JP2001327072A - Digital camera and power control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital camera capable of minimizing battery consumption by reducing current consumption, while the camera is not operating, and capable of warning an operator that battery voltage is low, when the battery voltage is below a prescribed voltage level. SOLUTION: This digital camera is provided with an operating switch SW 102 for turning on and off a battery 101, a control circuit 108A, and a power circuit 105A. The power circuit 105A operates, while the operating switch 102 is being operated or a control signal is being supplied from the control circuit 108A. This camera is also provided with a means 201 for detecting the voltage of the battery 101 and a warning means 202. If the voltage of the battery 101 is lower than a prescribed voltage, the power circuit 105A is turned off after warning operation by a warning means 202, without having a camera part 109 operate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a power control method for a digital camera and the like.

[0002]

2. Description of the Related Art Conventionally, as a technique in this kind of field, for example, there is one as shown in FIG.

FIG. 4 is a block diagram schematically showing a conventional digital camera.

In FIG. 1, reference numeral 101 denotes a battery for supplying power to the camera, 102 denotes an operation switch for turning on / off the power of the camera, and 103 denotes an operation switch 102.
, A switch (SW) detection circuit for detecting that the camera has been operated, 105 a power supply circuit for a control circuit for supplying power to the control circuit 108, and 106 a camera circuit for supplying power to the camera unit 109 A power supply circuit 108 is a control circuit for controlling the operation of the camera.

[0005] A camera unit 109 includes an imaging circuit composed of a CCD or the like, a signal processing circuit, a display circuit composed of an LCD or the like, a driver circuit for operating a lens or the like, and a memory for recording a captured image. And so on. Here, the detailed description of the camera unit 109 is omitted.

Next, the operation of the digital camera having the above configuration will be described.
In particular, the operation when the power is turned on and off will be described.

When the battery 101 is in the camera body, the power of the battery 101 is supplied to the control circuit power supply circuit 105. The power supply circuit 105 controls the voltage of the battery by the power supply voltage at which the control circuit 108 can operate. Into the control circuit 10
8 The control circuit 108 monitors a control signal output from the SW detection circuit 103. When the operation switch 102 is operated to turn on the power, the SW detection circuit 1
In step 03, the operation is output as a control signal to the control circuit 108, and the control circuit 108 starts the operation of the camera in response to the control signal. That is, the control circuit 108
A control signal for operating the camera power supply circuit 106 is output, and control for operating the camera unit 109 is started. Here, the details of the control are omitted.

Further, an operation switch 10 for turning off the power is provided.
2 is operated, the SW detection circuit 103 outputs the operation to the control circuit 108 as a control signal, and the control circuit 108 receives the control signal and stops the operation of the camera. , And a control signal for stopping the camera power supply circuit 106 is output.

[0009]

However, in the above-mentioned conventional digital camera, the control circuit power supply circuit 105 is always operated to control the operation of the operation switch 102 as shown in FIG. Since the power must be continuously supplied to the circuit 108, there is a problem that the battery 101 is consumed even when the camera is not operating.

Further, as the configuration of the power supply circuit 105, when the operating power supply voltage of the control circuit 108 is lower than the voltage of the battery 101, the power supply circuit 105 for the control circuit becomes a step-down circuit. In such a case, the power consumption of the power supply circuit itself is large, so that the battery is greatly consumed while the camera is not operating. In addition, when the step-down circuit is configured by a series regulator, the efficiency of the power supply circuit 105 is reduced, so that the battery consumption during operation is large. For this reason, it is conceivable to configure the step-down circuit by combining a switching regulator and a series regulator, and to switch between when the camera is operating and when it is not operating. However, the power supply circuit becomes complicated and causes an increase in cost.

In recent years, as the size of the battery has been reduced, the voltage of the battery has been reduced. In this case, the power supply circuit 105 for the control circuit must be configured as a booster circuit or a step-up / down circuit. Since the booster circuit and the step-up / step-down circuit can be constituted only by switching regulators, the current consumption in the power supply circuit itself is large and the efficiency is lower than that of the step-down circuit.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a digital camera or the like capable of reducing current consumption while the camera is not operating and reducing battery consumption. It is another object of the present invention to provide a digital camera or the like that can notify an operator that the battery voltage has dropped when the battery voltage falls below a predetermined voltage. It is an object of the present invention to provide a digital camera or the like that enables charging of a battery mounted in a camera body.

[0013]

In order to achieve the above object, a digital camera according to the first aspect of the present invention includes a battery for supplying power to the camera, and an operation switch for turning on / off the power of the camera. A control circuit for controlling the operation of the camera, a power supply circuit configured to be capable of on / off control and for supplying power to the control circuit, and detecting that the operation switch has been operated. And a SW detection circuit that supplies a control signal to the power supply circuit and the control circuit during a period in which the operation switch is operated, wherein the power supply circuit is supplied with a control signal from the SW detection circuit or the control circuit. The control circuit receives a control signal from the SW detection circuit, and supplies the control signal to the power supply circuit when the power supply circuit is off. To turn on the power supply circuit, and stop the supply of a control signal to the power supply circuit when the power supply circuit is on, thereby controlling the power supply circuit to be turned off. A control signal is supplied to the control circuit only when power is supplied to the circuit.

According to a second aspect of the present invention, in the digital camera according to the first aspect, a battery voltage detecting means for detecting a voltage of the battery, and a battery voltage detected by the battery voltage detecting circuit is a predetermined voltage. Warning means for issuing warning information to the outside when the voltage is lower than the predetermined value, wherein the power supply circuit includes a power supply that enables the control circuit to operate even when the voltage of the battery is equal to or less than the predetermined value. It is configured to be able to supply, and when power is supplied to the control circuit by operating the operation switch, when the battery voltage detection circuit detects that the battery voltage is below a predetermined value, The control circuit is configured to turn off the power supply circuit after issuing warning information by the warning means without operating the camera.

In the digital camera according to a third aspect of the present invention, in the digital camera according to the first or second aspect, the battery is constituted by a rechargeable battery. When a charging power supply terminal for supplying power and a charging circuit for generating power for charging the battery are provided outside the camera, and the charging circuit is connected to the charging power supply terminal, The supply of the control signal from the SW detection circuit to the power supply circuit and the control circuit is prohibited so that the power supply of the camera is not turned on.

In the power supply control method for a digital camera according to the present invention, a battery for supplying power to the camera is provided.
An operation switch for turning on / off the power of the camera, a control circuit for controlling the operation of the camera, a power supply circuit configured to enable on / off control and supplying power to the control circuit; Detecting that the switch has been operated and supplying a control signal to the power supply circuit and the control circuit during a period in which the operation switch is operated;
In a digital camera including a W detection circuit, the power supply circuit is configured to be turned on during a period in which a control signal is supplied from the SW detection circuit or the control circuit, and the SW detection circuit includes: Only when power is supplied to the control circuit, a control signal is supplied to the control circuit, and the control circuit receives a control signal from the SW detection circuit and The power supply circuit is turned on by supplying a control signal to the power supply circuit when the power supply circuit is off, and the power supply circuit is turned off by stopping supply of the control signal to the power supply circuit when the power supply circuit is on. I do.

According to a fifth aspect of the present invention, in the power supply control method for a digital camera according to the fourth aspect of the present invention, the power supply circuit may be adapted to operate when the voltage of the battery is lower than a predetermined value. Also, the power supply for enabling the operation of the control circuit is configured to be performed, and when power is supplied to the control circuit by operating the operation switch, if the voltage of the battery is lower than a predetermined value, ,
The method is characterized in that the power supply circuit is turned off after issuing warning information to the outside by a warning means without operating the camera using the control circuit.

According to a sixth aspect of the present invention, in the power control method for a digital camera according to the fourth or fifth aspect, the battery comprises a rechargeable battery, and the battery is rechargeable. A charging power supply terminal for supplying power from outside the camera for charging;
A charging circuit for generating a power supply for charging the battery is provided outside the camera, and when the charging circuit is connected to the charging power supply terminal, the charging circuit for the power supply circuit and the control circuit is provided. It is characterized in that the supply of the control signal from the SW detection circuit is prohibited so that the power supply of the camera is not turned on.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a block diagram of a main part of a digital camera according to a first embodiment of the present invention.
Elements common to those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, as shown in the figure, an SW detection circuit 103A, a control circuit power supply circuit 105A, and a control circuit 108A, which are different from the conventional circuit shown in FIG. Circuit 104 and AND circuit 1
07 is provided.

More specifically, the SW detection circuit 103A detects that the operation switch 102 has been operated, and controls the control circuit power supply circuit 105A and the control circuit 108A during the period in which the operation switch 102 is operated. The OR circuit 104 is configured to supply a signal.
03A and the control signal S output from the control circuit 108A.
1 and S2, and the AND circuit 107 performs a logical operation on the SW detection circuit 103A and the output of the control circuit power supply circuit 105A.

The OR circuit 104 and the AND circuit 10
7 are supplied to a power supply circuit 105A and a control circuit 108A, respectively.
5A and the control circuit 108A are configured not to operate while the camera is not operating. Here, the control circuit power supply circuit 105A is a switching regulator whose operation can be controlled by the control signal S5 output from the OR circuit 104.

Next, the operation of the digital camera of this embodiment, particularly, the operations (A) and (B) when the power is turned on and off will be described.

(A) Power-On Operation First, the power-on operation will be described. When the operation switch 102 is operated to turn on the power, the SW detection circuit 103A supplies the OR circuit 104 and the AND circuit 107 with "H" level signals as control signals S1 and S2 during the operation switch 102 operation. Supply.

The OR circuit 104 is provided with a SW detection circuit 103A.
When an "H" level signal is supplied from the CPU, an "H" level signal is output as the output signal S5. The operation of the control circuit power supply circuit 105A can be controlled by a control signal S5 output from the OR circuit 104.
Operates when “H” level is supplied from
Stop when the level is being supplied.

When the "H" level signal is supplied from the OR circuit 104, the control circuit power supply circuit 105A starts operating.
At the same time as converting the voltage of the battery 101 into a power supply voltage at which the control circuit 108A can operate and supplying it to the control circuit 108A,
The “H” level signal S4 is supplied to the AND circuit 107.
The control circuit 108A starts operating when power is supplied from the control circuit power supply circuit 105A. At the same time, the AND circuit 107 outputs “H” level signals S2 and S4 from the SW detection circuit 103A and the control circuit power supply circuit 105A.
Is supplied, an "H" level signal is output to the control circuit 108A as the output signal S6.

When the "H" level signal S6 is supplied from the AND circuit 107, the control circuit 108A operates the operation switch 1
02 is determined to have been operated, and the control circuit power supply circuit 1
In order to maintain the operation state of 05A, an “H” level signal S3 is output to the OR circuit 104, and the output of the “H” level signal is always continued during the operation of the camera.

If the "H" level signal S3 is supplied from the control circuit 108A to the OR circuit 104, even if the operation of the operation switch 102 is completed, the control circuit power supply circuit 105
The operation of A is continued.

When the operation time of the operation switch 102 is short, that is, when the output of the SW detection circuit 103A becomes "L" level before power is supplied to the control circuit 108A, the camera does not start operation. Will be. Further, the control circuit 108A outputs a control signal S7 for operating the camera power supply circuit 106 and starts control for operating the camera unit 109 in order to start the operation of the camera. Here, the details of the control are omitted.

(B) Operation at Power-off Next, the operation at power-off will be described. When the operation switch 102 is operated to turn off the power, the SW detection circuit 103A outputs “H” level control signals S1 and S2 to the OR circuit 104 and the AND circuit 107 during the period in which the operation switch 102 is operated. Supply signal.

When the power is on and the control circuit power supply circuit 105A is operating, the control circuit power supply circuit 1
Since the “H” level signal is supplied from 05A to the AND circuit 107, when the “H” level signal S2 is supplied from the SW detection circuit 103A, the AND circuit 107 becomes “H”.
The level signal S6 is output to the control circuit 108A.

When the "H" level signal S6 is supplied from the AND circuit 107, the control circuit 108A operates the operation switch 10
2 is determined to have been operated, and control of the camera unit 109 is terminated in order to stop the operation of the camera, and then a control signal S7 for stopping the power supply circuit for camera 106 is output. Further, the control circuit 108A supplies an “L” level signal S3 to the OR circuit 104 in order to stop the operation of the control circuit power supply circuit 105A.

When the operation of the operation switch 102 is completed, S
From the W detection circuit 103A, the "L" level signals S1 and S
2 is output, the "L" level signal S5 is output from the OR circuit 104, the operation of the control circuit power supply circuit 105A stops, and the supply of all power to the internal circuit of the camera is stopped. Stopping stops the operation of the camera.

As described above, while the camera is not operating, the operation of the power supply circuit 105A is stopped and power is not supplied to the control circuit 108A, and the power supply is started after the operation switch 102 is operated. By doing so, the current consumption while the camera is not operating is reduced, and the battery 101
Consumption can be reduced. Further, since the power supply circuit 105A can be constituted by a switching regulator, the efficiency of the power supply when the camera is operating is high, and the consumption of the battery can be suppressed. Further, the control signal is supplied from the SW detection circuit 103A to the control circuit 108A only when the power is supplied to the control circuit 108A.
By supplying an "H" level control signal from an external terminal when power is not supplied to 8A, there is no problem that the control circuit 108A causes latch-up.

[Second Embodiment] FIG. 2 is a block diagram of a main part of a digital camera according to a second embodiment of the present invention.
Components denoted by the same reference numerals as those in FIG. 1 indicate the same components, and description thereof will be omitted here.

In this embodiment, a battery voltage detection circuit 201 for detecting the voltage of the battery 101 in the configuration of FIG.
And a warning unit 202 for issuing a warning when the voltage of the battery 101 falls below a predetermined value. Warning means 2
Reference numeral 02 includes a sounding body such as a buzzer and a display device such as an LCD and an LED. Also, the control circuit 108B
Has a configuration corresponding to the battery voltage detection circuit 201 and the warning means 202 described above.

The power supply circuit 105B for the control circuit of the present embodiment controls the power supply circuit 105B even when the voltage of the battery 101 is lower than the predetermined value so that a warning can be issued when the voltage of the battery 101 falls below the predetermined value. The circuit 108B is configured to supply a predetermined power supply voltage at which the circuit 108B can operate. That is, when the voltage of the battery 101 is always higher than the power supply voltage of the control circuit 108B, the control circuit power supply circuit 105B
Is composed of a step-down circuit, and when the voltage of the battery 101 is always lower than the power supply voltage of the control circuit 108B,
When the voltage of the battery 101 is higher or lower than the power supply voltage of the control circuit 108B, it is constituted by a step-up / step-down circuit.

Next, the operation of the digital camera according to the second embodiment will be described.

First, the operation when the power is turned on will be described. After the operation switch 102 is operated, the control circuit 1
A series of operations from when power is supplied to 08B until the control circuit 108B outputs the "H" level signal S3 to the OR circuit 104 is the same as in the first embodiment, and a description thereof will be omitted here.

After supplying the “H” level signal S 3 to the OR circuit 104, the control circuit 108 B checks the voltage of the battery 101 via the battery voltage detection circuit 201. Battery 10
In the case where the voltage of No. 1 is a voltage sufficient to operate the camera, as in the first embodiment, the control circuit 108B
Outputs the control signal S7 for operating the camera power supply circuit 106 in order to start the operation of the camera, and also starts the control for operating the camera unit 109.

On the other hand, when the voltage of the battery 101 is lower than the predetermined value and the camera cannot be operated,
The control circuit 108B does not operate the camera power supply circuit 106 or the camera unit 109, and uses the warning unit 202 to warn the operator that the remaining amount of the battery 101 is low.
By supplying an “L” level signal to the circuit 104,
The control circuit power supply circuit 105B is stopped. The operation when the power is turned off is the same as that of the first embodiment, and the description is omitted here.

In the present embodiment, the same effects as those of the first embodiment can be obtained. Further, when the voltage of the battery 101 falls below a predetermined value, a warning is issued, and the operator turns off the power. It is possible to notify the operator that the voltage of the battery 101 has dropped. In addition, when the voltage of the battery 101 is low, the power supply other than the control circuit 108B is not turned on, and the operation of the camera is prohibited, thereby increasing the load current during the operation such as shooting or recording. In addition, it is possible to prevent the voltage of the battery 101 from suddenly decreasing and the camera from operating.

[Third Embodiment] FIG. 3 is a block diagram of a main part of a digital camera according to a third embodiment of the present invention.
Components denoted by the same reference numerals as those in FIG. 2 indicate the same components, and description thereof will be omitted here.

In the present embodiment, in the configuration of FIG. 2, a power supply terminal 301 for charging the battery 101 from outside the camera, an AND circuit 302 for performing a logical operation on the output of the OR circuit 104 and the power supply terminal 301, A charging circuit 303 for charging the battery 101 is provided. Note that the upper part of the broken line in the figure is a component inside the camera, and the lower part of the broken line is a component outside the camera. As is clear from the figure, the charging circuit 303 is provided outside the camera, and the power supply terminal 301 is The structure is exposed to the outside of the camera.

Next, the operation of the digital camera according to the third embodiment will be described.

When the power is not supplied to the power supply terminal 301, an "H" level signal is supplied from the power supply terminal 301 to the AND circuit 302, whereby the same operation as in the second embodiment is performed. Therefore, the description is omitted here.

When the charging circuit 303 is connected to the camera via the power supply terminal 301 to charge the battery 101, the power supply terminal 301 outputs an “L” level signal to the AND circuit 302. Therefore, here, the operation switch 10
2 is operated and the SW detection circuit 103 outputs the “H” level signal S1 to the OR circuit 104,
, The “L” level signal is continuously output, and the control circuit power supply circuit 105B does not start operating. When the camera is not operating, the charging circuit 303
01 is charged.

In this embodiment, the same effects as those of the first and second embodiments can be obtained. Furthermore, during charging, power is not supplied to the circuit inside the camera, so that the charging circuit 303 outside the camera can be obtained. , The battery 101 mounted in the camera body can be charged. Further, by providing the charging circuit 303 of the battery 101 outside the camera instead of inside, it is possible to reduce the size of the chargeable digital camera body and simplify the power supply circuit.

[0050]

As described above in detail, according to the first and fourth aspects of the present invention, while the camera is not operating, the operation of the power supply circuit is stopped to supply power to the control circuit. Instead, power supply can be started after the operation switch is operated, so that current consumption while the camera is not operating can be reduced, and battery consumption can be reduced. Further, since the power supply circuit can be constituted by a switching regulator, the efficiency of the power supply when the camera is operating is high, and the consumption of the battery can be suppressed. In addition, by supplying a control signal from the switch detection circuit to the control circuit only when power is supplied to the control circuit, an "H" level is output from an external terminal when power is not supplied to the control circuit. , The control circuit can be prevented from latching up.

According to the second and fifth aspects of the invention, the same effects as those of the first and fourth aspects of the invention can be obtained, and further, when the battery voltage falls below a predetermined value, a warning is issued. Since the power is turned off after performing the operation, when the voltage of the battery falls below the predetermined voltage, it is possible to notify the operator that the battery voltage is low. In addition, when the battery voltage is low, the power supply other than the control circuit is not turned on and the operation of the camera is prohibited. It is possible to prevent the voltage from dropping abruptly and the camera from operating.

According to the third and sixth aspects of the invention, the same effects as those of the first and fourth aspects of the invention and the second and fifth aspects of the invention are obtained. Since power is not supplied to the circuit inside the camera, the battery mounted inside the camera body can be charged using the charging circuit outside the camera. In addition, by providing the battery charging circuit outside the camera instead of inside, it is possible to reduce the size of the chargeable digital camera body and simplify the power supply circuit.

[Brief description of the drawings]

FIG. 1 is a main block diagram of a digital camera according to a first embodiment of the present invention.

FIG. 2 is a main block diagram of a digital camera according to a second embodiment of the present invention.

FIG. 3 is a main block diagram of a digital camera according to a third embodiment.

FIG. 4 is a block diagram schematically showing a conventional digital camera.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Battery 102 Operation switch 103 SW detection circuit 104 OR circuit 105A, 105B Power supply circuit for control circuit 106 Power supply circuit for camera unit 107 AND circuit 108A, 108B Control circuit 109 Camera unit 201 Battery voltage detection circuit 202 Warning means 301 Power supply terminal 302 AND circuit 303 Charge circuit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/225 H04N 5/225 F 5G065 A 5/232 5/232 Z F term (Reference) 2H054 AA01 2H100 DD08 DD15 2H102 AA71 5C022 AB67 AC03 AC16 AC18 AC42 AC69 AC73 5G003 AA01 BA01 CA11 CC02 DA07 DA13 EA06 GB03 GC05 5G065 AA01 DA07 EA02 GA06 JA02 KA02 KA05 LA07 MA09 MA10

Claims (6)

[Claims] 1. A battery for supplying power to a camera, an operation switch for turning on / off the power of the camera, a control circuit for controlling the operation of the camera, and a control circuit configured to enable on / off control. A power supply circuit for supplying power to the circuit; and a switch detection for detecting that the operation switch is operated and supplying a control signal to the power supply circuit and the control circuit during a period in which the operation switch is operated. A power supply circuit, wherein the power supply circuit is configured to be turned on during a period in which a control signal is supplied from the switch detection circuit or the control circuit, and the control circuit transmits a control signal from the switch detection circuit. Receiving a control signal to the power supply circuit when the power supply circuit is off, and turning on the power supply circuit when the power supply circuit is on. The power supply circuit is controlled to be turned off by stopping supply of a control signal to the control circuit, and the switch detection circuit controls the control circuit only when power is supplied to the control circuit. A digital camera characterized in that a signal is supplied. 2. A battery voltage detecting means for detecting a voltage of the battery, and a warning means for issuing warning information to the outside when the voltage of the battery detected by the battery voltage detecting circuit is lower than a predetermined value, The power supply circuit is configured to be capable of supplying power to enable operation of the control circuit even when the voltage of the battery is equal to or less than the predetermined value, and power is supplied to the control circuit by operating the operation switch. When supplied, when the battery voltage detection circuit detects that the battery voltage is lower than a predetermined value, the control circuit outputs warning information by the warning unit without operating the camera. The digital camera according to claim 1, wherein the power supply circuit is turned off after the power is emitted. 3. The battery comprises a rechargeable battery, and a charging power supply terminal for supplying power from outside the camera to charge the battery, and a power supply for charging the battery. When a charging circuit is provided outside the camera, and the charging circuit is connected to the charging power supply terminal, supply of a control signal from the switch detection circuit to the power supply circuit and the control circuit is prohibited. 3. The digital camera according to claim 1, wherein the power of the camera is not turned on. 4. A battery for supplying power to the camera, an operation switch for turning on / off the power of the camera, a control circuit for controlling the operation of the camera, and an on / off control capable of controlling on / off. A power supply circuit for supplying power to the circuit; and a switch detection for detecting that the operation switch is operated and supplying a control signal to the power supply circuit and the control circuit during a period in which the operation switch is operated. Wherein the power supply circuit is configured to be turned on during a period in which a control signal from the switch detection circuit or the control circuit is supplied, and the switch detection circuit includes the control circuit. The control circuit supplies a control signal to the control circuit only when power is supplied to the control circuit. Receiving a control signal from the switch detection circuit, turning on the power supply circuit by supplying a control signal to the power supply circuit when the power supply circuit is off, and supplying a control signal to the power supply circuit when the power supply circuit is on. A power control method for a digital camera, wherein the power supply circuit is turned off by stopping supply. 5. The power supply circuit is configured to supply power to enable operation of the control circuit even when the voltage of the battery is equal to or lower than a predetermined value, and the control is performed by operating the operation switch. When power is supplied to the circuit, if the voltage of the battery is lower than a predetermined value, after issuing warning information to the outside by warning means without operating the camera using the control circuit, 5. The method according to claim 4, wherein the power supply circuit is turned off. 6. The battery comprises a rechargeable battery, and a charging power supply terminal for supplying power from outside the camera to charge the battery, and a power supply for charging the battery. A charging circuit is provided outside the camera, and when the charging circuit is connected to the charging power supply terminal, supply of a control signal from the switch detection circuit to the power supply circuit and the control circuit is prohibited. 6. The power control method for a digital camera according to claim 4, wherein the power of the camera is not turned on.