Cooling device of electronic apparatus

• US 6,781,258 B2
• Filed: 09/18/2001
• Issued: 08/24/2004
• Est. Priority Date: 12/22/2000
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Hashimoto, Eiji
• Primary Examiner(s): DEBERADINIS, ROBERT L
• Application Number:
  US09/954,038
• Publication Number:
  US 20020079746A1
• Time in Patent Office: 1,071 Days
• Field of Search: 307/85, 307/87, 307/130, 307/140, 307/149, 307/116, 307/117, 361/696
• US Class Current: 307/87
• CPC Class Codes: G06F 1/206 comprising thermal management

Abstract

A control device of a cooling device controls a fan based on a desired temperature around a CPU set by a target value setting unit and a temperature detected by a temperature detecting unit, so that the temperature around the CPU substantially coincides with the set desired temperature. When the detected temperature exceeds the desired temperature, the control device causes the fan to rotate. At this time, the control device monitors the level of a noise generated by the fan by means of the noise detecting unit. The control device increases the value of the voltage supplied to the fan within a range in which the detected noise does not vary abruptly. As a result, the rotation speed is gradually increased to a predetermined value without causing an abrupt rise of a noise, which may acutely irritate the user.

Claims

1. A cooling device of an electronic apparatus comprising:

a temperature sensor;

a cooling fan;

a noise detecting unit configured to detect a sound pressure of a noise generated by the cooling fan; and

a fan control unit configured to control a rotation speed of the cooling fan based on a detection result of the temperature sensor and a detection result of the noise detecting unit,

wherein the noise detecting unit detects a change in the sound pressure per unit time, and

wherein the fan control unit controls the rotation speed of the cooling fan such that the change in the sound pressure per unit time detected by the noise detecting unit does not exceed a predetermined reference value.

2. A cooling device of an electronic apparatus comprising:

a cooling fan; and

a fan control unit configured to control a rotation speed of the cooling fan such that the rotation speed is increased stepwise at predetermined intervals by stepwise increasing a voltage supplied to the cooling fan when the fan control unit causes the cooling fan to operate, and the rotation speed is decreased stepwise at predetermined intervals by stepwise decreasing a voltage supplied to the cooling fan when the control unit causes the cooling fan to stop.