Optical assembly and projection devices using the same

A projection device comprising a light source and an optical assembly, the light source emitting light beams in a light path, the optical assembly being configured for cooperating with the light path for converting the light beam, wherein the optical assembly comprises:

• a color wheel comprising at least two color circles, wherein the at least two color circles are arranged concentrically and each comprises a plurality of color zones;
• a first drive assembly connected to the color wheel, wherein the first drive assembly is configured for driving the color wheel to rotate, and the plurality of color zones of each of the at least two color circles are illuminated by the light in the light path;
• a second drive assembly connected to the first drive assembly, wherein the second drive assembly is configured for driving the color wheel in a first direction, and each of the at least two color circles is illuminated a light beam defined by the light path, the first direction intersects with a directional extension of the light path.