JP4634258B2 - Print head, printing apparatus, and print head manufacturing method - Google Patents

Description

  The present invention relates to a technical field of a printing apparatus, and more particularly to a print head and a printing apparatus used for inkjet printing.

  Conventionally, inkjet printers have been used for manufacturing FPD fields, mounting wiring boards, etc., such as color filters for liquid crystal display elements, spacers, alignment films, light emitting layers for organic EL display elements, wiring for plasma display elements, etc. .

  FIG. 12 is a plan view for explaining a print head used in a conventional ink jet printer. A supply pipe 162 and a plurality of ink chambers 166 are provided in the print head 150.

  Each ink chamber 166 is connected to a supply pipe 162 by an introduction pipe 164, and ink flowing through the supply pipe 162 is distributed to each introduction pipe 164 and supplied to the ink chamber 166. A nozzle 165 is connected to the ink chamber 166. When pressure is applied to the ink chamber 166 by the ejection unit 170, the ink stored in the ink chamber 166 is ejected from the nozzle 165.

By the way, bubbles may be mixed in the ink flowing through the supply pipe 162. If the bubbles enter the ink chamber 166 through the introduction pipe 164, the amount of ink discharged from the nozzles 165 becomes unstable or severe. No ink is ejected from the nozzles 165.
Japanese Patent Laid-Open No. 2005-138445

  The present invention has been made to solve the above problems, and an object thereof is to provide a print head in which bubbles do not easily accumulate in an ink chamber.

In order to solve the above-mentioned problem, an invention according to claim 1 includes an ink chamber and an ejection port connected to a bottom surface of the ink chamber, and the ink chamber has a first inlet and a first stream. Outlets are respectively provided, ink is supplied to the ink chamber through the first inlet, and the ink is discharged from the ink chamber through the first outlet, A print head configured to eject the ink supplied to the ink chamber from the ejection port when the volume of the ink chamber is changed by an ejection unit provided in the ink chamber, wherein the ink chamber The height from the bottom of the first inlet is higher than the upper end of the first inlet , the supply pipe, the second outlet provided in the supply pipe, One end is connected to the second outlet and the other end is the first outlet An inlet pipe connected to an inlet, wherein the ink flows through the supply pipe, is distributed to the inlet pipe through the second outlet, and is introduced into the ink chamber through the first inlet. The print head is configured to be supplied, and the height from the bottom surface of the ink chamber is higher at the upper end of the supply pipe than at the upper end of the second outlet .
According to a second aspect of the present invention, a discharge pipe, a second inlet provided in the discharge pipe, one end is connected to the first outlet, and the other end is connected to the second inlet. The ink is discharged from the first outlet, then flows through the outlet, and is discharged to the outlet through the second inlet. a claim 1 Symbol mounting print head, the height from the bottom surface of the ink chamber to the upper end of the second inlet is either equal to the height from the bottom surface of the ink chamber to the upper end of the discharge pipe, The print head is lowered.
The invention according to claim 3 is the print head according to claim 1 or 2 , wherein only the ink that has passed through the ink chamber is discharged to the discharge pipe. Print head.
The invention according to claim 4 is the print head according to claim 1 or 2 , wherein the ink flows from a position of the supply pipe where the second outlet is provided. One end of the connection pipe is connected to the downstream side in the direction, and the other end of the connection pipe is connected to the upstream side in the ink flow direction from the position where the second inlet of the discharge pipe is provided. The discharge pipe is a print head that discharges the ink that has passed through the connection pipe in addition to the ink that has passed through the ink chamber.
A fifth aspect of the present invention is the print head according to the fourth aspect , wherein at least a part of the inner diameter of the connection pipe is narrower than the inner diameter of the discharge pipe.
A sixth aspect of the present invention is the print head according to the fourth aspect , wherein the connecting pipe is provided with conductance adjusting means, and the conductance adjusting means changes the width of the flow path of the ink. The print head is configured as follows .
A seventh aspect of the present invention is a printing apparatus including the print head according to any one of the first to sixth aspects and a supply system that supplies ink to the print head.
The invention according to claim 8 is a method of manufacturing a print head according to any one of claims 1 to 6 , wherein the first and second lower thickenings are formed on the nozzle plate. A cover sheet having a groove, a plurality of lower openings, an upper narrow groove having one end connected to the lower opening and the other end connected to the first lower thick groove; On top, first and second upper thick grooves formed at positions corresponding to the first and second lower thick grooves, and upper openings respectively formed at positions corresponding to the lower openings, An upper plate having an upper narrow groove with one end connected to the upper opening and the other end connected to the second upper thick groove; a surface of the nozzle plate on which the lower plate is disposed; Bonding the surface of the cover sheet with the surface on which the upper plate is disposed, The supply pipe is formed by communicating a thick groove with the first lower thick groove, the discharge pipe is formed by connecting the second upper thick groove with the second lower thick groove, Each upper opening communicates with the corresponding lower opening to form the ink chamber, the lower fine groove is covered with the upper layer to form the introduction pipe, and the upper fine groove is covered with the lower layer. This is a method for manufacturing a print head constituting the outflow pipe.
A ninth aspect of the present invention is the method of manufacturing the print head according to the eighth aspect , wherein the lower plate is disposed on the nozzle plate, and then the lower plate is etched to perform the first and second. The lower side thick groove, the lower openings, and the lower narrow grooves are formed.
The invention of claim 10 wherein the method of manufacturing a print head according to claim 9 Symbol mounting, after positioning the upper plate on the cover sheet, the first etching said upper plate, a second This is a method for manufacturing a print head in which an upper thick groove, each upper opening, and each upper narrow groove are formed.

  In the print head of the present invention, it is difficult for air bubbles to enter the ink chamber, and even if the air bubbles enter the ink chamber, the air bubbles are discharged together with the ink into the discharge pipe, so that the air bubbles are not easily accumulated in the ink chamber. Accordingly, the pressure generated when the volume of the ink chamber is reduced by the discharge means is not absorbed by the bubbles, and the ink is discharged well from the nozzles.

  Reference numeral 10 in FIGS. 1 and 2 represents a printing apparatus according to the present invention. The printing apparatus 10 includes a base 15, a holding body 16, and a plurality of print heads 20. Rails 17a and 17b are extended to the side of the base 15, and the holding body 16 is attached to the rails 17a and 17b so as to reciprocate along the extending direction of the rails 17a and 17b on the base 15. It has been.

  Reference numeral 7 in FIGS. 1 and 2 indicates a processing object, and the processing object 7 is arranged on the table 15 with the surface thereof directed vertically upward. Each print head 20 is attached to the holding body 16 so as to be separated from the surface of the processing object 7 by a predetermined distance. When the holding body 16 moves, each print head 20 also moves together with the holding body 16. Each print head 20 moves on the processing object 7 without contacting the processing object 7.

  Since the surface of the processing object 7 on the table 15 is directed vertically upward, and the surface of the print head 20 on which the discharge port is formed is directed vertically downward, the printing head 20 moves on the processing object 7. Sometimes, each discharge port moves while facing the surface of the processing object 7.

  Each print head 20 is connected to a supply system 4 to be described later. When ink is ejected from the ejection port while moving the print head 20 on the processing object 7, the print head 20 is placed on the surface of the processing object 7. Ink is applied along the moving direction.

  Reference numeral 4 in FIG. 1 indicates a supply system. The supply system 4 has a stationary tank 24 arranged outside the holding body 16 and a moving tank 21 arranged inside the holding body 16. The moving tank 21 and the stationary tank 24 are connected by a flexible pipe 29. Even when the holding body 16 moves, ink is supplied from the stationary tank 24 to the moving tank 21 by a pump (not shown).

  The stationary tank 24 is connected to the supply source 14, and ink is replenished from the supply source 14 to the stationary tank 24 by a pump (not shown). A thick pipe (header 22) is connected to the moving tank 21. Each print head 20 is provided with a flow path which will be described later. The flow path is connected to the header 22, and the ink supplied from the moving tank 21 to the header 22 is distributed to each flow path.

  The flow path is connected to the header 22 by a distribution pipe 26. A filter 23 is provided in the middle of the distribution pipe 26, and the ink after the foreign matter is removed by the filter 23 is supplied to the flow path.

  In addition to the header 22, the flow path is connected to the discharge main pipe 27. The discharge main pipe 27 is connected to a discharge system different from the moving tank 21 or the supply system 4, and the ink supplied to the flow path returns to the supply system 4 or is discharged to the discharge system.

Accordingly, the ink circulates between the supply system 4 and the flow path of the print head 20 or is discharged from the supply system 4 through the flow path to the discharge system.
FIG. 4 is a plan view schematically showing the print head 20, and the print head 20 has a supply pipe 41, a discharge pipe 42, and a plurality of ink chambers 46.

  FIG. 5 is a sectional view taken along the line AA in FIG. 4, and the print head 20 further includes a nozzle plate 50. The nozzle plate 50 is provided with a plurality of through holes 55 penetrating from the front surface to the back surface.

  On the surface of the nozzle plate 50, a lower plate 53, an upper plate 63, and a cover sheet 61 are laminated in the order described. An opening for communicating the lower plate 53 and the upper plate 63 is formed on the through hole 55, and the ink chamber 46 is formed by a space sandwiched between the nozzle plate 50 and the cover sheet 61. Therefore, the through hole 55 is connected to the ink chamber 46.

  The nozzle 45 described above is configured by an opening opposite to the lower plate 53 of the through hole 55 and is exposed to the external atmosphere, so that the ink chamber 46 is connected to the external atmosphere via the nozzle 45.

  Here, the nozzles 45 are arranged in a straight line, and the ink chambers 46 are located on the nozzles 45, so that the ink chambers 46 are also arranged on the same straight line as the nozzles 45.

  On both sides of the ink chamber 46, a thick groove that communicates the lower plate 53 and the upper plate 63 extends in parallel with the row of the ink chamber 46, and the supply pipe 41 is constituted by one thick groove, and the other The discharge pipe 42 is constituted by a thick groove.

  The lower plate 53 and the upper plate 63 are formed with a thick groove (not shown) having one end connected to one end of the supply pipe 41 and the other end connected to one end of the discharge pipe 42. A connecting pipe that connects the pipe 41 to the discharge pipe 42 is configured. Reference numeral 43 in FIG. 4 indicates the connecting pipe.

  One end of the supply pipe 41 is connected to the distribution pipe 26 described above, and one end of the discharge pipe 42 is connected to the discharge main pipe 27. Since the other end of the supply pipe 41 and the other end of the discharge pipe 42 are connected to each other by a connection pipe 43, the flow path 40 constituted by the supply pipe 41, the connection pipe 43 and the discharge pipe 42 is connected to the distribution pipe 26. Connected to both discharge mains 27.

  A pump (not shown) is connected to the supply system 4 described above. When ink is pushed out to the distribution pipe 26 by the pump, ink is supplied to one end of the supply pipe 41, and the ink passes through the flow path 40 on the supply pipe 41 side. From one end of the discharge pipe 42 to the discharge main pipe 27.

  The lower plate 53 is formed with a narrow groove having one end connected to the supply tube 41 and the other end connected to the ink chamber 46, and the upper plate 63 has one end connected to the ink chamber 46 and the other end discharged to the discharge tube. A narrow groove connected to 42 is formed.

  Reference numeral 47 in FIG. 4 indicates an introduction pipe constituted by a narrow groove connecting the ink chamber 46 to the supply pipe 41, and reference numeral 48 in FIG. 4 indicates an outflow pipe connecting the ink chamber 46 to the discharge pipe 42. The ink chamber 46 is connected to both the supply pipe 41 and the discharge pipe 42 by an introduction pipe 47 and an outflow pipe 48. Accordingly, the supply pipe 41 and the discharge pipe 42 are connected to each other not only via the connection pipe 43 but also via the ink chamber 46.

  Reference numerals 56 and 57 in FIG. 5 indicate a first inflow port and a first outflow port in which the introduction pipe 47 and the outflow pipe 48 are connected to the ink chamber 46, and reference numeral 58 in FIG. A second outlet port connected to the pipe 41 is shown. Reference numeral 59 in the figure denotes a second inlet port where the outflow pipe 48 is connected to the discharge pipe 42.

  As described above, the ink is pushed out from the pump of the ink supply system 4 into the flow path 40, and the pressure in the flow path 40 is higher near the pump and low near the pump.

  Of the flow path 40, the supply pipe 41 is closer to the pump than the discharge pipe 42, and the second outlet 58 is provided in the supply pipe 41, whereas the second inlet 59 is provided in the discharge pipe 42. Therefore, the second outlet 58 is provided near the pump at a high pressure, and the second inlet 59 is provided farther away from the pump than the second outlet 58 at a low pressure. That's right. Accordingly, the ink flowing in the supply pipe 41 is drawn into the second outlet 58 due to the pressure difference, and flows into the discharge pipe 42 from the second inlet 59 through the ink chamber 46.

  As described above, since the print head 20 is arranged with the nozzle 45 facing vertically downward, the supply pipe 41, the ink chamber 46, the introduction pipe 47, the outflow pipe 48, and the discharge pipe 42 are respectively located on the nozzle plate 50 side. The surface is the bottom surface, and the surface on the cover sheet 61 side is the ceiling.

  Since the thick groove constituting the supply pipe 41 and the discharge pipe 42 and the opening constituting the ink chamber 46 are sandwiched between the cover sheet 61 and the nozzle plate 50, the supply pipe 41, the discharge pipe 42, and the ink chamber 46 are separated. Each bottom surface is constituted by the surface of the nozzle plate 50, and each ceiling is constituted by the surface of the cover sheet 61.

  Since the nozzle plate 50 is exposed on the bottom surface of the narrow groove constituting the introduction pipe 47 and the ceiling is covered with the upper plate 63, the bottom surface is flush with the bottom surfaces of the ink chamber 46 and the supply pipe 41. The height of the ceiling from the bottom surface of the ink chamber 46 is lower than the ceilings of the ink chamber 46 and the supply pipe 41. Accordingly, the height from the bottom surface of the ink chamber 46 is higher in the ceiling of the supply pipe 41 than in the second outlet 58 of the introduction pipe 47.

  The specific gravity of the ink is heavier than the air bubbles, and when air bubbles are mixed in the ink flowing through the supply pipe 41, the air bubbles flow through the ceiling portion of the supply pipe 41, so that no air bubbles enter the second outlet 58 and only the ink. The ink is supplied to the ink chamber 46 through the introduction pipe 47.

  The first inlet 56 has a lower end located on the bottom surface of the ink chamber 46 and an upper end located at a position lower than the ceiling of the ink chamber 46, so that ink is supplied from the first inlet 56 to the bottom portion of the ink chamber 46. Is done.

Since the lower plate 53 is exposed on the bottom surface of the narrow groove of the upper plate 63 constituting the outflow pipe 48 and the ceiling is covered with the cover sheet 61, the bottom surface of the outflow pipe 48 is compared with the ink chamber 46 and the discharge pipe 42. The ceiling of the ink chamber 46 is higher than the bottom surface of the ink chamber 46, but its ceiling is in the same plane as the ceilings of the ink chamber 46 and the discharge pipe 42.
Therefore, the upper end of the first outlet 57 of the outflow pipe 48 is higher than the first inlet 56 from the bottom surface of the ink chamber 46 and is substantially equal to the ceiling of the ink chamber 46.

  If air bubbles are mixed into the ink supplied to the ink chamber 46 or air enters from the nozzle 45, the air bubbles accumulate in the ceiling portion of the ink chamber 46, so that the air bubbles and the ink flow along the first outlet 57. To the outflow pipe 48.

  As described above, since the surface of the print head 20 on which the nozzles 45 are formed is directed vertically downward and the surface of the cover sheet 61 is oriented substantially horizontally, the ink chamber 46, the discharge pipe 42, and the outflow pipe 48. Each ceiling is approximately horizontal. Therefore, the bubbles do not stay in the outflow pipe 48 but flow along the ink flow toward the discharge pipe 42.

  Since the ceiling of the outflow pipe 48 is flush with the ceiling of the discharge pipe 42, the upper end of the second inflow port 59 is the same height as the ceiling of the discharge pipe 42 from the bottom of the ink chamber 46. Accordingly, bubbles do not accumulate at the second inlet 59, and the bubbles are quickly discharged to the discharge pipe 42 together with the ink.

  As described above, in the print head 20 of the present invention, it is difficult for bubbles to enter the ink chamber 46, and even if the bubbles enter the ink chamber 46, the bubbles are quickly discharged, so that the bubbles do not accumulate in the ink chamber 46. .

  Discharge means 30 is disposed at a position directly above the ink chamber 46 of the cover sheet 61. For example, the ejection unit 30 includes first and second electrodes 32 and 33 and a piezoelectric body 31 sandwiched between the first and second electrodes 32 and 33.

  When the first and second electrodes 32 and 33 are energized and pressure is applied to the piezoelectric body 31, the ejection means 30 is deformed, and the cover sheet 61 that constitutes the ceiling of the ink chamber 46 together with the ejection means 30 is also deformed. Thus, the volume in the ink chamber 46 changes. When the volume of the ink chamber 46 is decreased and the internal pressure is increased, the ink in the ink chamber 46 is pushed out to the through hole 55, and the ink is ejected from the nozzle 45.

  At this time, if bubbles are accumulated in the ink chamber 46, the pressure generated by the ejection means 30 is canceled by the bubbles, resulting in ejection failure. However, as described above, since the bubbles do not accumulate in the ink chamber 46, the nozzle 45 Normally ejects ink.

  The diameter of the introduction tube 47 is set so that the amount of liquid supplied from the introduction tube 47 to the ink chamber 46 per unit time is larger than the amount of liquid discharged from the nozzle 45 per unit time. Therefore, even when ink is ejected from the nozzle 45, the ink that has passed through the outflow pipe 48 is discharged to the discharge pipe 42, and the ink does not flow backward from the discharge pipe 42 to the outflow pipe 48.

  As shown in FIG. 6A, if the pressure adjusting portion 44 whose inner diameter is narrower than the inner diameter of the discharge pipe 42 is provided in at least a part of the connecting tube 43, the ink flows in a direction more than the pressure adjusting portion 44. The upstream side has a higher pressure than the downstream side. Accordingly, the pressure in the supply pipe 41 becomes higher than that in the case where the pressure adjusting unit 44 is not provided, and the flow velocity of the ink flowing through the introduction pipe 47, the ink chamber 46, and the outflow pipe 48 can be increased.

  The formation method of the pressure adjusting portion 44 is not particularly limited, and the inner diameter of the connection pipe 43 may be reduced by reducing the width of the connection pipe 43 as shown in FIG. Even if the width is not narrowed, the connecting pipe 43 is constituted only by a thick groove formed in one of the lower plate 53 or the upper plate 63, and the inner diameter is narrowed by shortening the distance from the bottom surface to the ceiling. You can also.

  Further, by providing the variable conductance adjusting means 34 in the connection pipe 43, the flow velocity of the ink chamber 46 can be increased (FIG. 6B). Specifically, the conductance adjusting means 34 has valves such as a butterfly valve, a diaphragm valve, and a needle valve. When the valve of the valve is closed, the flow path of the ink is narrowed. The flowing flow path becomes wider.

  The pressure loss of the ink flowing through the flow path is small when the flow path is wide and large when the flow path is narrow. Therefore, the conductance adjusting means 34 adjusts the opening of the valve and changes the width of the flow path. Also, the pressure difference between the upstream side and the downstream side, that is, between the supply pipe 41 and the discharge pipe 42 is set to a desired value, and the flow velocity of the ink flowing through the introduction pipe 47, the ink chamber 46, and the outflow pipe 48 is controlled to a desired value. can do.

Further, a mass flow controller may be provided as the conductance adjusting means 34, and the conductance may be adjusted by controlling the flow rate of the ink flowing in the connection pipe 43 with the mass flow controller. In particular, when the ink contains a particulate material such as spacer particles, optimum conductance adjustment can be performed according to the diameter, concentration, and liquid viscosity of the particulate material.
Here, the width of the flow path is a cross-sectional area when a space in which ink flows is cut in a direction perpendicular to the direction in which ink flows.

  Further, as shown in FIG. 7, no connection pipe is provided, the supply pipe 41 and the discharge pipe 42 are separated, and the supply pipe 41 and the discharge pipe 42 are constituted by the introduction pipe 47, the ink chamber 46, and the outflow pipe 48. It is also possible to connect via only the flow path.

  The supply pipe 41 and the discharge pipe 42 are arranged in parallel with each other across the row of ink chambers 46. If the leading side of the row of ink chambers 46 is one end of the supply pipe 41 and the discharge pipe 42 and the end side of the row of ink chambers 46 is the other end of the supply pipe 41 and the discharge pipe, one end of the supply pipe 41 is a distribution pipe. 26, the other end of the discharge pipe 42 is connected to the discharge main pipe 27, and the direction F in which ink flows in the supply pipe 41 and the direction F in which ink flows in the discharge pipe 42 are set in the same direction. The ink chamber 46 connected to the upstream side of the supply pipe 41 with respect to the other ink chamber 46 is connected to the upstream side of the discharge pipe 42 with respect to the other ink chamber 46, and conversely the supply pipe with respect to the other ink chamber 46. It is desirable to connect the ink chamber 46 connected to the downstream side of 41 to the downstream side of the discharge pipe 42 rather than the other ink chambers 46.

Next, an example of a process for manufacturing the above-described print head 20 will be described.
The code | symbol 51 of Fig.8 (a) has shown the nozzle plate main body. A cover plate 52 is affixed to the surface of the nozzle plate body 51, and the nozzle plate 50 is constituted by the nozzle plate body 51 and the cover plate 52. The lower plate 53 is provided on the surface of the nozzle plate 50 on the cover plate 52 side. Is affixed.

  Etch the positions where the ink chamber 46, the supply pipe 41, the discharge pipe 42, and the introduction pipe 47 of the lower plate 53 are to be formed, and form the opening 46a at the position where the ink chamber 46 is formed. The thick grooves 41a and 42a are formed at positions where the supply pipe 41 and the discharge pipe 42 are formed, respectively, and the narrow grooves 47a which are narrower than the thick grooves 41a and 42a are formed at the positions where the introduction pipe 47 is formed. Is formed (FIG. 8B).

  Here, the lower plate 53 is etched until the cover plate 52 is exposed. Therefore, the bottom surfaces of the openings 46a, the thick grooves 41a and 42a, and the fine grooves 47a are the surfaces of the nozzle plate 51 on the cover plate 52 side. It consists of

  Next, the nozzle plate 50 located on the bottom surface of each opening 46a is excavated from the front surface to the back surface to form through holes. Reference numeral 11 in FIG. 8C indicates the first work-in-process with the through hole 55 formed therein.

Next, the second work-in-process that is bonded to the first work-in-process 11 will be described.
Reference numeral 61 in FIG. 9A denotes a cover sheet. An upper plate 63 is attached to the front surface of the cover sheet 61, and the above-described discharge means 30 is previously disposed at a predetermined position on the back surface of the cover sheet 61. Yes.

  The positions where the ink chamber 46, the supply pipe 41, the discharge pipe 42, and the outflow pipe 48 of the upper plate 63 are to be formed are etched, respectively, and the opening 46b is formed at the position where the ink chamber 46 is formed. The thick grooves 41b and 42b are formed at the positions where the supply pipe 41 and the discharge pipe 42 are formed, and the narrow grooves 48b thinner than the thick grooves 41b and 42b are formed at the positions where the outflow pipe 48 described above is formed (FIG. 9 (b)).

Next, a protective layer is formed on the surface of the cover sheet 61 on which the discharge means 30 is disposed, and at least the side surfaces exposed from the first and second electrodes 32 and 33 of the piezoelectric body 31 are covered with the protective layer.
Reference numeral 12 in FIG. 9C denotes a second work-in-process with the protective layer 64 formed, and the piezoelectric body 31 is covered with the protective layer 64 and the first and second electrodes 32 and 33. Since it is cut off from the external atmosphere, the piezoelectric body 31 is not deteriorated by oxygen or moisture.

  Next, as shown in FIG. 8D, the surface on which the lower plate 53 of the first and second work-in-progress items 11 and 12 is disposed and the surface on which the upper plate 63 is disposed are opposed to each other. The openings 46b of the upper plate 63 and the openings 46a of the lower plate 53 face each other, and the thick grooves 41b and 42b of the upper plate 63 and the thick grooves 41a and 42a of the lower plate 53 face each other. Align.

  After the alignment, when the first and second work-in-progress items 11 and 12 are pasted together, the opening 46a of the lower plate 53 and the opening 46b of the upper plate 63 are communicated to form the ink chamber 46, and the lower plate 53 The one thick groove 41a and one thick groove 41b of the upper plate 63 communicate with each other to form the supply pipe 41, and the other thick groove 42a of the lower plate 53 communicates with the other thick groove 42b of the upper plate 63. Thus, the discharge pipe 42 is formed.

  On the other hand, neither the groove nor the opening is formed in the upper plate 63 at a position corresponding to the narrow groove 47a of the lower plate 53, and the lower plate 53 has a groove at a position corresponding to the narrow groove 48b of the upper plate 63. Since neither the opening nor the opening is formed, the narrow groove 47a of the lower plate 53 is covered with the upper plate 63 to form the introduction pipe 47, and the narrow groove 48b of the upper plate 63 is covered with the lower plate 53 to An outflow tube 48 is formed.

  The lower plate 53 and the upper plate 63 are etched before being attached to the nozzle plate 50 and the cover sheet 61, respectively, and the thick grooves 41a, 41b, 42a and 42b, the openings 46a and 46b, The lower plate 53 and the upper plate 63 in the state where the grooves 47a and 48b are formed may be attached to the nozzle plate 50 and the cover sheet 61, respectively.

  Further, the step of forming the through hole 55 may be performed before the lower plate 53 is etched, and the step of disposing the discharge means 30 on the cover sheet 61 is performed after the step of etching the upper plate 63, You may carry out after bonding the 1st, 2nd work-in-process articles 11 and 12.

  The case where the lower plate 53 is etched until the surface of the nozzle plate 50 is exposed has been described above. However, the present invention is not limited to this, and as shown in FIG. The lower plate 53 may be etched halfway so that the surface of the plate 50 is not exposed, and the thick grooves 41a and 42a, the openings 46a, and the narrow grooves 47a in which the lower plate 53 is exposed are formed on the bottom surface.

  Each portion of the lower plate 53 is made of the same material, and the etching rates of the thick grooves 41a, 42a, the narrow grooves 47a, and the openings 46a are substantially equal. Therefore, the thick grooves 41a, 42a, the openings 46a, Each narrow groove 47a is etched to substantially the same depth. Accordingly, the thick grooves 41a and 42a and the bottom surfaces of the openings 46a are located in the same plane.

  When this work-in-process 49 is bonded to the second work-in-process 12 as shown in FIG. 9C, the bottom surfaces of the supply pipe 41, the discharge pipe 42, the ink chamber 46, and the introduction pipe 47 are flush with each other. In addition, a print head can be obtained in which the height from the bottom surface of the ink chamber 46 is higher at the ceiling of the outflow pipe 48 than at the ceiling of the introduction pipe 47.

  The above describes the case where the supply pipe 41, the discharge pipe 42, the ink chamber 46, the introduction pipe 47, and the outflow pipe 48 are configured by grooves and openings formed in the two plates of the lower plate 53 and the upper plate 63. However, the present invention is not limited to this. If the height from the bottom surface of the ink chamber 46 is higher at the first outlet 57 than at the upper end of the first inlet 56, 1 The supply pipe 41, the discharge pipe 42, the ink chamber 46, the introduction pipe 47, and the outflow pipe 48 may be configured by grooves or openings formed in one plate, or grooves formed in three or more plates. Alternatively, the supply pipe 41, the discharge pipe 42, the ink chamber 46, the introduction pipe 47, and the outflow pipe 48 may be configured with openings.

  Further, the lower plate and the upper plate described above are integrated with the nozzle plate 50, and the supply pipe 41, the discharge pipe 42, the ink chamber 46, the introduction pipe 47, and the outflow pipe 48 are formed by grooves and openings formed in the nozzle plate 50. It may be configured.

  The above has been described in the case where the ceilings of the ink chamber 46, the outflow pipe 48, and the discharge pipe 42 are flush with each other. However, the present invention is not limited to this, and for example, the height from the bottom surface of the ink chamber 46 is increased. The ceiling of the discharge pipe 42 may be made higher than the ceiling of the outflow pipe 48 so that the ceiling of the discharge pipe 42 is made higher than the upper end of the second inflow port 59. The ceiling of the outflow pipe 48 may be made higher than the ceiling of the 46 and the upper end of the first outlet 57 may be made higher than the ceiling of the ink chamber 46. In either case, the ink accumulated in the ink chamber 46 is not accumulated in the ink chamber 46 or the outflow pipe 48 but is discharged to the discharge pipe 42.

  The nozzle plate main body 51, the cover plate 52, the lower plate 53, and the upper plate 63 are made of, for example, a metal plate such as nickel, an alloy thereof, stainless steel (for example, material 316, 316L), aluminum, titanium, or quartz. A plate, a glass plate, a ceramic plate, a silicon plate, a plastic plate, or the like can be used.

  The cover sheet 61 is not particularly limited, but when the discharge means 30 is provided on the cover sheet 61 as shown in FIG. 5, it is preferable to use a vibration plate, specifically, a metal thin plate such as a stainless thin plate. Further, a piezoelectric element as the discharge means 30 may be directly formed on a vibration plate made of a silicon substrate or a ceramic substrate.

  The ejection unit 30 is not particularly limited as long as the volume of the ink chamber 46 can be changed and pressure can be applied. For example, the ejection unit 30 can be provided in the side wall, bottom wall, or ink chamber 46 of the ink chamber 46.

  For example, a liquid crystal panel spacer can be formed on the print head 20 of the present invention using ink in which spacer particles are dispersed in a solvent, or a conductive layer can be formed using ink in which metal particles are dispersed in a solvent. . In addition, a resin film can be formed using ink in which a resin is dissolved in a solvent, or a color filter can be formed using ink in which a dye is dissolved in a solvent or ink in which pigment particles are dispersed in a solvent.

Next, a print head of a comparative example will be described.
<Comparative example>
The supply pipe 141 and the discharge pipe 142 are each composed of a thick groove formed in the lower plate 53, the introduction pipe 147 and the outflow pipe 148 are each composed of a narrow groove formed in the upper plate 63, and the ink chamber 146 is formed on the upper side. The print head 120 of the comparative example was constructed by comprising openings formed in the plate 63 and the ceilings of the supply pipe 141 and the discharge pipe 142 were lower than the ceilings of the introduction pipe 147, the ink chamber 146, and the outflow pipe 148. (FIG. 11).

  When ink is supplied to the supply pipe 141, the ink is supplied to the ink chamber 156 through the introduction pipe 147. However, since the ceiling of the introduction pipe 147 is higher than the ceiling of the supply pipe 141, bubbles are introduced along with the ink. The ink chamber 146 was entered through 147.

  Further, since the ceiling of the discharge pipe 142 is lower than the outflow pipe 148, the bubbles are not discharged from the outflow pipe 148 to the discharge pipe 148, and eventually the air bubbles accumulate in the ink chamber 146, and pressure is applied to the ink chamber 146 by the discharge means 30. However, the amount of ink ejected from the nozzle 145 was small, resulting in ejection failure.

FIG. 2 is a plan view illustrating an example of a printing apparatus according to the invention. Sectional drawing explaining an example of the printing apparatus of this invention Block diagram for explaining an example of the relationship between the print head and the supply system The top view explaining the print head of the first example of the present invention Sectional drawing explaining the print head of 1st example of this invention (A): Plan view for explaining the print head of the second example of the present invention, (b): Plan view for explaining the print head of the third example of the present invention. The top view explaining the printing head of the 4th example of the present invention (A)-(d): Sectional drawing explaining the 1st work-in-process used for manufacture of the print head of this invention. (A)-(c): Sectional drawing explaining the 2nd work-in-process used for manufacture of the print head of this invention. Sectional drawing explaining other examples of the first work in process Sectional drawing explaining the print head of a comparative example Plan view for explaining a conventional print head

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Printing apparatus 20 ... Print head 41 ... Supply pipe 42 ... Discharge pipe 45 ... Nozzle 46 ... Ink chamber 47 ... Inlet pipe 48 ... Outflow pipe 56 ... First inlet 57 ... First outlet 58 …… Second outlet 59 …… Second inlet

Claims (10)

An ink chamber and an ejection port connected to the bottom surface of the ink chamber;
The ink chamber is provided with a first inlet and a first outlet, respectively.
Ink is supplied to the ink chamber through the first inlet, and the ink is configured to be discharged from the ink chamber through the first outlet.
A print head configured to eject the ink supplied to the ink chamber from the ejection port when the volume of the ink chamber is changed by the ejection means provided in the ink chamber,
The height from the bottom of the ink chamber is higher at the upper end of the first outlet than at the upper end of the first inlet .
A supply pipe, a second outlet provided in the supply pipe, an inlet pipe having one end connected to the second outlet and the other end connected to the first inlet,
The ink flows in the supply pipe, is distributed to the introduction pipe through the second outlet, and is supplied to the ink chamber through the first inlet;
The print head in which the height from the bottom of the ink chamber is higher at the upper end of the supply pipe than at the upper end of the second outlet . A discharge pipe, a second inlet provided in the discharge pipe, and an outlet pipe having one end connected to the first outlet and the other end connected to the second inlet,
The ink, said after being discharged from the first outlet, wherein the outflow pipe flow, the second configuration claims 1 Symbol placement of the print head so as to be discharged into the discharge pipe through the inlet Because
The height from the bottom of the ink chamber to the upper end of the second inlet is the same as or lower than the height from the bottom of the ink chamber to the upper end of the discharge pipe. Wherein the discharge tube is configured claim 1 or any one print head according to claim 2 so that only ink through the ink chamber is discharged. One end of a connection pipe is connected to a downstream side of the supply pipe in a direction in which the ink flows from a position where the second outflow port is provided,
The other end of the connection pipe is connected to the upstream side in the ink flow direction from the position where the second inlet of the discharge pipe is provided,
Wherein the discharge pipe, in addition to the ink through the ink chamber, according to claim 1 or any one print head according to claim 2 wherein the ink through the connection pipe is discharged. The print head according to claim 4 , wherein at least a part of an inner diameter of the connection pipe is narrower than an inner diameter of the discharge pipe. The print head according to claim 4 , wherein conductance adjusting means is provided in the connection pipe, and the conductance adjusting means is configured to change the width of the flow path of the ink. A print head according to any one of claims 1 to 6 ,
A printing apparatus having a supply system for supplying ink to the print head; A print head manufacturing method for manufacturing the print head according to any one of claims 1 to 6 ,
On the nozzle plate, first and second lower thick grooves, a plurality of lower openings, one end connected to the lower opening, and the other end connected to the first lower thick groove Place the lower plate with a narrow groove,
On the cover sheet, the first and second upper thick grooves formed at positions corresponding to the first and second lower thick grooves, and the upper openings formed at positions corresponding to the lower openings, respectively. And an upper plate having an upper narrow groove with one end connected to the upper opening and the other end connected to the second upper thick groove,
Bonding the surface of the nozzle plate on which the lower plate is disposed and the surface of the cover sheet on which the upper plate is disposed,
The first upper thick groove communicates with the first lower thick groove to constitute the supply pipe,
The second upper thick groove communicates with the second lower thick groove to constitute the discharge pipe,
The ink chamber is configured by communicating each upper opening with the corresponding lower opening,
The lower narrow groove is covered with the upper layer to constitute the introduction tube,
A method of manufacturing a print head in which the upper narrow groove is covered with the lower layer to constitute the outflow pipe. The lower plate is disposed on the nozzle plate, and then the lower plate is etched to form the first and second lower thick grooves, the lower openings, and the lower narrow grooves. Item 9. A method for producing a print head according to Item 8 . After placing the upper plate on the cover sheet, said first upper plate is etched, No placement claim 9 Symbol forming a second of said upper thick groove said each upper opening each of the upper thin groove A method of manufacturing a print head.

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