JPH04115351A - Compact electronic apparatus with voltage drop alarming function - Google Patents

Abstract

PURPOSE:To suggest the replacement of a battery to a user at a correct time by providing this compact electronic apparatus with a deciding means for deciding whether battery voltage is dropped down to a prescribed level or not and an alarm means. CONSTITUTION:When the output voltage of a battery 1 is dropped less than a voltage level L1 in a display state, a control part 3 outputs display data to a display part 7 and generates an alarm for suggesting the replacement of the battery 1 and a user knows the consumption of the battery 1 and replaces the battery 1 by a new one. The output of a message is stored by 'F = 1'. When the output voltage of the battery 1 is furthermore dropped less than a voltage level L2 in an arithmetic state, a message suggesting the replacement of the battery 1 is displayed on a display part 7 in the case of 'F = 0' immediately after turning on a power supply, and when the voltage level less than L1 is detected and 'F = 1' is set up, the compact electronic apparatus is forcedly turned to a power OFF state to end the processing.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a small electronic device with a voltage drop warning function.

[Prior Art] In small electronic devices such as electronic notebooks that are powered by batteries, the user is informed of the state of battery consumption. FIG. 3 is a diagram showing the operating state of a small electronic device and fluctuations in battery voltage. For example, if the battery voltage drops below voltage level 1 at which a warning should be displayed, a message prompting the user to replace the battery is displayed. If the user continues to use the battery in this state without replacing it, the battery voltage will further decrease and the CP
U goes out of control. To prevent this, conventionally C
The voltage level L2 before the PU goes out of control is detected and the small electronic device is forcibly turned off.

[Problem to be solved by the invention] On the other hand, recently, lithium batteries have been increasingly used as batteries. Lithium batteries have the property that when the current drawn out is increased, the internal resistance of the battery increases and the battery voltage drops rapidly. Therefore, in a small electronic device having a power saving function, the voltage difference between the calculation state and the display state (waiting for key input) becomes very large, as shown in FIG. 3(a). Therefore, in the calculation state, the battery voltage is at voltage level L□
However, the battery can still be used because it recovers to a sufficient voltage level in the display state.

However, since conventional small electronic devices constantly monitor the battery voltage, there is a problem in that each time the device enters a calculation state using the key manually, a voltage drop is detected and a message prompting the user to replace the battery is displayed.

This invention was made to solve the above problem, and an object thereof is to provide a small electronic device that can prompt the user to replace the battery at the correct time.

[Means for Solving the Problems] In order to solve the above problems, the present invention determines whether the battery voltage has decreased to a predetermined level when the small electronic device enters the display state, and determines whether the battery voltage has decreased to the predetermined level. The feature is that a warning is output when it is determined that the level has dropped to a certain level.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the circuit configuration of a small electronic device, such as an electronic notebook, to which the present invention is applied.

In the figure, a battery 1 is a power source for a small electronic device, and is composed of, for example, a lithium battery. The power supply section 2 rectifies and stabilizes the output voltage of the battery 1 and supplies it to the control section 3, and includes voltage detectors 2a and 2b.

The voltage detector 2a outputs an H level signal to the control unit 3 when the output voltage of the battery 1 becomes below the voltage level L (warning level) shown in FIG. Further, the voltage detector 2b outputs an H level signal to the control section 3 when the output voltage of the battery 1 becomes equal to or lower than the voltage level L2 (forced OFF level) shown in FIG.

The control section 3 controls each section based on a control program stored in advance in the ROM 4, and has a built-in flag register F.

The RAM 5 is a memory that stores various data, and the writing and reading of data is controlled by the control unit 3.

Although not shown, the key power section 6 is equipped with various keys such as numeric keys, letter keys, power key, etc., and outputs a key power signal to the control section 3 in accordance with the key power.

The display section 7 is composed of, for example, a dot matrix (IJ) type liquid crystal display panel, and performs display based on display data output from the control section 3.

Next, the operation of the above embodiment will be explained. FIG. 2 is a flowchart showing the operation. In this embodiment, the key human power section 6
When the power key is operated to turn on the power, the process shown in FIG. 2 starts.

■ When the output voltage of battery 1 decreases a little Figure 3 (a)
As shown in FIG. 2, a case will be described in which the output voltage of the battery 1 decreases a little and becomes equal to or lower than the voltage level LI in the calculation state.

First, in step S1, initialization processing is executed. Through this initialization processing, the calculation registers and the like of the RAM 5 are cleared, and "0" is written to the flag register F.

In step S2, it is determined whether the output voltage of battery 1 is equal to or lower than voltage level 2.

That is, the control unit 3 determines whether or not an H level signal is output from the voltage detector 2b. This detection timing is at the time (a) shown in FIG. 3(a), that is, at the time of the calculation state. If YES in this step S2, step S1
If the answer is No, the process advances to step S3.

Now, the output voltage of battery 1 is at voltage level LI in the calculation state.
Although it is below, it is sufficiently higher than voltage level L2. Therefore, the determination in step S2 is No, and step S3 is executed.

In the display process of step S3, the control section 3 outputs display data to the display section 7 for display, and also outputs a key sampling signal to the key human power section 6.

In step S4, it is determined whether or not there is a key, that is, whether or not a key human power signal has been output from the key human power section 6.

If it is determined No in this step S4, step S
4 is repeatedly executed and the key is placed in a waiting state. Then, when a key is operated in the key human power section 6 and a key human power signal is output, YES is determined in step S4, and the process proceeds to step S5.

In step S5, rF=1'? It is determined whether or not J, that is, the contents of flag register F, is "1". Flag register F stores "1" when a message is output. Since "0" has now been written in the flag register F by executing step S1, the determination is No and the process proceeds to step S6.

In step S6, it is determined whether the output voltage of the battery 1 is at a voltage level of 1 or less.

That is, the control unit 3 determines whether or not an H level signal is output from the voltage detector 2a. This detection timing is at the time (a) shown in FIG. 3(a), that is, during the display state. If the determination in step S6 is YES, the process proceeds to step S8, and if the determination is NO, the process proceeds to step S7.

Now, the output voltage of battery 1 is at voltage level L in the display state.
High enough. Therefore, the determination in step S6 is No, and step S7 is executed.

In step S7, arithmetic processing is executed based on key human power. After completing step S7, return to step S2,
Similarly to the above, the processes of steps 82 to S7 are repeatedly executed.

■ When the output voltage of battery 1 drops to the warning level Next, as shown in FIG. 3(b), we will explain the case where the output voltage of battery 1 further drops and becomes below voltage level L in the display state. do.

In step S2, as described above, it is determined whether or not voltage level L2 is detected in the calculation state. In this case, as shown in FIG. 3(b), since the output voltage of the battery 1 has not decreased to the voltage level L2, the determination is No and the process proceeds to step S3.

Then, in the same manner as described above, the processes of steps 83 to S5 are executed, and the process proceeds to step S6.

In step S6, as described above, it is determined whether or not voltage level L4 is detected in the display state.

Now, as shown in FIG. 3(b), since the output voltage of the battery 1 is below the voltage level L, the determination is YES and the process proceeds to step S8.

In step S8, the control unit 3 outputs display data to the display unit 7, and sends a message as a warning to prompt battery replacement.
For example, the display section 7 is made to display and output a message such as "Battery is exhausted" for a certain period of time (for example, 2 seconds). Thereby, the user knows that the battery 1 is exhausted and replaces the battery 1 with a new one.

Note that warnings to prompt battery replacement are not limited to message displays.
Audio output may also be used.

In the following step S9, "1" is set in the flag register F.
is written, rF=IJ, and it is stored that the message has been output. Therefore, from this point onwards, step S5
Since the answer is YES and step S7 is immediately executed, steps se and s8 are not executed and the message is not displayed again. After executing step S9, the process proceeds to step S7, where arithmetic processing is executed.

■ When the output voltage of battery 1 drops to the forced OFF level.Next, if the user neglects to replace battery 1 and continues to use the small electronic device, the output voltage of battery 1 decreases as shown in Figure 3 (C). A case will be described in which the voltage further decreases to voltage level 2 or lower in the calculation state.

It is assumed that the process proceeds to step S2 after executing step S7 or after the power is turned on and passing through the initialization process of step S1.

In step S2, as described above, it is determined whether or not voltage level L2 is detected in the calculation state. now,
As shown in FIG. 3(C), since the output voltage of battery 1 is below voltage level 2, it is determined YES and step S
Proceed to step 10.

In step SIO, r
F=1? It is determined whether or not J, that is, the contents of flag register F, is "1".

If rF=OJ immediately after power-on, step SIO
If the answer is No, the process proceeds to step S11. Step 8
In step S11, a message urging battery replacement is displayed on the display section 7, as in step S8.

Also, if a voltage level below LI has already been detected, step S
If rF=IJ is established by executing step 9, YES is determined in step S10, and the process proceeds to step S12.

In step S12, the small electronic device is forcibly turned off.
The state is set to F, and the process shown in FIG. 2 is completed.

The reason for displaying the message in step Sll above is that when the power is turned on with battery 1 depleted, the user will not be able to determine why the battery is 0FFu if the power is turned off immediately, so the message is displayed to inform the user that the battery is depleted. It is.

In addition, although the above embodiment shows an example in which the present invention is applied to an electronic notebook, the present invention is not limited to this, and can be widely applied to small electronic devices such as data bank devices and pocket computers.

[Effects of the Invention] As detailed above, according to the present invention, the timing of detecting the battery voltage can be made appropriate, the user can be prompted to replace the battery at the right time, and the battery can be replaced at a time when the battery can still be used. It is possible to prevent the user from accidentally replacing the battery.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration, FIG. 2 is a flowchart showing the operation, and FIG. 3 is a diagram showing the operating state of the small electronic device and fluctuations in battery voltage. l...Battery, 2...Power supply unit, 2a, 2b...Voltage detector, 3...Control unit, 4...ROM, 5...R
A.M. 6... Key human power section, 7... Display section.

Claims (1)

[Claims] In a small electronic device that uses a battery as a power source and has a larger battery voltage drop in a calculation state than in a display state, the battery voltage drops to a predetermined level when the small electronic device enters a display state. and a warning means for outputting a warning when the determining means determines that the battery voltage has decreased to a predetermined level. Small electronic equipment.