JPH04160419A - Portable terminal equipment - Google Patents

Abstract

PURPOSE:To take a proper preventive countermeasure before the operation of the portable terminal equipment by displaying the discharging state of a chargeable battery on a display device to the user. CONSTITUTION:When a 1st chargeable battery 16 is discharged during the operation of the equipment and a voltage measuring circuit 19 detects an unusable voltage V0, a switching signal is sent to a switch which switches the current battery to a 2nd adjacent chargeable battery 17. Then a pilot lamp 23 which illuminates is turned off. Similarly, the batteries 17 and 18 are discharged and when voltage measuring circuits 20 and 21 detect the voltage V0 in order, pilot lamps 24 and 25 are turned off in order. The user knows whether the charging capacity is consumed by 1/3 or left only by 1/3 on the pilot lamps 23 - 25.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a portable mobile terminal device (portable computer equipment).

BACKGROUND OF THE INVENTION FIG. 2 shows the configuration of a conventional portable terminal device of this type. In FIG. 2, 1 is a CPU that controls each part of the mobile terminal device, and 2 is a communication unit for communicating with the host computer! 10.3 is a keyboard for inputting data; 4
5 is a display device for displaying data; 5 is a memory for storing data; 6 is a battery pack that serves as a power source for the mobile terminal device; 7 is a voltage detection circuit for detecting the voltage of the battery pack 6; 8 is a power supply circuit for supplying power to each part of the mobile terminal device, and 9 is a charging terminal connected to an external charging device to receive charging current.

In such a mobile terminal device, after the battery pack 6 is charged by supplying a charging current from the charging terminal 9, the battery pack 6 is used as a power source for the device by utilizing its discharge characteristics.

By the way, the discharge characteristics of a rechargeable battery are as shown in Figure 3.
When the device operates for a certain period of time, the voltage of the rechargeable battery decreases. Therefore, each part of the mobile terminal device is designed so that its operation is no longer guaranteed if the voltage VO is cut off, and when the voltage VO is cut off, the voltage detection circuit 7 in FIG. When the CPU 1 quickly enters the HALT state by a signal or the like, a charging instruction is simultaneously displayed on the display device 4 to inform the operator of the necessity of charging.

Problems to be Solved by the Invention However, in the conventional mobile terminal device, the discharge characteristics of the rechargeable battery are almost constant up to the usable voltage of the mobile terminal device. Since it is not possible to know what percentage of the capacity has been used,
When a user takes a mobile terminal device outdoors to use it, there are cases where the rechargeable battery voltage drops to V during use and the user is unable to operate the mobile terminal device.

Generally, mobile terminal devices are often operated outdoors, and there are very few cases where an external charging device can be used immediately.

For this reason, it was necessary to charge the battery before taking it out for use, or to always carry a charged spare battery with you.

The present invention solves such conventional problems by displaying the approximate amount of battery usage of the rechargeable battery that is the power source of the mobile terminal device, and making it clear to the user whether or not it is necessary to charge the battery. The purpose of the present invention is to provide a mobile terminal device having a function of giving instructions.

Means for Solving the Problems In order to achieve the above object, the present invention uses a plurality of rechargeable batteries constituting a power source, a voltage measurement circuit that measures the voltage of each rechargeable battery, and a signal from the voltage measurement circuit. The battery is equipped with a changeover switch that automatically switches between each rechargeable battery in sequence, and a display device that displays the discharge state of the rechargeable battery in conjunction with the changeover switch.

Effect of the Invention With the above configuration, when one rechargeable battery is discharged and becomes unusable, the voltage measurement circuit detects this and operates the changeover switch to connect to another rechargeable battery, and also connects the unusable battery to another rechargeable battery. Since the display device indicates that there is a rechargeable battery or that there is a rechargeable battery that needs to be recharged, the user can take thorough precautions before using the mobile terminal device.

Embodiment FIG. 1 shows the structure of an embodiment of the present invention. In FIG. 1, 11 is a CPU that controls each part of the mobile terminal device.
, 12 is a communication I1 for communicating with the host computer.
0.13 is a keyboard for entering data manually; 14 is a display device for displaying data; and 15 is a memory for storing data. 16, 17. 18 is a nickel cadmium rechargeable battery that is a power source, 19, 20. 21
is a voltage measuring circuit connected in parallel to each rechargeable battery 16, 17, 18, 22 is an automatic changeover switch for sequentially selecting each rechargeable battery 16, 17, 18, 23, 24, 25 is each voltage measuring circuit 19 , 20° 21 is a voltage drop indicator lamp that indicates how much each rechargeable battery 16, 17, 18 is discharged. Each voltage measurement circuit 19, 20
．． 21 outputs a signal to light each indicator lamp 23, 24, 25 while detecting a voltage exceeding vLl in FIG.

Next, the operation of the above embodiment will be explained. First, when the first rechargeable battery 16 is discharged and the voltage drops while the device is in operation, and the voltage measurement circuit 19 detects the voltage vO, the voltage measurement circuit 19 supplies power to the adjacent second rechargeable battery 17. While outputting a signal to the automatic changeover switch 22 to switch,
The display lamp 23, which had been lit until then, is turned off. Next, the second rechargeable battery 17 is discharged in the same manner, and the voltage becomes v.

When this happens, the second voltage measuring circuit 20 detects this and turns off the second indicator lamp 24. Similarly, when the third rechargeable battery 18 is discharged and the voltage becomes Vo, the third voltage measuring circuit 21 detects this and turns off the third indicator lamp 25.

Thus, according to the embodiment, the rechargeable battery 16.17
．． 18 discharge one after another, the indicator lamps 23 and 24
．． '25 also turns off in sequence, so the user of the device can tell from the indicator lamps 23, 24, 25 whether one-third of the charge capacity has been consumed, or whether there is only one-third remaining. You can know.

If the user wants to know the discharge status in more detail,
This can be done by increasing the number of rechargeable batteries, voltage measuring devices, and indicator lamps.

Effects of the Invention As is clear from the embodiments described above, the present invention has the following advantages: Since the discharge state of the rechargeable battery is clearly shown to the user by the display device, the user can easily know when to charge the battery.
Measures to prevent failures can be taken in advance so as not to hinder the operation of the mobile terminal device outdoors.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of a mobile terminal device showing an embodiment of the present invention, FIG. 2 is a schematic block diagram showing an example of a conventional mobile terminal device, and FIG. 3 is a graph showing the discharge characteristics of a rechargeable battery. be. 11...CPU, 12...Communication I10.13...
Keyboard, 14...Display device, 15...Memory, ■6.17.18...Rechargeable battery, 19,20.21.
...Voltage measurement circuit, 22...Automatic changeover switch,
23.24.25...Voltage drop indicator lamp. Name of agent: Patent attorney Masahiro Kura Go #PJ1 Figure 2

Claims (1)

[Claims] A plurality of rechargeable batteries constituting a power source, a voltage measurement circuit that measures the voltage of each of the rechargeable batteries, a changeover switch that automatically switches between the rechargeable batteries in sequence based on a signal from the voltage measurement circuit, and the changeover switch. A display device that displays the discharge state of a rechargeable battery in conjunction with the mobile terminal device.