An image forming system includes an image forming apparatus configured to form a toner image on a recording material, a varnish application apparatus configured to apply a varnish to the recording material, and a control unit. The control unit is configured to apply a first application amount of varnish to the recording material per unit area in a case of executing the image forming job for forming a varnish layer on a recording material having a first grammage, and is configured to apply a second application amount of varnish to the recording material per unit area in a case of executing the image forming job for forming the varnish layer on a recording material having a second grammage smaller than the first grammage, the second application amount being larger than the first application amount.

A first light guide guides first light in a first light guiding path. The first light is of light irradiated from the light source to a sheet. A first detection unit receives reflected light from the sheet and outputs an image signal indicating an image of a surface of the sheet. A second light guide guides second light in a second light guiding path different from the first light guiding path. The second light is of the light irradiated from the light source and is different from the first light. A second detection unit receives the second light and output a detection signal corresponding to a light amount of the second light. A control unit controls a light emission amount of the light source based on the detection signal.

A sheet conveyance apparatus includes a conveyance unit configured to convey a sheet, a guide member disposed to define a conveyance path, a light-emitting element, a light-receiving element configured to output a detection signal that changes in accordance with an amount of received light, a first light-passing portion disposed to define an optical path from the light-emitting element to the conveyance path, and a second light-passing portion disposed to define an optical path from the conveyance path to the light-receiving element. The light-receiving element is configured such that the detection signal changes in accordance with whether or not a sheet is present in the conveyance path. Reflectance of each of the first light-passing portion and the second light-passing portion to the light emitted from the light-emitting element is higher than reflectance of the guide member to the light emitted from the light-emitting element.

A transmitter transmits ultrasonic wave of a predetermined volume. A reflected ultrasonic wave receiver receives reflected ultrasonic wave, transmitted from the transmitter and reflected by a sheet. A permeated ultrasonic wave receiver receives permeated ultrasonic wave, transmitted by the transmitter and permeated through the sheet. A volume detector detects reflected volume of the reflected ultrasonic wave, and permeated volume of the permeated ultrasonic wave. The decider identifies a thickness of the sheet being transported by a transport device, and decides whether multifeed of the sheets is occurring, on a basis of a comparison result between the detected reflected volume and a reference reflected volume, and a comparison result between the detected permeated volume and a reference permeated volume.

An image forming apparatus includes a cartridge including an abutting portion and an apparatus main body. The apparatus main body includes a mounting portion of the cartridge, a fixing portion for fixing the toner image, an attachable/detecting mechanism of the cartridge, a shutter, and a moving member. The attachable/detecting mechanism includes an acting member movable between a first position and a second position by the mounting of the cartridge. The shutter is movable between a closed position and an open position, and a moving member moves both the shutter and the acting member and includes an abutted portion. When the cartridge is moved, the moving member is moved by abutment of the abutting portion of the cartridge with the abutted portion, the acting member moves from the first position to the second position, and the shutter moves from the closed position to the open position.

An image forming system includes the following. An image former forms an image on a recording medium. A laminator performs lamination in which a film is laminated on a surface of the recording medium on which the image is formed by the image former. A hardware processor obtains information regarding image forming by the image former and that determines a condition of the lamination by the laminator based on the obtained information regarding the image forming.

A thickness detection mechanism arranged in a scanner or printer for measuring the thickness of mediums fed through the scanner or printer, which comprising: a conveyor section; at least a idle roller set arranged above the conveyor section, which includes at least a shaft and an idle roller pivotally arranged on the shaft; at least an elastic portion arranged above the shaft; and at least a pressure sensor secured on the elastic portion; wherein the thickness detection mechanism measures the thickness of the medium by measuring the pressure applied on the pressure sensor by the idle roller set as the idle roller set being pushed upward, and thus avoids the medium too thin or too thick to enter the scanner or the printer.

An image forming apparatus includes a sheet stacking portion, an image forming portion, a detection portion configured to detect a position, in a sheet width direction, a storage configured to store position information of a sheet, and a controller. The controller is configured to cause the storage to store the position information based on a position of a sheet detected by the detection portion during execution of the job, and if sheet information of a sheet used in a previous job is matches sheet information of a sheet used in a current job, cause the image forming portion to start formation of an image to be formed on a first sheet, before a position of the first sheet is detected by the detection portion, based on the position information stored in the storage in the previous job.

An image forming system includes: an image forming apparatus that includes a transfer device that transfers a toner image onto a sheet and a fixing device that fixes the toner image; a sheet heating device that heats the sheet on an upstream of the fixing device in a sheet conveyance direction; a first detector that detects a temperature inside the image forming apparatus; a second detector that detects a temperature of the sheet before the sheet heating device heats the sheet; and a controller that causes the sheet heating device to heat the sheet based on a detection result by the second detector and a sheet passing condition of the sheet, and corrects at least one of a transfer current and a transfer voltage in the transfer device based on a detection result by the first detector in a case where the sheet heating device heats the sheet.

According to at least one embodiment, an image forming apparatus includes a first sensor, a second sensor, and a controller. The first sensor is configured to detect a user. The second sensor is configured to detect a sheet in a sheet holder. The controller is configured to change a transition mode of an operation mode based on a first detection result of the sheet in the sheet holder by the second sensor in response to the detection of the user by the first sensor when the operation mode of the image forming apparatus is a second power-saving mode, which consumes less power than a first power-saving mode.