Projection device with brightness adjustment function and method thereof

A projection device with a brightness adjustment function comprising:

• three polarization beam splitters (3-PBS);
• three displays for displaying the same images;
• three light source mechanisms for respectively emitting light to the 3-PBS;
• the 3-PBS for respectively reflecting a portion of the light to the three displays, and transmitting a remaining portion of the light;
• a light integrating element for integrating the images from the three displays;
• a lens module for projecting the integrated images;
• a power supply unit for supplying power for the three light source mechanisms;
• a light detection unit for respectively acquiring three digital values of the light transmitted from the 3-PBS, and comparing the three digital values with a predetermined digital value to generate three control signals;
• and
• a power controller for adjusting power from the power supply unit to the three light source mechanisms according to the three control signals until the three digital values respectively match the predetermined digital value of the light from the three light source mechanisms.

A method with an illumination adjustment function implemented by a projection device;

• wherein the projection device comprises a light source, a polarization beam splitter (PBS), and a power supply unit, the method comprising:
• emitting light to the PBS;
• acquiring a digital value of the light transmitted from the PBS, and comparing the digital value with a predetermined digital value to generate a control signal;
• and
• adjusting power from the power supply unit to the light source according the control signal until the digital value matches the predetermined digital value of the light from the light source.