JPH1039367A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a very convenient camera by constituting the charging current of a camera battery repeatedly discharged/charged when a remaining amount is prescribed capacitance or more, to make the charging current switchable. SOLUTION: Power is supplied to a camera circuit from a main battery 34 and this main battery 34 is charged with a constant current by a charger 80, by using an auxiliary battery 40 such as a AA type dry cell, as a charging power source. A switch 82A turned on/off according to a signal from a CPU 70 is provided in a constant current circuit 82, so that the charging current of the main battery 34 is constituted to be switchable to a high or low level. Normally, low-current charging with a small loss of energy is attained. When photographing in a consecutive photographing mode or photographing with strobe light emission is executed, switching to quick charging is attained. Further, the remaining amount of the main battery 34 is observed through a shot counter and when the value of the remaining amount reaches a fixed counter value, the quick charging is attained to prevent the overdischarge of the main battery 34.

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 having a power supply device 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 of a metal lithium series. About the camera.

[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 used. Even under such conditions, charging can be performed safely under certain conditions. 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,
A method is disclosed in which a power supply device combining a lithium battery and a solar battery is 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 the characteristics of a primary battery and the characteristics of a secondary battery as described above will be referred to as an "improved battery".

[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, there has been proposed a power supply device having a configuration in which the improved battery is charged by an auxiliary battery such as an AA battery (see Japanese Patent Application No. 7-273050). When using the improved battery for a camera, it is desirable to consider the properties of the improved battery and to improve the convenience of the user. The present invention has been made in view of such circumstances, and it is an object of the present invention to use a battery (improved battery) that can be repeatedly discharged and charged, and to provide a camera that is highly convenient for a user in accordance with the characteristics of the battery. And

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a battery which is substantially equal to a self-discharge rate of a primary battery and has a predetermined charge current value or less when a remaining amount is equal to or more than a predetermined capacity. A main battery that can be repeatedly released and charged when charging with a current, a power consuming unit that is supplied with power from the main battery and performs an operation necessary for shooting, an auxiliary battery that supplies charging energy to the main battery, A first constant current means having boosting means for boosting the output voltage of the auxiliary battery and maintaining a current supplied to the main battery via the boosting means at a first current value equal to or less than the predetermined charging current value And a second constant current means for maintaining a current supplied to the main battery via the boosting means at a second current value smaller than the first current value, wherein the charging energy of the auxiliary battery is To the main battery, Charging means for charging, current switching control means for enabling one of the first constant current means or the second constant current means and disabling the other, and switching a charging current for charging the main battery; It is characterized by having.

According to the present invention, the main battery is charged by the auxiliary battery, and power is supplied from the main battery to the power consuming means required for the photographing operation. You only need to replace them. Therefore, by using an inexpensive and readily available auxiliary battery such as a manganese-based AA battery, there is a sense of security that it is more economical and easier to obtain than replacing the main battery. It has the advantage of being preferred. In particular, by using a metal lithium secondary battery as the main battery, a large capacity and a large current can be supplied from the main battery to the power consuming means in the camera. There is a sense of security that you can shoot anytime without it. In addition, since the output voltage of the auxiliary battery is boosted and applied to the main battery, there is an advantage that the main battery can be charged by the auxiliary battery having a small voltage, and the electric energy of the auxiliary battery can be used without waste.

Further, a first current for maintaining a charging current at a first current value.
A constant current means, and a second constant current means for maintaining a charging current at a second current value larger than the first current value,
Since the charging current of the main battery is configured to be switchable between large and small, charging can be performed with a preferable charging current depending on the situation within a range where the charging current does not exceed a predetermined charging current value. For example, low-current charging, which is usually safer and has less energy loss, is performed, and the charging current is increased in accordance with the remaining amount of the main battery, whereby rapid charging can be performed. As a result, it is possible to charge the main battery in a short time even if it is suddenly discharged in a large amount, and it is possible to respond to continuous use of the camera such as continuous shooting and to prevent overdischarge of the main battery.

In particular, in continuous shooting mode or shooting with strobe light emission, it is considered that the power consumption is large. In such a case, switching to quick charging is performed so that the energy of the consumed main battery is compensated for at an early stage. It is effective from the viewpoint of preventing overdischarge of the main battery. Then, the remaining amount of the main battery is detected by the remaining amount detecting means, and until the remaining amount of the main battery reaches a predetermined level value, low-current charging that can be performed more safely and with less energy loss is performed. By performing quick charging when the remaining amount reaches the predetermined level, overdischarging of the main battery can be prevented.

It is desirable to use a shot counter as a specific measure for detecting the remaining amount of the main battery. That is, when the main battery reaches a fully charged state (a fully charged state), the shot counter is reset to 0, and the number of shots is incremented by one each time shooting is performed by a release operation. . Then, as the electric energy is supplied from the auxiliary battery to the main battery, the count value of the shot counter is decremented as needed in accordance with an increase in the energy stored in the main battery, so that it is consumed in accordance with the shooting operation. By counting the amount of energy in units of one shot, the amount of discharge of the main battery can be grasped. In this case, low-current charging is performed until the value of the shot counter reaches a preset reference counter value, and when the value of the shot counter reaches the preset reference counter value, switching to rapid charging is performed, thereby allowing the main battery to be charged. Overdischarge can be prevented.

When a fractional part of less than one shot is provided in the count value of the shot counter, when at least one of a series of photographing operations constituting one shot is performed, energy consumed according to the operation is taken. By converting the amount into an energy ratio for one shot and adding it to the decimal part of the shot counter, the remaining amount of the main battery can be detected more accurately. Furthermore, the amount of energy consumed to maintain the main battery's spontaneous discharge or the camera's standby state is converted into the energy ratio for one shot with the passage of time and added to the decimal part of the shot counter, thereby obtaining the main battery's The remaining amount can be grasped more accurately.

[0013]

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.
3 is an internal perspective view of the camera to which the present invention is applied, FIG. 1 is a front view, FIG. 2 is a top view, and FIG. 3 is a left side view. Reference numeral 12 at the center of the camera 10 shown in FIG. 1 denotes a lens barrel storage section for storing a photographing lens barrel (not shown), and a film cartridge (patrone) (not shown) is provided on the right side of the lens barrel storage section 12. Is formed, and a film take-up chamber 16 is provided on the left side.
Are formed. The upper part of the cartridge chamber 14, that is,
A flash device 18 is provided at the upper right corner of the front of the camera. On the left side of the strobe device 18, an AF light projecting unit 20, an AF light receiving unit 22, and a finder unit 24 are provided in this order.

The cartridge chamber 14 is provided with a spool drive shaft 26 which engages with a spool of a film cartridge loaded in the chamber, and a detection switch (not shown) for detecting the presence or absence of the film cartridge. I have. On the other hand, the film take-up chamber 16 is provided with a take-up spool 28 for taking up the film sent from the film cartridge, and a film feed motor 30 is incorporated in the take-up spool 28. The torque of the feed motor 30 is transmitted to the take-up spool 28, and the gear trains 32A, 32 shown in FIG.
B,... The spool drive shaft 2 via 32I, 32J
6 is transmitted.

That is, when the feeding motor 30 is rotated forward, the film is fed out of the film cartridge loaded in the cartridge chamber 14 and is taken up by the take-up spool 28. Further, when the feeding motor 30 is reversed, the spool drive shaft 26 of the cartridge chamber 14 is reversed, and the film wound on the take-up spool 28 is rewound into the film cartridge. The rotation of the feed motor 30 is controlled by a control device including a central processing unit (CPU) 70, which will be described later, and the film is fed one frame (winding up). When the end of the film is detected after all the frames of the film have been photographed, the feed motor 30 is driven in reverse, and the drawn film is automatically rewound into the film cartridge.

A film rewind lever (not shown) is provided on the rear surface of the camera 10. By operating the film rewind lever, the film can be rewound to the cartridge before the completion of all frame shooting. I can do it. On the left side of the take-up spool 28, a main battery 34 for supplying power to various circuits in the camera and a main capacitor 36 are arranged in a vertical direction. That is, the main battery 34 is arranged coaxially above the cylindrical main capacitor 36. In addition, a partition plate 38 is provided between the main battery 34 and the main capacitor 36.

The main battery 34 is a rechargeable battery dedicated to a camera with a small self-discharge, and is an improved battery having both characteristics of a primary battery and a secondary battery. 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, and its voltage is 3.25 V when properly charged. The shape of the main battery 34 is not particularly limited. For example, the main battery 34 is formed in the same shape as a current CR2 type battery, and has a capacity of about 700 mAh.

An auxiliary battery 40 for supplying charging energy to the main battery 34 is disposed 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, and the positive electrode of the auxiliary battery 40 and the positive electrode of the main battery 34 are in contact with one contact piece member 41. Also, a battery cover 4 is provided at the rear corner of the camera 10.
2 is provided on the shaft 42A so as to be openable and closable (see FIG. 2), and the auxiliary battery 40 is stored in the auxiliary battery storage chamber inside the battery cover 42. By opening the battery cover 42, the auxiliary battery 40 stored in the auxiliary battery storage chamber can be taken out and replaced. Note that the battery cover 42 may be provided on the bottom surface of the camera 10.

The auxiliary battery storage chamber is, for example, one AA
A manganese-based AA battery is housed 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.

In FIG. 1, reference numeral 43 denotes a camera control circuit, reference numeral 44 denotes a boosting circuit for charging, and reference numeral 46 denotes a mounting space for a charging circuit for the main capacitor 36. The power supply of the camera 10 is the main battery 3
4, an auxiliary battery 40, a booster circuit 44, and the like, and power is supplied from the main battery 34 to the strobe device 16, the film feeding motor 30, the zoom motor 48, the control circuit 43, and the like.

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.

Although 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, it functions as a secondary battery thereafter. Has a property of rapidly decreasing. The amount of discharged energy is represented by the usage rate with respect to the total energy, with the fully charged electric capacity as the reference 100, and is referred to as “depth of discharge”.

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 the photographing of 3000 shots or more is sufficiently possible. . On the other hand, when used at a discharge depth of 30%, the performance of the main battery as a secondary battery is reduced, and the cycle life is shortened. In this case, only about 1000 shots can be repeatedly shot. As the depth of discharge increases, the cycle life sharply decreases,
Further, once the depth of discharge is deeply discharged, the performance as a storage battery decreases, the electric capacity stored in the main battery by subsequent recharging decreases, and the cycle life also decreases.

That is, it is desirable that the main battery be used so as to be repeatedly charged and discharged in a range of a shallow depth of discharge. Therefore, when this improved battery is actually used, a proper depth of discharge is set in accordance with the setting of the limit of use as a camera, and management is performed so that discharge and charge are repeated so as not to exceed the range of the depth of discharge. There is a need to. FIG. 4 shows an example of the configuration of a charging circuit for charging main battery 34 with auxiliary battery 40. The charging circuit 50 includes a charging control circuit 52 and a boosting circuit 54 as shown in FIG.
The charging control circuit 52, respectively detects a voltage V _CR and the voltage V _E of the auxiliary battery 40 of the main battery 34, for example, a main battery 34
The voltage V _CR, becomes smaller than the voltage value 3.25V full charge state (V _CR <3.25 V), and voltage of the auxiliary battery 40 V
_{When E} is V _E ≥ 0.9 V (the end voltage of the auxiliary battery 40), the booster circuit 54 is operated to charge the main battery 34.

On the other hand, the charging control circuit 52, when the main battery 34 has been fully charged (when becomes a voltage V _CR = 3.25 V), or the auxiliary battery 40 voltage V _E of the exhausted auxiliary battery 40 is V _{When E} <0.9V, the boosting circuit 54 is stopped. Further, the charge control circuit 52 outputs a signal indicating the voltage of the auxiliary battery 40 to the display control circuit 62 in order to display the remaining amount of the auxiliary battery 40 on the liquid crystal panel 60.

As described above, the display control circuit 62 receives the signal indicating the voltage of the auxiliary battery 40 from the charge control circuit 52, the signal from the film counter indicating the remaining amount of the film, the strobe switch, the shutter button, and the self-timer. Signals from a switch, a continuous shooting mode setting switch, and the like are added, and the liquid crystal panel 60 performs a required display based on these input signals. Details of the display contents of the liquid crystal panel 60 will be described later. The charging control circuit 52 is supplied with driving power from the main battery 34.

Next, the boosting circuit 54 will be described. FIG. 5 is a circuit diagram showing an example of the booster circuit. As shown in the figure, the booster circuit 54 is of a push-pull type, and the power source of the auxiliary battery 40 is
2, the current is converted into alternating current by the transistors Q 1 and Q 2 which are alternately turned on by the transistor T 2, and the voltage is boosted via the transformer T.
By rectifying by 5, the DC voltage is converted to a DC voltage necessary for charging the main battery 34.

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

[0031]

## 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:

[0032]

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

[0033]

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 55). Therefore, the turns ratio n ₂ / n ₁ of the transformer T is

[0034]

## EQU4 ## n ₂ / n ₁ = V ₂ / V ₁と 7.3 (4) As described above, the charging circuit 50 shown in FIG. 4 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 the use of the camera, the 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 34
The energy of the auxiliary battery 40 is transferred to the main battery 34 in accordance with the energy consumption of the main battery 34, so that the main battery 34 is always kept in a state close to full charge.

By doing so, there is an advantage that the main battery 34 can be easily handled without fear of overdischarge 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.

Now, when the charging 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 30 reaches its final voltage 0.9V), 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 dry battery, and thus has an 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 52 needs to receive a signal indicating the number of shots from the camera.

FIG. 6 is a block diagram showing the configuration of the control system of the camera. The central processing unit (CPU) 70, which plays a central role in the control system, stores the operation state of the camera including ON / OFF states of the main switch Sm, the release switch Sr, the continuous shooting mode setting switch Ss, the emergency switch SEMG, and the like. In addition to the input of various signals shown, circuits (hereinafter collectively referred to as “camera circuit”) corresponding to various camera operations, such as a shutter drive circuit 72, a strobe circuit 74, and a film feed circuit 76, are connected. . The CPU 70 operates by receiving power supply from the main battery 34, controls the operation of the camera circuit, and also has a role of a counter for counting the number of shots.

The CPU 70 has an EEPROM 78 from which data can be read and written, and a liquid crystal panel (LC) for displaying the status of the camera and inputting the mode setting.
D) 60 is connected. That is, the CPU 70
The display control circuit 62 and the charge control circuit 52 shown in FIG. 5 also play a role. The charger 80 for transferring the energy of the auxiliary battery 40 to the main battery 34 includes a booster circuit 54 and a constant current circuit 82.
Is controlled by a charge control signal output from the controller. Further, between the charger 80 and the main battery 34, C
A switch 84 that is turned on / off in response to a charge control signal from the PU 70 is provided. And CPU
When a charge control signal for instructing execution of charging is added from 70, the boosting circuit 54 operates and the switch 84 is turned on, so that energy transfer from the auxiliary battery 40 to the main battery 34 is permitted. When the CPU 70 outputs a charge control signal instructing that charging is not performed, the operation of the booster circuit 54 stops and the switch 8
4 is turned off, and energy transfer from the auxiliary battery 40 to the main battery 34 is prohibited.

The constant current circuit 82 has a switch 82 which is turned on / off in response to a charging current switching signal from the CPU 70.
A is provided, and the charging current is switched according to the charging current switching signal. The positive electrode of the main battery 34 is connected to an input terminal of a comparator 88 via a switch 86 that is turned on / off according to a control signal from the CPU 70. When the switch 86 is turned on, the main battery 34
Is divided and applied to the input terminal of the comparator 88. A constant voltage V is applied to the other input terminal of the comparator 88.
s is added, and a comparison result between the divided voltage value of the voltage of the main battery 34 and the predetermined voltage Vs is sent from the comparator 88 to the CPU 70.
Will be notified. Thereby, the voltage of the main battery 34 can be monitored.

FIG. 7 shows a specific configuration of the constant current circuit 82. Note that, for convenience, the booster circuit 54 will be omitted and described. In the constant current circuit shown in FIG. 3, a Zener diode ZD1 and a resistor R0 are connected in series to an auxiliary battery 40, and a transistor Q3 having a base terminal connected between the Zener diode ZD1 and a resistor R0 is provided. The emitter terminal of the transistor Q3 is
The auxiliary battery 40 is connected in parallel with the Zener diode ZD1 via a resistor R1, and a resistor R2 is connected in parallel with the resistor R1 via a switch 82A.
Then, a charging current flows from the collector terminal of the transistor Q3 to the main battery 34.

With this configuration, the voltage of the auxiliary battery 40 is divided by the Zener diodes ZD1 and R0, and the divided voltage is applied to the base terminal of the transistor Q3. Then, a current iz flows in the reverse direction of the Zener diode ZD1, a base current flows to the base terminal of the transistor Q3, and the transistor Q3 conducts. At this time, since the voltage VZ between the terminals of the Zener diode ZD1 is constant and the voltage VBE between the base and the emitter of the transistor Q3 is constant, the voltage between the terminals of the resistor R1 is constant and the collector voltage of the transistor Q3 is connected to the main battery. 34, the current flowing through the switch 34 turns ON the switch 82A.
According to the / OFF state, the following is performed. That is, when the switch 82A is off, the following equation (5)

[0044]

## EQU5 ## i1 = (VZ-VBE) / R1 is constant as shown in (5). Also, the switch 82A is ON.
In the case of the following equation (6)

[0045]

## EQU6 ## i2 = (VZ-VBE) / (R1.times.R2) / (R1 + R2) (6) It is constant. Thus, the switch 82A
Is turned on / off, the charging current can be switched to i1 or i2 (> i1). And, even if the voltage of the auxiliary voltage 40 fluctuates, the Zener diode Z
Since the voltage VZ between the terminals of D1 is constant, the main battery 34 is charged with a constant current of the current value i1 or i2.

As a result, the main battery 34 can be charged with a constant current regardless of the state of charge of the main battery 34 and even if the voltage of the auxiliary battery 40 changes with use. There is an advantage that the reaction can proceed at a constant speed, the battery can be charged safely, and the auxiliary battery 40 can be used without waste. In the improved battery, it is preferable that the upper limit of the charging current is set to a range in which no dendrite is generated in consideration of the fact that dendrite is generated when the charging current is large. According to experiments, 59
When the main battery 34 is charged with a charging current of mA, no dent transient is observed. For example, the current value i1 is 19 mA and the current value i2 is 59 mA.
The circuit is configured to be mA. In normal charging, 19 is safer and has less energy loss.
When low-current charging at mA is performed, especially when rapid charging is required, the charging current is switched to 59 mA to perform rapid charging.

Specifically, rapid charging is performed under the following conditions. That is, the continuous shooting mode is set by the mode setting operation of the camera, and the quick charging is performed when shooting is performed in the continuous shooting mode. When the continuous shooting mode is set, the continuous shooting mode setting switch Ss shown in FIG. 6 is turned on, and the CPU 70 can detect that the continuous shooting mode has been set. After shooting in continuous shooting mode, C
PU 70 outputs a charging current switching signal for turning on switch 82A of constant current circuit 82 shown in FIG. Then, when the switch 82A is turned on by the signal, the charging current becomes the current value i2 (59 mA) as described with reference to FIG.
, And rapid charging is performed.

In the continuous shooting mode, the energy stored in the main battery may be consumed in a large amount in a short period of time. I try to make up for it early. Thus, there is an advantage that the camera can be continuously used and overdischarge of the main battery can be prevented.

In addition to the above-described continuous shooting mode, rapid charging may be performed after the strobe light is emitted. That is, in the shooting with flash emission, there is a possibility that a large amount of energy stored in the main battery is consumed in a short time as in the shooting in the continuous shooting mode. Therefore, after the strobe light is emitted, the charging may be switched to the quick charging to supplement the consumed energy of the main battery at an early stage. Other conditions for switching the charging current will be further described later (FIG. 16).

Next, a method for 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 charging energy charged from the auxiliary battery 40 to the main battery 34, and
4 monitors the discharge energy discharged from the battery 4, and grasps the remaining amount of the main battery 34 based on a comparison between the two.

The charging energy of the auxiliary battery 40 is transferred to the main battery 34 via the charger 80, the resistor R4, and the constant voltage diode ZD2. The voltage between both ends of the resistor R4 is applied to a differential amplifier 92, and the output of the differential amplifier 92 is guided to a CPU 70 via an A / D converter 93. The electric energy released from the main battery 34 is guided to the camera circuit 94 via the resistor R5, and is consumed in the camera circuit 94. The voltage across the resistor R5 is applied to the differential amplifier 9.
6, and the output of the differential amplifier 96 is applied to the CPU 70 via the A / D converter 97.

According to this configuration, when a current is supplied from the auxiliary battery 40 to the main battery 34 via the charger 80, the charging current flows through the resistor R4. If the monitoring is performed, the charge amount charged in the main battery 34 is obtained. That is, assuming that the voltage across the resistor R4 is VR4, the charge amount QI charged in the main battery 34 is given by the following equation (7).

[0053]

## EQU7 ## QI = ∫VR4 / R4 × Δt (7) The charge amount QI can be obtained by performing an integral operation for each time Δt during which the charging current flows. On the other hand, the power for operating the camera circuit 94 is:
Since the voltage is supplied from the main battery 34 to the camera circuit 94 via the resistor R5, if the voltage at both ends of the resistor R5 is monitored by the differential amplifier 96, the amount of charge supplied from the main battery 34, that is, The discharge amount (consumption amount) can be obtained.
That is, assuming that the voltage across the resistor R5 is VR5, the main battery 34
The amount of charge QD discharged from the battery is expressed by the following equation (8).

[0054]

## EQU8 ## QD = ∫VR5 / R5 × Δt (8) The discharge charge amount QD can be obtained by performing an integral operation for each time Δt during which the discharge current flows. The difference .DELTA.Q between the charge amount QI obtained by the equation (7) and the discharge amount QD obtained by the equation (8) 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 78 of the CPU 70, ΔQ is lower than the level value A, and the following equation (9)

[0056]

When ΔQ = (charge charge amount QI−discharge charge amount QD) <A (9), 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 flash operation is not performed by the release operation because the steady light is bright or the like, it is unnecessary to charge the flash after one frame has been fed, so that the flash 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. In addition, even when there is no camera operation input, the clock function may be operating. Even when only the CPU 70 is operating while waiting for an operation input, the power consumption is low, but the energy of the main battery 34 is consumed. Have been. Therefore, 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 the energy ratio for one shot is:
For example, each time the standby time elapses, T1 is converted into a value of 0.01 shot.

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 shot counter value. The count value of the shot counter is EEPROM 78
The counter value is incremented for each shot, and its decimal part is incremented as time elapses as described above. When the main battery 34 is charged, the charging time (charge amount)
The count value is decremented according to. The charge amount of the main battery 34 is calculated by the following equation (10).

[0061]

## EQU10 ## Charge amount = Charging current × Charging time × Efficiency (10) On the other hand, the detection of the remaining amount of the auxiliary battery is applied a known battery check method, a current flows in a internal resistive load, 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 60 will be described. FIG. 10 shows an example of the display contents of the liquid crystal panel 60. The liquid crystal panel 60 has a graphic display unit 602 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 charge control circuit 52 shown in FIG. 4, the display control circuit 62 turns the graphic display unit 602 on, off, on, off, on and off. 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.

The main battery (CR) is provided on the liquid crystal panel 60.
Graphic display section 6 imitating the shape of (2 identical 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 604 for 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 photographed when the auxiliary battery 40 is not replaced is displayed on the display unit 605.

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 recordable images “99” is displayed on the display unit 605, and thereafter, the number of recordable images is counted down by one for each shot.

The liquid crystal panel 60 displays the remaining amount of film on the display unit 606 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 (602) of the auxiliary battery 40 and the BC display section (604) of the main battery, the user can clearly recognize which battery has been exhausted. be able to.

The liquid crystal panel 60 has a strobe mode display section 608 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. 610, a long-distance mode display section 610 that lights up when the timer mode is set.
2, and a date display unit 614 for displaying a date, a time, and the like. The display unit 605 for displaying the number of shootable images is shared as a part of the date display unit 614 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. FIG. 11 shows another display mode in which the remaining amount of the auxiliary battery 40 and the remaining amount of the main battery 34 are displayed on the liquid crystal panel 60.
As shown in the figure, a configuration is adopted in which a second graphic 630 simulating the shape of the auxiliary battery 40 is superimposed and displayed inside a first graphic 620 simulating the shape of the main battery 34.

When the remaining amount of the auxiliary battery 40 is sufficient, as shown in FIG.
The display section of the second figure 630 provided inside 0 is all turned on. Then, as the remaining amount of the auxiliary battery 40 decreases, the first half of the second graphic 630 is turned off (that is, turned on half). Further, when the remaining amount of the auxiliary battery 40 decreases and reaches the cutoff voltage, the second graphic 630 is completely turned off, as shown in FIG. Is displayed. By the graphic display shown in FIG.
The approximate number of images that can be photographed without replacing the auxiliary battery 40 can be recognized.

As described above, by displaying the second figure 630 simulating the shape of the auxiliary battery 40 on the inside of the first figure 620 simulating the shape of the main battery 34, the display area of the liquid crystal panel 60 is displayed. Can be saved in space, and both display contents can be easily recognized. Next, processing of the camera will be described.

FIG. 12 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 602 of the liquid crystal panel 60 (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 6
The graphic display unit 602 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, if the voltage value V _E across the battery is less than the second BC level V2, the graphic display section 602 of the liquid crystal panel 60 is turned off (S18).
The user is notified that the energy of the auxiliary battery 40 has been completely consumed. FIG. 13 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. 12 (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 a camera operation has been performed (S26). If there is an input by any switch operation, for example, a release operation, the charging ends (S40). As described above, when the camera operation is performed, the processing according to the operation is prioritized, and the main battery 34 is not charged during the execution of the camera processing. Therefore, the processing load on the CPU 70 is reduced. be able to. Normally, the camera processing and the charging processing cannot be performed in parallel in real time by one CPU 70, so that the amount of charge cannot be accurately managed during the camera processing and may be overcharged. During the period when the camera processing is being executed, charging is prohibited, and charging is allowed after the operation of the camera processing is completed, so that one CPU 70 controls camera operation and main battery charging. And the overcharge of the main battery can be prevented.

If there is no switch input in S26,
Charging is continued until the voltage of the main battery 34 reaches 3.25 V (fully charged state) (S26 to S32). While the voltage of the main battery 34 is less than 3.25 V, the charge amount increases according to the elapsed time, so the shot counter is decremented according to 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 charging ends (S40).

FIG. 14 shows the relationship between the remaining battery level of the main battery 34 and whether discharge is possible. For a full charge level (LF) indicating that the main battery 34 is fully charged,
The level of the discharge depth of 5% is the first level (L1), the level of the depth of discharge at which the main battery 34 can be repeatedly charged and discharged, for example,
A second level (L2) is set in advance for the level of the discharge depth of 30%, and a third level (L3) indicating the limit remaining level at which the main battery 34 can be used.

Since the remaining amount of the main battery 34 can be grasped from the counter value of the shot counter, each level L1, L2, L3 indicating the remaining amount of the main battery 34 is associated with the counter value of the shot counter. Is set. The data indicating the levels L1, L2 and L3 are shown in FIG.
The data is stored in the EPROM 78, and the data can be rewritten according to the change of the level setting.

Although the remaining amount of the main battery 34 gradually decreases from the full charge level LF as the camera is used, if the remaining amount of the auxiliary battery 40 is sufficient, the auxiliary battery 40
Thus, the main battery 34 is charged, and the main battery 34 is always maintained at a state close to full charge. However, when the camera continues to be used for a long time such as continuous shooting, or when the auxiliary battery 40 is exhausted and the charging energy cannot be supplied to the main battery 34, the counter value of the shot counter continues to be incremented with the shooting operation, The remaining amount of the main battery 34 decreases. The value of the shot counter is the first level L1
Is reached (when the remaining amount of the main battery 34 reaches the first level L1), the operation of the shutter button is locked (first lock), and the release is performed. Operation is not accepted and the main battery 34
Is displayed on the liquid crystal panel 60 to warn that the battery is insufficiently charged.

When the shutter button is locked,
The series of operations shown in FIG. 9 are prohibited, the energy consumption of the main battery 34 is suppressed, and the charging of the main battery 34 by the auxiliary battery 40 is allowed. At this time, a charging current switching signal for increasing the charging current is output from the CPU 70,
The switch 82A of the constant current circuit 82 is turned on, and is switched to quick charging. When the auxiliary battery 40 has a remaining amount or when the auxiliary battery 40 is replaced, the main battery 34 is charged by the auxiliary battery 40 (or a new auxiliary battery) and supplied to the main battery 34. Depending on the charging energy,
That is, the shot counter is decremented according to the charging time. Then, when the value of the shot counter becomes smaller than the first count value meaning the first level L1 with the charging, the first warning is released, the shutter lock is released, and the photographing is performed again. Will be able to do.

When full charge is reached, or when charging is prohibited by operating the camera, a charge current switching signal for turning off the switch 82A of the constant current circuit 82 is output from the CPU 70. On the other hand, after the auxiliary battery 40 is charged by the first lock and the main battery 34 is allowed to be charged, if the auxiliary battery 40 is not replaced even though the auxiliary battery is completely exhausted, the auxiliary battery 40 is not replaced. Accordingly, the main battery 34 cannot be charged. However, since the CPU 70 operates by receiving power supply from the main battery 34, and there is a leak current that cannot be avoided due to the circuit configuration, the remaining amount of the main battery 34 gradually decreases. Become.

When the auxiliary battery 40 is left for a long time without being replaced and the remaining amount of the main battery 34 reaches the second level L2, it is dangerous to recharge and use the main battery 34. In addition, even if the battery is recharged, the cycle life is greatly reduced.
, The charging of the main battery 34 is prohibited. Therefore, even if the auxiliary battery 40 is replaced thereafter, the main battery 34 is not recharged, and the main battery 34 can be used safely.

Incidentally, even when the remaining amount of the main battery 34 is lower than the first level L1 and the shutter button is locked, electric energy still remains in the main battery 34. In order to make effective use of this energy, an emergency switch SEMG for releasing the lock is provided (see FIG. 6). That is, by operating the emergency switch SEMG, the signal is transmitted to the CPU 7.
In addition to 0, the shutter button can be unlocked. When the shutter lock is released, the remaining amount of the main battery 34 or the number of images that can be photographed by the main battery 34 is displayed on the liquid crystal panel 60. By doing so, the exhausted auxiliary battery 40
Even when the camera cannot be replaced immediately, it is possible to take a picture as an emergency measure, and there is an advantage that there is a sense of security.

Unlocking the shutter button with the emergency switch SEMG to take a picture is an exceptional usage pattern. In this state, if the discharge of the main battery 34 is allowed indefinitely, the main battery 34 can be recharged and used. When the main battery 34 needs to be recharged and used, if the shutter button is unlocked by the emergency switch SEMG, the main battery 34 is used within a range where the remaining amount of the main battery 34 does not fall below the second level L2. It is desirable to do.

For example, an emergency switch SEMG
Is operated to release the lock, the main battery 34 is allowed to be used as long as the photographing of one new film cartridge (for example, 50 sheets) is guaranteed, and no further photographing can be performed. It is good to lock 2 As a result, after operating the emergency switch SEMG, there is a sense of security that at least one film cartridge can be photographed, and the energy of the main battery 34 is not excessively consumed. There is an advantage that it can be charged and used again.

On the other hand, when it is desired to replace the main battery 34 after exhausting the energy of the main battery 34 without considering the reuse of the main battery 34, the remaining amount of the main battery 34 is reduced to the third level shown in FIG. The energy stored in the main battery 34 may be taken out until reaching the level L3. In this case, the main battery 3
4 is completely consumed and the remaining amount of the main battery 34 is at the third level L3
After reaching, the shutter button is locked (second lock) so that the release operation is not accepted,
A warning prompting replacement of the main battery 34 is displayed on the liquid crystal panel 60.

Next, the allowable charging time of the main battery will be described with reference to FIG. As shown in the figure, first, an initial process required for 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.

Thereafter, the main battery 34 is charged (S52). That is, in S52, the processing described in FIG. 13 (S20 to S40) is executed, and when the main battery 34 reaches full charge and charging is completed, the camera enters a standby state of waiting for reception of a switch operation (S54). . If there is no operation input after a lapse of a predetermined time in the standby state, the CPU 70 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.

In this standby state, the switch is not operated, and every time the reception standby time elapses a predetermined time interval t, the decimal part of the shot counter is incremented in accordance with a predetermined energy ratio conversion value. ing. Then, when the shot counter reaches a predetermined value (for example, count value = 5),
The main battery 34 is charged. When the main battery 34 reaches full charge, the charging is terminated. Therefore, even if the main battery is left in the standby state for a long time, the main battery 3
4 is automatically charged as long as the auxiliary battery 40 has a remaining amount. Thus, the main battery 34 can be prevented from being over-discharged while the auxiliary battery 40 has energy.

If a switch input is detected in S54, the process proceeds to S60, where 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).
At this time, the amount of energy consumed according to the operation load is converted into an energy ratio for one shot and added to the decimal part of the shot counter, so that the discharge amount of the main battery can be grasped more accurately.

On the other hand, in S60, when the shutter button is pressed and the half-press operation (SP1 ON) is detected, the battery check of the main battery 34 and the auxiliary battery 40 is subsequently performed (S64). The battery check at this time may be performed based on the voltage between both ends of the main battery 34 shown in FIG. 6, or may be performed based on the measurement of the charge / discharge amount of the main battery shown in FIG.

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 the remaining amount of the main battery 34 becomes insufficient. Is displayed on the liquid crystal panel 60 (S66), and the process returns to S52. S
If it is determined in S64 that the electric capacity stored in the main battery 34 is sufficient, photometry and distance measurement are performed (S6).
8, S70), and an exposure value (AE value) and a flashmatic (FM) calculation are performed based on the result. Subsequently, it is detected whether or not the shutter button has been fully pressed (S72). If it is confirmed that the shutter button has been fully pressed (SP2 ON), a focusing operation is performed to move the taking lens to a focus position, and the shutter is released. Opens and closes (S76). In S72, the shutter button is fully pressed (SP
If 2 ON) is not detected, it is confirmed that the pressing operation of the shutter button is released (S74), and the process proceeds to S5.
Return to 2.

During the opening of the shutter in S76, the strobe light is emitted as needed. At S78, the presence or absence of flash emission is confirmed. If the flash is emitted, the main battery 34 is allowed to be charged after the flash emission (S80). As described above, the main battery 34 is allowed to be charged immediately after the strobe light emission with a large power consumption, and the consumed energy of the main battery 34 is supplemented at an early stage, thereby preventing overdischarge of the main battery. Thereafter, the film is fed (winding up one frame) (S82). After the feeding of one frame is completed, the shot counter is incremented, and the process returns to S52. In the present embodiment, as shown in FIG. 6, since the operation of the camera including the film feeding control and the charging control of the main battery are performed by one CPU 70, the charging of the main battery 34 is performed in S80. When the film feeding is executed in a state where the
Has been banned from charging.

Normally, the control of the camera operation and the control of the charging of the main battery 34 cannot be performed in parallel in real time by one CPU 70, and therefore, as described above, the main operation is performed during the film feeding (the camera operation control processing). The battery 34 is not charged. Thereby, the charging of the main battery 34 does not progress during the operation control of the camera, and the charge amount of the main battery 34 can be monitored after the operation of the camera is completed.
4 can be prevented from being overcharged.

If it is determined in step S78 that the flash has not been emitted, the process proceeds to step S82. After the film has been fed, the process returns to step S52 to start the charging process of the main battery 34. In addition to the shot counter, a total shot counter that keeps counting the total number of shots may be provided, and the life of the main battery 34 may be determined based on the value of the total shot counter.

When the photographing of all the frames of the photo film contained in the film cartridge is completed and the end of the film is detected, the automatic film rewinding process (auto return: AR) is started (S90). Then, the film counter indicating the remaining amount of the film is changed from "N" to "E".
, And after it is confirmed that the film has been completely rewound into the cartridge (S94), the process returns to S52, and charging of the main battery 34 is resumed.

When the film rewind lever is operated halfway before the completion of filming of all frames of the film and a command to rewind the film is issued, a manual return (MR) is started (S).
92). Then, the film counter changes from "N" to "E".
, And after it is confirmed that the film has been completely rewound into the cartridge (S94), the process returns to S52, and charging of the main battery 34 is resumed.

The film cartridge for which rewinding has been completed is removed from the cartridge chamber and replaced with a new film cartridge. Since the shutter button and the like are not operated during the period until a new film cartridge is loaded, a relatively long charging time can be secured by charging the main battery during this time.

After the completion of rewinding of the automatic return or the manual return is confirmed in S94, when it is further detected that the film has been taken out of the camera by the film presence / absence detection switch provided in the cartridge chamber 14. The charging process of the main battery 34 may be started. FIG. 16 is a flowchart showing the operation of step S5 shown in FIG.
FIG. 6 is a flowchart showing a flow of a charging current switching process regarding No. 2; When the charging process is started (S102), first, the remaining amount of the main battery 34 is checked. That is, it is determined whether the value of the shot counter has fallen below the reference value corresponding to the first level L1 shown in FIG. 14 (S10).
4). If the value of the shot counter exceeds the reference value, the CPU 70 outputs a charging current switching signal for turning off the switch 82A of the constant current circuit 82 shown in FIG. Then, the switch 82A
Is turned off, the charging current is set to the current value i1 (19 mA) as described with reference to FIG. 7, and low-current charging is performed (S106).

On the other hand, if the remaining amount of the main battery 34 is equal to or lower than the first level L1 in S104, the CPU 70 outputs a charging current switching signal for turning on the switch 82A of the constant current circuit 82 shown in FIG. You. When the switch 82A is turned on by the signal, the charging current is set to the current value i2 (59 mA) as described with reference to FIG. 7, and rapid charging is performed (S108).

In general, low-current charging has advantages in that charging can be performed safely and energy loss is small, but there is a disadvantage in that charging time is prolonged. On the other hand, when the charging current is increased, the charging time is shortened, but there is a disadvantage that generation of dendrant and energy loss are large. Therefore, normally, low-current charging is performed with emphasis on safety and energy loss, and when the remaining amount of the main battery 34 becomes equal to or lower than the first level, switching to quick charging is performed. Is to be prevented beforehand.

Subsequently, it is confirmed whether or not the battery has been fully charged (S110). If the battery has not been fully charged, the process proceeds to S1.
Return to 04. On the other hand, when it is confirmed in S110 that the main battery 34 is fully charged, the charging is stopped (S110).
112), the process returns to the main routine shown in FIG. 15, and the processing from S54 described above is executed. In the above embodiment, the case where the auxiliary battery and the charging circuit are incorporated in the camera together with the main battery has been described. However, the auxiliary battery and the charging circuit may be a separate charging device separated from the camera.

[0101]

As described above, according to the camera of the present invention, the main battery is charged by the auxiliary battery, and power is supplied from the main battery to the power consuming means required for the photographing operation. By using inexpensive and readily available batteries such as manganese AA batteries, when the power supply (auxiliary battery) is exhausted, it is only necessary to replace the auxiliary battery alone, compared to replacing the main battery. There is also a sense of security that it is economical and easy to obtain, and has the advantage of being environmentally friendly. In particular, by using a metal lithium secondary battery as the main battery, a large capacity and a large current can be supplied from the main battery to the power consuming means in the camera. There is a sense of security that you can shoot anytime without it. In addition, since the output voltage of the auxiliary battery is boosted and applied to the main battery, the main battery can be charged by the auxiliary battery having a small voltage,
There is an advantage that the electric energy of the auxiliary battery can be used without waste.

Further, the first and second constant current means are provided, and current switching control means for enabling either of them is provided, so that the charging current of the main battery can be switched between large and small. Therefore, charging can be performed with a preferable charging current in accordance with the usage state of the camera, the remaining amount of the main battery, and the like, while taking into account charging safety and energy loss. Therefore,
Normally, low-current charging enables safer and less energy-loss charging.In addition, it can be charged in a short time by increasing the charging current against a sudden large discharge of the main battery. There is an advantage that you can. Thereby, there is an advantage that it is possible to respond to continuous use of the camera such as continuous shooting and to prevent overdischarge of the main battery.

In particular, the advantage is that the camera can be used continuously by increasing the charging current and quickly compensating the consumed energy of the main battery after shooting in the continuous shooting mode or shooting with strobe light emission. There is an advantage that overdischarge of the main battery can be prevented. Further, the remaining amount of the main battery is monitored by a shot counter or the like, and when the remaining amount reaches a predetermined level, the mode is switched to quick charging, whereby overdischarge of the main battery can be prevented.

[Brief description of the drawings]

FIG. 1 is a front internal perspective view of a camera to which the present invention is applied.

FIG. 2 is a top internal perspective view of a camera to which the present invention is applied.

FIG. 3 is a side internal perspective view of a camera to which the present invention is applied.

FIG. 4 is a block diagram including a charging circuit for charging a main battery with an auxiliary battery.

FIG. 5 is a circuit diagram illustrating an example of a booster circuit.

FIG. 6 is a block diagram illustrating a configuration of a control system of the camera.

FIG. 7 is a circuit diagram showing a specific configuration of a constant current circuit.

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.

FIGS. 11A and 11B are explanatory diagrams used to explain another display mode displayed on the liquid crystal panel. FIG. 11A is an explanatory diagram showing a display when the remaining amount of the auxiliary battery is sufficient. ,
(B) is an explanatory view showing a display after the auxiliary battery is exhausted.

FIG. 12 is a flowchart illustrating a flow of a battery check process of an auxiliary battery.

FIG. 13 is a flowchart showing an example of a main battery charging sequence.

FIG. 14 is an explanatory diagram used to explain the relationship between the remaining battery level of the main battery and whether discharge is possible.

FIG. 15 is a flowchart showing the flow of processing of the camera used to explain the allowable charging time of the main battery.

FIG. 16 is a flowchart used to explain a charging current switching process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Camera 14 ... Cartridge chamber 16 ... Film winding chamber 18 ... Strobe device 28 ... Winding spool 30 ... Film feeding motor 34 ... Main battery 40 ... Auxiliary battery 43 ... Control circuit mounting space 44 ... Boost circuit mounting space 50 ... Charging circuit 52 ... Charge control circuit 54 ... Boost circuit 70 ... Central processing unit (CPU) 72 ... Shutter drive circuit 74 ... Strobe circuit 76 ... Film feeding circuit 78 ... EEPROM

 ──────────────────────────────────────────────────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 (8)

[Claims] 1. A main battery capable of repeatedly discharging and charging when the battery is charged with a charging current of a predetermined charging current value or less when the remaining amount is equal to or more than a predetermined capacity and the remaining capacity is equal to or more than a predetermined capacity. A power consuming unit that is supplied with power from the main battery and performs an operation necessary for photographing; an auxiliary battery that supplies charging energy to the main battery; and a boosting unit that boosts an output voltage of the auxiliary battery. A first current for maintaining a current supplied to the main battery via a booster at a first current value equal to or less than the predetermined current value;
And a second constant current means for maintaining a current supplied to the main battery via the boosting means at a second current value smaller than the first current value. Charging means for supplying charging energy of a battery to the main battery to charge the main battery; and enabling one of the first constant current means or the second constant current means and disabling the other, A camera comprising: current switching control means for switching a charging current for charging a main battery. 2. The apparatus according to claim 1, wherein said current switching control means activates said first constant current means when said camera is set to a continuous shooting mode and continuous shooting is performed. Camera. 3. The camera according to claim 1, wherein said current switching control means activates said first constant current means when photographing with strobe light emission is performed. 4. A remaining amount detecting means for detecting a remaining amount of the main battery, wherein the current switching control means sets a predetermined level value of the remaining amount of the main battery detected by the remaining amount detecting means. The second constant current means is made effective when the remaining power exceeds the reference value, and the first constant current charging means is made effective when the remaining amount of the main battery detected by the remaining amount detecting means falls below the level value. The camera according to claim 1, wherein 5. The camera according to claim 4, wherein the level value is set higher than a level indicating the predetermined capacity at which the main battery can be repeatedly discharged and charged. 6. The system according to claim 1, wherein the remaining amount detecting unit sets a series of photographing operations associated with the release operation as one shot,
A shot counter that adds and counts the number of shots for each release operation, and a reset unit that resets a counter value of the shot counter to zero when the main battery reaches a fully charged state by the charging unit. Energy is supplied from the auxiliary battery to the main battery via the boosting means, and as the energy supplied to the main battery increases, the decrement means decreases the count value of the shot counter. Wherein a reference counter value indicating the level value is set in the current switching control means, wherein the reference value indicating the level value is set in the current switching control means. Item 6. The camera according to Item 4. 7. The counter value of the shot counter is provided with a decimal part less than one shot, and when at least one of a series of shooting operations constituting one shot is performed, the operation is performed by the operation. 7. The camera according to claim 6, wherein the amount of energy consumed by the power consuming means is converted into an energy ratio for one shot, and the converted energy ratio is added to a decimal part of the shot counter in accordance with the operation content. . 8. The count value of the shot counter is provided with a fractional part of less than one shot, and the amount of energy consumed to maintain the spontaneous discharge of the main battery or the standby state of the camera over time is measured. 7. The camera according to claim 6, wherein the energy ratio is converted into an energy ratio for one shot, and the converted energy ratio is added to a fractional part of the shot counter in accordance with an unoperated time of the camera.