PROBLEM TO BE SOLVED: To reduce noise of a centrifugal fan to be used for heat radiation of a portable computer.;SOLUTION: A centrifugal fan 10 includes a casing, a heat sink arranged at an opening part of a side wall 11c of the casing, and a plurality of blades arranged around a rotary shaft. An air flow passage 23 is formed between the blade outer circumference 25 drawn by fore ends of the plurality of blades, and an inner surface of the side wall. A rectifying projection 200 is arranged in a range from the position defined by a line 203 at which the width of the air flow passage is rapidly expanded on the inner wall of the casing to the position defined by the line 205.;COPYRIGHT: (C)2013,JPO&INPIT
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