Abstract: A mount board tray is provided to hold multiple mount boards at different heights above and below the mount board tray. The mount board tray holds a topmost mount board placed at the topmost position among the multiple mount boards held by the mount board tray from below the topmost mount board. The mount board tray also holds a bottommost mount board placed at the bottommost position among the multiple mount boards from above the bottommost mount board at the same time.

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: An image forming apparatus includes a body; an openably closable drawer unit including an image forming section to form an image on a recording medium; and a circuit board. The circuit board is disposed in a substantial center of the drawer unit in a direction in which the drawer unit is pulled out of the body.

Abstract: A drawer unit including a housing and a drawer inserted into the housing in inserting direction and drawn therefrom in drawing direction is provided. A locking member is mounted on the housing or the drawer to extend in direction intersecting the inserting direction, and is rotatable on a rotating shaft extending in the inserting direction such that when the drawer is inserted, the locking member rotates from unlock position to lock position in locking direction while rotating from the lock position to the unlock position in unlocking direction prior to drawing of the drawer. A locking wall and a pushing wall are mounted on the other of the housing and the drawer. The locking member in the lock position is engaged with the locking wall. When being rotated in the unlocking direction, the locking member is contacted with the pushing wall, which pushes the drawer in the drawing direction.

Abstract: A mount board tray is provided to hold multiple mount boards at different heights above and below the mount board tray. The mount board tray holds a topmost mount board placed at the topmost position among the multiple mount boards held by the mount board tray from below the topmost mount board. The mount board tray also holds a bottommost mount board placed at the bottommost position among the multiple mount boards from above the bottommost mount board at the same time.

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 drawer unit including a housing and a drawer inserted into the housing in inserting direction and drawn therefrom in drawing direction is provided. A locking member is mounted on the housing or the drawer to extend in direction intersecting the inserting direction, and is rotatable on a rotating shaft extending in the inserting direction such that when the drawer is inserted, the locking member rotates from unlock position to lock position in locking direction while rotating from the lock position to the unlock position in unlocking direction prior to drawing of the drawer. A locking wall and a pushing wall are mounted on the other of the housing and the drawer. The locking member in the lock position is engaged with the locking wall. When being rotated in the unlocking direction, the locking member is contacted with the pushing wall, which pushes the drawer in the drawing direction.

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 image forming apparatus includes an image forming unit configured to form an image; a drawer unit configured to be pulled out from a body of the image forming apparatus; a first lock unit configured to receive power from a power supply and perform at least one of lock and unlock of the drawer unit with respect to the body; and a second lock unit configured to perform lock and unlock of the drawer unit with respect to the body by a mechanical operation performed by an operator.

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.

Abstract: An image forming apparatus includes an image forming unit configured to form an image; a drawer unit configured to be pulled out from a body of the image forming apparatus; a first lock unit configured to receive power from a power supply and perform at least one of lock and unlock of the drawer unit with respect to the body; and a second lock unit configured to perform lock and unlock of the drawer unit with respect to the body by a mechanical operation performed by an operator.