Information processing apparatus suitably controlling activation and stoppage of power consumption reducing function and power consumption controlling method of the apparatus

• US 20020099962A1
• Filed: 11/13/2001
• Published: 07/25/2002
• Est. Priority Date: 01/25/2001
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nakamura, Koji
• Application Number:
  US10/011,699
• Publication Number:
  US 20020099962A1
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode

Abstract

A microcomputer has a power consumption reducing function which may be activated and de-activated with a time delay provided by a hysteresis current. The microcomputer communicates with a memory incorporated in a battery pack. It reads from the memory the rated discharge current data specific to the battery pack, and stores it as a first predetermined value which corresponds to a current value at which the power consumption reducing function is activated. The power microcomputer subtracts the hysteresis current (defined as the maximum value of the reduced discharge current of the battery pack while the power consumption reducing function is active) from the first predetermined value, and stores the calculated value as a second predetermined value which corresponds to a current value at which the power consumption reducing function is de-activated. The hysteresis current prevents rapid cycling through activation and de-activation of the power consumption reducing function.

Claims

1. An information processing apparatus with a power consumption reducing function to temporarily reduce power consumption, the information processing apparatus being adapted to be driven by a battery and comprising:

measuring means for measuring a discharge current value of the battery;

first determining means for determining whether the discharge current value measured by the measuring means exceeds a first predetermined value;

second determining means for determining whether the discharge current value measured by the measuring means is less than a second predetermined value, which is smaller than the first predetermined value; and

control means for activating the power consumption reducing function if the first determining means determines that the discharge current measured by the measuring means exceeds the first predetermined value, and after the power consumption reducing function is activated, stopping the power consumption reducing function if the second determining means determines that the discharge current value measured by the measuring means is less than the second predetermined value.

2. An information processing apparatus according to claim 1, wherein the microprocessor retrieves battery data from the battery and calculates said first and second predetermined values based, at least in part, on said battery data, and wherein said information processing apparatus further comprises storing means for storing the first and second predetermined values.

3. An information processing apparatus according to claim 2, wherein the second predetermined value stored in the storing means is a value obtained by subtracting from a rated discharge current value of the battery a hysteresis current value equal to a maximum discharge current reduction value of the battery when the power consumption reducing function is activated.

4. An information processing apparatus according to claim 3, wherein the hysteresis current value is equal to {(a maximum value of a power consumption of a CPU mounted on the information processing apparatus)×

(a reduction ratio of a CPU speed when the power consumption reducing function is active)}/(a battery discharge termination voltage)/(a power efficiency)+(a predetermined margin value).

5. An information processing apparatus with a power consumption reducing function to temporarily reduce power consumption, comprising:

measuring means for measuring a discharge current value of a power source which supplies power to operate the information processing apparatus;

first determining means for determining whether the discharge current value measured by the measuring means exceeds a first predetermined value;

second determining means for determining whether the discharge current value measured by the measuring means is less than a second predetermined value, which is smaller than the first predetermined value; and

control means for activating the power consumption reducing function if the first determining means determines that the discharge current measured by the measuring means exceeds the first predetermined value, and after the power consumption reducing function is activated, stopping the power consumption reducing function if the second determining means determines that the discharge current value measured by the measuring means is less than the second predetermined value.

6. A power consumption control method of an information processing apparatus with a power consumption reducing function to temporarily reduce power consumption, the information processing apparatus being capable of driven by a battery, said method comprising:

measuring a discharge current value of the battery;

determining whether the measured discharge current value exceeds a first predetermined value;

activating the power consumption reducing function if it is determined that the measured discharge current value exceeds the first predetermined value;

determining whether the measured discharge current value is less than a second predetermined value, which is smaller than the first predetermined value; and

after the power consumption reducing function is activated, stopping the power consumption reducing function if it is determined that the measured discharge current value is less than the second predetermined value.

7. A power consumption control method according to claim 6, wherein the second predetermined value is a value obtained by subtracting from a rated discharge current value of the battery a hysteresis current value equal to a maximum discharge current reduction value of the battery when the power consumption reducing function is activated.

8. A power consumption control method according to claim 7, wherein the hysteresis current value is equal to {(a maximum value of a power consumption of a CPU mounted on the information processing apparatus)×

(a reduction ratio of a CPU speed when the power consumption reducing function is active)}/(a battery discharge termination voltage)/(a power efficiency)+(a predetermined margin value).

9. A power consumption control method of an information processing apparatus with a power consumption reducing function to temporarily reduce power consumption, said method comprising:

measuring a discharge current value of the battery;

determining whether the measured discharge current exceeds a first predetermined value;

activating the power consumption reducing function if it is determined that the measured discharge current value exceeds the first predetermined value;

determining whether the measured discharge current value is less than a second predetermined value, which is smaller than the first predetermined value; and

after the power consumption reducing function is activated, stopping the power consumption reducing function if it is determined that the measured discharge current value is less than the second predetermined value.

10. An information processing apparatus with a power consumption reducing function to temporarily reduce power consumption, the information processing apparatus adapted to be driven by a battery and comprising:

measuring means for measuring a discharge current value of the battery;

storing means for storing a plurality of predetermined values used to control activation and stoppage of the power consumption reducing function; and

control means for controlling the activation and stoppage of the power consumption reducing function based on the discharge current value measured by the measuring means and the plurality of predetermined values stored in the storing means.

11. An information processing apparatus with a power consumption reducing function to temporarily reduce power consumption, the information processing apparatus being adapted to be driven by a battery and comprising:

a measuring circuit for measuring a discharge current value of the battery;

said microprocessor operative for determining whether the discharge current value measured by the measuring circuit exceeds a first predetermined value;

said microprocessor operative for determining whether the discharge current value measured by the measuring means is less than a second predetermined value, which is smaller than the first predetermined value; and

a control device, including said microprocessor for activating the power consumption reducing function if the microcomputer determines that the discharge current measured by the measuring circuit exceeds the first predetermined value, and after the power consumption reducing function is activated, stopping the power consumption reducing function if the microcomputer determines that the discharge current value measured by the measuring device is less than the second predetermined value.

12. An information processing apparatus according to claim 11, further comprising a memory, accessible by said microcomputer, for storing the first and second predetermined values.

13. An information processing apparatus according to claim 12, wherein the second predetermined value stored in the memory is a value obtained by subtracting from a rated discharge current value of the battery a hysteresis current value equal to a maximum discharge current reduction value of the battery when the power consumption reducing function is activated.

14. An information processing apparatus according to claim 13, wherein the hysteresis current value is equal to {(a maximum value of a power consumption of a CPU mounted on the information processing apparatus)×

(a reduction ratio of a CPU speed when the power consumption reducing function is active)}/(a battery discharge termination voltage)/(a power efficiency)+(a predetermined margin value).

17. An information processing apparatus as recited in claim 16, wherein said information processing apparatus retrieves battery data from said battery and calculates said plurality of predetermined values based, at least in part, on said retrieved battery data.

15. An information processing apparatus with a power consumption reducing function to temporarily reduce power consumption, comprising:

a measuring circuit for measuring a discharge current value of a power source which supplies power to operate the information processing apparatus;

a first determining device for determining whether the discharge current value measured by the measuring circuit exceeds a first predetermined value;

a second determining device for determining whether the discharge current value measured by the measuring circuit is less than a second predetermined value, which is smaller than the first predetermined value; and

a control device for activating the power consumption reducing function if the first determining device determines that the discharge current measured by the measuring circuit exceeds the first predetermined value, and after the power consumption reducing function is activated, stopping the power consumption reducing function if the second determining device determines that the discharge current value measured by the measuring circuit is less than the second predetermined value.

16. An information processing apparatus with a power consumption reducing function to temporarily reduce power consumption, the information processing apparatus adapted to be driven by a battery and comprising:

a measuring device for measuring a discharge current value of the battery;

a storing device for storing a plurality of predetermined values used to control activation and stoppage of the power consumption reducing function; and

a control device for controlling the activation and stoppage of the power consumption reducing function based on the discharge current value measured by the measuring device and the plurality of predetermined values stored in the storing device.