Portable information terminal and power supply control method therefor

• US 20010005686A1
• Filed: 12/20/2000
• Published: 06/28/2001
• Est. Priority Date: 12/27/1999
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Yamaguchi, Syuji, Naito, Kosuke
• Granted Patent: US 6,735,455 B2
• Time in Patent Office: Days
• 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 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 which 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, stops power supply to the at least one of the function processing units and/or outputs warning signals.

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

a plurality of function processing units which respectively perform 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; and

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, when the remaining battery charge becomes lower than at least one of the power supply limiting values of the function processing units, controls the CPU so that the CPU restricts the operation of the at least one of the function processing units.

3. A power supply control method for a portable information terminal having function processing units which respectively perform a plurality of functions, comprising:

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

comparing 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, stopping power supply to the at least one of the function processing units and/or outputting warning signals.

4. A power supply control method for a portable information terminal having function processing units which respectively perform 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

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