Dustproof structure of communication device, using air filter having distributed dust collecting efficiency and pressure loss

Claim 1

A dustproof structure of a communication device, comprising: a cabinet having an air inlet for introducing the air and an air outlet for expelling the air, wherein at least one printed circuit board of the communication device is mounted in the cabinet; at least one fan mounted in the cabinet; and an air filter assembly, provided between the fan and the air inlet, for preventing dust from entering the inside of the cabinet; said air filter assembly having a first and second plurality of air filters of different dust collection efficiency and wherein the outside air is drawn in by the fan through the air filter assembly into the cabinet so that the printed circuit board is cooled; and the dust collecting efficiency and the pressure loss of the air filter assembly are not uniform, and have a distribution such that an area of the air filter assembly closer to the fan, within which the air flow is concentrated, has a higher dust collecting efficiency provided by said first plurality of air filters, and another area farther from the fan has a lower pressure loss provided by said second plurality of air filters; said first and second plurality of air filters being selectively attached to said frame assembly.