Portable telephone with built-in charger

• US 6,246,890 B1
• Filed: 07/28/1997
• Issued: 06/12/2001
• Est. Priority Date: 08/02/1996
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kunitomo, Kouichi, Sato, Takehiko
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): Trinh, Sonny
• Application Number:
  US08/901,604
• Time in Patent Office: 1,415 Days
• Field of Search: 320/113, 320/111, 320/114, 320/115, 320/116, 320/118, 320/127, 320/132, 320/134, 455/127, 455/572, 455/573, 455/343, 455/574, 455/38.3
• US Class Current: 455/573
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H04B 1/3883 Arrangements for mounting batteries or battery chargers
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

A portable telephone comprises a charging circuit for charging a battery with an external power supply, a voltage detector for detecting a terminal voltage of the battery, a memory storing charge-restart threshold voltages and charge-restart times corresponding to various use-states of the telephone, and a controller for monitoring the use-state of the telephone, selecting the optimum one of the charge-restart threshold voltage and optimum one of the charge-restart times in accordance with the use-state of the telephone, and carrying out timing control to recharge the battery.

Claims

1. A portable telephone using a chargeable battery as a power source, comprising:

a charging circuit for charging said battery with an external power supply;

a voltage detector for detecting a terminal voltage of said battery;

a memory having charging condition data stored therein in advance corresponding to various use-states of said telephone during discharge of said battery; and

a controller for monitoring the use-state of said telephone during discharge of said battery, selecting an optimum one of the charging condition data corresponding to the use-state at that time, and carrying out timing control during recharge of said battery.

2. The portable telephone as claimed in claim 1, wherein said charging condition data is charge-restart threshold voltages corresponding to various use-states of said telephone.

3. The portable telephone as claimed in claim 1, wherein said charging condition data is charge-restart times corresponding to various use-states of said telephone.

4. The portable telephone as claimed in claim 1, wherein said charging condition data is charge-restart threshold voltages and charge-restart times corresponding to various use-states of said telephone.

5. A portable telephone using a chargeable battery as a power source, comprising:

a charging circuit for charging said battery with an external power supply;

a voltage detector for detecting a terminal voltage of said battery;

a use-state monitor for detecting a present use-load state of said portable telephone during discharge of said battery;

a memory having charge-restart threshold voltages and charge-restart times stored therein in advance corresponding to various use-load states of said portable telephone during discharge of said battery;

a timer which starts upon completion of charging of said portable telephone; and

a controller which selects one of said charge-restart threshold voltages and one of said charge-restart times from said memory corresponding to the use-load state when said use-state monitor detects a change in the use-load state of said portable telephone, restarts said charging circuit when the voltage detected by said voltage detector is not higher than the selected charge-restart threshold voltage or when a count of said timer exceeds the selected charge-restart time, and finishes charge when the voltage detected by said voltage detector exceeds a predetermined full-charge threshold value.