Electronic device and fan controlling method

Abstract

According to one embodiment, an electronic device includes a fan, a temperature sensor and a controller. The temperature sensor is configured to output a value indicative of a detected temperature. The controller is configured to control a rotational speed of the fan. The controller is configured to keep the rotational speed of the fan constant when the value is within a first temperature zone or to change the rotational speed of the fan when the values is within a second temperature zone.

What is claimed is: 
     
         1 . An electronic device comprising:
 a fan;   a temperature sensor configured to output a value indicative of a detected temperature; and   a controller configured to control a rotational speed of the fan,   wherein the controller is configured to keep the rotational speed of the fan constant when the value is within a first temperature zone or to change the rotational speed of the fan when the values is within a second temperature zone.   
     
     
         2 . The device of  claim 1 , wherein the controller is configured to calculate, when the value is in the second temperature zone, the rotational speed of the fan corresponding to a temperature between a lower-limit temperature and an upper-limit temperature based on a lower rotational speed associated with the lower-limit temperature of the second temperature zone and an upper rotational speed of the upper-limit of the second temperature zone. 
     
     
         3 . The device of  claim 2 , wherein the controller is configured to calculate the rotational speed of the fan corresponding to the temperature between the lower-limit temperature and the upper-limit temperature by using an interpolation formula to interpolate the rotational speed of the fan linearly between the lower rotational speed and the upper rotational speed. 
     
     
         4 . The device of  claim 2 , wherein the controller is configured to calculate the rotational speed of the fan corresponding to the temperature between the lower-limit temperature and the upper-limit temperature by using an interpolation formula to interpolate the rotational speed of the fan curvilinearly between the lower rotational speed and the upper rotational speed. 
     
     
         5 . The device of  claim 2 , wherein the controller is configured to set whether a first interpolation formula or a second interpolation formula to calculate the rotational speed of the fan corresponding to the temperature between the lower-limit temperature and the upper-limit temperature, the first interpolation formula to interpolate the rotational speed of the fan linearly between a lower rotational speed of the fan associated with the lower-limit temperature and an upper rotational speed of the fan associated with the upper-limit temperature, and the second to interpolate the rotational speed of the fan curvilinearly between the lower rotational speed and the upper rotational speed. 
     
     
         6 . The device of  claim 1 , wherein the controller is configured to set the rotational speed of the fan when the detected value detected by the temperature sensor shifts from rising to falling or from falling to rising, and when a difference between a previously detected temperature and a currently detected temperature exceeds a first value, and to set the rotational speed of the fan during a time when the detected value detected by the temperature sensor is falling, to the rotational speed of the fan associated with a second value which is reduced by the first value, as compared to the set rotational speed of the fan during a time when the detected value is rising. 
     
     
         7 . A fan controlling method of an electronic device, the method comprising:
 detecting a temperature; and   controlling a rotational speed of a fan to keep the rotational speed of the fan constant when the detected temperature is within a first temperature zone or to change the rotational speed of the fan when the detected temperature is within a second temperature zone.   
     
     
         8 . The method of  claim 7 , wherein the controlling comprises calculating, when the detected temperature is in the second temperature zone, the rotational speed of the fan corresponding to a temperature between a lower-limit temperature and an upper-limit temperature based on a lower rotational speed associated with the lower limit of the second temperature zone and an upper rotational speed associated with the upper limit of the second temperature zone. 
     
     
         9 . The method of  claim 8 , wherein the controlling comprises calculating the rotational speed of the fan corresponding to the temperature between the lower-limit temperature and the upper-limit temperature by using an interpolation formula to interpolate the rotational speed of the fan linearly between the lower rotational speed and the upper rotational speed. 
     
     
         10 . The method of  claim 8 , wherein the controlling comprises calculating the rotational speed of the fan corresponding to the temperature between the lower-limit temperature and the upper-limit temperature by using an interpolation formula to interpolate the rotational speed of the fan curvilinearly between the upper rotational speed and the upper rotational speed. 
     
     
         11 . The method of  claim 8 , wherein the controlling comprises determining whether a first interpolation formula or a second interpolation formula is to be used to calculate the rotational speed of the fan corresponding to the temperature between the lower-limit temperature and the upper-limit temperature in the second temperature zone, the first interpolation formula to interpolate the rotational speed of the fan linearly between the lower rotational speed and the upper rotational speed, and the second interpolation formula to interpolate the rotational speed of the fan curvilinearly between the lower rotational speed and the upper rotational speed. 
     
     
         12 . The method of  claim 7 , wherein the controlling comprises setting the rotational speed of the fan when the detected temperature shifts from rising to falling or from falling to rising, and when a difference between a previously detected temperature and a currently detected temperature exceeds a first value, and setting the rotational speed of the fan during a time when the detected temperature is falling, to the rotational speed of the fan associated with a second value which is reduced by the first value, as compared to the set rotational speed of the fan during a time when the detected temperature is rising.