JP5328296B2 - Inkjet recording head and inkjet recording apparatus - Google Patents

Description

  The present invention relates to an ink jet recording apparatus that performs a recording operation by discharging ink and an ink jet recording head used in the recording apparatus.

  2. Description of the Related Art Conventionally, ink jet recording apparatuses are widely used and commercialized for computer-related output devices and the like because the running cost of color images is low and the apparatus can be miniaturized.

  In recent years, in order to realize high-definition image recording at higher speed, it is also desired to realize a recording head having a longer recording width (discharge port array length). Specifically, a recording head having a length of 4 inches to 13 inches is also required.

  As the recording head becomes longer and faster in this way, the input energy to the recording head increases and the temperature of the recording head during recording increases. As a result, it is necessary to cope with recording reliability, such as a variation in ejection amount for each page, unstable ejection at high temperatures, and a decrease in continuous recording performance.

  Conventionally, the cooling of the recording head has been carried out by air cooling from the outside of the recording head or by mounting a cooling pipe on the recording head. In the conventional method, since the heat pipe and the heat radiating member are externally attached to the completed recording head, there is a problem that the recording element substrate serving as a heat source and the heat pipe cannot be brought close to each other. Further, since the heat pipe is externally attached, the contact area between the heat pipe and the recording head is limited, and the heat exchange efficiency between the recording head and the heat pipe is poor. Even with the configuration of the conventional method, the effect of cooling and soaking may be sufficient depending on the recording execution conditions, but continuous recording is attempted with a longer and higher density recording head. In case. This is because the heat exchange efficiency that suppresses the uneven temperature distribution in the recording head due to long time recording and the recording failure due to the temperature rise is not obtained.

  Therefore, in view of the above-described problems of the prior art, an object of the present invention is to provide an inkjet recording head having high recording reliability even when high-speed recording is performed with a long and high-density recording head. .

For this reason, the ink jet recording head of the present invention is provided with a plurality of discharge ports, and the ink jet recording head provided with a plurality of discharge ports for discharging ink has a discharge port array in which a plurality of discharge ports are arranged. A recording element substrate provided with an element for generating thermal energy, a support plate provided with a surface for supporting the recording element substrate, a passage provided inside the support plate and provided with a heat pipe , and the support plate A flow path provided for flowing a cooling liquid therein, and in a region overlapping the recording element substrate in a direction perpendicular to the surface of the support plate, the recording element substrate, the passage, and the flow The path is arranged in this order in the thickness direction of the support plate .

  The ink jet recording apparatus of the present invention is an ink jet recording apparatus comprising the above-described ink jet recording head and a transporting means for transporting a recording medium, and further comprising means for flowing a cooling liquid through the flow path. It is characterized by that.

  According to the present invention, the temperature increase of the ink jet recording head and the temperature unevenness in the ink jet recording head due to the high speed recording and the high density of the discharge port array are suppressed, and the non-ejection due to the fluctuation of the discharge amount and the temperature rise is prevented. It becomes possible. Further, both high speed and high image quality can be achieved, and the reliability during continuous recording can be greatly improved.

Embodiments of the present invention will be described with reference to the drawings.
FIGS. 1 to 12 show a plurality of recording element substrates each having an ejection port array composed of a plurality of ejection ports for ejecting ink, to which the present invention can be applied, arranged along the row direction of the ejection ports on a support plate. It is a figure for demonstrating an inkjet recording head or an inkjet recording device. Hereinafter, the entire configuration will be described with reference to these drawings while describing each configuration.

  An ink jet recording head (hereinafter also simply referred to as a recording head) H1000 shown in FIG. 1 performs recording using an electrothermal transducer that generates thermal energy for causing film boiling in ink according to an electrical signal.

  As shown in the exploded perspective view of FIG. 2, the recording head H1000 includes a recording element unit H1001 and an ink supply member H1500 of an ink supply unit H1002. Further, as shown in the exploded perspective view of FIG. 3, the recording element unit H1001 includes a recording element substrate H1100, a support plate H1200, an electric wiring substrate H1300, a plate H1400, and a filter member H1600.

  4A is a diagram showing the configuration of the recording element substrate H1100, and FIG. 4B is a cross-sectional view taken along the line IVB-IVB shown in FIG. The recording element substrate H1100 has a thin film formed of, for example, a Si substrate H1108 having a thickness of 0.5 to 1 mm. In addition, an ink supply port H1101 composed of a long groove-like through-hole is formed as an ink flow path, and electrothermal conversion elements H1102 are arranged in a staggered pattern on each side of the ink supply port H1101. The electrothermal transducer H1102 and electric wiring such as Al are formed by a film forming technique. An electrode H1103 is provided to supply power to the electrical wiring.

  The ink supply port H1101 performs anisotropic etching using the crystal orientation of the Si substrate H1108. Further, an ejection port plate H1110 is provided on the Si substrate H1108, and an ink flow path H1104, an ejection port H1105, and a foaming chamber H1107 corresponding to the electrothermal conversion element H1102 are formed by photolithography. The ejection port H1105 is provided so as to face the electrothermal conversion element H1102, and the ink supplied from the ink supply port H1101 generates air bubbles by the electrothermal conversion element H1102 to eject the ink.

The support plate H1200 is made of, for example, an alumina (Al ₂ O ₃ ) material having a thickness of 0.5 to 10 mm. The material of the support plate is not limited to alumina, and has a linear expansion coefficient equivalent to that of the material of the recording element substrate H1100, and is equivalent to or equivalent to the thermal conductivity of the material of the recording element substrate H1100. It may be made of a material having the above thermal conductivity. The material of the support plate H1200 is, for example, any of silicon (Si), aluminum nitride (AlN), zirconia, silicon nitride (Si ₃ N ₄ ), silicon carbide (SiC), molybdenum (Mo), and tungsten (W). There may be.

  The support plate H1200 is formed with an ink supply port H1201 (first ink supply port) for supplying ink to the recording element substrate H1100. This is because the ink supply port H1101 (second ink supply port) of the recording element substrate H1100 corresponds to the ink supply port H1201 of the support plate H1200. Further, the recording element substrate H1100 is bonded and fixed to the support plate H1200 with high positional accuracy. Further, the support plate H1200 has an X-direction reference H1204, a Y-direction reference H1205, and a Z-direction reference H1206 that are positioning references.

  As shown in FIG. 1, the recording element substrates H1100 are arranged in a staggered manner on the support plate H1200, and enable wide recording with the same color. For example, four recording element substrates H1100a, H1100b, H1100c, and H1100d having a discharge port group length of at least 1 inch are arranged in a staggered manner to enable recording with a width of 4 inches.

  Further, the end portion of the ejection port group of each recording element substrate is provided with a region (L) overlapping with the end portion of the ejection port group of the recording element substrate adjacent to the staggered pattern in the recording direction. A gap is prevented from being generated between the recording areas of the substrate. For example, overlapping regions H1109a and H1109b are provided in the discharge port group H1106a and the discharge port group H1106b.

  The electrical wiring substrate H1300 applies an electrical signal for ejecting ink to the recording element substrate H1100, and has an opening for incorporating the recording element substrate H1100. A plate H1400 is bonded and fixed to the back surface. The electric wiring board H1300 has an electrode terminal H1302 corresponding to the electrode H1103 of the recording element board H1100, and an external signal input terminal H1301 for receiving an electric signal from the recording apparatus main body located at the end of the wiring. Yes.

  The electrical wiring board H1300 and the recording element board H1100 are electrically connected. As the connection method, for example, the electrode H1103 of the recording element substrate H1100 and the electrode terminal H1302 of the electric wiring substrate H1300 are electrically connected by a wire bonding technique using a gold wire H1303 (not shown). As a material of the electrical wiring board H1300, for example, a flexible wiring board having a two-layer structure is used, and a surface layer is covered with a polyimide film.

  The plate H1400 is formed of, for example, a stainless steel plate having a thickness of 0.5 to 1 mm. The material of the plate is not limited to stainless steel, and may be made of a material having ink resistance and good flatness. The plate H1400 has a recording element substrate H1100 that is adhesively fixed to the support plate H1200 and an opening for taking in the recording element substrate, and is adhesively fixed to the support plate.

  A groove formed by the opening H1402 of the plate and the side surface of the recording element substrate H1100 is filled with the first sealant H1304, and the electrical mounting portion of the electrical wiring substrate H1300 is sealed. Further, the electrode H1103 of the recording element substrate is sealed with a second sealant H1305 to protect the electrical connection portion from corrosion by ink and external impact. A filter member H1600 for removing foreign matter mixed in the ink is bonded and fixed to the back surface side ink supply port H1201 of the support plate H1200.

  The ink supply member H1500 is formed by resin molding, for example, and includes a common liquid chamber H1501 and a Z-direction reference surface H1502. The Z reference plane H1502 positions and fixes the recording element unit and serves as the Z reference for the recording head H1000.

  As shown in FIG. 2, the recording head H1000 is completed by coupling the recording element unit H1001 to the ink supply member H1500. The coupling is performed as follows. The opening of the ink supply member H1500 and the recording element unit H1001 are sealed with a third sealant H1503, and the common liquid chamber H1501 is sealed. Then, the Z reference H1502 of the recording element unit H1001 is positioned and fixed to the Z reference H1502 of the ink supply member by, for example, a screw H1900. The third sealant H1503 is desirably a sealant that has ink resistance, is cured at room temperature, and can withstand the linear expansion difference between different materials.

  Further, the external signal input terminal H1301 portion of the recording element unit H1001 is positioned and fixed on, for example, the back surface of the ink supply member H1500.

  As shown in FIG. 5, the ink jet recording apparatus M4000 according to the embodiment of the present invention includes, for example, recording heads for six colors corresponding to photographic image quality recording. The recording head H1000Bk is a recording head for black ink, the recording head H1000C is for cyan ink, the recording head H1000M is for magenta ink, and the recording head H1000Y is for yellow ink. Further, the recording head H1000LC is for light cyan ink, and the recording head H1000LM is for light magenta ink. These recording heads H1000 are fixedly supported by positioning means and electrical contacts M4002 of the recording head mounting portion M4001 mounted on the recording apparatus main body M4000.

  These recording heads H1000 are controlled by a drive circuit (not shown) to perform recording on a recording medium. The recording apparatus of FIG. 5 is a full line type in which the recording head has ejection openings corresponding to the width of the recording medium, the recording head is fixed, and the recording medium scans in the direction of the arrow (conveyed by the conveying means). This is a recording method. On the other hand, the recording apparatus of FIG. 6 has a serial drive system in which a recording head is mounted on a carriage as the head mounting portion M4001, and recording is performed while the carriage reciprocates in the main scanning direction (carriage moving direction). Recording device.

  Next, in the inkjet recording head of the present invention, a plurality of recording element substrates each having an ejection port array composed of a plurality of ejection ports for ejecting ink are arranged on a support plate along the ejection port array direction. It is what. And the inkjet recording head demonstrated in each following embodiment has the structure which has arranged the heat pipe inside the support plate.

(First embodiment)
7A is a longitudinal sectional view of the ink jet recording head according to the first embodiment of the present invention, and FIG. 7B is a transverse sectional view taken along VIIB-VIIB of FIG. 7A. On the support plate H1200, four recording element substrates H1100a, H1100b, H1100c, and H1100d are mounted in a staggered arrangement.

  FIG. 8 is a diagram schematically showing only the support plate H1200 of FIG. 7B. The support plate H1200 is composed of two plate-like members, and each is bonded together with an adhesive to form one substrate. Three grooves are independently formed on the opposite side of the first support plate H1200-1 from the recording element substrate placement surface, and the second support plate H1200-2 is bonded to cover each groove. And a passage H2001 as an installation space for installing the heat pipe H2000. The heat pipe installation passage H2001 has a cross section of a width of 4.2 mm and a depth of 2.2 mm, and a heat pipe H2000 having a cross section of a width of 4 mm and a thickness of 2 mm and a flat cross section is disposed in the passage H2001. The heat pipe H2000 was fixed to the support plate H1200 by filling the gap between the passage H2001 and the heat pipe H2000 with a silicon adhesive.

  In the case where only the heat pipe H2000 is installed, it is possible to equalize the temperature of the entire recording head support plate H1200. Depending on the conditions at the time of recording execution, there is a case where cooling of the support plate H1200 is not necessary, so that an effect can be expected for recording execution that is not high-speed recording but high-definition recording.

  In addition, when performing continuous high-speed recording, it is necessary to have a cooling function. As shown in FIG. 7A, one side of the heat pipe extends from the support plate and is connected to a cooling member such as a heat sink. It is also possible to cool. In this case, it is possible to have both the effects of soaking and cooling the recording head, resulting in an excellent configuration. In that case, it is necessary to install a heat sink in the recording apparatus or the like.

  With the configuration described above, the heat pipe H2000 can be disposed near the recording element substrate that is a heat source, so that the temperature range in the recording head can be reduced. In addition, since the heat pipe is connected to a cooling member such as a heat sink, the temperature rise of the recording head can be suppressed.

(Second Embodiment)
FIG. 9A is a longitudinal sectional view of an ink jet recording head according to the second embodiment of the present invention, and FIG. 9B is a transverse sectional view taken along the line IXB-IXB in FIG. In the present embodiment, the heat pipe H2000 and the cooling medium flow path H2002-2 are formed inside the support plate H1200. In the present embodiment, the heat pipe H2000 is arranged on the recording element substrate H1100 side inside the support plate H1200, and the heat pipe H2000 and the flow path H2002-2 are arranged so that they overlap in the thickness direction of the support plate H1200. Provided. That is, the recording element substrate H1100, the passage H2001 as an installation space in which the heat pipe H2000 is provided, and the flow path H2002-2 are arranged in this order along the thickness direction of the support plate H1200.

  FIG. 10 is a diagram schematically showing only the support plate H1200 of FIG. 9B. The support plate H1200 is composed of three members, and each is bonded to each other with an adhesive to constitute one substrate. Three grooves are independently formed on the side opposite to the recording element substrate placement surface of the first support plate H1200-1, and the heat pipe H2000 is installed by bonding the second support plate H1200-2. A passage H2001 as an installation space is formed. The third support plate H1200-3 is also formed with three independent grooves, and is bonded to the second support plate H1200-2 to form a flow path H2002-2 so that the cooling medium can flow. Yes.

  The shape of the groove for installing the heat pipe and the shape of the heat pipe to be used are the same as those in the first embodiment described above. By filling the gap between the passage H2001 and the heat pipe H2000 with a silicon adhesive, the heat pipe H2000 is formed. It fixed with respect to the support plate H1200. In the present embodiment, the cross section of the flow path H2002-2 has a width of 3 mm and a depth of 2 mm. The flow rate of the cooling liquid was about 20 ml / min to 100 ml / min. This flow rate may be an appropriate flow rate suitable for the conditions depending on the printing execution conditions and the print head specifications.

  As the heat pipe H2000, a commercially available heat pipe can be used. The shape is not particularly limited as long as a sufficient contact area with the support plate H1200 can be secured. Preferably, in view of the workability of the groove and the structure of the recording head, a type in which the heat pipe is crushed into a flat shape is easy to use. Moreover, the material which fills the clearance gap between the heat pipe H2000 and the support plate H1200 can be used if it has high thermal conductivity and is stable. A silicon-based adhesive can be used as such a material.

  The material of the support plate H1200 is preferably a material having ink resistance and good thermal conductivity, such as a ceramic material or a carbon graphite material. Among the ceramic materials, alumina is relatively inexpensive and rigid, and is optimal for a long recording head in which warping or waviness of the recording head is likely to be a problem. Further, an alumina substrate obtained by laminating and firing green sheets is preferable because it can be manufactured at low cost even for complicated structures such as the present invention. For this reason, the heat pipe can be arranged without using an adhesive serving as a heat insulating material, which is more preferable from the viewpoint of cooling and soaking the recording head.

  As for the arrangement of the heat pipes H2000 and the cooling flow paths in the support plate H1200, it is preferable that the heat pipes H2000 and the cooling flow paths H2004 are as close as possible to the recording element substrate H1100 that is a heat source. It is necessary to make the temperature distribution of the support plate H1200 partially raised by the temperature rise of the recording element substrate H1100 used for recording so as to equalize the temperature with the heat pipe H2000 with high heat exchange efficiency and to be cooled by the coolant. is there. Therefore, a configuration like this embodiment in which the heat pipe H2000 is arranged as close as possible to the recording element substrate H1100 side in the support plate H1200 and the cooling flow path is formed with the partition layer interposed therebetween is preferable.

  With such a configuration, the temperature range in the recording head can be reduced, and the temperature rise can be suppressed. Therefore, even when the electrothermal conversion elements H1102 are arranged at high density and recording is performed at high speed, partial density unevenness and non-ejection can be reduced, and high-quality images can be recorded at high speed. become.

  In addition, the configuration using the heat pipe and the cooling flow path as in this embodiment together with the heat sink as shown in the first embodiment can improve the cooling efficiency, so that it is optimal. It becomes the composition.

  The cooling medium that can be suitably used in the present invention includes water, ink, air, nitrogen gas, and the like, and particularly when temperature-adjusted medium is circulated and used, temperature management and control are easy. Become. Further, when the cooling flow path is divided into a plurality of parts, the temperature of the recording head can be finely controlled according to the flow direction of the coolant and the number of flow paths used.

  FIG. 13 shows a recording immediately after execution of full-frame recording on 50 sheets of A4 size paper by the recording heads of the first and second embodiments of the present invention and the conventional inkjet recording head without heat pipe and cooling. It is the graph which showed head temperature (increase). Of the four chips, the recording element substrate H1100 used was H1100-a and H1100-b, and H1100-c and H1100-d were not used. As a result of this test, in the conventional ink jet recording head, the recording element substrates of H1100-a and H1100-b reached a high temperature, the recording head temperature continued to rise, and finally ejection failure occurred. In the inkjet recording head to which the present invention is applied, the used H1100-a and H1100-b and the unused H1100-c and H1100-d are soaked at almost the same temperature, and the temperature rise is about 50 sheets. Therefore, it was suppressed to about half of the conventional inkjet recording head. Further, no discharge occurred even when recording was continued.

  The temperature rise (ΔT) varies depending on the heat transport amount of the heat pipe, the shape of the cooling groove, the flow rate of the cooling water, and the temperature, but it is optimal depending on the specifications such as the arrangement and discharge rate of the electrothermal conversion element of the ink jet recording head used. Make the conditions appropriate.

(Third embodiment)
FIG. 11 is a diagram schematically showing a support plate H1200 in the ink jet recording head according to the third embodiment of the present invention. In the present embodiment, the alumina support plate H1200 of the ink jet recording head of the second embodiment is changed to a laminated structure formed by laminating and firing green sheets. In this configuration, since it is not necessary to form the support plate H1200 with an adhesive having poor thermal conductivity, the substrate can be configured only with alumina having high thermal conductivity. In this embodiment, compared to the second embodiment, The temperature rise of the recording head can be suppressed.

(Fourth embodiment)
FIG. 12 is a diagram schematically showing a support plate H1200 in the ink jet recording head according to the fourth embodiment of the present invention. In this embodiment, the number of heat pipes and cooling channels is reduced. Although the heat exchange efficiency is reduced by reducing the number of heat pipes and cooling channels to two each, the flow channel system has a simple configuration, leading to downsizing and cost reduction of the recording head.

(Fifth embodiment)
FIG. 14A is a longitudinal sectional view showing the recording head of this embodiment, and FIG. 14B is a transverse section taken along line XIVB-XIVB in FIG. On the support plate H1200, four recording element substrates H1100a, H1100b, H1100c, and H1100d are mounted in a staggered arrangement.

  The support plate H1200 is composed of two members, and each member is bonded by an adhesive. Three grooves are independently formed on the surface of the first support plate H1200-1 opposite to the recording element substrate arrangement surface. A groove H2001 for installing the heat pipe H2000 is formed by bonding the second support plate H1200-2 here. The cross section of the heat pipe installation groove was 4.2 mm wide and 2.2 mm deep, and a flat heat pipe having a cross sectional shape of 4 mm wide and 2 mm thick was fixed to the bottom and side surfaces of the groove H2001 with a silicon adhesive. That is, the cross-sectional area of the heat pipe in the arrangement direction of the plurality of recording element substrates is smaller than the cross-sectional area of the passage where the heat pipe is arranged.

  Three independent grooves H2002-5 are formed on the lower surface of the second support plate H1200-2 at positions facing the grooves H2001 along the direction of the discharge port array, that is, the arrangement direction of the electrothermal transducers H1102. ing. The cross-sectional dimensions of this groove were also 4.2 mm wide and 2.2 mm deep. As described above, the heat pipe H2000 is installed below the passage H2003 formed by the groove H2001 and the groove H2002-5.

  On the other hand, the heat pipe H2000 is provided on the side close to the recording element substrate H1100 in the passage H2003 formed by the groove H2001 and the groove H2002-5. Therefore, in the passage H2003, a space with a height of more than 2 mm remains above the heat pipe H2000. In this space, for example, a coolant such as water can flow. That is, the space inside the passage H2003 formed by the two grooves H2001 and H2002-5, where the heat pipe H2000 does not exist, becomes the coolant flow path (cooling flow path) H2004. In other words, inside the support plate H1200, the recording element substrate H1100, the passage H2003, and the flow path H2004 are arranged in this order along the thickness direction of the support plate H1200. In this way, the heat pipe H2000 and the cooling flow path H2004 are arranged inside the support plate H1100 along the direction of the discharge port array (the arrangement direction of the electrothermal conversion elements H1102).

  The flow rate of the cooling liquid is about 20 ml / min to 100 ml / min. Of course, the flow rate may be an appropriate flow rate depending on the recording execution conditions and the recording head specifications. A configuration as shown in FIG. 14 is preferred in which the heat pipe H2000 is arranged as close as possible to the recording element substrate H1100 side in the support plate H1200, and the cooling flow path H2004 is formed so that the heat pipe H2000 can be directly cooled.

  In the present embodiment, since the heat pipe is directly cooled by the coolant, the cooling effect can be further enhanced as compared with the configuration in which the heat pipe and the cooling flow path are independently arranged.

  FIG. 15 shows a recording immediately after execution of full borderless recording on 50 sheets of A4 size paper by the recording heads of the fifth to seventh embodiments of the present invention and the conventional inkjet recording head without heat pipe and cooling. It is the graph which showed head temperature (increase). Of the four chips, the recording element substrate H1100 used was H1100-a and H1100-b, and H1100-c and H1100-d were not used. As a result of this test, in the conventional ink jet recording head, the recording element substrates of H1100-a and H1100-b reached a high temperature, the recording head temperature continued to rise, and finally ejection failure occurred. In the inkjet recording head to which the present invention is applied, the used H1100-a and H1100-b and the unused H1100-c and H1100-d are soaked at almost the same temperature, and the temperature rise is about 50 sheets. Therefore, it was suppressed to about half of the conventional inkjet recording head. Further, no discharge occurred even when recording was continued.

(Sixth embodiment)
FIG. 16 is a cross-sectional view showing the recording head of this embodiment. The ink jet recording head of this embodiment is an embodiment in which the number of passages H2003 passing through the heat pipe H2000 and the cooling flow path H2004 is reduced as compared with the fifth embodiment. Other than that, it is the same structure including that the flow path for heat pipe cooling is arranged inside the support plate along the direction of the discharge port array (the arrangement direction of the electrothermal conversion elements). By reducing the number of the passages H2003 from three to two, the heat exchange efficiency is lowered, but the flow path system has a simple configuration, which leads to downsizing and cost reduction of the recording head.

  As shown in FIG. 15, in the ink jet recording head of this embodiment, the temperature is saturated by recording about 50 sheets of paper, and thereafter, the temperature of the recording head does not increase even if recording is continued. In addition, the temperature difference in the length direction of the recording head could be suppressed to a level with no problem.

(Seventh embodiment)
FIG. 17 is a cross-sectional view showing the recording head of this embodiment. In the recording head of this embodiment, the two heat pipes on both sides of the three passages of the fifth embodiment are arranged so that the cross section thereof is vertically long (direction approaching the recording element substrate). Other than that, it is the same structure including that the flow path for heat pipe cooling is arranged inside the support plate along the direction of the discharge port array (the arrangement direction of the electrothermal conversion elements).

  Specifically, in this embodiment, the flat outer peripheral surface of the heat pipe H3000-2 is in contact with the inner side surface of the groove H3001 of the support plate H3200-1. By adopting such a configuration, it is possible to reduce the width dimension of the head in the short direction (direction intersecting the ejection port array).

  As shown in FIG. 15, the ink jet recording head of this embodiment was able to obtain a temperature rise characteristic substantially equivalent to that of the ink jet recording head of the fifth embodiment.

(Eighth embodiment)
FIG. 18A is a longitudinal sectional view showing the recording head of this embodiment, and FIG. 18B is a transverse sectional view taken along line XVIIIB-XVIIIB in FIG. The recording head of this embodiment is provided with irregularities on the inner surface of the flow path H2002-8 of the cooling medium in the recording head of the second embodiment. In other words, the cross section of the flow path H2002-8 in the arrangement direction of the plurality of recording element substrates has a concave shape. As for the second support plate H1200-2, it is possible to manufacture a concavo-convex shape, which is a complicated shape, at low cost by using an alumina substrate obtained by laminating and firing green sheets as described above.

  Thus, by making the cross section of the flow path H2002-8 into a concave shape, the surface area of the flow path H2002-8 can be increased, and a greater cooling effect can be achieved in a limited space.

(Ninth embodiment)
FIG. 19A is a longitudinal sectional view showing the recording head of this embodiment, and FIG. 19B is a transverse sectional view taken along line XIXB-XIXB in FIG. 19A. The recording head of this embodiment is provided with irregularities on the inner surface of the flow path H2002-9 of the cooling medium in the recording head of the fifth embodiment. Thus, the surface area can be increased by making the cross section of the flow path H2002-9 uneven, and a greater cooling effect can be achieved in a limited space. Similar to the eighth embodiment, with respect to the second support plate H1200-2, an uneven shape which is a complicated shape can be manufactured at low cost by using an alumina substrate obtained by laminating and firing green sheets.

  In this embodiment, since the heat pipe is directly cooled by the coolant, the cooling effect can be further enhanced as compared with the eighth embodiment.

  FIG. 20 is a diagram showing an example of a cooling system liquid circulation system used in each embodiment of the present invention. The cooling water is sent to the cooling liquid supply port of the recording head by the pump M4003, and returns to the constant temperature bath M4004 again through the cooling flow path in the head. The control device M4005 controls the temperature of the recording head to be suppressed by flowing a cooling liquid into the cooling flow path of the recording head. This control device M4005 is used for detecting conditions such as the flow rate of cooling water, inlet temperature, outlet temperature, head temperature (recording element substrate built-in sensor, etc.), environmental temperature, etc., the amount of heat exhausted from the head by the coolant, and recording conditions. The cooling conditions are set from the head to control the head temperature. Specifically, by independently controlling at least one of the liquid flow direction, fluid temperature, and flow velocity, it is possible to more effectively suppress the temperature rise and temperature unevenness of the recording head.

  When a recording liquid is used as a cooling medium, the number of tanks can be reduced to one and the size of the recording apparatus can be reduced as compared with a method using another medium.

1 is an external perspective view of a recording head of the present invention. FIG. 3 is an exploded perspective view of the recording head of the present invention. FIG. 3 is an exploded perspective view of a recording element unit. (A) is a perspective view explaining a recording element board | substrate, (b) is IVB-IVB sectional drawing in (a). 1 is a diagram illustrating a full-line inkjet recording apparatus. FIG. 1 is a diagram illustrating a serial drive type ink jet recording apparatus. FIG. (A) is a longitudinal cross-sectional view of the recording head concerning the 1st Embodiment of this invention, (b) is a cross-sectional view in (IB) -VIIB of (a). It is the figure which showed typically only the support plate H of FIG.7 (b). (A) is a longitudinal cross-section of the inkjet recording head which concerns on the 2nd Embodiment of this invention, (b) is a cross-sectional view in IXB-IXB of (a). It is the figure which showed typically only the support plate of FIG.9 (b). It is the figure which showed typically the support plate in the inkjet recording head which concerns on the 3rd Embodiment of this invention. It is the figure which showed typically the support plate in the inkjet recording head which concerns on the 4th Embodiment of this invention. 6 is a graph showing recording head temperatures of the recording heads of the first and second embodiments of the present invention and a conventional inkjet recording head. (A) is the longitudinal cross-sectional view which showed the recording head of 5th Embodiment, (b) is the cross section in XIVB-XIVB of (a). 6 is a graph showing recording head temperatures of a recording head according to fifth to seventh embodiments of the present invention and a conventional inkjet recording head. FIG. 10 is a cross-sectional view illustrating a recording head according to a sixth embodiment. FIG. 10 is a cross-sectional view illustrating a recording head according to a seventh embodiment. (A) is the longitudinal cross-sectional view which showed the recording head of 8th Embodiment, (b) is a cross-sectional view in XVIIIB-XVIIIB of (a). (A) is the longitudinal cross-sectional view which showed the recording head of 9th Embodiment, (b) is the cross-sectional view in XIXB-XIXB of (a). It is the figure which showed an example of the liquid circulation system of the cooling system used for each embodiment of this invention.

Explanation of symbols

H1000 recording head H1001 recording element unit H1100 recording element substrate H1104 ink flow path H1110 discharge port plate H1200 support plate H1300 electric wiring board H1302 electrode terminal H1400 plate H1500 ink supply member H1501 common liquid chamber H2000 heat pipe H2001 installation space H2004 cooling flow path

Claims (11)

An inkjet recording head provided with a plurality of ejection openings for ejecting ink is
A recording element substrate including an ejection port array in which a plurality of ejection ports are arranged, and provided with an element that generates thermal energy for ejecting ink from the plurality of ejection ports;
A support plate having a surface for supporting the recording element substrate;
A passage provided inside the support plate and provided with a heat pipe;
A flow path provided for flowing a cooling liquid inside the support plate,
In a region overlapping the recording element substrate in a direction perpendicular to the surface of the support plate, the recording element substrate, the passage, and the flow path are provided in this order in the thickness direction of the support plate. An ink jet recording head. The inkjet recording head according to claim 1, wherein the passage and the flow path are arranged along an arrangement direction of the plurality of ejection openings. Said passage and said flow passage is an ink jet recording head according to claim 1 or 2, characterized in that it is independently provided on the recording element substrate. Regarding the cross-section in the arrangement direction, the heat pipe has a cross-sectional area smaller than the cross-sectional area of the passage,
The inkjet recording head according to claim 2, wherein a portion of the passage other than the heat pipe is used as the flow path. The support plate, the ink jet recording head according to any one of claims 1 to 4, characterized in that it is constituted by a ceramic material. The support plate is laminated green sheets, the ink jet recording head according to any one of claims 1 to 5, characterized in that it is formed by firing stacked the supporting plate. The inkjet recording head according to claim 2 , wherein a shape of a cross section of the flow path in the arrangement direction is an uneven shape . The other path provided in the support plate, different from the path, including the heat pipe arranged along the arrangement direction; and
The flow path further includes a flow path different from the flow path, which is provided to flow a cooling liquid inside the support plate, and is disposed along the arrangement direction. ,
With respect to the direction crossing the arrangement direction, the are two said further passage and the further passage on both sides respectively provided passages, the different passages of the support plate than said another flow path The ink jet recording head according to claim 2 , wherein the ink jet recording head is disposed inside. The inkjet recording head according to claim 1, comprising a plurality of the recording element substrates. The inkjet recording head according to claim 9 , wherein the plurality of recording element substrates are arranged in a staggered pattern along the arrangement direction of the plurality of ejection openings on the support plate. An inkjet recording apparatus comprising: the inkjet recording head according to any one of claims 1 to 10 ; and a transport unit that transports a recording medium.
An ink jet recording apparatus comprising means for flowing a cooling liquid through the flow path.

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