KR20170083499A - Liquid discharge head, liquid discharge apparatus, and liquid discharge method - Google Patents

Abstract

The liquid discharge head includes a discharge port, a recording element for generating energy, a supply channel for supplying liquid to the recording element, a common supply channel for communicating with the supply channel, a recovery channel for recovering the liquid supplied to the recording element, A first inlet port for supplying liquid to the common supply channel, a first return port for withdrawing liquid from the first common supply channel, a second inlet port for supplying liquid to the common return channel, And a second recovery port for recovering liquid from the channel. The first inlet port and the first recovery port communicate without advancing through the channel portion where the recording element is disposed and the second inlet port and the second recovery port communicate without advancing through the channel portion where the recording element is disposed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid discharge head, a liquid discharge apparatus, and a liquid discharge method,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to a liquid discharge head for discharging a liquid such as ink, a liquid discharge apparatus, and a liquid discharge method.

An ink-jet recording head that performs recording by ejecting a liquid such as ink is representative of a liquid ejecting head. In the liquid discharge head, volatile components in the ink contained in the head evaporate from the discharge port. This changes the concentration of the color material in the ink near the ejection opening, which causes color unevenness in the recorded image, increases the viscosity in the vicinity of the ejection opening, changes the speed of the ejected droplet, and deteriorates the droplet landing accuracy It becomes a problem. A method for solving these problems is known, and in this method, the ink supplied to the liquid discharge head is circulated through the circulation path.

Japanese Patent Application Laid-Open No. 2008-142910 discloses an apparatus for preventing the enrichment of the ink in the vicinity of the discharge port in a state in which the discharge is not performed by circulating the ink. In addition, PCT Japanese Unexamined Patent Publication No. 2002-533247 discloses an apparatus for cleaning the inside of a chamber by ink circulation.

However, in the invention disclosed in Japanese Patent Laid-Open No. 2008-142910, the ink that flows into the head 11 from the first tank 12 as shown in Fig. 7 of Japanese Patent Laid-Open Publication No. 2008-142910 Passes through the pressure chamber, and is recovered from the head (11). In addition, the invention disclosed in PCT International Publication No. 2002-533247 is an ink jet recording method in which ink flowing into a head 2010 from a lower container 2050 as illustrated in Figs. 4, 5, and 8 of PCT International Publication No. 2002-533247 Passes through the chamber for discharging, and is recovered from the head 2010.

Therefore, both of the circulation configurations disclosed in both Japanese Patent Application Laid-Open No. 2008-142910 and PCT Specification Laid-open No. 2002-533247 involve ink that flows into the head through the pressure chamber and is recovered from the head. In this arrangement, for example, when the circulating flow rate is increased, the ink passes through the pressure chamber having a cross-sectional area that is smaller than the cross-sectional area of the other channel portion, so that the channel resistance at that portion is large and the pressure drop of the circulating flow increases . The channel resistance of that portion can be reduced by enlarging the cross-sectional area of the pressure chamber, but the larger pressure chamber affects ink ejection and further increases the head size.

It has been found desirable to provide a liquid discharge head, a liquid discharge apparatus and a liquid discharge method which can supply liquid into a liquid discharge head while suppressing a pressure drop due to supply of liquid.

The liquid discharge head includes a discharge port configured to discharge liquid; A plurality of recording elements configured to generate energy used to eject liquid; A plurality of supply channels configured to supply liquid to a plurality of recording elements; A common supply channel configured to communicate with a plurality of supply channels and to supply liquid to the plurality of supply channels; A plurality of recovery channels configured to recover liquid supplied to a plurality of recording elements by a plurality of supply channels; And a common recovery channel configured to communicate with the plurality of recovery channels and to recover liquid from the plurality of recovery channels. The liquid discharge head has a first inlet port configured to supply liquid from the outside of the liquid discharge head to the common supply channel and a first recovery port configured to recover liquid from the common supply channel to the outside of the liquid discharge head. The first inlet port and the first recovery port are communicated by the common supply channel without proceeding through the channel portion where the recording element is disposed. The liquid discharge head is formed therein with a second inlet port configured to supply liquid from the outside of the liquid discharge head to the common collecting channel and a second collecting port configured to collect liquid from the common collecting channel to the outside of the liquid discharge head. The second inlet port and the second recovery port are communicated by the common recovery channel without proceeding through the channel portion where the recording element is disposed.

The liquid ejection apparatus includes a plurality of ejection openings configured to eject liquid, a plurality of recording elements configured to generate energy used for ejecting the liquid, and a plurality of recording elements configured to communicate with the first inlet port and the first recovery port A plurality of first individual channels communicating with the first common channel and configured to supply liquid to a plurality of recording elements, a second common channel communicating with the second inlet port and the second return port, A liquid ejection head including a plurality of second individual channels communicating with the second common channel and configured to recover liquid in the pressure chamber with a second recovery channel; And a supply unit configured to supply a liquid to the first common channel, the first individual channel, the plurality of recording elements, the second individual channel, and the second common channel. The first inlet port and the first recovery port communicate with the first common channel without proceeding through the pressure chamber and the second inlet port and the second recovery port communicate with the second common channel without proceeding through the pressure chamber.

The liquid ejection method is a liquid ejection method for ejecting liquid from a liquid ejection head, wherein the liquid ejection head includes a plurality of ejection openings configured to eject liquid, a plurality of recording elements configured to generate energy used to eject liquid, A plurality of supply channels configured to supply liquid to the recording elements of the plurality of recording elements, a common supply channel configured to communicate with the plurality of supply channels and configured to supply liquid to the plurality of supply channels, A common recovery channel communicating with the plurality of recovery channels and configured to recover liquid from the plurality of recovery channels, a plurality of recovery channels configured to supply liquid from the outside of the liquid discharge head to the common supply channel, 1 inlet port, liquid is withdrawn from the common supply channel to the outside of the liquid discharge head A second inlet port configured to supply liquid from the outside of the liquid discharge head to the common return channel and a second return port configured to collect liquid from the common return channel to the outside of the liquid discharge head . The method recovers liquid from the first input port to the common supply channel from the first return port to the outside of the liquid discharge head and also allows the liquid flowing into the common return channel from the second input port from the second return port Withdrawing to the outside of the liquid discharge head; And discharging the liquid from the discharge port in a state where supply of the liquid is performed in the recovery step.

Other features will become apparent from the following description of an illustrative embodiment with reference to the accompanying drawings.

1 is a perspective view schematically illustrating the inside of a recording apparatus, which is a first example of a liquid ejecting apparatus according to an exemplary embodiment;
2 is a diagram illustrating a channel configuration of the liquid discharge apparatus according to the first embodiment.
3A and 3B are perspective views of the outer appearance of the liquid discharge head according to the first embodiment.
4 is an exploded perspective view of the liquid discharge head according to the first embodiment.
5A-5E are cross-sectional views of channel members at various locations in the first embodiment.
6 is a perspective view of the channel member of the first embodiment.
7 is a sectional view of the liquid discharge head according to the first embodiment.
8A and 8B are views illustrating a discharge module of the liquid discharge head 3 according to the exemplary embodiment, wherein FIG. 8A is a perspective view and FIG. 8B is an exploded view.
9 is a diagram illustrating a channel configuration of a liquid discharge apparatus according to an exemplary embodiment.
10 is a diagram illustrating the temperature distribution of the recording element during driving of the liquid discharge head according to the exemplary embodiment.
11 is a cross-sectional view of the liquid discharge head according to the third embodiment.
12 is a sectional view of the liquid discharge head according to the fourth embodiment.
13A to 13C are perspective views of a recording element substrate according to an embodiment.
14 is a partial cross-sectional perspective view of a recording element substrate according to an exemplary embodiment.
15 is a diagram illustrating a channel configuration of the liquid discharge apparatus according to the fifth embodiment.
16A and 16B are diagrams illustrating pressure distributions of the respective pressure chambers of the liquid discharge head according to the fifth embodiment. In FIG. 16A, the flow direction of the common channel is opposite, and in FIG. 16B, The same direction.
17 is a diagram illustrating a channel configuration of the liquid discharge apparatus according to the sixth embodiment.
18 is an equivalent circuit diagram of the internal channels of the liquid discharge head according to the sixth embodiment.
Figs. 19A and 19B are views illustrating a configuration of a liquid discharge head according to an exemplary embodiment. Fig.
20A and 20B are perspective views of a liquid discharge head according to an exemplary embodiment.
21 is an exploded perspective view of the liquid discharge head of Figs. 20A and 20B.
22A and 22E are a plan view and a bottom view of the channel member of the liquid discharge head of Fig.
Fig. 23 is a view for explaining the connection state of the recording element substrate and the channel member of the liquid discharge head of Fig. 20;
24A and 24B are views illustrating a discharge module of the liquid discharge head of FIG. 20, wherein FIG. 24A is a perspective view and FIG. 24B is an exploded view.
25A to 25C are views of the recording element substrate of the liquid discharge head of Fig. 20, wherein Fig. 25A is a plan view, Fig. 25B is an illustration of an intermediate portion, and Fig. 25C is a bottom view.
26 is a perspective view illustrating an inkjet recording apparatus according to the seventh embodiment.
27 is a perspective view illustrating an inkjet recording apparatus according to the eighth embodiment.
28 is a diagram illustrating a liquid circulation path according to the ninth embodiment.
29A and 29B are views illustrating a liquid discharge head according to the ninth embodiment.
30A to 30C are views illustrating a liquid discharge head according to the ninth embodiment.

A liquid discharge head, a liquid discharge device, and a liquid discharge method according to embodiments will be described below with reference to FIGS. 1 to 18. FIG. Embodiments of the liquid discharge head and the liquid discharge apparatus can be applied to devices such as a printer, a copying machine, a facsimile apparatus having a communication system, a word processor having a printer unit, and the like, It should be noted that the present invention is also applicable to an industrial recording apparatus which is combined. By way of example, the illustrative embodiments may be used in biochips, printed electronics and other such applications. Although the thermal system in which the heating element generates bubbles to eject liquid is employed in the following embodiments, the present disclosure can be applied to a liquid discharge head employing another liquid discharge system such as a piezoelectric system or the like.

Although the liquid ejecting apparatus according to the embodiment relates to an ink jet recording apparatus (or simply "recording apparatus") in the form of liquid circulating between the ink tank and the liquid ejecting head, such as ink, other forms can be used as well. As an example, instead of the ink circulation, two ink tanks are provided on the upstream side of the liquid discharge head and another one on the downstream side, and ink in the pressure chamber flows by moving the ink from one ink tank to the other tank Shape can be used.

Further, although the liquid discharge head according to the embodiment relates to a so-called line head having a length corresponding to the width of the recording medium, this embodiment may also be a so-called serial liquid discharge head which records while scanning on the recording medium. An example of a serial liquid discharge head is a configuration having one substrate for each of black ink recording and color ink recording, for example. However, this is not restrictive, and an array in which a short line head is formed shorter than the width of the recording medium, a plurality of recording element substrates are arranged to overlap the ejection orifices in the ejection orifice row direction, and they are scanned on the recording medium .

Thus, while the foregoing embodiments are a suitable specific example of the present invention, and thus various limitations that may be technically desirable apply, it is to be understood that the present invention is not limited to the embodiment But is not limited to a specific method.

First Embodiment

Explanation of inkjet recording apparatus

Fig. 1 illustrates a schematic configuration of a liquid ejecting apparatus, particularly, an inkjet recording apparatus 1000 (hereinafter, simply referred to as a "recording apparatus") for ejecting ink to perform recording. The recording apparatus 1000 includes a conveying unit 1 for conveying the recording medium 2 and a liquid ejection head 3 of a line type (page-wide type) arranged substantially orthogonal to the conveying direction of the recording medium 2 , And performs a single pass continuous recording while conveying a plurality of recording media 2 continuously or intermittently. The recording medium 2 is not limited to a cut sheet but may be a continuous roll sheet. The liquid discharge head 3 is capable of full color printing by cyan, magenta, yellow and black (abbreviated as "CMYK") inks. A liquid supply unit serving as a supply channel for supplying ink to the liquid discharge head 3 and two fluid-connected ink tanks (main tank and buffer tank) (see Fig. 2) are connected thereto. The liquid discharge head 3 is also electrically connected to an electric control unit, which transmits power and discharge control signals to the liquid discharge head 3. The liquid path and the electric signal path in the liquid discharge head 3 will be described later.

Description of the structure of the recording element substrate

Figs. 19A and 19B are diagrams for explaining a configuration example of a liquid discharge head for discharging a liquid such as ink. Fig. Fig. 19A is a plan view of the recording element substrate 10 of the liquid discharge head in which the discharge port 13 is formed, and Fig. 19B is a sectional view taken along line XIXB-XIXB in Fig. 19A. The recording element 15 is provided on the recording element substrate 10 so as to generate energy used for ejecting the liquid as illustrated in Fig. 19A. An individual supply channel 17a for supplying ink to the pressure chamber 23 including the recording element 15 and a separate recovery channel 17b for recovering the ink in the pressure chamber 23 are provided on the recording element substrate 10, As shown in FIG. The discharge port 13 for discharging the ink is formed in the discharge port forming member 12 which is one member constituting the recording element substrate 10. Although the recording element 15 will be described as a heater which is a heating element capable of generating thermal energy in this specification, the embodiment is not limited thereto. Various types of recording elements for generating energy for ejection, such as electromechanical conversion elements similar to piezoelectric elements and the like, can be used.

It can be understood from Figs. 19A and 19B that a plurality of individual supply channels 17a and individual recovery channels 17b are formed on the recording element substrate 10 and a plurality of pressure chambers 23 are formed therebetween have. The pressure chamber (23) is partitioned by a wall (22). The recording element 15 is disposed inside each pressure chamber 23 and the ejection port 13 is formed at a position facing the recording element 15. [ The recording element 15 is selectively driven in accordance with the recording data, and a desired amount of ink is ejected from the ejection opening 13. When the recording element 15 is not driven, the ink is supplied from the individual supply channel 17a to the pressure chamber 23, and then recovered from the recording element substrate 10 via the individual recovery channel 17b. The flow of this ink (circulating flow) occurs even when the recording element 15 is not driven, and the circulating flow also continues to occur while the recording element 15 is driven to discharge the ink. That is, the recording element 15 is driven in a state in which ink flows through the pressure chamber 23, and ink is ejected. The recording element 15 is electrically connected to the terminal 16 of Fig. 13A by electric wiring (not shown) provided in the recording element substrate 10. [ The recording element 15 is configured to heat the liquid based on the pulse signal inputted from the control circuit of the recording apparatus 1000 via the electric wiring substrate 90 (Fig. 4) and the flexible printed circuit board 40 (Fig. 8 And boil. The liquid is discharged from the discharge port 13 by the foaming force due to this boiling.

Description of the cyclic configuration

Therefore, in the system in which heat is transferred to the ink by driving the recording element 15, the temperature distribution in the head is stabilized when the recording element 15 is in the stopped state after a predetermined amount of time has elapsed since the driving. However, the situation is different in the transient state, and since the heat from the recording element 15 is transferred to the ink according to the predetermined time constant, the temperature of the ink inside the pressure chamber 23 in this transient state changes instantaneously, The discharge characteristics also change. Therefore, when the temperature in the vicinity of the pressure chamber 23 is monitored and it is determined that the temperature is lower than or equal to the predetermined threshold value, a heat source (not shown) for heating the recording element 15 or the pressure chamber 23 causes the ink to boil Level. Therefore, the temperature of the ink in the pressure chamber 23 is maintained in the set range, and the non-uniformity of the discharge characteristics can be suppressed.

The liquid discharge head 3 according to the first embodiment will be described with reference to Figs. 1 to 8B. Fig. 2 illustrates an example of the overall configuration of a channel system in a recording apparatus, which is an example of a liquid ejection apparatus according to the present embodiment. 2 is a schematic view illustrating a first circulation path as a first type of circulation path applied to the recording apparatus of this embodiment. 2 is a view showing a liquid discharge head 3 connected to a first circulation pump (high pressure side) 1001, a first circulation pump (low pressure side) 1002 and a buffer tank 1003 connected by fluid connection to be. Although FIG. 2 illustrates only the path through which one color ink flows for the sake of simplicity of explanation, in practice, circulation paths are provided for the liquid discharge head 3 and the recording apparatus main unit for as many colors as necessary. The buffer tank 1003 serving as a sub tank connected to the main tank 1006 is provided with an atmospheric communication opening (not shown), whereby the inside and the outside of the tank communicate with each other and the bubbles in the ink are discharged to the outside . Buffer tank 1003 is also connected to supplemental pump 1005. [ When the ink is consumed in the liquid discharge head 3 by discharging (discharging) ink from the discharge port of the liquid discharge head 3 by discharging the ink to perform recording, suction counting, etc., the replenishment pump 1005 supplies the main And serves to send the same amount of ink as that consumed from the tank 1006 to the buffer tank 1003.

The first circulation pumps 1001 and 1002 serve to suck liquid from the liquid connector 111 and to flow the ink to the buffer tank 1003. The first circulation pumps 1001 and 1002 are preferably positive displacement pumps having a quantitative liquid transfer function. Specific examples may include tube pumps, gear pumps, diaphragm pumps, syringe pumps, and the like. Arrangements in which a constant flow is ensured by disposing a common constant flow valve and a relief valve at the outlet of the pump may be used. The first circulation pump (high pressure side) 1001 and the first circulation pump (low pressure side) 1002 are configured so that a certain amount of ink is supplied to the common supply channel 211 and the common recovery channel (212).

The negative pressure control unit 230 is provided in the path between the liquid discharge unit 300 and the second circulation pump 1004. Accordingly, the negative pressure control unit 230 can control the flow rate of the refrigerant flowing from the negative pressure control unit 230 downstream (that is, on the side of the liquid discharge unit 300) from the negative pressure control unit 230 to a preset constant pressure even when the flow rate of the circulation system fluctuates due to the difference in duty during recording. ) So that the pressure can be maintained. Any mechanism can be used as the two pressure regulating mechanisms constituting the negative pressure control unit 230 if the downstream pressure from itself can be controlled to fluctuate within a predetermined range centered on the desired set pressure. As an example, a mechanism equivalent to a so-called "decompression regulator" can be used. This configuration makes it possible to suppress the influence of the head pressure on the liquid discharge head 3 of the buffer tank 1003 with respect to the liquid discharge head 3 so that the more of the layout of the buffer tank 1003 of the recording apparatus 1000 Provides wide freedom.

It is sufficient that the second circulation pump 1004 has a specific heading pressure or higher within a range of the circulating flow pressure of the ink used when driving the liquid discharge head 3, and a turbo pump, a volumetric pump, or the like can be used. Specifically, a diaphragm pump or the like can be used. Alternatively, by way of example, a water head tank arranged with a specific head difference to the negative pressure control unit 230 may be used instead of the second circulation pump 1004. [ Therefore, by integrating the pump that supplies the ink to the liquid discharge head 3, the number of pumps in the whole apparatus can be reduced, and the apparatus size can be reduced.

As illustrated in FIG. 2, the negative pressure control unit 230 has two pressure regulating mechanisms, which are set at different control pressures with respect to each other. 2) and the relative low-pressure setting side (indicated by L in Fig. 2) of the two negative pressure regulating mechanisms are connected to the liquid supply unit 220 via the liquid supply unit 220, The supply channel 211 and the common recovery channel 212. [ The liquid discharge unit 300 is provided with a branch supply channel 213 and a branch recovery channel 214 communicating between the common supply channel 211 and the common recovery channel 212 and the recording element substrate 10. A first inlet port 7a and a first recovery port 8a are formed in the common supply channel 211. [ The first inlet port 7a is connected to the pressure regulating mechanism H by fluid connection and the first return port 8a is connected to the first circulation pump 1001 by fluid connection . A second inlet port 7b and a second return port 8b are formed in the common collecting channel 212. [ The second inlet port 7b is connected to the pressure regulating mechanism L by fluid connection and the second return port 8b is connected to the first circulation pump (second recovery pump) 1002 by fluid connection . The following inequality is satisfied.

Pu_i> Pd_i Inequality 1

Pu_o> Pd_o Inequality 2

Where Pu_i represents the pressure value in the vicinity of the first inlet port 7a in the common supply channel 211, Pu_o represents the pressure value in the vicinity of the first recovery port 8a, Pd_i represents the pressure value in the vicinity of the common recovery channel 212 2 inlet port 7b, and Pd_o represents the pressure value in the vicinity of the second recovery port 8b.

The pressure regulating mechanism H is connected to the common supply channel 211 and the pressure regulating mechanism L is connected to the common recovery channel 212 so that the pressure difference between the two common channels Is generated. In addition, a predetermined amount of ink that satisfies inequality 2 flows through the common supply channel 211 and the common recovery channel 212 by the first circulation pumps 1001 and 1002.

According to this configuration, the flow of ink to each recording element substrate 10 is transmitted from the common supply channel 211 to the branch supply channel 213, the plurality of pressure chambers 23 in the recording element substrate 10, (214) and is created as a common collection channel (212) (outlined arrow in Figure 2). In addition, the ink supplied from the two inlet ports does not advance through the recording element substrate 10 but flows to the respective common channels at the same time. Therefore, even when a relatively large amount of ink is supplied, an increase in the pressure drop in the supply path in the liquid discharge head 3 can be suppressed, and ink flow is generated in the pressure chamber 23 where discharge is not performed . The heat generated in the recording element substrate 10 can be externally discharged from the liquid discharge head 3 by the flow of the common supply channel 211 and the common recovery channel 212. [ In addition, an ink flow can be generated in the pressure chambers 23 and the ejection openings 13 irrespective of the operating state, so that enrichment of the ink in these portions can be suppressed. In addition, enriched ink and foreign matter in the ink can be discharged to the common recovery channel 212. [ Therefore, the liquid discharge head 3 according to the present embodiment can record at a high speed with high image quality.

Description of the configuration of the head

The configuration of the liquid discharge head 3 according to the first embodiment will be described. 3A and 3B are perspective views of the liquid discharge head 3 according to the present embodiment. The liquid ejection head 3 is a line-type liquid ejection head, and 15 recording element substrates 10 capable of ejecting four color inks of C, M, Y and K, respectively, are arranged in a straight line (an inline layout ). 3A, the liquid discharge head 3 includes a recording element substrate 10, an input terminal 91 electrically connected to the flexible printed circuit board 40 via the electric wiring substrate 90, And a power supply terminal 92. The input terminal 91 and the power supply terminal 92 are electrically connected to the control unit of the recording apparatus 1000 and supply a discharge drive signal and power necessary for discharge to the recording element substrate 10, respectively. The integration of the wirings into the electric wiring substrate 90 by the electric circuit enables the number of the input terminals 91 and the electric power supply terminals 92 to be reduced as compared with the number of the recording element substrates 10. [ This makes it possible to reduce the number of electrical connection portions to be removed at the time of replacing the liquid discharge head 3 or in assembling the liquid discharge head 3 to the recording apparatus 1000. The liquid connection portion 111 provided at both ends of the liquid discharge head 3 is connected to the liquid supply system of the recording apparatus 1000, as shown in Fig. 3B. Thus, four colors of CMYK ink are supplied to the liquid discharge head 3, and the ink that has passed through the liquid discharge head 3 is recovered to the supply system of the recording apparatus 1000. [ In this way, the ink of each color can circulate the path of the recording apparatus 1000 and the path of the liquid discharge head 3.

Fig. 4 illustrates an exploded perspective view of components and units constituting the liquid discharge head 3. Fig. The liquid discharge unit 300, the liquid supply unit 220 and the electric wiring substrate 90 are attached to the case 80. [ 3) is provided in the liquid supply unit 220 and is provided with a filter 221 for each color in communication with each opening of the liquid connection portion 111 to remove foreign matter in the supplied ink, (Figs. 2 and 3) are provided inside the liquid supply unit 220. Fig. The two liquid supply units 220 each have a filter 221 for two colors. The ink that has passed through the filter 221 is supplied to each negative pressure control unit 230 provided in the corresponding liquid supply unit 220.

Next, the configuration of the channel member 210 included in the liquid discharge unit 300 will be described. The channel member 210 distributes the liquid supplied from each of the liquid supply units 220 to each of the discharge modules 200 as illustrated in FIG. 4 and transfers the liquid recycled from the discharge module 200 to the liquid supply unit 220 Returning the channel member. The channel member 210 is fixed to the liquid discharge unit support member 81 by a screw, thereby suppressing distortion and deformation of the channel member 210. 5A to 5E are exploded views for facilitating understanding of the channel portion of the channel member 210. FIG. 5A illustrates a side on which the discharging module 200 is mounted, and Fig. 5E illustrates a side in contact with the liquid discharging unit supporting member 81. Fig. The eight common channels extending in the longitudinal direction of the channel member are a common supply channel 211 and a common collecting channel 212 for each color. Each of the inlet port 7 and each of the recovery ports 8 communicates with the hole of the coupling rubber member 100 so as to communicate with the liquid supply unit 220 by fluid connection. The channel member 210 further includes a plurality of branch channels 213 formed in a direction crossing the common channel and communicating with the plurality of discharge modules 200 by fluid connection. The channel member 210 is preferably formed of a material that is corrosion resistant to liquid and has a low linear expansion coefficient. Exemplary suitable materials include alumina, liquid crystal polymer (LCP), and composite material (resin material), and the composite may be formed of an inorganic filler such as microsilica particles or fibers such as polyphenyl sulfide (PPS) or polysulfone Is added to the description.

Next, the connection relationship of the channels in the channel member 210 will be described with reference to FIG. 6 is a partially enlarged perspective view of the channel in the channel member 210 as viewed from the side on which the discharge module 200 is mounted. The channel member 210 has common supply channels 211 (211a, 211b, 211c and 211d) and common collecting channels 212 (212a, 212b, and 212c) extending in the longitudinal direction of the liquid discharge head 3, 212c, and 212d. The branch supply channel 213 is connected to the common supply channel 211 of each color via the communication port 61. The plurality of branch recovery channels 214 are connected to the common collecting channels 212 of the respective colors via the communication ports 61. This channel configuration allows ink to be incorporated in the recording element substrate 10 disposed in the middle of the channel member from the common supply channel 211 via the branch supply channel 213. [ In addition, the ink can be recovered from the recording element substrate 10 to the common recovery channel 212 via the branch recovery channel 214. [

FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6 illustrating a branch return channel 214 in communication with the dispensing module 200. Although FIG. 7 only illustrates the branch recovery channel 214, the branch supply channel 213 and the discharge module 200 communicate with each other as illustrated in FIG. 6 in the other cross section. The recording element substrate 10 included in each ejection module 200 is formed with a plurality of individual supply channels 17a and a plurality of individual recovery channels 17b and the branch supply channels 213 and the individual supply channels 17a ), And the branch recovery channel 214 and the individual recovery channel 17b are connected by a fluid connection, respectively.

Fig. 8A illustrates a perspective view of one discharge module 200, and Fig. 8B shows an exploded view thereof. The terminal 42 at the other end of the flexible printed circuit board 40 from the recording element substrate 10 is electrically connected to the connection terminal 93 (FIG. 4) of the electric wiring substrate 90. The supporting member 30 is a supporting member for supporting the recording element substrate 10 and is also a channel member communicating between the channel member 210 and the recording element substrate 10 by fluid connection. Therefore, the support member 30 should have a high degree of flatness and also be able to be coupled to the recording element substrate 10 with high reliability. Examples of suitable materials include alumina and resin materials. The support member 30 may be formed of a stacked structure of a first support member in which a supply channel and a recovery channel are formed, and a second support member in which a common supply channel and a common recovery channel are formed. In this case, the thermal diffusivity of at least the first supporting member is smaller than the thermal diffusivity of the recording element substrate 10.

As described above, this embodiment enables the backflow from the common collecting channel 212 to be prevented irrespective of the driving state in the recording element substrate 10, and further suppresses the change in the circulation (supply) flow rate can do. Thus, there is provided a head configuration in which circulation is maintained to ensure the advantage of circulation. Although the pressure regulating mechanism is used as a pressure generating source in this embodiment, the embodiment is not limited thereto. As an example, a water head difference control configuration using a water level sensor can be used. This configuration is also the same in the following embodiments.

Second Embodiment

9 is a schematic view illustrating a second circulation path in a circulation form different from the above-described first circulation path for the circulation path applied to the recording apparatus according to the present embodiment. The first difference of the above-described first circulation path is as follows. Both of the two pressure regulating mechanisms constituting the negative pressure control unit 230 are provided with a mechanism for controlling the upstream side pressure from the negative pressure control unit 230 to fluctuate within a certain range centered on the desired set pressure Back pressure regulator "). The second circulation pump 1004 serves as a negative pressure source for depressurizing the downstream side from the negative pressure control unit 230. The first circulation pump (high pressure side) 1001 and the first circulation pump (low pressure side) 1002 are disposed on the upstream side of the liquid discharge head 3 and the negative pressure control unit 230 is disposed on the upstream side of the liquid discharge head 3, As shown in Fig.

The negative pressure control unit 230 according to the second embodiment is capable of controlling the pressure fluctuation on the upstream side (i.e., on the side of the liquid discharge unit 300) even when the flow rate fluctuates due to the difference in duty during recording by the liquid discharge head 3. [ To within a predetermined range centered at a predetermined pressure. This provides a wider selection range for the layout of the buffer tank 1003 in the recording apparatus 1000 by making it possible to suppress the influence of the head pressure of the buffer tank 1003 on the liquid discharge head 3. Alternatively, by way of example, a water head tank arranged with a specific head difference to the negative pressure control unit 230 may be used instead of the second circulation pump 1004. [ In this embodiment, by integrating the pump into one side that recovers ink from the liquid discharge head 3, the number of pumps in the whole apparatus can be reduced and the apparatus size can be reduced. The negative pressure control unit 230 illustrated in FIG. 3 has two pressure regulating mechanisms, and they are set to have different control pressures in the same manner as in the first embodiment. 9) and the relative low-pressure setting side (indicated by L in Fig. 9) of the two negative pressure regulating mechanisms are connected to the liquid supply unit 220 via the liquid supply unit 220, The supply channel 211 and the common recovery channel 212. [ The first inlet port 7a and the first return port 8a are formed in the common supply channel 211 and the first inlet port 7a is connected to the first circulation pump (first liquid feed pump) (1001), and the first recovery port (8a) is connected to the pressure regulating mechanism (H) by a fluid connection. A second inlet port 7b and a second recovery port 8b are formed in the common recovery channel 212 and a second inlet port 7b is formed in fluid connection with a first circulation pump And the second recovery port 8b is connected to the pressure regulating mechanism L by the fluid connection.

The pressure of the common supply channel 211 is controlled relative to the pressure of the common recovery channel 212 by the two negative pressure regulating mechanisms and the two first circulation pumps. Therefore, a flow occurs in which ink flows from the common supply channel 211 to the common recovery channel 212 through the branch supply channel 213a and the inner channel in the recording element substrate 10, The ink does not flow through the recording element substrate 10 but flows back to the collecting port of each common channel. Therefore, the second circulation path produces the same ink flow state as that of the first circulation path in the liquid discharge unit 300, but has two advantages different from the case of the first circulation path.

One advantage is that the negative pressure control unit 230 is disposed on the downstream side of the liquid discharge head 3 in the second circulation path so that the dust and foreign matter generated in the negative pressure control unit 230 may flow into the head There is little. A second advantage is that the maximum value of the required flow rate supplied from the buffer tank 1003 to the liquid discharge head 3 can be smaller in the second circulation path than in the case of the first circulation path. The reason for this is as follows. The total flow rate in the common supply channel 211 and the common recovery channel 212 at the time of ink circulation during recording standby is denoted by A. [ The value of A is defined as a minimum flow rate required to maintain the temperature difference of the liquid discharge unit 300 within a preferable range when temperature control of the liquid discharge head 3 is performed during recording standby. The ejection flow rate when ink is ejected from all the ejection openings of the liquid ejection unit 300 (full ejection) is defined as F. Therefore, in the case of the first circulation path (Fig. 2), the set flow rate of the first circulation pump (high pressure side) 1001 and the first circulation pump (low pressure side) The maximum value of the liquid supply amount to the discharge head 3 is A + F.

On the other hand, in the case of the second circulation path (Fig. 9), the liquid supply amount to the liquid discharge head 3 necessary for recording standby is the flow rate A. [ This means that the supply amount to the liquid discharge head 3 required for the entire discharge is the flow rate F. [ Therefore, in the case of the second circulation path, the total value of the set flow rate of the first circulation pump (high pressure side) 1001 and the first circulation pump (low pressure side 1002), that is, The maximum value (A or F) of the required supply amount of the second circulation path is the maximum value (A + F) of the required flow amount of the first circulation path, if the liquid discharge unit 300 having the same configuration is used, As a result, the degree of freedom with respect to the circulating pump which can be used becomes higher in the case of the second circulation path, and this can be achieved by using a low-cost circulation pump having a simple structure as an example, (Not shown), so that the cost of the recording apparatus main unit can be reduced. This advantage is more pronounced in the line head, where the value of A or F is relatively large, The length of the line head in the longitudinal direction No longer to be more useful.

However, the first circulation path is more advantageous than the second circulation path. That is, in the second circulation path, the flow rate flowing through the liquid discharge unit 300 at the time of recording standby is the maximum value, so that the lower the recording duty of the image, the larger the negative pressure is applied in the vicinity of the discharge port. Therefore, the channel width (the length in the direction perpendicular to the liquid flow direction) of the common supply channel 211 and the common collecting channel 212 is reduced in order to reduce the head width (the length of the liquid discharge head in the transverse direction) , A high negative pressure is applied in the vicinity of the discharge port in a low duty image in which unevenness is well visible. This can lead to more impact of the satellite droplet. On the other hand, in the case of the first circulation path, a high negative pressure is applied in the vicinity of the ejection opening in the high-duty image formation, so that any generated satellites are less visible, which is advantageous in that the influence on the image quality is small. Which of these two circulation paths is more preferable can be selected from the viewpoints of specifications (discharge flow rate F, minimum circulation flow rate A and channel resistance in the head, etc.) of the liquid discharge head and recording apparatus main unit.

As described above, this embodiment enables reverse flow from the common collecting channel 212 to be prevented irrespective of the driving state in the recording element substrate 10 in the same manner as in the first embodiment, and further, (Supply) flow rate can be suppressed. Thus, there is provided a head configuration in which circulation is maintained to ensure the advantage of circulation.

The thermal diffusivity in the channel member

10 is a diagram illustrating a temperature distribution in the recording element substrate 10, which is suitable for explaining the characteristics of the liquid discharge head 3 according to the embodiment. The horizontal axis indicates the direction in which the common channel extends, and the vertical axis indicates the temperature of the recording element substrate 10. [ The thermal diffusivity in the channel member 210 according to the present embodiment is smaller than the thermal diffusivity of the recording element substrate 10 and the solid line indicates the head having the thermal diffusivity of the channel member 210 of 7 x ^10-7 m ² / . 10 illustrates the head with the thermal diffusivity of the channel member 210 of 8 x 10 ^-6 m ² / s as a dotted line for comparison with the effect of this embodiment. It can be seen from Fig. 10 that, when the thermal diffusivity of the channel member 210 becomes higher than the thermal diffusivity of the recording element substrate 10, a temperature difference is generated from the inlet port communicating with the common channel toward the collection port. On the other hand, in the case where the thermal diffusivity is low, the temperature is kept substantially constant regardless of the position on the recording element substrate 10. Therefore, in a configuration in which a plurality of recording element substrates 10 are arranged in the direction in which the common channels extend and ink flows through the common channel, heat is less easily transferred from the recording element substrate 10, So that the variation of the volume of the ink droplet can be suppressed. This configuration is not limited as long as the function of not allowing the heat from the recording element substrate 10 to be easily transmitted to the ink in the common channel is added, although it will be described here based on a specific numerical value with respect to the thermal diffusivity of the channel member.

Third Embodiment

The third embodiment will be described with reference to Fig. In this embodiment, the ink flow state is obtained in the same manner as in the first embodiment or the second embodiment. The same parts as in the above-described embodiment are denoted by the same reference numerals, and a description thereof will be omitted. 11 is a view illustrating a section of the liquid discharge head 3 of this embodiment in which a plurality of layers of channel members are formed. Common channels 211a to 211d and 212a to 212d extending in the direction in which the recording element substrate 10 is arranged (longitudinal direction of the channel member) are formed in the second channel member 60 and the third channel member 70 do. A plurality of branch channels 213d (individual channels) extending in a direction (transverse direction) orthogonal to the common channel of the channel member are formed on the first channel member 50. [ The formation of the branch channel grooves and the common channel grooves on different members makes it possible to form, by resin molding, a member in which long grooves and intersecting extremely fine grooves coexist, for example, .

Although the present embodiment describes three layers of channel members 50, 60, and 70, the concept that a common channel and a branch channel are constructed using different members is realized, There is no. One channel member for forming the branch channel may be formed for each recording element substrate 10 or one for each of the plurality of recording element substrates 10 or for all the recording element substrates 10 One can be formed. In any case, if the formation of a common channel and a branching channel on separate members is realized, the construction is not limited.

Fourth Embodiment

The connection relationship of the common channel, the branch channel, and the plurality of pressure chambers in the fourth embodiment is the same as in the above-described embodiment, and the flow of ink from the common supply channel and the pressure chamber An ink flow passing through the common return channel is obtained. 12 is a view illustrating a section of the liquid discharge head 3 according to the present embodiment. The channel member constituting the liquid discharge head 3 according to the present embodiment has a multilayer structure in the same manner as in the third embodiment. The elongated channel members constituting the common channel are formed of a material having a linear expansion coefficient substantially equal to that of the recording element substrate 10 in order to maintain the mounting accuracy of the recording element substrate 10 at a high precision level. Specific examples of materials assumed for the second channel member 60 include inorganic materials such as silicon and alumina, metal materials with lower linear expansion coefficients such as invar, etc., Which is a value similar to that of Fig. In this embodiment, the thermal diffusivity of the first channel member 50 forming a plurality of branch circuits is set to be lower than that of the recording element substrate 10 or the second channel member 60. This makes heat transfer from the recording element substrate 10 to the ink passing through the common channel more difficult, thereby making the volume of the ejected ink droplet uniform.

Although the present embodiment describes two layers of the channel members 50 and 60, there is no particular limitation on the number of layers, as long as the concept that the common channel and the branch channel are constructed using separate members is realized . Although only one common channel of one color is illustrated in the figure, the configuration is such that the first channel member 50 does not easily transfer heat between the recording element substrate 10 and the second channel member 60, If the two-channel member 60 is made not to be deformed due to disturbance such as heat, swelling, etc., a common channel for a plurality of colors can be formed.

Configuration of Recording Element Substrate

The configuration of the recording element substrate that can be applied to the embodiment will be described with reference to FIGS. 13A to 13C. The recording element substrate 10 has a discharge port forming member 12, and four discharge port rows corresponding to ink colors are formed in the discharge port forming member as shown in FIG. 13A. Hereinafter, it is mentioned that the direction in which the discharge orifice row in which the plurality of discharge orifices 13 are arranged will be referred to as the "discharge orifice row" direction. As illustrated in Fig. 13 (b), the liquid supply channel 18 extends along one side of each discharge port row, and the liquid recovery channel 19 extends along the other side. The liquid supply channel 18 and the liquid recovery channel 19 are channels extending in the direction of the ejection orifice row provided in the recording element substrate 10 and are respectively connected to the ejection openings 13 and 17 via the supply port 17a and the recovery port 17b Communicate. The sheet-like cover plate 20 is laminated on the rear surface from the surface of the recording element substrate 10 on which the ejection openings 13 are formed and the cover plate 20 is formed as shown in Figs. 13C and 14, Has a plurality of openings (21) communicating with the liquid supply channel (18) and the liquid recovery channel (19). Three openings 21 are provided in cover plate 20 for each supply channel 18 and two openings 21 are provided for each liquid recovery channel 19. In this embodiment, The opening 21 of the cover plate 20 communicates with the plurality of communication ports 51 as illustrated in Fig. 13B. 14, which is a cross-sectional view taken along the line XIV-XIV in Fig. 13A, the cover plate 20 is provided with a liquid supply channel 18 formed in the substrate 11 of the recording element substrate 10, 19 as shown in Fig. The cover plate 20 is preferably sufficiently corrosion resistant to the liquid and should have a high degree of precision regarding the shape and position of the opening of the opening 21 from the standpoint of preventing color mixing. Therefore, the photosensitive resin material or silicon is used as a material for the cover 20, and the opening 21 is preferably formed by a photolithography process. Thus, the cover plate 20 is for changing the pitch of the channel by the opening 21. [ The cover plate 20 is preferably thin, preferably formed of a film material, in view of the pressure drop.

Next, the flow of the ink in the recording element substrate 10 will be described. The liquid supply channel 18 and the liquid recovery channel 19 constituted by the substrate 11 and the cover plate 20 are connected to the common supply channel 211 via the branch supply channel 213a and to the common supply channel 211 via the branch recovery channel 213b to the common recovery channel 212. [ Therefore, a differential pressure exists between the liquid supply channel 18 and the liquid recovery channel 19 due to the two negative pressure regulating mechanisms, and the ink is supplied from the liquid supply channel 18 to the supply port 17a, the pressure chamber 23, And the recovery port 17b to the liquid recovery channel 19 (flow indicated by arrow C in Fig. 14).

Next, the flow of the ink in the liquid discharge head 3 will be described. The first inlet port 7a and the first recovery port 8a are in fluid communication with the common supply channel 211 and the second inlet port 7b and the second recovery port 8b communicate with the common recovery channel 212 ). This configuration satisfies the same two inequalities as in the first embodiment, so that the flow of the ink in the liquid discharge head 3 largely constitutes the following three paths. The first is the flow from the first inlet port 7a to the first return port 8a through the common supply channel 211. [ The second is the flow from the second inlet port 7b to the second recovery port 8b through the common recovery channel 212. [ Third, a common supply channel 211, a branch supply channel 213a, a liquid supply channel 18, a pressure chamber 23, a liquid recovery channel 19, a branch recovery channel 213b, And the common recovery channel 212 to the second recovery port 8b. The enriched ink generated by the evaporation from the discharge port 13, bubbles, foreign matter or the like is recovered to the liquid recovery channel 19 by these flows from the pressure chamber 23 and the discharge port 13 when recording is stopped . Enrichment of the ink in the pressure chamber 23 and the discharge port 13 can also be suppressed. Accordingly, it is possible to provide a non-progressive flow path through the recording element substrate 10 even when the recording element substrate 10 has a fine channel having a large flow resistance, as in this embodiment, . Therefore, the liquid discharge head 3 according to the present embodiment can suppress the enrichment of the liquid in the pressure chamber 23 and in the vicinity of the discharge port 13, thereby suppressing the deviation in the discharge direction and the discharge of defects And as a result, high quality can be recorded.

The amount of ink supplied to the liquid discharge head

In this embodiment, the total amount of ink supplied to the inlet ports of the common supply channel 211 and the common recovery channel 212 is greater than the sum of the amounts of ink discharged from all the recording element substrates 10 disposed on the channel member . Therefore, the flow through each common channel is a one-way flow from the inlet port to the recovery port irrespective of the discharge operation, so that the backflow into the head of the ink in which the volatile components of the ink have evaporated at the time of passing through the discharge port 13 does not exist. Even when the ink heated by the heating unit flows through the liquid recovery channel 19, the branch recovery channel 213b and the common recovery channel 212 in order to keep the amount of the ink to be discharged at a constant level, The temperature rise of the ink in the channel 212 can be suppressed.

About temperature control of ink

The configuration and advantages of the present embodiment will be described based on a specific relation formula. In the case where the thermal diffusivity of the first channel member 50 is relatively small and the heat generated by the recording element substrate 10 is not easily transferred to the ink in the channel member, Meets the equation.

T _{outflow _out} = (Q _outflow x T _ini + Q _branch x T _{outflow _branch)} / (Q + Q _{outflow branch)} Equation (1)

T _ini <T _{outflow _ branch} Equation (2)

Here, T _ini indicates the ink temperature in said second inlet port (7b), T _{outflow _branch} denotes the ink temperature at the branch number of the channel (213b), T _{outflow _out} is commonly recovered from the second inlet port (7b) Q _branch represents the ink temperature of the communication port 61 communicating with the common recovery channel 212 and Q _outflow represents the ink temperature of the branch recovery channel 213b ) &Lt; / RTI &gt;

The increase of the temperature of the ink in the common recovery channel 212 is controlled based on the above-described equations (1) and (2), so that the liquid discharge from the buffer tank 1003 is made larger than the amount supplied to the first inlet port 7a Can be suppressed by controlling the ink flow rate supplied to the second inlet port 7b of the head 3. Even when the ink heated by the heating unit flows through the liquid recovery channel 19, the branch recovery channel 213b and the common recovery channel 212 at the time of passing through the discharge port 13, The temperature increase can be suppressed by the ink flowing through the recording medium, and as a result, high-quality recording can be performed.

This embodiment will be described using specific numerical values. The flow resistance of the branch channel and the common channel is substantially less than the pressure chamber 23 to a point at which the flow resistance of the branch channel and the common channel is substantially negligible to flow ink at a flow rate of 30 mm / s through the pressure chamber 23 having a width of 30 μm and a height of 15 μm , This can be realized by setting the pressure difference between the two pressure regulating mechanisms to about 1400 Pa.

When the discharge amount is 5 x 10 ^-15 m ³ , the discharge amount from the discharge port 13 is less than the supply amount due to the pressure difference when the drive frequency is lower than 2.7 kHz, so that, at the macroscopic time scale, Passes through the supply port 17a and reaches the recovery port 17b. The ink in the pressure chamber 23 is heated to within the set temperature range so that the temperature of the ink in the vicinity of the liquid supply channel 18 and the liquid recovery channel 19 is somewhat high. However, when performing the ejection operation, approximately the same amount of ink as the ink to be ejected flows, so that the ink temperature around the pressure chamber 23 is lower than that of the non-activated state. That is, even if the flow of the ink from the supply port 17a to the recovery port 17b is the same on the macroscopic time scale, the manner in which the heat is transferred depends on whether the ink is driven or not, The temperature of the ink changes excessively and causes a variation in the discharge characteristic. The fluctuation of the ejection characteristics causes deterioration of the image quality, but deterioration of the image quality is visually recognized more easily especially when the recording medium solid is not filled with ink. That is, the influence of the fluctuation of the discharge characteristic is larger when the driving frequency is not so high.

To suppress such a phenomenon, the present embodiment has a configuration in which the flow rate is increased by increasing the flow rate only at the first circulation pump (high pressure side) 1001 connected to the common supply channel 211. The total discharge amount (Q _inje ) is expressed as follows,

Q _inje = Q _in - Q _out

Q _in represents the flow rate flowing into the ink supply port 17a through the common supply channel 211 when performing the ejection operation and Q _out represents the flow rate through which the ink is ejected to the common recovery channel 212 via the recovery port 17b And Q _inje represents the total discharge amount due to driving.

Further, the ink temperature (T _inje ) in the individual liquid chamber of the _bullet is expressed as follows,

T _inje (S _heater + T _in-ch (t) x Q _in - T _{out - ch} (t) x Q _out ) / Q _inje

Here, S _heater represents the amount of heat generated by the heater due to the discharging operation,

T _in-ch (t) &lt; / = T _out-ch (t)

Here, the time function T _in-ch (t) represents the ink temperature at the liquid supply channel 18 and the branch supply channel 213a, and the time function T _out-ch (t) Represents the ink temperature in the recovery channel 213b.

By increasing the amount of ink supplied from the buffer tank 1003 in accordance with the aforementioned equations, proportional mathematical expressions and inequalities, a transient increase in the ink temperature by lowering the temperature of ink introduced from the supply port 17a Can be suppressed. However, there is a disadvantage in increasing the ink supply amount in that the pressure drop is large in the pressure chamber 23 and the channel communicating therewith. Therefore, it is effective to suppress the transient ink temperature by lowering the temperature of the ink flowing from the supply port 17a. Further, only the flow rate of the first circulating pump (high-pressure side) 1001 is changed, so that the increase in power consumption of the entire apparatus is minimized.

As described above, the increase in the ink temperature at the inlet side due to the heat from the propagating temperature control is suppressed by increasing the flow rate in the common supply channel 211 in this embodiment. Therefore, the rise of the ink temperature due to the change of the driving state can be reduced.

Fifth Embodiment

The fifth embodiment will be described with reference to Fig. The flow direction of the ink is opposite between the common supply channel 211 and the common collecting channel 212 in this embodiment as illustrated in Fig. 16A illustrates the distribution of the negative pressure applied to the pressure chamber 23 in the direction in which the common channel extends. The solid line represents the pressure distribution in the common supply channel 211, the one-dot chain line represents the pressure distribution in the common recovery channel 212, and the dashed line represents the pressure distribution in the pressure chamber 23. The flow direction of the common supply channel 211 is from left to right in FIG. 15, and the direction of flow of the common collecting channel 212 is from right to left in FIG. The pressure value in the pressure chamber 23 is substantially uniform as shown in FIG. 16A. For example, when the size of the ejection opening 13 is large, the amount of ink ejected from the ejection opening 13 is sensitive to the positive pressure value applied to the pressure chamber 23. However, the configuration according to the present embodiment allows uniform ink to be ejected from all the pressure chambers 23 in the liquid ejection head 3, so that high-quality printing can be obtained. Further, the negative pressure control unit 230 can be divided as illustrated in FIG. 15, so that the dimensions can be reduced, and the separate units can be disposed at different positions. This greatly improves the placement freedom of the negative pressure control unit 230 in the liquid discharge head 3 and realizes a form that the user can handle easily. Further, the pumps communicating with the negative pressure control unit 230 are integrated in the same manner in this embodiment, so that the number of pumps of the whole apparatus can be reduced, and the size of the apparatus can be reduced.

On the other hand, Fig. 16B shows a case in which the common channel is applied to the pressure chamber 23 in the direction in which the common channel extends when the flow direction of the ink in the common supply channel 211 and the common recovery channel 212 are the same as in the above- The distribution of the negative pressure is illustrated. The direction of the flow in the common channel is from left to right in Fig. In this case, although the pressure value in the pressure chamber 23 drops along the direction of the flow, the pressure difference between the common supply channel 211 and the common recovery channel 212 is kept almost the same. When the ink is made in such a composition that the physical properties of the ink change in the pressure chamber 23 due to the evaporation of the volatile medium in the ink from the discharge port 13 as an example, the pressure chamber 23 It is necessary to suppress the change in the physical property by moving the ink through the recovery port 17b. In this case, the change in the physical properties of the ink changes in accordance with the flow direction of the common supply channel 211 and the common recovery channel 212 so that the change in the physical properties of the ink in all the pressure chambers 23 in the liquid discharge head 3 The desired ejection characteristics can be maintained, and the resulting printing with a high reliability level can be realized. When forming a plurality of common supply channels 211 and a common collecting channel 212 in the channel member 210, the channel cross-sectional area of the common channel needs to be increased in order to suppress the pressure drop in the common channel to a certain level. However, as a result, the short side direction of the channel member becomes long. Generally, the liquid ejection apparatus has a mechanism for mechanically pressing the recording medium to keep the gap between the liquid ejection head 3 and the recording medium at a specific value. However, the farther away from the position in which the recording medium is pressed in the radial direction, the more difficult it becomes to keep the gap between the liquid discharge head 3 and the recording medium constant. Therefore, it is preferable that the dimension of the liquid discharge head 3 in the short-side direction (length in the conveying direction of the recording medium) is as small as possible, and the flow direction of the common channel is the same. Therefore, if the opposite direction is more preferable according to the specifications of the liquid discharge head 3, high-quality printing with high reliability can be realized by setting the flow direction of the common channel to be opposite and setting the same direction to the same direction if desired.

Sixth Embodiment

In the sixth embodiment, the common supply channel 211 and the common collecting channel 212 are formed with resistance portions 217a and 217b, and the flow resistance in this resistance portion is locally larger than other channels. Specifically, the resistance of the resistive portion 217b is greater than the upstream portion of the common supply channel 211, and the resistance of the resistive portion 217a is greater than the downstream portion of the common return channel 212. The resistance portion 217a is formed between the recovery port 8 and the branch supply channel 213a closest to the recovery port 8. The resistive portion 217b is formed between the inlet port 7 and the branch return channel 213b closest to the inlet port 7.

Fig. 17 illustrates the entire configuration of the liquid discharging apparatus according to the present embodiment, and Fig. 18 is an equivalent circuit diagram of the internal channels of the liquid discharging head 3. Fig. The inlet port 7 is connected to the buffer tank 1003 and the recovery port 8 is connected to the second circulation pump 1004. This configuration creates a differential pressure between the common supply channel 211 and the common recovery channel 212 that is equivalent to the amount of the pressure drop in the resistance portions 217a and 217b. Therefore, the flow that flows through the pressure chamber 23 regardless of the driving state of each recording element substrate 10 and the flow that flows from the inlet port 7 to the recovery port 8 without going through the pressure chamber 23, Can be formed. The inlet port 7 and the recovery port 8 of the liquid discharge unit 300 are integrated into one each so that the number of engagement portions for liquid communication with the liquid discharge head 3 can be reduced. In addition, providing the resistive portions 217a, 217b allows a significant reduction in the number of pumps in the overall apparatus, and a reduction in size of the apparatus can be realized. The liquid inlet and the outlet provided for the common supply channel 211 and the common recovery channel 212 are arranged in the same manner as in the embodiment described above, (3).

The total flow rate per unit time of the liquid flowing through the common supply channel 211 and the common recovery channel 212 is equal to the total flow rate per unit time from all the discharge ports 13 communicating with the common supply channel 211, Is larger than the total amount of discharged liquid per unit time. Therefore, even when all the discharge ports 13 communicating with the common supply channel 211 are driven, the flow direction of the common supply channel 211 and the common recovery channel 212 does not change.

A differential pressure is generated in the liquid discharge head 3 in this embodiment so that a circulating flow that flows through the discharge port 13 can be generated without forming a complicated configuration of the apparatus main unit. Although any unit providing flow resistance is not explicitly embodied in this embodiment, any such arrangement may be used, such as reducing the channel cross-sectional area or making the wall surface more roughened, as long as channel resistance is applied There are no specific restrictions on its composition.

The channel configuration according to the present embodiment includes a first circulation pump (high pressure side) fluidly connected to the first and second inlet ports, a first circulation pump (low pressure side), and a fluid connection connected to the first and second recovery ports 2 circulation pump (high pressure side) and a second circulation pump (low pressure side). The configuration of this embodiment enables a more accurate control of the pressure or the flow rate in the common supply channel 211 and the common recovery channel 212 as compared with the above-described embodiment. As a result, a stable discharge characteristic can be realized irrespective of the operating state, and a higher quality image can be output.

Seventh Embodiment

The inkjet recording apparatus 1000 and the liquid discharge head 3 according to the seventh embodiment will be described. The following description is mainly made on the differences from the first to sixth embodiments, and the same parts as those in the first embodiment will not be described.

Explanation of inkjet recording apparatus

26 illustrates an inkjet recording apparatus according to the present embodiment. The recording apparatus 1000 according to the present embodiment is different from the first embodiment in that full color recording is performed on a recording medium by arranging four monochromatic liquid ejecting heads 3 corresponding to one of the CMYK inks in parallel . Although the number of discharge port rows usable per color in the first embodiment is two columns, the number of discharge ports usable per color in this embodiment is 20 columns (Fig. 25A). This makes it possible to perform recording at an extremely high speed by performing recording by allocating recording data to a plurality of ejection opening rows. The reliability can be improved by the ejection port at the corresponding position in the conveying direction of the recording medium of the other row performing ejection in a complementary manner even when ejection orifices representing ink defect ejection are present and thus this arrangement is suitable for industrial printing . The supply system of the recording apparatus 1000, the buffer tank 1003 and the main tank 1006 (ink tank) (Fig. 2) are connected to the liquid discharge head 3 by fluid connection in the same manner as in the first embodiment . Each of the liquid discharge heads 3 is also electrically connected to an electric control unit, which transmits power and discharge control signals to the liquid discharge head 3.

Description of the structure of the liquid discharge head

The structure of the liquid discharge head 3 according to this embodiment will be described. 20A and 20B are perspective views of the liquid discharge head 3 according to the present embodiment. The liquid discharge head 3 is a line-type liquid discharge head having sixteen recording element substrates 10 arranged in a straight line in the longitudinal direction of the liquid discharge head 3. The liquid discharge head 3 has a liquid connecting portion 111, a signal input terminal 91 and a power supply terminal 92 in the same manner as in the first embodiment. Since the liquid discharge head 3 according to the present embodiment has a larger number of discharge port rows, the input terminal 91 and the power supply terminal 92 are disposed on both sides of the liquid discharge head 3, different. This is intended to reduce the voltage drop and the signal transmission delay occurring in the wiring portion provided on the recording element substrate 10. [

21 is an exploded perspective view of the liquid discharge head 3 illustrating each part or unit constituting the liquid discharge head 3 which is disassembled according to the function. There is a liquid discharge unit support member 81 connected to both ends of the second channel member 60 in this embodiment. This liquid discharge unit 300 is mechanically coupled to the carriage of the recording apparatus 1000, whereby the liquid discharge head 3 is located. The liquid supply unit 220 having the electric wiring substrate 90 and the negative pressure control unit 230 is coupled to the liquid discharge unit support member 81. [ A filter (not shown) is built in the two liquid supply units 220. The two negative pressure control units 230 are set at different pressures and are a negative pressure control unit 230 which is a negative pressure but a relatively high pressure and a negative pressure control unit 230 which is a negative pressure and a relatively low pressure. The common supply channel 211 extending in the longitudinal direction of the liquid discharge head 3 when the high-pressure side and low-pressure side negative pressure control units 230 are disposed at the end of the liquid discharge head 3 as illustrated in Fig. And common flow channels 212 are opposite to each other. This facilitates the heat exchange between the common supply channel 211 and the common return channel 212 so that the temperature difference between the two common channels can be reduced. This is advantageous in that a temperature difference does not easily occur between the plurality of recording element substrates 10 disposed along the common channel, and consequently, unevenness in recording due to a temperature difference does not easily occur.

The channel member 210 of the liquid discharge unit 300 will be described in detail below. The channel member 210 is a first channel member 50 and a second channel member 60 which are stacked as illustrated in Fig. 21 and the liquid supplied from the liquid supply unit 220 is supplied to the discharge module 200 Distribution. The channel member 210 also functions as a channel member for the liquid to be recycled from the discharge module 200 to the liquid supply unit 220. The second channel member 60 of the channel member 210 is a channel member in which the common supply channel 211 and the common collecting channel 212 are formed and mainly assumes the stiffness of the liquid discharge head 3 . Thus, the material of the second channel member 60 is sufficiently corrosion resistant to liquids and has high mechanical strength. Examples of suitable materials include stainless steel, titanium (Ti), alumina, and the like.

22A is a view illustrating a side of the first channel member 50 on the side where the discharging module 200 is mounted and FIG. 22B is a view illustrating a back side from which the second channel member 60 comes into contact. Unlike the first embodiment, the first channel member 50 according to the seventh embodiment is an arrangement in which a plurality of members corresponding to the discharge module 200 are arranged adjacently. The use of such a segmented structure allows the length corresponding to the length of the liquid discharge head to be realized by arranging a plurality of modules and thus, for example, a B2 size and a relatively long scale liquid corresponding to a larger sheet It can be particularly suitably used for the discharge head. The communicating port 51 of the first channel member 50 communicates with the discharging module 200 by fluid connection as illustrated in Figure 22A and the individual communicating port 53 of the first channel member 50 communicates with the outlet And communicates with the communication port 61 of the second channel member 60 by fluid connection as illustrated in Figs. 22C illustrates a side view of the second channel member 60 in contact with the first channel member 50 and FIGURE 22D illustrates a cross-sectional view of the middle of the second channel member 60 taken in the thickness direction, 22e is a view illustrating a surface of the second channel member 60 to be brought into contact with the liquid supply unit 220. Fig. The functions of the channel and the communication port of the second channel member 60 are the same as those of one color in the first embodiment. One of the common channel grooves 71 of the second channel member 60 is the common supply channel 211 illustrated in FIG. 23, and the other is the common collecting channel 212. Both have a liquid supplied from one end side toward the other end side along the longitudinal direction of the liquid discharge head 3. [ Unlike the case of the first embodiment, the ink flow directions for the common supply channel 211 and the common collecting channel 212 are opposite to each other.

23 is a perspective view illustrating the connection relationship between the recording element substrate 10 and the channel member 210 with respect to the liquid. A common supply channel 211 and a common collecting channel 212 extending in the longitudinal direction of the liquid discharge head 3 are provided in the channel member 210 as illustrated in Fig. The communication ports 61 of the second channel member 60 are positioned and connected to the respective communication ports 53 of the first channel member 50 so that the communication between the communication channels 61 of the second channel member 60 The liquid supply path from the port 72 to the communication port 51 of the first channel member 50 via the common supply channel 211 is formed. A liquid supply path from the communication port 72 of the second channel member 60 to the communication port 51 of the first channel member 50 via the common recovery channel 212 is also formed in the same manner.

A channel is formed on the recording element substrate 10 and the discharge module 200 so as to communicate with the discharge port 13 and a part or all of the supplied liquid is discharged from the discharge port 13 (the pressure chamber 23) ) In the same manner as in the first embodiment. The common supply channel 211 is connected to the negative pressure producing unit 230 (high pressure side) via the liquid supply unit 220 in the same manner as in the first embodiment, and the common collecting channel 212 is connected to the negative pressure control unit 230 (low pressure side). Therefore, a flow occurs due to the differential pressure, and this flow flows from the common supply channel 211 to the ejection port 13 (the pressure recovery chamber 23 through the common recovery channel 212) of the recording element substrate 10.

Description of Discharge Module

Fig. 24A illustrates a perspective view of one discharge module 200, and Fig. 24B is an exploded view thereof. The difference from the first embodiment is that a plurality of terminals 16 are arranged and arranged on both sides (the long side portion of the recording element substrate 10) along the direction of the plurality of ejection orifice rows of the recording element substrate 10, One flexible printed circuit board 40 is provided on one recording element substrate 10 and is electrically connected to the terminal 16. This is because the number of ejection orifice rows provided on the recording element substrate 10 is 20 columns, which is greatly increased compared to the eight columns in the first embodiment. The object is to reduce the voltage drop and the signal transmission delay occurring in the wiring portion provided on the recording element substrate 10 by keeping the maximum distance from the terminal 16 to the recording element 15 provided corresponding to the discharge port row short, I will. The liquid communication port 31 of the support member 30 is opened to cover all the ejection orifice rows provided in the recording element substrate 10. [ The difference is the same as in the first embodiment.

Description of the structure of the recording element substrate

25A is a schematic view illustrating the surface of the recording element substrate 10 on the side where the ejection orifices 13 are disposed, and FIG. 25C is a schematic view illustrating the back surface of the element illustrated in FIG. 25A. 25B is a schematic view illustrating the surface of the recording element substrate 10 in a state in which the cover plate 20 provided on the rear surface side of the recording element substrate 10 is removed in Fig. 25C. The liquid supply channel 18 and the liquid recovery channel 19 are alternately provided on the rear surface of the recording element substrate 10 along the discharge port column direction as illustrated in Fig. 25B. A significant difference from the first embodiment is that the terminals 16 are disposed on both side portions of the recording element substrate 10 along the discharge port row direction, although the number of the discharge port rows is much larger than that of the first embodiment. A basic structure is the same as that of the first embodiment. For example, a set of liquid supply channels 18 and a liquid recovery channel 19 are provided in each of the ejection orifice rows, and the liquid communication port 31 of the support member 30 An opening 21 is provided in the cover plate 20 and the like.

Eighth Embodiment

The configuration of the liquid discharge head 3 and the inkjet recording apparatus 1000 according to the eighth embodiment will be described. The liquid discharge head 3 according to the eighth embodiment is a page-wide head which records in a B2 size recording medium sheet in a single scan. The differences of the eighth embodiment of the above-described embodiment will be mainly described later, and the same parts will not be described again.

Explanation of inkjet recording apparatus

27 is a schematic view of an inkjet recording apparatus according to this embodiment. The recording apparatus 1000 forms an image by ejecting liquid onto the intermediate transferring member (intermediate transferring drum 1007) without directly recording onto the recording medium from the liquid discharge head 3, The recording apparatus 1000 has four monochromatic liquid discharge heads 3 corresponding to the four ink types of CMYK arranged in the arcuate portion along the intermediate transfer drum 1007. [ Therefore, the full-color printing is performed on the intermediate transferring member, the recorded image is dried in an appropriate state on the intermediate transferring member, and then the recording medium 1008 is transferred by the transferring unit 1008 by the sheet conveying roller 1009 The sheet conveying system of the above-described embodiment mainly has a horizontal conveying path for conveying the cutting sheet, whereas the present embodiment is a sheet conveying system in which a continuous sheet (not shown) supplied from a main roll The drum conveying system of this kind can easily convey the sheet in a state in which a specific tension is applied, so that conveyance jamming is small in performing high-speed recording, and therefore the reliability of the apparatus is improved The buffer tank 1003 and the main tank 1006 are connected to the liquid discharge head 3 by a fluid connection. Each liquid discharge head (not shown) 3 are also electrically connected to an electric control unit, which transmits power and discharge control signals to the liquid discharge head 3.

Example 9

Although the circulation path illustrated in Figs. 2 and 9 between the tank of the recording apparatus 1000 and the liquid discharge head 3 can be applied as a liquid circulation path, the circulation path exemplified in Fig. 28 is suitable. The main difference to the circulation path described above is that a bypass valve 1010 is added in communication with the channels of the first circulation pump 1001, 1002 and the second circulation pump 1004, respectively. The bypass valve 1010 functions to lower the pressure on the upstream side of the bypass valve 1010 due to the valve opening even if the pressure exceeds a predetermined pressure (first function). Further, the bypass valve 1010 functions to open and close the valve at a predetermined timing by a signal from the control board in the recording apparatus main unit (second function).

According to the first function, an excessively large or excessively small pressure can be prevented from being applied to the channel on the downstream side of the first circulating pump 1001, 1002 and on the upstream side of the second circulating pump 1004. For example, when the functions of the first circulation pumps 1001 and 1002 malfunction, an excessive flow rate or pressure can be applied to the liquid discharge head 3. This may cause the liquid to leak from the discharge port 13 of the liquid discharge head 3 or cause the bonded portion in the liquid discharge head 3 to be damaged. When a bypass valve is added to the first circulation pumps 1001 and 1002 as in the present embodiment, the opening of the bypass valve 1010 opens the liquid path to the upstream side of the circulation pump, so that excessive pressure is generated The problem as described above can be suppressed.

Further, due to the second function, when the circulation operation is stopped, all the bypass valves 1010 are controlled by the control signal from the main unit side after the first circulation pumps 1001, 1002 and the second circulation pump 1004 are stopped, As shown in FIG. This allows the high negative pressure (for example, several kPa to several tens kPa) of the downstream portion of the liquid discharge head 3 (between the negative pressure control unit 230 and the second circulation pump 1004) to be released in a short time . When a volumetric pump such as a diaphragm pump is used as the circulating pump, a check valve is usually incorporated in the pump. However, opening of the bypass valve 1010 similarly enables the pressure release from the downstream buffer tank 1003 to be performed on the downstream side of the liquid discharge head 3. Although there is a pressure drop in the channel in the liquid discharge head 3 and in the channel on the upstream side of the liquid discharge head 3 although the pressure release on the downstream side of the liquid discharge head 3 can be performed from the upstream side as well do. Therefore, there is a concern that the pressure discharge takes time, the pressure in the common channel in the liquid discharge head 3 temporarily drops too much, and the meniscus at the discharge port may be destroyed. The opening of the bypass valve 1010 on the upstream side of the liquid discharge head 3 promotes the discharge of pressure on the downstream side of the liquid discharge head 3 and thus the risk of destruction of the meniscus at the discharge port is reduced.

Description of the structure of the liquid discharge head

The structure of the liquid discharge head 3 according to the ninth embodiment will be described. 29A is a perspective view of the liquid discharge head 3 according to the present embodiment, and FIG. 29B is an exploded perspective view thereof. The liquid discharge head 3 has 36 recording element substrates 10 arranged in a straight line (in-line) in the longitudinal direction of the liquid discharge head 3 and has a line-type (page-wide ) Ink jet recording head. The liquid discharge head 3 has a signal input terminal 91 and a power supply terminal 92 and also has a shielding plate 132 for protecting the longitudinal side surface of the head.

Fig. 29B is an exploded perspective view of the liquid discharge head 3 exemplifying each part or unit constituting the liquid discharge head 3 according to the function (the shield plate 132 is not shown). The roles of the unit and the member and the order of the liquid flow through the liquid discharge head 3 are the same as in the above-described embodiment. This mainly differs with respect to the shape of the first channel member 50, the position of the negative pressure control unit 230, and the points of the electric wiring substrate 90 which are divided and arranged in plural. For example, in the case of the liquid discharge head 3 having a length corresponding to the B2 size recording medium, since the amount of electric power used by the liquid discharge head 3 is large, as in the case of this embodiment, A substrate 90 is provided. Each of the four electric wiring boards 90 is attached to both sides of the electric wiring board support member 82 attached to the liquid discharge unit support member 81. [

30A is a side view of the liquid discharge head 3 having the liquid discharge unit 300, the liquid supply unit 220 and the negative pressure control unit 230, FIG. 30B is a schematic view illustrating the liquid flow, and FIG. 30A is a perspective view illustrating a section taken along the line XXXC-XXXC of FIG. Portions of the configuration are simplified to facilitate understanding.

The liquid connection portion 111 and the filter 221 are provided in the liquid supply unit 220 and the negative pressure control unit 230 is integrally formed under the liquid supply unit 220. [ This allows the distance in the height direction between the recording element substrate 10 and the negative pressure control unit 230 to be reduced as compared with the above-described embodiment. This configuration is also advantageous in that the number of channel connecting portions in the liquid supply unit 220 is reduced, and the number of components and the assembling process can be reduced as well as increased reliability regarding leakage of the recording liquid.

In addition, the difference in head between the negative pressure control unit 230 and the surface on which the discharge port is formed is relatively small, and therefore, the inclination angle of the liquid discharge head 3 with respect to each liquid discharge head 3, Can be suitably applied to other recording apparatuses. This is because, even when each of the plurality of liquid discharge heads 3 is used at different inclination angles, a reduced head difference enables the negative pressure difference applied to the discharge port of each recording element substrate 10 to be reduced. Reducing the distance from the negative pressure control unit 230 to the recording element substrate 10 also reduces the pressure drop due to fluctuations in the flow of the liquid because the flow resistance is reduced and a more stable negative pressure control can be performed .

30B is a schematic view illustrating the flow of the recording liquid in the liquid discharge head 3; The circuit is the same as the circulation path exemplified in Fig. 28, and Fig. 30B illustrates the liquid flow in each component in the actual liquid discharge head 3. The common supply channel 211 and the common recovery channel 212 are provided in the second channel member 60 whose set is narrow and extend in the longitudinal direction of the liquid discharge head 3. [ The common supply channel 211 and the common collecting channel 212 are configured such that the liquid flows in mutually opposite directions and the filter 221 is disposed on the upstream side of these channels to capture the foreign substance introduced from the connecting portion 111, do. This arrangement in which liquid flows in mutually opposite directions in the common supply channel 211 and the common recovery channel 212 is preferable in that the temperature gradient in the longitudinal direction in the liquid discharge head 3 is reduced. The flow directions of the common supply channel 211 and the common collecting channel 212 are shown to be the same in Fig. 28 to simplify the description.

The negative pressure control unit 230 is disposed on the downstream side of each of the common supply channel 211 and the common recovery channel 212. [ The common supply channel 211 has a branch portion to a plurality of branch supply channels 213 along a path and the common recovery channel 212 has a branch portion to a plurality of branch recovery channels 214 along a path. The branch supply channel 213 and the branch recovery channel 214 are formed in the plurality of first channel members 50. Each of the branch channels communicates with the opening 21 of the cover plate 20 provided on the back surface of the recording element substrate 10 (see Fig. 13C)

The negative pressure control unit 230 indicated by H and L in Fig. 30B is a high pressure side (H) and a low pressure side (L) unit. Each of the negative pressure control units 230 is a reverse pressure regulating mechanism that is set to control the upstream pressure of the negative pressure control unit 230 at relatively high (H) and low (L) negative pressures. The common supply channel 211 is connected to the negative pressure control unit 230 (high pressure side), and the common recovery channel 212 is connected to the negative pressure control unit 230 (low pressure side). Which creates a differential pressure between the common supply channel 211 and the common recovery channel 212. This differential pressure is generated when the liquid passes from the common supply channel 211 to the branch supply channel 213 and the discharge port 13 (the pressure chamber 23 and the branch recovery channel 214) in the recording element substrate 10 To flow into the collection channel 212.

30C is a perspective view illustrating a cross-section taken along the line XXXC-XXXC in FIG. 30A. Each ejection module 200 of this embodiment is configured to include a first channel member 50, a recording element substrate 10, and a flexible printed circuit board 40. The present embodiment does not have the support member 30 (Fig. 8) described in the above embodiment, and the recording element substrate 10 has a cover plate 20 that is directly coupled to the first channel member 50 . The common supply channel 211 provided in the second channel member 60 is branched from the communication port 61 provided on the upper surface thereof through the individual communication port 53 formed in the lower surface of the first channel member 50, And supplies the liquid to the channel 213. Thereafter, the liquid passes through the pressure chamber 23 and is recovered to the common recovery channel 212 via the branch recovery channel 214, the individual communication port 53, and the communication port 61 in that order.

The individual communication ports 53 on the lower surface of the first channel member 50 (the surface facing the second channel member 60), unlike the arrangement exemplified in the above-described embodiment, And is an opening of a sufficient size with respect to the communication port 61 formed on the upper surface. According to this configuration, even when there is a positional deviation when the discharging module 200 is mounted on the second channel member 60, the gap between the first channel member 50 and the second channel member 60 can be maintained in a reliable manner Fluid communication is realized, and therefore the yield is improved during head manufacturing, thereby reducing the cost.

Although two pressure regulating mechanisms and flow resistance members have been presented herein as pressure difference generating sources in the above description, other configurations can be used as long as they are in accordance with the concept of the present invention. Although the channel resistance has disclosed a higher configuration than the other portions as a normal means, an arrangement in which the channel resistance can be changed more highly at the time when the problem is solved is also effective.

Although the present disclosure can be applied to a liquid discharge head using various types of discharge arrangements (for example, a piezoelectric element, a heating element and an electrostatic system), the present disclosure is not limited to the channel portion 23 and the channel 24 in communication therewith) are particularly suitable for application to liquid discharge heads having a large resistance. By way of example, the present disclosure can be applied to a liquid discharge head in which the height h of the channel 24 communicating with the pressure chamber 23 is 8 占 퐉 or less. The present disclosure is also well suited for application to a full-line type liquid discharge head in which a plurality of recording element substrates 10 are arranged, having a high-density discharge port having an array density of discharge ports of 600 dpi or more.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the concept and scope of the present invention. Accordingly, the scope of the invention is defined by the appended claims.

According to the present disclosure, liquid can be supplied to the liquid discharge head while suppressing an increase in pressure drop.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims (34)

A liquid discharge head comprising:
A plurality of discharge ports configured to discharge liquid;
A plurality of recording elements configured to generate energy used to eject liquid;
A plurality of supply channels configured to supply liquid to the plurality of recording elements;
A common supply channel configured to communicate with the plurality of supply channels and to supply liquid to the plurality of supply channels;
A plurality of recovery channels configured to recover liquid supplied to the plurality of recording elements by the plurality of supply channels; And
And a common recovery channel communicating with the plurality of recovery channels and configured to recover liquid from the plurality of recovery channels,
Inside the liquid discharge head
A first inlet port configured to supply liquid from the outside of the liquid discharge head to the common supply channel,
A first recovery port configured to recover liquid from the common supply channel to the outside of the liquid discharge head,
Respectively,
The first inlet port and the first recovery port are communicated by the common supply channel without proceeding through the channel portion where the recording element is disposed,
Inside the liquid discharge head
A second inlet port configured to supply liquid from the outside of the liquid discharge head to the common return channel, and
And a second recovery port configured to recover liquid from the common recovery channel to the outside of the liquid discharge head
Respectively,
The second inlet port and the second recovery port are communicated by the common recovery channel without proceeding through the channel portion where the recording element is disposed. The method according to claim 1,
Wherein the liquid in the common supply channel is supplied to the common recovery channel through the supply channel, the channel portion in which the recording element is disposed, and the recovery channel in this order. 3. The method according to claim 1 or 2,
Wherein the channel portion in which the recording element is disposed faces the ejection opening and includes a pressure chamber for accommodating the recording element therein. 3. The method according to claim 1 or 2,
Wherein the plurality of supply channels extend in a direction perpendicular to a direction in which the common supply channel extends and the plurality of recovery channels extend in a direction perpendicular to a direction in which the common recovery channel extends. 3. The method according to claim 1 or 2,
Wherein the common supply channel and the common recovery channel extend in parallel with each other. 3. The method according to claim 1 or 2,
Wherein the liquid flowing through the common supply channel and the liquid flowing through the common recovery channel are the same. 3. The method according to claim 1 or 2,
Wherein a flow direction of the liquid flowing through the common supply channel and a direction of the liquid flowing through the common return channel are different. 3. The method according to claim 1 or 2,
Wherein the static pressure value of the liquid in the vicinity of the inlet port of the common supply channel is greater than the static pressure value in the vicinity of the inlet port of the common recovery channel,
Wherein the static pressure value near the recovery port of the common supply channel is greater than the static pressure value near the recovery port of the common recovery channel. 3. The method according to claim 1 or 2,
Wherein the total amount of liquid supplied to the common supply channel and the common recovery channel is greater than the total amount of liquid discharged from the entire discharge port. 10. The method of claim 9,
Wherein the flow rate through the common supply channel per unit time is greater than the flow rate through the common return channel per unit time. 10. The method of claim 9,
Wherein the flow rate through the common recovery channel per unit time is greater than the flow rate through the common supply channel per unit time. 3. The method according to claim 1 or 2,
The liquid discharge head
A recording element substrate including the recording element, and
A support member configured to support the recording element substrate;
Lt; / RTI &gt;
Wherein the common supply channel, the supply channel, the common recovery channel, and the recovery channel are formed on the support member. 13. The method of claim 12,
Wherein the thermal diffusivity of the support member is smaller than the thermal diffusivity of the recording element substrate. 3. The method according to claim 1 or 2,
The liquid discharge head
A recording element substrate including the recording element, and
A support member configured to support the recording element substrate;
Lt; / RTI &gt;
The support member
A first support member on which the supply channel and the recovery channel are formed,
Wherein the common supply channel and the common recovery channel are formed by a second support member
And a liquid discharge head. 15. The method of claim 14,
Wherein the thermal diffusivity of at least the first support member among the support members having the laminated structure is smaller than the thermal diffusivity of the recording element substrate. A liquid discharge head comprising:
As a recording element substrate,
A plurality of discharge ports configured to discharge liquid,
A plurality of pressure chambers having recording elements therein for discharging the liquid from the discharge ports,
A plurality of first common channels configured to supply liquid to the plurality of pressure chambers,
A plurality of second common channels configured to recover liquid from the plurality of pressure chambers,
A recording element substrate;
A plurality of supply channels in communication with the first common channel;
A plurality of collection channels communicating with the second common channel;
A common supply channel in fluid communication with the plurality of supply channels; And
And a common recovery channel in fluid communication with the plurality of recovery channels,
Inside the liquid discharge head
A first inlet port configured to supply liquid to the common supply channel,
A first recovery port configured to recover liquid from the common supply channel,
A second inlet port configured to supply liquid to the common return channel, and
A second recovery port configured to recover liquid from the common recovery channel,
Is formed in the liquid discharge head. 17. The method of claim 16,
The first inlet port and the first recovery port are communicated by the common supply channel without proceeding through the pressure chamber,
Wherein the second inlet port and the second recovery port are communicated by the common recovery channel without proceeding through the pressure chamber. 18. The method according to claim 16 or 17,
A support member configured to support a plurality of the recording element substrates, wherein the plurality of recording element substrates are arranged on the support member,
Wherein the plurality of supply channels, the plurality of recovery channels, the common supply channel, and the common recovery channel are provided on the support member. A liquid ejecting apparatus comprising:
As a liquid discharge head,
A plurality of discharge ports configured to discharge liquid,
A plurality of pressure chambers having therein a plurality of recording elements used for generating energy for discharging the liquid,
A first common channel in communication with the first inlet port and the first return port,
A plurality of first individual channels communicating with the first common channel and configured to supply liquid to the plurality of recording elements,
A second common channel in communication with the second inlet port and the second return port, and
And a plurality of second individual channels communicating with the second common channel and adapted to collect liquid in the pressure chamber into the second common return channel
A liquid discharge head,
And a supply unit configured to supply liquid in this order to the first common channel, the first individual channel, the plurality of recording elements, the second individual channel, and the second common channel,
The first inlet port and the first return port are communicated by the first common channel without proceeding through the pressure chamber and the second inlet port and the second return port do not proceed through the pressure chamber And communicates by the second common channel. 20. The method of claim 19,
And the pressure chamber faces the discharge port. 21. The method according to claim 19 or 20,
A first negative pressure control unit in communication with the first inlet port; And
And a second negative pressure control unit in communication with the second inlet port. 21. The method according to claim 19 or 20,
A first liquid delivery pump in communication with said first and second inlet ports and configured to deliver liquid,
A first recovery pump communicating with the first recovery port and configured to recover liquid,
And a second recovery pump configured to communicate with the second recovery port and to recover the liquid. 21. The method according to claim 19 or 20,
A first liquid delivery pump in communication with said first inlet port and configured to deliver liquid,
A second liquid delivery pump in communication with said second inlet port and configured to deliver liquid,
A first recovery pump communicating with the first recovery port and configured to recover liquid,
And a second recovery pump configured to communicate with the second recovery port and to recover the liquid. 21. The method according to claim 19 or 20,
A first liquid delivery pump in communication with said first inlet port and configured to deliver liquid,
A second liquid delivery pump in communication with said second inlet port and configured to deliver liquid,
And a first recovery pump configured to communicate with the first and second recovery ports and to recover the liquid. 21. The method according to claim 19 or 20,
A first liquid delivery pump in communication with said first and second inlet ports and configured to deliver liquid,
And a first recovery pump configured to communicate with the first and second recovery ports and to recover the liquid. 21. The method according to claim 19 or 20,
And an ink tank communicating with the first negative pressure control unit and the second negative pressure control unit. A liquid discharge head comprising:
As a recording element substrate,
A plurality of discharge ports configured to discharge liquid,
A plurality of pressure chambers having recording elements therein for discharging the liquid from the discharge ports,
A plurality of first common channels configured to supply liquid to the plurality of pressure chambers,
A plurality of second common channels configured to recover liquid from the plurality of pressure chambers,
A recording element substrate;
A plurality of supply channels in communication with the first common channel;
A plurality of collection channels communicating with the second common channel;
A common supply channel in fluid communication with the plurality of supply channels;
A common collection channel in fluid communication with the plurality of collection channels;
An inlet port configured to supply liquid to the liquid discharge head; And
And a recovery port configured to recover liquid from the liquid discharge head,
The inlet port communicates with one end of the common supply channel and one end of the common return channel,
The inlet port communicates with the other end of the common supply channel and the other end of the common return channel,
Wherein the flow resistance at the one end side of the common recovery channel is larger than the flow resistance at the one end side of the common supply channel,
And the flow resistance on the other end side of the common supply channel is larger than the flow resistance on the other end side of the common recovery channel. 27. A method according to any one of claims 1, 2, 16, 17 and 27,
Wherein a height of a channel adjacent to the pressure chamber having the recording element therein is 8 占 퐉 or less. 3. The method according to claim 1 or 2,
Wherein the liquid discharge head is a line-shaped liquid discharge head having a length corresponding to the recording medium. 3. The method according to claim 1 or 2,
Wherein the liquid in the pressure chamber having the recording element therein circulates between the inside of the pressure chamber and the outside of the pressure chamber. A liquid discharging method for discharging liquid from a liquid discharging head,
The liquid discharge head
A plurality of discharge ports configured to discharge liquid,
A plurality of pressure chambers having therein a plurality of recording elements configured to generate energy used to eject liquid,
A plurality of supply channels configured to supply liquid to the plurality of recording elements,
A common supply channel configured to supply liquid to the plurality of supply channels,
A plurality of recovery channels configured to recover liquid supplied to the plurality of recording elements by the plurality of supply channels,
A common recovery channel configured to recover liquid from the plurality of recovery channels,
A first inlet port configured to supply liquid from the outside of the liquid discharge head to the common supply channel,
A first recovery port configured to recover liquid from the common supply channel to the outside of the liquid discharge head,
A second inlet port configured to supply liquid from the outside of the liquid discharge head to the common return channel, and
And a second recovery port configured to recover liquid from the common recovery channel to the outside of the liquid discharge head
Lt; / RTI &gt;
The liquid discharge method
And a liquid recovery mechanism for recovering the liquid flowing from the first inlet port to the common supply channel to the outside of the liquid discharge head from the first recovery port, Withdrawing the liquid from the second recovery port to the outside of the liquid discharge head; And
Discharging the liquid from the discharge port in a state where supply of the liquid is performed in the collecting step
And discharging the liquid. 32. The method of claim 31,
Wherein the liquid is discharged from the discharge port in a state where a flow of liquid is formed inside the pressure chamber in the recovery step. 33. The method according to claim 31 or 32,
Wherein the pressure of the liquid flowing through the common supply channel is greater than the pressure of the liquid flowing through the common return channel. 33. The method according to claim 31 or 32,
And the liquid recovered from the first recovery port does not proceed through the pressure chamber.

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