Optical module

An optical module comprising:

• a driving unit having a rotating shaft;
• a first color wheel fixed on the rotating shaft, the first color wheel comprising a plurality of first filters;
• a second color wheel freely disposed on the rotating shaft, the second color wheel comprising a plurality of second filters;
• a first electromagnet disposed on the first color wheel;
• a plurality of first magnets disposed on the second color wheel, a north pole of at least one of the first magnets facing the first color wheel, a south pole of at least another one of the first magnets facing the first color wheel;
• and
• a polarity control unit electrically connected to the first electromagnet;
• wherein the driving unit drives the first color wheel to rotate, such that the first electromagnet rotates along with the first color wheel;
• the polarity control unit controls a direction of current flow in the first electromagnet to control a polarity of the first electromagnet, such that the first electromagnet attracts one of the first magnets during rotation to drive the second color wheel to rotate along with the first color wheel.