Patent attributes
A wavelength conversion module and a projection device are provided. The wavelength conversion module includes a rotating member and a light sensing element. The rotating member includes a shaft and a positioning structure. An excitation beam forms a first spot on the rotating member. The shaft is located at the center of the rotating member. The positioning structure is located on the rotating member. The light sensing element is disposed adjacent to the rotating member for emitting a sensing beam toward a first surface of the rotating member, wherein the sensing beam forms a second spot on the rotating member. A first connecting line is formed by connecting the first spot and the shaft, a second connecting line is formed by connecting the second spot and the shaft, and an angle between the first connecting line and the second connecting line is greater than 30 degrees.
