JP5451910B2 - Liquid discharge head - Google Patents

Description

  The present invention relates to a liquid discharge head that supplies energy to a discharge energy generating element to apply energy to the liquid and discharge the liquid from a discharge port.

  2. Description of the Related Art Conventionally, many recording heads as liquid ejection heads in commonly used ink jet recording apparatuses are manufactured by bonding an orifice plate and a substrate on which a liquid supply port or the like is formed. The structure of such a recording head is shown in FIGS. 11 (a) and 11 (b). FIG. 11A shows a plan view of a conventional liquid discharge head 501, and FIG. 11B shows the AA ′ line of FIG. 11A in the conventional liquid discharge head 501. A cross-sectional view along is shown. In this type of recording head, the substrate 503 and the orifice plate 502 are bonded together to form a common liquid chamber 504 in a part of the space between them. A liquid supply port 505 is formed in the substrate 503 so as to penetrate the substrate, and the liquid supply port 505 communicates with the common liquid chamber 504. A liquid channel 507 extends in communication with the common liquid chamber 504, and a pressure chamber 508 is formed at the end of the liquid channel 507 opposite to the common liquid chamber 504. A discharge port 506 is formed in the orifice plate 502 so as to communicate with the pressure chamber 508. A heater 509 as a discharge energy generating element for supplying discharge energy to the liquid in the pressure chamber 508 is disposed at a position corresponding to the discharge port 506. The liquid supplied to the common liquid chamber 504 via the liquid supply port 505 is supplied to the pressure chamber 508 via the liquid channel 507, and energy is supplied to the liquid by the heater 509 in the pressure chamber 508, and the discharge port 506. The liquid is discharged from.

  In the recording head 501 shown in FIGS. 11A and 11B, the liquid is supplied from the liquid supply port 505 to the discharge port 506 only in one direction.

  When such a recording head 501 is used to perform recording by ejecting liquid, bubbles generated by the heater 509 grow in a direction deviating from the common liquid chamber 504 toward the liquid supply port 505. Accordingly, the discharged liquid is discharged while receiving a force in that direction. At this time, the tail portion of the ejected liquid is broken while being pulled in the direction of the common liquid chamber 504, so that a so-called satellite is formed small, and it does not land on the recording medium and easily becomes a mist that floats inside the printer housing. .

  Even when satellites land on the recording medium without becoming a floating mist, satellites with a small mass are easily affected by the air current, and the flight direction is likely to fluctuate due to the air current. As a result, the landing position of the satellite on the recording medium fluctuates and density unevenness is likely to occur.

  In addition, when the satellite receives a force in the direction of the common liquid chamber 504 and discharges it, the flying direction differs from that of the main droplet. Therefore, when recording is performed by reciprocating scanning of the recording head on the recording medium, the main path is the forward path and the return path. The way in which the droplets and satellites overlap changes and density unevenness is likely to occur.

  As measures against the satellite portion becoming small as described above, there are those disclosed in Patent Document 1 and Patent Document 2. FIG. 12A is a perspective view showing the components of the recording head disclosed in Patent Document 1 in an exploded manner. FIG. 12B is a cross-sectional view of the periphery of the ejection port, which is a main part of the recording head in which the component parts are assembled. FIG. 13A is a cross-sectional view in which the main part of the recording head disclosed in Patent Document 2 is enlarged and broken. FIG. 13B is a cross-sectional view of the recording head shown in FIG.

  In Patent Documents 1 and 2 described above, the ink guided to the ink supply port is further guided in the ejection direction, from which the ink is guided in a direction orthogonal to the ejection direction, where thermal energy is given to the liquid by the heater. Yes. The passage for supplying the liquid to the discharge port is formed on both sides of the discharge port, and the liquid to be discharged is supplied from both sides of the discharge port to the discharge port. Ink flow bias that affects growth is suppressed. As a result, it is possible to suppress applying a biased force to the droplets during ejection.

  As a result, the bubbles grow substantially symmetrically around the heater and contract almost symmetrically. For this reason, the tail of the ejected ink is likely to be straight, short and thick. As a result, satellites formed by the tail splitting in the droplet formation process are likely to be large, and the flight direction of the droplets is also ejected straight in the ejection direction substantially perpendicular to the ejection port formation surface. Further, the flight direction of the main droplet portion at this time is also straight in the discharge direction substantially orthogonal to the discharge port forming surface. In this way, the satellite generated when the liquid is ejected becomes large, so the landing position of the satellite is less affected by the airflow and stabilized, and density unevenness occurs even during high-speed recording or recording with small droplets It becomes difficult to do. In addition, since the satellite becomes larger, the arrival rate to the recording medium is increased, and mist floating in the printer housing without landing on the recording medium is reduced. Is difficult to break down. When both satellites and main droplets are ejected straight in a direction that is almost perpendicular to the ejection port formation surface, the deviation of the landing positions of the main droplets and satellites on the forward and return passes during recording operation is reduced, so reciprocal recording operation Sometimes the density difference is less likely to occur. This makes it difficult for density unevenness to occur in an image obtained on a recording medium.

JP 60-206653 A US Pat. No. 6,660,175

  However, according to the method of Patent Document 1, the ink once stored in the storage tank is further guided in the ink ejection direction by the supply pipe, but the guided ink is arranged in a row of ejection ports in the ink flow path. It only communicates near the center of the direction. Accordingly, since the ink in the common liquid chamber located in the central portion of the ink flow path is ejected or sucked out by suction recovery, the recording head does not remain in the common liquid chamber. Discharged from. However, the ink in the common liquid chamber located at a site away from the supply pipe is likely to remain without being sucked because the ink flow hardly occurs even if the suction recovery is performed. Accordingly, bubbles tend to accumulate in the portion, the bubbles affect ink ejection, and the ejection characteristics are likely to fluctuate, and it is difficult to stably maintain a good ejection state.

  Further, according to the method of Patent Document 2, the ink guided to the ink supply port is formed with a hole in the layer disposed between the substrate and the orifice plate, and the ink is further guided in the ejection direction through the hole. It is. However, the ink flow resistance is supplied through the hole. This resistance increases as the size of the hole decreases, and increases as the length of the flow path inside the hole increases. As this resistance increases, the ink refilling speed (hereinafter referred to as refilling speed) decreases, and the droplet repeated ejection frequency (hereinafter referred to as driving frequency) decreases. This reduces the throughput in the recording apparatus.

  As measures against the resistance to the ink flow, it is conceivable to increase the diameter of the hole and to reduce the thickness of the layer in which the hole is formed. By increasing the diameter of the hole through which the ink passes, it is possible to reduce the resistance of the ink flow. Thereby, the throughput in the recording apparatus is improved. However, when the hole diameter is increased, the pressure chamber itself is increased, so that the distance between the discharge ports is increased and the interval between the discharged droplets is increased. Accordingly, since the density of the ejection ports on the recording head is reduced, the resolution due to the ejected droplets is lowered, and the throughput of the recording apparatus is eventually suppressed. In addition, with regard to reducing the thickness of the layer in which the hole is formed in order to shorten the flow path formed by the hole, the required strength of the recording head cannot be maintained if this is made extremely thin. In addition, since the amount of heat that is diffused and radiated through this layer decreases, the heat generated by the heater cannot be released and the temperature of the heater increases. Accordingly, the drive frequency cannot be increased to suppress the temperature rise of the recording head, and the throughput cannot be increased.

  Therefore, in view of the above circumstances, the object of the present invention is to stably discharge liquid droplets with a high-density nozzle arrangement and a high driving frequency while preventing bubble accumulation in the common liquid chamber, and the main droplets and satellites are recorded on the recording medium. It is to provide a recording head that stably lands.

The liquid ejection head of the present invention includes a plurality of energy generation element arrays in which a plurality of energy generation elements that generate energy used to eject liquid are arranged in a first direction, and the plurality of energy generation element arrays And a supply port extending in the first direction for supplying a liquid via a flow path to the substrate, wherein the plurality of energy generating element rows are at one end of the substrate. A first energy generating element array formed on the side, and a second liquid ejecting a larger amount of liquid droplets than the liquid droplets ejected by the first energy generating element array formed on the center side of the substrate. Each energy generating element included in the first energy generating element array is connected to one flow path and included in the second energy generating element array. A first flow path extending on one side to the energy generating element s, the the one side, wherein a second flow passage extending to the other side of the opposite are connected.

  According to the present invention, while preventing accumulation in the common liquid chamber, liquid discharge that stably discharges droplets with a high-density nozzle arrangement and a high driving frequency, and stably landes main droplets and satellites on a recording medium. A head can be provided.

(A) is a top view of the recording head concerning a first embodiment of the present invention, and (b) is a sectional view which meets an A-A 'line in (a). (A) is a top view of the recording head which concerns on 2nd embodiment of this invention, (b) is sectional drawing which follows the A-A 'line in (a). (A) is a top view of the recording head which concerns on 3rd embodiment of this invention, (b) is sectional drawing which follows the A-A 'line in (a). (A) is a top view of the recording head which concerns on 4th embodiment of this invention, (b) is sectional drawing which follows the A-A 'line in (a). (A) is a top view of the recording head which concerns on 5th embodiment of this invention, (b) is sectional drawing which follows the A-A 'line in (a). (A) is a top view of the recording head which concerns on 6th embodiment of this invention, (b) is sectional drawing which follows the A-A 'line in (a). (A) is a top view of the recording head based on 7th Embodiment of this invention, (b) is sectional drawing which follows the A-A 'line in (a). (A) is a top view of the recording head based on 8th Embodiment of this invention, (b) is sectional drawing which follows the A-A 'line in (a). (A) is a top view of the recording head which concerns on 9th embodiment of this invention, (b) is sectional drawing which follows the A-A 'line in (a). (A) is a top view of the recording head based on 10th Embodiment of this invention, (b) is sectional drawing which follows the A-A 'line in (a). (A) is a plan view of a conventional recording head, and (b) is a cross-sectional view taken along the line A-A ′ in (a). (A) is a perspective view of each part of another example of a conventional recording head, and (b) is a cross-sectional view when the recording head in (a) is assembled. (A) is the perspective view which fractured | ruptured the conventional recording head of another example, (b) is sectional drawing of the recording head in (a).

(First embodiment)
Hereinafter, a first embodiment for carrying out the present invention will be described with reference to the accompanying drawings.

  FIG. 1A is a plan view of a recording head 1 as a liquid ejection head of the present invention. FIG. 1B is a cross-sectional view taken along the line A-A ′ shown in FIG. The recording head 1 of this embodiment is formed by bonding an orifice plate 3 to a substrate 2. FIG. 1A shows a plan view of the orifice plate 3.

  In the substrate 2, in order to introduce ink into the recording head 1, an ink supply port 4 as a liquid supply port is formed through the substrate 2 from the back surface to the front surface. When ink is supplied into the ink supply port 4 and introduced into the recording head 1, the ink is supplied in the direction from the back surface of the substrate 2 to the surface at the ink supply port 4. In the present embodiment, three ink supply ports 4 are formed along the line A-A ′ in FIG. Then, the common liquid chamber 5 is defined between the substrate 2 and the orifice plate 3 by joining them. An ink supply port 4 communicates with the common liquid chamber 5, and a portion where the ink supply port 4 and the common liquid chamber 5 communicate with each other in the common liquid chamber 5 is an ink supply port as a liquid supply port communication portion. The communication unit 6 is used. In the present embodiment, the ink supply ports 4 communicating with the common liquid chamber 5 are formed long in one direction, and the ink supply ports 4 are arranged in a plurality of rows. A heater 9 is disposed on the substrate 2 as an ejection energy generating element that generates energy used for ejecting ink so as to face the common liquid chamber 5. In the present embodiment, the heater 9 is an electrothermal conversion element that generates heat in response to energization. The orifice plate 3 faces the heater 9 and discharges the common liquid chamber 5 and the outside of the recording head 1 so that the ink stored in the common liquid chamber 5 can be discharged to the outside. An outlet 7 is formed. A plurality of discharge ports 7 are formed and formed in a row in a predetermined direction. In the present embodiment, a plurality of ejection ports 7 are arranged in the same direction as the direction in which the ink supply port 4 extends, and are arranged in two rows along the line A-A ′ in FIG. A portion where the common liquid chamber 5 and the discharge port 7 communicate with each other is referred to as a discharge port communication portion 8. In the present embodiment, two ejection port communication portions 8 are formed between the three ink supply port communication portions 6 in the cross section taken along the line A-A ′ of FIG.

  In this embodiment, corresponding to the two rows of discharge ports 7, two rows of heaters 9 are embedded in the substrate 2 and are disposed to face the discharge ports 7. Between the adjacent ink supply ports 4, the distance from the edge portion 10 of each ink supply port 4 to the edge portion 11 of the ejection port 7 closest to the ink supply port 4 is the same. That is, the ink flow path from the ejection port 7 to the ink supply port 4 is formed symmetrically with the ejection port 7 as the center.

  Ink supply ports 4 are arranged on both sides of the arrangement of the plurality of flow paths 17, and a predetermined number of ink supply openings 4 on at least one side are arranged along the entire range of the arrangement of the flow paths 17. In addition, at least one of the flow paths 17 connected to the pressure chamber 14 is connected to the ink supply port 4 via the common liquid chamber 5. In the present embodiment, both of the flow paths 17 connected to the pressure chamber 14 are connected to the ink supply port 4 via the common liquid chamber 5. Here, the predetermined number of the ink supply ports arranged may be one ink supply port arranged in the direction of the arrangement of the discharge ports, or the ink supply ports are divided into a plurality as described later. May be arranged. The ink supply port 4 is arranged so that the plurality of channels 17 communicate with each other in the arrangement direction of the channels 17, and has a length along the arrangement of the plurality of channels 17. In the present embodiment, three continuous ink supply ports 4 having substantially the same length as the plurality of arranged flow paths 17 are arranged. The three ink supply ports 4 sandwich the two flow paths 17. In this way, since the ink supply port 4 is arranged, the ink is supplied from both one side and the other side in the plurality of flow paths 17.

  In the present embodiment, a partition wall 12 is formed between each of the ejection ports 7 arranged in the same direction as the direction in which the ink supply port 4 extends. As a result, the ejection port 7 and the heater 9 are disposed inside the flow path 17 partitioned by the partition wall 12 in the direction in which the ink supply port 4 extends. Therefore, droplets are efficiently ejected by expansion of bubbles generated by the heater 9 described later. A plurality of columnar nozzle filters 13 are arranged on both sides of the discharge port array in which the discharge ports 7 are arranged. Accordingly, it is possible to suppress the influence of the ink ejection due to the entry of foreign matters such as dust contained in the ink around the ejection port 7 and the heater 9. Further, the strength of the recording head 1 is improved by the nozzle filter 13 supporting the load. Here, a region surrounded by the substrate 2, the orifice plate 3, and the partition wall 12 and adjacent to the discharge port 7 is referred to as a pressure chamber 14. The pressure chamber 14 communicates with the common liquid chamber 5 and is formed between the ink supply port communication portions 6. A plurality of flow paths 17 are connected to positions facing the pressure chamber 14. Then, the ink supplied to each of the plurality of flow paths 17 through the ink supply port 4 is discharged to the outside as the heater 9 is driven.

  Next, the operation of the recording head 1 when ink is ejected will be described.

  When the heater 9 is energized, the electrical energy is converted into heat and the heater 9 generates heat. As a result, the ink positioned on the heater 9 in the pressure chamber 14 facing the heater 9 boils down and bubbles are generated. Since pressure is generated when bubbles are generated inside the pressure chamber 14, the ink inside the pressure chamber 14 is pushed toward the ejection port 7 by the generated pressure, and the ink is ejected toward the ejection port 7. It is discharged from. The ink ejected from the ejection port 7 lands on a predetermined position on the recording medium.

  At this time, ink stored in the pressure chamber 14 in the common liquid chamber 5 is ejected by driving the heater 9, and ink is supplied from the ink supply port 4 to the inside of the common liquid chamber 5. The ink that has entered the common liquid chamber 5 from the ink supply port 4 through the ink supply port communication portion 6 passes between the nozzle filters 13 and enters the pressure chamber 14, passes through the discharge port communication portion 8, and It is discharged from the discharge port 7. Here, the ink supply ports 4 for supplying ink to the pressure chambers 14 through the common liquid chamber 5 are formed on both sides of the discharge ports 7. Accordingly, the ink is supplied from both the ink supply ports 4 sandwiching the pressure chamber 14 to the ejection port 7, that is, the ink is supplied from both one side and the other side of the flow path 17. . As a result, the flow of ink supplied to the ejection port 7 is not biased only from one direction, and the ink is supplied to the ejection port 7 in a well-balanced manner.

  Further, in this embodiment, the distance between the edge 10 of each ink supply port 4 and the edge 11 of the ejection port 7 closest to the ink supply port 4 between adjacent ink supply ports 4 is the same. Are equally formed. The ink flow path to the ink supply port 4 is symmetrically formed with the ejection port 7 as the center. Accordingly, conditions such as loss of ink flow when supplied from the ink supply port 4 to the pressure chamber 14 do not substantially change between the adjacent ink supply ports 4, so that the supply from each ink supply port 4 to the ejection port 7 is performed. The inks used are approximately equal. Therefore, when the bubbles grow, the flow rate of the ink supplied to the ejection port 7 is substantially equal between the adjacent ink supply ports 4, so that it is possible to suppress the growth of the bubbles from being biased.

  Also, even when contracting, the bubbles are contracted in a balanced manner toward the center of the heater 9 without being biased.

  Since the bubbles grow and contract in a well-balanced manner without being biased, the tail of the ejected ink is thick and straight. As a result, the satellite formed by the tail splitting in the droplet formation process becomes larger, and the flight direction of the satellite is ejected straight in the ejection direction substantially perpendicular to the ejection port formation surface. At this time, since the flight directions of the plurality of satellites coincide with each other, the adjacent satellites merge to form a larger satellite. Further, the flight direction of the main droplet portion at this time is also straight in the discharge direction orthogonal to the discharge port forming surface 15 substantially orthogonal to the discharge port forming surface.

  As described above, when the satellite becomes larger, the landing position of the satellite is less affected by the air current, and density differences are less likely to occur during high-speed recording or recording with small droplets, resulting in density unevenness in the image. It becomes difficult to do. Further, when the satellite becomes large, the satellite arrival rate to the recording medium increases, and the mist floating between the recording head and the recording medium decreases. As a result, the contamination of the paper surface due to the floating mist adhering to the inside of the printer body is reduced, and the electric board and encoder are less likely to fail. Also, if both satellites and main droplets are ejected straight in a direction that is substantially perpendicular to the ejection port formation surface, the deviation of the landing positions of the main droplets and satellites on the forward and return paths during the recording operation will be small, so reciprocation It is difficult for density differences to occur during the recording operation.

  Further, in Patent Document 2, ink is supplied to a flow path in which an ejection port is formed through a hole. On the other hand, in this embodiment, ink is supplied to the flow path in which the discharge ports are formed through the ink supply port having a large opening area. Therefore, the resistance to the ink flow can be reduced until the ink is supplied to the ejection port and ejected from the ejection port. As a result, the ink refill speed is improved, and accordingly, the drive frequency when ink is ejected is increased, and the throughput of the recording apparatus is improved.

  At the time of suction recovery, the discharge port 7 is capped, and negative pressure is applied thereto, whereby ink stored in the pressure chamber 14 is sucked. In this embodiment, the length of the ink supply port 4 in the longitudinal direction is formed to be approximately equal to the length of the array of the ejection ports 7 arranged. Accordingly, when suction is recovered, the ink is uniformly sucked from the respective ejection ports 7, whereby the ink flow can be generated over the entire row of the pressure chambers 14 or the ink supply ports 4. Accordingly, it is possible to prevent the ink that is not removed from remaining in a part of the inside of the pressure chamber 14 over the entire common liquid chamber 5. As a result, the ink is refreshed throughout the common liquid chamber 5 due to suction and subsequent refilling of the ink, and bubbles are less likely to accumulate in the common liquid chamber 5. As a result, proper discharge can be stably maintained. On the other hand, in the recording head of Patent Document 1, since the supply pipe supplies ink only to the central portion with respect to the ink flow path in which the discharge ports are formed, the flow in the common liquid chamber 5 becomes uneven. There is a problem that bubbles are accumulated in the common liquid chamber 5 and proper discharge becomes difficult to maintain.

  Further, since the pressure chamber 14 is outside the flow path, the discharge ports 7 can be arranged at a high density to maintain high resolution recording.

  In this embodiment, the length of the ink supply port 4 and the length of the row of the ejection ports 7 are substantially equal, but the length of the ink supply port 4 may be longer than the length of the row of the ejection ports 7. I do not care. In this embodiment, the ink supply ports 4 are formed in three rows along the line AA ′. However, the number of the ink supply ports 4 formed in the recording head 1 is as follows. It is not limited to three rows, but may be four or more rows or two rows.

(Second embodiment)
Next, a second embodiment will be described with reference to FIGS. In addition, about the part which can be comprised similarly to said 1st embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  FIG. 2A is a plan view of the recording head 21 in the second embodiment. FIG. 2B is a cross-sectional view taken along line A-A ′ shown in FIG.

  In the recording head 1 of the first embodiment, all of the three rows of ink supply ports extend in the same direction as the direction in which the rows of ejection ports extend, and are continuously formed over the entire longitudinal direction. . On the other hand, the recording head 21 of the second embodiment is formed by dividing the ink supply port 24 into a plurality in the longitudinal direction.

  In the first embodiment, among the ink supply ports arranged in three rows along the line AA ′ in FIG. 1, the two ink supply ports arranged on the outside are continuous over the entire longitudinal direction. The ink supply port 4 is disposed. Therefore, the wiring for supplying electric power to the heaters 9 arranged in the center row must be arranged between the opening and the heater while bypassing the ink supply port 4 arranged on the outside. Therefore, as the number of discharge ports and corresponding heaters increases, the area occupied by the wiring increases accordingly. As a result, the distance between the ejection port and the ink supply port is increased, and the cost for manufacturing the recording head may increase due to an increase in the substrate.

  On the other hand, according to the recording head 21 in the second embodiment, at least one of the ink supply ports arranged on both sides of the arrangement of the plurality of flow paths 17 is the discharge port 7. It is divided into a plurality of parts in the arrangement direction. In the present embodiment, the ink supply port 24 is divided into three in the direction in which the flow paths 17 are arranged. In the present embodiment, the predetermined number of the ink supply ports 24 arranged is three, but is not limited to three and may be four or more. At that time, one ink supply port among the plurality of ink supply ports is formed along the two or more flow paths 17 along the direction of arrangement of the discharge ports 7.

  According to the recording head 21 of the present embodiment, since the ink supply port 24 is divided into a plurality of parts in the direction in which the flow paths are arranged, electric power is supplied to the heater 9 between the divided ink supply ports 24. It is possible to pass the wiring for supplying. Since it is not necessary to bypass the ink supply port for arranging the wiring, the space for arranging the wiring can be reduced. In addition, this makes it possible to reduce the distance between the heater and the ink supply port. As a result, the substrate 2 can be made small, and the cost for manufacturing the recording head 21 can be reduced.

  In the recording head, part of heat generated by driving the heater 9 disposed on the substrate 2 is diffused outside the recording head 1 through the substrate 2. However, in the recording head 1 of the first embodiment, the heaters 9 arranged at the positions corresponding to the ejection ports 7 are sandwiched between the long ink supply ports 4 that are continuous in the longitudinal direction. The heat generated in the center must be diffused around the ink supply port 4. Thereby, the amount of heat diffusion in the direction perpendicular to the longitudinal direction of the ink supply port 4 is small. Accordingly, the heat generated from the periphery of both ends of the heaters 9 arranged is cooled by diffusing in the longitudinal direction of the ink supply port 4, but the heat generated from the central part of the row of the heaters 9. It may not be diffused so much and the periphery of the center may be relatively hot.

  On the other hand, according to the recording head 21 of the present embodiment, heat can be diffused between the ink supply ports 24 divided into a plurality of parts, and the heat generated from the center of the row of the heaters 9 is also ink. Heat is radiated to the outside of the recording head 21 through the supply ports 24 and cooled. Therefore, the difference due to the position of the temperature distribution on the substrate 2 around the heater 9 is reduced. As a result, the discharge amount distribution is uniform in the column direction of the discharge ports 7 and the density difference for each discharge port 7 is reduced. Accordingly, density unevenness in an image obtained by recording using the recording head 21 is unlikely to occur.

  In the present embodiment, the recording head in which three rows of ink supply ports are arranged has been described. However, the recording head of the present invention is not limited to this. A recording head in which three or more rows of ink supply ports are arranged may be used as long as the ink supply ports located on the outside are divided into a plurality in the direction in which the rows of ejection ports extend. Further, although the number of divided ink supply ports is three, the number of divided ink supply ports is not limited to this, and may be four or more or two.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS. In addition, about the part which can be comprised similarly to said 1st embodiment and 2nd embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  FIG. 3A is a plan view of the recording head 31 in the third embodiment. FIG. 3B is a cross-sectional view taken along line A-A ′ shown in FIG.

  In the first embodiment, all of the three ink supply ports extend in the same direction as the direction in which the discharge port columns extend, and are formed continuously over the entire longitudinal direction. In the second embodiment, the plurality of ink supply ports arranged on the outer side are divided into a plurality of portions, and those located in the central portion are continuously provided over the entire longitudinal direction. It was decided that it was formed. On the other hand, in the recording head 31 of the third embodiment, for all the ink supply ports among the plurality of ink supply ports arranged in a direction orthogonal to the direction in which the row of ejection ports extends, The discharge ports are divided into a plurality of rows in the extending direction.

  As a result, the heat generated from the central portion of the heater row arranged at a position corresponding to the ejection port can be diffused through a portion between the divided ink supply ports, and from there It becomes possible to dissipate heat. Thereby, since the temperature rise around the center part of the heater row can be further suppressed, the difference in the temperature distribution around the heater row can be kept small. As a result, the difference in the ink ejection amount for each ejection port can be kept small, and the density difference in the obtained image can be kept small.

  In the present embodiment, the recording head in which three rows of divided ink supply ports are arranged has been described. However, the recording head of the present invention is not limited to this. The divided ink supply ports may be four or more rows or two rows.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIGS. In addition, about the part which can be comprised similarly to said 1st embodiment thru | or 3rd embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  FIG. 4A is a plan view of the recording head 41 in the fourth embodiment. FIG. 4B is a cross-sectional view taken along line A-A ′ shown in FIG.

  In the first to third embodiments, a relatively large ink supply port is formed over substantially the entire direction in which the rows of ejection ports in the recording head are arranged. On the other hand, in the recording head 41 of the present embodiment, a flow path 46 extending outward from the common liquid chamber 45 is formed. Of the ink supply ports arranged on both sides of the arrangement of the plurality of flow paths 46, the ink supply port 24 on one side is formed to communicate with the common liquid chamber 45. The ink supply port 44 in the flow channel formed on the other side of the ink supply ports arranged on both sides of the arrangement of the plurality of flow channels 46 is formed so as to communicate with the flow channel 46. .

  In the present embodiment, a flow path 46 is formed which communicates with the common liquid chamber 45 and extends in a direction orthogonal to the arrangement direction of the ink supply ports. An in-channel ink supply port 44 is formed so as to communicate with the channel 46. Here, a portion where the common liquid chamber 45 and the ink flow path 17 communicate with each other is referred to as a flow passage communication portion 49, and a portion where the ink supply port 44 in the flow passage and the flow passage 46 communicate with each other is defined as an ink supply port communication portion within the flow path. 47. In the present embodiment, the ejection port 7 is formed in a space between the flow channel communication portion 49 and the in-flow channel ink supply port communication portion 47 so as to communicate with the flow channel 46. A portion where the flow path 46 and the discharge port 7 communicate with each other is referred to as a discharge port communication portion 48. In the present embodiment, the in-channel ink supply port 44 formed so as to communicate with the channel 46 communicates with almost the outer end of the channel 46, and the ejection port 7 is connected to the outer end of the channel 46. The channel 46 communicates with a portion inside the portion.

  According to the recording head 41 of the present embodiment, the structure does not hinder the growth of bubbles generated by driving the heater 9 and the opening area of the ink supply port 44 in the flow channel communicating with the flow channel 46 is narrowed. Will be able to. Therefore, the area of the substrate 2 can be reduced accordingly. Thereby, the manufacturing cost of the recording head 41 can be reduced accordingly.

  In this embodiment, the ink is supplied from the ink supply port 44 in the flow channel communicating with the flow channel 46 and the ink supply port 24 in the center, but two inks in the flow channel are provided inside the flow channel 46. A configuration in which the supply port 44 is formed so as to communicate with each other and the discharge port is formed therebetween is also conceivable. However, when the ink is ejected from the ejection port 7 sandwiched between the two ink supply ports 47 in the flow channel communicating with the flow channel 46 as in the configuration of Patent Document 2, a high-resolution nozzle arrangement will be realized. Then, the opening area of the ink supply port 47 in the flow path becomes small. In this case, in order to supply ink to the pressure chamber 14 in the flow path 46, the ink must be supplied through the ink supply port 47 in the flow path having a small opening area and a large resistance, and the ink is discharged into the pressure chamber after ink discharge. The refill speed for refilling the ink is reduced. As a result, the drive frequency decreases, and the throughput of the recording head 41 decreases. On the other hand, if the opening area of the ink supply port 44 is increased in order to reduce the flow resistance, the nozzle resolution has to be reduced, and it is difficult to achieve both higher nozzle density and a higher refill frequency.

  Therefore, as in the present embodiment, two ink supply ports formed across the ejection port do not communicate with the flow channel 46, but one of them communicates with the flow channel 46 and the other communicates with the common liquid chamber. It is preferable that the communication path is formed relatively large along the plurality of flow paths 46. With this configuration, while the nozzles are arranged at a high density, the resistance of the flow path through which the ink flows during ink refilling is not increased, and reduction in the refilling speed can be suppressed.

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to FIGS. In addition, about the part which can be comprised similarly to said 1st embodiment thru | or 4th embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  FIG. 5A is a plan view of the recording head 51 in the fifth embodiment. FIG. 5B is a cross-sectional view taken along line A-A ′ shown in FIG.

  In the third embodiment, the configuration in which three rows of ink supply ports 4 divided into a plurality in the direction in which the row of ejection ports extends is described. In the recording head 51 of the fifth embodiment, in addition to the three rows of ink supply ports 4, ink supply ports 24 that are divided one by one on the outside of both sides are formed in communication with the common liquid chamber 5. A heater 9 is disposed between the ink supply ports 24 at the discharge ports 7 and corresponding positions. The discharge port 7 formed on the outermost side of the recording head 51 of the present embodiment is formed to have a smaller diameter so that the discharge amount is smaller than the discharge port 7 formed on the inner side. Has been. By forming discharge ports with different discharge amounts, it is possible to adjust the amount of liquid droplets discharged during recording, and high-quality image recording can be performed. Also, the recording speed can be increased.

  As described above, in the recording head of the present invention, the ink supply ports are not limited to three rows, but may be four or more rows. Further, the ejection ports formed between the ink supply ports may not be two rows, but may be three or more rows. Further, the size of the discharge port may not be uniform, and the size of the discharge port may be changed according to a desired discharge amount.

(Sixth embodiment)
Next, the sixth embodiment will be described with reference to FIGS. In addition, about the part which can be comprised similarly to said 1st embodiment thru | or 5th embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  FIG. 6A is a plan view of the recording head 61 in the sixth embodiment. FIG. 6B is a cross-sectional view taken along the line A-A ′ shown in FIG.

  In the third embodiment, the configuration in which three rows of ink supply ports 4 divided into a plurality in the direction in which the row of ejection ports extends is described. In addition to this, the recording head 61 of the sixth embodiment extends to a part of the outside of the common liquid chamber 67 once in a direction toward the outside of the common liquid chamber 67 and then returns to the common liquid chamber 67 again. Thus, an ink passage 62 as a liquid passage communicating with the common liquid chamber 67 is formed. A discharge port 65 is formed in a part of the ink passage 62, and a discharge port communication portion 66 where the ink passage 62 and the discharge port 65 communicate with each other is formed there. A heater 9 is disposed at a position corresponding to the discharge port 65, and a pressure chamber 14 is formed there. In the present embodiment, the ink passage has a recess 63 formed in a part of the outer edge of the common liquid chamber 67 so that the common liquid chamber 67 protrudes outward, and a partition wall 64 is formed inside the recess 63. By disposing, the ink passage 62 is formed inside the recess 63.

  According to the recording head 61 of the present embodiment, it is not necessary to form an ink supply port outside the pressure chamber 14 in order to prevent the bubble growth from being restricted. Therefore, the recording head 61 is not enlarged correspondingly. Also good. Therefore, since the increase in the size of the substrate in the recording head 61 can be suppressed, the manufacturing cost in the recording head 61 can be suppressed.

  Further, in the recording head 61 of the present embodiment, the outermost ejection port 65 formed in the ink passage 62 has a smaller diameter than the ejection ports 7 in the inner ejection port array formed between the ink supply ports 24. The amount of discharge formed from the outer discharge port 65 is small. As a result, it is possible to adjust the amount of droplets ejected during recording, and high-quality images can be recorded. Also, the recording speed can be increased.

(Seventh embodiment)
Next, a seventh embodiment will be described with reference to FIGS. In addition, about the part which can be comprised similarly to said 1st embodiment thru | or 6th embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  FIG. 7A is a plan view of the recording head 71 in the seventh embodiment. FIG. 7B is a cross-sectional view taken along the line A-A ′ shown in FIG.

  In the third embodiment, the configuration in which three rows of ink supply ports 4 divided into a plurality in the direction in which the row of ejection ports extends is described. In addition to this, in the recording head 71 of the seventh embodiment, the plurality of discharge ports 72 are relatively large in discharge amount of liquid discharged from the large discharge amount discharge port 73 and the large discharge amount discharge port 73. And a small discharge amount discharge port 74 which is formed to be small. The large discharge amount discharge ports 73 and the small discharge amount discharge ports 74 are formed so as to be alternately arranged in the direction in which the rows extend. Therefore, according to the recording head 71 of the present embodiment, it is possible to adjust the amount of droplets ejected during recording without increasing the number of ejection ports, and the cost can be reduced without increasing the size of the recording head. High-quality images can be recorded. Also, the recording speed can be increased.

(Eighth embodiment)
Next, an eighth embodiment will be described with reference to FIGS. In addition, about the part which can be comprised similarly to said 1st embodiment thru | or 7th embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  FIG. 8A is a plan view of the recording head 81 in the eighth embodiment. FIG. 8B is a cross-sectional view taken along line A-A ′ shown in FIG.

  In the third embodiment, the configuration in which three rows of ink supply ports 4 divided into a plurality in the direction in which the row of ejection ports extends is described. In addition to this, the recording head 81 of the eighth embodiment has an ink passage 82 as a liquid passage extending from the common liquid chamber 5 toward the outer periphery of the substrate 2 between the orifice plate 3 and the substrate 2. It is formed on the outer periphery of the substrate 2. An ink passage discharge port 83 as a liquid passage discharge port is formed in the orifice plate so as to communicate with the ink passage 82 at a position close to the outer end of the ink passage 82. On the substrate 2, an in-ink passage heater 89 is disposed as an in-liquid passage discharge energy generating element so as to face the in-ink passage outlet 83.

  In the present embodiment, an ink flow path 82 that protrudes to the outside of the common liquid chamber 5 is formed, and an ink passage discharge port 83 is formed at the outermost end of the ink flow path 82. An ink passage heater 89 is disposed at a position corresponding to the ink passage discharge port 83, whereby the pressure chamber 14 is formed at the outermost end of the ink passage 82. Since the pressure chamber 14 formed in the outer peripheral portion of the substrate 2 is formed at the outermost end portion of the ink flow path 82, except for the connection portion where the ink flow path 82 is connected to the pressure chamber 14, The three sides are surrounded by the wall surface that defines the ink flow path 82. An ink passage discharge port 83 is formed on the outermost side of the ink passage 82 as a small discharge amount discharge port having a smaller diameter than the inner discharge port 7 sandwiched between the ink supply ports 24. In this way, the amount of ink discharged from the ink passage discharge port 83 formed in the ink passage 82 is set to be smaller than that of the inner discharge port 7 formed between the ink supply ports. .

  In the present invention, an ink flow path is formed between the portions of the common liquid chamber 5 communicating with the ink supply port, and the ink is discharged without restricting the growth of bubbles generated by the heater by communicating with the discharge port there. To do. However, the ink passage discharge port 83 arranged on the outer side in this embodiment is formed at the outermost end portion of the ink passage 82 and is generated by the heater by the wall surface of the outer end portion of the ink passage 82. It is conceivable that bubble growth is limited. However, the in-ink passage ejection port 83 having a small diameter and a small ejection amount is set to a droplet with respect to the bubble growth being restricted more than the inner ejection port 7 having a relatively large ejection amount. The influence of is small. As described above, the discharge port with a small discharge amount is less affected by the hindrance to the growth of bubbles, and therefore a heater and a discharge port may be formed at the end of the ink passage. Depending on the amount of ink ejected from the ejection port, the ejection port may be formed between the ink supply ports or may be formed at the end of the ink flow path.

  By forming the outermost discharge port at the end of the ink passage 82 as in this embodiment, the ink supply port does not have to be formed outside the outermost discharge port. 2 can be prevented from increasing in size, and the manufacturing cost of the recording head can be suppressed.

(Ninth embodiment)
Next, the ninth embodiment will be described with reference to FIGS. In addition, about the part which can be comprised similarly to said 1st embodiment thru | or 8th embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  FIG. 9A is a plan view of the recording head 91 in the ninth embodiment. FIG. 9B is a cross-sectional view taken along line A-A ′ shown in FIG.

  In the recording head according to the eighth embodiment, an ink passage protruding by the same length is formed outside the common liquid chamber 5, and an ejection port is formed at the outer end of the ink passage. In addition to this, in the recording head 91 of the present embodiment, the ejection openings in the ink passages have a plurality of types of ejection openings in the ink passages having different ejection amounts of the ejected liquid. Specifically, a plurality of ink passages 92 having different lengths projecting to the outside of the common liquid chamber 5 are formed in a staggered manner, and an ejection port is formed at the outermost end of the ink passage 92. Yes. A small ejection amount ejection port 94 having the smallest diameter in the recording head 91 is formed at the outermost end of the short ink passage 93 having a short protruding length. A discharge port that is larger in diameter than the small discharge amount discharge port 94 and is sandwiched by the inner ink supply port 24 is formed at the outermost end of the long long ink flow path 95 that protrudes. A medium discharge amount discharge port 97 having a diameter smaller than that of the large discharge amount discharge port 96 is formed. As described above, by forming a plurality of types of ejection openings having different ink ejection amounts, it is possible to finely adjust the amount of liquid droplets ejected during recording, and to record higher quality images. It can be carried out. Further, the recording speed can be further increased.

  Further, by arranging the discharge ports in a staggered manner, discharge ports of a plurality of types of discharge amounts are formed while maintaining a high density of the discharge ports, so that an increase in the size of the substrate 2 is suppressed when improving the image quality. This can reduce the manufacturing cost of the recording head.

  In this embodiment, three types of ejection ports having different diameters are formed according to the ejection amount of ink ejected from the ejection ports. However, the types of ejection ports are not limited to three types, and It may be more than types. Further, the length of the ink flow path may be changed accordingly.

(Tenth embodiment)
Next, the tenth embodiment will be described with reference to FIGS. In addition, about the part which can be comprised similarly to said 1st embodiment thru | or 9th embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  FIG. 10A is a plan view of the recording head 101 in the tenth embodiment. FIG. 10B is a cross-sectional view taken along the line A-A ′ shown in FIG.

  The recording head according to the seventh embodiment has a large discharge amount discharge port formed with a large diameter and a small discharge amount discharge port formed with a small diameter, which extend in a row. It was decided to be arranged alternately in the direction. The large discharge amount discharge port and the small discharge amount discharge port are partitioned by a partition wall, and a space defined by the partition wall functions as a pressure chamber. In addition to this, in the recording head 101 of the present embodiment, among the plurality of flow paths 17 respectively corresponding to the plurality of ejection ports, a part of the flow paths is closed on one side of the flow path so that three sides are surrounded. The one-side supply ink channel 104 as the one-side supply liquid channel defined as described above is used. A one-side supply ink channel ejection port 102 is formed as a one-side supply liquid channel ejection port so as to communicate with the one-side supply ink channel 104. In the present embodiment, the one-side supply ink channel ejection port 102 formed in the one-side supply ink channel 104 is an ejection port formed in the channel 17 that is open on both sides and allows ink to flow in both directions. 7 differs from the discharge amount of discharged ink. In the present embodiment, the one-side supply ink channel ejection port 102 is set to have a smaller diameter than the ejection port 7 formed in the channel 17 and a smaller ejection amount of the ejected ink. In the one-side supply ink flow path 104, one end of the partition wall 103 sandwiching the one-side supply ink flow path discharge port 102 is connected, so that the outer three sides of the one-side supply ink flow path discharge port 102 are connected to the partition wall 103. Surrounded by

  As described above, at the discharge port with a small discharge amount, the influence on the growth of bubbles generated by driving the heater is hindered. Therefore, even if the three sides of the ejection port 102 in the one-side supply ink channel in this embodiment are surrounded by the partition wall 103, there is little deterioration in the quality of the image obtained by ejecting the ink, and the generation of satellites is in an allowable range. Will fit within. Further, since the partition wall 103 is connected at one end of the discharge port 102 in the one-side supply ink flow path, the bonding area bonded between the substrate 2 and the orifice plate 3 via the partition wall 103 is increased. Can be made. Moreover, the support area which the partition 103 supports between the board | substrate 2 and the orifice plate 3 can be increased. Thereby, it can suppress that the orifice plate 3 leaves | separates from the board | substrate 2. FIG. Further, since the common liquid chamber 5 which is a relatively large space is defined between them, the strength can be improved by supporting the relatively low strength portion by the partition wall 103, and the recording head 101. Can improve the reliability.

1, 21, 31, 41, 51, 61, 71, 81, 91, 101 Recording head 2 Substrate 3 Orifice plate 4, 24 Ink supply port 5, 45, 67 Common liquid chamber 6 Ink supply port communication portion 7 Ejection port 8 Discharge port communication part 9 Heater 62 Ink passage

Claims (6)

A plurality of energy generating element arrays in which a plurality of energy generating elements that generate energy used for discharging the liquid are arranged in a first direction; and the plurality of energy generating element arrays are supplied with liquid via a flow path A liquid ejection head having a substrate on which a supply port extending in the first direction is formed;
The plurality of energy generating element arrays are ejected by a first energy generating element array formed on one end side of the substrate and the first energy generating element array formed on the center side of the substrate. A second energy generating element array that discharges a larger amount of droplets than the first energy generating element array, and one flow path is connected to each energy generating element included in the first energy generating element array. Each energy generating element included in the second energy generating element array is connected to a first flow path extending to one side and a second flow path extending to the other side opposite to the one side. A liquid discharge head.   The supply port includes a first supply port formed between the first energy generating element array and the second energy generating element array, and the first energy generating element array with respect to the first energy generating element array. The liquid discharge head according to claim 1, further comprising: a second supply port formed on a side opposite to the side on which the supply port is formed. A third energy generating element array that discharges a smaller amount of droplets than the droplets discharged by the second energy generating element array is formed on the other end side opposite to the one end side of the substrate. The liquid discharge head according to claim 1, wherein one flow path is connected to each energy generation element included in the third energy generation element array.   4. The liquid ejection head according to claim 2, wherein the first supply port and the second supply port include a plurality of supply ports arranged in the first direction. 5. Said second of said second passage and said first flow path being connected to the energy generating elements each contained in the energy generating element array, claim 1, which is formed symmetrically with respect to the energy generating element 4 The liquid discharge head according to any one of the above. The second liquid ejection head according to claims 1 to channel wall between each of the energy generating elements are formed on either the 5 included in the energy generating element array.

Images