Abstract: An optical diaphragm device includes: diaphragm blades each including a first fixing boss and a moving boss protruding from the other surface of a first planar plate toward a side in a second direction; light leakage prevention blades each having a second fixing boss and forming a pair with the diaphragm blade; a drive ring on which first cam grooves are formed; and a housing body capable of housing the diaphragm blades, the light leakage prevention blades, and the drive ring. A second cam groove is further formed in the light leakage prevention blade, the moving boss of the diaphragm blade is inserted into the second cam groove of the light leakage prevention blade, and is inserted into the first cam groove of the drive ring. The light leakage prevention blade has a light leakage prevention blade extending portion which extends toward the other side from the second fixing boss.

Abstract: A lens barrel is provided with: a stationary barrel having a large-diameter section and a recessed section which is recessed further toward the inner diameter side than the large-diameter section; a printed circuit board which is mounted so that at least part thereof is disposed along the outer peripheral surface of the stationary barrel; movable barrels positioned further toward the outer diameter side than the stationary barrel and moving relative to the stationary barrel; and a cable member having flexibility which allows the cable member to deform flexibly, the cable member being provided with a mounting section which is mounted on the printed circuit board, and also with a passage section which passes between the printed circuit board and the stationary barrels.

Abstract: An optical diaphragm device includes a plurality of diaphragm blades including a first fixing boss protruding from one surface of a first planar plate toward a side in a first direction; and a moving boss protruding from another surface of the first planar plate toward a side in a second direction. The optical diagram device includes a plurality of light leakage prevention blades including a second fixing boss protruding from one surface of a second planar plate toward the side in the first direction. The optical diagram device includes a drive ring including a plurality of first cam grooves; a housing body capable of accommodating the diaphragm blades, the light leakage prevention blades, and the drive ring. A second cam groove is in the light leakage prevention blade. The moving boss is in the second cam groove, and is in the first cam groove.

Abstract: An optical diaphragm device includes: diaphragm blades each including a first fixing boss and a moving boss protruding from the other surface of a first planar plate toward a side in a second direction; light leakage prevention blades each having a second fixing boss and forming a pair with the diaphragm blade; a drive ring on which first cam grooves are formed; and a housing body capable of housing the diaphragm blades, the light leakage prevention blades, and the drive ring. A second cam groove is further formed in the light leakage prevention blade, the moving boss of the diaphragm blade is inserted into the second cam groove of the light leakage prevention blade, and is inserted into the first cam groove of the drive ring. The light leakage prevention blade has a light leakage prevention blade extending portion which extends toward the other side from the second fixing boss.

Abstract: In order to provide a projection lens barrel and a projection display device that are capable of correcting the optical characteristics of a plurality of lens groups, a projection lens barrel, comprising a lens optical system causing light from an image display element to be formed as a projected image on a screen, also comprises correction mechanisms that move each of at least two lens groups along an optical axis and correct the optical characteristics to be corrected, said lens groups each having different optical characteristics for correction in order to suppress reduction in image quality of a projected image caused by changes in optical characteristics caused by temperature changes in the projection lens barrel.

Abstract: A lens unit includes a lens barrel holding lenses and an attachment attached to an end portion of the lens barrel in a detachable manner. The lens barrel includes magnets for attaching the attachment to the end portion of the lens barrel. The attachment includes magnets attracted to the magnets. The lens barrel has a contact surface for positioning the attachment to the lens barrel in a direction orthogonal to an optical axis direction of the lenses. The contact surface is an inclined surface inclined with respect to the optical axis direction of the lenses. The attachment has a contact surface in contact with the contact surface.

Abstract: An optical diaphragm device includes a plurality of diaphragm blades including a first fixing boss protruding from one surface of a first planar plate toward a side in a first direction; and a moving boss protruding from another surface of the first planar plate toward a side in a second direction. The optical diagram device includes a plurality of light leakage prevention blades including a second fixing boss protruding from one surface of a second planar plate toward the side in the first direction. The optical diagram device includes a drive ring including a plurality of first cam grooves; a housing body capable of accommodating the diaphragm blades, the light leakage prevention blades, and the drive ring. A second cam groove is in the light leakage prevention blade. The moving boss is in the second cam groove, and is in the first cam groove.

Abstract: In order to provide a projection lens barrel and a projection display device that are capable of correcting the optical characteristics of a plurality of lens groups, a projection lens barrel, comprising a lens optical system causing light from an image display element to be formed as a projected image on a screen, also comprises correction mechanisms that move each of at least two lens groups along an optical axis and correct the optical characteristics to be corrected, said lens groups each having different optical characteristics for correction in order to suppress reduction in image quality of a projected image caused by changes in optical characteristics caused by temperature changes in the projection lens barrel.

Abstract: In order to provide a projection lens barrel and a projection display device that are capable of correcting the optical characteristics of a plurality of lens groups, a projection lens barrel, comprising a lens optical system causing light from an image display element to be formed as a projected image on a screen, also comprises correction mechanisms that move each of at least two lens groups along an optical axis and correct the optical characteristics to be corrected, said lens groups each having different optical characteristics for correction in order to suppress reduction in image quality of a projected image caused by changes in optical characteristics caused by temperature changes in the projection lens barrel.

Abstract: In order to provide a projection lens barrel and a projection display device that are capable of correcting the optical characteristics of a plurality of lens groups, a projection lens barrel, comprising a lens optical system causing light from an image display element to be formed as a projected image on a screen, also comprises correction mechanisms that move each of at least two lens groups along an optical axis and correct the optical characteristics to be corrected, said lens groups each having different optical characteristics for correction in order to suppress reduction in image quality of a projected image caused by changes in optical characteristics caused by temperature changes in the projection lens barrel.