JP2001008376A - Apparatus and method for control of charging as well as apparatus with battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an apparatus which is provided with a battery and which prevents the degradation of the battery while maintaining the usage convenience of a user. SOLUTION: The usage start time of a battery 7 is set. The charging start time is found on the basis of the set usage start time and on the basis of a present battery voltage so as to be stored in a memory 22. The charging start time and the present time are compared by a comparator 23. A charging circuit 9 is controlled on the basis of a compared result. The battery 7 is charged. As a result, the degradation of the battery 7 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge control device and method, and a device having a battery, and more particularly to a charge control device and method for portable equipment and the like, and a device having a battery.

[0002]

2. Description of the Related Art Conventionally, portable telephones, PHS telephones,
Various portable devices such as a portable PC, a PDA, a camera, and a video deck have been realized. In many cases, a rechargeable secondary battery, particularly a lithium ion secondary battery, is used as an operation power supply of these devices.

In these devices, when a built-in secondary battery is discharged, charging is performed by attaching the secondary battery to a dedicated charger. When a charging control circuit is built in the portable device, charging is performed using power from an AC adapter.

[0004] As a charging method of a lithium ion secondary battery, the following has been realized. (1) When external power is supplied from the AC adapter, charging is started immediately. (2) Monitor the terminal voltage of the battery, and start charging when the terminal voltage drops to a predetermined value.

[0005] It is also known that when a lithium ion battery is stored in a fully charged state, its characteristics deteriorate. Specifically, the internal resistance is increased, and the battery usable time is shortened. It is known that a state of charge of about 50% is good in order to suppress deterioration and store.

[0006]

However, in the conventional charge control method described above, the storage characteristics of the lithium ion battery were not considered at all. Therefore, it will be left in a fully charged state from the completion of charging to the start of use,
In some cases, the battery deteriorated.

[0007] For example, in a commercial portable device, an AC adapter is connected when returning home at night, and the AC adapter is removed and used when going out in the morning. The standard use time of the lithium ion battery is, for example, about 3 hours. Therefore, in the conventional method (1), the battery is always left fully charged for several hours every day. Also, in the case of (2), since charging is started regardless of the connection time of the adapter, the time of full charge leaving is long in the usage as in the above example.

In order to avoid deterioration of the battery in such a situation, the user needs to take care to shorten the time of full charge, which is very troublesome.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and aims to improve the usability of a user and prevent the battery from deteriorating.
It is an object of the present invention to provide a suitable charge control device and method, and a device having a battery.

[0010]

In order to achieve the above object, a charging control device according to the present invention comprises a charging unit, a storage unit for storing a start time of use of a battery, and a storage unit for storing a time stored in the storage unit. Control means for controlling the charging means based on the control information.

[0011] Further, according to the charging control method of the present invention, a use start time of the battery is set, and based on the set time,
Control the charging circuit.

[0012] Further, the charging control method of the present invention sets a use start time of a battery, determines a charge start time by a charging circuit based on a current time and the use start time, and The charging circuit starts charging.

[0013] In addition, the charge control method according to the present invention sets a use start time of a battery, obtains a charge current by a charging circuit based on a current time and the use start time, and based on the obtained charge current, The charging circuit performs charging.

Further, an apparatus having a battery according to the present invention includes a storage means for storing an operation history of the apparatus, an estimation means for estimating a battery use start time from the stored operation history, and the battery based on the estimation means. Charge control means for charging the battery.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

(First Embodiment) <Structure of Entire Device> FIG. 1 is a block diagram showing a schematic structure of a portable information device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a CPU that controls the entire apparatus, and performs operations, I / O, and the like according to a program stored in a memory unit 2.
It performs processes such as control, communication, and display.

The memory unit 2 is composed of a primary storage element such as a RAM or a ROM, and a secondary storage element such as a hard disk device, and stores a control program of the CPU 1, user data, and the like.

Reference numeral 3 denotes a communication interface, which is a TCP
It performs data input / output with external devices in accordance with protocols such as / IP and IrDA. 4 is a liquid crystal display (LCD)
And display and output various data. Reference numeral 5 denotes a digitizer for inputting data from a user, and detects a position coordinate on the tablet specified by a dedicated pen.

Reference numeral 6 denotes a DCDC converter, which includes a battery and A
The input voltage from the C adapter is stabilized and supplied to each unit in the device. When the power is supplied from the AC adapter 8, the power from the AC adapter 8 is used, and otherwise, the power of the lithium ion battery 7 is used.

Reference numeral 7 denotes a lithium ion battery, which supplies operating power when the device is carried and used. 8 is AC
An adapter that converts an external AC voltage into a DC voltage and supplies the DC voltage to the device.

Reference numeral 9 denotes a charging circuit for charging the lithium ion battery 7 with electric power from the AC adapter 8. The charging circuit 9 of the present embodiment is of a constant current / constant voltage type and includes a constant current control circuit and a constant voltage control circuit. The constant current / constant voltage method is a known method for charging a lithium ion battery, and the description thereof is omitted. Reference numeral 10 denotes a charging control unit, which drives the charging circuit 9 according to an algorithm described later.

<Structure of Charge Control Unit 10> FIG. 2 is a block diagram showing the internal structure of the charge control unit 10, and the operation of the charge control unit will be described with reference to FIG.

In the figure, reference numeral 20 denotes an A / D converter, which measures the terminal voltage of the battery 7 by converting an analog voltage value of the lithium ion battery 7 into a digital value. Reference numeral 21 denotes a real-time clock which counts and outputs the current time. Reference numeral 22 denotes a time memory, and a CPU
The charge start time written from 1 is stored. Reference numeral 23 denotes a comparator, which includes a real-time clock 21 and a time memory 22.
Compare the output of If the two times match, a signal for turning on the charging circuit 9 is output.

Reference numeral 24 denotes an adapter detection unit which detects whether power is supplied from the AC adapter 8 and
An interrupt signal is generated to CPU1. The circuit of the detection unit may be constituted by a voltage comparator, and the A / D converter 2
A free channel of 0 may be used.

The charging operation in the above configuration will be described.

The charging start time is written in the time memory 22 when the A / C adapter is detected. When the output of the real-time clock 21 matches the content of the time memory 22, the comparator 23 generates an ON signal for the charging circuit 9. Charging circuit 9
Starts charging the battery 7 upon receiving the ON signal. In this way, charging is started at the set charging start time. When the battery is fully charged, the charging is completed.

<Processing Flow When Adapter is Detected> FIG.
5 is a flowchart illustrating a flow of a process when an adapter is detected, and a process of setting a charging start time will be described with reference to FIG.

Prior to the processing, the user specifies the use time of the device (battery) and stores it in the memory 2. For example, A
If the user goes out at M10: 00, the time is set by inputting AM10: 00 using a dedicated pen.

When the A / C adapter 8 is inserted into the apparatus, the adapter detecting section 24 generates an interrupt signal to the CPU 1, and the following processing is started.

At step S100, the CPU 1 executes A / D
The battery voltage is detected through the converter 20. Subsequently, in step S101, a time required for full charge is calculated based on the current battery voltage value. The relationship between the battery voltage value and the required charging time may be tabulated and searched.

Next, in step S102, a charging start time is calculated. This is obtained by subtracting the required charging time from the preset battery use start time.

In step S103, the charging start time is set in the time memory 22, and the process ends.

Thereafter, the charging process is performed as described above.

If the disconnection of the adapter is detected before the end of charging, a process for inhibiting generation of a charging ON signal is performed (not shown).

As described above, according to the present embodiment, the charging start time is calculated when the adapter is inserted, and the charging start is delayed until that time, so that the battery is fully charged just at the battery use start time. be able to. This will prevent you from being left in a fully charged state,
Battery deterioration can be prevented.

(Second Embodiment) In the first embodiment, the charging start time is calculated when the adapter is inserted, and the charging start is delayed until that time. In the present embodiment, an example will be described in which the time until the battery use start time is calculated when the adapter is inserted, and the charging current is controlled accordingly.

The configuration of the apparatus according to this embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

<Structure of Charge Control Unit 10> In this embodiment, the internal structure of the charge control unit 10 is partially different from that of the first embodiment.

FIG. 5 is a block diagram showing the internal configuration of the charge control unit 10. The operation of the charge control unit will be described with reference to FIG.

Reference numeral 25 denotes a current selector for switching the charging current of the charging circuit 9.

<Processing Flow When Adapter is Detected> FIG.
5 is a flowchart illustrating a flow of a process at the time of adapter detection, and a process of setting a charging current will be described with reference to FIG.

Prior to the process, the user specifies the battery use start time and stores it in the memory 2 as in the first embodiment.

When the A / C adapter 8 is inserted, the adapter detecting section 24 generates an interrupt signal to the CPU 1, and the following processing is started.

In step S200, the CPU 1 executes A / D
The battery voltage is detected through the converter 20. In step S201, a charging current is calculated. That is, the capacity required for charging is obtained from the battery voltage value. The current time is subtracted from the battery use start time, and a current value at which the required capacity can be fully charged is calculated at this time interval. If the time interval is long, the charging current is set low, and if the time interval is short, the charging current is set high. This may be tabulated as in the first embodiment.

In step S202, the calculated charging current value is set in the current selector 25, and the process ends.

Thereafter, the charging process is performed as described above.

As described above, according to this embodiment,
By setting the charging current in accordance with the time during which the A / C adapter is inserted, it is possible to control the battery to be fully charged just at the battery use start time. As a result, since the battery is not left in a fully charged state, deterioration of the battery can be prevented.

When the time is long, the charging can be performed with a small current, which is economical.

(Third Embodiment) In the above-described embodiment, the case where the user specifies the battery use start time has been described. In the present embodiment, an example will be described in which the battery use start time is estimated and the battery is fully charged at the estimated time. The average value of the daily A / C adapter removal time is controlled as an estimated value of the battery use start time.

The configuration of the apparatus according to this embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

<Structure of Charge Control Unit 10> FIG. 6 is a block diagram showing the internal structure of the charge control unit 10. The operation of the charge control unit will be described with reference to FIG.

Reference numeral 30 denotes a time memory, which records the time at which the A / C adapter 8 was removed. For example, the past 3
Stores 0 times of removal. Reference numeral 31 denotes a time calculation unit that estimates and outputs a charging start time. In the present embodiment, the average value of the data stored in the time memory 30 is calculated and used as the estimated value of the battery use start time. A value obtained by subtracting the time required for charging from this value is output as an estimated value of the charging start time.

A comparator 32 compares the output of the real-time clock 21 with the output of the time calculator 31. If the two times match, a signal for turning on the charging circuit 9 is output.

As described above, according to the present embodiment, by setting the charging current according to the time during which the A / C adapter is inserted, the battery is controlled to be fully charged just at the battery use start time. be able to. This prevents the battery from being left in a fully charged state, thereby preventing the battery from deteriorating.

In addition, since the battery use start time is estimated from the past use history, the user does not need to set the time. Therefore, the usability of the user can be further improved.

In this embodiment, an example in which the charging start time is controlled has been described. However, the charging current may be controlled as in the second embodiment.

Although the average value is used as the method of estimating the battery use start time, other estimation methods such as a mode value and a median value can be widely used. Alternatively, the earliest time may be set as the set time to prevent charging. Further, various types of weighting may be performed. For example, the newer the data, the greater the weight may be. The weight may be divided into weekdays and holidays in consideration of the day of the week information.

The recording medium storing the program according to the present embodiment is supplied to a system or an apparatus, and the computer of the system or apparatus reads out and executes the program code stored in the recording medium to execute the present embodiment. Is achieved.

[0059]

As described above, according to the present invention, deterioration of the battery can be prevented by setting the use start time in advance and controlling the battery to be fully charged at the set time.

Further, by predicting the battery use start time from the use history of the device and controlling the battery to be fully charged at the predicted time, the usability of the user is further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a portable information device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an internal configuration of a charge control unit 10 according to the first embodiment.

FIG. 3 is a flowchart illustrating a flow of processing when an adapter is detected in the first embodiment.

FIG. 4 is a flowchart illustrating a flow of processing when an adapter is detected in the second embodiment.

FIG. 5 is a block diagram showing an internal configuration of a charge control unit 10 according to a second embodiment.

FIG. 6 is a block diagram illustrating an internal configuration of a charge control unit 10 according to a third embodiment.

[Explanation of symbols]

 1 CPU 2 Memory 5 Digitizer 6 DCDC Converter 7 Lithium-ion Battery 8 A / C Adapter 9 Charging Circuit 10 Charge Control Unit 20 A / D Converter 21 RTC 22 Time Memory 23 Comparator 24 Adapter Detector 25 Current Selector 30 Time Memory 31 Time Calculation unit 32 Comparator

Claims (10)

[Claims] 1. A charging device comprising: a charging unit; a storage unit configured to store a use start time of a battery; and a control unit configured to control the charging unit based on the time stored in the storage unit. Charge control device. 2. The control apparatus according to claim 1, further comprising: a calculating unit configured to determine a charging start time by the charging unit based on a current time and the use starting time. The charging control device according to claim 1, wherein charging is started by controlling a control unit. 3. The control device according to claim 1, further comprising: a calculating unit configured to calculate a charging current by the charging unit based on a current time and the use start time, wherein the control unit determines the charging current based on the charging current determined by the calculating unit. The charge control device according to claim 1, wherein the control is performed so as to perform charging. 4. A charging control method comprising: setting a use start time of a battery; and controlling a charging circuit based on the set time. 5. A use start time of a battery is set, a charge start time by a charging circuit is obtained based on a current time and the use start time, and the charge circuit starts charging at the obtained charge start time. A charge control method characterized by the above-mentioned. 6. A method for setting a use start time of a battery, obtaining a charge current by a charging circuit based on a current time and the use start time, and performing charging by the charge circuit based on the obtained charge current. Characteristic charge control method. 7. An apparatus having a battery, wherein: storage means for storing an operation history of the apparatus; estimating means for estimating a battery use start time from the stored operation history; and estimating the battery based on the estimating means. An apparatus having a battery, comprising: charge control means for charging. 8. The apparatus according to claim 7, wherein said estimating means calculates an average value of the data stored in said storage means.
An apparatus having the battery according to claim 1. 9. A charging unit for calculating a charging start time based on a current time and the use start time, wherein the charging control unit starts charging at the charging start time obtained by the calculating unit. An apparatus having a battery according to claim 7. 10. A charging device for calculating a charging current based on a current time and the use start time, wherein the charging control device controls charging based on the charging current calculated by the calculating device. An apparatus having a battery according to claim 7.