Imaging device having an optical image stabilizer

1. An imaging device comprising:

a photographing optical system including an image sensor positioned at an imaging position of said photographing optical system;

an image stabilizer configured to detect vibration applied to said photographing optical system and to move said image sensor in a plane orthogonal to an optical axis of said photographing optical system to counteract image shake in accordance with a direction and a magnitude of said vibration;

a movable unit comprising a holder body, a sealing member, and a pressure plate, said image sensor being positioned between said sealing member and said pressure plate;

a rearmost lens group comprising a filter positioned between a flange on an inner surface of said holder body and said sealing member in front of said image sensor, and further comprising a rearmost lens element positioned in front of said filter and supported by said holder body at a front end of said holder body,

wherein said filter and said sealing member in front of said image sensor provide a dust resistant environment for a light-receptive surface of said image sensor, and

wherein said image sensor and said rearmost lens group are integrally moved by said image stabilizer.

2. The imaging device according to claim 1 , further comprising:

a first moving frame configured to hold said holder body and being linearly movable in a first direction in said plane that is orthogonal to said optical axis; and

a second moving frame configured to hold said first moving frame and being linearly movable in a second direction perpendicular to said first direction in said plane that is orthogonal to said optical axis.

3. The imaging device according to claim 1 , further comprising a radially-retracting device configured to move said movable unit to a radially-retracted position, at which said movable unit is radially retracted away from said optical axis along a direction perpendicular to said optical axis beyond a predetermined range of movement of said movable unit for image stabilization, when said imaging device changes from a photographic state to a non-photographing state.

4. The imaging device according to claim 3 , wherein, when said movable unit is at said radially-retracted position, another optical element of said photographing optical system enters a space in which said movable unit is positioned at a photographing position at which said movable unit is located on said optical axis in said photographic state.

5. The imaging device according to claim 4 , wherein said another optical element is positioned in front of said movable unit on said optical axis in said photographic state.

6. The imaging device according to claim 1 , wherein said rearmost lens element is mounted to said holder body, independently of said sealing member.