Air guiding structure and projecting device incorporating the same

An air guiding structure is applied in a projecting device. The projecting device at least includes an optical element. The air guiding structure includes a first side wall and a second side wall. The first side wall having a first opening is disposed near a side of the optical element. The second side wall having a second opening is disposed near the other side of the optical element. Furthermore, the first side wall and the second side wall are connected to each other. The air is guided into the first opening, circulated through the optical element and is vented out via the second opening.