Patent ID: 8322865

Claim:
A projection apparatus comprising: an illumination system capable of emitting an illumination beam; a light valve disposed in the transmission path of the illumination beam and capable of converting the illumination beam into an image beam; a color filtering module disposed in the transmission path of the illumination beam between the illumination system and the light valve and comprising a plurality of colored filters and a gray filter, wherein the gray filter is capable of reducing the intensity of the illumination beam passing through the gray filter; an image processing unit capable of receiving an image signal; and a controlling unit electrically connected to the image processing unit and the color filtering module; wherein the controlling unit commands the color filtering module to make the colored filters move into the transmission path of the illumination beam in sequence and make the time for the gray filter passing through the transmission path of the illumination beam less than the time for any of the colored filters passing through the transmission path of the illumination beam when the image processing unit judges that the average brightness of the image signal is greater than or equal to a first reference brightness.