JP4001520B2 - Method for determining the remaining battery level of battery-powered equipment - Google Patents

Description

により算出される。
【００２９】
ここで、実動時の最大負荷状態における消費電流が２．００Ａで、第２負荷状態における消費電流が０．５０Ａなので、実動時の最大負荷状態における消費電流は、第２負荷状態における消費電流の４倍である。
【００３０】
そして、電圧差は、主に電池２の内部インピーダンスに依存するため、最大負荷状態における電圧差ΔＶｍａｘは

により算出される。
【００３１】
そして、実動時の最大負荷状態の電池２の電圧の予測値Ｖｅは、

により正確に算出される。
【００３２】
つぎに、ステップＳＴ13において、予測値Ｖｅが予め設定されている閾値Ｖｃ以上（Ｖｅ≧Ｖｃ）か否かを判断し、予測値Ｖｅが閾値Ｖｃ以上（Ｖｅ≧Ｖｃ）であるＹＥＳの場合には、つぎのステップＳＴ14において、電池２の残量を「有り」と判断し終了する。
【００３３】
前記ステップＳＴ14の判断が、予測値Ｖｅが閾値Ｖｃ未満（Ｖｅ＜Ｖｃ）であるＮＯの場合には、つぎのステップＳＴ15において、電池２の残量を「無し」と判断し終了する。
【００３４】
なお、電池２の残量を「無し」と判断した場合には、電池２の残量が残り少ないことをユーザーに警告するべく、ＬＥＤなどを点灯させる警告表示を実行するように構成するとよい。
【００３５】
また、本実施形態の電池駆動プリンタ１における電池残量判別を実行するタイミングとしては、電源投入時および所定枚数の印刷を行う毎に実行するとよい。勿論、１枚の印刷を行う毎に電池残量判別を実行することもできる。
【００３６】
このような構成からなる本実施形態の電池駆動プリンタ１における電池残量判別方法によれば、最大消費電流を通電することなく、電池２の残量を正確に判別することができるとともに、環境温度、電池２の劣化などによる電池能力の低下時においても、電池２の残量を正確に判別することができる。
【００３７】
すなわち、本実施形態の電池駆動プリンタ１における電池残量判別方法によれば、電池２を有効利用することができるとともに、電池２の残量を正確に判別することができる。
【００３８】
したがって、本実施形態の電池駆動プリンタ１における電池残量判別方法によれば、電池２を無駄なく使用することができるとともに、システムダウンなどの不都合が生じるのを確実に防止することができる。
【００３９】
なお、本発明の電池残量判別方法を適用することのできる電池駆動機器としては、電池駆動プリンタの他に、デジタルスチルカメラ、携帯型パーソナルコンピュータ、ビデオカメラなどを例示できる。
【００４０】
また、本発明は、前記実施形態に限定されるものではなく、必要に応じて種々変更することができる。
【００４１】
【発明の効果】
以上説明したように本発明に係る電池駆動機器の電池残量判別方法によれば、電池を有効利用することができるとともに、電池の残量を正確に判別することができるなどの極めて優れた効果を奏する。
【図面の簡単な説明】
【図１】 本発明に係る電池残量判別方法を適用した電池駆動機器の実施形態の要部を示すブロック図
【図２】 本発明に係る電池駆動機器の電池残量判別方法の実施形態を示すフローチャート
【符号の説明】
１ 電池駆動プリンタ
２ 電池
３ 電源スイッチ
４ モータドライバ
５、６ モータ
７、８ ＤＣ／ＤＣコンバータ
９ 制御部
１０ 電池電圧検出部
１１ サーマルヘッド
Ｒ１、Ｒ２ 抵抗器
Ｖ１、Ｖ２ 電圧
Ｖｃ 閾値
Ｖｅ 予測値
ΔＶ、ΔＶｍａｘ 電圧差[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery remaining amount determining method for a battery-driven device suitable for accurately determining the remaining amount of a battery.
[0002]
[Prior art]
Conventionally, battery-driven devices using a battery as a drive source are known. In such a battery-driven device, it is necessary to prevent the system from being lowered due to the remaining battery level during operation, or to allow the operator to recognize when to replace or charge the battery. For this reason, in the battery drive device, the remaining battery level is determined at a predetermined timing. The determination of the remaining amount of the battery is performed in the control unit of the battery-driven device.
[0003]
As conventional battery remaining amount determination methods, the following two methods are mainly used.
[0004]
The first battery remaining amount determining method compares the battery voltage detected by the control unit with a threshold value set by experiment or the like, and determines that the remaining battery amount is “none” if the battery voltage is less than the threshold value. Is. In this case, the detected voltage is one kind in an arbitrary load state smaller than the maximum load or a minimum load state such as an energized state of only the control power source.
[0005]
In the second battery remaining amount determining method, dummy energization is performed so that the maximum load state during actual operation is obtained, and the battery voltage is detected before actual operation.
[0006]
[Problems to be solved by the invention]
However, in the conventional first battery remaining capacity determining method described above, the voltage when an actual load is applied cannot be predicted due to environmental temperature, battery deterioration, etc., and the remaining battery capacity is accurately determined. There was a problem that it could not be determined.
[0007]
Further, in the above-described second conventional battery remaining amount determination method, when the battery voltage is detected, the battery is consumed at the maximum load, so the battery is wasted, in other words, the battery is effectively used. There was a problem that could not.
[0008]
The present invention has been made in view of this point, and provides a method for determining the remaining battery level of a battery-driven device capable of effectively using a battery and accurately determining the remaining battery level. Objective.
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, the battery remaining capacity determination method of the battery-driven device according to the present invention is characterized in that each of the detected battery voltages in two different load states smaller than the maximum load during actual operation is detected. The potential difference in the two types of load states is calculated from the voltage of the current , and then in the maximum load state in the actual operation from the calculated potential difference, the maximum load state in actual operation, and the current consumption in each of the two types of load states. Calculate the potential difference, then calculate the predicted value of the battery voltage in the maximum load state during actual operation from the detected voltage and the calculated potential difference in the maximum load state during actual operation. And if the predicted value is equal to or greater than the threshold value, the remaining battery level is determined to be present. And by adopting such a configuration, it is possible to accurately determine the remaining amount of the battery without energizing the maximum current consumption, and even when the battery capacity is reduced due to environmental temperature, battery deterioration, etc. The remaining battery level can be accurately determined.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to embodiments shown in the drawings.
[0011]
FIG. 1 is a block diagram illustrating a main part of an embodiment of a battery-driven device to which a battery remaining amount determining method for a battery-driven device according to the present invention is applied.
[0012]
The battery-driven device of the present embodiment exemplifies a small portable battery-powered printer, specifically a thermal transfer printer capable of full-color printing. The configuration of each part of the thermal transfer printer is conventionally known, and detailed description thereof will be omitted, and only the gist will be described.
[0013]
As shown in FIG. 1, a battery-driven printer 1 according to this embodiment includes a battery 2, which is a DC power source as a power source for the printer, a power switch 3, two resistors R1, R2, a motor driver 4, and 2 It has two motors 5 and 6, two DC / DC converters 7 and 8, and a control unit 9 that controls the operation of each unit.
[0014]
The positive electrode of the battery 2 is connected to one end of the power switch 3, and the negative electrode of the battery 2 is grounded. The other end of the power switch 3 is commonly connected to the motor driver 4 and the input ends of the two DC / DC converters 7 and 8 and one end of the resistor R1. The other end of the resistor R1 is commonly connected to the battery voltage detection unit 10 of the control unit 9 and one end of the resistor R2. Further, the other end of the resistor R2 is grounded.
[0015]
The input terminals of the two motors 5 and 6 are connected to the output terminal of the motor driver 4. These motors 5 and 6 are used as a drive source for the printer mechanism, and include a paper transport motor, a head contact / separation motor, and the like, so that the necessary number is arranged according to the design concept and the like. It has become. Further, a thermal head 11 as a print head is connected to the output end of one DC / DC converter 7, and the power input end of the control unit 9 is connected to the output end of the other DC / DC converter 8. Has been.
[0016]
The two motors 5 and 6 and the thermal head 11 are driven at a predetermined timing based on a control command sent from the control unit 9. The control unit 9 includes a CPU, a memory, and the like. In the memory, the program and data necessary for at least the printing operation, various programs such as a program and data for executing the battery remaining amount determination method, and the like Data is stored.
[0017]
According to the battery-driven printer 1 having such a configuration, the voltage of the battery 2 passes through the power switch 3 and is divided by the two resistors R1 and R2, and the A / D is supplied to the battery voltage detection unit 10 of the control unit 9. It is detected (read) by being input to the converter.
[0018]
Next, a method for determining the remaining battery level in the battery-driven printer 1 of the above-described embodiment will be specifically described.
[0019]
FIG. 2 is a flowchart showing an embodiment of a method for determining the remaining battery level of a battery-driven device according to the present invention.
[0020]
In the battery-powered printer 1 according to this embodiment, the remaining battery level determination method sets two different load states smaller than the maximum load during actual operation as a first load state and a second load state. On the other hand, as the first load state, a light load state of only the control power source operating only the logic control unit of the control unit 9, for example, a load state with a current consumption of 0.05A is used. As the other second load state, an intermediate load state in which the two motors 5 and 6 are dummy energized, for example, a load state with a current consumption of 0.50 A is used. Here, the current consumption in the maximum load state during actual operation is 2.00 A. Further, 21.00 V is used as the threshold value Vc used for determining whether or not the battery 2 is remaining.
[0021]
As shown in FIG. 2, the battery remaining amount determining method in the battery-driven printer 1 according to the present embodiment is as shown in FIG. V1 and V2 are detected, respectively, and the process proceeds to the next step ST12.
[0022]
Step ST11 includes step ST11a and step ST11b.
[0023]
On the other hand, in step ST11a, the voltage V1 of the battery 2 in the first load state, for example, 22.71V (V1 = 22.71V) is detected.
[0024]
In the other step ST11b, the voltage V2 of the battery 2 in the second load state, for example, 22.37V (V2 = 22.37V) is detected.
[0025]
Note that, in step ST11a, detects a voltage V2 of the battery 2 in a second load state, in step ST11b, may be in reverse order on so that issuing detects the voltage V1 of the battery 2 in the first load state.
[0026]
Next, in step ST12, a predicted value Ve of the voltage of the battery 2 in the maximum load state during actual operation is calculated from the detected voltages V1 and V2 of each battery 2, and the process proceeds to the next step ST13.
[0027]
The calculation of the predicted value Ve of the voltage of the battery 2 in the step ST12 starts by calculating the voltage difference ΔV between the voltages V1 and V2 of the battery 2 detected in the step ST11.
[0028]
This voltage difference ΔV is

Is calculated by
[0029]
Here, since the current consumption in the maximum load state during actual operation is 2.00 A and the current consumption in the second load state is 0.50 A, the current consumption in the maximum load state during actual operation is the consumption in the second load state. Four times the current.
[0030]
Since the voltage difference mainly depends on the internal impedance of the battery 2, the voltage difference ΔVmax in the maximum load state is

Is calculated by
[0031]
And the predicted value Ve of the voltage of the battery 2 in the maximum load state during actual operation is

Is calculated accurately.
[0032]
Next, in step ST13, it is determined whether or not the predicted value Ve is greater than or equal to a preset threshold value Vc (Ve ≧ Vc). If YES, the predicted value Ve is greater than or equal to the threshold value Vc (Ve ≧ Vc). In the next step ST14, it is determined that the remaining amount of the battery 2 is “present”, and the process ends.
[0033]
If the determination in step ST14 is NO when the predicted value Ve is less than the threshold value Vc (Ve <Vc), it is determined in step ST15 that the remaining amount of the battery 2 is “None” and the process ends.
[0034]
When it is determined that the remaining amount of the battery 2 is “None”, a warning display for turning on an LED or the like may be executed to warn the user that the remaining amount of the battery 2 is low.
[0035]
Further, the timing for executing the remaining battery level determination in the battery-driven printer 1 of the present embodiment may be performed when the power is turned on and every time a predetermined number of prints are performed. Of course, the remaining battery level can be determined every time one sheet is printed.
[0036]
According to the battery remaining amount determining method in the battery-driven printer 1 of the present embodiment having such a configuration, the remaining amount of the battery 2 can be accurately determined without energizing the maximum current consumption, and the environmental temperature Even when the battery capacity is reduced due to deterioration of the battery 2 or the like, the remaining amount of the battery 2 can be accurately determined.
[0037]
That is, according to the battery remaining amount determining method in the battery-driven printer 1 of the present embodiment, the battery 2 can be used effectively and the remaining amount of the battery 2 can be accurately determined.
[0038]
Therefore, according to the battery remaining amount determination method in the battery-driven printer 1 of the present embodiment, the battery 2 can be used without waste and it is possible to reliably prevent inconveniences such as system down.
[0039]
Examples of battery-powered devices to which the battery remaining amount determining method of the present invention can be applied include digital still cameras, portable personal computers, video cameras and the like in addition to battery-driven printers.
[0040]
Further, the present invention is not limited to the above-described embodiment, and various modifications can be made as necessary.
[0041]
【The invention's effect】
As described above, according to the method for determining the remaining battery level of the battery-operated device according to the present invention, it is possible to effectively use the battery, and it is possible to determine the remaining battery level accurately. Play.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main part of an embodiment of a battery drive device to which a battery remaining amount determination method according to the present invention is applied. FIG. 2 shows an embodiment of a battery remaining amount determination method of a battery drive device according to the present invention. Flow chart shown [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Battery drive printer 2 Battery 3 Power switch 4 Motor driver 5, 6 Motor 7, 8 DC / DC converter 9 Control part 10 Battery voltage detection part 11 Thermal head R1, R2 Resistor V1, V2 Voltage Vc Threshold Ve Predicted value (DELTA) V, ΔVmax Voltage difference

Claims (1)

The battery voltage in two different load conditions smaller than the maximum load during actual operation is detected, the potential difference in the two load conditions is calculated from each detected voltage , and then the calculated potential difference and actual operation The potential difference in the maximum load state during actual operation is calculated from the current consumption in each of the maximum load state and the two types of load states, and then the actual operation is performed from the detected voltage and the calculated potential difference in the maximum load state during actual operation. Calculate the predicted value of the voltage of the battery in the maximum load state at the time, compare this predicted value with a preset threshold value, and determine that the remaining battery level is present if the predicted value is equal to or greater than the threshold value A battery remaining capacity determination method for battery-driven equipment, which is characterized.

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