Hewlett-packard Development Company, L.P.

Other

Timothy Jacob Luedeman

Robert M Yraceburu

Daniel James Magnusson

Wesley R Schalk

Kevin Lo

William F Winters

James D Plymale

In some examples, a system can include: a heating device, a Proportional Integral Derivative (PID) controller and a switching mechanism to selectively enable transmission of signals to the heating device based on a real time temperature in proximity to the heating device, wherein the PID controller is to continuously output pulse width modulation (PWM) signals independent of selective transmission of signals by the switching mechanism.

Signals controllers

An example of a print system including a dryer to dry a sheet of paper. The print system includes a media feeder to feed the sheet of paper into the dryer and a controller to vary a speed of the media feeder. The print system includes a communication interface to receive data associated with an image to print on the sheet of paper and a processor. The processor is coupled to the controller and the communication interface. The processor is to determine a first density index for a first portion of the image and to determine a second density index for a second portion of the image. The processor is to adjust the speed of the media feeder via the controller based on the first density index and the second density index.

Drying speed adjustments via density index analysis

A printer including a print bar and a dryer system. The print bar operates to deposit printing material in accordance with a print job. The dryer system operates to intake and heat air from an internal region in which one or more electrical components of the printer are located. The dryer system directs the heated air through multiple outlets that are acutely angled with respect to a location or media of deposited printing material, to dry the printing material while cooling the internal region of the printer.

Dryer system to cool printer

In one example, a method for controlling temperature of a print dryer. High power is applied to a heater of the print dryer. A series of temperatures of the print dryer are periodically measured and stored until a target temperature for the print dryer is exceeded. Low power is applied to the heater after the target temperature is exceeded. A rate of temperature change at a time when the target temperature was exceeded is calculated from the stored temperatures. Using the rate, an initial heater duty cycle defining an initial heater power determined. PID control of the heater power is performed, beginning with the initial heater duty cycle, to maintain the print dryer temperature at the target temperature within a predefined accuracy.

Print dryer heater control

Examples described herein include a star wheel mount that includes a support element. The support element includes a first clip element coupled to a first end to engage a first mounting element on a media handler housing, and a second clip element coupled to a second end opposite the first end to engage a second mounting element on the media handler housing. The star wheel mount also includes a star wheel support axle coupled to hold a star wheel in a plane perpendicular to a surface of the media handler housing.

Star wheel mounts

In one example, a media guide for use in a printer having a print bar and a print zone adjacent to the print bar includes a movable blocker downstream from the print zone along a media path and movable though a range of motion to block print media from leaving the media path when exiting the print zone.

Print media guide

In an example, a printing device can include a pivot point, a bias arm formed of a rigid member to rotate about the pivot point, the bias arm comprising a first end to extend into a print zone and a second end opposite the first end, and a spring in communication with the second end of the bias arm to bias the first end to contact the platen.

Bias arms

In one example, a shroud to protect a printhead in a print bar includes: an elongated body having an opening therein through which a printhead may dispense liquid past the shroud when the shroud is affixed to the print bar; and a bump on an exterior surface of the body next to the opening. The bump is configured to guide a leading edge of print media away from the printhead during printing when the shroud is affixed to the print bar and the print bar is installed in a printer.

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Portland, OR, United States of America

Timothy Jacob Luedeman