Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
1998-07-10
2001-05-29
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C347S020000, C347S044000
Reexamination Certificate
active
06239821
ABSTRACT:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
FIELD OF THE INVENTION
The present invention relates to ink jet printing and in particular discloses a direct firing thermal bend actuator ink jet printer.
The present invention further relates to the field of drop on demand ink jet printing.
BACKGROUND OF THE INVENTION
Many different types of printing have been invented, a large number of which are presently in use. The known forms of print have a variety of methods for marking the print media with a relevant marking media Commonly used forms of printing include offset printing, laser printing and copying devices, dot matrix type impact printers, thermal paper printers, film recorders, thermal wax printers, dye sublimation printers and ink jet printers both of the drop on demand and continuous flow type. Each type of printer has its own advantages and problems when considering cost, speed, quality, reliability, simplicity of construction and operation etc.
In recent years, the field of ink jet printing, wherein each individual pixel of ink is derived from one or more ink nozzles has become increasingly popular primarily due to its inexpensive and versatile nature.
Many different techniques on ink jet printing have been invented. For a survey of the field, reference is made to an article by J Moore, “Non-Impact Printing: Introduction and Historical Perspective”, Output Hard Copy Devices, Editors R Dubeck and S Sherr, pages 207-220 (1988).
Ink Jet printers themselves come in many different types. The utilization of a continuous stream of ink in ink jet printing appears to date back to at least 1929 wherein U.S. Pat. No. 1,941,001 by Hansell discloses a simple form of continuous stream electro-static ink jet printing.
U.S. Pat. No. 3,596,275 by Sweet also discloses a process of a continuous ink jet printing including the step wherein the ink jet stream is modulated by a high frequency electro-static field so as to cause drop separation. This technique is still utilized by several manufacturers including Elmjet and Scitex (see also U.S. Pat. No. 3,373,437 by Sweet et al).
Piezo-electric ink jet printers are also one form of commonly utilized ink jet printing device. Piezo-electric systems are disclosed by Kyser et. al. in U.S. Pat. No. 3,946,398 (1970) which utilizes a diaphragm mode of operation, by Zolten in U.S. Pat. No. 3,683,212 (1970) which discloses a squeeze mode of operation of a piezo electric crystal, Stemme in U.S. Pat. No. 3,747,120 (1972) discloses a bend mode of piezoelectric operation, Howkins in U.S. Pat. No. 4,459,601 discloses a Piezo electric push mode actuation of the ink jet stream and Fischbeck in U.S. Pat. No. 4,584,590 which discloses a shear mode type of piezo-electric transducer element
Recently, thermal ink jet printing has become an extremely popular form of ink jet printing. The ink jet printing techniques include those disclosed by Endo et al in GB 2007162 (1979) and Vaught et al in U.S. Pat. No. 4,490,728. Both the aforementioned references disclosed ink jet printing techniques which rely upon the activation of an electrothermal actuator which results in the creation of a bubble in a constricted space, such as a nozzle, which thereby causes the ejection of ink from an aperture connected to the confined space onto a relevant print media. Printing devices utilizing the electro-thermal actuator are manufactured by manufacturers such as Canon and Hewlett Packard.
As can be seen from the foregoing, many different types of printing technologies are available. Ideally, a printing technology should have a number of desirable attributes. These include inexpensive construction and operation, high speed operation, safe and continuous long term operation etc. Each technology may have its own advantages and disadvantages in the areas of cost, speed, quality, reliability, power usage, simplicity of construction operation, durability and consumables.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an alternative form of actuation of ink drops for an ink jet printhead.
In accordance with the first aspect of the present invention there is provided a nozzle arrangement which includes a thermal actuator comprising a heater element encased within a material having a high coefficient of thermal expansion. The actuator operates by electrically heating the heater element of the thermal actuator. The heater element has a corrugated structure so as to improve the thermal distribution of heat from the heater element to the actuation material so as to increase the speed of actuation of the thermal actuator. Further the heater element can be of a serpentine or concertina form so as to allow substantially unhindered expansion of the actuation material during heating. The thermal actuator is utilized in an ink jet nozzle for the ejection of ink from a nozzle chamber. Advantageously, both surfaces of the actuator are hydrophilic and the heater material within he actuator can comprise substantially copper. The hydrophilic material can be formed by means of suitable processing of a hydrophobic material.
In accordance with a second aspect of the current invention, there is provided a thermal actuator comprising a heater element having a low coefficient of thermal expansion surrounded by an actuation material having a high coefficient of thermal expansion wherein the thermal actuator includes first and second layers of actuation material and a third layer of conductive material, at least a portion of which is utilized as a heating element, wherein a portion of the conductor material has a series of slots or holes so as to allow the actuation material to be integrally joined together so as to reduce the likelihood of delamination of the layers. Thus a portion of the actuator including slotted or holed conductor is stiff.
The stiff portion of the actuator can include a regularly spaced array of holes defined therein.
In accordance with a third aspect of the current invention, there is provided an ink jet nozzle arrangement comprising the thermal actuator as one wall of an ink chamber, wherein the thermal actuator is attached to a wall of the nozzle chamber, and an ink chamber with an ejection port for the ejection of ink in a wall opposite to the wall formed by the thermal actuator.
REFERENCES:
patent: 4456804 (1984-06-01), Lasky et al.
patent: 4575619 (1986-03-01), Porzky
patent: 4696319 (1987-09-01), Gant
patent: 5317869 (1994-06-01), Takeuchi
patent: 5519191 (1996-05-01), Ketcham et al.
patent: 5666141 (1997-09-01), Matoba
patent: 5719604 (1998-02-01), Inui
patent: 5812159 (1998-09-01), Anagnostopoulos et al.
patent: 6067797 (2000-05-01), Silverbrook
patent: 195 16 997 (1995-11-01), None
patent: 713774 (1996-05-01), None
patent: 196 23 620 (1996-12-01), None
Patent Abstracts of Japan, M997, p. 32 JP-108544, Apr. 20, 1990, Sieko Epson Corp.
Patent Abstracts of Japan, M989, p. 131 JP 2-92643, Apr. 3, 1990, Sieko Epson Corp.
Barlow John
Do An H.
Silverbrook Research Pty Ltd
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