An image forming apparatus includes a detection sensor to irradiate light to a recording medium passing through a printing path, and detect an amount of light, a driving device to move a cleaning member to a cleaning region overlapping the printing path to clean a light window of the detection sensor, and a processor to confirm a position of the cleaning member based on the amount of light detected by the detection sensor and control the driving device to move the cleaning member based on the confirmed position.

Offset print apparatus comprises: a blanket to receive print agent; a non-contact temperature sensor to monitor electromagnetic radiation from a measurement location of the blanket and generate a respective output; and a controller to: receive the output from the non-contact temperature sensor; determine coverage information relating to a print agent coverage of the blanket at the measurement location; and calculate a temperature of the blanket at the measurement location taking into account both the output from the non-contact temperature sensor and the determined coverage information.

A water content sensor for a recording medium includes a single light emitting part, a wavelength separation device and a detector device. The single light emitting part emits infrared light in a wavelength range including an absorption wavelength of water along one incident light path toward the recording medium. The wavelength separation device separates infrared light, either reflected from or transmitted through the recording medium, into a first light in a first wavelength range including the absorption wavelength of water and a second light in a second wavelength range excluding the first wavelength range. The detector device receives the first light in the first wavelength range and the second light in the second wavelength range, and generates a first output corresponding to an intensity of the first light received and a second output corresponding to an intensity of the second light received, respectively.

Offset print apparatus comprises: a blanket to receive print agent; a non-contact temperature sensor to monitor electromagnetic radiation from a measurement location of the blanket and generate a respective output; and a controller to: receive the output from the non-contact temperature sensor; determine coverage information relating to a print agent coverage of the blanket at the measurement location; and calculate a temperature of the blanket at the measurement location taking into account both the output from the non-contact temperature sensor and the determined coverage information.

Type and moisture content of a sheet of paper are determined with high accuracy for controlling an image forming condition, accordingly. A coping machine includes a transmitted-light measuring unit, a reflected-light measuring unit, a type determination unit configured to determine a type of a sheet of paper, a moisture content calculation unit configured to calculate a moisture content of the sheet of paper, based on the type of the sheet of paper determined by the type determination unit and the intensity of the light measured by the reflected-light measuring unit, and an image forming condition setting unit configured to set an image forming condition for the sheet of paper.

A toner coverage sensing system is provided for sensing toner particles printed onto a surface of a process element using an electrophotographic printing system. The printed toner particles include porous color toner particles. An infrared radiation source directs infrared radiation onto the printed toner particles on the surface of the process element A diffused radiation detector senses infrared radiation scattered from the printed toner particles, wherein the diffused radiation detector is oriented such that that the sensed infrared radiation does not include specular reflections from the surface of the process element. A data processing system determines a sensed toner coverage for the porous color toner particles on the surface of the process element responsive to the sensed scattered infrared radiation.

A sheet characteristic detection device includes a first conveyance path on which a sheet is conveyed, a second conveyance path that is branched from the first conveyance path and on which a sheet to be purged is conveyed without passing through an image former, and a first detector that is disposed on the first conveyance path and allows detection of sheet characteristic information corresponding to at least one of a size, a sheet thickness, a basis weight, or a moisture amount of the sheet.

Type and moisture content of a sheet of paper are determined with high accuracy for controlling an image forming condition, accordingly. A coping machine includes a transmitted-light measuring unit, a reflected-light measuring unit, a type determination unit configured to determine a type of a sheet of paper, a moisture content calculation unit configured to calculate a moisture content of the sheet of paper, based on the type of the sheet of paper determined by the type determination unit and the intensity of the light measured by the reflected-light measuring unit, and an image forming condition setting unit configured to set an image forming condition for the sheet of paper.

An image forming apparatus includes: a conveyor that conveys a sheet along a conveyance path; a detector that is disposed on the conveyance path and detects a physical property of a sheet with first detection accuracy or second detection accuracy lower than the first detection accuracy; an image former that forms an image on a sheet under an image forming condition based on a result of detection performed by the detector with the first detection accuracy; and a determiner that determines that a physical property of a sheet has changed among a plurality of sheets that is conveyed along the conveyance path on the basis of a result of detection performed by the detector on the plurality of sheets that is conveyed with the second detection accuracy.

An image forming apparatus includes a fixing member that includes a heater that generates heat in accordance with a predetermined fixing temperature to fix an unfixed image held on a medium, a bend detector that is disposed upstream from the fixing member in a medium transport direction to detect a bend of a medium having a leading end arriving at the fixing member, and a heating control member that controls the heater based on the bend of the medium detected by the bend detector.