Embodiments of this application provide a rear cover of an electronic device, an electronic device, and an air tightness detection system of an electronic device. The electronic device may include a mobile or fixed terminal having waterproof performance such as a mobile phone, a tablet computer, or a notebook computer. The rear cover includes a body portion and a structure layer fixed to a rear surface of the body portion. A smooth detection plane is formed on a rear surface of the structure layer, and a rear end of a balance channel of the rear cover is located within the detection plane, thereby resolving the problem that the material of the rear cover affects air tightness detection on the electronic device.

A breathable element for lighting of vehicle includes a housing, a cylinder, and a breathable film. The housing has a peripheral wall and a bottom to enclose a receiving room. The peripheral wall has a positioning structure at the opening end. The bottom has a protruding structure. The cylinder includes an inner cylinder and an outer cylinder. The inner cylinder is connected with the outer cylinder via plural connection portions arranged spacedly. An air channel is defined between any two adjacent connection portions and extends axially. The inner cylinder is axially formed with a channel. The cylinder abuts against the protruding structure. The cylinder is received in the receiving room so that the channel communicates the air channel. The cylinder is prevented from leaving the housing freely by the positioning structure. The breathable film is disposed on an end of the inner cylinder inside the housing.

A housing kit (90) includes a housing body (20) and a ventilation member (10). The housing body (20) has a vent hole (21). The ventilation member (10) has a leg portion (26). The leg portion (26) is a portion adapted to be inserted into the vent hole (21). The housing body (20) has an inner peripheral surface (23) that defines the vent hole (21). The inner peripheral surface (23) includes a first rounded segment (23.sub.R1), a first straight segment (23.sub.S1), a second rounded segment (23.sub.R2), and a second straight segment (23.sub.S2) that are formed in order from an exterior space (24) side to an interior space (22) side of the housing body (20). The first rounded segment (23.sub.R1) and the second rounded segment (23.sub.R2) each form a curve convex toward a central axis (O) of the vent hole (21) in a cross section of the housing body (20) including the central axis (O). The first straight segment (23.sub.S1) and the second straight segment (23.sub.S2) each form a straight line in this cross section.

A ventilation member is attached to a through hole of a housing. The ventilation member includes: a support body in which a ventilation path that forms a flow path for gas between the interior and the exterior of the housing; a sealing member that seals between the support body and the housing; a ventilation membrane that is provided on the ventilation path to prevent a liquid and a solid from passing through and to allow gas to pass through; and a contacted portion that is provided to the support body and is formed with a uniform height to surround an end portion opening of the ventilation path. This makes it possible to easily close the ventilation path of the ventilation member.

A gas-permeable porous fluororesin membrane (4) made of a fluororesin is welded to a resin component (2) made of a thermoplastic resin using a welding horn (62) having a working surface (62p) adapted to be brought into contact with a work object and provided with a projection (62t). The working surface (62p) of the welding horn (62) is provided with, for example, a plurality of projections (62t). The plurality of projections (62t) may be arranged in a grid pattern on the working surface (62p).

A breather valve and a portable communication device including a breather valve are provided. The breather valve includes a housing having a bottom portion having an opening and side portions, a rigid substrate located within the housing and a breathable membrane mounted to the rigid substrate. The breather valve further includes a gasket having a top surface and a bottom surface, and a preloaded compression element across the gasket and the rigid substrate. The gasket has an upper energy director located at the top surface and a lower energy director located at the bottom surface. The preloaded compression element provides at least a first compressive position providing a contact between the lower energy director and the bottom portion of the housing and a second compressive position in which air passes around the lower energy director and the upper energy director.

Fasteners and fastener systems that can act as air vents for enclosures are described. The fasteners can be configured to secure a component to a wall of an enclosure, while at the same time providing a passageway for air to pass between an internal cavity of the enclosure and an outer environment. The venting feature of the fastener can serve to equalize pressures between the internal cavity and outer environment so as to prevent pressure build up or condensation within the internal cavity. The dual functionality of the fasteners is suitable for use in portable electronic devices where compactness and space saving measures can be of importance.

A pressure equalising device for a housing, including an inside, an outside, and a lattice-like cage having a gas passage opening. The gas passage opening connects the inside and the outside in a differential pressure-dependent and flow-conducting manner. The gas passage opening is covered by a gas-permeable membrane which includes at least one nonwoven layer. The nonwoven layer includes fibers which are substantially completely sheathed by a sheath of an elastomer.

A pressure compensating device includes a diaphragm and a holding element. The holding element has a bearing surface facing the diaphragm. A cohesive or materially-bonded connection is formed at the bearing surface between the diaphragm and the holding element. The diaphragm is fixed to the bearing surface of the holding element by the cohesive connection. A cover which is fixed to the holding element has at least one first receiving device or receptacle at least partly receiving the diaphragm. The cover presses the diaphragm at least partly onto the cohesive connection and presses the cohesive connection onto the bearing surface of the holding element. A housing component having a pressure compensating device and a control unit having a housing are also provided.

An electronic control device has a housing and an air breathing filter assembled to a through-hole of the housing. The air breathing filter has a filter supporting member and a filter cover member. A cylindrical portion of the filter supporting member is inserted into the through-hole from an inside space of the housing, while the filter cover member is fixed to the cylindrical portion of the filter supporting member from an outside of the housing. A pushing portion is formed in a leg portion of the filter cover member for pushing a wall of the housing in a downward direction. A water-proof sealing member is interposed between an inner wall surface of the housing and a flanged portion of the filter supporting member, so that a gap between the housing and the air breathing filter is surely sealed.