Abstract: Examples relate to methods to heat a print agent deposited on a print agent, print an image on a print media and heating systems for a heating a print agent deposited on a print media. A heating system comprises a radiation emitter to irradiate a print agent deposited on a print media, a reflector to reflect a radiation emitted by the radiation emitter back to the radiation emitter, and a displacing member to shift the heating system between a pre-heating position wherein the radiation reflected back to the radiation emitter has a higher magnitude and a heating position wherein the radiation reflected back to the radiation emitter has a lower magnitude.

Abstract: A thermal treatment unit for a printer is mountable on a carriage that moves across a printing medium. The thermal treatment unit comprises an emitter element to emit radiation towards the printing medium to thermally treat the printing medium, wherein the thermal treatment unit varies a radiation power output of the emitter element in terms of a spatial position of the carriage along a width direction of the printing medium.

Abstract: A method, a printing device and a calibration module to check an alignment element of a printer by comparing a relative alignment of a calibration mark with respect to a reference mark, wherein the calibration mark indicates an alignment of the alignment element and the reference mark indicates an alignment of a printhead scanning direction of the printer.

Abstract: Examples of the present disclosure relate to a method for providing a status of a radiation emitter of a printing device, the method comprising image sensing at least part of a print agent after deposition onto a print substrate and after heating by the radiation emitter: obtaining, based on the image sensing, an irradiance applied on the heated print agent and providing a status of the radiation emitter in response to determining a deviation of the irradiance with respect to an expected irradiance.

Abstract: Obstacle detection for a moving element activated by a motor is disclosed. The obstacle detection may comprise a controller to: move the element at a substantially constant speed; determine an actual torque value to move the element at the constant speed; determine a torque parameter based on the actual torque value; comparing the torque parameter with a threshold value; and determining the presence of an obstacle if the torque parameter is above the torque parameter threshold; wherein the torque parameter is determined based on a set of historical torque values and the actual torque value.

Abstract: Obstacle detection for a moving element activated by a motor is disclosed.

Abstract: Light emitted from an obliquely angled LED source is directed by peripheral light tube walls which extend vertically toward media displaying printed indicia. The emitted light provides an illuminated area surrounding the printed indicia, while the light tube walls shield the printed indicia from excessive external light, so that a sensor measures the intensity of emitted light directly reflected from the media through a protective aperture.

Abstract: Light emitted from an obliquely angled LED source is directed by peripheral light tube walls which extend vertically toward media displaying printed indicia. The emitted light provides an illuminated area surrounding the printed indicia, while the light tube walls shield the printed indicia from excessive external light, so that a sensor measures the intensity of emitted light directly reflected from the media through a protective aperture.

Abstract: A method of monitoring and controlling the quality of pen markings on a plotting medium by qualifying each pen based on optically sensing across a sample line drawn on an actual medium. During each subsequent plotting task of a particular pen which has been qualified, an actual line plot is optically sensed across a selected point to make a comparison with the sample line. If the actual line plot is unsatisfactory, the deficient pen is replaced and the plot is restarted from the beginning, or retraced from the last good verification, or is stopped to allow the user to select an appropriate corrective procedure.