JP5294615B2 - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the temperature rise of a head due to the speeding-up and the densifying of recording. <P>SOLUTION: In the inkjet recording head, in which a plurality of recording element board H1100 having delivery port trains composing of a plurality of delivery ports H1105 for delivering ink therethrough are arranged among the direction of the delivery port train on a supporting plate, flow passages H2001 are provided apart from ink flow passages H1104 to the recording element board extending along the arranging direction of a plurality of the recording element boards arranged on the supporting plate H1200. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

The present invention is related to an ink jet recording apparatus which performs a recording operation by discharging ink.

  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 head having a length of 4 inches to 13 inches or the like has been required.

  As the head becomes longer and faster in this way, the energy input to the head increases and the head temperature rises during recording. 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 head is cooled by air cooling from the outside of the head or mounting a cooling pipe on the head.
JP-A-8-276575

  However, in the conventional method, the cooling pipe is attached to the head or the cooling member is attached to the member forming the ink liquid chamber for cooling, so the distance from the cooling unit to the ink supply port in the vicinity of the recording element substrate is small. It was long. For this reason, the cooling efficiency is lowered, so that sufficient cooling cannot be performed. Therefore, temperature rise becomes a problem for speeding up and improvement of continuous recording performance, and it is a problem to suppress this.

  Accordingly, an object of the present invention is to provide a head with high recording reliability in view of the above-described problems of the prior art.

To achieve the above object, the present invention provides a plurality of recording element substrates each having an ejection port array comprising a plurality of ejection ports for ejecting ink, and the plurality of the plurality of recording element substrates arranged along the direction of the ejection port array. an ink jet recording apparatus odor having an ink jet recording head comprising a support plate for supporting the recording element substrate, the Te, and extend along the direction of the ejection opening array, the ink flow path for flowing the ink supplied to the recording element substrate In the case where the difference between the recording duty at the both ends of the inkjet recording head with respect to the direction of the discharge port array and the plurality of flow paths for flowing the fluid for cooling the inkjet recording head is relatively small , At least one of the flow paths, the fluid is allowed to flow from one end side to the other end side of the both ends, and at least one other than the at least one flow path. When a fluid flows from the other end side to the one end side in one of the flow paths, and the difference in recording duty at the both end portions is relatively large, And control means capable of controlling a fluid to flow from one end side having a high recording duty to the other end side having a low recording duty .

  According to the present invention, it is possible to provide an ink jet recording head capable of more efficiently dissipating heat from a recording element substrate. Further, the ink supplied to the recording element substrate can be efficiently cooled. As a result, it is possible to suppress an increase in the recording head temperature due to high-speed and high-density recording, and it is possible to greatly improve the reliability in continuous recording.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIGS. 1 to 11 show a plurality of recording element substrates each having an ejection port array composed of a plurality of ejection ports for ejecting ink, arranged on a support plate along the row direction of the ejection ports. FIG. 2 is an explanatory diagram for explaining a recording head and an ink jet recording apparatus that are used. In particular, the ink jet recording head of the present invention has a flow path for flowing liquid separately from the ink flow path to the recording element substrate, which extends along the arrangement direction of the plurality of recording element substrates arranged on the support plate. Is provided.

  Hereinafter, the entire configuration will be described with reference to these drawings while describing the configuration of each part.

  The recording head H1000 shown in FIG. 1 performs recording using an electrothermal transducer that generates thermal energy for generating film boiling for 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.

  FIG. 4A is a diagram for explaining the configuration of the recording element substrate H1100, and FIG. 4B is a cross-sectional view taken along line AA 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 rectangular 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, a flow path forming member H1110 is provided on the Si substrate H1108, and an ink flow path H1104, a discharge 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 array 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 array 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 array H1106a and the discharge port array 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 SUS plate having a thickness of 0.5 to 1 mm. The material of the plate is not limited to SUS, 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 the back surface of the ink supply member H1501, for example.

  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. H1800Bk is black ink, H1800C is cyan ink, H1800M is magenta ink, H1800Y is yellow ink, H1800LC is light cyan ink, and H1800LM is light magenta ink. 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 a carriage M4001 mounted on the recording apparatus main body M4000.

  These recording heads are controlled by a drive circuit (not shown) to perform recording on the recording medium K1000. In the recording apparatus of FIG. 5, the recording head is a full-line type having an ejection port array corresponding to the width of the recording medium, and the recording head is fixed and performs recording by scanning the recording medium in the direction of the arrow. is there.

  On the other hand, the recording apparatus of FIG. 6 is a serial drive type recording apparatus in which the recording head performs recording while reciprocating in the main scanning direction (carriage movement direction).

  FIG. 7 is a diagram schematically showing a partial cross section of the recording head according to the embodiment of the present invention.

  The support plate is composed of two members, and at least one of the support plates is provided with a groove through which the cooling liquid passes, and a cooling flow path is formed by bonding the two plates together. The inlet / outlet of the cooling liquid is taken out on the opposite side of the ink supply member from the recording element substrate (not shown). Three cooling channels H2001 are formed so that the coolant can flow independently. That is, a plurality of flow paths provided on the support plate are provided independently. The cross section of the cooling flow path H2001 is 2 mm wide and 1.5 mm deep in this embodiment. The flow rate of the cooling liquid is 20 ml / min to 100 ml / min. This flow rate is set according to the recording conditions and head specifications (power, discharge amount, etc.). A common ink liquid chamber is provided on the side of the support plate opposite to the recording element substrate, and ink is supplied to the recording element substrate substrate through each ink supply port provided in the support plate.

  In this way, when the cooling flow path is divided into a plurality, the head temperature can be finely controlled depending on the flow direction of the cooling liquid, the number of lines used, and the like.

For example, as shown in FIG. 8 (a), in the case of substantially uniform recording data, one of the fluid flow directions is reversed in the three flow paths. Since the upstream side is easy to cool, a temperature distribution is generated. However, by changing the flow direction, it acts in a direction to cancel the distribution, and cooling can be performed while keeping the distribution uniform. The same effect can be expected by adjusting the flow rate and the coolant inlet temperature.

Further, when the offset to either the recording data as shown in FIG. 8 (b), it is also possible to control was all the same direction a flow of cooling fluid to higher recording duty as an upstream temperature.

  The material of the support substrate is preferably a material having ink resistance and good thermal conductivity, such as alumina or carbon graphite.

FIG. 9 shows a comparison of temperature rise between the present invention and a head without water cooling. Under the conditions of this example, in the case of no water cooling, a high image temperature was reached by solid image recording of about 50 A4 size borderless images, and the head temperature continued to rise and discharge failure occurred. In the method of the present invention, the head temperature is saturated at about 50 A4 size under the same recording conditions, and the head temperature does not increase even if recording is continued thereafter. The temperature rise depends on the shape of the cooling channel, the flow rate of the cooling water, and the temperature, and the optimum conditions are set according to the specifications of the head used.

10 (a) to 10 (d) show another embodiment of the present invention.
FIG. 10A shows the three cooling channels H2001 of the first embodiment as a single cooling channel h2001. Although the three cooling channels H2001 cannot be controlled independently, the channel structure is simplified by using one cooling channel H2001.
FIG. 10B shows an embodiment in which the reciprocating flow path type is further simplified.
FIG. 10C shows a more efficient cooling of the ink flowing through the coolant around the ink supply port H1201 to each recording element substrate.
FIG. 10 (d) has basically the same flow path configuration as the embodiment of FIG. 10 (c), but the embodiment of FIG. 10 (c) allows the coolant to flow in two systems. On the other hand, it is simplified to one system.

FIG. 11 shows a cooling system of an embodiment according to the present invention.
The cooling water is sent to the coolant supply port H2002 of the recording head by the pump M4003, and returns to the constant temperature bath M4004 through the in-head cooling flow path H2001. The control device M4005 controls the temperature of the recording head to be suppressed by flowing a cooling liquid into the cooling flow path H2001 of the recording head. This control device M4005 is provided with various conditions such as detection data such as cooling water flow rate, inlet temperature, outlet temperature, head temperature (recording element substrate built-in sensor, etc.), environmental temperature, 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. In addition, when the control device M4005 controls at least one of the cooling liquid flow direction, the fluid temperature, and the flow velocity independently for each of the plurality of cooling flows H2001, Fine control according to the difference in recording duty can be performed.

1 is an external perspective view of a recording head according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a recording head according to an embodiment of the present invention. FIG. 3 is an exploded perspective view of a recording element unit. 2A and 2B are diagrams illustrating a recording element substrate, in which FIG. 1A is a perspective view, and FIG. It is a figure explaining an inkjet recording device (full line system). It is a figure explaining an inkjet recording device (serial drive system). It is a cross-sectional schematic diagram of the recording head of the Example of this invention. It is a figure explaining the recording duty of the Example of this invention, and the flow direction of a cooling fluid. It is a figure explaining the temperature rising suppression effect of the Example of this invention. It is a schematic diagram of the other Example of this invention. It is the schematic of the cooling system of the Example of this invention.

Explanation of symbols

H1000 recording head H1001 recording element unit H1002 ink supply unit H1100 recording element substrate H1101 ink supply port H1102 electrothermal transducer H1104 ink flow path H1105 discharge port H1200 support plate H1201 ink supply port H2001 cooling flow path

Claims (2)

A plurality of recording element substrates having a discharge port array comprising a plurality of discharge ports for discharging ink, and a support plate for supporting the plurality of recording element substrates which are arranged along the direction of the ejection opening array, the an ink jet recording apparatus odor having an ink jet recording head comprising Te,
A plurality of flow paths extend, where different from the ink flow path for flowing the ink supplied to the recording element substrate, flowing a fluid for cooling the ink jet recording head along the direction of the ejection opening array,
When a difference in recording duty at both ends of the inkjet recording head with respect to the direction of the ejection port array is relatively small, at least one of the flow paths from one end to the other end of the both ends The fluid flows to the one end side from the other end side in at least one of the flow paths different from the at least one flow path, and the difference in recording duty at the both end portions is relatively large. In the case, in the plurality of flow paths, control means capable of controlling the fluid to flow from one end side having a high recording duty to the other end side having a low recording duty among the both end portions;
An ink jet recording apparatus comprising: A plurality of recording element substrates each having an ejection port array composed of a plurality of ejection ports for ejecting ink; and a support plate for supporting the plurality of recording element substrates arranged along the direction of the ejection port array. In an inkjet recording apparatus having an inkjet recording head comprising:
A plurality of flow paths that flow along a direction of the ejection port array and that flow a fluid for cooling the inkjet recording head, different from an ink flow path that flows the ink supplied to the recording element substrate;
When the difference in temperature at both ends of the inkjet recording head with respect to the direction of the ejection port array is relatively small, from one end side to the other end side of the both ends in at least one of the flow paths. When flowing a fluid, flowing the fluid from the other end side to the one end side in at least one flow path different from the at least one flow path, and when the temperature difference between the both ends is relatively large Is a control means capable of controlling the fluid to flow from one end having a high temperature to the other end having a low temperature among the both ends in the plurality of flow paths;
An ink jet recording apparatus comprising:

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