Patent Description:
In the related art, a liquid discharge apparatus includes a liquid discharge head having a nozzle face on which a nozzle is disposed, a cap to cover and moisturize the nozzle face, and a wiper to wipe the nozzle face, to recover the state of the nozzle of the liquid discharge head.

However, the liquid discharge apparatus including the cap and the wiper may increase the size of the apparatus. For example, <CIT> discloses a head cleaning jig which is detachably attachable to a receiver of the liquid discharge apparatus instead of a platen that holds a cloth. The head cleaning jig includes a first cleaner and a second cleaner that contact the head. The head cleaning jig disclosed in <CIT> may not sufficiently maintain and recover the state of the nozzle of the liquid discharge head.

Document <CIT> discloses an ink-jet recording apparatus including a brush, a suction unit, and a wiper. The brush brushes off matters adhering to an ink ejection face of an ink-jet head. The suction unit sucks the matters brushed off by the brush.

Document <CIT> discloses a wiper unit comprising a wiper holder a driving mechanism which moves the wiper holder.

The present disclosure has an object to provide a head maintenance device that can maintain and recover the state of a nozzle of a liquid discharge head.

Embodiments of the present disclosure describe an improved head maintenance device that includes a housing, a wiper, and a cap. The housing is detachably attachable to a conveyor of a liquid discharge apparatus. The conveyor conveys a medium in one direction. The wiper is disposed in the housing to wipe a nozzle face of a liquid discharge head of the liquid discharge apparatus. The cap is disposed in the housing to cover nozzles arrayed on the nozzle face of the liquid discharge head in the one direction.

As a result, according to one aspect of the present disclosure, the state of the nozzle of the liquid discharge head can be maintained and recovered.

Embodiments of the present disclosure are described below with reference to the drawings. In the drawings, like reference signs denote like elements, and overlapping description may be simplified or omitted as appropriate. In the following description, a liquid discharge apparatus according to an embodiment of the present disclosure discharges a liquid onto a cloth as a recording medium.

<FIG> is a perspective view of a liquid discharge apparatus <NUM> according to an embodiment of the present disclosure, with covers closed, and <FIG> is a plan view thereof. <FIG> is a perspective view of the liquid discharge apparatus <NUM> with the covers open, and <FIG> is a plan view thereof. X directions in <FIG> are the front-rear direction, sub-scanning direction, and recording-medium conveyance direction of the liquid discharge apparatus <NUM> (i.e., one direction). Y directions in <FIG> are the lateral direction and main scanning direction of the liquid discharge apparatus <NUM> (i.e., another direction intersecting the one direction). Z directions in <FIG> are the vertical directions of the liquid discharge apparatus <NUM>. The X directions and the Y directions are parallel to a surface, onto which a liquid is discharged, of a recording medium on a platen <NUM>, but may have some error. The X, Y, and Z directions are orthogonal to each other.

As illustrated in <FIG>, the liquid discharge apparatus <NUM> includes the platen <NUM> in front of a housing <NUM>. The platen <NUM> is attached onto a stage <NUM> mounted on a guide rail <NUM>. The platen <NUM> is detachably attachable to the stage <NUM>. The stage <NUM> is a conveyor that conveys the recording medium to a liquid discharge position of the liquid discharge apparatus <NUM> via the platen <NUM>. The guide rail <NUM> extends in the X directions. A control panel <NUM> is disposed on the front face of the housing <NUM>. An ink cartridge <NUM> is detachably attached to a side face of the housing <NUM>. A front cover <NUM> and a rear cover <NUM> as covers are disposed over the housing <NUM>.

The platen <NUM> has a flat upper face on which the recording medium is placed. The upper face of the platen <NUM> is parallel to the X directions and the Y directions. The platen <NUM> moves on the guide rail <NUM> to reciprocate in both the X directions. The platen <NUM> is movable up and down in the Z directions. Thus, the height of the recording medium placed on the platen <NUM> is adjustable.

The front cover <NUM> and the rear cover <NUM> are movable in both the X directions. In <FIG>, the front cover <NUM> has been moved backward and the rear cover <NUM> has been moved forward to close the front cover <NUM> and the rear cover <NUM> (i.e., a closed position). On the other hand, in <FIG>, the front cover <NUM> is moved forward and the rear cover <NUM> is moved backward to open the front cover <NUM> and the rear cover <NUM> (i.e., an open position). As described above, the front cover <NUM> and the rear cover <NUM> are slidably opened and closed. As a result, an occupied space of the liquid discharge apparatus <NUM> including an opening and closing space of each of the front cover <NUM> and the rear cover <NUM> can be reduced as compared with a configuration in which a front cover and a rear cover are opened and closed in the vertical direction. The front cover <NUM> and the rear cover <NUM> have openings at both ends in the front-rear direction. When the front cover <NUM> and the rear cover <NUM> are closed, the front cover <NUM> and the rear cover <NUM> are continuously arranged in the front-rear direction.

As illustrated in <FIG>, an apparatus body <NUM> of the liquid discharge apparatus <NUM> includes, for example, the housing <NUM> and liquid discharge units 9A and 9B mounted on the housing <NUM>. In the present embodiment, specifically, the apparatus body <NUM> is a portion of the liquid discharge apparatus <NUM> other than the front cover <NUM> and the rear cover <NUM>. The front cover <NUM> and the rear cover <NUM> are slidable in the X directions relative to the apparatus body <NUM>.

The front cover <NUM> and the rear cover <NUM> are opened to expose the liquid discharge units 9A and 9B to the outside of the liquid discharge apparatus <NUM>. When the liquid discharge units 9A and 9B are exposed to the outside, an operator can clean a liquid discharge head and the surrounding thereof, or can replace a carriage. The front cover <NUM> and the rear cover <NUM> are closed during image formation. As a result, the liquid discharge units 9A and 9B are covered by the front cover <NUM> and the rear cover <NUM> to block access to operation units such as carriages of the liquid discharge units 9A and 9B from the outside. The liquid discharge units 9A and 9B are disposed in the closed space in the front cover <NUM> or the rear cover <NUM>. Accordingly, a mist of ink (liquid) is prevented from scattering to environs outside the liquid discharge apparatus <NUM> while the liquid discharge head discharges the ink to the recording medium (i.e., during liquid discharge operation). Further, the liquid discharge units 9A and 9B may include a fan to circulate airflow in the front cover <NUM> or the rear cover <NUM> to collect the generated mist of the ink (i.e., ink mist) in the front cover <NUM> or the rear cover <NUM>.

The liquid discharge apparatus <NUM> according to the present embodiment includes the two liquid discharge units 9A and 9B arranged side by side in the X directions. The liquid discharge unit 9A discharges color ink and white ink. The liquid discharge unit 9B discharges a pretreatment liquid. The liquid discharged by each of the liquid discharge units 9A and 9B is not limited to the above example, and any liquid of the color ink, the white ink, and the pretreatment liquid may be discharged by each of the liquid discharge units 9A and 9B. In particular, when the recording medium is a fabric, the pretreatment liquid is preferably applied to the recording medium before the image formation using the ink. In other words, one of the liquid discharge units 9A and 9B preferably discharges the pretreatment liquid.

Since the liquid discharge units 9A and 9B have similar configurations, the liquid discharge unit 9A is described below. The liquid discharge unit 9A includes a carriage 10A, a guide rod <NUM>, and an electrical component unit <NUM> including, for example, a board and an electrical component cover. A position facing the carriage 10A or a carriage 10B in the X directions is referred to as a liquid discharge position where the liquid is discharged onto the recording medium on the platen <NUM>. The liquid discharge units 9A and 9B and the carriages 10A and 10B are also referred to simply as a liquid discharge unit <NUM> and a carriage <NUM>, respectively, unless distinguished.

The guide rod <NUM> extends in the main scanning direction. The carriage <NUM> is movable in the main scanning direction along the guide rod <NUM>. The carriage <NUM> includes multiple liquid discharge heads.

The process of forming an image on the recording medium by the liquid discharge head is described below.

The recording medium is placed on the platen <NUM> and conveyed along the guide rail <NUM>. The recording medium is conveyed to a rear side of the liquid discharge apparatus <NUM>, and the pretreatment liquid is applied to the recording medium by the liquid discharge unit 9B. Specifically, while the carriage 10B moves in the main scanning direction along the guide rod <NUM>, the liquid discharge unit 9B discharges the pretreatment liquid from the nozzles of the liquid discharge head to apply the pretreatment liquid to the entire width of the recording medium in the main scanning direction. The application of the pretreatment liquid is repeated at multiple positions in the sub-scanning direction. Thus, the pretreatment liquid is applied to the entire recording medium. After that, the platen <NUM> moves forward, and the liquid discharge unit 9A discharges the color ink of multiple colors onto the recording medium using a method similar to that of the liquid discharge unit 9B. When white color is printed on the recording medium, for example, the liquid discharge unit 9A discharges the white ink onto the recording medium, the platen <NUM> moves to the rear side of the liquid discharge unit 9A again, and the liquid discharge unit 9A discharges the color ink onto the recording medium. Thus, an image is formed on the recording medium.

As illustrated in <FIG>, the carriage <NUM> may include multiple liquid discharge heads 20A and 20B. The multiple liquid discharge heads 20A and 20B may collectively be referred to as liquid discharge heads <NUM>, each of which may referred to as a liquid discharge head <NUM> unless distinguished. In this case, for example, the pretreatment liquid is discharged by the liquid discharge head 20A, and the white or the color ink is discharged by the liquid discharge head 20B.

As illustrated in <FIG>, the liquid discharge head <NUM> according to the present embodiment includes a head cover <NUM> attached to the peripheral area of a nozzle face 20a. The head cover <NUM> is disposed around the entire nozzle face 20a (see <FIG>). The nozzle face 20a is a surface of the liquid discharge head <NUM> facing the recording medium. An opening end of the nozzle is formed on the nozzle face 20a.

A head maintenance device according to an embodiment of the present disclosure is described below with reference to <FIG> and <FIG>. The head maintenance device maintains and recovers the state of the liquid discharge head <NUM> of the liquid discharge apparatus <NUM>.

As illustrated in <FIG> and <FIG>, a head maintenance device <NUM> includes a housing <NUM>, a first absorber <NUM>, a second absorber <NUM>, and a cap <NUM>. The X, Y, and Z directions illustrated in <FIG> indicate the orientation of the head maintenance device <NUM> attached to the liquid discharge apparatus <NUM> described above. The first absorber <NUM> and the second absorber <NUM> are non-windable wipers secured on the housing <NUM>, and in the present embodiment, are sponges made of polyethylene. The first absorber <NUM> and the second absorber <NUM> may be made of urethane, but not limited thereto.

Bosses of the first absorber <NUM> and the second absorber <NUM> are fitted into holes of the housing <NUM>. Alternatively, holes of the first absorber <NUM> and the second absorber <NUM> are fitted onto bosses of the housing <NUM>. The first absorber <NUM> extends in the X directions, and the second absorber <NUM> extends in the Y directions. The first absorber <NUM> and the second absorber <NUM> move in the X directions or the Y directions relative to the liquid discharge head <NUM> while contacting the liquid discharge head <NUM> to wipe the liquid discharge head <NUM>. The first absorber <NUM> and the second absorber <NUM> are replaced with new ones at an appropriate point in time because the wiping performance of the first absorber <NUM> and the second absorber <NUM> deteriorates due to repeated use. At this time, the fitting of the first absorber <NUM> and the second absorber <NUM> to the housing <NUM> by the bosses and the holes facilitates the replacement of the first absorber <NUM> and the second absorber <NUM>.

The cap <NUM> is open upward in <FIG> and can cover and seal the nozzle face 20a of the liquid discharge head <NUM>. The cap <NUM> filled with a cleaning liquid is kept covering the nozzle face 20a for a predetermined length of time to dissolve the thickened ink in the nozzle of the liquid discharge head <NUM>. Thus, the clogging of the nozzle can be eliminated. Further, the cap <NUM> retains the moisture inside the nozzle. The same number of caps <NUM> are preferably provided for the liquid discharge heads <NUM> mounted on the carriage <NUM>, but the cap <NUM> may move multiple times to cover all of the liquid discharge heads <NUM>. In <FIG>, multiple caps <NUM> are arrayed in the Y directions, and each of the multiple caps <NUM> extends in the X directions.

As illustrated in <FIG>, the multiple caps <NUM> and the second absorber <NUM> are arranged along the transverse side of the housing <NUM> in the transverse direction, which is the movement direction of the housing <NUM> relative to the nozzle face 20a of the liquid discharge head <NUM> by the stage <NUM> (i.e., the X directions). The second absorber <NUM> overlaps with the multiple caps (at least one of the multiple caps <NUM>) in the Y directions. Accordingly, the multiple caps <NUM> can cover the nozzles arrayed on the nozzle face 20a immediately after the second absorber <NUM> wipes the nozzle face 20a, or the second absorber <NUM> can wipe the nozzle face 20a immediately after the the multiple caps <NUM> separate the nozzle face 20a.

The multiple caps <NUM> are disposed at one end of the longitudinal side of the housing <NUM> in the Y directions, and the first absorber <NUM> is disposed at the other end of the longitudinal side of the housing <NUM> in the Y directions. The longitudinal side of the housing <NUM> is parallel to the second absorber <NUM>. Thus, the first absorber <NUM>, the second absorber <NUM>, and the multiple caps <NUM> can be compactly arranged in the housing <NUM>.

The head maintenance device <NUM> attached to the liquid discharge apparatus <NUM> is described below with reference to <FIG> and <FIG>.

As illustrated in <FIG> and <FIG>, the head maintenance device <NUM> according to the present embodiment is attached onto the stage <NUM> instead of the platen <NUM> (see <FIG>). The stage <NUM> moves on the guide rail <NUM> to move the head maintenance device <NUM> to the liquid discharge position of each of the liquid discharge heads 20A and 20B. The stage <NUM> moves up and down to adjust the relative positions of the liquid discharge head <NUM> and the head maintenance device <NUM> in the vertical direction.

The head maintenance device <NUM> includes a positioning pin <NUM> as a positioner illustrated in <FIG>. As illustrated in <FIG>, the positioning pin <NUM> is fitted into a fitting hole 10a on the bottom face of the carriage <NUM> to position the head maintenance device <NUM> relative to the carriage <NUM>. Accordingly, the liquid discharge head <NUM> can be positioned relative to absorbers (e.g., a first absorber <NUM> and a second absorber <NUM>) and caps (e.g., caps <NUM>) of the head maintenance device <NUM>. For example, when the liquid discharge apparatus <NUM> and the head maintenance device <NUM> are shipped from a factory, the positioning pin <NUM> is fitted into the fitting hole 10a, and the position of the head maintenance device <NUM> relative to the carriage <NUM> is stored in the liquid discharge apparatus <NUM>. Accordingly, when the head maintenance device <NUM> is used after shipment, the head maintenance device <NUM> can be accurately positioned relative to the liquid discharge head <NUM>. In particular, in the case of a large liquid discharge apparatus <NUM>, the absolute value of the positional error between the liquid discharge head <NUM> and the head maintenance device <NUM> is likely to be large, but the configuration according to the present embodiment can position the head maintenance device <NUM> relative to the liquid discharge head <NUM> with high accuracy.

The first absorber <NUM> and the second absorber <NUM> wiping the liquid discharge head <NUM> are described below.

The stage <NUM> moves on the guide rail <NUM> (see <FIG>), and the carriage <NUM> (see <FIG>) moves in the main scanning direction to cause the head maintenance device <NUM> to face the carriage <NUM>. Then, the stage <NUM> moves upward to bring the first absorber <NUM> or the second absorber <NUM> into contact with the liquid discharge head <NUM>.

<FIG> are diagrams each illustrating the liquid discharge head <NUM> which is wiped by the first absorber <NUM> or the second absorber <NUM> as viewed from the bottom face side of the carriage <NUM>.

As illustrated in <FIG>, as the stage <NUM> reciprocally moves in the X directions, the first absorber <NUM> reciprocates in the X directions between the liquid discharge heads <NUM> while contacting the liquid discharge heads <NUM>. Thus, the first absorber <NUM> can wipe the peripheral area of the head cover <NUM> extending in the X directions. The first absorber <NUM> reciprocates twice at five positions in total including three positions between the liquid discharge heads <NUM>, the left side of the leftmost liquid discharge head <NUM> in <FIG>, and the right side of the rightmost liquid discharge head <NUM> in <FIG>. Thus, the first absorber <NUM> reciprocates ten times in total to wipe the peripheral area extending in the X directions of all the liquid discharge heads <NUM>.

As illustrated in <FIG>, the second absorber <NUM> contacts one end of the liquid discharge heads <NUM> in the X directions. As the stage <NUM> moves, the second absorber <NUM> moves in one of the X directions while contacting the liquid discharge heads <NUM>. Accordingly, the second absorber <NUM> can wipe the entire bottom faces of the liquid discharge heads <NUM> including the nozzle faces 20a of the liquid discharge heads <NUM> in one wiping.

Further, as illustrated in <FIG>, the second absorber <NUM> contacts one end or the other end of the liquid discharge heads <NUM> in the X directions. As the carriage <NUM> moves along the guide rod <NUM> (see <FIG>), the second absorber <NUM> moves in the Y directions relative to the liquid discharge heads <NUM> while contacting the one end or the other end of the liquid discharge heads <NUM>. Specifically, the second absorber <NUM> reciprocates in the Y directions four times at the one end or the other end of the liquid discharge heads <NUM> in the X directions. Thus, the second absorber <NUM> can wipe the peripheral area of the head cover <NUM> extending in the Y directions.

The liquid discharge heads <NUM> can be wiped by the first absorber <NUM> and the second absorber <NUM> by the above operations. The movement of the stage <NUM> in the X directions and the movement of the carriage <NUM> in the Y directions cause the first absorber <NUM> or the second absorber <NUM> to contact the liquid discharge heads <NUM> and reciprocally move relative to the liquid discharge heads <NUM> as described above.

The head maintenance device <NUM> is arranged at a predetermined position relative to the carriage <NUM> by the movement of the stage <NUM> or the movement of the carriage <NUM> so that the caps <NUM> (see <FIG>) face the liquid discharge heads <NUM>. Under these conditions, the stage <NUM> moves upward to cause the caps <NUM> to cover the nozzle faces 20a of the liquid discharge heads <NUM>. Thus, the clogging of the nozzles of the liquid discharge head <NUM> can be eliminated as described above.

As described above, in the present embodiment, due to such a configuration in which the head maintenance device <NUM> is attached to the stage <NUM>, a head maintenance device is not necessarily accommodated in the liquid discharge apparatus <NUM>, so that the liquid discharge apparatus <NUM> can be downsized. The head maintenance device <NUM> can perform the wiping operation of the liquid discharge heads <NUM> and the capping operation with respect to the nozzle faces 20a of the liquid discharge heads <NUM>. Accordingly, the nozzles of the liquid discharge head <NUM> can be maintained and recovered by one head maintenance device <NUM>. In addition, due to such a configuration in which the head maintenance device <NUM> is attached to the stage <NUM>, the wiping operation and the capping operation described above can be performed using the movement of the stage <NUM> in the X directions and the movement of the carriage <NUM> in the Y directions. Accordingly, the nozzles of the liquid discharge head <NUM> can be maintained and recovered without another driving mechanism.

A head maintenance device <NUM> according to a modification of the present embodiment is described below.

The head maintenance device <NUM> illustrated in <FIG> is different in that a web unit <NUM> including a windable web <NUM> is provided instead of the above-described absorbers (e.g., the first absorber <NUM> and the second absorber <NUM>).

As illustrated in <FIG>, the web unit <NUM> includes the web <NUM> as a wiper, a feed roller <NUM>, a take-up roller <NUM>, guide rollers <NUM> and <NUM>, a pressing member <NUM>, a spring <NUM>, a drive motor <NUM>, and a transmission mechanism <NUM>. The web <NUM> is wound around the outer circumferential surface of the feed roller <NUM> to form a roll 51A of the web <NUM> to be fed. The web <NUM> is wound around the outer circumferential surface of the take-up roller <NUM> to form a roll 51B of the wound web <NUM>. The web <NUM> is fed in the direction indicated by arrow A. In <FIG>, the illustration of the head cover <NUM> of the liquid discharge head <NUM> is omitted. The feed roller <NUM>, the take-up roller <NUM>, and the guide rollers <NUM> and <NUM> are rotatably attached to side plates <NUM> (see <FIG>) in the housing <NUM> (see <FIG>) of the head maintenance device <NUM>. The upper portion of the web unit <NUM> in <FIG> corresponds to the web unit <NUM> illustrated in <FIG>, and the lower portion of the web unit <NUM> in <FIG> is accommodated in the housing <NUM> of the head maintenance device <NUM>. In other words, the lower portion of the web unit <NUM> is covered by the housing <NUM> in <FIG>.

The spring <NUM> presses the pressing member <NUM> between the guide rollers <NUM> and <NUM> to cause the pressing member <NUM> to press the web <NUM> against the nozzle face 20a to be wiped. The portion of the web <NUM> pressed against the nozzle face 20a by the pressing member <NUM> is a wiping portion 51a of the web <NUM>.

Preferably, the web <NUM> is a sheet-shaped material that has absorbency and liquid resistance, at least, against the liquid to be used and does not cause fuzz and dust. Examples of such materials include, but are not limited to, nonwoven fabric, cloth, film, and paper.

The driving force of the drive motor <NUM> is transmitted to the take-up roller <NUM> via the transmission mechanism <NUM>. The take-up roller <NUM> is rotated by the driving force of the drive motor <NUM> to wind and convey the web <NUM> in the direction indicated by arrow A.

A code wheel <NUM> is attached to the guide roller <NUM>, and an encoder sensor <NUM> including a transmissive photosensor detects a pattern formed on the code wheel <NUM>. The code wheel <NUM> and the encoder sensor <NUM> together serve as an encoder <NUM> that detects the distance of movement (feed amount) of the web <NUM>. When the end state (i.e., depletion) of the web <NUM> is detected by the encoder <NUM> based on the feed amount, the web <NUM> is replaced with a new one.

As illustrated in <FIG>, the stage <NUM> reciprocally moves in the X directions at multiple positions in the Y directions while the wiping portion 51a of the web <NUM> is pressed against the liquid discharge head <NUM> to wipe the entire nozzle face 20a and the head cover <NUM>. In addition, the caps <NUM> can perform the capping operation with respect to the nozzle face 20a of the liquid discharge head <NUM>. As described above, the nozzles of the liquid discharge head <NUM> can be maintained and recovered by the head maintenance device <NUM> according to the present embodiment. Further, the web unit <NUM> may include an absorber in addition to the web <NUM>.

In the present disclosure, the liquid to be discharged is not limited to a particular liquid as long as the liquid has a viscosity or surface tension to be discharged from a head (liquid discharge head). However, preferably, the viscosity of the liquid is not greater than <NUM> millipascal-second (mPa·s) under ordinary temperature and ordinary pressure or by heating or cooling. Examples of the liquid to be discharged include a solution, a suspension, or an emulsion including, for example, a solvent, such as water or an organic solvent; a colorant, such as dye or pigment; a functional material, such as a polymerizable compound, a resin, or a surfactant; a biocompatible material, such as deoxyribonucleic acid (DNA), amino acid, protein, or calcium; and an edible material, such as a natural colorant. Such a solution, a suspension, or an emulsion can be used for, e.g., inkjet ink; surface treatment liquid; a liquid for forming an electronic element component, a light-emitting element component, or an electronic circuit resist pattern; or a material solution for three-dimensional fabrication.

The term "liquid" includes not only ink but also paint, a pretreatment liquid, a binder, and an overcoat liquid.

In the present disclosure, the term "liquid discharge apparatus" includes a carriage including a liquid discharge head and drives the liquid discharge head to discharge liquid. The term "liquid discharge apparatus" used in the present disclosure includes, in addition to apparatuses to discharge liquid to a recording medium serving as a medium onto which liquid can adhere, apparatuses to discharge the liquid into gas (air) or liquid.

For example, the "liquid discharge apparatus" may further include devices relating to feeding, conveying, and ejecting of the medium onto which liquid can adhere and also include a pretreatment device and an aftertreatment device.

The "liquid discharge apparatus" may be, for example, an image forming apparatus to form an image on a sheet by discharging ink, or a three-dimensional fabrication apparatus to discharge fabrication liquid to a powder layer in which powder material is formed in layers to form a three-dimensional object.

The "liquid discharge apparatus" is not limited to an apparatus that discharges liquid to visualize meaningful images such as characters or figures. For example, the liquid discharge apparatus may be an apparatus that forms patterns having no meaning or an apparatus that fabricates three-dimensional images.

The above-described term "medium onto which liquid can adhere" represents a medium on which liquid is at least temporarily adhered, a medium on which liquid is adhered and fixed, or a medium into which liquid adheres and permeates. Specific examples of the "medium onto which liquid can adhere" include, but are not limited to, a recording medium such as a paper sheet, recording paper, a recording sheet of paper, a film, or cloth, an electronic component such as an electronic substrate or a piezoelectric element, and a medium such as layered powder, an organ model, or a testing cell. The "medium onto which liquid can adhere" includes any material to which liquid adheres, unless otherwise specified.

Examples of materials of the "medium onto which liquid can adhere" include any materials to which liquid can adhere even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, and ceramic.

The term "liquid discharge apparatus" may be an apparatus in which the liquid discharge head and the medium onto which liquid can adhere move relative to each other. However, the liquid discharge apparatus is not limited to such an apparatus. For example, the liquid discharge apparatus may be a serial head apparatus that moves the liquid discharge head or a line head apparatus that does not move the liquid discharge head.

Examples of the liquid discharge apparatus further include: a treatment liquid applying apparatus that discharges a treatment liquid onto a sheet to apply the treatment liquid to the surface of the sheet, for reforming the surface of the sheet; and an injection granulation apparatus that injects a composition liquid, in which a raw material is dispersed in a solution, through a nozzle to granulate fine particle of the raw material.

Claim 1:
A head maintenance device (<NUM>) for use in a liquid discharge apparatus (<NUM>) having a conveyor (<NUM>) to convey a medium in one direction, the head maintenance device (<NUM>) comprising:
a housing (<NUM>) ;
a wiper (<NUM>) in the housing (<NUM>) to wipe a nozzle face (20a) of a liquid discharge head (<NUM>) of the liquid discharge apparatus (<NUM>); and
a cap (<NUM>) in the housing (<NUM>) to cover nozzles arrayed on the nozzle face (20a) of the liquid discharge head (<NUM>) in the one direction, characterized in that
the housing (<NUM>) is detachably attachable to the conveyor (<NUM>).