JPH1068978A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain electric power saving by suppressing unnecessary current consumption in a left state and to prevent the overdischarge of an improved battery at a camera using the improved battery capable of being repeatedly discharged and charged. SOLUTION: Power is supplied from a main battery 34 to a camera circuit 90, and the main battery 34 is charged by a charging circuit by having an auxiliary battery 40 such as an AA type battery or the like as a charging power source at this camera. In this case, a current is not supplied from the main battery 34 to a CPU 90 controlling the camera circuit of a shutter and film-feeding or the like when a main switch is turned off, so that the leaked current of a circuit is suppressed. On the other hand, the CPU 92 controlling a boosting circuit 74 is always energized by using the CPU whose function is low and whose electric power is small as compared with the CPU 90. The residual amount of the main battery 34 is monitored by the CPU 92, and the main battery 34 is replenished with energy by operating the boosting circuit 74 as occasion demands when the residual amount reaches a specified level value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly, to a camera provided with a power supply capable of supplying a large capacity and a large current to a circuit such as a strobe or a film winding means using a rechargeable battery.

[0002]

2. Description of the Related Art A conventional camera uses a manganese or lithium primary battery as a power source and a secondary battery such as a NiCd battery as a power source. Also, a power supply device for charging a secondary battery built in a camera using a solar cell has been proposed (JP-A-63-91641). However, a manganese primary battery has a low voltage, and therefore requires a plurality of batteries to obtain a high voltage, and it is difficult to obtain a large capacity current. However, there is a problem that it is not suitable for a camera which consumes a large current in recent years. on the other hand,
Lithium-based primary batteries have the advantage of being able to obtain high voltage and large capacity current, but the batteries themselves are expensive and environmental problems at the time of disposal have been pointed out. Furthermore,
Lithium-based primary batteries are sometimes more difficult to obtain in travel destinations or overseas than manganese or alkaline primary batteries. In such cases, use the camera when the batteries are exhausted. There is a problem that it is necessary to give up or to carry a spare battery in advance in order to prevent such a situation, which is complicated.

[0003] Although charging of a primary battery is generally prohibited, as described in detail in JP-A-7-130400 and JP-A-8-84619, a lithium-based primary battery is described. Even under a certain condition, the battery can be charged safely. The lithium batteries (especially metal lithium batteries) described in these publications are charged at a time rate current of about 2 μC to 5 mC when the remaining amount is within the range of 5 to 95% of the capacity C. By doing so, without impairing the properties of the primary battery,
Charge and discharge can be repeated. In each of the above publications,
There is disclosed a method in which the lithium battery and the solar battery are combined and applied to a camera, and the lithium battery is charged by electric power generated by the solar battery.

[0004] In the present specification, a battery having both characteristics of a primary battery and characteristics of a secondary battery is referred to as an "improved battery".
I will call it.

[0005]

However, in a power supply device having a solar cell, the solar cell itself is expensive, and the temperature of the camera increases due to the need to expose the camera to high illuminance during charging. There was a risk of failure. Furthermore, when the secondary battery (improved battery) is rapidly consumed, the problem that the camera cannot be used has not been solved because the amount of power generated by the solar battery is small and it takes time to charge.

From this point of view, a power supply device for charging the improved battery with an auxiliary battery such as an AA battery has been proposed (see Japanese Patent Application No. 7-273050). Although the improved battery has little self-discharge, it consumes a small amount of current when connected to a circuit or the like. There is.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a camera capable of suppressing unnecessary current consumption and effectively utilizing the energy of a rechargeable battery (improved battery). Aim.

[0008]

According to the present invention, in order to achieve the above object, it is possible to repeatedly discharge and charge when the self-discharge rate of a primary battery is substantially equal to and the remaining amount is more than a predetermined capacity.
A main battery that supplies power to a power consuming unit that performs an operation necessary for photographing; an auxiliary battery that supplies charging energy to the main battery; and a booster that boosts an output voltage of the auxiliary battery. Charging means for supplying power to the main battery through the main battery and charging the main battery; main battery remaining amount detecting means for detecting the remaining amount of the main battery; and power from the main battery only when the power switch is on. And a first control circuit for controlling the operation of the power consuming means in accordance with the operation of the external operating member, and a constant supply of power from the main battery, and And a second control circuit that outputs a control signal for operating the booster when the remaining amount of the battery reaches a predetermined level value and controls charging of the main battery.

According to the present invention, the first control circuit for controlling the power consuming means for performing the photographing operation in response to the operation of the external operation member operates only when the power switch is ON and turns off the power switch. In this state, current is not supplied from the main battery, and leakage current of the circuit is eliminated. On the other hand, the second control circuit for controlling the boosting means is always operably connected irrespective of the state of the power switch. When the remaining amount of the main battery reaches a predetermined level value, the second control circuit operates the booster circuit as needed to connect the main battery to the main battery. Replenish energy. Thus, unnecessary current consumption while the power switch is turned off can be suppressed, and overdischarge of the main battery can be prevented.

When the camera is provided with a clock function (calendar function) which requires constant power supply, it is preferable that the camera is also provided with a second control circuit which is always supplied with power. Thus, the date and time can be maintained regardless of the state of the power switch. Further, a power save mode is provided in the first control circuit, and when the operation by the external operation member is not performed for a certain period of time while the power switch is ON, the operation of the control circuit is stopped, and thereafter, a signal for instructing a restart. By entering a power saving standby state in which the power consumption is suppressed until the power is input, unnecessary current consumption can be suppressed even when the power switch is turned on and left for a long time.

It is preferable to provide a display means for notifying the user of the remaining amount of the auxiliary battery, the remaining amount of the main battery, the date or time, and the like. It is good to display even when it is off. In addition, the present invention, in order to achieve the above object,
In a camera including the main battery, the auxiliary battery, and a charging unit, a main battery remaining amount detecting unit that detects a remaining amount of the main battery, and receives power supplied from the main battery and responds to an operation of an external operation member. First controlling the operation of the power consuming means by
And a control signal for receiving the power supply from the main battery and outputting a control signal for operating the booster when the remaining amount of the main battery reaches a predetermined level value by the main battery remaining amount detector. A second control circuit for controlling charging of the main battery, display means for receiving power supply from the main battery and displaying at least one of date and time, and the auxiliary battery being detachably mounted. An auxiliary battery chamber to be stored, presence / absence detection means for detecting whether or not the auxiliary battery is loaded in the auxiliary battery chamber, and when the unloading of the auxiliary battery is detected by the presence / absence detection means, Displaying at least one of the date and time on the display means for a certain period of time,
And a third control circuit for terminating the display on the display means after the elapse of the certain period when the presence or absence of the auxiliary battery is not detected by the presence / absence detection means during the period.

According to the present invention, the presence / absence detecting means for detecting the presence / absence of the auxiliary battery is provided, and the date and time are displayed for a certain period even after the auxiliary battery is removed.
This is convenient because it is not necessary to reset the date and time each time the auxiliary battery is replaced. By ending the display of the date and time after the fixed period has elapsed without the auxiliary battery being loaded, unnecessary current consumption can be suppressed, and power saving can be achieved.

Further, the present invention has been made in order to achieve the above-mentioned object.
In a camera including the main battery, the auxiliary battery, a charging unit, and a main battery remaining amount detecting unit, power is supplied from the main battery, and the remaining amount of the main battery is determined in advance by the main battery remaining amount detecting unit. A control circuit that outputs a control signal to operate the boosting means when the level reaches the level, controls charging of the main battery, and controls an operation of the power consuming means in accordance with an operation of an external operation member; An auxiliary switch that is provided in an electrical connection path between the main battery and the control circuit and that closes / opens the electrical connection path in conjunction with an on / off operation of a power switch operation member. And

According to the present invention, when the power switch is turned off, the auxiliary switch is turned off, and the conduction path connecting the main battery and the control circuit is cut off. Thus, when the camera is not used, the main battery is electrically isolated, the leakage current due to the control circuit or the like can be eliminated, and power saving can be achieved. In addition, a second auxiliary switch is provided in the connection path between the auxiliary battery and the booster circuit, the second auxiliary switch being interlocked with the power switch, and when the power switch is turned off, the second auxiliary switch is turned off, so that the camera is turned off. When not used, the auxiliary battery can be isolated, and unnecessary current consumption can be suppressed.

Further, when the presence / absence of the auxiliary battery is detected by the presence / absence detection means for detecting the presence / absence of the auxiliary battery, that is, when the main battery cannot be charged, the control from the main battery is performed. By cutting off the power supply to the circuit, overdischarge of the main battery can be prevented. When the control circuit is provided with a clock function, if the clock function is stopped every time the auxiliary battery is replaced, the user must set the date and time each time, and in view of the complexity, the GPS (Globl Positi
time setting means for receiving a radio wave from a satellite of an oning system or a standard radio wave transmitted from a standard frequency station and setting the time of the clock function of the control circuit based on the received radio wave. Thereby, the operation can be simplified and the convenience is improved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the camera according to the present invention will be described below in detail with reference to the accompanying drawings. FIG.
1 to 3 are internal perspective views of the camera according to the embodiment of the present invention. FIG. 1 is a front view, FIG. 2 is a top view, and FIG. 3 is a right side view. As shown in FIG. 1, a lens barrel 12 holding a photographing lens 11 is provided at the center of the camera 10, and a film cartridge (not shown in FIG. 1) is stored on the right side of the lens barrel 12. Cartridge chamber 14 is formed, and a spool chamber 16 is formed on the left side. A flash device 18 is provided in the upper part of the cartridge chamber 14, that is, in the upper right corner of the front of the camera, and an AF light emitting unit 20 and an AF light receiving unit 2 are sequentially provided on the left side of the flash device 18.
2, and a finder section 24 are provided.

The cartridge chamber 14 is provided with a spool drive shaft 26 which is engaged with a spool of a film cartridge loaded in the chamber. On the other hand, the spool chamber 16 is provided with a take-up spool 28 for taking up the film sent from the film cartridge. The take-up spool 28 is formed in a hollow cylindrical shape, and has a film transport motor 30 incorporated therein.
The rotational force of the film transport motor 30 is transmitted to the take-up spool 28 and transmitted to the spool drive shaft 26 via gear trains 32A, 32B,..., 32I, 32J shown in FIG. It has become so.

When the film transport motor 30 rotates forward, the film is fed out of the film cartridge loaded in the cartridge chamber 14 and taken up by the take-up spool 28. The film transport motor 30
Is reversed, the spool drive shaft 2 of the cartridge chamber 14
6 is reversed, and the film wound on the winding spool 28 is rewound into the film cartridge.

The rotation of the film transport motor 30 is controlled by a camera controller, and the film is automatically fed by one frame after filming (winding). When the photographing of all frames of the film is completed and the end of the film is detected, the film transport motor 30 is driven in reverse, and the film wound on the take-up spool 28 is automatically rewound into the film cartridge. It is configured as follows.

A film rewind lever (not shown) is provided on the back of the camera 10. By operating the film rewind lever, the film can be rewound to the film cartridge halfway before the completion of all frame shooting. Is available. In addition, a lens barrier open / close switch and a power switch (main switch) (not shown) are provided on the rear surface of the camera 10.

On the left side of the take-up spool 28, a main battery 34 for supplying electric power to various circuits in the camera and a main condenser 36 for a strobe are arranged vertically one above the other. Note that a partition plate 38 is provided between the main battery 34 and the main capacitor 36. Main battery 34
Is a rechargeable battery dedicated to a camera with low self-discharge, and an improved battery having both characteristics of a primary battery and a secondary battery is used. Although the configuration of the main battery 34 will be described in detail later, for example, a battery having a self-discharge rate of 5% / year or less is used.
V. The shape of the main battery 34 is not particularly limited, but is formed, for example, in the same shape as a current CR2-type battery.

An auxiliary battery 40 for supplying charging energy to the main battery 34 is arranged behind the main battery 34 and the main capacitor 36 (see FIG. 3). Auxiliary battery 40
Are arranged vertically in parallel with the arrangement direction of the main battery 34 and the main capacitor 36. In addition, a battery cover 42 is provided at the rear corner of the camera 10 so as to be openable and closable on a shaft 42A, and an auxiliary battery 40 is stored in an auxiliary battery storage chamber formed inside the battery cover 42. .

An auxiliary battery presence / absence detection switch for detecting the presence or absence of the auxiliary battery 40 is provided on the contact member 47 with which the positive electrode of the auxiliary battery 40 contacts. The configuration of the auxiliary battery presence / absence detection switch will be described later (see FIG. 4). The auxiliary battery storage chamber is formed so as to store, for example, one AA battery, and a manganese AA battery is stored as the auxiliary battery 40. The auxiliary battery 40 is not limited to an AA battery, but may be a primary battery of another form. However, manganese-based AA batteries are widely used and can be easily obtained at low cost anywhere in the world. There are advantages.

A main battery storage chamber for storing the main battery 34 is provided at the back of the auxiliary battery storage chamber. The auxiliary battery 40 stored in the auxiliary battery storage chamber by opening the battery lid 42 is provided. Can be taken out and replaced, and the main battery 34 disposed at the back can be taken out with the auxiliary battery 40 taken out.

In FIG. 1, reference numeral 43 denotes a camera control circuit, reference numeral 44 denotes a booster circuit for charging, and reference numeral 4 denotes a two-dot chain line.
Reference numeral 6 denotes each mounting space of the charging circuit of the main capacitor 36. The power supply of the camera 10 includes the main battery 34, the auxiliary battery 40, the booster circuit 44, and the like.
Is electrically connected to a booster circuit, a control circuit, and the like via contact pieces 47, 48 and the like. Then, power is supplied from the main battery 34 to the strobe device 18, the film transport motor 30, the zoom motor 49, the control circuit, and the like.

FIG. 4 shows a configuration example of the auxiliary battery presence / absence detection switch. As shown in FIG.
The contact piece member 47 provided on the positive electrode side has a substantially V-shaped bent portion, and one end thereof is fixed to a wall member 52 defining an auxiliary battery storage chamber with screws 54. The auxiliary battery 4
The right end of the contact piece 47A that contacts the zero positive electrode is bent upward by approximately 90 degrees to form a lever portion 47B, and an insulating member 56 is fixed to the tip of the lever portion 47B. A switch 60 including a pair of upper and lower detecting contact pieces 58 and 59 is provided above the lever portion 47B.

According to the auxiliary battery presence / absence detection switch having the above configuration, the contact piece member 47 on the positive electrode side of the auxiliary battery 40 allows the contact piece 47A to swing up and down in FIG. When the auxiliary battery 40 is loaded, the contact piece 47A is pushed up, and the lever portion 47 is raised.
When the lever 47B rises, the detecting contact piece 58 is pushed up via the insulating member 56, the detecting contact pieces 58 and 59 come into contact with each other, and the switch 60 is turned on.
On the other hand, when the auxiliary battery 40 is removed,
7, the contact piece 47A is lowered to the lower side in the figure by the elastic force,
With this movement, the lever portion 47B descends, and the detection contact 5
8,59 contacts separate. That is, the switch 60 is turned off.
Is done. Therefore, whether or not the auxiliary battery 40 is loaded can be detected based on the ON / OFF state of the switch 60.

Next, the main battery will be described. Main battery 3
4, the improved battery is used as described above. As the positive electrode active material of the improved battery, manganese dioxide is preferable, and particularly, manganese dioxide synthesized by electrolysis and manganese dioxide chemically synthesized are preferable. As a material that can be used as the negative electrode active material, lithium metal and lithium alloy (any metal that forms an alloy with lithium may be used, but Al, Mn, Sn, Mg, Cd, and In are particularly preferable, and an alloy containing Al is particularly preferable). Preferably, it is used.

A conductive agent, a binder, a filler, and the like can be added to the electrode mixture. The conductive agent may be any electronic conductive material that does not cause a chemical change in the configured battery. The addition amount is not particularly limited,
It is preferably from 1 to 50% by weight, particularly preferably from 2 to 30% by weight. As the binder, a polysaccharide, a thermoplastic resin, a polymer having rubber elasticity, or a mixture thereof can be used. The amount of the binder added is not particularly limited, but is preferably 1 to 50% by weight, and particularly preferably 2 to 30% by weight.

As the filler, any fibrous material that does not cause a chemical change in the constructed battery can be used. Usually, fibers such as olefin-based polymers such as polypropylene and polyethylene, glass, and carbon are used. Although the amount of the filler is not particularly limited,
~ 30% by weight is preferred. The non-aqueous electrolyte is generally composed of a solvent and a lithium salt (anion and lithium cation) dissolved in the solvent, and comprises propylene carbonate and / or butylene carbonate and 1,2-dimethoxyethane and / or diethyl carbonate. An electrolyte containing LiCF ₃ SO ₃ , LiClO ₄ , LiBF ₄ and / or LiPF ₆ in the mixed solution of the carbonate is preferable. The amount of these electrolytes to be added to the battery is not particularly limited, but may be used in a required amount depending on the amounts of the positive electrode active material and the negative electrode active material and the size of the battery.

The volume ratio of the solvent is not particularly limited,
In the case of a mixture of propylene carbonate and / or butylene carbonate to 1,2-dimethoxyethane,
0.4 / 0.6 to 0.6 / 0.4 is preferred. The concentration of the supporting electrolyte is not particularly limited, but may be 0.1 to 1 liter of the electrolytic solution.
2-3 moles are preferred. The metal lithium-based battery having such a configuration has a self-discharge rate as small as that of a primary battery, and when discharged from a fully charged state to below a specified energy value, the function as a storage battery thereafter rapidly increases. It has the property of decreasing to With the capacity in a fully charged state as 100 as a reference, the amount of discharged energy is represented by the usage rate with respect to the total energy,
I will call it.

According to the experiment, when the discharge and the charge are repeated within the range where the depth of discharge does not exceed 5%, the deterioration of the main battery is small, the cycle life is large, and photographing of 3000 shots or more is sufficiently possible. . On the other hand, when used at a depth of discharge of 30%, the performance of the main battery as a storage battery is reduced, and the cycle life is shortened. In this case, only about 1000 shots can be repeatedly shot. The deeper the depth of discharge, the shorter the cycle life becomes.The deeper the depth of discharge, the lower the performance as a storage battery, and the smaller the electrical capacity that can be stored in the main battery by recharging. Cycle life is also reduced.

That is, the main battery is discharged in a range of a shallow depth of discharge.
It is desirable to use it so that charging is repeated. But
Therefore, when actually using this improved battery,
The appropriate depth of discharge in accordance with the usage limit setting as
And charge and discharge so as not to exceed the range of the depth of discharge.
It needs to be managed to repeat. Figure 5 shows the main battery
34 is charged by the auxiliary battery 40.
An example of the configuration of a camera including the camera is shown. Charging circuit 70
Are a charge control circuit 72 and a booster circuit 74 as shown in FIG.
Consisting of The charge control circuit 72 controls the main battery 34
Voltage V_CRAnd the voltage V of the auxiliary battery 40_EDetect and compare
If the voltage V of the main battery 34 _CRHas a fully charged voltage of 3.2
Smaller than V (V_CR<3.2V) and auxiliary battery 4
Voltage V of 0_EIs V_E≧ 0.9V (Power cut off of auxiliary battery 40
Pressure), the booster circuit 74 is operated to charge the main battery 34.
Make electricity work.

On the other hand, the charge control circuit 72 is mainly when the battery 34 is fully charged (when becomes a voltage V _CR = 3.25 V), or the voltage V _E of the auxiliary battery 40 is exhausted auxiliary battery 40 is V _{When E} <0.9V, the booster circuit 74 is stopped. Further, the charge control circuit 72 supplies a signal indicating the voltage of the auxiliary battery 40 to the display control circuit 82 in order to display the remaining amount of the auxiliary battery 40 on a liquid crystal panel (LCD) 80.
Output to The liquid crystal panel 80 is provided on the upper surface or the rear surface of the camera 10.

The display control circuit 82 receives the signal indicating the voltage of the auxiliary battery 40 from the charge control circuit 72 as described above, and outputs a signal from a film counter indicating the remaining amount of the film, a strobe switch, a shutter button, and a self-timer. The signal from the switch etc. is added,
The required display is performed on the liquid crystal panel 80 based on these input signals.

Next, the boosting circuit 74 will be described. FIG. 6 is a circuit diagram showing an example of the booster circuit. As shown in the figure, the booster circuit 74 is of a push-pull type, and the power supply of the auxiliary battery 40 is turned on by a transistor Q which is alternately turned on by a charge control circuit (IC) 72.
1. Convert to AC in Q2, boost through transformer T,
By rectifying by the rectifier circuit 75, the main battery 34
Is converted to a DC voltage required for charging.

Here _, assuming that the number of turns on the primary side and the secondary side of the transformer T is n _1, n ₂ , the voltage V on the primary side of the transformer T
₁ and the voltage V ₂ on the secondary side are expressed by the following equation (1):

[0038]

## EQU1 ## There is a relationship of V ₁ / V ₂ = n ₁ / n ₂ (1). On the other hand, the voltages V ₁ and V ₂ required on the primary side and the secondary side of the transformer T are:

[0039]

## EQU2 ## V ₁ = 0.9−V _DS = 0.7 [V] (Min) (2)

[0040]

V ₂ = 3.25 + 0.7 × 2 + 0.5 = 5.15 [V] (3) (provided that 0.9 is the final voltage of the auxiliary battery 40) V _{DS is} the saturation voltage between the drain and source of the transistors Q1 and Q2 3.25: The maximum voltage of the main battery 34 is 0.7 × 2: the voltage drop in the rectifier circuit 75). Therefore, the turns ratio n ₂ / n ₁ of the transformer T is

[0041]

## EQU4 ## n ₂ / n ₁ = V ₂ / V ₁と 7.3 (4) Thus, the charging circuit 70 shown in FIG. 5 transfers the charging energy of the auxiliary battery 40 to the main battery 34 every time the voltage V _CR of the main battery 34 becomes V _CR <3.25 V, and Charge. Then, when the main battery 34 is fully charged (when the voltage V _CR becomes 3.25 V), the charging operation is stopped.

After the main battery 34 is fully charged,
When the electric capacity of the main battery 34 decreases due to use of a camera or the like, charging energy is transferred from the auxiliary battery 40.
The electric capacity of the main battery 34 increases with the charging time, and the electric capacity of the auxiliary battery 40 decreases. Thus, the main battery 3
Since the energy of the auxiliary battery 40 is transferred to the main battery 34 in accordance with the energy consumption of No. 4, the main battery 34 is always kept close to full charge.

Thus, there is an advantage that the main battery 34 can be easily handled without fear of over-discharge deterioration. Further, since the main battery 34 is a lithium-based battery,
As compared with the auxiliary battery 40, a high voltage and a large current can be supplied to the camera, so that a camera requiring a large current can be supported, and the charging time of the strobe can be shortened.

When the charge energy of the auxiliary battery 40 is transferred to the main battery 34 and the capacity of the auxiliary battery 40 reaches almost 0 (when the voltage of the auxiliary battery 40 reaches its final voltage 0.9 V), thereafter, Unless you replace the auxiliary battery 40,
The charging energy is not supplied from the auxiliary battery 40 to the main battery 34. However, the main battery 34 has its voltage V
_{Since the CR} is maintained in a state of charge close to full charge, there is a certain amount of electricity that can be consumed (for example, an amount of electricity capable of taking 100 shots) until the voltage V _CR reaches a predetermined battery check level. doing. Therefore, the camera can be continuously used without immediately replacing the auxiliary battery 40 with a new one.

Also, when replacing the auxiliary battery 40, the auxiliary battery 40 may be an AA battery, and thus has the advantage that it can be easily obtained at low cost anywhere in the world.
Further, since the charging circuit 50 has the boosting circuit 54,
AA batteries that have been used in other devices can be used to some extent. In this embodiment, when the voltage V _CR of the main battery 34 falls below 3.25 V, the auxiliary battery 4
Although the zero charging energy is transferred to the main battery 34, the present invention is not limited to this, and charging may be started after the voltage of the main battery 34 reaches a predetermined voltage value (for example, 3.0 V). Alternatively, the number of shots after the state of full charge may be counted, and when the number of shots reaches a predetermined value (for example, 100 shots), the charging energy of the auxiliary battery 40 may be transferred to the main battery 34. However, in this case, the charge control circuit 72 needs to receive a signal indicating the number of shots from the camera side.

FIG. 7 shows an example of the connection relationship of the control circuit of the camera. As shown in the figure, the main battery 34 controls circuits (hereinafter, collectively referred to as "camera circuits") corresponding to various camera operations such as shutter driving, auto focus (AF), strobe, and film feeding. Processing unit (CPU) 90 for controlling the boosting circuit 74
PU92 is connected.

The CPU 90 is configured to operate by supplying current from the main battery 34 when the main switch is ON. This CPU suspends its operation when there is no input signal for a certain period of time, and enters a power saving standby state (power save mode). Thereafter, when a predetermined active signal is input, the apparatus returns from the power save mode and enters a normal operation state.

On the other hand, the CPU 92 is a low-power CPU having a lower function than the CPU 90, and is always connected to the main battery 34 and is in an energized state. The switching of the transistors Q1 and Q2 of the booster circuit 74 is controlled by the CPU 92 regardless of the state of the main switch. The CPU 92 has a clock function (calendar function), and constantly receives power from the main battery 34 to maintain a clock for the clock function.

Next, a method of managing the remaining amount of the main battery will be described. FIG. 8 is a block diagram showing a configuration of a management unit for managing the charge amount and the discharge amount of the main battery. The management means shown in the figure monitors the charging energy charged from the auxiliary battery 40 to the main battery 34, monitors the discharging energy discharged from the main battery 34, and based on a comparison between the two, the remaining power of the main battery 34 is monitored. It is to grasp the quantity.

The charging energy of the auxiliary battery 40 is transferred to the main battery 34 via the charging circuit 70, the resistor R1, and the constant voltage diode ZD. The voltage across the resistor R1 is applied to the differential amplifier 102, and the output of the differential amplifier 102 is A / A
It is guided to the CPU 92 via the D converter 103. The electric energy released from the main battery 34 is guided to the camera circuit 104 via the resistor R2, and is consumed in the camera circuit 104. The voltage across the resistor R2 is applied to a differential amplifier 106, and the output of the differential amplifier 106 is applied to a CPU 92 via an A / D converter 107.

With this configuration, when current is supplied from the auxiliary battery 40 to the main battery 34 via the charging circuit 70,
Since the charging current flows through the resistor R1, if the voltage across the resistor R1 is monitored by the differential amplifier 92, the charge amount of the main battery 34 can be obtained. That is, the voltage across the resistor R1 is set to VR1
Then, the charge amount QI charged in the main battery 34 is
The following equation (5)

[0052]

## EQU5 ## QI = ∫VR1 / R1 × Δt (5), and the charge amount QI can be obtained by performing an integral operation every time Δt during which the charging current flows. On the other hand, electric power for operating the camera circuit 104 is supplied from the main battery 34 through the resistor R2.
If the voltage across the resistor R2 is monitored by a differential amplifier, the amount of charge supplied from the main battery 34, that is, the amount of discharge (consumption) can be obtained in the same manner as described above.

That is, assuming that the voltage between both ends of the resistor R2 is VR2, the discharge charge amount QD discharged from the main battery 34 is expressed by the following equation (6).

[0054]

## EQU6 ## QD = ∫VR2 / R2 × Δt (6) The discharge charge amount QD can be obtained by performing an integral operation every time Δt during which the discharge current is flowing. The difference .DELTA.Q between the charge amount QI obtained by the equation (5) and the discharge amount QD obtained by the equation (6) is obtained, and the charge amount and the discharge amount are compared. That is, the difference ΔQ = (charged charge amount Q
It is monitored whether or not (I-discharge charge amount QD) falls below a predetermined level A.

The value of the predetermined level A is a value which is set in advance and stored in the ROM or the EEPROM of the CPU 92, and ΔQ is lower than the level value A.

[0056]

When ΔQ = (charge charge amount QI−discharge charge amount QD) <A (7), the shutter is locked so as not to accept the release operation, and photographing is prohibited. It is also possible to set a plurality of level values for monitoring the discharge amount of the main battery 34 stepwise, and to display a remaining amount or a warning display according to the amount of energy stored in the main battery 34 at each stage. Conceivable.

Next, a method of managing the amount of discharge of the main battery by the number of shots in which shooting has been performed will be described. When the release operation is performed, normally, as shown in FIG. 9, the focusing operation is started by AF, and then the shutter is opened, the flash is fired, the shutter is closed, the photographing lens position is returned, the film is fed one frame, and the flash is charged continuously. Executed
After the strobe charge is completed, the system enters the standby state. This series of operations is defined as one shot, and the amount of charge and the amount of discharge can be grasped in units of electric energy consumed in one shot.

For example, if the strobe light is not emitted by the release operation because the steady light is bright or the like, the strobe charge after one frame advance becomes unnecessary, so that it is consumed compared to the defined one shot. The amount of energy is small. Therefore, with the energy ratio for one complete shot,
Convert to 0.2 shots. Further, even when there is no camera operation input, the clock function is operating and the energy of the main battery 34 is consumed by the CPU 92 while waiting for the operation input. Accordingly, the power consumed in the no-operation state is obtained from the circuit current × time t according to the elapsed time of the no-operation time, and converted into an energy ratio for one shot, for example, 0.01 shots when the standby time elapses T1. .

Further, the energy of the main battery 34 slightly decreases over time due to a change in chemical composition or spontaneous discharge to the atmosphere. Although the improved battery has a self-discharge rate as small as a primary battery, it cannot be completely neglected. Therefore, the amount of energy lost over time T in consideration of self-discharge is calculated as an energy ratio with respect to one shot. For example, when the time T2 elapses, it is converted into a condition of 0.01 shot.

As described above, the electric capacity consumed for less than one shot is represented as a decimal part of the shot counter.
The decimal part of the shot counter can be incremented in accordance with the operation state of the camera or the passage of time, and the discharge amount of the main battery 34 can be managed based on the value of the shot counter. The count value of the shot counter is stored in a storage device such as an EEPROM, and the count value is incremented for each shot, and the fractional part is incremented with time as described above. When the main battery 34 is charged, the count value is decremented according to the charging time (charging amount).
The charge amount of the main battery 34 is calculated by the following equation (8).

[0061]

[Equation 8] Charge amount = Charge current × Charge time × Efficiency (8) On the other hand, a known battery check method is applied for detecting the remaining amount of the auxiliary battery,
Flowing a current in a internal resistive load, it detects a battery voltage across value V _E at this time. When _VE is smaller than a predetermined value, a warning is issued.

Next, the display contents of the liquid crystal panel 80 will be described. FIG. 10 shows an example of the display contents of the liquid crystal panel 80. The liquid crystal panel 80 has a graphic display unit 802 imitating the shape of an auxiliary battery (AA battery).
Is provided to display the remaining amount of the auxiliary battery 40 or the replacement time. Specifically, based on a signal indicating the voltage of the auxiliary battery 40 output from the charging control circuit 72 shown in FIG. 5, the display control circuit 82 turns on, turns off, flashes, and turns off the graphic display unit 802. The display is switched step by step to inform the user of the remaining amount of the auxiliary battery 40 and to prompt the user to replace the battery. In particular, when the auxiliary battery 40 has not been loaded, a special display indicating that the auxiliary battery 40 has not been loaded is displayed to prompt the user to load the auxiliary battery.

The main battery (CR)
Graphic display section 8 imitating the shape of (2 identical type improved batteries)
04 is provided to indicate the remaining amount of the main battery 34 or the replacement time. However, unlike the auxiliary battery 40, the main battery 34 is not replaced frequently by the user.
Since it is used as a built-in battery of the camera, it is not necessary to constantly display the remaining amount of the main battery 34. Therefore, the graphic display unit 804 related to the main battery 34
It is normally turned off, and when the capacity of the auxiliary battery 40 reaches almost 0 and the charging energy from the auxiliary battery 40 is no longer supplied to the main battery 34, it is fully lit, and the consumption is consumed until the replacement of the auxiliary battery 40. Let us indicate the possible electricity quantities. In addition to this display, the number of images that can be captured when the auxiliary battery 40 is not replaced is displayed on the display unit 805.

As described above, even if the auxiliary battery 40 is exhausted, the main battery 34 has a certain amount of electricity that can be consumed (for example, the amount of electricity that can capture 100 shots). It is possible to continue shooting even after exhaustion. Therefore, when the auxiliary battery 40 is exhausted, for example, the number of images that can be taken “99” is displayed on the display unit 805, and thereafter, the number of images that can be taken is counted down by one for each shot.

The liquid crystal panel 80 displays the remaining amount of film on the display unit 806 so that the number of recordable images and the remaining amount of film are not confused.
The display of the remaining amount of the film is displayed in characters larger than the display of the number of shootable images. By separately providing the battery check (BC) display section (802) of the auxiliary battery 40 and the BC display section (804) of the main battery, the user can clearly recognize which battery has been exhausted. be able to.

The liquid crystal panel 80 has a strobe mode display section 808 for displaying a strobe mode such as an automatic light emission mode, a red-eye reduction mode, and a backlit shooting mode in order from the upper left. A long-distance mode display section 810 that lights when the timer mode is set, and a timer mode display section 81 that lights when the timer mode is set
2, and a date display unit 814 for displaying a date, a time, and the like. Display unit 8 for displaying the number of shootable images
05 is shared as a part of the date display unit 814 and is also shared as a display unit of the subject distance in the manual focus (MF) mode.

The method of displaying the number of images that can be photographed is not limited to the above-described embodiment. For example, the voltage of the main battery 34 may be detected and displayed based on the detected voltage. Further, the display of the number of images that can be taken is not limited to numbers, but may be displayed graphically so that the approximate number of images can be recognized. Next, processing of the camera configured as described above will be described.

FIG. 11 shows a flow of a battery check process of the auxiliary battery 40. The remaining amount of the auxiliary battery 40 is detected by measuring the voltage V _E across the battery during the period when current is flowing to the load connected to the auxiliary battery 40. That is, the first BC level V, which means the voltage V _E of the measured auxiliary battery that the battery remaining amount is sufficient
Compared 1 (step S10, shown only following step numbers.), If the battery voltage across V _E is greater than the first BC level V1 causes the full lighting the graphic display unit 802 of the liquid crystal panel 80 (S12) The user is notified that the remaining battery level is sufficient.

In S10, the voltage V _E across the battery becomes the first voltage.
Is smaller than the second BC level V1 which is the final voltage of the auxiliary battery 40 (S14). And the voltage V _E across the battery is the second
Is larger than the BC level V2 of the liquid crystal panel 8
The graphic display unit 802 of 0 is half-lit (S16),
The user is informed that the remaining amount is low, and the user is prompted to replace the battery.

In S14, when the voltage value V _E across the battery is less than the second BC level V2, the graphic display section 802 of the liquid crystal panel 80 is turned off (S18).
The user is notified that the energy of the auxiliary battery 40 has been completely consumed. FIG. 12 shows an example of a sequence of charging the main battery. When charging of the main battery 34 is permitted (S20), the battery check of the auxiliary battery 40 is performed as described with reference to FIG. 11 (S22), and after it is confirmed that the auxiliary battery is not exhausted, Charging of the battery 34 is started (S24).

During the charging period, it is monitored whether or not the camera operation has been performed (S26). If there is an input by any switch operation, for example, a release operation, the charging ends (S40). If there is no switch input in S26, charging is continued until the voltage of the main battery 34 reaches 3.25V (full charge state) (S26 to S32). Main battery 3
4 is less than 3.25 V, the charge amount increases in accordance with the elapsed time. Therefore, the shot counter is decremented in accordance with the elapsed time T (S30, S3).
2). By repeating S26 to S32, energy is stored in the main battery 34. Then, when the voltage of the main battery reaches 3.25 V, the process proceeds to S34, the shot counter is reset to 0 (S34), and the charging ends (S40).

FIG. 13 is a flowchart showing the flow of processing of the camera. Initial processing required by the camera system is performed by power-on reset when the auxiliary battery is loaded or by replacing the main battery (S50). The initial processing includes, for example, setting of initial values for clock display, start of charging the main battery 34, and the like. Then, the charging process of the main battery 34 is performed (S52). That is, in S52, the processing (S20 to S40) described with reference to FIG.
When the charging is completed after the battery 4 has reached the full charge, the camera enters a standby state in which the camera waits for reception of a switch operation (S5).
4). If there is no operation input after a lapse of a predetermined time in the standby state, the CPU 90 enters a power save mode (power saving standby state), and thereafter, switches corresponding to an arbitrary camera operation (for example, operation of a shutter button or zoom operation). When an input (key “ON”) is detected, the process immediately exits the power save mode and performs processing.

When a switch input is detected in S54, the process proceeds to S60, and it is determined whether or not a release switch is input. In S60, if there is an operation input using a switch other than SP1 indicating a half-press operation of the shutter button, for example, a zoom switch, the zoom motor is driven, and an operation corresponding to the switch operation such as moving the zoom lens is executed. (S62). Thereafter, the processing returns to S52. Similarly, when other switches are input in S60, the operation returns to S52 after an operation corresponding to each operation is performed (S63).

On the other hand, in S60, when the shutter button is pressed and the half-press operation (SP1 ON) is detected, the remaining amount of the main battery 34 and the auxiliary battery 40 is checked (battery check) (S64). ). If it is determined in S64 that the electric capacity stored in the main battery 34 is insufficient, the release operation is locked to prohibit the release operation, and that the remaining amount of the main battery 34 is insufficient. Is displayed on the liquid crystal panel 80 (S6).
6), the process returns to S52.

If it is determined in S64 that the electric capacity stored in the main battery 34 is sufficient, photometry and distance measurement are performed (S68, S70), and the exposure value (AE value) is determined based on the results. And a flashmatic (FM) operation. Subsequently, it is detected whether or not the shutter button is fully pressed (S72), and when it is confirmed that the shutter button is fully pressed (S72).
When P2 is on, the focusing operation is performed, the taking lens moves to the in-focus position, and the shutter opens and closes (S2).
76). If it is determined in step S72 that the shutter button has not been fully pressed (SP2 ON), it is confirmed that the shutter button pressing operation has been released (S74).
The process returns to S52.

After the shutter operation in S76, the film is fed (winding up one frame) (S78). Then, after one frame feeding is completed, the shot counter is incremented (S80), the total shot counter is incremented (S82), and the process returns to S52.
The total shot counter keeps counting the total number of shots for one main battery without being decremented as the main battery 34 is charged. Based on the value of the total shot counter, the total shot counter Life is determined.

In the above embodiment, the CPU 92 for controlling the booster circuit 74 and the CPU for controlling the camera circuit 104
Although the case where the clock 90 is provided separately and the former CPU 92 which is always energized also has a clock function has been described, the present invention is not limited to this, and the camera circuit 104 and the booster circuit 74 can be controlled together by one CPU 90. It is. in this case,
For example, as shown in FIG. 14, a first auxiliary switch SW1 linked to a main switch is provided in a connection path between the auxiliary battery 40 and the booster circuit 74, and a main switch is provided in a connection path connecting the booster circuit 74 and the main battery 34. A second auxiliary switch SW2 interlocked with the switch, and when the main switch is turned off, the first and second auxiliary switches SW1,
SW2 is turned off, and the auxiliary battery 40 and the main battery 3 are turned off.
4 is separated from each circuit, and all operations of the camera including the CPU 90 are completely stopped. As a result, leakage current of the circuit can be eliminated, and current consumption can be suppressed. This is particularly effective when a clock function is not provided.

If the CPU 90 shown in the figure is provided with a clock function, the clock function is stopped every time the auxiliary battery is replaced, so that the time must be adjusted at the time of starting after the auxiliary battery is inserted. Therefore, although not shown in detail, the camera is provided with a receiving device for receiving radio waves from GPS satellites, and detecting means for detecting time information from the radio waves received by the receiving device, and the time detected by the detecting means is provided. The time of the clock function of the CPU is adjusted based on the information. This eliminates the need for the user to manually set the time every time the auxiliary battery is replaced, thereby simplifying the operation.

Instead of using the time information contained in the positioning radio wave from the GPS satellite, a standard radio wave generally supplied by a standard frequency station may be used. The standard radio waves in Japan are transmitted based on the standards maintained at the frequency and time standard facilities of the Radio Research Laboratory, Ministry of Posts and Telecommunications. It is also possible to omit the first auxiliary switch shown in FIG.
As shown in FIG. 15, the second auxiliary switch SW2 may be provided on the power supply path of the CPU 90.

Further, as shown in FIG.
A third auxiliary switch SW3 interlocking with an auxiliary battery presence / absence detection switch is provided in a connection path connecting the battery and the main battery 34, and when the auxiliary battery 40 is removed, the third auxiliary switch SW3 is turned off and the main battery 34 is turned off. The battery 34 may be electrically isolated to suppress current consumption. When the main switch is turned on in a state where the auxiliary battery 40 is not loaded, it is desirable to display on the liquid crystal panel 80 that the auxiliary battery 40 is not loaded and to urge the user to load the auxiliary battery. .

In the above-described embodiment, a case has been described in which the liquid crystal panel 80 indicates that the auxiliary battery 40 has not been loaded. However, the present invention is not limited to the liquid crystal panel 80, and the light emitting diode (LED) may be used to indicate this. Is also good.

[0082]

As described above, according to the camera of the present invention, when the power switch is off, the current is not supplied from the main battery to the first control circuit for controlling the power consuming means. Since the second control circuit for controlling the boosting means is always operable irrespective of the state of the power switch, unnecessary current consumption can be suppressed, and the remaining amount of the main battery is reduced to a predetermined level. When the level value is reached, the booster circuit can be operated at any time to replenish energy to the main battery, so that overdischarge of the main battery can be prevented.

Further, a power save mode is provided in the first control circuit, and the power switch is turned on by setting a power saving standby state when no operation is performed by an external operation member for a certain period of time while the power switch is on. Unnecessary current consumption can be suppressed even when left in a state for a long time. Since the presence or absence of the auxiliary battery is detected and the date and time are displayed for a certain period even after the auxiliary battery is removed,
There is an advantage that the operation can be simplified without having to reset the date and time every time the auxiliary battery is replaced. By ending the display of the date and time after the fixed period has elapsed without the auxiliary battery being loaded, unnecessary current consumption can be suppressed, and power saving can be achieved.

According to the present invention, an auxiliary switch interlocked with the power switch is provided in the electric connection path between the control circuit for controlling the operation of the power consuming means and the main battery, and when the power switch is turned off. Since the auxiliary switch is turned off and the conduction path of the control circuit is cut off, the main battery can be electrically isolated when the camera is not used, and leakage current due to the control circuit and the like can be eliminated. This allows
Power saving can be achieved.

Further, when the presence / absence of the auxiliary battery is detected by the presence / absence detection means for detecting the presence / absence of the auxiliary battery, that is, when charging of the main battery is impossible, the control from the main battery is performed. By cutting off the power supply to the circuit, overdischarge of the main battery can be prevented. Furthermore, by providing a time setting means for receiving a radio wave indicating time and setting the time of the clock function of the control circuit based on the received radio wave, the clock function is stopped every time the auxiliary battery is replaced. Can be set automatically at the correct time after loading the auxiliary battery. Thus, there is an advantage that the user can avoid a complicated operation of setting the time every time the auxiliary battery is replaced.

[Brief description of the drawings]

FIG. 1 is a front internal perspective view of a camera according to an embodiment of the present invention.

FIG. 2 is a top internal perspective view of the camera shown in FIG. 1;

FIG. 3 is a side internal perspective view of the camera shown in FIG. 1;

FIG. 4 is a diagram illustrating a configuration of an auxiliary battery presence / absence detection switch;

FIG. 5 is a block diagram including a charging circuit for charging a main battery with an auxiliary battery.

FIG. 6 is a circuit diagram illustrating an example of a booster circuit.

FIG. 7 is a block diagram showing a main configuration of another embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a management unit for managing a charge amount and a discharge amount of a main battery.

FIG. 9 is a flowchart for explaining a series of operations for one shot associated with a release operation.

FIG. 10 is a plan view of the liquid crystal panel used for explaining an example of display contents of the liquid crystal panel.

FIG. 11 is a flowchart illustrating a flow of a battery check process of an auxiliary battery.

FIG. 12 is a flowchart showing an example of a main battery charging sequence.

FIG. 13 is a flowchart showing the flow of processing of the camera.

FIG. 14 is a block diagram showing a main configuration of a camera according to another embodiment of the present invention.

FIG. 15 is a block diagram showing a main configuration of a camera according to another embodiment of the present invention.

FIG. 16 is a block diagram showing a main configuration of a camera according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Camera 12 ... Lens barrel 14 ... Cartridge chamber 16 ... Spool chamber 18 ... Strobe device 30 ... Film transport motor 36 ... Main condenser 40 ... Auxiliary battery 49 ... Zoom motor 58, 59 ... Detection contact piece 60 ... Presence / absence detection Switch 70 ... Charging circuit 72 ... Charge control means 74 ... Boost circuit 80 ... Liquid crystal panel 90 ... CPU (corresponding to first control circuit) 92 ... CPU (corresponding to second control circuit) 102, 106 ... Differential amplifier SW1 ... First auxiliary switch SW2 ... Second auxiliary switch SW3 ... Third auxiliary switch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenta Hashioka 3-11-46 Izumi, Asaka City, Saitama Prefecture Inside Fujisha Shin Film Co., Ltd. (72) Inventor Miyoshi Takahashi 1-324 Uetakecho, Omiya City, Saitama Prefecture Address Fuji Photo Optical Co., Ltd.

Claims (10)

[Claims] 1. A main power supply means for supplying power to a power consuming means capable of repeatedly discharging and charging when a self-discharge rate of a primary battery is substantially equal to and a remaining amount is equal to or more than a predetermined capacity, and performing an operation required for photographing. A battery; an auxiliary battery for supplying charging energy to the main battery; and a booster for boosting an output voltage of the auxiliary battery. The power is supplied to the main battery via the booster to charge the main battery. Charging means; main battery remaining amount detecting means for detecting the remaining amount of the main battery; power supply from the main battery only when a power switch is on, and power consumption according to operation of an external operation member. A first control circuit for controlling the operation of the means, and a power supply which is constantly supplied from the main battery, and the main battery remaining amount detecting means sets the main battery remaining amount to a predetermined level when the remaining amount of the main battery reaches a predetermined level. Outputs control signal to operate booster A camera characterized by comprising a second control circuit for controlling the charging of the main battery, the. 2. The camera according to claim 1, wherein the second control circuit has a clock function. 3. The first control circuit shifts to a power saving standby state in which the operation is suspended and power consumption is suppressed when the operation by the external operation member is not performed for a certain period of time while the power switch is on, 2. The camera according to claim 1, further comprising a power save mode in which the power saving standby state is maintained until a signal for instructing restart is input. 4. A display unit for receiving power from the main battery and displaying at least one of the remaining amount of the auxiliary battery, the remaining amount of the main battery, date and time. 3. The camera according to claim 2, wherein: 5. An auxiliary battery chamber receiving power supply from the main battery and displaying at least one of a date and a time, an auxiliary battery chamber in which the auxiliary battery is detachably stored, Presence / absence detection means for detecting whether or not an auxiliary battery is loaded in the battery chamber; and when the presence / absence detection means detects that the auxiliary battery is not loaded, the display means displays a date and time on the display means for a certain period. If at least one of the auxiliary batteries is not detected by the presence / absence detection means during that period,
3. The camera according to claim 2, further comprising: a third control circuit configured to terminate the display on the display unit after the elapse of the certain period. 6. A main power supply for supplying power to a power consuming means which is capable of repeatedly discharging and charging when the self-discharge rate of the primary battery is substantially equal to and the remaining amount is equal to or more than a predetermined capacity, and performs an operation required for photographing. A battery; an auxiliary battery for supplying charging energy to the main battery; and a booster for boosting an output voltage of the auxiliary battery. The power is supplied to the main battery via the booster to charge the main battery. A charging unit; a main battery remaining amount detecting unit that detects a remaining amount of the main battery; a first unit that receives supply of power from the main battery and controls an operation of the power consuming unit according to an operation of an external operation member. And a control signal for receiving power supply from the main battery and outputting a control signal for operating the booster when the remaining amount of the main battery reaches a predetermined level value by the main battery remaining amount detecting unit. Control for controlling charging of the main battery A road, display means for receiving power supply from the main battery and displaying at least one of date and time, an auxiliary battery chamber in which the auxiliary battery is detachably stored, and the auxiliary battery Presence / absence detection means for detecting whether or not the auxiliary battery is loaded in the auxiliary battery chamber; and when the presence / absence detection means detects that the auxiliary battery is not loaded, at least one of date and time is displayed on the clock display means. A third control circuit for displaying one of the auxiliary batteries for a certain period of time, and when the presence / absence detection unit does not detect the loading of the auxiliary battery during the period, ending the display of the display unit after the lapse of the certain period of time. A camera characterized in that: 7. A main power supply means for supplying power to a power consuming means which is capable of repeatedly discharging and charging when a self-discharge rate of a primary battery is substantially equal to and a remaining amount is equal to or more than a predetermined capacity and performs an operation required for photographing. A battery; an auxiliary battery for supplying charging energy to the main battery; and a booster for boosting an output voltage of the auxiliary battery. The power is supplied to the main battery via the booster to charge the main battery. Charging means; main battery remaining amount detecting means for detecting the remaining amount of the main battery; power supplied from the main battery; and the remaining amount of the main battery being predetermined by the main battery remaining amount detecting means. A control circuit that outputs a control signal for operating the booster when the value reaches a value, controls charging of the main battery, and controls operation of the power consuming unit in accordance with an operation of an external operation member; Connection between the control circuit and the control circuit Provided in the road, a camera, characterized in that and a supplementary switch for closing / opening the electrical connection path in conjunction with the ON / OFF operation of the power switch operating member. 8. An on / off switch for a power switch operating member, which is provided in an electrical connection path between the auxiliary battery and the booster circuit.
The camera according to claim 7, further comprising an auxiliary switch that closes / opens the electrical connection path in conjunction with an OFF operation. 9. An auxiliary battery chamber in which the auxiliary battery is removably accommodated, presence / absence detection means for detecting whether or not an auxiliary battery is loaded in the auxiliary battery chamber; 8. The camera according to claim 7, further comprising: switch means for interrupting power supply from the main battery to the control circuit when an unloaded auxiliary battery is detected. 10. The control circuit also has a clock function, and after the power supply to the control circuit is interrupted by the switch means and the clock function is stopped, the presence / absence detection means detects the loading of the auxiliary battery. 10. The camera according to claim 9, further comprising time setting means for receiving a radio wave indicating a time when the time is set, and setting a time of a clock function of the control circuit based on the received radio wave.