Abstract: A projection lens includes a lens that is made of a resin, a first holding frame that holds the lens, and a second holding frame that is not in contact with the lens and holds the first holding frame; and a thermal expansion coefficient of the first holding frame is higher than a thermal expansion coefficient of the second holding frame.

Abstract: A lens unit 10 includes: a second lens 14 that is received in a lens barrel 18; and a lens holding ring 20 that is formed in a shape of a ring, is fitted into the lens barrel 18, includes lens receiving portions 24AS formed on an inner peripheral surface 24A thereof at three or more different positions in a circumferential direction, and allows the second lens 14 to be fitted into the lens holding ring while the second lens 14 is received by the lens receiving portions 24AS.

Abstract: A lens unit is provided that includes: a first lens that is housed inside a lens-barrel, the first lens including a first lens section and a first flange section that juts out from the first lens section in a direction orthogonal to an optical axis direction; a second lens that is housed inside the lens-barrel further toward an imaging plane side than the first lens, the second lens including a second lens section and a second flange section that juts out from the second lens section in a direction orthogonal to the optical axis direction; and a spacing ring that is sandwiched between the first lens and the second lens and that defines a spacing between the first lens and the second lens, the spacing ring includes a main body disposed between the first flange section and the second flange section in the optical axis direction, first protrusion portions that protrude in the optical axis direction from an object side of the main body, and second protrusion portions that protrude in the optical axis direction fr

Abstract: A lens unit 10 includes: a second lens 14 that is received in a lens barrel 18; and a lens holding ring 20 that is formed in a shape of a ring, is fitted into the lens barrel 18, includes lens receiving portions 24AS formed on an inner peripheral surface 24A thereof at three or more different positions in a circumferential direction, and allows the second lens 14 to be fitted into the lens holding ring while the second lens 14 is received by the lens receiving portions 24AS.

Abstract: A lens unit is provided that includes: a first lens that is housed inside a lens-barrel, the first lens including a first lens section and a first flange section that juts out from the first lens section in a direction orthogonal to an optical axis direction; a second lens that is housed inside the lens-barrel further toward an imaging plane side than the first lens, the second lens including a second lens section and a second flange section that juts out from the second lens section in a direction orthogonal to the optical axis direction; and a spacing ring that is sandwiched between the first lens and the second lens and that defines a spacing between the first lens and the second lens, the spacing ring includes a main body disposed between the first flange section and the second flange section in the optical axis direction, first protrusion portions that protrude in the optical axis direction from an object side of the main body, and second protrusion portions that protrude in the optical axis direction fr

Abstract: An actuator which drives a lens frame in an optical axis direction is constructed by piezoelectric elements, driving members, and a pressing spring. The piezoelectric elements are placed at opposite sides with a driven plate therebetween, and the driving members are fixed to the respective piezoelectric elements. The driving members are pressed against the driven plate from both sides by the pressing spring.

Abstract: The rear projection lens device comprises a fixed lens barrel, a first lens barrel having a front lens group, a second lens barrel having a rear lens group, and a rotation stopper. The first lens barrel is helicoid-coupled with the fixed lens barrel, and moves in an optical axial direction by rotating relative to the fixed lens barrel. The second lens barrel is helicoid-coupled with the first lens barrel and moves in the optical axial direction so as to change an interval between the front lens group and the rear lens group when the first lens barrel rotates. The rotation stopper allows the second lens barrel to move in the optical axial direction, but stops the rotation around the optical axis. A zoom adjustment and aberration correction associated with the zoom adjustment are conducted concurrently only by rotating the first lens barrel.

Abstract: A lens supporting frame is provided and includes a lens holder supporting a lens and a moving frame which is fitted to a cylindrical part of the lens holder to support the same. Ribs are provided at equal intervals in a rotation direction on a rear end face of the lens holder, the ribs having a plurality of inclined surfaces inclined respectively toward the front or rear ends of an optical axis. Abutting parts are provided on a rear end face of the moving frame so as to abut on the ribs. When the lens holder is rotated after mounting it in the moving frame, parts of the lens holder facing the abutting parts are moved in directions along the optical axis as a result of abutment between the inclined surfaces of the ribs and the abutting parts to change the inclination of the lens holder relative to the optical axis.

Abstract: An actuator of the present invention comprises a piezoelectric element, one end face of the piezoelectric element in a displacement direction being supported by a fixing member, a block shaped driving member attached to the other end face of the piezoelectric element in the displacement direction, and a driven member frictionally engaged with at least one end face of the driving member in a direction orthogonal to the displacement direction, the driven member being extended along the displacement direction.

Abstract: An image displayed on a liquid crystal panel is projected on a projection surface by a projection lens such that the optical axis of the projection lens is perpendicular to the projection surface. An optical axis of a distance measurement light and an optical axis of a light receiving lens are each inclined a specified angle with respect to the optical axis of the projection lens to be not perpendicular to the projection surface so as to reduce noise caused by specularly reflected light that otherwise would be detected by the distance measurement unit when a highly reflective whiteboard is utilized as the projection surface. The distance measurement unit is formed by unitizing a light emitting element, a light emitting lens, the light receiving lens, and a light receiving element, and the distance measurement unit is held with the projection lens by a common holder.

Abstract: A lens device includes a plurality of lens groups, a lens holder for holding each lens group, a cam barrel for receiving the lens holder therein so as to allow axial movement of the lens holder, and a cam mechanism having cam slots formed in the cam barrel and cam followers provided on the lens holder in slide engagement with the cam slots, respectively, through which rotation of the cam barrel causes the axial movement of the lens holder. The lens holder includes a lens mounting frame for fixedly mounting the lens group therein; and a union collar fixedly coupled to the lens mounting frame; and the cam followers are fix to the union collar.

Abstract: A lens supporting frame is provided and includes a mirror chamber supporting a lens and a moving frame which is fitted to a cylindrical part of the mirror chamber to support the same. Ribs are provided at equal intervals in a rotation direction on a rear end face of the mirror chamber, the ribs having a plurality of inclined surfaces inclined respectively toward the front or rear ends of an optical axis. Abutting parts are provided on a rear end face of the moving frame so as to abut on the ribs. When the mirror chamber is rotated after mounting it in the moving frame, parts of the mirror chamber facing the abutting parts are moved directions along the optical axis as a result of abutment between the inclined surfaces of the ribs and the abutting parts to change the inclination of the lens relative to the optical axis.

Abstract: An actuator which drives a lens frame in an optical axis direction is constructed by piezoelectric elements, driving members, and a pressing spring. The piezoelectric elements are placed at opposite sides with a driven plate therebetween, and the driving members are fixed to the respective piezoelectric elements. The driving members are pressed against the driven plate from both sides by the pressing spring.

Abstract: An actuator of the present invention comprises a piezoelectric element, one end face of the piezoelectric element in a displacement direction being supported by a fixing member, a block shaped driving member attached to the other end face of the piezoelectric element in the displacement direction, and a driven member frictionally engaged with at least one end face of the driving member in a direction orthogonal to the displacement direction, the driven member being extended along the displacement direction.

Abstract: The rear projection lens device comprises a fixed lens barrel, a first lens barrel having a front lens group, a second lens barrel having a rear lens group, and a rotation stopper. The first lens barrel is helicoid-coupled with the fixed lens barrel, and moves in an optical axial direction by rotating relative to the fixed lens barrel. The second lens barrel is helicoid-coupled with the first lens barrel and moves in the optical axial direction so as to change an interval between the front lens group and the rear lens group when the first lens barrel rotates. The rotation stopper allows the second lens barrel to move in the optical axial direction, but stops the rotation around the optical axis. A zoom adjustment and aberration correction associated with the zoom adjustment are conducted concurrently only by rotating the first lens barrel.

Abstract: An image displayed on a liquid crystal panel is projected on a projection surface by a projection lens. An optical axis of a projection lens is perpendicular to the projection surface. However, alight emitting optical axis of a distance measurement light and an optical axis of a light receiving lens is inclined with respect to the optical axis of a projection lens, not to be perpendicular to the projection surface. A distance measurement unit is formed by unitizing a light emitting element, a light emitting lens, the light receiving lens, and a light receiving element, and the distance measurement unit is held with the projection lens by a common holder. Even if a surface like a whiteboard which has high reflectivity is used as the projection surface, high accuracy of the distance measurement is kept because diffused light from the light emitting lens, which is regularly reflected from the projection surface, is away from an effective photodetecting region of the light receiving element.