An image forming apparatus includes a main body, a sheet cassette attachable to the main body and configured to support one or more sheets to be supplied to the image forming unit, and a controller. The main body includes an electrode movable relative to the main body, a capacitance detector configured to output a signal indicating a value corresponding to a quantity of electricity stored in the electrode, and a wire. The sheet cassette includes a metal member, and a sheet supporting plate made of metal, movable relative to the sheet cassette in an up-down direction, and configured to support one or more sheets from below. The controller is configured to determine whether the sheet cassette is at an installation position in the main body from a level of the value of the signal outputted from the capacitance detector connected to the electrode via the wire.

A method (600) for detecting and tracking a feature of a web of packaging material (102), using a first capacitor (106) placed at a distance (d) from the web of packaging material (102) is provided. The method (600) comprises; feeding (602) a section of the web of packaging material (102) to a first position (p), so that the section influences a dielectric property of the first capacitor (106), measuring (604), at a point of time (t), a capacitance of the first capacitor (106), and determining (612) the feature of the section passing the first capacitor (106) at the point of time (t), based on the capacitance.

A sensor device is provided to detect a filling status of a consumable in a dispenser, the consumable being web material, and the filling status relating to a spatial extension of the consumable in the dispenser. The sensor device includes a capacitive sensor having an elongated and planar sensor area; and a first measurement section configured to measure the filling status of the dispenser. The capacitive sensor includes a first channel and a second channel. The first measurement section is configured to measure the filling status of the dispenser based on changes in capacitance detected by the first channel and the second channel.

A winding machine for web-type materials, in particular film materials, comprises a feeding device and at least one winding shaft which is capable of being driven and designed to receive a winding core for the winding of the web-type film material, wherein the winding machine is allocated a system for regulating and/or reducing an electrostatic charge of the web-type material during the winding process.

A sheet conveying apparatus capable of conveying a sheet as a conveyance target in a conveyance path includes a detector that detects capacitance in a predetermined detection region in the conveyance path; and a basis weight identifier that identifies a basis weight of the sheet as the conveyance target on the basis of first capacitance detected by the detector while the sheet as the conveyance target does not pass through the detection region and second capacitance detected by the detector while the sheet as the conveyance target passes through the detection region.

A capacitive sensing system based on projected self-capacitance is suitable for use in printing systems/products to sense paper tray status. In example embodiments, a capacitive sensing system is adapted for sensing the condition/characteristics of paper in the paper tray, such as paper size, stack height and page count and paper dielectric. The capacitive sensing system can be configured with one or more shielded capacitive sensors incorporated into the paper tray, and oriented relative to the paper according to the paper condition/characteristic sensed.

A sheet feeding device includes a cassette and a first sensor unit. The first sensor unit includes a first conductive plate and a first coil circuit board, so as to output a first output value corresponding to a position of the first conductive plate. A first moving mechanism moves the first conductive plate according to remaining quantity of paper sheets. The first conductive plate is attached to the cassette. The first coil circuit board is not attached to the cassette. A control unit determines current remaining quantity of paper sheets based on a magnitude of the first output value. The control unit determines whether or not the cassette is attached based on the magnitude of the first output value and a reference value.

A sheet conveying device includes a sheet cassette including a first housing, a pressing plate, a raising plate, a first resilient member, and a second resilient member. The sheet conveying device further includes a second housing, a sheet-cassette accommodating portion, a first electrode, a second electrode, a sheet conveyor, a driver, a first signal output device, and a second signal output device. When controlling the driver to move the raising plate to move the pressing plate upward, the controller detects a state change in the first signal output device from not outputting a conduction signal to outputting the conduction signal; upon this detection, starts counting the number of pulse signals; and determines an amount of upward movement of the pressing plate based on the counted number.

A sheet conveying device includes: a sheet cassette including a first housing, a pressing plate, a raising plate, a first resilient member, and a second resilient member; a second housing; a sheet-cassette accommodating portion; a first electrode; a second electrode; a sheet conveyor; a driver; a first output device that outputs a first signal and a second signal; a second output device that outputs a rotation pulse signal; and a controller that receives the first signal, the second signal, and the rotation pulse signal. The controller counts pulses of the rotation pulse signal received from the second output device, determines the number of pulses of the rotation pulse signal, and determines an amount of upward movement of the pressing plate based on the number of pulses of the rotation pulse signal.

A sheet feeding device includes a cassette and a first sensor unit. The first sensor unit includes a first conductive plate and a first coil circuit board, so as to output a first output value corresponding to a position of the first conductive plate. A first moving mechanism moves the first conductive plate according to remaining quantity of paper sheets. The first conductive plate is attached to the cassette. The first coil circuit board is not attached to the cassette. A control unit determines current remaining quantity of paper sheets based on a magnitude of the first output value. The control unit determines whether or not the cassette is attached based on the magnitude of the first output value and a reference value.