A system to monitor available media in a printer is disclosed. The system may include a media holder that includes a support frame and a support member that extends from the support frame. The support member may be configured to receive a media roll. The system may include an optical sensor attached to the support frame of the media holder. The optical sensor may be configured to include an axial end of the media roll within a field of view of the optical sensor. The optical sensor may be configured to output sensor data that indicates whether the media roll has available media according to a radius of the axial end.

Method for controlling a sheet feeding device (1) comprising an elevator (2) for a stack of sheets, and an air supply system (3) configured to supply and direct one of more air streams towards an upper region (4) of the sheet feeding device for floating a plurality of upper sheets of the stack of sheets, wherein the elevator comprises a vertically movable support (5) for supporting the stack of sheets from below, wherein the sheet feeding device comprises an optical sensor (6) positioned adjacent the floated sheets for measuring light reflected from the floated sheets at a plurality of different heights, wherein the method comprises the steps of: continuously deriving from the optical sensor a density reading (DR) indicating the density of sheets floated, continuously deriving an average density (AD) based on a plurality of density readings, continuously deriving an upper density limit (UDL) based on the average density multiplied by a predetermined upper density limit factor (UDLF), continuously deriving a lower density limit (LDL) based on the average density multiplied by a predetermined lower density limit factor (LDLF), adjusting a first operating parameter (OP) of the sheet feeding device should the density reading exceed the upper density limit, wherein the adjustment of the first operating parameter is such as to decrease the density of floated sheets, and adjusting the first operating parameter of the sheet feeding device should the density reading subceed the lower density limit, wherein the adjustment of the first operating parameter is such as to increase the density of floated sheets. Also, a sheet feeding device connected to a controller configured to operate according to this method.

Method for controlling a sheet feeding device (1) comprising an elevator (2) for a stack of sheets, and an air supply system (3) configured to supply and direct one of more air streams towards an upper region (4) of the sheet feeding device for floating a plurality of upper sheets of the stack of sheets, wherein the elevator comprises a vertically movable support (5) for supporting the stack of sheets from below, wherein the sheet feeding device comprises an optical sensor (6) positioned adjacent the floated sheets pot for measuring light reflected from the floated sheets at a plurality of different heights, wherein the method comprises the steps of: continuously deriving from the optical sensor a density reading (DR) indicating the density of sheets floated, continuously deriving an average density (AD) based on a plurality of density readings, continuously deriving an upper density limit (UDL) based on the average density multiplied by a predetermined upper density limit factor (UDLF), continuously deriving a lower density limit (LDL) based on the average density multiplied by a predetermined lower density limit factor (LDLF), adjusting a first operating parameter (OP) of the sheet feeding device should the density reading exceed the upper density limit, wherein the adjustment of the first operating parameter is such as to decrease the density of floated sheets, and adjusting the first operating parameter of the sheet feeding device should the density reading subceed the lower density limit, wherein the adjustment of the first operating parameter is such as to increase the density of floated sheets. Also, a sheet feeding device connected to a controller configured to operate according to this method.

A sheet conveying device, which is incorporated in an image forming apparatus, includes a first detector to detect an angle deviation of a recording medium to a sheet conveying direction, a second detector to detect a lateral shift of the recording medium to a width direction, a third detector to detect at least one of the angle deviation and the lateral shift after correction of the angle deviation detected by the first detector and the lateral shift detected by the second detector, and a rotary body to perform a primary movement by (1) rotating in the sheet conveying direction and returning to a reference position and by (2) moving in the width direction and returning to the reference position, and a secondary movement by performing at least one of (1) and (2) after the primary movement.

A method for detecting an edge of an object is carried out by means of a detection device (10), which has a transmission region running along a first straight line and has a receiving region which runs along a second straight line, which is arranged in parallel to the first straight line. A transmission subregion (11a-p) of the transmission region is selected, which extends up to a first end of the transmission region. Light is transmitted from the transmission subregion (11a-p) and a light signal of light reflected on the object is received in the receiving region. The transmission subregion (11a-p) is then shifted along the first straight line in the direction of a second end of the transmission region. Transmitting, receiving and shifting are repeated until the transmission subregion (11a-p) extends up to the second end at the start of the shifting step. A signal course is compiled from the received light signals, and the detection of the edge from the signal course is carried out.

An image forming device includes an image forming unit, a reading unit, a registration-less unit, and an engine control unit. The reading unit reads a sheet to be conveyed. The engine control unit moves the other end side of the registration-less unit to correct skew. The engine control unit obtains a deviation amount (first deviation amount) of the position of the sheet based on the correction, and changes a sheet conveyance speed from a first speed to a second speed when the sheet enters the registration-less unit. The engine control unit adjusts the timing to change from the first speed to the second speed based on the first deviation amount.

According to one embodiment, a post-processing apparatus includes a first sensor, a second sensor, and a control unit. The first sensor detects an object in a predetermined area in which a predetermined post-process is performed on a sheet conveyed from an image forming apparatus. The second sensor detects an object at a position closer to an opening in the area than the position of the first sensor with respect to the opening through which the sheet passes when the post-processed sheet is discharged from the area. When the second sensor detects an object before the first sensor detects the object, the control unit performs a predetermined process for preventing the occurrence of a failure.

An edge position detecting apparatus includes a light emitting device, a detecting device, and a calculating circuit. The light emitting device includes a plurality of light sources with different emission wavelengths. The light emitting device irradiates a conveyed object with linear light along a width direction of the conveyed object, the width direction being perpendicular to a conveying direction of the conveyed object. The detecting device detects, at a plurality of positions in the width direction of the conveyed object, intensity of reflected light of light emitted by the light emitting device. The calculating circuit calculates, based on a detection result of the detecting device, a position of an edge of the conveyed object in the width direction.

A device having a receiving device for receiving at least one ribbon-shaped substrate and with a first and a second driving means, wherein the first and the second driving means for the transport of the ribbon-shaped substrate in x-direction are designed to cooperate such that the first driving means engages in the region of the one edge of the ribbon-shaped substrate and the second driving means engages in the region of the other edge of the ribbon-shaped substrate, wherein both driving means can be controlled such that they can drive the edge area of the ribbon-shaped substrate assigned to each driving means at adjustably different drive speeds. At least the first driving means is arranged in the device via a first displacement device allowing for a displacement essentially limited to the y-direction of the first driving means, relative to the receiving device.

A method of testing a functional unit includes an optical sensor system (28) for detecting an optical signal from at least a part of a moving material web (14), a data processing system (36) for valuating the optical signals, and a display (38) displaying a state of the material web (14) and arranged in a sensitive range (30) of the sensor system (28).