JPH0548997A - Electronic still camera - Google Patents

Abstract

PURPOSE:To prevent the extinction of recorded image information. CONSTITUTION:The voltage of a backup battery 23 for retaining the storage contained in a memory card 21 is compared with a prescribed reference voltage by a battery check circuit 7. Based on the comparison result, when the power supply voltage is below the reference voltage, a control part 6 inhibits the operation of a release 10 for a release switch SW1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic still camera having a memory card as a storage medium.

[0002]

2. Description of the Related Art Recently, a so-called memory card, which is a card type memory cartridge having a thickness of, for example, about 2 mm in which a memory such as an LSI is built in a cartridge, has been put into practical use. A card camera that records and / or reproduces a subject using such a memory card as a storage medium has been developed.

In this type of camera, an optical signal of a subject image obtained through an image pickup lens is converted into an electric signal by a photoelectric conversion element, and the electric signal is sent to a memory card detachably attached to the camera body for recording. It is supposed to do.

On the other hand, since the memory card is a writable and readable RAM memory, it has a built-in backup battery. By the way, in the case of long-term storage of a card with a built-in backup battery, stored information may be lost due to battery exhaustion. Therefore, a backup power supply device used as a backup power supply is prepared for a time other than imaging.

[0005]

As described above, when the recorded memory card is stored, if the memory card is connected to the backup power supply device, the stored information will not be lost due to exhaustion of the built-in backup battery. However, at the time of image capturing, especially at the time of outdoor image capturing such as traveling, the built-in backup battery must be relied upon. For example, if you take and record on a memory card where the power supply of the built-in backup battery has dropped to the minimum voltage required to hold the memory card, the battery voltage will drop during the trip, and important images taken Information was sometimes lost.

An object of the present invention is to provide an electronic still camera which solves the above problems.

[0007]

According to the present invention, in an electronic still camera using a memory card as a storage medium, a comparison means for comparing the voltage of a backup power supply for storing data contained in the memory card with a reference voltage. And, as a result of comparison by the comparing means, when the power supply voltage is equal to or lower than the reference voltage, a prohibiting means for prohibiting the release operation is provided.

[0008]

The voltage of the backup power supply for holding the memory built in the memory card is compared with a predetermined reference voltage by the comparison means, and when the comparison result is less than the predetermined value, the prohibition means is provided. Release operation is prohibited by.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

This is an example of a so-called memory card camera, and its appearance is shown in FIG.

In FIG. 2, reference numeral 1 denotes a memory card camera main body, which is generally known as a taking lens 2,
It has a strobe window 11 and a viewfinder opening 9 and is provided with a release button 10 for performing a shooting operation.

Further, an opening 12 for inserting the memory card 21 is provided, the memory card 21 is inserted in the direction of the arrow and mounted in the camera body, and the camera body 1 is connected to the camera body 1 by the interface connector 8 shown in FIG. It is connected.

In FIG. 1, reference numerals 1, 2, 9 to 11 and 21 indicate the same parts as in FIG. A CCD and an image pickup circuit 3 convert an optical image formed by the taking lens 2 into an electric signal. Reference numeral 4 denotes a signal processing circuit, which processes the electric signal photoelectrically converted by the image pickup circuit 3. An A / D conversion circuit 5 converts the analog signal processed by the signal processing circuit 4 into a digital signal. The signal converted into the digital signal is passed through the interface connector 8 to the card camera 1
It is sent to and stored in the memory chip 22 in the memory card 21 loaded in.

A battery check circuit 7 receives the voltage of the backup battery 23 for holding the memory in the memory card 21 through the interface connector 8 and compares it with a predetermined reference voltage. SW1 is a release switch, and the release button 1 shown in FIG.
It is linked to 0 and is normally open. Reference numeral 6 is a control unit, which controls the entire camera and is a CCD.
/ The image pickup circuit 3, the signal processing circuit 4, and the A / D conversion circuit 5 are controlled respectively. The control unit 6 turns on the release switch SW1 according to the comparison result of the battery check circuit 7.
It is an OFF control.

When the release button 10 is pushed, the release switch SW1 is closed, so that the control section 6 normally transmits a command to the photographing operation to each section, and the subject is stored in the memory card 21 as image information in the memory card 21. Remembered.

Next, the operation at the time of photographing in the above-mentioned structure will be described.

First, as shown in FIG. 2, the memory card 21
Is inserted into the camera body 1 through the opening 12. The inserted memory card 21 and the camera body 1 are connected by the interface connector 8 as shown in FIG.

In this state, in the camera body 1, electric power is received from the built-in backup battery 23 in the memory card through the interface connector 8 and compared with a predetermined reference voltage by the battery check circuit 7, and the result is controlled by the controller. 6 is transmitted. At this time, when the voltage of the backup battery 23 is higher than the reference voltage, the control unit 6 issues a photographing operation command to each unit in accordance with the closing of the release switch SW1 accompanying the pressing of the release button 10.
Then, the optical image formed by the taking lens 2 is CC
The signal photoelectrically converted by D3 and the signal photoelectrically converted is processed by the signal processing circuit 4. After that, the analog signal is converted into a digital signal by the A / D conversion circuit 5, and the memory card 2 is passed through the interface connector 8.
1 is sent to the memory chip 22 in the memory 1 and stored.

On the other hand, when the power supply voltage is lower than the reference voltage, even if the release switch SW1 is closed, the control section 6 does not issue a photographing operation command and prohibits the release operation. Therefore, the photographer can know that the voltage of the backup battery has decreased.

In this case, the photographer must be provided with the memory card 21.
It is also conceivable to issue a warning notifying that the power supply voltage of the backup battery 23 therein is low.

Further, it is preferable that the reference voltage is set to be slightly higher than the voltage required for the memory card to retain the memory. For example, even if the memory card is left unattended for a while after photographing, the stored content is retained. You need to be prepared to do so.

[0023]

As described above, according to the present invention, the release operation of the camera is prohibited when the voltage of the backup power supply for storing the memory built in the memory card is below a predetermined value. Therefore, there is an effect that it is possible to protect important image information taken by making it impossible to record on a memory card in which stored information disappears in a short period of time due to a voltage drop of a backup power supply.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view showing appearances of a memory card camera body and a memory card.

[Explanation of symbols]

 1 memory card camera main body 2 taking lens 3 CCD and image pickup circuit 4 signal processing circuit 5 A / D conversion circuit 6 control unit 7 battery check circuit 8 interface connector 10 release button 21 memory card 22 memory chip 23 backup battery SW1 release switch

Claims (1)

[Claims] 1. An electronic still camera using a memory card as a storage medium, and a comparing means for comparing a voltage of a backup power supply for storing the memory built in the memory card with a reference voltage,
As a result of comparison by the comparison means, when the power supply voltage is equal to or lower than the reference voltage, the electronic still camera is provided with a prohibition means for prohibiting the release operation.