Abstract:
Provided is a box-shaped soundproof structure that is small and light and can sufficiently reduce noise with a natural frequency of a sound source. A box at least a part of which is opened; and a sound reduction structure including a resonator disposed in the box are included, and a sound generated from a sound source disposed in contact with an outer surface of a wall of the box or in the box and emitted from an open surface of the box to the outside is reduced by the sound reduction structure.
Abstract:
A soundproof structure includes two or more kinds of resonant type sound absorbing cells including different kinds of a first resonant type sound absorbing cell and a second resonant type sound absorbing cell that are adjacent to each other; and an opening part provided in the second resonant type sound absorbing cell, in which a resonance frequency of the first resonant type sound absorbing cell and a resonance frequency of the second resonant type sound absorbing cell match each other. As a result, the soundproof structure is capable of achieving an absorptance of more than 50%, preferably, close to 100% even in a compact, light, and thin structure which is much smaller than a wavelength, thereby obtaining a high soundproofing effect. Further, the soundproof structure is capable of obtaining air permeability and/or heat conductivity by providing a passage of air and/or heat.
Abstract:
Provided is an earmuff that is compact and lightweight, has high sound insulating performance, is capable of insulating sound of a specific frequency range, and has excellent air permeability. The earmuff includes a headband, and two ear cups each having a housing attached to an end part of the headband and an ear pad locked to the housing, the housing has a housing opening part, a sound insulation structure is disposed in the housing opening part and insulates sound of a specific frequency range, and the housing opening part having the sound insulation structure disposed therein has a ventilation hole.
Abstract:
A soundproof structure includes one or more soundproof cells. Each of the one or more soundproof cells includes a frame having a hole portion, a vibratable film fixed to the frame so as to cover the hole portion, and one or more through holes drilled in the film. Both end portions of the hole portion of the frame are not closed, and the frame and the film are formed of the same material and are integrally formed. Therefore, it is possible to provide a soundproof structure and a soundproof structure manufacturing method capable of not only stably insulating sound due to increased resistance to environmental change or aging but also avoiding problems in manufacturing, such as uniform adhesion or bonding of a film to a frame.
Abstract:
An optical electrical field enhancing device includes: a transparent substrate having a structure of fine protrusions and recesses on the surface thereof; and a metal structure layer of fine protrusions and recesses formed on the surface of the structure of fine protrusions and recesses. The metal structure layer of fine protrusions and recesses has a structure of fine protrusions and recesses, in which the distances among adjacent protrusions are less than the distances among corresponding adjacent protrusions of the structure of fine protrusions and recesses of the transparent substrate.
Abstract:
Performing a measurement using an optical field enhancement device which includes a transparent substrate having a transparent fine uneven structure on a surface and a metal film formed on a surface of the fine uneven structure on the surface of the substrate, in which a subject is placed on the metal film of the optical field enhancement device, then excitation light is projected onto an area of the optical field enhancement device on which the subject is placed, and light generated by the projection of the excitation light is detected from a back surface side of the transparent substrate.
Abstract:
Provided is an air passage type silencer that can reduce pressure loss even in a case where the flow rate of a gas flowing in the air passage type silencer is high. An air passage type silencer includes an inlet-side ventilation pipe, an expansion portion that communicates with the inlet-side ventilation pipe and of which a cross-sectional area is larger than a cross-sectional area of the inlet-side ventilation pipe, and an outlet-side ventilation pipe that communicates with the expansion portion and of which a cross-sectional area is smaller than the cross-sectional area of the expansion portion. A level difference d satisfies Equation (1): d≥100 μm, satisfies Equation (2): d≤25×Sa+193 μm in a case where an arithmetic average height Sa is equal to or smaller than 50 μm, and satisfies Equation (3): d≤1450 μm in a case where the arithmetic average height Sa exceeds 50 μm, where Sa (μm) is an arithmetic average height of a surface on a central side in the expansion portion and d (μm) is an average value of level differences between a ventilation pipe interior wall and the surface on the central side at at least one of a connection portion between the expansion portion and the inlet-side ventilation pipe or a connection portion between the expansion portion and the outlet-side ventilation pipe.
Abstract:
An object is to provide a ventilation system that can suppress generation of a pressure loss and wind noise in a silencer. The ventilation system of the present invention has the silencer disposed at an intermediate position of a ventilation path. In a housing of the silencer, an in-housing ventilation path extending from an inlet opening to an outlet opening is surrounded by a sound absorbing member. The ventilation path has a first ventilation path that is adjacent to the inlet opening and that is continuous to the in-housing ventilation path and a second ventilation path that is adjacent to the outlet opening and that is continuous to the in-housing ventilation path. The farther from the in-housing ventilation path, the smaller a size of a cross section of at least one ventilation path of the first ventilation path or the second ventilation path. A size of a cross section of an end of at least one of the ventilation paths on an in-housing ventilation path side and a size of an opening of the inlet opening or the outlet opening, which is adjacent to the end, are identical to each other.
Abstract:
To provide an air passage type silencer and an acoustic impedance change structure of which the absorbance is high, that suppresses generation of a wind noise, and that has a high sound attenuation effect in a low-frequency band. Provided is an acoustic impedance change structure through which a sound propagates, the acoustic impedance change structure including at least in this order: a first impedance matching region that is connected to an inlet portion and in which an acoustic impedance gradually decreases; an acoustic impedance constancy region; and an outlet portion, in which Zcham
Abstract:
A fan silencing system includes a fan, and an acoustic resonance structure, in which the acoustic resonance structure is disposed in a near field region of a sound generated by the fan.