Patent ID: 8753086

Claim:
A blower fan, comprising: an impeller; a motor arranged to drive the impeller; a base portion arranged to support the motor; and a housing arranged to surround an outer circumference of the impeller; wherein the impeller includes: a substantially cylindrical cup portion arranged to rotate about a center axis; a plurality of blades fixed to an outer circumferential surface of the cup portion and arranged to rotate with the cup portion to draw air from a first axial side and to discharge the air to a second axial side; and a substantially annular connector portion arranged to interconnect the plurality of blades; the connector portion is provided with a substantially cylindrical shape in a position spaced apart about 70% to about 90% of a radial length of the blades from a base of each of the blades on the outer circumferential surface of the cup portion, and a ratio of a total axial height of the connector portion to a total radial gap between the outer circumferential surface of the cup portion and an inner circumferential surface of the connector portion is substantially equal to or smaller than about 0.9; and an axial intake side end of the connector portion is substantially flush with axial intake side ends of the blades in areas of the blades connected by the connector portion, and the total axial height of the connector portion is smaller than a total axial height of the blades.