Abstract: In a cleaning device, a signal processing circuit determines that a foreign substance has adhered to a surface of a protection cover based on at least two pieces of information among a change amount of a resonant frequency when a vibration portion is driven at a first voltage, a change amount of a current value relating to an impedance detected by an impedance detector, and a temporal change of an image captured by an imaging portion, and cleans the surface of the protection cover by controlling the vibration portion in accordance with the determination.

Abstract: A projector includes a projection lens and a projector body. In the projection lens, a U-shaped optical path is formed by optical axis to optical axis. A lens barrel is a U-shaped barrel. A housing of the projector body includes a storage section. The projection lens is supported rotatably about the optical axis with respect to the housing, in an up-down direction and a right-left direction of the housing perpendicular to the optical axis, between a first position where the projection lens is stored inside a storage section provided in the housing and a second position where the projection lens is protruding from the housing.

Abstract: The image forming optical system is capable of forming an image on a conjugated plane on a reduction side as an intermediate image and re-forming the intermediate image as a magnified image on a conjugated plane on a magnification side. The image forming optical system includes: a first adjustment group that moves along an optical axis in adjusting an image formation position of a region of the magnified image including a farthest point from the optical axis; and a second adjustment group that moves along the optical axis in adjusting an image formation position of a region of the magnified image including a nearest point from the optical axis. An optical element disposed closest to the magnification side is a lens. The second adjustment group has a positive refractive power as a whole, and is disposed closest to the reduction side.

Abstract: A projector includes a projection lens and a projector body. In the projection lens, a U-shaped optical path is formed by optical axis to optical axis. A lens barrel is a U-shaped barrel. A housing of the projector body includes a storage section. The projection lens is supported rotatably about the optical axis with respect to the housing, in an up-down direction and a right-left direction of the housing perpendicular to the optical axis, between a first position where the projection lens is stored inside a storage section provided in the housing and a second position where the projection lens is protruding from the housing.

Abstract: A zoom lens forms an intermediate image at a position conjugate to a reduction side imaging plane and forms the intermediate image again on a magnification side imaging plane. The zoom lens includes a plurality of lens groups including at least two movable lens groups, which move by changing spacings between the groups adjacent to each other in a direction of an optical axis during zooming, at a position closer to the reduction side than the intermediate image. Among the plurality of lens groups, a final lens group closest to the reduction side has a positive refractive power, and remains stationary with respect to the reduction side imaging plane during zooming. The zoom lens satisfies predetermined conditional expressions (1) and (2) about the focal lengths of the movable lens groups.

Abstract: Provided is an image display apparatus that can present a high-quality image in a case in which a composite image is presented to an observer. An image display unit (10) includes a first display image light input device (20A) and a second display image light input device (20B) that input display image light, a first light guide plate (30A) and a second light guide plate (30B) that receive input of the display image light individually from the first display image light input device (20A) and the second display image light input device (20B), and propagate the input display image light to an output surface while individually reflecting the input display image light, and a mechanism that adjusts a disposition relationship between the first light guide plate (30A) and the second light guide plate (30B).

Abstract: The zoom lens consists of a first unit, a second unit, a third unit, a fourth unit, and a fifth unit in order from the magnification side, and forms an intermediate image. The first unit consists of one lens group which has a positive refractive power. The second unit consists of two lens groups which move during magnification change and has a negative refractive power as a whole at the wide angle end. The third unit includes one or more lens groups which move during magnification change. The fourth unit includes one or more lens groups which move during magnification change.

Abstract: A first holding barrel, a first mirror bending a first optical axis of the first holding barrel at 90°, a second holding barrel, a second mirror bending a second optical axis of the second holding barrel at 90°, and a third holding barrel are disposed on an optical axis from a screen side to an image forming panel. A first connection member connects the first holding barrel including the first mirror to the second holding barrel to be rotationally movable in increments of 90°. A second connection member connects the second holding barrel and the second mirror to the third holding barrel to be rotationally movable in increments of 90°. An orientation of a display image of the image forming panel is changed based on rotational movement states of an optical axis of a first sensor and an optical axis of a second sensor to make an orientation of a projection image on the screen match an original image.

Abstract: The zoom lens consists of a first optical system including a lens at a position closest to the magnification side and a second optical system forming an intermediate image in order from the magnification side. The first optical system reforms the intermediate image on a magnification side imaging plane. The second optical system includes a lens group including an aperture stop, having a negative refractive power, and moving during zooming. The zoom lens satisfies a conditional expression: 0.1<f2w/fAp<2.1, where fAp is a focal length of the lens group having the aperture stop and f2w is a focal length of the second optical system at a wide angle end.

Abstract: A zoom lens forms an intermediate image at a position conjugate to a reduction side imaging plane and forms the intermediate image again on a magnification side imaging plane. The zoom lens includes a plurality of lens groups including at least two movable lens groups, which move by changing spacings between the groups adjacent to each other in a direction of an optical axis during zooming, at a position closer to the reduction side than the intermediate image. Among the plurality of lens groups, a final lens group closest to the reduction side has a positive refractive power, and remains stationary with respect to the reduction side imaging plane during zooming. The zoom lens satisfies predetermined conditional expressions (1) and (2) about the focal lengths of the movable lens groups.

Abstract: One embodiment according to the technique of the present disclosure provides a projection device having a plurality of modes in which relationships between an incidence region and an emission region in an electro-optical panel are different from each other. In the projection device according to one aspect of the present invention, a control unit controls a first mode and a second mode. The first mode is a mode in which a first range of an optical region is the incidence region and a range within the first range is the emission region, and the second mode is a mode in which a second range narrower than the first range of the optical region is the incidence region and a range within the second range is the emission region.

Abstract: The imaging optical system forms a first intermediate image at a position conjugate to a magnification side imaging surface and a second intermediate image at a position closer to a reduction side than the first intermediate image on an optical path and conjugate to the first intermediate image. The imaging optical system consists of a first optical system, a second optical system, and a third optical system in order from the magnification side to the reduction side along the optical path. The imaging optical system does not include a reflective member having a power.

Abstract: A zoom lens forms an intermediate image at a position conjugate to a reduction side imaging plane and forms the intermediate image again on a magnification side imaging plane. The zoom lens includes a plurality of lens groups including at least two movable lens groups, which move by changing spacings between the groups adjacent to each other in a direction of an optical axis during zooming, at a position closer to the reduction side than the intermediate image. Among the plurality of lens groups, a final lens group closest to the reduction side has a positive refractive power, and remains stationary with respect to the reduction side imaging plane during zooming. The zoom lens satisfies predetermined conditional expressions (1) and (2) about the focal lengths of the movable lens groups.

Abstract: A projection lens is a projection lens that emits incident light through a plurality of lenses, and includes a first lens that is disposed to be closest to an emission side, a second lens which is adjacent to the first lens and of which a diameter is smaller than a diameter of the first lens, and a frame that includes a first surface and is positioned outside the second lens in a radial direction. The first surface faces the first lens, the first surface has a light reflection-reducing structure, and a value of G1/G2 is 1.7 or more in a case where a diameter of the first lens is denoted by G1 and a diameter of the second lens is denoted by G2.

Abstract: A projection lens, which is mounted on a housing of a projection device including an electro-optical element, includes a first holding part that holds a first optical system disposed along a first optical axis along which light emitted from the housing passes, a first reflective part that bends light parallel to the first optical axis to form light parallel to a second optical axis, a second reflective part that bends the light parallel to the second optical axis to form light parallel to a third optical axis, and a second holding part holds the first reflective part and the second reflective part. A distance along the first optical axis between a first lens, which is disposed to be closest to a reduction side in the first optical system, and the first reflective part is longer than a distance along the second optical axis between the first reflective part and the second reflective part.

Abstract: A projector includes a projection lens and a projector body. In the projection lens, a U-shaped optical path is formed by optical axis to optical axis. A lens barrel is a U-shaped barrel. A housing of the projector body includes a storage section. The projection lens is supported rotatably about the optical axis with respect to the housing, in an up-down direction and a right-left direction of the housing perpendicular to the optical axis, between a first position where the projection lens is stored inside a storage section provided in the housing and a second position where the projection lens is protruding from the housing.

Abstract: A projection lens, which is mounted on a housing of a projection device including an electro-optical element, includes a first holding part that holds a first optical system disposed along a first optical axis along which light emitted from the housing passes, a first reflective part that bends light parallel to the first optical axis to form light parallel to a second optical axis, a second reflective part that bends the light parallel to the second optical axis to form light parallel to a third optical axis, and a second holding part holds the first reflective part and the second reflective part. A distance along the first optical axis between a first lens, which is made of glass and is disposed to be closest to a reduction side in the first optical system, and the first reflective part is longer than a distance along the second optical axis between the first reflective part and the second reflective part.

Abstract: A projector includes a projection lens and a projector body. In the projection lens, a U-shaped optical path is formed by optical axis to optical axis. A lens barrel is a U-shaped barrel. A housing of the projector body includes a storage section. The projection lens is supported rotatably about the optical axis with respect to the housing, in an up-down direction and a right-left direction of the housing perpendicular to the optical axis, between a first position where the projection lens is stored inside a storage section provided in the housing and a second position where the projection lens is protruding from the housing.

Abstract: A first holding barrel, a first mirror bending a first optical axis of the first holding barrel at 90°, a second holding barrel, a second mirror bending a second optical axis of the second holding barrel at 90°, and a third holding barrel are disposed on an optical axis from a screen side to an image forming panel. A first connection member connects the first holding barrel including the first mirror to the second holding barrel to be rotationally movable in increments of 90°. A second connection member connects the second holding barrel and the second mirror to the third holding barrel to be rotationally movable in increments of 90°. An orientation of a display image of the image forming panel is changed based on rotational movement states of an optical axis of a first sensor and an optical axis of a second sensor to make an orientation of a projection image on the screen match an original image.

Abstract: An imaging optical system consists of, in order from a magnification side: a first optical system that forms an intermediate image on a position conjugate to a magnification side imaging surface; and a second optical system that re-forms the intermediate image on a reduction side imaging surface. The first optical system includes at least two focusing lens groups that move with different loci during focusing. The imaging optical system satisfies predetermined conditional expressions relating to the focusing lens groups.