Patent ID: 7990706

Claim:
A cooling duct for cooling heat generating elements inside a casing with outside air, the cooling duct comprising: an intake vent through which outside air taken in from outside the casing is drawn; a guiding unit configured to guide the outside air drawn through the intake vent to a first target element being a heat generating element to be cooled; a discharge vent through which the outside air guided by the guiding unit is discharged to the first target element; and a branch pipe provided in the guiding unit and configured to guide part of the outside air flowing in the guiding unit downward to a second target element located below the guiding unit, wherein the branch pipe includes: an internal branch pipe located inside the guiding unit and having a branch vent for taking in part of the outside air flowing inside the guiding unit; and an external branch pipe located outside the guiding unit and configured to guide the outside air taken in through the internal branch pipe to the second target element, and wherein the external branch pipe has a notch for discharging part of the outside air taken in through the internal branch pipe to a third target element located near the second target element and being a heat generating element to be cooled.