Metal working – Method of mechanical manufacture – Fluid pattern dispersing device making – e.g. – ink jet
Reexamination Certificate
1998-12-09
2003-12-30
Tugbang, A. Dexter (Department: 3729)
Metal working
Method of mechanical manufacture
Fluid pattern dispersing device making, e.g., ink jet
C029S896900, C347S044000, C347S047000, C219S121610, C219S121620, C219S121700, C219S121710, C219S121760
Reexamination Certificate
active
06668454
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid-discharging recording head in which liquid channels or discharging ports are formed, for example, in a resin top plate according to grooving, drilling or the like by laser irradiation, a method and apparatus for manufacturing the same, a head cartridge, and a liquid-discharging recording apparatus.
2. Description of the Related Art
In general, a liquid-discharging recording head for performing recording or printing on a recording medium (recording paper or the like) by discharging a recording liquid (ink) from fine discharging ports (orifices) in the form of flying droplets includes a substrate (heater board) having a plurality of electrothermal transducers and lead electrodes thereof provided thereon. A resin nozzle layer (liquid-channel forming layer) for forming liquid channels (nozzles) and a common liquid chamber is laminated on the substrate, and a glass top plate having recording-liquid supply tubes provided therein is superposed on the resin nozzle layer. Recently, liquid-discharging recording heads, in which the above-described glass top plate is omitted, a resin top plate is integrally formed according to injection molding or the like by providing recording-liquid supply tubes and the like so as to be integrated with liquid channels and a common liquid chamber, discharging ports are then formed therein, and the top plate is pressed against the substrate by a spring member so as to be integrated therewith, have been developed. In such liquid-discharging recording heads, the number of assembling components is greatly reduced, and the assembling process is greatly simplified. As a result, it is expected that the cost of such a liquid-discharging recording apparatus can be greatly reduced.
FIG. 1
is a schematic partially-broken perspective view illustrating the basic configuration of a liquid-discharging recording head Eo using a resin top plate which is formed in the above-described manner. In
FIG. 1
, the liquid-discharging recording head Eo indicated by partially breaking the resin top plate includes a substrate
101
having a plurality of electrothermal transducers
101
a,
serving as discharging-energy generating elements for generating thermal energy as energy utilized for discharging a liquid, provided thereon, and a resin top plate
102
having liquid channels
102
f
provided on corresponding ones of the electrothermal transducers
101
a,
and a common liquid chamber
102
c.
A discharging-port plate portion
102
b
having discharging ports (orifices)
102
g
communicating with corresponding ones of the liquid channels
102
f,
and a cylindrical projection
102
d
having a liquid supply port
102
e
opened to the common liquid chamber
102
c
are integrally provided.
The resin top plate
102
having the liquid channels
102
f,
the common liquid chamber
102
c,
the dicharging-port plate portion
102
b
and the cylindrical projection
102
d
is integrally formed according to injection molding, and then, the discharging ports
102
g
are formed. After positioning the resin top plate
102
so that the liquid channels
102
f
are positioned above corresponding ones of the electrothermal transducers
101
a
on the substrate
101
, the top plate
102
is pressed against the substrate
101
by an elastic member (not shown) so as to be integrated with the substrate
101
. The substrate
101
is fixed on a base plate
104
together with a circuit substrate
103
mounting a driving circuit for generating an electric signal to each of the electrothermal transducers
101
a,
according to a known method, such as screwing or the like.
A method for manufacturing the resin top plate
102
has also been developed in which after integrally forming a blank (primary molding), comprising a main-body portion
102
a
before providing the liquid channels
102
f,
the discharging port plate
102
b
before providing the discharging ports
102
g,
and the like, according to injection molding, the liquid channels
102
f
are formed in the main-body portion
102
a
of the resin top plate
102
using excimer laser, and the discharging ports
102
g
are also formed in the discharging-port plate
102
b
using excimer laser.
Since the resin top plate can be inexpensively manufactured by combining injection molding and laser processing, the cost of the liquid-discharging recording head can be further reduced. An excimer laser apparatus is suitable as a laser processing apparatus for grooving and drilling a blank obtained by injection molding by projecting a laser beam. Such an excimer laser apparatus generally includes a laser oscillator serving as a laser light source, a mask having an aperture pattern for forming liquid channels and discharging ports of a liquid-discharging recording head, and an optical system for projecting the aperture pattern of the mask using a laser beam.
When forming grooves, serving as liquid channels of a liquid-discharging recording head, and forming holes, serving as discharging ports of the head, it is necessary to perform such processing by projecting a laser beam having a high energy density per unit time, in order to obtain grooves and holes having good shapes, obtain large discharging ports, and shorten times required for forming the grooves and holes. In general, as the energy density per unit time of the projected laser beam is larger, the cone angle in processing by the laser beam is smaller, so that accuracy is improved, and grooves and holes having good shapes can be obtained. Particularly when forming holes serving as discharging ports, the cone angle in processing is reduced by projecting a laser beam having a high energy density per unit time, so that large threaded discharging ports can be obtained.
As the energy density per unit time of the projected laser beam is larger, the processing speed by the laser beam is higher. Hence, processing by a laser beam having a high energy density per unit time has many advantages such that grooves and holes can be formed in a short time.
However, when forming grooves, serving as liquid channels, and holes, serving as liquid discharging ports, using a laser beam having a high energy density per unit time as in the above-described conventional technique, if a laser beam having a high energy density per unit time exceeding a threshold is projected onto a resin, the resin tends to be deformed due to instantaneous energy concentration, thereby causing deviation in the dimensions or the pitch of formed grooves and holes, and generation of burrs around threaded discharging ports.
FIG. 2
is a schematic cross-sectional view illustrating a result of conventional laser processing.
In
FIG. 2
, there are shown a material to be processed
300
, a through hole
303
, and a laser beam
304
. As laser ablation processing is performed for the material
300
, a sheet-like lid
301
is formed on the surface of the material
300
immediately before the through hole
303
is threaded. By further projecting the laser beam
304
from this state, the lid
301
is further processed to provide a state in which the through hole
303
is threaded. If the processing by the laser beam
304
is performed within the through hole
303
at a constant speed, the lid
301
is projected directly in the direction of the processing. However, if variations are present in the processing speed of the laser beam
304
within the through hole
303
, a portion where the processing speed is low operates as a hinge portion
302
, and the lid
301
is opened as a door is opened. The hinge portion
302
is torn due to a shock when the lid
302
has been moved, to produce barrs at the torn portion.
When deviation in the dimensions and the pitch of the grooves occurs, misalignment between the grooves and the electrothermal transducers occurs when the top plate is pressed against the substrate (heater board) having the electrothermal transducers in order to be integrated therewith. This misalignment will cause a decrease in the efficiency of conversion from thermal e
Furukawa Masao
Goto Akira
Hasegawa Toshinori
Inaba Masaki
Ishimatsu Shin
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