JP2006224599A - Liquid jetting recording head and liquid jetting recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet printer which can prevent printing omission during printing from occurring, caused by sudden non-delivering of ink triggered by presence of residual bubbles. <P>SOLUTION: A liquid jetting recording head or an inkjet head of the inkjet printer comprises delivering ports from which liquid is delivered, a delivering energy generating section for applying energy for delivering the liquid from the delivering ports, a substrate on which the delivering energy generating section is arranged, a second liquid storing section arranged adjacently to the substrate and containing no liquid absorber etc. therein, and a liquid storing section for mainly storing therein the liquid. Herein, the inkjet head has projections formed on a surface of a flow channel in the substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid jet recording head and a liquid jet recording apparatus capable of recording a high-quality image on a recording medium.

  The present invention is applicable to all devices that record on a recording medium such as paper, cloth, leather, nonwoven fabric, and OHP paper. Specific examples of applicable equipment include office equipment such as printers, copiers, and facsimiles.

  Conventionally, liquid jet recording apparatuses have been widely used as recording apparatuses for printers, facsimiles, and the like because of low noise, low running cost, and easy size reduction and colorization of the apparatus.

Currently, in order to record higher-quality images, inkjet printers are becoming higher in nozzle resolution and smaller in ink droplets. In order to increase the printing speed, the drive frequency is increased, the nozzle density is increased, and the number of nozzles is increased. As such an ink jet printer, for example, a configuration as described in JP-A-11-198394 is known.
JP-A-11-198394

  Inkjet printers have continued to be improved in recent years with the aim of improving photographic image quality.However, a feature of photographic image quality printing is that the liquid jet recording head is operated in a form that is almost similar to solid printing for each ink color used. is there. In addition to this, the printing speed is further improved. The present inventor has recognized the following problems while studying the liquid jet recording head in order to cope with photographic image quality and high speed.

  In other words, as a result of increasing the number of droplets ejected per unit time in order to improve the printing speed, there arises a problem that printing omission occurs during printing due to undischarge due to residual gas in the ink. I came.

  Since the generation of residual gas is one of the causes of the release of gas from the ink in the liquid jet recording head due to pressure fluctuations resulting from the liquid jet operation, the increase in jetting operation per unit time due to the improvement in printing speed remains. Increase gas evolution. This release of residual gas is also triggered by a temperature rise. This is evident from the rapid decrease in water solubility in water as the temperature increases.

  When the liquid jet recording head is used in an environment with a high jetting operation rate such as photographic image printing or large plate printing, the problem of undischarge caused by residual gas becomes more severe.

  FIG. 5 shows a cross-sectional view (FIG. 5 (b)) of a conventional liquid jet recording head and a plan view (FIG. 5 (a)) at a position where a heating element is provided. The substrate 430 constituting the liquid jet recording head is connected to the liquid storage unit 48 by the connecting member 46. A filter 47 or the like is generally installed at the connection portion. The ink is guided from the liquid storage section 48 to the flow path 44 of the substrate section through the filter section 47 and the liquid second storage section 45 (formed by the connecting member 46). Thereafter, the nozzles 43 are filled up to the discharge ports 41 through the nozzle channels 43 communicating with the discharge ports 41.

  Residual gas may exist as small bubbles or may be combined to exist as larger bubbles 11. The shape of the bubble may be a spherical shape or a shape that conforms to the shape of the space (FIG. 5B). In any case, it has been clarified by various actual machine observations that the residual gas accumulates in the liquid channel bend and the liquid channel constriction. When a large amount of residual gas accumulates in the liquid flow path bending portion or the liquid flow path narrowing portion, the residual gas blocks the flow of ink supplied from the liquid storage section 48. As a result, the supply of ink to the discharge port 41 is cut off, and the ink is suddenly discharged without being discharged.

  In particular, it is impossible to predict when the discharge failure due to such a cause will occur during operation of the recording apparatus, and this problem will be fatal as the recording apparatus because it occurs during printing. In addition, if the recovery operation (removal of residual gas by suction) is frequently performed in consideration of such undischarge, a lot of ink is wasted.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid jet recording head that does not cause printing failure during printing due to undischarge due to residual gas, and further to provide a liquid jet recording apparatus equipped with the liquid jet recording head. .

Therefore, a liquid jet recording head according to the present invention includes a discharge port for discharging a liquid, a discharge energy generation unit for applying energy for discharging the liquid from the discharge port, a substrate provided with the discharge energy generation unit, A liquid second storage part that is adjacent to the substrate and does not contain a liquid absorber and the like; and a liquid storage part that mainly stores the liquid, and the connection position between the substrate and the liquid second storage part In the relationship between the channel width B of the liquid second storage unit and the channel width W of the substrate unit,
W <B
In a liquid jet recording head satisfying
A protrusion is provided on the flow path surface of the substrate portion.

According to another aspect of the invention, a liquid jet recording head includes a discharge port from which a liquid is discharged, a discharge energy generation unit that applies energy for discharging the liquid from the discharge port, a substrate provided with the discharge energy generation unit, A liquid second storage section that is adjacent to the substrate and does not contain a liquid absorber or the like; and a liquid storage section that mainly stores the liquid, at a connection position between the substrate and the liquid second storage section. In the relationship between the channel width B of the liquid second storage unit and the channel width W of the substrate unit,
W <B
In a liquid jet recording head satisfying
A partition portion is provided on the flow path surface of the substrate portion.

  As described above, the liquid jet recording head and the apparatus of the present invention introduce partitions or protrusions into the flow path portion of the substrate portion, so that residual bubbles are prevented from growing in the longitudinal direction in the flow path portion of the substrate portion. And rapidly expands toward the liquid second reservoir. As a result, the volume of residual bubbles in the portion protruding to the liquid second storage portion becomes larger than the volume of residual gas in the flow path portion of the substrate portion, and the bubbles try to be spherical in the region-wide liquid second storage portion. And the residual gas of the part pinched | interposed into the flow-path part of a board | substrate part is also dragged out, and it becomes a spherical shape in a liquid 2nd storage part. As a result, a wide ink supply path to the ejection port is ensured, so that it is possible to reliably avoid printing skipping during printing due to sudden non-discharge due to residual bubbles.

  FIG. 7 is a perspective view of a liquid jet recording apparatus applicable to the present invention. The recording medium 106 inserted into the paper feeding position of the recording apparatus 100 is conveyed to a recordable area of the recording head unit 103 by a feed roller 109. A platen 108 is provided at a lower position of the recording medium 106 in the recordable area. The carriage 101 is guided by two guide shafts 104 and 105 so as to be movable along their extending direction (main scanning direction), and reciprocally scans the recording area. The scanning direction of the carriage 101 is the main scanning direction, and the conveyance direction of the recording medium 106 is the sub-scanning direction. Mounted on the carriage 101 is a recording head unit 103 including a recording head for ejecting ink droplets of a plurality of colors and a liquid storage unit for supplying ink to each recording head. The inks of a plurality of colors in the liquid jet recording apparatus of this example are four colors of black (Bk), cyan (C), magenta (M), and yellow (Y). The position of each color is in no particular order.

  A recovery system unit 110 is arranged at the lower left end of the area where the carriage 101 can move, and capping the ejection port of the recording head during non-recording operations. This left end position is called the home position of the recording head. Reference numeral 107 denotes a switch unit and a display element unit. The switch unit is used when turning on / off the power of the recording apparatus or setting various recording modes. The display element unit plays a role of displaying the state of the recording apparatus.

  FIG. 8 is a perspective view of the recording head unit 103. In the case of this example, the liquid storage portions of the respective color inks (Bk, C, M, Y) of black, cyan, magenta, and yellow are configured to be independently replaceable. The carriage 101 includes a recording head group 102 that ejects Bk ink droplets, C ink droplets, M ink droplets, and Y ink droplets, a Bk liquid storage unit 20K, and a C liquid storage unit 20C. The liquid storage unit 20M for M and the liquid storage unit 20Y for Y are mounted. Each liquid storage unit is connected to the recording head group 102 and supplies ink into a nozzle flow path communicating with the ejection port of the recording head group 102. In addition to this example, for example, the liquid storage portions for the respective colors may be combined into an integral structure in any combination.

  FIG. 3A is a plan view of the recording head 102, and FIG. 3B is a cross-sectional view of the position of the heating element in the recording head 102 (the position indicated by the one-dot chain line BB 'in FIG. 3A).

  In the liquid jet recording apparatus of this example, a heating element 2 as an electrothermal converter is disposed corresponding to each ejection port 1 of the recording head 102, and a driving signal corresponding to recording information is applied to the heating element 2. A recording method in which ink droplets are ejected from the ejection port 1 is adopted. The heating element 2 corresponding to each of the discharge ports 1 is configured to be able to generate heat independently.

  The ink in the nozzle rapidly heated by the heat generated by the heating element 2 generates bubbles due to film boiling, and the ink droplet 111 is ejected toward the recording medium 106 as shown in FIG. Then, characters and images are formed on the recording medium 106. Each of the ejection ports 1 is provided with an ink nozzle channel 3 communicating with the ejection port 1, and behind the nozzle channel 3, a flow of a substrate portion is supplied to supply the ink to the nozzle channel 3. A path 4 is formed (see FIG. 4). As described above, the nozzle flow path 3 corresponding to each of the discharge ports 1 has a heating element 2 as an electrothermal converter that generates thermal energy used to discharge ink droplets from these discharge ports 1, and Electrode wiring (not shown) for supplying electric power to this is provided. The heating element 2 and the electrode wiring are formed on the surface of the substrate 30 made of silicon or the like by a film forming technique. A protective film (not shown) is formed on the heating element 2 so that the ink and the heating element 2 are not in direct contact with each other. Further, the discharge port 1, the nozzle flow path 3, the flow path 4 of the substrate section, and the like are configured by laminating a partition wall 10 made of resin or glass material on the substrate 30.

  FIG. 6 shows the recording head unit. The configuration of this unit is a configuration in which a Bk chip 2302, a C chip 2303, an M chip 2304, and a Y chip 2305 are fixed to a frame 2306. Each of the chips 2302, 2303, 2304, and 2305 has the same configuration as that of the recording head 102 in FIG. The intervals between the chips 2302 to 2305 are ½ inch, and are arranged at equal intervals in the main scanning direction in FIG. Each of the chips 2302 to 2305 has 256 ejection ports 1 (see FIG. 3A), that is, 256 nozzles, and these nozzle rows are arranged so as to be substantially orthogonal to the main scanning direction.

  Each nozzle has 128 nozzles arranged in two rows at a nozzle pitch of about 84 μm, and the two rows are called “staggered” (that is, the two rows are shifted by about 42 μm, which is a half pitch). It has been fabricated (FIG. 3A). As a result, a band for 256 nozzles can be recorded at a resolution of 600 dpi in one main scan. In addition, each part dimension mentioned above, the number of nozzles, etc. do not limit this invention.

(Conventional example 1)
A conventional liquid jet recording head is shown in FIG. A liquid jet recording head having a discharge amount of 8.5 × (10 to the power of 15) cubic meters and 600 dpi was manufactured. In Conventional Example 1, the cross-sectional shape (see FIG. 5) of the channel 44 in the substrate portion is a trapezoid because it is fabricated by performing anisotropic etching with a plane orientation <100>. Here, the thickness of the substrate was 625 microns, the minimum channel width of the substrate unit was 155 microns, and the maximum channel width of the substrate unit was 800 microns. Moreover, the flow path width B of the liquid 2nd storage part 45 was 2 mm.

  Normally, in order to prevent the discharge failure of the liquid droplets by counting the number of liquid droplets to be discharged and the numerical values related to them during the operation of the print head, suction is performed to remove the residual gas in the print head when a certain count number is reached. Although it is programmed to shift to the recovery operation, here, in order to clarify when the occurrence of discharge failure actually occurs, the shift control to the suction recovery operation is released.

  When solid printing of cyan (C) color was performed on A3 size paper, printing was lost in about 3 sheets due to undischarge caused by residual gas (bubbles). When the inside of the ink jet head was observed immediately after this state, it was confirmed that air had entered (occupied) the flow path 44 portion of the substrate section and the liquid second storage section 45.

  When a detailed observation experiment was conducted, as the discharge operation repeated, small bubbles adhered to the portion of the channel 44 of the substrate portion (surface subjected to anisotropic etching with a plane orientation <100>) through the nozzle channel 43. And found that it started to accumulate. In addition, these small bubbles start to merge and some of them move toward the liquid second storage part 45 by buoyancy, but some adhere to them while repeating coalescence and growth in the channel 44 part of the substrate part. It was observed that it remained as it was (FIG. 5 (b)). The bubbles that expand while adhering to the liquid block the supply of the liquid (ink) from the liquid storage unit 48 to the discharge port 41, causing non-discharge and causing printing to be lost.

  From this observation result, it has been attempted to improve the wettability of the flow path portion 44 of the substrate portion to promote the ease of bubble separation and to promote the movement toward the liquid storage portion 48 by buoyancy. The improvement effect is not obtained.

  Therefore, as a result of extensive studies, the present inventor has effectively removed unnecessary bubbles close to the discharge port by actively utilizing the phenomenon that the gas (bubbles) in the liquid wants to become spherical due to surface tension. I found a way away from the position. Moreover, as a method for effectively causing this phenomenon, it has been found effective to stop the growth and expansion of residual bubbles in the longitudinal direction in accordance with the surface of the flow path portion 44 of the substrate. The method will be specifically described below based on examples.

  FIG. 9 shows a specific embodiment of the present invention.

  In Example 1, a liquid jet recording head having a discharge amount of 8.5 × (10 to the 15th power) cubic meter and 600 dpi was manufactured. The cross-sectional shape (see FIG. 9A) of the channel 64 in the substrate portion is a trapezoid because it is fabricated by performing anisotropic etching with a plane orientation <100>. Here, the thickness of the substrate was 625 microns, the minimum channel width of the substrate unit was 155 microns, and the maximum channel width of the substrate unit was 800 microns. Moreover, the flow path width B of the liquid 2nd storage part 65 was 2 mm.

  In Example 1, the partition structure 70 shown in FIGS. 9C to 9D is manufactured, and the partition 70 is formed by being sandwiched and connected between the substrate 630 and the connecting member 66 (FIG. 9B). (Refer to the above) The partition thickness e is uniform). The arrangement pitch L was 300 microns, which is equal to the channel width m of the substrate portion (see FIG. 9B). Moreover, the flow path width B of the liquid 2nd storage part 5 was 2 mm.

  Normally, in order to prevent the discharge failure of the liquid droplets by counting the number of liquid droplets to be discharged and the numerical values related to them during the operation of the print head, suction is performed to remove the residual gas in the print head when a certain count number is reached. Although it is programmed to shift to the recovery operation, here, in order to clarify when the occurrence of discharge failure actually occurs, the shift control to the suction recovery operation is released.

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were found on the portion of the flow path 64 of the substrate portion (surface subjected to anisotropic etching with a plane orientation <100>).

  Consideration will be made based on the results of Conventional Example 1 and Example 1 described above. According to detailed experimental observation, although the flow path 4 portion of the substrate portion produced by anisotropic etching with a plane orientation <100> spreads in a divergent shape in the opposite direction (upward direction) of gravity. Most of the remaining spherical spherical bubbles remain attached, that is, it cannot be expected that the residual bubbles are peeled and removed by buoyancy. However, as shown in FIG. 2 (a), when the relationship B> W is established, if t is sufficiently smaller than W, residual bubbles having a certain size will adhere to the anisotropic etching surface forever. No separation and levitation due to buoyancy can be expected. However, there is a limit in securing the strength of the substrate, and (t / (W / 2)) cannot be reduced without limit.

  On the other hand, the situation changes when the parameter ratio (t / (W / 2)) exceeds “1” (FIG. 2B). That is, the substantially spherical residual bubbles that have expanded while adhering to the anisotropic etching surface with a surface orientation of <100> are sandwiched between the etching surfaces on both sides, and in this case, the adhering force to both surfaces is superior to buoyancy. Becomes difficult (FIG. 2C).

  When the residual gas coalesced further after this state and the volume of the residual bubbles increases, the residual bubbles are in the longitudinal direction of the flow path 4 of the substrate portion in a state of conforming to the end spreading surface of the flow path 4 of the substrate portion. At the same time as starting to grow (FIG. 5 (b)), it expands in both directions on the discharge port side and the liquid storage unit side (FIG. 2 (c)). Of these, the forefront of residual bubbles near the discharge port side is unfortunate In addition, if it communicates with the outside air through the discharge port, a discharge failure occurs.

  On the other hand, when the partition structure 70 shown in the first embodiment is introduced, the residual gas in the portion sandwiched between the two parallel partition surfaces is prevented from growing in the longitudinal direction of the flow path 64 of the substrate portion. (FIG. 9B) The liquid rapidly expands toward the liquid second storage part (FIG. 2D). As a result, compared with the residual gas volume (the gas volume below the DD line in FIG. 2D) in the flow path 64 of the substrate part, the volume of the residual gas in the portion protruding to the liquid second storage part ( When the gas volume above the line D-D in FIG. 2D increases, the bubbles tend to be spherical in the region-wide liquid second reservoir, and the residual gas in the channel 64 of the substrate portion is removed. It drags out and becomes spherical in the liquid second reservoir (FIG. 2 (e)). In addition, the residual bubbles that have once passed through the second liquid storage section and turned into a spherical shape do not enter the flow path section 64 of the substrate section again except during the suction recovery operation. As a result, it is considered that a wide ink supply path to the ejection port is ensured and discharge failure is avoided.

  In Example 2, the flow path 4 of the substrate part was manufactured by performing anisotropic etching with a plane orientation <100>. In this case, the cross-sectional shape (see FIG. 1A) of the flow path 4 in the substrate portion is rectangular, and a partition 12 having a uniform partition thickness e can be formed simultaneously in the flow path 4 portion of the substrate portion (FIG. 1). (See (b)). Here, the thickness t of the substrate was 625 microns, and the flow path width of the substrate portion was 300 microns. The arrangement pitch L was 300 microns, which is equal to the channel width m of the substrate portion (see FIG. 1B).

  As a head of Example 2, a liquid jet recording head having a discharge amount of 8.5 × (10 to the 15th power) cubic meter and 600 dpi was prepared. Moreover, the flow path width B of the liquid 2nd storage part 5 was 2 mm.

  Normally, in order to prevent the discharge failure of the liquid droplets by counting the number of liquid droplets to be discharged and the numerical values related to them during the operation of the print head, suction is performed to remove the residual gas in the print head when a certain count number is reached. Although it is programmed to shift to the recovery operation, here, in order to clarify when the occurrence of non-discharge occurs, the shift control to the suction recovery operation is canceled in this example as well as in the conventional example 1. .

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  In the head of this Example 3, a head was produced in the same manner as the method described in Example 2, and an additional process using a laser was performed on the partition 12 among them. Thereby, the protrusion 512 was formed only on one of the two etching surfaces constituting the flow path 54 of the substrate portion (see FIG. 10). The height h of the projections 512 is 150 microns, and the arrangement pitch L is 300 microns, which is equal to the flow path width m of the substrate portion (see FIG. 10). All other conditions are the same as in Example 2. In this case as well, when an attempt was made to perform cyan (C) solid color printing on A3 size paper, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  In the head of the fourth embodiment, a head was manufactured in the same manner as described in the second embodiment, and an additional process using a laser was performed on the partition 12 (see FIG. 11). Thereby, the protrusions 812 were formed in a staggered pattern on the two etching surfaces constituting the flow path 84 of the substrate portion. The height h of the protrusions 812 was 150 microns, and the arrangement pitch L was 300 microns, which is equal to the channel width m of the substrate portion (see FIG. 11). All other conditions are the same as in Example 2. In this case as well, when an attempt was made to perform cyan (C) solid color printing on A3 size paper, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  Consideration will be made based on the results of Example 3 and Example 4 shown above. According to the detailed observation experiment, the introduction of the protrusions 512 and 812 shown in the third and fourth embodiments also suppresses the growth in the longitudinal direction of the flow paths 54 and 84 of the substrate part, and the liquid storage part side Expand rapidly. As a result, compared with the residual gas volume (the gas volume below the line DD in FIG. 2D) in the flow paths 54 and 84 of the substrate portion, the portion of the portion protruding to the liquid second storage portion 55 and 85 When the volume of the residual gas (the gas volume above the line DD in FIG. 2D) increases, the bubbles tend to be spherical in the region-wide liquid second reservoir 55, 85, Residual gas in the flow paths 54 and 84 is dragged to form a spherical shape in the liquid second storage section 55 and 85 (FIG. 2E). In addition, the residual bubbles that have once passed through the liquid second storage portions 55 and 85 and become spherical as described above will not enter the flow path portions 54 and 84 of the substrate portion again except during the suction recovery operation. As a result, it is considered that a wide ink supply path to the ejection port is ensured and discharge failure is avoided.

  In addition, since the occupied volume of the protrusions 512 and 812 in the third and fourth embodiments can be made smaller than the occupied volume of the partition 70 in the second embodiment, it is advantageous in supplying ink from the liquid storage unit to the ejection port. The ejection driving frequency can be increased.

  In Example 5, only the arrangement pitch L was changed to 500 microns (see FIG. 1B), and the manufacturing method and other dimensions and the printing test method were the same as those in Example 2 described above.

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing continued without any missing prints until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  In Example 6, only the arrangement pitch L was changed to 700 microns (see FIG. 1B), and the manufacturing method and other dimensions and printing test methods were the same as those in Example 2.

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  In Example 7, only the arrangement hitch L was changed to 500 microns (see FIG. 10), and the manufacturing method and other dimensions and printing test methods were the same as those in Example 3 described above.

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  In Example 8, only the arrangement pitch L was changed to 700 microns (see FIG. 10), and the manufacturing method and other dimensions and printing test methods were the same as those in Example 3 described above.

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  In Example 9, only the arrangement pitch L was changed to 500 microns (see FIG. 11), and the manufacturing method and other dimensions and printing test methods were the same as those in Example 4 described above.

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  In Example 10, only the arrangement pitch L was changed to 700 microns (see FIG. 11), and the manufacturing method and other dimensions and printing test methods were the same as those in Example 4 described above.

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  In Example 11, only the height h of the protrusion 812 was changed to 200 microns (see FIG. 11), and the manufacturing method and other dimensions and the printing test method were the same as those in Example 4 described above.

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  In Example 12, only the height h of the protrusion 812 was changed to 100 microns (see FIG. 11), and the manufacturing method and other dimensions and the printing test method were the same as those in Example 4 described above.

  Attempting to perform cyan (C) solid color printing on A3 size paper using this head, printing was continued without causing any omission until the built-in ink was used up (19 sheets of A3 paper). . Immediately after this, the inside of the ink jet head was observed, and no large bubbles or the like were observed on the portion of the channel 4 of the substrate portion (surface subjected to anisotropic etching with a surface orientation <110>).

  Further, in the conventional example 1 and the examples 1 to 4 described above, the flow path width of the liquid second storage unit is fixed to 2 mm. On the other hand, in order to improve the mountability of the inkjet head, there is a case where an attempt is made to reduce the channel width of the liquid second storage unit. In a detailed study on this point, the following conditions have been found.

2 × t × W ^ 2 <4π / 3) × (B / 2) ^ 3
That is, if the flow path shape of the substrate portion is formed with a combination dimension of t and W that satisfies this condition, the remaining bubbles that are spherical in the liquid second storage portion adhere to both wall surfaces of the liquid second storage portion. Without buoyancy and further away from the discharge port, the forefront of residual bubbles close to the discharge port side will not unfortunately communicate with the outside air through the discharge port, and will not be discharged, it is more preferable It is.

  Further, the present invention is also suitable in a configuration in which the position where the flow path 94 of the substrate part is provided is not the center but the edge part as shown in FIG.

(A) is sectional drawing of the inkjet head in this invention, (b) is a top view in the heating element arrangement position of the inkjet head in this invention. Sectional drawing for demonstrating the relationship between the thickness of the board | substrate in the inkjet head in this invention, the flow path width of a board | substrate part, and a residual bubble. FIG. 2 is a plan view of the ink jet head in the present invention. The figure for demonstrating the printing state by the inkjet head in this invention. (A) is sectional drawing of the inkjet head of a prior art example, (b) is a top view in the heating element arrangement position of the inkjet head of a prior art example. The figure for demonstrating the state which mounted the chip | tip for each color in the flame | frame. 1 is a schematic perspective view of a liquid jet recording apparatus applicable to the present invention. 1 is a schematic perspective view of a liquid jet recording head applicable to the present invention. (A) is sectional drawing of the inkjet head which is another Example in this invention, (b) is a top view in the heating element arrangement position of the inkjet head which is another Example in this invention, (c)-( d) The figure for demonstrating a partition structure. The top view in the heat generating element arrangement | positioning position of the inkjet head which is another Example in this invention. The top view in the heat generating element arrangement | positioning position of the inkjet head which is another Example in this invention. Sectional drawing of the inkjet head which is another Example in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ejection port 2 Heat generating body 3 Nozzle flow path 4 Substrate part flow path 5 Liquid 2nd storage part 6 Connect member 7 Filter part 8 Liquid storage part 9 Ink absorber 10 Partition 11 Residual gas (bubble)
12 partition 20K Bk tank 20C C tank 20M M tank 20Y Y tank 30 Substrate 41 Discharge port 42 Heating element 43 Nozzle channel 44 Substrate channel 45 Liquid second storage unit 46 Connect member 47 Filter unit 48 Liquid Storage part 49 Ink absorber 51 Discharge port 52 Heat generating element 53 Nozzle flow path 54 Substrate part flow path 55 Liquid second storage part 56 Connect member 57 Filter part 58 Liquid storage part 59 Ink absorber 70 Partition structure 100 Recording apparatus 101 Carriage 102 Recording head group 103 Recording head unit 104 Guide shaft 105 Guide shaft 106 Recording medium 107 Switch / display element portion 108 Platen 109 Feed roller 110 Recovery system unit 111 Ink droplet 430 Substrate 512 Protrusion 530 Substrate 812 Protrusion 230 2 Bk chip 2303 C chip 2304 M chip 2305 Y chip 2306 Frame

Claims (12)

A discharge port from which liquid is discharged, a discharge energy generation unit for applying energy for discharging the liquid from the discharge port, a substrate provided with the discharge energy generation unit, a liquid absorber formed adjacent to the substrate, and the like A liquid second storage part that does not contain the liquid and a liquid storage part that mainly stores the liquid, and a flow path width B of the liquid second storage part at a connection position between the substrate and the liquid second storage part. And the flow path width W of the substrate part,
W <B
In a liquid jet recording head satisfying
A liquid jet recording head, wherein a projection is provided on a flow path surface of the substrate portion. A discharge port from which liquid is discharged, a discharge energy generation unit for applying energy for discharging the liquid from the discharge port, a substrate provided with the discharge energy generation unit, a liquid absorber formed adjacent to the substrate, and the like A liquid second storage part that does not contain the liquid and a liquid storage part that mainly stores the liquid, and a flow path width B of the liquid second storage part at a connection position between the substrate and the liquid second storage part. And the flow path width W of the substrate part,
W <B
In a liquid jet recording head satisfying
A liquid jet recording head, wherein a partition portion is provided on a flow path surface of the substrate portion.   The liquid jet recording head according to claim 1, wherein the protrusions are provided in a staggered manner on two opposing surfaces constituting the substrate portion of the flow path.   2. The liquid jet recording head according to claim 1, wherein the protrusion is provided on only one of two opposing surfaces constituting the flow path of the substrate portion.   5. The liquid jet recording head according to claim 1, wherein an arrangement pitch L of the protrusions is an integral multiple of an arrangement pitch p of the ejection energy generation unit.   3. The liquid jet recording head according to claim 2, wherein the arrangement pitch L of the partition portion is an integral multiple of the arrangement pitch p of the ejection energy generating portion.   The arrangement pitch of the projections at the center position of the flow path of the substrate portion is different from the pitch of the projection sections at the position of the flow path end portion of the substrate section. The liquid jet recording head according to any one of Items 5 to 5.   7. The arrangement pitch according to claim 2 or 6, wherein an arrangement pitch of the partitioning portion at a central position of the flow path of the substrate portion is different from an arrangement pitch of the protrusions at a flow path end position of the substrate portion. 2. A liquid jet recording head according to 1.   The liquid jet recording head according to claim 1, wherein a flow path width W of the substrate portion is uniform over the entire thickness t of the substrate.   10. The liquid jet recording head according to claim 1, wherein the flow path of the substrate portion is disposed between or in the middle of the rows of the ejection ports.   The liquid jet recording head according to claim 1, wherein the ejection energy generation unit includes an electrothermal converter that generates thermal energy.   12. A liquid jet recording apparatus equipped with a liquid jet recording head according to claim 1, comprising a moving means for moving the liquid jet recording head and a transport means for transporting a recording medium.

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