Patent ID: 9733218
Date: 2017-08-15
CPC Classifications: B65H,G01N

Claim:
1. A sheet conveying device comprising: an ultrasonic wave generator to generate an ultrasonic wave; a receiver facing the ultrasonic wave generator across a conveyance path, along which a sheet is conveyed, and to receive a first ultrasonic wave, the first ultrasonic wave being an ultrasonic wave sent from the ultrasonic wave generator and passed through the sheet, and output a first voltage corresponding to the first ultrasonic wave; a voltage controller to adjust the first voltage into an adjusted first voltage according to a setting; an amplifier to amplify the adjusted first voltage by a preset amplification factor for multi-feed determination into an amplified first voltage; processing circuitry configured to determine whether or not multi-feed of the sheet has occurred based on the amplified first voltage; and processing circuitry configured to adjust the setting, wherein the receiver receives a second ultrasonic wave, the second ultrasonic wave being an ultrasonic wave sent from the ultrasonic wave generator and reaching the receiver without passing through the sheet, and outputs a second voltage corresponding to the second ultrasonic wave, and the processing circuitry configured to adjust the setting adjusts the setting such that an adjusted second voltage generated by the voltage controller falls within a range between a first reference value, inclusive, and a second reference value, exclusive.