Patent Description:
PTL <NUM> discloses an automatic drawing apparatus that includes a spray gun head unit, an X-direction driver, a Y-direction driver, and a Z-direction driver. The spray gun head unit holds a plurality of spray gun heads that is movable along a Z-axis. The X-direction driver drives the spray gun head unit along a horizontal X-axis. The Y-direction driver drives the spray gun head unit along a vertical Y-axis. The Z-axis is perpendicular to the X-axis and the Y-axis. Each of the spray gun heads discharges ink. The Z-direction driver individually drives each spray gun head of the spray gun head unit based on setting data and measurement data related to a distance between the spray gun head and an object to which the ink is applied.

PTL <NUM> discloses:In a print head support assembly for carrying a number of print heads and for positioning the number of print heads, the print head support assembly comprises a carriage plate provided with reference elements for positioning the number of print heads, the carriage plate being further provided with at least four support positions and a support sub-assembly provided with at least four adjustable mounting points for coupling to said at least four support positions and for supporting the carriage plate at said at least four support positions. The support sub-assembly is configured to constrain the carriage plate in six degrees of freedom with respect to a position of the carriage plate and to constrain the carriage plate in at least one degree of freedom with respect to a shape of the carriage plate. Thus, a light-weight and compliant carriage plate may be used to provide for a light-weight carriage suitable for high-speed printing.

In the above-described automatic drawing apparatus, when the spay gun head is about to collide with a projection or the like of the object to which the ink is applied while drawing on the object, it is necessary to move the spray gun head unit away from the object to avoid the collision. At this time, if the entire spray gun head unit is moved away from the object, it takes a long time to move the spray gun head unit, and the above-described collision may be not avoided.

An object of the present invention is to provide a liquid discharge apparatus that can quickly move a liquid discharge head away from the object.

Embodiments of the present invention describe an improved liquid discharge apparatus that includes a carriage, a liquid discharge head having a discharge port, a first driver, and a second driver. The carriage is movable along at least one of a first axis and a second axis intersecting the first axis. The liquid discharge head is held by the carriage and discharges a liquid from the discharge port toward an object in a direction along a third axis intersecting the first axis and the second axis. The first driver moves the carriage along the third axis. The second driver moves the liquid discharge head along the third axis relative to the carriage.

According to the present invention, the liquid discharge apparatus can be provided that can quickly move the liquid discharge head away from the object.

In addition, identical or similar reference numerals designate identical or similar components throughout the several views.

However, the invention of this specification is not intended to be limited to the specific terminology so selected.

It is to be noted that the suffixes Y, M, C, K, W, and S attached to each reference numeral indicate only that components indicated thereby are used for forming yellow, magenta, cyan, and black images, respectively, and hereinafter may be omitted when color discrimination is not necessary.

Embodiments of the present disclosure are described below with reference to the drawings.

<FIG> are schematic views illustrating an overall configuration of a liquid discharge apparatus <NUM> according to an embodiment of the present disclosure. <FIG> is a side view, and <FIG> is a plan view of the liquid discharge apparatus <NUM>.

The liquid discharge apparatus <NUM> is installed so as to face an object <NUM> on which images are drawn. The liquid discharge apparatus <NUM> includes a carriage <NUM> on which a head <NUM> is mounted. The head <NUM> discharges ink, which is as an example of a liquid, toward the object <NUM>. The carriage <NUM> is held by a Z-axis rail <NUM> and movable along a Z-axis. The head <NUM> is an example of a liquid discharge head.

The Z-axis rail <NUM> is held by an X-axis rail <NUM> and movable along an X-axis, and the X-axis rail <NUM> is held by a Y-axis rail <NUM> and movable along a Y-axis. Here, the X-axis is an example of a "first axis", the Y-axis is an example of a "second axis intersecting the first axis", and the Z-axis is an example of a "third axis intersecting the first axis and the second axis. " The carriage <NUM> is an example of a "liquid discharger.

Further, the liquid discharge apparatus <NUM> includes a first Z-direction driver <NUM> and an X-direction driver <NUM>. The first Z-direction driver <NUM> moves the carriage <NUM> along the Z-axis along the Z-axis rail <NUM>. The X-direction driver <NUM> moves the Z-axis rail <NUM> along the X-axis along the X-axis rail <NUM>. The liquid discharge apparatus <NUM> further includes a Y-direction driver <NUM> that moves the X-axis rail <NUM> along the Y-axis along the Y-axis rail <NUM>. The first Z-direction driver <NUM> is an example of a "first driver" and moves the carriage <NUM> along the Z-axis intersecting the X-axis and the Y-axis.

The liquid discharge apparatus <NUM> further includes a second Z-direction driver <NUM> mounted on the carriage <NUM>. The second Z-direction driver <NUM> is an example of a "second driver" and moves the head <NUM> along the Z-axis relative to the carriage <NUM>. In the present embodiment, the term "move along the third axis intersecting the first axis and the second axis" is not limited to the case in which the carriage <NUM> and the head <NUM> are moved parallel to the Z-axis. The term "move along the third axis intersecting the first axis and the second axis" also includes the case in which the carriage <NUM> and the head <NUM> are moved in an oblique direction including at least a Z-axis component.

The liquid discharge apparatus <NUM> described above discharges ink from the head <NUM> toward the object <NUM> while moving the carriage <NUM> along the X-axis, the Y-axis, and the-Z axis, thereby drawing images on the object <NUM>. Although the object <NUM> illustrated in <FIG> has a flat plate shape, the object <NUM> may have a curved surface which is nearly vertical or a curved surface with the large radius of curvature, such as a surface of a car, a truck, or an aircraft.

<FIG> is a perspective view of the carriage <NUM> according to the present embodiment.

The carriage <NUM> is movable along the Z-axis along the Z-axis rail <NUM> by driving force of the first Z-direction driver <NUM>. The carriage <NUM> holds a head unit <NUM> including a head fixing plate <NUM> for attaching the head <NUM>. In the present embodiment, a head 300Y for yellow, a head <NUM> for magenta, a head 300C for cyan, a head <NUM> for black, a head 300W for white, and a head <NUM> for spot color are attached to the head fixing plate <NUM>. In the following description, these heads are also collectively referred to as "heads <NUM>" for convenience of explanation. In addition to the head <NUM>, the head unit <NUM> including the heads <NUM> also corresponds to an example of the "liquid discharge head.

Each of the heads <NUM> includes a nozzle face 302a having a plurality of nozzles <NUM> thereon. The nozzle <NUM> is an example of a "discharge port", and the nozzle face 302a is an example of a "liquid discharge surface. " Note that the types and number of colors of the inks used in the heads <NUM> are not limited to the above-described example. For example, all inks used in the heads <NUM> may be the same color.

The head <NUM> is secured to the head fixing plate <NUM> such that the nozzle face 302a intersects the horizontal plane and the plurality of nozzles <NUM> is obliquely arrayed with respect to the X-axis. Thus, the head <NUM> discharges ink from the nozzle <NUM> in a direction intersecting the direction of gravity.

Further, the carriage <NUM> includes a cleaning device to clean the head <NUM>. In the present embodiment, a wiper unit <NUM> is an example of the cleaning device. The configuration of the wiper unit <NUM> is described below.

<FIG> are perspective views of the wiper unit <NUM> according to the present embodiment. <FIG> is a perspective front view of the wiper unit <NUM>, and <FIG> is a perspective rear view of the wiper unit <NUM>.

As illustrated in <FIG>, the wiper unit <NUM> moves parallel to the X-axis along a pair of guide rails 9R secured to an upper portion and a lower portion of a frame <NUM>. The wiper unit <NUM> includes an ink receiving surface <NUM>, a wiper <NUM>, and a cleaning liquid supplier <NUM> as illustrated in <FIG>, and further includes a cleaning liquid collector <NUM> as illustrated in <FIG>.

The cleaning liquid supplier <NUM> is connected to a cleaning liquid supply tube and supplies a cleaning liquid supplied through the cleaning liquid supply tube, to the wiper <NUM> and the ink receiving surface <NUM> from above in the downward direction (negative Y-axis direction). The cleaning liquid collector <NUM> is disposed below the wiper <NUM> and the ink receiving surface <NUM> (on the negative side along the Y-axis), and collects ink and the cleaning liquid that has cleaned the wiper <NUM> and the ink receiving surface <NUM>. The cleaning liquid collector <NUM> is connected to a cleaning liquid collection tube, and the ink and the cleaning liquid accumulated in the cleaning liquid collector <NUM> are drained to the outside through the cleaning liquid collection tube.

As illustrated in <FIG>, a motor <NUM> is provided to move the wiper unit <NUM> along the X-axis, and sensors 17a and 17b are provided to detect the position of the wiper unit <NUM> on the X-axis. In the present embodiment, the sensor 17a detects that the wiper unit <NUM> is at a waiting position (home position), and the sensor 17b detects that the wiper unit <NUM> is at a moving end position (return position).

With the above configuration, the motor <NUM> transmits driving force to a belt <NUM> illustrated in <FIG> to move the wiper unit <NUM> coupled to the belt <NUM> along the X-axis along the guide rails 9R.

As the wiper unit <NUM> reaches a position facing the nozzle face 302a of the head <NUM>, the wiper <NUM> comes into contact with the nozzle face 302a. Further, the ink receiving surface <NUM> can receive ink discharged from the nozzle <NUM> in a recovery operation of ink discharge of the nozzle <NUM> (head <NUM>).

As the wiper unit <NUM> moves in the positive X-axis direction while the wiper unit <NUM> facing the nozzles <NUM>, the wiper <NUM> wipes and cleans the nozzle face 302a and the nozzles <NUM>.

As the wiper unit <NUM> further moves in the positive X-axis direction, the wiper <NUM> and the ink receiving surface <NUM> do not face the nozzle <NUM>. After the wiper unit <NUM> reaches the moving end position, the movement direction of the wiper unit <NUM> is switched to the negative X-axis direction, and the wiper unit <NUM> returns to the waiting position.

<FIG> is a perspective view of the carriage <NUM> according to the present embodiment. <FIG> illustrates a state in which the head <NUM> moves toward the object <NUM> in the positive Z-axis direction from a state illustrated in <FIG>.

The head <NUM> moves along the Z-axis between an ink discharge position illustrated in <FIG> at which ink is discharged toward the object <NUM> and a standby position illustrated in <FIG> at which the head <NUM> is away from the object <NUM> compared with the ink discharge position. The first Z-direction driver <NUM> includes a drive motor to move the carriage <NUM> along the Z-axis. The second Z-direction driver <NUM> includes a power cylinder to move the head <NUM> along Z-axis relative to the carriage <NUM>.

<FIG> is a perspective view of the second Z-direction driver <NUM> to move the head <NUM> along the Z-axis according to the present embodiment.

As described above, the second Z-direction driver <NUM> for driving the head unit <NUM> along the Z-axis relative to the carriage <NUM> includes the power cylinder. In the second Z-direction driver <NUM>, various types of the power cylinders such as a pneumatic type, an oil hydraulic type, a water hydraulic type, and an electric type can be used.

In the present embodiment, a pneumatic cylinder (air cylinder) is used. The air cylinder illustrated in <FIG> is a double-acting air cylinder and has two ports P1 and P2 to which air pressure is applied. The port P1 and the port P2 are connected to an air solenoid valve 93D.

For example, when the air solenoid valve 93D is turned off, air is supplied to the port P1 and air is discharged from the port P2, and the second Z-direction driver <NUM> moves a piston 93B in the positive Z-axis direction in which the piston 93B is pushed out with respect to a cylinder body 93A.

Contrary to the above-description, when the air solenoid valve 93D is turned on, air is supplied to the port P2 and air is discharged from the port P1, and the second Z-direction driver <NUM> moves the piston 93B in the negative Z-axis direction in which the piston 93B is pulled into the cylinder body 93A.

Thus, the second Z-direction driver <NUM> turns on and off the air solenoid valve 93D to switch between the air supply and air discharge of the ports P1 and P2, thereby switching the operation direction of the piston 93B.

The cylinder body 93A includes an attachment portion 93C for attaching the cylinder body 93A to a housing <NUM> of the carriage <NUM>. A support 70A that supports the head unit <NUM> holding the head <NUM> is provided at an end of the piston 93B.

With the above-described configuration, the second Z-direction driver <NUM> moves the piston 93B back and forth along the Z-axis based on an instruction from a controller <NUM> (see <FIG>). Thus, the head unit <NUM> moves along the Z-axis.

The second Z-direction driver <NUM> moves the head unit <NUM> along the Z-axis with a stroke length of about <NUM> at a moving speed of about <NUM>/s to <NUM>/s by the power cylinder. On the other hand, the first Z-direction driver <NUM> does not directly move the head unit <NUM> but moves the head unit <NUM> together with the carriage <NUM> along the Z-axis. As described above, the liquid discharge apparatus <NUM> includes the first Z-direction driver <NUM> that moves the entire carriage <NUM> and the second Z-direction driver <NUM> that moves the head unit <NUM> relative to the carriage <NUM>. Therefore, the first Z-direction driver <NUM> is not required to move the head unit <NUM> at a high speed, and thus, the second Z-direction driver <NUM> moves the head unit <NUM> along the Z-axis faster than the first Z-direction driver <NUM>.

The driving source of the second Z-direction driver <NUM> is not limited to the power cylinder. The second Z-direction driver <NUM> may include other types of actuators, such as a drive motor, that can urgently retract the head <NUM> when an abnormality occurs.

As illustrated in <FIG>, a left side wall plate <NUM> and a right side wall plate 7R, which are examples of the projection member, are disposed on the upstream side and the downstream side in the X-axis direction (on both sides along the X-axis) with respect to the nozzle face 302a of the head <NUM>, respectively. Each of the left side wall plate <NUM> and the right side wall plate 7R is swingable around one end thereof supported by a shaft of carriage <NUM> parallel to the Y-axis.

The other end (distal end) of each of the left side wall plate <NUM> and the right side wall plate 7R projects to the same position as a surface position of the nozzle face 302a or to a position closer to the object <NUM> than the surface position of the nozzle face 302a along the Z-axis. The left side wall plate <NUM> and the right side wall plate 7R serves as collision detection plates that detect a collision object with which the head unit <NUM> is about to collide when the head <NUM> discharges ink to the object <NUM>, and the operation thereof is described below.

<FIG> and <FIG> are schematic views for explaining the projection member according to the present embodiment. For example, when the carriage <NUM> moves in a direction indicated by arrow X1 as illustrated in <FIG>, if the right side wall plate 7R comes into contact with a collision object B as illustrated in <FIG>, the second Z-direction driver <NUM> described above operates based on an instruction from the controller <NUM> (see <FIG>).

The second Z-direction driver <NUM> moves the head unit <NUM> together with the piston 93B in the negative Z-axis direction, thereby avoiding a collision between the head unit <NUM> and the collision object B. Similarly, when the carriage <NUM> moves in a direction opposite to the direction indicated by arrow X1 in <FIG>, if the left side wall plate <NUM> comes into contact with a collision object, the second Z-direction driver <NUM> also operates to move the head unit <NUM> in the negative Z-axis direction, thereby avoiding a collision between the head unit <NUM> and the collision object.

At the time of abnormality as described above, the second Z-direction driver <NUM> moves the head <NUM> together with the head unit <NUM> in the negative Z-axis direction. Therefore, as compared with the case in which the entire carriage <NUM> is moved, the weight of components to be moved can be reduced, and the head <NUM> can be quickly moved.

<FIG> is a schematic view for explaining a contact member 7Z according to the present embodiment. The head unit <NUM> includes the contact member 7Z in front of the nozzle face 302a of the head <NUM> along the Z-axis so that the contact member 7Z can contact the object <NUM>.

The contact member 7Z is attached to the head unit <NUM>. The contact member 7Z is temporarily positioned in front of the nozzle face 302a to measure a distance between the object <NUM> and the nozzle face 302a before the head <NUM> starts discharging ink to the object <NUM>.

The head unit <NUM> to which the contact member 7Z is attached is connected to the controller <NUM> illustrated in <FIG> via the carriage <NUM>, and the controller <NUM> causes the first Z-direction driver <NUM> to move the carriage <NUM> along the Z-axis so that the head unit <NUM> approaches the object <NUM>. The controller <NUM> acquires data such as the movement amount and coordinate at the time when the contact member 7Z comes into contact with the surface of the object <NUM>, and stores the data in a storage unit <NUM>. The controller <NUM> repeats such an operation multiple times along the X-axis and Y-axis, and stores data of the surface shape of the object <NUM> in advance.

<FIG> is a block diagram of a portion related to movement control of the carriage <NUM> according to the present embodiment.

The liquid discharge apparatus <NUM> includes the carriage <NUM>, the head unit <NUM>, the left and right side wall plates (collision detection plates) <NUM> and 7R, the wiper unit <NUM>, the X-direction driver <NUM>, the Y-direction driver <NUM>, the first Z-direction driver <NUM>, the second Z-direction driver <NUM>, the controller <NUM>, the storage unit <NUM>, a display <NUM>, and a control panel <NUM>.

The carriage <NUM> is movable along the X-axis, Y-axis, and Z-axis with respect to the object <NUM>, and includes the head unit <NUM>, the left and right side wall plates (collision detection plates) <NUM> and 7R, the wiper unit <NUM>, and the second Z-direction driver <NUM>.

The head unit <NUM> is movable along the Z-axis relative to the carriage <NUM> and includes the head <NUM> that discharges ink toward the object <NUM>.

When the liquid discharge apparatus <NUM> performs the ink discharge of the head <NUM> or measures the position of the head unit <NUM> with respect to the object <NUM>, the left and right side wall plates (collision detection plates) <NUM> and 7R detect a contact (collision) with a collision object to avoid a collision between the head unit <NUM> and the object <NUM>. When detecting the contact (collision), the left and right side wall plates (collision detection plates) <NUM> and 7R transmit a detection signal indicating the contact (collision) to the controller <NUM>.

The wiper unit <NUM> cleans the head <NUM> based on an instruction from the controller <NUM>.

The X-direction driver <NUM> drives the carriage <NUM> along the X-axis based on an instruction from the controller <NUM>.

The Y-direction driver <NUM> drives the carriage <NUM> along the Y-axis based on an instruction from the controller <NUM>.

The first Z-direction driver <NUM> drives the carriage <NUM> along the Z-axis based on an instruction from the controller <NUM>.

The second Z-direction driver <NUM> drives the head unit <NUM> along the Z-axis relative to the carriage <NUM> based on an instruction from the controller <NUM>.

The controller <NUM> includes a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an interface (I/F). The CPU controls the entire liquid discharge apparatus <NUM>. The ROM stores programs, which include a program to cause the CPU to perform the control of a drawing operation, for example, and other fixed data. The RAM temporarily stores drawing data including patterns and characters drawn on the object <NUM>, body data such as the surface shape of the object <NUM>, and the like. The I/F transmits data and signals that are used when the controller <NUM> receives drawing data and the like from a host such as a personal computer (PC).

The controller <NUM> causes the X-direction driver <NUM>, the Y-direction driver <NUM>, the first Z-direction driver <NUM>, and the second Z-direction driver <NUM> to drive the carriage <NUM> and the head unit <NUM>. In addition, the controller <NUM> causes the head <NUM> included in the head unit <NUM> to discharge ink and causes the wiper unit <NUM> to clean the nozzle face 302a of the head <NUM>.

Further, when an abnormality occurs in the operations of the carriage <NUM>, the head unit <NUM>, and the head <NUM>, the controller <NUM> displays information indicating the abnormality to a user on the display <NUM>. The controller <NUM> receives an instruction from the control panel <NUM>.

The storage unit <NUM> stores, for example, position data (three dimensional coordinates on the X, Y, and Z axes) indicating a position where the contact (collision) of the left and right side wall plates (collision detection plates) <NUM> and 7R occurs.

When an abnormality occurs in the liquid discharge apparatus <NUM>, the display <NUM> displays the information indicating the abnormality to the user.

The control panel <NUM> is used to input a value (coordinates) for specifying an area (drawing area) where ink is discharged onto the object <NUM>, a moving speed of the carriage <NUM>, drawing data and three dimensional coordinates (body data) used for drawing on the object <NUM>, a distance between the head <NUM> and the object <NUM>, and the like. Note that the display <NUM> and the control panel <NUM> may be combined into one screen with a touch panel or the like.

Next, the configuration of the head <NUM> is described in detail.

<FIG> is a schematic cross-sectional view of one nozzle part of the head <NUM> according to the present embodiment. A part (a) of <FIG> illustrates a state in which the nozzle <NUM> is closed, and a part (b) of <FIG> illustrates a state in which the nozzle <NUM> is opened.

The head <NUM> includes a hollow housing <NUM> including the nozzle <NUM> at a distal end of the head <NUM> to discharge a liquid. The housing <NUM> includes an injection port <NUM> near the nozzle <NUM>, and the liquid is injected inside the housing <NUM> from the injection port <NUM>. The head <NUM> includes a piezoelectric element <NUM>, a valve <NUM>, and a valve mover <NUM> in the housing <NUM>. The piezoelectric element <NUM> expands and contracts in response to an externally applied voltage. The valve <NUM> opens and closes the nozzle <NUM>. The valve mover <NUM> is disposed between the valve <NUM> and the piezoelectric element <NUM>. The valve mover <NUM> moves the valve <NUM> toward or away from the nozzle <NUM>.

The piezoelectric element <NUM> is housed in a case <NUM>, and a pair of wirings 310a and 310b to apply a voltage to the piezoelectric element <NUM> are drawn outside the housing <NUM>. The piezoelectric element <NUM> drives the valve <NUM> via the valve mover <NUM>.

A sealing <NUM> is disposed between the valve <NUM> and the housing <NUM> to prevent the pressurized liquid injected from the injection port <NUM> from entering the piezoelectric element <NUM> side of the housing <NUM>, thereby forming a liquid chamber <NUM>. The housing <NUM> has a cylindrical body such as a cylinder or a square tube and has an enclosed space that is closed except for the nozzle <NUM> and the injection port <NUM>.

The nozzle <NUM> is an opening having a length Ln and formed at the distal end of the housing <NUM>, and ink <NUM> is discharged from the nozzle <NUM>. That is, in the present embodiment, the liquid (ink <NUM>) is discharged in a liquid discharge direction along the longitudinal axis of the nozzle <NUM> as illustrated in the part (b) of <FIG>.

The injection port <NUM> is formed on a side surface of the housing <NUM> near the nozzle <NUM>. The pressurized liquid is continuously supplied to the injection port <NUM>.

The piezoelectric element <NUM> is an element using zirconia ceramics or the like. A drive waveform (drive voltage) is applied to the piezoelectric element <NUM> via the wirings 310a and 310b. The sealing <NUM> is, for example, a packing, an O-ring, or the like. The sealing <NUM> externally fitted on the valve <NUM> can prevent a liquid from flowing into the piezoelectric element <NUM> side from the injection port <NUM> side of the housing <NUM>.

The valve mover <NUM> includes a deformable part 308a having a substantially trapezoidal cross-section formed of a resiliently deformable elastic member, such as rubber, soft resin, a thin metal plate, or the like. A coupling portion 308e corresponding to a top side of the substantially trapezoidal cross-section of the deformable part 308a is secured to a base end surface of the valve <NUM>. A long side corresponding to a bottom of the substantially trapezoidal cross-section of the deformable part 308a is coupled to a bent side 308d. A center portion of the bent side 308d in the radial direction is coupled to a guide part 308c, and a part between the center portion and an end portion in the radial direction of the bent side 308d is coupled to a fixed part <NUM>. One end of the fixed part <NUM> is coupled to the case <NUM>.

When a predetermined voltage is applied to the piezoelectric element <NUM>, the piezoelectric element <NUM> expands to move the valve mover <NUM> so that the guide part 308c moves toward the nozzle <NUM> by a distance "e", for example, as illustrated in the part (b) of <FIG>. Thus, a vicinity of the center portion of the bent side 308d is pushed into the valve mover <NUM> as indicated by arrow A1 in the part (b) of <FIG>.

Then, the bent side 308d is displaced in the direction indicated by arrows A2 in the part (b) of <FIG> from a coupling portion with the fixed part <NUM> as a starting point of displacement because the bent side 308d is coupled to the fixed part <NUM> on an outer peripheral side of the guide part 308c. When the bent side 308d is displaced in the direction indicated by arrows A2 in the part (b) of <FIG>, the deformable part 308a is deformed so that a coupling portion 308e with the valve <NUM> is pulled in the direction indicated by arrow A3 in the part (b) of <FIG>.

As the deformable part 308a of the valve mover <NUM> is deformed, the valve <NUM> secured to the coupling portion 308e of the deformable part 308a is retracted by a distance "d", thereby opening the nozzle <NUM>. That is, the guide part 308c moves toward the nozzle <NUM> by the distance "e" due to an expansion of the piezoelectric element <NUM>, so that the valve <NUM> moves by the distance "d" in the direction (rightward) opposite a moving direction (leftward or the direction of expansion of the piezoelectric element <NUM>) of the guide part 308c.

Here, a distance between the coupling portion 308e and the bent side 308d or a length of the bent side 308d is adjusted to increase a moving amount of the valve <NUM> to be longer than a displacement amount of the piezoelectric element <NUM>. The valve <NUM> is secured to the deformable part 308a of the valve mover <NUM> at the coupling portion 308e as described above. That is, the valve mover <NUM> can amplify the displacement of the piezoelectric element <NUM> and reduce the displacement of the piezoelectric element <NUM>, so that the size of the piezoelectric element <NUM> can be downsized.

Hereinafter, a first variation based on the present disclosure is described.

<FIG> is a schematic view of a liquid discharge apparatus <NUM> according to the first variation of the present disclosure. <FIG> is an enlarged perspective view of the liquid discharge apparatus <NUM> according to the first variation.

The liquid discharge apparatus <NUM> includes a linear rail <NUM> and a multi-articulated robot <NUM>. The linear rail <NUM> guides the carriage <NUM> that reciprocally and linearly moves along the linear rail <NUM>. The multi-articulated robot <NUM> appropriately moves the linear rail <NUM> to a predetermined position and holds the linear rail <NUM> at the predetermined position.

The multi-articulated robot <NUM> includes a robot arm 405a that is freely movable like a human arm by a plurality of joints. The multi-articulated robot <NUM> can freely move a distal end of the robot arm 405a and arrange the distal end of the robot arm 405a at an accurate position.

An industrial robot of a six-axis control-type having six axes (six joints) can be used as the multi-articulated robot <NUM>, for example. According to the multi-articulated robot <NUM> of the six-axis control-type, it is possible to previously teach data related to a movement of the multi-articulated robot <NUM>. As a result, the multi-articulated robot <NUM> can accurately and quickly position the linear rail <NUM> at a predetermined position facing a target object <NUM> (aircraft). The number of axes of the multi-articulated robot <NUM> is not limited to six, and a multi-articulated robot having an appropriate number of axes such as five axes or seven axes can be used.

The robot arm 405a of the multi-articulated robot <NUM> includes a fork-shaped support <NUM> bifurcated into two. A vertical linear rail 423a is attached to a tip of a left branch 424a of the support <NUM>, and a vertical linear rail 423b is attached to a tip of a right branch 424b of the support <NUM>. The vertical linear rail 423a and the vertical linear rail 423b are parallel to each other.

Further, both ends of the linear rail <NUM> that movably holds the carriage <NUM> are supported by the vertical linear rails 423a and 423b to bridge between two of the vertical linear rails 423a and 423b.

The carriage <NUM> has the configuration in the embodiment described with reference to <FIG> and the like, and includes a head that discharges a liquid toward the target object <NUM>. The carriage <NUM> includes, for example, the head <NUM> described with reference to <FIG> and the like, a plurality of heads <NUM> that discharges liquids of respective colors (e.g., yellow, magenta, cyan, black, and white), or a head <NUM> having a plurality of nozzle rows. The liquids of respective colors are respectively supplied from ink tanks <NUM> to the heads <NUM> or the nozzle rows of the head <NUM> of the carriage <NUM>.

The carriage <NUM> moves on the linear rail <NUM> along the first axis. As the linear rail <NUM> moves on the vertical linear rails 423a and 423b, the carriage <NUM> moves along the second axis intersecting the first axis.

The carriage <NUM> includes a first driver that moves the carriage <NUM> along the third axis intersecting the first axis and the second axis. In the first variation, the head <NUM> discharges a liquid to the target object <NUM> in the liquid discharge direction along the third axis. The carriage <NUM> further includes the second driver that moves the head <NUM> along the third axis relative to the carriage <NUM>.

In the liquid discharge apparatus <NUM>, the multi-articulated robot <NUM> moves the linear rail <NUM> to a desired drawing area of the target object <NUM>, and the heads <NUM> are driven to draw images on the target object <NUM> while moving the carriage <NUM> along the linear rail <NUM> according to drawing data.

When the liquid discharge apparatus <NUM> ends drawing of one line, the liquid discharge apparatus <NUM> causes the vertical linear rails 423a and 423b of the multi-articulated robot <NUM> to move the heads <NUM> of the carriage <NUM> from the one line to the next line.

The liquid discharge apparatus <NUM> repeats the above-described operation to draw images on the desired drawing area of the target object <NUM>.

During the drawing operation, the carriage <NUM> including the wiper unit <NUM> can wipe and clean the nozzle face 302a of the head <NUM> at any time although a moving distance of the carriage <NUM> (head <NUM>) increases.

In the first variation, the wiper unit <NUM> wipes the nozzle <NUM> before and after the drawing operation of one line. Thus, the liquid discharge apparatus <NUM> can continuously draw high quality images with small downtime.

<FIG> is a schematic perspective view of a liquid discharge apparatus according to a second variation of the present disclosure.

In the liquid discharge apparatus according to the second variation, the carriage <NUM> including the head unit <NUM> moves along the X-axis and the Y-axis with respect to the object <NUM> to draw images on the object <NUM>. The object, such as paper, film, wood plate, or the like is positioned on a horizontal table <NUM>.

The carriage <NUM> moves along the X-axis (an example of the first axis) along the X-axis rail <NUM>. In addition, as a frame <NUM> supporting the X-axis rail <NUM> moves along the Y-axis rail <NUM> disposed on the side surface of the table <NUM>, the carriage <NUM> moves along the Y-axis (an example of the second axis).

Similarly to the above-described embodiments, the head unit <NUM> includes a head, and a head surface of the head is movable along the Z-axis (an example of the third axis).

Also in the second variation, the carriage <NUM> includes the first driver that moves the carriage <NUM> along the Z-axis and the second driver that moves the head unit <NUM> along the Z-axis relative to the carriage <NUM>.

The liquid discharge apparatus according to the second variation is different from the above-described embodiments in that a liquid is discharged downward in the direction of gravity to the object <NUM> horizontally placed on the table <NUM>. The present disclosure is applicable to such a liquid discharge apparatus.

<FIG> is a schematic perspective view of a liquid discharge apparatus according to a third variation of the present disclosure.

The liquid discharge apparatus according to the third variation is different from the liquid discharge apparatus according to the second variation in that the object <NUM> is conveyed on the table <NUM> in the direction indicated by arrow a. In the liquid discharge apparatus according to the third variation, the carriage <NUM> including the head unit <NUM> moves along the X-axis (an example of the first axis) to draw images on the object <NUM>. The object <NUM> is fed from an object feeder <NUM>. As the carriage <NUM> ends drawing of one line, the object <NUM> is conveyed by a predetermined length. Then, the carriage <NUM> draws the next line while moving along the X-axis.

Similarly to the liquid discharge apparatus according to the second variation, the carriage <NUM> moves along the X-axis along the X-axis rail <NUM>. The liquid discharge apparatus according to the third variation is different from the liquid discharge apparatus according to the second variation in which the carriage <NUM> also moves along the Y-axis. In the third variation, since the object <NUM> is conveyed on the table <NUM>, the carriage <NUM> is not required to move along the Y-axis (an example of the second axis) while drawing on the object <NUM>, and is secured (stopped) at a predetermined position.

The object <NUM> that has passed under the carriage <NUM> is wound by an object winder <NUM>. Also in the third variation, similarly to the above-described embodiments, the head unit <NUM> includes a head, and a head surface of the head is movable along the Z-axis (an example of the third axis).

Also in the third variation, the carriage <NUM> includes the first driver that moves the carriage <NUM> along the Z-axis and the second driver that moves the head unit <NUM> along the Z-axis relative to the carriage <NUM>.

The liquid discharge apparatus according to the third variation is different from the above-described embodiments in that the carriage <NUM> moves only along the X-axis and the Z-axis and does not move along the Y-axis because the object <NUM> is conveyed along the Y-axis. The present disclosure is applicable to such a liquid discharge apparatus.

As described above, the liquid discharge apparatus <NUM> according to the above embodiments of the present disclosure includes the head <NUM> (an example of a liquid discharge head) having the nozzle <NUM> (an example of a discharge port), the carriage <NUM> (an example of a liquid discharger), the first Z-direction driver <NUM> (an example of a first driver), and the second Z-direction driver <NUM> (an example of a second driver). The head <NUM> discharges ink (an example of a liquid) from the nozzle <NUM> toward the object <NUM> (an example of an object) in a direction along the Z-axis (an example of a third axis) intersecting the X-axis (an example of a first axis) and the Y-axis (an example of a second axis). The carriage <NUM> holds the head <NUM>. The carriage <NUM> is movable along at least one of the X-axis and the Y-axis intersecting the X-axis. The first Z-direction driver <NUM> moves the carriage <NUM> along the Z-axis. The second Z-direction driver <NUM> moves the head <NUM> along the Z-axis relative to the carriage <NUM>.

Accordingly, the head <NUM> can be quickly moved in a direction away from the object <NUM>.

In the liquid discharge apparatus <NUM>, the second Z-direction driver <NUM> moves the nozzle face 302a (head <NUM>) along the Z-axis faster than the first Z-direction driver <NUM>.

Accordingly, the nozzle face 302a can be quickly moved relative to the carriage <NUM>.

In the liquid discharge apparatus <NUM>, the first Z-direction driver <NUM> includes a drive motor.

Accordingly, the first Z-direction driver <NUM> can be controlled so as to finely move the carriage <NUM> and align the nozzle face 302a together with the carriage <NUM> with respect to the object <NUM> with high accuracy.

In the liquid discharge apparatus <NUM>, the second Z-direction driver <NUM> includes a power cylinder.

Accordingly, when the nozzle <NUM> and the nozzle face 302a need to be cleaned or when urgency is required, the second Z-direction driver <NUM> can quickly retract the nozzle face 302a from the object <NUM>.

In the liquid discharge apparatus <NUM>, the head <NUM> includes the nozzle face 302a (an example of a liquid discharge surface) on which the nozzle <NUM> is formed. The second Z-direction driver <NUM> moves the nozzle face 302a relative to the carriage <NUM> along the Z-axis between an ink discharge position (liquid discharge position) at which the head <NUM> discharges the ink to the object <NUM> and a standby position at which the carriage <NUM> is away from the object <NUM> compared with the ink discharge position. The carriage <NUM> includes the wiper unit <NUM> (an example of a cleaning device) that cleans the nozzle face 302a at the standby position.

Accordingly, when the nozzle face 302a needs to be cleaned (wiping, dummy discharge, or the like), the nozzle face 302a can be quickly moved from the ink discharge position to the standby position, and the time until the start of cleaning can be shortened.

In the liquid discharge apparatus <NUM>, the head <NUM> includes the nozzle face 302a on which the nozzle <NUM> is formed. The second Z-direction driver <NUM> moves the nozzle face 302a relative to the carriage <NUM> along the Z-axis between the ink discharge position at which the head <NUM> discharges the ink to the object <NUM> and the standby position at which the carriage <NUM> is away from the object <NUM> compared with the ink discharge position. The carriage <NUM> includes the left side wall plate <NUM> and the right side wall plate 7R (examples of projection member) on both sides of the nozzle face 302a along the X-axis. Each of the left side wall plate <NUM> and the right side wall plate 7R has a distal end projecting to the same position as the nozzle face 302a or a position closer to the object <NUM> than the nozzle face 302a along the Z-axis.

Accordingly, when the left side wall plate <NUM> or the right side wall plate 7R comes into contact with the collision object B, the nozzle face 302a can be quickly moved from the ink discharge position to the standby position, thereby avoiding the collision with the collision object B.

In the liquid discharge apparatus <NUM>, the head <NUM> includes the nozzle face 302a on which the nozzle <NUM> is formed and the contact member 7Z (an example of a contact member). The contact member contacts the object <NUM> in front of the nozzle face 302a along the Z axis. The first Z-direction driver <NUM> moves the nozzle face 302a in a direction toward the object <NUM> and in a direction away from the object <NUM> along the Z-axis.

Accordingly, before starting to draw on the object <NUM>, the liquid discharge apparatus <NUM> can acquire data related to the surface shape of the object <NUM>.

The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings.

Claim 1:
A liquid discharge apparatus (<NUM>) comprising:
a carriage (<NUM>) being movable along at least one of a first axis (X, Y) and a second axis (Y, X) intersecting the first axis;
a liquid discharge head (<NUM>) having a discharge port (<NUM>), the liquid discharge head held by the carriage and configured to discharge a liquid from the discharge port toward an object (<NUM>) in a direction along a third axis (Z) intersecting the first axis and the second axis;
a first driver (<NUM>) configured to move the carriage holding the liquid discharge head along the third axis; and
a second driver (<NUM>) configured to move the liquid discharge head along the third axis relative to the carriage.