CA1087674A - System for self-cleaning ink jet head - Google Patents
System for self-cleaning ink jet headInfo
- Publication number
- CA1087674A CA1087674A CA265,858A CA265858A CA1087674A CA 1087674 A CA1087674 A CA 1087674A CA 265858 A CA265858 A CA 265858A CA 1087674 A CA1087674 A CA 1087674A
- Authority
- CA
- Canada
- Prior art keywords
- manifold
- fluid
- flow path
- orifice
- jet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D15/00—Component parts of recorders for measuring arrangements not specially adapted for a specific variable
- G01D15/16—Recording elements transferring recording material, e.g. ink, to the recording surface
- G01D15/18—Nozzles emitting recording material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
- B41J2/165—Preventing or detecting of nozzle clogging, e.g. cleaning, capping or moistening for nozzles
- B41J2/16517—Cleaning of print head nozzles
- B41J2/1652—Cleaning of print head nozzles by driving a fluid through the nozzles to the outside thereof, e.g. by applying pressure to the inside or vacuum at the outside of the print head
- B41J2/16526—Cleaning of print head nozzles by driving a fluid through the nozzles to the outside thereof, e.g. by applying pressure to the inside or vacuum at the outside of the print head by applying pressure only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/17—Ink jet characterised by ink handling
- B41J2/18—Ink recirculation systems
- B41J2/185—Ink-collectors; Ink-catchers
Abstract
SYSTEM FOR SELF-CLEANING INK JET HEAD
Abstract A system for fluid jet heads such as ink jet adapted for self-cleaning of certain clogs and purging of air from the head. The head includes a manifold communicating with at least one orifice to project a stream of fluid therefrom.
Two fluid supply paths at different sides of the manifold supply pressurized fluid thereto. One of the supply paths is located at the top of the manifold and is reversible. If air or an impurity causing a nozzle clog is encountered in the head, the top path may be reversed so the fluid enters from one path and exits at the top. This establishes a crossing flow at the orifice, tending to loosen and remove the clog and purging the impurity or air from the head and out the reversible path.
Abstract A system for fluid jet heads such as ink jet adapted for self-cleaning of certain clogs and purging of air from the head. The head includes a manifold communicating with at least one orifice to project a stream of fluid therefrom.
Two fluid supply paths at different sides of the manifold supply pressurized fluid thereto. One of the supply paths is located at the top of the manifold and is reversible. If air or an impurity causing a nozzle clog is encountered in the head, the top path may be reversed so the fluid enters from one path and exits at the top. This establishes a crossing flow at the orifice, tending to loosen and remove the clog and purging the impurity or air from the head and out the reversible path.
Description
Background of the Invention A need for high-quality, high-speed computer printers and other output printers with changeable formats has been evidenced in recent years. Developments have proceeded with ; 20 respect to ink jet technology in an effort to answer this need. l~any of the developments in the field of ink jet have related to pressurized ink jet systems wherein a stream or streams of ink are ejected from one or more orifices in the form of filaments and perturbated so that each filament breaks into a stream of uniformly sized droplets.
Examples of such systems include magnetic ink jet wherein droplets of magnetic ink are selectively deflected to a recording medium or to a gutter. Another example com-prises electrostatic deflected ink jet such as taught by Sweet U.S. Patent 3,596,275, wherein a single stream of dropl~ets are selectively SA974060 ;
.
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1 charged and passed through a uniform deflection field to impact various locations on a recording medium in accordance with the charge of each droplet. Thus, by applying suitable charging signals to the droplets, readable printed charac-ters may be formed on the recording surface. Still another example comprises electrostatic binary ink jet such as taught by Sweet et al, U.S. Patent No. 3,373,437. This type of system generates a plurality of jets in one or more rows, selectively charging droplets with a single charge level for deflection by a constant field to an ink drop catcher. The uncharged drops continue undeflected along the original jet path to impact the recording surface and form readable printed characters.
It appears that good print quality for printed charac- ;
ters requires that the lines forming character legs com-prise more than a single row of spots resulting from the impact of ink jet droplets. Hence, the droplets required to form characters must be of an extremely small size. If the droplets are small, the spots formed therefrom may be sufficiently small and closely spaced so as to be relatively indiscernible as individual drops, but rather discernible only as part of the resultant printed symbol.
The most important factor in producing small droplets is the diameter of the orifice through which the ink is ejected. For example, to achieve a spot diameter of less than seven mils in diameter requires orifices no larger than two mils in diameter. Orifices may even reach less than one mil in diameter.
Orifices of such size are easily clogged by small 30 particles of foreign material even though advanced filter-ing techniques are used.
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~7674 .
1 An object of the present invention is to provide an ink jet head structure which allows cleaning of certain clogs and removal of the foreign material.
Summary of the Invention Briefly, the head structure of the invention for pressurized ink jet includes at least one orifice, a mani-fold communicating with the orifice, a source of pressurized fluid, and at least two flow paths for supplying the fluid from the source to the manifold, with one of the paths being reversible so as to establish a crossing flow at the ori-fice. Further, the reversible path may communicate with the manifold at the highest point therein to purge any air from the head.
The foregoing and other objects, features and advanta-ges of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
Brief Descri~tion of the Drawinqs _ FIGURE 1 is an exploded perspective view of a fluid jet head constructed in accordance with the invention;
FIGURE 2 is a rear view of the cavity plate of Figure l;
FIGURE 2a is a sectional view of the cavity plate of Figure 2;
FIGURE 3 is a perspective view of the mounting block of Figure l;
FIGURE 4 is a schematic view of the assembled fluid jet head of Figure 1 and a fluid supply system in accordance with the invention;
FIGURE 5 is a schematic view of an alternative fluid jet head constructed in accordance with the present inven-tion.
" ~: '"' ' 6~74 1 Description of the Preferred Embodiments Referring to Figure 1, a fluid jet head assembly is shown for the generation of fluid streams which break into streams of uniform drops.
Should the fluid comprise an electrostatic writing fluid, the drops may selectively be given an electrostatic charge upon breakoff and the charged drops subsequently deflected to a gutter while the uncharged - drops continue towards the recording medium for selective impingement thereon in accordance with the system described in the Sweet et al patent, above. Specific charging deflection and guttering means are 10described in U.S. Patent No. 3,955,203, Chocholaty, issued May 4, 1976 an~ entitled "High Voltage Deflection Electrode Apparatus for Ink Jet,"
assigned in common with the present application. Alternatively, the fluid may comprise a magnetic writing fluid wherein the droplets may be selectively deflected by magnetic fields.
15The fluid jet head of Figure 1 includes a cavity plate 10, a nozzle plate 11, an 0-ring 12, a piezoelectric crystal driver 13 and a mounting block 14. Alternatively, in an obvicus variation of the device, other kinds of driver mechanisms could be used, e.g. magnetic, electromagnetic, acoustic, etc. As will be explained, pressurized fluid supplied to the head may be perturbated by the piezoelectric crystal driver and ejected from orifices of the nozzle plate 11 to form streams of uniformly sized droplets. The orifices are of such small dimensions, e.g., 0.8 mils diameter, that very small particles of foreign material can clog a nozzle orifice. This can result either -in a complete blockage of the orifice or in a partial blockage. A
complete blockage prevents the flow of fluid and prevents printing from , ,' '.
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1 the orifice. A partial blockage chan~es the direction and flow
Examples of such systems include magnetic ink jet wherein droplets of magnetic ink are selectively deflected to a recording medium or to a gutter. Another example com-prises electrostatic deflected ink jet such as taught by Sweet U.S. Patent 3,596,275, wherein a single stream of dropl~ets are selectively SA974060 ;
.
' ::.
:, - , .~ , ', ~ ' ' . ' . , , , ' ~ . ' ' --. ~ ............................ .
': ' ' ' ' ' ~ ' ' - ' ' ' ' :' ' . - : .: . . . .. .: , . . , - - .
1 charged and passed through a uniform deflection field to impact various locations on a recording medium in accordance with the charge of each droplet. Thus, by applying suitable charging signals to the droplets, readable printed charac-ters may be formed on the recording surface. Still another example comprises electrostatic binary ink jet such as taught by Sweet et al, U.S. Patent No. 3,373,437. This type of system generates a plurality of jets in one or more rows, selectively charging droplets with a single charge level for deflection by a constant field to an ink drop catcher. The uncharged drops continue undeflected along the original jet path to impact the recording surface and form readable printed characters.
It appears that good print quality for printed charac- ;
ters requires that the lines forming character legs com-prise more than a single row of spots resulting from the impact of ink jet droplets. Hence, the droplets required to form characters must be of an extremely small size. If the droplets are small, the spots formed therefrom may be sufficiently small and closely spaced so as to be relatively indiscernible as individual drops, but rather discernible only as part of the resultant printed symbol.
The most important factor in producing small droplets is the diameter of the orifice through which the ink is ejected. For example, to achieve a spot diameter of less than seven mils in diameter requires orifices no larger than two mils in diameter. Orifices may even reach less than one mil in diameter.
Orifices of such size are easily clogged by small 30 particles of foreign material even though advanced filter-ing techniques are used.
., .
, . . . . . . - : : ~ . .
. . . : .. - , . . :
~7674 .
1 An object of the present invention is to provide an ink jet head structure which allows cleaning of certain clogs and removal of the foreign material.
Summary of the Invention Briefly, the head structure of the invention for pressurized ink jet includes at least one orifice, a mani-fold communicating with the orifice, a source of pressurized fluid, and at least two flow paths for supplying the fluid from the source to the manifold, with one of the paths being reversible so as to establish a crossing flow at the ori-fice. Further, the reversible path may communicate with the manifold at the highest point therein to purge any air from the head.
The foregoing and other objects, features and advanta-ges of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
Brief Descri~tion of the Drawinqs _ FIGURE 1 is an exploded perspective view of a fluid jet head constructed in accordance with the invention;
FIGURE 2 is a rear view of the cavity plate of Figure l;
FIGURE 2a is a sectional view of the cavity plate of Figure 2;
FIGURE 3 is a perspective view of the mounting block of Figure l;
FIGURE 4 is a schematic view of the assembled fluid jet head of Figure 1 and a fluid supply system in accordance with the invention;
FIGURE 5 is a schematic view of an alternative fluid jet head constructed in accordance with the present inven-tion.
" ~: '"' ' 6~74 1 Description of the Preferred Embodiments Referring to Figure 1, a fluid jet head assembly is shown for the generation of fluid streams which break into streams of uniform drops.
Should the fluid comprise an electrostatic writing fluid, the drops may selectively be given an electrostatic charge upon breakoff and the charged drops subsequently deflected to a gutter while the uncharged - drops continue towards the recording medium for selective impingement thereon in accordance with the system described in the Sweet et al patent, above. Specific charging deflection and guttering means are 10described in U.S. Patent No. 3,955,203, Chocholaty, issued May 4, 1976 an~ entitled "High Voltage Deflection Electrode Apparatus for Ink Jet,"
assigned in common with the present application. Alternatively, the fluid may comprise a magnetic writing fluid wherein the droplets may be selectively deflected by magnetic fields.
15The fluid jet head of Figure 1 includes a cavity plate 10, a nozzle plate 11, an 0-ring 12, a piezoelectric crystal driver 13 and a mounting block 14. Alternatively, in an obvicus variation of the device, other kinds of driver mechanisms could be used, e.g. magnetic, electromagnetic, acoustic, etc. As will be explained, pressurized fluid supplied to the head may be perturbated by the piezoelectric crystal driver and ejected from orifices of the nozzle plate 11 to form streams of uniformly sized droplets. The orifices are of such small dimensions, e.g., 0.8 mils diameter, that very small particles of foreign material can clog a nozzle orifice. This can result either -in a complete blockage of the orifice or in a partial blockage. A
complete blockage prevents the flow of fluid and prevents printing from , ,' '.
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1 the orifice. A partial blockage chan~es the direction and flow
2 of the jet, therehv disrupting the normal operation of the device.
3 If the foreign material is fir~lY wedae~ or lodged in
4 the nozzle issuing the jet, the resultina clog is called a hard clog. A hard clog usually results from particles of relativelv 6 large size, usually comparable to the size of the orifice itself 7 Such hard clogs require a relatively large force to dislodge 8 them g If the foreign material is not firmly wedg~d or lodged in the nozzle, the resulting clog is called a soft clog. Soft 11 clogs generally result from an accumulation of smaller particle.s 12 in the nozzle, and may be more easily dislodged.
With advanced filtering of the fluid, the relative 14 occurrence of hard cloqs is considerably less. Therefore, soft clogs are the more significant as a recurring problem. Further, 16 if no~ cleaned, a soft clog can result in a hard clog due to 17 agglomeration of the foreian material or to crusting of the 18 fluid around the orifice.
19 Referring to Figures 1, 2 and 2A, the ca~itv plate 10 includes a cavity 20 cut to within a small distance from the 21 face 21 of the plate forming wall member 24. Two parallel slots 22 22 and 23 are cut through the thin member 24 of the plate into 23 the cavity 20. A second, larger cavitv 25 is cut to form a space 24 for the piezoelectric cyrstal driver 12. A notch 26 is cut below the face 27 of the second cavity 25 to form a space for the O-ring ;
26 12 to form a seal between the cavity plate 10 and the piezo-27 electric driver 13. Face 27 of the second cavity 25 is arranged .
28 to contact piezoelectric driver 13 and transmit vibrations of 29 the driver to nozzle plate 11. Fluid inlets 30 and 31 are :
6'7'4 1 provided and connected via lines 32, 33 and 34, 35 to the cavity 20.
Lines 33 and 35 may be made by drilling through the cavity plate 10 and subsequently plugging the portion of the drilled hole extending beyond lines 32 and 34 by means of plugs 36 and 37. Cavity plate 10 is provided with a number of threaded holes 39 to allow the cavity plate to be bolted to mounting block 14.
Couplers 42 and 43 are threaded into fluid inlets 30 and 31 and sealed by 0-rings 44 and 45. Hoses 46 and 47 are positioned on the couplers 42 and 43 and are held by clamps 48 and 49. Pressurized fluid may thus be supplied through the hoses, couplers and lines to the cavity 20.
Figure 1 illustrates the nozzle plate 11 formed of a thin material and having two rows 40 and 41 of small nozzle orifices extending therethrough. The nozzle plate 11 may be formed in a number of different ways, for example having a planar single crystal material with an inorganic membrane such as taught in U.S. Patent No.
3,958,255 issued May 18, 1976, Chiou et al, entitled "Ink Jet Nozzle Structure and Method of Making," and assigned in common with the present application. Another example is found in U.S. Patent No.
4,007,464, E. Bassous et al, entitled "Ink Jet Nozzles," issued February 8, 1977, for forming square orifices. The nozzle plate 11 is then cemented to the bottom of cavity 20 such that the rows 40 and 41 are each in alignment with the corresponding slot 22 and 23.
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~7674 1 The words nozzle, orifice and nozzle orifice are all 2 similar in meaning, nozzle referring to a fluid outlet structure 3 and orifice and nozzle orifice referring to the actual opening 4 formed by the outlet structure.
Referring to Figures 1 and 3, mounting block 14 is 6 formed ~ith a large cavity 50 having a face 51 against which 7 the rear of the piezoelectric crystal driver 13 mav firmly seal.
8 A second smaller cavity 52 and slot 53 are provided to allow 9 adeq~late clearance for wire 55 to be connected to the rear of the piezoelectric driver. A small slot 56 is supplied to allow 11 the wire 55 to exit from the mounting block for connection to 12 driver circuitry. Referring also to Figures 2 and 2A, when 13 mounte~ within the assembly, piezoelectric driver 13 is thus 14 clamped between surface 51 of backing plate 14 and O-ring 12 in notch 26 of cavity plate 10, and is maintained under slight 16 comr?ression. Cavity 20 is made of an electrically conductive 17 material such that the cavity forms an electrical grounding 18 surface contacting electrically conductive ink therein. The 19 ink further contacts the face of the piezoelectric driver 13 so that the ink and cavity plate 10 form the grounding connection 21 therefor. An electrical voltage applied to wire 55 thus creates 22 a potential between the rear of driver 13 and the grounded facing 23 thereof to thereby excite the piezoelectric driver. Lastly, 24 mounting block 14 includes a number of countersunk holes 58 aligned with threaded holes 39 in cavity plate 10. These holes 26 allow standard clamping screws 59 to be employed to clamp to-27 gether with assembly of Figure 1.
23 Figure 4 comprises an assembled schematic view of the 29 elements of Figure 1. Outlet 61 of fluid source 60 is connected 1 to input 30 and via valve 62 to input 31 of cavit~ plate lO to 2 thereby supply the fluid to cavity 20.
3 Input 31 of cavity plate 10 is also connected to valve 4 63. Valves 62 and 63 may comprise solenoid operated valves.
During normal operation, valve 62 is open and valve 63 is 6 closed to supply the fluid to cavitv 20 under a desired pressure.
7 The pressure is such that a plurality of fluid jets 64 emanate 8 from the nozzles of nozzle plate 11. A perturbation voltage g source 65 is connected via wire 55 to piezoelectric crystal driver 13. The front of the piezoelectric driver 13 is in con-11 tact with the electrically conductive fluid in cavity 20 which 12 further contacts the cavity surfaces of cavitv plate 10. which 13 is connected to ground 66. The perturbation voltage of 14 source 65 may comprise, for example a sine wave of 100 kilo-hertz frequency.
16 Application of the perturbation voltage from source 65 17 to the piezoelectric crystal driver causes the driver to tend 18 to expand and contract between surface 70 and surface 71. The 19 resultant vibration from the clamping of the piezoelectric driver between face 51 of mounting block and co~pressed O-ring 21 12 in notch 26 of cavity plate 10 is transmitted by the mounting 22 block from face 51, via the screws 59 and cavitv plate 10 to 23 wall member 24 at the front of the cavity plate. Some vibra-24 tion is also transmitted by compressed O-ring 12 via the cavity plate 10 to wall member 24. ~en vibrated in this manner, wall 26 24 tends to oscillate at the drive frequency of the perturbation 27 voltage source 65 axially with respect to fluid streams 61.
28 Also, some vibration is transmitted directly through the fluid 29 filling the space between the driver face and the nozzle plate . . .
6t74 1 in cavity 20. Nozzle plate 11 is ce~ented to wall 24 and 2 similarly flexes in an oscillating mode to therel~y provide a 3 velocity modulation of the fluid streams 61 in the axi~l direction.
4 At the same time, the remainder of faces 70 and 71 of the piezo-
With advanced filtering of the fluid, the relative 14 occurrence of hard cloqs is considerably less. Therefore, soft clogs are the more significant as a recurring problem. Further, 16 if no~ cleaned, a soft clog can result in a hard clog due to 17 agglomeration of the foreian material or to crusting of the 18 fluid around the orifice.
19 Referring to Figures 1, 2 and 2A, the ca~itv plate 10 includes a cavity 20 cut to within a small distance from the 21 face 21 of the plate forming wall member 24. Two parallel slots 22 22 and 23 are cut through the thin member 24 of the plate into 23 the cavity 20. A second, larger cavitv 25 is cut to form a space 24 for the piezoelectric cyrstal driver 12. A notch 26 is cut below the face 27 of the second cavity 25 to form a space for the O-ring ;
26 12 to form a seal between the cavity plate 10 and the piezo-27 electric driver 13. Face 27 of the second cavity 25 is arranged .
28 to contact piezoelectric driver 13 and transmit vibrations of 29 the driver to nozzle plate 11. Fluid inlets 30 and 31 are :
6'7'4 1 provided and connected via lines 32, 33 and 34, 35 to the cavity 20.
Lines 33 and 35 may be made by drilling through the cavity plate 10 and subsequently plugging the portion of the drilled hole extending beyond lines 32 and 34 by means of plugs 36 and 37. Cavity plate 10 is provided with a number of threaded holes 39 to allow the cavity plate to be bolted to mounting block 14.
Couplers 42 and 43 are threaded into fluid inlets 30 and 31 and sealed by 0-rings 44 and 45. Hoses 46 and 47 are positioned on the couplers 42 and 43 and are held by clamps 48 and 49. Pressurized fluid may thus be supplied through the hoses, couplers and lines to the cavity 20.
Figure 1 illustrates the nozzle plate 11 formed of a thin material and having two rows 40 and 41 of small nozzle orifices extending therethrough. The nozzle plate 11 may be formed in a number of different ways, for example having a planar single crystal material with an inorganic membrane such as taught in U.S. Patent No.
3,958,255 issued May 18, 1976, Chiou et al, entitled "Ink Jet Nozzle Structure and Method of Making," and assigned in common with the present application. Another example is found in U.S. Patent No.
4,007,464, E. Bassous et al, entitled "Ink Jet Nozzles," issued February 8, 1977, for forming square orifices. The nozzle plate 11 is then cemented to the bottom of cavity 20 such that the rows 40 and 41 are each in alignment with the corresponding slot 22 and 23.
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~7674 1 The words nozzle, orifice and nozzle orifice are all 2 similar in meaning, nozzle referring to a fluid outlet structure 3 and orifice and nozzle orifice referring to the actual opening 4 formed by the outlet structure.
Referring to Figures 1 and 3, mounting block 14 is 6 formed ~ith a large cavity 50 having a face 51 against which 7 the rear of the piezoelectric crystal driver 13 mav firmly seal.
8 A second smaller cavity 52 and slot 53 are provided to allow 9 adeq~late clearance for wire 55 to be connected to the rear of the piezoelectric driver. A small slot 56 is supplied to allow 11 the wire 55 to exit from the mounting block for connection to 12 driver circuitry. Referring also to Figures 2 and 2A, when 13 mounte~ within the assembly, piezoelectric driver 13 is thus 14 clamped between surface 51 of backing plate 14 and O-ring 12 in notch 26 of cavity plate 10, and is maintained under slight 16 comr?ression. Cavity 20 is made of an electrically conductive 17 material such that the cavity forms an electrical grounding 18 surface contacting electrically conductive ink therein. The 19 ink further contacts the face of the piezoelectric driver 13 so that the ink and cavity plate 10 form the grounding connection 21 therefor. An electrical voltage applied to wire 55 thus creates 22 a potential between the rear of driver 13 and the grounded facing 23 thereof to thereby excite the piezoelectric driver. Lastly, 24 mounting block 14 includes a number of countersunk holes 58 aligned with threaded holes 39 in cavity plate 10. These holes 26 allow standard clamping screws 59 to be employed to clamp to-27 gether with assembly of Figure 1.
23 Figure 4 comprises an assembled schematic view of the 29 elements of Figure 1. Outlet 61 of fluid source 60 is connected 1 to input 30 and via valve 62 to input 31 of cavit~ plate lO to 2 thereby supply the fluid to cavity 20.
3 Input 31 of cavity plate 10 is also connected to valve 4 63. Valves 62 and 63 may comprise solenoid operated valves.
During normal operation, valve 62 is open and valve 63 is 6 closed to supply the fluid to cavitv 20 under a desired pressure.
7 The pressure is such that a plurality of fluid jets 64 emanate 8 from the nozzles of nozzle plate 11. A perturbation voltage g source 65 is connected via wire 55 to piezoelectric crystal driver 13. The front of the piezoelectric driver 13 is in con-11 tact with the electrically conductive fluid in cavity 20 which 12 further contacts the cavity surfaces of cavitv plate 10. which 13 is connected to ground 66. The perturbation voltage of 14 source 65 may comprise, for example a sine wave of 100 kilo-hertz frequency.
16 Application of the perturbation voltage from source 65 17 to the piezoelectric crystal driver causes the driver to tend 18 to expand and contract between surface 70 and surface 71. The 19 resultant vibration from the clamping of the piezoelectric driver between face 51 of mounting block and co~pressed O-ring 21 12 in notch 26 of cavity plate 10 is transmitted by the mounting 22 block from face 51, via the screws 59 and cavitv plate 10 to 23 wall member 24 at the front of the cavity plate. Some vibra-24 tion is also transmitted by compressed O-ring 12 via the cavity plate 10 to wall member 24. ~en vibrated in this manner, wall 26 24 tends to oscillate at the drive frequency of the perturbation 27 voltage source 65 axially with respect to fluid streams 61.
28 Also, some vibration is transmitted directly through the fluid 29 filling the space between the driver face and the nozzle plate . . .
6t74 1 in cavity 20. Nozzle plate 11 is ce~ented to wall 24 and 2 similarly flexes in an oscillating mode to therel~y provide a 3 velocity modulation of the fluid streams 61 in the axi~l direction.
4 At the same time, the remainder of faces 70 and 71 of the piezo-
5 electric driver remain unclamped so that the crystal ma~ more
6 freely expand and contract. Surface 71 of the driver is in
7 contact with the pressurized fluid so as to form the rear wall of
8 cavity 20. Expansion and contraction of the crystal results g in surface 71 causing the contraction and ex~ansion of the volume 10 of the cavity 20, thereby inducing a pressure perturbation of 11 the f luid within the cavity.
12 The vibration and pressure wave transmission rates are 13 so high that within the small dimensions of the head, the 14 velocity modulation of fluid streams 61 is in aiding phase to 15 the pressure modulation of the fluid in cavitv 20 as it exits 16 from the orifices in nozzle plate 11. Proper modulation occurs 17 with a peak-to-peak voltage-of perturbation source 65 of approxi-18 mately 5.5 volts.
19 Valve 63, normally closed, is connected on its output 20 side to inlet 73 of fluid source 60. Durinq normal operation 21 with valve 62 open and valve 63 closed, fluid flows from outlet 22 61 of f luid source 60 to both input 30 and input 31 of cavity.
23 plate 10. As a variation for certain systems, inlet 73 and : 24 outlet 61 may be appropriately sized to control the ultimate- :
25 pressure in the head during the jet production and the cleaning 26 mode.
27 Upon occurrence of a soft clog in one or more of the 28 nozzle orifices, valves 62 and 63 are reversed. With valve 62 29 thus closed and valve 63 open, the fluid from fluid source 60 76~4 1 now flows from outlet 61 to input 30 and line 33 of cavity 2 plate 10, across nozzle plate 11, and outline 35 and input 31 3 to inlet 73 of the fluid source. The flow across nozzle plate 4 11 thus tends to dislodge any soft clogs from the nozz]e orifices.
The dislodged foreign material is then carried bv the fluid out 6 line 35 to fluid source 60. It has been found preferab]e to 7 discontinue operation of perturbation voltage source 65 during 8 the unclogging, since the pressure in the cavity is reduced g because of the increased outflow of fluid througll line 35 which 10 i5 much larger than the accumulated opening of the orifices.
11 An alternative arrangement of an ink jet head is illustrated 12 in Figure 5.-The head employs a single nozzle 80 and is of the 13 type usable in the ink jet system, of the character described 14 in the Sweet patent, above. Nozzle 80 is mcunted by support 81 to body 82 of the head. A piezoelectric cry~stal 83 is mounted 16 on a support 84 and connected bv wire 85 to a perturbation voltage 17 source. An O-ring 86 is employed to seal the interior of the 18 cavity formed by body 82. Fluid is supplied by a fluid source 19 to lines 87 and 88 to eject a fluid jet from nozzle 80. The fluid is perturbated by the piezoelectric crystal to cause the 21 jet to break into a stream of uniform droplets.
22 Should nozzle 80 become wholly or partially clogged by 23 a soft clog, the fluid flow at line 88 is reversed as discussed 24 with respect to the embodiment of Figure 4. This causes the fluid to flow from line 87, across nozzle 80 and out line 88, 26 thereby tending to dislodge the clog.
27 Referring to both Figure 4 and Figure 5, bv positioning 28 the opening from the reversible line 35 or 88 at the highest 29 point of the cavity, any air in the head will be purged from .
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1 the system when the fluid flow is out that line. Ahsence of 2 air is desirable since the compressible nature of air allows 3 its presence to defeat pressure modulation of the jet by the 4 piezoelectric crystal.
If the reversible line is not at the highest point 6 in the cavity, air may still be purged from the head in a less 7 efficient manner if the velocity of the fluid in the cavity is 8 maintained at a high rate during the reversal mode.
12 The vibration and pressure wave transmission rates are 13 so high that within the small dimensions of the head, the 14 velocity modulation of fluid streams 61 is in aiding phase to 15 the pressure modulation of the fluid in cavitv 20 as it exits 16 from the orifices in nozzle plate 11. Proper modulation occurs 17 with a peak-to-peak voltage-of perturbation source 65 of approxi-18 mately 5.5 volts.
19 Valve 63, normally closed, is connected on its output 20 side to inlet 73 of fluid source 60. Durinq normal operation 21 with valve 62 open and valve 63 closed, fluid flows from outlet 22 61 of f luid source 60 to both input 30 and input 31 of cavity.
23 plate 10. As a variation for certain systems, inlet 73 and : 24 outlet 61 may be appropriately sized to control the ultimate- :
25 pressure in the head during the jet production and the cleaning 26 mode.
27 Upon occurrence of a soft clog in one or more of the 28 nozzle orifices, valves 62 and 63 are reversed. With valve 62 29 thus closed and valve 63 open, the fluid from fluid source 60 76~4 1 now flows from outlet 61 to input 30 and line 33 of cavity 2 plate 10, across nozzle plate 11, and outline 35 and input 31 3 to inlet 73 of the fluid source. The flow across nozzle plate 4 11 thus tends to dislodge any soft clogs from the nozz]e orifices.
The dislodged foreign material is then carried bv the fluid out 6 line 35 to fluid source 60. It has been found preferab]e to 7 discontinue operation of perturbation voltage source 65 during 8 the unclogging, since the pressure in the cavity is reduced g because of the increased outflow of fluid througll line 35 which 10 i5 much larger than the accumulated opening of the orifices.
11 An alternative arrangement of an ink jet head is illustrated 12 in Figure 5.-The head employs a single nozzle 80 and is of the 13 type usable in the ink jet system, of the character described 14 in the Sweet patent, above. Nozzle 80 is mcunted by support 81 to body 82 of the head. A piezoelectric cry~stal 83 is mounted 16 on a support 84 and connected bv wire 85 to a perturbation voltage 17 source. An O-ring 86 is employed to seal the interior of the 18 cavity formed by body 82. Fluid is supplied by a fluid source 19 to lines 87 and 88 to eject a fluid jet from nozzle 80. The fluid is perturbated by the piezoelectric crystal to cause the 21 jet to break into a stream of uniform droplets.
22 Should nozzle 80 become wholly or partially clogged by 23 a soft clog, the fluid flow at line 88 is reversed as discussed 24 with respect to the embodiment of Figure 4. This causes the fluid to flow from line 87, across nozzle 80 and out line 88, 26 thereby tending to dislodge the clog.
27 Referring to both Figure 4 and Figure 5, bv positioning 28 the opening from the reversible line 35 or 88 at the highest 29 point of the cavity, any air in the head will be purged from .
.:
- - : . :
1 the system when the fluid flow is out that line. Ahsence of 2 air is desirable since the compressible nature of air allows 3 its presence to defeat pressure modulation of the jet by the 4 piezoelectric crystal.
If the reversible line is not at the highest point 6 in the cavity, air may still be purged from the head in a less 7 efficient manner if the velocity of the fluid in the cavity is 8 maintained at a high rate during the reversal mode.
9 While the invention has been particularly shown and described wi~h reference to a preferred embodiment thereof ! it 11 will be understood by those skilled in the art that the fore-12 going and other changes in form and details may be made therein 13 without departing from the spirit and scope of the invention.
14 What is claimed is:
-:
14 What is claimed is:
-:
Claims (5)
1. In a pressurized fluid jet system including at least one orifice, a manifold communicating with said orifice, and a source of pressurized fluid, the improvement comprising:
a first flow path means for supplying said fluid from said source to said manifold; and a second flow path means for supplying said fluid from said source to said manifold, said second flow path means being reversible;
said first and said second flow path means communicating with said manifold through ports at opposite sides thereof and said at least one orifice being located at another side thereof and disposed between said ports, whereby reversal of said second flow path establishes a crossing flow at said orifice tending to remove any clogs.
a first flow path means for supplying said fluid from said source to said manifold; and a second flow path means for supplying said fluid from said source to said manifold, said second flow path means being reversible;
said first and said second flow path means communicating with said manifold through ports at opposite sides thereof and said at least one orifice being located at another side thereof and disposed between said ports, whereby reversal of said second flow path establishes a crossing flow at said orifice tending to remove any clogs.
2. The pressurized fluid jet system improvement of claim 1 wherein:
said second flow path port communicates with said mani-fold at the highest point therein, whereby reversal of said second flow path tends to purge any air from said manifold.
said second flow path port communicates with said mani-fold at the highest point therein, whereby reversal of said second flow path tends to purge any air from said manifold.
3. The pressurized fluid jet system improvement of claim 2 wherein:
said source of pressurized fluid and said first and said second flow path means are arranged to provide suffi-cient fluid pressure in said manifold to produce a jet stream from said at least one orifice, and are arranged to provide upon reversal of said second flow means a pressure in said manifold slightly greater than the external air pressure and less than required to form a jet stream from said orifice.
said source of pressurized fluid and said first and said second flow path means are arranged to provide suffi-cient fluid pressure in said manifold to produce a jet stream from said at least one orifice, and are arranged to provide upon reversal of said second flow means a pressure in said manifold slightly greater than the external air pressure and less than required to form a jet stream from said orifice.
4. In a pressurized multi-jet ink system including a source of pressurized fluid and an ink jet head including a manifold and a multi-orifice nozzle plate communicating with one side of said manifold, the improvement comprising:
first and second ports communicating respectively with opposite sides of said manifold with said nozzle plate on a side of said manifold between said ports; and first and second flow path means communicating respec-tively with said first and second ports for supplying said fluid from said source to said manifold at sufficient fluid pressure to produce jet streams from said orifices of said nozzle plate, and said second flow path being reversible co provide a crossing flow at said orifice tending to remove any clogs.
first and second ports communicating respectively with opposite sides of said manifold with said nozzle plate on a side of said manifold between said ports; and first and second flow path means communicating respec-tively with said first and second ports for supplying said fluid from said source to said manifold at sufficient fluid pressure to produce jet streams from said orifices of said nozzle plate, and said second flow path being reversible co provide a crossing flow at said orifice tending to remove any clogs.
5. The pressurized multi-jet ink jet system improve-ment of claim 4 wherein:
said second port communicates with said manifold at the highest point therein, whereby reversal of said second flow path tends to purge any air from said manifold.
said second port communicates with said manifold at the highest point therein, whereby reversal of said second flow path tends to purge any air from said manifold.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/632,534 US4007465A (en) | 1975-11-17 | 1975-11-17 | System for self-cleaning ink jet head |
| US632,534 | 1975-11-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1087674A true CA1087674A (en) | 1980-10-14 |
Family
ID=24535895
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA265,858A Expired CA1087674A (en) | 1975-11-17 | 1976-11-16 | System for self-cleaning ink jet head |
Country Status (15)
| Country | Link |
|---|---|
| US (1) | US4007465A (en) |
| JP (1) | JPS5262024A (en) |
| AR (1) | AR217066A1 (en) |
| AU (1) | AU501713B2 (en) |
| BE (1) | BE847364A (en) |
| BR (1) | BR7607690A (en) |
| CA (1) | CA1087674A (en) |
| CH (1) | CH596992A5 (en) |
| DE (1) | DE2648079C3 (en) |
| ES (1) | ES453361A1 (en) |
| FR (1) | FR2331383A1 (en) |
| GB (1) | GB1551990A (en) |
| IT (1) | IT1072422B (en) |
| NL (1) | NL7612221A (en) |
| SE (1) | SE418911B (en) |
Families Citing this family (37)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5932313B2 (en) * | 1976-06-07 | 1984-08-08 | コニカ株式会社 | Method for cleaning ink passages in inkjet recording devices |
| GB1527444A (en) * | 1977-03-01 | 1978-10-04 | Itt Creed | Ink drop printhead |
| US4095232A (en) * | 1977-07-18 | 1978-06-13 | The Mead Corporation | Apparatus for producing multiple uniform fluid filaments and drops |
| US4138687A (en) * | 1977-07-18 | 1979-02-06 | The Mead Corporation | Apparatus for producing multiple uniform fluid filaments and drops |
| US4188635A (en) * | 1977-10-03 | 1980-02-12 | International Business Machines Corporation | Ink jet printing head |
| US4170016A (en) * | 1977-12-12 | 1979-10-02 | Gould Inc. | Priming apparatus for liquid ink writing instruments |
| JPS5621863A (en) * | 1979-07-31 | 1981-02-28 | Ricoh Co Ltd | Multinozzle head for ink jet |
| JPS5675867A (en) * | 1979-11-22 | 1981-06-23 | Seiko Epson Corp | Ink jet recorder |
| JPS5683840U (en) * | 1979-11-26 | 1981-07-06 | ||
| JPS5787957A (en) * | 1980-11-21 | 1982-06-01 | Nec Corp | Ink jet recorder |
| JPS5751475A (en) * | 1980-09-12 | 1982-03-26 | Seiko Epson Corp | Ink jet recording apparatus |
| US4340897A (en) * | 1981-07-29 | 1982-07-20 | Pitney Bowes Inc. | Cleaning device for writing heads used in ink jet recorders and printers |
| JPS59123672A (en) * | 1982-12-28 | 1984-07-17 | Canon Inc | Liquid jet recorder |
| US4563688A (en) * | 1983-05-16 | 1986-01-07 | Eastman Kodak Company | Fluid jet printer and method of ultrasonic cleaning |
| GB2152877A (en) * | 1984-01-16 | 1985-08-14 | Howtek Inc | Droplet ejector with control of fluid inlet to a reservoir |
| US4591873A (en) * | 1985-04-12 | 1986-05-27 | Eastman Kodak Company | Ink jet printing apparatus with orifice array cleaning system |
| US4600928A (en) * | 1985-04-12 | 1986-07-15 | Eastman Kodak Company | Ink jet printing apparatus having ultrasonic print head cleaning system |
| US4849769A (en) * | 1987-06-02 | 1989-07-18 | Burlington Industries, Inc. | System for ultrasonic cleaning of ink jet orifices |
| US4881085A (en) * | 1987-08-18 | 1989-11-14 | Burlington Industries, Inc. | Vacuum powered manually operated cleaning tool for active surfaces of fluid-jet print head |
| US5291215A (en) * | 1987-11-20 | 1994-03-01 | Canon Kabushiki Kaisha | Ink jet recording apparatus with a thermally stable ink jet recording head |
| JP2607274B2 (en) * | 1988-06-21 | 1997-05-07 | キヤノン株式会社 | Inkjet recording head |
| GB9001606D0 (en) * | 1990-01-24 | 1990-03-21 | Domino Printing Sciences Plc | Continuous ink jet printer |
| US5231424A (en) * | 1990-02-26 | 1993-07-27 | Canon Kabushiki Kaisha | Ink jet recording apparatus with efficient circulation recovery |
| JP2690379B2 (en) * | 1990-03-19 | 1997-12-10 | キヤノン株式会社 | Ink jet recording device |
| EP0573256B1 (en) * | 1992-06-04 | 1997-03-26 | Tektronix, Inc. | Drop-on-demand ink jet print head having improved purging performance |
| GB9301602D0 (en) * | 1993-01-27 | 1993-03-17 | Domino Printing Sciences Plc | Nozzle plate for ink jet printer |
| JPH07231736A (en) * | 1993-12-30 | 1995-09-05 | Hiroaki Sugiyama | Floating ball for fishery |
| EP0876223B1 (en) * | 1996-01-23 | 2000-04-26 | Koenig & Bauer Aktiengesellschaft | Method and device for keeping clean ends of spray damping mechanism nozzles on a rotary printing press |
| US5890655A (en) * | 1997-01-06 | 1999-04-06 | The Procter & Gamble Company | Fan spray nozzles having elastomeric dome-shaped tips |
| US6497472B2 (en) * | 2000-12-29 | 2002-12-24 | Eastman Kodak Company | Self-cleaning ink jet printer and print head with cleaning fluid flow system |
| GB0121625D0 (en) * | 2001-09-07 | 2001-10-31 | Xaar Technology Ltd | Droplet deposition apparatus |
| US20050157112A1 (en) | 2004-01-21 | 2005-07-21 | Silverbrook Research Pty Ltd | Inkjet printer cradle with shaped recess for receiving a printer cartridge |
| US7448734B2 (en) | 2004-01-21 | 2008-11-11 | Silverbrook Research Pty Ltd | Inkjet printer cartridge with pagewidth printhead |
| US7850290B2 (en) * | 2006-12-28 | 2010-12-14 | Toshiba Tec Kabushiki Kaisha | Ink jet recording apparatus, ink supplying mechanism and ink supplying method |
| US7878056B2 (en) * | 2007-12-19 | 2011-02-01 | Siargo Ltd. | Micromachined thermal mass flow sensor with self-cleaning capability and methods of making the same |
| JP5161986B2 (en) * | 2010-04-05 | 2013-03-13 | パナソニック株式会社 | Inkjet head and inkjet apparatus |
| CN110561907A (en) * | 2019-08-15 | 2019-12-13 | 上海奥色智能科技有限公司 | Multi-channel ink jet device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3900162A (en) * | 1974-01-10 | 1975-08-19 | Ibm | Method and apparatus for generation of multiple uniform fluid filaments |
| JPS5418919Y2 (en) * | 1974-08-20 | 1979-07-14 | ||
| US3974508A (en) * | 1974-12-16 | 1976-08-10 | Gould Inc. | Air purging system for a pulsed droplet ejecting system |
-
1975
- 1975-11-17 US US05/632,534 patent/US4007465A/en not_active Expired - Lifetime
-
1976
- 1976-09-16 GB GB38425/76A patent/GB1551990A/en not_active Expired
- 1976-09-24 IT IT7627576A patent/IT1072422B/en active
- 1976-10-11 FR FR7631438A patent/FR2331383A1/en active Granted
- 1976-10-15 BE BE171574A patent/BE847364A/en not_active IP Right Cessation
- 1976-10-15 CH CH1306776A patent/CH596992A5/xx not_active IP Right Cessation
- 1976-10-23 DE DE2648079A patent/DE2648079C3/en not_active Expired
- 1976-10-29 JP JP51129618A patent/JPS5262024A/en active Granted
- 1976-11-04 NL NL7612221A patent/NL7612221A/en not_active Application Discontinuation
- 1976-11-11 SE SE7612588A patent/SE418911B/en unknown
- 1976-11-16 AR AR265498A patent/AR217066A1/en active
- 1976-11-16 CA CA265,858A patent/CA1087674A/en not_active Expired
- 1976-11-16 AU AU19689/76A patent/AU501713B2/en not_active Expired
- 1976-11-16 ES ES453361A patent/ES453361A1/en not_active Expired
- 1976-11-17 BR BR7607690A patent/BR7607690A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| NL7612221A (en) | 1977-05-20 |
| IT1072422B (en) | 1985-04-10 |
| AU501713B2 (en) | 1979-06-28 |
| FR2331383B1 (en) | 1978-12-22 |
| JPS5528868B2 (en) | 1980-07-30 |
| AU1968976A (en) | 1978-05-25 |
| DE2648079B2 (en) | 1978-10-19 |
| DE2648079C3 (en) | 1979-06-21 |
| AR217066A1 (en) | 1980-02-29 |
| US4007465A (en) | 1977-02-08 |
| SE7612588L (en) | 1977-05-18 |
| BE847364A (en) | 1977-01-31 |
| GB1551990A (en) | 1979-09-05 |
| DE2648079A1 (en) | 1977-05-18 |
| BR7607690A (en) | 1977-10-04 |
| CH596992A5 (en) | 1978-03-31 |
| JPS5262024A (en) | 1977-05-23 |
| ES453361A1 (en) | 1977-12-01 |
| SE418911B (en) | 1981-06-29 |
| FR2331383A1 (en) | 1977-06-10 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |