Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
2001-11-06
2003-09-23
Nguyen, Judy (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
Reexamination Certificate
active
06623102
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid discharge head that records by discharging recording liquid, and also, to a method for manufacturing a liquid discharge head. More particularly, the invention relates to a liquid discharge head to which recording liquid is supplied, and the inner surface of which is made lyophilic. The invention also relates to a surface modifying method of the inner face of the liquid discharge head, as well as to a method for manufacturing such liquid discharge head. In this respect, the liquid discharge head of the present invention is applicable not only to a general printing apparatus, but also, to apparatuses such as a copying machine, a facsimile equipment provided with communication systems, and a word processor provided with a printing unit, among some others. Further, the invention is applicable to a recording apparatus for industrial use, which is complexly combined with various kinds of processing apparatuses.
2. Related Background Art
The liquid discharge apparatus (ink jet recording apparatus) is a recording apparatus of the so-called non-impact type, which is characterized by its capability of recording on a recording medium of various kinds at high speed with almost no noise in recording. With such advantages, the liquid discharge apparatus is widely adopted as the one that bears recording mechanism for a printer, a copying machine, a facsimile equipment, or the like.
As the typical liquid discharge method of a liquid discharge head mounted on a liquid discharge apparatus of the kind, there is known the one that used electro-mechanical converting member, such as piezoelectric element, the one that irradiates laser or some other electromagnetic waves to generate heat for discharging liquid by the action of this heating, or the one that heats liquid by use of the electrothermal converting member, which is provided with heat generating resistive element, and discharges liquid droplets by the action of film boiling, among some others. For the liquid discharge head that uses the electrothermal converting member as the discharge energy generating element, the electrothermal converting member is arranged in liquid flow path. The electric pulse that serves as recording signal is supplied thereto for heating and providing thermal energy for ink. Then, by the utilization of bubbling pressure at the time of liquid bubbling (at the time of film boiling) generated by phasic changes of liquid at that time, fine liquid droplets are discharged from each of the fine discharge ports for the performance of recording on a recording medium. Generally, there are provided the discharge ports for discharging liquid droplets, and a supply system that supplies ink to the discharge ports.
A liquid discharge head of the kind is generally formed by bonding plural members. In other words, the head is structured, for example, by a heater board having a plurality of electrothermal converting members arranged thereon, the common liquid chamber, which is bonded on the heater board, for inducing recording liquid from outside to that bonding surface, and a ceiling plate having a plurality of liquid flow paths formed to communicate with the discharge ports through above each of the electrothermal converting members. Further, an orifice plate having a plurality of discharge ports, which are open thereon corresponding to the discharge ports, may be prepared as a separate member in some cases, and bonded together with the heater board and the ceiling plate so as to position the discharge ports at each end of the liquid flow paths, respectively.
For such ceiling place and orifice plate, it is preferable to use polysulfone, epoxy, or some other resin material, which facilitates the excellent formation of a highly precise structure. Also, for bonding between the heater board, the ceiling plate, the orifice plate, and others, silicon or epoxy sealant or bonding agent is usually used in order to prevent recording liquid from leaking out into the liquid discharge head when the recording liquid is supplied.
The material, such as polysulfone or epoxy, used for the ceiling plate and orifice plate as described above, has a comparatively low surface energy, and in the liquid discharge head, difference may occur in the surface energy between the heater board and the ceiling plate or the orifice plate. Also, the plural members that form the liquid discharge head as described above are usually bonded by use of sealant or bonding agent. Then, the sealant or bonding agent thus applied allows its water-repellent property to affect recording liquid in the area surrounding such bonding portions. As a result, even if the heater board has hydrophilic property itself, it tends to present hydrophobic tendency eventually on the area surrounding the portion where the heater board is bonded.
Then, particularly when the head is used for a long time, or in the similar condition, there is a fear that air accumulation is caused to take place near the ceiling plate or orifice plate where the surface energy is comparatively low, such as the bonded portion having sealant applied thereto in particular, as indicated at
105
in
FIG. 16
, for example: there occurs an air accumulation centering the portion surrounding the bonding portion between the heater board
101
and the ceiling plate
102
where sealant
103
is applied. If such air accumulation as indicated at
105
occurs, the discharge performance of recording liquid is caused to change or the colorant contained in recording liquid is caused to be condensed, because the recording liquid is in contact with air, among some other unfavorable influences that may be exerted.
Here, a method for suppressing the occurrence of such air accumulation is disclosed in the specification of Japanese Patent Laid-Open Application 11-42798, in which before ink is initially filled in a head, the liquid that has a high wettability is filled in the head so as to remove any hydrophobic film formed on the inner face of the head, and also, to cover the inner face with such liquid in order to fill ink in good condition. With this method, however, it is impossible to maintain such cover for a long time. After a certain period elapses, the sealant portion that has water-repellent property, or the like, is exposed on the inner face of the head, and then, there is a fear that air accumulation occurs eventually.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to solve the problems discussed above, and provide a highly reliable lipid discharge head capable of filling recording liquid inside in a good condition and maintaining such condition for a long time, and also, provide a surface modifying method for the inner face of the liquid discharge head, as well as a method for manufacturing such liquid discharge head.
In order to achieve this object, the liquid discharge head of the present invention, which records by discharge recording liquid, is characterized by having:
a first portion with lyophilic group for lyophilic processing on a partial surface formed at least on a part of the inner face having recording liquid internally filled to be in contact therewith, and a second portion with a group having substantially the same or the same interfacial energy as the surface energy of the partial surface but different from the interfacial energy of the lyophilic group, while the second portion being orientated toward the partial surface, and the first portion being orientated in the direction different from the partial surface.
With the structure thus arranged, the surface energy of the inner face of the liquid discharge head is essentially uniformalized, hence preventing air accumulation from being generated in the portion having lower surface energy.
The present invention is particularly effective for a liquid discharge head for which the portion where recording liquid is filled is formed by bonding a plurality of members together. In other words, bonding agent or sealant is used usually for bonding th
Hayashi Hiroki
Sanada Mikio
Sugama Sadayuki
Brooke Michael S
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Nguyen Judy
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