A sheet conveyance apparatus comprises a first sheet accommodation unit, a second sheet accommodation unit, a conveyance path and a controller. The first sheet accommodation unit and the second sheet accommodation unit are both provided with a movable guide plate which determines the size of an accommodated sheet. The conveyance path conveys a sheet between the first sheet accommodation unit and the second sheet accommodation unit. The controller carries out a control processing so as to change, in a case in which the accommodation size of the first sheet accommodation unit is changed, the accommodation size of the second sheet accommodation unit to be the same as that of the first sheet accommodation unit.

A decoloring apparatus includes a sheet conveying unit, a scanner, a decoloring unit, and a controller. The decoloring unit decolors the image on the sheet conveyed through the sheet conveying unit. The decoloring unit is positioned downstream of the scanner in a sheet conveying direction. A distance along the sheet conveying direction between the scanner and the decoloring unit is shorter than a length of a first predetermined sheet size and longer than a length of a second predetermined sheet size. A controller determines whether the sheet conveyed by the sheet conveying unit is the first predetermined sheet size or the second predetermined sheet size. The controller performs a mode limiting process if the sheet size is determined to be the first predetermined sheet size.

A decoloring apparatus includes a sheet conveying unit, a scanner, a decoloring unit, and a controller. The decoloring unit decolors the image on the sheet conveyed through the sheet conveying unit. The decoloring unit is positioned downstream of the scanner in a sheet conveying direction. A distance along the sheet conveying direction between the scanner and the decoloring unit is shorter than a length of a first predetermined sheet size and longer than a length of a second predetermined sheet size. A controller determines whether the sheet conveyed by the sheet conveying unit is the first predetermined sheet size or the second predetermined sheet size. The controller performs a mode limiting process if the sheet size is determined to be the first predetermined sheet size.

A light irradiation apparatus includes an irradiation unit including a light source to emit light to a process-target object, a light source driving circuit to drive the light source, a light source controller to control the light source driving circuit to change a light output level of the light source, and a light spot controller to control energy or energy density of a beam spot of the light on the process-target object depending on an operation mode, and a transition mode that one operation mode is being changed to another mode. The light spot controller sets the energy or energy density during the transition mode lower compared to either of the energy or energy density during the one operation mode before the transition mode and the energy or energy density during the another mode after the transition mode.

An image processing system includes an image forming unit, an image decoloring unit, a first sheet stacking unit, a second sheet stacking unit, a first detector for the first sheet stacking unit, a second detector for the second sheet stacking unit, and a control unit. The control unit controls a transport path of a sheet discharged from one of the image forming unit and the image decoloring unit.

A light irradiation apparatus includes an irradiation unit including a light source to emit light to a process-target object, a light source driving circuit to drive the light source, a light source controller to control the light source driving circuit to change a light output level of the light source, and a light spot controller to control energy or energy density of a beam spot of the light on the process-target object depending on an operation mode, and a transition mode that one operation mode is being changed to another mode. The light spot controller sets the energy or energy density during the transition mode lower compared to either of the energy or energy density during the one operation mode before the transition mode and the energy or energy density during the another mode after the transition mode.

A conveyor line system including an image processing device configured to irradiate a recording part with laser light to perform at least one of image recording and image erasing, the conveyor line system being configured to manage at least one conveying container each including: the recording part in which the image recording is performed by irradiation with the laser light; and an image part in which a displayed image has been drawn, wherein a formula below is satisfied at a wavelength of the laser light with which the recording part is irradiated during the image recording: A+30>B where A denotes an absorbance of the recording part and B denotes an absorbance of the image part of the conveying container.

An image processing system includes an image forming unit, an image decoloring unit, a first sheet stacking unit, a second sheet stacking unit, a first detector for the first sheet stacking unit, a second detector for the second sheet stacking unit, and a control unit. The control unit controls a transport path of a sheet discharged from one of the image forming unit and the image decoloring unit.

An image processing system includes an image forming unit, an image decoloring unit, a first sheet stacking unit, a second sheet stacking unit, a first detector for the first sheet stacking unit, a second detector for the second sheet stacking unit, and a control unit. The control unit controls a transport path of a sheet discharged from one of the image forming unit and the image decoloring unit.

A color erasing apparatus according to an embodiment includes a color erasing unit with a heating unit that heats a paper to erase an image formed on the paper by a heat-erasable coloring material. A sensor outputs a sensor signal indicative of a thickness of the paper. A paper thickness detector determines the thickness of the paper based on the sensor signal. A heating unit controller controls temperature of the heating unit based on the thickness of the paper determined by the paper thickness detector. When the thickness of the paper determined by the paper thickness detector is greater than a predetermined thickness, the temperature is controlled to be a first temperature. When the thickness of the paper determined by the paper thickness detector is less than the predetermined thickness, the temperature is controlled to be a second temperature less than the first temperature.