JP2007283548A - Cap unit for inkjet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent ink adhering to a face in the delivery from dropping when a cap unit is attached to a body. <P>SOLUTION: The cap unit is configured to be detachably attached to a face of an inkjet head for performing recording by ejecting a recording liquid from an opening of a nozzle, the face having the opening of the nozzle formed thereon. The cap unit comprises: a protection member for protecting the face of the inkjet head having the opening of the nozzle; an elastic cap which is fixed to the protection member and is adapted to cover a region of the nozzle by being brought into intimate contact with the face; and a liquid absorption member provided in the elastic cap. When the cap unit is detached or attached, the liquid absorption member once approaches the face having the opening of the nozzle as compared with the case where the cap is attached. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a storage form at the time of physical distribution of an ink jet head that performs recording by discharging a recording liquid from an ejection port.

  Among conventional recording methods, an ink jet recording method that performs recording on a recording medium by ejecting ink from an ejection port has been widely adopted in recent years because it can perform a recording operation at a high density and at a high speed. ing.

  A general recording apparatus adopting this method includes an inkjet head that ejects ink for recording an image on a recording medium, and a conveying apparatus for the recording medium. The inkjet head uses an electromechanical transducer element such as a piezo element or an electrothermal transducer element such as a heating resistor in a nozzle communicating with the ejection port in order to eject ink droplets from the ejection port. And those using electromagnetic wave mechanical transducer elements or electromagnetic heat transducer elements of radio waves or lasers. Among them, an ink jet recording apparatus that discharges ink droplets using thermal energy can perform high-resolution recording because the nozzles can be arranged at high density.

  In particular, an inkjet head using an electrothermal transducer element as a thermal energy generating element is easier to miniaturize than an inkjet head using an electromechanical transducer element. By applying IC technology and micro-machining technology that are remarkably improved and fully utilizing their advantages, high-density mounting can be easily provided at low cost.

  In general ink jet heads, an ink amount necessary for recording is stably supplied from an ink tank containing ink to nozzles. The ink supply pressure from the ink tank to the nozzle is adjusted to a negative pressure in order to prevent the ink from leaking from the discharge port, and in detail to maintain the ink meniscus of the discharge port. As a method of adjusting the ink supply pressure to a negative pressure, a method of utilizing a water head difference from an ink outlet port to an ejection port of an ink tank directly storing ink, or an ink absorber as a negative pressure generating member in the ink tank is used. There is a way to store.

  As a method of supplying ink to the nozzles of the ink jet head, a method of supplying ink to the nozzles by incorporating an ink tank into the ink jet head so as to be integrated or separable, or connecting the ink jet head via an ink tank and a tube There is a so-called tube supply method for supplying ink to the nozzles. In an ink jet printer that consumes a large amount of ink, the ink tank also has a large capacity. Therefore, if the ink jet head includes an ink tank, the strength of the casing is increased and the ink jet recording apparatus itself becomes heavy. Therefore, such a printer employs a tube supply system.

  In addition, in an ink jet head, an ink reservoir or a buffering unit such as a filter is often provided between the ink tank and the ink tank so as not to generate a sudden pressure change that easily affects ejection.

  That is, in any system, the ink jet head generally includes a nozzle serving as an ink droplet discharge unit, an ink storage space, and an ink introduction port.

  In such an ink jet head, if the inside of the nozzle is in a dry state during use, when ink is supplied to the inside of the head, the ink is not sufficiently filled in each nozzle, and ejection failure occurs due to insufficient ink filling in the nozzle. It is possible. For this reason, in the physical distribution process until the manufactured head reaches the user, the ink in the head (transparent ink not including the color material) is stored in the head to make the inside of the head a moisture atmosphere. Specifically, a method of filling the distribution ink between the filter and the nozzle is common.

For example, Patent Document 1, Patent Document 2, and Patent Document 3 can be cited as conventional examples.
JP-A-6-64160 Japanese Patent Laid-Open No. 10-250091 Japanese Patent Laid-Open No. 10-250091

  However, it is difficult to completely fill the gap between the filter and the nozzle with the distribution ink. When the head after manufacture is filled with the distribution ink, the environmental preservation test performed after the head manufacture until the product shipment and the head shipment If the internal pressure of the head rises due to the expansion of air between the filter and the nozzle due to the environmental change in the physical distribution process from the user to the user, the ink for physical distribution may leak out from the nozzle ejection port or the ink introduction port. In addition, physical distribution ink may leak from the ejection port even when an impact is applied to the head by dropping or vibration. As a result, there is a risk that the ink leaking out from the discharge port and dripping on the face surface will drip at the time of mounting or the like.

  Therefore, in view of the above problems, the object of the present invention is to keep the ink in the ink storage space in the head as much as possible during the physical distribution, and to keep the inside of the head, particularly the nozzle, in the moisture-retaining state. An object of the present invention is to provide a storage form for logistics of an inkjet head.

  In order to achieve the above object, an aspect of the present invention is a cap unit that can be attached to and detached from the surface on which the nozzle opening is formed, of an inkjet head that performs recording by discharging recording droplets from the nozzle opening. A protective member that protects the surface of the inkjet head in which the nozzle opening is formed, and an elastic cap that is fixed to the protective member and covers the area of the nozzle in close contact with the surface in which the nozzle opening is formed And a liquid absorbing member disposed in the elastic cap, when the cap unit is attached / detached, the liquid absorbing member comes closer to the surface on which the nozzle opening is formed than when the cap is attached. It is a structure.

  In a state where the cap unit is mounted on the inkjet head, it is preferable that the liquid absorbing member is disposed so as not to contact the surface on which the nozzle opening is formed.

  Further, in the cap unit, the protective member is provided with a positioning portion that can be positioned with respect to the inkjet head, and a clip-shaped engagement portion that is once expanded and hooked on the inkjet head. Preferably it is.

  Moreover, it is preferable that the storage-type head as described above is provided with a positioning part for positioning the cap unit and an engaging part with which a part of the cap unit is engaged.

  As described above, the cap unit is provided with the positioning portion that can be positioned with respect to the inkjet head and the clip-shaped engagement portion that is once expanded and hooked with respect to the inkjet head. Accurate desorption operation is easy.

  Further, by adopting a configuration in which the water absorbing resin in the cap sucks a large ink droplet on the head face surface when the cap is removed due to the shape of the engaging portion, it is possible to prevent ink sagging when the head is mounted on the main body.

  Further, according to the cap unit of the present invention, the liquid absorbing member of the cap unit is arranged so as to be in non-contact with the surface on which the nozzle opening is formed. The nozzles can be moisturized without damage.

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

  First, an example of an ink jet recording apparatus using an ink jet head of an example to which the storage method of the present invention for head distribution is applied will be described.

  FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to an embodiment of the present invention.

  The ink jet recording apparatus shown in FIG. 1 repeats the reciprocating movement (main scanning) of the ink jet head 201 and the conveyance (sub scanning) of recording sheets S such as general recording paper, special paper, and OHP film at a predetermined pitch. This is a serial type ink jet printer that forms characters, symbols, images, and the like by selectively ejecting ink from the ink jet head 201 and making it adhere to the recording sheet S while synchronizing with these movements.

  In FIG. 1, an inkjet head 201 is detachably mounted on a carriage 202 that is slidably supported by two guide rails and reciprocated along the guide rails by a driving means such as a motor (not shown). The recording sheet S is opposed to the ink ejection surface of the inkjet head 201 by the conveying roller 203 and crosses the moving direction of the carriage 202 so as to maintain a constant distance from the ink ejection surface (for example, It is conveyed in the direction of arrow A, which is a direction orthogonal to each other.

  The inkjet head 201 has a plurality of nozzle rows for ejecting inks of different colors. A plurality of independent main tanks 204 are detachably attached to the ink supply unit 205 in accordance with the color of ink ejected from the inkjet head 201. The ink supply unit 205 and the inkjet head 201 are connected to each other by a plurality of ink supply tubes 206 corresponding to the colors of the ink, and the main tank 204 is mounted on the ink supply unit 205 so that the ink is stored in the main tank 204. Each color ink can be independently supplied to each nozzle row of the inkjet head 201.

  A recovery unit 207 is disposed so as to face the ink ejection surface of the inkjet head 201 in a non-recording area that is within the reciprocating range of the inkjet head 201 and outside the passing range of the recording sheet S. Yes.

  Next, the detailed configuration of the ink supply system of the ink jet recording apparatus will be described with reference to FIG. FIG. 2 is a diagram for explaining the ink supply path of the ink jet recording apparatus shown in FIG. 1, and only the path for one color is shown for ease of explanation.

  First, the inkjet head 201 will be described.

  Ink is supplied to the inkjet head 201 from a connector insertion port 201a to which a liquid connector provided at the tip of the ink supply tube 206 is airtightly connected. The connector insertion port 201 a communicates with a sub tank portion 201 b formed on the upper part of the inkjet head 201. A liquid chamber 201f that directly supplies ink to a nozzle portion having a plurality of nozzles 201g arranged in parallel is formed below the sub tank portion 201b in the direction of gravity. The sub-tank portion 201b and the liquid chamber 201f are partitioned by the filter 201c. The boundary between the sub-tank portion 201b and the liquid chamber 201f has a partition portion 201e in which an opening 201d is formed. It is installed on 201e.

  With the above-described configuration, the ink supplied from the connector insertion opening 201a to the inkjet head 201 is supplied to the nozzle 201g via the sub tank 201b, the filter 201c, and the liquid chamber 201f. The space from the connector insertion port 201a to the nozzle 201g is kept airtight with respect to the atmosphere.

  An opening is formed on the upper surface of the sub tank 201b, and this opening is covered with a dome-shaped elastic member 201h. The space (pressure adjusting chamber 201i) surrounded by the elastic member 201h has a function of adjusting the pressure in the sub tank 201b as described later, with the volume changing according to the pressure in the sub tank 201b.

  The nozzle 201g has a cylindrical structure with a cross-sectional width of about 20 μm, and discharges ink from the nozzle 201g by applying discharge energy to the ink in the nozzle 201g. After the ink is discharged, the nozzle 201g is driven by the capillary force of the nozzle 201g. The ink is filled inside. In order to give ejection energy to the ink in the nozzle 201g, the inkjet head 201 has an energy generating means for each nozzle 201g. In this embodiment, a heating resistor element that heats the ink in the nozzle 201g is used as the energy generating means, and the heating resistor element is selected by a command from a head control unit (not shown) that controls the driving of the inkjet head 201. The ink in the desired nozzle 201g is boiled, and ink is ejected from the nozzle 201g using the pressure of the bubbles generated thereby.

  The nozzle 201g is arranged with the tip for discharging ink facing downward, but no valve mechanism for closing the tip is provided, and the ink fills the nozzle 201g in a state where a meniscus is formed. Therefore, the inside of the inkjet head 201, particularly the inside of the nozzle 201g, is kept in a negative pressure state. However, if the negative pressure is too small, if foreign matter or ink adheres to the tip of the nozzle 201g, the ink meniscus may collapse and the ink may leak out of the nozzle 201g. On the other hand, if the negative pressure is too large, the force for pulling the ink back into the nozzle 201g becomes stronger than the energy given to the ink during ejection, resulting in ejection failure. Therefore, the negative pressure in the nozzle 201g is kept in a certain range slightly lower than the atmospheric pressure. The range of this negative pressure varies depending on the number of nozzles 201g, the cross-sectional area, the performance of the heating resistance element, and the like.

  In this embodiment, the ink supply unit 205 and the inkjet head 201 are connected by the ink supply tube 206, and the position of the inkjet head 201 with respect to the ink supply unit 205 can be set relatively freely. In order to obtain a negative pressure, the inkjet head 201 is arranged at a position higher than the ink supply unit 205.

  The filter 201c is made of a metal mesh having fine holes of 10 μm or less smaller than the cross-sectional width of the nozzle 201g to prevent foreign matter that clogs the nozzle 201g from flowing out from the sub tank 201b to the liquid chamber 201f. The When the ink contacts only one surface of the filter 201c, the filter 201c has an ink meniscus formed by capillary force in each minute hole, and the ink easily permeates but the air flow is difficult. The smaller the size of the micropores, the stronger the meniscus, and the more difficult it is to pass air.

  In the filter 201c as used in the present embodiment, the pressure required to transmit air is about 0.1 atm (10.1325 kPa) (experimental value). Therefore, if air exists in the liquid chamber 201f located downstream of the filter 201c with respect to the ink moving direction in the inkjet head 1, the air cannot pass through the filter 201c with the buoyancy of the air itself. The air inside remains in the liquid chamber 201f. In this embodiment, this phenomenon is utilized, the liquid chamber 201f is not filled with ink, and an air layer exists between the ink in the liquid chamber 201f and the filter 201c. A predetermined amount of ink is stored in the liquid chamber 201f so that the ink and the filter 201c are separated from each other.

  The amount of ink stored in the liquid chamber 201f is at least the amount necessary to fill the nozzle 201g with ink. If air from the liquid chamber 201f enters the nozzle 201g, the nozzle 201g after ink ejection is not replenished with ink, resulting in ejection failure. Therefore, the nozzle 201g must always be filled with ink.

  The ink in the sub tank 201b is in contact with the upper surface of the filter 201c. The area in contact with this ink is the effective area of the filter 201c. The pressure loss due to the filter 201c depends on the effective area of the filter 201c. In this embodiment, the filter 201c is arranged so as to be horizontal in the usage state of the inkjet head 201, and the ink is brought into contact with the entire upper surface of the filter 201c to maximize the effective area of the filter and reduce the pressure loss. .

  The pressure adjustment chamber 201i is a chamber whose volume decreases as the internal negative pressure increases. When the pressure adjustment chamber 201i is configured by the elastic member 201h as in the present embodiment, the elastic member 201h is a rubber material. Etc. are preferably used. Moreover, you may comprise by the combination of a plastic sheet | seat and a spring other than the elastic member 201h. Providing such a pressure adjustment chamber 201i stabilizes ink ejection and suppresses the influence of pressure loss in the ink supply path from the main tank 204 to the inkjet head 201. For this reason, the ink supply tube 206 driven by the carriage 202 can also have a small diameter, which contributes to a reduction in the load of movement of the carriage 202.

  Next, the ink supply unit 205 and the main tank 204 will be described.

  The main tank 204 is detachable from the supply unit 205, and has an ink supply port sealed with a rubber plug 204b and an air introduction port sealed with a rubber plug 204c at the bottom. The main tank 204 is an airtight container by itself, and the ink 209 is stored in the main tank 204 as it is.

  On the other hand, the ink supply unit 205 includes an ink supply needle 205 a for taking out the ink 209 from the main tank 204 and an air introduction needle 205 b for introducing the atmosphere into the main tank 204. The ink supply needle 205a and the air introduction needle 205b are both hollow needles, and are arranged with the needle points upward corresponding to the positions of the ink supply port and the air introduction port of the main tank 204. By being mounted on the ink supply unit 205, the ink supply needle 205a and the air introduction needle 205b penetrate the rubber plugs 204b and 204c, respectively, and enter the main tank 204.

  The ink supply needle 205a is connected to the ink supply tube 206 through the liquid path 205c. The atmosphere introduction needle 205b communicates with the atmosphere via the liquid path 205e, the buffer chamber 205f, and the atmosphere communication port 205g. The liquid path 205c at the lowest position in the ink supply path from the ink supply needle 205a to the ink supply tube 206 and the lowest position in the path from the atmosphere introduction needle 205b to the atmosphere communication port 205g. Both of the liquid passages 205e have the same height.

  With the above configuration, when ink in the inkjet head 201 is consumed, the negative pressure causes ink to be supplied from the main tank 204 to the inkjet head 201 via the ink supply unit 205 and the ink supply tube 206 as needed. At that time, the same amount of air as the ink supplied from the main tank 204 is introduced into the main tank 204 from the atmosphere communication port 205g through the buffer chamber 205f and the atmosphere introduction needle 205b.

  The appearance of the inkjet head 201 used in the ink supply method described above is as shown in FIGS. 3 and 4, for example. FIG. 3 is an external view of the ink jet head 201 viewed from an oblique lower side, and FIG. 4 is an external view of the ink jet head 201 viewed from an oblique upper side.

  3 is an opening of the nozzle 201g, and a plurality of rows formed of a plurality of discharge ports are arranged in parallel to the carriage movement direction B.

  FIG. 5 is a head longitudinal sectional view showing a storage mode of the inkjet head 201 during distribution.

  In FIG. 5, a joint rubber 211 is inserted into the connector insertion port 201a connected to the sub tank 201b of the inkjet head 201 by press fitting. The ink joint rubber 211 has a slit into which a joint needle (needle tube) of a liquid connector provided at the tip of the ink supply tube 206 is inserted. That is, the ink introduction part into the ink jet head is a slit of the elastic member. The joint needle insertion slit seals the connector insertion port 201a except when the joint needle is inserted.

  At the time of distribution, a cap unit 212 is attached to the face surface (formation surface of the discharge port 210 shown in FIG. 3) where the discharge port of the nozzle 201g of the inkjet head 201g opens.

(First embodiment)
6A and 6B are views for explaining the face face cap unit 212 of the present invention, in which FIG. 6A is a plan view of a side joined to the face face, and FIG. 6B is a plan view of AA of FIG. Line sectional drawing, (C) has shown the side view of the direction of the arrow C in (A).

  As shown in FIG. 6, the cap unit 212 includes a protective cap 212 a that is a protective member that protects the face surface as a unit outer shell, and a cap rubber (elastic cap) 212 b that is fixed to the concave portion of the protective cap 212 a. It consists of a water-absorbing resin (liquid absorbing member) 212c fixed to the recess of the cap rubber 212b. In the cap rubber 212b, a rib is formed in an annular shape so as to be in close contact with an outer peripheral portion of a region composed of a plurality of ejection port arrays on the face surface of the inkjet head 201. Here, the uppermost surface of the absorbent resin 212c is positioned lower than the uppermost surface of the cap rubber 212b. As a result, the cap rubber 212b at the time of capping forms a sealed space without contact with the discharge port of the nozzle 201g as shown in FIGS. With such a configuration, the nozzle 201g can be moisturized without causing damage to the nozzle 201g.

  The protective cap 212a is provided with a positioning guide 214 for a positioning boss (reference numeral 213 in FIGS. 3 and 4) provided on the ink jet head 201 side, and a hook portion (on the ink jet head 201 side). 3 and 4 is provided with a clip portion 219 having claw portions 217 and 218 that can be expanded once and then fitted.

  The cap unit 212 having such a configuration is positioned by a boss 213 serving as a positioning portion provided in the ink jet head 201, and further, hooks 215 and 216 provided in the ink jet head 201 and claw portions 217 and 218 of the clip portion 219. Can be attached to the ink-jet head 201 by engaging with (see FIG. 7). The feature of this embodiment is the shape of the tip of the claw portions 217 and 218, which is an anti-sagging shape.

  First, the storage mode during distribution with the cap unit 212 attached will be described. As shown in FIGS. 5 and 7, in the storage mode at the time of distribution with the cap unit 212 mounted, at least the distribution ink is present in the nozzle 201g in the head 201, and the upper and lower spaces sandwiching the filter 201c. There is almost no distribution ink. This space becomes a sealed space by the cap unit 212 and the joint rubber 211. For this reason, the inside of the head is dampened by the distribution ink in the nozzle. At this time, it is desirable that the amount of the distribution ink in the nozzle is slightly larger than the saturated water vapor amount with respect to the volume of “head + cap”. Further, the water absorbing resin 212c has the ability to sufficiently absorb the quantity of physical distribution ink in the nozzle.

  In the structure of this embodiment, when an increase in the internal pressure of the head due to an environmental preservation test or the like occurs, the pressure is released by the deformation of the elastic member 201h or the cap 212 being connected to the outside air for a moment. Further, even when the distribution ink in the nozzle is dripped from the face surface due to the increase in internal pressure, the water absorbing resin 212c absorbs the ink, so that no ink leakage occurs outside the head. That is, since no ink leaks outside, the amount of ink in the sealed space does not change, and the nozzle is kept filled with ink or saturated water vapor.

  As described above, it is possible to provide a highly reliable ink jet head that does not leak ink to the outside of the head at the time of distribution even if there is air between the filter and the nozzle.

  In particular, in the head having a structure in which air tends to remain under the filter as in the present embodiment, it is difficult to fill the space between the filter and the nozzle with the distribution ink, so that the embodiment of the present embodiment is effective.

  However, since the face surface is capped, ink does not leak to the outside of the head, but there is a risk that the distribution ink may ooze out from the nozzle due to an environmental change during distribution or an impact such as dropping.

  FIG. 8 shows an embodiment for preventing ink sagging from the face surface.

  FIG. 8 is a diagram schematically showing the fitting with the ink jet head 201. FIG. 8A shows a physical distribution (cap fitting) state where ink droplets 209a are attached to the face surface.

  Usually, the head face surface and the water absorbing resin 212c of the cap have a certain gap. This is because the positional relationship between the head 201 and the cap 212a has a tolerance with each fitting portion. In designing the cap, in consideration of this tolerance, the crushing amount of the tip rib of the cap rubber 212b and the gap between the face surface and the water-absorbing resin 212c are determined to ensure the sealing performance of the cap. Normally, the face surface and the water-absorbing resin are not touched during distribution. This is because the face surface is usually water-repellent, and when the water-absorbing resin is touched during distribution, the face surface is always immersed in the distribution ink and may cause deterioration of water repellency. Furthermore, there is a risk of causing damage to the face surface in addition to the influence of the eluate from the water-absorbing resin 212c and the risk of adhesion of dust and the like. Further, a protrusion (212d in FIG. 6) for fixing the water absorbing resin 212c is provided on the cap rubber 212b. The protrusion 212d does not affect the sealing performance by affecting the crush of the cap rubber end rib. It is necessary to set a certain distance from the cap tip rib.

  For the above reason, the head face surface and the water absorbing resin 212c of the cap have a certain gap. Further, there is a risk that the distribution ink may ooze out from the nozzle due to the environmental change during the distribution described above or an impact such as dropping.

  FIG. 8A is a diagram showing a case where the distribution ink oozes out and the ink droplet 209a adheres to the face surface, and the ink droplet 209a may have a size corresponding to the gap between the maximum face surface and the water absorbent resin 212c. .

  If the cap is removed in this state, the ink droplets 209a remain on the face surface, and the ink droplets 209a may coalesce and become larger when the head is handled such as when the main body is mounted, and may drop from the face surface.

  However, in this embodiment, when the cap is removed, the head face surface and the water absorbing resin 212c of the cap are closer to each other than the cap as shown in FIG. 8B, so that a large ink droplet 209a on the face surface is absorbed by the water absorbing resin. Since the ink is sucked into 212c, large ink droplets disappear on the face surface.

  As a result, there are no large ink droplets after the cap is removed, so that the ink droplets do not drip from the face surface when the head is handled such as when the main body is mounted.

1 is a perspective view illustrating a schematic configuration of an ink jet recording apparatus according to an embodiment of the present invention. It is a figure for demonstrating the ink supply path | route of the inkjet recording device shown in FIG. It is the external view which looked at the inkjet head shown in FIG. 2 from diagonally lower side. It is the external view which looked at the inkjet head shown in FIG. 2 from diagonally upper side. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a head longitudinal sectional view showing a storage form of an inkjet head as a first embodiment of the present invention. It is a figure for demonstrating the cap unit of FIG. 5, (A) is the top view which looked at the side joined with a face surface, (B) is the sectional view on the AA line of (A), (C) is ( A) A side view in the direction of the middle arrow C is shown. It is the fragmentary sectional view seen from the side surface of the inkjet head with which the cap unit of FIG. 6 was mounted | worn. It is a head longitudinal cross-sectional view which shows operation | movement of the cap of this invention.

Explanation of symbols

201 Inkjet head 201a Connector insertion port 201b Sub tank part 201c Filter 201d Opening part 201e Partition part 201f Liquid chamber 201g Nozzle 201h Elastic member 201i Pressure adjustment chamber 202 Carriage 203 Transport roller 204 Main tank 204b, 204c Rubber stopper 205 Ink supply unit 205a Ink supply Needle 205b Air introduction needle 205f Buffer chamber 205g Air communication port 206 Ink supply tube 207 Recovery unit 209 Ink 209a Ink droplet 210 Nozzle outlet 211 Joint rubber 212 Cap unit 212a Protective cap 212b Cap rubber 212c Water absorbing resin 213 Protective cap positioning boss 214 Positioning guide 215, 216 Hook 217, 218 Part 219 clip portion A sheet conveying direction B carriage moving direction

Claims (3)

  An ink jet head that performs recording by discharging recording droplets from an opening of a nozzle, and is a cap unit that can be attached to and detached from a surface on which the nozzle opening is formed, wherein the nozzle opening of the ink jet head is formed. A protective member that protects the surface of the nozzle, an elastic cap that is fixed to the protective member and covers the area of the nozzle in close contact with the surface on which the nozzle opening is formed, and a liquid absorber disposed in the elastic cap A cap unit comprising a member, wherein when the cap unit is attached / detached, the liquid absorbing member is once closer to a surface on which the nozzle opening is formed than when the cap is attached.   2. The cap according to claim 1, wherein in a state in which the cap unit is mounted on the inkjet head, the liquid absorbing member is disposed so as to be in non-contact with a surface on which the nozzle opening is formed. unit.   The protective member is provided with a positioning portion that can be positioned with respect to the inkjet head and a clip-shaped engagement portion that is once expanded and hooked to the inkjet head. Cap unit as described.

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