A document feeding device includes a document placement unit at which a document is placed, a feeding roller for feeding the document, and a ranging sensor for measuring a distance to the document located most upward on the document placement unit. A control unit stops feeding the document by the feeding roller based on post-processing distance data obtained by statistically processing time series data of the distance measured by the ranging sensor.

A system and control method for determining an amount of paper product dispensed from a dispenser or remaining in the dispenser is provided. The paper product is initially loaded in the dispenser as a paper product formation, such as a roll or stack of the product. At defined intervals, a digital image of an aspect of the paper product formation in the dispenser is taken and transmitted to a digital imager processor. A feature of the digital image that changes as the paper product formation decreases in size as the paper product is dispensed is analyzed and compared with a predetermined value of the feature at a predefined size of the paper product formation to determine an amount of the paper product dispensed or remaining in the dispenser.

A post-processing apparatus includes a guiding unit that faces a placement surface onto which sheets are transported and stacked as a stack of sheets and that is capable of changing a gap in a thickness direction of the stack of sheets, the guiding unit being configured to guide the sheets which are transported, and a controller that controls a size of the gap and a change pattern of the gap.

An example finisher includes a first portion extending in a vertical direction and including a height adjustment unit, a second portion extending from the first portion in a lateral direction and including a finishing unit to perform a finishing process, and a stacker to receive paper discharged from the finishing unit, the stacker extending in an opposite direction to the second portion in the lateral direction. The height adjustment unit is to adjust a height of the second portion from an installation surface and includes a base plate including a horizontal slot, a guide plate including an inclined slot, and a slide lever coupling the horizontal slot and the inclined slot.

An example finisher includes a first portion extending in a vertical direction and including a height adjustment unit, a second portion extending from the first portion in a lateral direction and including a finishing unit to perform a finishing process, and a stacker to receive paper discharged from the finishing unit, the stacker extending in an opposite direction to the second portion in the lateral direction. The height adjustment unit is to adjust a height of the second portion from an installation surface and includes a base plate including a horizontal slot, a guide plate including an inclined slot, and a slide lever coupling the horizontal slot and the inclined slot.

A sheet feeding device includes a sheet loading table on which a bundle of sheets is stacked, an identification mark on an end face of the sheet loading table, and an imaging unit to identify the identification mark.

The invention relates to a method for winding up a web of material (4) by means of an apparatus (1) including at least: one winding-up space (2) for accommodating an at least partially wound up web of material (wound roll (3)) having a winding center (Z); means for conveying and/or manipulating the web of material prior to and/or during winding-up; including the following steps: a) operating the apparatus (1); b) monitoring the web of material (4) and/or the resulting wound roll (3) by means of at least one image capturing device (30) for obtaining at least one current state (actual state) of the web of material (4) and/or of the wound roll (3); c) comparing at least one actual state to at least one target state and corresponding to the actual state, and determining at least one deviation of the actual state from the corresponding target state; d) if the deviation exceeds/falls below at least one predetermined limit value, performing a correction of at least one operating parameter of the apparatus (1) which operating parameter is at least a contributing factor for the deviation.

An example paper feed device includes a tray to feed printing paper, a magnetic force generation element to generate a magnetic flux, a 3D magnetic sensor to detect changes in the a density of the magnetic flux generated by the magnetic force generation element in each of three axes, and a controller. The tray has a movable element that is movable in relation to the printing paper. Either the magnetic force generation element or the 3D magnetic sensor is attached to the movable element. The controller determines the position of the movable element based on a detection signal received from the 3D magnetic sensor.

An example paper feed device includes a tray to feed printing paper, a magnetic force generation element to generate a magnetic flux, a 3D magnetic sensor to detect changes in the a density of the magnetic flux generated by the magnetic force generation element in each of three axes, and a controller. The tray has a movable element that is movable in relation to the printing paper. Either the magnetic force generation element or the 3D magnetic sensor is attached to the movable element. The controller determines the position of the movable element based on a detection signal received from the 3D magnetic sensor.

A sheet stacking device includes a sheet stacker, an image capturing device, and circuitry. The sheet stacker stacks a sheet. The image capturing device captures an image of a whole face of the sheet stacked in the sheet stacker. The circuitry detects a size of the sheet stacked in the sheet stacker, whether the sheet stacked in the sheet stacker is a last sheet, or whether an image is formed on an image forming face of the sheet, based on image data of the image captured by the image capturing device.