Detecting a continuous level of paper in a paper supply providing paper for a printing device. A length of the paper supply includes applied indicia, with the indicia extend contiguously across the length of the paper supply. When a paper section is dispensed, the position of the indicia on the dispensed portion of paper is determined, with the position reflecting a level pertaining to the paper supply remaining or dispensed.

Detecting a continuous level of paper in a paper supply providing paper for a printing device. A length of the paper supply includes applied indicia, with the indicia extend contiguously across the length of the paper supply. When a paper section is dispensed, the position of the indicia on the dispensed portion of paper is determined, with the position reflecting a level pertaining to the paper supply remaining or dispensed.

In a printing system, an attached-time remaining sheet amount at detecting attachment of a sheet feed tray to the printing system is detected. And current remaining sheet amount at end of image printing is detected. Then, it is determined whether the attached-time sheet remaining amount is greater than a first threshold value. In response to determination that an attached-time sheet remaining amount is greater than a threshold value and the current remaining sheet amount is less than or equal to the threshold value, a controller executes an alert process corresponding to controlling a display to display an alert. In response to determination that the attached-time sheet remaining amount and the current remaining sheet amount are equal to or less than the first threshold value, the controller inhibits executing the alert process.

A post-processing apparatus of an embodiment includes a first tray configured to receive a sheet on which the post processing is not executed by a processing section, a second tray configured to temporarily place a sheet, an inlet roller configured to carry in a sheet discharged from an image forming apparatus into the post-processing apparatus, a first roller configured to convey the sheet to the first tray, a second roller configured to convey the sheet to the second tray, a detection sensor configured to detect whether or not there is sheet being conveyed in a sheet conveyance path from the inlet roller to the first or the second tray, and a roller control section configured to drive the first or the second roller if an image forming apparatus stops the discharge of the sheet that is being printed and the detection sensor detects the sheet.

Detecting a continuous level of paper in a paper supply providing paper for a printing device. A length of the paper supply includes applied indicia, with the indicia extending contiguously across the length of the paper supply. When a paper section is dispensed, the position of the indicia on the dispensed portion of paper is determined, with the position reflecting a level pertaining to the paper supply remaining or dispensed.

Detecting a continuous level of paper in a paper supply providing paper for a printing device. A length of the paper supply includes applied indicia, with the indicia extending contiguously across the length of the paper supply. When a paper section is dispensed, the position of the indicia on the dispensed portion of paper is determined, with the position reflecting a level pertaining to the paper supply remaining or dispensed.

A sheet processing apparatus capable of properly stacking sheets by detecting abnormality of a sheet stacking state during a sheet stacking operation to thereby prevent stack overflow. In the sheet processing apparatus, a conveyed sheet is stacked on a stacking tray. A sheet presence sensor detects a sheet on a sheet stacking surface of the stacking tray. A sheet height reduction sensor detects sheets within a predetermined distance downward from the uppermost surface of sheets stacked on the stacking tray. When the sheet presence sensor detects no sheet, and the sheet height reduction sensor detects a sheet during an operation for discharging a plurality of sheets onto the stacking tray, it is determined that an abnormal stacking state has occurred, and conveyance of a sheet is stopped.

A sheet processing apparatus capable of properly stacking sheets by detecting abnormality of a sheet stacking state during a sheet stacking operation to thereby prevent stack overflow. In the sheet processing apparatus, a conveyed sheet is stacked on a stacking tray. A sheet presence sensor detects a sheet on a sheet stacking surface of the stacking tray. A sheet height reduction sensor detects sheets within a predetermined distance downward from the uppermost surface of sheets stacked on the stacking tray. When the sheet presence sensor detects no sheet, and the sheet height reduction sensor detects a sheet during an operation for discharging a plurality of sheets onto the stacking tray, it is determined that an abnormal stacking state has occurred, and conveyance of a sheet is stopped.

A sheet feeder control method for controlling a sheet feeder of an image forming apparatus includes feeding a sheet through a sheet feed path exposable to the exterior of the sheet feeder, detecting the feeding of the sheet at at least a first position on the sheet feed path, discharging the fed sheet to the exterior of the sheet feeder, detecting the discharge of the sheet at a second position downstream of the first position in a sheet feeding direction, detecting a sheet jam during the feeding and discharging of the sheet, and if the jammed sheet is detected at the second position but not at the first position, cancelling a malfunction state due to the sheet jam when the sheet stops being detected at the second position, irrespective of whether the sheet feed path is covered or exposed.

A sheet feeder control method for controlling a sheet feeder of an image forming apparatus includes feeding a sheet through a sheet feed path exposable to the exterior of the sheet feeder, detecting the feeding of the sheet at at least a first position on the sheet feed path, discharging the fed sheet to the exterior of the sheet feeder, detecting the discharge of the sheet at a second position downstream of the first position in a sheet feeding direction, detecting a sheet jam during the feeding and discharging of the sheet, and if the jammed sheet is detected at the second position but not at the first position, cancelling a malfunction state due to the sheet jam when the sheet stops being detected at the second position, irrespective of whether the sheet feed path is covered or exposed.