A transport apparatus includes a speaker and a mike disposed at respective positions between which a transport path of a medium is interposed, where the speaker and the mike face each other, a drive circuit that outputs a drive signal to the speaker, an amplifier circuit formed by coupling a plurality of amplifiers in series, where the amplifier circuit amplifies and outputs an output signal of the mike, a processor to which the output signal of the amplifier circuit is input, an attenuation circuit disposed in a stage preceding a predetermined amplifier, where the attenuation circuit attenuates an input signal and outputs the input signal to the predetermined amplifier, and a switch that switches an attenuation factor by the attenuation circuit.

In order to miniaturize an image forming system, the present invention provides an image forming system which is provided with a sheet feed apparatus including a transport roller pair capable of transporting a sheet in a sheet transport direction S, and an image forming apparatus including an image forming section capable of forming an image on the sheet acquired from the sheet feed apparatus, including a switch member disposed on the downstream side of the transport roller pair in the sheet transport direction to be switched between a first position for guiding the sheet transported by the transport roller pair to the image forming apparatus, and a second position for guiding the sheet transported by the transport roller pair downward, and a storage tray disposed below the switch member predetermined space apart to be able to store the sheet guided to below the switch member positioned in the second position.

A medium conveying apparatus includes a floating sensor located on an upstream side of a first roller in the medium conveying direction to detect a floating of the medium placed on a medium tray, a skew sensor located on a downstream side of a second roller in the medium conveying direction to detect a skew of the medium conveyed by the second roller, and a processor to determine whether the floating of the medium has occurred based on an output signal from the floating sensor, determine whether the skew of the medium has occurred based on an output signal from the skew sensor, and determine that a conveyance abnormality of the medium has occurred when the processor determines that the floating of the medium has occurred and the processor determines that the skew of the medium has occurred.

A medium feeding device is provided with a feeding section for feeding a medium and sensors for detecting the medium. The feeding section includes a feed roller and a separation roller, the sensors form a sensor line in which the plurality of sensors is aligned in a feeding direction of the medium to be fed, the two sensor lines are arranged in such a manner that the sensors overlap with each other in a width direction of the medium to be fed, and the sensor lines are so configured as to extend, in the feeding direction, from an upstream region upstream of a nip point where the feed roller and the separation roller make contact with each other, a nip region including the nip point, and to a downstream region downstream of the nip point.

Provided are a medium conveying apparatus, a control method, and a control program is to enable further reduction in the time required for conveying the medium while suppressing the occurrence of the conveyance abnormality of the medium. A medium conveying apparatus includes a conveying mechanism to convey a medium, a determination module to determine whether a conveyance abnormality of the medium has occurred, and a control module to control the conveying mechanism so as to increase a conveyance speed of the medium to be conveyed thereafter, or reduce a conveyance interval of the medium to be conveyed thereafter if the conveyance abnormality of the medium has not occurred when a predetermined number of medium is conveyed.

According to an embodiment, a sheet conveying device detects double feeding of sheets by an ultrasonic wave oscillator and an ultrasonic waves receiver provided across a conveying path of the sheets. The sheet conveying device calibrates a threshold voltage on the basis of an offset voltage of an amplifier circuit when the receiver has not received ultrasonic waves.

When a medium detector detects that a state where a medium is absent is switched to a state where the medium is present with a light quantity of the medium detector set to a first light quantity, a controller in an image reading apparatus switches the light quantity from the first light quantity to a second light quantity, which is larger than the first light quantity. When a quantity of the light received by the medium detector exceeds a threshold, the controller determines whether the media overlaps each other, based on the detection result of the multi-feed detector. When the quantity of the light received does not exceed the threshold, the controller skips the determination of whether the media overlaps each other.

A medium feeding apparatus capable of switching between a first feeding mode and a second feeding mode, in which in the first feeding mode, when a first detection section positioned downstream of a feeding roller in a medium feeding direction detects passage of a trailing end of a preceding medium in a feeding standby state in which driving of the feeding roller that feeds the medium is stopped, starting the driving of the feeding roller to perform feeding of a succeeding medium, and in the second feeding mode, when a second detection section positioned downstream of the first detection section in the medium feeding direction detects the passage of the trailing end of the preceding medium in the feeding standby state, starting the driving of the feeding roller to perform the feeding of the succeeding medium.

Provided are a medium conveying apparatus, a control method, and a control program to enable more accurate detennination whether a medium conveyance abnormality has occurred. A medium conveying apparatus includes an ultrasonic transmitter capable of outputting an ultrasonic wave, an ultrasonic receiver opposed to the ultrasonic transmitter, to receive the ultrasonic wave and output an ultrasonic signal corresponding to the received ultrasonic wave, a pressure detection module to detect atmospheric pressure, based on the ultrasonic signal, a sound receiver to receive a sound and generate a sound signal corresponding to the received sound, an abnormality determination module to determine whether a medium conveyance abnormality has occurred, based on the sound signal, and a modification module to modify sensitivity of the sound receiver, correct the sound signal, or modify a criterion for determination of a medium conveyance abnormality by the abnormality determination module, based on the atmospheric pressure.

An image processing apparatus includes a transmitter, a receiver, a comparison circuit, and a control unit. The transmitter transmits an ultrasonic wave to a conveyance path through which a sheet is conveyed. The receiver faces the transmitter with the conveyance path in between, and receives the ultrasonic wave transmitted by the transmitter. The comparison circuit compares a level signal indicating a reception level of the ultrasonic wave received by the receiver with a threshold signal for determining whether or not the sheet is double-fed in the conveyance path, and outputs a comparison result signal according to the comparison result. The control unit determines whether or not there is a possibility of a defect in the double feed detection function of detecting double feed based on the comparison result signal and the level signal.