Hewlett-packard Company

Robert N Low

Frank L Cloutier

Paul H McClelland

Niels J Nielsen

J P Harmon

John H Dion

Donald R McClelland

F Duncan Terry

Gary L Siewell

Roy T Buck

R Ernst Erni

Ink-jet print cartridge

An orifice plate is provided of an electroformed material which incorporates an integral ink distribution manifold and integral hydraulic separators between orifices. The general approach to the method of making the orifice plate is to first construct a two-part mandrel made up of a 'hard' mandrel which can be reused many times and a 'soft' mandrel which is renewed each time the mandrel is used. Typically, the surface of the 'hard' mandrel is configured by mask and etch techniques, or by mask and electroplate techniques to define the ink distribution manifold and the hydraulic separators, while the 'soft' mandrel is configured by mask and develop techniques to define the orifices and edges between orifice plates. Upon completion of the mandrel, its surface is electroplated with a relatively uniform thickness of metal, and the newly electroplated surface having the orifice plates patterned therein is separated from the mandrel.

Ink jet orifice plate having integral separators

An ink reservoir which incorporates a negative back pressure source coupled to a membrane wall of the reservoir to prevent ink leakage from a reservoir orifice is disclosed. The back pressure is created by either a linear or nonlinear spring which can be either independent of, or integral with, the membrane. The result is freedom from ink leakage and improved quality printing when the reservoir is used in conjunction with an ink pen such as used in ink jet printing.

Ink reservoir with essentially constant negative back pressure

A thermal ink jet head is disclosed in which the jetting resistors, fluid interconnections, ink reservoir, electrical connections, and jetting orifices are fully integrated to provide an inexpensive, disposable jetting head. The entire hydraulic ink system is sealed to eliminate user interaction with the liquid ink, and ink can only exit the head via the jetting orifices under the influence of the jetting resistors. Once the ink is expended the user disposes with the old head and installs a new one by breaking and making a simple mechanical and low voltage electrical connection.

Disposable ink jet head

A method of making a monolithic bubble-driven ink jet print head is provided which eliminates the need for using glue or other adhesives to construct multiple part assemblies. The concept of the method is to provide a layered structure which can be manufactured by relatively standard integrated circuit and printed circuit processing techniques. First, a substrate/resistor combination is manufactured. Then a foundation of conductive material is firmly attached to the substrate and a resist layer is used to define a perimeter/wall combination over the foundation, with the perimeter/wall combination surrounding the resistors and providing hydraulic separation between them. The perimeter/wall combination is then electroplated in place. A flash coat of metal is applied over the resist which is inside the perimeter of the perimeter/wall combination and a second layer of resist is used to define the desired orifices and the external shape of the part. A second layer of metal is then electroplated in place on the flash coat covering the first layer of resist and the perimeter/wall combination. The flash coat and resists are then stripped, leaving a void defined by the second layer of metal and the perimeter/wall combination, with this second layer of metal having an orifice therein. The void forms the firing chamber for supplying ink to the resistors during operation.

Monolithic ink jet print head

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Corvallis, OR, United States of America

Robert N Low