JP2002131404A - Detector of battery residual quantity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that a time judging threshold for battery residual quantity for every considered temperature must be stored in a time judging threshold memory for battery residual quantity for every temperature and that the requirement of memory means with large memory capacity leads to the increase of cost. SOLUTION: By providing a correction function memory 13 of temperature/ battery residual quantity and a temperature-corrected battery residual quantity voltage calculator 14, the time judging threshold information for battery residual quantity stored for every temperature can be reduced. Also battery residual time indication similar to conventional one becomes possible because a calculation approximating the battery voltage at a reference temperature is performed even under different working temperature environment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a remaining battery time.

[0002]

2. Description of the Related Art Conventionally, a battery remaining amount detecting device has been widely used in portable equipment using a battery, such as a camera-integrated recording and storage unit. However, in the conventional battery remaining time display, since the discharge characteristics of the battery significantly change depending on the environmental temperature conditions during use, the voltage threshold value of the battery remaining time based on the battery discharge time corresponding to the environmental temperature is stored. It is necessary to keep. However, such means has a problem that the amount of information stored in accordance with the use environment temperature also increases. Here, an outline of the above-described battery remaining amount detection device will be described with reference to the drawings.

FIG. 2 is a block diagram showing a configuration of a conventional battery remaining amount detecting device. In FIG. 2, the battery voltage information generated by the battery voltage information generation unit 20 is the voltage of the battery or information created based on the battery voltage. The battery type information generated by the battery type information generating unit 21 is information for distinguishing types of batteries having different capacities, and indicates different information for each battery type. The temperature information is the temperature at the time of using the battery or information generated based on the temperature. The battery level correction function storage unit outputs information on the battery level correction function for each battery type from the input battery type information. The battery remaining amount correction function is a function required to approximate the reference battery voltage even when batteries of different capacities are used, based on the discharge time of a battery of a given capacity. That is.

Here, it is assumed that the discharge characteristics of an arbitrary battery 1 and battery 2 are shown in FIG. When the battery 1 is used as a reference battery, the difference between the discharge characteristics of the battery 1 and the battery 2 at each time can be approximated to a curve as shown in FIG. That is, when the battery 2 is used, the difference between the battery 1 and the battery 1 can be obtained as a solution of a higher-order curve function. Therefore, the battery 2 can be approximated to the discharge characteristics of the battery 1 from the difference. Here, the battery voltage of battery 1 at an arbitrary discharge time is D1, and the battery voltage of battery 2 is D2.
Assuming that Y is a higher-order curve function obtained from the difference between battery 1 and battery 2, D1 = D2 + Y (D2). This function Y is called a battery remaining amount correction function.

Therefore, the battery remaining amount correction function storage unit stores therein a coefficient of a higher-order curve function that enables approximation to the discharge characteristic of the reference battery for each battery type, and stores this coefficient in the battery remaining amount. It is output as correction function information.

The battery remaining voltage calculator calculates and outputs a battery voltage corresponding to a discharge characteristic of the battery with an arbitrary reference based on the battery remaining correction function information and the battery voltage information.
Here, in the above-described example, D1 = D2 + Y (D2)
Is actually performed.

[0007] The battery remaining time determination threshold storage unit for each temperature stores a battery voltage corresponding to the battery remaining time at an arbitrary interval for each temperature at which the battery is used. Here, FIG. 3 shows the discharge characteristics of an arbitrary battery at normal temperature and at low temperature. As shown in FIG. 3, if the temperature environment during use of the battery is different, the discharge characteristics of the battery change. Therefore, if the temperature during use is different even if the battery remaining voltage value is the same, the threshold value for calculating the battery remaining time is reduced. different. In FIG. 3, an arbitrary time interval Xa determined by the threshold value of the remaining battery time at normal temperature
.About.Xh are also shown, but when the threshold value of the battery remaining time is determined in this manner, a corresponding battery remaining voltage threshold value is obtained. This battery remaining voltage threshold is called a battery remaining time determination threshold, and threshold information for each temperature is stored in advance in a temperature remaining battery determination threshold storage unit.

The battery remaining time determination unit determines and outputs the remaining battery time based on the input remaining battery voltage and the remaining battery time determination threshold. Now, assuming that the remaining battery voltage is equal to or less than Yb and equal to or greater than Yc in FIG. 3, the remaining battery time determining unit compares the remaining battery voltage with the remaining battery voltage as a result of comparing the remaining battery voltage with the remaining battery voltage. The time Xb is output.

The display unit displays the remaining battery time, which is the output of the remaining battery time determination unit. FIG. 7 shows an example in which the remaining battery time is expressed in terms of minutes remaining.

[0010]

However, in the discharge curve shown in FIG. 3, the characteristics of the discharge curve change depending on the temperature. Therefore, in order to accurately display the remaining battery level in accordance with the use environment, it is necessary to consider this. The battery remaining time determination threshold value for each temperature must be stored in the battery remaining time determination threshold storage unit 25 for each temperature, and a storage unit having a large storage capacity is required.
There is a problem that the cost is increased.

SUMMARY OF THE INVENTION In view of the above problems, the present invention performs a temperature correction function calculation that approximates the discharge characteristics of a plurality of types of batteries having different capacities to the discharge characteristics of a single battery even when a plurality of different temperatures are used. Thus, it is possible to determine the remaining battery time from the remaining battery time determination threshold information under one temperature condition.

[0012]

In order to solve the above-mentioned problems, a battery remaining amount detecting device according to the present invention calculates a correction function from input battery type information and battery temperature information and stores the correction function. Storage means; battery remaining voltage calculating means for calculating and outputting remaining battery voltage from input battery voltage information and a correction function output from the correction function storing means; and battery remaining time determination threshold And a battery remaining time based on the remaining battery voltage output from the remaining battery voltage calculating means and the remaining battery time determination threshold output from the threshold storing means. And a display means for displaying the remaining battery time output from the remaining battery time determination means.

According to the present invention, with the above-described structure, the discharge characteristics of a given battery at different use environment temperatures are determined in advance, and the discharge characteristics at a reference temperature are determined from the correlation of the battery voltage between the use temperatures. When a correction function that approximates the battery voltage above is obtained in advance and the coefficient of the function is stored, the correction calculation is performed even in an arbitrary temperature environment, and the correction function is used under the reference temperature. It is possible to perform the remaining battery time determination in the same manner as that described above, and it is possible to determine the remaining battery time under various temperature conditions using a threshold value under one condition.

[0014]

According to the first aspect of the present invention, a correction function storing means for calculating and storing a correction function from inputted battery type information and battery temperature information, Battery remaining voltage calculating means for calculating and outputting the remaining battery voltage from the battery voltage information and the correction function output from the correcting function storing means, and threshold storage for storing the remaining battery time determination threshold Means for determining and outputting the remaining battery time from the remaining battery voltage output from the remaining battery voltage calculation means and the remaining battery time determination threshold output from the threshold storage means. And a display means for displaying the remaining battery time output from the remaining battery time determination means. With such a configuration, different usage environment temperatures of a given battery can be obtained. The discharge characteristics below Therefore, from the correlation of the battery voltage between the operating temperatures, a correction function that approximates the battery voltage on the discharge characteristics at the reference temperature is obtained in advance, and the coefficient of the function is stored. Compensation calculation is performed even under the temperature environment, and it is possible to perform the same battery remaining time judgment as when the battery is used under the reference temperature. It is possible to determine the remaining battery time of the condition.

Hereinafter, an apparatus for detecting a remaining battery level according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram of a battery remaining amount detecting device according to an embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a battery voltage information generation unit that generates battery voltage information, which may be a battery voltage value itself or an information signal generated based on the battery voltage. Reference numeral 11 denotes a battery type information generation unit that generates battery type information, and generates battery identification information for distinguishing types of batteries having different capacities. Reference numeral 12 denotes a temperature information generation unit that generates temperature information of the battery, and may be configured to output the temperature information itself when the battery is used, or may generate an information signal based on the temperature information. . Reference numeral 16 denotes a battery remaining time determining unit which is a battery remaining time determining means for determining the remaining battery time based on the input remaining battery voltage and the remaining battery time determining threshold. FIG. 7 shows a display example of the display unit which is a display unit for displaying the remaining battery time determined in the step (a).

Reference numeral 13 denotes a temperature / battery level correction function storage unit which is a correction function storage means for outputting a temperature correction function and a battery level correction function information from the input battery type information and temperature information. The temperature correction function is a function necessary for performing correction to obtain the same battery characteristics under arbitrary conditions even under different temperature conditions. When the discharge characteristics at normal temperature and low temperature of an arbitrary battery are shown as in FIG. 3, the difference between the temperatures at the battery voltage is as shown in FIG. Since this difference can be approximated by a curve, the difference between temperatures at an arbitrary battery voltage can be obtained as a solution of a higher-order curve function. That is, if the battery voltage under the reference temperature condition is Da, the battery voltage at times other than the reference temperature is Db, and the higher-order curve function obtained from the difference is R, the relationship of Da = Db + R (Db) holds. Here, this higher-order curve function R is referred to as a temperature correction function. The correlation between the temperatures does not depend on the battery capacity. Therefore, the correction is established by the same temperature correction function even in batteries having different battery capacities.

The battery remaining amount correction function is the same as that of the conventional system, and when there are two batteries having different battery capacities, it is possible to approximate the battery voltage on the battery voltage characteristics based on the arbitrary battery voltage. Is a function. Now, assuming that the reference battery voltage of any battery is D1, the battery voltage of any battery 2 is D2, and the remaining battery time correction function is Y, D1 = D2 + Y (D2). Here, if the battery voltage of the arbitrary battery 2 at the reference temperature is D2a, and the battery voltage of the arbitrary battery 2 at the arbitrary temperature is D2b, D2a = D2b + R (D2b) The formula approximating the reference battery voltage is: D1 = D2a + Y (D2a) = D2b + R (D2b) +
Y (D2b + R (D2b)).

In the temperature / battery remaining amount correction function storage unit 13,
The coefficients of the above-described temperature correction function R and battery remaining amount correction function Y are obtained and stored in advance, and information is output according to the input battery type information and temperature information.

Reference numeral 14 denotes a temperature-corrected battery remaining voltage calculator which is a battery remaining voltage calculator. The reference is based on temperature conditions in which the input battery voltage information is arbitrarily determined by a temperature correcting function and a battery remaining voltage correcting function. Is calculated to correct the battery voltage on the battery voltage discharge characteristic to be used, and the remaining battery voltage is output.

Reference numeral 15 denotes a battery remaining time determination threshold storage unit serving as threshold storage means. In the conventional method, information for each temperature is stored. Only the battery remaining time determination threshold is stored.

As described above, even when the operating temperature environment is different, it is possible to approximate the voltage at a certain reference temperature. It can be determined and displayed.

The operation of the battery remaining amount detecting device of the present embodiment configured as described above will be described below.

First, a battery voltage information generation unit 10 generates a battery voltage information signal, and the temperature correction battery remaining voltage calculation unit 14
Output to The battery type information generation unit 11 generates an information signal of the battery type based on the capacity of the battery in use, and outputs the information signal to the temperature / battery remaining amount correction function storage unit 13. further,
The temperature information generation unit 12 generates an information signal from the temperature of the battery in use and outputs the information signal to the temperature / battery remaining amount correction function storage unit 13.

In the temperature / battery remaining amount correction function storage unit 13,
The coefficients of the temperature correction function R and the battery level correction function Y are obtained and stored in advance based on the above-described formula, and the battery level correction function calculated according to the input battery type information and the temperature information is a temperature correction battery. It is output to the remaining voltage calculator 14.

The temperature-corrected remaining battery voltage calculator 14 calculates the remaining battery charge based on the battery voltage information generated by the battery voltage information generator 10 and the remaining battery correction function from the temperature / battery remaining correction function storage 13. The voltage is calculated, and the calculation result is output to the battery remaining time determination unit 16.

The battery remaining time determining unit 16 calculates the battery remaining time based on the threshold value from the battery remaining time determining threshold value storage unit 15 and the battery remaining voltage information from the temperature correction battery remaining voltage calculating unit 14. Judge the remaining agency time. The determination result is displayed on the display 17 as in the display example shown in FIG.

As described above, according to the present embodiment, by providing the temperature / battery remaining amount correction function storage unit 13 and the temperature corrected battery remaining amount voltage calculating unit 14, the battery remaining amount stored for each temperature is provided. Even if the operating temperature environment is different, the approximate calculation of the battery voltage at the reference temperature is performed while the time determination threshold information is reduced.

[0029]

As described above, according to the present invention, since the temperature correction function coefficient for each use environment temperature is stored, the battery remaining time voltage threshold for each temperature is stored as in the conventional method. It is unnecessary, and it is possible to reduce the amount of information to be stored, and it is possible to accurately display the remaining time with the same accuracy as the conventional one. As a result, a useful effect can be brought about in the camera-integrated recording storage unit. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a battery remaining amount detecting device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional battery remaining amount detection device.

FIG. 3 is a characteristic diagram showing a relationship between discharge time and voltage in an arbitrary battery at normal temperature and low temperature.

FIG. 4 is a characteristic diagram showing a difference between discharge characteristics of arbitrary batteries having different operating temperature environments and an approximate curve thereof.

FIG. 5 is a characteristic diagram showing a relationship between discharge time and voltage at room temperature of two batteries having different battery capacities.

FIG. 6 is a characteristic diagram showing a difference between discharge characteristics of two batteries and an approximate curve thereof.

FIG. 7 is a schematic diagram showing a display of a remaining battery time display.

[Explanation of symbols]

 Reference Signs List 10 Battery voltage information generation unit 11 Battery type information generation unit 12 Temperature information generation unit 13 Temperature / battery remaining correction function storage unit 14 Temperature correction battery remaining voltage calculation unit 15 Battery remaining time judgment threshold storage unit 16 Battery remaining Quantity / time judgment unit 17 Display

Continuing from the front page (72) Inventor Hironori Arima 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 2G016 CB02 CB12 CC01 CC03 CC04 CC06 CC13 CF06 5G003 BA01 CA11 CB01 EA05 5H030 AS11 FF00 FF22 FF41 FF44

Claims (1)

[Claims] 1. A correction function storage means for calculating and storing a correction function based on input battery type information and battery temperature information, and input battery voltage information and correction output from the correction function storage means. Battery remaining voltage calculating means for calculating and outputting the remaining battery voltage from the function, threshold storing means for storing a remaining battery time determination threshold, and output from the remaining battery voltage calculating means. Battery remaining time determining means for determining and outputting the remaining battery time from the remaining battery voltage and the remaining battery time determination threshold output from the threshold storage means; and the remaining battery time determining means And a display unit for displaying the remaining battery time output from the battery.