JP2009190371A - Liquid discharge head and liquid discharge apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid discharge head and a liquid discharge apparatus capable of catching foreign matter such as dust while ensuring the supply of liquid to a liquid passage from a common liquid chamber, and moreover removing the caught foreign matter. <P>SOLUTION: A plurality of projections 11 in the common liquid chamber 6 are arranged so that a shortest distance between the mutually adjacent projections 11 is gradually shortened in an ink supply direction toward the ink passage 3 from the common liquid chamber 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid discharge head and a liquid discharge apparatus that can be widely applied, for example, as an ink jet recording head capable of discharging ink, and an ink jet recording apparatus using the ink jet recording head.

  This type of liquid discharge head is generally provided with a liquid flow path from the upstream side in the liquid supply direction to the discharge port. The liquid flow path includes an electrothermal transducer (heater), a piezoelectric element, and the like. A discharge energy generating element is provided. When the electrothermal converter is provided, the liquid in the liquid flow path can be foamed by the heat generation, and the liquid can be discharged from the discharge port using the foaming energy.

  In such a liquid discharge head, in order to stably supply the liquid to the discharge port, the cross-sectional area of the liquid channel is larger than the cross-sectional area of the discharge port. Therefore, when dust such as impurity particles is present in the liquid, the dust may pass through the liquid flow path and reach the vicinity of the discharge port. When dust reaches the vicinity of the discharge port, when discharging the liquid, there is a possibility that the discharge direction is shifted or the discharge amount is changed, so that normal discharge cannot be performed. Further, when the discharge port is blocked with dust, there is a possibility that the liquid cannot be discharged. Further, when a liquid in which bubbles are mixed is supplied to the liquid ejection head, the smooth flow of the liquid is hindered by the bubbles that have entered the liquid flow path, and the ejection performance may become unstable.

  In Patent Document 1, in order to avoid such an adverse effect due to dust, the positions (a), (b), (c), ( A liquid discharge head having any one of the filter structures d) is described. (A) is a filter structure in which a plurality of openings form a curved path, (b) is a filter structure having a cross section formed by the openings and protrusions, and (c) is a recess on the discharge port side of the openings. (D) is a filter structure having a cross section provided with a plurality of protrusions.

Japanese Patent Laid-Open No. 6-312506 JP 2006-264128 A

  However, although the filter structure in Patent Document 1 can capture various kinds of dust and the like present in the liquid so as not to reach the vicinity of the discharge port when the liquid is discharged, the following problems may occur. .

  In the filter structures of (a) and (c), although dust is easily captured, there is a possibility that the flow path resistance in the region of the filter structure part is greatly increased. In the filter structures (b) and (d), although dust is easily captured and the increase in flow resistance is suppressed, the filter structure formed by the inverted conical or needle-like protrusions Once dust is captured, it becomes difficult to remove it. That is, since the captured dust is held by the protrusion, even if a recovery operation for discharging the liquid in the liquid discharge head is performed to remove bubbles in the liquid discharge head, the dust or the like is removed together with the liquid. It is difficult to remove. For this reason, dust or the like is always captured in the filter structure, and the liquid supply performance to the liquid flow path decreases as the liquid discharge head is used for a long period of time.

  An object of the present invention is to provide a liquid ejection head and a liquid ejection apparatus capable of capturing foreign matter such as dust and removing the captured foreign matter while ensuring supply of liquid from a common liquid chamber to a liquid flow path Is to provide.

  The liquid discharge head of the present invention is a liquid discharge head capable of discharging a liquid supplied from a common liquid chamber into a liquid flow path from a discharge port using discharge energy generated by a discharge energy generating element. A plurality of protrusions are arranged in the chamber, and the plurality of protrusions are arranged so that the shortest distance between the adjacent protrusions decreases as the liquid is supplied from the common liquid chamber to the liquid flow path. It is characterized by being.

  The liquid discharge apparatus of the present invention uses a liquid discharge head capable of discharging a liquid, and applies the liquid discharged from the liquid discharge head to a processing member. And a circulation recovery means capable of circulating the liquid through the common liquid chamber by a circulation path connected to the common liquid chamber of the liquid discharge head.

  According to the present invention, a plurality of protrusions are provided in the common liquid chamber, and the shortest distance between adjacent protrusions is reduced as the liquid is supplied from the common liquid chamber into the flow path. Large foreign matter can be captured between the protrusions on the upstream side in the liquid supply direction. In this way, by changing the capturing position according to the size of the foreign matter, the foreign matter can be captured while ensuring the supply of the liquid from the common liquid chamber to the liquid flow path. In addition, the trapped foreign matter can be removed by creating a liquid flow in the common liquid chamber in a direction different from the direction in which the liquid is supplied into the flow path.

  The present invention can be applied to an ink jet recording head capable of ejecting ink. In this case, foreign matter such as dust mixed in the ink can be captured, and the ink ejection state can be maintained satisfactorily. . The liquid ejection apparatus of the present invention can be used in an ink jet recording apparatus that can record an image using an ink jet recording head. In this case, stable recording quality can be maintained for a long time. Further, the trapped foreign matter can be removed by performing a circulation recovery operation of circulating through the ink circulation path in the ink jet recording head.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a front view showing an outline of the internal structure of an ink jet recording apparatus (liquid ejecting apparatus) 200, which includes an ink jet recording head 100 as an embodiment of the liquid ejecting head of the present invention. The recording apparatus 200 is provided with a plurality of replaceable recording heads 100 that eject ink as liquid. Reference numeral 201 denotes a recovery unit individually corresponding to each recording head 100, 201 denotes a cartridge-type ink tank that stores ink, and 203 denotes an operation panel unit. Reference numeral 204 denotes a recording medium transport unit, and 205 denotes a paper feeding unit that feeds the recording medium to the recording apparatus main body.

  The recording apparatus 200 of this example is a so-called full-line type inkjet recording apparatus, and ejects ink from the ejection port of the recording head 100 while continuously transporting a recording medium from right to left in FIG. Thus, an image can be recorded on the recording medium. In the case of this example, yellow (Y), light magenta (LM), magenta (M), light cyan (LC), cyan (C), and black (K) inks supplied from the ink tank 201 correspond to recording. The ink is discharged from the head 100. Thereby, a color image can be recorded. The recovery unit 210 is used for a recovery process for maintaining a good ink discharge state in the recording head 100. The recovery processing can include a circulation recovery operation in which ink is circulated between the recording head and the ink tank, and dust and bubbles in the ink are removed in the circulation path. Furthermore, it includes a preliminary ejection operation for ejecting ink that does not contribute to image recording into the cap from the ejection port, and a pressure recovery operation forcibly pressing the ink in the recording head from the ejection port into the cap. Can do. Further, it may include a suction recovery operation for sucking and discharging ink from the ejection port into the cap, and a wiping operation for wiping the ejection port surface of the recording head 100 where the ejection port is formed.

  FIG. 2 is an exploded perspective view of the recording head 100.

  Reference numeral 101 denotes a discharge element which forms the main part of the recording 100, and is supported by a ceramic base plate 102 on one side surface. As will be described later, the discharge element 101 includes a common liquid chamber, a plurality of discharge ports, a plurality of ink channels (liquid channels) communicating between the common liquid chamber and the discharge ports, and a discharge energy generating element. And are provided. In the case of this example, an electrothermal converter (heater) is provided as a discharge energy generating element. A wiring board 103 is disposed on the other side surface of the ejection element 101, and the wiring board 103 is connected to an electrode portion of a wiring (a wiring for ejection energy generating element and its driving element) provided on the ejection element 101. Then, they are electrically connected by wire bonding. Reference numeral 104 denotes an ink flow path forming member for forming an ink supply path to the discharge element 101, and is connected to a later-described common liquid chamber provided in the discharge element 101 through an opening provided in the wiring substrate 103.

  The ink supply path in this example forms a circulation path through which ink can be circulated between the recording head 100 and the ink tank 202. That is, the ink in the ink tank 202 is transferred to the common liquid chamber in the ejection element 101 via the ink flow path forming member 104, and the transferred ink is distributed from the common liquid chamber to each nozzle. The ink in the common liquid chamber can be returned to the ink tank 202 via the ink flow path forming member 104.

  FIG. 3 is a partially broken perspective view showing the vicinity of the nozzle of the discharge element 101. On the heater board 1, electrothermal transducers (heaters) 2 serving as ejection energy generating elements are arranged at positions corresponding to the plurality of ink flow paths 3. The ink in the ink flow path 3 is foamed by the heat generated by the heater 2, and the ink can be ejected from the ejection port 7 using the foaming energy. Hereinafter, the ink flow path 3 and the ejection port 7 are collectively referred to as “nozzles”. As the heater 2, a resistor such as tantalum nitride is used, its thickness is 0.01 to 0.5 μm, and its sheet resistance is 10 to 300Ω per unit square. The heater 2 may be formed of a material other than tantalum nitride, such as hafnium boride, and the thickness and sheet resistance are not particularly limited.

  A pair of electrode wirings (not shown) made of aluminum or the like for energization is connected to both ends of the heater 2, and a switching transistor (non-energization) for turning on / off energization is connected to one electrode wiring. Are connected. A control IC (not shown) including a circuit including a gate element controls a switching transistor in accordance with a recording signal input from the outside of the recording head.

  On the heater board 1, nozzle side walls 4 are formed between adjacent heaters 2. A top plate 5 made of Si or the like is disposed on the upper surface of the nozzle side wall 4 via a top plate adhesive layer (not shown) having a thickness of about 2 μm. Thereby, the tubular ink flow path 3 surrounded by the heater board 1, the nozzle side wall 4, and the top plate adhesive layer is defined. An opening 5A is formed in the top plate 5 by a method such as anisotropic etching, and the ink flow path forming member 104 is connected to the opening 5A, thereby introducing ink into the common liquid chamber 6 and the like. It becomes possible.

  The common liquid chamber 6 is provided with a plurality of columnar protrusions 11 located in the vicinity of the ink flow path 3. The plurality of protrusions 11 function as filters for capturing foreign matters such as dust and bubbles, and are disposed on the first, second, and third rows L1, L2, and L3 parallel to the nozzle arrangement direction. They are arranged side by side. The extending direction of these rows L1, L2, and L3 intersects with the ink supply direction from the common liquid chamber 6 to the ink flow path 3, as will be described later (in this example, orthogonal). The plurality of protrusions 11 on the first row L1 are arranged at regular intervals by a constant interval a, and the plurality of projections 11 on the second row L2 are arranged at regular intervals by a constant interval b. The plurality of protrusions 11 on the third row L3 are arranged at equal intervals by a constant interval c. These intervals a, b, and c are the shortest distances between the adjacent protrusions 11 on the rows L1, L2, and L3, respectively, and are set to satisfy a <b <c. That is, the intervals a, b, and c are set to increase as the distance from the position near the nozzle increases.

  In the heater board 1, an electric pad 8 for transmitting a recording signal to the heater 2 is formed on the side opposite to the side where the nozzle is formed. The electric pad 8 is electrically connected to the pad portion 10 of the electric wiring board 9 and the wire 13.

  In the configuration described above, the heater 2 is turned on / off by the control IC drivingly controlling the switching transistor in accordance with a recording signal input from the outside of the recording head. The ink supplied from the common liquid chamber 6 to each ink flow path 3 is heated and foamed on the heater 2. The ink on the downstream side in the ink supply direction from the heater 2 is ejected from the ejection port 7 by the pressure due to the foaming. The ink droplets fly and land on the recording medium to form dots.

  FIG. 4 is a conceptual diagram for explaining the flow of ink in the ejection element 101. Reference numeral 21 denotes an introduction part capable of introducing ink, and reference numeral 22 denotes a lead-out part capable of leading out ink, which can be connected to a circulation path of a recording apparatus for forcibly circulating ink. During the circulation recovery operation of the recording head as will be described later, the ink supplied from the circulation path of the recording apparatus is introduced into the common liquid chamber 6 from the introduction unit 21 as indicated by the arrow in FIG. The ink passes between the protrusions 11, flows in the common liquid chamber 6 from the left to the right in the figure, and returns from the lead-out portion 22 to the circulation path of the recording apparatus. A circulation path of the recording apparatus is provided with a mechanism for removing foreign matters such as dust and bubbles in the ink, and an ink tank. As described above, during the circulation recovery operation, the ink can be forcibly recirculated between the recording head and the ink tank. During the recording operation, the ink can be introduced into the common liquid chamber 6 from the introduction unit 21 as the ink in the recording head is consumed. Further, at the time of this recording operation, ink may be introduced into the common liquid chamber 6 also from the lead-out portion 22.

  FIG. 5 is an explanatory diagram of nozzles and protrusions 11 in the recording head.

  The protrusions 11 in the present embodiment are cylindrical, and are arranged along the three rows L1, L2, and L3 as described above to form the first, second, and third protrusion groups A, B, and C. is doing. The columns L1, L2, and L3 extend in a direction that intersects (orthogonally in this example) the ink supply direction (arrow X direction) from the common liquid chamber 6 to the ink flow path 3. The protrusion groups C, B, A are located in that order from the upstream side to the downstream side in the ink supply direction (arrow X direction). As described above, the intervals c, b, a in the projection groups C, B, A are reduced in that order. D1 is the distance between the protrusion groups A and B in the arrow X direction, D2 is the distance between the protrusion groups B and C in the arrow X direction, and the distances D1 and D2 have a relationship of D1 <D2. . The interval D1 is the interval between the rows L1 and L2 adjacent to each other on the downstream side in the ink supply direction (arrow X direction). In this example, the interval D1 and the projection 11 on the column L2 The shortest distance between. The interval D2 is an interval between the rows L2 and L3 adjacent to each other on the upstream side in the ink supply direction (arrow X direction). In this example, the interval D2 and the projection 11 on the column L3 The shortest distance between.

  As described above, the intervals a, b, and c have a relationship of a <b <c. The smallest interval a is set to be smaller than the width x of the discharge port 7. That is, the distance a and the width x are set to satisfy the relationship x> a.

  Due to the relationship of x> a, even when foreign matter such as dust or bubbles flows in the vicinity of the ink flow path 3, they do not reach the ejection port 7. Further, due to the relationship of a <b <c, relatively large dust 12A and the like can be captured by the protrusion 11 positioned on the upstream side in the ink supply direction (arrow X direction). Accordingly, it is difficult to prevent the supply of ink flowing into the ink flow path 3. In addition, since minute dust 12B, 12C, and the like can be reliably captured by the protrusion 11 located on the downstream side in the ink supply direction (arrow X direction), the dust and the like reach the vicinity of the ejection port 7. There is nothing.

  Next, the recovery operation of the recording head will be described.

  As described above, the recording head 100 of this example uses the heater (electrothermal converter) 2 to generate ink ejection energy. That is, the ink is foamed by the thermal energy generated by the heater 2 on the heater board 1, and the ink is ejected from the ejection port 7 using the foaming energy. Therefore, when the recording operation is continued for a long time, the thermal energy is accumulated in the ink, the temperature of the ink rises, and the gas dissolved in the ink may be accumulated in the recording head 100. In addition, there is a possibility that gas permeates through a resin tube generally used for supplying ink to the recording head 100 and flows into the recording head 100. If the bubbles in the recording head 100 generated in this way are not removed, ink cannot be ejected properly.

  In this example, a circulation recovery operation is performed in order to remove bubbles in the recording head 100. That is, ink is circulated between the recording head and the ink tank by a pump or the like, and bubbles and dust are removed in the circulation path. At that time, an ink flow as indicated by an arrow in FIG.

  FIG. 6 is an explanatory view of the nozzle and the projection 11 during such a circulation recovery operation.

  During the circulation recovery operation, an ink flow Y1 from the left to the right in FIGS. 4 and 6 and an ink flow Y2 and Y3 including components from the top to the bottom in FIGS. 4 and 6 are generated. By such ink flows Y1, Y2, and Y3, dust 12A, 12B, and 12C, bubbles, and the like captured by the protrusions 11 are removed. For the ink flows Y2 and Y3, the distance between the protrusions 11 in the protrusion group located on the upstream side is small, and the distance between the protrusions 11 in the protrusion group located on the downstream side is large. Therefore, in particular, dust 12A, 12B, 12C and bubbles trapped by the protrusions 11 are easily removed by the ink flows Y2, Y3. Accordingly, dust 12A, 12B, 12C, bubbles, and the like trapped by the protrusion 11 follow the ink flow in the recording head 100 generated during the circulation recovery operation, as indicated by arrows E1, E2, E3 in FIG. It becomes easy to be removed.

  In this way, by removing dust or bubbles trapped by the protrusions 11, it is possible to maintain the ink ejection performance in the recording head and stably record a high-quality image for a long period of time.

(Comparative example)
As a comparative example with respect to the recording head 100 of the present embodiment, a configuration of a recording head having a different arrangement of the protrusions 11 will be described (see FIGS. 7 to 9).

  The plurality of protrusions 11 in the recording head of FIG. 7 are arranged at a constant interval a on a row L11 that is close to the ink flow path 3 and extends in the nozzle arrangement direction. The interval a is set smaller than the width x of the discharge port 7 (x> a). Therefore, even when dust 12A, 12B, 12C, bubbles, or the like flows near the ink flow path 3, they do not reach the ejection port 7. However, when continuous recording operation is performed, dust, bubbles, and the like are accumulated in the vicinity of the ink flow path 3, and in the worst case, the protrusions 7 are blocked as shown in FIG. There is a risk that it may be difficult to supply ink to the flow path 3. In this case, recording failure may occur.

  The plurality of protrusions 11 in the recording head of FIG. 8 are arranged at a constant interval a on each of the two rows L11 and L12 along the nozzle arrangement direction. Further, the protrusions 11 on the rows L11 and L12 are arranged in a staggered manner. Therefore, the flow path between the protrusions 11 forms a curved path, and dust and bubbles are less likely to reach the vicinity of the ink flow path 3 as compared with the recording head of FIG. However, since the area where the protrusions 11 are formed is large, the flow path resistance of the ink flowing through this area increases.

  The plurality of protrusions 11 in the recording head of FIGS. 9A and 9B are needle-like protrusions. Therefore, an increase in ink flow path resistance can be suppressed. However, once dust or the like is captured by the protrusion 11, it is very difficult to remove it. That is, the captured dust or the like is held at the tip of the projection 11 as shown in FIG. 9B, and it is difficult to remove them even if the circulation recovery operation as described above is performed.

(Discharge element manufacturing method)
Next, a method for manufacturing the ejection element 101 in the recording head 100 will be described (see FIGS. 10 and 11).

  10A to 10E are cross-sectional views of the discharge element 101 in the manufacturing stage as viewed from the discharge port 7 side. FIGS. 11A to 11E are cross-sectional views taken along the line XI-XI in FIGS. 10A to 10E, respectively. The ejection element 101 in the manufacturing stage is arranged along the longitudinal direction of the nozzle. FIG. In this embodiment, after passing through the stage which manufactures the two discharge elements 101 integrally, it cut | disconnects along the cutting line CL in FIG.11 (d), and discharge elements as shown in FIG.11 (e). Two 101 are manufactured, and the discharge port 7 is formed in the cut surface along the cutting line CL. The manufacturing method of the discharge element is not limited to the method of this example, and may be a method of manufacturing it alone.

  First, as shown in FIG. 10A and FIG. 11A, on the heater board 1 made of a silicon wafer, using a device similar to the manufacturing device used in the semiconductor manufacturing process, hafnium boride, tantalum nitride, etc. The heater 2 consisting of is formed. A drive circuit including a semiconductor element such as a switching transistor for selectively driving the heater 2 can be built in the heater board 1 in advance. Thereafter, the surface of the heater board 1 is treated in order to improve the adhesion between the heater board 1 and the photosensitive resin film in the next step. That is, after the surface of the heater board 1 is cleaned, the surface is modified by ultraviolet-ozone or the like, and then a solution obtained by diluting, for example, a silane coupling agent with ethyl alcohol to 1% by weight on the modified surface. Spin coat.

  Next, after the surface of the heater board 1 is cleaned, a photosensitive resin film DF is laminated on the heater board 1 with improved adhesion, as shown in FIGS. 10B and 11B. Then, ultraviolet rays are irradiated to the portions of the photosensitive resin film DF that are to be left as the nozzle side walls 4 and the protrusions 11 through the photomask.

  Next, the photosensitive resin film DF is developed with a developer composed of a mixed solution of xylene and butyl cellosolve acetate, and the unexposed portion of the photosensitive resin film DF is melted. As a result, as shown in FIGS. 10C and 11C, the nozzle side wall 4 and the protrusion 11 having a desired shape are formed on the heater board 1.

  Next, as shown in FIGS. 10 (d) and 11 (d), a top plate 5 on which a top plate adhesive layer made of a photosensitive resin film is laminated in advance is welded onto the nozzle side wall 4. At this time, curing at about 200 ° C. is required.

  After the two discharge elements 101 are integrally manufactured through the above steps, cutting lines corresponding to the butting surfaces of the discharge ports 7 of the discharge elements 101 as shown in FIGS. 10 (e) and 11 (e). Cut along CL. As a result, the two discharge elements 101 are separated. For example, the two discharge elements 101 are separated by cutting using a dicing machine to which a diamond blade having a thickness of 0.05 mm is attached. Then, the discharge element 101 is completed by performing polishing for smoothing the cut surfaces.

(Second Embodiment)
FIG. 12 is an explanatory diagram of the vicinity of the nozzles of the recording head according to the second embodiment of the present invention.

  The protrusions 11 in the present embodiment have a triangular prism shape, and a plurality of the protrusions 11 are on the rows L1, L2, and L3 extending in a direction substantially orthogonal to the ink supply direction (arrow X direction) to the ink flow path 3. It is arranged. The protrusions 11 on the rows L1, l2, and L3 are arranged at fixed intervals (shortest distances) a, b, and c, respectively, to form protrusion groups A, B, and C. In the order of the protrusion groups C, B, A located in the direction from the upstream side to the downstream side in the ink supply direction (arrow X direction), the arrangement intervals c, b, a are set to be sequentially smaller. Further, the interval a in the projection group A located on the most downstream side in the ink supply direction (arrow X direction) is set to be smaller than the width x of the ejection port 6. Therefore, as in the above-described embodiment, the width x and the interval a have a relationship of x> a, and the intervals a, b, and c have a relationship of x> a and a <b <c.

  Further, the triangular prism-shaped protrusion 11 is formed so that the cross-sectional area increases from the upstream side to the downstream side in the ink supply direction (arrow X direction). Accordingly, in each of the protrusion groups A, B, and C, the interval between the adjacent protrusions 11 decreases from the upstream side to the downstream side in the ink supply direction (arrow X direction).

  When the circulation recovery operation is performed on the recording head having such a configuration in the same manner as in the above-described embodiment to generate the ink flow as indicated by arrows Y1, Y2, and Y3 in FIG. The trapped dust 12A, 12B, 12C, bubbles and the like are reliably removed. That is, as in the above-described embodiment, the interval between the projections 11 in the projection group located on the upstream side of the ink flow Y2, Y3 is small and the interval between the projections 11 in the projection group located on the downstream side is large. Easy to remove dust and bubbles. Further, since the interval between the adjacent protrusions 11 in each of the protrusion groups A, B, and C increases from the upstream side to the downstream side of the ink flows Y2 and Y3, the dust 12A and 12B trapped by the protrusions 11 is obtained. , 12C and bubbles are more reliably removed.

  In this way, by removing dust or bubbles trapped by the protrusions 11, it is possible to maintain the ink ejection performance in the recording head and stably record a high-quality image for a long period of time.

(Other embodiments)
The liquid ejection head of the present invention can be widely applied as an ink jet recording head capable of ejecting ink, as well as a head for ejecting various liquids, for example, for ejecting various processing liquids and chemicals. It can also be used as a head. Moreover, the liquid discharge apparatus of the present invention can be widely applied as an apparatus for applying various processing liquids, chemicals, and the like to a processing member in addition to an inkjet recording apparatus using an inkjet recording head.

  Further, the plurality of protrusions functioning as a filter may be disposed so that the shortest distance between the adjacent protrusions becomes smaller in the liquid supply direction from the common liquid chamber to the liquid flow path. Is not specified only in the above-described embodiment. Since the plurality of protrusions in the embodiment described above have the same shape, they are arranged so as to increase in density in the direction of liquid supply from the common liquid chamber to the liquid flow path. However, a plurality of protrusions having different sizes may be provided. Further, as described above, when a plurality of protrusions are provided along a plurality of rows extending in a direction intersecting with the liquid supply direction from the common liquid chamber to the liquid flow path, the rows are specified as only three rows. It is sufficient that it is two or more rows. When the number of rows is three or more, as in the above-described embodiment, the interval between the columns adjacent to each other on the downstream side in the liquid supply direction is set between the columns adjacent to each other on the upstream side in the liquid supply direction. It can be made smaller than the interval.

  The shape of the protrusion is not limited to the cylindrical shape and the triangular prism shape, and is arbitrary. In addition, it is preferable that the formation material of the protrusion is the same formation material (photosensitive resin material or the like) as the liquid channel.

1 is a schematic front view of a recording apparatus including a recording head as a liquid ejection head according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the recording head in FIG. 1. FIG. 3 is a partially cutaway perspective view of a nozzle portion of the recording head in FIG. 2. FIG. 3 is an explanatory diagram of ink flow in the recording head in FIG. 2. FIG. 3 is an explanatory diagram of a nozzle portion in the recording head in FIG. 2. FIG. 3 is an explanatory diagram of a state where a circulation recovery operation is performed on the recording head in FIG. 2. It is explanatory drawing of the nozzle part of the recording head as a comparative example of this invention. It is explanatory drawing of the nozzle part of the recording head as another comparative example of this invention. (A) is explanatory drawing of the nozzle part of the recording head as another comparative example of this invention, (b) is sectional drawing which follows the IX-IX line of (a). (A) to (e) is a cross-sectional view for explaining a manufacturing process of the discharge element in FIG. (A) to (e) is a cross-sectional view for explaining the manufacturing process of the ejection element in FIG. 2, and is a cross section taken along line XI-XI in FIGS. 10 (a) to (e). It is explanatory drawing of the nozzle part of the recording head as a liquid discharge head of the 2nd Embodiment of this invention.

Explanation of symbols

1 Heater board 2 Electrothermal converter (heater)
3 Ink channel (liquid channel)
6 Common liquid chamber 11 Protrusion 12A, 12B, 12C Dust 21 Introducing section 22 Deriving section 100 Recording head (liquid ejection head)
101 Discharge element 200 Recording device (liquid discharge device)
202 Ink tank

Claims (12)

In the liquid discharge head capable of discharging the liquid supplied from the common liquid chamber into the liquid flow path from the discharge port using the discharge energy generated by the discharge energy generating element,
Providing a plurality of protrusions in the common liquid chamber;
The plurality of protrusions are arranged such that the shortest distance between the protrusions adjacent to each other decreases in the liquid supply direction from the common liquid chamber to the liquid flow path. head. The plurality of protrusions are arranged to form a plurality of rows extending in a direction crossing the liquid supply direction;
The shortest distance between the protrusions adjacent to each other in the row located on the downstream side in the liquid supply direction is shorter than the shortest distance between the protrusions adjacent to each other in the row located on the upstream side in the liquid supply direction. The liquid discharge head according to claim 1, wherein the liquid discharge head is small.   3. The liquid discharge head according to claim 2, wherein a shortest distance between the protrusions adjacent to each other in the row located on the most downstream side in the liquid supply direction is smaller than a width of the discharge port. The plurality of columns is three or more columns,
The interval between the columns adjacent to each other on the downstream side in the liquid supply direction is smaller than the interval between the columns adjacent to each other on the upstream side in the liquid supply direction. The liquid discharge head described.   The liquid ejection head according to claim 1, wherein the protrusion has a cylindrical shape.   5. The liquid ejection head according to claim 1, wherein the protrusion has a columnar shape in which a cross-sectional area increases from an upstream side to a downstream side in the liquid supply direction.   5. The shape of the protrusions is a shape such that an interval between the protrusions adjacent to each other in the row decreases from an upstream side to a downstream side in the liquid supply direction. The liquid discharge head according to any one of the above.   The liquid ejection head according to claim 1, wherein a material for forming the protrusion is the same as a material for forming the liquid flow path.   The liquid discharge head according to claim 8, wherein a material for forming the protrusion and the liquid flow path is a photosensitive resin material. An introduction part and a lead-out part connectable to a circulation path for circulating the liquid through the common liquid chamber;
The introduction unit can introduce liquid from the circulation path into the common liquid chamber,
The liquid discharge head according to any one of claims 1 to 9, wherein the lead-out portion can lead the liquid in the common liquid chamber to the circulation path. In a liquid ejection apparatus that uses a liquid ejection head capable of ejecting liquid and applies liquid ejected from the liquid ejection head to a processing member.
Using the liquid discharge head according to any one of claims 1 to 10 as the liquid discharge head,
A liquid discharge apparatus comprising: circulation recovery means capable of circulating liquid through the common liquid chamber by a circulation path connected to the common liquid chamber of the liquid discharge head.   The liquid discharge apparatus according to claim 11, wherein an ink jet recording apparatus is configured by using the liquid discharged from the liquid discharge head as ink and using the processing member as a recording medium.

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