JP2015186359A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus that eliminates the need for a pseudo load circuit such as a constant current load circuit and that makes it possible to estimate an operation at the time of start, in a configuration in which it is estimated whether the electronic apparatus can be operated.SOLUTION: An electronic apparatus comprises: a first battery that can be inserted into/removed from an electronic apparatus and that supplies power to an electronic apparatus; a second battery that supplies power to part of the apparatus even when the first battery has been removed; a power converting section that converts to voltage required for the apparatus from the first battery; a battery voltage detecting part that detects the voltage of the first battery and operates with the first or second battery; a power source operating section that operates ON/OFF of the power source of the electronic apparatus; and a power source control section that ON/OFF controls the power converting section in response to a signal from a power source operating section and operates with the first or second battery. The internal resistance value of the first battery is calculated from the first battery voltage when the power converting section is OFF and the first battery voltage when the power converting section is ON. Then, it is determined whether the apparatus can be operated.

Description

  The present invention relates to an electronic device for calculating an internal resistance of a battery and determining whether operation is possible based on the result.

  Electronic devices such as digital cameras can accommodate a battery that supplies power for operating the device. When an operation with large power consumption is performed, the digital camera starts an operation after estimating whether the operation can be performed with the current remaining battery capacity (see Patent Document 1). As a battery remaining amount estimation circuit configuration, a block diagram shown in FIG. 7 can be cited.

  The configuration of the remaining battery level estimation circuit will be described below with reference to FIG. The battery 701 is connected to a battery voltage detection unit 706 in which voltage-dividing resistors R1 and R2 connected in series are connected in parallel, and a constant current load unit 705 capable of flowing a constant current. The constant current load unit 705 is configured to be capable of ON / OFF control. A power supply unit 702 that supplies power to the digital camera system 703 converts a plurality of constant voltages required by the digital camera system 703 from the voltage of the battery 701 to supply power. The control unit 704 controls the entire digital camera system. FIG. 7 shows only blocks related to the battery remaining amount estimation circuit.

  The power supply control unit 710 controls the power supply unit 702 to turn on the voltage supplied from the power supply unit 702 required by the operation of the digital camera and to turn off the unnecessary voltage. The operation switch 708 is a switch for instructing an operation such as a release switch or a mode switch for selecting an operation mode. The switch state detection unit 709 is connected to the operation switch 708 and monitors the state of the operation switch 708.

  The constant current load control unit 711 controls ON / OFF of the constant current load unit 705 based on the switch state information detected by the switch state detection unit 709. The battery voltage detection signal divided by the battery voltage detection unit 706 is connected to the A / D conversion unit 712, and the battery voltage information is converted into a digital value by the A / D conversion unit 712. The remaining amount calculation unit 714 performs battery remaining amount estimation using the battery voltage information sent from the A / D conversion unit 712 and the coefficient provided for each operation state recorded in the coefficient recording unit 713. The remaining amount display unit 707 displays the battery remaining amount estimation result calculated by the remaining amount calculation unit 714.

Next, the operation will be described with reference to FIG. Operation digital camera system 703 and the camera operation instruction is input (S801) by the switch 708 via a battery voltage detection unit 706 acquires the current battery voltage information _{V 0} which has been digitally converted by the A / D converter 712 (S802). After obtaining the battery voltage information _{V 0,} the constant current load control unit 711 is turned ON the constant current load unit 705, supplies a constant load current _{I L} which is determined in advance from the battery 701 (S803). It acquires battery voltage information _{V 1} obtained by digital conversion of the battery voltage at that time by the A / D converter 712 (S804). After obtaining the battery voltage information _{V 1,} the constant current load control unit 711 is OFF constant current load unit 705 (S805), performs arithmetic processing and the following comparison with the remaining amount calculating unit 714 (S806).

Vth <V ₀ −K × ΔV
ΔV = V ₀ −V ₁
Vth is a predetermined lower limit value for camera operation, and K is a coefficient for each predetermined operation mode corresponding to the camera operation input from the operation switch 708, and is stored in the coefficient recording unit 713. . As a result of the calculation process and comparison (S806) performed by the remaining amount calculation unit 714, if the calculation process result is greater than Vth, the operation input in S801 is enabled, the operation is started (S807), and the operation is ended. The operation is completed (S808). If the result of the arithmetic processing and comparison (S806) is smaller than Vth as a result of the arithmetic processing and comparison (S806), it is determined that the operation input in S801 is impossible and a battery replacement mark is displayed on the remaining amount display unit 707 (S809). . Then, the power supply control unit 710 turns off the power supply unit 702 (S810).

  Further, with the configuration as shown in FIG. 9, the voltage value and the current value when the circuit 1, the circuit 2, and the circuit 3 are operating without the constant current load (pseudo load) are detected, and the respective current values and A method for calculating the internal resistance of a battery from a voltage value is disclosed (see Patent Document 2).

JP 2004-150951 A JP 2010-198899 A

  However, in the prior art disclosed in the above-mentioned patent document, a constant current load circuit is required to operate a constant current load to perform prediction, and it is necessary to pass a wasteful current to the constant current load. . Further, when a current is passed through the constant current load circuit, a voltage drop occurs and the system may become inoperable.

  Even in a circuit configuration without a constant current load circuit, a current detection circuit is required, and the current detection circuit calculates a voltage by detecting a voltage by connecting a low resistance in series with the power supply line, so the power consumed by the low resistance is wasted. Met. In this configuration, since it is necessary to operate a plurality of circuits, it is impossible to predict at the time of startup.

  Accordingly, the present invention is to provide an electronic device that does not require a pseudo load such as a constant current load circuit, and that enables operation prediction even at startup.

  To achieve the above object, the present invention provides a first battery that can be inserted and removed to supply power to an electronic device, and a second device that supplies power to a part of the electronic device even when the first battery is removed. A battery, a power converter that converts the voltage from the first battery to a voltage required for the electronic device, a battery voltage detector that operates on the first battery or the second battery that detects the voltage of the first battery, A power operation unit for operating the power ON / OFF of the electronic device, and a power control unit that operates on the first battery or the second battery that controls ON / OFF of the power conversion unit with a signal from the power operation unit, The internal resistance value of the first battery is calculated from the first battery voltage when the power control unit turns off the power conversion unit and the first battery voltage when the power conversion unit is turned on. Calculated internal resistance Electronic device from which is characterized in that to determine whether it is operational.

  According to the present invention, it is possible to provide an electronic device that does not require a pseudo load such as a constant current load circuit and that can predict an operation even at the time of startup.

1 is a block diagram for explaining Example 1. FIG. 1 is a configuration of a digital camera for explaining a first embodiment. 3 is a flowchart of basic operations for explaining the first embodiment. 3 is a flowchart for explaining Example 1; FIG. 6 is a block diagram for explaining a second embodiment. 6 is a flowchart for explaining a second embodiment; It is a figure for demonstrating a prior art example. It is a flowchart for demonstrating a prior art example. It is a figure for demonstrating a prior art example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a digital camera according to an embodiment of the present invention.

  An embodiment of the present invention will be described below with reference to FIGS. The configuration of the digital camera in the present embodiment is shown in FIG. A lens 201 forms an optical image of a subject on the solid-state image sensor 203. Reference numeral 202 denotes an aperture / shutter having a shutter function and also serving as an aperture for controlling the amount of light passing through the lens 1. Reference numeral 203 denotes a solid-state imaging device for taking in subject light imaged by the lens 201 as an electric signal.

  Reference numeral 204 denotes a CDS unit that performs correlated double sampling for removing a clock of an electric signal output from the solid-state image sensor 203 and reducing noise. A clamp circuit unit 205 clamps the output signal of the CDS unit 204 to a predetermined reference voltage at the timing of a clamp pulse supplied from a timing generation unit 208 described later. Reference numeral 206 denotes an A / D converter that converts a clamp output signal from an analog signal to a digital signal. A signal processing unit 207 performs various signal processing and conversion so that a desired format is obtained for display and recording.

  A timing pulse generation unit 208 generates necessary pulses to the solid-state imaging device 203, the CDS unit 204, the clamp circuit unit 205, and the A / D conversion unit 206. An optical system driving unit 209 drives the lens 201 and the aperture / shutter 202. A system control unit 210 controls the entire imaging apparatus and performs various calculations. A display unit 211 receives a signal from the signal processing unit 207 and displays it on an LCD or the like. Reference numeral 212 denotes a recording medium such as a semiconductor memory for recording or reading image data. A power supply unit 213 supplies power to all blocks of the digital camera. Reference numeral 214 denotes a main switch (operation unit) that performs an operation for turning on / off the power of the digital camera.

  Next, the basic operation of the digital camera of the present invention will be briefly described with reference to the flowchart of FIG. When the main switch 214 is turned on (S301), the power supply unit 213 starts the operation, and supplies the main power and the control system power. It is determined whether the mode is shooting or playback (S302). If it is a shooting mode, the shooting sequence is entered. If it is in the reproduction mode, the reproduction sequence is performed, data is once taken from the recording medium 212 into the signal processing unit 207 (S319), signal processing for display is performed, and an image is displayed on the LCD or the like (S320). Thereafter, an image is displayed until the main switch 214 is turned off. When the main switch 214 is turned off (S321), the image display is stopped and the power is turned off.

  If the shooting sequence is entered in the determination of S302, the lens position of the AF lens is driven to the reset position, and the power of the imaging system circuits such as the solid-state imaging device 203 and the timing pulse generator 207 is turned on. Under the control of the system control unit 210, the aperture / shutter 202 is first opened by a signal from the optical system driving unit 209 (S304), and the photometry sequence is started. The signal passing through the solid-state image sensor 203 is correlated double sampling by the CDS unit 204, the OB unit is clamped by the clamp circuit unit 205, and A / D conversion is performed by the A / D conversion unit 206. The converted image data is processed by the signal processing unit 207, and further input to the system control 210, where an exposure control value is calculated from the photometric value (S305). In accordance with the calculation result, the system control 210 determines and controls the aperture and shutter speed according to the program diagram (S306). The display mode is confirmed (S307). If the display is in the display ON mode, the LCD or the like is displayed (S308). If not, the process waits until the first switch of the release switch is turned on.

  When the first switch is turned on (S309), the photometry sequence is entered again, and photometry and calculation are performed (S310). In accordance with the result, the system control 210 again determines the aperture and shutter speed according to the program diagram and controls again. (S311). Next, a high-frequency component is extracted from a signal that has passed through the solid-state imaging device 203, the CDS unit 204, the clamp unit 205, and the A / D conversion unit 206, and the distance to the subject is calculated by the system control 210 (S312). ). Thereafter, the lens is driven to determine whether or not it is in focus (S313). When it is determined that the lens is not in focus, the lens is driven again to perform distance measurement. After focusing, the system waits until the second switch of the release switch is turned on. When the second switch is turned on (S314), exposure of a still image is performed (S315).

  When the exposure is completed, the image data that has passed through the solid-state imaging device 203, the CDS unit 204, the clamp unit 205, and the A / D conversion unit 206 is subjected to desired signal processing by the signal processing unit 207, and the semiconductor memory is controlled by the system control 210. Or the like is recorded on the recording medium 212. At this time, if the second switch is kept pressed (S316), an image is displayed on the LCD or the like (S317), and the display is continued until the second switch is turned off. Exit. If the second switch has been turned off from the beginning in S318, the shooting is terminated without displaying. If the main switch is not turned off (S318), the sequence until the first switch of the release switch is pressed is performed again, and the process waits until the first switch of the release switch is turned on. When the main switch 214 is turned off, each mechanism of the optical block returns to a predetermined position and turns off the main power.

  Hereinafter, the detailed configuration of the system control unit 210, the power source 213, and the switch unit 214 of FIG. 2 will be described with reference to FIG.

  A main battery 101 supplies power for the entire camera system. A power supply unit 102 includes a DC / DC converter that generates and supplies a voltage necessary for the camera system from the main battery. Reference numeral 103 denotes a battery voltage detector that divides the voltage of the main battery by resistors R1 and R2. Reference numeral 104 denotes a power supply SW for instructing activation or shutdown of the camera system. Reference numeral 105 denotes a backup battery for supplying power to a circuit that continues to operate even when the camera system is in a shutdown state. Reference numeral 106 denotes a battery internal resistance calculation unit for calculating the internal resistance of the main battery. The battery internal resistance calculation unit 106 operates with power supplied from the main battery 101 or the backup battery 105.

  Below, the detailed structure of a battery internal resistance calculation part is demonstrated. Reference numeral 107 denotes an AD conversion unit configured by an A / D converter for a battery detection signal obtained by dividing the main battery by the battery detection unit 103. Reference numeral 108 denotes an SW detection unit that detects a signal from the power supply SW 104. A control unit 109 controls the power supply unit 102 and the AD conversion unit 107 according to the state of the power supply SW detected by the SW detection unit 108 and a command from the main CPU.

  Reference numeral 110 denotes a coefficient storage unit that stores coefficients necessary for calculating the internal resistance of the battery. The coefficient storage unit 110 stores a current value consumed by the digital camera after the initialization operation with respect to the voltage value of the main battery 101. Reference numeral 111 denotes a calculation unit that calculates a battery internal resistance value using the result of the AD conversion unit 107 and the coefficient stored in the coefficient storage unit 110. Reference numeral 112 denotes an I / F unit for the main CPU to communicate with the battery internal resistance calculation unit 106.

Next, the operation flow of the present invention will be described with reference to FIG. The SW detection unit 108 monitors whether the power SW 104 is pressed to turn on the power when the digital camera according to the present invention is in a shutdown state (S401). In S401, when it is detected that the power SW104 is pressed, the control unit 109 obtains a voltage value _{V 0} which _is the main battery 101 from a signal from the battery detection unit 103 by operating the AD conversion unit 107 (S402). It is determined whether the voltage value V ₀ acquired in S402 is higher than a predetermined voltage at which the digital camera can be activated (S403).

In S403, the voltage value V ₀ digital camera is lower than the predetermined voltage is bootable maintains the shutdown state without starting the digital camera (S404).
In S403, if the voltage value V ₀ is higher than the predetermined voltage digital cameras can be started, the control unit 109 performs an instruction to supply power to the camera system to the power supply unit 102, a camera system The power is supplied to (S405).

In step S405, the power is supplied to the camera system, the main CPU initializes, and the control unit 109 monitors the normal startup response through the I / F unit 112 (S406).
In S406, the control unit 109 after confirming the response from the main CPU operates the AD conversion unit 107 acquires the voltage value _{V 1} of the main battery 101 from a signal from the battery detection unit 103 (S407).

The calculation unit 111 calculates the internal resistance value r of the main battery 101 using the voltage values V ₀ and V ₁ acquired in S 402 and S 407 and the coefficient stored in the coefficient storage unit 110. The current value in a state in which the camera system is performing a predetermined operation at the voltage value V ₁ is known, and is stored in the coefficient storage unit 110 with the known current value as I. A predetermined current value I is called from the coefficient storage unit 110, and the internal resistance r is calculated from the following equation (S408).

r = (V ₁ −V ₀ ) / I (I)
The main CPU determines whether the activation mode of the digital camera is the shooting mode or the playback mode (S409).

If the camera activation mode is the shooting mode in S409, the main CPU reads the internal resistance value r calculated in S408 via the I / F unit 112. Further, the main CPU uses the internal resistance value r and the current value I _REC that flows when the imaging mode is known in advance to infer whether the imaging mode can be activated (S410).

The following formula is used as the formula estimated in S410.
The main battery voltage at which the digital camera can operate is assumed to be V _LB.

V ₁ −r × I _REC > V _LB (II)
In S410, if the expression (II) is satisfied, the shooting mode can be started, so the shooting mode is started (S411). In S410, if the formula (II) is not satisfied, it is impossible to start the shooting mode. Therefore, the main CPU performs a shutdown process and does not start the shooting mode (S412).

If the camera start mode is the playback mode in S409, the main CPU reads the internal resistance value r calculated in S408 via the I / F unit 112. Further, the main CPU uses the internal resistance value r and the current value I _PLAY flowing in the reproduction mode that is known in advance to infer whether the reproduction mode can be activated (S413).
The following formula is used as the formula estimated in S413.
The main battery voltage at which the digital camera can operate is assumed to be V _LB.

V ₁ −r × I _PLAY > V _LB (III)
If the expression (III) is satisfied in S413, the reproduction mode can be activated, so the imaging mode is activated (S414). If the formula (III) is not satisfied in S413, it is impossible to start the playback mode, so the main CPU shuts down by performing a shutdown process without starting the playback mode (S412).

  By adopting such a configuration, it is possible to predict whether it can be activated or not without using a dummy load circuit outside.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  The configuration of the second embodiment of the present invention is the same as the basic configuration of the first embodiment, but the operation flow is different from the configuration of a part of the battery internal resistance calculation unit. The different points will be described.

  The configuration of the battery internal resistance calculation unit according to the second embodiment will be described with reference to FIG. Reference numeral 506 denotes a battery internal resistance calculation unit for calculating the internal resistance of the main battery. The battery internal resistance calculation unit 506 operates with power supplied from the main battery 101 or the backup battery 105. Reference numeral 507 denotes an AD conversion unit configured by an A / D converter for a battery detection signal obtained by dividing the main battery by the battery detection unit 103. Reference numeral 508 denotes an SW detection unit that detects a signal from the power supply SW 104.

  A control unit 509 controls the power supply unit 102 and the AD conversion unit 507 in accordance with the state of the power supply SW detected by the SW detection unit 508 and a command from the main CPU. Reference numeral 510 denotes a coefficient storage unit that stores coefficients necessary for calculating the internal resistance of the battery. The coefficient storage unit 510 stores the current value consumed by the digital camera after the initialization operation with respect to the voltage value of the main battery 101. Reference numeral 511 denotes a calculation unit that calculates the battery internal resistance value using the result of the AD conversion unit 507 and the coefficient stored in the coefficient storage unit 510. Reference numeral 512 denotes an I / F unit for the main CPU to communicate with the battery internal resistance calculation unit 506. Reference numeral 513 denotes a storage unit that stores internal resistance and voltage values.

Next, the operation flow of the present invention will be described with reference to FIG. In a state where the digital camera according to the present invention is operating, the SW detection unit 508 monitors whether the power SW 104 is pressed to shut down (S601). If it is detected in step S601 that the power SW 104 has been pressed, the main CPU performs a shutdown process for making the camera ready for shutdown (S602). The voltage values V ₀ and V ₁ and the internal resistance value r acquired at the time of startup in FIG. 3 are stored in the storage unit 513 (S603).

The control unit 509 sends a signal to turn off the power to the power supply unit 102 in order to turn off the entire power supply of the digital camera (S604). The control unit 509 periodically operates the AD conversion unit 507 to monitor whether the main battery 101 is removed (S605). In S605, when it is detected that the main battery 101 is removed, the voltage values V ₀ and V ₁ and the internal resistance value r stored in the storage unit 513 are reset, and monitoring of the main battery 101 is stopped (S606). .

  In step S605, if the battery is not removed, the SW monitoring unit 508 monitors whether or not there is a start instruction to turn on the digital camera by pressing the power SW 104 (S607). If it is not detected in step S607 that the SW 104 has been pressed, the process returns to step S605.

If it is detected in step S607 that the SW 104 has been pressed, the control unit 509 operates the AD conversion unit 507 to acquire the voltage value V ₀ ′ of the main battery 101 from the signal from the battery detection unit 103 (S608). . It is determined whether the voltage value V ₀ ′ of the main battery 101 acquired in S608 is higher than a predetermined voltage that can be activated (S609).

If the voltage value V ₀ ′ is lower than the predetermined voltage that can be activated in S609, the digital camera is not activated and the shutdown state is maintained (S610). In step S609, when the voltage value V ₀ ′ is higher than a predetermined voltage that can be activated, the control unit 509 instructs the power supply unit 102 to supply power to the camera system, and supplies power to the camera system. Is supplied (S611).

In step S611, power is supplied to the camera system, the main CPU initializes, and the voltage value V ₁ ′ of the main battery 101 in a state where the main CPU 101 has normally started up is acquired from the AD converter 507 (S612). Comparison between the voltage value V ₀ stored in the storage unit 513 and the voltage value V ₀ ′ acquired in S608 is the same value, and the voltage value V ₁ stored in the storage unit 513 and acquired in S612 It is compared whether the voltage values V ₁ ′ are the same (S613).

In S613, if both have the same voltage, the internal resistance r stored in the storage unit 513 as the internal resistance of the main battery is adopted as the resistance value for the activation confirmation (S614). In S613, to calculate the internal resistance r of the main battery with a long one is a different voltage, the voltage value _{V 0} 'and the voltage value _{V 1'} (S615).

  With such a configuration, when the voltage value of the main battery is the same as the voltage value at the time of previous activation, there is an effect that it is not necessary to perform the process of calculating the internal resistance value.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  In the first and second embodiments, the digital camera has been described as an example. However, the processing and control described in the first and second embodiments may be performed in an electronic device other than the digital camera.

101: Main battery 102: Power supply unit 103: Battery detection unit 104: Power supply SW
105: backup battery 106: battery internal resistance detection unit 107: AD conversion unit 108: SW detection unit 109: control unit 110: coefficient recording unit 111: calculation unit 112: I / F unit

Claims (3)

A first battery capable of supplying power to the electronic device;
A second battery for supplying power to a part of the electronic device even when the first battery is removed;
A power supply unit for converting the first battery into a voltage required for the electronic device;
A battery voltage detector that operates on the first battery or the second battery that detects the voltage of the first battery; and
An operation unit for operating whether to turn on or off the power of the electronic device;
A control unit that operates on a first battery or a second battery that controls the power supply unit with a signal from the operation unit;
In an electronic apparatus comprising a calculation unit that calculates the internal resistance of the first battery from the voltage value detected by the battery voltage detection unit,
The calculation unit uses the first battery voltage when the control unit is turning off the power supply unit and the first battery voltage when the power supply unit is on, An electronic device characterized by calculating an internal resistance value of a battery and determining whether the electronic device is operable from the calculated internal resistance value. When turning OFF from the state where the electronic device is ON,
The first battery voltage when the power supply unit is turned off, which is obtained when calculating the internal resistance of the first battery, and the first battery voltage when the power supply unit is turned on. The electronic apparatus according to claim 1, further comprising a storage unit that stores the calculated internal resistance value. The first battery voltage when the control unit turns off the power supply unit, and the first battery voltage when the power supply unit is turned on are voltage values stored in the storage unit And determining whether the electronic device is operable using the internal resistance value of the first battery stored in the storage unit. The electronic device as described in.