JP6498252B2 - Liquid discharge head and liquid discharge apparatus - Google Patents

Description

  The present invention relates to a liquid ejection head and a liquid ejection apparatus capable of ejecting liquid such as ink from ejection ports.

  In the ink-jet field in which recording is performed by discharging a liquid such as ink, recording applications have been diversified in recent years, and the demand for high-definition and high-quality recording has further increased. A method for increasing the resolution of recording by arranging a plurality of discharge ports at a high density is known for high definition of recording. In addition, in order to realize further high-quality recording, it is necessary to suppress the increase in the viscosity of the ink due to moisture evaporation from the discharge port, which causes a decrease in the discharge speed of the droplets and the modulation of the color material density. Yes.

  As a method for suppressing ink thickening due to moisture evaporation from the discharge port, the ink in the pressure chamber in which the discharge port is disposed is forced to flow, so that the thickened ink staying in the pressure chamber is removed. A method of draining is known. However, when the variation in the circulation flow rate of the ink flowing through each pressure chamber increases or the variation in the pressure of each pressure chamber increases, the difference in discharge characteristics and color material concentration between the discharge ports increases. was there. In order to solve this problem, Patent Document 1 discloses a flow path resistance of a pressure chamber, a flow path resistance of a flow path for supplying ink to the pressure chamber, and a flow path of a flow path for discharging ink from the pressure chamber. A method for keeping the resistance to 1/100 or less is described.

JP 2009-179049 A

  However, in order to arrange a plurality of discharge ports at high density, if the number of discharge ports constituting the discharge port array is increased or the interval between the discharge port arrays is narrowed, there is a problem with the method of Patent Document 1. I found a certain point. That is, it has been found that it may be difficult to suppress variations in the circulation flow rate of ink flowing in each pressure chamber and variations in pressure in each pressure chamber. As the number of ejection ports constituting the ejection port array increases, the distribution of ejection ports in the row direction of the ejection port array (the direction in which the ejection ports are arranged) becomes wider. Therefore, variations in the circulation flow rate of ink flowing in the pressure chambers and variations in pressure in the pressure chambers are likely to occur between the plurality of pressure chambers arranged in the row direction of the ejection port array. In addition, when a plurality of discharge port arrays are arranged at a high density, the width of the flow channel extending in the column direction of the discharge port columns (the length in the direction in which the plurality of discharge port columns are arranged) in relation to the adjacent flow channels It will be difficult to increase. For this reason, the effect of pressure loss is increased, and variation in the circulation flow rate of ink flowing in each pressure chamber and variation in pressure in each pressure chamber may occur between the plurality of pressure chambers arranged in the row direction of the ejection port array. is there.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to suppress variations in the circulation flow rate and variations in pressure of a liquid flowing in a flow path of a liquid discharge head in which a plurality of discharge ports are arranged at high density.

  The liquid ejection head of the present invention includes first and second recording element substrates each including an ejection port that ejects liquid and a recording element that generates energy for ejecting liquid from the ejection port, and the first recording element substrate. And a support member on which the first and second recording element substrates are arranged in the first direction, wherein each of the first and second recording element substrates has a surface on the support member side. Includes a supply port for supplying liquid from the support member to the first and second recording element substrates, and a recovery for recovering the liquid from the first and second recording element substrates to the support member. The supply port and the recovery port provided in each of the first and second recording element substrates, the supply ports are provided on both end sides in the first direction. It is characterized by That.

According to the present invention, it is possible to suppress variations in the circulation flow rate and pressures of the liquid flowing in the liquid discharge head.

It is the figure which showed schematic structure of the liquid discharge apparatus which discharges a liquid. It is a schematic diagram which shows the 1st circulation form of the circulation path applied to a recording device. It is a schematic diagram which shows the 2nd circulation form of the circulation path applied to a recording device. FIG. 6 is a schematic diagram illustrating a difference in the amount of ink flowing into a liquid ejection head. It is the perspective view which showed the liquid discharge head. FIG. 6 is an exploded perspective view showing each component or unit constituting the liquid discharge head. It is the figure which showed the surface and back surface of each flow path member of a 1st-3rd flow path member. It is the perspective view shown from the surface where the discharge module of (alpha) part of Fig.7 (a) is mounted. It is the figure which showed the cross section in IX-IX of FIG. It is the perspective view and exploded view which showed one discharge module. FIG. 3 is a diagram illustrating a recording element substrate. FIG. 3 is a perspective view showing a cross section of a recording element substrate and a lid member. FIG. 6 is a plan view showing a partially enlarged adjacent portion of a recording element substrate. It is the perspective view which showed the liquid discharge head. It is a perspective exploded view showing a liquid discharge head. It is the figure which showed the 1st flow path member. FIG. 6 is a perspective view illustrating a liquid connection relationship between a recording element substrate and a flow path member. It is the figure which showed the cross section in XVIII-XVIII of FIG. It is the perspective view and exploded view which showed one discharge module. It is a schematic diagram showing a recording element substrate. 1 is a diagram illustrating an ink jet recording apparatus that performs recording by discharging a liquid. FIG. 3 is an exploded view of a main part of the liquid discharge head according to the first embodiment of the present invention. FIG. 3 is an exploded view of a part of the liquid ejection head in the first embodiment. FIG. 3 is a cross-sectional view of a part of the liquid ejection head in the first embodiment. FIG. 3 is an equivalent circuit diagram in which a part of the liquid ejection head in the first embodiment is cut out. FIG. 3 is an equivalent circuit diagram in which a part of the liquid ejection head according to the first embodiment is cut out and a diagram illustrating a pressure distribution in a flow path. FIG. 3 is a top view of a recording element substrate in the first embodiment. 3 is a top transparent view of a part of the liquid ejection head in the first embodiment. FIG. It is an exploded view of the principal part of the liquid discharge head in the 2nd Embodiment of this invention. FIG. 6 is a top view of a recording element substrate in a second embodiment. FIG. 6 is a top transparent view of a part of a liquid ejection head in a second embodiment. It is a figure explaining the dispersion | variation in the circulation flow volume in 2nd Embodiment. It is an exploded view of the principal part of the liquid discharge head in the 3rd Embodiment of this invention. It is an exploded view of the principal part of the liquid discharge head in the 4th Embodiment of this invention. 1 is an overall view of a liquid discharge head to which the present invention can be applied. It is a conceptual diagram explaining an example of the ink supply system of this invention. It is a figure explaining the influence of the dispersion | variation in the flow volume of an ink circulation flow. It is a figure which shows one example of the manufacturing process of the liquid discharge head of this invention. It is a figure explaining the temperature distribution of the recording element board | substrate in 2nd Embodiment. 12 is a schematic explanatory diagram of a liquid ejection apparatus in Application Example 1. FIG. It is a figure explaining the 3rd circulation form. 10 is a diagram illustrating a liquid discharge head in Application Example 1. FIG. 10 is a diagram illustrating a liquid discharge head in Application Example 1. FIG. 10 is a diagram illustrating a liquid discharge head in Application Example 1. FIG. 12 is a schematic explanatory diagram of a liquid ejection apparatus in Application Example 3. FIG. It is a figure explaining the 4th circulation form. 12 is a diagram illustrating a liquid ejection head in Application Example 3. FIG. 12 is a diagram illustrating a liquid ejection head in Application Example 3. FIG.

  Hereinafter, a liquid discharge head and a liquid discharge apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  The liquid discharge head and the liquid discharge apparatus according to the present invention are used in an apparatus such as a printer, a copying machine, a facsimile having a communication system, a word processor having a printer unit, and an industrial recording apparatus combined with various processing apparatuses. Applicable. The liquid discharge head and the liquid discharge apparatus of the present invention can be used for applications such as biochip fabrication and electronic circuit printing, for example.

  Further, each application example and each embodiment described below are appropriate specific examples of the present invention, and thus various technically preferable limitations are attached. However, the present embodiment is not limited to the embodiments of the present specification and other specific methods as long as the concept of the present invention is met.

  Hereinafter, each application example to which the present invention can be applied will be described.

(Application example 1)
(Description of inkjet recording apparatus)
FIG. 1 is a diagram showing a schematic configuration of a liquid ejection apparatus for ejecting a liquid according to the present invention, in particular, an ink jet recording apparatus (hereinafter also referred to as a recording apparatus) 1000 that performs recording by ejecting ink. The recording apparatus 1000 includes a transport unit 1 that transports the recording medium 2, and a line type (page wide type) liquid ejection head 3 that is disposed substantially orthogonal to the transport direction of the recording medium 2, and includes a plurality of recording media. This is a line type recording apparatus that performs continuous recording in one pass while conveying 2 continuously or intermittently. The liquid discharge head 3 includes a negative pressure control unit 230 that controls the pressure (negative pressure) in the circulation path, a liquid supply unit 220 that is in fluid communication with the negative pressure control unit 230, and supply and discharge of ink to the liquid supply unit 220. The liquid connection part 111 used as an exit and the housing 80 are provided. The recording medium 2 is not limited to cut paper but may be a continuous roll medium. The liquid discharge head 3 is capable of full-color recording with cyan C, magenta M, yellow Y, and black K inks, and includes a liquid supply means, a main tank, and a buffer tank, which are supply channels for supplying liquid to the liquid discharge head 3. (See FIG. 2 described later) are fluidly connected. The liquid discharge head 3 is electrically connected to an electric control unit that transmits power and a discharge control signal to the liquid discharge head 3. The liquid path and the electric signal path in the liquid discharge head 3 will be described later.

  The recording apparatus 1000 is an ink jet recording apparatus configured to circulate a liquid such as ink between a tank described later and the liquid ejection head 3. The circulation forms are a first circulation form in which two circulation pumps (for high pressure and low pressure) are circulated on the downstream side of the liquid discharge head 3 and two circulation pumps on the upstream side of the liquid discharge head 3. There is a second circulation form in which (for high pressure, low pressure) is circulated by moving. Hereinafter, the first circulation mode and the second circulation mode of the circulation will be described.

(Description of first circulation mode)
FIG. 2 is a schematic diagram showing a first circulation form of a circulation path applied to the recording apparatus 1000 of this application example. The liquid discharge head 3 is fluidly connected to a first circulation pump (high pressure side) 1001, a first circulation pump (low pressure side) 1002, a buffer tank 1003, and the like. In FIG. 2, for the sake of simplicity, only the path through which one of the inks of cyan C, magenta M, yellow Y, and black K flows is shown. A circulation path is provided in the liquid discharge head 3 and the recording apparatus main body.

  In the first circulation mode, the ink in the main tank 1006 is supplied to the buffer tank 1003 by the replenishment pump 1005, and then to the liquid supply unit 220 of the liquid discharge head 3 through the liquid connection portion 111 by the second circulation pump 1004. Supplied. Thereafter, the ink adjusted to two different negative pressures (high pressure and low pressure) by the negative pressure control unit 230 connected to the liquid supply unit 220 circulates in two flow paths on the high pressure side and the low pressure side. The ink in the liquid discharge head 3 circulates in the liquid discharge head by the action of the first circulation pump (high pressure side) 1001 and the first circulation pump (low pressure side) 1002 downstream of the liquid discharge head 3, and the liquid connection portion 111. Then, the liquid is discharged from the liquid discharge head 3 and returned to the buffer tank 1003.

  A buffer tank 1003 that is a sub tank is connected to the main tank 1006, has an air communication port (not shown) that communicates the inside and outside of the tank, and can discharge bubbles in the ink to the outside. A replenishment pump 1005 is provided between the buffer tank 1003 and the main tank 1006. The replenishment pump 1005 transports ink consumed by ejecting (discharging) ink from the ejection port of the liquid ejection head 3 from the main tank 1006 to the buffer tank 1003, such as recording by ink ejection and recovery of suction.

  The two first circulation pumps 1001 and 1002 draw liquid from the liquid connection portion 111 of the liquid discharge head 3 and flow it to the buffer tank 1003. As the first circulation pump, a positive displacement pump having a quantitative liquid feeding capacity is preferable. Specific examples include a tube pump, a gear pump, a diaphragm pump, and a syringe pump. For example, a general constant flow valve or a relief valve may be arranged at the pump outlet to ensure a constant flow rate. When the liquid discharge head 3 is driven, the first circulation pump (high-pressure side) 1001 and the first circulation pump (low-pressure side) 1002 are operated, so that the inside of the common supply channel 211 and the common recovery channel 212 have a predetermined flow rate, respectively. Ink flows. By flowing ink in this way, the temperature of the liquid discharge head 3 during recording is maintained at an optimum temperature. The predetermined flow rate at the time of driving the liquid discharge head 3 is preferably set to be equal to or higher than a flow rate that can be maintained so that the temperature difference between the recording element substrates 10 in the liquid discharge head 3 does not affect the recording image quality. However, if the flow rate is set too high, the negative pressure difference is increased in each recording element substrate 10 due to the pressure loss of the flow path in the liquid discharge unit 300, resulting in uneven density of the image. Therefore, it is preferable to set the flow rate in consideration of the temperature difference and the negative pressure difference between the recording element substrates 10.

  The negative pressure control unit 230 is provided in a path between the second circulation pump 1004 and the liquid discharge unit 300. The negative pressure control unit 230 controls the pressure downstream of the negative pressure control unit 230 (that is, the liquid discharge unit 300 side) even when the ink flow rate in the circulation system fluctuates due to a difference in the discharge amount per unit area. It operates to maintain a preset constant pressure. As the two negative pressure control mechanisms constituting the negative pressure control unit 230, as long as the pressure downstream of the negative pressure control unit 230 can be controlled with a fluctuation within a certain range around a desired set pressure, Any mechanism may be used. As an example, a mechanism similar to a so-called “pressure reduction regulator” can be employed. In the circulation channel in this application example, the second circulation pump 1004 pressurizes the upstream side of the negative pressure control unit 230 via the liquid supply unit 220. In this way, the influence of the water head pressure on the liquid discharge head 3 of the buffer tank 1003 can be suppressed, so that the layout flexibility of the buffer tank 1003 in the recording apparatus 1000 can be expanded.

  The second circulation pump 1004 may be any pump that has a lift pressure that is equal to or higher than a certain pressure in the range of the ink circulation flow rate that is used when the liquid discharge head 3 is driven, and a turbo pump or a positive displacement pump can be used. Specifically, a diaphragm pump or the like is applicable. Further, instead of the second circulation pump 1004, for example, a water head tank arranged with a certain water head difference with respect to the negative pressure control unit 230 can be applied. As shown in FIG. 2, the negative pressure control unit 230 includes two negative pressure adjustment mechanisms each having a different control pressure. Of the two negative pressure adjustment mechanisms, the relatively high pressure setting side (denoted as H in FIG. 2) and the relatively low pressure setting side (denoted as L in FIG. 2) pass through the liquid supply unit 220, respectively. Thus, the common supply flow path 211 and the common recovery flow path 212 in the liquid discharge unit 300 are connected. The liquid discharge unit 300 is provided with a common supply channel 211, a common recovery channel 212, and individual channels 215 (individual supply channel 213, individual recovery channel 214) communicating with each recording element substrate. A negative pressure control mechanism H is connected to the common supply flow path 211, and a negative pressure control mechanism L is connected to the common recovery flow path 212, and a differential pressure is generated between the two common flow paths. Since the individual flow path 215 communicates with the common supply flow path 211 and the common recovery flow path 212, a part of the liquid passes through the internal flow path of the recording element substrate 10 from the common supply flow path 211. A flow (arrow in FIG. 2) flowing to the common recovery flow path 212 is generated.

  In this way, in the liquid ejection unit 300, a part of the liquid passes through each recording element substrate 10 while flowing the liquid so as to pass through the common supply flow path 211 and the common recovery flow path 212. Flow occurs. Therefore, the heat generated in each recording element substrate 10 can be discharged to the outside of the recording element substrate 10 by the ink flowing through the common supply channel 211 and the common recovery channel 212. Further, with such a configuration, when recording is performed by the liquid ejection head 3, it is possible to cause ink to flow even in ejection ports and pressure chambers where ejection is not performed. As a result, the viscosity of the ink that has increased in viscosity within the ejection port is reduced, thereby suppressing the increase in the viscosity of the ink. Further, the thickened ink and the foreign matter in the ink can be discharged to the common recovery channel 212. For this reason, the liquid discharge head 3 of this application example can perform high-speed and high-quality recording.

(Description of second circulation mode)
FIG. 3 is a schematic diagram illustrating a second circulation form that is a circulation form different from the first circulation form described above, among the circulation paths applied to the recording apparatus of the present application example. The main difference from the first circulation mode described above is that the two negative pressure control mechanisms constituting the negative pressure control unit 230 are both centered on the pressure upstream of the negative pressure control unit 230 and the desired set pressure. It is a point to control with fluctuation within a certain range. Further, the difference from the first circulation mode is that the second circulation pump 1004 acts as a negative pressure source for reducing the pressure downstream of the negative pressure control unit 230. Further, a first circulation pump (high pressure side) 1001 and a first circulation pump (low pressure side) 1002 are arranged on the upstream side of the liquid discharge head 3, and a negative pressure control unit 230 is arranged on the downstream side of the liquid discharge head 3. This is also different.

  In the second circulation mode, the ink in the main tank 1006 is supplied to the buffer tank 1003 by the replenishment pump 1005. Thereafter, the ink is divided into two flow paths, and circulates in the two flow paths on the high pressure side and the low pressure side by the action of the negative pressure control unit 230 provided in the liquid ejection head 3. The ink divided into the two flow paths on the high-pressure side and the low-pressure side is supplied to the liquid discharge head 3 via the liquid connection portion 111 by the action of the first circulation pump (high-pressure side) 1001 and the first circulation pump (low-pressure side) 1002. To be supplied. Thereafter, the ink circulated in the liquid discharge head by the action of the first circulation pump (high-pressure side) 1001 and the first circulation pump (low-pressure side) 1002 passes through the negative pressure control unit 230 and passes through the liquid connection portion 111. It is discharged from the discharge head 3. The discharged ink is returned to the buffer tank 1003 by the second circulation pump 1004.

  In the second circulation mode, the negative pressure control unit 230 changes the pressure on the upstream side of the negative pressure control unit 230 (that is, the liquid discharge unit 300 side) even if the flow rate changes due to the change in the discharge amount per unit area or the like. Is stabilized within a certain range around a preset pressure. In the circulation channel of this application example, the second circulation pump 1004 pressurizes the downstream side of the negative pressure control unit 230 via the liquid supply unit 220. In this way, since the influence of the water head pressure of the buffer tank 1003 on the liquid discharge head 3 can be suppressed, the selection range of the layout of the buffer tank 1003 in the recording apparatus 1000 can be expanded. Instead of the second circulation pump 1004, for example, a water head tank arranged with a predetermined water head difference with respect to the negative pressure control unit 230 can be applied. In the second circulation mode, similarly to the first circulation mode, the negative pressure control unit 230 includes two negative pressure control mechanisms in which different control pressures are set. Of the two negative pressure adjusting mechanisms, the high pressure setting side (denoted as H in FIG. 3) and the low pressure setting side (denoted as L in FIG. 3) pass through the liquid supply unit 220, respectively, in the liquid discharge unit 300. Are connected to the common supply channel 211 or the common recovery channel 212. By making the pressure of the common supply flow path 211 relatively higher than the pressure of the common recovery flow path 212 by two negative pressure adjusting mechanisms, the internal flow paths from the common supply flow path 211 to the individual flow paths 215 and the inside of each recording element substrate 10 A liquid flow that flows to the common recovery channel 212 via the channel is generated.

  In such a second circulation mode, a liquid flow state similar to that in the first circulation mode is obtained in the liquid discharge unit 300, but there are two advantages different from the case of the first circulation mode. The first advantage is that, in the second circulation mode, the negative pressure control unit 230 is disposed downstream of the liquid discharge head 3, so that dust and foreign matters generated from the negative pressure control unit 230 flow into the liquid discharge head 3. There is little concern to do. The second advantage is that in the second circulation mode, the maximum required flow rate supplied from the buffer tank 1003 to the liquid ejection head 3 is smaller than in the first circulation mode. The reason is as follows.

  The total of the flow rates in the common supply channel 211 and the common recovery channel 212 when circulating during recording standby is defined as a flow rate A. The value of the flow rate A is defined as the minimum flow rate required to bring the temperature difference in the liquid discharge unit 300 within a desired range when adjusting the temperature of the liquid discharge head 3 during recording standby. Further, a discharge flow rate when ink is discharged from all the discharge ports of the liquid discharge unit 300 (at the time of full discharge) is defined as a flow rate F (discharge amount per discharge port × discharge frequency per unit time × number of discharge ports).

  FIG. 4 is a schematic diagram illustrating a difference in the amount of ink flowing into the liquid ejection head 3 between the first circulation mode and the second circulation mode. 4A shows the standby time in the first circulation mode, and FIG. 4B shows the full discharge time in the first circulation mode. FIGS. 4 (c) to 4 (f) show the second circulation flow path. FIGS. 4 (c) and 4 (d) show the case where the flow rate F <the flow rate A, and FIGS. ) Is the case where the flow rate F> the flow rate A, and shows the flow rates during standby and full discharge, respectively.

  In the case of the first circulation mode in which the first circulation pump 1001 and the first circulation pump 1002 having a quantitative liquid feeding capacity are arranged on the downstream side of the liquid discharge head 3 (FIGS. 4A and 4B), The total set flow rate of the first circulation pump 1001 and the first circulation pump 1002 is the flow rate A. With this flow rate A, the temperature in the liquid discharge unit 300 during standby can be managed. When the liquid discharge head 3 performs full discharge, the total set flow rate of the first circulation pump 1001 and the first circulation pump 1002 remains at the flow rate A. However, the maximum flow rate supplied to the liquid ejection head 3 is caused by the negative pressure generated by the ejection of the liquid ejection head 3, and the flow rate F corresponding to the total ejection is added to the total flow rate A. Therefore, since the flow rate F is added to the flow rate A, the maximum value of the supply amount to the liquid ejection head 3 becomes the flow rate A + the flow rate F (FIG. 4B).

  On the other hand, in the case of the second circulation mode in which the first circulation pump 1001 and the first circulation pump 1002 are arranged on the upstream side of the liquid discharge head 3 (FIG. 4C to FIG. 4F), the recording standby The supply amount to the liquid discharge head 3 that is sometimes required is the flow rate A as in the first circulation mode. Therefore, in the second circulation mode in which the first circulation pump 1001 and the first circulation pump 1002 are arranged on the upstream side of the liquid discharge head 3, the flow rate A is higher than the flow rate F (FIG. 4C, (d )), The flow rate A is sufficient for the supply amount to the liquid discharge head 3 even during full discharge. At that time, the discharge flow rate from the liquid discharge head 3 is flow rate A−flow rate F (FIG. 4D). However, when the flow rate F is higher than the flow rate A (FIGS. 4E and 4F), the flow rate becomes insufficient if the supply flow rate to the liquid ejection head 3 is the flow rate A at the time of full ejection. Therefore, when the flow rate F is higher than the flow rate A, the supply amount to the liquid ejection head 3 needs to be the flow rate F. At this time, if the full discharge is performed, the flow rate F is consumed in the liquid discharge head 3, and therefore, the discharge flow rate from the liquid discharge head 3 is hardly discharged (FIG. 4F). When the flow rate F is higher than the flow rate A and discharge is performed but not all discharges, an amount obtained by subtracting the amount consumed by the discharge from the flow rate F is discharged from the liquid discharge head 3. When the flow rate A and the flow rate F are equal, the flow rate A (or flow rate F) is supplied to the liquid discharge head 3 and the flow rate F is consumed in the liquid discharge head 3. The discharge flow rate is almost not discharged.

  As described above, in the case of the second circulation mode, the total value of the set flow rates of the first circulation pump 1001 and the first circulation pump 1002, that is, the maximum value of the necessary supply flow rate is the larger value of the flow rate A or the flow rate F. . Therefore, as long as the liquid discharge unit 300 having the same configuration is used, the maximum value of the required supply amount (flow rate A or flow rate F) in the second circulation mode is the maximum value of the required supply flow rate (flow rate A + flow rate) in the first circulation mode. Smaller than F).

  Therefore, in the case of the second circulation mode, the degree of freedom of the applicable circulation pump is increased. For example, a low-cost circulation pump with a simple configuration is used, or a load of a cooler (not shown) installed in the main body side path is reduced. There is an advantage that the cost of the recording apparatus can be reduced. This advantage increases as the line head has a relatively large value of the flow rate A or the flow rate F. Among line heads, a line head having a long length in the longitudinal direction is more beneficial.

  On the other hand, however, the first circulation mode is advantageous over the second circulation mode. That is, in the second circulation mode, the flow rate that flows through the liquid ejection unit 300 during recording standby is maximum, so that the smaller the amount of ejection per unit area (hereinafter also referred to as a low-duty image), A high negative pressure is applied. For this reason, when the flow path width is narrow and the negative pressure is high, a high negative pressure is applied to the discharge port in a low-duty image in which unevenness is easily visible, so that many so-called satellite droplets are discharged along with the main ink droplets. It may occur and the recording quality may deteriorate.

  On the other hand, in the case of the first circulation mode, since a high negative pressure is applied to the discharge port when an image with a large discharge amount per unit area (hereinafter also referred to as a high duty image) is formed, satellite droplets are temporarily generated. Even if it is difficult to see, there is an advantage that the influence on the image is small. These two circulation modes can be selected in light of the specifications of the liquid discharge head and the recording apparatus main body (discharge flow rate F, minimum circulation flow rate A, and in-head flow path resistance).

(Description of third circulation mode)
FIG. 41 is a schematic diagram showing a third circulation form which is one form of a circulation path applied to the recording apparatus of the present embodiment. A description of functions and configurations similar to those in the first and second circulation modes will be omitted, and different points will be mainly described.

  In this circulation mode, the liquid is supplied into the liquid discharge head 3 from two places in the center of the liquid discharge head 3 and a total of three places on one end side of the liquid discharge head 3. The liquid passes through the pressure chambers 23 from the common supply flow path 211 and is then recovered in the common recovery flow path 212 and is recovered to the outside from the recovery opening at the other end of the liquid discharge head 3. The individual flow path 213 communicates with the common supply flow path 211 and the common recovery flow path 212, and the recording element substrate 10 and the pressure chamber 23 disposed in the recording element substrate are provided in the path of each individual flow path 213. It has been. Therefore, a part of the liquid that flows through the first circulation pump 1002 flows from the supply channel 211 into the common recovery channel 212 through the pressure chamber 23 of the recording element substrate 10 (arrow in FIG. 41). This is because a pressure difference is provided between the pressure adjustment mechanism H connected to the common supply flow path 211 and the pressure adjustment mechanism L connected to the common recovery flow path 212, so that the first circulation pump 1002 can perform the common recovery flow. This is because it is connected only to the path 212.

  In this way, in the liquid ejection unit 300, the liquid flow that passes through the common recovery channel 212 and the common recovery channel that passes from the common supply channel 211 to the pressure chamber 23 in each recording element substrate 10. A flow occurs at 212. Therefore, heat generated in each recording element substrate 10 can be discharged to the outside of the recording element substrate 10 by the flow from the common supply channel 211 to the common recovery channel 212 while suppressing an increase in pressure loss. Further, according to this circulation path, it is possible to reduce the number of pumps which are liquid transporting means as compared with the first and second circulation paths.

(Description of liquid discharge head configuration)
The configuration of the liquid ejection head 3 according to Application Example 1 will be described. FIG. 5A and FIG. 5B are perspective views showing the liquid ejection head 3 according to this application example. In the liquid discharge head 3, 15 recording element substrates 10 capable of discharging ink of four colors of cyan C / magenta M / yellow Y / black K are arranged in a straight line (arranged inline). This is a line type liquid discharge head.

  As shown in FIG. 5A, the liquid ejection head 3 includes each recording element substrate 10, a signal input terminal 91 and a power supply terminal 92 electrically connected via the flexible wiring substrate 40 and the electric wiring substrate 90. Prepare. The signal input terminal 91 and the power supply terminal 92 are electrically connected to the control unit of the recording apparatus 1000, and supply an ejection drive signal and electric power necessary for ejection to the recording element substrate 10, respectively. By consolidating the wiring by the electric circuit in the electric wiring board 90, the number of the signal input terminals 91 and the power supply terminals 92 can be reduced as compared with the number of the recording element boards 10. This reduces the number of electrical connections that need to be removed when the liquid ejection head 3 is assembled to the recording apparatus 1000 or when the liquid ejection head is replaced.

  As shown in FIG. 5B, the liquid connection portions 111 provided at both ends of the liquid ejection head 3 are connected to the liquid supply system of the recording apparatus 1000. Accordingly, cyan C / magenta M / yellow Y / black K four color inks are supplied from the supply system of the recording apparatus 1000 to the liquid discharge head 3, and ink that has passed through the liquid discharge head 3 is supplied to the supply system of the recording apparatus 1000. It has come to be collected. As described above, the ink of each color can be circulated through the path of the recording apparatus 1000 and the path of the liquid discharge head 3.

  FIG. 6 is an exploded perspective view showing each component or unit constituting the liquid ejection head 3. The liquid discharge unit 300, the liquid supply unit 220, and the electric wiring substrate 90 are attached to the housing 80. The liquid supply unit 220 is provided with a liquid connection portion 111 (see FIG. 3), and the liquid supply unit 220 communicates with each opening of the liquid connection portion 111 in order to remove foreign matter in the supplied ink. A filter 221 (see FIGS. 2 and 3) for each color is provided. The two liquid supply units 220 are each provided with filters 221 for two colors. The liquid that has passed through the filter 221 is supplied to the negative pressure control unit 230 disposed on the liquid supply unit 220 corresponding to each color. The negative pressure control unit 230 is a unit composed of a negative pressure control valve for each color, and the inside of the supply system of the recording apparatus 1000 that is generated in accordance with the fluctuation of the liquid flow rate by the action of a valve, a spring member, or the like provided in each of the negative pressure control units. A change in pressure loss of the (supply system upstream of the liquid discharge head 3) is greatly attenuated. Thus, the negative pressure control unit 230 can stabilize the negative pressure change on the downstream side (liquid ejection unit 300 side) from the negative pressure control unit within a certain range. In the negative pressure control unit 230 for each color, two negative pressure control valves for each color are incorporated as described in FIG. The two negative pressure control valves are set to different control pressures, and the high pressure side is supplied with the common supply channel 211 (see FIG. 2) in the liquid discharge unit 300, and the low pressure side is supplied with the common recovery channel 212 (see FIG. 2). It communicates via the unit 220.

  The casing 80 includes a liquid discharge unit support part 81 and an electric wiring board support part 82, supports the liquid discharge unit 300 and the electric wiring board 90, and ensures the rigidity of the liquid discharge head 3. The electric wiring board support part 82 is for supporting the electric wiring board 90 and is fixed to the liquid discharge unit support part 81 by screws. The liquid discharge unit support portion 81 has a role of correcting the warp and deformation of the liquid discharge unit 300 and ensuring the relative positional accuracy of the plurality of recording element substrates 10, thereby suppressing streaks and unevenness in the recorded matter. . Therefore, the liquid discharge unit support portion 81 preferably has sufficient rigidity, and a metal material such as SUS or aluminum, or a ceramic such as alumina is preferable as the material. The liquid discharge unit support portion 81 is provided with openings 83 and 84 into which the joint rubber 100 is inserted. The liquid supplied from the liquid supply unit 220 is guided to the third flow path member 70 constituting the liquid discharge unit 300 via the joint rubber.

  The liquid discharge unit 300 includes a plurality of discharge modules 200 and a flow path member 210, and a cover member 130 is attached to the surface of the liquid discharge unit 300 on the recording medium side. Here, the cover member 130 is a member having a frame-like surface provided with a long opening 131 as shown in FIG. 6. From the opening 131, the recording element substrate 10 included in the discharge module 200 and the sealing member 130 are sealed. The stop member 110 (see FIG. 10 described later) is exposed. The frame portion around the opening 131 functions as a contact surface of a cap member that caps the liquid ejection head 3 during recording standby. For this reason, a closed space is formed at the time of capping by applying an adhesive, a sealing material, a filler, or the like along the periphery of the opening 131 and filling the irregularities and gaps on the discharge port surface of the liquid discharge unit 300. It is preferable to do so.

  Next, the configuration of the flow path member 210 included in the liquid discharge unit 300 will be described. As shown in FIG. 6, the flow path member 210 is a laminate of the first flow path member 50, the second flow path member 60, and the third flow path member 70, and allows the liquid supplied from the liquid supply unit 220 to flow. Distribute to each discharge module 200. The flow path member 210 is a flow path member for returning the liquid circulating from the discharge module 200 to the liquid supply unit 220. The flow path member 210 is fixed to the liquid discharge unit support portion 81 with screws, thereby suppressing warpage and deformation of the flow path member 210.

  FIGS. 7A to 7F are views showing the front and back surfaces of each flow path member of the first to third flow path members. 7A shows a surface of the first flow path member 50 on the side where the discharge module 200 is mounted, and FIG. 7F shows a liquid discharge unit support portion 81 of the third flow path member 70. The surface on the abutting side is shown. The first flow path member 50 and the second flow path member 60 are joined so that FIG. 7B and FIG. 7C, which are contact surfaces of the respective flow path members, face each other. The member and the third flow path member are joined so that FIG. 7D and FIG. 7E which are contact surfaces of the respective flow path members face each other. By joining the second flow path member 60 and the third flow path member 70, the eight flow paths extending in the longitudinal direction of the flow path member from the common flow path grooves 62 and 71 formed in each flow path member. Common flow paths (211a, 211b, 211c, 211d, 212a, 212b, 212c, 212d) are formed. As a result, a set of the common supply channel 211 and the common recovery channel 212 is formed in the channel member 210 for each color. Ink is supplied from the common supply flow path 211 to the liquid discharge head 3, and the ink supplied to the liquid discharge head 3 is recovered by the common recovery flow path 212. The communication port 72 (see FIG. 7F) of the third flow path member 70 communicates with each hole of the joint rubber 100, and fluidly circulates with the liquid supply unit 220 (see FIG. 6). On the bottom surface of the common channel groove 62 of the second channel member 60, there are communication ports 61 (a communication port 61-1 communicating with the common supply channel 211 and a communication port 61-2 communicating with the common recovery channel 212). A plurality are formed and communicate with one end of the individual flow channel 52 of the first flow channel member 50. A communication port 51 is formed at the other end of the individual flow channel 52 of the first flow channel member 50, and is in fluid communication with the plurality of discharge modules 200 via the communication port 51. The individual flow channel 52 enables the flow channels to be concentrated on the center side of the flow channel member.

  It is preferable that the first to third flow path members are made of a material having corrosion resistance against a liquid and a low linear expansion coefficient. For example, alumina can be used as the material. Also suitable is a composite material (resin material) in which inorganic fillers such as silica fine particles and fibers are added using LCP (liquid crystal polymer), PPS (polyphenyl sulfide), PSF (polysulfone), and modified PPE (polyphenylene ether) as a base material. Can be used. As a method of forming the flow path member 210, three flow path members may be laminated and bonded to each other. When a resin composite resin material is selected as the material, a joining method by welding may be used.

  FIG. 8 shows the α part of FIG. 7A, and the flow path in the flow path member 210 formed by joining the first to third flow path members is the first flow path member 50. It is the perspective view which expanded and showed a part from the surface side in which the discharge module 200 is mounted. The common supply flow path 211 and the common recovery flow path 212 are alternately arranged from the flow paths at both ends. Here, the connection relation of each flow path in the flow path member 210 will be described.

  The channel member 210 is provided with a common supply channel 211 (211a, 211b, 211c, 211d) and a common recovery channel 212 (212a, 212b, 212c, 212d) extending in the longitudinal direction of the liquid ejection head 3 for each color. It has been. A plurality of individual supply channels 213 (213 a, 213 b, 213 c, and 213 d) formed by the individual channel grooves 52 are connected to the common supply channel 211 of each color via the communication port 61. A plurality of individual recovery channels 214 (214a, 214b, 214c, 214d) formed by the individual channel grooves 52 are connected to the common recovery channel 212 of each color via the communication port 61. With such a flow path configuration, it is possible to collect ink from each common supply flow path 211 via the individual supply flow path 213 to the recording element substrate 10 located at the center of the flow path member. Ink can be recovered from the recording element substrate 10 to each common recovery channel 212 via the individual recovery channel 214.

  FIG. 9 is a view showing a cross section taken along line IX-IX in FIG. Each individual recovery channel (214a, 214c) communicates with the discharge module 200 via the communication port 51. Although only the individual recovery flow paths (214a, 214c) are shown in FIG. 9, the separate supply flow path 213 and the discharge module 200 communicate with each other in another cross section as shown in FIG. A flow path for supplying ink from the first flow path member 50 to the recording element 15 provided on the recording element substrate 10 is formed in the support member 30 and the recording element substrate 10 included in each ejection module 200. . Further, the support member 30 and the recording element substrate 10 are provided with a flow path for collecting (circulating) part or all of the liquid supplied to the recording element 15 to the first flow path member 50.

  Here, the common supply flow path 211 of each color is connected to the corresponding negative pressure control unit 230 (high pressure side) via the liquid supply unit 220, and the common recovery flow path 212 is connected to the negative pressure control unit 230. (Low pressure side) and the liquid supply unit 220 are connected. By this negative pressure control unit 230, a differential pressure (pressure difference) is generated between the common supply channel 211 and the common recovery channel 212. For this reason, as shown in FIGS. 8 and 9, in the liquid discharge head of this application example in which the flow paths are connected, the common supply flow paths 211 to the individual supply flow paths 213 to the recording element substrates 10 to the individual colors are used for the respective colors. A flow that flows in order from the recovery channel 214 to the common recovery channel 212 is generated.

(Description of discharge module)
FIG. 10A is a perspective view showing one discharge module 200, and FIG. 10B is an exploded view thereof. As a manufacturing method of the discharge module 200, first, the recording element substrate 10 and the flexible wiring substrate 40 are bonded onto the support member 30 provided with the liquid communication port 31 in advance. Thereafter, the terminals 16 on the recording element substrate 10 and the terminals 41 on the flexible wiring substrate 40 are electrically connected by wire bonding, and then the wire bonding portion (electrical connection portion) is covered with the sealing member 110 and sealed. . A terminal 42 on the opposite side of the flexible wiring substrate 40 from the recording element substrate 10 is electrically connected to a connection terminal 93 (see FIG. 6) of the electric wiring substrate 90. The support member 30 is a support member that supports the recording element substrate 10, and is a flow path member that fluidly communicates the recording element substrate 10 and the flow path member 210. Therefore, the support member 30 has high flatness and is sufficiently high. Those that can be reliably bonded to the recording element substrate are preferable. As a material, for example, alumina or a resin material is preferable.

(Description of structure of recording element substrate)
FIG. 11A shows a plan view of the surface of the recording element substrate 10 on which the ejection port 13 is formed, and FIG. 11B shows an enlarged view of the portion indicated by A in FIG. FIG.11 (c) shows the top view of the back surface of Fig.11 (a). Here, the configuration of the recording element substrate 10 in this application example will be described. As shown in FIG. 11A, the four ejection port arrays corresponding to the respective ink colors are formed on the ejection port forming member 12 of the recording element substrate 10. Hereinafter, the direction in which the ejection port array in which the plurality of ejection ports 13 are arranged is referred to as “row direction of the ejection port array”. As shown in FIG. 11B, recording elements 15 that are heat generating elements for foaming the liquid by thermal energy are arranged at positions corresponding to the respective ejection ports 13. A partition 22 defines a pressure chamber 23 having the recording element 15 therein. The recording element 15 is electrically connected to the terminal 16 by electrical wiring (not shown) provided on the recording element substrate 10. The recording element 15 generates heat based on the pulse signals input from the control circuit of the recording apparatus 1000 via the electric wiring board 90 (see FIG. 6) and the flexible wiring board 40 (see FIG. 10) to boil the liquid. Let The liquid is discharged from the discharge port 13 by the foaming force due to the boiling. As shown in FIG. 11B, along each discharge port array, a liquid supply flow path 18 extends on one side, and a liquid recovery flow path 19 extends on the other side. The liquid supply flow path 18 and the liquid recovery flow path 19 are flow paths extending in the column direction of the discharge port array provided in the recording element substrate 10, and communicate with the discharge port 13 through the supply port 17a and the recovery port 17b, respectively. doing.

  As shown in FIG. 11C, a sheet-like lid member 20 is laminated on the back surface of the recording element substrate 10 on which the ejection port 13 is formed, and the lid member 20 has a liquid supply channel. A plurality of openings 21 communicating with 18 and the liquid recovery channel 19 are provided. In this application example, three openings 21 are provided in the lid member 20 for one of the liquid supply channels 18 and two for one of the liquid recovery channels 19. As shown in FIG. 11B, each opening 21 of the lid member 20 communicates with a plurality of communication ports 51 shown in FIG. The lid member 20 is preferably a material having sufficient corrosion resistance to the liquid, and high accuracy is required for the opening shape and the opening position of the opening 21 from the viewpoint of preventing color mixing. For this reason, it is preferable to use a photosensitive resin material or a silicon plate as the material of the lid member 20 and provide the opening 21 by a photolithography process. As described above, the lid member 20 converts the pitch of the flow path by the openings 21, and it is desirable that the thickness is thin in consideration of the pressure loss, and it is desirable that the lid member 20 is formed of a film-like member.

  FIG. 12 is a perspective view showing a cross section of the recording element substrate 10 and the lid member 20 along XII-XII in FIG. Here, the flow of the liquid in the recording element substrate 10 will be described. The lid member 20 has a function as a lid that forms part of the walls of the liquid supply channel 18 and the liquid recovery channel 19 formed on the substrate 11 of the recording element substrate 10. The recording element substrate 10 includes a substrate 11 formed of Si and a discharge port forming member 12 formed of a photosensitive resin, and a lid member 20 is bonded to the back surface of the substrate 11. A recording element 15 is formed on one surface side of the substrate 11 (see FIG. 11), and a liquid supply channel 19 and a liquid recovery channel 18 extending along the ejection port array are formed on the back side thereof. Are formed. The liquid supply flow path 18 and the liquid recovery flow path 19 formed by the substrate 11 and the lid member 20 are connected to the common supply flow path 211 and the common recovery flow path 212 in the flow path member 210, respectively. A differential pressure is generated between the flow path 18 and the liquid recovery flow path 19. When recording is performed by discharging the liquid from the discharge port 13, the liquid in the liquid supply channel 18 provided in the substrate 11 is supplied to the supply port 17a by the differential pressure at the discharge port that is not discharging. Then, it flows to the liquid recovery passageway 19 via the pressure chamber 23 and the recovery port 17b (arrow C in FIG. 12). With this flow, the thickened ink, bubbles, foreign matters, and the like generated by evaporation from the discharge port 13 can be recovered in the liquid recovery channel 19 in the discharge port 13 and the pressure chamber 23 where recording is paused. Further, it is possible to prevent the ink in the ejection port 13 and the pressure chamber 23 from being thickened. The liquid recovered in the liquid recovery channel 19 is shared by the communication port 51 in the channel member 210, the individual recovery channel 214, through the opening 21 of the lid member 20 and the liquid communication port 31 (FIG. 10 b) of the support member 30. They are collected in the order of the collection channel 212 and collected to the collection path of the recording apparatus 1000. That is, the liquid supplied from the recording apparatus main body to the liquid discharge head 3 flows in the following order, and is supplied and recovered.

  The liquid first flows into the liquid ejection head 3 from the liquid connection part 111 of the liquid supply unit 220. The liquid is the joint rubber 100, the communication port 72 and the common channel groove 71 provided in the third channel member, the common channel groove 62 and the communication port 61 provided in the second channel member, and the first channel. The individual flow channel 52 and the communication port 51 provided in the member are supplied in this order. After that, the liquid communication port 31 provided in the support member 30, the opening 21 provided in the lid member 20, the liquid supply flow path 18 provided in the substrate 11 and the supply port 17 a are sequentially supplied to the pressure chamber 23. . Of the liquid supplied to the pressure chamber 23, the liquid that has not been discharged from the discharge port 13 is the recovery port 17 b and the liquid recovery channel 19 provided in the substrate 11, the opening 21 provided in the lid member 20, and the support member. 30 sequentially flows through the liquid communication port 31 provided at 30. Thereafter, the liquid is provided in the communication port 51 and the individual flow channel 52 provided in the first flow channel member, the communication port 61 and the common flow channel 62 provided in the second flow channel member, and the third flow channel member 70. The common channel groove 71, the communication port 72, and the joint rubber 100 are sequentially flowed. Then, the liquid flows from the liquid connection part 111 provided in the liquid supply unit 220 to the outside of the liquid discharge head 3.

  In the form of the first circulation form shown in FIG. 2, the liquid flowing in from the liquid connecting portion 111 is supplied to the joint rubber 100 after passing through the negative pressure control unit 230. In the second circulation mode shown in FIG. 3, the liquid recovered from the pressure chamber 23 passes through the joint rubber 100 and then passes from the liquid connection unit 111 to the outside of the liquid discharge head via the negative pressure control unit 230. To flow. Further, not all the liquid that has flowed from one end of the common supply channel 211 of the liquid discharge unit 300 is supplied to the pressure chamber 23 via the individual supply channel 213a. That is, there is a liquid that flows from one end of the common supply channel 211 and flows from the other end of the common supply channel 211 to the liquid supply unit 220 without flowing into the individual supply channel 213a. As described above, by providing a path that flows without passing through the recording element substrate 10, even when the recording element substrate 10 including a fine flow path having a high flow resistance is provided as in this application example, The reverse flow of the circulating flow can be suppressed. As described above, in the liquid discharge head 3 of this application example, it is possible to suppress the increase in the viscosity of the liquid in the pressure chamber 23 and the vicinity of the discharge port. High-quality recording can be performed.

(Description of positional relationship between recording element substrates)
FIG. 13 is a plan view partially enlarged showing the adjacent portion of the recording element substrate in two adjacent ejection modules. In this application example, a substantially parallelogram recording element substrate is used. The ejection port arrays (14 a to 14 d) in which the ejection ports 13 in each recording element substrate 10 are arranged are arranged so as to be inclined at a certain angle with respect to the longitudinal direction of the liquid ejection head 3. The ejection port arrays in the adjacent portions of the recording element substrates 10 are configured such that at least one ejection port overlaps in the conveyance direction of the recording medium. In FIG. 13, the two discharge ports on the line D are in a relationship of overlapping each other. With such an arrangement, even if the position of the recording element substrate 10 is slightly deviated from the predetermined position, black stripes and white spots in the recorded image can be made inconspicuous by driving control of the overlapping discharge ports. Even when a plurality of recording element substrates 10 are arranged in a straight line (in-line) instead of in a staggered arrangement, the recording elements are controlled while suppressing an increase in the length of the liquid ejection head 10 in the recording medium conveyance direction by the configuration as shown in FIG. It is possible to take measures against black streaks and white spots at the connecting portions of the substrates 10. In this application example, the main plane of the recording element substrate is a parallelogram, but the present invention is not limited to this, and the configuration of the present invention is preferable even when a recording element substrate having a rectangular shape, trapezoid, or other shape is used. Can be applied.

(Description of Modification of Liquid Discharge Head Configuration)
A modification of the configuration of the liquid ejection head will be described with reference to FIGS. 40 and 42 to 44. The description of the same configuration and function as those of the above-described example is omitted, and different points are mainly described. In this modification, as shown in FIGS. 40 and 42, a plurality of liquid connection portions 111, which are liquid connection portions between the liquid discharge head 3 and the outside, are concentrated on one end side in the longitudinal direction of the liquid discharge head. Has been placed. A plurality of negative pressure control units 230 are collectively arranged on the other end side of the liquid discharge head 3 (FIG. 43). The liquid supply unit 220 included in the liquid discharge head 3 is configured as a long unit corresponding to the length of the liquid discharge head 3 and includes a flow path and a filter 221 corresponding to the four colors of liquid to be supplied. As shown in FIG. 43, the openings 83 to 86 provided in the liquid discharge unit support portion 81 are provided at different positions from the liquid discharge head 3 described above.

  FIG. 44 shows a stacked state of the flow path members 50, 60, and 70. A plurality of recording element substrates 10 are linearly arranged on the upper surface of the channel member 50 that is the uppermost layer of the plurality of channel members 50, 60, 70. The flow paths communicating with the openings 21 (FIG. 19) formed on the back side of each recording element substrate 10 are two individual supply flow paths 213 and one individual recovery flow path 214 for each liquid color. Yes. Correspondingly, the opening 21 formed in the lid member 20 provided on the back surface of the recording element substrate 10 also has two supply openings 21 and one recovery opening 21 for each liquid color. As shown in FIG. 44, common supply channels 211 and common recovery channels 212 extending along the longitudinal direction of the liquid ejection head 3 are alternately arranged in parallel.

(Application example 2)
Hereinafter, configurations of the ink jet recording apparatus 2000 and the liquid discharge head 2003 according to Application Example 2 of the present invention will be described with reference to the drawings. In the following description, only portions different from Application Example 1 will be mainly described, and description of portions similar to Application Example 1 will be omitted.

(Description of inkjet recording apparatus)
FIG. 21 is a diagram showing an ink jet recording apparatus 2000 that performs recording by discharging a liquid, to which the present application example can be applied. The recording apparatus 2000 according to this application example performs full-color recording on a recording medium by arranging four monochromatic liquid ejection heads 2003 corresponding to each ink of cyan C, magenta M, yellow Y, and black K in parallel. Is different from Application Example 1. In the application example 1, the number of discharge port rows that can be used per color is one, whereas in this application example, the number of discharge port rows that can be used per color is 20 rows. For this reason, it is possible to perform very high-speed recording by appropriately recording the recording data to a plurality of ejection port arrays. Furthermore, even if there is a discharge port that does not discharge, reliability is improved by performing complementary discharge from the discharge ports in other rows that are in positions corresponding to the transport direction of the recording medium with respect to that discharge port. And suitable for commercial records. Similar to Application Example 1, the supply system of the recording apparatus 2000, the buffer tank 1003 (see FIGS. 2 and 3), and the main tank 1006 (see FIGS. 2 and 3) are fluidly supplied to each liquid discharge head 2003. It is connected. Each liquid discharge head 2003 is electrically connected to an electric control unit that transmits power and a discharge control signal to the liquid discharge head 2003.

(Explanation of circulation route)
Similar to Application Example 1, as the liquid circulation form between the recording apparatus 2000 and the liquid ejection head 2003, the first and second circulation forms shown in FIG. 2 or FIG. 3 can be used.

(Description of liquid discharge head structure)
14A and 14B are perspective views showing a liquid discharge head 2003 according to this application example. Here, the structure of the liquid discharge head 2003 according to this application example will be described. The liquid discharge head 2003 is an ink jet type line recording head that includes 16 recording element substrates 2010 arranged in a straight line in the longitudinal direction of the liquid discharge head 2003 and can perform recording with one type of liquid. The liquid discharge head 2003 includes the liquid connection part 111, the signal input terminal 91, and the power supply terminal 92, as in Application Example 1. However, since the liquid discharge head 2003 of this application example has more discharge port arrays than the application example 1, the signal output terminal 91 and the power supply terminal 92 are arranged on both sides of the liquid discharge head 2003. This is to reduce voltage drop and signal transmission delay that occur in the wiring portion provided on the recording element substrate 2010.

  FIG. 15 is an exploded perspective view showing the liquid discharge head 2003, and shows each component or unit constituting the liquid discharge head 2003 divided for each function. The role of each unit and member and the order of liquid circulation in the liquid discharge head are basically the same as in Application Example 1, but the function of ensuring the rigidity of the liquid discharge head is different. In the application example 1, the liquid discharge head support portion 81 mainly secures the liquid discharge head rigidity. However, in the liquid discharge head 2003 of the application example 2, the liquid discharge head is included by the second flow path member 2060 included in the liquid discharge unit 2300. The rigidity of is secured. The liquid discharge unit support portion 81 in this application example is connected to both ends of the second flow path member 2060, and the liquid discharge unit 2300 is mechanically coupled to the carriage of the recording apparatus 2000, and the liquid discharge head 2003. Perform positioning. The liquid supply unit 2220 including the negative pressure control unit 2230 and the electrical wiring board 90 are coupled to the liquid discharge unit support portion 81. Each of the two liquid supply units 2220 includes a filter (not shown).

  The two negative pressure control units 2230 are set so as to control the pressure with different relatively high and low negative pressures. When the high-pressure side and the low-pressure side negative pressure control units 2230 are installed at both ends of the liquid discharge head 2003, the liquid in the common supply channel and the common recovery channel extending in the longitudinal direction of the liquid discharge head 2003 is provided. Are opposite to each other in the extending direction. The configuration is illustrated in FIGS. 14 and 15. In such a configuration, heat exchange is promoted between the common supply channel and the common recovery channel, and a temperature difference between the two common channels is reduced. Accordingly, there is an advantage that a temperature difference in each of the recording element substrates 2010 provided along the common flow path is reduced, and recording unevenness due to the temperature difference is less likely to occur.

  Next, details of the flow path member 2210 of the liquid discharge unit 2300 will be described. As shown in FIG. 15, the flow path member 2210 is formed by stacking the first flow path member 2050 and the second flow path member 2060, and distributes the liquid supplied from the liquid supply unit 2220 to each discharge module 2200. To do. The flow path member 2210 functions as a flow path member for returning the liquid circulating from the discharge module 2200 to the liquid supply unit 2220. The second flow path member 2060 of the flow path member 2210 is a flow path member in which a common supply flow path and a common recovery flow path are formed, and has a function of mainly responsible for the rigidity of the liquid discharge head 2003. For this reason, as a material of the 2nd flow path member 2060, what has sufficient corrosion resistance with respect to a liquid and high mechanical strength is preferable. Specifically, SUS, Ti, alumina or the like can be used.

  FIG. 16A is a view showing a surface of the first flow path member 2050 on which the discharge module 2200 is mounted, and FIG. 16B shows the back surface thereof, and the second flow path member 2060 is shown. It is the figure which showed the surface contact | abutted with. Unlike the application example 1, the first flow path member 2050 in this application example is obtained by arranging a plurality of members corresponding to the respective discharge modules 2200 adjacent to each other. By adopting such a divided structure, a plurality of modules can be arranged to correspond to the length of the liquid discharge head 2003. For example, a relatively long scale corresponding to the B2 size or longer The present invention can be particularly preferably applied to the liquid discharge head. As shown in FIG. 16A, the communication port 51 of the first flow path member 2050 is in fluid communication with the discharge module 2200, and as shown in FIG. The communication port 53 is in fluid communication with the communication port 61 of the second flow path member 2060. FIG. 16C shows a surface of the second flow path member 60 that comes into contact with the first flow path member 2050, and FIG. 16D shows a cross section of the central portion in the thickness direction of the second flow path member 60. FIG. 16E is a diagram showing a surface of the second flow path member 2060 that comes into contact with the liquid supply unit 2220. The functions of the flow path and the communication port of the second flow path member 2060 are the same as those for one color of Application Example 1. One of the common flow channel grooves 71 of the second flow channel member 2060 is a common supply flow channel 2211 shown in FIG. 17 to be described later, and the other is a common recovery flow channel 2212. The longitudinal direction of the liquid discharge head 2003, respectively. The liquid is supplied from one end side to the other end side. This application example is different from application example 1 in that the liquid flows in the common supply channel 2211 and the common recovery channel 2212 are in opposite directions.

  FIG. 17 is a perspective view showing a liquid connection relationship between the recording element substrate 2010 and the flow path member 2210. In the flow path member 2210, a set of a common supply flow path 2211 and a common recovery flow path 2212 extending in the longitudinal direction of the liquid discharge head 2003 are provided. The communication port 61 of the second flow channel member 2060 is connected to the individual communication port 53 of the first flow channel member 2050 in alignment, and is connected to the common supply flow channel 2211 of the second flow channel member 2060 via the communication port 61. Thus, a liquid supply flow path communicating with the communication port 51 of the first flow path member 2050 is formed. Similarly, a liquid supply path that communicates from the communication port 72 of the second flow channel member 2060 to the communication port 51 of the first flow channel member 2050 via the common recovery flow channel 2212 is also formed.

  18 is a view showing a cross section taken along line XVIII-XVIII in FIG. The common supply channel 2211 is connected to the discharge module 2200 via the communication port 61, the individual communication port 53, and the communication port 51. Although not shown in FIG. 18, it is apparent with reference to FIG. 17 that in another cross section, the common recovery flow path 2212 is connected to the discharge module 2200 through a similar path. As in Application Example 1, each ejection module 2200 and the recording element substrate 2010 are formed with a flow path communicating with each ejection port, and a part or all of the supplied liquid pauses the ejection operation. It can be recirculated through the discharge port. Similarly to Application Example 1, the common supply flow path 2211 is connected to the negative pressure control unit 2230 (high pressure side), and the common recovery flow path 2212 is connected to the negative pressure control unit 2230 (low pressure side) via the liquid supply unit 2220. Has been. Therefore, a flow that flows from the common supply channel 2211 through the pressure chamber of the recording element substrate 2010 to the common recovery channel 2212 is generated by the differential pressure.

(Description of discharge module)
FIG. 19A is a perspective view showing one discharge module 2200, and FIG. 19B is an exploded view thereof. The difference from Application Example 1 is that a plurality of terminals 16 are respectively arranged on both sides (each long side portion of the printing element substrate 2010) along the row direction of the plurality of ejection port arrays of the printing element substrate 2010. is there. Accordingly, two flexible wiring boards 40 that are electrically connected to the recording element substrate 2010 are also arranged on one recording element substrate 2010. This is because the number of ejection port arrays provided on the recording element substrate 2010 is 20, which is significantly larger than the eight arrays in Application Example 1, and the maximum distance from the terminal 16 to the recording element is shortened for recording. This is for reducing a voltage drop and a signal delay generated in the wiring portion in the element substrate 2010. Further, the liquid communication port 31 of the support member 2030 is provided in the recording element substrate 2010 and is opened so as to straddle all the ejection port arrays. Other points are the same as in Application Example 1.

(Description of structure of recording element substrate)
FIG. 20A is a schematic diagram of the surface on which the ejection port 13 of the recording element substrate 2010 is arranged, and FIG. 20C is a schematic diagram showing the back surface of the surface of FIG. FIG. 20B is a schematic diagram showing the surface of the recording element substrate 2010 when the lid member 2020 provided on the back side of the recording element substrate 2010 is removed in FIG. As shown in FIG. 20B, the liquid supply channel 18 and the liquid recovery channel 19 are alternately provided on the back surface of the recording element substrate 2010 along the row direction of the ejection port array. Although the number of ejection port arrays is significantly increased as compared with the application example 1, the essential difference from the application example 1 is that the terminals 16 are aligned in the direction of the ejection port array of the printing element substrate as described above. It is arranged on both sides. A pair of the liquid supply flow path 18 and the liquid recovery flow path 19 are provided for each discharge port array, and the opening 21 communicating with the liquid communication port 31 of the support member 2030 is provided in the lid member 2020. The basic configuration is the same as that of the first application example.

(Application example 3)
The configurations of the ink jet recording apparatus 1000 and the liquid discharge head 3 according to Application Example 3 of the present invention will be described. The liquid discharge head of Application Example 3 is a page-wide type that performs recording in one scan on a B2 size recording medium. Since the application example 3 is similar in many respects to the application example 2, in the following description, parts different from the second application example will be mainly described, and description of parts similar to the second application example will be omitted.

(Description of inkjet recording apparatus)
FIG. 45 is a schematic diagram of an ink jet recording apparatus according to this application example. The recording apparatus 1000 does not perform direct recording on the recording medium from the liquid ejection head 3, and once the liquid is ejected onto the intermediate transfer body (intermediate transfer drum 1007) to form an image, the image is recorded on the recording medium 2. This is a configuration for transferring. In the recording apparatus 1000, four single-color liquid ejection heads 3 respectively corresponding to four types of CMYK inks are arranged in an arc along the intermediate transfer drum 1007. As a result, full-color recording is performed on the intermediate transfer member, and the recorded image is appropriately dried on the intermediate transfer member and then transferred to the recording medium 2 conveyed by the paper conveying roller 1009 by the transfer unit 1008. Transcribed. The paper conveyance system of Application Example 2 is a horizontal conveyance mainly intended for cut paper, but in this application example, it can also be applied to continuous paper supplied from a main body roll (not shown). In such a drum transport system, it is easy to transport the paper while applying a constant tension to the paper, so that there is little transport jam even at high speed recording. For this reason, the reliability of the apparatus is improved and it is suitable for commercial printing and the like. As in the first and application examples 2, the supply system of the printing apparatus 1000, the buffer tank 1003, and the main tank 1006 are fluidly connected to each liquid ejection head 3. Each liquid discharge head 3 is electrically connected to an electric control unit that transmits electric power and a discharge control signal to the liquid discharge head 3.

(Explanation of the fourth circulation mode)
Similar to Application Example 2, as the liquid circulation path between the tank of the recording apparatus 1000 and the liquid discharge head 3, the first and second circulation paths shown in FIG. 2 or FIG. 3 can be applied. The circulation path shown in FIG. 46 is preferable. The main difference from the second circulation path of FIG. 3 is that a bypass valve 1010 communicating with the flow paths of the first circulation pumps 1001 and 1002 and the second circulation pump 1004 is added. The bypass valve 1010 has a function (first function) of lowering the pressure on the upstream side of the bypass valve 1010 by opening the valve when a preset pressure is exceeded. Also, it has a function (second function) for opening and closing the valve at an arbitrary timing by a signal from the control board of the printing apparatus main body.

  By the first function, it is possible to suppress an excessive or excessive pressure from being applied to the flow path on the downstream side of the first circulation pumps 1001 and 1002 or the upstream side of the second circulation pump 1004. For example, when troubles occur in the functions of the first circulation pumps 1001 and 1002, an excessive flow rate or pressure may be applied to the liquid discharge head 3. As a result, liquid may leak from the discharge port of the liquid discharge head 3 or the joints in the liquid discharge head 3 may be broken. However, when a bypass valve is added to the first circulation pumps 1001 and 1002 as in this application example, even when excessive pressure is generated, the bypass valve 1010 is opened so that the liquid path is upstream of each circulation pump. Since this is opened, the above trouble can be suppressed.

  Further, due to the second function, when the circulation drive is stopped, all the bypass valves 1010 are quickly opened based on a control signal from the main body side after the first circulation pumps 1001 and 1002 and the second circulation pump 1004 are stopped. Thereby, the high negative pressure (for example, several to several tens kPa) in the downstream portion (between the negative pressure control unit 230 and the second circulation pump 1004) of the liquid discharge head 3 can be released in a short time. When a positive displacement pump such as a diaphragm pump is used as the circulation pump, a check valve is usually built in the pump. However, by opening the bypass valve, the pressure in the downstream portion of the liquid discharge head 3 can be released also from the downstream buffer tank 1003 side. Although the pressure release in the downstream portion of the liquid discharge head 3 can be performed only from the upstream side, there is a pressure loss in the upstream flow path of the liquid discharge head and in the liquid discharge head. For this reason, it takes a long time to release the pressure, and the pressure in the common flow path in the liquid discharge head 3 may drop transiently, possibly destroying the meniscus at the discharge port. By opening the bypass valve 1010 on the downstream side of the liquid discharge head 3, pressure release on the downstream side of the liquid discharge head is promoted, so that the risk of meniscus destruction of the discharge port is reduced.

(Description of liquid discharge head structure)
The structure of the liquid ejection head 3 according to Application Example 3 of the present invention will be described. 47A is a perspective view of the liquid discharge head 3 according to this application example, and FIG. 47B is an exploded perspective view thereof. The liquid discharge head 3 includes 36 recording element substrates 10 arranged in a straight line (inline) in the longitudinal direction of the liquid discharge head 3, and is an ink jet page-wide recording head that performs recording with one color liquid. is there. Like the application example 2, the liquid ejection head 3 includes a signal input terminal 91 and a power supply terminal 92, and a shield plate 132 that protects the longitudinal side surface of the head.

  FIG. 47B is a perspective exploded view of the liquid discharge head 3, and each component or unit constituting the liquid discharge head 3 is divided and displayed for each function (the shield plate 132 is not shown). The role of each unit and each member and the order of liquid circulation in the liquid discharge head 3 are the same as in Application Example 2. The main differences from Application Example 2 are the electrical wiring board 90, the position of the negative pressure control unit 230, and the shape of the first flow path member. As in this application example, in the case of the liquid ejection head 3 having a length corresponding to a recording medium of B2 size, for example, the power consumption of the liquid ejection head 3 is large, so that eight electrical wiring boards 90 are provided. Each of the electrical wiring boards 90 is attached to each side surface of the long electrical wiring board support part 82 attached to the liquid discharge unit support part 81 by four.

  48A is a side view of the liquid discharge head 3 including the liquid discharge unit 300, the liquid supply unit 220, and the negative pressure control unit 230. FIG. 48B is a schematic view illustrating the flow of the liquid. FIG. 49 is a perspective view showing a cross section taken along line GG in FIG. In order to facilitate understanding, some configurations are simplified.

  A liquid connection unit 111 and a filter 221 are provided in the liquid supply unit 220, and a negative pressure control unit 230 is integrally formed below the liquid supply unit 220. Accordingly, the distance in the height direction between the negative pressure control unit 230 and the recording element substrate 10 is shorter than that in the application example 2. This configuration has the advantage that not only the number of flow path connection portions in the liquid supply unit 220 is reduced and the reliability against leakage of the recording liquid is improved, but also the number of parts and the number of assembly steps can be reduced.

  Further, since the water head difference between the negative pressure control unit 230 and the surface where the discharge port is formed becomes relatively small, the inclination angle of the liquid discharge head 3 as shown in FIG. 45 is different for each liquid discharge head. Therefore, the present invention can be suitably applied to various recording devices. This is because the difference in water and the like can be reduced, so that the negative pressure difference applied to the discharge ports of the respective recording element substrates can be reduced even when the plurality of liquid discharge heads 3 are used at different inclination angles. In addition, since the distance between the negative pressure control unit 230 and the recording element substrate 10 is reduced, the flow resistance therebetween is reduced, so that the pressure loss difference due to the change in the flow rate of the liquid is also reduced, so that more stable negative pressure control can be performed. .

  FIG. 48B is a schematic diagram showing the flow of the recording liquid inside the liquid ejection head 3. Compared with the circulation path shown in FIG. 46, the circuit is the same, but FIG. 48B shows the flow of the liquid in each component of the actual liquid discharge head 3. In the long second flow path member 60, a set of a common supply flow path 211 and a common recovery flow path 212 extending in the longitudinal direction of the liquid ejection head 3 are provided. The common supply flow channel 211 and the common recovery flow channel 212 are configured such that liquid flows in directions opposite to each other, and a filter 221 is provided on the upstream side of each flow channel, and foreign matter entering from the connection portion 111 or the like. Trap. As described above, the common supply channel 211 and the common recovery channel 212 are preferable in that the temperature gradient in the longitudinal direction in the liquid discharge head 3 is reduced by flowing the liquid in the opposite direction. In FIG. 46, the flows of the common supply channel 211 and the common recovery channel 212 are shown in the same direction for the sake of simplicity.

  A negative pressure control unit 230 is connected to the downstream side of the common supply channel 211 and the common recovery channel 212, respectively. Further, in the middle of the common supply channel 211, there are branches to the plurality of individual supply channels 213a, and in the middle of the common recovery channel 212, there are branches to the plurality of individual recovery channels 213b. The individual supply channel 213 a and the individual recovery channel 213 b are formed in the plurality of first channel members 50, and each individual channel is an opening 21 of the lid member 20 provided on the back surface of the recording element substrate 10. (See FIG. 19C).

  The negative pressure control unit 230 indicated by H and L in FIG. 48B is a unit having a high pressure side (H) and a low pressure side (L). Each negative pressure control unit 230 has a relatively high (H) and low (L) negative pressure, and is configured to control the pressure upstream of the negative pressure control unit 230. It is. The common supply flow path 211 is connected to the negative pressure control unit 230 (high pressure side), and the common recovery flow path 212 is connected to the negative pressure control unit 230 (low pressure side), whereby the common supply flow path 211 and the common recovery flow path are shared. A differential pressure is generated between the flow paths 212. Due to the differential pressure, the liquid sequentially passes from the common supply channel 211 to the individual supply channel 213a, the discharge port 13 (pressure chamber 23) in the recording element substrate 10, and the individual recovery channel 213b. It flows to.

  FIG. 48C is a perspective view showing a cross section taken along the line G-G in FIG. In this application example, each discharge module 200 includes the first flow path member 50, the recording element substrate 10, and the flexible wiring substrate 40. In the present embodiment, the support member 30 (FIG. 18) described in Application Example 2 is not provided, and the recording element substrate 10 including the lid member 20 is directly bonded to the first flow path member 50. The common supply flow channel 211 provided in the second flow channel member is connected to the individual supply flow channel from the communication port 61 formed on the upper surface thereof through the individual communication port 53 formed on the lower surface of the first flow channel member 50. 213a. Thereafter, the liquid is recovered via the pressure chamber 23 to the common recovery channel 212 via the individual recovery channel 213b, the individual communication port 53, and the communication port 61 in this order.

  Here, unlike the application example 2 shown in FIG. 15, the individual communication port 53 on the lower surface of the first flow channel member 50 (the surface on the second flow channel member 60 side) is the upper surface of the second flow channel member 60. The opening is sufficiently large with respect to the communication port 61 formed at the bottom. With this configuration, even when the position is shifted when the discharge module 200 is mounted on the second flow path member 60, fluid communication is reliably performed between the first flow path member and the second flow member. Therefore, the yield at the time of manufacturing the head can be improved and the cost can be reduced.

  Note that the description of the application example does not limit the scope of the present invention. As an example, in this application example, the thermal method in which bubbles are generated by a heating element to discharge liquid has been described. However, the present invention is also applied to a liquid discharge head that employs a piezo method and other various liquid discharge methods. be able to.

  In this application example, the ink jet recording apparatus (recording apparatus) in which liquid such as ink is circulated between the tank and the liquid discharge head has been described, but other forms may be used. In another embodiment, for example, two tanks are provided upstream and downstream of the liquid discharge head without circulating ink, and the ink in the pressure chamber is caused to flow by flowing ink from one tank to the other tank. It may be.

  Further, in this application example, an example using a so-called line type head having a length corresponding to the width of the recording medium has been described. However, a so-called serial type liquid discharge head that performs recording while scanning the recording medium. The present invention can also be applied to. As the serial type liquid discharge head, for example, a configuration in which a recording element substrate for discharging black ink and a recording element substrate for discharging color ink are mounted one by one, but the present invention is not limited to this. In other words, a short liquid ejection head shorter than the width of the recording medium is created by arranging a plurality of recording element substrates so that the ejection openings overlap in the row direction of the ejection opening row, and scan the recording medium with respect to the recording medium. It may be a form to be made.

  Embodiments showing the features of the present invention will be described below.

(First embodiment)
The liquid discharge head according to the first embodiment of the present invention will be described with reference to FIGS. The liquid supply channel in the application example described above corresponds to the first common supply channel in the embodiment. Similarly, the liquid recovery channel corresponds to the first common recovery channel, the first communication port corresponds to the opening, the common supply channel corresponds to the third common supply channel, and the common recovery channel corresponds to the third common recovery channel.

  FIG. 22 is an exploded view of the main part of the liquid ejection head in the embodiment of the present invention. 22 (a) to (g) are perspective views of the disassembled components, and FIGS. 22 (h) to (m) are the disassembled components shown in FIGS. 22 (b) to (g). It is a corresponding top view. FIG. 23 is a diagram schematically showing the structure focusing on one ejection port array 3024 of the plurality of ejection port arrays 3024 shown in FIG. 23 (a) to (d) are perspective views corresponding to FIGS. 22 (a) to (d), and FIGS. 23 (e) to (g) correspond to FIGS. 22 (h) to (j). FIG. 24A is a cross-sectional view taken along line XXIVa-XXIVa in FIGS. 23E to 23G, and FIG. 24B is a cross-sectional view taken along line XXIVb-XXIVb. FIG. 25 is an equivalent circuit diagram in which a part of the liquid ejection head of the present embodiment is cut out. FIG. 26 is a diagram illustrating an equivalent circuit diagram in which a part of the liquid ejection head according to the present embodiment is cut out and a pressure distribution in the flow path. FIG. 27 is a top view for explaining the shape of the recording element substrate of the present embodiment. FIG. 28 is a schematic transmission diagram for explaining an end portion of the ejection port array.

  As shown in FIGS. 22 to 24, the liquid discharge head according to the present embodiment includes the discharge port forming member 3012, the first flow path layer 3011, the second flow path layer 3050, the third flow path layer 3060, and the fourth flow path layer 3070. , A fifth channel layer 3080, and a sixth channel layer 3090.

  The discharge port forming member 3012 is provided with a plurality of discharge port arrays 3024 in which a plurality of discharge ports 3013 are arranged in a line. The first flow path layer 3011 is provided with a recording element 3015 that generates energy used for discharging liquid at a position corresponding to the discharge port 3013. The discharge port forming member 3012 and the first flow path layer 3011 are stacked so that a space serving as the pressure chamber 3023 and the flow path 3310 (FIG. 24) is formed therebetween. The liquid discharge head can discharge a liquid such as ink in the pressure chamber 3023 (in the flow path 3310) from the discharge port 3013 by the energy generated by the recording element 3015. The pressure in the static state of the flow path 3310 and the pressure chamber 3023 is maintained at a negative pressure so that a meniscus of liquid (ink) is stretched at the ejection port 3013. When the pressure in the pressure chamber varies, the ejection characteristics such as the liquid ejection speed and the volume of the ejected droplets are affected.

  As shown in FIG. 22, in the present embodiment, the plurality of ejection port arrays 3024 are arranged at a high density of 600 dpi. In the second channel layer 3050, a first common supply channel 3313 and a first common recovery channel 3314 are formed along the main surface. The third flow path layer 3060 is formed with a first communication port 3315a (supply side communication port) and a first communication port 3315b (collection side communication port). The first flow path layer 3011 is formed with a recording element array in which the recording elements 3015 are arranged and a through hole array in which through holes 3017 for supplying / collecting liquid are arranged. As shown in FIG. 24, these through holes 3017 include a supply port 3017a and a recovery port 3017b. The plurality of supply ports 3017a extend in a direction (second direction) intersecting the surface on which the recording elements 3015 are arranged to form a supply flow path, and the recording elements 3015 serving as the row direction of the ejection port array. Are arranged along the arrangement direction (first direction) in order to form a supply port array. Similarly, the plurality of recovery ports 3017b extend in a direction (second direction) intersecting with the surface on which the recording element 3015 is disposed to form a supply flow path, and are in the row direction of the discharge port array. The recording element 3015 is arranged along the arrangement direction (first direction) to form a collection port array.

  As shown in FIG. 24, the first common supply flow path 3313 communicates with the flow path 3310 and the pressure chamber 3023 via the supply port 3017a. Similarly, the first common recovery channel 3314 communicates with the channel 3310 and the pressure chamber 3023 via the recovery port 3017b. The first common supply flow path 3313 receives the supply of liquid from the first communication port 3315a (supply side communication port) formed in the third flow path layer 3060. Similarly, the first common recovery channel 3314 communicates with a first communication port 3315b (collection side communication port) formed in the third channel layer 3060. As shown in FIGS. 22D and 22J, the plurality of first communication ports 3315a are arranged in a direction intersecting with the row direction of the ejection port row to form a first communication port row. The plurality of first communication ports 3315b are also arranged in the same direction to form a first communication port array.

  In the fourth flow path layer 3070, a second common supply flow path 3331 and a second common recovery flow path 3332 are formed. In the fifth flow path layer 3080, a second communication port 3333a (supply side communication port) and a second communication port 3333b (collection side communication port) are formed. In the sixth flow path layer 3090, a third common supply flow path 3335 and a third common recovery flow path 3336 are formed.

  The first common supply channel 3313 of the second channel layer 3050 communicates with the plurality of supply ports 3017a on one surface side and communicates with the first communication port 3315a on the other surface side. Similarly, the first common recovery channel 3314 of the second channel layer 3050 communicates with the plurality of recovery ports 3017b on one surface side, and communicates with the first communication port 3315b on the other surface side. Further, the second common supply flow path 3331 of the fourth flow path layer 3070 communicates with the first communication port 3315a on one surface side, and communicates with the plurality of second communication ports 3333a on the other surface side. Similarly, the second common recovery channel 3332 of the fourth channel layer 3070 communicates with the first communication port 3315b on one surface side, and communicates with the second communication port 3333b on the other surface side. Here, at least one of the first communication port 3315a and the first communication port 3315b is plural. Further, the third common supply channel 3336 of the sixth channel layer 3090 communicates with the plurality of second communication ports 3333a. Similarly, the third common recovery channel 3336 of the sixth channel layer 3090 communicates with a plurality of second communication ports 3333b.

  The plurality of first communication ports 3315a (supply-side first communication ports) are arranged along the direction (third direction) intersecting the row direction (first direction) of the discharge port array, and the supply-side first A communication port array is formed. The plurality of first communication ports 3315b (collection side first communication ports) are arranged along the direction (third direction) intersecting the row direction (first direction) of the discharge port array, and the collection side first A communication port array is formed.

  The plurality of second communication ports 3333a (supply-side second communication ports) are arranged along the row direction (first direction) of the discharge port row to form a supply-side second communication port row. The plurality of second communication ports 3333b (collection side second communication ports) are arranged along the row direction (first direction) of the discharge port row to form a collection side second communication port row.

  The arrangement density of the plurality of second communication ports 3333a and the arrangement density of the plurality of second communication ports 3333b are smaller than the arrangement density of the plurality of first communication ports 3315a and the arrangement density of the plurality of first communication ports 3315b. In addition, the arrangement density of the plurality of first communication ports 3315a and the arrangement density of the plurality of first communication ports 3315b are lower than the arrangement density of the plurality of supply ports 3017a and the arrangement density of the plurality of recovery ports 3017b. Each of the first common supply flow path 3313 and the first common recovery flow path 3314 extends in the first direction, and the first common supply flow path 3313 and the first common recovery flow path 3314 are the first Are alternately arranged in parallel in a third direction that intersects the direction. The second common supply flow path 3331 and the second common recovery flow path 3332 extend along a third direction that intersects the first direction, and the second common supply flow path 3331 and the second common recovery flow path 3332 The paths 3332 are alternately arranged in parallel in the first direction. The third common supply channel 3335 and the third common recovery channel 3336 extend along the first direction.

  The liquid ejection head of this embodiment has a configuration in which the flow path density gradually increases from the sixth flow path layer 3090 to the first flow path layer 3011 by stacking the plurality of flow path layers in this way. can do. Accordingly, it is possible to provide a liquid discharge head including a plurality of high-density discharge port arrays while suppressing an increase in size of the recording element substrate and each flow path member.

  The flow of the liquid (hereinafter referred to as ink) in the liquid discharge head of this embodiment will be described. The ink supplied from the outside flows into the liquid outflow head from the third common supply channel 3336 as the inflow opening. Then, the ink that has flowed in passes through the second communication port 3333a, the second common supply channel 3331, the first communication port 3315a, the first common supply channel 3313, and the supply port 3017a in this order, and then the channel 3310 (pressure chamber 3023). ) Is supplied. The ink then flows out through the recovery port 3017b, the first common recovery channel 3314, the first communication port 3315b, the second common recovery channel 3332, the second communication port 3333b, and the third common recovery channel 3336 in this order. It flows out from the third common recovery flow path 3336 as an opening.

  By forcibly flowing the ink in this way, it is possible to suppress the increase in the viscosity of the ink in the ejection head. As a result, the ink ejection speed is reduced and the color material density of the recorded dots is modulated. Can be suppressed. Hereinafter, in this specification, such a forced flow of ink is referred to as “ink circulation flow”.

  This embodiment has the following configuration so as to suppress variations in the flow rate of the ink circulation flow flowing in each pressure chamber and variations in pressure in each pressure chamber. That is, as shown in FIG. 23, the first communication port 3315 a communicates with one first common supply flow path 3313. Similarly, the first communication port 3315b communicates with one first common recovery channel 3314. Here, at least one of the first communication port 3315a and the first communication port 3315b is plural. The first communication port 3315a and the first communication port 3315b are within a range in which the variation in the flow rate of the ink circulation flow flowing in each pressure chamber 3023 and the variation in the pressure in each pressure chamber do not significantly affect the ejection characteristics. Is arranged. In particular, with respect to one ejection port array 3024, the first communication ports 3315a and the first communication ports 3315b are alternately arranged in the column direction of the ejection port arrays. By arranging alternately, the space | interval of the 1st communicating port 3315a and the 1st communicating port 3315b can be made narrower. In other words, even when the channel widths of the first common supply channel 3313 and the first common recovery channel 3314 are relatively narrow, variations in the flow rate of the ink circulation flow flowing in each pressure chamber 3023 (each channel 3310) and each pressure It becomes possible to suppress variations in the pressure in the chamber.

  Further, the arrangement relationship between the first communication port 3315a and the first communication port 3315b is as follows. First, for each of the plurality of pressure chambers 3023 (channel 3310), the channel between the first common supply channel 3313 and the first common recovery channel 3314 including the pressure chamber 3023 (channel 3310). Let r be the resistance. Further, in the first common supply channel 3313, the channel resistance of the channel between the adjacent supply ports 3017a (that is, between the supply channels) is R. Similarly, in the first common recovery channel 3314, the channel resistance of the channel between adjacent recovery ports 3017b (that is, between the recovery channels) is R. In addition, regarding the flow rate of ink flowing through each flow path 3310 (pressure chamber 3023), the average flow rate thereof is q, and the discharge flow characteristics are not affected, that is, the maximum flow rate in a range where landing position deviation and color unevenness are not affected as an image. The difference between the flow rate and the minimum flow rate is Δq, and the ratio between the two is X. That is, the flow rate ratio X = Δq / q. At this time, the first communication port 3315 is arranged so that the number N of discharge ports between the first communication port 3315a and the first communication port 3315b satisfies the following expression.

  By disposing the first communication port 3315a and the first communication port 3315b under such conditions, variation in the flow rate of the ink circulation flow flowing in each pressure chamber 3023 (each flow path 3310) between the pressure chambers is discharged. It is possible to suppress the flow rate difference that does not affect the characteristics.

  The conditional expression (1) for suppressing the variation between the pressure chambers of the flow rate of the ink circulation flow flowing in each pressure chamber 3023 will be described in detail with reference to FIG. FIG. 25 is an equivalent circuit in which a part between the first communication port 3315a and the first communication port 3315b adjacent to each other in the first direction is cut out. The case where N pressure chambers 3023 (flow paths 3310) are included between the adjacent first communication port 3315a and first communication port 3315b is shown.

In this case, among the N pressure chambers 3023, the largest amount of ink is placed in the pressure chamber 3023 (pressure chamber 1 in FIG. 25) closest to the first communication port 3315a and the pressure chamber 3023 closest to the first communication port 3315b. Flows. Further, it has been found that the flow rate of the ink flowing into the pressure chamber 3023 at the intermediate position between the first communication port 3315a and the first communication port 3315b among the N pressure chambers 3023 is minimized. When the maximum flow rate and the minimum flow rate are q ₁ and q ₂ , respectively, and the average value of the flow rate of the ink flowing through each pressure chamber 3023 is q, the total ink amount Q to be supplied is Q = Nq.

The first communication port 3315a passes through the pressure chamber 3023 (pressure chamber 1 in FIG. 25) closest to the first communication port 3315a, passes through the first common recovery flow path 3314, and reaches the first communication port 3315b. The pressure loss p _{1 up} to is shown below.

The first common recovery channel from the first communication port 3315a through the first common supply channel 3313 and the pressure chamber (pressure chamber 2 in FIG. 25) located at an intermediate position between the first communication port 3315a and the first communication port 3315b. The pressure loss p ₂ until reaching the first communication port 3315b through 3314 is shown below.

Since the pressure loss p ₁ and the pressure loss p ₂ are equal, the flow rate difference Δq ′ between the maximum flow rate q ₁ and the minimum flow rate q _{2 of} ink flowing through each pressure chamber is calculated from the equations (2) and (3). The following equation holds.

Here, in order not to affect the ejection characteristics, the flow rate difference Δq ′ = q ₁ −q ₂ between the maximum flow rate and the minimum flow rate of the ink flowing through each pressure chamber and the average of the ink flowing through each pressure chamber. The ratio with the flow rate q needs to be set to a predetermined flow rate ratio X or less. For this purpose, at least the conditions shown by the following formula are required.

  When Expression (5) is transformed by paying attention to the number N of pressure chambers between the first communication port 3315a and the first communication port 3315b, Expression (1) is obtained.

  In the embodiment of the present invention, when the flow rate of the ink circulation flow is increased or decreased to a certain ratio or more, the ink collection effect by the ink circulation flow flowing under the ejection port is changed, and the ejection speed and the ejection droplet volume are changed. It is known that the difference in color material density becomes large. In particular, in one non-limiting example of the present embodiment, when the flow rate is increased or decreased by about 10% with respect to a certain flow rate of the ink circulation flow, the discharge speed and the discharge droplet volume change, and the color material density difference. Became bigger. Further, in this example, when the ratio Δq / q between the flow rate difference between the maximum flow rate and the minimum flow rate and the average flow rate is set to a predetermined flow rate ratio X0.2 or less, the discharge characteristics and the color material density are greatly affected. No longer occurs.

  Next, an example of the influence of variations in the flow rate of the ink circulation flow will be described with reference to FIG.

  FIG. 37 shows the flow rate (circulation flow rate) of the ink circulation flow that flows under each ejection port, and the ejection of the ink that is ejected for the first time after the ink ejection is paused for a fixed time while circulating the ink at each circulation flow rate. It is a graph which shows one non-limiting example of the relationship with speed. In this example, when the circulation flow rate is around 7000 pl / s with the circulation flow rate around 7000 pl / s as the boundary, the ink can be discharged from the first at a discharge rate of 90% or more of the normal discharge rate. did it. On the other hand, when the circulation flow rate was less than about 7000 pl / s, the first ink discharge speed was less than 90% of the steady-state discharge speed. When the ink ejection speed is reduced, the position where the ejected ink arrives at the recording medium (at the time of landing) is displaced, and as a result, the image quality is degraded.

  Therefore, in order to prevent a decrease in image quality due to a positional deviation at the time of landing, it is effective to increase the circulation flow rate to some extent so as to suppress a decrease in the ink ejection speed after a certain period of pause.

  Here, FIG. 36 shows an example of an ink supply system applicable to the liquid ejection head of the present invention. In FIG. 36, the liquid discharge head 3003 is in fluid communication with the first liquid tank 3044 on the upstream side and the second liquid tank 3045 on the downstream side. The first liquid tank 3044 supplies ink to the third common supply channel 3335. The supplied ink is supplied to the pressure chamber 3023 (flow path 3310) through the second common supply flow path 3331 and the first common supply flow path 3313 through each communication port. In addition, the second liquid from the third common recovery flow path 3336 passes through the first common recovery flow path 3314 and the second common recovery flow path 3332 from the pressure chamber 3023 (flow path 3310) via each communication port. It is collected into the tank 3045. In such a structure, there is a method of using a water head difference between the first liquid tank 3044 and the second liquid tank 3045 as means for generating the ink circulation flow. There is also a method of controlling the pressure of the first liquid tank 3044 and the second liquid tank 3045 and using the pressure difference between the first liquid tank 3044 and the second liquid tank 3045. There is also a method of generating a flow with a pump or the like.

  However, when the pressure difference between the first liquid tank 3044 and the second liquid tank 3045 is increased to increase the circulation flow rate, or when a large flow rate is caused to flow by a pump or the like, it is difficult to control the pressure below the discharge port. There is. Therefore, the circulation flow rate is preferably made as small as possible so that the discharge speed does not decrease excessively in consideration of both the deterioration in image quality due to the positional deviation of the ink upon landing and the difficulty of pressure control.

  As described above, in the present embodiment, the first common supply flow path 3313 and the first communication port 3313 and the first communication port 3315b are formed so as to satisfy at least one of the first communication port 3315a and the first communication port 3315b so as to satisfy the expression (1). One common collection flow path 3314 is disposed. As a result, the ratio (flow rate ratio) X between the flow rate difference between the maximum flow rate and the minimum flow rate and the average flow rate (flow rate ratio) X can be reduced while the ratio r / R of the fluid resistance is fixed. That is, without increasing the width of the first common supply flow path 3313 and the first common recovery flow path 3314, the variation in the flow rate of the ink circulation flow flowing through each pressure chamber 3023 is suppressed between the pressure chambers. can do. Accordingly, it is possible to suppress a drop in the discharge speed of the droplets due to the evaporation of moisture from the discharge port 3013 and the modulation of the color material density, so that it is possible to form a higher-definition and high-quality image.

  Similarly, in the present embodiment, it is possible to suppress the variation of the pressure of each pressure chamber 3023 between the pressure chambers. The pressure loss that occurs in the first common supply flow path 3313 and the first common recovery flow path 3314 is a variation in pressure between the pressure chambers in the row direction of the discharge port array. That is, when the pressure variation is ΔP, the following equation is established.

  Here, assuming that the maximum pressure variation that can be allowed within a range that does not affect the discharge characteristics is ΔPm, the first communication port 3315a and the first communication port 3315b are such that the number N of discharge ports between the two satisfies the following formula. Is arranged.

  As described above, in the present embodiment, the plurality of first communication ports 3315a and the plurality of first communication ports 3315b are replaced with the first common supply flow channel 3313 and the first common recovery flow channel 3314 so as to satisfy Expression (7). Respectively. Thereby, the dispersion | variation between the pressure chambers of each pressure chamber can be suppressed, without expanding the width | variety of the flow path of the 1st common supply flow path 3313 and the 1st common collection | recovery flow path 3314. Therefore, variation in ink ejection speed and volume of ejected ink droplets can be suppressed, so that higher-definition and high-quality image formation can be achieved.

  Furthermore, in the present embodiment, the variation in the flow rate of the ink circulation flow flowing through the pressure chambers corresponding to the discharge ports 3013 arranged at a high density between the pressure chambers and the variation in the pressure of each pressure chamber between the pressure chambers. In order to suppress, it is good to be as follows. That is, as shown in FIG. 22, the second common supply flow path 3331 extends in the direction (third direction) intersecting the row direction (first direction) of the discharge port row 3024 and is in the third direction. Are communicated with a plurality of first communication ports 3315a. Similarly, the second common recovery flow path 3332 extends in a third direction intersecting the row direction (first direction) of the discharge port row 3024, and has a plurality of first communication lines arranged in the third direction. It communicates with the mouth 3315b. Further, the plurality of second common supply channels 3331 are combined into one channel as the third common supply channel 3336 via the second communication port 3333a. Similarly, the plurality of second common third common recovery flow paths 3332 are combined into one flow path as the third common recovery flow path 3336 via the second communication port 3333b.

  Thus, in the present embodiment, the first flow path layer 3011, the second flow path layer 3050, the third flow path layer 3060, the fourth flow path layer 3070, and the fifth flow path with respect to the discharge port forming member 3012. A flow path is connected in a six-layer structure of a layer 3080 and a sixth flow path layer 3090. Accordingly, the first communication ports 3315a are arranged so that the plurality of first common supply channels 3313 arranged at a narrow pitch with respect to the plurality of discharge port arrays 3024 arranged at high density satisfy the formula (1). However, it can be combined into one. Similarly, a plurality of first common recovery channels 3314 arranged at a narrow pitch with respect to a plurality of discharge port arrays 3024 arranged at high density are arranged with first communication ports 3315b so as to satisfy the formula (1). However, it can be combined into one. That is, a high-density discharge port array can be formed without increasing the channel widths of the first common supply channel 3313 and the first common recovery channel 3314. In addition, the variation in the flow rate of the ink circulation flow flowing in each pressure chamber 23 (flow path 3310) corresponding to the ejection ports 3013 of the plurality of ejection port arrays 3024 arranged at high density, and the pressure in each pressure chamber. Variations between the pressure chambers can be suppressed. Further, with respect to the discharge ports 3013 arranged at a high density, the ink from the liquid tank is suppressed while suppressing the variation in the flow rate of the ink circulation flow in each pressure chamber 3023 (channel 3310) and the variation in the pressure in each pressure chamber. And the recovery of the ink to the liquid tank can be performed easily. Accordingly, there is an advantage that not only the liquid discharge head is made compact, but also the entire system of the liquid discharge apparatus including the liquid discharge head is made compact.

  In the present embodiment, the number of pressure chambers 3023 arranged in each discharge port row 3024 is large (for example, 100 or more), and the arrangement density of the plurality of discharge port rows 3024 (the discharge port row in the direction intersecting the discharge port row) This is effective when the arrangement density is high (for example, 50 dpi or more). In such a case, even if the ratio (r / R) of the flow path resistance between the pressure chamber and the flow path is small (for example, about 1/1000), the variation in the flow rate of the ink circulation flow tends to increase. . In other words, when the number of discharge ports constituting the discharge port array is further increased or the interval between the discharge port arrays is narrowed, the variation in the flow rate of the ink circulation flow in each pressure chamber, In order to suppress the pressure variation, the configuration of the present invention is effective. Therefore, the present invention is particularly effective for a line head that is a liquid ejection head having a length corresponding to the width of the recording medium, and a liquid ejection head having an ejection port arrangement density of 600 dpi or more.

  Next, in the present embodiment, a case where ink is ejected from a large number of ejection ports 3013 will be described. In the present embodiment, when ink is ejected from a large number of ejection ports 3013, it is preferable that the following be performed so as to suppress variations in the flow rate of the ink circulation flow that flows into the pressure chamber 3023 that is at rest. Let I be the flow rate of ink ejected from each ejection port 3013 by ejection. At this time, the 1st communicating port 3315a and the 1st communicating port 3315b are arrange | positioned so that the number N of the discharge ports 3013 between both may satisfy | fill the following formula | equation.

  In the present embodiment, the first communication port 3315a and the first communication port 3315b are arranged under such conditions. As a result, when ink is ejected from a large number of ejection ports 3013, variation in the flow rate between the pressure chambers of the circulating ink flow that flows through each pressure chamber 3023 is suppressed to a flow rate difference that does not affect the ejection characteristics. It becomes possible to do.

  With reference to FIG. 26, the conditional expression (8) for suppressing variation in the flow rate of the ink circulation flow that flows into the pressure chamber 3023 that is at rest when ink is ejected from a large number of ejection ports 3013 will be described in detail.

  In the case where the ink circulation flow is caused to flow at a flow rate sufficient to suppress the influence of water evaporation from the discharge ports 3013, the discharge amount when ink is discharged from a large number of discharge ports 3013 is more than the flow rate of the ink circulation flow. May increase. In such a case, as shown in FIG. 26A, the ink in the first common recovery flow path 3314 flows backward. That is, in FIG. 26A, in the first common supply flow path 3313, the ink flows in the direction from the first communication port 3315a toward the first communication port 3315b as indicated by an arrow. In addition, in each of the large number of pressure chambers 3023, the ink is discharged from the discharge ports at a flow rate I. Accordingly, in the first common recovery flow path 3314, the ink flows in the direction from the first communication port 3315b toward the first communication port 3315a.

  FIG. 26B is a graph showing the relationship between the pressure distributions of the first common supply flow path 3313 and the first common recovery flow path 3314 at this time. The horizontal axis of the graph indicates a relative position L from the adjacent first communication port 3315a toward the first communication port 3315b, and the vertical axis indicates the pressure P. When the ejection of ink from the pressure chamber 3023 is stopped in the state shown in FIG. 26A, the first common supply flow path 3313 side and the first common recovery flow path 3314 side with respect to each pressure chamber. Let the ratio of the amount of ink supplied be t: 1-t. At this time, if the pressure loss generated in the first common supply flow path 3313 is ΔPin1, and the pressure loss generated in the first common recovery flow path 3314 is ΔPout1, the following two expressions hold.

  In addition, the pressure generated on the first common supply flow path 3313 side for each pressure chamber is Pin, the pressure generated on the first common recovery flow path 3314 side is Pout, and the maximum value of the pressure variation in each pressure chamber is ΔPmax. And the minimum value is ΔPmin. At this time, since ΔPmax = Pin−Pout + ΔPout1 and ΔPmin = Pin−Pout−ΔPin1, the flow rate variation Δq ′ of the ink circulation flow is expressed by the following equation.

  In order to set the flow rate variation Δq ′ of the ink circulation flow to be equal to or less than the predetermined flow rate ratio X, a condition represented by the following equation is required.

  When Expression (12) is transformed by paying attention to the number N of pressure chambers between the first communication port 3315a and the first communication port 3315b, Expression (8) is obtained.

  Here, in this embodiment, as a non-limiting example of the present invention, the channel width of the first common supply channel 3313 and the first common recovery channel 3314 of the liquid ejection head is 200 μm, and the channel height is 500 μm. It was. Further, the discharge ports 3013 in the discharge port array 3024 are arranged so as to be arranged at a density of 600 dpi, and the shape of the flow channel 3310 below the discharge ports 3013 is 30 μm, the flow channel height is 14 μm, and the flow channel length is The thickness was set to 100 μm. In this liquid ejection head, the case where the flow rate of the ink circulation flow at the lower part of the ejection port was set to 0.01 m / s, and ink was ejected at an ejection amount of 5 pl and a driving frequency of 10 kHz was examined. In this case, by setting the number N of discharge ports between the first communication port 3315a and the first communication port 3315b to be about 65 or less, it was possible to suppress the influence of the flow rate variation.

  As described above, in this embodiment, at least one of the first communication port 3315a and the first communication port 3315b is plural so as to satisfy the expression (8), and the first common supply channel 3313 and the first common recovery channel 3314 are provided. Respectively. Thereby, the value of the flow rate ratio X can be reduced while the ratio r / R of the channel resistance is fixed. That is, when ink is ejected from a large number of ejection ports without increasing the channel widths of the first common supply channel 3313 and the first common recovery channel 3314, the pressure chamber 3023 (flow Variation in the flow rate of the ink circulation flow that flows through the path 3310) can be suppressed. Accordingly, it is possible to suppress a drop in ink droplet discharge speed and color material density modulation due to water evaporation from the discharge port 3013, and thus high-definition and high-quality image formation is possible.

  Furthermore, this embodiment preferably has the following configuration so as to suppress variations in the flow rate of the ink circulation flow flowing in each pressure chamber and variations in pressure in each pressure chamber. That is, the first communication port 3315a or the first communication port 3315b arranged on both end sides in the row direction of the discharge port row 3024 is more than the first communication port 3315a or the first communication port 3315b arranged on the side other than the both end sides. Has a small shape (opening area).

  When viewed from the first communication port 3315a or the first communication port 3315b disposed on both ends, the discharge port 3013 is disposed only on one side in the column direction of the discharge port array. Therefore, the total ink amount Q passing through the first communication port 3315a or the first communication port 3315b is equal to the first communication port 3315a or the first communication port arranged at a location different from the both end sides in the column direction of the ejection port array. This is less than the total amount of ink passing through 3315b. Accordingly, the first communication port 3315a or the first communication port 3315b on both ends is made smaller in shape than the center, and the flow resistance is increased, so that the first communication is arranged at a location different from the end. The pressure loss generated at 3315a or the first communication port 3315b can be approached. Therefore, the flow of the ink circulation flow passing through the pressure chamber communicating with the first communication port 3315a or the first communication port 3315b on both ends, and the pressure chamber communicating with the first communication port 3315a or the first communication port 3315b different from the flow. The difference in the flow of the ink circulation flow through the ink can be reduced. Thereby, it is possible to further suppress variation in the flow rate of the ink circulation flow flowing in each pressure chamber.

  The further aspect of this embodiment is demonstrated using FIG. 27 and FIG. The present embodiment is configured as follows so as to suppress variations in the flow rate of the ink circulation flow that flows in each pressure chamber 3023.

  FIG. 27 is a top view of the recording element substrate of the liquid ejection head according to the present embodiment. As shown in FIG. 27, in the recording element substrate 3010 of this embodiment, the area between the end of the ejection port array 3024 and the end of the recording element substrate 3010 is large. For example, in this region, a pad for transmitting / receiving an electric signal to / from the recording element substrate 3010 and a circuit for driving are arranged.

  FIG. 28 is a schematic top transparent view in which a part of one ejection port array 3024 of the liquid ejection head of this embodiment is cut off. In FIG. 28, the arrows indicate the direction of the ink circulation flow. In the case of the recording element substrate 3010 as shown in FIG. 27, as shown in FIGS. 28A and 28B, the first communication port 3315b overlaps with the discharge port 3013 at the end of the discharge port array 3024. Has been placed. On the other hand, FIG. 28C shows an example of an arrangement in which the first communication port 3315 b does not overlap the end of the discharge port 3013. 28A and 28B, compared with the configuration of FIG. 28C, the first communication port passes through the pressure chamber 3023 from the first communication port 3315a at the end of the discharge port array 3024. The length of ink flow up to 3315b can be shortened. That is, by arranging as shown in FIG. 28A and FIG. 28B, the maximum pressure loss generated in the first common supply flow path 3313 and the first common recovery flow path 3314 near the end of the discharge port array 3024 is reduced. Can be small. Therefore, the flow rate variation of the ink circulation flow flowing through each pressure chamber 3023 can be suppressed. A configuration in which the first communication port 3315a is arranged to overlap the discharge port at the end of the discharge port array 24 instead of the first communication port 3315b is also applicable.

  The further aspect of this embodiment is demonstrated using FIG. This embodiment is as follows in order to suppress the temperature distribution in the chip (recording element substrate 3010). That is, as shown in FIGS. 22D and 22J, the first communication ports 3315 on both ends in the row direction of the discharge port row 3024 are both first communication ports 3315b.

  When the ink in each pressure chamber is forcibly convected as in the configuration of the present embodiment, the recovery side that normally flows out of the pressure chamber is recovered by the liquid (ink) recovering the heat generated from the recording element 3015 or the like. The temperature of the ink becomes high. Further, even when the ink circulation flow is made at a flow rate sufficient to suppress the influence of moisture evaporation from the ejection ports 3013, the ejection amount when ejecting ink from the large number of ejection ports 3013 may be larger. is there. At that time, ink is also supplied from the first communication port 3315b through the third common recovery flow path 3336. That is, when ink is ejected from many ejection ports 3013, high-temperature ink may be supplied from the first communication port 3315b. As a result, the temperature in the vicinity of the first communication port 3315b is higher than that in the vicinity of the first communication port 3315a, and the discharge is performed between the discharge port 3013 in the vicinity of the first communication port 3315a and the discharge port 3013 in the vicinity of the first communication port 3315b. A speed difference occurs. Therefore, when different types are arranged such that one end side of the first communication ports 3315 on both end sides of the discharge port array 3024 is the first communication port 3315a and the other end side is the first communication port 3315b. When the entire row 3024 is viewed, a gradient of heat distribution occurs in the row direction. For this reason, the heat distribution width of the entire chip is increased, and as a result, the ejection characteristics vary as a whole chip. In other words, since the first communication port 3315b, which is the same type of flow path, is used at both ends in the column direction of the discharge port array 3024, the inclination of the heat distribution can be suppressed, and thus the discharge characteristics vary. Can be suppressed.

  In FIGS. 22D and 22J, both end portions are both the first communication port 3315b, but both end portions are also used as the first communication port 3315a. There is. However, as shown in FIGS. 22D and 22J, it is preferable that both end portions in the row direction of the discharge port row 3024 are the first communication port 3315b. The recording element substrate 3010 of this embodiment has a large area where the ejection ports 3013 between the both ends of the ejection port array 3024 and the end of the recording element substrate 3010 are not arranged, and the heat generated during ink ejection is in this area. Heat is dissipated. For this reason, when ink is ejected from a large number of ejection ports 3013, the temperature tends to be lower at both ends in the column direction of the ejection port array 3024 than at other locations. On the other hand, by setting both ends to the first communication port 3315b, it is possible to supply ink having a high temperature to both ends, and the temperature at both ends can be further increased. The temperature difference can be reduced. That is, since the heat distribution width of the entire chip can be reduced, it is possible to suppress variations in ejection characteristics.

  In the present embodiment, the first communication port 3315a and the first communication port 3315 are provided with a plurality of both, but the present invention is provided with a plurality of at least one of the first communication port 3315a and the first communication port 3315. I need it. That is, the present invention includes a configuration in which a plurality of at least one of the first communication port 3315a and the first communication port 3315b is provided to suppress variation in ejection characteristics. For example, a configuration including two first communication ports 3315a and one first communication port 3315b is also included in the present invention. As another example, the present invention includes a configuration including one first communication port 3315a and two first communication ports 3315b.

  Further, the relationship between each flow path layer and the member configuration in each embodiment of the present invention does not limit the present invention. In each layer configuration of the discharge port forming member and the first flow path layer to the sixth flow path layer, the liquid discharge head may be configured by laminating different members, or a plurality of layers are integrally formed. A liquid discharge head may be configured as the member. As an example, the following two configuration examples can be given. In one configuration example, the first flow path layer 3011 and the second flow path layer 3050 are integrally formed as the recording element substrate 10 in the application example described above. Specifically, a supply port 3017a, a recovery port 2017b, a first common supply channel 3313, and a first common recovery channel 3314 are formed on a Si substrate provided with a recording element 3015. The third flow path layer 3060 is formed on the lid member 20 or 2020, and a part of the fourth flow path layer 3070 is formed on the support member 30 in FIG. The other part of the fourth flow path layer 3070 is formed in the first flow path member 50 in FIG. 7, and the fifth flow path layer 3080 and the sixth flow path layer 3090 are part of the second flow path member 60. To form. Another part of the sixth flow path layer 3090 is formed in the third flow path member 70. In the second configuration example, the first flow path layer 3011 and the second flow path layer 3050 are formed on the recording element substrate 10 in the application example described above. The third flow path layer 3060 is formed on the lid member 20 or 2020, and a part of the fourth flow path layer 3070 is formed on the support member 2030. The other part of the fourth flow path layer 3070 and the fifth flow path layer 3080 are formed in the first flow path member 2050, and the sixth flow path layer 3090 is formed in the second flow path member 2060. The first flow path layer 3011 may be formed on the recording element substrate 10 and the second flow path layer 3050 may be formed on the second substrate.

(Liquid discharge head manufacturing process)
FIG. 38 shows an example of a manufacturing process of the liquid discharge head of this embodiment. As shown in FIG. 38, in this example, first, in step S91, an ejection port forming member 3012 is provided on a recording element substrate 3010 on which the recording element 3015 and necessary circuits have already been formed. Is formed (discharge port forming step). Next, in step S92, a supply port 3017a and a recovery port 3017b are formed on the back surface that is the surface opposite to the discharge port forming surface of the recording element substrate 3010 (back surface supply / recovery flow path forming step). Next, in step S93, the lid member 20 is formed on the back surface of the recording element substrate 10 so as to cover the supply port 3017a and the recovery port 3017b (lid member forming step). Next, in step S94, the outer shape of the recording element substrate 10 having the laminated structure obtained in step S93 is processed from the wafer form to the chip form (cutting process). In step S95, the chip-shaped recording element substrate 10 obtained in step S94 is joined to the support member 30 (joining step).

  Thus, in this example, the third flow path layer 3060 (lid member 20) is formed on the back surface of the recording element substrate 3010 (recording element substrate 10) by the lid member forming step (S93) before the joining step (S95). Form. Thereby, the 1st communication port 3315a and the 1st communication port 3315b can be formed in the wafer process which processes a board | substrate with a wafer form. By forming the lid member 20 in the wafer process, the shape accuracy of the member becomes better than when the member is manufactured by machining or molding. Therefore, it becomes possible to form finer holes with higher density. Further, the lid member 20 can be made thinner. Therefore, the discharge ports can be arranged with high density. In addition, the flow resistance of the first communication port 3315a and the first communication port 3315b can be reduced, and variation thereof can be reduced. Therefore, it is possible to stabilize the differential pressure that generates the ink circulation flow, and to reduce the variation in the circulation flow rate.

  Here, from the viewpoint of the manufacturing process, the lid member 20 may be made of a silicon substrate. That is, since the lid member 20 made of a silicon substrate in the wafer form can be bonded to the recording element substrate 10 in the wafer form, the number of processes can be reduced compared to bonding the lid member 20 for each chip obtained by cutting the wafer. It becomes possible.

  Alternatively, the lid member 20 may be made of a resin film. As in the case of the silicon substrate, the lid member 20 can be joined by laminating the resin in the form of a film on the recording element substrate 10 in the wafer form. Can be reduced.

  Here, the order of the steps shown in the present embodiment and the contents of the steps are examples of the present invention and do not limit the present invention. In other words, the order of the discharge port forming step, the back surface supply / recovery channel forming step, the lid member forming step, and the cutting step does not limit the present invention, and the order before the joining step (S95). May have a lid member forming step (S93).

(Second Embodiment)
A liquid discharge head according to a second embodiment of the present invention will be described with reference to FIGS. The same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 29 is an exploded view of the main part of the liquid ejection head in the embodiment of the present invention. 29 (a) to 29 (g) are perspective views of the disassembled components, and FIGS. 29 (h) to 29 (m) are plan views of the disassembled components.

  FIG. 30 is a top view illustrating the shape of the recording element substrate of the liquid ejection head according to the present embodiment. FIG. 31 is a schematic transparent view of the liquid discharge head for explaining the end portion of the discharge port array. FIG. 32 is a diagram for explaining the variation in the circulation flow rate of the present embodiment. 32 (a) and 32 (b) are top surface transparent views of the recording element substrate, and FIGS. 32 (c) and 32 (d) show the pressure distribution in the first common supply channel and the first common recovery channel. It is an image figure.

  As shown in FIG. 30, the recording element substrate 4010 in the present embodiment has a parallelogram shape, and compared with the configuration of the recording element substrate 3010 of the first embodiment shown in FIG. Area between the recording element and the end of the recording element substrate 4010 is small. In such a case, a pad formed on the recording element substrate 4010 for transmitting / receiving an electric signal to / from the outside and a circuit for driving are arranged on the long side of the recording element substrate 4010. In this embodiment, such a recording element substrate 4010 is used. As a result, even in a line head in which a plurality of recording element substrates 4010 are arranged in a substantially single row instead of a staggered pattern, the ejection port arrays of adjacent recording element substrates 4010 are adjacent to each other in the adjacent portions of the recording element substrates 4010. Can be easily superimposed on the scanning direction. Here, the scanning direction refers to a moving direction of the liquid discharge head relative to the medium when recording is performed on the medium by the liquid discharge head. The substantially one-line shape means that adjacent recording element substrates 4010 are partially overlapped in both the longitudinal direction of the liquid discharge head (arrangement direction of the recording element substrates) and the scanning direction. It is that.

  As shown in FIG. 30, in the second embodiment, the ejection port 3013 is arranged near the end of the recording element substrate 4010. As described with reference to FIGS. 28A and 28B, in the first embodiment, the first communication port 3315a and the first communication port 3315b are provided at positions that overlap the end of the ejection port array of the recording element substrate 3010. It was arranged. However, in the second embodiment, unlike the first embodiment, the first communication port 3315a and the first communication port 3315b are arranged at a position overlapping the end of the ejection port array of the recording element substrate 4010. This is difficult in forming the member. Therefore, as shown in FIG. 31, the first communication port 3315a and the first communication port 3315b are arranged at a position farther from the end of the discharge port array 3024 to the center side in the column direction of the discharge port array.

  In the present embodiment, in order to suppress the variation in the flow rate of the ink circulation flow flowing between the pressure chambers (between the flow paths), the pressure variation in the pressure chambers (flow paths), and the temperature distribution in the recording element substrate 4010, It is as follows. That is, as shown in FIG. 29, the first communication port 3315a is arranged on both end sides in the row direction of the discharge port row 3024.

  FIG. 32 is a diagram showing an example of a state when liquid is discharged from a large number of discharge ports. 32A and 32B, arrows indicate the direction of ink flow, and ΔPin2, ΔPout2, ΔPin3, and ΔPout3 indicate pressure losses that occur in the respective flow paths. Fig. 32 (c) shows the pressure distribution corresponding to the state of Fig. 32 (a), and Fig. 32 (d) shows the pressure distribution corresponding to the state of Fig. 32 (b). 32C and 32D, the solid line indicates the pressure in the first common supply flow path 3313, and the two-dot chain line indicates the pressure in the first common recovery flow path 3314.

As shown in FIG. 32 (a), the first common at the end of the discharge port array 3024 when the first communication port 3315 at the end in the column direction of the discharge port array is the first communication port 3315a. A differential pressure between the supply flow path 3313 and the first common recovery flow path 3314 is denoted by ΔP2. Similarly, as shown in FIG. 32B, when the first communication port 3315 at the end in the row direction of the discharge port row is the communication port 3315b, the first at the end of the discharge port row 3024 is displayed. A differential pressure between the common supply flow path 3313 and the first common recovery flow path 3314 is denoted by ΔP3. At this time, the following equations are obtained.
ΔP2 = (Pin−ΔPin2) − (Pout−ΔPout2) = (Pin−Pout) + (ΔPout2−ΔPin2) (13)
ΔP3 = (Pin−ΔPin3) − (Pout−ΔPout3) = (Pin−Pout) − (ΔPin3−ΔPout3) (14)

  Here, from the positional relationship between the end of the discharge port array and the first communication port 3315 (the first communication port 3315a and the first communication port 3315b), the pressure loss becomes ΔPout2> ΔPin2 and ΔPin3> ΔPout3. . Thereby, the differential pressure ΔP2 becomes larger than the initial differential pressure (Pin−Pout) when the initial ejection is not performed, and the differential pressure ΔP3 becomes smaller than the initial differential pressure. When the differential pressure becomes smaller, the ink circulation flow becomes smaller, and the effect of suppressing the drop in the discharge speed of the droplets due to the evaporation of water from the ejection port and the modulation of the color material density becomes smaller. Is big. Therefore, by arranging the first communication port 3315a at both ends of the discharge port array 3024 in the column direction, it is possible to reduce the influence of flow rate variation.

  Further, the first communication port 3315a has a pressure higher than that of the first communication port 3315b in order to generate an ink circulation flow, thereby making it easier to supply ink when ink is ejected. The first communication port 3315a that can easily supply ink is disposed near the end of the ejection port array 3024. As a result, when ink is ejected from a large number of ejection ports, the pressure loss that occurs in the first common supply channel 3313 and the first common recovery channel 3314 can be reduced by bringing the ink communication port 3315b closer to the end of the ejection port array 24. It can be made smaller than when it is placed.

  Further, as shown in FIG. 30, in the present embodiment, unlike the first embodiment, in the recording element substrate 4010, between the both ends in the column direction of the ejection port array 3024 and the end of the recording element substrate 4010. The area where there is no ejection port (no printing element) is small.

  In the case of such a structure, heat dissipation from this region of heat generated during ejection is limited. Conversely, the lengths of the first common supply channel 3313 and the first common recovery channel 3314 from the first communication port 3315a and the first communication port 3315b to the end in the column direction of the discharge port array 3024 become longer. The ink flowing through the long flow path easily receives heat from the recording element substrate 4010, and when ink is ejected from a large number of ejection ports 3013, the temperature is higher at both ends in the column direction of the ejection port array 3024 than at other locations. Tend. In addition, due to the length of the flow path, the pressure loss that occurs in each flow path during discharge also increases, and the pressure variation at the end of the discharge port array 3024 tends to increase.

  On the other hand, in this embodiment, the 1st communicating port 3315a is arrange | positioned together in the both end part side of the discharge port row | line | column 3024. FIG. As a result, the discharge port 3013 near the end in the column direction of the discharge port array 3024 is closer to the first communication port 3315a, which is the first communication port 3315 disposed closer than the first communication port 3315b. A lot of ink will be supplied. Accordingly, when ink is ejected from a large number of ejection ports 3013, the amount of high-temperature ink supplied from the first communication port 3315b is reduced, so that the temperature rise at the end of the ejection port array 3024 can be reduced. .

  As described above, in this embodiment, the both ends in the row direction of the discharge port row 3024 are both the first communication ports 3315a, thereby reducing the influence of flow rate variation, pressure variation, and in-chip temperature distribution. be able to. Therefore, it is possible to suppress the drop in the discharge speed of the droplets due to the evaporation of moisture from the discharge port, the modulation of the color material density, and the variation in the discharge characteristics, so that higher-definition and high-quality image formation can be achieved. It becomes possible.

  Next, the temperature distribution of the entire recording element substrate 4010 in this embodiment will be described with reference to FIG. FIG. 39 is a graph showing the temperature distribution when discharging from all the discharge ports in the column direction of the discharge port array 3024. The recording element substrate 4010 is in a state where temperature control is performed at 50 degrees Celsius.

  A case where the flow rate of ink ejected from the ejection port by ejection is greater than the flow rate of the ink circulation flow will be described. The direction of the ink circulation flow in the first communication port 3315a and the first communication port 3315b is a flow toward the ejection port 3013. Further, the ink flow rate at the first communication port 3315a and the first communication port 3315b tends to be higher at the first communication port 3315a.

  FIGS. 39A and 39B are graphs showing the relationship between the position and temperature of the first communication port 3315a and the first communication port 3315b in one ejection port array 3024. FIG.

  FIG. 39A shows a temperature distribution in the case where one first communication port 3315a and one first communication port 3315b are arranged for one discharge port array 3024 as a comparative example. Since the ink flowing through the first common supply channel 3313 and the first common recovery channel 3314 receives heat from the recording element substrate 4010, the temperature of the central portion of the channel away from the communication port is high. Further, when comparing the temperatures of the first communication port 3315a and the first communication port 3315b, the first communication port 3315a has a lower temperature because the flow rate of the ink circulation flow is larger.

  Even when the ink does not flow back toward the ejection port 3013 at the first communication port 3315b, the ink that has received heat from the recording element substrate flows through the first communication port 3315b. Therefore, the temperature of the first communication port 3315a tends to be low.

  FIG. 39B shows a temperature distribution when a plurality of first communication ports 3315a and a plurality of first communication ports 3315b are alternately arranged with respect to one ejection port array in the present embodiment.

  In the present embodiment, a plurality of first communication ports 3315a and a plurality of first communication ports 3315b are arranged. Therefore, compared with the comparative example of FIG. 39A, the distance between the adjacent first communication port 3315a and the first communication port 3315b is short. Therefore, the length of the ink flowing through the first common supply channel 3313 and the first common recovery channel 3314 is shortened, and the temperature rise of the ink due to receiving heat from the recording element substrate while flowing through the channel is small. It has become. In this example, in particular, the temperature of the first communication port 3315b is similar to the temperature of the first communication port 3315a.

  In the present embodiment, since the first communication port 3315a and the first communication port 3315b are alternately arranged in the row direction of the discharge port array, the ink is supplied to the first common supply channel 3313 and the first common recovery flow. The maximum length flowing through the path 3314 is shortened. This also reduces the temperature rise of the ink due to receiving heat from the recording element substrate while flowing through the flow path.

  As described above, in the present embodiment, a plurality of first communication ports 3315a and a plurality of first communication ports 3315b are alternately arranged with respect to one ejection port array, as shown in FIG. Compared with the comparative example, the temperature difference in the recording element substrate 4010 can be reduced. Therefore, since variation in ejection characteristics can be suppressed, higher-definition and high-quality image formation can be performed.

  FIG. 39C shows the case where the first communication port 3315a and the first communication port 3315b with respect to the plurality of ejection port arrays 3024 are shifted in accordance with the parallelogram outline of the recording element substrate 4010. The temperature distribution of the communication port in the discharge port array 3024 is shown. In the drawing, the description of the discharge port forming member and the discharge port is omitted.

  Although there is a difference in the absolute value of the temperature of each ejection port array itself depending on the position of the ejection port array, the positions of the first communication port 3315a and the first communication port 3315b in the column direction of the ejection port array among the plurality of ejection port arrays. It can be seen that the position where the temperature is high and the position where the temperature is low are shifted according to the deviation.

  FIG. 39D is a graph in which the temperature distribution in FIG. 39C is averaged with respect to the direction in which the plurality of ejection port arrays 3024 are arranged. Since the position where the temperature is high and the position where the temperature is low in each ejection port array is shifted, the temperature difference in the recording element substrate 4010 when averaged is the temperature when all the ejection port arrays in FIG. 39C are considered individually. It is smaller than the difference. Accordingly, if the scanning direction of the recording medium (the relative scanning direction of the liquid ejection head and the recording medium) is a direction (particularly the vertical direction) that intersects the direction of the ejection port array 3024, the ejection characteristics due to the temperature difference. The effect of variation can be averaged.

  As described above, in the present embodiment, the positions of the first communication port 3315a and the first communication port 3315b in the row direction of the first communication port 3315a with respect to the plurality of discharge port rows are shifted from each other between the discharge port rows. Thereby, the temperature difference resulting from the arrangement position of the 1st communicating port 3315a and the 1st communicating port 3315b can be averaged. Therefore, since variation in ejection characteristics can be suppressed, higher-definition and high-quality image formation can be performed.

(Third embodiment)
FIG. 33 is a diagram for explaining a liquid ejection head according to the third embodiment of the present invention. The same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 33 is an exploded view of the main part of the liquid ejection head in the embodiment of the present invention. 33 (a) to 33 (f) are perspective views, and FIGS. 33 (g) to 33 (l) are plan views.

  In the present embodiment, as shown in FIG. 33, one first common supply channel 5313 communicates with a pressure chamber 3023 disposed in two discharge port arrays 3024. Similarly, one first common recovery flow path 5314 communicates with the pressure chamber 3023 arranged in the two discharge port arrays 3024. That is, as shown in FIGS. 33 (g) and 33 (h), one first common supply flow path 5313 or one first common recovery flow path 5314 is positioned between two adjacent discharge port arrays 3024. It has been.

  This embodiment is preferable in the following points in addition to the effects of the first embodiment. That is, by sharing the first common supply flow path 5313 and the first common recovery flow path 5314 of two adjacent discharge port arrays, the number of partition walls between the flow paths can be reduced. In addition, since the flow path resistance is proportional to the square of the flow path width, when the number of discharge ports is the same N, the first common supply flow path 3313 or the first common recovery flow path 3314 in the first embodiment is equivalent to two. Equation (1) can be established for the two discharge port arrays with a channel width smaller than the channel width. Further, in the case of the same discharge port row interval, the flow channel resistance R of the first common supply flow channel 5313 or the first common recovery flow channel 5314 of the formula (1) for one discharge port row can be reduced, and the discharge The number N can be increased.

  Accordingly, the discharge port arrays 3024 can be arranged at a higher density than in the above-described embodiment while further suppressing variations in the flow rate of the ink circulation flow flowing in each pressure chamber and variations in pressure in each pressure chamber. Can do. Therefore, the size (chip size) of the recording element substrate can be reduced. Further, when the density of the ejection port array 3024 is the same, the variation in the flow rate of the ink circulation flow flowing in each pressure chamber between the pressure chambers and the variation in the pressure in each pressure chamber between the pressure chambers are further suppressed. However, the number of first communication ports 3315a and first communication ports 3315b can be reduced. Therefore, the flow path structure of the liquid discharge head can be further simplified.

(Fourth embodiment)
FIG. 34 is a diagram for explaining a liquid discharge head according to the fourth embodiment of the present invention. The same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 34 is an exploded view of the main part of the liquid ejection head in the embodiment of the present invention. 34 (a) to (g) are perspective views, and FIGS. 34 (h) to (m) are plan views.

  As shown in FIG. 34, in this embodiment, an ejection port 6051 for ink 1 and an ejection port 6061 for ink 2 for ejecting different colors or different types of ink are arranged in one liquid ejection head. Yes. The first flow path member 3050 includes a first common supply flow path 6052 for ink 1, a first common supply flow path 6062 for ink 2, a first common recovery flow path 6053 for ink 1, and a first common supply flow path 6053 for ink 2. One common recovery channel 6063 is formed. Further, the second flow path member 3060 has a first communication port 6054a for ink 1, a first communication port 6064a for ink 2, a first communication port 6054b for ink 1, and a first communication port 6064b for ink 2. Is formed. Further, the third flow path member 3070 includes a second common supply flow path 6056 for ink 1, a second common supply flow path 6066 for ink 2, a second common recovery flow path 6057 for ink 1, and an ink 2 use. The second common recovery flow path 6067 is formed. Further, the fourth flow path member 3080 has a second communication port 6058a for ink 1, a second communication port 6068a for ink 2, a second communication port 6058b for ink 1, and a second communication port for ink 2. 6068b is formed. The fifth channel member 3090 includes a third common supply channel 6070 for ink 1, a third common supply channel 6080 for ink 2, a third common recovery channel 6071 for ink 2, and an ink 2 A third common recovery flow path 6081 is formed. For each of the inks 1 and 2, as in the third embodiment, the ink supplied from the third common supply channels 6070 and 6080 passes through the pressure chamber 3024 (channel 3310) and the third common recovery channel 6071. , 6081 so as to flow out.

  Note that, as in the third embodiment, a mode in which one first common supply channel communicates with pressure chambers arranged in two discharge port arrays may be taken. Similarly, a mode in which one first common recovery channel communicates with pressure chambers arranged in two discharge port arrays can be taken.

  Further, the third common supply channel 6070 and the third common recovery channel 6071 for the ink 1 and the third common supply channel 6080 and the third common recovery channel 6081 for the ink 2 are connected to the sixth channel layer. The size 3090 may be larger than the recording element substrate 3010. That is, the sixth flow path layer 3090 can take a form that becomes wider in a direction (for example, a vertical direction) intersecting with the discharge port array 3024 array direction, for example.

  Further, as in the present embodiment, when liquids of different colors are ejected by one liquid ejection head, the liquid ejection head can be reduced in size while suppressing color mixing with the following configuration. Specifically, the interval between the first common supply flow path 6052 and the first common recovery flow path 6053 for supplying the same color liquid in FIGS. It is preferable to make it smaller than the interval between the flow paths supplying liquids of different colors (thickness of the wall partitioning both flow paths). More specifically, the first common supply flow path 6052 for supplying the liquid for the ink 1 and the first common recovery flow path for recovering the liquid for the ink 2 adjacent to the first common supply flow path 6052 for supplying the liquid for the ink 1 It is set to be smaller than the interval with 6053.

  As described above, even in the liquid discharge head for multi-color ink or multi-type ink, the ink flowing between the pressure chambers without increasing the width of the first common supply channel and the first common recovery channel. Variations in circulation amount and pressure variations in each pressure chamber can be suppressed. Therefore, it is possible to suppress the drop in the discharge speed of the droplets and the modulation of the color material density due to the evaporation of moisture from the discharge port, so that higher-definition and high-quality image formation is possible.

(Fifth embodiment)
FIG. 35 is an external perspective view showing examples of various liquid discharge heads to which the present invention can be applied.

  FIG. 35A shows an example of a liquid discharge head in the form of a single recording element substrate to which the present invention can be applied. The liquid discharge head performs recording while repeating reciprocating movement with respect to the recording medium. A fifth flow path layer 7080 is disposed on the sixth flow path layer 7090, and a fourth flow path layer 7070 is disposed thereon. Further, a recording element substrate 7010 including a third flow path layer 7060 and a second flow path layer 7050 is disposed on the support member 7030.

  FIGS. 35B and 35C show examples of liquid discharge heads in the form of line heads in which a plurality of recording element substrates 7010 are arranged in a staggered manner. In FIG. 35B, the recording element substrates 7010 are disposed on a common support member 7032. In FIG. 35C, each recording element substrate 7010 is disposed on an individual support member 7034.

  FIGS. 35D and 35E show examples of a liquid discharge head in the form of a line head in which a plurality of recording element substrates 7010 are arranged in a line. In FIG. 35D, each recording element substrate 7010 is disposed on a common support member 7032. In FIG. 35E, each recording element substrate 7010 is disposed on an individual support member 7034. In this case, the recording element substrate 7010 may be shaped like the recording element substrate 4010 in the fourth embodiment.

  Such various liquid ejection heads of this embodiment can generate the above-described ink circulation flow. Thereby, it is possible to suppress variations in the amount of circulating ink flowing between the pressure chambers and pressure variations in the pressure chambers. Therefore, it is possible to suppress the drop in the discharge speed of the droplets and the modulation of the color material density due to the evaporation of moisture from the discharge port, so that higher-definition and high-quality image formation is possible.

3003 Liquid discharge head 3010 Recording element substrate 3011 First flow path layer 3012 Discharge port forming member 3013 Discharge port 3015 Recording element 3310 Flow path 3315a First communication port (supply side)
3315b 1st communication port (collection side)
3017a Supply port 3017b Recovery port 3023 Pressure chamber 3050 Second channel layer 3060 Third channel layer 3070 Fourth channel layer 3080 Fifth channel layer 3090 Sixth channel layer

Claims (22)

First and second recording element substrates each including an ejection port for ejecting liquid and a recording element for generating energy for ejecting liquid from the ejection port;
A liquid ejection head comprising: a support member in which the first and second recording element substrates are arranged in a first direction;
A supply port for supplying liquid from the support member to the first and second recording element substrates on each of the surfaces of the first and second recording element substrates on the support member side, and the liquid A recovery port for recovering from the first and second recording element substrates to the support member, and
In the liquid supply port and the recovery port provided in each of the first and second recording element substrates, the supply port is provided at both end sides in the first direction. head. First and second recording element substrates each including an ejection port for ejecting liquid and a recording element for generating energy for ejecting liquid from the ejection port;
A support member in which the first and second recording element substrates are arranged in a first direction;
A liquid ejection head comprising:
A supply port for supplying liquid from the support member to the first and second recording element substrates on each of the surfaces of the first and second recording element substrates on the support member side, and the liquid A recovery port for recovering from the first and second recording element substrates to the support member, and
In the supply port and the recovery port provided in each of the first and second recording element substrates, the recovery port is provided on both end sides in the first direction ,
The liquid ejection head according to claim 1, wherein the total number of the supply ports and the recovery ports in each of the first and second recording element substrates is an odd number .   First and second recording element substrates each including an ejection port for ejecting liquid and a recording element for generating energy for ejecting liquid from the ejection port;
  A support member in which the first and second recording element substrates are arranged in a first direction;
A liquid ejection head comprising:
  A supply port for supplying liquid from the support member to the first and second recording element substrates on each of the surfaces of the first and second recording element substrates on the support member side, and the liquid A recovery port for recovering from the first and second recording element substrates to the support member, and
  In the supply port and the recovery port provided in each of the first and second recording element substrates, the recovery port is provided on both end sides in the first direction,
  A liquid different from the liquid is supplied from the support member to the first and second recording element substrates on the surfaces of the first and second recording element substrates on the support member side. A liquid comprising: a second supply port; and a second recovery port for recovering the different types of liquid from the first and second recording element substrates to the support member. Discharge head. The first and second recording element substrates are each provided with a supply channel that communicates with the supply port and a recovery channel that communicates with the recovery port, extending along the first direction. The liquid discharge head according to claim 1, wherein the liquid discharge head is provided.   Each of the first and second recording element substrates is provided with a pressure chamber provided with the recording element therein, and the liquid supplied from the supply port includes the supply channel, the pressure chamber, The liquid discharge head according to claim 4, wherein the liquid discharge head flows through the recovery channel and the recovery port in this order.   6. The liquid ejection head according to claim 1, wherein the first and second recording element substrates are provided linearly along the first direction. 7.   The support member extends along the first direction, and supplies a common supply channel for supplying the liquid to the supply ports of the first and second recording element substrates. The liquid discharge head according to claim 1, further comprising a common recovery flow path for recovering from the recovery ports of the first and second recording element substrates.   2. The liquid ejection head according to claim 1, wherein in each of the first and second recording element substrates, the number of the supply ports is larger than the number of the recovery ports.   3. The liquid ejection head according to claim 2, wherein in each of the first and second recording element substrates, the number of the recovery ports is larger than the number of the supply ports. 5. The liquid ejection head according to claim 4 , wherein each of the supply flow paths of the first and second recording element substrates communicates with the plurality of supply ports. 5. The liquid ejection head according to claim 4 , wherein each of the recovery flow paths of the first and second recording element substrates communicates with a plurality of the recovery ports.   The liquid discharge head according to claim 7, comprising a pressure control unit for controlling the pressure of the common supply flow path higher than the pressure of the common recovery flow path. The liquid discharge head according to claim 12 , wherein the pressure control unit includes a first pressure control unit communicating with the common supply flow path and a second pressure control unit communicating with the common recovery flow path. . Wherein the shape of each of the first and second recording element substrate is substantially a parallelogram, a liquid discharge head according to any one of claims 1 to 13. Wherein each of the first and second recording element substrate, 4 discharges the type of liquid, the liquid discharge head according to any one of claims 1 14. 16. The liquid ejection head according to claim 15 , wherein each of the first and second recording element substrates includes a supply channel and a recovery channel corresponding to each of the four types of liquids. A first flexible wiring board connected to the first recording element substrate, and a second flexible wiring board connected to the second recording element substrate, any one of claims 1 to 16, 1 The liquid discharge head according to item. A liquid discharge head of the page-wide type that corresponds to the length of the recording medium, a liquid discharge head according to any one of claims 1 17. The liquid discharge head according to claim 5 , wherein the liquid in the pressure chamber is circulated between the pressure chamber and the outside.   2. The liquid discharge head according to claim 1, wherein the recovery port is provided between the supply ports provided on both end sides in the first direction.   3. The liquid ejection head according to claim 2, wherein the supply port is provided between the recovery ports provided on both end sides in the first direction.   In the second supply port and the second recovery port provided in each of the first and second recording element substrates, the second recovery port is provided on both end sides in the first direction. The liquid discharge head according to claim 3, wherein the liquid discharge head is provided.