Bi-directional excitation color wheel and light source system thereof

A bi-directional excitation color wheel, comprising:

• a first working surface, comprising a first working ring and a second working ring which are concentric rings, the first working ring comprising a first translucent region and a green fluorescent region, the second working ring comprising a second translucent region;
• and
• a second working surface, which is of the same size with the first working surface, comprising a third working ring and a fourth working ring which are concentric rings, the third working ring comprising a third translucent region, the fourth working ring comprising a fourth translucent region and a first fluorescent region;
• wherein, the angle of the third translucent region is equal to the sum of the angles of the fourth translucent region and the first fluorescent region, and the fourth translucent region and the first fluorescent region are continuously distributed;
• the angle extension lines, which pass through the center of a circle, of the ring where the fourth translucent region and the first fluorescent region are located fall within the third translucent region;
• the first translucent region and the third translucent region are the same translucent region, and the second translucent region and the fourth translucent region are the same translucent region.