Electronic apparatus having cooling unit for cooling heat-generating component

1. An electronic apparatus comprising:

a housing containing a heat-generating component; and

a cooling unit contained in the housing, the cooling unit including a heat sink thermally connected to the heat-generating component, a first air passage which guides air outside the housing to the heat sink and guides air heated by heat exchange with the heat sink to an outside of the housing, and a second air passage which guides air within the housing to the outside of the housing.

2. An electronic apparatus according to claim 1 , wherein the housing includes inlets at an located upstream end of the first air passage, a first outlet located at a downstream end of the first air passage, and a second outlet located at a downstream end of the second air passage.

3. An electronic apparatus according to claim 1 , wherein the housing includes an upper surface, and a peripheral wall extending from an outer peripheral edge of the upper surface, the inlets being formed in the upper surface and the peripheral wall of the housing, respectively.

4. An electronic apparatus according to claim 1 , wherein the heat-generating component includes a first element and at least one second element, the first element generating a larger amount of heat than the second element.

5. An electronic apparatus according to claim 4 , wherein the heat sink is thermally connected to the first element.

6. An electronic apparatus comprising:

a housing having a first outlet and a second outlet;

a heat-generating component contained in the housing; and

a cooling unit contained in the housing, the cooling unit including a first air passage facing to the first outlet, a second air passage facing to the second outlet, a fan which guides air outside the housing into the first air passage, and also guides air within the housing into the second air passage, and a heat sink thermally connected to the heat-generating component, the heat sink being cooled by air flowing through the first air passage.

7. An electronic apparatus according to claim 6 , wherein the housing includes inlets which guides air outside the housing into the housing, and external air introduction passages facing to the respective inlets, the fan includes a fan casing having suction ports, and an impeller contained in the fan casing, the impeller introducing air into the fan casing through the suction ports, the suction ports of the fan casing having respective first areas facing to the external air introduction passages, and respective second areas facing to an interior of the housing.

8. An electronic apparatus according to claim 7 , wherein the external air introduction passages are isolated from the interior of the housing.

9. An electronic apparatus according to claim 7 , wherein the first areas of the suction ports are larger than the second areas.

10. An electronic apparatus according to claim 7 , wherein the impeller of the fan is located between the first and second air passages and surrounded by the upstream ends of the first and second air passages, the first and second air passages extending in different directions with respect to the fan casing.

11. An electronic apparatus according to claim 10 , wherein the fan casing has a partition wall which isolates the upstream end of the first air passage from the upstream end of the second air passage.

12. An electronic apparatus according to claim 6 , wherein the heat-generating component includes a first element and at least one second element, the first element generating a larger amount of heat than the second element, and the heat sink being thermally connected to the first element.

13. An electronic apparatus according to claim 6 , wherein the housing includes a wall in which the first outlet is formed, and another wall in which the second outlet is formed.

14. An electronic apparatus according to claim 6 , wherein the heat sink is interposed between the fan and the first outlet.