JP2003125541A - Battery-powered portable device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a battery-powered portable device, such as a portable digital camera, once or several times, even after the battery runs down in normal use and enable the use of the device during an emergency. SOLUTION: If the starting operation, different from normal starting operation, is performed after the battery has run down, for example, a power switch 4 is depressed while a release switch 7 which is a switch for actuating the device is held depressed, a controlling means (not shown) changes the set value of lower limit voltage of a secondary battery 3 to a lower value, subject to this operation. Thus, exposure can be made once or several times for emergency purposes after the battery runs down.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery-powered portable device such as a portable digital camera or a handy camcorder.

[0002]

2. Description of the Related Art In a portable digital camera or the like, for example, a secondary battery mounted from the outside is used as a main battery, which serves as a power source for strobe and zoom operations.
The lower limit voltage of the secondary battery, which is the lower limit of the energy that enables shooting operation, is detected at a level with some margin, not at zero potential, from the viewpoint of ensuring protection of image data. It has become so. When the lower limit voltage is detected by the built-in detection means, "battery exhausted" is displayed on the LCD. When the battery exhaustion is displayed, the device cannot be activated after that, unless the secondary battery is charged or replaced, and the photographing operation and the like cannot be performed at all.

Japanese Patent Application Laid-Open No. 8-317326 describes a digital camera having various power saving modes during operation. This is because when the camera operation cannot be guaranteed due to the decrease of the power supply voltage of the camera, the image data is surely protected and the number of shootable images is prevented from decreasing. Then, the image data is recorded by switching to an appropriate recording medium.

[0004]

When the battery runs out, it is common to give up shooting at that time. However, depending on the user's usage situation and purpose, even if there is a deterioration in image quality, some images will be taken after that. There may be an emergency situation in which you want to or should shoot. However, in the conventional configuration, although the power saving mode or the like corresponding to the change in the power supply voltage can be executed, as described above, the shooting operation after the battery is dead cannot be performed at all, and the emergency use is not possible. There wasn't.

An object of the present invention is to provide a battery-powered portable device which can be operated once or several times even after detecting a dead battery and which can be used for emergency purposes.

[0006]

In order to achieve the above object, the present invention effectively utilizes the voltage remaining after the normal detection of a dead battery in a secondary battery. In particular,
According to the invention of claim 1, in a battery-powered portable device using a secondary battery as a main battery, there is provided control means for changing a detection value of the lower limit voltage of the secondary battery under a certain condition, and the lower limit voltage before change is provided. It is configured to operate within the range of the changed lower limit voltage even after is detected.

In the invention according to claim 2, the main battery is 2
A battery-powered portable device using a secondary battery has a control means for executing a constraint mode that restricts operations and functions under certain conditions, and operates in the constraint mode even after the lower limit voltage of the secondary battery is detected. It has a configuration that allows it.

In the invention according to claim 3, as the main battery, 2
A battery-powered portable device using a secondary battery has a control means for changing the control of the internal system under certain conditions.
The configuration is such that it operates in the power saving control mode even after the lower limit voltage of the secondary battery is detected.

According to a fourth aspect of the present invention, in the battery-powered portable device according to the first aspect, the control means executes the constraint mode for restricting the operation / function after changing the detection value of the lower limit voltage. The composition is adopted.

According to a fifth aspect of the present invention, in the battery-powered portable device according to the first aspect, the control means executes the power saving control mode in which the control of the internal system is changed after the detection value of the lower limit voltage is changed. Is adopted.

According to a sixth aspect of the present invention, the first to fifth aspects are provided.
In the battery-powered portable device described in any one of the above ones, the certain condition is that a startup operation different from a normal startup operation is performed.

According to a seventh aspect of the invention, in the battery-powered portable device according to the sixth aspect, the normal starting operation is pressing down a power switch, and the different starting operation is
The configuration is that the power switch is pressed while pressing the switch for operating the device.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. First, a schematic configuration of a portable digital camera as a battery-powered portable device according to the present embodiment will be described with reference to FIG. The portable digital camera 1 includes a camera body 2, a secondary battery 3 attached to the camera body 2, a power switch 4, and a zoom mechanism 5.
2, a strobe 6, a release switch 7 as a switch for operating the device, a finder 8 and the like. Inside the camera body 2, a control means 9 shown in FIG. 2 is provided. The control means 9 is a CPU, RAM, RO
It is a microcomputer including an M, I / O interface and the like. When the power switch 4 is turned on, the subject to be photographed is confirmed with the finder 8 and the release switch 7 is pressed, the strobe 6 is fired according to the amount of light, and photographing is performed. These operations are controlled by the control means 9.

The discharge curve of the secondary battery 3 shows a curve as shown in FIG. 3, and the lower limit voltage in the normal photographing operation is set to Va1 with some margin left until the zero potential. When the set value Va1 is detected by the voltage detection means (not shown), the control means 8 displays “battery exhausted” on the LCD 10. When the battery is displayed, the subsequent shooting operation cannot be performed in the normal usage.

In this state, when a start-up operation (restart) different from a normal condition is performed as a certain condition, the control means 9 causes the lower limit voltage of the secondary battery 3 to be lower than that in the normal case, as shown in FIG. Change to a lower Vb1. In the present embodiment, an unusual starting operation is to press the power switch 4 while pressing the release switch 7. By doing so, the operation can be performed for a time period of about ΔT1 (tb1-ta1) compared to the normal operation, and the shooting can be performed for an emergency purpose. This control operation will be described based on the flowchart of FIG.

First, the control means 9 checks whether or not the power switch 4 is turned on (S1), and if it is turned on, it is checked whether or not the release switch 7 is simultaneously turned on (S2). When the release switches 7 are not turned on at the same time, the normal operation is performed (S3). That is, the lower limit voltage of the secondary battery 3 is set to Va1.
When the release switch 7 is turned on, the control means 9 changes the set value of the lower limit voltage of the secondary battery 3 to Vb1 (Sb).
4).

Next, a second embodiment will be described with reference to FIG. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and the explanations on the configuration and the function which have already been made are omitted unless particularly necessary. Further, only a main part will be described (same in other embodiments below). In the present embodiment, when an unusual starting operation as a certain condition is performed, the control means 9 executes the restriction mode in which the operation / function is restricted. In the present embodiment, an unusual starting operation is to press the power switch 4 while pressing the release switch 7. Restrictions on operation / function include, for example, prohibition of strobe charging, which consumes a large amount of current, prohibition of zoom operation, and prohibition of liquid crystal display. When the constraint mode is executed, FIG.
As shown in, since the voltage level at the time of startup rises as compared with the normal operation, the arrival of the set value Va2 of the lower limit voltage of the secondary battery 3 deviates on the time axis. That is, the operation can be performed for a time period of about ΔT2 (tb2-ta2) compared to the normal operation, and shooting can be performed for an emergency purpose.

When an unusual starting operation (certain condition) is performed, for example, when the power switch 4 is pressed while the release switch 7 is being pressed, the control means 9 changes the control of the internal system, and in the power saving control mode. You may make it operate | move (3rd Embodiment). For changing (restricting) the control of the internal system, for example, DR the operation program
It is conceivable to switch to the execution in the ROM when switching to the AM, to switch the operating frequency of the CPU (system) to a low speed, or the like. Also in the present embodiment, as in the case shown in FIG. 5, the voltage level at the time of startup increases due to the power saving control, and therefore about ΔT2 (tb2
It becomes possible to operate for the time period of -ta2), and shooting can be performed for emergency purposes.

Next, a fourth embodiment will be described with reference to FIG. In the present embodiment, the control unit 9 causes the secondary battery 3 to operate when a start-up operation that is different from normal as a certain condition is performed.
The lower limit voltage of is changed to Vb1 which is lower than that in the normal case, and the restriction mode for restricting the operation / function is executed. In the present embodiment, an unusual starting operation is to press the power switch 4 while pressing the release switch 7. In the present embodiment, in addition to the increase in the voltage level at the time of startup due to the restriction mode, the change of the set value of the lower limit voltage of the secondary battery 3 causes about ΔT3 (tb3
The operation for the time period of -ta3) becomes possible, and it is possible to perform emergency shooting.

When an unusual starting operation is performed as a certain condition, the control means 9 changes the lower limit voltage of the secondary battery 3 to Vb1 which is lower than the normal case, and changes the control of the internal system. The power saving control mode may be operated (fifth embodiment). In the present embodiment as well, as in the case shown in FIG. 6, in addition to the increase in the voltage level at the time of startup due to the power saving control, the setting value of the lower limit voltage of the secondary battery 3 is changed, so that about ΔT3 (tb3-t).
The operation for the time period of a3) becomes possible, and it is possible to perform emergency shooting. As a start-up operation different from usual, the power switch 4 may be pressed while pressing the release switch 7.

In each of the above embodiments, the portable digital camera has been described, but the invention can be similarly applied to other battery type portable equipment such as a handy camcorder.

[0022]

According to the invention described in claim 1, a battery-powered portable device using a secondary battery as a main battery has a control means for changing the detection value of the lower limit voltage of the secondary battery under certain conditions. However, since it is configured to operate within the range of the changed lower limit voltage even after the lower limit voltage before change is detected, it can be operated once or several times even after the battery runs out, and it can be used for emergency applications. Is possible.

According to the second aspect of the present invention, the battery-powered portable device using the secondary battery as the main battery has the control means for executing the restriction mode for restricting the operation / function under certain conditions. Since it is configured to operate in the restricted mode even after the lower limit voltage of the secondary battery is detected, the voltage level at the time of restart is increased, and the operation can be performed once or several times even after the battery runs out. It can be used for various purposes.

According to the invention of claim 3, in a battery-powered portable device using a secondary battery as a main battery, it has a control means for changing the control of the internal system under certain conditions, and the lower limit of the secondary battery is provided. Since it is configured to operate in the power saving control mode even after the voltage is detected, the voltage level at restart is increased due to power saving, and it is possible to perform the operation once or several times even after the battery runs out. Is possible.

According to a fourth aspect of the present invention, in the battery-powered portable device according to the first aspect, the control means executes a constraint mode in which the operation / function is constrained after the detection value of the lower limit voltage is changed. Since the configuration is adopted, in addition to changing the set value of the lower limit voltage, it is possible to increase the voltage level at the time of restart by the restriction mode, and it is possible to further increase the number of operations due to restart after battery exhaustion.

According to a fifth aspect of the invention, in the battery-powered portable device according to the first aspect, the control means executes the power saving control mode in which the control of the internal system is changed after the detection value of the lower limit voltage is changed. With this configuration, in addition to changing the set value of the lower limit voltage, it is possible to increase the voltage level at the time of restart by the power saving mode, and it is possible to further increase the number of operations by restarting after the battery runs out.

According to a sixth aspect of the present invention, in the battery-powered portable device according to any of the first to fifth aspects, the certain condition is that an activation operation different from a normal activation operation is performed. Therefore, it is not necessary to newly install equipment for satisfying a certain condition, so that the existing configuration can be used for emergency purposes after the battery is dead.

According to a seventh aspect of the present invention, in the battery-powered portable device according to the sixth aspect, the normal starting operation is pressing down a power switch, and the different starting operation is a switch for operating the device. Since the configuration is such that the power switch is depressed while pressing, the existing configuration can be used for emergency purposes after the battery runs out.

[Brief description of drawings]

FIG. 1 is a perspective view of a portable digital camera as a battery-powered portable device according to a first embodiment of the present invention.

FIG. 2 is a control block diagram.

FIG. 3 is a graph showing the relationship between the discharge curve of the secondary battery and the set value of the lower limit voltage.

FIG. 4 is a flowchart showing a control operation.

FIG. 5 is a graph showing the relationship between the discharge curve of the secondary battery and the set value of the lower limit voltage in the second embodiment.

FIG. 6 is a graph showing the relationship between the discharge curve of the secondary battery and the set value of the lower limit voltage in the fourth embodiment.

[Explanation of symbols]

3 Rechargeable Battery 4 Power Switch 7 Release Switch 9 as a Switch to Operate Equipment Control Unit

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Claims (7)

[Claims] 1. A battery-powered portable device using a secondary battery as a main battery, comprising control means for changing a detection value of a lower limit voltage of the secondary battery under a certain condition, and the lower limit voltage before the change is detected. A battery-operated portable device characterized by being operated within the range of the changed lower limit voltage even after being charged. 2. A battery-powered portable device using a secondary battery as a main battery, having control means for executing a restriction mode for restricting operation / function under certain conditions, and detecting a lower limit voltage of the secondary battery. A battery-operated portable device characterized in that it is operated in the restricted mode even after being struck. 3. A battery-powered portable device using a secondary battery as a main battery, having control means for changing control of an internal system under certain conditions, and saving power even after the lower limit voltage of the secondary battery is detected. A battery-powered portable device characterized by being operated in a control mode. 4. The battery-powered portable device according to claim 1, wherein the control means executes a restriction mode for restricting an operation / function after the detection value of the lower limit voltage is changed. machine. 5. The battery-powered portable device according to claim 1, wherein the control means executes a power saving control mode in which the control of the internal system is changed after the detection value of the lower limit voltage is changed. Mobile device. 6. The battery-powered portable device according to claim 1, wherein the certain condition is that a startup operation different from a normal startup operation is performed. . 7. The battery-powered portable device according to claim 6, wherein the normal startup operation is pressing a power switch, and the different startup operation is pressing a power switch while pressing a switch for operating the device. A battery-powered portable device characterized in that