JP2002270248A - Battery voltage detecting device and method - Google Patents

Abstract

(57) Abstract: detecting the battery change of the electronic device, which aims to more accurately display the remaining battery capacity. SOLUTION: In a battery voltage detecting device for detecting a state of a power supply voltage of an electronic device operating normally in a predetermined voltage range, a battery replacement detecting device 17 for detecting replacement of a battery.
A battery remaining amount detecting means 16 for comparing and judging the battery voltage with a predetermined voltage; a non-volatile memory 28 for storing the battery voltage at the end of the operation of the electronic device; and a detection result of the battery replacement detecting device 17. And a CPU 8 for controlling the detection operation of the battery remaining amount detection circuit 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery voltage detecting device and a detecting method mounted on a portable electronic device.

[0002]

2. Description of the Related Art Conventionally, a battery-operated digital camera is disclosed in Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent Application Publication No. 523, when the remaining amount of the battery becomes equal to or less than a predetermined value, the battery remaining amount is notified by voice or finder. Also, current, voltage, and temperature are detected as battery information for knowing the remaining battery level, and the remaining battery level of the currently used battery is predicted.

[0003]

Generally, in a battery voltage detecting device of a digital camera, as a means for knowing the remaining battery level, the battery voltage is predicted from the battery voltage and the remaining battery level is displayed. In order to prevent malfunction, the microcomputer displayed a warning and turned off the digital camera.

A battery has a voltage drop due to internal resistance.
Even if the battery voltage becomes too low in the shooting mode where the current consumption is large and the battery cannot be used, the voltage drop due to the internal resistance of the battery is small in the playback state where the current consumption is small, and the remaining capacity display with sufficient battery capacity can be obtained only by detecting the voltage. It showed.

Further, the keep left for a while the battery runs out in battery level of the battery voltage detection device, appears to be a battery residual amount is revived voltage of the battery, the user is used once It was not possible to identify whether the battery was dead or a new one. For this reason, in the case of a battery that has been used once, even when a sufficient remaining amount is displayed when the power is turned on, the voltage suddenly drops during shooting, and shooting may not be performed.

[0006]

In order to solve the above problems SUMMARY OF THE INVENTION The battery voltage detecting device of the present invention, a battery voltage detector for detecting a state of the battery voltage of the electronic device which normally operates at a voltage within a predetermined range A battery replacement detecting means for detecting battery replacement, a battery remaining amount detecting means for comparing and determining the battery voltage with a predetermined voltage, a memory means for storing a battery voltage at the end of operation of the electronic device, in accordance with the detection result of the replacement detection unit, it is obtained by comprising the CPU for controlling the operation of detecting the battery remaining amount detecting means.

According to the present invention, the fact that the battery has been replaced is detected and stored, and when the battery has been used up, the information is written into the memory means, and the power supply of the electronic device main body is maintained until the battery is replaced. It is also possible to prohibit turning on the battery, and in the case of a battery in use, the voltage in the state where the power was last turned off is stored in the memory means, and the power is finally turned off until the battery is replaced. By continuously displaying the remaining amount from the state, it is possible to provide a battery voltage detecting device capable of more accurately displaying the remaining amount of the battery.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram of a digital camera which is a portable electronic device, and FIG.
4, 5, 6, and 7 are flowcharts showing a method of detecting a remaining battery level, and FIG. 8 is a diagram showing an example of a remaining battery level display. .

In FIG. 1, a photographic lens 2 is attached to a digital camera 1 and a CCD which is a photoelectric conversion element for photoelectrically converting an optical image photographed on the optical axis of the photographic lens 2.
3 are arranged. Image data converted photoelectrically is converted into digital data from analog data by the A / D circuit 4. The image data converted into digital data is stored in the memory 5. The image data stored in the memory 5 is compressed by a signal processing circuit 6 for compressing and expanding the data.

[0011] The switching device 7 is a central processing unit CPU8
Control of the access to the recording device 9 is controlled based on the judgment of. The image data compressed by the signal processing circuit 6 is stored in the recording device 9 via the switching device 7, and the image data recorded in the recording device 9 is read from the recording device 9 via the switching device 7. The data is expanded by the signal processing circuit 6 and displayed on the monitor device 10.

The communication device 11 enables the exchange of data with the external device 12.
1 and the recording device 9, and when the access is permitted, data in the recording device 9 is transmitted to the external device 12, and data for recording from the external device 12 to the recording device 9 is transmitted. Receive.

A clock circuit 27 is operated by a clock battery 26, and adds date and clock data to the image data via the CPU 8 and displays the data on the monitor device 10.

The non-volatile memory 28 is connected to the CPU 8 and stores the remaining battery power and information on the exchange of the battery.

The power supply device 13 switches the supply of external power from the replaceable battery 14 and the external power terminal 15 to supply necessary power to the monitor device 10 and other devices.

The remaining amount detecting circuit 16 in the power supply unit 13 monitors the remaining amount of the battery 14 and transmits the remaining amount to the CPU 8, and the battery replacement detecting device 17 detects that the battery 14 has been replaced.

The CPU8 when no power is supplied from the external power supply terminal 15, and displays the remaining battery capacity on the monitor 10 based on the information on the presence of the remaining amount and battery replacement of the battery 14.
That is, whether is in the voltage range which the voltage of the battery 14 is to ensure the normal operating range of the digital camera 1, whether in the lower limit voltage of the normal operating range, and displays whether the state in which the battery is used up. When the battery voltage is lower than the lower limit voltage of the normal operation range, a warning is displayed and control is performed so that the power switch is not turned on until the battery is replaced.

Next, the operation of the battery replacement detecting device 17 for detecting battery replacement will be described in detail with reference to FIG.

[0019] In FIG 2, 21 is a capacitor for charging and discharging, 18 charging circuit to the capacitor 21, 19
Is a discharge circuit to the capacitor 21, and 20 is the capacitor 2
The battery replacement detection device 17 is constituted by the voltage detection circuit for detecting the charge / discharge state of No. 1 above. 24 is the battery 14
Is an input terminal of the battery replacement detection device 17 (that is, an input terminal of the charging circuit 18), and 23 is an output terminal (that is, voltage) of the battery replacement detection device 17. Output terminal of the detection circuit 20).

The CPU 8 sends a first control signal having a predetermined voltage value to an input terminal 22 of the battery replacement detection device 17 (that is, an input terminal of the charging circuit 18) to start charging the capacitor 21. Increase the capacitor voltage. That is, by applying a voltage of L level to the input terminal 22, and turns on the transistor of the charging circuit 18 to charge the capacitor 21.

[0021] The capacitor 21 voltage detecting circuit 20 connected to the output terminal 23 and the voltage reaches a predetermined level is input is set from the H level to L level. The CPU 8 monitors the voltage of the output terminal 23 and, when the voltage changes from the H level to the L level, the battery replacement detecting device 17.
Is determined to be in the initial state, the input of the control signal having the first predetermined voltage to the input terminal 22 is stopped, and the charging of the capacitor 21 is stopped.

Next, the operation when the battery 14 is replaced will be described. If the battery 14 is removed a new battery is attached, the second control signal according to the voltage of the battery 14 is input to the battery detection terminal 24. As a result, the transistor of the discharge circuit 19 is turned on, the electric charge of the capacitor 21 is discharged, and the capacitor voltage of the capacitor 21 decreases. Then, the output of the voltage detection circuit 20 connected to the capacitor 21 changes from the L level to the H level (that is, the output terminal 23 changes from the L level to the H level).
8 determines that the battery has been replaced. Capacitor 29 turns on the transistor of the discharge circuit 19, a charge and discharge element for turning off. When the battery 14 is replaced, when the battery is removed, the transistor of the discharge circuit 19 is grounded by the resistor 30 and is in the off state, and the capacitor 21 keeps the charged state and is not discharged. Then, the voltage of the battery detection terminal 24 changes from the L level to the H level, and the transistor of the discharge circuit 19 is turned on. Then, the charge of the capacitor 21 is discharged, the transistor of the voltage detection circuit 20 is turned off, the output terminal 23 is changed from L to H, the H level is detected at the output terminal 23, and it is detected that the battery is replaced.

[0023] If the battery 14 is not replaced, the transistor of the discharge circuit 19 is not turned on, the capacitor 2
1 maintains the capacitor voltage, and the output of the voltage detection circuit 20 (that is, the output terminal 23) does not change at the L level.
Further, as described above when the battery 14 is replaced, the charge of capacitor 21 is a capacitor voltage is discharged decrease,
The output of the voltage detection circuit 20 (that is, the output terminal 23) changes from L level to H level.

As described above, when the power supply 13 is turned on, the first control signal of the CPU 8 is applied to the input terminal 22 to charge the capacitor 21. When the power supply 13 is disconnected, the power supply 13 is replaced. The capacitor 21 is discharged by the battery voltage of the battery 14 that has been used. As described above, since the presence or absence of battery replacement is determined based on the state of the charge / discharge voltage of the capacitor 21, the battery is replaced while the power supply unit 13 is stopped and the CPU 8 is turned off or is operated by an external power supply. However, the CPU 8 can detect whether or not the battery has been replaced by reading the voltage level of the output terminal 23 of the voltage detection circuit 20 connected to the capacitor 21.

Next, referring to FIG.
Another embodiment will be described.

The battery replacement detecting device 17 comprises a flip-flop circuit 25 and a clock battery 26. The clock battery 26 uses a battery or a large-capacity capacitor, and is used as a backup for the clock circuit 27 of the digital camera 1.
Also, by using the clock battery 26 as a power source for the flip-flop circuit 25 of the battery replacement detection device 17,
The power supply of the battery replacement detection device 17 becomes unnecessary.

First, the CPU 8 sends an L level voltage, which is a first control signal having a predetermined voltage value, to the input terminal 22 of the battery replacement detection device 17 (ie, the set terminal S of the flip-flop circuit 25). Then, the flip-flop circuit 25 is set. At this time, the battery replacement detection device 17
Output terminal 23 (ie, flip-flop circuit 25)
Are set to L level.

When the battery 14 is replaced, a second control signal (voltage changes from H to L and changes to H when the battery is connected) based on the voltage of the battery 14 is applied to the battery voltage detection terminal 24 (ie, flip-flop). Is input to the reset terminal R) of the loop 25. Thus L level is input is reset to the reset input terminal of the flip-flop circuit 25, the output terminal 23 of the battery exchange detection unit 17 is reset from the L level to the H level.

The CPU 8 can detect whether or not the battery has been replaced by reading the voltage level of the output terminal 23 as in the case of the embodiment using the capacitor 21.
Further, even when the digital camera 1 is operating when the power supply device 13 is cut off or the external power supply is supplied to the external power supply terminal 15 because the operation is performed by the independent clock battery 26, it is possible to detect whether or not the battery is replaced. It can become.

Next, the battery voltage detection method and the operation of switching the remaining amount display will be described with reference to FIGS. 4, 5, 6, 7, and 8 in comparison with FIG.

Referring to FIG. 4, a case where the digital camera 1 is driven using a built-in battery will be described. Step a
1 is a start of the replacement detection process whether the battery has been replaced. In step a2, it is determined whether the battery has been replaced. If the battery has not been replaced, step a
In 3, the battery voltage information at the time of the previous end is read from the nonvolatile memory 28, and since the previous battery voltage was read by the CPU 8, the battery replacement detection device 17 is initialized in step a 4. When the battery is replaced in step a2, the battery replacement detection device 17 is directly initialized in step a4 without skipping to step a3, the digital camera 1 is operated with a new battery, and the normal battery voltage is reduced. Detect and display the remaining battery level.

FIG. 5 is a detailed flowchart of the battery remaining amount detecting operation when the battery has not been replaced in step a2 of the flowchart of FIG. b1 step is the start of the processing Denzan quantity display 1, if it is not replaced battery, reads battery voltage information of last time from the nonvolatile memory 28.

Here, for the sake of simplicity, various predetermined battery voltages are defined. That is, the battery voltage at the end of the previous operation of the digital camera 1 is represented by X (the nonvolatile memory 2).
8), the actual battery voltage detected by the battery level detection circuit 16 is Y, the battery voltage that can guarantee the normal operation of the digital camera is A, the battery voltage at the lower limit of the normal operation is B, and several minutes. Let C be the warning battery voltage that can only be used.

[0034] In step b2, the battery voltage X at the time of the last end
The remaining battery level is determined. The battery voltage X read from the non-volatile memory 28 is compared with a predetermined lower limit voltage B. When the battery voltage X is not higher than the lower limit voltage B, that is, when X <B, the battery voltage X during the previous operation of the digital camera 1 Is determined to have been used up, and the process jumps to step b8 to display the remaining battery level warning. FIG. 8C shows a warning display example.

If the battery voltage X is higher than the lower limit voltage B, that is, if X> B, the next battery voltage is determined in step b3. In step b3, if the battery voltage X at the end of the previous time is lower than the battery voltage A that can guarantee normal operation, that is, if X <A, the lower limit voltage B in step b6
The remaining battery level is determined by comparing with the remaining battery level. If the battery voltage X at the end of the previous time is greater than A, the remaining battery charge is determined in step b4.

At step b4, if the actual battery voltage Y of the battery 14 obtained by the remaining amount detection circuit 16 is higher than the battery voltage A that can guarantee normal operation, that is, if Y> A, then at step b5, The quantity display A is executed to indicate that the operation range is normal. Battery level in FIG. 8 (a) shows a display example at the time of full indicating normal operating range.

The battery voltage Y <If A, perform the remaining battery level determination in step b6, the battery voltage Y obtained in the battery remaining amount detection circuit 16, from the large lower limit voltage B, that Y> if B, step The lower limit voltage is indicated by b7. FIG. 8B shows a display example of the remaining amount when the battery voltage is smaller than A and larger than B. If the battery voltage Y <B, step b8
A warning display of FIG. 8C showing a battery remaining amount warning display for indicating that the voltage is the warning voltage is performed. Of course, the remaining battery level can be displayed in three levels using other display methods. For example, when the number of signs is full, two marks are displayed, the next is indicated by one mark, and a warning is indicated by a surprised mark. Can be displayed using

In FIG. 4, step a2 for determining battery replacement is performed.
The flow of the normal battery remaining amount display after determining that the battery has been replaced will be described in detail with reference to FIG. FIG.
In step c1, a step for starting the battery remaining amount display 2 is performed. In step c2, the battery remaining amount of the battery voltage Y of the operating battery 14 is determined, and the battery remaining amount of the battery 14 obtained by the battery remaining amount detection circuit 16 is determined. If the voltage Y is higher than the normal voltage A, that is, if Y> A, a battery remaining amount display indicating that the battery voltage of the battery 14 is the normal voltage A is performed in step c3 (that is, FIG. 8A). Full display). Y <A, then the perform battery residual quantity determined in step c4, the battery voltage Y is a lower limit voltage B of the battery 14 obtained in the battery remaining amount detection circuit 16
If it is larger, that is, if Y> B, the remaining battery level is displayed in step c5 to indicate that the lower limit voltage B is reached (FIG. 8)
(B) display). If Y <B, battery 1 in step c6
4 is displayed (warning display of FIG. 8C).

At the end of the operation of the digital camera 1, FIG.
As shown in (1), the battery remaining amount storage process is started in step d1, the battery voltage of the battery 14 is written in the nonvolatile memory 28 in step d2, and information on the battery remaining amount is stored.

As a result, when the battery has not been replaced, the information on the remaining battery level at the end of the previous time can be used, so that a more accurate display of the remaining battery level can be performed.

[0041]

As described above, according to the battery voltage detecting device and the detecting method of the present invention, it is detected whether or not the battery has been replaced, and if not, the previous operation of the electronic device is terminated. Since the state is stored and the battery information can be used, an accurate remaining battery level can be displayed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital camera including a battery replacement detection device according to a first embodiment of the present invention.

Detailed block diagram of a battery exchange detection device in the first embodiment of the present invention; FIG

Detailed block diagram of a battery exchange detection device according to another embodiment of the present invention; FIG

FIG. 4 is a flowchart of a battery voltage detection method according to an embodiment of the present invention.

Flowchart showing a battery voltage detection method in the case where the battery of the first embodiment of the present invention; FIG not replaced

FIG. 6 is a flowchart showing a battery voltage detecting method when the battery is replaced according to the first embodiment of the present invention;

FIG. 7 is a flowchart of operations at the end of the battery voltage detection method of Embodiment 1 of the present invention

Illustrates an example of a battery remaining amount display method according to the first embodiment of the present invention; FIG

[Explanation of symbols]

 1 Digital Camera (Electronic Equipment) 8 CPU 10 Monitor 13 Power Supply 14 Battery 15 External Power Terminal 16 Battery Remaining Detector 17 Battery Replacement Detector 18 Charger 19 Discharge Circuit 20 Voltage Detector 21, 29 Capacitor 22 Battery Detector Input terminal 23 output terminal of battery detection device 24 battery detection terminal 25 flip-flop circuit 26 clock battery 27 clock circuit 28 non-volatile memory

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G016 CA04 CB12 CC03 CC04 CC06 CC14 CC16 CC27 CC28 CD04 CD10 2H054 AA01 2H102 AB02 5G003 BA01 DA02 EA05 GA01 GC05 5H030 AA06 AS11 FF44 FF51

Claims (5)

[Claims] 1. A battery voltage detecting device for detecting a battery voltage state of an electronic device that normally operates in a predetermined voltage range, wherein a battery replacement detecting unit detects battery replacement.
Battery level detecting means for comparing and determining the battery voltage with a predetermined voltage; memory means for storing the battery voltage at the end of the operation of the electronic device; and battery level detecting means in accordance with the detection result of the battery replacement detecting means A battery voltage detecting device comprising a CPU for controlling the detecting operation of the battery voltage. 2. A battery replacement detection unit receives a predetermined control signal from a CPU, sets an output of the battery replacement detection unit to a predetermined logic level and initializes the logic, and then executes a logic corresponding to the initialization state. 2. The battery voltage detecting device according to claim 1, wherein whether the battery is replaced is detected by detecting whether the state is reset. 3. A battery voltage detecting device for detecting a battery voltage state of an electronic device that normally operates in a predetermined voltage range, wherein a battery replacement detecting means detects battery replacement.
Battery remaining amount detecting means for comparing and determining the battery voltage with a predetermined voltage; memory means for storing the battery voltage at the end of the operation of the electronic device; and battery voltage detecting operation controlled in accordance with the detection result of the battery replacement detecting means When a battery replacement is detected by the output of the battery replacement detection unit, the battery voltage value is read from the memory unit, and the battery voltage is compared with a predetermined voltage. A battery voltage detecting device for displaying a remaining battery level. 4. A battery voltage detection method for detecting a battery voltage state of an electronic device that normally operates in a predetermined voltage range, detects whether or not the battery is replaced, and replaces the battery when the battery is replaced. Initialize the detecting means, when the battery is not replaced, read the battery voltage from the memory means in which the battery voltage at the time of the last battery operation of the electronic device is stored, and compare the battery voltage with a predetermined voltage. And a battery voltage detection method, wherein a remaining battery level is displayed. 5. After a predetermined control signal is input from a CPU, an output of the battery replacement detection means is set to a predetermined logic level and initialized, and then whether a logic state corresponding to the initialized state has been reset. The battery voltage detection method according to claim 4, wherein the presence or absence of battery replacement is detected by detecting the battery voltage.