Charge Control Apparatus and Charge Control Method For Portable Telephone Terminal

• US 20080113691A1
• Filed: 12/27/2005
• Published: 05/15/2008
• Est. Priority Date: 01/06/2005
• Status: Abandoned Application

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Otsuki, Michihito
• Application Number:
  US11/794,568
• Publication Number:
  US 20080113691A1
• Time in Patent Office: Days
• US Class Current: 455/573
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

There is provided a charge control apparatus and a charge control method for a portable telephone terminal in which an operation to charge a battery is controlled according to a voltage of the battery and a use state of the user to prevent generation of heat in the portable telephone terminal due to the operation with consumption of a large current. The use state judge circuit 111 determines whether a sufficient voltage is being applied from an AC adapter 102 to the battery 109, temporarily stops the battery charge to supply the current only to the load circuit 107 if the consumption current consumed by the load circuit 107 is large and a sufficient current is not supplied to the battery 109, thereby suppressing the heat generated when a sufficient current cannot be supplied to the battery 109. Also, it is possible to prevent the restriction of the use of the load circuit 107 due to the heat generation or the insufficient current.

Claims

1. A charge control apparatus for a portable telephone terminal for supplying operation power to a load circuit possessed by the portable telephone terminal and for charging a battery incorporated in the terminal, comprising:

a battery voltage detector that detects a battery voltage;

a charge current detector that detects a charge current to charge the battery;

a load current detector that detects a load current used for the load circuit; and

a charge controller that controls the charge to the battery, wherein

the charge controller comprises

a timer that measures a period of time in which the battery voltage detected by the battery voltage detector means is equal to or less than a predetermined voltage, and

a use state judge circuit that determines whether the period of time measured by the timer means has reached a predetermined time, and

the charge controller stops the charge to the battery and supplies a current only to the load circuit if it is determined that the period of time measured by the timer means has reached the predetermined time.

2. The charge control apparatus for a portable telephone terminal in accordance with claim 1, wherein the charge to the battery is restarted if the charge current detected by the charge current detector is equal to or less than a predetermined current.

3. The charge control apparatus for a portable telephone terminal in accordance with claim 1, wherein the charge controller supplies quite a small current to the battery before the charge is started and determines whether the voltage detected by the battery voltage detector is a voltage for which it is determined that the battery requires the charge.

4. The charge control apparatus for a portable telephone terminal in accordance with claim 1, wherein the charge controller applies a termination voltage to the load circuit during the charge to the battery is stopped.

5. The charge control apparatus for a portable telephone terminal in accordance with claim 1, further comprising a first diode for preventing an inverse current to an external power source.

6. The charge control apparatus for a portable telephone terminal in accordance with claim 1, further comprising a second diode for supply a current from the external power source and the battery to the load circuit during the charge to the battery is stopped.

14. The charge control apparatus for a portable telephone terminal in accordance with claim 2, wherein the charge controller supplies quite a small current to the battery before the charge is started and determines whether the voltage detected by the battery voltage detector is a voltage for which it is determined that the battery requires the charge.

15. The charge control apparatus for a portable telephone terminal in accordance with claim 2, wherein the charge controller applies a termination voltage to the load circuit during the charge to the battery is stopped.

16. The charge control apparatus for a portable telephone terminal in accordance with claim 3, wherein the charge controller applies a termination voltage to the load circuit during the charge to the battery is stopped.

17. The charge control apparatus for a portable telephone terminal in accordance with claim 2, further comprising a first diode for preventing an inverse current to an external power source.

18. The charge control apparatus for a portable telephone terminal in accordance with claim 3, further comprising a first diode for preventing an inverse current to an external power source.

19. The charge control apparatus for a portable telephone terminal in accordance with claim 4, further comprising a first diode for preventing an inverse current to an external power source.

20. The charge control apparatus for a portable telephone terminal in accordance with claim 2, further comprising a second diode for supply a current from the external power source and the battery to the load circuit during the charge to the battery is stopped.

7. A charge control method for use with a charge control apparatus comprising battery voltage detector means for detecting a battery voltage, charge current detector means for detecting a charge current to charge the battery, load current detector means for detecting a load current used for the load current, and charge control means for controlling the charge to the battery, for supplying operation power to a load circuit possessed by the portable telephone terminal and for charging a battery incorporated in the terminal,

the charge control method comprising:

a step of measuring a period of time in which the battery voltage detected by the battery voltage detector means is equal to or less than a predetermined voltage,

a use state judge step of determining whether the period of time measured by the timer means has reached a predetermined time, and

a step of stopping the charge to the battery and supplying a current only to the load circuit if it is determined that the period of time measured by the timer means has reached the predetermined time.

8. The charge control method for a portable telephone terminal in accordance with claim 7, further comprising a step of restarting the charge to the battery if the charge current detected by the charge current detector means is equal to or less than a predetermined current.

9. The charge control method for a portable telephone terminal in accordance with claim 7, further, wherein the charge control means comprises:

a step of supplying quite a small current to the battery before the charge is started; and

a step of determining whether or not the voltage detected by the battery voltage detector means is a voltage for which it is determined that the battery requires the charge.

10. The charge control method for a portable telephone terminal in accordance with claim 7, wherein the charge control means applies a termination voltage to the load circuit during the charge to the battery is stopped.

11. The charge control apparatus for a portable telephone terminal in accordance with claim 7, further comprising a first diode for preventing an inverse current to an external power source.

12. The charge control apparatus for a portable telephone terminal in accordance with claim 7, further comprising a second diode for supply a current from the external power source and the battery to the load circuit during the charge to the battery is stopped.

13. A charge control apparatus for a portable telephone terminal for supplying operation power to a load circuit possessed by the portable telephone terminal and for charging a battery incorporated in the terminal, comprising:

battery voltage detector means for detecting a battery voltage;

charge current detector means for detecting a charge current to charge the battery;

load current detector means for detecting a load current used for the load circuit; and

charge control means for controlling the charge to the battery, wherein

the charge control means comprises

timer means for measuring a period of time in which the battery voltage detected by the battery voltage detector means is equal to or less than a predetermined voltage, and

use state judge means for determining whether the period of time measured by the timer means has reached a predetermined time, and

the charge control means stops the charge to the battery and supplies a current only to the load circuit if it is determined that the period of time measured by the timer means has reached the predetermined time.