A fastening member detection device includes a contact structure that moves with respect to a medium while contacting the medium, a vibration detector that detects vibration that occur in the contact structure, and a controller that determines whether there is a fastening member that fastens the medium, based on the vibration.

A plate-like detection plate portion that undergoes strain due to contact with an object is used for detecting the presence of an object that can come into contact with a liquid ejecting unit with relative movement between a medium and the liquid ejecting unit, and is provided with a piezoelectric film sensor that outputs an electric signal corresponding to strain of the detection plate portion. The piezoelectric film sensor includes a detection film portion in which a piezoelectric element that causes a voltage change corresponding to the strain is arranged, and an output circuit portion that converts the voltage change of the detection film portion into an electric signal and outputs the electric signal. The output circuit portion is provided on a second plate surface, which is a rear surface of a first plate surface facing the medium, of the detection plate portion.

A method for monitoring a machine element in a paper finishing machine (10). The machine element mounted for rotation machine elements (16-19) equipped with a sensor assembly (24) measuring force or pressure, and a counter-pair (15, 20, 33, 44) for said machine element. The machine element is made to rotate against the counter-pair, a measurement signal (25) is generated between the machine element and the counter-pair with the sensor assembly, and recording a reference cross-directional profile (21) of force or pressure generated. Condition monitoring (38) of vibration with the reference profile is by comparison of current signals with the reference so as to detect periodic variation (39.1, 39.2) in the cross-directional pressure profile, and producing visual information (37) from the analysis for monitoring. The invention also relates to a corresponding system, a rotating machine element for the method or the system, and a computer program product.

A plate-like detection plate portion that undergoes strain due to contact with an object is used for detecting the presence of an object that can come into contact with a liquid ejecting unit with relative movement between a medium and the liquid ejecting unit, and is provided with a piezoelectric film sensor that outputs an electric signal corresponding to strain of the detection plate portion. The piezoelectric film sensor includes a detection film portion in which a piezoelectric element that causes a voltage change corresponding to the strain is arranged, and an output circuit portion that converts the voltage change of the detection film portion into an electric signal and outputs the electric signal. The output circuit portion is provided on a second plate surface, which is a rear surface of a first plate surface facing the medium, of the detection plate portion.

Provided is a roller with pressure sensor. The roller includes a pressure sensor mounted to the roller. The pressure sensor includes a plurality of pressure sensing units distributed on a thin film. The pressure sensing units are electrically connected to each other with a metal wire but not in contact with each other. Also provided is a roll-to-roll device, which includes a roller mechanism and a pressure sensor.