Mechanism with component position adjusting function

A mechanism with a component position adjusting function, comprising:

• a drive unit rotating alternatively in a first direction and a second direction being opposite to the second direction;
• a drive shaft with an end fixed to the drive unit and driven by the drive unit to rotate;
• a plate body having a unidirectional component disposed at a center of the plate body, and the unidirectional component having a through hole, and the other end of the drive shaft being passed through the through hole and exposed from a side of the plate body, and the drive shaft synchronously driving the plate body to perform a rotation in the first direction through a limitation of the unidirectional component;
• at least one passive component disposed on the plate body, wherein each passive component has a first containing portion penetrated through the passive component and accommodating an optical element comprising a polarization element, a cylindrical lens, a grating, an optical lens, a filter waveplate, an optical attenuator or a diffraction element;
• a drive wheel fixed to the drive shaft and exposed from an end of the plate body, and the drive shaft synchronously driving the drive wheel to rotate;
• at least one fixing component disposed onto the drive wheel and corresponding to the at least one passive component;
• and
• a brake disposed at a position corresponding to a height of the plate body, and the plate body remaining still through a rotation of the unidirectional component in the second direction and a contact of the brake with the plate body;
• wherein in response to that the drive unit drives the drive shaft to rotate in the first direction, the drive shaft synchronously rotates with the plate body and switches one of the at least one passive component to a predetermined position;
• in response to that the drive unit drives the drive shaft to rotate in the second direction, the plate body would not rotate with the drive shaft in the second direction and the drive shaft synchronously rotates with the drive wheel to rotate the at least one passive component.