Abstract: An image forming apparatus includes a frame; an external cover to cover an external face of the frame; and a passive sensor including a pyroelectric element. The pyroelectric element includes a light receiving part to detect infrared rays; and a signal output part to emit output signals based on the infrared rays detected by the light receiving part, in which the passive sensor is mounted to the external cover with the light receiving part exposed outside the external cover.

Abstract: An electronic device comprises: a shielding object that is arranged at least in a plurality of directions and shields noise; and a Helmholtz silencer that is arranged in a direction where the shielding object does not exist, the shielding object and the silencer being arranged with respect to a noise source causing noise such as a driving source that is arranged inside an apparatus body, wherein a neck portion of the Helmholtz silencer is directed to the noise source, a plurality of such Helmholtz silencers are provided to correspond to at least two kinds of frequencies, and installed number of the Helmholtz silencers corresponding to at least two kinds of the frequencies respectively, is made different depending on a distance from the noise source.

Abstract: A sound absorbing device including a Helmholtz resonator having a projection part which includes a shape of protruding from an outer wall surface of a communicating part forming plate among the communicating part forming plate and a cavity forming member that are cavity part forming members forming a cavity part of the Helmholtz resonator, and surrounding an opening of a communicating part that causes the cavity part to communicate with the outside.

Abstract: A sound absorbing device including a Helmholtz resonator also includes a projection part having a shape of protruding from an outer wall surface of a communicating part forming plate among the communicating part forming plate and a cavity forming member that are cavity part forming members forming a cavity part of the Helmholtz resonator, and surrounding an opening of a communicating part that causes the cavity part to communicate with the outside.

Abstract: An arrangement structure of a main power switch includes an apparatus body, the main power switch, and a movable member. The apparatus body has a dead space on a front side. The main power switch is disposed in the dead space. The movable member is disposed in the apparatus body to cover the main power switch. The movable member is drawable from the apparatus body in a horizontal direction. The movable member includes an opening opposed to the main power switch, to expose the main power switch to outside.

Abstract: An image forming apparatus includes a first human body detector, a second human body detector, and a controller. The first human body detector has a first detection span to detect a human body to output a signal. The second human body detector has a second detection span to detect a human body to output a signal. The controller changes a state of the image forming apparatus from a standby state to an operation state in accordance with the output signal from each of the first human body detector and the second human body detector. A first center line of the first detection span intersects with a second center line of the second detection span at a portion where the first detection span and the second detection span overlap with each other in a planar view.

Abstract: A housing structure includes an exterior cover having an opening through which an interior of the exterior cover communicates with an exterior of the exterior cover, an interior cover disposed inside the exterior cover and facing the exterior cover with a clearance secured therebetween, an inward projection projecting from the exterior cover to the interior cover, and an outward projection projecting from the interior cover to the exterior cover. The inward projection and the outward projection define an airflow passage in the clearance between the exterior cover and the interior cover, and the airflow passage includes multiple bent portions. The outward projection is greater in width than the inward projection in an airflow direction toward the opening, and the airflow direction perpendicular to a direction in which the interior cover faces the exterior cover.

Abstract: According to an aspect of the invention, an image forming apparatus includes an apparatus body, a sound absorbing device utilizing a Helmholtz resonator, and a hinged exterior cover operable to open and close relative to the apparatus body. The hinged exterior cover is a hinged cover configured to pivot about a pivot shaft arranged at a lower end portion of the hinged exterior cover. At least a part of the hinged exterior cover has a multiplex structure made by overlaying a plurality of plate-like members on one another. The sound absorbing device is formed by utilizing space between two plate-like members of the plurality of plate-like members making up the multiplex structure as a cavity of the Helmholtz resonator.

Abstract: According to an aspect of the invention, an image forming apparatus includes an apparatus body, a sound absorbing device utilizing a Helmholtz resonator, and a hinged exterior cover operable to open and close relative to the apparatus body. The hinged exterior cover is a hinged cover configured to pivot about a pivot shaft arranged at a lower end portion of the hinged exterior cover. At least a part of the hinged exterior cover has a multiplex structure made by overlaying a plurality of plate-like members on one another. The sound absorbing device is formed by utilizing space between two plate-like members of the plurality of plate-like members making up the multiplex structure as a cavity of the Helmholtz resonator.

Abstract: According to an aspect of the invention, an image forming apparatus includes an apparatus body, a sound absorbing device utilizing a Helmholtz resonator, and a hinged exterior cover operable to open and close relative to the apparatus body. The hinged exterior cover is a hinged cover configured to pivot about a pivot shaft arranged at a lower end portion of the hinged exterior cover. At least a part of the hinged exterior cover has a multiplex structure made by overlaying a plurality of plate-like members on one another. The sound absorbing device is formed by utilizing space between two plate-like members of the plurality of plate-like members making up the multiplex structure as a cavity of the Helmholtz resonator.

Abstract: An electronic device comprises: a shielding object that is arranged at least in a plurality of directions and shields noise; and a Helmholtz silencer that is arranged in a direction where the shielding object does not exist, the shielding object and the silencer being arranged with respect to a noise source causing noise such as a driving source that is arranged inside an apparatus body, wherein a neck portion of the Helmholtz silencer is directed to the noise source, a plurality of such Helmholtz silencers are provided to correspond to at least two kinds of frequencies, and installed number of the Helmholtz silencers corresponding to at least two kinds of the frequencies respectively, is made different depending on a distance from the noise source.

Abstract: A sound absorbing device including a Helmholtz resonator also includes a projection part having a shape of protruding from an outer wall surface of a communicating part forming plate among the communicating part forming plate and a cavity forming member that are cavity part forming members forming a cavity part of the Helmholtz resonator, and surrounding an opening of a communicating part that causes the cavity part to communicate with the outside.