A conveying unit conveys a sheet to a tray. A first surface of a wall member and the tray define a first space. A structural member has a facing surface which faces a second surface of the wall member. A wall surface of a frame, the second surface of the wall member, and the facing surface of the structural member define a second space. The wall member has a plurality of through holes including a first through hole and a second through hole. A first imaginary plane containing an edge of the first through hole in the second surface is away from the facing surface of the structural member by a first distance, and a second imaginary plane containing an edge of the second through hole in the second surface is away from the facing surface by a second distance which is different from the first distance.

Systems and methods for detecting the presence of metallic objects in media to be conveyed in a medium transport system are disclosed. One or more induction sensors are included in the medium transport system to detect the presence of metal in the transported media, with detection signals sent from the sensors to a system processing unit. An ultrasonic detector is employed in some embodiments to output another detection signal. One or more microphones may also be included, for detecting the sound created as the medium is being transported. The system processing unit analyzes various detection signals and analyzes computed sound values from the microphones, to determine the presence and location of metal in the media. A position jam detector may assist in determining jams of the media along the medium transport path.

Systems and methods for detecting the presence of metallic objects in media to be conveyed in a medium transport system are disclosed. One or more induction sensors are included in the medium transport system to detect the presence of metal in the transported media, with detection signals sent from the sensors to a system processing unit. An ultrasonic detector is employed in some embodiments to output another detection signal. One or more microphones may also be included, for detecting the sound created as the medium is being transported. The system processing unit analyzes various detection signals and analyzes computed sound values from the microphones, to determine the presence and location of metal in the media. A position jam detector may assist in determining jams of the media along the medium transport path.

A sheet feeding device comprises sheet storage for storing a sheet, a merging conveying unit for feeding the sheet from the sheet storage to an image forming apparatus, a transmitting element for transmitting an ultrasonic signal to the sheet conveyed on the merging conveying unit, and a receiving element for receiving the ultrasonic signal having passed through the sheet and outputting an output signal according to strength of the received ultrasonic signal. When the sheet is a Japanese paper, the sheet feeding device detects double feeding of the sheet according to an average value of a plurality of the output signals and variation in a plurality of the output signals obtained for the one sheet. If the sheet is not double fed, the sheet is fed to the image forming apparatus. If the sheet is double fed, the sheet is discharged to the escape tray.

A sheet feeding device comprises sheet storage for storing a sheet, a merging conveying unit for feeding the sheet from the sheet storage to an image forming apparatus, a transmitting element for transmitting an ultrasonic signal to the sheet conveyed on the merging conveying unit, and a receiving element for receiving the ultrasonic signal having passed through the sheet and outputting an output signal according to strength of the received ultrasonic signal. When the sheet is a Japanese paper, the sheet feeding device detects double feeding of the sheet according to an average value of a plurality of the output signals and variation in a plurality of the output signals obtained for the one sheet. If the sheet is not double fed, the sheet is fed to the image forming apparatus. If the sheet is double fed, the sheet is discharged to the escape tray.

A printer includes an apparatus body having a recording head for performing recording onto a sheet of paper. The printer also includes a unit body that is accommodated inside the apparatus body and has a path-forming surface formed at least on a portion of the periphery of the unit body. The path-forming surface forms a medium transport path. The unit body includes a plurality of openings that are in communication with a sound absorber disposed inside the unit body. The plurality of the openings are provided at least on a portion of the path-forming surface.

A sheet conveying device, which is included in an image reading device and an image forming apparatus, includes a passage forming body and a sound absorber. The passage forming body is configured to define a sheet conveying passage through which a sheet passes. The sound absorber includes a hollow portion and a communication portion configured to communication the hollow portion and the sheet conveying passage. A position of the communication portion of the sound absorber is changeable in the sheet conveying passage. The sheet conveying device included in the image reading device includes an original document conveying device configured to convey an original document having an image on a surface. The sheet conveying device included in the image forming apparatus includes a recording medium conveying device configured to convey the recording medium accommodated in a recording medium container to the image forming device.

A system and method of detecting the presence of metallic objects in media to be conveyed in a medium transport system is disclosed. One or more metal detectors are included in the medium transport system to detect the presence of metal in the medium being transported. Signals from the metal detectors are sent to a system processor, which analyzes the signals, and produces proximity, duration, and/or intensity values therefrom. One or more microphones may also be included which detect the sound created as the medium is being transported. The processor computes sound values from the microphone signals, and analyzes the computed sound values along with the proximity, duration, and/or intensity values in order determine if the conveyance of the medium along the transport path should be stopped due to the presence of metal in the media or a jam occurring within the medium transport path.

A system and method of detecting the presence of metallic objects in media to be conveyed in a medium transport system is disclosed. One or more metal detectors are included in the medium transport system to detect the presence of metal in the medium being transported. Signals from the metal detectors are sent to a system processor, which analyzes the signals, and produces proximity, duration, and/or intensity values therefrom. One or more microphones may also be included which detect the sound created as the medium is being transported. The processor computes sound values from the microphone signals, and analyzes the computed sound values along with the proximity, duration, and/or intensity values in order determine if the conveyance of the medium along the transport path should be stopped due to the presence of metal in the media or a jam occurring within the medium transport path.

A sheet conveying device includes a conveyer to convey a sheet and a primary sheet guide, disposed downstream from the conveyer in a sheet conveyance direction, to guide the sheet conveyed by the conveyer in the sheet conveyance direction. A secondary sheet guide is disposed opposite the primary sheet guide and includes a bending portion to bend the sheet while the sheet slides over the bending portion to change the sheet conveyance direction. A sheet conveyance path is defined by the primary sheet guide and the secondary sheet guide. The primary sheet guide includes a cavity disposed opposite the sheet conveyance path and a communication through-hole communicating with the cavity and the sheet conveyance path. The communication through-hole is disposed opposite the bending portion in a direction perpendicular to the sheet conveyance direction.