A sound absorber includes a side surface section (a first wall section) in which a plurality of first holes are provided, the side surface section including a first surface and a second surface, a thin film stuck to the first surface of the side surface section, a partition wall (a second wall section) opposed to the second surface and provided in a position separated from the second surface, at least one second hole being provided in the partition wall, and a porous material provided to be opposed to the second wall section in a position separated from the partition wall.

Provided is a soundproofing structure including: a plate-like member which has a plurality of through-holes passing therethrough in a thickness direction, in which in a case where an average opening diameter of the through-holes is 0.1 m or greater and less than 100 m, and in a case where the average opening diameter of the through-holes is set as phi (m) and a thickness of the plate-like member is set as t (m), an average opening ratio rho of the through-holes is greater than 0 and less than 1 and falls in a range where a center is rho_center=(2+0.25t)phi.sup.1.6, a lower limit is rho_center(0.052(phi/30).sup.2), and an upper limit is rho_center+(0.795(phi/30).sup.2).

An image display apparatus includes: a first light modulation device that includes a plurality of display pixels and modulates light based on input first image information; an illumination unit that includes a plurality of light adjustment elements and emits adjusted light to the first light modulation device; an illumination distribution storage unit that stores an illumination range in which the light emitted from the light adjustment elements illuminates the display pixels of the first light modulation device; and a light adjustment information decision unit that decides light adjustment information to control the light adjustment elements of the illumination unit based on a feature amount of the first image information corresponding to the display pixels of the illumination range stored in the illumination distribution storage unit.

Two or more soundproof cells arranged in a two-dimensional manner are provided. At least one of the soundproof cells is a first soundproof cell configured to include a first frame having a first through-hole. At least one of the other soundproof cells is a second soundproof cell including a second frame having a second through-hole and a film fixed to the second frame. A first shielding peak frequency, which is determined by the first through-hole of the first soundproof cell and at which a transmission loss is maximized, is present on a lower frequency side than a first natural vibration frequency of the film of the second soundproof cell, and sound in a predetermined frequency band centered on the first shielding peak frequency is selectively insulated.

A light source apparatus includes a light source, a substrate provided rotatably around a predetermined axis of rotation, a scattered light generator which is provided on the substrate and on which light from the light source is incident, a pickup lens provided on the light exiting side of the scattered light generator, and a holding member that holds the pickup lens, and at least one of the contour of a surface closest to the substrate among the surfaces of the holding member and the contour of a surface facing the substrate among the surfaces of the pickup lens is located inside the contour of the substrate when viewed in the direction parallel to the axis of rotation.

A lens shift mechanism includes a movable portion configured to support a projection lens and movable in two directions orthogonal to each other in a plane orthogonal to an optical axis; first and second operating units configured to generate drive forces for moving the movable portion in the two directions, respectively, first and second rotating portions to which the drive forces generated by the first and second operating units are transmitted, and a lock mechanism configured to be capable of switching between a locked state in which the two operating units are locked and an unlocked state in which the two rotating portions are rotatable, and the lock mechanism includes first and second locking members configured to lock the first and second rotating portions respectively and a lever mechanism configured to move the two locking members.

An ambient image projection device includes a lens assembly and a projection assembly. The projection assembly includes a first light source and a display screen. Content displayed on the display screen forms dynamic images to be projected into space under guidance of the lens assembly. The first light source, the display screen, and the lens assembly are arranged along an optical path direction of the projection assembly. The display screen is arranged on a light-emitting side of the first light source and is coaxially arranged with the first light source.

An ambient image projection device includes a lens assembly and a projection assembly. The projection assembly includes a first light source and a display screen. Content displayed on the display screen forms dynamic images to be projected into space under guidance of the lens assembly. The first light source, the display screen, and the lens assembly are arranged along an optical path direction of the projection assembly. The display screen is arranged on a light-emitting side of the first light source and is coaxially arranged with the first light source.