Information
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Patent Grant
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6364470
-
Patent Number
6,364,470
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Date Filed
Thursday, December 30, 199924 years ago
-
Date Issued
Tuesday, April 2, 200222 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 377 77
- 342 82
- 342 20
- 342 54
- 342 44
- 342 47
- 347 82
- 347 77
- 347 74
- 347 73
- 347 54
- 347 20
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International Classifications
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Abstract
There is provided by this invention a unique printing system that utilizes a notch deflector in the ink delivery channel of a continuous ink jet printing system to control the angle of deflection ink droplets in a print and non-print direction. The width and depth of the notch in the ink delivery channel can be varied to produce different angles of deflection of the ink droplets for a given velocity of ink through the channel. Also, for any predetermined width and depth of the notch in the ink delivery channel, the deflection angle of the droplets will vary with varying velocities of ink flow. Control circuits are connected to the notch deflector to adjust the depth of the deflector for different angles of deflection.
Description
FIELD OF THE INVENTION
This invention relates generally to the field of digitally controlled printing devices and methods, and in particular to continuous ink jet print heads and methods which integrate multiple nozzles on a single substrate and in which the breakup of a liquid ink stream into droplets is caused by a periodic disturbance of the liquid ink stream.
BACKGROUND OF THE INVENTION
Many different types of digitally controlled printing systems have been invented, and many types are currently in production. These printing systems use a variety of actuation mechanisms, a variety of marking materials, and a variety of recording media. Examples of digital printing systems in current use include: laser electrophotographic printers; LED electrophotographic printers; dot matrix impact printers; thermal paper printers; film recorders; thermal wax printers; dye diffusion thermal transfer printers; and ink jet printers. However, at present, such electronic printing systems have not significantly replaced mechanical printing presses, even though this conventional method requires very expensive setup and is seldom commercially viable unless a few thousand copies of a particular page are to be printed.
Inkjet printing has become recognized as a prominent contender in the digitally controlled, electronic printing arena because of its non-impact, low-noise characteristics, its use of plain paper and its avoidance of toner transfers and fixing. Ink jet printing mechanisms can be categorized as either continuous ink jet or drop on demand ink jet. Continuous ink jet printing dates back to at least 1929. See U.S. Pat. No. 1,941,001 issued to Hansell.
U.S. Pat. No. 3,373,437, which issued to Sweet et al. in 1967, discloses an array of continuous ink jet nozzles wherein ink drops to be printed are selectively charged and deflected towards the recording medium. This technique is known as binary deflection continuous ink jet.
U.S. Pat. No. 3,416,153, which issued to Hertz et al. in 1966, discloses a method of achieving variable optical density of printed spots in continuous ink jet printing using the electrostatic dispersion of a charged drop stream to modulate the number of droplets which pass through a small aperture.
U.S. Pat. No. 3,878,519, which issued to Eaton in 1974, discloses a method and apparatus for synchronizing droplet formation in a liquid stream using electrostatic deflection by a charging tunnel and deflection plates.
U.S. Pat. No. 4,346,387, which issued to Hertz in 1982, discloses a method and apparatus for controlling the electric charge on droplets formed by the breaking up of a pressurized liquid stream at a drop formation point located within an electric field having an electric potential gradient. Drop formation is effected at a point in the field corresponding to the desired predetermined charge to be placed on the droplets at the point of their formation.
Conventional continuous ink jet utilizes electrostatic charging rings that are placed close to the point where the drops are formed in a stream. In this manner individual drops may be charged. In addition to charging rings, deflection plates having a large potential difference between them may be used to deflect drops which are charged downstream. Uncharged drops are not deflected.
In all such continuous ink jet printers, a gutter (sometimes referred to as a “catcher”) intercepts ink drops not intended for printing. For example, charged drops may be deflected so as to miss the gutter and thereby pass on as print drops to a receiver, whereas uncharged drops are captured by the gutter.
U.S. Pat. No. 6,079,821, issued Jun. 27, 2000, discloses a continuous ink jet printer system in which heat is applied asymmetrically to an ink stream to control the direction of the stream between a print direction and a non-print direction. This method renders unnecessary the electrostatic charging tunnels of conventional continuous ink jet technologies and serves to better couple the functions of droplet formation and droplet deflection. However, the ink stream must be heated for deflection to occur.
The continuous ink jet printer described in accordance with the present invention eliminates the need for electrostatic charging systems and deflection plates in continuous ink jet printers without requiring the addition of heat to control the direction of the ink stream between a print direction and a non-print direction.
It is an object of the present invention to provide a high speed apparatus and method of page width printing utilizing a continuous ink jet method whereby drop formation and deflection may occur at high repetition.
It is another object of the present invention to provide an apparatus and method of continuous ink jet printing with a drop deflection mechanism which can be integrated with the print head utilizing the advantages of silicon processing technology offering low cost, high volume methods of manufacture.
It is another object of the present invention to provide an apparatus and method of high speed printing that can use a wide variety of inks.
It is yet another object of the present invention to provide an apparatus and method for continuous ink jet printing that does not require electrostatic charging plates.
It is still another object of this invention to provide a continuous ink jet printing system that integrates an ink stream deflection means into the nozzle of a continuous ink jet printer.
The invention, and its objects and advantages, will become more apparent in the detailed description of the preferred embodiments presented below.
SUMMARY OF THE INVENTION
There is provided by this invention a print head of the continuous ink jet type wherein multiple nozzles are fabricated into a silicon substrate. Annular heaters may be fabricated around the nozzles to create variable size drop formation in the ink stream. A notch in the nozzle bore having a predetermined width and adjustable depth accomplishes deflection of the drops for printing.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings, in which:
FIG. 1
shows a simplified block schematic diagram of one exemplary printing apparatus according to the present invention;
FIG. 2
shows schematically a view of the nozzle bore in cross-section with a notch deflector for deflection of the ink drops for printing;
FIG. 3
shows a sectional view of the nozzle bore with the notch incorporating the principles of this invention;
FIG. 4
is a view taken along section line
4
—
4
of
FIG. 3
, this view showing a nozzle bore having three notch deflectors spaced equally around the periphery of the nozzle bore incorporating the principles of this invention;
FIG. 5
shows the angle of deflection variations of water based inks and isopropyl alcohol (IPA) based inks versus a range of inflow velocities for a given notch deflector depth;
FIG. 6
shows schematically a view of the nozzle bore in cross-section with a notch deflector for deflection of the ink drops for printing; and
FIG. 7
shows a sectional view of the nozzle bore with two notch deflectors.
DETAILED DESCRIPTION OF THE INVENTION
The present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art.
Referring to
FIG. 1
, there is shown a continuous ink jet printer system that includes an image source
10
such as a scanner or computer which provides raster image data, outline image data in the form of a page description language, or other forms of digital image data. This image data is converted to multi-level half-toned bitmap image data by an image-processing unit
12
that also stores the image data in memory. A plurality of heater control circuits
14
read data from the image memory and applies time-varying electrical pulses to a set of nozzle heaters
50
that are part of a print head
16
. These pulses are applied at an appropriate time, and to the appropriate nozzle, so that drops formed from a continuous ink jet stream will form spots on a recording medium
18
in the appropriate position designated by the data in the image memory. Micro-actuator control circuits
13
apply a signal to the nozzle to control the deflection of the drops to the recording medium
18
in a manner hereinafter described.
Recording medium
18
is moved relative to print head
16
by a recording medium transport system
20
, which is electronically controlled by a recording medium transport control system
22
, and which in turn is controlled by a micro-controller
24
. The recording medium transport system shown in
FIG. 1
is a schematic only, and many different mechanical configurations are possible. For example, a transfer roller could be used as recording medium transport system
20
to facilitate transfer of the ink drops to recording medium
18
. Such transfer roller technology is well known in the art. In the case of page width print heads, it is most convenient to move recording medium
18
past a stationary print head. However, in the case of scanning print systems, it is usually most convenient to move the print head along one axis (the sub-scanning direction) and the recording medium along an orthogonal axis (the main scanning direction) in a relative raster motion.
Ink is contained in an ink reservoir
28
under pressure. In the non-printing state, continuous ink jet drop streams are unable to reach recording medium
18
due to an ink gutter
17
that blocks the stream and which may allow a portion of the ink to be recycled by an ink recycling unit
19
. The ink-recycling unit reconditions the ink and feeds it back to reservoir
28
. Such ink recycling units are well known in the art. The ink pressure suitable for optimal operation will depend on a number of factors, including geometry and thermal properties of the nozzles and thermal properties of the ink. A constant ink pressure can be achieved by applying pressure to ink reservoir
28
under the control of ink pressure regulator
26
.
The ink is distributed to the back surface of print head
16
by an ink channel device
30
. The ink preferably flows through slots and/or holes etched through a silicon substrate of print head
16
to its front surface, where a plurality of nozzles, micro-actuators, and heaters are situated. With print head
16
fabricated from silicon, it is possible to integrate heater control circuits
14
and micro-actuator control circuits
13
with the print head.
Referring to
FIG. 2
there is shown a cross-sectional view of one nozzle tip of an array of such tips in a silicon substrate that forms a continuous ink jet print head
16
of
FIG. 1
according to a preferred embodiment of the present invention. Ink is delivered to lateral ink delivery channels
40
in substrate
42
and flows through vertical ink delivery channels
64
and out of the substrate through nozzle bores
46
. Thereby, lateral ink delivery channels
40
, along with a plurality of vertical ink delivery channels
64
and nozzle bores
46
are provided in the substrate
42
. In the preferred embodiment, the substrate is made of silicon and the delivery channels and nozzle bores are formed by reactive plasma etching, as is well known in the art of micro-machining. In other preferred embodiments, the substrate is plastic (i.e. a polymer) and injection molding is used to form the delivery channels and nozzle bores. In yet another preferred embodiment, the substrate is glass and the delivery channels and nozzle bores are formed by wet etching and abrasive cutting. The nozzle bores
46
, which define the ink exit apertures at the top surface of substrate
42
of vertical ink delivery channels
64
, are preferably circular in cross-section when viewed from the top; but shapes other than circular may be advantageously used as well. In the preferred embodiment of the present invention, as shown in FIG.
2
and
FIG. 3
, the vertical ink delivery channels
64
are substantially cylindrical channels that allow ink to be delivered from the lateral ink delivery channels
40
to the top surface of substrate
42
. As shown in
FIGS. 2 and 3
, notch deflectors
62
, to be described, lie in the walls of the upper portions of vertical ink delivery channels
64
. The nozzle bores
46
are at the top of the vertical ink delivery channels
64
and hence at the top surface of substrate
42
. The nozzle bores
46
lie above the notch deflectors
62
to be described.
Ink
44
in lateral ink delivery channel
40
is pressurized above atmospheric pressure, and thereby forms an ink stream
48
which is ejected from the nozzle bore, as is well known in the art of continuous ink jet printing. At a distance above nozzle bore
46
, stream
48
breaks into a plurality of drops
66
, preferably due to heat pulses supplied by a heater
50
. The droplets so produced are regularly spaced and of equal size, so that the heater may be said to perform the function of a drop regulator
52
. The heater
50
may be in the form of a ring which surrounds stream
48
and provides heat to stream
48
from all sides or may alternatively be in the form of a split heater which provides heat asymmetrically to stream
48
. The heat required to break stream
48
into a plurality of drops
66
is very small, so that no thermal damage to the ink occurs, thermal damage being a problem known in the art of thermal ink jet printing. Heater
50
provides heat pulses to stream
48
under the control of heater control circuits
14
shown in FIG.
1
. Heater
50
is preferably separated from substrate
42
by thermal and electrical insulating layers
56
to minimize heat loss to the substrate. In this case, the nozzle bore may be made in insulating layers
56
.
In the preferred embodiment, the ink stream
48
is heated by heat pulses from heater
50
and breaks into droplets
66
shown in FIG.
2
. The droplets so produced are regularly spaced and of equal size. However, other means of drop regulation are possible. For example, high frequency sound waves, may also be employed, alone or in conjunction with heat pulses, to break ink stream
48
into drops, as is well known in the art of continuous ink jet printing. Referring to
FIG. 6
, such sound waves may be provided by an ultrasonic transducer
54
disposed near or in place of heater
50
. Alternatively, the ink stream may be allowed to break up into drops at random by excluding or minimizing externally produced perturbations, such as external heat pulses or sound waves, as is well known in the art of fluid instabilities in small streams. However, in this latter case, the size of the drops will not generally be identical one to another nor will they be spaced regularly. In this case, no drop regulator
52
is used.
As shown in FIG.
2
and in detail in
FIG. 3
, a notch deflector
62
, which for purposes of illustration may be thought of as a moveable piston located in the wall of ink delivery channel
64
, has a predetermined width “W” along the direction of vertical ink delivery channel
64
(shown vertically disposed) and an adjustable depth shown as (t-δt) in
FIG. 3
which measures the distance by which the left edge (dotted line in
FIG. 3
) of the notch deflector
62
is displaced from the right (dotted line in
FIG. 3
) edge of the vertical ink delivery channel
64
in a direction substantially perpendicular to direction of vertical ink delivery channel
64
. Preferably, depth (t-δt) is positive, as shown in
FIG. 3
, so that a depression is formed in the wall of the vertical ink delivery channel. The maximum distance of the left edge (
FIG. 3
) of the notch deflector
62
is displaced from the right (
FIG. 3
) edge of the vertical ink delivery channel
64
in a direction substantially perpendicular to direction of vertical ink delivery channel
64
is “t” in FIG.
3
. In accordance with the present invention, the depth (t-δt) can be varied. Preferably, depth (t-δt) is positive, as shown in
FIG. 3
, so that generally a depression is formed in the wall of the vertical ink delivery channel. As the depth (t-δt) is varied by moving the notch deflector to the right in
FIG. 3
, the depth of the “depression” in the vertical ink delivery channel just below the nozzle bore increases. Thus, the notch deflector generally includes a depression in the wall of the vertical ink delivery channel and a means of controlling the depth of the depression.
The notch deflector
62
, when the distance (t-δt) is not zero, surprisingly promotes ink drop deflection for printing. It is the presence of notch deflector
62
in
FIG. 2
that accounts for the direction of motion of ink drops
66
lying away from the vertical axis by an angle labeled “θ” in FIG.
2
. If the distance (t-δt) in
FIG. 3
is not zero, then the ink flowing along the right edge (
FIG. 3
) of vertical ink delivery channel
64
flows along a surface which is not planar, and, as will be shown, such flow causes a deflection of the stream
48
and drops
66
from the vertical direction. If the distance (t-δt) in
FIG. 3
is made zero, then ink flowing along the right edge (
FIG. 3
) of vertical ink delivery channel
64
flows along a surface which is planar in FIG.
3
and which therefore resembles a surface of an ink delivery channel having no notch deflector. In this case, no deflection occurs. The notch deflector
62
is connected to the micro-actuator circuits
13
to control the depth (t-δt) of the edge of the notch deflector
62
from the edge of the vertical ink delivery channel
64
as shown in FIG.
1
. In this regard notch deflector
62
may be formed of a piezoelectric material that moves when electrically stimulated by circuits
13
. Alternatively, notch deflector
62
may be connected to a suitable mechanical or hydraulic mechanism (not shown) capable of moving deflector
62
. While it is possible in accordance with the present invention for the micro-actuator circuits
13
to cause the notch deflector to extend into the ink delivery channel
64
, this is not the preferred method of operation. Thus, the notch deflector generally includes a depression in the wall of the vertical ink delivery channel.
The angle θ (
FIG. 2
) of deflection of the ink drop stream is dependent upon the width (W) and depth (t-δt) of the notch and the velocity of the ink passing through the vertical ink delivery channel
64
, as will be shown. In accordance with the present invention, ink droplets
66
are deflected away from the gutter
17
for printing on the recording medium
18
(
FIG. 2
) and non-deflected droplets
68
fall into the gutter
17
for non-printing in a manner determined by the depth (t-δt). In an alternate printing scheme, ink gutter
17
may be placed to block deflected drops
66
so that only non-deflected drops
68
will be allowed to reach recording medium
18
.
In printing, an important system parameter is the angle θ which characterizes the angle at which the ink stream deflects. The angle θ is shown in
FIG. 2
as the angle formed between a line connecting the deflected ink drops
66
to the center of the nozzle bore on the surface of electrical insulating layers
56
and a line normal to the electrical insulating layers
56
centered at the nozzle bore
46
. Greater drop deflection results in a more robust system. The larger the deflection angle θ the closer the ink gutter
17
may be placed to the print head
16
(
FIG. 1
) and hence print head
16
can be placed closer to recording medium
18
. The distance D from the top surface of the substrate
42
to the gutter
17
is shown in FIG.
2
. In general, shorter drop travel distances D will result in lower drop placement errors, which will result in higher image quality. Also, for a particular distance D, larger deflection angles θ result in larger deflected drop
66
to ink gutter
17
spacing (this distance is shown as S in
FIG. 2
) which would allow a larger ink gutter
17
to print head
16
alignment tolerance.
FIG. 3
illustrates a detailed sectional view of nozzle bore
46
and the notch-actuator
62
in the vertical ink delivery channel
64
. It will be appreciated that the apparatus may vary as to configuration and as to details of the parts without departing from the basic concept as disclosed herein. In particular, the heater
50
at the top surface of substrate
42
shown in
FIG. 2
where ink stream
48
exits the nozzle bore
46
is not shown. As noted previously, its function of breaking ink stream
48
into drops
66
can be achieved by other means or heater
50
may be omitted entirely. Referring to
FIG. 3
, the notch deflector
62
, which for purposes of illustration may be thought of as a moveable piston located in the wall of ink delivery channel
64
, has an initial position such that its left edge (dotted line in
FIG. 3
) is in line with the edge of ink delivery channel
64
(equivalent to the conditions depth=0 or δt=t) so that ink would flow in ink delivery channel
64
in the region of the notch deflector just as if no notch actor were present. In the initial position, the ink stream direction is not deflected, i.e. the angle θ of
FIG. 2
is zero. When the notch deflector is moved from the initial position so that it is displaced to the right (
FIG. 3
) by an amount (t-δt), the ink stream direction is deflected, i.e. the angle θ is no longer zero. This is the condition shown in FIG.
3
. We have found that a surprising small notch depth, in particular a depth which is not difficult to accomplish experimentally, is sufficient to generate a relatively large deflection angle, in particular an angle sufficient to provide the deflection required by the ink jet printing system describe in FIG.
1
. For example it has been found that for a geometry such that the diameter of nozzle bore
46
of 8.8 microns, a notch deflector width W=8.8 microns, and a notch deflector depth t-δt=0.88 microns, an angle of deflection of 5 degrees is achieved in the case of water based inks with an ink stream velocity of 9 m/s. This data is shown in
FIG. 5
which plots the angle of deflects for two inks, one IPA based and one water based, as a function of the velocity of the ink stream in the nozzle bore. As is well known in the art of continuous ink jet printing, an angle of deflection of 5 degrees is adequate for robust print systems.
Although a cross-sectional view, such as that shown in
FIG. 3
, represents the device in two dimensions and serves to illustrate the essential features of the present invention, the actual device and models of the device depend on its three dimensional geometry. As noted previously, the examples cited here correspond to a three dimensional geometry in which the vertical ink delivery channel
64
is substantially cylindrical in shape, and the notch deflector occupies about one-half of the inner periphery of the vertical ink delivery channel
64
when the device is viewed from above. The notch deflector can occupy more of less than one-half of the inner periphery of the vertical ink delivery channel
64
when the device is viewed from above in other preferred embodiments. Also, other preferred embodiments of the present invention include positioning more than one notch deflector
62
around the periphery of the vertical ink delivery channel
64
, the notch deflectors occupying an appreciable amount of the inner periphery of the vertical ink delivery channel
64
when the device is viewed from above, for example a fraction between 0.015 and 1.0 of the total inner periphery.
In the case of more than one notch deflector, each notch deflector exerts an influence on the deflection of the ink stream in the direction of a line between the notch deflector and the center of the bore. Referring to
FIG. 7
, in a preferred embodiment of the present invention, there are two notch deflectors disposed across from one another, each similar to the notch deflector
62
shown in the cross-section of FIG.
3
. In
FIG. 7
, the notch deflectors appear fully symmetric about a vertical line through the middle of the nozzle bore, with a notch deflector on both left and right sides. In this case, the ink stream could be deflected from to the left or to the right, depending on whether the right or left notch deflector were moved right or left, respectively, the deflection still lying in the plane of the paper in FIG.
2
.
In another preferred embodiment, as shown in
FIG. 4
, three notch deflectors
62
are positioned approximately symmetrically about nozzle bore
46
. When viewed from above, each notch deflector
62
preferably occupies about 0.25 of the inner periphery of the nozzle bore
46
. As in the discussion related to
FIG. 3
, the dotted line in
FIG. 4
indicates the edge of the notch deflector nearest the nozzle bore, and the distance between this edge and the inner wall of the vertical ink delivery channel forms a depression in the wall of the ink delivery channel.
As in the case of a single notch deflector, the position of the additional notch deflectors shown in
FIG. 4
is controlled by additional micro actuator control circuits B (not shown). Also, as shown in
FIG. 4
, the positions of all three notch deflectors are similar in that the depths of the depression they form in the wall of the vertical ink delivery channel underneath nozzle bore
46
are about equal. Thus the ink drops ejected from the nozzle bore
46
come straight out of the plane of the paper in
FIG. 4
because of the symmetric actions of three notch deflectors on the ink stream. However, by altering the positions of one or more of the notch deflectors, ink stream
48
may be directed in an arbitrary direction with respect to the axis of the vertical ink delivery channel underneath the nozzle bore
46
. This axis is perpendicular to the plane of FIG.
4
and centered on the nozzle bore
46
. The ability to steer the ink stream in an arbitrary direction is illustrated schematically by region
63
in
FIG. 4
which depicts an imaginary plane located above (out of the plane of) nozzle bore
46
, preferably a circular region located about 5 mm above the nozzle bore. Then, for example, by adjusting one or more of the notch deflectors, the ink drops from the ink stream ejected from nozzle bore
46
can be caused to pass anywhere within the region
63
. For example, if the edge of the notch deflector (dotted line) in the lower left of
FIG. 4
is controlled to move closer to the nozzle bore
46
, ink drops will pass through the lower left of region
63
. The small displacements that we have discovered are required of notch deflectors to achieve substantial deflection of ink stream
48
enables manufacture of devices having three or more notch deflectors. In particular, the use of 4 notch deflectors is also advantageous when each are equally spaced about a nozzle bore viewed from above because the motion of the ink stream can be controlled in orthogonal directions.
FIG. 5
illustrates the angle of deflection for the geometrical and fluid parameters of
FIG. 3
but for various flow velocities of ink through the nozzle bore
46
and for two different fluids. The angle of deflection for water and isopropyl alcohol (IPA) based inks is shown. It can be seen that the angle of deflection is similar for the two fluids at higher velocities (it levels off) and increases with decreasing channel inflow velocities. As is well known in the art of ink jet printheads, it is advantageous from a system point of view to have a printhead which ejects drops similarly for fluids of widely differing compositions.
Although the descriptions above contains much specificity, these should not be constructed as limiting the scope of the invention but merely providing illustration of some of the presently preferred embodiments of this invention. Thus, it should be understood that variations and modifications could be effected within the spirit and scope of the invention.
PARTS LIST
10
scanner
12
image processing unit
13
micro actuator control circuits
14
heater control circuits
16
print head
17
ink gutter
18
recording medium
19
ink recycling unit
20
medium transport system
22
medium transport control system
24
micro-controller
26
ink pressure regular
28
ink reservoir
40
lateral vertical ink delivery channel
42
silicon substrate
44
ink
46
nozzle bore
48
ink stream
50
resistive heater
52
drop regulator
54
ultrasonic transducer
56
electrical insulating layers
62
notch deflector
63
region
64
vertical ink delivery channel
66
ink drops
68
non-deflected drops
Claims
- 1. An apparatus for controlling fluid in which a continuous stream of the fluid is emitted from a nozzle, said apparatus comprising:a) a substrate having formed therein a fluid delivery channel having an interior wall; b) a nozzle bore in the substrate forming an opening into the fluid delivery channel; and c) a notch deflector positioned inside the fluid delivery channel in proximity to the nozzle bore, wherein the notch deflector comprises a depression in the interior wall of the fluid delivery channel having a predetermined width and adjustable depth such that a direction of the continuous stream of the fluid is controlled.
- 2. The apparatus as set forth in claim 1, the notch deflector including an edge moveably positioned in the depression in the interior wall of the fluid delivery channel, wherein the position of the edge is varied to control an angle of deflection of the continuous stream of the fluid.
- 3. The apparatus as set forth in claim 1, wherein the notch deflector is a first notch deflector, the apparatus further comprising a second notch deflector positioned in the fluid delivery channel opposite the first notch deflector such that the continuous stream of the fluid is controlled in a plurality of directions.
- 4. The apparatus as set forth in claim 1, wherein the notch deflector is a first notch deflector, the apparatus further comprising at least two additional notch deflectors positioned around a periphery of the fluid delivery channel such that the continuous stream of the fluid is controlled in a plurality of directions.
- 5. A method for controlling ink in a continuous ink jet printer in which a continuous stream of ink is emitted from a nozzle, the method comprising:providing a source of pressurized ink; placing the source of pressurized ink in communication with an ink delivery channel having a wall; forming a nozzle bore that opens into the ink delivery channel to establish a continuous flow of ink in a stream, the nozzle bore defining a nozzle bore perimeter; providing a droplet regulator that causes the stream to break up into a plurality of droplets at a position spaced from the nozzle bore; and providing a notch in the ink delivery channel wherein the notch includes a depression in the wall of the ink delivery channel to control a direction of the droplets between a print direction and a non-print direction, and the notch includes an edge moveably positioned relative to the fluid delivery channel such that the depression has a variable depth.
- 6. The method for controlling ink in a continuous ink jet printer as recited in claim 5, wherein said droplet regulator comprises a resistive heater positioned around the nozzle bore perimeter.
- 7. A method for controlling ink in a continuous ink jet printer in which a continuous stream of ink is emitted from a nozzle; said process comprising:providing a source of pressurized ink; placing the source of pressurized ink in communication with an ink delivery channel having a wall; forming a nozzle bore that opens into the ink delivery channel to establish a continuous flow of ink in a stream, the nozzle bore defining a nozzle bore perimeter; providing a droplet regulator that causes the stream to break up into a plurality of droplets at a position spaced from the nozzle bore; and providing a notch deflector in the ink delivery channel, the notch deflector including a depression in the wall of the ink delivery channel, wherein a predetermined width and adjustable depth of the depression in the wall of the ink delivery channel control a direction of the droplets between a print direction and a non-print direction.
- 8. An apparatus for controlling fluid in which a continuous stream of the fluid is emitted from a nozzle, said apparatus comprising:a) a substrate having formed therein a fluid delivery channel; b) a nozzle bore in the substrate forming an opening into the fluid delivery channel; and c) a notch positioned inside the fluid delivery channel in proximity to the nozzle bore, wherein a direction of the continuous stream of the fluid is controlled, the notch including a depression formed in the fluid delivery channel and an edge moveably positioned relative to the fluid delivery channel such that the depression has a variable depth.
- 9. The apparatus as set forth in claim 8 in which the substrate is silicon.
- 10. The apparatus as set forth in claim 8 in which the substrate is a molded plastic.
- 11. The apparatus as set forth in claim 8, further comprising a component for breaking up the continuous stream of ink emitted from the nozzle into discreet ink droplets at a position spaced from the nozzle bore.
- 12. The apparatus as set forth in claim 11, wherein the component for breaking up the continuous stream of ink emitted from the nozzle includes a resistive heater positioned in proximity to the nozzle bore.
- 13. The apparatus as set forth in claim 11, wherein the component for breaking up the continuous stream of ink emitted from the nozzle includes an ultrasonic transducer.
- 14. The apparatus as set forth in claim 8, further comprising:a source of fluid communicating with the fluid delivery channel wherein the fluid is pressurized above atmospheric pressure producing a continuous flow of the fluid in a stream from the nozzle bore.
US Referenced Citations (12)
Foreign Referenced Citations (1)
Number |
Date |
Country |
4-294147 |
Oct 1992 |
JP |