JP2002011892A - Liquid ejection device and device for discharging air and obstacles from the ejection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink ejection device capable of maintaining a front face of a print head clean during the ejection of ink. SOLUTION: This liquid ejection device comprises an orifice for ejecting a fluid during the ejection operation, a vacuum opening and a discharge opening. A device for discharging an air or obstacles from the liquid ejection device during the operation for cleaning and washing is equipped with a plate having an opening formed therein. The plate is disposed on a part of the liquid ejection device and the opening of the plate is positioned on an orifice of the liquid ejection device. The plate comprises a vacuum passage and a discharge passage. A part of the vacuum passage is positioned on the vacuum opening of the liquid ejection device and a part of the discharge passage is positioned on the discharge opening. The vacuum passage and the discharge passage are connected to the openings on the plate, respectively so that flows therethrough can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates generally to fluid ejection devices and, more particularly, to the means and methods used to maintain the fluid ejectors of a fluid ejection device in the correct sequence of operation.

[0002]

2. Description of the Related Art An example of a fluid ejector according to the present invention is a printer head of an ink ejection printer. In certain instances, the printer head relies on capillary action to move a working fluid (eg, ink) to the printer head and to guide ink mounted inside the head through an orifice toward a target substrate. Contains. Such ink guiding means may include an actuator, such as a piezoelectric element or an electrostatic coating, to guide the ink through the orifice with proper actuation of the actuator.
Or, alternatively, it may include a thermal device in which the heat applied to the ink acts as a mechanism to guide the ink through the orifice.

[0003] Usually, the fluid chamber or ink flow passage is
It is provided on the printer head which introduces ink from the source by a conduit which is connected between the source and the printer head and passes through the ink guide means to the orifice. During normal operation of the printer head, ink is provided to the ink flow passage so that the ink guide draws the ink into the passage and subsequently forces the ink under pressure through the orifice toward the target surface. It must be extruded. However, if air enters the ink flow passage through the orifice (as if the printhead were accidentally hit or dislodged), or the orifice would be closed, e.g., by dirt or dust, which would remain inside the orifice. If so, actuation of the ink guide means will not draw any more ink into the passage and will not push the ink through the orifice. As a result, for efficient operation of the printhead, the ink flow passage must be free of air and the orifices of the printhead must not be blocked.

The air present between the printhead ink flow passage and the clogged orifice (surface or internal clogging) in the printhead is usually purged.
Alternatively, the ink may be removed by a head cleaning action, which action pushes the ink through the conduit toward the orifice of the printer head, with additional ink being pushed through the conduit and the ink flow passage by a pump or other means. You need to do so. However, such purging or head cleaning steps typically involve extruding the ink and air or obstructions (eg, debris) through the orifice so that the ink ejected from the orifice moves downward along the front side (ie, faceplate) of the printer head. Let it flow. To prevent the ink flowing down the front of the printer head from touching or smearing the surface that needs to be kept free of ink, the ink is hand-fed by the absorbent sheet material to the front of the printer head. Wipe from. However, this purging and subsequent cleaning steps require manual intervention and interruption of the printing operation and are usually confusing and undesirable operations.
Furthermore, if this process is required to be performed on a printer head located along the assembly line, the production of the assembly line must be paused to operate the printer head satisfactorily. The production time is lost.

[0005]

Accordingly, the front side of the print head is compared even when ink is forced through the orifice of the print head during a purging or head cleaning operation in which air or closure material is expelled from the ink flow passage. It would be desirable to provide new and improved devices and methods that can be kept clean.

Accordingly, it is an object of the present invention to provide a new method for cleaning or flushing a fluid chamber of a fluid ejection device, such as a printer head of an ink ejection device, which keeps the front or outer surface of the fluid ejection device relatively clean. It is to provide an improved apparatus and method.

It is another object of the present invention to provide a cleaning and cleaning operation which can be performed in a manner consistent with the prior art cleaning and cleaning operations and which can be performed in a fluid ejector in a conventional manner. It is to provide such an apparatus and method.

It is yet another object of the present invention to provide an apparatus and method that does not require wiping the front or outer surface of the fluid ejection device during cleaning or cleaning operations performed in the fluid ejection device.

It is yet another object of the present invention to be well-adapted to automatic operation, thereby eliminating the need for manual intervention, and to perform without interruption the operation of the fluid ejection operation or the assembly line in which it is used. To provide a device and method that can be used.

Yet another object of the present invention is to provide an apparatus and method that can be used to keep the orifice of a fluid ejection device relatively free of obstructions such as dirt and dust.

Yet another object of the present invention is to provide a device which is not complicated in structure and operates efficiently.

[0012]

SUMMARY OF THE INVENTION The present invention resides in an apparatus and method for use in purging or purging air or obstructions from a fluid chamber of a fluid ejection device during a cleaning operation, the fluid chamber comprising an outer surface. A chamber wall having an inner surface adjacent to the fluid chamber;
And at least one orifice through which fluid is ejected by the fluid ejection device during the ejection operation.

[0013] The apparatus includes a cavity proximate to the chamber wall, wherein fluid flowing through at least one orifice flows through the at least one orifice into the cavity during cleaning or cleaning.

The method of the present invention comprises the steps of providing a cavity proximate an outer surface of a chamber wall through which fluid flowing from at least one orifice flows through the at least one orifice during a cleaning or cleaning operation; Aspirating the fluid contained therein.

In another form of the apparatus and method of the present invention, the cavity forms a region of pressure above atmospheric pressure in a region proximate to the outer surface of the chamber such that air leakage from said region is at least one. Used to help keep the orifice relatively clean. For this purpose, air is introduced under pressure into the interior of the cavity, so that leakage of air from the cavity into the atmosphere causes a flow of air out of the cavity.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the claims.

The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the art after reviewing the following detailed description and accompanying drawings.

While the invention may be embodied in various forms, the specific embodiments are illustrated in the drawings and described below, the disclosure being considered to be exemplary of the present invention, and the present invention being not limited to this particular embodiment. It is understood that this is not intended to be limited to the illustrated embodiment. In addition, the title of this part,
It should be understood that normally the "detailed description of the invention" is in relation to the requirements of the United States Patent and Trademark Office and does not limit the disclosed subject matter and the patented invention.

Referring now to the drawings in more detail, and first to FIG. 1, there is shown an ink jet printing apparatus 20 incorporating therein the embodiment of the cleaning / cleaning apparatus shown generally herein. Furthermore, the printing device 20 is typically used to print indicia such as bar codes 24 on the side of a carton (carton) moving along a conveyor 28 moving in the direction indicated by arrow 29. It is shown where it is used in the usage environment. For this purpose,
The printing apparatus 20 includes an ink jet printer head 30 mounted stationary in proximity to a conveyor 28, an ink supply source 32, and an ink supply source 32 from the printer head 3.
And a conduit or hose 34 leading to the inlet. In this regard, ink is introduced into head 30 via conduit 34 by capillary action.

The printer head 30 of the illustrated apparatus 20 includes suitable ink guide means, generally indicated at 31, for guiding ink through the head 30 toward a target surface, such as the side of a carton 26. I have. The ink guide means 31 may be a multiple such as a thermal ink jet mechanism (as implemented in a printer head available from Canon USA under the trademark "Bubble Jet") or an electrostatic transducer. The ink guide means 31 of the illustrated apparatus 20 is such that the actuation of the piezo elements inside the printer head 30 is passed through the head 30 such as the side of the carton 26. This is due to the piezo element generating a movement of the ink towards the target surface. Furthermore, although the device 20 described herein is an ink jet printing device, the principles of the present invention may be embodied in other fluid jet devices. Therefore, the principles of the present invention can be widely applied.

Ink guide means 31 of printer head 30
A suitable control circuit (not shown) for controlling the operation of
A control box 36 is mounted proximate the printer head 30 and a plurality of wires 38
And a control circuit located inside the control box 36. The printing device 20 is also provided with sensing means, which includes an electrical eye 40, suitably wired to the control box 36, for sensing the presence of the carton 26 moving along the conveyor 28. I have. Carton 2 along conveyor 28 during operation of printing device 20
6 movement is detected by the electrical eye 40 which initiates a predetermined sequence of actions leading to the operation of the print head 30. In particular,
Appropriate piezoelectric elements of the head 30 are actuated as desired to print the indicia 24 on the sides of the carton 26 according to the time required for the carton 26 to move from the electrical eye 40 to the desired location in front of the printer head 30. Thus, it can be seen that the operation of the printer head 30 is coordinated with the speed of the carton as the carton 26 moves along the conveyor 28.

The structure and operation of a piezo-based ink jet printer head are well known and need not be described in detail. However, to better understand the contribution of the cleaning / cleaning device 22 of FIG.
A face plate 46 defining an orifice 48 mounted across the front side of the body 44;
Element 50 mounted inside the body 44 in close proximity to
A portion of a prior art printer head 42 having the following is schematically illustrated. Further, an ink flow passage 52 (or a fluid chamber) through which ink can flow from the ink supply source to the orifice 48 is defined inside the main body 44. In the illustrated head 42, face plate 46 provides a chamber wall for ink flow passage 52 and face plate 4
The outer surface of 6 provides the front side of the head 42.

Under normal circumstances, due to the surface tension of the ink on the orifice 48 during the operating cycle of the printer head 42, the ink will not flow through the orifice 48 unless it is normally so forced. However, by energizing and de-energizing the piezoelectric element 50 so that the element 50 rapidly contracts and expands, ink is drawn into the passage 52 from the supply and then under pressure the orifice 48 And is extruded toward the target surface. However, if air was present in the ink passage 52, the expansion and contraction of the piezoelectric element 50 would not cause enough ink to be drawn into the passage 52 that would subsequently be pushed through the orifice 48. Therefore, if air is injected or sucked into passage 52 through orifice 48 (head 4
2 (as if pushed or impacted by carton 26 moving along conveyor 28), the air must be expelled from passage 52 and printer head 42 fully activated.

The printer head 42 is similarly deactivated according to its intended purpose if its orifice 48 is blocked by an obstruction such as dirt or dust. More specifically, the obstacle (the orifice 4 on the surface of the face plate 46)
A surface obstruction that blocks occlusion 8 or an internal obstruction that can become lodged within orifice 48 or ink flow passage 52) prevents ink from escaping through orifice 48 by actuation of piezoelectric element 50 and as desired. To prevent the ink from flowing through the passage 52 of the head 42. Thus, if the orifice 48 becomes blocked by an obstruction such as dirt, the obstruction must be removed, for example, by being expelled from the passage 52 in a head cleaning operation. As will become clear below,
The cleaning / cleaning device 22 associated with the printing device 20 of FIG. 1 is adapted to expel air and obstructions easily from the orifice 48 and the passage 52 in an advantageous manner.

With the above in mind, and referring to FIGS. 3 and 4, the printer head 3 of the ink jet printing apparatus 20 of FIG.
0 includes a face plate 58 (FIG. 4) in which a linear row of orifices 60 are defined, and the cleaning / cleaning device 22 incorporated inside the device 20 of FIG. A plate 58 coupled to provide or define a collection cavity 64 (best shown in FIG. 10) proximate the face plate 58 for collecting ink ejected from the printer head 30 by the orifices 60; 1 and means for aspirating ink collected or contained within the collection cavity 64, generally indicated at 66. As best shown in the exploded view of FIG. 4 in addition to the face plate 58, the printhead 30 also has an internal operation (i.e., a piezoelectric Component) and component 70
And outer housing members 72, 74 secured therearound. The internal component 70 includes a mounting 76 to which the face plate 58 is mounted and which is held stationary against the front surface of the component 70.

The face plate 58 has a front surface 7 and a rear surface 7.
8,80, the row of orifices 60
8 are arranged along a straight line 68 extending centrally along the length. Further, the face plate 58 has a rectangular outer periphery and is inserted into the mounting portion 76 through a screw receiving opening 84 provided along the face plate 58 so that the mounting portion 76
(Eg, a total of 16) screws 82 threadably received by the internally threaded openings provided in the
Mounted by As will become apparent, four screws 82 secured to the corners of the face plate 58 are removed from the face plate 58 and secure the cavity forming means 62 to the mounting portion 76 with the same threaded holes in the face plate 58. Used for

Although the collection cavity 64 can be formed by any of a number of components and in any of a number of structures, the illustrated collection cavity 64 is a plurality of cavities as described herein. Forming plate member or face plate 5
8 are formed by appropriately shaped cutouts and grooves formed in plates 86, 88 and 90 which are arranged in an overlapping or stacked relationship to the front surface 78. Each plate 86, 88 and 90 is relatively thin and the screws 82
(Eg, the four screws 82) and the mounting aperture used to mount the face plate 58 to the mounting portion 76 maintain a stationary relationship to the face plate 58. Accordingly, each of the cavity forming plates 86, 88 and 90 is aligned with the screw receiving opening 84 of the face plate 58 to receive the shank of the screw 82 so that the plates 86, 88 and 90 together with the face plate 58 can have the head of the screw 82. It is provided within a screw receiving opening 91 defined in the corners of the plates 86, 88 and 90 which can be held firmly between the plate 86 and the surface of the mounting 76. Further, each of the plates 86, 88 and 90 has a pair of through holes 93.
Is provided, and the plate 8 is connected to the printer head 30.
An alignment pin is received to facilitate assembly of the 6,88 and 90 alignments.

Inside the illustrated cleaning / cleaning device 22,
Referring to FIGS. 5 and 6, the cavity-forming means 62, comprising cavity-forming plates 86, 88 and 90, comprises a first plate 86 (hereinafter referred to as "contact") disposed substantially over the front surface 78 of the face plate 58. Gasket 86).
A second or overflow plate 88 disposed in contact substantially over the front surface 76 of the gasket 86 and a third disposed in contact substantially over the front surface of the overflow plate 88. Or, a cover plate 90 is included.

Referring to FIGS. 5-9, the gasket 86 is of a platen-like type and has a substantially rectangular outer dimension substantially matching the dimensions of the face plate 58. further,
The gasket 86 includes a through-opening 92 extending along the length of the gasket 86 and opposing rows of cuts 94 that communicate with the through-opening 92 and extend laterally from the through-opening 92. The material from which gasket 86 is constructed can be any of a number of materials, but is preferably stainless steel.

The overflow plate 88 (best shown in FIGS. 5 and 11) is also of a platen-like form, but is slightly L-shaped, with three parallel plates extending laterally along the length of the plate 88. Groove-shaped through openings 96, 98, and 100. The other two (outer) through openings 96 and 100
(Central) through opening 98 located between the gaskets 86
And two outer through-openings 96, 100 are positioned to communicate with the cuts 94 in the gasket 86 when the overflow plate 88 is operatively operated and overlap the gasket 86. It is in. Further, as best shown in FIG.
A pair of grooves 102, 103 are defined along one of the legs of the character (and along its side facing the gasket 86), and the pair of grooves 102, 103 are formed in the outer through-opening 9.
6,100 extend from one end (i.e., the lower end) to a pair of internally threaded openings or through holes 106, 108 formed proximate the ends of the L-shaped corresponding legs of plate 88.

The cover plate 90 (best shown in FIGS. 5 and 6) has a slot-like through-opening 11 which substantially matches the L-shape of the overflow plate 88 and extends substantially along the center.
2 is provided in a somewhat L-shaped plate-like form. The material that constitutes each of the overflow plate 88 and the cover plate 90 is stainless steel, but other materials can be used.

When the gasket 86, overflow plate 88 and cover plate 90 are connected to the face plate 58 (by the four screws 82) in the above-described overlapping relationship, as best shown in FIGS. The orifice 60 provided inside the plate 58 is aligned with the central through opening 92 of the gasket 86, the central through opening 98 of the overflow plate 88, and the through opening 112 of the cover plate 90. With the through openings 92, 98 and 112 aligned with the orifice 60 in this manner, ink forced through the orifice 60 by the piezoelectric element mounted on the printer head 30 will have the cavity forming plates 86, 88.
And 90 can be run toward a target surface or substrate. In practice, the printer head 30 of the illustrated printing device 20 has a maximum emission distance or ink that is actually about 0.25 inches (6.35 mm).
It has a distance radiated from the orifice 60. This results in a total thickness of gasket 86 and plates 88 and 90 of about 0.10 inches (2.54 mm) with the target surface, e.g., the side of carton 26, close to orifice 60 near the front of cover plate 90. Preferably, it can pass across a distance of no more than 0.25 inch (2.54 mm).

From the above, a pair of continuous passages is formed by the gasket 86, the overflow plate 88 and the cover plate 90 connected to the face plate 58 in the above-described overlapping relationship, the cutout 94, the outer through openings 96 and 100, and the groove 10.
It can also be seen that 2,103 extends between the orifice 60 and the through holes 106,108 of the overflow plate 88. Thus, the orifice 60 is
The orifice 60 communicates with the through hole 108 through the outer through opening 100 and the groove 102. As will be described in more detail herein, a vacuum is formed in the cavity 64 by a through hole 108 during a cleaning or head cleaning operation, and pressurized air is introduced into the cavity 64 by a through hole 106. Allows the flow of air across the orifice 60
6 to the through-opening 100. This introduced air flow, together with the tilted state (as shown in FIG. 1) of the head 30, which places this (compressed) through-opening 96 above the through-opening 100, cleans or cleans the orifice 60. Not through-opening 96 but through-opening 1
A flow of ink released at 00 is generated. Due to this result and the action of gravity and the introduced flow of air from the through-opening 96 to the through-opening 100, the ink released from the orifice 60 during the cleaning or cleaning operation is the portion of the cavity 64 obtained by the through-opening 96. Not through openings 100
Into the cavity 64 obtained by the above.

Referring to FIGS. 1 and 12, in addition to the cavity forming means 62, the illustrated cleaning / cleaning device 22 is also generally 11
Means for expelling air from the ink flow passages and obstructions stuck inside the orifice 60 of the printer head 30, indicated at 4, and on the front surface of the face plate 58 expelled from the orifice 60, generally indicated at 116 Means for aspirating existing ink. In the illustrated cleaning / washing device 22, the discharging means 114 comprises a discharging pump 118.
And a pump 118 is connected in line with the conduit 34 leading to the printer head 30 to pump a desired amount of ink from the supply 32 through the conduit 34, thereby causing the air contained in the ink flow passage to be contained. And any obstructions stagnating in orifice 60 are pushed or ejected by ejection pump 118 along with ink pumped through printer head 30 through orifice 60.
To relieve the pressure introduced by the pump inside the print head 30, a return line 120 (with a non-return valve 122 mounted inside) is connected between the print head 30 and the supply 32, whereby the pump 118 To return a part of the ink sent to the printer head 30 to the supply source 32.

The operation of the discharge pump 118 discharges ink, air, and obstacles from the orifice 60 of the printer head 30 and the discharged ink is typically applied to the face plate 58.
It can be seen that it flows downward along the front surface of. However, the cavity forming means 62 prevents the released ink from being exposed on the surface where cleanliness is desired, and the suction means 116 cooperates with the through-opening 100 of the cavity forming means 62. The discharged ink is applied to the face plate 58.
To prevent ink from accumulating on the face plate 58.

Still referring to FIGS. 1 and 12, the suction means 116 of the illustrated cleaning / cleaning device 22 includes a vacuum pump 124, a control device 126 having the vacuum pump 124 mounted therein, and a vacuum pump 124 which overflows. And an air flow circuit 128 connected between the plate 88 and the through hole 168. The air flow circuit 128 of the illustrated device 22 includes a first vacuum hose 130 connected between the collection storage assembly 132 and the inlet of the vacuum pump 124, and a through hole 108 in the collection storage assembly 132 and the overflow plate 88. (FIG. 5). To facilitate attachment of the vacuum hose 134 to the overflow plate 88, an air hose fitting 136 (FIGS. 5 and 6) is threadably received by the through-hole 108 and a sealing ring 138 is provided on a suitable surface of the fitting 136. The connector 136 is inserted between the overflow plate 88 and the overflow plate 88.
Seal against

Referring again to FIGS. 1 and 12, the collection and storage assembly 132 includes a reservoir 142 and a pair of conduit sections 146,1.
48 includes a lid 144 extending therethrough. Each conduit section 146 or 148 is connected to a corresponding section of vacuum hose 130 or 134, and lid 144, reservoir 142 and conduit sections 146 and 148 are connected in a sealed manner to each other so that the vacuum generated by pump 124 is Flow circuit 12
Prevent leakage through 8. Control of the operation of vacuum pump 124 and discharge pump 118 is provided by a suitable control plate mounted inside controller 126 and suitably wired to vacuum pump 124 and discharge pump 118.

During operation of the cleaning / cleaning device 22, the vacuum pump 124 directs air toward the pump 124 to form the cavity forming means 6.
The second cavity 64 is actuated to draw through the air flow circuit 128 and the discharge pump 118 is activated to pump a small amount of ink through the orifice 60 of the printer head and thereby reside in the ink passage. Air and obstructions stagnating inside the orifice 60 of the printer head 30 are expelled through the orifice 60. The inside of the cavity 64 of the cavity forming means 62 is cut 94
Communicates with the atmosphere by means of gasket 86 and plate 8
8, 90, which are in communication with the aligned through openings 92, 98, 112, so that air is drawn from the atmosphere so that the air is sequentially directed to the vacuum pump 124 by the groove 102.
The through hole 108 allows the air to flow through the cavity 64 of the cavity forming means 62 and then through the air flow circuit 128.

Thus, ink ejected from the orifice 60 during the air flushing or head cleaning operation and beginning to flow down along the front surface 78 of the face plate 58 causes the cut 94 to be formed by the action of the vacuum pump 124 and gravity. It is sucked into the outer through-opening 100 of the overflow plate 88. As a result, the gasket 86 acts as a manifold that allows ink to be drawn into the outer through-opening 100 of the overflow plate 88 from the front surface 78 of the face plate 58. As the ink enters the through-opening 100, the ink is sucked downward by the vacuum pump 124 (and by the action of gravity) toward the through-hole 108, where air passes through the air flow circuit 128 to the vacuum pump 124. Is sucked. Therefore, the through opening 100 and the groove 10
2 acts as a flow passage through which the ejected ink moves downward through the cavity forming means 62. Upon reaching the collection reservoir 142 (FIG. 12) by the air flow circuit 128, ink falls from the inlet conduit portion 148 and is collected in the reservoir 142 for reuse or disposal. Ink reservoir 14
Only air is moved along vacuum hose 130 extending from reservoir 142 to vacuum pump 124 to separate the mixed air and ink contents drawn through air flow circuit 128 at 2.

The operation of the cleaning / cleaning device 22 can be initiated, for example, by pressing a "start" switch incorporated in a controller 126 that operates the vacuum pump 124 and the discharge pump 118. Vacuum and discharge pumps 124,1
The interruption of 18 is performed after a predetermined time (for example, after a few seconds) by appropriate timing control. Purification / cleaning device 22
The ability to manually initiate the actuation of the print head 30 is advantageous when or when air is drawn into the ink flow passage of the printer head 30 or the orifice 60 is closed during operation, and the flushing action is immediately initiated. It is desirable to eliminate the condition. Alternatively or additionally, the operation of the cleaning / cleaning device 22 is automatically started at predetermined intervals, and the orifices 60 or the ink flow passages of the printer head 30 are separated from air and orifice obstructions according to predetermined time intervals. Guarantee not to. For example, by appropriate programmed components mounted in the controller 126, the controller 126 is programmed to automatically start the cycle of operation of the cleaning / cleaning device 22 at the beginning of assembly line operation. 30 ensures that it is free from air and obstacles at the start of operation.

If the discharge pump 118 selected for use with the displacement means 114 is significantly more powerful than the vacuum pump 124, the discharge pump 118 is operated intermittently rather than continuously during operation of the vacuum pump 124. It is desirable. For this purpose, the control of the control device 126
Discharge pump 118 may be selected (or programmed) to operate intermittently and not operate during the operating cycle of cleaning / washing device 22 while 24 is activated.

From the above, the ink is supplied to the printer head 3.
The cleaning / cleaning device 22 removes from the front surface 78 of the face plate 58 during the air expelling and head cleaning operations performed on the
It can be seen that the face plate 58 of the print head 30 is kept relatively free of ink expelled from the orifice 60 during the air bleeding and head cleaning operations, and Eliminating the need for a manual method of wiping the ink from the surface without contacting or marking the surface where it is desired to keep the released ink free of ink.

Also shown in FIGS. 1 and 12 at 152 is an area above atmospheric pressure in the area adjacent to the front plate 58 of the printer head 30 of the printing apparatus to maintain the orifice 60 of the front plate 58 relatively clean. It is a feature of the purifying / washing device 22 that it includes means for assisting in cleaning, in other words, means for eliminating materials such as unnecessary dirt and dust that become lodged within the orifice 60. In the illustrated device 22, the generating means 152 corresponds to the cavity 6 of the cavity forming means 62.
4 and this formed cavity 64 surrounds an area adjacent to the front plate 58 where an area above atmospheric pressure is desired to be formed.

Further, the generating means 152 also
9 and a source 169 of pressurized air, which may be a fan or compressor 171 located on one side of the printing device 20, and further comprising a source 169 of pressurized air and a through hole 106.
And a conduit 170 for introducing pressurized air from a source 169 to a portion of the cavity 64 obtained by the through-opening 96. In this regard, an air flow connector 137 (FIGS. 5 and 6) is threadably received by through-hole 106 and conduit 170 is joined to connector 137.
The connector 137 is sealed to the overflow plate 88 by a seal ring 138. Therefore, the pressure generating means 15
During operation, air from pressurized air source 169 is introduced into through-opening 96 of cavity 64 by conduit 170 and fitting 137 such that the internal pressure of cavity 64 exceeds atmospheric pressure.

In practice, the internal pressure of the cavity 64
Does not need to exceed atmospheric pressure by an appreciable amount to penetrate the interior of the housing (which can in fact be as low as 1.0 pounds per square inch-6.895 kpa). Passing through the 98 and 112 reduces the collection of unnecessary dirt and dust, and thereby prevents accumulation inside the orifice 60. As a result, the pressure of the air distributed from the source 169 to the cavity 64 need not be very high, so that the increased energy to pressurize the air at the source 169 can be relatively small (for energy storage means).

As long as the pressure-generating means 152 is activated, there is a relatively small possibility that unnecessary dust and dirt will collect inside the orifice 60 of the printer head 30 and clog the orifice 60. As a result, the pressure-generating means 15
2 are operated continuously-preferably also during the printing operation performed by the printing device in which the cleaning / cleaning device 22 is used. During the simultaneous operation of the purifying / cleaning device 22 and the pressure-generating means 152 as previously described, the ink ejected from the orifice 60 during the flushing or head cleaning operation passes through the orifice 60 and through the orifice 60 under the action of gravity. And the flow of air introduced into the through-opening 100 forces the flow into the through-opening 100 of the collection cavity 94 rather than through the through-opening 96.

It will be appreciated that many modifications and substitutions can be made in the above-described devices without departing from the spirit of the invention. For example, the above-mentioned cleaning / cleaning device 22 is provided with the discharging means 1
Although illustrated and described as including ink 14 through the face plate orifice 60 during flushing or head cleaning operations, the cavity forming means 62 and the suction means 116 are used without the flushing means 114. The printer head of an existing ink jet printing apparatus is modified so that the ink discharged from the face plate by the known ejection means incorporated in the printing apparatus is used to form the cavity forming means 62 and the suction means 1.
16 and can be removed.

Purification / Washing Device 22 Another embodiment of this part is shown in FIGS. In this embodiment,
Vacuum and air pressure conduits 234, 270 are formed as part of printer head 230 rather than as separate conduits as shown in the embodiment illustrated in FIG. That is, both conduits 234 and 270 pass through head 230 and provide openings 236 and 272 in face plate 258. In this embodiment, a single plate, designated 288, is used to provide a cavity 264 used to draw ink and a cavity 252 for obtaining positive air pressure. This plate 288 is commonly referred to as a maintenance module.

The plate 288 has a front surface 290 facing the surface on which printing is performed (for example, a target) and a rear surface 2 abutting the face plate 258 of the printer head.
92. Plate 288 includes a slot-like opening 298 through which ink is ejected onto the target. This slot-like opening 298 is similar to the opening 92,
98 and 112.

An ink suction cavity 252 is formed as a vacuum passage generally indicated at 274 and formed in the rear surface 292 of the plate 288. A plurality of finger-like cuts 276 are formed in plate 288 and extend between vacuum passage 274 and slot opening 298. Notch 276 thus provides for flow communication between slot 298 and vacuum passage 274. In this embodiment, the passage 274 is disposed substantially parallel to the narrow groove 298, and the cut 276 is formed across the narrow groove 298 and the passage 274.

The passage 274 terminates at the end of the face plate 258 corresponding to the vacuum opening 236. In this manner, passage 274 is provided around face 258 around end 278.
Above the vacuum opening 236. Thus, a vacuum is provided to the plate 288 (and also through the notch 276 in the slot 298) by direct communication of the opening 236 with the passage 274.

A positive pressure air cavity 252 is formed as a burst or positive pressure passage 280 and is formed in the rear surface 292 of the plate 288. Like the vacuum passage 274, the discharge passage 280 is disposed substantially parallel to the narrow groove 298, and a finger-like cut 282 extends between the narrow groove 298 and the passage 280. Discharge passage 280 terminates at end 284 located above a discharge or pressure opening 272 formed in face plate 258. Air is applied at a positive pressure to the narrow groove 298 and through the passage 280 (notch 282) to effect the above-described release action.

In the embodiment shown, the vacuum and discharge passage 2
74, 280 are formed in the plate 288 substantially parallel to each other and opposite the narrow groove 298. In a preferred embodiment, the vacuum passage 274 is located above the narrow groove 298,
Passage end 278 is sloped or angled downward with respect to the main portion of passage 274. In this way, as the ink is drawn from around the narrow groove 298, the ink flows downward by gravity toward the vacuum opening 236 of the face plate 258.

Conversely, the release passage 280 is located below the narrow groove 298, and the release air rises and enters the narrow groove 298.
Discharge passage end 284 is formed substantially in line with a major portion of passage 280.

In this embodiment, plate 288 has a thickness of about 0.010 inches (about 10 mils) (0.254 mm), and has channels 274,280 and cuts 276,282.
Is formed by acid etching. The acid etched area has a depth of about 5 mils (0.127 mm). The thickness and etching depth of the plate 288 provide sufficient rigidity for the plate 288 and sufficient flow capacity for the passages 274, 280 and cuts 276, 282 to provide vacuum and discharge for the maintenance module. I do. Other depths, methods and means for forming passages and cuts will be recognized by those skilled in the art and are within the scope and spirit of the present invention.

A further enhancement of the other maintenance module is that it is configured to easily attach to the print head 230 with respect to the face plate 258. In this embodiment, a clip-like portion 238 extends rearward and substantially transversely from plate 288. These clips 238 are curved so as to engage with the side surfaces of the face plate 258 to fix the maintenance module plate 288 by snap fitting. This arrangement reduces or eliminates the need for screws or other fasteners to secure maintenance module plate 288 to printhead 230. Thus, maintenance module plate 288 is held in place by simple friction or snap fit to printer head face plate 258.

This snap-fit configuration allows two or more fasteners or screw openings to be used to provide vacuum and release openings 236, 272 in printer head faceplate 258. Accordingly, the printer head 230 includes conduits 234 and 270 carried therein.
Can collide with the overall size of the printer head 230 at all or only slightly. further,
The snap-fit structure also allows plate 288 to be
58 so that they can be easily aligned. This alignment is based on the fact that the ejected ink has a narrow groove-like opening 29 in the plate.
Needed to ensure that it is guided over the target to print through 8.

Further, it has been found that during operation, contaminants happen to spread on the maintenance module plate 288. In the operation of a tinting line, such as a boxing or packing operation where the adhesive is applied to a box or crate, a ribbon of adhesive may adhere to the front surface of plate 288. As will be appreciated by those skilled in the art, this adhesive is removed so that the adhesive is removed from surface 290 of plate 288.
It must not be overlaid and maintain proper operation of the printer head 230.

The maintenance module 288 of the present invention can include a coating or layer of low friction material, shown at C in FIG. This material is a fluoropolymer, such as TEFLON® and others. Such a material facilitates cleaning of the front surface 290 of the plate 288 if the plate 288 is soiled or contaminated, for example, by an adhesive ribbon or the like. Other easily cleaned low friction materials will be recognized by those skilled in the art and are within the scope and spirit of the present invention.

From the foregoing, it will be appreciated that many modifications and variations may be made without departing from the spirit and scope of the novel concept of the present invention. It should be understood that no limitations are intended or construed as to the particular embodiments illustrated. This disclosure is intended to be covered by the appended claims, and all such modifications are within the scope of the appended claims.

[Brief description of the drawings]

FIG. 1 is a perspective view of an ink jet printing apparatus in which one embodiment of the cleaning / cleaning apparatus of the present invention is used.

FIG. 2 is a longitudinal cross-sectional view of a portion of a prior art printer head schematically illustrating components of the printer head located proximate one embodiment of ink guide means mounted inside the printer head. .

3 is a perspective view of the printer head of the printing apparatus of FIG. 1 with the cavity forming assembly of FIG. 1 fitted with a cleaning / cleaning device.

FIG. 4 is an exploded perspective view of the printer head of FIG.

FIG. 5 is an exploded view of the cavity-forming assembly of FIG.

FIG. 6 is an assembly view of the cavity-forming assembly of FIG. 3;

FIG. 7 is a view of a portion of the gasket of the cavity-forming assembly, with the portion encircled by line 7-7 of FIG. 5 shown somewhat enlarged.

8 is a longitudinal sectional view of a portion of the assembly of FIG. 6 taken along line 8-8 of FIG. 6;

FIG. 9 is a sectional view taken along line 9-9 in FIG. 8;

FIG. 10 is a sectional view taken along the line 10-10 in FIG. 9;

FIG. 11 is a view of the overflow plate of the assembly of FIG. 6 as viewed from the rear side of FIG. 5;

FIG. 12 is a schematic view of a purifying, suctioning and pressure generating means of the purifying / cleaning device of FIG. 1;

FIG. 13 is a perspective view of a printer head similar to FIG. 4 showing another embodiment of each part of the cleaning / cleaning device.

FIG. 14 is a rear view showing an acid etching area of the maintenance module plate of FIG. 13;

FIG. 15 is an enlarged view of a defined area of FIG. 14 showing an etching pattern of the plate.

FIG. 16 is a front bevel view of the plate of FIG. 14 showing an attachment clip for attaching the plate to a printer head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 ... Ink jet printing apparatus 22 ... Purification / cleaning apparatus 24 ... Barcode 28 ... Conveyor 30 ... Ink jet printer head 31 ... Ink guide means 32 ... Ink supply source 34 ... Conduit (hose) 36 ... Control box 40 ... Electric eye 42 ... Printer head 44 ... Main body 46 ... Surface plate 48 ... Orifice 50 ... Piezoelectric element 52 ... Ink passage 58 ... Surface plate 60 ... Orifice 62 ... Cavity forming means 64 ... Cavity 66 ... Ink suction means 70 ... Internal operating components 72, 74 ... Housing member 76 ... Mounting part 78 ... Front plate front surface 80 ... Face plate rear surface 86 ... Plate (gasket) 88 ... Overflow plate 90 ... Cover plate 92 ... Through opening 94 ... Cut 96,98,100 ... Through opening 102, 103 ... groove 106, 108 ... through-hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B41J 2/185 F-term (Reference) 2C056 EA15 EA16 EA27 EC23 EC51 HA05 JB16 JC06 JC13 JC20 KA01 KB04 KB09 KB16 KD02 2C057 AF80 AG25 AG44 AG99 BA03 BA14

Claims (10)

[Claims] An apparatus for expelling air, surface obstructions, or internal obstructions from a fluid ejection device during a cleaning or cleaning operation, wherein the fluid ejection device causes fluid to flow through the fluid ejection device during the ejection operation. A device having at least one orifice to be ejected, a vacuum opening, and a discharge opening, wherein the device for discharging air and obstacles includes a plate having an opening formed therein, the plate being a part of a fluid injection device. Is configured to be located on the
The opening of the plate is located above the orifice of the fluid ejector, the plate having a vacuum passage and a discharge passage, a portion of the vacuum passage being located above the vacuum opening of the fluid ejector and A part of the discharge passage is located above the discharge opening of the fluid ejection device, and the vacuum passage and each of the discharge passages are connected so that the flow communicates with the opening of the plate. A device that is expelled from the device. 2. The release device according to claim 1, wherein the opening of the plate is an elongated groove. 3. The device according to claim 2, wherein a vacuum passage and a discharge passage extend parallel to the elongated groove. 4. The release device according to claim 3, wherein a vacuum passage and a discharge passage are arranged on opposite sides of the elongated groove. 5. The release device of claim 4, wherein each of the vacuum passage and the release passage includes a plurality of cuts extending between each passage and the elongated groove. 6. The dislodging device according to claim 5, wherein the cut extends across and between each of the passages and the elongated groove. 7. The expulsion device according to claim 1, wherein the plate defines a front side surface and a rear side surface, the rear side surface contacts the ink ejecting device, and the front side surface has a low friction coating. apparatus. 8. The dislodging device according to claim 1, wherein said plate is a single integral plate. 9. The device of claim 1, wherein the plate is an assembly of a number of adjacent plates. 10. A fluid ejection device for injecting fluid onto a target, comprising: a body having at least one orifice in which fluid is ejected during an ejection operation by the fluid ejection device; A face plate having an orifice to be sprayed and further having a discharge opening and a vacuum opening formed therein, a vacuum source operatively connected to the vacuum opening, a pressurized air source operatively connected to the discharge opening, and a fluid A cover plate configured to be located over a portion of the injector and over an orifice of the face plate, the cover plate having a vacuum passage and a discharge passage, and a portion of the vacuum passage. Is located above the vacuum opening of the face plate and a part of the release passage is located above the release opening of the face plate;
Each of the vacuum passage and the discharge passage is connected so that the flow communicates with the opening of the face plate, and the discharge passage and the vacuum passage are configured to cooperate with the vacuum source and the pressurized air source. A fluid ejecting device, wherein the obstacle is expelled from the fluid ejecting device during a cleaning or cleaning operation.