Projection device

A projection device, comprising:

• a light source module, an optical engine module, a projection lens and a housing, wherein:
• the light source module is adapted to emit an illumination beam,
• the optical engine module is disposed on a transmission path of the illumination beam and adapted to receive the illumination beam and form an image beam,
• the projection lens is disposed on a transmission path of the image beam and adapted to receive the image beam and project the image beam to an outside of the projection device, and
• the housing has a bottom portion, a top portion opposite to the bottom portion, and a side wall connected between the bottom portion and the top portion, the side wall surrounds the top portion and the bottom portion, the side wall has an air inflow region adjacent to the bottom portion and an air exhaust region adjacent to the top portion, and wherein the light source module, the optical engine module and the projection lens are disposed in the housing and the light source module, the optical engine module and the projection lens are adjacent to the top portion, a distance between the projection lens and the bottom portion is greater than a distance between the projection lens and the top portion, and the projection lens is adapted to project the image beam to the outside of the projection device toward the bottom portion of the housing.