Abstract: A printing apparatus is disclosed herein. The apparatus comprises a platform defining a printing zone to hold a media moveable along a media path direction; a first sensor at a first location along the media path direction to measure a media advance at the first location; a second sensor located at a second location along the media path direction downstream the first location, the second sensor to measure the media advance at the second location; and a controller. The controller to determine a deformation gradient of the media based on a first set of measurements of the media advance by the sensors at the first and second locations and adjust an image to be printed based on the deformation gradient.

Abstract: An apparatus is disclosed herein. The apparatus comprises a carriage to move laterally in a scanning direction over a platen, a scan beam to support the carriage over the platen, a mechanism to move the scan beam vertically, and a media holder. The media holder comprises a central portion to hold a media on the platen, a first end couplable to the platen at a coupling position, and a second end couplable to the scan beam such that the second end moves vertically along with the scan beam.

Abstract: Example implementations relate to substrate porosity determination. Some examples refer to a substrate porosity determination comprising an image capture device a controller to obtain a reference image by the image capture device; obtain a measurement image after a printing operation has been performed on a substrate located over the image capture device; compare the reference image and the measurement image—determine whether the substrate is porous based on the comparison; and determine a print parameter based on the determination of whether the substrate is porous.

Abstract: A printing apparatus is disclosed. The printing apparatus comprises a printhead and a controller. The printhead is to spit a printing fluid comprising a first mode and a second mode. The first mode corresponds to using a first energy level to spit the printing fluid and the second mode corresponds to using a second energy level to spit the printing fluid. The second energy level comprises a higher energy level than the first energy level. The controller is to determine a decap risk zone associated with the printing fluid, determine in view of the decap risk zone a decap location, and instruct the printhead to spit using the second mode at the decap location.

Abstract: A system is disclosed. The system comprises a roller with a spindle to wind and/or unwind a roll of media, a media advancement sensor to measure the advancement of the media, and a controller. The controller is to control the spindle to rotate an angular displacement, and to determine a calculated media advancement based on the angular displacement and a radius of the roll of media. The controller is also to receive from the media advancement sensor a measured media advancement. The controller is further to detect that a displacement difference between the measured media advancement and the determined media advancement exceeds a predetermined threshold. If the displacement difference exceeds the predetermined threshold a slippage condition is detected.

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: A printing apparatus is disclosed. The printing apparatus comprises a printhead and a controller. The printhead is to spit a printing fluid comprising a first mode and a second mode. The first mode corresponds to using a first energy level to spit the printing fluid and the second mode corresponds to using a second energy level to spit the printing fluid. The second energy level comprises a higher energy level than the first energy level. The controller is to determine a decap risk zone associated with the printing fluid, determine in view of the decap risk zone a decap location, and instruct the printhead to spit using the second mode at the decap location.

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

Abstract: Measuring the thickness of a print media supported by a platen or belt by: moving a measurement bar to a first position to contact a surface of the platen or belt, moving the measurement bar to a second position to contact a surface of the print media when supported by the platen or belt, and determining the spatial difference between the first and second positions such as to measure the thickness of the print media. The measurement bar is arranged to cover a width of the print media when supported by the platen or belt.

Abstract: Measuring the thickness of a print media supported by a platen or belt by: moving a measurement bar to a first position to contact a surface of the platen or belt, moving the measurement bar to a second position to contact a surface of the print media when supported by the platen or belt, and determining the spatial difference between the first and second positions such as to measure the thickness of the print media. The measurement bar is arranged to cover a width of the print media when supported by the platen or belt.