US 12,358,743 B2
Image reading device, multi-feed detecting method, and multi-feed detecting program
Yasunori Fukumitsu, Kitakyushu (JP)
Assigned to Seiko Epson Corporation, Tokyo (JP)
Filed by Seiko Epson Corporation, Tokyo (JP)
Filed on Jul. 28, 2021, as Appl. No. 17/387,655.
Claims priority of application No. 2020-129540 (JP), filed on Jul. 30, 2020.
Prior Publication US 2022/0033209 A1, Feb. 3, 2022
Int. Cl. B65H 7/12 (2006.01); B65H 3/06 (2006.01)
CPC B65H 7/125 (2013.01) [B65H 3/0669 (2013.01); B65H 2553/30 (2013.01)] 4 Claims
OG exemplary drawing
 
1. An image reading device comprising:
a transport roller unit configured to transport a medium;
an emission speaker unit configured to emit an ultrasonic wave in accordance with a driving voltage and a reception microphone unit configured to receive the ultrasonic wave, the emission speaker unit and the reception microphone unit being disposed so that a transport path for the medium transported by the transport roller unit is interposed therebetween;
a reading unit configured to read the medium transported by the transport roller unit; and
a control unit configured to detect presence or absence of multi-feed of the medium on a basis of a signal received by the reception microphone unit, wherein
the image reading device is configured to switch a posture into any of a first posture or a second posture, the first posture being a posture in which the transport path is sloped relative to a mounting surface where the image reading device is mounted, the second posture being a posture in which an angle of the transport path relative to the mounting surface is smaller than that in the first posture,
the control unit sets a first driving voltage as the driving voltage when the posture is the first posture, and sets a second driving voltage lower than the first driving voltage as the driving voltage when the posture is the second posture,
when power supply to the image reading device is turned on, the control unit executes a determination processing for determining whether a signal received by the reception microphone unit in a state where no medium exists in the transport path exceeds a threshold value for calibration,
the control unit sets a third driving voltage greater than the first driving voltage as the driving voltage when determining, in the determination processing, that the signal does not exceed the threshold value for calibration, and
the control unit sets the driving voltage corresponding to the posture when determining, in the determination processing, that the signal exceeds the threshold value for calibration.