JPH11109439A - Data recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute a proper operation, regardless of the temp. of a battery by detecting the temp. of the battery, comparing the detected battery temp. with a prescribed threshold and suppressing the load current of the battery, when it is decided that the battery temp. is higher than the prescribed threshold. SOLUTION: A camera is constituted of a CPU 1, the battery 6, a battery temperature detecting circuit 8, a power supply switch 71, or the like. The CPU 1 suppresses each circuit of the whole camera and the battery 6 is loaded in a camera main body, to supply power to a specific circuit in the camera. The battery temperature detecting circuit 8 detects the battery temp. of the battery 6 and transmits the result of the detection to the CPU 1. The power supply switch 71 is connected to the CPU 1, to turn on/off the supply of the power in the camera main body. The temp. of the battery 6 is measured by the battery temperature detecting circuit 8 consisting of a thermistor, or the like, and when the temp. of the battery 6 becomes the prescribed threshold or more, a fixed load current is limited to suppress the self-heat-generation of the battery 6, so that the rising of the temp. of the battery 6 can be minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a data recording apparatus,
More specifically, the present invention relates to a data recording device having a battery temperature detecting function.

[0002]

2. Description of the Related Art Conventionally, in a device such as a digital camera, which is driven by a loaded or built-in battery, particularly a device which operates at a large current, a battery replacement time which may occur due to the self-heating of the battery due to the driving current. As a safety measure for preventing a burn or the like, there is known a technical measure in which the temperature of a battery is measured during use of the device and the operation of the device is stopped when the temperature reaches a predetermined temperature.

In particular, alkaline batteries, which have been used frequently in recent years, have high internal impedance and easily generate heat.
The above-mentioned problem appears more remarkably.

[0004]

However, in such technical means, since the operation of the device is stopped when the temperature reaches a predetermined temperature, it may happen that the user cannot use the device when he really wants to use it.

[0005] On the other hand, due to its structure, the performance of the battery deteriorates remarkably at low temperatures, and when the current consumption on the device side is large, the battery may become unusable. That is, when the temperature of the battery becomes low due to its structure, the apparent internal impedance increases, and the performance deteriorates remarkably. This is due to the fact that when the internal impedance increases, the output voltage drops significantly as compared with the normal state even at the same load current. As a result, although there is still room for the energy of the battery, there is a possibility that the device may shut down due to the power reduction detection level on the device side due to a decrease in the output voltage.
This phenomenon becomes more remarkable as the load current increases.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a data recording device capable of performing an appropriate operation regardless of a battery temperature.

[0007]

In order to achieve the above object, a first data recording apparatus according to the present invention comprises a battery for supplying power to a predetermined circuit, and a battery temperature detecting device for detecting the temperature of the battery. Means, a battery temperature determining means for comparing a battery temperature detected by the battery temperature detecting means with a predetermined threshold, and a battery when the battery temperature determining means determines that the battery temperature is higher than a predetermined threshold. And a load current suppressing means for suppressing the load current.

In order to achieve the above object, a second aspect of the present invention is provided.
The data recording device includes a battery for supplying power to a predetermined circuit, a battery temperature detecting means for detecting a temperature of the battery, and a battery for comparing the battery temperature detected by the battery temperature detecting means with a predetermined threshold value. The battery temperature determining device further includes a load current suppressing device that suppresses a load current of the battery when the battery temperature determining device determines that the battery temperature is lower than a predetermined threshold.

In order to achieve the above object, a third aspect of the present invention is provided.
In the data recording device of the first or second data recording device, the load current suppressing means stops power supply to the focus adjusting means for performing the focus adjusting operation during the zoom operation. It is characterized in that it is.

In order to achieve the above object, a fourth aspect of the present invention is provided.
The data recording device of the present invention is characterized in that, in the first or second data recording device, the load current suppressing means is configured to make the charging current of the strobe smaller than usual.

[0011] To achieve the above object, a fifth aspect of the present invention is provided.
The data recording device of the present invention is characterized in that in the first or second data recording device, the load current suppressing means is configured to reduce the speed of an operation clock inside the device.

[0012] In order to achieve the above object, a sixth aspect of the present invention is provided.
The data recording device of the first or second data recording device, further comprising a control unit that suppresses the data recording device to a power saving state in order to suppress battery consumption when a predetermined time is reached, The load current suppressing means is characterized in that the predetermined time is made shorter than usual.

[0013]

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

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

As shown in FIG. 1, the camera according to the first embodiment includes a CPU 1 for controlling each circuit of the entire camera, and a C
An autofocus motor (hereinafter, referred to as an AF motor) 2 for autofocus driving the optical lens 9 under the control of the PU 1, an AF motor drive circuit 3 which is a driving unit of the AF motor 2, and under the control of the CPU 1 A zoom motor 4 for driving the optical lens 9 for zooming; a zoom motor driving circuit 5 which is a driving unit of the zoom motor 4; and a battery 6 which is mounted on the camera body and supplies power to a predetermined circuit in the camera. , The battery 6 under the control of the CPU 1.
A power supply circuit 7 for supplying power to each circuit of the camera body;
A battery temperature detection circuit 8 that detects the battery temperature of the battery 6 under the control of the CPU 1 and sends the detection result to the CPU 1, and an imaging device that captures a subject image from the optical lens 9 under the control of the CPU 1. A device (CCD) 10 and first release switches 11 and 2 connected to the CPU 1
an nd release switch 12, an image processing circuit 31 for performing predetermined image processing on image data captured by the CCD 10 under the control of the CPU 1, and a recording medium I / F 41 for the CPU 1.
A recording medium 42 for recording the image data under the control of the CPU 1, an image display unit 51 for displaying the image data from the image processing circuit 31 under the control of the CPU 1, and an image display unit Backlight 61 for 51
The main part is composed of a strobe charging circuit 21 for generating a charging voltage for the strobe light emitting section 22 and a power switch 71 connected to the CPU 1 for turning on and off the power supply of the camera body.

The first release switches 11 and 2nd
The release switch 12 constitutes switch means.
The first release switch 11 is a switch that is turned on by pressing one step, and when this switch is turned on, for example, processing related to distance measurement or the like is performed. The second release switch 12 is a switch that is turned on by two-step pressing, and the recording operation is performed when this switch is turned on.

The battery temperature detecting circuit 8 is composed of, for example, a known thermistor. Here, the operation of the first embodiment will be briefly described. The temperature of the battery 6 is measured by a battery temperature detection circuit 8 including a thermistor or the like, and the temperature of the battery 6 becomes equal to or higher than a predetermined threshold. In this case, a predetermined load current is limited, self-heating of the battery 6 is suppressed, and a rise in the temperature of the battery 6 is controlled to a minimum.

In the first embodiment, the following processing is appropriately performed as the load current limiting processing. That is: (1) Stop zoom tracking during zooming. The zoom tracking is a zoom method generally used in a camera having a zoom function, in which an in-focus state is always obtained during zoom driving by simultaneously controlling two motors, a zoom motor and an AF motor, during zooming. It is. For this reason, during zooming, two motors, the zoom motor and the AF motor, are simultaneously driven, so that a large current is required. Therefore, by stopping the zoom tracking, only the zoom motor is driven, so that the current consumption is halved. (2) Limit the flash charging current in the flash charging circuit 21. By limiting the strobe charge current, the charge time is increased but the maximum load current is reduced. (3) The operation clock inside the camera, especially the clock of the CPU 1 itself, is slowed down. As a result, the operating speed of the entire device is reduced, but the current consumption of the device is reduced. (4) The set time of the auto power off is shortened. Normally, if no operation is performed, the standby state is set for a certain period of time and the battery consumption is reduced. However, this time is shortened to immediately shift to the standby state.

Next, a battery temperature measurement sequence in the camera of the first embodiment will be described with reference to a flowchart shown in FIG.

As shown in FIG. 2, under the control of the CPU 1,
The temperature of the battery 6 is measured by the battery temperature detecting circuit 8 such as a thermistor (step S11). Here, the measured temperature of the battery 6 is compared with a predetermined threshold (threshold temperature) (step S12), and when the measured temperature is higher than the threshold, a current saving mode flag is set (step S1).
3) On the other hand, if the threshold has not been reached, the current saving mode flag is cleared (step S14).

Next, the load current limiting process will be described in detail.

First, a zoom drive sequence and a strobe charge sequence whose operations are different depending on the current saving mode flag will be described with reference to flowcharts shown in FIGS. 3 and 4, respectively.

First, the zoom drive sequence will be described.
As shown in FIG. 3, in the zoom drive sequence,
The CPU 1 first determines whether or not the current saving mode flag has been set (step S21). Here, if the current saving mode flag is not set, the temperature of the battery 6 is equal to or lower than a predetermined threshold value.
The F motor 2 is driven (Step S23).

On the other hand, if the current saving mode flag is set in step S21, since the temperature of the battery 6 has reached a predetermined threshold, the CPU 1 stops driving the AF motor 2 and drives only the zoom motor 4 ( Step S
22). Thereby, the current consumption is reduced, and the temperature rise of the battery 6 is suppressed.

The above operation is performed as long as the zoom button (not shown) is pressed (step S24), and the sequence ends when the zoom button is released.

Next, a strobe charging sequence will be described. As shown in FIG. 4, in the strobe charging sequence, the CPU 1 first determines whether or not the current saving mode flag is set (step S31).
Here, if the current saving mode flag is not set, since the temperature of the battery 6 is equal to or lower than the predetermined threshold value,
U1 releases the strobe charging current limit of the strobe charging circuit 21 (step S33), and performs strobe charging (step S34).

On the other hand, if the current saving mode flag is set in step S31, the temperature of the battery 6 has reached a predetermined threshold, and the CPU 1 turns on the flash charging current limit of the flash charging circuit 21 (step S31).
32), strobe charging is performed (step S34).
Thereby, the current consumption is reduced, and the temperature rise of the battery 6 is suppressed.

The above operation is performed until the strobe charge is completed (step S35), and the sequence ends when the strobe charge is completed.

Next, the process of limiting the load current by changing the operation clock of the CPU 1 will be described with reference to the flowchart shown in FIG.

As shown in FIG. 5, under the control of the CPU 1,
The temperature of the battery 6 is measured by the battery temperature detecting circuit 8 such as a thermistor (step S41). Here, the measured temperature of the battery 6 is compared with a predetermined threshold (threshold temperature) (step S42). When the measured temperature is higher than the threshold, the operation clock of the CPU 1 is slowed down (step S42).
43). As a result, the operating speed of the entire device is reduced, but the current consumption of the device is reduced. On the other hand, if the threshold has not been reached, the operation clock of the CPU 1 is accelerated to a specified value (step S44).

Next, a description will be given, with reference to the flowchart shown in FIG. 6, of a process for limiting the load current by changing the set time of the auto power off.

As shown in FIG. 6, under the control of the CPU 1,
The temperature of the battery 6 is measured by the battery temperature detecting circuit 8 such as a thermistor (step S51). Here, the measured temperature of the battery 6 is compared with a predetermined threshold (threshold temperature) (step S52), and when the measured temperature is higher than the threshold, the set time of the auto power off is shortened (step S52). S43). As a result, the state shifts to the standby state in a short time, and the consumption of the battery can be suppressed. On the other hand, when the threshold value is not reached, the set time of the auto power off is set to a normal setting (step S54).

As described above, according to the camera of the first embodiment, the temperature of the battery 6 is measured by the battery temperature detecting circuit 8 composed of a thermistor or the like, and the temperature of the battery 6 becomes equal to or higher than the predetermined threshold. In this case, the predetermined load current is limited and the battery 6
Of the battery 6 can be controlled to minimize the temperature rise of the battery 6.

Next, a second embodiment of the present invention will be described.

The camera according to the second embodiment has the same basic structure as that of the first embodiment, but is characterized in that the first embodiment prevents the temperature of the battery 6 from rising. On the other hand, the present embodiment is characterized in that even when the battery 6 is kept at a low temperature, the voltage drop of the battery 6 is suppressed and the operation of the device is ensured.

Therefore, here, only the differences will be mentioned, and the description of the same parts as in the first embodiment will be omitted.

In general, the performance of a battery is significantly deteriorated at a low temperature due to its structure, and the battery may be unusable when the current consumption of the device is large. That is, when the temperature of the battery becomes low due to its structure, the apparent internal impedance increases, and the performance deteriorates remarkably. This is due to the fact that when the internal impedance increases, the output voltage drops significantly as compared with the normal state even at the same load current. As a result, although there is still room for the energy of the battery, there is a possibility that the device may shut down due to the power reduction detection level on the device side due to a decrease in the output voltage. This phenomenon becomes more remarkable as the load current increases.

The camera according to the second embodiment is made in consideration of such circumstances. Even when the battery 6 is kept at a low temperature, the voltage drop of the battery 6 is suppressed and the operation of the device is ensured. And

That is, the temperature of the battery 6 is measured by the battery temperature detecting circuit 8, and when the battery temperature becomes equal to or lower than a predetermined threshold, a predetermined load current is limited and a control for suppressing a peak current is performed. Thus, even when the battery 6 is at a low temperature and the internal impedance is increased, the peak current is suppressed, so that it is possible to prevent the output voltage from being significantly reduced.

Therefore, by suppressing the peak current, the drop of the output voltage can be minimized, so that the energy of the battery can be used up irrespective of the power reduction detection level on the device side.

In the present embodiment, the predetermined load current limiting process is performed by appropriately performing the same process as in the first embodiment. That is: (1) Stop zoom tracking during zooming. (2) Limit the flash charging current in the flash charging circuit 21. (3) The operation clock inside the camera, especially the clock of the CPU 1 itself, is slowed down. (4) The set time of the auto power off is shortened.

According to the camera of the second embodiment, even when the battery 6 is kept at a low temperature, the voltage drop of the battery 6 can be suppressed and the operation of the device can be ensured.

[0043]

As described above, according to the present invention, it is possible to provide a data recording apparatus capable of performing an appropriate operation regardless of the battery temperature.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a battery temperature measurement sequence in the camera of the first embodiment.

FIG. 3 is a flowchart showing a zoom drive sequence in the camera of the first embodiment.

FIG. 4 is a flowchart showing a strobe charge sequence in the camera of the first embodiment.

FIG. 5 is a flowchart showing an operation clock change sequence of a CPU in the camera of the first embodiment.

FIG. 6 is a flowchart showing an auto power off set time changing sequence in the camera of the first embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 CPU 2 AF motor 3 AF motor drive circuit 4 Zoom motor 5 Zoom motor drive circuit 6 Battery 7 Power supply circuit 8 Battery temperature detection circuit 9 Optical lens 10 CCD 11 First release switch 12 ... 2nd release switch 21 ... strobe charging circuit 22 ... strobe light emitting section 31 ... image processing circuit 41 ... recording medium I / F 42 ... recording medium 51 ... image display section 61 ... backlight 71 ... power switch

Claims (6)

[Claims] A battery for supplying power to a predetermined circuit; a battery temperature detecting means for detecting a temperature of the battery; and a battery temperature for comparing the battery temperature detected by the battery temperature detecting means with a predetermined threshold value. A data recording device comprising: a determination unit; and a load current suppression unit that suppresses a load current of the battery when the battery temperature determination unit determines that the battery temperature is higher than a predetermined threshold. . 2. A battery for supplying power to a predetermined circuit; a battery temperature detecting means for detecting a temperature of the battery; and a battery temperature for comparing the battery temperature detected by the battery temperature detecting means with a predetermined threshold value. A data recording device comprising: a determination unit; and a load current suppression unit that suppresses a load current of the battery when the battery temperature determination unit determines that the battery temperature is lower than a predetermined threshold. . 3. The apparatus according to claim 1, wherein said load current suppressing means stops power supply to a focus adjusting means for performing a focus adjusting operation during a zoom operation. 3. The data recording device according to 2. 4. The data recording apparatus according to claim 1, wherein said load current suppressing means is configured to reduce a charging current of a strobe in a normal state. 5. The data recording apparatus according to claim 1, wherein said load current suppressing means reduces the speed of an operation clock inside the apparatus. 6. A control means for suppressing the power consumption of the data recording device when a predetermined time has been reached, and further comprising control means for suppressing the data recording apparatus to a power saving state. 3. The data recording apparatus according to claim 1, wherein the data recording apparatus is configured to be shorter.