Portable information terminal and power supply control method therefor

• US 6,735,455 B2
• Filed: 12/20/2000
• Issued: 05/11/2004
• Est. Priority Date: 12/27/1999
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Yamaguchi, Syuji, Naito, Kosuke
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): Lee, John J
• Application Number:
  US09/739,875
• Publication Number:
  US 20010005686A1
• Time in Patent Office: 1,238 Days
• Field of Search: 455/574, 455/343.1, 455/555, 455/572, 455/573, 455/571, 455/566, 455/567, 455/556.2, 455/343.2, 455/343.15, 455/343.5, 455/343.6
• US Class Current: 455/574
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H04N 1/00307 with a mobile telephone apparatus constructional features of portable telephone sets H04M1/0202; mobile radio systems H04W84/00
• CPC Class Codes: H04N 1/00885 Power supply means, e.g. arrangements for the control of power supply to the apparatus or components thereof
• CPC Class Codes: H04N 1/00888 Control thereof
• CPC Class Codes: H04N 1/00899 Detection of supply level or supply failure
• CPC Class Codes: H04N 1/00904 Arrangements for supplying power to different circuits or for supplying power at different levels H04N1/00896 takes precedence
• CPC Class Codes: H04N 2201/001 Sharing resources, e.g. processing power or memory, with a connected apparatus or enhancing the capability of the still picture apparatus
• CPC Class Codes: H04N 2201/0096 Portable devices

Abstract

This invention relates to a portable information terminal having a plurality of functions such as a radio communication terminal unit, a data processing terminal unit, a digital camera unit, etc. The portable information terminal comprises a plurality of function processing units which respectively perform the functions; a battery which supplies electric power to the function processing units; a remaining battery charge detecting unit which detects remaining battery charge of the battery; and a power supply control unit. This power supply control unit compares the remaining battery charge with each of power supply limiting values determined in advance with respect to the function processing units, and, when the remaining battery charge becomes lower than at least one of the power supply limiting values of the function processing units, the power supply control unit stops power supply to the at least one of the function processing units and/or outputs warning signals.

Claims

1. A portable information terminal having a plurality of functions, comprising:

a plurality of function processing units, each function processing unit performing one of the functions;

a battery which supplies electric power to the function processing units;

a remaining battery charge detecting unit which detects remaining battery charge of the battery;

a power supply control unit which compares the remaining battery charge with each of power supply limiting values determined in advance with respect to the function processing units; and

an input unit for inputting a procedure to follow when the remaining battery charge becomes lower than at least one of the power supply limiting values of the function processing units, said procedure comprising at least one of stopping said power supply to at least one of the function processing units and outputting warning signals.

2. The portable information terminal according to claim 1, wherein said input unit comprises a user input setting.

3. The portable information terminal according to claim 1, wherein said power supply control unit retrieves said procedure for said function processing units.

4. The portable information terminal according to claim 1, wherein said function processing units comprise at least one of a radio communication terminal unit, a data processing terminal unit, and an image pick-up unit.

5. The portable information terminal according to claim 1, wherein said power supply control unit comprises a memory for storing said power supply limiting values.

6. The portable information terminal according to claim 1, wherein said power supply control unit controls a power supply from said battery to said function processing units based on signals outputted from said remaining battery charge detecting unit.

7. The portable information terminal according to claim 1, wherein said power supply limiting values comprise an operational range of 20% to 80% of a full battery charge.

8. The portable information terminal according to claim 1, wherein said power limiting values for each of said function processing units are inputted via said input unit.

9. The portable information terminal according to claim 1, wherein said power supply limiting values comprise a relative value based on said remaining battery charge.

10. The portable information terminal according to claim 1, further comprising:

an output unit for providing said warning signals,

wherein said warning signals comprise at least one of an image display warning signal, an audio warning signal and a vibrational warning signal.

11. The portable information terminal according to claim 1, wherein said power supply control unit inputs an instruction for performing a predetermined operation which temporarily cancels said operation of at least one of said function processing units.

12. The portable information terminal according to claim 1, wherein said stopping of said power supply comprises at least one of completely and partially stopping said power supply to at least one of said function processing units in order to maintain a minimum function of at least one of said function processing units.

13. The portable information terminal according to claim 1, wherein said power supply limiting values comprise at least 10 percent of said battery having 100% charge.

14. The portable information terminal according to claim 1, wherein said processing control unit inputs an instruction for performing a predetermined operation which temporarily cancels said operation of at least one of said function processing units.

15. A portable information terminal having a plurality of functions, comprising:

a plurality of function processing units, each function processing unit performing one of the functions;

a battery which supplies electric power to the function processing units;

a CPU which controls the function processing units;

a remaining battery charge detecting unit which detects remaining battery charge of the battery;

a processing control unit which compares the remaining battery charge with each of power supply limiting values determined in advance with respect to the function processing units; and

an input unit for inputting a procedure to follow when the remaining battery charge becomes lower than at least one of the power supply limiting values of the function processing units, said procedure comprising controlling the CPU so that the CPU restricts the operation of at least one of the function processing units.

16. The portable information terminal according to claim 15, wherein said power supply limiting values are inputted via said input unit.

17. A power supply control method for a portable information terminal having function processing units, each function processing unit performing one of a plurality of functions, comprising:

detecting a remaining battery charge of a battery which supplies electric power to the function processing units;

comparing the remaining battery charge with each of power supply limiting values determined in advance with respect to the function processing units; and

inputting a procedure to follow when the remaining battery charge becomes lower than at least one of the power supply limiting values of the function processing units, said procedure comprising at least one of stopping said power supply to at least one of the function processing units and outputting warning signals.

18. A power supply control method for a portable information terminal having function processing units, each function processing unit performing one of a plurality of the functions, comprising:

detecting a remaining battery charge of a battery which supplies electric power to the function processing units;

comparing the remaining battery charge with each of power supply limiting values determined in advance with respect to the function processing units; and

inputting a procedure to follow when the remaining battery charge becomes lower than at least one of the power supply limiting values of the function processing unit, said procedure comprising controlling a CPU, which controls the function processing units, so as to restrict the operation of at least one of the function processing units.