JP6719920B2 - Liquid ejection head and liquid ejection device - Google Patents

Description

The present invention relates to a liquid ejection head for ejecting various liquids including ink and the like, and a liquid ejection device.

In an inkjet recording head as a liquid ejection head capable of selectively ejecting ink as a liquid from a plurality of ejection ports, moisture in the ink evaporates from the ejection ports that do not eject ink for a long period of time, and The ink may thicken. In such a case, thereafter, there is a possibility that the ink cannot be accurately ejected from the ejection port.

Patent Document 1 discloses a configuration in which ink is circulated through an ink chamber (pressure chamber) corresponding to an ejection port when ink is not ejected in order to suppress thickening of the ink inside the ejection port when ink is not ejected. Have been described. Specifically, a plurality of ink chambers corresponding to the plurality of ejection ports are connected in parallel between the first common channel and the second common channel, and It is configured to generate a predetermined pressure difference between one end and one end of the second common channel. With such a configuration, ink is circulated through the first common flow path, the ink chamber corresponding to the ejection port when ink is not ejected, and the second common flow path.

JP, 2008-142910, A

In Patent Document 1, since the pressure of the ink in the first and second common flow paths is attenuated from one end to the other end of the common flow passage, the pressure of the ink with respect to the ink chamber connected to the other end thereof is decreased. Ink is hard to circulate.

Even when the configuration of Patent Document 1 is adopted when a plurality of element substrates having ejection ports are arranged to form an inkjet recording head and the ink chamber of Patent Document 1 is replaced with the element substrate, There are similar challenges to.

The present invention has been made in view of the above problems. An object of the present invention is to provide a liquid ejection head and a liquid ejection device that can circulate a liquid in each of a plurality of element substrates.

In order to solve the above problems, a liquid discharge head according to the present invention includes a plurality of element substrates including a discharge port that discharges a liquid and a discharge energy generation element that discharges the liquid from the discharge port; A first common channel to which each first portion of the element substrate is connected, a second common channel to which each second portion of the plurality of element substrates is connected, and the first common channel A liquid ejection head including a plurality of first introduction parts communicating with a flow path and a plurality of second introduction parts communicating with the second common flow path , wherein the liquid is ejected from the liquid ejection head. If not, the liquid supplied from the plurality of first introduction parts to the first common flow path passes through the first part, the element substrate, and the second part, and the second common part When flowing into the flow path, discharged from the plurality of second introduction parts, and discharging the liquid from the liquid discharge head, the liquid is supplied from the plurality of first introduction parts to the first common flow path. In addition, it is characterized in that the liquid can be supplied from the plurality of second introduction parts to the second common flow path in accordance with the discharge state of the liquid .

According to the above configuration, by providing a plurality of liquid introduction parts in each of the first and second common flow paths connected to the plurality of element substrates, a sufficient liquid differential pressure can be obtained with respect to each element substrate. The liquid can be reliably circulated in each element substrate by acting.

FIG. 3 is a schematic perspective view showing an internal configuration of a liquid ejection device. FIG. 6 is an explanatory diagram for explaining an example of an ink supply system for a head. (A) And (b) is a schematic diagram which shows an element substrate. It is a schematic perspective view which shows the back surface of an element substrate. It is a schematic sectional drawing which shows an element substrate and a support substrate. FIG. 3 is a schematic diagram showing a configuration of a head in the first embodiment. (A)-(c) is a figure for demonstrating a comparative example. (A)-(c) is a figure for demonstrating the structure of 1st Embodiment. 7 is a graph showing the relationship between the position of a chip and the flow rate ratio of ink. It is a schematic diagram which shows the structure of the head in 2nd Embodiment. It is a graph which compares the flow rate ratio of 2nd Embodiment, and the flow rate ratio of 1st Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic perspective view showing the internal configuration of the liquid ejection apparatus of this embodiment. In the following, a case where an inkjet recording device (hereinafter referred to as “recording device”) 200 is used as a liquid ejection device will be described.

As shown in FIG. 1, the recording apparatus 200 includes a transport mechanism including rollers 205, 206 and a transport belt 207 stretched around these rollers. By the rotation of the roller 205 driven by a motor (not shown) and the rotation of the roller 206 following this rotation, the recording medium 208 placed on the transport belt 207 is downstream in the transport direction (the y direction shown in the drawing). Is transported to the side.

The recording apparatus 200 uses recording heads 201 to 204 as liquid ejection heads. Here, the case of using a plurality of recording heads will be described. On the surface of each recording head facing the recording medium 208, an ejection port for ejecting a liquid is provided. Here, black ink is ejected from the ejection port of the recording head 201, cyan ink is ejected from the ejection port of the recording head 202, magenta ink is ejected from the ejection port of the recording head 203, and yellow ink is ejected from the ejection port of the recording head 204. It Although details will be described later with reference to FIG. 6 and the like, the recording head in this embodiment is a full-line type in which a plurality of element substrates (hereinafter also referred to as “chips”) provided with a plurality of ejection ports are arranged. Recording head. A plurality of ejection openings are formed so as to form an ejection opening array extending in a direction intersecting the transport direction of the recording medium 208. Further, here, a heating resistance element (heater) is used as an ejection energy generation element that generates energy for ejecting the liquid from the ejection port. The recording apparatus 200 includes a supply mechanism (not shown) for supplying ink to the recording head.

A control unit (not shown) controls the transport mechanism, the supply mechanism, and the heater based on the image data input to the printing apparatus 200, so that the print head ejects the print medium 208 transported by the transport mechanism. Ink is ejected from the outlet in the direction of arrow z in the figure. In this way, by applying ink to the recording medium 208, an image is recorded on the recording medium 208.

It should be noted that in the following, the recording head 201 among the recording heads 201 to 204 will be described, but it is assumed that other recording heads have the same configuration.

FIG. 2 is an explanatory diagram for explaining an example of a supply system (liquid supply system) capable of supplying ink to the recording head 201. The recording head 201 can have various configurations. For example, a structure for mounting the recording head 201 itself in the recording device, a structure for connecting the recording head 201 to an ink supply system, a structure that can be connected to an ink tank, or the like can be provided. As will be described later with reference to FIG. 6, the recording head 201 is provided with supply ports 20 and 21 (first introduction part) and discharge ports 22 and 23 (second introduction part). As shown in FIG. 2, the supply port 20 (first opening) fluidly connected to the outside of the liquid ejection head is connected to the sub tank 104a via the tube pump 103a, and the supply port 21 (second opening). Part) is directly connected to the sub tank 104a. Further, the discharge port 22 (third opening) is connected to the sub tank 104b via the tube pump 103b, and the discharge port 23 (fourth opening) is directly connected to the sub tank 104b. Ink is stored in the main tank 108. The main tank 108 is connected to the sub tanks 104a and 104b. A pump 105 is arranged between the main tank 108 and the sub tanks 104a and 104b. Further, a valve 102a is provided between the pump 105 and the sub tank 104a, and a valve 102b is provided between the pump 105 and the sub tank 104b.

Water level sensors 106a and 106b are attached to the sub tanks 104a and 104b, respectively, and detection signals from the water level sensors 106a and 106b are input to the controller 107. The controller 107 controls the pump 105 and the valves 102a and 102b according to the detection signals from the water level sensors 106a and 106b. As a result, the ink is appropriately supplied from the main tank 108 to the sub tanks 104a and 104b, the ink is discharged from the sub tanks 104a and 104b to the main tank 108, and the position of the ink surface of the sub tanks 104a and 104b can be adjusted. Therefore, the ink head difference H1 between the recording head 201 and the sub tank 104a and the ink head difference H2 between the recording head 201 and the sub tank 104b can be maintained at a predetermined magnitude. The head difference H2 is larger than the head difference H1 (H2>H1).

When ejecting the ink, the tube pumps 103a and 103b are set to the release state so that the ink can flow from the sub tank 104a to the supply ports 20 and 21, and the ink can flow from the sub tank 104b to the discharge ports 22 and 23. It will be in a state. As a result, a relatively small negative pressure corresponding to the head difference H1 acts on the ink in the supply ports 20 and 21, and a comparison corresponding to the head difference H2 occurs in the ink in the discharge ports 22 and 23. Large negative pressure acts. In the resting state in which the recording head 201 does not eject ink, the ink in the recording head 201 is circulated due to the pressure difference between them. That is, the ink in the sub tank 104 a is supplied from the supply ports 20 and 21 into the pressure chamber R of the recording head 201, and the ink in the pressure chamber R is discharged through the discharge ports 22 and 23 into the sub tank 104 b. The controller 107 adjusts the position of the liquid surface of the ink in the sub tanks 104a and 104b so that the water head differences H1 and H2 are maintained constant.

The differential pressure generating unit that generates a differential pressure between the ink in the supply ports 20 and 21 and the discharge ports 22 and 23 is not limited to the configuration using the water head difference as in this example, and the sub tanks 104a and 104b. May function as a pressure chamber that can be adjusted to different pressures. In short, it suffices that a pressure difference be generated between the supply ports 20 and 21 and the discharge ports 22 and 23 so that the ink that does not affect the ejection of the ink circulates through the pressure chambers.

The surface of the recording head 201 on which the ejection openings are formed is covered with the cap 109 when the recording operation is not performed, so that the ink is prevented from being dried and dust is not attached.

3A and 3B are schematic views showing the element substrate 1 provided in the recording head 201 as a liquid ejection head, and FIG. 3A is a plan view showing the ejection port and its periphery, FIG. 3B is a cross-sectional view showing a cross section taken along line IIIb-IIIb shown in FIG. 3A and 3B show a state in which ink is not ejected from the ejection port and ink is circulating.

As shown in FIG. 3A, the element substrate 1 of the recording head 201 is provided with a plurality of ejection openings 3, flow path walls 4, ink supply openings 5, and ink ejection openings 6. A pressure chamber R partitioned by the flow path wall 4 is provided at a position between the ink supply port 5 and the ink discharge port 6. Each pressure chamber R is located between the heater 2 and the discharge port 3 which face each other. Further, a drive circuit (not shown) for driving the heater 2 is formed on the element substrate 1.

As shown in FIG. 3B, the element substrate 1 is configured by disposing the ejection port forming member 7 forming the ejection port 3 on the substrate on which the heater 2 is formed. A plurality of pressure chambers (foaming chambers) R partitioned by the flow path wall 4 are formed in the discharge port forming member 7, and each pressure chamber R is located between the discharge port 3 and the heater 2 facing each other. Located in. The element substrate 1 is provided with an ink supply port 5 connected to one side portion of each pressure chamber R and an ink discharge port 6 connected to the other side portion of each pressure chamber R.

Based on the image data input to the recording apparatus 200, the heater 2 is selectively driven under the control of a control unit (not shown), and ink is ejected from the ejection ports 3 corresponding to the driven heater 2. In the state where the heater 2 is not driven, the ink at the ejection port 3 forms a meniscus, and the ink is not ejected from the ejection port 3. When the heater 2 is driven, the heat thereof causes the ink to foam, and the pressure generated thereby causes the ink to be pushed out from the ejection port 3. In this way, after the ink is ejected from the ejection port 3, the ink is supplied from the ink supply port 5 and the ink ejection port 6 to the pressure chamber R and the ejection port 3, and the ink is filled. Then, the meniscus is formed again at the ejection port 3, and the next ink can be ejected. When the ink is not ejected from the ejection port 3, that is, when the heater 2 corresponding to the ejection port 3 is not driven, the ink supplied from the ink supply port 5 passes through the pressure chamber R and is ejected from the ink ejection port 6. Then, it is circulated in the recording device 200.

Further, as shown in FIG. 3B, the element substrate 1 is formed with a supply flow path 8 and a discharge flow path 9, and the ink supply port 5 is in communication with the supply flow path 8 and the The outlet 6 communicates with the discharge flow path 9.

FIG. 4 is a schematic perspective view showing the back surface of the element substrate 1. As shown in FIG. 4, a plurality of supply channels 8 and a plurality of discharge channels 9 are formed on the back surface of the element substrate 1. Further, the flow path 18 (first flow path) communicating with the plurality of supply flow paths 8 is connected to one end of the element substrate 1, and the plurality of discharge flow paths 9 are connected to the other end. Flowing channels 19 (second channel) are formed respectively.

FIG. 5 is a schematic sectional view showing the element substrate 1 and the support substrate 13, and is a diagram showing a part of the recording head 201. As shown in FIG. 5, the element substrate 1 is supported by the support substrate 13. A common supply channel 11 (first common channel) and a common discharge channel 12 (second common channel) are formed on the support substrate 13. An element is provided on the support substrate 13 so that the flow path 18 of the element substrate 1 and the common supply flow path 11 of the support substrate 13 communicate with the flow path 19 of the element substrate 1 and the common discharge flow path 12 of the support substrate, respectively. The substrate 1 is arranged. The part on one side of the element substrate 1 is connected to the common supply flow path 11 through the flow path 18, and the part on the other side is connected to the common discharge flow path 12 through the flow path 19. Here, the recording head 201 is configured to include the element substrate 1 and the support substrate 13. The support substrate 13 supports the plurality of element substrates 1. An intermediate substrate supporting each element substrate 1 may be provided between the supporting substrate 13 and the element substrate 1, and the supporting substrate 13 may support a plurality of intermediate substrates.

FIG. 6 is a schematic diagram showing the configuration of the recording head 201 in this embodiment. As shown in FIG. 6, a plurality of chips (element substrates) of the chips C1 to Cn are arranged in a staggered pattern to form the recording head 201. These chips are connected to the common supply channel 11 and the common discharge channel 12, respectively. The common supply flow path 11 and the common discharge flow path 12 extend along the arrangement direction of the discharge ports formed in the chip and are arranged in parallel.

A supply port 20 is connected to one end of the common supply channel 11, and a supply port 21 is connected to the other end. A discharge port 22 is connected to one end of the common discharge flow path 12, and a discharge port 23 is connected to the other end. That is, the common supply channel 11 is in fluid communication with the outside through the supply ports 20 and 21, and the common discharge channel 12 is in fluid communication with the outside through the discharge ports 22 and 23. As shown in FIG. 6, in the present embodiment, the supply ports are provided at both ends of the common supply flow channel 11, and the discharge ports are provided at both ends of the common discharge flow channel 12. The connection portion of each chip with the common supply channel 11 is arranged between the supply port 20 and the supply port 21. Similarly, the connection part of each chip with the common discharge channel 12 is arranged between the discharge port 22 and the discharge port 23.

Although details will be described later with reference to FIGS. 8A to 8C, when the ink is not ejected from any of the chips, that is, when the ink is circulated, the ink is supplied from the supply ports 20 and 21 to the chips C1 to Cn. The ink is supplied and the ink is discharged from the chips C1 to Cn to the discharge ports 22 and 23. When ink is ejected from at least one of the chips, the ink is also supplied from the discharge ports 22 and 23 according to the ink ejection state, that is, the ink ejection amount. As described above, in the present embodiment, the supply ports are provided at both ends of the common supply flow channel 11, and the discharge ports are provided at both ends of the common discharge flow channel 12. The effect of this configuration will be described in comparison with the case where the supply port is provided only at one end of the common supply flow channel 11 and the discharge port is provided only at the other end of the common discharge flow channel 12.

7A to 7C are diagrams for explaining a comparative example, FIG. 7A is a schematic diagram showing the configuration of the recording head 201', and FIG. 7B is an equivalent circuit diagram. is there. FIG. 7C is a graph showing the pressure difference between the common supply channel 11 and the common discharge channel 12 for each chip position, where the vertical axis represents pressure and the horizontal axis represents chip position. ..

In this comparative example, a relatively small negative pressure corresponding to the head difference H1 acts on the common supply flow passage 11 only from the supply port 20, and the common discharge flow passage 12 receives the water head only from the discharge port 23. A relatively large negative pressure corresponding to the difference H2 acts. The pressure difference between the supply port 20 and the discharge port 23 is ΔP.

In this comparative example, if the chip C2 is a non-ejection chip and the other chips C1, C3,... Cn are ejection chips that eject ink drops I1, I3,... In, common supply Ink is supplied from both the flow channel 11 and the common discharge flow channel 12. In that case, as shown in FIG. 7C, the pressure PA in the common supply channel 11 drops from the chip C1 toward the chip Cn, and the pressure PB in the common discharge channel 12 changes from the chip Cn to the chip N1. Descend towards. As a result, the pressure difference at both ends of the chip varies greatly depending on the position of the chip, and the pressure difference at both ends of the chip located on the right side in FIG. Almost no flow.

As described above, when the circulation flow rate of the ink in the non-ejection chip is reduced, the effect of the circulation is reduced, and the viscosity of the ink is increased in the ejection port 3 at the tip of the nozzle due to evaporation of water in the ink. However, good ejection of ink may be hindered. Further, when the ink circulation flow rates in the respective chips are greatly different and the fluctuation range of the circulation flow rates deviates from a predetermined permissible range, there is a risk that the image recording quality may be impaired due to defective ink ejection.

On the other hand, in the present embodiment, the fluctuation range of the circulation flow rate of the ink in each chip is suppressed to be small, the circulation of the ink is maintained, and the effect of the circulation is sufficiently secured.

8A to 8C are diagrams for explaining the configuration of the present embodiment. 8A and 8C show that the ink in the recording head 201 is not discharged due to the pressure difference between the supply ports 20 and 21 and the discharge ports 22 and 23 in a rest state where the recording head 201 does not eject ink. It is explanatory drawing when circulating. FIG. 8A is an equivalent circuit diagram during ink circulation, and FIG. 8B is an equivalent circuit diagram during ink ejection. FIG. 8C is a graph showing the pressure difference between the common supply channel 11 and the common discharge channel 12 for each chip position, where the vertical axis represents pressure and the horizontal axis represents chip position. ..

In FIG. 8A, Rc is a flow resistance between adjacent pressure chambers R, C1, C2, C3,... Cn are chip numbers attached to a plurality of (n) chips, and each chip Includes a corresponding heater 2, pressure chamber R, and discharge port 3. As described above, the negative pressure corresponding to the head difference H1 acts on each of the supply ports 20 and 21, and the negative pressure corresponding to the head difference H2 acts on each of the outlets 22 and 23. The pressure PA in the common supply flow channel 11 and the pressure PB in the common discharge flow channel 12 change in the chip arrangement direction as shown in FIG. 8C, and the flow channel 18 and the flow channel 19 of the respective chips are changed. An equivalent pressure difference ΔP occurs between them. As a result, in each chip, the ink flows from the common supply flow channel 11 connected to the supply ports 20 and 21 toward the common discharge flow channel 12 connected to the discharge ports 22 and 23.

During the recording operation, since the heaters 2 of the nozzles of the plurality of chips are selectively driven according to the recording data obtained by performing various image processing on the image data, a chip that ejects ink (ejection chip) and an ink And chips that do not discharge (non-discharge chips) are mixed.

FIG. 8B is an explanatory diagram of the ink flow in the state where the ejection tip and the non-ejection tip are mixed. Depending on the ink ejection state in the recording head 201, the state becomes different from that during ink circulation as shown in FIGS. 8A and 8C. That is, after the ink is ejected by the foaming energy of the ink in the pressure chamber R of the ejection chip, the negative pressure generated by the defoaming in the pressure chamber resists not only the ink supply port 5 but also the pressure difference ΔP. Ink is also supplied from the ink discharge port 6 into the pressure chamber R. Therefore, the discharge ports 22 and 23, the common discharge flow path 12, and the ink discharge port 6 supply the ink in the sub-tank 104b into the pressure chamber R, contrary to the circulation of the ink.

For example, as shown in FIG. 8B, when the chip C2 is a non-ejection chip and the other chips C1, C2,..., Cn are ejection chips that eject ink drops I1, I3,. Suppose. In this case, as shown in FIG. 8B, approximately equal amounts of ink IA and IB flow through both ends of the non-ejection chip C2, that is, the flow paths 18 and 19 of the non-ejection chip C2. The difference between these amounts IA and IB is a slight amount corresponding to the pressure difference ΔP, and the pressure loss in the common supply flow passage 11 and the common discharge flow passage 12 due to the flow resistance Rc between the chips is almost equal. Become. Therefore, the pressure difference between both ends of the non-ejection chip C2 is hardly affected even when another chip is the ejection chip, and the ink flows in the direction of the arrow A in the non-ejection chip C2.

FIG. 9 shows the amount of ink (circulation amount) in the direction of the arrow A flowing in the chip when the ink is circulated as shown in FIG. 8A, and when the ejection chip and the non-ejection chip are mixed as shown in FIG. 7 is a graph showing a ratio (flow rate ratio) of the amount (circulation amount) of ink flowing in the non-ejection chip in the direction of arrow A. Regarding the former ink circulation amount, the ink circulation amount in the chips C1 and Cn located at both ends of the chip row is set to "1". In FIG. 9, the vertical axis represents the flow rate ratio and the horizontal axis represents the chip position.

In this example, as shown in FIG. 9, even if the position of the non-ejection chip changed, the difference in the ink circulation amount between the two could be suppressed to about several percent. Further, even when the ink is circulated as shown in FIG. 8A, the distribution of the amount of ink circulated in the chip arrangement direction can be suppressed to a difference of about several percent, which is almost the same as in FIG. ..

As described above, in the present embodiment, the fluctuation range of the ink flow rate for each chip can be suppressed while ensuring the flow rate required for circulating the ink. As a result, in each chip, it is possible to prevent the ink from remaining without flowing and evaporating the water content of the ink to increase the viscosity of the ink. Therefore, in the present embodiment, it is possible to prevent deterioration of ink ejection accuracy and the like.

(Second embodiment)
In the present embodiment, in addition to the configuration of the first embodiment described with reference to FIG. 6, a supply flow path 11a, a discharge flow path 12a, a supply port 24, and a discharge port 25 are provided. The other configurations are similar to those of the first embodiment, and thus the description thereof will be omitted.

FIG. 10 is a schematic diagram showing the configuration of the recording head 201 in this embodiment. As shown in FIG. 10, a supply channel 11a connected to the common supply channel 11 at approximately the center in the chip arrangement direction and a discharge channel 12a connected to the common discharge channel 12 at the substantially center in the chip arrangement direction are provided. They are provided respectively. Further, the supply port 24 is provided at the end of the supply flow channel 11a opposite to the end connected to the common supply flow channel 11, and is opposite to the end of the discharge flow channel 12a connected to the common discharge flow channel 12. The discharge ports 25 are provided at the end portions on the side.

With this configuration, when the ink is circulated, the ink is supplied from the supply ports 20, 21, and 24, and the ink is discharged from the discharge ports 22, 23, and 25. In addition, depending on the ejection state at the time of ejecting the ink, the ink is supplied not only from the supply ports 20, 21 and 24 but also from the discharge ports 22, 23 and 25. Thus, when the number of chips is relatively large, even if the lengths of the common supply channel 11 and the common discharge channel 12 are relatively long in the chip arrangement direction, the chips and the supply ports and the discharge ports are The distance between the chips is prevented from becoming relatively large, and the difference in the ink flow rate between the chips is suppressed.

FIG. 11 is a graph showing the ink flow rate ratio in the present embodiment and the ink flow rate ratio in the first embodiment, and is a graph corresponding to the graph shown in FIG. 9 described above. FIG. 11 shows the distribution of the flow rate ratio when the number of chips is the same. As described above, in the present embodiment, the supply passage 11a is connected to the common supply passage 11 and the discharge passage 12a is connected to the common discharge passage 12 at the approximate center in the chip arrangement direction (the approximate center of the chip position). Are connected. As a result, the ink is supplied from the supply port 24 to the chip located substantially at the center in the chip arrangement direction, and the ink is also supplied from the discharge port 25 depending on the ejection state. Ink is ejected to the ejection port 25 from the tip located substantially in the center of the tip arrangement direction. Therefore, as shown in FIG. 10, the flow rate ratio of the chip located substantially in the center is smaller in the configuration of the second embodiment than in the configuration of the first embodiment. That is, in the chip located in the substantially central portion, the flow rate of ink when ejecting ink and the flow rate of ink when not ejecting ink do not substantially change.

As described above, in the present embodiment, it is possible to further suppress the difference in flow rate between the time of ejection and the time of non-ejection, as compared with the configuration of the first embodiment.

(Other embodiments)
In the above embodiment, the configuration in which the supply ports 20 and 21 are provided at both ends of the common supply flow channel 11 and the discharge ports 22 and 23 are provided at both ends of the common discharge flow channel 12 have been described. However, the positions of the supply port and the discharge port in the common supply flow path and the common discharge flow path are not limited to the examples described above. That is, in any of the flow paths, if a plurality of openings serving as ink inlets/outlets are provided at positions displaced in the extending direction of each flow path, the same effect as that of the above embodiment can be obtained. The ink supply port 5 and the ink discharge port 6 may correspond to the pressure chamber R in a one-to-one relationship.

In the above embodiment, the configuration has been described in which the difference in the flow rate of ink between chips is suppressed while circulating the ink in each of the chips in which a plurality of ejection ports are formed. However, even when the chip in the present embodiment is replaced with the ejection port, the same effect as the present invention can be obtained.

Further, in the above embodiment, the case where the heat generating resistance element is used as the recording element has been described, but a piezo element may be used as the recording element. The case where the four recording heads respectively eject different colors of ink has been described, but the number of recording heads that can be used, the type of ink color, and the like are not particularly limited.

INDUSTRIAL APPLICABILITY The present invention is not limited to an inkjet recording head and an inkjet recording apparatus, and can be widely applied as a liquid ejection head for ejecting various liquids and a liquid ejection apparatus. The present invention can be applied not only to the full-line type recording apparatus as in the above-described embodiment but also to various types of recording apparatuses such as so-called serial scan type.

1 element substrate 2 heater (ejection energy generating element)
3 Discharge port 11 Common supply flow path (first common flow path)
12 Common discharge channel (second common channel)
20, 21 Supply port (first introduction part)
22, 23 outlet (second inlet)
201 recording head (liquid ejection head)

Claims (14)

A plurality of element substrates each including an ejection port for ejecting a liquid and an ejection energy generating element for ejecting the liquid from the ejection port;
A first common flow path to which a first portion of each of the plurality of element substrates is connected;
A second common flow path to which a second portion of each of the plurality of element substrates is connected;
A plurality of first introducing portions that communicate with the first common flow path,
A plurality of second introducing portions communicating with the second common flow path,
A liquid ejection head including :
When the liquid is not ejected from the liquid ejection head, the liquid supplied from the plurality of first introduction portions to the first common flow channel is the first portion, the element substrate, and the second portion. Flow to the second common flow path, and are discharged from the plurality of second introduction parts,
When the liquid is ejected from the liquid ejection head, the liquid is supplied from the plurality of first introduction portions to the first common flow path, and the plurality of second liquid ejection heads are provided in accordance with the ejection state of the liquid. A liquid ejection head, which is configured to be able to supply a liquid from an introduction portion to the second common flow path . The plurality of first introduction portions are provided at a plurality of positions in the first common flow path that are offset in the extending direction of the first common flow path,
The liquid according to claim 1, wherein the plurality of second introduction parts are provided at a plurality of positions in the second common flow path that are offset from each other in the extending direction of the second common flow path. Discharge head. The first portion of each of the plurality of element substrates is connected to a position offset in the extending direction of the first common channel in the first common channel,
The second portion of each of the plurality of element substrates is connected to a position in the second common channel that is offset in the extending direction of the second common channel. Alternatively, the liquid ejection head according to item 2. At least one of the plurality of first introduction portions is provided at an end portion in the extending direction of the first common flow path,
4. At least one of the plurality of second introduction parts is provided at an end portion in the extending direction of the second common flow path, according to any one of claims 1 to 3. Liquid ejection head. At least two of the plurality of first introduction parts are provided at both ends in the extending direction of the first common flow path,
At least 2 of the said 2nd several introduction part is provided in the both ends in the extending direction of the said 2nd common flow path, The any one of Claim 1 to 4 characterized by the above-mentioned. Liquid ejection head. One of the plurality of first introduction parts is communicated with the first common flow path via a flow path connected to a substantially central portion in the extending direction of the first common flow path,
One of the plurality of second introduction parts is connected to the second common flow path via a flow path connected to a substantially central portion in the extending direction of the second common flow path. The liquid ejection head according to claim 5, wherein The plurality of element substrates are arranged along a first direction,
The first common channel and the second common flow path, a liquid discharge head according to any one of claims 1 to 6, characterized in that extending along the first direction. The first portion of each of the plurality of element substrates is connected to the first common channel through a first channel corresponding to each of the plurality of element substrates,
The second portion of each of the plurality of element substrates is connected to the second common channel through a second channel corresponding to each of the plurality of element substrates. 7. The liquid ejection head according to any one of items 1 to 7 . A liquid discharge head according to any one of claims 1 to 8 ;
Control means for controlling the discharge energy generating element,
A liquid supply means capable of supplying a liquid to the plurality of first introduction parts and the plurality of second introduction parts;
When the liquid is not ejected from the liquid ejection head, the liquid is supplied from the plurality of first introduction parts and the liquid is discharged from the plurality of second introduction parts so as to discharge the liquid from the plurality of first introduction parts . A pressure difference generating means for generating a pressure difference between the introduction part and the plurality of second introduction parts;
A liquid ejecting apparatus comprising: 10. The liquid ejecting apparatus according to claim 9 , wherein the differential pressure generating means generates the differential pressure by the head difference of the liquid. A pressure chamber that communicates with the first and second common flow paths and internally includes the discharge energy generating element, wherein liquid in the pressure chamber is exchanged with the outside through the first and second common flow paths. liquid ejecting apparatus according to claim 9 or 10, characterized in that it is circulated between. First and second element substrates provided with ejection energy generating elements that generate energy used for ejecting the liquid;
A support substrate for supporting the first and second element substrates,
A liquid ejection head comprising:
The support substrate has a first common channel connected to first portions of the first and second element substrates, and second portions of the first and second element substrates. A second common flow path connected,
The first common flow path includes first and second openings that are in fluid communication with the outside, and the second common flow path includes third and fourth openings that are in fluid communication with the outside. The connection portion of the first common channel with the first portion is disposed between the first and second openings, and the connection portion of the second common channel with the second portion is , Disposed between the third and fourth openings ,
When the liquid is not ejected from the liquid ejection head, the liquid supplied to the first common channel from the first and second openings is the first liquid of the first and second element substrates, respectively. Flow through the first portion, each of the first and second element substrates, each second portion of each of the first and second element substrates to the second common flow path, and And discharged from the fourth opening,
When the liquid is ejected from the liquid ejection head, the liquid is supplied from the first and second openings to the first common flow path, and the third and third liquid passages are ejected depending on the ejection state of the liquid. wherein the fourth opening portion and the second liquid ejection head is characterized that you have been configured to be capable of supplying the liquid to the common channel. The liquid ejection head according to claim 12 , wherein the first common flow path and the second common flow path are arranged in parallel. A pressure chamber that communicates with the first and second common flow paths and internally includes the discharge energy generating element, wherein liquid in the pressure chamber is exchanged with the outside through the first and second common flow paths. The liquid ejection head according to claim 12 , wherein the liquid ejection head is circulated between the liquid ejection head and the liquid ejection head.