JPH04224A - Electronic machine provided with battery exhaustion indicating function - Google Patents

Abstract

PURPOSE:To notice an operator exhaustion of battery reliably by indicating exhaustion of battery until turn OFF of power supply, upon temporary droppage of battery voltage below a predetermined level, and storing the battery voltage drop in an erasable memory means. CONSTITUTION:When battery voltage drop sustains for a predetermined time, a battery exhaustion flag is set in an EEPROM 157. A battery exhaustion lamp at an operation indicating section 156 is then lighted and monitoring of battery voltage resumes. If a power switch 13 is turned OFF at that time, the battery exhaustion lamp is unlighted. When the power switch 13 is turned ON again, the operation resumes. The battery exhaustion flag is now set in the EEPROM 157. In such case, the battery exhaustion lamp is lighted immediately and the monitoring operation is performed similarly. Lighting of the battery exhaustion lamp notices an operator exhaustion of the battery.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic device having a dead battery display function.

[Prior Art] In recent years, small portable facsimile machines that use batteries as an operating power source have been put into practical use.

Generally, devices that use a battery as a power source are provided with a display or the like that gives notice of the state when the battery is nearing the end of battery life, when the battery is exhausted and becomes inoperable.

One well-known method for detecting battery exhaustion is to detect when the battery voltage has fallen below a preset constant value and display it using a lamp or the like.

By the way, nickel cadmium batteries are often used in such various electronic devices.

Nickel cadmium batteries, for example, have a rated voltage of 1
In the case of 2V, the battery voltage is 1, as shown in Figure 8.
There is a discharge characteristic in which when the voltage drops to about 0V, it then drops rapidly. Therefore, in the case of a rated voltage of 12v, when the battery voltage drops to, for example, 10.5v or less, it is determined that the battery is dead.

By the way, in the case of a facsimile machine that records images with a thermal head, when recording images line by line,
The current consumption increases several times compared to before and after.

Therefore, as shown in Fig. 9, the voltage of the battery that has been exhausted to some extent drops to less than 10.5V only during the period of recording the received image line by line, and at time t when all lines have been recorded. , a situation occurs in which the voltage recovers to 10.5v or more.

[Problems to be Solved by the Invention] In this case, in the above detection method, the battery voltage is 10.5
When the voltage drops below v, a dead battery is displayed.

However, conventionally, when the battery voltage recovers to 10°5V or higher, the display disappears, or even if the display continues, the battery voltage does not rise to 10.5V or higher when the power is turned off and then turned on again. While recovering,
That display had disappeared.

For this reason, there is a problem in that the operator may continue to use the device without realizing that the battery is about to run out, and the device may stop during the transmission/reception operation.

In addition, in order to eliminate display instability caused by short-term fluctuations in voltage around 10.5V, we have set a high transition voltage V↑, where the circuit output changes from off to on, and a low transition voltage, where the output changes from on to off. It is known to use a voltage drop detection circuit having hysteresis characteristics in which the transposition voltage V↓ is different. According to this voltage drop detection circuit, for example, FIG.
As shown in a), the high transition voltage V↑ and the low transition voltage V↓ are each 11. Ov, 10.5v, when the battery voltage decreases and becomes less than 10.5v, a dead battery is displayed. Then, if the battery is exhausted is displayed once, even if the battery voltage becomes 10.5V or higher, 11. The display will not disappear unless it recovers to Ov or higher.

In this way, even if the battery voltage temporarily exceeds 10.5V once a dead battery is displayed,
Since the display does not disappear unless the voltage recovers to 1.0V or more, it is possible to notify the operator that the battery is about to run out.

However, if a battery with a voltage of, for example, 10.9V is attached to a facsimile machine equipped with such a voltage drop detection circuit, the voltage will be lower than the high transition voltage ■↑, even though it can actually be used. , when the switch is turned on, the output of the circuit remains off, indicating a dead battery. Therefore, in order to turn off this low battery display, the voltage must be 11. There was a problem in that a battery of Ov or more had to be installed.

Furthermore, other methods for detecting battery exhaustion that do not depend on battery voltage are known. In this method, the operating time of the device corresponding to the capacity of the installed battery is determined in advance, the operating time is accumulated each time the device is activated, and the ratio of the actual operating time to the above operating time is calculated. It is to be displayed.

This method is used in electric razors, etc. whose current consumption is always constant. However, as mentioned above, this method could not be applied to facsimile machines that have large variations in current consumption.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide an electronic device equipped with a battery exhaustion display function that allows an operator to reliably know the battery exhaustion status.

[Means for Solving the Problems] To this end, the present invention, when the battery voltage once drops below a certain voltage, displays an indication that the battery is dead until the power is turned off, and prevents the battery voltage from decreasing. is stored in an erasable storage means, and when the power is turned on again, if a drop in battery voltage is stored in the storage means, an indication that the battery is dead is immediately displayed, and the battery voltage is no longer detected. In this case, it is determined that the battery has been removed, and the storage state of the storage means is canceled.

[Operation] Once the battery is exhausted and the battery voltage drops once, even if the power is turned off, the battery continues to be displayed, allowing the operator to know with certainty that the battery has run out.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a block diagram of a facsimile machine according to an embodiment of the present invention. In the figure, a main body 1 is formed so that a battery 2 can be attached thereto, and when the battery 2 is attached, the contacts 2a and 2b on the battery 2 side come into contact with the contacts 1a and lb on the main body 1 side. Power is supplied to l. Battery 2 is
It is a nickel cadmium battery with a rated voltage of 12V.

In the main body 1, the contact 1a is connected to the voltage drop detection circuit 11.
12, and is also connected to the input of a DC/DC converter 14 via a power switch 13. The voltage drop detection circuit 11 detects that the battery voltage is 10.5.
When the voltage drops below v, the voltage drop detection circuit 12 also
When the battery voltage drops to less than 5V, a detection signal that becomes low level is output.

The DC/DC converter 14 converts the input voltage from the battery 2 into a power supply voltage of, for example, 5 .ANG., for circuit operation, and its output power is supplied to the facsimile processing section 15. Voltage stabilizing capacitors CI and C2 are connected to the input and output of the DC/DC converter 14, respectively.
are connected at one end and their other ends are grounded.

Note that the capacitor C2 has a capacity that can maintain an open operating voltage of several looms even if the battery 2 is removed while the facsimile processing unit 15 is in operation.

In the facsimile processing section 15, a scanner 151 reads an original image and extracts image information, and a plotter 152 records an image on thermal recording paper using a thermal head. The encoding/decoding unit 153 encodes image information to be transmitted and decodes received image information.

The modem 154 modulates and demodulates image information and transmits it.
It transmits various procedure signals in transmission control procedures. The network control device 155 is connected to a telephone line and controls the line for making and receiving calls.

The operation display section 156 displays the operating status of the device and allows the operator to perform various operations.
A battery exhaustion indicator lamp is provided to indicate when the battery 2 is exhausted. EEPROM
(Electrically Erasable PR
The ROM 157 is a ROM in which data can be electrically written and erased repeatedly, and in this embodiment, it is used to store a dead battery state.

The system control section 158 controls each of the above sections using a microcomputer.
．． Twelve detection signals are input.

With the above configuration, when using this facsimile machine, the operator charges the battery 2 and attaches it to the main body 1. Then, each operation is activated by a predetermined operation to perform image transmission/reception processing.

The facsimile machine performs battery voltage monitoring during each operation. That is, as shown in FIG. 2, when the power switch 13 is turned on (process 301), the facsimile machine starts its monitoring operation and first outputs the EEPRO.
The flag information of M157 is checked (process 302).

EEFROM157 stores information when battery 2 is exhausted.
A dead battery flag is set.

This normal battery dead flag is not set.

In this case (N in process 302), the battery voltage is 10
．． Please check whether it is 5v or more. 3o3)
If it is 10.5v or more (Y in process 303), then it is checked whether the battery voltage is 5v or more (process 304).

Assuming that the battery 2 is not exhausted, the battery voltage will be 10.5V or more.

In this case (Y in process 304), the battery voltage monitoring is repeated (proceed to process 303).

Next, if the battery 2 is exhausted to some extent, the battery voltage will drop to less than 10.5V for a certain period of time during image reception, as shown in FIG.

In the facsimile machine, once the battery voltage drops below 10°5V (N in process 303), the voltage drop
- Monitor whether the period L in FIG. 9 continues for a certain period of time, for example, 3 seconds (process 305), rather than a temporal one.
.

For example, when recording an image in which all pixels of the l line are black,
- Current consumption increases significantly over time. At this time, if the battery 2 has been exhausted to some extent, the battery voltage will be 10.
It drops below 5v. However, such a temporary voltage drop poses no practical problem.

Therefore, if the voltage recovers immediately (N in process 305), the process returns to monitoring the battery voltage (proceeds to process 303).

If the voltage drop continues for the above-mentioned predetermined period of time (process 305 (7) Y), the EEPROM 1 571: sets the battery exhaustion flag (process 3o6).

Next, the battery-out lamp on the operation display unit 156 is turned on (process 307), and the process returns to monitoring the battery voltage (proceed to process 303). In addition, in process 303, the fall of the voltage drop is determined and the above-mentioned flag setting and display operation are executed,
To prevent the operation from being repeated even if a state in which the battery voltage drops continues.

As a result, image recording is completed and the battery voltage is reduced to 10.
Even if the voltage recovers to 5V or more, the low battery lamp remains lit.

Here, when the power switch 13 is turned off, the out-of-battery lamp is also turned off.

Then, when the power switch 13 is turned on again, the above operation resumes. A battery dead flag is now set in the EEPROMI 57. In this case (processing 302
Y), immediately turn on the low battery lamp (Process 3)
08). Then, the same monitoring operation as above is performed.

The operator can notice that the battery is exhausted by lighting the battery exhaustion lamp. When the operator notices that the battery is dead, he removes the battery 2 and charges it.

Now, if the battery 2 is removed, the power supply to the main body 1 is stopped. Then capacitor c1 and capacitor C
As the accumulated charges of 2 are discharged, their voltage drops rapidly.

When the voltage drop detection circuit 12 determines that the battery voltage has fallen below 5V (process 304 (7) N), the facsimile apparatus resets the battery exhaustion flag of the EEPROMI 57 (process 309). This operation will be activated by the power discharged from capacitor c2.

When the battery 2 is fully charged, the operator
and use it as usual.

When the facsimile machine is powered on, the battery exhaustion flag is reset. Therefore, a predetermined communication operation is executed together with the battery monitoring operation.

As described above, in this embodiment, once the battery voltage drops, the battery is always depleted even if the power is turned off, so the operator can definitely know when the battery is depleted. .

Furthermore, when the battery is removed, the memory of a dead battery in the EEPROM 157 is cleared, so the operator does not need to perform manual operations such as a reset operation when a charged battery is installed.

In the above embodiment, an EEPROM is used to store the dead battery state, but other components such as an electromagnetic relay may also be used. In addition, although a lamp is used to indicate when the battery is low, various other methods of displaying the battery may be considered, such as using other electrical indicators or mechanically exposing a mark. Furthermore, although the battery voltage is set to 10.5v and 5v as thresholds to determine voltage drop, it may be set arbitrarily depending on the battery used and circuit conditions.

Next, other embodiments of the present invention will be described.

FIG. 3 shows a block diagram of a facsimile apparatus according to another embodiment of the present invention, which is equipped with a voltage drop detection circuit having hysteresis characteristics.

Here, the same reference numerals as in FIG. 1 indicate the same parts, and the difference from FIG.
1.22 was provided.

In FIG. 3, one voltage drop detection circuit 21 has a hysteresis characteristic of 11.0V to 10°5V as shown in FIG. 10.5v to 10.5v as shown in (b). O
It has a hysteresis characteristic of v.

Now, 11. The relationship between the voltage of the battery 2 and time when the facsimile machine is used after installing the battery 2 having a sufficient voltage of Ov or more is as shown in FIG. 8 described above.

Here, 11 in FIG. When a battery 2 having a voltage of Ov or higher, for example 13°5V, is attached, the outputs PI and P2 of the two voltage drop detection circuits 21 and 22 have the hysteresis characteristics shown in FIGS. 4(a) and 4(b). In other words, at the moment when the battery 2 is installed, both PI and P2 are off, and at this time, the operation display section 15
6 will be displayed indicating that the battery is dead. However, battery 2
Immediately after installing P2, P2 turns from OFF to ON when it detects that the voltage of battery 2 has a high transition voltage V↑ of 10.5V, and Pl turns on when the voltage of battery 2 is P1.
When it is detected that the high transition voltage V↑ of 11° Ov is detected, the switch turns from off to on.

Note that when this P2 is turned on, the operation display section 15
The low battery display disappears from 6 onwards.

Also, l O,5v ~ l 1. When the battery 2 having a voltage of Ov is installed, both PL and P2 are off at the moment the battery 2 is installed, and the operation display section 156 displays an indication that the battery is exhausted. However, immediately after battery 2 is installed, Pl remains off, but P2 turns from off to on when it detects that the voltage of battery 2 exceeds 1O65V, which is the high transition voltage V↑ of P2. At this point, the display indicating that the battery is exhausted disappears from the operation display section 156.

If battery 2 with a voltage of 10.5v or less is installed, both PL and P2 will remain off and will not change, and a dead battery indication will appear from the moment battery 2 is installed, and this indication will never disappear. do not have.

If this is tabulated, it will look like FIG. 5(a).

On the other hand, as this facsimile device is used, the voltage of battery 2 gradually decreases, but if the voltage is 10.5V or more, both PL and P2 are on, and the battery depletion message will not be displayed. do not have.

Furthermore, using a facsimile machine, the battery voltage
When it becomes 0.5v or less, P2 remains on, but Pl detects that the battery voltage has become 10.5v or less, which is the low transition voltage of Pl, and changes from on to off. .

Note that when Pl is turned off, a display indicating that the battery is exhausted is displayed on the operation display section 156.

In addition, if the battery voltage once drops below 10.5V due to the use condition of the facsimile machine and recovers to above 11°0V, the operation display unit 156 will display a dead battery indication when Pl is turned on from off. disappear.

If this is tabulated, it will look like FIG. 5(b).

Next, the battery depletion display function of the facsimile machine equipped with the voltage drop detection circuits 21 and 22 having the above-described hysteresis characteristics will be explained using the flowchart shown in FIG.

FIG. 6(a) is a flowchart regarding the battery exhaustion display function when the battery is attached.

First, when using this facsimile machine, an operator charges the battery 2, attaches it to the main body 1, and turns on the power. At this time, the system control unit 158 checks the output PL of the voltage drop detection circuit 21 and the output P2 of the voltage drop detection circuit 22 (process 401). Normally, the battery 2 after charging has a voltage of 12V or more, so the moment the battery 2 is attached, PL and P2 check 0 (processing 402), so a dead battery is displayed (processing 403). ), but immediately after that, when P2 becomes 1 (N of judgment 404)
, the battery exhaustion display disappears (process 405). Then, Pl also changes from ◯ to 1, but of course no indication that the battery is exhausted is displayed at this time.

Note that even if the installed battery voltage is 12V or less,
If it is 5V or more, P2 becomes 1 (N of judgment 404).
), at this point, even if a battery exhaustion display is displayed, it immediately disappears (process 405).

In this way, the voltage at which the state of P2 changes from 0 to 1, that is, 10
, if a battery 1 having a battery voltage of 5V or more is attached, the battery exhaustion display will not be displayed.

FIG. 6(b) is a flowchart regarding the battery exhaustion display function when using the facsimile machine after installing the battery.

First, the operator charges the battery 2, attaches it to the main body 1, and uses this facsimile machine.

At this time, the system control unit 158 checks the output P1 of the voltage drop detection circuit 21 and the output P2 of the voltage drop detection circuit 22 at a predetermined timing (process 401). Normally, the battery 2 after charging has a voltage of 12V or more, so P
Since L and P2 are 1 (Y in decision 4306), the facsimile machine continues to monitor PL and P2 by repeating the process of once entering another processing routine and then returning to this battery monitoring routine.

As the facsimile machine is used, the battery voltage gradually decreases, and when it eventually falls below 10.5V, P2 remains at 1, but it is detected that PL has become 0. Process 407);
At this point, the facsimile machine turns on the battery-out indicator lamp 156a (process 408).

However, this drop in battery voltage to 10.5V or less is temporary due to the usage status of the facsimile machine, and the battery voltage drops to 11.5V again. There are cases where the temperature returns to Ov or higher. In this case, when Pl changes from O to 1 (N in decision 409), the battery exhaustion display disappears (Y in decision 410).

Processing 411).

In this way, by equalizing the low transition voltage of one of the two voltage drop detection circuits with hysteresis characteristics and the high transition voltage of the other, the output of P2 sometimes changes when the battery is installed, as shown in Figure 5. When the battery is in use, the display indicating the battery status can be changed when the output of Pl changes.

That is, as shown in FIG. 5(a), after installing a battery with a voltage of 10.5 V or more, the battery exhaustion display can be turned off when the state of P2 changes from O to 1.

Further, as shown in FIG. 5(b), when the battery is exhausted and the voltage becomes 10.5 V or less and the state of Pl changes from 1 to O, a battery-depleted display can be turned on.

This causes the voltage to rise to 11. Even if a battery with a voltage of 10°5V or more is installed, even if it is less than OV, the battery exhaustion display can be turned off when the state of P2 changes from 0 to 1.

Further, when the battery voltage becomes 10.5 V or less and the state of Pl changes from 1 to 0, it is possible to display that the battery is exhausted. Furthermore, depending on the usage status of the facsimile machine, the battery voltage may temporarily drop below 10.5V, and although the battery is displayed as dead, in reality, if the battery voltage is 11.0V or above, the state of Pl changes from 0 to 1. You can turn off the low battery display when the battery changes to .

Incidentally, as shown in FIG. 7, the above embodiment may be provided with a voltage drop detection circuit 12 that detects when the battery voltage has decreased to 5 V or less and an EEPROM 157 that sets a battery exhaustion flag.

Then, when the battery voltage drops below 10.5V,
As shown in the flowchart in Figure 2 above, sea urchin, EEPR
A flag is set in the OMI 57 to store the dead battery state (process 306), and when the power switch 13 is turned off and then turned on by this flag, the battery dead lamp can be lit immediately (process 307). ).

Further, when the battery is removed, the voltage drop detection circuit 12 can reset the EEPROMI 57 battery-dead flag (process 309), and the battery-depletion display can also be canceled.

[Effects of the Invention] As described above, according to the present invention, when the battery is exhausted and the battery voltage once drops, even if the power is once turned off, the battery depletion continues to be displayed.
The operator will be able to reliably know when the battery is running out.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a facsimile machine according to an embodiment of the present invention, FIG. 2 is a flowchart of battery monitoring operation, FIG. 3 is a block diagram of a facsimile machine according to another embodiment of the present invention, and FIG. is a diagram showing the hysteresis characteristics of the voltage drop detection circuit, FIG. 5 is a diagram showing the output of the voltage drop detection circuit, FIG. 6 is a flowchart of battery monitoring operation according to another embodiment of the present invention, and FIG. 7 is a diagram showing the battery monitoring operation according to another embodiment of the present invention. Other embodiments include a voltage drop detection circuit for 5V detection and an EEPROM.
FIG. 8 is a graph diagram showing the discharge characteristics of a nickel cadmium battery, and FIG. 9 is an explanatory diagram showing an example of battery voltage fluctuation. 1... Main body, 2... Battery, 11, 12, 21,
22... Voltage drop detection circuit, 13... Power switch, 14... DC/DC converter, 15... Facsimile processing section, 151... Scanner, 152... Plotter, 153... Code 154...Modem, 155...Network control device, 156...Operation display unit, 157...EEPRoMl 158...System control unit, C1°C2...Capacitor.

Claims (3)

[Claims] (1) Equipped with a removable battery for operating power, a power switch that turns on and off the power supplied from the battery to the inside of the device, and an indicator that warns when the battery is exhausted and the device becomes inoperable. In electronic equipment equipped with a dead battery display function, there is a monitoring means for monitoring battery voltage, and a low voltage display that indicates that the battery is dead until the power is turned off if the battery voltage once drops below a certain voltage. a starting means, an erasable storage means for continuously storing the decrease in the battery voltage even when the power is turned off, and the decrease in the battery voltage is stored in the storage means when the power is turned on; The device is equipped with an immediate display start means for immediately displaying an indication that the battery is exhausted, and a memory canceling means for determining that the battery has been removed and canceling the memory state of the memory means when the battery voltage is no longer detected. An electronic device with a distinctive feature that indicates when the battery is dead. (2) Equipped with a removable battery for operating power, a power switch that turns on and off the power supplied from the battery to the inside of the device, and an indicator that warns when the battery runs out and the device becomes inoperable. In an electronic device equipped with a dead battery display function, a monitoring means for monitoring a drop in battery voltage by combining two voltage drop detection means each having different hysteresis characteristics, and a monitoring means for monitoring a drop in battery voltage once the battery voltage drops below a certain voltage. What is claimed is: 1. An electronic device having a dead battery display function, comprising a voltage drop display start means for displaying a dead battery until the power is turned off. (3) Erasable storage means that continues to store the drop in battery voltage even when the power is turned off, and if the drop in battery voltage is stored in the storage means when the power is turned on, immediately The device is characterized by comprising an immediate display start means for displaying an indication that the battery is exhausted, and a memory canceling means for determining that the battery has been removed when the battery voltage is no longer detected and canceling the memory state of the memory means. An electronic device having a dead battery display function according to claim 2.