A housekeeping manifold is provided at the end of a row of ejector apertures of a drop-on-demand printhead module. The housekeeping manifold includes upper and lower parts disposed on opposite sides of the row of ejector apertures, a trench extending between the manifold parts through which ink drops from the ejector apertures are discharged, openings between the manifold parts and the trench and a ducting arrangement for supplying environmental fluids to or exhausting such fluids from the regio...

An electrographic printhead assembly comprises first and second sets of electrodes which define an array of crossing regions for generating packets of electric charge. An RF electrode burst actuates a first electrode to generate charge carriers while a varying extraction potential is developed. A second electrode is then activated with one or more control pulses which are synchronized with the RF burst and with selected portions of the varying extraction potential to gate charge carriers from th...

A duplex edge type thermal printhead assembly includes a pair of top and bottom substrates each of which is provided with a plurality of top and bottom heat-producing elements arranged in the form of an array on its main surface. The top and bottom substrates are fixedly attached together with their main surfaces facing each other so that the top and bottom electrodes are alternately arranged at an equal interval to define an integrated array of heat-producing elements. An edge type thermal prin...

In apparatus for thermally transferring ink from a ribbon, having backing and ink donor layers, to a letter, wherein the apparatus includes a frame, a thermal printhead, structure for controlling the printhead, and a roller rotatably connected to the frame for rotation when in engagement with a letter fed between the roller and a ribbon, there is provided an improvement for urging a ribbon and letter into engagement with one another. The improvement includes the printhead controlling structure i...

The light output of light emitting diodes on an LED printhead for a photosensitive printer is temperature compensated so that light output remains constant regardless of temperature changes of the LED chips. An LED chip has a plurality of exposure LEDs and a dummy LED. The voltage across the dummy LED is sensed and combined with an adjustable reference voltage. This provides the input to an op-amp, the output of which provides a chip reference voltage which controls the current to the LEDs.

A dot matrix printer including a single printhead having two columns of print wires, the wires in one column being used to print only odd numbered dot columns on a record member and the wires in the other column being used to print only even numbered dot columns on the record member. In one embodiment the wire columns are spaced apart a distance equal to an even number multiple of the space between two adjacent dot columns and the wires in each column are then energized alterntely as the printhe...

A wire matrix printer mechanism is designed to print a series of alpha-numeric characters and symbols by mechanically impacting an inked ribbon with a column of small diameter steel wires, driving the ribbon into paper riding on a platen. The body through which the print members pass is a molded structure having a separate channel for each print member. Each channel has a path consistent with the elastic curvature of the corresponding print member to provide a path of least resistance.

Systems, methods, and devices are provided for printhead calibration. A method includes printing a swath. A temperature rise of a printhead is measured during the swath and an operating energy of the printhead is calibrated based on the measured temperature rise while performing a non-test print job.

The present invention relates to a printhead assembly. The printhead assembly comprises an elongate body aligned with a body axis which, in use, is located transverse to the feed direction of paper. There is also provided a plurality of elongate print chips arranged along the body axis and each aligned with a print chip axis. Each print chip comprises a row of nozzles along its length. An acute angle is formed between the body axis and the print chip axis so that the separation between adjacent ...

A printhead assembly include a carrier, a first plurality of printhead dies each mounted on the carrier and adapted to print a first color, and a second plurality of printhead dies each mounted on the carrier and adapted to print a second color. Each of the first plurality of printhead dies are offset from and partially overlap an adjacent one of the first plurality of printhead dies, and each of the second plurality of printhead dies are offset from and partially overlap an adjacent one of the ...