Information processing apparatus and cooling control method

1. An information processing apparatus comprising:

a main body;

a heating device provided in the main body;

a cooling fan provided in the main body, the cooling fan to cool the heating device;

a temperature sensor provided in the main body, the temperature sensor to sense a temperature of the heating device;

a fan control unit provided in the main body, the fan control unit to (i) rotate the cooling fan at a first rotation speed or higher during power-on of the information processing apparatus, the first rotation speed being a value within a rotation speed range which allows the cooling fan to rotate at a constant speed, and (ii) switch a rotation speed of the cooling fan to a second rotation speed which is higher than the first rotation speed when the temperature of the heating device sensed by the temperature sensor reaches a threshold value; and

a threshold value control unit to (i) set the threshold value to a first value when the information processing apparatus is set in a performance mode in which performance has higher priority than power saving and the cooling fan is used for cooling the heating device and (ii) set the threshold value to a second value which is higher than the first value when the information processing apparatus is set in a power-saving mode in which power saving has higher priority than performance and the cooling fan is used for cooling the heating device, the threshold value, the first value and the second value being temperature values,

wherein the fan control unit

supplies the cooling fan with a control signal having a first control signal value for rotating the cooling fan at a start up rotation speed upon power-on of the information processing apparatus,

monitors a rotation speed of the cooling fan, and

when the monitored rotation speed reaches a minimum value of the rotation speed range, changes a value of the control signal from the first control signal value to a second control signal value for rotating the cooling fan at a first rotation speed, the start up rotation speed being higher than the first rotation speed.

2. The information processing apparatus according to claim 1 , wherein the fan control unit includes a rotation speed setting unit which sets the rotation speed of the cooling fan at the first rotation speed before an operating system is booted up.

3. The information processing apparatus according to claim 1 , wherein the heating device is a central processing unit (CPU).

4. The information processing apparatus according to claim 1 , wherein the heating device is a display controller which controls a display device.

5. The information processing apparatus according to claim 1 , wherein the heating device is a central processing unit (CPU), and further comprising:

a power supplier determination unit which determines which of a battery and an external power supply drives the information processing apparatus;

a threshold value control unit which sets the threshold value to a first value when the main body is driven by the external power supply and sets the threshold value to a second value which is higher than the first value when the main body is driven by the battery; and

an operation speed control unit which performs an operation speed control process to decrease an operation speed of the central processing unit (CPU) in accordance with a temperature of the central processing unit (CPU) sensed by the temperature sensor when the main body is driven by the battery.

6. A cooling control method of cooling a heating device provided in an information processing apparatus, the method comprising:

sensing a temperature of the heating device by a temperature sensor;

performing a fan control process (i) to rotate a cooling fan, which cools the heating device, at a first rotation speed during power-on of the information processing apparatus, the first rotation speed being a value within a rotation speed range which allows the cooling fan to rotate at a constant speed, and (ii) to switch a rotation speed of the cooling fan to a second rotation speed which is higher than the first rotation speed when the temperature of the heating device sensed by the temperature sensor reaches a threshold value;

setting the threshold value to a first value when the information processing apparatus is set in a performance mode in which performance has higher priority than power saving and the cooling fan is used for cooling the heating device; and

setting the threshold value to a second value which is higher than the first value when the information processing apparatus is set in a power-saving mode in which power saving has higher priority than performance and the cooling fan is used for cooling the heating device, the threshold value, the first value and the second value being temperature values,

wherein the fan control process is performed

to supply the cooling fan with a control signal having a first control signal value for rotating the cooling fan at a start up rotation speed upon power-on of the information processing apparatus,

to monitor a rotation speed of the cooling fan, and

when the monitored rotation speed reaches a minimum value of the rotation speed range, to change a value of the control signal from the first control signal value to a second control signal value for rotating the cooling fan at a first rotation speed, the start up rotation speed being higher than the first rotation speed.

7. The method according to claim 6 , wherein the fan control process includes a process of setting the rotation speed of the cooling fan at the first rotation speed before an operating system is booted up.

8. The method according to claim 6 , wherein the heating device is a central processing unit (CPU), and further comprising:

determining which of a battery and an external power supply drives the information processing apparatus;

setting the threshold value to a first value when the information processing unit is driven by the external power supply and setting the threshold value to a second value which is higher than the first value when the information processing unit is driven by the battery; and

performing an operation speed control process to decrease an operation speed of the central processing unit (CPU) in accordance with a temperature of the central processing unit (CPU) sensed by a temperature sensor when the information processing unit is driven by the battery.

9. An apparatus comprising:

a cooling fan;

a temperature sensor; and

a fan control unit in communication with the cooling fan and the temperature sensor, the fan control unit to (i) rotate the cooling fan at a first rotation speed during power-on of the apparatus, the first rotation speed being a value within a rotation speed range which allows the cooling fan to rotate at a constant speed, and (ii) switch a rotation speed of the cooling fan to a second rotation speed that is higher than the first rotation speed when the temperature sensed by the temperature sensor reaches a threshold value; and

a threshold value control unit to (i) set the threshold value to a first value when the apparatus is set in a performance mode in which performance has higher priority than power saving and the cooling fan is used for cooling the heating device and (ii) set the threshold value to a second value which is higher than the first value is set in a power-saving mode in which power saving has higher priority than performance and the cooling fan is used for cooling the heating device, the threshold value, the first value and the second value being temperature values,

wherein the fan control unit

supplies the cooling fan with a control signal having a first control signal value for rotating the cooling fan at a start up rotation speed upon power-on of the information processing apparatus,

monitors a rotation speed of the cooling fan, and

when the monitored rotation speed reaches a minimum value of the rotation speed range, changes a value of the control signal from the first control signal value to a second control signal value for rotating the cooling fan at a first rotation speed, the start up rotation speed being higher than the first rotation speed.

10. The apparatus according to claim 9 , wherein the temperature sensor to sense the temperature of a heating device.

11. The apparatus according to claim 10 , wherein the heating device is a central processing unit.

12. The apparatus according to claim 10 , wherein the heating device is a display controller which controls a display device.