not in the REC state, it may be displayed large in the center of the screen of the display unit 11 .

[0078] Also, for example, the CPU 26 may change the display content (notification content) of the notification screen according to the imaging state of the electronic device 200. The notification content is, for example, information such as a message prompting switching to the power saving mode, the remaining time before and after power mode switching, and functions that are invalidated when switching to the power saving mode. When the CPU 26 is in the REC state, it is preferable to display a message prompting switching to the power saving mode and the remaining time before and after power mode switching on the notification screen. On the other hand, when the CPU 26 is not in the REC state, in addition to a message prompting switching to the power saving mode and the remaining time before and after power mode switching, functions that are invalidated when switching to the power saving mode may also be displayed on the notification screen. When the CPU 26 is in the REC state, in order to make the captured image easier to view, it is preferable to display less information than when it is not in the REC state. Note that the information included in the notification may be appropriately combined according to the imaging state of the electronic device 200.

[0079] Also, for example, the CPU 26 may change the transparency of the notification screen according to the imaging state of the electronic device 200. For example, when the CPU 26 is in the REC state, it is preferable to make the transparency larger than when it is not in the REC state. In this way, by changing the display mode such as the display area, display content, and transparency of the notification screen, the CPU 26 can prompt the user to shift to the power saving mode while ensuring the visibility in the REC state.

[0080] Also, the CPU 26 may change the number of times to repeat the notification according to the imaging state of the electronic device 200. For example, when the display conditions other than the remaining time are satisfied, the CPU 26 displays the notification screen when the remaining time is 2 minutes (the first threshold value) in the REC state. In contrast, if the CPU 26 is not in the REC state, it may display the notification screen when the remaining time is 5 minutes (the second threshold value), and if the power saving mode cannot be switched, it may display the notification screen again when the remaining time is 2 minutes. Note that the first threshold value and the second threshold value are not limited to 2 minutes or 5 minutes, and other values may be set.

[0081] Also, when the electronic device 200 has a plurality of power saving modes, the remaining time can be extended each time the power mode is switched. When the CPU 26 is not in the REC state, it notifies when the remaining time is 5 minutes. When the remaining time is extended by switching the power mode, it displays the notification screen again when the remaining time becomes 5 minutes again. In this way, when the CPU 26 is not in the REC state, it may display the notification screen repeatedly a plurality of times.

[0082] Note that the timing and number of times to display the notification screen are just examples. In this way, by displaying more notification screens when not in the REC state than in the REC state, when not in the REC state, the user can switch to the power saving mode with ease. On the other hand, in the REC state, since the notification screen is not repeatedly displayed, the user can concentrate on shooting.

[0083] Note that the CPU 26 may control so as not to redisplay the notification screen after displaying it once, or may control to display the notification screen the number of times set by the user. Also, when the CPU 26 can display the notification screen a plurality of times, it may display different contents depending on the display timing.

[0084] ​Note that the CPU 26 may change at least one of the conditions for determining whether to issue a notification prompting switching to the power saving mode, the display mode of the notification, and the number of times the notification is displayed, according to the imaging state of the electronic device 200.

[0085] Also, when the electronic device 200 has three or more power modes with different power consumptions, the CPU 26 may display a prompt to enable the power mode with the lowest power consumption. Note that the CPU 26 may display a prompt to change to a power mode with a power consumption one level lower than the current one, or may display a plurality of options for power modes with a lower power consumption than the current one.

[0086] In addition, the CPU 26 may issue a notification prompting switching of the power mode by means other than display. For example, if the electronic device 200 has a voice output / voice recognition function, it can notify the user by voice. The user can perform a switching operation by voice in response to the voice notification from the electronic device 200. By receiving the notification by voice and performing the switching operation, the user can switch the power mode of the electronic device 200 while maintaining the visibility of the display screen.

[0087] As described above, in Embodiment 2, unlike Embodiment 1, the CPU 26 changes the threshold for displaying the notification screen according to the imaging state of the electronic device 200. The electronic device 200 described in Embodiment 2 can provide a convenient setting means by displaying the notification screen at a timing suitable for the user's imaging state.

[0088] Note that when the electronic device 200 determines in step S1204 to issue a notification prompting switching to the power saving mode, it may not notify the user and automatically switch to the power saving mode. Also, the electronic device 200 may automatically switch to the power saving mode in the REC state and notify the user when not in the REC state. By automatically switching to the power saving mode, the user can extend the remaining time without switching the power mode himself / herself.

[0089] <Embodiment 3> In Embodiment 3, the electronic device controls whether to change or maintain the power mode according to whether or not switching conditions regarding the switching of the power mode are satisfied. Thereby, it is possible to prevent an immediate shutdown due to insufficient power supply of the battery, which may occur when switching to a power mode with higher power consumption.

[0090] Referring to FIG. 5, a part of the configuration of the electronic device 200a in Embodiment 3 will be described. Matters not mentioned as the configuration and operation of Embodiment 3 may follow Embodiment 1. In Embodiment 3, the processor 10, the communication unit 20, and the power mode switching unit 25 in Embodiment 1 are replaced with a processor 10a, a communication unit 20a, and a power mode switching unit 25a, respectively.

[0091] The electronic device 200a in Embodiment 3 further includes a switching determination unit 24. The switching determination unit 24 determines whether any one of the remaining time of the electronic device 200a, the remaining amount of the battery, and the battery voltage satisfies the switching condition to a power mode with higher power consumption than the current one. When the power mode switching unit 25a receives an instruction to switch to a power mode with higher power consumption than the current one (for example, from the power saving mode to the normal mode), it controls the switching of the power mode according to the determination result of the switching determination unit 24. When the switching determination unit 24 determines that the switching condition to the normal mode is satisfied, the power mode switching unit 25a changes the power mode according to the input power mode information. When the switching determination unit 24 determines that the switching condition is not satisfied, the power mode switching unit 25a maintains the current power mode. When the switching determination unit 24 does not satisfy the switching condition, the operation unit 12 may be configured not to receive an instruction to switch from the power saving mode to the normal mode.

[0092] Also, the power mode switching unit 25a outputs display content including information regarding the power mode to the display unit 11 according to the determination result of the switching determination unit 24. The operation unit 12 outputs the operation content selected by the user to the power mode switching unit 25a. Here, the display unit 11 displays as a non-selectable state by the operation unit 12 the power mode determined by the switching determination unit 24 not to satisfy the switching condition. By the operation unit 12 not accepting the selection of the power mode that does not satisfy the switching condition, it is possible to prevent immediate shutdown due to insufficient supply power of the battery that may occur with power mode switching. The power mode switching unit 25a outputs the power mode selected by the user to the power consumption determination unit 23 as power mode information. Thereafter, the remaining time is calculated by the method described in Embodiment 1. The CPU 26 ends the drive of the electronic device 200a based on the remaining time acquired by the remaining time acquisition unit 21. Note that the CPU 26 may end the drive of the electronic device 200a based on a preset battery remaining amount (reference capacity) or battery voltage (reference voltage).

[0093] FIG. 6 is a flowchart illustrating the display switching process 600 of the power mode. The display switching process 600 starts when the power of the electronic device 200a is turned on.

[0094] In step S601, the communication unit 20a acquires the battery voltage of the battery 100. Note that the battery voltage is acquired, for example, at predetermined intervals.

[0095] In step S602, the switching determination unit 24 determines whether or not the battery voltage acquired in step S601 satisfies the switching condition for switching from the power saving mode to the normal mode. Note that the switching determination unit 24 determines that the switching condition is satisfied for switching from the normal mode to the power saving mode. If the battery voltage satisfies the switching condition for the normal mode, the process proceeds to step S603, and if the battery voltage does not satisfy the switching condition for the normal mode, the process proceeds to step S604.

[0096] Here, with reference to FIG. 7, the determination of the switching conditions to the normal mode will be described. The switching conditions to the normal mode can be determined, for example, by any one of whether the battery voltage is higher than the threshold voltage, whether the remaining battery level is greater than the threshold capacity, or whether the remaining time is longer than the threshold remaining time. Note that the switching determination unit 24 may combine a plurality of the three conditions to determine whether the switching conditions are satisfied. Hereinafter, each condition will be described.

[0097] When determining the switching conditions by whether the battery voltage is higher than the threshold voltage, the switching determination unit 24 compares the battery voltage acquired by the communication unit 20a with the threshold voltage pre-stored in the ROM 27. When the battery voltage is equal to or higher than the threshold voltage, the switching determination unit 24 determines that the switching conditions are satisfied. When the battery voltage is lower than the threshold voltage, the switching determination unit 24 determines that the switching conditions are not satisfied.

[0098] With reference to FIG. 7, the determination of the switching conditions based on the battery voltage will be described. FIG. 7 is a graph showing the change in the battery voltage with respect to the actual operating time (real time) of the electronic device 200a. The vertical axis represents the battery voltage, and the horizontal axis represents the real time. The remaining time of the electronic device 200a is calculated so as to become 0 when the battery voltage drops to the reference voltage a1. When the remaining time of the electronic device 200a becomes 0, the electronic device 200a ends its operation (shuts down). The threshold voltage a2 is a value different from the reference voltage a1 and is set to a value higher than the reference voltage a1. When the battery voltage is equal to or higher than the threshold voltage a2 (range a3 in FIG. 7), the switching determination unit 24 determines that the switching conditions to the normal mode are satisfied. When the battery voltage is lower than the threshold voltage (range a4 in FIG. 7), the switching determination unit 24 determines that the switching conditions to the normal mode are not satisfied.

[0099] By setting the threshold voltage to a value higher than the reference voltage, for example, the following effects can be obtained. When the switching determination unit 24 sets the threshold voltage and the reference voltage to the same value, when the battery voltage is equal to the reference voltage, it determines that the switching condition from the power saving mode to the normal mode is satisfied. However, when the power mode switching unit 25a switches from the power saving mode to the normal mode while the battery voltage is equal to the reference voltage, the reference voltage is pulled up. When the reference voltage is pulled up, the battery voltage is determined to be less than the reference voltage, and the remaining time is calculated as 0. Therefore, the electronic device 200a shuts down immediately at the timing when the power mode is changed. Therefore, a power mode switch that is not beneficial to the user is performed. Therefore, the threshold voltage may be set to a value higher than the reference voltage. By setting the threshold voltage to a value higher than the reference voltage, the switching determination unit 24 determines that the switching condition from the power saving mode to the normal mode is not satisfied when the battery voltage is equal to the reference voltage. The power mode switching unit 25a does not switch from the power saving mode to the normal mode and maintains the normal mode, so that immediate shutdown due to insufficient supply power of the battery can be prevented.

[0100] The threshold voltage may be, for example, the reference voltage plus an offset voltage based on the minimum operating time (the time that should operate before the drive ends) of the electronic device 200a after the power mode is switched. More specifically, the offset voltage may be determined based on the operating time of the electronic device 200a until the battery voltage in the normal mode drops from the threshold voltage to the reference voltage. For example, when the minimum operating time after switching from the power saving mode to the normal mode is 5 minutes, the threshold voltage may be a value obtained by actually measuring the battery voltage ΔV that drops when operating for 5 minutes in the normal mode and adding ΔV to the reference voltage. The minimum operating time may be a preset value or a value that can be set by the user.

[0101] When determining the switching condition based on whether the remaining battery level is greater than the threshold capacity, the switching determination unit 24 compares the remaining battery level acquired by the communication unit 20a with the threshold capacity pre-stored in the ROM 27. When the remaining battery level is equal to or greater than the threshold capacity, the switching determination unit 24 determines that the switching condition to the normal mode is satisfied. When the remaining battery level is less than the threshold capacity, the switching determination unit 24 determines that the switching condition to the normal mode is not satisfied. The threshold capacity may be a value higher than the reference capacity for performing the shutdown process of the electronic device 200a. The threshold capacity may be, for example, the reference capacity plus an offset capacity based on the minimum operating time of the electronic device 200a after the power mode switch. More specifically, the offset capacity may be determined based on the operating time of the electronic device 200a until the remaining battery level in the normal mode decreases from the threshold capacity to the reference capacity and may be determined based on the operating time of the electronic device 200a until the remaining battery level in the normal mode decreases from the threshold capacity to the reference.

[0102] When determining the switching condition based on whether the remaining time is longer than the threshold remaining time, the switching determination unit 24 compares the remaining time after the power mode switch with the threshold time pre-stored in the ROM 27. The remaining time is calculated by the method described in Embodiment 1. When the remaining time is equal to or greater than the threshold remaining time, the switching determination unit 24 determines that the switching condition to the normal mode is satisfied. When the remaining time is less than the threshold remaining time, the switching determination unit 24 determines that the switching condition to the normal mode is not satisfied. The threshold remaining time may be, for example, the minimum operating time after the power mode switch.

[0103] In step S603 of FIG. 6, the power mode switching unit 25a determines whether a switching instruction for the power mode has been received from the user. Specifically, the power mode switching unit 25a determines whether a switching instruction to the normal mode has been received while operating in the power saving mode. If a switching instruction to the normal mode has been received, the process proceeds to step S605; if not, the process proceeds to step S606.

[0104] In step S604, the display unit 11 displays a state where the normal mode cannot be selected. For example, the display unit 11 displays a state where the power mode switching display menu itself cannot be selected. Note that the display unit 11 may display a state where the power mode switching display menu can be selected but the normal mode cannot be selected. The non-selectable state is, for example, a state where it is displayed but cannot be selected, or a grayed-out state. Note that, in addition to grayed-out display, in a non-selectable state, the display unit 11 may display in a manner that allows the user to understand that the switching display menu and the normal mode are not selectable by icons or the like, or may not display them. Also, for example, when the display unit 11 receives a non-selectable power mode, the display unit 11 may display a message screen notifying the user that it cannot be selected. Also, for example, instead of displaying options for the normal mode and the power saving mode, the display unit 11 may display ON and OFF of the power saving mode. When the display unit 11 displays ON and OFF of the power saving mode, the display unit 11 may display the OFF of the power saving mode as a non-selectable state according to the determination result of the switching determination unit 24. Note that the display method is not limited to this, and any display method may be used as long as it indicates to the user that it is not possible to change to a power mode with higher power consumption than the current one. In this way, in a state where the supplied power is insufficient, switching to a power mode with high power consumption is suppressed. This can prevent an immediate shutdown due to insufficient supply power of the battery that may occur when switching the power mode.

[0105] In step S605, the calculation method change unit 22 changes the calculation method of the remaining time of the electronic device 200a according to the power mode that received the instruction in step S603. The calculation method change unit 22 changes the correction coefficient k used for calculating the remaining time from the value in the power saving mode to the value in the normal mode.

[0106] In step S606, the remaining time acquisition unit 21 calculates the remaining time of the electronic device 200a using the calculation method described in Embodiment 1. While the electronic device 200a is operating, the processes from step S601 to step S606 are repeatedly executed at a predetermined interval.

[0107] In FIG. 8, the processing when the electronic device 200a has three power modes will be described. In FIG. 7, the case where there are two power modes, namely the normal mode and the power saving mode, has been described as an example. However, the method described above is also applicable when there are three or more power modes. For example, assume that the electronic device 200a has three power modes: the normal mode, the first power saving mode, and the second power saving mode, in descending order of power consumption. In this case, the battery voltage at which the processor 10a performs the shutdown process of the electronic device 200a is the reference voltage c 1 in the normal mode and the reference voltage d1 in the first power saving mode.

[0108] The switching determination unit 24 compares the battery voltage with the threshold voltage c2 to determine whether the switching condition from the first power saving mode or the second power saving mode to the normal mode is satisfied. Also, the switching determination unit 24 compares the battery voltage with the threshold voltage d2 to determine whether the switching condition from the second power saving mode to the first power saving mode is satisfied. When the battery voltage is equal to or higher than the threshold voltage c2 (in the range of c3 in FIG. 8), the switching determination unit 24 determines that the switching condition from the first power saving mode or the second power saving mode to the normal mode is satisfied. When the battery voltage is equal to or higher than the threshold voltage d2 (in the range of d3 in FIG. 8), the switching determination unit 24 determines that the switching condition from the second power saving mode to the first power saving mode is satisfied. The power mode switching unit 25a outputs the display content to the display unit 11 so that the power mode determined by the switching determination unit 24 not to satisfy the switching condition is displayed in a non-selectable state, such as being grayed out. In this way, even when there are three or more power modes, it is possible to prevent immediate shutdown that may occur with the switching of the power mode. Note that even when there are three or more power modes, similar to the case of two power modes, the switching condition used by the switching determination unit 24 for determination is not limited to the comparison of the battery voltage, and other conditions such as the comparison with the remaining battery level and the remaining time of the electronic device 200a may also be used. Note that when there are three or more power modes, the switching determination unit 24 can determine that the switching conditions are satisfied for the switching from the normal mode to the first power saving mode or the second power saving mode and the switching from the first power saving mode to the second power saving mode.

[0109] According to Embodiment 3, the electronic device 200a can prevent immediate shutdown due to insufficient power supply of the battery that may occur with the switching of the power mode.

[0110] <Embodiment 4> At least one of the various functions, processes, and methods described in the above embodiments can also be realized by a personal computer, a microcomputer, a CPU, or a microprocessor executing a program. Hereinafter, in Embodiment 4, a personal computer, a microcomputer, a CPU, or a microprocessor is referred to as "computer X". In Embodiment 4, a program for controlling computer X and realizing at least one of the various functions, processes, and methods described in the above embodiments is referred to as "program Y".

[0111] At least one of the various functions, processes, and methods described in the above embodiments is realized by computer X executing program Y. In this case, program Y is supplied to computer X via a computer-readable storage medium. The computer-readable storage medium in Embodiment 4 includes at least one of a hard disk device, a magnetic storage device, an optical storage device, a magneto-optical storage device, a memory card, a volatile memory, a non-volatile memory, and the like. The computer-readable storage medium in Embodiment 4 is a non-transitory storage medium.

Explanation of Reference Numerals

[0112] 11: Display unit 21: Remaining time acquisition unit 26: CPU 100: Battery 200: Electronic device

Claims

1. An electronic device, an acquisition means for acquiring the remaining time which is the remaining available time of the electronic device; a control means for performing control to switch to any one of a plurality of power modes including a first power mode and a second power mode in which power consumption of the electronic device is lower than that in the first power mode; when the current power mode of the electronic device is the first power mode, the remaining time acquired by the acquisition means is less than a threshold value, and a switching condition for switching from the first power mode to the second power mode is satisfied, the control means performs control to issue a notification for prompting the switching from the first power mode to the second power mode An electronic device characterized by the above.

2. The control means in response to receiving an operation for switching to the second power mode by a user, stops the notification and switches the power mode of the electronic device from the first power mode to the second power mode, when the operation for switching to the second power mode by the user is not received, sets the power mode of the electronic device as the first power mode and stops the notification The electronic device according to claim 1, characterized by the above.

3. The switching condition includes that at least one function that is available in the first power mode and not available in the second power mode among the functions of the electronic device is in a stopped state, when the remaining time in the first power mode is less than the threshold value and the at least one function is stopped, the control means issues the notification, and when the remaining time in the first power mode is less than the threshold value but the at least one function is not stopped, the control means does not issue the notification The electronic device according to claim 1, characterized by the above.

4. The notification includes information on the remaining time in the first power mode and information on the remaining time after switching to the second power mode The electronic device according to any one of claims 1 to 3, characterized in that...

5. When the current power mode of the electronic device is the second power mode, the control means controls so as not to give the notification even if the remaining time becomes less than the threshold value. The electronic device according to any one of claims 1 to 4, characterized in that...

6. Even when the current power mode of the electronic device is the first power mode, if the switching condition is not satisfied, the control means controls so as not to give the notification even if the remaining time becomes less than the threshold value. The electronic device according to any one of claims 1 to 5, characterized in that...

7. The electronic device operates on power from a battery, and the acquisition means acquires the remaining time based on the remaining amount of the battery. The electronic device according to any one of claims 1 to 6, characterized in that...

8. An imaging means, and a recording means for recording image data captured by the imaging means, The electronic device according to any one of claims 1 to 7, further comprising...

9. A control method for an electronic device, an acquisition step of acquiring a remaining time which is the remaining usable time of the electronic device, and a control step of performing control for switching to any one of a plurality of power modes including a first power mode and a second power mode in which power consumption of the electronic device is lower than that in the first power mode, In the control step, when the current power mode of the electronic device is the first power mode, the remaining time acquired in the acquisition step is less than a threshold value, and a switching condition for switching from the first power mode to the second power mode is satisfied, control is performed to give a notification for prompting the switching from the first power mode to the second power mode. A control method characterized by the above. A program for causing a computer of an electronic device to execute, an acquisition step of acquiring a remaining time which is a remaining available time of the electronic device, and a control step of performing control for switching to any one of a plurality of power modes including a first power mode and a second power mode in which power consumption of the electronic device is lower than that in the first power mode, wherein in the control step, when the current power mode of the electronic device is the first power mode, the remaining time acquired in the acquisition step is less than a threshold value, and a switching condition for switching from the first power mode to the second power mode is satisfied, control is performed to give a notification prompting the switching from the first power mode to the second power mode A program characterized by the above.

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