Patent ID: 7801439

Claim:
An image taking device having a removable optical unit, comprising: an image taking device body; an optical unit having an optical axis that is detachable with respect to the image taking device body, and that is configured to be able to be displaced around the optical axis with respect to the image taking device body in a state where the optical unit is attached to the image taking device body; an attachment detection unit that is configured to detect attachment of the optical unit to the image taking device body; a displacement detecting unit that is configured to detect at least one of relative displacement amount and displacement direction of the optical unit around the optical axis with respect to the image taking device body in the state where the optical unit is attached to the image taking device body; and a control unit that is configured to turn on a power supply of the image taking device body when attachment of the optical unit to the image taking device body is detected by the attachment detection unit, to turn off the power supply of the image taking device body when attachment of the optical unit to the image taking device body is not detected by the attachment detection unit, and to switch the image taking device body between a photographing mode and a playback mode on a basis of information of at least one of the relative displacement amount and the displacement direction of the optical unit around the optical axis with respect to the image taking device body detected by the displacement detecting unit.