| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optical device constituted so that image data showing a high-quality image may be acquired or the high-quality image may be projected by surely removing minute dust or the like with simpler constitution. <P>SOLUTION: The optical device for an imaging unit or a projection type image display apparatus or the like is equipped with: an image forming body including image forming elements 133, 135 and 137 or an imaging element 27; an optical system 12a disposed ahead of the image forming body; a dust-proof member 21 arranged between the optical system and the image forming body and having a transmission part 21c capable of transmitting luminous flux for an image, wherein the transmission part is arranged to be opposed to the image forming body at a predetermined interval; an excitation member 18d performing stretching vibration so as to give the vibration in nearly perpendicular direction to a direction going along the optical axis of the optical system to the dust-proof member; and a control means 41 performing driving control for the excitation member so that vibration speed given to the dust-proof member may differ between when the excitation member is elongated and when it is contracted. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
