text: 1. Field of the Invention
  The present invention relates to an imaging device and an optical device.
  2. Description of the Related Art
  In recent years, in a lens interchangeable digital camera and the like, there are problems such that dust is shown in a taken image due to accretion of the dust on a surface of a filter of an image pick-up element. In order to solve such problems, a system has been developed wherein an anti-dust member is provided between an image pick-up element and an optical system to ensure dust-prevention for the image pick-up element and filters as well as removing the attached dust on the anti-dust member by vibration (refer to JP Patent Publication No. 2003-319222).
  However, according to conventional systems, since the anti-dust member is a circular shape, for covering the image pick-up element, an anti-dust member having large size is necessary which is contrary to a requirement for downsizing of the image pick-up device. Also, in the conventional systems, because a vibration mode of the anti-dust member is not considered, it has been difficult to remove the attached dust on a asurface of the anti-dust member effectively.