JP5020730B2 - Liquid discharge head - Google Patents

Description

  The present invention relates to a liquid ejection head that performs recording on a recording medium by ejecting droplets by an inkjet method.

  In recent years, many recording apparatuses have been used, and these recording apparatuses are required to have high-speed recording, high resolution, high image quality, low noise, and the like. An ink jet apparatus is an example of a recording apparatus that meets such a requirement.

  The ink discharge method using an electrothermal conversion element in the inkjet method does not require a large space for disposing the discharge energy generating element, has a simple printhead structure, and facilitates nozzle integration. There are advantages such as. On the other hand, problems inherent to this ink ejection method include cavitation caused by fluctuations in the volume of flying ink droplets due to the heat generated by the electrothermal conversion element being stored in the recording head, and defoaming. Had an adverse effect on the electrothermal conversion element. In addition, this ink ejection method has an adverse effect on ink ejection characteristics and image quality because air dissolved in the ink becomes residual bubbles in the recording head.

  As methods for solving these problems, Patent Documents 1, 2, 3, and 4 disclose an ink jet recording method and a recording head.

  By adopting this ink jet recording method, it is possible to stabilize the volume of the flying ink droplets and discharge a small amount of ink droplets at high speed. In addition, by adopting this ink jet recording method, it becomes possible to eliminate cavitation that occurs when bubbles are defoamed and to improve the durability of the heater, so that further high-definition images can be easily obtained. Become. In the above-mentioned publication, as a configuration for communicating bubbles with the outside air, the shortest distance between the electrothermal conversion element that generates bubbles in the ink and the discharge port that is an opening through which the ink is discharged is compared with the conventional one. Therefore, a configuration that greatly shortens is mentioned.

  On the other hand, in this type of recording method, in order to make the granularity inconspicuous, a conventional inkjet recording apparatus has been proposed in which two nozzle rows for ejecting light ink and dark ink are provided. .

  However, in order to discharge light ink and dark ink respectively as described above, an ink tank for each ink is required, leading to an increase in manufacturing cost. In order to avoid this problem, multiple types of nozzles with different ink droplet sizes are provided, recording dots are formed with relatively small ink droplets from the bright part of the image to the intermediate part, and the halftone part to the dark part are compared. A recording method has been proposed in which a recording dot is formed with a relatively large ink droplet.

  However, when a plurality of ejection openings with different recording dot diameters are arranged, or when aiming for further droplet reduction, if the resolution in the nozzle row direction is not changed, the droplets are small, so a desired ejection amount is injected. I can't do that. There is a method of increasing the ejection amount by increasing the resolution in the scanning direction of the recording head, but in this case, it is necessary to increase the ejection frequency or to decrease the recording speed. Also, a method has been proposed in which the number of scans of the recording head is increased and the ejection amount is increased by multipass. However, this also requires a decrease in recording speed as the number of scans increases. For this reason, it is necessary to increase the resolution of the nozzle array as the droplet size is reduced, but this also has a limit. In general, it is a well-known fact that the efficiency decreases when the droplet size is reduced. At some point, the ratio of the heater size to the nozzle resolution becomes very large, making it difficult to pass the wiring through the heater. It becomes impossible to arrange in a line. This applies not only to the heater but also to the flow path for supplying ink.

Therefore, as shown in FIG. 12, a configuration is known in which the heaters 4000 are alternately staggered and arranged. In the case of this configuration, nozzles having different dot diameters may be arranged depending on the position of the heater 4000, or nozzles having the same dot diameter may be arranged regardless of the position of the heater 4000.
JP 54-161935 A JP-A 61-185455 JP 61-249768 A Japanese Patent Laid-Open No. 04-10941

  The example in the high resolution nozzle row shown in FIG. 12 is shown. The nozzle dimensions will be described in detail with reference to FIG. In each adjacent nozzle, the pitch in the direction parallel to the longitudinal direction of the ink supply port 5000 is 42.5 μm pitch (600 dpi), and nozzle rows of this pitch are alternately arranged in a staggered manner. The external dimensions are 13 μm × 26 μm. In the case of this configuration, there is a pressure chamber 2000 of a nozzle (short nozzle) corresponding to the first ejection port 1000 whose distance from the ink supply port 5000 is relatively small. For this reason, the thickness of the nozzle wall is formed to about 8 μm for manufacturing reasons, and the long nozzle is formed to have a width dimension parallel to the long side direction of the ink supply port 5000 in the narrow part of the ink supply path 3000 of about 10 μm. Has been.

  However, there are also problems with this configuration. As a first problem, since the long nozzle heater 4000 is arranged farther from the ink supply port 5000 than the short nozzle, it is sufficient even if the short nozzle heater 4000 is rectangular and the ink supply path 3000 is kept long. There is a problem that a refill frequency cannot be obtained.

  The second problem is that by using such a rectangular heater 4000, a dead zone in which ink does not flow easily is generated on the back side of the pressure chamber 2000. Therefore, bubbles are easily accumulated in the dead zone, and the discharge operation becomes unstable. It is known to be easy to become. It is known that the problem of the instability of the discharge operation becomes more prominent as the droplet becomes a small droplet of about several pl.

  The third problem is an increase in manufacturing cost accompanying an increase in the area of the nozzle portion having a plurality of nozzles. At present, the substrate on which the heater is disposed is a semiconductor substrate, and as the chip area increases, the number obtained from one wafer decreases and the manufacturing cost increases. In this case, since the heater has a rectangular shape, a heater with a long nozzle is arranged farther from the ink supply port, and the area of the nozzle portion increases correspondingly, and the manufacturing cost increases due to the enlarged nozzle substrate. .

  In order to solve these problems, proposals have been made to form a long nozzle heater in a square shape.

  However, in such a configuration in which the shape of the heater is different between the short nozzle and the long nozzle, the heater resistance is different, so if the drive energization time (drive pulse width) is constant, is there a plurality of drive power supplies? It is necessary to provide a transformer circuit. For this reason, as a fourth problem, there is a disadvantage that the manufacturing cost of the power source is increased.

  In addition, there is a method to change the drive pulse width, but the drive pulse does not fall within the time allowed from the recording speed, the foaming efficiency due to the long pulse is deteriorated, and the heat flux changes. There was also a problem such as instability of discharge. It is known that the problem of ejection instability becomes more prominent as the droplet size becomes smaller than several pl.

  Therefore, the present invention provides a high-resolution nozzle that realizes high image quality without increasing the chip cost, without increasing the manufacturing cost due to the drive power supply, deteriorating the foaming efficiency due to long pulses, or destabilizing the discharge operation. An object of the present invention is to provide a liquid discharge head having the above. It is another object of the present invention to provide a liquid discharge head that can realize further smaller droplets in a nozzle row.

In order to achieve the above-described object, a liquid discharge head according to the present invention supplies a plurality of discharge ports for discharging droplets, a plurality of liquid channels communicating with the discharge ports, and a liquid to the liquid channel. A liquid supply port and a plurality of recording elements made of a heating resistor and disposed at positions facing the discharge port, wherein the discharge port is located at least on one side of the liquid supply port. A first discharge port having a relatively short distance from the second discharge port and a second discharge port having a relatively long distance from the liquid supply port, and the first discharge port and the second discharge port Are arranged in a staggered pattern, and the plurality of recording elements include a first recording element and a second recording element corresponding to the first ejection port and the second ejection port, respectively. In the ejection head, the first recording element includes the plurality of the recording elements. It consists of one heating resistor formed in a rectangle whose longitudinal direction is the direction intersecting the outlet arrangement direction, the second recording element has a plurality of heating resistors formed in a rectangle, The plurality of heating resistors are connected in series and arranged adjacent to each other on the long side. Wiring for energizing the first recording element and the second recording element is connected to the short side of the heating resistor. The second recording element includes two heating resistors, and the length of the long side of the heating resistor of the first recording element is the long side of the heating resistor of the second recording element. Is approximately twice as long.

  Note that the present invention includes a configuration in which the heating resistors are formed in a square shape. In this configuration, one of the sides of each square heating resistor is adjacent to each other.

  According to the present invention, high image quality can be realized without increasing the chip cost, without increasing the manufacturing cost by the driving power supply, deteriorating the foaming efficiency due to the long pulse, and making the discharge operation unstable.

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

  First, the overall configuration of the ink jet recording head of this embodiment will be described. FIG. 1 is a perspective view showing the ink jet recording head of the embodiment with a part cut away. As shown in FIG. 1, the ink jet recording head of this embodiment includes an element substrate 110 provided with a plurality of recording elements (heaters) 400 that are electrothermal conversion elements, and a plurality of ink supply paths as liquid channels. And a flow path forming member 111 to be configured.

  The element substrate 110 is made of, for example, glass, ceramics, a resin material, a metal material, or the like, and is generally made of Si. On the main surface of the element substrate 110, for each ink flow path, a heater 400, an electrode (not shown) for applying a voltage to the heater 400, and a wiring (not shown) connected to the electrode. Are provided in a predetermined wiring pattern. In addition, an insulating film (not shown) that improves heat dissipation is provided on the main surface of the element substrate 110 so as to cover the heater 400. In addition, a protective film (not shown) is provided on the main surface of the element substrate 110 so as to cover the insulating film to protect against cavitation generated when bubbles are eliminated.

  The flow path forming member 111 is laminated and bonded to the element substrate 110. As shown in FIG. 1, the flow path forming member 111 includes a plurality of ink supply paths (nozzles) 300 through which ink flows, and long ink supply ports (liquid supply ports) that supply ink to the nozzles 300. 500. In addition, the flow path forming member 111 has a plurality of discharge ports 100 that are opening ends of the nozzles 300 that discharge ink droplets. The discharge port 100 is formed at a position facing the heater 400 formed in a substantially flat shape on the element substrate 110.

  A plurality of heaters 400 and a plurality of nozzles 300 are disposed on the element substrate 110. The inkjet recording head includes a first nozzle row in which the longitudinal directions of the nozzles 300 are arranged in parallel, and the longitudinal direction of each nozzle 300 at a position facing the first nozzle row with respect to the short side direction of the ink supply port 500. And a second nozzle row arranged in parallel in the direction. In the first and second nozzle rows, the interval between adjacent nozzles is formed at a pitch of 600 dpi or 1200 dpi. Further, the nozzles 300 in the second nozzle row are arranged with the pitches between adjacent nozzles shifted from each other as necessary for the reasons of dot arrangement with respect to the nozzles 300 in the first nozzle row. Yes.

  Such an ink jet recording head has an ink discharge means to which the ink jet recording method disclosed in Japanese Patent Laid-Open Nos. 4-10940 and 4-10941 is applied. In some ink jet recording heads, bubbles generated when ink is ejected are communicated with the outside air through ejection ports.

  The nozzle structure of the ink jet recording head will be described below with various modifications.

(First embodiment)
FIG. 2 shows the nozzle structure of the ink jet recording head of the first embodiment. In particular, one side of the ink supply port 500 will be described, but the present invention is not limited to this, and a nozzle group described below may be configured on the other side of the ink supply port. One end of each of the first liquid channel 300 a and the second liquid channel 300 b communicates with the pressure chambers 200 a and 200 b and the other end communicates with the ink supply port 500. As shown in FIG. 2, the inkjet recording head of this embodiment has a relatively large distance from the plurality of first ejection ports 100 a that are relatively small from the ink supply port 500 and the ink supply port 500. A plurality of second discharge ports 100b. The first discharge ports 100 a and the second discharge ports 100 b are alternately arranged in a staggered manner with respect to the short side direction of the ink supply port 500. Further, in the ink jet recording head of the present embodiment, the first and second heaters 400a and 400b are arranged corresponding to the first and second ejection ports 100a and 100b, respectively.

  In FIG. 2, the dimensions in this embodiment are 42.3 μm (600 dpi) for nozzles with a long nozzle pitch in the nozzle array direction and short nozzles, respectively. By combining these long and short nozzles, a nozzle resolution of 1200 dpi is realized. ing. In addition, nozzle rows having the same configuration are also arranged at positions facing the short side direction of the ink supply port 500, and each nozzle row shifts the pitch to achieve a resolution of 2400 dpi. A first heater (first recording element) 400a, which is a recording element having a relatively small distance from the ink supply port 500, is formed in a rectangle of 13 μm × 26 μm on each side.

  The first ejection port 100a having a relatively small distance from the ink supply port 500 is formed with an inner diameter of φ10 μm to φ15 μm. As shown in FIG. 2, the first heater 400a is configured so that the longitudinal direction of the rectangle is arranged in parallel to the direction intersecting the arrangement direction of the discharge ports 100a. Further, the ink supply path 300b, which is a relatively long nozzle, has a width dimension parallel to the long side direction of the ink supply port 500 at a portion located between the adjacent first heaters 400a. It is formed below the dimension of the short side of the heating resistor of the heater 400a.

  A second heater (second recording element) 400b having a relatively large distance from the ink supply port 500 is composed of two heating resistors having a rectangular shape of 9.5 μm × 13.5 μm, and is electrically connected in series. It is connected to the. These two heating resistors are arranged in parallel so that the long sides are adjacent to each other, and the separation distance is set to about 2 μm to 4 μm. Further, the ejection port 100b having a relatively large distance from the ink supply port 500 is formed to have an inner diameter of φ5 μm to φ10 μm. In order to record multi-tone dots, not only the diameters of the first and second ejection ports 100a and 100b but also the droplets ejected from the first and second ejection ports 100a and 100b can be changed. The areas of the first and second heaters 400a and 400b are also different.

  The clearance between the pressure chambers 200a, 200b and the heaters 400a, 400b is about 2 μm, and the walls of the pressure chambers 200a, 200b are formed at positions 2 μm wider than the outer size of the heaters 400a, 400b. The distance from the ink supply port 500 is such that the distance from the ink supply port 500 is about 44 μm for the first heater 400a, and the distance between the centers of the first heater 400a and the second heater 400b. Is about 35 μm to 45 μm.

  As described above, since the length of the ink supply path 300b can be shortened as compared with the conventional nozzle even when the distance from the ink supply port 500 is long, the refill time, which is the first problem, is shortened compared with the conventional one. It is possible to record at high speed. In addition, the second problem, that is, a dead zone in which the ink generated on the back side of the pressure chamber is difficult to flow is reduced, and unstable ejection due to bubbles can be avoided.

  The longitudinal dimension of the first heater 400a having a relatively small distance from the ink supply port 500 is the length in the longitudinal direction of the second heater 400b having a relatively large distance from the ink supply port 500. It is approximately doubled. Accordingly, the heater resistance becomes the same, and the first and second heaters 400a and 400b can be driven by a common power source. For this reason, regarding the increase in the manufacturing cost of the power source, which is the fourth problem, it is not necessary to add a power source, and the effect of reducing the manufacturing cost can be obtained.

  Next, FIG. 5 shows a schematic diagram of the wiring state on the element substrate of the first and second heaters 400a and 400b in this configuration. 8A to 8C are cross-sectional views taken along lines AA, BB, and CC in FIG.

  As shown in FIG. 5 and FIG. 8A to FIG. 8C, from the lower layer side, a through hole 800 is formed on the first wiring layer 703, and a heater layer is formed on the through hole 800. A (resistor layer) 700 and a second wiring layer 702 are sequentially stacked. The first wiring layer 703 and the second wiring layer 702 are electrically connected through the through hole 800. All of the portions excluding the first and second wiring layers 703 and 702, the heater layer 700, and the through hole 800 are covered with insulating layers 701a and 701b.

  The first heater 400a having a relatively small distance from the ink supply port 500 includes a first wiring layer 703 and a second wiring layer 703 that are connected to each other through a through hole 800 provided in the vicinity of the heater 400a. , 702 are electrically connected.

  Further, the first and second heaters 400a and 400b are regions where only the heater layer 700 is provided without the first and second wiring layers 703 and 702. As shown in FIG. 5, both the first heater 400a and the second heater 400b are electrically connected to the short side thereof.

  As shown in FIG. 8A and FIG. 8B, the second wiring layer 702 does not exist immediately below the first and second heaters 400a and 400b, and the nozzle due to the influence of heat dissipation and the level difference of the substrate. The structure is less susceptible to the steps of the members. Furthermore, the through hole 800 is disposed in the vicinity of the heaters 400a and 400b, and has a configuration with good area efficiency. Further, the through hole 800 is installed in the middle between the adjacent first heaters 400a, and is configured not to be affected by the step difference of the nozzle member due to the through hole 800. Further, the center of the through hole 800 and the center of the first heater 400a are located on the same straight line parallel to the nozzle row direction.

  As described above, by adopting such a configuration, it is possible to solve an increase in manufacturing cost due to the substrate size, which is the third problem, which can be arranged with good layout efficiency on the element substrate.

  FIG. 9 is a circuit diagram in the present embodiment. A processing block 630 that controls various data processing and time-division driving determines heaters 400a and 400b that are selectively driven based on the input recording data. Since the power supply element 610 and the GND terminal 611 for supplying a driving voltage to the heaters 400a and 400b can be driven at the same voltage as described above, they are shared by the heaters 400a and 400b.

  The drive time determination signal terminals 600 and 601 determine the drive energization time of the heaters 400a and 400b, respectively. In this embodiment, a separate system is used, but it may be shared. The power transistor 650 is configured such that the heaters 400a and 400b to be driven can be selectively operated in an appropriate driving time by the AND circuits 640a and 640b, and an appropriate discharge operation can be performed.

  As described above, according to the present embodiment, without increasing the manufacturing cost of the chip, without increasing the manufacturing cost due to the driving power supply, deteriorating the foaming efficiency due to the long pulse, and destabilizing the discharge operation, Image quality can be realized. A further object of the present invention is to realize a further small droplet nozzle array.

  Furthermore, the layout efficiency of the heater and the wiring is improved not only by improving the layout efficiency of the heater and the wiring by making the wiring to energize the first heater into two layers, but the layout efficiency is further improved by providing the through hole in the vicinity of the heater. can do. Furthermore, it is possible to minimize the influence of the nozzle step due to the substrate step in the through hole. Further, the second recording element described above has a length obtained by adding the length of each short side of the two heating resistors and the distance between the two heating resistors. More than half of the arrangement pitch.

(Second Embodiment)
FIG. 3 is a plan view showing the nozzle structure of the ink jet recording head of the second embodiment. In the present embodiment, as in the first embodiment, one end of the ink supply passages 300 a and 300 b communicates with the pressure chambers 200 a and 200 b and the other end communicates with the ink supply port 500. As shown in FIG. 3, the inkjet recording head of this embodiment has a relatively small distance from the plurality of first ejection ports 100 a that are relatively small from the ink supply port 500 and the ink supply port 500. It has a plurality of large second discharge ports 100b. The first discharge ports 100 a and the second discharge ports 100 b are alternately arranged in a staggered manner with respect to the short side direction of the ink supply port 500. In the present embodiment, the first and second heaters 400a and 400b are arranged corresponding to the first and second discharge ports 100a and 100b, respectively.

  Further, the ink supply path 300b, which is a relatively long nozzle, has a width dimension parallel to the long side direction of the ink supply port 500 at a portion located between the adjacent first heaters 400a. It is formed below the dimension of the short side of the heating resistor of the heater 400a.

  As shown in FIG. 3, the nozzle pitch in the nozzle array direction is such that long nozzles and short nozzles are formed at 42.3 μm (600 dpi), respectively, as in the first embodiment, and these long nozzles and short nozzles are combined. The nozzle resolution of 1200 dpi is realized. In addition, nozzle rows having long and short nozzles of the same configuration are provided at positions where these nozzles and the ink supply port 500 are opposed to each other in the short side direction, and each nozzle row has a resolution of 2400 dpi by shifting the pitch. .

  The first heater 400a having a relatively small distance from the ink supply port 500 is formed in a rectangle of 13 μm × 26 μm on each side. The first ejection port 100a having a relatively small distance from the ink supply port 500 is formed with an inner diameter of φ10 μm to φ15 μm.

  The second heater 400b having a relatively large distance from the ink supply port 500 is composed of two heat generating resistors that form a 13 μm × 13 μm square. These two heating resistors are arranged in parallel so that the long sides are adjacent to each other, and the separation distance is set to about 2 μm to 4 μm.

  This embodiment is different from the first embodiment in that the second ejection port 100b having a relatively large distance from the ink supply port 500 is used for the first ejection in which the distance from the ink supply port 500 is relatively small. The same as the outlet 100a is that the inner diameter is φ10 μm to φ15 μm. Unlike the first embodiment, this embodiment has a configuration in which only the nozzle resolution is improved with substantially the same, that is, substantially the same discharge amount. Therefore, in this embodiment, not only the first and second discharge ports 100a and 100b but also the first and second heaters 400a and 400b have the same area.

  The clearance between the pressure chambers 200a and 200b and the heaters 400a and 400b is about 2 μm as in the first embodiment, and the walls of the pressure chambers 200a and 200b are formed at a position 2 μm wider than the outer size of the heaters 400a and 400b. Has been. The distance from the ink supply port 500 is about 44 μm for the heater having a relatively small distance from the ink supply port 500, and the distance between the centers of the first heater 400a and the second heater 400b is 35 μm to 45 μm. It is about.

  As described above, since the length of the ink supply path can be made shorter than that of the conventional nozzle even when the distance from the ink supply port 500 is large, the refill time, which is the first problem, can be reduced compared to the conventional case. It becomes possible to record at high speed. Further, the dead zone in which the ink generated on the back side of the pressure chamber, which is the second problem, is less likely to flow, is reduced, and unstable ejection due to bubbles can be avoided.

  The longitudinal dimension of the first heater 400a having a relatively small distance from the ink supply port 500 is approximately the longitudinal dimension of the second heater 400b having a relatively large distance from the ink supply port 500. It has been doubled. As a result, the first and second heaters 400a and 400b can be driven by a common power source, so that it is not necessary to add a power source for the increase in the manufacturing cost of the power source, which is the fourth problem, and the manufacturing cost is increased. The effect of reducing can also be obtained.

  A schematic diagram of wiring on the element substrate of the heaters 400a and 400b in this configuration is exactly the same as that of the first embodiment shown in FIGS. 5 and 8, and a description thereof will be omitted. The circuit configuration is also the same as that of the first embodiment shown in FIG.

  However, the present invention is not limited to the above-described configuration. For example, the present invention can be applied even in a wiring state as shown in FIG. By forming the width of the wiring as narrow as possible according to the required conditions, it is possible to configure the wiring as shown in FIG. This makes it possible to solve the above-described problem as in the configuration shown in FIG.

(Third embodiment)
FIG. 4 is a plan view showing the nozzle structure of the ink jet recording head of the third embodiment. The ink supply paths 300 a and 300 b have one end communicating with the pressure chambers 200 a and 200 b and the other end communicating with the ink supply port 500. As shown in FIG. 4, the inkjet recording head of this embodiment has a relatively large distance from the plurality of first ejection ports 100 a that are relatively small from the ink supply port 500 and the ink supply port 500. A plurality of second discharge ports 100b. The first discharge ports 100 a and the second discharge ports 100 b are alternately arranged in a staggered manner with respect to the short side direction of the ink supply port 500. In the ink jet recording head, first and second heaters 400a and 400b are disposed corresponding to the first and second ejection ports 100a and 100b, respectively.

  In FIG. 4, the nozzle pitch in the nozzle row direction is set to 42.3 μm (600 dpi) for the long nozzle and the short nozzle, respectively, as in the first embodiment. By combining these long and short nozzles, a nozzle of 1200 dpi The resolution is realized. Also, nozzle rows having the same configuration are provided at positions facing the short side direction of the ink supply port 500, and a resolution of 2400 dpi is achieved by shifting the pitch of the nozzle rows.

  The first heater 400a having a relatively small distance from the ink supply port 500 is formed in a rectangle of 13 μm × 26 μm on each side. Further, the second ejection port 100a having a relatively small distance from the ink supply port 500 is formed with an inner diameter of φ10 μm to φ15 μm.

  The second heater 400b having a relatively large distance from the ink supply port 500 is composed of two heating resistors each having a rectangular shape with sides of 7 μm × 13.5 μm. These two heating resistors are arranged in parallel so that the long sides are adjacent to each other, and the separation distance is set to about 2 μm to 4 μm.

  Further, the ink supply path 300b, which is a relatively long nozzle, has a width dimension parallel to the long side direction of the ink supply port 500 at a portion located between the adjacent first heaters 400a. It is formed below the dimension of the short side of the heating resistor of the heater 400a.

  This embodiment is different from the first embodiment in that the second ejection port 100b having a relatively large distance from the ink supply port 500 is formed to have an inner diameter φ3 μm to φ7 μm that is smaller than that of the first embodiment. It is a point. According to the present embodiment, it is suitable for the case where it is desired to configure more gradations than the first embodiment, and smaller droplets can be ejected. As in the first embodiment, not only the inner diameters of the first and second discharge ports 100a and 100b but also the first and second discharge ports 100a and 100b can be changed. The areas of the first and second heaters 400a and 400b are also different.

  Further, this embodiment is different from the first embodiment in that the longitudinal direction of the heater 400b having a relatively large distance from the ink supply port 500 is rotated by 90 degrees with respect to the longitudinal direction of the ink supply path 300b. It has become the direction. The present embodiment is configured to have the effect of blocking the ink from the ink supply path 300b during ejection in order to improve the tail cut of the ejected droplets.

  The clearance between the pressure chambers 200a, 200b and the heaters 400a, 400b is about 2 μm, as in the first embodiment, and the pressure chamber 200a is at a position 2 μm wider than the outer size of the first and second heaters 400a, 400b. , 200b walls are formed. Further, the distance from the ink supply port 500 is such that the first heater 400a having a relatively small distance from the ink supply port 500 is about 44 μm, and the distance between the centers of the first heater 400a and the second heater 400b. The distance is about 35 μm to 45 μm.

  In this way, the length of the ink supply path 300b can be made shorter than that of the conventional nozzles (long nozzles) having a relatively large distance from the ink supply port 500. For this reason, the refill time, which is the first problem, can be shortened compared to the conventional case, and recording can be performed at a relatively high speed. In addition, the second problem, that is, a dead zone in which the ink generated on the back side of the pressure chamber is difficult to flow is reduced, and unstable ejection due to bubbles can be avoided.

  The longitudinal dimension of the first heater 400a having a relatively small distance from the ink supply port 500 is the length in the longitudinal direction of the second heater 400b having a relatively large distance from the ink supply port 500. Almost doubled. As a result, the first and second heaters 400a and 400b can be driven by a common power source, so that it is not necessary to add a power source for the increase in the manufacturing cost of the power source, which is the fourth problem. The effect of reducing cost can also be obtained.

  Next, FIG. 7 shows a schematic wiring diagram on the element substrate of the heaters 400a and 400b in this configuration. 8B to 8D are cross-sectional views taken along lines BB, CC, and DD in FIG. 7, respectively.

  As shown in FIGS. 8B to 8D, the layer configuration of the present embodiment is the same as the configuration of the first embodiment.

  As shown in FIG. 7, similarly to the first embodiment, the first heater 400a having a relatively small distance from the ink supply port 500 has two upper and lower sides through a through hole 800 in the vicinity of the heater 400a. The first and second wiring layers 703 and 702 of the layer are electrically connected. The regions where only the heater layer is present without the wiring layers 703 and 702 are the first and second heaters 400a and 400b.

  As in the first embodiment, the second wiring layer 702 does not exist immediately below the first and second heaters 400a and 400b, and is affected by heat dissipation and the step of the nozzle member due to the step of the substrate. It has a difficult structure. Furthermore, the through-hole 800 is disposed in the vicinity of the first and second heaters 400a and 400b, and has a configuration with good area efficiency. In addition, the through hole 800 is installed in the middle between the adjacent first heaters 400a, and is configured to be hardly affected by the step difference of the nozzle member due to the through hole 800. Further, the center of the through hole 800 and the center of the first heater 400a are located on the same straight line parallel to the nozzle row direction.

  This embodiment is different from the other embodiments in that the wiring pattern in the second heater 400b having a relatively large distance from the ink supply port 500 is different. The longitudinal direction of the two heating resistors in the second heater 400b having a relatively large distance from the ink supply port 500 is orthogonal to the longitudinal direction of the ink supply path, and is rotated 90 degrees. Therefore, it is necessary to devise wiring. In the present embodiment, as shown in FIG. 7, the wiring having the above-described configuration is realized by bending the second wiring layer 702 into an S shape.

  As described above, also in this embodiment, by adopting such a configuration, the layout on the substrate can be arranged efficiently, and the third problem, which is an increase in manufacturing cost due to the substrate size, is solved. be able to.

  Also, the circuit configuration is completely the same as that of the first embodiment shown in FIG.

  Finally, an ink jet printer using the above-described ink jet recording head will be briefly described.

<Outline of inkjet printer>
FIG. 10 is an external perspective view showing an outline of the configuration of an inkjet printer IJRA that is a representative embodiment of the present invention.

  As shown in FIG. 10, the carriage HC is supported by a lead screw 5005 that rotates via drive force transmission gears 5009 to 5011 in conjunction with forward and reverse rotation of the drive motor 5013, and a guide rail 5003. It is reciprocated in the b direction. The carriage HC has a pin (not shown) that engages with the spiral groove 5004 of the lead screw 5005. On the carriage HC, an integrated ink-jet cartridge IJC incorporating a recording head IJH and an ink tank IT is mounted.

  The paper pressing plate 5002 presses the recording paper P against the platen 5010 over the moving direction of the carriage HC. The photocouplers 5007 and 5008 are home position detectors for confirming the presence of the lever 5006 of the carriage HC in this region and switching the rotation direction of the motor 5013 and the like. A cap member 5022 that caps the front surface of the recording head IJH is supported by a support member 5016. A suction device 5015 that sucks the inside of the cap member 5022 performs suction recovery of the recording head IJH through the cap opening 5023. The main body support plate 5018 supports a cleaning blade 5017 and a member 5019 that enables the blade 5017 to move in the front-rear direction. The cleaning blade 5017 is not limited to this configuration, and it goes without saying that a known cleaning blade can be applied to this embodiment. A lever 5021 for starting suction for suction recovery is moved in accordance with the movement of the cam 5020 engaged with the carriage HC, and the driving force from the driving motor is moved through a known transmission mechanism such as clutch switching. Be controlled.

  These capping, cleaning, and suction recovery operations are configured such that when the carriage HC moves to the region on the home position side, the lead screw 5005 is driven to rotate so that desired processing can be performed at those corresponding positions. Yes. Note that any configuration may be applied to the present embodiment as long as a desired operation is performed at a known timing.

<Control system configuration>
Next, the configuration of a control system that controls the recording operation of the above-described ink jet printer will be described.

  FIG. 11 is a block diagram showing the configuration of the control circuit of the inkjet printer IJRA. As shown in FIG. 11, the control circuit has an interface 1700 to which a recording signal is input and an MPU 1701 as a logic circuit. The control circuit also includes a ROM 1702 in which a control program executed by the MPU 1701 is stored, and a DRAM 1703 in which various data (such as recording signals and recording data supplied to the recording head IJH) are stored. The control circuit also includes a gate array (GA) 1704 that controls the supply of recording data to the recording head IJH. The gate array 1704 also controls data transfer between the interface 1700, MPU 1701, and RAM 1703. .

  The control circuit drives and controls the recording head IJH via a head driver 1705 that drives the recording head IJH, that is, switches the energization state of the recording element. The control circuit drives and controls a carrier motor 1710 for transporting the recording head IJH and a transport motor 1709 for transporting recording paper via motor drivers 1706 and 1707 that drive the transport motor 1709 and carrier motor 1710. To do.

  The processing of the above control circuit will be described. When a recording signal is input to the interface 1700, the recording signal is converted into recording data for printing between the gate array 1704 and the MPU 1701. Then, the motor drivers 1706 and 1707 are driven, and the recording head IJH is driven according to the recording data output to the head driver 1705, and recording is performed on the recording paper.

  Next, the ink jet recording head IJH will be described. The ink jet recording head according to the present invention includes, among other ink jet recording methods, a means for generating thermal energy as energy used for discharging liquid ink, and a method for causing a change in the state of the ink by the thermal energy. Is adopted. By using this method, higher density and higher definition of recorded characters and images are achieved. In particular, in the present embodiment, an electrothermal conversion element is used as a means for generating thermal energy, and the ink is ejected by using the pressure caused by bubbles generated when the ink is heated and boiled by the electrothermal conversion element. ing.

FIG. 2 is a perspective view showing a part of the inkjet recording head of the present embodiment by cutting away. It is a schematic diagram which shows a part of nozzle row in 1st Embodiment. It is a schematic diagram which shows a part of nozzle row in 2nd Embodiment. It is a schematic diagram which shows a part of nozzle row in 3rd Embodiment. It is a schematic diagram which shows an example of the wiring of the element substrate in 1st and 2nd embodiment. It is a schematic diagram which shows the other example of the wiring of the element substrate in 1st and 2nd embodiment. It is a schematic diagram which shows the wiring of the element substrate in 3rd Embodiment. It is typical sectional drawing which shows the element substrate in the 1st-3rd embodiment. FIG. 6 is a circuit diagram relating to recording element driving of an element substrate in the first to third embodiments. It is a figure which shows the inkjet printer of this embodiment. It is a block diagram for demonstrating the said inkjet printer. It is a schematic diagram which shows a part of nozzle row in the inkjet recording head of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 Element substrate 111 Flow path formation member 100a 1st discharge port 100b 2nd discharge port 200 Pressure chamber 300 Nozzle 400a 1st heater 400b 2nd heater 500 Ink supply port 700 Heater layer 701a, 701b Insulating layer 702,703 Wiring layer 800 Through hole

Claims (11)

A plurality of discharge ports for discharging liquid droplets, a plurality of liquid flow channels communicating with the discharge ports, a liquid supply port for supplying liquid to the liquid flow channel, and a position facing the discharge port, including a heating resistor A plurality of recording elements disposed on the first discharge port, the first discharge port having a relatively short distance from the liquid supply port on at least one side of the liquid supply port, and the liquid A second discharge port having a relatively long distance from the supply port, the first discharge port and the second discharge port are arranged in a zigzag pattern, and the plurality of recording elements include the second discharge port. In a liquid ejection head configured to include a first recording element and a second recording element respectively corresponding to one ejection port and the second ejection port,
The first recording element is composed of one heating resistor formed in a rectangle whose longitudinal direction is a direction intersecting the arrangement direction of the plurality of ejection openings,
The second recording element has a plurality of heating resistors formed in a rectangular shape, and the plurality of heating resistors are connected in series and arranged adjacent to each other on the long side ,
The wiring for energizing the first recording element and the second recording element is connected to the short side of the heating resistor,
The second recording element includes two heating resistors, and the length of the long side of the heating resistor of the first recording element is the long side of the heating resistor of the second recording element. A liquid discharge head characterized by being approximately twice the length of the liquid discharge head. The plurality of liquid channels include a first liquid channel in which the first recording element is disposed, and a second liquid channel in which the second recording element is disposed,
The second liquid channel has a width parallel to the arrangement direction of the plurality of ejection ports at a portion located between the adjacent first recording elements, and the heating resistance of the first recording element. The liquid discharge head according to claim 1, wherein the liquid discharge head is formed to be equal to or smaller than a short side dimension of the body. It said second of said amount of liquid droplets discharged from the discharge port first liquid discharge head according to claim 1 or 2 less than the amount of liquid droplets discharged from the discharge port. The first discharge port and the second amount of liquid droplets discharged from the discharge port is substantially equal claims 1 to liquid discharge head according to any one of 3. In the second recording element, a length obtained by adding the lengths of the short sides of the two heating resistors and the distance between the two heating resistors is the arrangement pitch of the second ejection ports. The liquid ejection head according to claim 1 , wherein the liquid ejection head is half or more. Power supply means for supplying a driving voltage to the plurality of recording elements, a driver arranged for each recording element for switching the energization state of the recording elements, and a logic circuit for selectively driving the drivers In addition,
Said power supply means, said first and second liquid discharge head according to any one of recording claims 1 supplies a driving voltage, respectively to the element 5. Power supply means for supplying a driving voltage to the plurality of recording elements, a driver arranged for each recording element for switching the energization state of the recording elements, and a logic circuit for selectively driving the drivers In addition,
The logic circuit includes drive time determination signal means for outputting a signal related to the drive time of the recording element to the driver, and the drive time determination signal means is common to the first and second recording elements. The liquid discharge head according to any one of claims 1 to 6 . The wiring for energizing the first recording element has two upper and lower wiring layers electrically connected through a through hole provided in the vicinity of the heating resistor. 8. The liquid discharge head according to any one of items 7 . Interconnection layers of the upper and lower layers, the wiring layer of the lower layer is not bordered the resistor layer constituting the heat generating resistor, according to claim 8 which is arranged at a position except for immediately below the first recording element Liquid discharge head. The liquid ejection head according to claim 8 , wherein the through hole that electrically connects the upper and lower two wiring layers is disposed between the adjacent first recording elements. The centers of the plurality of through holes that electrically connect the wiring layers of the upper and lower layers and the centers of the plurality of first recording elements are positioned on the same straight line in the arrangement direction of the plurality of ejection ports. The liquid discharge head according to claim 10 .

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