| 摘要 |
A projection device with a brightness adjustment function includes a polarization beam splitter (PBS), a light source, a reflective display, a lens module, a power supply unit, a light detection unit and a power controller. The light source emits light to the PBS. The PBS reflects a portion of the light to the reflective display, and transmits a remaining portion of the light. The lens module projects the images. The light detection unit acquires a digital value of a portion of the light reflected by the PBS that is not received by the reflective display, and compares the digital value with a predetermined digital value to generate a control signal. The power controller for adjusts power from the power supply unit to the light source according to the control signal until the digital value matches the predetermined digital value of the light from the light source. |
