A system for an electrophotographic image forming device includes a toner container having a reservoir for storing toner and an impact member configured to selectively impart an impulse force on the toner container to cause vibration of the toner container. A sensor is configured to sense the vibration of the toner container upon the impact member imparting the impulse force on the toner container. Processing circuitry in communication with the sensor is configured to determine an estimate of an amount of toner in the reservoir based on the sensed vibration of the toner container.

A natural frequency measuring device includes a receiving unit and a measuring unit. The receiving unit receives information of an image formed on a recording medium with vibrations of different frequencies provided to a member used to form the image. The measuring unit measures a natural frequency of the member from a frequency response characteristic using a misregistration amount of the image represented by the information of the image received by the receiving unit.

An image forming apparatus includes a stack portion having recording materials, an image forming unit, a basis weight detection unit, an operating sound detection unit, and a mode selection unit. The basis weight detection unit detects a recording material basis weight based on an ultrasonic wave. The operating sound detection unit detect an abnormality of a generated operating sound. The mode selection unit selects, for each recording material fed to the image forming unit, between transmitting to the basis weight detection unit a first instruction for detecting the recording material basis weight and transmitting to the operating sound detection unit a second instruction for detecting the operating sound abnormality. In determining an interval at which each second instruction is transmitted, the mode selection unit determines the interval so that the interval and a cycle, in which properties of recording materials on the stack portion are repeated, do not continuously coincide.

A detection section that detects a value used for determining whether or not a jam of a paper sheet has occurred includes a sound detection unit that detects a sound and an auxiliary detection unit that detects a value different from the magnitude of a sound in the case where a jam of the paper sheet has occurred, and, in the case where the sound detection unit has detected a sound of a magnitude equal to or greater than a first threshold value, a control unit controls determines whether or not a jam of the paper sheet has occurred with reference to a detection result of the auxiliary detection unit, and controls a transport unit on the basis of a result of the determination.

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.

An abnormality determination apparatus includes: an audio data acquisitor that acquires audio data of an apparatus to be judged for determining presence or absence of abnormality; an abnormal sound detector that detects an abnormal sound based on the audio data acquired by the audio data acquisitor; and a hardware processor that determines whether the abnormal sound is such a sound that an operation of the apparatus to be judged should be restricted based on a subsequent secular change of the abnormal sound when the abnormal sound is detected by the abnormal sound detector, and restricts the operation of the apparatus to be judged when the hardware processor determines that the abnormal sound is such a sound that the operation of the apparatus to be judged should be restricted.

A printing apparatus including a plurality of print driving units for printing a print dot on a print medium, a storage unit that stores a generated electromagnetic wave noise value which is a value of an electromagnetic wave noise to be generated by driving the print driving unit and an allowable electromagnetic wave noise value indicating tolerance of the generated electromagnetic wave noise, as electromagnetic wave noise data, and a control unit that controls driving of the print driving unit, in which the control unit controls the number of the print driving units to be simultaneously driven so as to be the generated electromagnetic wave noise value equal to or less than the allowable electromagnetic wave noise value.

An image forming apparatus includes an image forming unit, a transmission unit, a reception unit, a control unit configured to obtain a time period until the reception unit receives a first ultrasonic wave via a first recording material and an amplitude value thereof at a reference temperature, obtain a time period until the reception unit receives a second ultrasonic wave via a second recording material and an amplitude value thereof at a different temperature, control an image formation condition for forming the image on the first recording material on the basis of the amplitude value of the first ultrasonic wave, obtain a difference time period between reception of the first and second ultrasonic waves, and control an image formation condition for forming the image on the second recording material on the basis of the difference time period and the amplitude value of the second ultrasonic wave.

An image forming apparatus includes a conveying unit, an image forming unit, a fixing unit, a first driving unit, a second driving unit, a transmission unit to transmit an ultrasonic wave, and a reception unit. Where a determination is made that a timing at which excitation of the first driving unit is switched or a timing at which excitation of the second driving unit is switched overlaps with a timing to obtain a value of the ultrasonic wave received by the reception unit, the transmission unit does not transmit an ultrasonic wave. Where a determination is made that the timing at which the excitation of the first driving unit is switched or the timing at which the excitation of the second driving unit is switched does not overlap with the timing to obtain the value of the received ultrasonic wave, the transmission unit transmits an ultrasonic wave.

An image forming apparatus includes a stack portion having recording materials, an image forming unit, a basis weight detection unit, an operating sound detection unit, and a mode selection unit. The basis weight detection unit detects a recording material basis weight based on an ultrasonic wave. The operating sound detection unit detect an abnormality of a generated operating sound. The mode selection unit selects, for each recording material fed to the image forming unit, between transmitting to the basis weight detection unit a first instruction for detecting the recording material basis weight and transmitting to the operating sound detection unit a second instruction for detecting the operating sound abnormality. In determining an interval at which each second instruction is transmitted, the mode selection unit determines the interval so that the interval and a cycle, in which properties of recording materials on the stack portion are repeated, do not continuously coincide.