JP2000324719A - Electronic apparatus, control method therefor, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus, which supplies backup power for only a period of time similar to normal time, even when power supply is abnormal, and backup power is not supplied from a sub-battery, a control method for the electronic apparatus, and a storage medium. SOLUTION: The voltage of a sub-battery 4 is detected by a voltage detector 32. When the voltage is equal to or higher than a normal value, a signal SBIN of a high level is outputted. When the voltage is lower than the normal value, a signal SBIN of a low level is outputted. The output signal SBIN is supplied to the inversion input terminal of a buffer circuit 38 via a NOT circuit 39, along with being supplied to the inversion input terminal of a buffer circuit 37. When the signal SBIN is at high level, a reference voltage VL0 for turning off the main power source of an electronic apparatus body is selected, and when the signal SBIN is at low level, a reference voltage VL1(>VL0) for turning on the main power of the electronic apparatus body is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having a main battery and a sub-battery, for controlling on / off of power supply from the main battery to a device body, a control method thereof, and a storage medium.

[0002]

2. Description of the Related Art A portable electronic device usually includes a battery (main battery) such as a nickel-cadmium battery or a lithium ion battery as a main power supply, and the main battery supplies power to the electronic device body. As a result, the remaining amount decreases, and the battery voltage also decreases.

A conventional power supply circuit built in an electronic device main body constantly monitors a voltage value of a main battery, and when the power of the electronic device is turned on, the voltage value of the main battery decreases to reach a predetermined voltage value. Then, it is judged that it is impossible to continue power supply with the main battery any more,
Give a warning to the user and turn off the main unit. Hereinafter, this predetermined voltage value is referred to as a low battery voltage value.

The portable electronic device has a sub-battery as a power source different from the main battery. When the electronic device is turned off, the main battery can be replaced or the main battery can be replaced. When the remaining power of the battery becomes low and power cannot be supplied, backup power is supplied to a memory such as an SRAM (static RAM) by supplying power from the sub-battery to prevent loss of the stored data and the like. Like that.

[0005]

However, in the above-mentioned conventional electronic device, when the sub-battery is not connected to the main body of the electronic device, when the remaining amount of the sub-battery is exhausted, or when the sub-battery is broken down or deteriorated, In some cases, backup power could not be supplied.

In a normal state, the power supply of the electronic device main body is turned off after detecting the low battery voltage value of the main battery. First, power is supplied from the main battery to a backup circuit for holding data and the like in a memory or the like. When the main battery voltage falls below the battery voltage value for driving the backup circuit, power is supplied from the sub-battery so that data stored in the memory or the like is maintained for a predetermined time. I have to.

However, if power is not supplied from the sub-battery due to the above reasons, the power is continuously supplied to the backup circuit only by the main battery, and the time during which data and the like can be held becomes shorter than in the normal state. Could be

The present invention has been made in view of this point, and it is possible to supply the backup power for the same time as the normal time even in the case of an abnormality where the backup power is not supplied from the sub-battery. It is an object to provide an electronic device, a control method thereof, and a storage medium.

[0009]

In order to achieve the above object, an electronic device according to the present invention is an electronic device comprising a main battery for a main power supply and a sub-battery for a backup power supply, wherein a voltage value of the main battery is provided. Voltage detecting means for detecting the main battery, when the detected voltage value of the main battery drops below a reference value, control means for controlling so as to stop power supply from the main battery to the electronic device, Abnormality detecting means for detecting abnormality of the sub-battery, and setting means for setting the reference value higher than a normal value when abnormality of the sub-battery is detected by the abnormality detecting means; When a battery abnormality is detected, only the main battery is used as a backup power supply.

[0010] The abnormality of the sub-battery detected by the abnormality detecting means includes at least that the sub-battery is not connected to the electronic device and that the sub-battery does not output a predetermined voltage value. It is characterized by being one.

In order to achieve the above object, a control method of an electronic device according to the present invention is a control method of an electronic device comprising a main battery for a main power supply and a sub-battery for a backup power supply, wherein the voltage value of the main battery is When the detected voltage value of the main battery falls below a reference value, control is performed to stop the power supply from the main battery to the electronic device, and the abnormality of the sub-battery is detected. When the abnormality of the sub-battery is detected, the reference value is set higher than a normal value, and when the abnormality of the sub-battery is detected, only the main battery is used as a backup power supply. I do.

In addition, the detected abnormality of the sub-battery is at least one of the fact that the sub-battery is not connected to the electronic device and that the sub-battery does not output a predetermined voltage value. It is characterized by.

[0013] In order to achieve the above object, a storage medium of the present invention includes a method of controlling an electronic device including a main battery for a main power supply and a sub-battery for a backup power supply.
A storage medium storing a program that can be realized by a computer, wherein the control method detects a voltage value of the main battery, and when the detected voltage value of the main battery falls below a reference value, Control to stop the power supply from the battery to the electronic device,
When the abnormality of the sub-battery is detected, when the abnormality of the sub-battery is detected, the reference value is set higher than a normal value, and when the abnormality of the sub-battery is detected, only the main battery is backed up. It is characterized by being used as a power supply.

Further, the detected abnormality of the sub-battery is that at least one of the sub-battery is not connected to the electronic device and the sub-battery does not output a predetermined voltage value. It is characterized by.

[0015]

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

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

As shown in FIG. 1, an electronic device 1 according to the present embodiment includes a system section 2, a main battery 3 for supplying power to the main body of the electronic device 1, and a backup circuit 2e.
Battery 4 for supplying power to the electronic device 1
It is mainly composed of a power on / off switch 5 for turning on / off the power of the main body, and a power supply circuit section 6 for supplying a rated power to the system section 1.

The system unit 2 includes a CPU (Central Processing Unit) 2a that controls the entire electronic device 1, a main storage device 2b that stores application programs and data,
A display device 2c for displaying characters and the like, an auxiliary storage device 2d for reading and writing files such as a memory card and a hard disk, and a backup circuit having a function of retaining data and the like when the power of the electronic device 1 is turned off. 2
e. The backup circuit 2e
In the present embodiment, when an RTC (Real Time Clock) is driven or an SRAM is employed as the main storage device 2b, data is retained in the main storage device 2b even when the power of the electronic device 1 is turned off. It has a function to make it work.

The power supply circuit section 6 supplies a power supply VBB to the backup circuit 2e and the like via the power supply line L1 when the power supply of the main body of the electronic equipment 1 is turned off. The power supply VCC is supplied to the system unit 2 when the power of one main body is turned on and operating.
In this embodiment, the power supply VBB is supplied to the backup circuit 2e even when the power of the electronic device 1 is turned on. In this case, the main battery 3 is used as a power supply source.

The power supply circuit section 6 includes a power supply controller 6a having a function of turning on / off the power supply of the main body of the electronic apparatus 1 and turning off the power supply when a low battery voltage is detected.

FIG. 2 is a diagram showing the time transition of the output voltage of the main battery 3 when the main battery 3 is connected to the main body of the electronic apparatus 1 and a predetermined current value is constantly supplied to the main body.

In the figure, the voltage value VL0 is normal, that is, the sub-battery 4 is connected to the main body of the electronic device 1 and the sub-battery 4 is functioning normally.
If the remaining power is sufficient, the main battery 3 connected to the main body of the electronic device 1 runs out and the power supply for continuing the operation of the electronic device 1 cannot be performed. A main battery detection voltage value (low battery voltage value) for making a determination is shown.

When the voltage value VL1 is not normal, that is, the sub-battery 4 is not connected to the main body of the electronic device 1, the sub-battery 4 has a low voltage due to deterioration or the like, or has almost no remaining power. Electronic device 1
The main battery 3 connected to the main unit runs out of power,
A main battery detection voltage value (low battery voltage value) for determining to turn off the power assuming that power supply for continuing the operation of the electronic device 1 cannot be performed is shown.

The hatched portion shows the difference between the low battery voltage value VL0 and the remaining amount remaining in the main battery 3 when the power is turned off to the low battery voltage value VL1, and the low battery voltage value is “VL1 (V)” indicates that “M1 (Ah)” remains.

In the present embodiment, the main battery 3 is charged by removing the main battery 3 from the main body of the electronic device 1 and using a dedicated charger. When the low battery voltage is detected once, the main battery 3 is charged. 3
Power shall not be turned on unless is replaced.

FIG. 3 shows a case where the sub-battery 4 is connected to the main body of the electronic device 1 and a predetermined current value required for the operation of the backup circuit 2e is constantly supplied to the main body side while the power supply of the main body of the electronic device 1 is off. FIG. 5 is a diagram showing a time transition of an output voltage of a sub-battery 3.

In FIG. 3, a voltage value SVL0 indicates a voltage value at which the remaining amount of the sub-battery 4 becomes small and the backup circuit 2e cannot operate.

The time Tf (h) indicates the time during which the backup circuit 2e can continue to operate when the remaining amount of the sub-battery 4 is 100%. This shows the time during which the backup circuit 2e can continue to operate when it is assumed that the remaining amount is 80%.

A hatched portion indicates a current value S1 (A) required for the backup circuit 2e to continue operating for the operation time T.
h).

In the present embodiment, when the sub-battery 4 is not normal, that is, the sub-battery 4 is not connected to the main body of the electronic device 1, the sub-battery 4 has decreased in voltage due to deterioration, or has almost no remaining amount. In this case, the amount of current for the time during which the sub-battery 4 supplies power and continues to operate the backup circuit 2e is left in the main battery 3 even when the main body is turned off at the low battery voltage. , The data retention time is the same as that in the normal state.

In this embodiment, the sub-battery 4
Assuming that 80% of the remaining amount is always on average,
The sub-battery 4 supplies power and the backup circuit 2e
The time during which the operation can be continued is defined as T (h).

Therefore, the current amount S1 required for the operation time T (h) of the backup circuit 2e in the sub-battery 4
(Ah) and the low battery voltage value V of the main battery 3
A current amount M1 (A) expressed as a difference between L0 and VL1
h) can be regarded as S1 (Ah) ≒ M1 (Ah).

As a result, if the sub-battery 4 is not normal as shown in FIG. 2, that is, if the sub-battery 4 is not connected to the main body of the electronic device 1 or if the voltage has dropped due to the deterioration of the sub-battery 4, etc. When there is almost no amount, the main battery 3 connected to the electronic device 1 main body runs out and the power supply for continuing the operation of the electronic device 1 cannot be performed, and a determination to turn off the power is made. , Main battery detection voltage value (low battery voltage value) VL1
Can be led.

FIG. 4 is an electric circuit diagram showing a detailed configuration of the power supply circuit section 6. As shown in FIG.

In the figure, the main battery 3 and DC-
A Pch FET Q1 is connected between the DC converter 30 and the DC converter 30. The transistor Q2 is an NPN transistor for driving the FET Q1.

A Pch FET Q3 is connected between the sub-battery 4 and the backup circuit 2e. The transistor Q4 is an NPN transistor for driving the FET Q3.

The resistor R1 is a resistor for driving the FET Q1, the resistor R2 is a resistor for driving the FET Q3, the resistor R3 is a resistor for controlling the current of the connected shunt regulator 34, and the resistors R4 and R5. , R6 are resistors for pulling up the connected signal lines, and the resistors R6
7, R8 are voltage-dividing resistors connected to the comparator 36 for detecting the low battery voltage value VL0;
The resistors R9 and R10 are connected to the comparator 35,
Resistors for voltage division for detecting the low battery voltage value VL1. The resistors R11 and R13 are connected to the comparator 35, and apply positive feedback for stabilizing the output when the input signal contains noise. The resistors R12 and R14 are connected to the comparator 36. The resistors R12 and R14 are provided with a positive feedback to stabilize the output when noise is included in the input signal, thereby providing the hysteresis characteristic. For the resistance.

The diode D1 is a backflow preventing diode connected to the voltage regulator 31, and the diode D2 is a backflow preventing diode connected to the voltage regulator 33.

The DC-DC converter 30 is connected to the FET
Q1 is a DC-DC converter for supplying power VCC to the system unit 2. A voltage regulator 31 is connected to the main battery 3 and converts a voltage to a voltage value required for the backup circuit 2e. The voltage detector 32 is connected to the sub-battery 4, detects the output voltage of the sub-battery 4, sets the output signal SBIN to a high level when a voltage equal to or higher than the normal voltage value is detected, and If it is not possible, that is, if the sub-battery 4 is not connected or the required voltage is not output, the output signal SBIN
Is set to a low level.

The voltage regulator 33 is connected to the FE.
The shunt regulator 34 is connected to the sub-battery 4 and is connected to the sub-battery 4 to convert a voltage to a voltage value required for the backup circuit 2e. This is a shunt regulator for outputting the value Vref.

The comparator 35 outputs the reference voltage Vref
And the voltage value of the main battery 3 is changed to a resistor R9 and a resistor R10.
A comparator for detecting the low battery voltage value VL1 by comparing the divided voltage value with
The comparator 36 is a comparator for detecting the low battery voltage value VL0 by dividing the reference voltage Vref and the voltage value of the main battery 3 by the resistors R7 and R8 and comparing the voltage values.

The buffer circuit 37 is a buffer circuit that outputs the output signal of the comparator 35 as the signal LBAT * when the signal SBIN is at the low level, and cuts off the signal when the signal SBIN is at the high level. Is controlled by a signal obtained by inverting the output signal SBIN of FIG.
When the signal SBIN is at the gh level, the signal is output as the signal LBAT *, and when the signal SBIN is at the low level, the buffer circuit cuts off the signal. The NOT circuit 39 is connected to the control terminal of the buffer circuit 38 and inverts the logic of the signal SBIN.
This is a T circuit.

The control signal PWON is supplied to the power controller 6
a is a control signal for controlling power supply to the system unit 2 by controlling the FET Q1. The power is turned on at a high level and turned off at a low level.

The voltage value Vref is a reference voltage value output from the shunt regulator 34, and the signal SBIN
Is an output signal of the voltage detector 32 for monitoring the power supply voltage value of the sub-battery 4. When it is at the high level, it indicates that the sub-battery 4 is connected and normal, and when it is at the low level, it is This indicates that the battery 4 is not connected, or that the output voltage is low for some reason.

The signal LBAT * is supplied to comparators 35 and 3
6, which is a signal output from the low battery voltage detection circuit unit constituted by the power supply controller 6 and input to the power supply controller 6a.
In the case of the low level, it indicates that the output voltage value of the main battery 3 has decreased to the low battery voltage value.

The power supply voltage VCC is a power supply voltage whose voltage value is converted by the DC-DC converter 30 and supplied to the system unit 2. The power supply voltage VBB is a voltage converted by the voltage regulator 31 from the main battery 3. The power supply and the power supply obtained by converting the voltage from the sub-battery 4 by the voltage regulator 33 are the power supply voltages connected by the backflow prevention diodes D1 and D2.

In this embodiment, the voltage dividing resistor R7,
R8 and R9, R10 fixed the resistance value,
The present invention is not limited to this, and may be changed using a variable resistor. Further, in the present embodiment, the detection of the low battery voltages VL0 and VL1 is performed by using hardware as described above. However, the present invention is not limited to this.
O interface is provided, and the voltage of the main battery 3 is directly input to this interface, and this voltage is
Monitoring by 2a may be performed by software.

FIG. 5 is a diagram for explaining the operation of the power supply controller 6a.

In the figure, the power controller 6a
The electronic device 1 is driven by the power supply voltage VBB and can operate even when the power supply of the electronic device 1 is off.

The power controller 6a receives a signal L
BAT * and the output signal of the power on / off switch 5 are supplied.
By monitoring the off switch 5, it outputs a signal PWON to perform on / off control of the power supply of the electronic device 1 body.

The signal LBAT * is input to the interrupt terminal of the power supply controller 6a, and when the low level of the signal LBAT * is detected, if the power of the electronic device 1 is turned on, the user After a warning is displayed, the power is turned off. In the present embodiment,
The power controller 6a has a function of detecting whether or not the main battery 3 has been replaced. When the power is turned off after the low battery voltage is detected, the power on / off switch 5 is operated unless the main battery 3 is replaced. Even if the power is turned off, the power is not turned off again.

FIG. 6 is a flowchart showing the procedure of the process (power-off process) after the detection of the low battery voltage.
This process indicates a process of turning off the power when a low battery voltage is detected while the power of the electronic device 1 is turned on. It is assumed that a program for realizing this processing is stored in a storage device (not shown) built in the power supply controller 6a. The low battery detection signal LBAT * is supplied to the power controller 6
This is a factor of interrupt processing for a.

In the figure, first, in step S1,
A warning sound, display, or the like is provided to notify the user that the power is turned off by detecting the low battery voltage.

Next, in step S2, the signal PWON is set to Low level to turn off the FET Q1, and the power supply to the system unit 2 is cut off, so that the power supply of the electronic device 1 is turned off.

Then, in step S3, it is monitored whether or not the main battery 3 has been replaced. The main battery 3 is kept in a standby state until it is replaced. When the replacement of the main battery 3 is detected, the processing is terminated. End the interrupt processing by the program.

The above-described power supply control method can be realized by storing the program according to the flowchart in the storage device in the power supply controller 6a and operating the program.

As described above, in this embodiment, the electronic device 1 can detect two kinds of low battery voltages VL0 and VL1 (VL0 <VL1), and can detect abnormal voltage of the sub-battery 4. If the voltage abnormality of the sub-battery 4 is detected while the power supply of the main body is on, when the reference voltage Vref of the main battery 3 reaches VL1, the power supply of the main body of the electronic device 1 is turned off and the backup circuit 2e When the backup power is supplied to the sub-battery 4 and the abnormal voltage of the sub-battery 4 is not detected, the reference voltage Vref of the main battery 3 is
When the power reaches L0, the power of the electronic device 1 is turned off and the backup power is supplied from the sub-battery 4 to the backup circuit 2e. Therefore, the backup power may not be supplied to the backup circuit 2e due to the abnormality of the sub-battery 4. However, the backup power can be supplied to the backup circuit 2e for the same time as in the normal state.

A storage medium storing a program code of software for realizing the functions of the above-described embodiments is supplied to a system or an apparatus, and a computer (or CPU 2a or MPU) of the system or apparatus stores the storage medium in the storage medium. Needless to say, the object of the present invention can be achieved by reading and executing the program code.

In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

The storage medium for supplying the program code includes a storage medium installed in the auxiliary storage device,
For example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, non-volatile memory card, ROM, and the like can be used. Also, a communication interface is provided,
The program code may be supplied from a server computer via a communication network.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also an OS or the like running on the computer operates based on the instruction of the program code. It goes without saying that a case where a part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing is also included.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that the CPU 2a or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0063]

As described above, according to the present invention, the voltage value of the main battery is detected, and the detected voltage value of the main battery falls below the reference value. Is controlled to stop the power supply from the main battery to the electronic device, and when an abnormality of the sub-battery is detected, the reference value is set higher than a normal value, and Since only the battery is used as backup power,
Even in the event of an abnormality in which backup power is not supplied from the sub-battery, backup power can be supplied to the electronic device for the same period of time as during normal operation.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an electronic device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a time transition of an output voltage of a main battery of FIG. 1;

FIG. 3 is a diagram showing a time transition of an output voltage of the sub-battery of FIG. 1;

FIG. 4 is an electric circuit diagram illustrating a detailed configuration of a power supply circuit unit in FIG. 1;

FIG. 5 is a diagram for explaining the operation of the power supply controller of FIG. 1;

FIG. 6 is a flowchart illustrating a procedure of a power-off process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic device main body 2 System part 2a CPU 2b Main storage device 2c Display device 2d Auxiliary storage device 2e Backup circuit 3 Main battery 4 Sub battery 5 Power on / off switch 6 Power supply circuit part 6d Power supply controller L1 Power supply line for backup circuit operation L2 Power supply line for system section operation

Claims (6)

[Claims] 1. An electronic device comprising a main battery for a main power supply and a sub-battery for a backup power supply, a voltage detecting means for detecting a voltage value of the main battery, and a detected voltage value of the main battery. A control unit that controls the supply of power from the main battery to the electronic device to be stopped when the reference battery value falls below a reference value; an abnormality detection unit that detects an abnormality of the sub-battery; and the abnormality detection unit. Setting means for setting the reference value to be higher than a normal value when the abnormality of the sub-battery is detected, and using only the main battery as a backup power source when the abnormality of the sub-battery is detected Electronic equipment characterized by the following. 2. The abnormality of the sub-battery detected by the abnormality detection means includes at least that the sub-battery is not connected to the electronic device and that the sub-battery does not output a predetermined voltage value. The electronic device according to claim 1, wherein the electronic device is one. 3. A control method for an electronic device comprising a main battery for a main power supply and a sub-battery for a backup power supply, wherein a voltage value of the main battery is detected, and the detected voltage value of the main battery is determined. When the voltage falls below a reference value, control is performed so as to stop the power supply from the main battery to the electronic device, and an abnormality of the sub-battery is detected. Is set higher than a normal value, and when an abnormality of the sub-battery is detected, only the main battery is used as a backup power supply. 4. The detected abnormality of the sub-battery is that the sub-battery is not connected to the electronic device and / or that the sub-battery does not output a predetermined voltage value. The method for controlling an electronic device according to claim 3, wherein: 5. A storage medium storing a program that can be realized by a computer, including a method for controlling an electronic device including a main battery for a main power supply and a sub-battery for a backup power supply, wherein the control method includes: Detecting the voltage value of the main battery, and controlling the power supply from the main battery to the electronic device to be stopped when the detected voltage value of the main battery falls below a reference value; When the abnormality of the sub-battery is detected, the reference value is set higher than the normal value, and when the abnormality of the sub-battery is detected, only the main battery is used as a backup power supply. A storage medium characterized in that: 6. The detected abnormality of the sub-battery is that the sub-battery is not connected to the electronic device and / or that the sub-battery does not output a predetermined voltage value. The storage medium according to claim 5, wherein: