JP2007144696A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording device which can keep a discharge surface of a recording head almost free from an ink residue sticking to the injection surface of a recording head even after discharging the ink into a cap and prevent a discharge orifice from clogging during wiping the discharge surface again by cutting a transfer of the ink from the discharge surface to a wiper. <P>SOLUTION: This inkjet recording device comprises a recording head 7 which discharges the ink and records data from a discharge orifice 7a and the cap 22 which covers the discharge orifice of a recording head. In addition, contact absorbers 23 and 25 with ink absorption characteristics and elastic absorbers 24 and 26 or flexible protrusion parts 22g, 22h, 22i and 22m, are provided inside the cap 22. Further, the contact absorbers 23 and 25 are pressed into contact with a peripheral region apart from the discharge orifice 7a of the discharge surface by the compression elastic force of the elastic absorbers 24 and 26 or the flexible protrusion parts 22g, 22h, 22i and 22m, when the recording head 7 is capped. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that includes a recording head that performs recording by discharging ink from a discharge port onto a recording medium, and a cap that covers the discharge port of the recording head.

  In printers, copiers, facsimile machines, scanners, or composite devices and systems thereof, a recording apparatus that forms an image on a recording medium such as recording paper based on image information is used. As one form of such a recording apparatus, an ink jet recording apparatus that records an image by discharging ink from a discharge port of a recording head to a recording medium is widely used. The image here includes characters, symbols, and the like. The ink jet recording apparatus has advantages such as low noise, low running cost, and easy miniaturization and colorization of the apparatus. A recording head used in the ink jet recording apparatus is provided with an ejection surface (also referred to as a face surface) facing the recording medium, and an ejection port (also referred to as a nozzle) is formed on the ejection surface.

  Usually, the discharge surface is provided with a discharge port array in which a plurality of discharge ports are arranged at a predetermined pitch. In general, an ink jet recording apparatus selectively drives each ejection port with an ejection signal based on image information (recording data) sent from a host device such as a personal computer to eject ink droplets. The size of such discharge ports is, for example, circular in cross section and has a diameter of about several tens of μm. In recent years, as the quality of recorded images is improved, the size is becoming smaller and higher in density. Also, the configuration of the recording head is required to be compatible with high-quality recording images (for example, black image density improvement, colorization, high definition (high resolution), water resistance improvement, etc.).

  In a serial type inkjet recording apparatus, a recording head is mounted on a carriage that can reciprocate, and ink is ejected from the ejection port of the recording head in synchronization with the movement of the carriage, thereby forming an image composed of dots on a recording medium. Is done. A recording head as shown in FIG. 4 is used in order to satisfy the above-described demand for high-quality recording images and to realize it at low cost. In the configuration of FIG. 4, black (Bk) ink ejection port array 13, yellow (Y) ink ejection port array 14, and magenta (M) ink ejection port array are disposed on ejection surface (face) 12 of recording head 7. 15 and cyan (C) ink ejection port arrays 16 are arranged in parallel in the carriage movement direction (main scanning direction).

  The pitch of the discharge ports (nozzles) in each discharge port array is about 600 dpi (dots / inch) to about 1200 dpi with higher definition. In order to reduce the size of the recording head and thus the apparatus, the distance (pitch) between the ejection port arrays is small, and the array width of the four ejection port arrays is about 3.5 mm, for example.

  Also, from the standpoint of improving the water resistance of recorded images and preventing bleeding between ink colors, for example, ink that causes a chemical reaction between black ink and other color inks is used, thereby insolubilizing dyes and the like. Are used. Specifically, for example, a cationic ink is used as the black ink, and an anionic ink is used as the other color ink (for example, the three color inks). As a result, when the two are ionically bonded, a coloring material such as a dye is insolubilized, water resistance is improved, and bleeding between inks of different colors can be prevented.

  In the ink jet recording apparatus, ink is ejected from minute ejection ports as described above, so that the ejection ports are likely to be clogged, and the permissible range for fluctuations in ink fluidity (viscosity) is relatively small. For this reason, a recovery process for maintaining and recovering the ink ejection performance of the recording head to an appropriate state by preventing clogging of the ejection opening and increasing the viscosity of the ink, or eliminating them when they occur is performed. Done. One of the recovery processes is capping that covers the ejection port of the recording head with a cap during non-recording. When ink is not ejected, such as during non-recording, the viscosity of the ink near the ejection port increases as the ink solvent evaporates according to the ambient temperature, humidity, etc., and in extreme cases it may dry and solidify . Due to the increase in the viscosity of the ink, a discharge failure or non-discharge occurs due to a decrease in the discharge amount or deflection in the discharge direction, leading to a decrease in recording quality. The capping is a recovery process for preventing such a phenomenon.

  As another recovery process, when clogging or solidification occurs due to the extreme thickening of the ink, a suction recovery process is performed to forcibly remove these. In this suction recovery process, the cap is in close contact with the ejection surface of the recording head and the ejection port is capped, and the inside of the cap is decompressed by a pump as a negative pressure generation source, and foreign matter such as thickened ink and bubbles is discharged from the ejection port. It is a process to discharge. As a pump in this case, a piston pump that reciprocates a piston in a cylinder type to generate a negative pressure, or a tube made of an elastic material is handled by a roller (roller) to generate a negative pressure by a restoring force of the tube. A tube pump or the like is used.

  As another recovery process, there is wiping that wipes (cleans) the ejection surface of the recording head with a wiper. Paper dust, dust, ink mist, or the like generated from a recording medium such as an opposing recording paper adheres to the discharge surface where the discharge ports are arranged. The ink mist in this case is mainly generated by the ejected ink droplets rebounding on the surface of the recording medium. If these paper dust, ink mist, or the like adheres to minute ejection openings, ink ejection failure or ejection failure may occur. The wiping is performed in order to prevent such a discharge failure. For example, when a certain amount of time has elapsed during recording, or when a certain amount of recording has been performed, a predetermined amount of recording is being performed. Done at the timing.

  This wiping is performed by an operation in which the wiper and the recording head are relatively moved and rubbed. By this wiping, foreign matters such as ink and dust adhering to the vicinity of the discharge port on the discharge surface can be removed. This wiping operation may be performed based on the user's instruction operation, for example, when the user observes image degradation due to ejection failure in a recorded image. Further, wiping is often performed along with other recovery processing described above or later.

  That is, in preliminary discharge described later and the above-described suction recovery process, ink is discharged into the cap, or suction is performed by reducing the pressure in the cap while the cap is in contact with the discharge surface of the recording head. After these recovery processes, the ink often adheres to the cap. Ink adhering to the cap may come into contact with the ejection surface and be transferred to the ejection surface during the next recovery process. As described above, the adhering ink due to the transfer causes ejection failure. Accordingly, wiping is performed after the cap is separated from the ejection surface following other recovery processes such as preliminary ejection and suction recovery process.

  Still another recovery process is so-called preliminary ejection. When recording an image, ink is not ejected from all the ejection ports, and depending on the recording data, there may be ejection ports that do not eject ink at all for a certain period. Such a discharge port does not discharge even the ink that is thickening due to the ink being not discharged, and further increases the degree of viscosity increase. In order to prevent such a situation, preliminary discharge is performed.

  This preliminary discharge is performed by causing the recording head to face an ink receiver (which may be a cap) after a certain period of time or a certain amount of recording, and discharging ink from all or some of the discharge ports. The ink in the ejection port is refreshed. When this preliminary discharge is performed toward the cap or the ink receiver, when the preliminary discharge amount reaches a certain amount, the pump (usually, the pump used in the above-described suction recovery process) is operated to enter the cap or the ink receiver. The ink inside is also sucked and discharged.

  The original function of the cap is to cover the ejection surface of the recording head and prevent the ink in the vicinity of the ejection port from drying. On the other hand, in order to absorb the waste ink discharged by preliminary discharge etc. in the cap, mounting | wearing with the absorber which has ink absorptivity is performed (for example, patent document 1). When the ejection surface is capped with a cap equipped with such an absorber, the inside of the cap is moistened by the absorber containing a certain amount of ink, so that the viscosity increase of the ink near the ejection port is reduced and the ejection failure occurs. There is an advantage that is suppressed.

  The absorber in this cap also has another function. That is, when preliminary ejection is performed in the cap, if the opposing surface on which preliminary ejection is performed is a member that hardly absorbs ink, the ink may splash back on the opposing surface, and the bounced ink may adhere to the ejection surface. If such ink adhesion is repeated and the attached ink covers the ejection port, the ink cannot be ejected from the ejection port, and the quality of the recorded image is significantly deteriorated due to non-ejection or ejection failure. By mounting the absorber in the cap and using the surface opposite to the ejection surface as the absorber, the ejected ink droplets can be absorbed without being rebounded, resulting from the above-described rebound ink. Deterioration of image quality due to non-ejection or ejection failure can be prevented.

However, if the amount of absorption of the absorber in the cap approaches saturation due to preliminary ejection, etc., or if the ink overflows from the absorber, capping the recording head will cause a large number of ejection ports on the ejection surface to be in the cap. It will be covered with ink. As a result, the contaminated ink flows backward from the ejection port, so that dust or the like is clogged in the ejection port, which may cause ejection failure. In addition, when capping a plurality of ejection port arrays for color recording with a single cap, a phenomenon in which different colors of ink are ejected by pressing different colors of ink into each ejection port (mixed color) May occur and image quality may deteriorate due to color mixing. In order to avoid such inconvenience, the number of ink droplets ejected into the cap is counted, and when the absorber in the cap approaches saturation, the ink is automatically sucked with a pump to remove the ink in the cap. It has been proposed.
JP 2000-203060 A

  However, in the conventional ink jet recording apparatus, the absorber in the cap is not in direct contact with the ejection surface of the recording head, and foreign matters such as ink adhering to the ejection surface remain as they are. In particular, the ink that has been sucked and discharged tends to remain attached to the portion where the peripheral lip portion of the cap is in contact, and normal ink ejection may not be possible as it is. Therefore, normal ink discharge is impossible if ink remains on the discharge surface, so that the cap is separated from the discharge surface after the suction recovery process or preliminary discharge or prior to the recording operation, and thereafter Wiping is performed by wiping the discharge surface with a wiper. Further, following this wiping, in order to remove ink or the like adhering to the wiper, a cleaning process for scraping and cleaning the wiper with a wiper cleaner is performed. The ink scraped off at this time adheres to the wiper cleaner, and this adhered ink may thicken or stick until the next wiper cleaning.

  The ink adhering to the wiper cleaner may be reversely transferred to the wiper again when the wiper passes the wiper cleaner again. Then, when the ejection surface is wiped next, the ink reversely transferred to the wiper is transferred to the ejection surface and further pushed into the ejection port. Ink that has been reversely transferred in this way may cause defective ejection or non-ejection of the ink, resulting in a reduction in image quality.

  The present invention has been made in view of such technical problems, and an object of the present invention is to reduce ink adhering to the ejection surface after ejecting ink into the cap, from the ejection surface to the wiper. It is an object of the present invention to provide an ink jet recording apparatus that can reduce the ink transfer and eliminate clogging of the discharge port when the discharge surface is wiped again.

  In order to achieve the above object, the present invention provides an ink jet recording apparatus comprising: a recording head that performs recording by discharging ink from a discharge port to a recording medium; and a cap that covers the discharge port of the recording head. An ink-absorbing contact absorber that is press-contacted to a peripheral region that avoids the ejection port on the ejection surface when the recording head is capped is mounted inside the cap.

  According to the present invention, since the contact absorber that is pressed against the peripheral area avoiding the discharge port of the discharge surface when the recording head is capped is provided, the ink adhering to the discharge surface after discharging the ink into the cap is reduced. An ink jet recording apparatus that can reduce the ink transfer from the ejection surface to the wiper and eliminate clogging of the ejection port when the ejection surface is wiped again is provided.

  Embodiments of the present invention will be specifically described below with reference to the drawings. Note that the same reference numerals denote the same or corresponding parts throughout the drawings. FIG. 1 is a perspective view showing a main part of an embodiment of an ink jet recording apparatus according to the present invention. In FIG. 1, a recording medium 3 such as recording paper separated and fed from an unillustrated auto sheet feeder (automatic paper feeder) is conveyed by a transport roller 1 and a pinch roller 2, a paper discharge roller 17 and a spur 18. And conveyed through the image forming unit. The image forming unit includes a recording head 7, a platen 4, and the like. The transport roller 1 is rotationally driven by a transport motor (not shown), and the paper discharge roller 17 is driven in synchronization with the transport roller 1.

  The transport roller 1 is disposed on the upstream side in the transport direction of the platen 4, and the paper discharge roller 17 is disposed on the downstream side in the transport direction of the platen 4. A main scanning range by the recording head 7 mounted on the carriage 5 is formed therebetween. The The carriage 5 is guided and supported so as to be movable in a direction crossing the conveying direction along a guide shaft 6 installed in the apparatus main body, and is reciprocally driven by a carriage motor (not shown) via a timing belt (not shown). . On the ejection surface 12 (FIG. 4) of the recording head 7 facing the recording medium 3, an ejection port array 13 for black ink and ejection port arrays 14, 15, 16 for color ink are provided.

  Therefore, the recording operation is performed by driving the recording head 7 in synchronization with the movement of the carriage 5. That is, by selectively driving the ejection ports constituting each ejection port array based on recording data (image information) to eject ink, an image composed of dots (including characters and symbols) is recorded on the recording medium 3. It is formed (recorded) on top. In the carriage 5, an ink tank for supplying ink of each color to the recording head 7, that is, an ink tank 8 for black (Bk) ink, an ink tank 9 for yellow (Y) ink, and an ink tank 10 for magenta (M) ink. Ink tanks 11 for cyan (C) ink are mounted. The recording head 7 of the present embodiment causes the ink in the discharge port to boil with the heat energy generated by the electrothermal converter (heater such as a heating element) disposed in each discharge port, and the bubbles generated thereby Ink is ejected by pressure.

  FIG. 2 is a perspective view of the cap 22 of the recovery unit 19 of the ink jet recording apparatus according to the first embodiment. FIG. 3 is a cross-sectional view of the cap 22 taken along a vertical plane parallel to the carriage movement direction at a portion indicated by line 3-3 in FIG. 2, and (a) shows a state when capping is not performed, and (b) ) Indicates a capping state. 1 to 3, a recovery unit 19 for maintaining and recovering the ink ejection performance of the recording head 7 is disposed at a position within the moving range of the recording head 7 and out of the recording scanning range (recording area). ing. The recovery unit 19 includes a cap 22 for sealing the discharge port of the recording head 7, a suction pump as a negative pressure generation source connected to the cap 22, and a discharge surface of the recording head (face surface on which the discharge ports are arranged). Wiping means (wiper 21) for wiping is provided.

  FIG. 4 is a front view showing the arrangement of the ejection port arrays on the ejection surface 12 of the color recording head 7. In the present embodiment, a recording head as shown in FIG. 4 is used in order to satisfy the demand for high-quality recording images and to realize it at low cost. In FIG. 4, black (Bk) ink discharge port array 13, yellow (Y) ink discharge port array 14, magenta (M) ink discharge port array 15, and cyan (C) ink discharge are formed on discharge surface 12. The outlet rows 16 are arranged in parallel in the carriage movement direction (main scanning direction).

  FIG. 5 is a cross-sectional view showing a capping state before the recovery operation of the recovery unit of the inkjet recording apparatus according to the first embodiment, taken along a vertical plane in a direction crossing FIG. 1 to 5, the cap 22 is formed by integrating a cap 22 a for covering the black ink ejection port array 13 and a cap 22 b for covering the three color ink ejection port arrays 14, 15, 16. Has been. Accordingly, the cap 22a is a cap that sucks only the black ink ejection port 13, and the cap 22b is a cap that simultaneously sucks the three ejection port rows 14, 15, and 16 of yellow, magenta, and cyan. The integral cap 22 is integrated with a cap base 27 made of a molded product. The cap 22 including the caps 22a and 22b is formed of an elastic member that can be elastically deformed, such as rubber having a predetermined hardness.

  In the present embodiment, the contact absorber 23 and the elastic absorber 24 are mounted inside the cap 22a, and the same contact absorber 25 and the elastic absorber 26 are mounted also inside the cap 22b. Each of these absorbers is formed of a member having ink absorbability. The contact absorber contacts the ejection surface 12 in the capped state, and the elastic absorber presses the contact absorber against the ejection surface with an appropriate pressure contact force. Therefore, in the present embodiment, an absorber structure having a two-layer structure in which the elastic absorber is disposed on the lower side is formed in the cap.

  In FIG. 1 to FIG. 5, the contact absorbers 23, 25 that come into contact with the ejection surface 12 of the recording head 7 are composed of absorbers having a density lower (lower) than the density of the elastic absorber below. . That is, the density of the upper contact absorber in the cap is made lower than the density of the lower elastic absorber, resulting in a two-layer structure with a density difference. This prevents or reduces color mixing particularly when ink is sucked from a plurality of ejection port arrays of different ink colors through one cap, such as the cap 22b of the color ejection port array. The contact absorbers 23 and 25 are formed with recesses 23a and 25a in order to avoid the discharge ports 7a (and thus the respective discharge port arrays) on the discharge surface 12 when the recording head 7 is capped. In other words, the contact absorber is configured to be in pressure contact with the peripheral area while avoiding the discharge port on the discharge surface.

  Concave portions (engagement portions) 23b and 25b are formed at a plurality of locations around the upper surface of the contact absorbers 23 and 25, and the caps 22a and 22b are associated with the respective concave portions at positions corresponding to the concave portions. Locking stoppers 22c and 22d are provided. As a result, the contact absorber and the elastic absorber are held so as not to deviate from a predetermined position in the cap. The material of the contact absorbers 23 and 25 is Sunfine (trade name), which is a porous body of a polyolefin sintered material, and the thickness thereof is 3 mm. The contact absorbers 23 and 25 are formed of a porous rigid body, and are brought into pressure contact with the discharge surface 12 by the compressive elastic force of the elastic absorbers 24 and 26 as elastic members mounted on the lower side thereof. .

  On the other hand, the material of the lower elastic absorbers 24 and 26 is a polyurethane foam elastic body, and the thickness thereof is 3 mm. The elastic absorber constituting the elastic member of the present embodiment is configured by a separate member independent of the contact absorbers 23 and 25. When the elastic absorbers 24 and 26 and the contact absorbers 23 and 25 are mounted in the caps 22a and 22b, the elastic absorber is installed so as to have a higher density than the contact absorber.

  Here, the reason why the upper and lower contact absorbers 23 and 25 are formed of a rigid sintered body is that they are not in contact with the discharge port array (discharge port) of the discharge surface 12 in any state, but only in contact with the periphery thereof. This is to make it happen. That is, if the contact absorbers 23 and 25 are elastic bodies, even if the recesses 23a and 25a are provided, there is a possibility that they will be elastically deformed and come into contact with the discharge port 7a even if they are in a capping state. Then, when it comes into contact with the discharge port 7a, there is a risk that dust or ink may enter the discharge port or damage the discharge port portion. Furthermore, when the contact absorber is an elastic body, in the case of a plurality of color discharge port arrays, the discharge ports of the other adjacent colors and the absorber may be crushed by the pressure contact force and come into contact on the same surface. There is a risk of color mixing. In the present embodiment, such inconveniences are prevented by making the contact absorbers 23 and 25 rigid.

  When the elastic absorbers 24 and 26 are mounted in the cap, they are compressed and deformed by the pre-compression by the aforementioned 22c and 22d. For this reason, in the capping state, the contact absorbers 23 and 25 are pressed against the ejection surface 12 by the restoring elastic force of the elastic absorbers 24 and 26. If an excessive pressing force acts between the rigid contact absorbers 23 and 25 and the discharge surface 12, the discharge surface may be damaged. Therefore, in this embodiment, the absorber in the cap has a two-layer structure, and the lower side is an elastic absorber that can be elastically deformed, so that the upper contact absorber is pressed against the discharge surface by its elastic restoring force. It is configured. As a result, interference between the contact absorber and the recording head and excessive pressing force in contact can be prevented, and an absorber structure that contacts the recording head 7 with an appropriate pressing force can be obtained.

  As described above, the density of the contact absorbers 23 and 25 in contact with the discharge surface is smaller (lower) than the density of the rear elastic absorbers 24 and 26. For this reason, when suction is performed by the suction pump 28 with the recording head 7 capped, the ink columns generated from the ejection ports 7a to the cap side are likely to be generated from the low density side to the high density side. It is possible to prevent or reduce color mixing of ink in the ejection port array.

  In FIG. 5, an integrated cap 22 having caps 22a and 22b is integrally formed with a cap base 27, which is a mold, by two-color molding or the like. In the capping state, the contact absorbers 23 and 25 held in the cap by the stoppers 22c and 22d are caused to react with the elastic force of the elastic suction members 24 and 26 as elastic members by the pressing reaction force from the discharge surface 12. It is mounted to move against. Further, the lip portion 22j around the cap 22a and the lip portion 22k around the cap 22b are ejected when the contact absorbers 23 and 25 are moved by a predetermined amount in the capping state shown in FIG. 12 is contacted.

  FIG. 5 is a cross-sectional view showing the capping state before the recovery operation of the recovery unit of the ink jet recording apparatus according to the first embodiment, taken along the vertical plane in the direction crossing FIG. 3, as described above. 6 is a cross-sectional view similar to FIG. 5 showing a state where the cap is filled with ink during the recovery operation of the recovery unit of FIG. FIG. 7 is a cross-sectional view similar to FIG. 5 showing a state in which ink collected in the cap during the recovery operation in the recovery unit of FIG. 5 is removed by suction. FIG. 8 is a cross-sectional view similar to FIG. 5 showing a state in which the ink collected in the cap in the recovery unit of FIG. 5 is removed by suction and then the cap is separated from the recording head and the ejection surface is wiped. Next, the configuration and operation of the recovery unit of the ink jet recording apparatus according to the first embodiment will be described with reference to these drawings.

  5 to 8 show the black ink cap 22a and the recovery processing mechanism connected thereto, the color ink cap 22b and the recovery processing mechanism connected thereto have substantially the same configuration. is doing. Accordingly, the items described below with reference to FIGS. 5 to 8 are similarly applied to the configuration, operation, and effect of the recovery processing mechanism for the color ink including the cap 22b unless otherwise specified. .

  5 to 8, holes 22e and 22f are provided at two locations on the cap 22a. One hole 22e communicates with the through hole of the dowel 27a of the cap base 27, and is connected to the tube pump 28 by a tube 29 closely fitted to the dowel 27a. The tube pump 28 is a suction pump as a negative pressure generation source. The tube pump 28 has rollers 30 that are rotatably supported at two locations on the rotating body 28a. The pump tube 29 is disposed along an arcuate guide portion of a recovery base 37 that is a chassis of the recovery unit 19. When the rotating body 28a rotates in the direction of arrow G, the roller 30 handles (s ladders) the tube 29 while rotating. This handling generates a negative pressure in the tube, and the generated negative pressure acts in the cap 22a to generate a suction force.

  The other hole 22f in the cap 22a communicates with the through hole of the dowel 27b of the cap base 27, and can communicate with the atmosphere through the atmosphere communication tube 31 closely fitted to the dowel 27b. A molded joint adapter 32 is tightly fitted to the tip of the tube 31, and a rubber atmospheric valve 33 is tightly fitted to the joint adapter. The tip of the atmospheric valve 33 has a shape that is easily elastically deformed, and the rotary lever 34 is in pressure contact with this portion, thereby closing the valve. The rotating lever is made of a mold, and is normally held at the valve closing position by a spring 35. When the rotation lever 34 moves against the spring 35 by the rotation of the cam 36, the atmospheric valve 33 is opened (opened to the atmosphere).

  When the tube pump 28 rotates in the arrow G direction in the capping state of FIG. 5, a negative pressure is applied to the discharge ports (discharge ports of the black ink discharge port array 13) 7a via the cap 22a. As a result, ink is sucked from the ejection port 7a. FIG. 6 shows a state in which the inside of the cap is filled with the sucked ink at this time. By sucking ink from the ejection port, the ink in the ejection port is refreshed and an image is formed with the original characteristics.

  FIG. 7 shows a state in which suction for removing ink filled in the cap 22a is performed. Ink is sucked from the discharge port 7a when the inside of the cap is in a predetermined negative pressure state. When the inside of the cap is at or near atmospheric pressure, ink cannot be sucked from the discharge port. Therefore, the inside of the cap 22a is communicated with the atmosphere by rotating the cam 36 and rotating the cam lever 34 to open the atmosphere valve 33. In this atmospheric communication state, the tube pump 28 is rotated in the arrow G direction. Then, the ink in the cap can be almost completely discharged and removed by sucking air from the atmospheric valve 33 without sucking ink from the discharge port 7a of the recording head 7. At this time, since the contact absorber 23 in the cap is pressed against the part of the discharge surface 12 that is outside the discharge port, the ink adhering to the discharge surface is almost completely sucked through the porous contact absorber. Removed.

  8, the cap 22a is separated from the ejection surface 12 from the state of FIG. 7, and the wiper holder 20 holding the wiper (two wipers in the illustrated example) 21 is moved in the arrow H direction in that state. Accordingly, the wiper rubs the ejection surface and wipes and removes ink and the like adhering to the ejection surface. After wiping the discharge surface, the wiper 21 is further moved, and the wiper is rubbed against the edge 38a of the wiper cleaner 38, thereby removing deposits such as ink on the wiper. As a result, the deposit transferred from the ejection surface to the wiper is transferred to the wiper cleaner 38. In the above description, the cap 22a and the ejection port array 13 related to the black ink have been mainly described with reference to FIGS. 3 to 8. However, the cap 22b and the ejection port arrays 14, 15, and 16 related to the color inks of a plurality of colors are also described. Similar processing is performed with the same configuration.

  According to the embodiment described above, the ink absorbing contact absorbers 23 and 25 that are pressed against the peripheral area of the ejection surface 12 that avoids the ejection port 7a when the recording head 7 is capped are provided, so that the cap 22a, 22b can reduce the amount of ink adhering to the ejection surface of the recording head after ejecting the ink, and by reducing ink transfer from the ejection surface to the wiper 21, the ejection port when wiping the ejection surface again is reduced. An ink jet recording apparatus capable of preventing clogging is provided. That is, the ink in the cap 22 after suction is not transferred to the ejection surface 12 of the recording head 7, and when the ejection surface is wiped with the wiper 21, the ink does not adhere to the wiper, and the wiper cleaner 38 is also contaminated. As a result, contamination of the wiper can be prevented, clogging of the ejection port of the recording head, ink non-ejection and ejection failure due to the clogging can be prevented, and the reliability of the ink jet recording apparatus can be improved. be able to.

  FIG. 9 is a perspective view showing the cap of the recovery unit according to the second embodiment with the contact absorber removed. FIG. 10 is a perspective view showing a state in which the contact absorber is attached to the cap of FIG. FIG. 11 is a cross-sectional view of the cap 22 taken along a vertical plane parallel to the carriage movement direction at a portion indicated by a line 11-11 in FIG. 10, and (a) shows a state when capping is not performed. ) Shows the state when capping. FIG. 12 is a cross-sectional view showing a capping state of the recovery unit 19 according to the second embodiment, taken along a vertical plane in a direction crossing FIG. The cap 22 shown in FIGS. 9-12 uses the protrusion part provided in cap 22 itself which consists of an elastic member instead of the elastic absorbers 24 and 26 in above-mentioned 1st Embodiment.

  The cap 22 according to the present embodiment includes compression-deformable projecting portions 22g, 22h, 22i, and 22m formed on the cap 22 itself made of an elastic member, instead of the elastic absorbers 24 and 26 in the first embodiment. It is what is used. That is, in this embodiment, the elastic member as an elastic means for pressing the contact absorbers 23 and 25 against the discharge surface 12 is integrally formed inside the caps 22a and 22b made of an elastic member (bottom surface portion). It is comprised by the protrusion part which can be compressed elastically. This embodiment is different from the first embodiment in this point, and has substantially the same configuration in other points, and corresponding portions are denoted by the same reference numerals, and detailed descriptions thereof are omitted. .

  9-12, protrusions 22g and 22h are formed at two locations on the inner bottom surface of the cap 22a, and protrusions 22i and 22m are formed at two locations on the inner bottom surface of the cap 22b. Each protrusion of each cap is formed with holes 22e and 22f that pass through the protrusion and the bottom of the cap. Inside each cap, one hole 22e communicates with a dowel 27a of the cap base 27, and is further connected to a tube pump 28 by a tube 29 closely fitted to the dowel 27a. The other hole 22f communicates with the dowel 27b of the cap base 27, and further communicates with the atmosphere through the atmosphere communication tube 31 closely fitted to the dowel 27b.

  When the cap 22 is separated from the recording head, the cap 22 is in the state shown in FIG. In the state where the recording head 7 is capped, the protrusions 22g, 22h, 22i, and 22m are compressed by the contact absorbers 23 and 25 that receive the pressing reaction force from the ejection surface 12, as shown in FIG. The contact absorber is brought into pressure contact with the discharge surface 12 with an appropriate pressure contact force by the elastic reaction force. At this time, the reaction force due to the deformation and crushing of each protrusion is set to a value that does not damage the recording head 7. Further, the gap between the bottom surfaces of the caps 22a and 22b and the contact absorbers 23 and 25 is made as small as possible so that ink does not remain on the bottom surfaces.

  In this embodiment, the cap 22a for capping one ejection port array 13 for black ink and the cap 22b for capping three ejection port arrays 14, 15, 16 for three color inks are substantially provided. It has the same structure and produces the same effect, and here, it demonstrates further focusing on one cap 22a. When the contact absorber 23 is attached to the cap 22a as shown in FIG. 11A, a pressing force due to deformation of the protrusions 22g and 22h acts on the contact absorber. Then, as shown in FIG. 11B, when the recording head 7 is capped, the contact absorber 23 comes into close contact with the ejection surface 12 with an appropriate pressure contact force.

  Hereinafter, when the tube pump 28 is operated in this capping state, the ink is sucked and discharged from the ejection port as in the case of the first embodiment. The atmospheric valve 32 is opened when the inside of the cap is in a negative pressure state close to a constant atmospheric pressure by this suction and discharge. Further, when sucked by the tube pump 28, the ink adhering to the discharge surface 12 of the recording head 7 is also discharged through the contact absorber 23 and the tube 29, and the discharge surface becomes a clean surface. Accordingly, the wiper is not contaminated by subsequent wiping, and the ejection opening of the recording head can be prevented from being clogged. The processing operations of these recovery units 19 are the same as those in the first embodiment described with reference to FIGS.

  Therefore, also in the second embodiment, the ink in the cap 22 after suction is not transferred to the ejection surface 12 of the recording head 7, and the ink does not adhere to the wiper when the ejection surface is wiped with the wiper 21. . In addition, the wipe park liner 38 is not contaminated. As a result, contamination of the wiper can be prevented, non-ejection and ejection failure of the recording head can be prevented, and reliability can be improved. Thus, according to the second embodiment as well, it is possible to reduce ink adhering to the ejection surface after ejecting ink into the caps 22a and 22b, reducing ink transfer from the ejection surface to the wiper 21, and reducing the ejection surface. The same effect as in the case of the first embodiment can be obtained that the discharge port can be prevented from being clogged when wiping is performed again.

  In the above embodiment, a serial type ink jet recording apparatus that records with a recording head mounted on a carriage that moves along the recording medium has been described as an example. However, the present invention includes a recording head for full line recording, and the like. The present invention can be similarly applied to a line-type ink jet recording apparatus that performs recording only by sub-scanning, and has the same effects. In addition, the present invention can be similarly applied to any inkjet recording apparatus regardless of the number of recording heads, the number of ink types to be used, the properties, and the like, and has the same effects. .

It is a perspective view which shows the principal part of the inkjet recording device to which this invention is applied. It is a perspective view of the cap of the recovery unit of the ink jet recording apparatus according to the first embodiment. FIG. 3 is a cross-sectional view of the cap taken along a vertical plane parallel to the carriage movement direction at a portion indicated by line 3-3 in FIG. 2, (a) shows a state when capping is not performed, and (b) is capping. Indicates the state when FIG. 3 is a front view illustrating the arrangement of ejection port arrays on the ejection surface of a color recording head. FIG. 4 is a cross-sectional view showing a capping state before a recovery operation of the recovery unit of the ink jet recording apparatus according to the first embodiment, taken along a vertical plane in a direction intersecting with FIG. 3. FIG. 6 is a cross-sectional view similar to FIG. 5, showing a state in which the cap is filled with ink during the recovery operation of the recovery unit of FIG. 5. FIG. 6 is a cross-sectional view similar to FIG. 5 showing a state in which ink collected in the cap during the recovery operation in the recovery unit of FIG. 5 is removed by suction. FIG. 6 is a cross-sectional view similar to FIG. 5 showing a state in which, after the ink collected in the cap in the recovery unit of FIG. 5 is sucked and removed, the cap is separated from the recording head and the ejection surface is wiped. It is a perspective view which shows the state which removed the contact absorber of the cap of the recovery unit of the inkjet recording device which concerns on 2nd Embodiment. It is a perspective view which shows the state which mounted | wore the contact absorber with the cap of FIG. FIG. 11 is a cross-sectional view of the cap taken along a vertical plane parallel to the carriage movement direction at a portion indicated by a line 11-11 in FIG. 10, where (a) shows a state when capping is not performed, and (b) shows capping. Indicates the state when FIG. 12 is a cross-sectional view showing a capping state before a recovery operation of a recovery unit of an ink jet recording apparatus according to a second embodiment, taken along a vertical plane in a direction intersecting with FIG. 11.

Explanation of symbols

1 Conveying roller 3 Recording medium (recording paper, etc.)
4 Platen 5 Carriage 6 Guide Shaft 7 Recording Head 7a Ejection Port 12 Ejection Surface 13 Black Ink Ejection Row 14 Yellow Ink Ejection Row 15 Magenta Ink Ejection Row 16 Cyan Ink Ejection Row 17 Paper Discharge Roller 19 Recovery Unit 20 Wiper holder 21 Wiper 22 Cap 22a Black ink cap 22b Color ink cap 22c, 22d Retaining stopper 22e, 22f Hole 22g, 22h, 22i, 22m Protruding part 22j, 22k Lip part 23, 25 Contact absorber 23a, 25a Recess 23b, 25b Recess (engagement part)
24, 26 Elastic absorber 27 Cap base 27a, 27b Dowel 28 Suction pump (tube pump)
28a Rotating body 29 Pump tube 30 Roller 31 Atmospheric communication tube 32 Joint adapter 33 Atmospheric valve 34 Rotating lever 35 Spring 36 Cam 37 Recovery base

Claims (11)

In an ink jet recording apparatus comprising: a recording head for recording by discharging ink from a discharge port to a recording medium; and a cap for covering the discharge port of the recording head;
An ink-jet recording apparatus, wherein an ink-absorbing contact absorber that is pressed against a peripheral area that avoids a discharge port on a discharge surface when the recording head is capped is mounted inside the cap.   2. The ink jet recording apparatus according to claim 1, wherein the contact absorber is a porous rigid body.   The inkjet recording apparatus according to claim 1, wherein the contact absorber is pressed against the ejection surface by a compression elastic force of an elastic member.   The ink jet recording apparatus according to claim 3, wherein the contact absorber is movable against an elastic force of the elastic member by a reaction force from the discharge surface.   The inkjet recording apparatus according to claim 4, wherein a peripheral lip portion of the cap contacts the ejection surface when the contact absorber moves by a predetermined amount.   The ink jet recording apparatus according to claim 1, wherein a concave portion for avoiding contact with the discharge port of the discharge surface is formed in the contact absorber.   The inkjet recording according to any one of claims 3 to 6, wherein the elastic member is an ink-absorbing elastic absorber attached to the lower side of the contact absorber inside the cap. apparatus.   The ink jet recording apparatus according to claim 7, wherein the elastic absorber is an open-cell elastic body.   9. The ink jet recording apparatus according to claim 7, wherein the density of the contact absorber is smaller than the density of the elastic absorber.   The inkjet recording apparatus according to claim 3, wherein the elastic member is a projecting portion that is formed inside a cap made of an elastic member and is capable of compressive and elastic deformation.   The ink jet recording apparatus according to claim 1, wherein the recording head uses thermal energy to generate bubbles in the ink and discharges the ink with the pressure of the bubbles.

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