Abstract: A lens unit includes a correction lens that corrects movement of a focus position of an optical system, a holding frame that holds the lens, a stationary tube that movably supports the frame along a direction of an optical axis, a movement guide portion that is provided between the tube and the frame in a radial direction of the tube and limits rotation of the frame in a direction intersecting with a plane orthogonal to the optical axis and guides movement of the frame in the direction of the optical axis, bimetals that are provided between the tube and the frame in the direction of the optical axis and change a distance between the frame and the tube along the direction of the optical axis, and a first biasing means that relatively biases the frame against the tube via the movement guide portion in the radial direction of the tube.

Abstract: A lens unit includes a correction lens that corrects movement of a focus position of an optical system, a holding frame that holds the lens, a stationary tube that movably supports the frame along a direction of an optical axis, a movement guide portion that is provided between the tube and the frame in a radial direction of the tube and limits rotation of the frame in a direction intersecting with a plane orthogonal to the optical axis and guides movement of the frame in the direction of the optical axis, bimetals that are provided between the tube and the frame in the direction of the optical axis and change a distance between the frame and the tube along the direction of the optical axis, and a first biasing means that relatively biases the frame against the tube via the movement guide portion in the radial direction of the tube.

Abstract: A lens barrel and a lens unit of the present invention each include a cam drum having a cam groove, a lens holding frame for holding a moving lens group, and a cam follower installed on an outer periphery of the lens holding frame. The cam groove has two groove side walls, and an inclined wall that extends outward in a radial direction of the cam drum from one of the two groove side walls to the other thereof, and the cam follower has a contact member that contacts the inclined wall and a cam follower main unit respectively, and a biasing member that biases the contact member outward in the radial direction.

Abstract: A lens barrel and a lens unit of the present invention each include a cam drum having a cam groove, a lens holding frame for holding a moving lens group, and a cam follower installed on an outer periphery of the lens holding frame. The cam groove has two groove side walls, and an inclined wall that extends outward in a radial direction of the cam drum from one of the two groove side walls to the other thereof, and the cam follower has a contact member that contacts the inclined wall and a cam follower main unit respectively, and a biasing member that biases the contact member outward in the radial direction.

Abstract: A high-expansion compensating member and a low-expansion compensating member respectively have contact surfaces that make contact with each other in a state inclined with respect to the optical axis such that, when a variation in temperature causes the high-expansion compensating member to expand or contract in the direction perpendicular to the optical axis, the low-expansion compensating member is displaced in the optical axis direction. As the low-expansion compensating member is displaced in the optical axis direction, a compensator lens holding frame and a compensator lens move in the optical axis direction, and thereby a displacement in focal position occurring in an image-taking lens due to a variation in temperature is compensated for.