JPH09101354A - Indicating device for residual capacity of battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To indicate residual capacity of battery and to prevent occurrence of exhaustion of power supply in the course of an operation by providing a memory storing voltage of the battery at the time when a power source of equipment is turned off, and others. SOLUTION: When a power switch 2 is operated to be turned on, a microprocessor (microcomputer) 4 detects voltage of a battery 1 with a voltage detector 3. A supply voltage at the time of the end when the switch 2 was turned off at the preceding time is read out from a memory 5 and the present voltage of the battery 1 and the voltage thereof at the preceding time of the end are compared with each other. In the case where the present voltage of the battery 1 is lower than the supply voltage thereof at the preceding time of the end, a natural discharge voltage value stored beforehand in the memory 5 is read out and it is checked whether a forced discharge was made or not. The natural discharge voltage value is classified and set according to the kind of the battery 1. In indication of a residual capacity of the battery 1, it is compared with comparative values stored beforehand in the memory 5 and indicated in a staged manner by LED in an indicator 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for displaying a remaining capacity (remaining capacity) of a battery of a power source of electronic equipment or the like.

[0002]

2. Description of the Related Art Conventionally, in order to display the remaining amount of a battery, the remaining amount is displayed by a predetermined threshold voltage.

[0003]

However, when the discharge characteristics are different for each battery and the battery is charged and replaced, the displayed content and the actual remaining amount are different, and the remaining amount display error is large, resulting in a display effect. I couldn't show it.

[0004]

DISCLOSURE OF THE INVENTION The present invention includes a voltage detecting means for detecting the voltage of a battery used as a power source when a power switch is turned on and off, and the voltage detecting means when the power source of the device is turned off first. Storage means for storing the voltage detected by the detection means; comparison means for comparing the value stored in the storage means with the value detected by the voltage detection means when the power switch is turned on; Discrimination means for discriminating between natural discharge and forced discharge from the time from the time of storage to the time of next detection, and the threshold value of the remaining battery level in the natural discharge state are read from the storage means and compared. And a display unit for displaying the remaining amount obtained by the comparison by the comparison unit.

Further, according to the present invention, the power switch is turned on and off.
Voltage detecting means for detecting the voltage of the battery used as the power source when the power is turned off, storage means for storing the voltage detected by the voltage detecting means when the power source of the device is turned off, and the storage means for storing the voltage. And a comparison means for comparing the value detected by the voltage detection means when the power switch is turned on, and whether the spontaneous discharge is performed from the time from the time when the voltage is stored in the storage means to the time when the next detection is performed. The judgment means for judging whether the battery is forcibly discharged, the setting means for setting the threshold value of the remaining battery level in the forced discharge state, the threshold value set by the setting means and the value detected by the detection means are set. A battery residual quantity display device comprising a comparing means for comparing and a displaying means for displaying the residual quantity obtained by the comparison by the comparing means.

In the present invention, the power switch is turned on and off.
Voltage detecting means for detecting the voltage of the battery used as the power source when the power is turned off, storage means for storing the voltage detected by the voltage detecting means when the power source of the device is turned off, and the storage means for storing the voltage. And a comparison means for comparing the value detected by the voltage detection means when the power switch is turned on, and whether the spontaneous discharge is performed from the time from the time when the voltage is stored in the storage means to the time when the next detection is performed. When the comparison means determines that the voltage detected by the detection means is higher than the value stored in the storage means, a new battery threshold value is set. A threshold setting means for storing in the storage means, a comparing means for reading out and comparing the threshold value of the remaining amount of the battery from the storage means, and a display means for displaying the remaining amount obtained by comparison by the comparing means. Have A quantity display device of the pond.

Further, the present invention comprises display means for notifying the danger of the remaining amount when the voltage of the battery used as the power source is at the threshold of the remaining amount of the battery when the power switch is turned off. It is a remaining battery level display device for a battery.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The operation of the battery level indicator of an electronic device according to the present invention will be described with reference to the flow chart of FIG. When the power switch 2 of the main body 10 of the electronic device for displaying the remaining amount of the battery is operated and turned on, the microprocessor (microcomputer) 4 detects the power supply voltage with the voltage detector 3, and the battery (including the rechargeable battery is included). ) 1 voltage V is obtained (S1). Last time, the power switch 2 of the device was turned off.
The power supply voltage Vend at the end when FF is performed is stored in the memory 5
Is read (S2), and the current voltage V of the battery 1 is compared with the power supply voltage Vend at the time of the end (S3).

When the current power supply voltage V is equal to or lower than the power supply voltage Vend at the time of the previous termination, the spontaneous discharge voltage value Vdown stored in the memory 5 in advance is read (S4), and it is checked whether the forced discharge has been performed (S5). . The value of Vdown checks whether the battery 1 has been replaced.
Since the self-discharge occurs even if the battery is not replaced, the self-discharge voltage value Vdown can be calculated from the self-discharge characteristic of the battery 1 from the elapsed time from the previous power OFF. Natural discharge voltage value Vd
The "own" is classified and set according to the type of the battery 1 that is normally used, and it is determined whether or not the battery is forcibly discharged depending on whether the difference between Vend and V is larger than Vdown.

When Vend-V becomes smaller than Vdown, the mode shifts to the battery remaining capacity display mode (S6). The remaining battery level is displayed in a stepwise manner as shown in FIG. 3 by comparing the comparison values Vref [n] and V stored in advance in the memory.
The power supply voltage V which is the voltage of the battery 1 is Vstart ≧ V> V
In the case of ref [1], the remaining capacity of the battery 1 is 100 to 80%
The display state of the display 6 is displayed in five stages by lighting five LEDs.

When Vref [1] ≧ V> Vref [2] and the remaining capacity of the battery 1 is 80 to 60%, four LEs are used.
D is lit and displayed. Vref [2] ≧ V> Vref
Assuming that the remaining capacity of the battery 1 is 60 to 40% in [3],
Three LEDs are lit and displayed. Vref [3] ≧ V>
It is assumed that the remaining capacity of the battery 1 is 40 to 20% at Vref [4], and two LEDs are lit and displayed. Vref
[4] ≧ V> Vend and one LED is turned on to display the remaining amount (S7).

When the indicator 6 for displaying the remaining amount of the battery 1 which is the remaining capacity is commonly used with other display contents such as the signal level display, the capacity of the battery is displayed for several tens of seconds after the power is turned on. It is made to switch. The microcomputer 4 detects that the power switch 2 of the main body 10 of the electronic device is turned off (S8), and the microcomputer 4 constantly detects the voltage of the battery 1 by the voltage detector 3 and stores the latest data in the memory 5 as the discharge characteristic. Is calculated, the correct battery voltage is stored, and the power supply voltage Vend when the power is finally turned on is detected (S9). Next, Vend, Vre
Writes and updates f [1] to [4] in the memory 5, and ends.
(S10).

If V> Vend in S3, it is considered that the battery has been newly replaced, and the battery remaining amount display mode (S11) is entered. In S5, if Vend-V≥Vdown, forced discharge or a different type. When it is determined that the battery of No. 1 is installed, the battery remaining amount display mode is entered (S11). Consider the power supply voltage in this case as the first battery voltage Vstart = V
(S12), Vstart = V is compared with Vstart min and displayed (S13). Vstart min
Is the minimum value of the initial voltage Vstart of the fully charged battery 1, and when Vstart = V is larger than Vstart min, first, the end voltage V'end is predicted and determined in consideration of the memory effect and overdischarge of the battery. To do. The average T of the time t at which V (t) = V'end is obtained from the discharge characteristics of the battery, and tstep = T / 5 in order to have five steps.

Next, the threshold voltage is determined by first setting Vref [4]. From the discharge characteristics of the battery 1, when the battery voltage V is near Vref [4], the voltage change is small, so that Vref [4] = V is 4T / 5. But,
Since the voltage change is large at the battery remaining capacity of 100 to 80%, Vref [1] is corrected by Vstart. Therefore, Vref [1] is replaced by Vref [1] = A × Vstart + B from the discharge characteristic. Note that Vref [2] = C × (Vref [1] −Vref [4]) + Vref
[4] Similarly, Vref [3] = D × (Vref [1] −Vref [4]) + Vref
[4] is replaced and temporarily stored in the memory, and the threshold voltage V
The remaining amount is displayed by ref [1] to [4] (S14).

If V <Vstart min in S13, average V'end and Vre are calculated based on the discharge data.
f [1] to [4] are calculated by the microcomputer 4, temporarily stored in the memory 5, compared with the voltage V of the battery 1, and the remaining amount is displayed on the display 6 (S15).

After the remaining capacity of the battery is displayed in S14 and S15, the power of the device body is turned off (S8) even if the LED is also used as another display function of the device body (S8). When the final voltage Vend is detected and the remaining amount is small, it is temporarily displayed (S9), and Vend, V'end, Vre are displayed.
f [1] to [4] are written in the memory 5 (S10). The memory 5 has the final power supply voltages Vend, V'end and Vre.
f [1] to [4], the amount of spontaneous discharge, and the like are stored, and the time is counted and backed up by the back-up power supply 9 until the power is turned on next time.

[0017]

According to the present invention, since the remaining capacity of the battery capacity is confirmed and displayed at the start of use of the device, it is possible to prevent the power from being cut off during the operation.

[Brief description of the drawings]

FIG. 1 is a flowchart of a battery remaining amount display device of the present invention.

FIG. 2 is a block diagram of a battery remaining amount display device of the present invention.

FIG. 3 is a diagram showing ranks of displays according to the present invention.

[Explanation of symbols]

 1 Battery 2 Power Switch 3 Voltage Detector 4 Microcomputer 5 Memory 6 Display 7 Load 9 Backup Power Supply 10 Main Unit

Claims (4)

[Claims] 1. A voltage detecting means for detecting a voltage of a battery used as a power source when a power switch is turned on and off, and a voltage detected by the voltage detecting means when the power source of the device is turned off. Storing means for comparing the value stored in the storing means with a value detected by the voltage detecting means when the power switch is turned on;
Discriminating means for discriminating between natural discharge and forced discharge from the time from the time of being stored in the storage means to the time of the next detection, and a threshold value of the remaining amount of the battery in the natural discharge state is stored in the memory. A battery residual quantity display device comprising: a comparing means for reading and comparing the reading means and a displaying means for displaying the residual quantity obtained by the comparison means. 2. A voltage detecting means for detecting a voltage of a battery used as a power source when the power switch is turned on and off, and a voltage detected by the voltage detecting means when the power source of the device is turned off first. Storing means for comparing the value stored in the storing means with a value detected by the voltage detecting means when the power switch is turned on;
A determination unit that determines whether the battery is spontaneously discharged or forcedly discharged from the time from the time when it is stored in the storage unit until the time when it is detected next, and a threshold value of the remaining battery level in the forced discharge state are set. It comprises: setting means, comparing means for comparing the threshold value set by the setting means with the value detected by the detecting means, and display means for displaying the remaining amount obtained by comparison by the comparing means. A battery remaining amount display device characterized by. 3. A voltage detecting means for detecting the voltage of a battery used as a power source when the power switch is turned on and off, and a voltage detected by the voltage detecting means when the power source of the device is turned off. Storing means for comparing the value stored in the storing means with a value detected by the voltage detecting means when the power switch is turned on;
Discrimination means for discriminating between spontaneous discharge and forced discharge from the time from the time of being stored in the storage means to the time of next detection, and the detection means detected from the value stored in the storage means. When the comparison means determines that the voltage is large, a threshold value setting means for setting a new battery threshold value and storing it in the storage means, and a threshold value for the remaining battery capacity are read from the storage means and compared. And a display unit for displaying the remaining amount obtained by the comparison by the comparison unit. 4. A display means for notifying the danger of the remaining amount when the voltage of the battery used for the power source when the power switch is turned off is in the remaining amount critical level of the threshold value of the remaining amount of the battery. The battery remaining amount display device according to any one of 1 to 3.