JP2002262217A - Electronic camera device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize damage due to voltage reduction even when voltage drops while effectively utilizing the battery power of an electronic camera. SOLUTION: When a controller 15 detects that battery voltage drops down below V2, the controller sets this camera device in a low power consumption mode by interrupting a signal reading operation by an imaging part 13 from a CCD 12, a driving operation of an image lens 11 by an AF lens driving part 18, a charging operation of a strobe 17, or the like and then preferentially performs only recording processing of image data. When the battery voltage drops down below V1 being lower than V2 during recording the image data, the controller 15 also stops recording, but when the battery voltage drops down to V1 during performing update processing of management data, the update processing of the management data is continued while a peak current is reduced by a detection signal DET from a voltage detection circuit 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera device for recording image data obtained by photographing on a recording medium.

[0002]

2. Description of the Related Art Generally, in an electronic camera, image data of a subject obtained by photographing is recorded as a file on a recording medium such as a memory card. Although it depends on the data size of the image data, a relatively long time is required for recording the image data on the recording medium. If the power supply voltage of the battery drops during the recording process, the power of the electronic camera is turned off without photographed image data being correctly recorded on the recording medium, and the photographed image data is lost. .

The following techniques are known as techniques for avoiding the problem associated with a decrease in power supply voltage.

Japanese Unexamined Patent Publication No. Hei 5-48997 discloses that a voltage of a backup battery for storing data stored in a memory card is compared with a predetermined reference voltage, and when the power supply voltage is lower than the reference voltage, a release is performed. A technique is disclosed in which a switch is turned off to prohibit a user from performing a release operation.

[0005] Japanese Patent Application Laid-Open No. 5-37828 discloses that
There is disclosed a technique of issuing a warning of a low battery using a set voltage value for warning set according to a type of a battery to be used.

[0006]

However, Japanese Patent Application Laid-Open No. 5-4 / 1993
The technique disclosed in Japanese Patent No. 8997 prohibits a release operation when the power supply voltage is equal to or lower than the reference voltage. Therefore, if the power supply voltage suddenly drops after the release operation, the recording of the image data after photographing is performed. No protection will be provided. Also, in such a method, it is necessary to set a high reference voltage in advance for safety.
It is difficult to make full use of battery capacity.

The same applies to the technique disclosed in Japanese Patent Application Laid-Open No. 5-37828. In some cases, the photographing operation has already been performed depending on the timing at which the warning is issued. It is difficult.

By the way, when recording image data, it is usually necessary to update management data such as a file management table on a recording medium in accordance with the recording of the image data. If the power of the electronic camera is forcibly turned off due to a drop in the power supply voltage on the way, there is a risk that the contents of the management data itself on the recording medium may be destroyed due to erroneous updating. In this case, not only the newly written image data but also the image data already written on the recording medium cannot be normally read.

Therefore, it is necessary to sufficiently consider not only protection of image data obtained by photographing but also protection of image data already written on a recording medium.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to effectively use the power of a battery and minimize the damage caused by a voltage drop even when the voltage drops. To provide an electronic camera device capable of performing the following.

[0011]

In order to solve the above problems, the present invention employs the following configuration.

That is, the present invention relates to an electronic camera device for recording image data obtained by photographing on a recording medium,
Recording means for recording image data obtained by photographing and updating management data on the recording medium in accordance with the recording of the image data, and a first means for determining a power supply voltage
And a reference voltage generating means for generating a second reference voltage higher than the first reference voltage, wherein the power supply voltage has dropped below the second reference voltage during the recording of the image data. If it is detected, the electronic camera device is set to the low power consumption mode to cause the recording of the image data to be executed prior to other processing, and the power supply voltage is set to the first power during the recording of the image data. And control means for stopping recording of the image data in order to prevent erroneous updating of the management data when it is detected that the voltage has dropped below the reference voltage.

According to this configuration, when the power supply voltage is between the second reference voltage and the first reference voltage, the image data is recorded in another processing mode by setting the mode to a low power consumption mode such as suspending the processing other than the recording. , The peak current can be reduced, so that recording of image data and updating of management data can be performed reliably. on the other hand,
If the power supply voltage drops below the first reference voltage during the recording of the image data, the recording of the image data is stopped at that point, so that the image data is lost, but the management data is erroneously updated. Can prevent logical destruction of the recording medium.

The present invention also relates to an electronic camera device for recording image data obtained by photographing on a recording medium, wherein the recording of the image data obtained by photographing and the recording of the image data are performed on the recording medium. Means for performing a recording process including an update process of management data, and a first reference voltage for determining a power supply voltage and a reference voltage generating means for generating a second reference voltage higher than the first reference voltage And when it is detected that the power supply voltage has dropped below the second reference voltage during the recording of the image data or the update processing of the management data, the electronic camera device is set to the low power consumption mode. The setting is made to execute the recording process by the recording unit prior to other processes, and it is detected that the power supply voltage has dropped below the first reference voltage during the recording of the image data. Expediently, it stops the recording of the image data in order to prevent erroneous update of the management data,
During the update process of the management data, the power supply voltage becomes the first power supply voltage.
If it is detected that the voltage drops below the reference voltage,
Control means for setting the electronic camera device to the low power consumption mode so that a predetermined power supply voltage is secured at least during the management data updating process, and for continuing the management data updating process. It is characterized by the following.

In this configuration, recording of the image data requires a relatively long time, but taking into consideration that the management data can be updated in a short time, the power supply voltage is set to the first reference value during the recording of the image data. When the voltage drops below the voltage, the recording is stopped.
, The management data updating process is continued with the peak current reduced by setting the low power consumption mode. By setting the low power consumption mode and reducing the peak current, the power supply voltage is restored although it is temporary, so the update of the management data is completed during that time, so that the image data to be recorded is lost. Can also be prevented.

Also, the third reference voltage higher than the second reference voltage may be used.
It is desirable to further provide a means for generating the reference voltage and a warning means for generating a warning when it is detected that the power supply voltage has fallen below the third reference voltage.
This allows the photographer to know in advance that the power supply voltage may drop below the second reference voltage or the first reference voltage during data recording. Can take appropriate measures such as replacing the battery.

In the case where the power supply voltage drops below the second reference voltage or the first reference voltage during recording of image data or updating of the management data,
By further providing a means for presenting that fact prior to the next shooting, it is possible to confirm in advance that danger such as loss of shooting data has occurred in the previous shooting.

Further, the present invention relates to an electronic camera device for recording image data obtained by photographing on a recording medium, wherein the recording of the image data obtained by photographing and the recording of the image data are performed on the recording medium. Recording means for performing a recording process including an update process of the management data of the electronic camera device, detecting a power supply voltage, and detecting that the power supply voltage has dropped below a predetermined first reference voltage. Means for stopping the operation of other parts other than the part relating to the recording processing, and when it is detected that the power supply voltage has dropped below the first reference voltage, the recording processing being executed is It is determined whether the process is a recording process or an update process of the management data, and if the image data is being recorded, the recording process is stopped. Characterized by comprising a control means for performing control to continue the recording process.

Also in this configuration, it is possible to perform an optimal response according to the execution state of the recording process when the power supply voltage falls below the first reference voltage.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an electronic camera according to an embodiment of the present invention.

This electronic camera is a digital still camera that shoots a subject image using a solid-state image sensor such as a CCD, compresses image data obtained by the shooting, and records it on a recording medium. This camera has a
Photographing lens 11, CCD area sensor 12, imaging unit 1
3, image processing unit 14, controller 15, memory 16,
Memory card 17, AF lens drive 18, strobe 1
9, battery (battery) 20, DC / DC converter 2
1, a voltage detection circuit 22, and a reference voltage generation circuit (re
f) 23 and the like are provided.

The photographing lens 11 constitutes a photographing optical system, and includes a movable varifocal lens for AF (automatic focusing) and a zoom lens. The subject image is formed on the imaging surface of the CCD area sensor 12 by the photographing lens 11. CCD area sensor 12
Is photoelectrically converted by the CCD area sensor 12 into an electric image signal. This image signal is subjected to A / D conversion via an imaging unit 13 for controlling the imaging operation of the CCD area sensor 12, and then input to the image processing unit 14 as digital image data.

The image processing unit 14 stores the data in the memory 16 after performing color correction, gamma correction, and the like. Memory 1
Reference numeral 6 denotes a memory for temporarily storing image data taken in from the CCD area sensor 12 and image data to be reproduced read from the memory card 17, and includes various kinds of images such as image compression / expansion processing. It is used as a work memory area for processing.

The controller 15 controls the operation of the camera as a whole. The controller 15 includes functions for controlling the photographing operation and recording the image data obtained by the photographing operation on the memory card 17. Battery (battery)
A function is provided for protection of image data obtained by photographing when the power supply voltage of the power supply 20 drops, and protection of image data already written in the memory card 17.

A battery (battery) 20 is a power supply of the camera, and a power supply voltage of the battery (battery) 20 is DC / D
The power is converted into an appropriate operating power supply voltage V by the C converter 21 and supplied to each unit in the camera. The power supply voltage of the battery (battery) 20 is constantly monitored by the voltage detection circuit 22. The voltage detection circuit 22 includes a battery (battery)
When it is detected that the power supply voltage of the power supply 20 has dropped below the predetermined reference voltage V1, a detection signal DET is generated.
The detection signal DET is supplied to a portion not related to the recording process of the image data, for example, the imaging unit 13, the AF lens driving unit 18, and the strobe 19 as a signal for stopping the operation. That is, when a power supply voltage (hereinafter, referred to as a battery voltage) of a battery (battery) 20 becomes equal to or lower than a predetermined reference voltage V1, a signal reading operation from the CCD 12 by the imaging unit 13 and a shooting lens 11 by the AF lens driving unit 18 are performed.
, And the charging operation of the strobe 17 are all forcibly stopped. The detection signal DET is also input to the controller 15 to notify that the battery voltage has dropped to the reference voltage V1 or less.

The controller 15 has a reference voltage generation circuit (ref) 23 for determining the current battery voltage.
Is also input. The reference voltage V2 is set higher than the reference voltage V1.
The controller 15 A / D converts the input voltage of the DC / DC converter 21 and the reference voltage V2, respectively, and compares them to detect that the battery voltage has dropped to V2 or lower. Further, the camera also uses a third reference voltage V3 higher than the reference voltage V2. The reference voltage V3 can be generated by the same mechanism as the reference voltage generation circuit (ref) 23. The same applies to the above-described reference voltage V1.

Hereinafter, these three reference voltages V1, V2,
Operation control performed using V3 will be described.

FIG. 2 shows the relationship between the battery voltage and the operation mode of the camera. 1) V3 = Warning: The controller 15 detects that the battery voltage is V3.
When it is detected that the battery voltage has dropped below
Warn the photographer before dropping to 1.

2) V2 = recording priority: controller 15
When detecting that the battery voltage has dropped to V2 or less, the recording of image data is performed prior to other processing. That is,
Normally, the image data recording process is performed in parallel with other processes such as image capturing. However, when performing the image data recording process, the controller 15
The camera device is set to a low power consumption mode by interrupting a signal reading operation from the camera, a driving operation of the photographing lens 11 by the AF lens driving unit 18, a charging operation of the strobe 17, and only a recording process of image data. Priority. The interrupted process is restarted after the image data recording process is completed. The processing other than the recording processing is interrupted in order to suppress a decrease in battery voltage by reducing the peak current.

3) V1 = Protection of Data in Medium: As described above, when recording image data, it is necessary to update management data such as a file management table on the memory card 17 with the recording of the image data. Becomes That is, the recording process includes: 1. recording of image data; Update of management data is performed.
If the power of the camera is forcibly turned off due to a drop in battery voltage during the management data update process, there is a risk that the management data itself in the memory card 17 may be destroyed due to erroneous update of the management data. In order to prevent this, during recording of image data, the battery voltage becomes lower than V2.
If it is detected that the number has dropped to 1 or less, the controller 15 stops recording the image data at that point.
Although the image data is lost, it is possible to prevent a problem due to erroneous updating of the management data. If it is detected that the battery voltage has dropped to V1 or less during the management data update process, the controller 15
Continues the management data update process. This utilizes the fact that recording of image data requires a relatively long time, but management data can be updated in a short time. When the battery voltage drops to V1 or less, the operation of hardware not related to recording is forcibly stopped by the detection signal DET, so that the battery voltage is restored although temporarily as shown in FIG. By completing the management data update process during that time, it is possible to prevent the image data to be recorded from being lost.

Next, referring to FIG.
The above-described image data management structure will be described. In the present embodiment, the image data on the memory card 17 is managed as a file by the FAT file system in order to maintain compatibility with other electronic devices such as a personal computer.

In this case, the storage area of the memory card 17 is composed of a management data area and an image data area for recording actual image data. In the management data area, as management data for managing the storage position of each image data in the image data area, F
A file management table including ATs (File Allocation Tables) is stored. The file management table includes a directory area and a FAT area. The directory area includes directory entries corresponding to the number of image data files that can be recorded in the image data area. Each directory entry is composed of file management information (file name, file attribute, file creation date and time, file start cluster number, file size, etc.) corresponding to the corresponding image data recorded in the image data area. The first cluster number indicates the first cluster in which the corresponding file is recorded. Here, a cluster means a minimum management data unit for logically managing a physical storage area.

The FAT is for managing the connection of the data constituting the file recorded in the data area in cluster units, and the file is managed by the FAT and the above-mentioned directory entry. The file in the image data area is configured in units of clusters, but the physical positions of the clusters are not always continuous. Therefore, the order in which these clusters are connected to form one file is managed by the FAT. Each entry in the FAT has a one-to-one correspondence with each cluster in the image data area, and indicates the usage status of the corresponding cluster (free cluster, last cluster in the file) and the cluster number where the next data is recorded. ing. In the FAT entry corresponding to the cluster in which the last data of the file is recorded, an end code “FFFF” indicating the end of the file is written. An unused code “0000” is written in the FAT entry corresponding to an unused empty cluster in which no valid data is recorded.

The management data area is stored in a specific block of the flash memory constituting the memory card 17. In the flash memory, data erasure is performed in block units. Therefore, in order to update management data in accordance with recording of new image data, block erasure of the management data area and writing of new management data are executed. Hereinafter, the process of updating the management data area is referred to as “FAT writing”.

Next, the relationship between the control of the photographing / recording sequence and the detected voltage will be specifically described with reference to FIG.

The photographing / recording sequence is 1) AE / AF
An imaging operation for performing exposure and signal reading by the CCD 12 under control, 2) image processing for generating image data for recording from the image signal obtained thereby, and 3) recording image data on the memory card 17 Image data writing, 4) and FAT writing are performed.

If it is detected that the battery voltage has dropped to V2 or less immediately before or immediately before the writing of the image data or FAT, as described above, the signal reading operation from the CCD 12 by the imaging unit 13 and the AF lens Driving operation of the photographing lens 11 by the driving unit 18
In the state where the charging operation and the like are interrupted, the writing of the image data and the writing of the FAT are executed with priority. When the writing of the image data and the FAT is completed, the task in the controller 15 corresponding to the interrupted operation is restarted, so that the imaging unit 13, the AF lens driving unit 18, and the strobe 17 restart the operation.

On the other hand, when it is detected that the battery voltage has dropped to V1 or less during or immediately before the writing of the image data or FAT, the time of the detection was during or immediately before the writing of the image data. Then, the writing of the image data is stopped at that time, and the writing of the FAT is also stopped. If the detection time is during or immediately before the writing of the FAT, the writing of the FAT is continued. The operation of the imaging unit 13, the AF lens driving unit 18, and the strobe 17 is stopped by hardware when the battery voltage drops to V1 or less. Therefore, the tasks executed in the controller 15 for controlling them are performed. Are all discarded (stop processing), and the control is not resumed.

Next, referring to the flowchart of FIG.
The operation of the controller 15 when detecting V2 will be described.

Before the battery voltage drops below V2 (NO in step S101), the controller 15 executes the recording process of image data (writing of image data, writing of FAT) in parallel with other processes such as imaging. (Step S102). In the normal processing mode, a warning is issued when the battery voltage drops below V3.

When it is detected that the battery voltage has dropped to V2 or less in the normal processing mode (step S10).
1 (YES), the controller 15 operates in the recording priority mode. That is, the controller 15 determines whether or not image data recording processing (image data writing, FAT writing) is being performed (step S103).
Perform processing related to F motor and imaging (step S10)
4). On the other hand, if the recording process is being performed (step S103
YES), the controller 15 interrupts the processes related to the strobe, the AF motor, and the imaging, and preferentially executes the image data recording process (image data writing, FAT writing) (step S105). Then, when all the recording processes of the image data are completed, the controller 15
The interrupted process is restarted (step S107). That is, in the above-described normal operation mode, after shooting, in parallel with the recording process, in preparation for the next shooting, charging of the strobe, driving of the AF motor based on half-pressing of the shutter button,
Then, a CCD drive or the like for EVF display or the like is performed. However, when the battery voltage drops to V2 or less, other processing is not performed during the image data recording processing, and after the image data recording processing is completed, The charging operation of the strobe, the driving of the AF motor based on the half-press operation of the shutter button, and the driving of the CCD for displaying the EVF and the like are started.

Next, referring to the flowchart of FIG.
The operation of the controller 15 when V1 is detected will be described.

When it is detected that the battery voltage has dropped to V1 or less, a detection signal DET is generated from the voltage detection circuit 22, and the operation of hardware not related to recording is forcibly stopped. Then, the fact that the battery voltage has dropped to V1 or less is determined by the detection signal DET.
Will also be notified. The controller 15 outputs the detection signal DET
When it is detected that the voltage has dropped to V1 or less (step S111), it is first determined whether or not image data recording processing (image data writing, FAT writing) is in progress (step S112).

If the image data recording process is being performed (image data writing, FAT writing), specifically, if the image data recording process is not completed after shooting,
The controller 15 determines whether the current operation is during or immediately before the writing of the image data itself, or
It is determined whether the data is being written or immediately before (step S113). When the image data is being written or immediately before the writing, the controller 15 stops the recording process at that time (step S114), and the subsequent F
AT writing is not performed. As a result, erroneous updating of the management data can be prevented. And
After the controller 15 issues a warning that the battery has run out (step S115), the power of the camera is forcibly turned off.

On the other hand, if the writing of the image data itself has been completed and the current state is during or immediately before the writing of the FAT, the controller 15 sets the FA 15
The writing of T is continued, and the writing is completed (steps S116 and S117). Unlike the image data, the FAT writing has a small data size. For example, the FAT is written only by updating one erase block of data.
The writing of T is completed. Therefore, even after the battery voltage drops to V1, the operation of all the hardware not related to recording is stopped to reduce the peak current, thereby reducing the FAT.
Can be completed normally. Then, after the controller 15 issues a warning that the battery has run out (step S115), the power of the camera is forcibly turned off.

As described above, in the present embodiment, the operation mode is changed according to the state of the decrease in the battery voltage, and when V1 is detected, whether the recording processing is continued or stopped according to the state of the recording processing is determined. By providing a control function, it is possible to effectively use the power of the battery and to prevent the worst case such as the destruction of the FAT even when the voltage drops, thereby minimizing the damage. Become. As for the detection of V1, the other parts other than the part related to the recording process are stopped in hardware by the detection signal from the detection circuit 22, so that the power supply voltage can be recovered immediately. The set value of V1 can be set sufficiently low.

When V2 or V1 is detected during the recording process, it is preferable that the controller 15 presents the fact to the user before the next photographing. This allows the user to confirm in advance that a danger such as loss of the photographed data has occurred in the previous photographing.

The present invention is not limited to the above-described embodiment, and can be variously modified in an implementation stage without departing from the gist of the invention. Further, the embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some components are deleted from all the components shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effects described in the column of the effect of the invention can be solved. If you get
A configuration from which this configuration requirement is deleted can be extracted as an invention.

[0049]

As described above, according to the present invention,
It is possible to effectively use the power of the battery and minimize the damage caused by the voltage drop even when the voltage drops.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of an electronic camera according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a battery voltage and an operation mode of the camera in the embodiment.

FIG. 3 is a diagram showing a state of generation of a detection signal DET and recovery of a battery voltage due to the generation of the detection signal in the embodiment.

FIG. 4 is an exemplary view for explaining a management structure of image data according to the embodiment;

FIG. 5 is an exemplary view for explaining a relationship between control of a shooting / recording sequence and a detection voltage in the embodiment.

FIG. 6 is a flowchart for explaining the operation of the controller executed when V2 is detected in the embodiment.

FIG. 7 is an exemplary flowchart for explaining the operation of the controller executed when V1 is detected in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Photographing lens, 12 ... CCD area sensor, 13 ... Image pick-up part, 14 ... Image processing part 15 ... Controller 17 ... Memory card 18 ... AF lens drive part 19 ... Strobe 20 ... Battery 21 ... DC / DC converter 22 ... Voltage detection circuit

Claims (5)

[Claims] 1. An electronic camera device for recording image data obtained by photographing on a recording medium, comprising: recording of image data obtained by photographing and management data on the recording medium accompanying the recording of the image data. Recording means for performing an update process; reference voltage generating means for generating a first reference voltage for determining a power supply voltage and a second reference voltage higher than the first reference voltage; If it is detected that the power supply voltage has dropped below the second reference voltage, the electronic camera device is set to a low power consumption mode, and recording of the image data is prioritized over other processing. And when it is detected that the power supply voltage has dropped below the first reference voltage during the recording of the image data, the recording of the image data is prevented to prevent erroneous updating of the management data. An electronic camera apparatus characterized by comprising a control means for stopping the. 2. An electronic camera device for recording image data obtained by photographing on a recording medium, comprising: recording of image data obtained by photographing and management data on the recording medium accompanying the recording of the image data. Recording means for performing recording processing including update processing; reference voltage generating means for generating a first reference voltage for determining a power supply voltage and a second reference voltage higher than the first reference voltage; If it is detected that the power supply voltage has dropped below the second reference voltage during data recording or update processing of the management data, the electronic camera device is set to a low power consumption mode and The recording process by the recording unit is executed prior to other processes, and when it is detected that the power supply voltage has dropped to the first reference voltage or less during the recording of the image data, When the recording of the image data is stopped to prevent erroneous updating of the management data, and when it is detected that the power supply voltage has dropped to the first reference voltage or less during the updating process of the management data, Control means for setting the electronic camera device to the low power consumption mode so that a predetermined power supply voltage is secured at least during the management data updating process, and for continuing the management data updating process. An electronic camera device, characterized in that: 3. A means for generating a third reference voltage higher than the second reference voltage, and generating a warning when it is detected that the power supply voltage has dropped below the third reference voltage. The electronic camera device according to claim 1, further comprising: a warning unit that performs the warning. 4. If the power supply voltage falls below the second reference voltage or the first reference voltage during recording of the image data or updating of the management data, the power supply voltage is reduced prior to the next photographing. 4. The electronic camera device according to claim 1, further comprising means for presenting the fact. 5. An electronic camera device for recording image data obtained by photographing on a recording medium, comprising: recording of image data obtained by photographing and management data on the recording medium accompanying the recording of the image data. Recording means for performing a recording process including an update process; detecting a power supply voltage;
Means for stopping the operation of other parts of the electronic camera device other than the part related to the recording process when detecting that the power supply voltage has dropped below the first reference voltage. When it is detected, it is determined whether the recording process in progress is the recording of the image data or the update process of the management data, and when the image data is being recorded, the recording process is stopped. An electronic camera device comprising control means for performing control for continuing the recording process when the management data is being updated.