Actuator for tilting reflecting mirror of digital micromirror device for digital light processing type projection

An actuator for tilting a reflecting mirror disposed, digital light processing (DLP) type projection such that the reflecting mirror changes a reflecting angle of the light according to an image signal, wherein the actuator comprises:

• a base having an inner space defined therein;
• a mirror holder comprising a fixing part fixed to the base, and a horizontal part integrally connected with the fixing part by a resilient connection part, the mirror holder being provided with at least one resilient member for resiliently supporting the reflecting mirror upward;
• a mirror supporting unit comprising a cover attached to the upper surface of the horizontal part, and a mirror stopper disposed between the horizontal part and the cover while surrounding the frame of the reflecting mirror;
• a tilting unit comprising an actuating member, whose upper end comes into contact with the horizontal part, for transmitting vertical reciprocating movement to the horizontal part, and a tilting stopper, whose upper end comes into contact with the horizontal part, for restricting the tiling angle of the horizontal part;
• and
• a horizontal adjusting unit comprising at least one adjustment screw, whose lower end contacts the mirror stopper through at least one adjustment hole formed at the cover such that the mirror stopper spaced apart by a predetermined gap from the horizontal part is exposed upward through the adjustment hole, for adjusting flatness of the reflecting mirror.