Ricoh Company, Ltd.

Hitachi Koki Imaging Solutions, Inc.

Hiroshi Nishimura

Giang Vo

Connor Matsumori

Shogo Nobumori

Cesar Hurtado

Norimasa Sohgawa

Printheads and design of printheads. In one embodiment, a printhead comprises a plurality of jetting channels, and a manifold apparatus fluidly coupled to the jetting channels. For each jetting channel, the printhead includes a first fluid path between the jetting channel and the manifold apparatus, and a second fluid path between the jetting channel and the manifold apparatus. The jetting channel is configured to jet a print fluid via pressure waves generated in a pressure chamber of the jetting channel. Lengths of the first fluid path and the second fluid path are different by a threshold length so that an arrival time of the pressure waves at the manifold apparatus are different by a threshold time.

Printhead design with multiple fluid paths to jetting channels

Printheads for a jetting apparatus. In one embodiment, a printhead comprises a plurality of flow-through jetting channels each configured to jet a print fluid out of a nozzle. The printhead further includes a supply manifold fluidly coupled to the flow-through jetting channels, a return manifold fluidly coupled to the flow-through jetting channels, and one or more bypass manifolds fluidly coupled between the supply manifold and the return manifold.

Flow-through printhead with bypass manifold

Printheads and methods of operation. In one embodiment, a printhead includes a plurality of jetting channels comprising first jetting channels configured to jet a first print fluid and second jetting channels configured to jet a second print fluid, and a driver circuit communicatively coupled to actuators of the jetting channels. The driver circuit receives a drive waveform comprising non-jetting pulses and jetting pulses, and gating signals comprising a first active gating signal designated for jetting the first print fluid, and a second active gating signal designated for jetting the second print fluid. The driver circuit selectively applies the non-jetting pulses and the jetting pulses to actuators of the first jetting channels based on the first active gating signal to jet the first print fluid, and selectively applies the jetting pulses to actuators of the second jetting channels based on the second active gating signal to jet the second print fluid.

Driver circuit for a printhead

Printheads and methods of operation. In one embodiment, a printhead includes a plurality of jetting channels comprising first jetting channels configured to jet a first print fluid and second jetting channels configured to jet a second print fluid, and a driver circuit communicatively coupled to actuators of the jetting channels. The driver circuit receives a drive waveform comprising first jetting pulses provisioned for the first print fluid and second jetting pulses provisioned for the second print fluid, and gating signals comprising a first active gating signal designated for jetting the first print fluid and a second active gating signal designated for jetting the second print fluid. The driver circuit selectively applies the first jetting pulses to actuators of the first jetting channels based on the first active gating signal, and selectively applies the second jetting pulses to actuators of the second jetting channels based on the second active gating signal.

Printheads and manifolds within printheads. In one embodiment, a method comprises determining a resonant frequency of jetting channels for a printhead, and selecting a target length for a manifold fluidly coupled to the jetting channels such that resonant frequencies of the manifold differ from the resonant frequency of the jetting channels by a threshold amount.

Manifold length in a printhead

Printheads for a jetting apparatus. In one embodiment, a printhead comprises a plurality of jetting channels having nozzles on a bottom surface configured to jet a print fluid, and longitudinal sides disposed between the bottom surface and a top surface. The printhead also comprises Input/Output (I/O) ports disposed on one or more of the longitudinal sides, and configured to convey the print fluid into or out of the printhead. The printhead further includes one or more chain manifolds disposed between the I/O ports.

Input/output (I/O) design of a printhead allowing for daisy-chaining

A service media and method for cleaning printheads. In one embodiment, a method of cleaning includes inserting a service media beneath one or more printheads, inflating the service media so that an absorbent material of the service media contacts a nozzle surface of the printheads, and deflating the service media.

Service media and methods for cleaning printheads

Printheads for a jetting apparatus. In one embodiment, a printhead includes inlet ports each configured to receive one of eight or more types of print fluids, and a plurality of nozzles arranged in one or two nozzle rows. Each of the nozzles is fluidly coupled to one of the inlet ports. In groupings of eight or more adjacent nozzles of the plurality, the adjacent nozzles are each configured to jet a different one of the types of print fluids.

Printhead having one or two nozzle rows that jet at least eight different types of print fluids

Apparatus and method for providing a print fluid to a flow-through printhead. The printhead has a row of jetting channels configured to jet droplets of a print fluid, a supply manifold fluidly coupled to the row of jetting channels, and a return manifold fluidly coupled to the row of jetting channels. A first reservoir is fluidly coupled to the supply manifold, and a second reservoir is fluidly coupled to the return manifold. The first reservoir and the second reservoir are fluidly isolated except through the printhead.

Independent reservoirs for supplying a print fluid to a flow-through printhead

Devices and method for performing temperature measurements in a printhead. In one embodiment, a printhead includes at least one row of jetting channels configured to jet droplets of a print fluid using piezoelectric actuators. A drive circuit includes an input voltage generator that applies a step voltage to a piezoelectric actuator of a jetting channel, and an output voltage detector that detects an output voltage across the piezoelectric actuator over time in response to the step voltage. The drive circuit also includes a temperature detector that determines a voltage response to the step voltage at the piezoelectric actuator based on the output voltage over time, and determines a temperature measurement for the piezoelectric actuator based on the voltage response of the piezoelectric actuator.

Temperature sensing in a printhead using piezoelectric actuators

Printheads for a jetting apparatus. In one embodiment, a printhead includes inlet ports each configured to receive one of four or more types of print fluids. The printhead further includes a plurality of nozzles arranged in one or two nozzle rows, where each of the nozzles is fluidly coupled to one of the inlet ports. In groupings of four or more adjacent nozzles of the plurality, the adjacent nozzles are each configured to jet a different one of the types of print fluids.

Growing community of inventors

West Hills, CA, United States of America

Hiroshi Nishimura