Patent attributes
A focusing mechanism, including a positioning seat, a focus ring, a lens, and a knob is provided. The lens has an optical axis. The positioning seat has a first surface, a second surface opposite to the first surface, and a sliding groove penetrating the first surface and the second surface. The focus ring is slidably and rotatably disposed on the second surface of the positioning seat. The lens is fixed to the focus ring. The focus ring has a positioning hole and is located between the positioning seat and the lens. The positioning hole is aligned to the sliding groove in a direction perpendicular to the optical axis. The knob passes through the sliding groove and is inserted into the positioning hole. The knob is pressed against the first surface of the positioning seat. A projection device is also provided.
