JPH0519030A - Electronic equipment - Google Patents

Abstract

PURPOSE:To enable capacity of a battery to be consumed effectively without any waste and a drive time of an electronic equipment which can be driven to be extended in an electronic equipment which has a battery as a power supply and supplies power to each portion of the electronic equipment through a power-supply voltage stabilization circuit from this battery. CONSTITUTION:A control portion 8 detects output voltages VB and VP of a battery power supply portion 1 and a power-supply voltage stabilization circuit 5 with a voltage detection circuit 6, compares each reference voltage which is stored in a memory M2, and then performs specified processings such as an alarm output for replacing the battery and operation disable. Detection can be performed highly accurately by selecting which of the output voltages VB and VP is compared according to a drive state of, for example, a printer 7. Also, the detection can be performed highly accurately by setting a reference voltage of an output voltage of the stabilization circuit 5 based on an actual detection value of the output voltage, thus enabling the reference voltage to be set to a smaller value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device, and more particularly to an electronic device driven by a battery as a power source.

[0002]

2. Description of the Related Art Conventionally, in an electronic device driven by a battery such as a calculator, the output voltage of the battery is detected,
There is known a technique of outputting warning information prompting the user to replace the battery when the voltage becomes lower than a predetermined reference voltage, or prohibiting the operation of the electronic device. The technique of prohibiting the operation is indispensable for preventing loss of stored data in an electronic device with a memory function.

[0003]

However, in the configuration for detecting the output voltage of the battery as described above, when the configuration of the device includes a printer or the like having a load characteristic with a large peak current, the battery voltage is detected. If a printer or the like is driven at the time of reading, a reading error of voltage detection occurs. In consideration of this error, the setting of the above reference voltage becomes high, so the battery replacement warning is output and the battery is replaced unnecessarily even though the battery still has power supply capacity. However, there is a drawback that the operation of the electronic device is prohibited and the electronic device cannot be used.

Therefore, the object of the present invention is to solve the above-mentioned drawbacks in this kind of electronic equipment, to effectively consume the capacity of the battery without waste, and to prolong the driving time of the electronic equipment which can be driven by the battery. To provide a configuration.

[0005]

In order to solve the above-mentioned problems, according to the present invention, an electronic device uses a battery as a power source and supplies power from the battery to each part of the electronic device through a power supply voltage stabilizing circuit. In the control means, detecting means for detecting the output voltage of the battery and the stabilizing circuit, and a detection result of the output voltage of the battery or the stabilizing circuit are compared with respective reference voltages, and a predetermined process is performed according to the comparison result. And a storage unit for storing the data of the reference voltage, the control unit, based on the detection result of the output voltage of the stabilization circuit, when the power supply is normal at the initialization of the electronic device, The reference voltage of the output voltage of the stabilizing circuit is set, and the data is stored in the storage means.

[0006]

According to this structure, when the voltage is detected, the output voltage of the battery and the power supply voltage stabilizing circuit is detected more depending on a predetermined condition, for example, the driving state of the printer provided in the electronic device. Can be used to determine whether or not to perform the above-described predetermined process, and the detection can be performed with high accuracy, and the reference voltage can be set to a low level. Further, since the reference voltage of the output voltage of the power supply voltage stabilizing circuit is set based on the actual detected value of the output voltage, it can be set lower.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. Here, an electronic device with a printer driven by using a battery as a power source is exemplified.

First, FIG. 1 shows the structure of the main part of the electronic equipment of the embodiment relating to the present invention. In FIG. 1, reference numeral 1 is a battery power supply unit as a first power supply, and reference numeral 2 is a second power supply.
It is an AC adapter as a power source of. Either the output voltage VB of the battery power supply unit 1 or the output voltage VA of the AC adapter 2 is selected by the switch 3 and used for power supply.

The output of either the battery power supply unit 1 or the AC adapter 2 is fed through a power switch 4 to a power supply voltage stabilizing circuit (hereinafter abbreviated as "stabilizing circuit") 5 composed of a DC-DC converter, and It is input to the voltage detection circuit 6.

The stabilizing circuit 5 is a unit that serves as a load of the power source of the electronic device, that is, the printer 7, the control unit 8, the display unit 9,
A stabilized power supply voltage is supplied to the buzzer 13 and the like, and this voltage is also input to the voltage detection circuit 6.

The voltage detection circuit 6 is composed of a three-channel A / D converter, and is a voltage input through the signal lines 11 to 13, that is, an input voltage of the stabilization circuit 5 immediately after the switch 4 (of the battery power supply unit 1). Each of the output voltage VB or the output voltage VA of the AC adapter 2, the printer supply voltage VP which is the output voltage of the stabilizing circuit 5, and the supply voltage VS to the control unit 8 is converted into digital data and transmitted via the bus line l4. Input to the control unit 8. The detection data is read by the control unit 8 at a predetermined cycle determined by a timer TC provided in the control unit 8.

The control unit 8 is composed of a microprocessor and controls the entire electronic equipment. The control unit 8 is provided with memories M1 to M3 in addition to the timer. Memory M
A control program of the control unit 8 is stored in 1. The memory M2 stores the data of the reference voltage for comparing the detected power supply voltages as described later. Memory M3
Stores data such as the power supply voltages VB and VP detected as described above. A rewritable RAM is used for the memories M2 and M3. The data in the memory M2 is backed up by the backup circuit BU including the diodes D1 and D2 and the battery B, and is stored even when the power of the electronic device is off.

The control unit 8 controls the printer 7 via the sensor amplifier 10 and the drive circuit 11. That is, a detection signal from a sensor (not shown) that detects the presence or absence of recording paper or the position of the printer 7 is input to the control unit 8 via the amplifier 10, and accordingly the control unit 8 drives the printer 7 via the drive circuit 11. The controlled members such as the recording head and the driving motor of (1) are controlled to perform the recording operation.

The control unit 8 also controls the display operation of the display unit 9 such as a liquid crystal display unit via the drive circuit 12 to display and output various information. In addition, a sound such as a warning can be output using the buzzer 13.

Further, the control unit 8 has a function in addition to the control of each unit described above.
According to the detection result of each power supply voltage read from the voltage detection circuit 6 in a predetermined cycle by the timer TC, the operation of the electronic device is prohibited, or the display 9 displays warning information prompting the user to replace the battery. .

In this control, the output voltage (hereinafter referred to as "battery voltage") VB of the battery power source 1 and the printer supply are taken into consideration in consideration of the load characteristic when the battery is driven according to the operating state of the printer 7 shown in FIG. This is performed based on the detection result of the voltage VP. Details of this control will be described below with reference to FIG.

FIG. 2 shows changes with time in the battery voltage VB and the printer supply voltage VP when the electronic device is driven by the battery.
FIG. 2A shows a voltage change when the printer is operating, and a ripple ΔvB is generated in the battery voltage VB according to the load change of the printer. Further, when the battery voltage VB approaches the end voltage v1 of the battery, the printer supply voltage VP is also disturbed in stabilization, and when the voltage drop Δvp exceeds a predetermined value, the operation is out of the guaranteed range.

During such a printer operation, the battery voltage V
B has ripple ΔvB, which cannot be detected with high accuracy. Therefore, the printer supply voltage VP is detected, and at the time T1 when the stabilization of the printer supply voltage VP begins to be disturbed, a battery replacement warning is output and stabilization is performed. It is better to prohibit the operation when the disturbance becomes larger than a predetermined value.

On the other hand, FIG. 2B shows a voltage change when the printer 7 is not operating. In this case, the printer 7
Since there is no load fluctuation of, the battery voltage VB has almost no ripple. Further, even if the battery voltage VB approaches the end voltage v1 of the battery, since the printer 7 is almost no load, the end voltage v1 of the battery is reached.
The stabilization of the printer supply voltage VP is maintained until immediately before.

In this case, at the time T2 when the stabilization of the printer supply voltage VP is disturbed, similarly, the stabilization of the supply voltage VS to the control unit 8 begins to be disturbed, so that it is difficult to guarantee the operation of the control unit 8 at the time T2. Therefore, prior to time T2, it is preferable to issue a battery replacement warning or prohibit operation at time T3 when the battery voltage VB crosses the reference voltage v2 which is higher than the final voltage v1 by a predetermined value.

Therefore, in the present embodiment, the control unit 8 detects the power supply voltage at a predetermined cycle determined by the timer TC when the battery is driven, and if the detection time is the printer drive, the printer supply voltage VP is the first. 1 reference voltage VPR1
Also, depending on whether or not the voltage is equal to or lower than the second reference voltage VPR2, an operation prohibition of the electronic device or a battery replacement warning is given. Further, if the detection time is not driving the printer, the operation prohibition or the battery replacement warning is given depending on whether the battery voltage VB is equal to or lower than the first reference voltage VBR1 or the second reference voltage VBR2.

Even when the battery is driven and the power supply is normal, the printer supply voltage VP output from the stabilizing circuit 5 varies depending on the components and the voltage adjustment for each electronic device. In consideration of this, in the present embodiment, the reference voltages VPR1 and VPR2 of the printer supply voltage VP are not uniquely determined, and when the power supply is normal at the time of initialization of the electronic device, the control unit 8 detects the printer supply voltage VP. Then, the reference voltages VPR1 and VPR2 are set based on the detected value.

Next, details of the processing operation of the control unit 8 relating to the voltage detection as described above will be described with reference to the flowcharts of FIGS. 3 and 4. The following process is performed on the assumption that the battery is driven. The data of each of the reference voltages is backed up and stored in the memory M2 even when the power is off before the processing of FIG. 3 is started.

First, FIG. 3 shows a process at the time of initialization of the electronic device. First, in step S11 of FIG.
When the reset is released, the control unit 8 initializes internal registers, input / output ports, etc. in step S12.

Next, in step S13, the battery voltage VB detected by the voltage detection circuit 6 and the printer supply voltage VP are detected.
Is read and the data is stored in the memory M3 in step S14.
To store. Printer supply voltage VP detected at this time
The initial value of VPA is VPA.

Next, in step S15, it is compared whether or not the initial value VPA of the printer supply voltage is equal to or higher than the first reference voltage VPR1 of the printer supply voltage stored in the memory M2.

As a result, when the initial value VPA is lower than the reference voltage VPR1, it is judged that the printer supply voltage is out of the operation guarantee range due to the voltage drop due to the decrease in the battery capacity of the battery power source unit 1, and the electronic device is determined in step S19. Operation is prohibited.
Specifically, the power supply to the stabilizing circuit 5 is turned off, or the system is fixed in a standby state where power consumption is minimized, and the operation of the printer 7 and access to the internal memory are prohibited.

On the other hand, as a result of the comparison in step S15, when the initial value VPA is equal to or higher than the reference voltage VPR1, it is determined that the printer supply voltage VP has not dropped due to the battery capacity decrease, and the process proceeds to step S16. Perform printer initialization operation.

Then, in step S17, the initialization of the system of the electronic device is completed. At this point, it can be determined that the system is operating normally and the printer supply voltage VP is stable, and the printer supply voltage VP is set to the voltage level. Detection circuit 6
The reference voltages VPR1 and VPR2 of the printer supply voltage are set based on the detected value and stored in the memory M2. As described above, the memory M2 is backed up by the backup circuit BU, and the data of the reference voltage is stored even when the power switch 4 is turned off. After step S17, a standby state is entered (step S18).

Next, FIG. 4 shows control relating to voltage detection after initialization. Here, the process proceeds from the standby state after initialization (step S21) to step S22, and the count of the timer TC causes a predetermined time T from the previous voltage determination loop.
Determine whether (msec) has elapsed.

When step S22 is denied, the normal system operation processing, that is, the display output of the data by the display 9 or the recording output processing by the printer 7 is performed in step S28. After step S28, the process returns to the standby state of step S21.

On the other hand, if the result at step S22 is affirmative, the routine proceeds to step S23, where the printer supply voltage VP is read from the voltage detection circuit 6 if the printer 7 is currently driven, and the battery voltage is read if the printer 7 is not driven. VB is read and the value is stored in the memory M3 as the detection voltage VD.

Subsequently, in step S24, it is compared whether or not the value of the detection voltage VD is equal to or lower than the first reference voltage VPR1 or VBR1 for operation inhibition determination stored in the memory M2. In this case, if the printer 7 is currently driven, it is compared with the first reference voltage VPR1 of the printer supply voltage, and if the printer 7 is not driven, it is compared with the first reference voltage VBR1 of the battery voltage. .

If the result at step S24 is affirmative, the process proceeds to step S29 to prohibit the operation of the electronic device.

On the other hand, if the result in step S24 is negative, the process proceeds to step S25, in which it is compared whether the voltage VD is the second reference voltage VPR2 or VBR2 for battery replacement determination. Also in this case, when the printer 7 is in the driving state, it is compared with the second reference voltage VPR2 of the printer supply voltage, and in the non-driving state, it is compared with the second reference voltage VBR2 of the battery voltage.

If step S25 is denied, it is determined that the battery has a sufficient capacity, and the process proceeds to step S28 to perform normal system operation processing.

If the result at step S25 is affirmative, it is determined that the battery needs to be replaced, and step S27 is performed.
Then, the display 9 is used to display a character string indicating battery replacement or the like to prompt the user to replace the battery. The display example is shown in FIG. A message prompting battery replacement may be displayed as shown in FIG. 5A, or a battery symbol prompting battery replacement may be displayed as shown in FIG. 5B. It is also possible to sound the buzzer 13 to warn the user. In a system that does not have a display or a buzzer, it is possible to give a warning by printing with a printer or a blinking of a specific pattern of a lamp.

After step S27, normal system operation processing is performed in step S28, and then step S28.
Return to the standby state of 21.

According to the present embodiment as described above, the power supply voltage is detected by the printer supply voltage VP, which has little fluctuation in the printer driving state where the battery voltage VB has a ripple when the battery is driven, so that the detection can be performed with high accuracy. Can be done. Therefore, the reference voltages VPR1 and VPR2 in this case can be set to a lower level without much allowance. Moreover, since this reference voltage is set based on the actual printer supply voltage VP detected at the end of initialization, it is not necessary to take into account variations in parts for each electronic device and errors due to voltage adjustment.
From this point as well, the reference voltages VPR1 and VPR2 can be set lower.

Since the reference voltages VPR1 and VPR2 can be set lower in this way, a warning for replacement is issued or the operation is prohibited even though the reference voltage is set higher and the battery capacity still has a margin as in the conventional case. You can avoid the problem of That is, the capacity of the battery can be effectively consumed without waste, and the driving time of the electronic device that can be driven by the battery can be lengthened.

Further, since the power supply voltage is detected by the battery voltage VB in a non-driving state of the printer in which the battery voltage VB does not cause a ripple, the detection accompanying the printer supply voltage VP is avoided. It can be performed with high accuracy.

In the above description, the power supply voltage is detected by the battery voltage VB and the printer supply voltage VP.
Supply voltage VS to the control unit 8 according to the load characteristics of the system
Alternatively, the voltage supplied to the display 9 may be used. In the case of a device having a floppy disk device, the voltage supplied to the device may be detected to prompt battery replacement.

Regarding the battery, a normal primary battery or a secondary battery is used.
According to the characteristics such as the discharge characteristics of various batteries such as the secondary battery (Ni-Cd battery, lead storage battery), a plurality of reference voltage data indicating the battery consumption set in the data memory M2 is set,
By selecting it, optimized voltage determination is possible, and various batteries can be used effectively.

In the above description, the memory M2 for storing the data of the reference voltage is used as a RAM and backed up by the backup circuit BU, but an electrically erasable and additionally recordable EEPROM may be used as the memory M2. If the electronic device is provided with a magnetic disk device (FDD or HDD), the data of the reference voltage may be stored in the magnetic disk.

[0045]

As is apparent from the above description, according to the present invention, in an electronic device which uses a battery as a power source and supplies power from the battery to each part of the electronic device through a power supply voltage stabilizing circuit, Detection means for detecting the output voltage of the battery and the stabilizing circuit, and a control means for comparing the detection result of the output voltage of the battery or the stabilizing circuit with respective reference voltages, and performing predetermined processing according to the comparison result, If the power supply is normal at the time of initialization of the electronic device, the control means has a storage means for storing the data of the reference voltage, and the stabilization circuit is based on the detection result of the output voltage of the stabilization circuit. Since the reference voltage of the output voltage is set and the data is stored in the storage means, the power supply voltage can be detected more appropriately and highly accurately, and the reference voltage for the determination can be lowered. To It can be constant. Therefore, it is possible to effectively consume the capacity of the battery without waste, and it is possible to obtain an excellent effect that the driving time of the electronic device that can be driven by the battery can be extended.

[Brief description of drawings]

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

FIG. 2 is a characteristic diagram showing changes with time in battery voltage and printer supply voltage when the electronic device is driven by a battery.

FIG. 3 is a flowchart showing an initialization process by a control unit of the electronic device.

FIG. 4 is a flowchart of a power supply voltage detection process by the control unit.

FIG. 5 is an explanatory diagram showing a display example of a warning prompting battery replacement.

[Explanation of symbols]

1 Battery power supply 2 AC adapter 3 Power supply selection switch 4 power switch 5 Power supply voltage stabilization circuit 6 Voltage detection circuit 7 printer 8 control unit 9 Display 13 buzzer M1 to M3 memory TC timer

Claims (4)

[Claims] 1. An electronic device that uses a battery as a power source and supplies power from the battery to each part of the electronic device via a power supply voltage stabilizing circuit, and a detecting unit that detects output voltages of the battery and the stabilizing circuit. The detection result of the output voltage of the battery or the stabilizing circuit is compared with each reference voltage, and has a control means for performing a predetermined process according to the comparison result, and a storage means for storing the data of the reference voltage, The control means sets the reference voltage of the output voltage of the stabilizing circuit based on the detection result of the output voltage of the stabilizing circuit when the power supply is normal at the time of initialization of the electronic device, and stores the data. An electronic device characterized by being stored in a means. 2. The control means, as the predetermined processing,
The electronic device according to claim 1, wherein at least one of outputting warning information for prompting a user of the electronic device to replace the battery and prohibiting operation of the electronic device is performed. 3. The electronic device according to claim 1, wherein the data of the reference voltage in the storage means is stored even when the power of the electronic device is off. 4. The control means periodically detects the output voltage, and at the time of detection, selects one of the battery and the output voltage of the stabilizing circuit according to a predetermined condition to select the reference voltage. The electronic device according to any one of claims 1 to 3, wherein the electronic device is compared with.