JPH08304898A - Charging equipment for camera - Google Patents

Abstract

PURPOSE: To quickly charge the in-camera battery of a camera in an emergency. CONSTITUTION: The charging equipment for the camera is constituted of an external battery adapter 10 and a charging circuit provided in the adapter 10. An external battery 14 is housed in the external batter adapter 10, connectors 16A projected therefrom are connected to the external battery 14 and when the adapter 10 is attached to the side surface part of the camera 20, the connectors 16A are connected to the in-camera battery 22 housed in the camera 20 with a power supply input terminal on the side of the camera 20. The charging control circuit of the charging circuit provided in the adapter 10 transfers the electricity of the external battery 14 to the in-camera battery 22, to charge it when its voltage VCR is <3.2V. Moreover, the charge control circuit makes a boosting circuit inoperative, to stop the charging of the in- camera battery 22, when its voltage VCR is 3.2V.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for a camera, and more particularly to a charging device for a camera that charges a battery in the camera built in the camera.

[0002]

2. Description of the Related Art Conventionally, when a camera is housed in a camera case, a solar battery provided in the camera case can be used to charge a battery in the camera (such as a nickel-cadmium battery or a silver battery), and a camera case with a solar battery is proposed. (Japanese Utility Model Publication No. 56-79126).

In Japanese Utility Model Laid-Open No. 56-79126, a solar battery is attached to the camera case, so that the battery inside the camera can be charged while being carried, and compared with the case where the solar battery is attached to the camera body. There is a description that allows sufficient charging time.

[0004]

By the way, a solar cell of a size that can be attached to a camera case generates extremely weak electric power. Therefore, in order to charge the battery in the camera as desired, the camera is housed. The camera case must be left in direct sunlight for a long time. Therefore, if the battery in the camera is exhausted and it becomes impossible to shoot, the battery in the camera cannot be rapidly charged. Therefore, the camera cannot be used unless the battery in the camera is replaced with another battery in the camera that has been charged separately. There is a problem that you cannot do it.

Further, if a rechargeable camera-dedicated battery with less self-discharge is used as the battery in the camera,
In some cases, it may not be easily available at travel destinations, overseas, etc., and the battery inside the camera may not be sold outside and may be replaced only at the camera store.In these cases, the battery inside the camera may be replaced in an emergency. There is a problem that can not be exchanged.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a charging device for a camera capable of rapidly charging the battery in the camera in an emergency.

[0007]

In order to achieve the above object, the present invention provides a camera body having a rechargeable camera battery, an external battery adapter that accommodates an external battery and is detachable from the camera body. It is provided on the external battery adapter, and when the external battery adapter is attached to the camera body,
Charging means for charging the in-camera battery by an external battery in an external battery adapter.

[0008]

According to the present invention, when the external battery adapter is attached to the camera body, the battery in the camera is rapidly charged by the external battery in the external battery adapter by the charging means provided on the external battery adapter side.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a charging device for a camera according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing an external appearance of a camera charging device and a camera according to the present invention. The charging device for the camera shown in the figure includes an external battery adapter 10 and a charging circuit 12 (FIG. 2) provided in the external battery adapter 10.

The external battery adapter 10 is provided with a printed circuit board (not shown) on which a charging circuit to be described later is mounted. This printed circuit board has an external battery adapter 1
The external battery 14 housed in the 0 is electrically connected. The external battery 14 is, for example, an AA battery. Further, connectors 16A, 16A protruding from the external battery adapter 10 are electrically connected to the printed circuit board. When the external battery adapter 10 is attached to the side surface portion of the camera 20, these connectors 16A, 16A are Camera 2
It is adapted to be connected to the in-camera battery 22 housed in the camera 20 via the power input terminal on the 0 side. The in-camera battery 22 is a battery dedicated to a rechargeable camera with little self-discharge, and for example, a battery having a self-discharge rate of 5% or less is used.

Next, details of the in-camera battery 22 charged by the charging device for the camera will be described. Charging of primary batteries is generally prohibited. The reason is that, for example, an alkaline battery may leak or explode, and a lithium battery may be extremely dangerous because it may cause an explosion or a fire. This is also due to the fact that the reversibility of redox of electrolytic manganese dioxide, which is the positive electrode active material, is low. However, when lithium (or its alloy) is charged, a protrusion called dendrite is formed. Is extremely dangerous.

Although a lithium primary battery has a very small leakage current and is preferable as a battery for a camera in which the unused period is relatively long, when the lithium primary battery is charged, a dendrite is formed as described above, and the lithium It is extremely dangerous that the primary battery burns out, and it has been conventionally impossible to charge the lithium primary battery. However, even a non-aqueous electrolyte battery such as a lithium primary battery having a positive electrode active material, a light metal negative electrode active material, and a non-aqueous electrolyte can be safely charged under certain conditions. Found. This charging method is a method of charging with a time rate current of 2 μC to 5 mC only when the remaining amount of the positive electrode active material of the non-aqueous electrolyte battery is within the range of 5 to 95% of the capacity C of the positive electrode active material. Is. Here, the above charging method is suitable for charging a so-called lithium primary battery in which the positive electrode active material is manganese dioxide and the negative electrode active material is lithium or a lithium alloy.

When the remaining amount of the positive electrode active material of the non-aqueous electrolyte battery reaches near 0%, charging becomes almost impossible, and when the remaining amount of the positive electrode active material is near 100%, the electrolyte may be decomposed. Therefore, the remaining amount is 5% to 95%
The requirement was to be within the range. Especially, the capacity of 10
Charging at ~ 90% is preferred. Here, the reason why only the capacity of the positive electrode active material is focused is that the capacity of the negative electrode active material is generally larger than that of the positive electrode active material in a non-aqueous electrolyte battery using a light metal as the negative electrode active material.

Further, if the charging speed is high, the risk of dendrites is increased, but according to the experimental results, 10 mC
Almost no generation of dendrites was observed in the hourly rate charging, and some dendrites were produced in the 20mC hourly charging. Therefore, in consideration of safety, the upper limit was set to a rate charge of 5 mC, which is half of 10 mC in which generation of dendrite was hardly observed. Further, the lower limit is not particularly specified from the viewpoint of generation of dendrites, but since the purpose of charging is not achieved at a low charging speed at which charging is not substantially performed, 5 μC is set as the lower limit. For the same reason as the upper limit, the charging speed is especially 10 μC
A time rate of ˜1 mC is preferable, and further 20 μC to 0.5
The time rate of mC is most preferred.

As the positive electrode active material, manganese dioxide is preferable, but manganese dioxide synthesized by electrolysis and manganese dioxide chemically synthesized are particularly preferable. As a material that can be used as the negative electrode active material, lithium metal or lithium alloy (any metal that forms an alloy with lithium may be used, but Al, Mn, Sn, Mg, Cd, and In are particularly preferable. Among them, an alloy containing Al). It is preferable to use.

A conductive agent, a binder, a filler and the like can be added to the electrode mixture. The conductive agent may be any electronically conductive material that does not undergo a chemical change in the constructed battery. The amount added is not particularly limited,
1 to 50% by weight is preferable, and 2 to 30% by weight is particularly preferable. As the binder, one of polysaccharides, thermoplastic resins, and polymers 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 can be used as long as it does not cause a chemical change in the constructed battery. Generally, olefin polymers such as polypropylene and polyethylene, fibers such as glass and carbon are used. The amount of the filler added is not particularly limited, but is 0
-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 is a mixed liquid of propylene carbonate and / or butylene carbonate and 1,2-dimethoxyethane and / or diethyl carbonate. the _{LlCF 3 SO 3, LiCl0 4,} LiBF 4 and / or an electrolyte containing LiPF ₆ is preferred. The amount of these electrolytes to be added into the battery is not particularly limited, but can be used in a required amount depending on the amount of the positive electrode active material or 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 and 1,2-dimethoxyethane,
0.4 / 0.6 to 0.6 / 0.4 are preferable. The concentration of the supporting electrolyte is not particularly limited, but it is 0.
2-3 mol is preferable. FIG. 2 is a circuit diagram showing an embodiment of the charging circuit 12 provided in the external battery adapter 10 shown in FIG. The charging circuit 12 shown in the figure is mainly composed of a charging control circuit 24, a booster circuit 26, and the like.
In addition, the charge control circuit 24 is connected with a display 28 that displays a liquid crystal display such as a charge amount. The power input terminal of the camera 20 is connected to the connectors 16A and 16A of the charging circuit 12.

The charge control circuit 24 controls the booster circuit 26 and the display 28. Further, the charge control circuit 24 controls the booster circuit 26 to be inoperable, for example, when the voltage V _{CR of the} battery 22 in the camera is V _CR ≧ 3.2V. Further, the charge control circuit 24 determines that the voltage V _{CR of the} battery 22 in the camera is V _CR <
In the case of 3.2 V, the booster circuit 26 is controlled to charge the battery 22 in the camera with the external battery 14. That is, the charging control circuit 24 determines that the voltage V _{CR of the} battery 22 in the camera is V _CR <3.2V.
Sometimes the booster circuit 26 is driven.

FIG. 3 is a circuit diagram showing an embodiment of the booster circuit 26. The booster circuit 26 shown in the figure is of a push-pull type and has a transistor Q for alternately turning on the DC power supply of the external battery 14 by the charge control circuit 24.
It is converted into an alternating current at 2, Q3, boosted through the transformer T, and then rectified by the rectifier circuit 26A to be converted into a direct current voltage necessary for charging the battery 22 in the camera.

Here, when 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 of the secondary side, a relationship of the following _{equation, 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: V ₁ = 0.9−V _DS = 0.7 [V] (Min) (2) V ₂ = 3.2 + 0.7 × 2 + 0.5 = 5.1 [V] (3) (However, V _DS : Saturation voltage between drain and source of transistors Q2 and Q3 3.2: Maximum voltage of battery 22 in camera 0.7 × 2: Voltage drop in rectifier circuit 26A ) Is. Therefore, the turns ratio n ₂ / n ₁ of the transformer T is n ₂ / n ₁ = V ₂ / V ₁ ≈7.3. Further, in order to obtain I _CHG = 100 mA as the charging current I _CHG of the battery 22 in the camera, the transformer T needs to be 1
The current I _FT on the next side is I _FT = 730 mA.

As described above, the charge control circuit 24 uses the external battery 1 when the voltage V _{CR of the} battery 22 in the camera is V _CR <3.2V.
The amount of electricity of 4 is transferred to the battery 22 in the camera to charge the battery 22 in the camera. When the voltage V _CR of the in-camera battery 22 becomes V _CR = 3.2 V, the charge control circuit 24 disables the booster circuit 26 and stops the charging of the in-camera battery 22.

Next, the case of rapidly charging the battery 22 in the camera will be described. First, the external battery adapter 10 accommodating the external battery 14 is attached to the camera 20 (see FIG. 1). As a result, the output terminal 16A of the external battery 14 in the external battery adapter 10 is connected to the external power input terminal (not shown) on the camera 20 side, and the voltage V _E of the external battery 14 is 0.9 ≦ V _E ≦ 1.5. As long as the amount of electricity in the external battery 14 is within the range of
Transferred to 2.

According to this external battery 14, it takes about 1 minute in about 1 minute.
The battery 22 in the camera can be charged with the amount of electricity required for a shot. In addition, a new external battery (AA battery) 14
When the battery is used, it is possible to fully charge the battery 22 in the camera, which is 60% used, and it is possible to take at least 100 shots. Furthermore, a used AA battery can be used to some extent.

Further, the external battery adapter 10 is connected to the camera 20.
When it is attached to the camera 20, the charging control circuit 24 detects that the external battery adapter 10 is attached to the camera 20, and causes the display 28 to be displayed. As shown in FIG. 4, the display unit 28 has a display section showing charging from the external battery 14 to the in-camera battery 22, and the charging control circuit 24 is configured such that the external battery adapter 10 is attached to the camera 20 When the battery 22 in the camera is being charged by the battery 14, the arrow 29 on the display unit is made to blink. In addition, the charge control circuit 24 uses the voltage V _{CR of the} battery 22 in the camera for charge control as described above.
And the voltage V _E of the external battery 14 is detected. Based on the detected voltage V _CR , the charge amount of the battery 22 in the camera is graphically displayed on the display unit, and the detected voltage V _E is detected.
Based on _E , the remaining amount of the external battery 14 is graphically displayed on the display unit.

On the other hand, the battery 22 in the camera is charged by the charging camera case shown in FIG. 5 at the time of charging other than the quick charging. The charging camera case mainly includes a case body 30, a lid 32, a solar cell 34, a display unit 36,
And a charging circuit (not shown) and the like. The case body 30 and the lid 32 are formed of a metal such as aluminum or a plastic having a light shielding property, and the case body 30 is formed with a camera housing portion 30A for housing the camera 20. A solar cell 34 having a size of, for example, 100 mm × 55 mm is arranged on the lid 32.

The lid 32 is rotatably arranged around the support shaft 34A with respect to the case body 30, and the opening angle thereof is adjustable with respect to the case body 30. This allows the solar cell 34 to be directed toward the sun. A printed circuit board (not shown) on which a charging circuit and the like are mounted is arranged in the case body 30. A solar cell 34 is electrically connected to the printed circuit board, and a power output terminal (not shown) that is spring-biased so as to move back and forth toward the camera storage section 30A is connected. When the camera 20 is housed in the camera housing section 30A, the power output terminal is connected to the in-camera battery 22 housed in the camera 20 via the power input terminal on the camera side.

When charging the battery 22 in the camera, the camera 20 is stored in the charging camera case. And preferably, this charging camera case is placed near the window so that sunlight through the window can enter the solar cell 34 provided in the charging camera case. Further, the angle of the lid 32 is adjusted so that the sunlight enters the solar cell 34 substantially vertically. As shown in FIG. 6, the display unit 36 has a display section that indicates charging from the solar battery 34 to the in-camera battery 22. When the in-camera battery 22 is being charged by the solar battery 34, a display is displayed. The arrow 37 on the part blinks. Further, the charge amount of the battery 22 in the camera is graphically displayed on the display unit. Thus, the use of the charging camera case is convenient for charging other than quick charging.

[0029]

As described above, according to the camera charger of the present invention, the battery in the camera is rapidly charged by the external battery in the external battery adapter by the charging means provided on the external battery adapter side. Therefore, it is possible to deal with an emergency when there is not enough time to fully charge the battery in the camera with the solar battery.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of a camera charging device and a camera according to the present invention.

FIG. 2 is a circuit diagram showing an embodiment of a charging circuit provided in an external battery adapter.

FIG. 3 is a circuit diagram showing details of the booster circuit shown in FIG.

FIG. 4 is an explanatory diagram showing display contents of a display provided on the external battery adapter.

FIG. 5 is a perspective view showing an external appearance of a camera and a charging camera case equipped with a solar cell.

FIG. 6 is an explanatory diagram showing the display contents of a display provided on the charging camera case.

[Explanation of symbols]

 10 ... External battery adapter 12 ... Charging circuit 14 ... External battery 24 ... Charging control circuit 26 ... Booster circuit 28 ... Indicator

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[Procedure amendment]

[Submission date] June 16, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

The external battery adapter 10 is provided with a printed circuit board (not shown) on which a charging circuit to be described later is mounted. This printed circuit board has an external battery adapter 1
The external battery 14 housed in the 0 is electrically connected. The external battery 14 is, for example, an AA battery. Further, connectors 16A, 16A protruding from the external battery adapter 10 are electrically connected to the printed circuit board. When the external battery adapter 10 is attached to the side surface portion of the camera 20, these connectors 16A, 16A are Camera 2
It is adapted to be connected to the in-camera battery 22 housed in the camera 20 via the power input terminal on the 0 side. The in-camera battery 22 is a rechargeable camera-dedicated battery with less self-discharge, and for example, a self-discharge rate of 5% / year or less is used.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

Next, details of the in-camera battery 22 charged by the charging device for the camera will be described.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Delete

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Delete

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Delete

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

As the positive electrode active material of the battery in the camera, manganese dioxide is preferable, but manganese dioxide chemically synthesized and manganese dioxide chemically synthesized are particularly preferable. As a material that can be used as the negative electrode active material, lithium metal, lithium alloy (any metal that forms an alloy with lithium may be used, but particularly Al, Mn, Sn, Mg,
Cd and In are preferable. Above all, it is preferable to use an alloy containing Al).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiro Nishitani 3-11-46 Izumi, Asaka-shi, Saitama Fuji Shashin Film Co., Ltd. (72) Inventor Yoshiaki Sakamoto 7-29-2 Okusawa, Setagaya-ku, Tokyo Stock Company Rick

Claims (2)

[Claims] 1. A camera body having a rechargeable camera battery, an external battery adapter for accommodating an external battery and being detachable from the camera body, the external battery adapter being provided on the camera body, A charging device for a camera, comprising: a charging unit configured to charge the in-camera battery by an external battery in an external battery adapter when mounted on the camera. 2. The charging device for a camera according to claim 1, wherein the external battery adapter is attached to the camera body during an emergency quick charge.