U.S. patent number RE38,710 [Application Number 09/935,689] was granted by the patent office on 2005-03-15 for laser process for making a filter for an ink jet.
This patent grant is currently assigned to Canon Kabushiki Kaisha. Invention is credited to Akira Goto, Kimiyuki Hayasaki, Masaki Inaba, Shin Ishimatsu, Seiichiro Karita, Toshio Kashino, Yutaka Koizumi, Shuji Koyama, Kiyomitsu Kudo, Kouichi Omata, Takayuki Ono, Tsuyoshi Orikasa, Haruhiko Terai.
United States Patent |
RE38,710 |
Goto , et al. |
March 15, 2005 |
**Please see images for:
( Certificate of Correction ) ** |
Laser process for making a filter for an ink jet
Abstract
A common recess, grooves, and common recess and/or column
members in the grooves are formed on a base board at the same time,
and such board is made a second base board, which is coupled to a
first base board on which elements for liquid discharging energy
are formed; hence obtaining an ink jet recording head provided with
a filter unit in an arbitrary position in the region formed by the
ink paths and the common liquid chamber. The filter unit can be
processed by a single processing in the ink paths and/or the common
liquid chamber to make it possible to prevent disabled discharge
from taking place due to dust particles intermingled at the time of
head manufacture. In this way, the discharging stability is
enhanced, making a high-speed printing possible. A workpiece is
efficiently processed by a single processing which is performed to
process a three-dimensional configuration with respect to the
direction in which the laser beam is irradiated.
Inventors: |
Goto; Akira (Yokohama,
JP), Inaba; Masaki (Kawasaki, JP), Koizumi;
Yutaka (Yokohama, JP), Orikasa; Tsuyoshi
(Musashimurayama, JP), Kashino; Toshio (Fujisawa,
JP), Karita; Seiichiro (Yokohama, JP),
Koyama; Shuji (Kawasaki, JP), Terai; Haruhiko
(Yokohama, JP), Hayasaki; Kimiyuki (Yokohama,
JP), Omata; Kouichi (Kawasaki, JP), Kudo;
Kiyomitsu (Yokohama, JP), Ono; Takayuki
(Kawasaki, JP), Ishimatsu; Shin (Yokohama,
JP) |
Assignee: |
Canon Kabushiki Kaisha (Tokyo,
JP)
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Family
ID: |
26373805 |
Appl.
No.: |
09/935,689 |
Filed: |
August 24, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
397360 |
Mar 2, 1995 |
05940957 |
Aug 24, 1999 |
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Foreign Application Priority Data
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Mar 4, 1994 [JP] |
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6-034932 |
May 11, 1994 [JP] |
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6-097428 |
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Current U.S.
Class: |
29/611;
219/121.72; 29/890.1; 347/65; 347/93 |
Current CPC
Class: |
B41J
2/1604 (20130101); B41J 2/1634 (20130101); B41J
2/1637 (20130101); B23K 26/066 (20151001); Y10T
29/49083 (20150115); Y10T 29/49401 (20150115); B41J
2002/14403 (20130101) |
Current International
Class: |
B23K
26/00 (20060101); H05B 3/00 (20060101); H05B
003/00 (); B23K 026/00 () |
Field of
Search: |
;29/611,890.1
;219/121.68,121.69,121.72 ;347/47,93 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0379781 |
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0488033 |
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EP |
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573014 |
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EP |
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0 670 221 |
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Sep 1995 |
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EP |
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54-56847 |
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May 1979 |
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JP |
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56-006208 |
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Jan 1981 |
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JP |
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59-123670 |
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Jul 1984 |
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JP |
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59-138461 |
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Aug 1984 |
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60-71260 |
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Apr 1985 |
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63-200524 |
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63-200584 |
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Aug 1988 |
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63-290755 |
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Nov 1988 |
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JP |
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2-121842 |
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May 1990 |
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JP |
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2-121845 |
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May 1990 |
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JP |
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2-187346 |
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Jul 1990 |
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JP |
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3-101954 |
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Apr 1991 |
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JP |
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3-101960 |
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Apr 1991 |
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JP |
|
3-180355 |
|
Aug 1991 |
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JP |
|
4-9291 |
|
Jan 1992 |
|
JP |
|
4-339585 |
|
Nov 1992 |
|
JP |
|
4-368855 |
|
Dec 1992 |
|
JP |
|
5-4348 |
|
Jan 1993 |
|
JP |
|
5-208503 |
|
Aug 1993 |
|
JP |
|
5-254120 |
|
Oct 1993 |
|
JP |
|
5-338186 |
|
Dec 1993 |
|
JP |
|
Primary Examiner: Rosenbaum; I Cuda
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Parent Case Text
.Iadd.Notice: More than one reissue application has been filed for
the reissue of Pat. No. 5,940,957. The reissue applications are
application Nos. 09/935,689 (the present application) and
10/360,670, which is a divisional reissue of Pat. No.
5,940,957..Iaddend.
Claims
What is claimed is:
1. A method for manufacturing an ink jet recording head, comprising
the steps of: forming on a base board a recess portion serving as a
part of an ink passage .[.leading to.]. .Iadd.communicating with
.Iaddend.an ink discharge .[.opening.]. .Iadd.portion .Iaddend.and
a projection having a shape in .[.said.]. .Iadd.the .Iaddend.ink
passage by .[.a.]. laser irradiation through a mask portion having
a predetermined mask pattern corresponding to the shape of
.[.said.]. .Iadd.the .Iaddend.projection, wherein .[.said.].
.Iadd.the .Iaddend.mask pattern .[.at least one of.]. reflects
.[.and.]. .Iadd.or .Iaddend.absorbs at least a part of .[.said.].
.Iadd.the .Iaddend.laser .[.irradiation;.]. .Iadd.radiation;
.Iaddend.and forming .[.said.]. .Iadd.the .Iaddend.ink passage by
coupling a side of .[.said.]. .Iadd.the .Iaddend.base board on
which .[.said.]. .Iadd.the .Iaddend.recess portion is formed to
another base board.
2. A method for manufacturing an ink jet recording head according
to claim 1, wherein .[.said.]. .Iadd.the .Iaddend.ink passage
comprises a plurality of flow paths communicating with respective
.[.said.]. ink discharge openings .Iadd.in the ink discharge
portion .Iaddend.and a common liquid chamber communicating with
.[.said.]. .Iadd.the .Iaddend.flow paths.
3. A method for manufacturing an ink jet recording head according
to claim 2, wherein .[.said.]. .Iadd.the .Iaddend.projection
comprises a filter, and .[.said.]. .Iadd.the .Iaddend.projection is
disposed in a given .[.said.]. .Iadd.one of the .Iaddend.flow
path.Iadd.s.Iaddend..
4. A method for manufacturing an ink jet recording head according
to claim 3, wherein .[.said.]. .Iadd.the .Iaddend.projection is
column-shaped.
5. A method for manufacturing an ink jet recording head according
to claim 2, wherein .[.said.]. .Iadd.the .Iaddend.projection
comprises a filter located in the vicinity of an opening
.[.communicating with said flow paths.]. in .[.said.]. .Iadd.the
.Iaddend.common liquid chamber, .Iadd.the opening communicating
with the flow paths.Iaddend..
6. A method for manufacturing an ink jet recording head according
to claim 5, wherein .[.said.]. .Iadd.the .Iaddend.projection is
column-shaped.
7. A method for manufacturing an ink jet recording head according
to claim 2, wherein .[.said.]. .Iadd.the .Iaddend.common liquid
chamber is formed by molding and .[.said.]. .Iadd.the .Iaddend.flow
path.Iadd.s .Iaddend..[.is.]. .Iadd.are .Iaddend.formed by laser
processing.
8. A method for manufacturing an ink jet recording head according
to claim 1, wherein an energy generation means for generating
energy for discharging .[.the.]. ink from .[.said discharge
opening.]. .Iadd.the ink discharge portion .Iaddend.is provided at
a portion on .[.said.]. .Iadd.the .Iaddend.other board
corresponding to .[.the.]. .Iadd.a .Iaddend.position of .[.said.].
.Iadd.the .Iaddend.ink passage.
9. A method for manufacturing an ink jet recording head according
to claim 8, wherein .[.said.]. .Iadd.the .Iaddend.energy generating
means is an electro-thermal energy conversion element which
generates heat energy as .[.said.]. .Iadd.the .Iaddend.energy.
10. A method for manufacturing an ink jet recording head,
.[.wherein.]. .Iadd.comprising the step of: forming .Iaddend.a
recess portion serving as an ink passage communicating with an ink
discharge portion and a projection having a shape and provided in
.[.said.]. .Iadd.the .Iaddend.ink passage .[.are formed.]. by
.[.a.]. laser irradiation through a mask portion having a
predetermined mask pattern corresponding to the shape of .[.said.].
.Iadd.the .Iaddend.projection, wherein .[.said.]. .Iadd.the
.Iaddend.mask pattern .[.at least one of.]. reflects .[.and.].
.Iadd.or .Iaddend.absorbs at least a part of .[.said.]. .Iadd.the
.Iaddend.laser .[.irradiation.]. .Iadd.radiation.Iaddend..
11. A method for manufacturing an ink jet recording head according
to claim 10, wherein .[.said.]. .Iadd.the .Iaddend.ink passage
comprises a plurality of flow paths communicating with respective
.[.said.]. ink discharge openings .Iadd.in the ink discharge
portion .Iaddend.and a common liquid chamber communicating with
.[.said.]. .Iadd.the .Iaddend.flow paths.
12. A method for manufacturing an ink jet recording head according
to claim 11, wherein .[.said.]. .Iadd.the .Iaddend.projection
comprises a filter located in a given .[.said.]. .Iadd.one of the
.Iaddend.flow path.Iadd.s.Iaddend..
13. A method for manufacturing an ink jet recording head according
to claim 12, wherein .[.said.]. .Iadd.the .Iaddend.projection is
column-shaped.
14. A method for manufacturing an ink jet recording head according
to claim 11, wherein .[.said.]. .Iadd.the .Iaddend.projection
comprises a filter located in the vicinity of an opening
.[.communicating with said flow paths.]. in .[.said.]. .Iadd.the
.Iaddend.common liquid chamber.Iadd., the opening communicating
with the flow paths.Iaddend..
15. A method for manufacturing an ink jet recording head according
to claim 14, wherein .[.said.]. .Iadd.the .Iaddend.projection is
column-shaped.
16. A method for manufacturing an ink jet recording head according
to claim 10, wherein an energy generating means for generating
energy for discharging .[.the.]. ink from .[.said.]. .Iadd.the ink
.Iaddend.discharge .[.opening.]. .Iadd.portion .Iaddend.is provided
in .[.said liquid.]. .Iadd.the ink .Iaddend.passage.
17. A method for manufacturing an ink jet recording head according
to claim 16, wherein .[.said.]. .Iadd.the .Iaddend.energy
generating means is an electro-thermal energy conversion element
which generates heat energy as .[.said.]. .Iadd.the
.Iaddend.energy..Iadd.
18. A method for manufacturing a board member for use in an ink jet
recording head, the board member including a recess that serves as
part of an ink passage in fluid communication with an ink discharge
opening and a plurality of protrusions arranged in the recess, said
method comprising the steps of: providing a board member formed of
polymer resin; and irradiating a laser beam through a mask portion
having a mask pattern corresponding to a shape of the plurality of
protrusions, the mask pattern reflecting at least a part of the
laser beam or absorbing at least a part of the laser beam..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet recording head and a
method of manufacture therefor. More particularly, the invention
relates to a method for manufacturing an ink jet recording head
which comprises a fine structure that is formed by use of laser
beam.
Also, the present invention relates to a laser processing apparatus
for processing grooves or the like by irradiating laser beam onto a
workpiece, an ink jet recording head whose grooves are processed by
the laser processing apparatus, and an ink jet recording apparatus
provided with such an ink jet recording head.
2. Related Background Art
Along with the provision of many nozzles and further reduction of
its orifice diameter in order to obtain a high resolution by use of
an ink jet recording head which performs printing by discharging
ink droplets from the orifices of, for example, tens of .mu.m each,
the influence of dust particles intermingled when the head is
manufactured or when ink flows in the head has become increasingly
greater. Therefore it is necessary to take appropriate measures
against such unfavorable influences. For example, there has been
proposed a method for forming an ink supply inlet and filter at a
time by application of Si anisotropic etching as disclosed in
Japanese Patent Laid-Open Application No. 5-208503, and a method
for providing a filter structure by use of a filter of a
three-dimensional configuration in the ink path as disclosed in
Japanese Patent Laid-Open Application No. 5-4348. Also, there is a
method known as disclosed in Japanese Patent Laid-Open Application
No. 3-180355 wherein a stainless steel mesh filter is provided in
the ink path.
However, in accordance with the disclosure of Japanese Patent
Laid-Open Application No. 5-208503, for example, the filter unit is
obtained by such a patterning as to change its resistance against
etching solution by implanting boron ions. This undesirably
increases greatly the number of head manufacturing processes. Also,
while the filter is provided for the ink supply inlet arranged on
the upper part of the ink liquid chamber, no particular measures
are taken in the manufacture processes to prevent the dust
particles from adhering to the space between the ink liquid chamber
and other parts.
Also, in accordance with the disclosure of the Japanese Patent
Laid-Open Application No. 5-4348, a filler is to be mixed with
resin. This makes it difficult to set the hole diameter of the
filter freely. Also, in accordance with the disclosure of the
Japanese Patent Laid-Open Application No. 3-180355, the number of
manufacture processes needed to make the device are increased
because of the steps needed to bury the stainless steel mesh filter
in the liquid path.
Further, in recent years, laser oscillators are often used as light
source for laser processing equipment. Particularly, attention is
given to the ultraviolet pulse laser oscillators as a light source
of laser processing at the time of abrasion when patterning is
performed on polymer without any development. As laser processing
apparatuses or systems for processing polymer by utilizing
abrasion, there have been proposed those given below. Such
apparatuses (disclosed in Japanese Patent Laid-Open Application No.
4-9291 and Japanese Patent Laid-Open Application No. 4-339585)
comprise a laser light source; a given pattern; a masking unit
provided with a mask which transmits the laser beam from the laser
light source to the workpiece side through this pattern; a
projection optical system for projecting the laser beam from the
laser light source; and measurement and driving system for
measuring the workpiece position and causing the workpiece to
move.
A laser processing apparatus of this sort is mainly used for
processing the discharge ports of an ink jet recording apparatus
(refer to Japanese Patent Laid-Open Application No. 2-121842,
Japanese Patent Laid-Open Application No. 2-187346, Japanese Patent
Laid-Open Application No. 3-101954, Japanese Patent Laid-Open
Application No. 3-101960) or for processing the ink paths of an ink
jet recording head (Japanese Patent Laid-Open Application No.
2-121845), and for fine processing of other kinds.
In this respect, the ink jet recording head described above is
particularly the one which adopts bubble jet method among those
heads using ink jet recording methods. Here, the typical structure
and principle of a recording apparatus using the bubble jet method
are disclosed in the specifications of U.S. Pat. Nos. 4,723,129 and
4,740,796. These are applicable to either of the so-called
on-demand type and the continuous type heads. To describe this
method by exemplifying the on-demand type, electrothermal
transducing elements are arranged for a sheet or liquid passage
(ink path) capable of retaining liquid (ink), and then, these
elements are caused to generate thermal energy in response to
driving signals, hence creating film boiling on the thermoactive
surface of a recording head. In this way, a resultant air bubble is
formed in the liquid (ink) path one to one with respect to driving
signals described above. With the development and contraction of
this air bubble, liquid (ink) is discharged from each of the
discharge ports in the form of an ink droplet. Here, as the driving
signals thus given, it is preferable to make them pulse signals as
disclosed in the specifications of U.S. Pat. Nos. 4,463,359 and
4,345,262. Also, regarding the rate of temperature rise on the
aforesaid thermoactive surface, it is desirable to adopt the
conditions disclosed in the specification of U.S. Pat. No.
4,313,124 for better performance.
The structure of the ink jet recording head described above is
arranged by combining discharge ports (orifices), linear or
right-angled liquid paths (ink paths), and electro-thermal
transducing elements as disclosed in each of the specifications
described above, but beside these, it may be possible to arrange a
structure where the thermoactive portion is provided in a curved
domain as disclosed in the specifications of U.S. Pat. Nos.
4,558,333 and 4,459,600. Furthermore, the structure of the ink jet
recording head described above may be such that a common slit is
arranged as the discharge ports of electrothermal transducing
elements in a plurality thereof as disclosed in Japanese Patent
Laid-Open Application No. 59-138461, for example, or an aperture,
which absorbs the pressurized waves of thermal energy, is arranged
to face the discharge ports as disclosed in Japanese Patent
Laid-Open Application No. 59-138461. In this respect, the ink jet
recording heads disclosed in the specifications described above are
arranged to secure its length corresponding to a given width by
combining a plurality of recording heads, respectively. However, it
may be possible to construct a single recording head having a
length corresponding to a given width (the maximum width of the
recording medium that a recording apparatus may be able to record
on).
Also, the ink jet recording heads described above may be of the
exchangeable chip type wherein the head can be electrically
connected with the main body of an apparatus and is ready to
receive ink supply, or can be of the cartridge type which is formed
as a recording head itself.
However, when fine grooves and others are processed by use of a
laser processing apparatus on a workpiece which constitutes a part
of an ink jet recording head, it is impossible to form a groove
having a three-dimensional wall in a single operation if the wall
faces to be formed are three-dimensional with respect to the
direction in which the laser beam is irradiated. In this case,
multistage processing must be performed using two or more kinds of
masks. As a result, a problem is inevitably encountered in that it
takes a considerable time to complete processing of the workpiece.
Further, the positions of subsequent processings and so on must be
arranged to agree with the position of the first processing
exactly, necessitating extremely high precision for the required
image processing and the provision of a system enabling the precise
stepping of workpiece movement, among some others, in order to
execute such precise positioning exactly. These requirements result
in making the apparatus itself large and more complicated.
On the other hand, among ink jet recording heads, there are some in
which extrusions are formed in the ink paths to provide resistance
to the ink flow for the purpose of enhancing the discharging
properties of ink by controlling the ink supply force so that it
stays more in the discharge port side, and that the ink foaming
energy is not allowed to escape to the side opposite to the
discharge ports. When the conventional laser processing apparatus
is used to process grooves each with extrusions for the formation
of the ink paths having such extrusions, productivity is extremely
reduced for the reasons described above.
SUMMARY OF THE INVENTION
The present invention is designed in consideration of the problems
described above. It is an object of the invention to provide an ink
jet recording head having means for reducing the influence of dust
particles to be mixed at the time of manufacture or flowing ink,
which becomes increasingly greater along with the provision of many
more nozzles and the reduction of the orifice diameter. In order to
achieve this object, the present invention is provided in the
following manner by:
(1) forming on a base board one or more elements for generating
liquid discharging energy for discharging ink and making it a first
base board;
(2) forming on another base board, a) a common recess, b) one or
more grooves extending from the common recess to the end of the
base board, having aperture serving as ink discharge ports, and c)
one or more column members in an arbitrary portion of a region
formed by the groove and common recess, and while maintaining
conductivity from the common recess to the aperture, making the
base board as a second base board;
(3) coupling the first base board and second base board in a mode
in which the element for generating liquid discharging energy and
the grooved recess correspond to each other; and providing one or
more ink paths having a common liquid chamber and elements for
generating liquid discharging energy, one end of the ink path being
open to the common liquid chamber, and the end thereof becoming ink
discharge ports; and forming a head in which the portion where the
column members are arranged is made to be a filter unit for
ink.
Now, in accordance with the present invention, it is also an object
to provide a laser processing apparatus capable of processing a
workpiece efficiently by processing a three-dimensional
configuration with a single processing in the direction of laser
beam irradiation. Also, this processing by use of such laser
processing apparatus is meant to provide an ink jet recording head
having excellent discharge properties while maintaining good
productivity.
In order to achieve the objects described above, the laser
processing apparatus of the present invention is provided with a
laser light source, given patterns corresponding to the processing
configuration of a workpiece, and a mask unit is provided with the
mask which transmits laser beam from the laser light source to the
workpiece side through such patterns.
This laser processing apparatus is characterized in that the mask
unit is positioned in the luminous flux of the laser beam apart
from the surface of the aforesaid mask by a certain distance, and
arranged to be capable of installing on it a member which reflects
or absorbs at least a part of the aforesaid laser beam.
Also, it may be possible to provide the laser processing apparatus
with at least one system such as a beam adjustment optical system
for reforming the laser beam from the laser light source, an
optical system for illuminating the mask or a projection optical
system for focusing the image of the pattern of the mask on the
surface of the workpiece by a given magnification.
The aforesaid mask may be arranged in close contact with the
aforesaid workpiece.
Further, the member which reflects or absorbs at least a part of
the laser beam may be either the one which is able to adjust its
position of installation relatively with respect to the mask or the
one which is fixedly installed with respect to the mask.
Then the member which reflects or absorbs at least a part of the
laser beam may be the one whose transmissively of the laser beam
differs depending on its regions.
The laser light source may be one which can generate ultraviolet
pulse laser. In this case, the ultraviolet pulse laser may be an
Xe--Cl excimer laser, Kr--F excimer laser, Ar--F excimer laser,
fourth harmonic of YAG laser, mixed waves of basic wave and
secondary harmonic of YAG laser, or nitrogen gas laser.
An ink jet recording head of the present invention is provided with
a base board having on it the elements for generating energy which
can be utilized for discharging ink, and a board member coupled to
this base board.
On this board member, there are formed a recess which constitutes
an ink chamber for provisionally retaining the ink to be supplied
to the discharge ports, and a groove each with an extrusion
arranged in the intermediate section of the bottom wall, which
forms each of the ink paths by conductively connecting the
discharge ports and the ink liquid chamber through each element for
generating energy.
At the same time, there is provided a mask having the pattern which
corresponds to the aforesaid groove, and then, the grooves each
with an extrusion are processed by the laser processing apparatus
of the present invention where a member is installed for reflecting
or absorbing at least a part of the laser beam by the provision of
such extrusion. This constitutes the characteristics of the present
invention.
Also, the aforesaid board member is made of polymer resin, and so
it may be possible to adopt a laser light source which generates
ultraviolet laser pulses laser in the laser processing apparatus.
Further, it may be possible to use electrothermal transducing
elements for generating thermal energy to be utilized for
discharging ink as the aforesaid energy generating elements.
In this case, ink may be discharged from the discharge ports by
utilization of film boiling to be created in ink by the thermal
energy applied by the aforesaid electrothermal transducing
element.
Then an ink jet recording apparatus of the present invention is
provided with the aforesaid ink jet recording head prepared in
accordance with the present invention, and records by discharging
ink from the discharge ports of the ink jet recording head in
response to recording signals.
In the laser processing apparatus constructed as described above in
accordance with the present invention, it is possible to install a
member which reflects or absorbs at least a part of the laser beam
within the luminous flux of laser beam and in a position apart from
the surface of the mask. Therefore, when a groove processing is
executed, for example, the power of the laser beam irradiated
becomes weaker on a workpiece in the location corresponding to the
installed position of the aforesaid member than that of the laser
beam irradiated on the other locations, making it possible to
process the three-dimensional configuration by a single processing.
Then, since the three-dimensional configuration can be processed by
the single processing, it is unnecessary to provide means for
exactly positioning the laser processing apparatus for the second
processing and so on, simplifying the structure of the apparatus,
accordingly.
Also, the aforesaid member can be installed in such a manner that
its position is relatively adjustable with respect to the mask,
thus making it possible to adjust the position and height of the
three-dimensional portion corresponding to the processing part of
the workpiece with respect to the pattern of the mask. As a result,
when the aforesaid member is fixedly installed with respect to the
mask, the processing configuration of a workpiece is uniquely
determined. Further, with the transmissivity of the aforesaid
member being made different for the laser beam depending on the
regions, it becomes possible to process more complicated
configurations. Then, with the laser light source being able to
generate ultraviolet laser pulses, the polymer resin can be
processed with fine resolution.
In accordance with an ink jet recording head and an ink jet
recording apparatus of the present invention, grooves formed on the
board member are processed by use of the laser processing apparatus
of the present invention. Then the grooves each with an extrusion
can be processed just by a single processing. Each extrusion thus
processed provides resistance against ink flow in the ink path and
enhances the discharging properties of ink by controlling the ink
supply force to stay more on the discharge port side, and also, the
ink foaming energy is not allowed to escape to the side opposite to
discharge ports. As a result, compared to the case where no
extrusion is provided, the discharging properties of ink become
superior while there is no possibility that the productivity is
unfavorably affected.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view which schematically shows an ink jet
recording head in accordance with a first embodiment of the present
invention.
FIG. 1B is a schematic view of the first embodiment of the
invention showing a mold for a common liquid chamber.
FIG. 2 is an exploded perspective view which shows a method for
manufacturing the head represented in FIG. 1A.
FIG. 3 is a perspective view which schematically shows an ink jet
recording head in accordance with a second embodiment of the
present invention.
FIG. 4 is a view which schematically shows a mask configuration
used for the second embodiment.
FIG. 5 is a perspective view which schematically shows an ink jet
recording head in accordance with a third embodiment of the present
invention.
FIG. 6 is a perspective view which schematically shows an ink jet
recording head in accordance with a fourth embodiment of the
present invention.
FIG. 7 is a view which schematically shows the structure of an ink
jet recording head in accordance with a fifth embodiment of the
present invention, which is manufactured by a laser processing
apparatus.
FIG. 8 is a perspective view which shows a part of an ink jet
recording head finely processed by a laser processing apparatus of
the present invention.
FIG. 9 is a partial cross-sectional view which shows the ink jet
recording head represented in FIG. 8.
FIG. 10 is a partial cross-sectional view which shows a workpiece
which serves as the ceiling represented in FIG. 8 and FIG. 9.
FIG. 11 is a perspective view which shows a mask unit of the laser
processing apparatus represented in FIG. 7.
FIG. 12 is a perspective view which shows a mask unit in accordance
with a sixth embodiment of the present invention, which is
processed by a laser processing apparatus.
FIG. 13 is a perspective view which shows a mask unit in accordance
with a seventh embodiment of the present invention, which is
processed by a laser processing apparatus.
FIG. 14 is a perspective view which shows a mask unit in accordance
with an eighth embodiment of the present invention, which is
processed by a laser processing apparatus.
FIG. 15 is a partial cross-sectional view which shows a workpiece
whose grooves are processed by a laser processing apparatus using
the mask unit represented in FIG. 14.
FIG. 16 is a perspective view which schematically shows one
embodiment of an ink jet recording apparatus in accordance with the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, in conjunction with the accompanying drawings, the
present invention will be described in detail.
FIG. 1A is a view which schematically shows one embodiment of an
ink jet recording head in accordance with the present invention. In
FIG. 1A, a reference numeral 1 designates an element for generating
liquid discharging energy; 2, a first base board having the element
for generating liquid discharging energy formed on it; 3, a recess
for forming an ink path corresponding to the portion where the
element 1 for generating liquid discharging energy is arranged; 4,
a common liquid chamber; 5, a second base board having the recess 3
for forming the ink path and the common liquid chamber 4; 6,
discharge ports for discharging ink by being conductively connected
to the recess 3 for forming the ink path; 7, column members; and 8,
a filter unit formed by the column members 7.
Here the term "passage" is used for representing both an ink path
(flowing path) and a common liquid chamber.
In this case, the filter unit is arranged in the ink path, but if
only the filter can produce an effect to prevent any defective
discharge from being caused by dust particles, it may be possible
to provide the filter in any mode in any location in the region
formed by the common liquid chamber and the ink path. For example,
as shown in FIG. 3, it may be arranged in the mode where the column
members are arranged in parallel with the surface to which the ink
path in the common liquid chamber is open or as shown in FIG. 5, it
can be arranged just in front of the discharge ports. Further, as
shown in FIG. 6, it may be in the mode where one end of a column
member is in contact with the wall face of the ink path, and then,
the column member adjacent to this one is in contact with the wall
face of the ink path opposite thereto. Also, the location where the
filter unit is arranged is not necessarily limited to one place,
but it may be arranged in plural locations in one path or in both
the ink path and the common liquid chamber.
In conjunction with the schematic view in FIG. 2, description will
be made of a method for manufacturing an ink jet recording head
having a filter unit of the kind described above as one embodiment
of a manufacture made by use of a laser processing apparatus. In
FIG. 2, reference numeral 9 designates the laser beam for
processing a resin base board 5a which will become a second base
board 5; 10, a mask for forming the groove 3a which should serve as
the recess 3 for forming the ink path (or a part of the common
liquid chamber or including the common recess which serve as an
entire body), and column members 7; 11, a coating layer which does
not allow the laser beam to be transmitted by reflecting or
absorbing the laser beam; 12, a mask holder to fix the mask 10; 13,
a board member A for supporting the mask holder 12; 14, a resin
holder to fix the resin base board 5a; and 15, a board member B for
supporting the resin holder 14.
As material for the second base board, resin is used, but
preferably, polyether etherketone, polyether sulfone, or the like
are used. Further, from the viewpoint of workability, it is
preferable to use polysulfone as a desirable resin.
As the laser beam 9, an excimer laser beam of 248 nm wavelength can
be used, for example. The mask 10 is formed from a material which
transmits the laser beam such as one having quartz or glass as its
base material.
In an arbitrary position of the pattern of the ink path and the
common liquid chamber formed on the mask 10, the pattern serving to
produce the column members is formed by a material which does not
allow the laser beam to be transmitted (in FIG. 2, an example is
shown in which this is formed in the pattern of the ink path).
It is possible to form the second base board used for a recording
head of the present invention as a part or the entire body of the
common liquid chamber, the grooves each serving as the ink path,
and so the column members can be formed individually or entirely at
one time. However, as described above, it is more advantageous if
these are formed together keeping in mind considerations of cost,
and also, keeping in mind avoiding any complicated operations.
The ink jet recording head, which can be obtained by coupling the
second base board thus prepared and the first base board, is
provided with the filter unit, contributing to reducing the
frequency of disabled discharge due to the dust particles in ink,
and providing a good printing quality.
Further, in accordance with the method of the present invention, it
is possible to position the filter unit arbitrarily, and set the
filter interval freely. Therefore, not only an appropriate measure
can be taken against the dust particles, but also, an effect is
obtainable to suppress the backward motion of the ink meniscus in
high frequency printing. As a result, discharge stability is
enhanced to improve high-speed printing.
Embodiment 1
Hereinafter, the present invention will be described in accordance
with the embodiments.
FIG. 1A is a view which schematically shows an ink jet recording
head in accordance with the present invention. In FIG. 1A, a
reference numeral 1 designates an element for generation liquid
discharging energy; 2, a first base board having the element for
generating liquid discharging energy formed on it; 3, a recess for
forming an ink path corresponding to the portion where the element
1 for generating liquid discharging energy is arranged; 4, a common
liquid chamber; 5, a second base board having the recess 3 for
forming the ink path and the common liquid chamber 4; 6, discharge
ports for discharging ink by being conductively connected to the
recess 3 for forming the ink path; 7, column members; and 8, a
filter unit formed by the column members 7.
An element for generating thermal energy is used as the element 1
for generating liquid discharging energy. For the first base board
2, a thin board cut from a five-inch silicon wafer is used. For the
second base board 5, polysulfone or some other resin, which is
provided with a dent portion for a common liquid chamber formed
from mold 4a shown in FIG. 1B, is used because this type of
material is easy to be formed or processed by a laser beam.
Now, in conjunction with a schematic view shown in FIG. 2, the
description will be made of a method for manufacturing an ink jet
recording head having a filter unit 8 described above. In FIG. 2, a
reference numeral 9 designates the laser beam used for processing
the second base board 5; 10, the mask for forming the recess 3 to
provide the ink path and column members 7; 11, the coating layer
which reflects or absorbs the laser beam; 12, the mask holder which
holds the mask; 13, a board member A for supporting the mask holder
12; 14, a resin holder for fixing the second base board 5; 15, a
board member B for supporting the resin holder 14. An excimer laser
beam having wavelength of 248 nm is used as laser beam 9. The mask
10 is formed from the quartz or glass as its base material which
transmits the laser beam. The coating layer 11 is formed from
deposited nickel or other suitable material. The structure of mask
for forming the recess 3 and the column members 7 for the formation
of the ink path is arranged in such a manner that the coating layer
is provided for the mask 10 which is laminated in its configuration
in advance, and after that, the laminated layer which is not
exposed is removed. It is easy to change the size of the gaps in
the filter unit 8 by designating the mask 10 accordingly.
In the present embodiment, the resin base material 5a is irradiated
by 200 pulses of the laser energy concentration on the processing
surface as IJ/cm.sup.2 /pulse, and then,
a) it is possible to process a filter unit 8 having gaps of 13
.mu.m at a time with the following arrangement:
256 pieces of ink path groove 6 each configured to be 50
.mu.m.times.50 .mu.m.times.500 .mu.m in size (representing
(dimension in the direction A).times.(dimension in the direction
B).times.(dimension in the direction C) as seen in FIG. 1A) are
formed with a pitch of 70 .mu.m. In one ink path groove 6, there
are formed in two rows, two column members 7 each configured to be
5 .mu.m.times.50 .mu.m.times.10 .mu.m in the direction A in FIG.
1A, and two in the direction C, respectively.
b) also, it is possible to process a filter unit 8 having gaps of
10 .mu.m under the same conditions of laser irradiation with the
formation of two column members 7 each configured to be 10
.mu.m.times.50 .mu.m.times.10 .mu.m in the direction A in FIG.
7.
c) likewise, it is possible to process the filter unit at a time in
case of a structure where the column members are arranged in two
rows in the direction C in FIG. 1A.
In the present embodiment, a relatively large common liquid chamber
which communicates with plural liquid paths is previously formed by
resin molding and relatively fine liquid paths are formed by laser
projection, as a filter. The embodiment is preferable because a
proper working process is applied to each liquid path.
With the provision of the filter unit 8 described above, the rate
of disabled discharge due to dust particles at the time of printing
is reduced by approximately 5% in either one of a) to c) in the
preceding paragraphs as compared with the head which is not
provided with the filter unit 8.
Also, when printing by using an ink jet recording head having the
filter unit 8, it is possible to obtain a good printing quality
even at the high driving frequency where the printing quality is
usually lowered when using a head which is not provided with the
filter unit 8.
Embodiment 2
Now, another embodiment of the present invention will be described.
A schematic view of an ink jet recording head is shown in FIG. 3 in
which the filter unit described in the embodiment 1 is provided for
the common liquid chamber. Also, FIG. 4 shows the configuration of
the mask 10 used when manufacturing this head.
As shown in FIG. 3, two rows of the column members 7 each
configured to be 10 .mu.m.times.50 .mu.m.times.10 .mu.m (direction
A.times.direction B.times.direction C) are arranged in the common
liquid chambers 4 so that the gaps thereof become 10 .mu.m. The
column members can be processed at a time by the laser beam
processing as in the embodiment 1, and the processing yield of the
ink jet recording heads and the printing quality thereof are
improved.
Embodiment 3
Now, the description will be made of another embodiment in
accordance with the present invention. FIG. 5 is a view which
schematically shows an ink jet recording head for which the filter
unit is provided between the elements for generating liquid
discharging energy and the orifices. In the ink path groove 6, a
filter unit having a gap of 13 .mu.m can be manufactured by laser
beam processing under the same condition as the first embodiment by
arranging two column members 7 each configured to be 5
.mu.m.times.50 .mu.m.times.5 .mu.m (direction A.times.direction
B.times.direction C) in one row in the direction A. Also, both the
manufacturing yield and printing quality of the ink jet recording
heads thus processed are improved.
Embodiment 4
Description will be made of another embodiment in accordance with
the present invention. As shown in FIG. 6, the column members 7
each in contact with one side face of the ink path 6 and configured
to be 30 .mu.m.times.50 .mu.m.times.10 .mu.m (direction
A.times.direction B.times.direction C) are arranged in two rows
alternately in the ink path groove 6, and then, an ink jet
recording head is manufactured with its filter unit 8 having a gap
of 20 .mu.m.
Laser beam processing is conducted under the same conditions as in
the second embodiment. The manufacturing yield and printing quality
of the ink jet heads thus processed are improved. Also, in this
case, the mask 10 for forming the filter unit 8 can be prepared by
depositing the coating layer 11 in order to provide the same
structure as the one used for the embodiment 2, but the mask may be
prepared by etching Ni or some other metals.
Embodiment 5
FIG. 7 is a view schematically shows the structure of a laser
processing apparatus in accordance with a fifth embodiment of the
present invention. As shown in FIG. 7, the laser processing
apparatus of the present embodiment comprises a laser oscillator 1
serving as the last light source for generating the laser beam 2;
an apparatus frame 6 having a processing system for processing a
workpiece W by application of the laser beam 2 from the laser light
source; an information processing and controlling system 7 for
processing information and performing control with respect to the
processing of the workpiece W.
The laser beam 2 generated from the laser oscillator 1 is partially
reflected by a beam splitter 3. The reflected beam is monitored by
a power detector 4. On the other hand, the laser beam 2, which is
transmitted through the beam splitter 3, is reflected by a total
reflection mirror 5 to be incident upon the apparatus frame 6. As
the beam splitter 3, a plane-parallel board made of synthetic
quartz is used for separating a part of the laser beam 2 only by
the surface reflection.
The apparatus frame 6 comprises an optical system 8, an observation
and measurement system 9 for observing and measuring the position
of a workpiece W; a mask unit 10; and a work station 11 for
operating the workpiece W to move. The optical system 8 comprises a
beam reformation optical system and Kohler illumination optical
system 8a arranged on the optical axis a of the laser beam 2
incident upon the apparatus frame 6, and a projection optical
system 8a for focusing the image of the mask unit 10 on the
processing surface of the workpiece W. The mask unit 10 is arranged
between the beam reformation optical system and kohler illumination
optical system 8a, and the projection optical system 8b. Here, in
consideration of the durability of the mask unit 10, it is
preferable to use a contraction optical system for the projection
optical system 8b. In the present embodiment, a projection optical
system 8b of 1/4 contraction power is adopted.
In order to adjust the inclination of the workpiece W with respect
to the optical axis a described above, it is preferable to provide
the work station 11 with an appropriate adjusting means. For
example, it may be possible to structure the work station 11 by
combining three axes orthogonal to each other, and a stage having
freedom with respect to the five axes which can rotate around two
axes. It is possible to simplify the control of the adjusting means
by arranging the structure so that the center of rotational
adjustment is brought into agreement with the processing center of
the workpiece W.
To position the workpiece W on the work station 11, it is
preferable to provide a jig 11a for installing the workpiece W on
the work station 11 with a plurality of standard pins which abut
upon the workpiece W mounted on the work station 11. Also, on the
jig 11a, a clamp mechanism using air suction may be arranged in
addition to the abutting mechanism described above, and this clamp
mechanism is integrated with an auto-hand so that the workpieces W
can be supplied to the work station 11 automatically. Also, it may
be possible to shorten the time occasionally by setting a plurality
of works W on the work station 11 at a time. In this case, however,
it is necessary to change the standard values at the time of
measuring and moving the workpiece W because one axis in the
rotational direction of the adjusting means cannot be positioned in
the center of the workpiece W.
The observation and measurement system 9 comprises a lens barrel 9a
having an object lens; a light source 9b for downward illumination
incorporated in the lens barrel 9a; a pair of measuring instruments
having a CCD camera sensor 9c connected to the lens barrel 9a; and
a two-faced mirror 9d arranged on the optical axis a. Each of the
measuring instruments and mirror 9d is arranged between the
projection optical system 8b and the work station 11, and then,
when the laser beam is irradiated, the mirror 9d is removed from
the optical axis a. It is shifted onto the optical axis a only when
the measurement is conducted. In the present embodiment, the
movement of the mirror 9d is controlled by an air cylinder
mechanism.
To the information processing and controlling system 7, the
positional data on the workpiece W provided by the observation and
measurement system 9, and data on the beam power provided by the
power detector 4 are obtained as feedback information. At first,
the result of measurements by the observation and measurement
system 9 is brought to the image processing system 7a per measuring
instrument, while the result of the signal processing is supplied
to the controlling system 7b. In accordance with the result of the
measurement described above, the controlling system 7b calculates
the moving distance of the workpiece W, thus enabling the moving
means 7c to effectuate stepping movements in the work station 11.
Then, when the value of the observation and controlling system 9
reaches a specific value, the positional adjustment by the moving
means 7c is terminated. The mirror 9d is removed from the optical
axis a. Then the signals for actuating the laser oscillator 1 are
given to generate the laser beam 2 for a given period or a given
number of pulses. Also, the information of the beam power from the
power detector 4 is supplied to the controlling system 7b as
feedback information so as to adjust the output given to the laser
oscillator 1 through an interface 7d.
As the laser oscillator 1 used for the laser processing apparatus
of the present invention, a YAG laser oscillator, CO.sub.2 laser
oscillator, excimer laser oscillator, N.sub.2 laser oscillator, or
other oscillators having high output can be used, but in the
present embodiment, a kind of polymer resin, polysulfone resin, is
used for the workpiece W. For the reasons given below, therefore,
an excimer laser oscillator, particularly, a Kr--F excimer laser
oscillator, is used.
The excimer laser is one capable of oscillating ultraviolet beams,
thus outputting a highly intensified energy. This has superior
monochromatism, and is capable of providing a good orientation,
among other advantages such as making short pulses oscillation
possible, and providing a great concentration of energy by use of a
converting lens. In other words, the excimer laser oscillator is
capable of oscillating ultraviolet beam of short pulses (15 to 35
ns) by discharge pumping of a mixed gaseous body of rare gas and
halogen, and Kr--F, Xe--Cl, Ar--F laser or the like is often used.
The energy of the beam is 100 mJ/pulse. The pulse repeating
frequency is 30 to 100 Hz. When such a short ultraviolet pulse beam
having a high luminance is irradiated on the surface of polymer
resin, the irradiated portion is instantaneously decomposed and
caused to spread with accompanying plasma luminescence and
impacting sound. The so-called ablative photodecomposition (APD)
process takes place, thus making it possible to process polymer
resin. This gives a distinct difference from other types of laser
processing, such as drilling by application of a CO.sub.2 laser,
which is infrared. For example, if a laser beam is irradiated onto
a polyimide (PI) film by use of excimer laser (Kr--F laser), it is
possible to drill a fine hole because the light absorption
wavelength of the PI film is in the UV domain. However, the use of
YAG laser which is not in the UV domain results in a hole having a
rough edge. The use of a CO.sub.2 laser brings about a crater on
the circumference of the hole.
As described above, the laser which can oscillate ultra-violet beam
is excellent in processing polymer resin. As a laser capable of
oscillating ultraviolet beam, there can be used a fourth harmonic
wave of YAG laser, a mixed beam of the base wave of the YAG laser
and second harmonic wave thereof, and a N.sub.2 laser, as well as
an excimer laser. These lasers are also usable for the protein
invention.
Now, the description will be made of the workpiece W. The workpiece
W processed in the present embodiment is one of the parts
constituting an ink jet recording head used for an ink jet
recording apparatus. More specifically, it is a ceiling board 19, a
board member of the ink jet recording head shown in FIG. 8 and FIG.
9. Here, in conjunction with FIG. 8 and FIG. 9, description will be
made of an ink jet recording head. The ink jet recording head
comprises a silicon substrate 20 on which the energy generating
elements are patterned for generating the energy which is utilized
for discharging ink, and a ceiling board 19 which is coupled to the
substrate 20. As the energy generating elements, electrothermal
transducing elements 18 (heat generating resistive elements or the
like) are used, which generate thermal energy when voltage is
applied thereto. A plurality of electrothermal transducing elements
18 are arranged in parallel, and are formed integrally on the
substrate 20 by application of film formation technique, together
with wiring made of aluminum or the like for supplying power to the
electrothermal transducing elements 18. On the other hand, for the
ceiling board 19, there are generally provided altogether the
grooves 19b, which constitute ink paths 14, being formed
corresponding to each of the electrothermal transducing elements; a
recess 19a which constitutes an ink liquid chamber 13 for
provisionally retaining ink to be supplied to each of the ink paths
14; an ink supply inlet 12 for supplying ink from an ink tank (not
shown) to the ink liquid chamber 13; and an orifice plate 17 having
a plurality of discharge ports formed on it corresponding to each
of the ink paths 14. Also, on the bottom wall in the intermediate
section of each groove 19b, an extrusion 15 is formed,
respectively, thus the cross-section of each ink path 14 is made
smaller in the intermediate section thereof.
This extrusion 15 functions to provide resistance when ink flows in
each of the ink paths 14 to enhance the ink discharge properties by
preventing the ink foaming energy given by each of the
electrothermal transducing elements from escaping to the ink liquid
chamber side. On the basis of the structure described above, when
each of the electrothermal transducting elements 18 is supplied
with power, the respective electrothermal transducing element is
caused to generate thermal energy to create film boiling in ink on
the electrothermal element, thus foaming air bubble in the ink
path. Then by the development of this air bubble, an ink droplet is
discharged from each of the discharge ports 16.
As shown in FIG. 10, each of the grooves 19b on the ceiling board
19 (workpiece W) each with the extrusion 15 described above is
processed by irradiating laser beam 2 from the side of the surface
coupled with the substrate 20 (see FIG. 9) by use of the laser
processing apparatus of the present embodiment. Also, each of the
discharge ports 16 is processed by use of the laser processing
apparatus of the present embodiment. In this respect, the discharge
ports 16 may be processed either before or after the grooves 19b
are processed. In the present embodiment, the discharge ports 16
are processed by the irradiation of a Kr--F excimer laser from the
groove 19b side after the grooves 19b are processed. Also, it is
preferable to form the workpiece W by injection molding of material
such as polysulfone, polyether sulfone, polyphenylene oxide or
other materials having a good resistance to ink. In the present
embodiment, the workpiece is formed by injection molding of
polysulfone.
Also, when each of the grooves 19 is processed, it is preferable to
incline the workpiece W slightly to the optical axis a in order to
prevent the laser beam 2 from being blocked by the orifice plate
17. In the present embodiment, the grooves 19 are processed while
the workpiece W is inclined at an angle of 5.degree. with respect
to the optical axis a.
Now, with reference to FIG. 11, mask unit 10 will be described.
FIG. 11 is a perspective view of the mask unit represented in FIG.
1A. In FIG. 11, a board member 23 is fixed to a second movable
mechanism 21 arranged for the apparatus frame 6 (see FIG. 7) which
is finely movable in the direction X, direction Y, and direction Z.
On the one end of the board member 23 on the laser light source
side, there is arranged a holder 24 for detachably holding a member
25 for forming extrusions which serve as a member for reflecting or
absorbing at least a part of laser beam. The extruded portions 15
(see FIG. 19) are thus formed through a first movable mechanism 22
which is also finely moveable in the direction X, direction Y, and
direction Z. Also on the end of the board member 23 on the
workpiece W (see FIG. 7) side, a mask holder 26 is fixed for
detachably holding the mask 27 for forming the grooves 19b (see
FIG. 9). The mask 27 and the member 25 for forming extrusions are
arranged in parallel within the luminous flux of the laser beam 2,
and are separated from each other by a distance L in the optical
axis of the laser beam 2. In this way, it is possible to adjust the
position of the member 15 for forming extrusions in the X, Y, and Z
directions with respect to the mask, and also the position of the
mask 27 in the X, Y, and Z directions with respect to the direction
of the optical axis of the laser beam 2. It is preferable to make
the first movable mechanism 22 and second movable mechanism 21 the
movable stages which provide three or more axes. Also, the first
movable mechanism 22 may be installed on the mask holder 26.
The mask 27 is provided with the pattern of grooves 19 formed in a
size of as large as four times, and the laser beam 2 which
transmits the mask 27 is contracted to a size as small as 1/4 times
by means of the projection optical system 8b (see FIG. 7) as
described earlier. Therefore, the pattern of a desirable size is
focused on the workpiece W. Mask 27 can be made from material such
as stainless steel, Ni, phosphor bronze, Al, opaque ceramics,
quartz plate with a reflective coating, Si, or the like, so that
the mask is not affected by the irradiation of the laser beam 2 of
excimer laser in the atmosphere (air). In the present embodiment,
the mask is prepared for use by forming the pattern on phosphor
bronze by application of etching and others.
On the other hand, the member 25 for forming extrusions is the one
prepared by the material which does not allow the laser beam 2 to
transmit and positioned to face the extrusion 15 (see FIG. 9). In
the present embodiment, this member is prepared for use by
adhesively bonding to the frame of phosphor bronze an Al wire of
.phi.50 .mu.m for wire bonding use as the member which does not
allow the laser beam 2 to transmit. In this aspect, the projection
optical system used for the present embodiment projects the mask
image with its left, right, up and down sides reversely. Therefore,
the member 25 for forming extrusions should be arranged in
consideration of this particular point.
With the structure described above, the grooves 19b of the ceiling
board 19 shown in FIG. 9 are formed. The height h of the extrusion
15 shown in FIG. 9 can be adjusted by changing the distance L from
the surface of the mask 27 to the member 25 for forming extrusions
shown in FIG. 10. In the present embodiment, the distance L is set
at 20 mm. Also, the position of the extrusion 15 with respect to
each groove 19b is arbitrarily changeable by adjusting the holder
24 in the direction Z by use of the first movable mechanism shown
in FIG. 10. In the present embodiment, it is possible to form by a
single processing 64 grooves 19b each having an extrusion 15 of 30
.mu.m high in a dimension of height, 50 .mu.m.times.width, 50
.mu.m.times.length, 500 .mu.m at a pitch of 70 .mu.m. This way, an
ink jet recording head having excellent discharge properties can be
obtained without reducing productivity.
Embodiment 6
FIG. 12 is a perspective view which shows a sixth embodiment of a
mask unit for a laser processing apparatus in accordance with the
present invention. The present embodiment differs from the
embodiment 5 in that a mask 47 is arranged on the laser light
source side, and a member 45 for forming extrusions is arranged. In
other words, the mask 47 is fixed on the end portion of the board
member 43 on the laser light source side, and the member 45 for
forming extrusions is arranged on the end portion on the workpiece
side through a first movable mechanism 42. The structure of the
entire body of the laser processing apparatus including the other
structural aspects of the mask unit 40 are the same as that of the
embodiment 5. Therefore, description thereof will be omitted.
Using such mask unit 40, the grooves are processed on the same
workpiece as shown in the embodiment 5 under the same processing
conditions as those in the embodiment 5. With a single processing,
it is possible to obtain grooves equal to those shown in FIG. 10.
In the present embodiment, too, the height of the extrusion 15 can
be adjusted by changing a distance from the surface of mask 47 to
the member 45 for forming extrusion minus L.
Embodiment 7
In the two embodiments described above, examples are shown, in
which the mask and the member for forming extrusions are arranged
with its relative positional relationship being adjustable.
However, it is not required for the work of the same specifications
to adjust any relative positions between the mask and the member
for forming extrusions once the position and height of extrusion is
determined with respect to each groove to be processed by the laser
processing apparatus.
In the present embodiment, therefore, a mask 67 is detachably held
by a mask holder 66 fixed to the board member 63 as shown in FIG.
13, and then, two spacers 68 are provided for this mask 67
integrally. To the leading end of each spacer 68, Al wire 65 of
.phi.50 .mu.m for wire bonding use is fixedly by use of UV
hardening adhesives as a member for reflecting or absorbing at
least a part of the laser beam. The fixing position of each spacer
68 and the distance L from the surface of the mask 67 to the Al
wire 65 are determined by the position of extrusion 15 and the
height of the extrusion 15 with respect to the groove 19 shown in
FIG. 10. The other structures are the same as those of the
embodiment 5. Therefore, the description thereof will be
omitted.
With the mask unit 60 described above, grooves are processed on the
same workpiece as shown in the embodiment 5 under the same
conditions as the embodiment 5. Then, it is possible to obtain the
grooves equal to those shown in FIG. 10 in a single processing. In
this respect, Al wire 65 may be arranged either on the laser light
source side with respect to the mask 67 as shown in FIG. 13 or on
the workpiece side which is opposite thereto. Also, each spacer 68
may be installed on the mask holder 66 which supports the mask
67.
As described above, by fixing the positional relationship between
the mask 67 and Al wire 65, the processing configuration of a
workpiece can be determined uniquely, thus avoiding any errors in
selling the position and height of each extrusion to be formed on
the workpiece.
Embodiment 8
FIG. 14 is a perspective view which shows an eighth embodiment of a
mask unit for a laser processing apparatus in accordance with the
present invention. In the present embodiment, a member for forming
extrusions is different from that shown in the embodiment 5. The
other structures are the same as those of the embodiment 5.
Therefore, description thereof will be omitted. Now, the
description will be made of the member 85 for forming extrusions as
given below.
The member 85 for forming extrusions is prepared by a synthetic
quartz base board. On the outer circumference (portion indicated by
slanted lines), a totally reflective film 85a for the beam of 248
nm wavelength is coated. Also, on the lower part of the region
surrounded by the totally reflective film 85a (portion indicated by
horizontal lines), a transmitting film 85b, which transmits a 30%
of the beam of 248 nm, is coated.
Using the mask unit 80 structured as described above, groove
processing is performed on a workpiece W under the same processing
conditions as the embodiment 5. Such workpiece is represented in
FIG. 15. As shown in FIG. 15, the extrusion 95 is formed in step on
the end portion of the groove 99b, processed by the irradiation of
the laser beam on the recess 99a side. The depth of the groove 99b
becomes smaller in the portion where the extrusion 95 is formed. An
ink jet recording head is manufactured by coupling the workpiece W
with such grooves 99b serving as the ceiling board to the base
board where the energy generating elements are arranged. In this
way, the ink paths are formed by the grooves 99b and the base
board, while the ink liquid chamber is formed by a recess 99a and
the base board. In the ink liquid chamber, the extrusion 95 is
formed which functions as resistance to ink flow. Therefore, with
this extrusion 95, the supply force to the ink discharge ports 96
side is controlled, and at the same time, the escape of ink foaming
energy to the ink liquid chamber side is prevented.
In the present embodiment, it is possible to form with a single
processing the groove 99b of depth, 50 .mu.m.times.width, 50 .mu.m,
and the height h of the extrusion being 35 .mu.m, with the tapering
dimension 1 being 10 .mu.m in the stepped portion. The height h of
the extrusion 95 can be adjusted by changing the transmissivity of
the transmitting film 85b shown in FIG. 14. The tapering dimension
1 in the stepping portion can be adjusted by changing the distance
L from the surface of the mask 87 to the member 85 for forming
extrusion shown in FIG. 14. Also, in the present embodiment, while
the description has been made of the case where the extrusion 95
has only one step, it is possible to provide a plurality of steps
in the extrusion just by coating on the member 85 for forming
extrusions the plural kinds of transmitting films which provide
different transmissivities of laser beam accordingly.
In each of the embodiments described above, the examples as shown,
in which the projection optical system 8b is used (see FIG. 7).
However, it may be possible to use a processing apparatus of the
contact type which processes by arranging a workpiece and a mask to
be in contact with each other without adopting any projection
optical system 8b. Also, in each of the embodiments described
above, the examples are shown, in which a ceiling board, one of the
parts constituting an ink jet recording head, is being processed by
use of the laser processing apparatus of the present invention, but
this apparatus can be used not only for laser processing, but also
can be adopted as an exposure equipment for the photo-sensitive
resin which is used when manufacturing a semiconductor or the
like.
Now, the description will be made of an ink jet recording apparatus
in accordance with the present invention.
In FIG. 16, an ink jet recording heat 101 which records desired
images by discharging ink in response to given recording signals is
of the same structure as that of the ink jet recording head
described above.
A carriage 102 upon which the ink jet recording head 101 is mounted
is fitted into two guide shafts 103 and 104 slidably in the
directions indicated by arrows B, and is coupled to one portion of
a timing belt 108 tensioned around a pulley 107 fixed to the output
shaft of a carriage motor 105 and a polly 106 rotatively supported
by a shaft. The ink jet recording head 101 is structured to
reciprocate in the directions indicated by the arrows B when the
timing belt 108 rotates regularly or inversely following the
regular or inverse rotation of the pulley 107 by application of
driving force of the carriage motor 105.
A recording sheet 109, a recording material, is guided by a paper
pan 110 and fed by a feed roller (not shown) with which a pinch
roller is in contact under pressure. This feeding is performed by a
sheet feed motor 116 as its driving source. The recording sheet 109
thus fed is tensioned by means of a sheet exhaust roller 113 and a
spur 114, and pressed to a heater 111 by means of a sheet pressure
board 112 formed by an elastic material. As a result, it is fed
while being pressed to the heater 111. The recording sheet 109 to
which discharged ink adheres by the ink jet recording head 101 is
warmed up by the heater 111. Thus the moisture of the adhering ink
is evaporated to allow the ink to be fixed on the recording sheet
109.
A recovery unit 115 is provided to maintain the discharging
properties at a normal condition by removing foreign particles and
overly viscous ink adhering to the discharge ports 16 of the ink
jet recording head 101 (see FIG. 8).
The recovery unit 115 is provided with a cap 118a to cap the
discharge ports of the ink jet recording head 111, thus preventing
any clogging from taking place. In the interior of the cap 118a, an
ink absorbent 118 is arranged.
Also, on the recording area side of the recovery unit 115, a
cleaning blade 117 is provided for cleaning foreign particles and
ink droplets adhering to the surface where the discharge ports 16
are formed.
The ink jet recording head, the laser processing apparatus, and ink
jet recording apparatus in accordance with the present invention
serve to bring about excellent effects on the recording head and
recording apparatus of the ink jet method, particularly of the
method in which recording is performed by forming flying droplets
using thermal energy.
Regarding the typical structure and operational principle of such a
method, it is preferable to adopt those which can be implemented
using the fundamental principle disclosed in the specifications of
U.S. Pat. Nos. 4,723,129 and 4,740,796. This method is applicable
to the so-called on-demand type recording system and a continuous
type recording system as well. Particularly, however, the method is
suitable for the on-demand type because the principle is such that
at least one driving signal, which provides a rapid temperature
rise beyond a departure from nucleation boiling point in response
to recording information, is applicable to an electrothermal
transducing element disposed on a liquid (ink) retaining sheet or
liquid passage whereby to cause the electrothermal transducing
element to generate thermal energy to produce film boiling on the
thermoactive portion of recording head, thus effectively leading to
the resultant formation of a bubble in the recording liquid (ink)
one to one in response to each of the driving signals. By the
development and contraction of the bubble, the liquid (ink) is
discharged through each discharging port to produce at least one
droplet. The driving signal is more preferably in the form of
pulses because the development and contraction of the bubble can be
effectuated instantaneously, and, therefore, the liquid (ink) is
discharged with particularly quick response.
The driving signal in the form of pulses is preferably such as
disclosed in the specification of U.S. Pat. Nos. 4,463,359 and
4,345,262. In this respect, the temperature increasing rate of the
heating surface is preferably such as disclosed in the
specification of U.S. Pat. No. 4,313,124 for an excellent recording
in a better condition.
The structure of the recording head may be as shown in each of the
above-mentioned specifications wherein the structure is arranged to
combine the discharging ports, liquid paths, and the electrothermal
transducing elements (linear type liquid paths or right-angled
liquid paths). Besides, the structure such as disclosed in the
specifications of U.S. Pat. Nos. 4,558,333 and 4,459,600 wherein
the thermal activation portions are arranged in a curved area is
also included in the present invention.
In addition, the present invention is effectively applicable to the
structure disclosed in Japanese Patent Laid-Open Application No.
59-123670 wherein a common slit is used as the discharge ports for
plural electrothermal transducing elements, and to the structure
disclosed in Japanese Patent Laid-Open Application No. 59-138461
wherein an aperture for absorbing pressure wave of the thermal
energy is formed corresponding to the discharge ports.
Furthermore, as a full-line type recording head where its length is
provided for the width of a maximum recordable medium which can be
recorded by such recording apparatus, the present invention is
applicable to either the structure which can satisfy such length by
combining a plurality of recording heads disclosed in the
specifications described above or the structure in which one
recording head is integrally formed for the purpose.
In addition, the present invention is effectively adoptable
irrespective of whether the recording head as of an exchangeable
chip type which can be electrically connected with the apparatus
main body or to which ink can be supplied from the apparatus main
body when the head is installed in it, or the recording head of a
cartridge type in which an ink tank is formed together with the
recording head itself.
Also, for the present invention, it is preferable to additionally
provide a recording heat with recovery means and preliminary
auxiliary means as constituents of the recording apparatus because
these additional means will contribute to making the effectiveness
of the present invention more stabilized. To name them
specifically, these are pressing or sucking means with respect to a
recording head, preheating means such as electrothermal transducing
elements or heating elements other than such transducing elements
or the combination of those types of elements, and the adoption of
a predischarge mode, which performs discharge other than the
regular discharge. This mode is also effective in executing a
stabilized recording.
Moreover, as the recording mode of the recording apparatus, the
present invention is extremely effective when applied not only in
the recording mode in which only major color such as black is used,
but also, in using an apparatus which is provided with at least
either one of complex colors having different colors and full color
arranged by mixing colors irrespective of a recording head being
integrally structured or it is structured by combination of plural
heads.
In the embodiments of the present invention described above, while
the ink has been described as liquid, it may be an ink material
which is solidified below the room temperature but liquefied at the
room temperature or in the form of liquid, or in the ink jet method
described above, it is generally practiced that the temperature
adjustment of ink itself is conducted in a range of temperatures
not lower than 30.degree. C. and not higher than 70.degree. C. in
order to stabilize its viscosity for the provision of the stable
discharge. Therefore, it is good enough if ink can be liquefied
when the recording signals are provided for use.
In addition, while positively preventing the temperature from
rising due to the thermal energy by consuming such energy as an
energy to be utilized for changing states of ink from solid to
liquid, or by use of the ink which will be solidified when left
intact for the purpose of preventing the ink from being evaporated,
it may be possible to adopt the present invention for use of an ink
having a nature of being liquefied only by the application of
thermal energy, such as an ink capable of being discharged as ink
liquid by enabling itself to be liquefied anyway when the thermal
energy is given in accordance with recording signals, and an ink
which will have already begun solidifying itself by the time it
reaches a recording medium. In such a case, it may be possible to
retain the ink in the form of liquid or solid in the recesses or
through holes of a porous sheet such as disclosed in Japanese
Patent Laid-Open Application No. 54-56847 or 60-71260 in order to
enable the ink to face the electrothermal transducing elements. In
the present invention, the most effective method for the various
kinds of ink mentioned above is the one which is capable of
implementing the film boiling method as described above.
Further, as the mode of the recording apparatus in accordance with
the present invention, it may be possible to adopt a copying
apparatus combined with a reader in addition to the image output
terminal which is integrally or independently provided for a word
processor, a computer, or other information processing apparatuses,
and further, it may be possible to adopt the mode of a facsimile
apparatus having transmission and reception functions.
As described above, in accordance with the present invention, a
filter unit can be arranged by a single processing in the ink path
and/or in the common liquid chamber. Also, with the provision of
this filter unit, it becomes possible to take a required measure
against dust particles. As a result, a yield rate can be improved,
leading to the achievement of reducing the processing cost.
Further, the filter unit can be arranged in an arbitrary position,
and also, the filter gap can be set freely. Therefore, not only the
provision of the filter unit contributes to taking a countermeasure
against dust particles, but also, to suppress the extent of
backward meniscus retraction when printing at high frequencies.
Hence the discharge stabilization is enhanced to make high speed
printing possible.
Also, a laser processing apparatus for the present invention can
include a member for reflecting or absorbing at least a part of
laser beam in a position apart from the surface of a mask within
the luminous flux of the laser beam. Therefore, it is possible to
process by a single processing a three-dimensional configuration in
the direction in which the laser beam is irradiated. Thus, there is
no need for any means for positioning the processing for the second
time and on because a three-dimensional configuration can be
processed by only a one-time processing. This makes it possible to
simplify the structure of the laser processing apparatus, resulting
in the reduction of the processing cost of a workpiece eventually,
while the process itself can be built at a lower cost.
Also, the aforesaid member can be installed with its position
relatively adjustable with respect to the mask, making it possible
to adjust the position and height of a three-dimensional portion
with respect to the processing part of a workpiece. Therefore, when
the aforesaid member is installed fixedly with respect to the mask,
it is possible to determine the processing configuration of a
workpiece uniquely. Further, more complicated configuration can be
processed by arranging the aforesaid member so that the
transmissivity of laser beam is caused to differ depending on the
different regions of the member. Then, by arranging the laser light
source to enable it to generate ultraviolet pulse laser, polymer
resin can be processed finely.
An ink jet recording head and ink jet recording apparatus of the
present invention are such that grooves formed on a board member
thereof are processed by a laser processing apparatus of the
present invention. Therefore, it is possible to form the grooves
each with an extrusion by only a single processing. As a result,
superior discharge properties can be obtained without marring
productivity when a head is manufactured, as compared to those
having no extrusions.
Also, the board member is formed by polymer resin while using a
laser light source which can generate ultraviolet pulse laser as
the one for the laser processing apparatus of the present
invention. Hence the grooves can be processed finely, resulting in
the provision of the stabilized ink discharges.
* * * * *