Patent ID: 8427533

Claim:
An image pickup apparatus that varies optical properties by moving a part of lenses of an objective lens, the image pickup apparatus comprising: a solid-state image pickup device unit that is arranged at a rear-end section and that subjects a subject image to photoelectric conversion; a fixed lens frame that retains the objective lens that is disposed to the front of the solid-state image pickup device unit; a movable lens frame that retains the part of lenses that moves along a photographing optical axis inside the fixed lens frame; and an actuator that moves the movable lens frame forward and backward, the actuator including: a rod-shaped rigid member that has one end connected to the movable lens frame; a shape memory alloy that is coupled to the rod-shaped rigid member; a guide pipe into which the rod-shaped rigid member is insertedly fitted in a condition in which the rod-shaped rigid member can move forward and backward, the guide pipe being fixed to the fixed lens frame and rectilinearly guiding the rod-shaped rigid member in a photographing optical axis direction of the solid-state image pickup device unit; and a fixing member that fixes an axial position of the guide pipe in the fixed lens frame in a condition in which the axial position of the guide pipe can be varied within a clearance in a circumferential direction of the guide pipe, the clearance being formed between the guide pipe and the fixed lens frame.