Patent Description:
A certain publicly known liquid discharge apparatus is provided with a head, a wiper which makes contact with a nozzle surface of the head and which wipes the nozzle surface, and a spring applying a force in an opposite direction to a restoring force, of the wiper, by which the wiper deformed by the contact with the nozzle surface of the head attempts to be restored to the original shape thereof, so as to weaken the restoring force. The spring is used so as to weaken the restoring force of the wipe, and to thereby suppress a restoring speed by which the wiper is restored, which in turn prevents an ink adhered to a forward end (tip end) of the wiper from scattering. <CIT> discloses a grooved tip wiper for cleaning inkjet printheads. <CIT> discloses an inkjet recording apparatus.

In the publicly known liquid discharge apparatus, even in a case that the forward end of the wiper makes contact with the nozzle surface of the head and wipes the nozzle surface, the spring pulls the wiper. Accordingly, a pressure generated in a case that the wiper makes contact with the nozzle surface is weakened as compared with a case that the spring is not provided, which in turn lowers the wiping performance of the wiper.

An object of the present invention is to provide a technique of suppressing any lowering in the wiping performance of the wiper while suppressing the scattering of the ink adhered to the forward end of the wiper.

According to an aspect of the present invention, there is provided a liquid discharge apparatus as defined in claim <NUM>.

In the above-described configuration, the projection projects from the wiper body toward the other side in the wiping direction. Accordingly, while the wiper is (being) moved toward the one side in the wiping direction so that only the wiping part of the wiper body wipes the nozzle surface of the head, there is not any fear that the projection might make contact with the lower surface of the head and that the wiping performance of the wiping part might be lowered thereby. Further, the projection is configured to make contact with the lower surface of the head after the wiping part of the wiper body is separated from the end part on the one side in the wiping direction of the nozzle surface. With this, the projection is capable of suppressing the restoring force, of the wiper, by which the deformation of the wiper body is restored, after the wiping part of the wiper body is separated from the nozzle surface. Accordingly, it is possible to suppress the restoring speed of the wiper body and to thereby suppress the scattering of the ink adhered to the wiping part of the wiper body. Further, there is no need to separately provide a member different from the wiper in order to suppress the restoring force of the wiper body. With this, is it possible to suppress the manufacturing cost of the liquid discharge apparatus. Furthermore, the projection does not affect the deformation of the wiper body in a case that the wiper body wipes the nozzle surface. Accordingly, even in a case that the projection is formed in order to suppress the restoring force of the wiper body, there is no such a fear that the wiping performance of the wiper might be lowered.

In the following, an ink-jet printer <NUM> according to an embodiment of the present invention will be explained, with reference to the drawings.

In <FIG>, the upstream side in a conveying direction of a medium M is defined as the front side of the ink-jet printer <NUM>, and the downstream side in the conveying direction is defined as the rear side of the ink-jet printer <NUM>. Further, a direction which is parallel to a plane or surface (conveyance plane or surface) in which the medium M such as print paper (print sheet, print paper sheet) is conveyed (a plane or surface parallel to the sheet surface of <FIG>) and which is orthogonal to the conveying direction is defined as a wiping direction. The wiping direction coincides with a width direction of the medium M. As will be described later on, the wiping direction is a direction in which the head <NUM> is moved with respect to a wiper <NUM> in a case that a wiping operation is performed by using the wiper <NUM>. One side of the wiping direction corresponds to the left side in a case that the ink-jet printer <NUM> is seen from the front side (the left side in <FIG>), and the other side of the wiping direction corresponds to the right side in a case that the ink-jet printer <NUM> is seen from the front side (the right side in <FIG>). Further, a direction orthogonal to the conveyance plane of the medium M (a direction orthogonal to the sheet surface of <FIG>) is defined as the up-down direction of the ink-jet printer. In <FIG>, a side to which the front surface of the sheet is oriented or faces is the upper side, and a side to which the rear surface of the sheet is oriented or faces is the lower side. In the following explanation, the front (front side), the rear (rear side), the left (left side), the right (right side), the up (upper side) and the down (lower side) are appropriately used.

As depicted in <FIG>, the ink-jet printer <NUM> is provided with a casing <NUM>, a platen <NUM>, a head bar <NUM>, conveying rollers 5A and 5B, a head holder <NUM>, a maintenance system <NUM> and a controller <NUM>. Note that the ink-jet printer <NUM> is an example of a "liquid discharge apparatus". The configuration in which the head bar <NUM> and the maintenance system <NUM> are combined is an example of a "head bar system".

As depicted in <FIG>, the head holder <NUM> is arranged in the casing <NUM> so that the head holder <NUM> is movable in the wiping direction. The head holder <NUM> is arranged to sandwich, in the wiping direction, the both sides of the platen <NUM>. The head bar <NUM> is fixed to the head holder <NUM>. The head bar <NUM> is arranged at a location above the platen <NUM> so that a predetermined spacing distance is formed (defined) between the head bar <NUM> and the platen <NUM>. The medium M which is, for example, paper, etc., is conveyed on the upper surface of the platen <NUM>.

As depicted in <FIG>, the head bar <NUM> is provided with <NUM> pieces of an ink-jet head <NUM> (hereinafter simply referred to as the "head(s) <NUM>". The ten heads <NUM> are arranged to form two rows along the wiping direction. Further, five heads <NUM>, among the ten heads <NUM>, which construct each of the two rows are arranged with equal spacing distances therebetween in the wiping direction. The two rows of the heads <NUM> are arranged to be shifted from each other in the wiping direction. Namely, the five heads <NUM> arranged on the upstream side in the conveying direction (the front side) are arranged to be shifted toward one side in the wiping direction (leftward) with respect to the five heads <NUM> arranged on the downstream side in the conveying direction (the rear side). In other words, the ten heads <NUM> are arranged in the staggered manner in the wiping direction. In the present embodiment, an ink supplied from a non-illustrated ink supplying part is discharged or ejected from each of the heads <NUM>.

The conveying roller 5A is arranged on the front side with respect to the platen <NUM>, and the conveying roller 5B is arranged on the rear side with respect to the platen <NUM>. Each of the conveying rollers 5A and 5B is driven by a non-illustrated motor, and conveys the medium M on the platen <NUM> rearward. Note that the medium M may be a roll-shaped sheet including a supply roll arranged on the upstream side in the conveying direction with respect to the platen <NUM>, and a recovery roll arranged on the downstream side in the conveying direction with respect to the platen <NUM>. In such a case, the medium M which is fed out from the supply roll passes on the platen <NUM>, and then is wound around (is taken up by) the recovery roll. Note that the supply roll may be attached to the conveying roller 5A, and that the recovery roll may be attached to the conveying roller 5B. Alternatively, the medium M may be a roll-shaped sheet including only a supply roll arranged on the upstream side in the conveying direction with respect to the platen <NUM>. In this case, the supply roller may be attached to the conveying roller 5A.

The maintenance system <NUM> is arranged, in the inside of the casing <NUM>, at a location between the platen <NUM> and the head bar <NUM> regarding the up-down direction. As depicted in <FIG>, the maintenance system <NUM> is mainly provided with two wipers <NUM>, a maintenance base <NUM>, a pinion gear <NUM>, a rack gear <NUM>, a guide <NUM>, a driving motor <NUM> (see <FIG>) and an engaging block <NUM> (see <FIG>). In a case that maintenance is performed, the wiper <NUM> is caused to wipe a lower surface (a nozzle surface 41A and a lower surface of a nozzle cover <NUM> (see <FIG>) which will be described later on) of each of the heads <NUM> while moving the head holder <NUM> (and the head bar <NUM>) along the rack gear <NUM> toward the one side (right side) in the wiping direction. As depicted in <FIG>, the rack gear <NUM> extends up to the right side with respect to (beyond) the maintenance base <NUM>. In a case that the maintenance is not performed, the head bar <NUM> is arranged at a position at which the head bar <NUM> does not interfere with the maintenance base <NUM> on the left side with respect to the maintenance base <NUM> (stand-by position, printing position). The detailed configuration of the maintenance system <NUM> will be described later on.

The controller <NUM> is capable of mutually communicating with an external apparatus <NUM> such as a personal computer, etc. The controller <NUM> controls the operations of the respective heads <NUM> included in the head bar <NUM>, the conveying rollers 5A and 5B and the maintenance system <NUM>, based on an instruction from the external apparatus <NUM> or an instruction from a user via an operating part (not depicted) provided on the ink-jet printer <NUM>.

Next, the lower surface of the head bar <NUM> and the lower surface of each of the heads <NUM> will be explained, with reference to <FIG>. Note that <FIG> depicts only a head <NUM> which is arranged rightmost among the five heads <NUM> arranged on the upstream side in the conveying direction and a head <NUM> which is arranged rightmost among the five heads <NUM> arranged on the downstream side in the conveying direction, and remaining heads <NUM> other than these two heads <NUM> are omitted in the illustration.

A bottom surface of each of the heads <NUM> faces or is opposite to the platen <NUM>. Further, a nozzle surface 41A in which <NUM> pieces of a nozzle 11a are opened is included in the bottom surface of each of the heads <NUM>. In the nozzle surface 41A, the <NUM> nozzles 11a form <NUM> pieces of a nozzle row arranged side by side in the conveying direction. Furthermore, each of the <NUM> nozzle rows includes <NUM> pieces of the nozzle 11a arranged side by side in the wiping direction with equal spacing distances therebetween. Each of the <NUM> nozzles 11a constructing one of the nozzle rows is arranged to be shifted in the wiping direction with respect to one of the <NUM> nozzles 11a constructing another nozzle row adjacent thereto in the conveying direction. In the following explanation, a virtual area which is an area which is on the inner side with respect to an outer edge of the nozzle surface 41A of each of the heads <NUM> and which includes all the nozzles 11a formed in the nozzle surface 41A in the inside of the area is referred to as a nozzle formation area 41B. Further, each of the heads <NUM> has a nozzle cover <NUM> which is arranged therein and which is configured to cover the nozzle 41A from therebelow so as to surround the nozzle formation area 41B of the nozzle surface 41A (see <FIG> and <FIG>). As depicted in <FIG>, the lower surface of the nozzle cover <NUM> protrude downward beyond the nozzle surface 41A. In the following explanation, the lower surfaces of the nozzle surface 41A and the nozzle cover <NUM> are collectively referred to as the "lower surface" of the head <NUM>, in some cases.

Ten pieces of an opening 4A corresponding to the ten heads <NUM>, respectively, are formed in the lower surface of the head bar <NUM>. The ten openings 4A are arranged in two rows in the staggered manner along the wiping direction. Five openings 4A included in the ten openings 4A and constructing each of the two rows are arranged in the wiping direction with equal spacing distances therebetween. As depicted in <FIG>, each of the openings 4A has a size which is substantially same as the lower surface of one of the heads <NUM>; and the nozzle cover <NUM> and the nozzle surface 41A (nozzle formation area 41B) of each of the heads <NUM> is exposed from one of the openings 41A corresponding thereto. Note that in the present embodiment, although not depicted in the drawings, the lower surface of the head bar <NUM> is flush with the nozzle surface 41A of each of the heads <NUM>, and a lower end of the nozzle cover <NUM> of each of the heads <NUM> projects downward beyond the lower surface of the head bar <NUM>. Note that it is not necessarily indispensable that the lower surface of the head bar <NUM> is flush with the nozzle surface 41A of each of the heads <NUM>. For example, it is allowable that the nozzle surface 41A of each of the heads <NUM> protrudes downward beyond the lower surface of the head bar <NUM>.

Next, a channel unit <NUM> and an actuator unit <NUM> constructing each of the heads <NUM> will be explained, with reference to <FIG>. Note that since the configurations of the channel unit <NUM> and the actuator unit <NUM> are common to the ten heads <NUM>, the explanation will be given about the channel unit <NUM> and the actuator unit <NUM> in one piece of the head <NUM>.

As depicted in <FIG>, the channel unit <NUM> is formed of a plurality of metal plates and a nozzle plate <NUM> which are stacked in the up-down direction. An ink channel such as individual channels <NUM> which include pressure chambers 12a, respectively, a manifold <NUM>, etc., is formed in the plurality of metal plates by the etching. The nozzle plate <NUM> is formed, for example, of a polymeric synthetized resin material such as polyimide, etc., and is adhered to a lower surface of the stacked metal plates with an adhesive. A lower surface of the nozzle plate <NUM> becomes to be the above-described nozzle surface 41A. Note that it is allowable that the nozzle plate <NUM> is also formed of a metallic material such as stainless steel, etc..

As depicted in <FIG>, the individual channels <NUM> each of which communicates with one of the nozzles 11a, and the manifold <NUM> communicating with the individual channels <NUM> are formed in the inside of the channel unit <NUM>. Although not depicted in the drawings, the manifold <NUM> extends in the wiping direction (in <FIG>, a direction perpendicular to the sheet surface). The ink is supplied, via a non-illustrated ink supply port formed in the channel unit <NUM>, to the manifold <NUM> from a non-illustrated ink supplying part which is provided at the outside of the head <NUM>.

Note that although not depicted in the drawings, <NUM> pieces of the individual channel <NUM> are arranged so as to form <NUM> individual channel rows extending in the wiping direction, in corresponds to that the <NUM> nozzles 11a are arranged so as to form the <NUM> nozzle rows extending in the wiping direction, as described above. Further, <NUM> pieces of the manifold <NUM> are provided on the channel unit <NUM>; each of the <NUM> manifolds <NUM> communicates with <NUM> individual channels <NUM>, among the <NUM> individual channels <NUM>, constructing two individual channel rows among the <NUM> individual channel rows. With this, in the inside of the channel unit <NUM>, a plurality of ink channels is formed, each of the plurality of ink channel starting from the manifold <NUM>, passing the pressure chamber 12a of one of the plurality of individual channels <NUM>, and reaching one of the nozzles 11a. Note that the number (quantity) of the manifold <NUM> formed in the channel unit <NUM> and the number (quantity) of the individual channel <NUM> communicating with the manifold <NUM> are not limited to or restricted by the above-described numbers (quantities).

As depicted in <FIG>, one of the pressure chambers 12a is formed in each of the individual channels <NUM>, and the actuator unit <NUM> is arranged at a location above the pressure chambers 12a. The actuator unit <NUM> is provided with a vibration plate <NUM> arranged on the upper surface of the channel unit <NUM> so as to cover all the pressure chambers 12a, a piezoelectric body <NUM> arranged to cover the entire surface (entirety) of the upper surface of the vibration plate <NUM>, and <NUM> individual electrodes <NUM> each of which is arranged, on the upper surface of the piezoelectric body <NUM>, at a position facing one of the pressure chambers 12a. As will be described later on, the vibration plate <NUM> functions as a common electrode. The vibration plate <NUM> as the common electrode, each of the individual electrodes <NUM>, and a part, of the piezoelectric body <NUM>, which is sandwiched by one of the individual electrodes <NUM> and the vibration plate <NUM> form one piece of a driving element <NUM>. Namely, the actuator unit <NUM> includes <NUM> pieces of the driving element <NUM>.

The vibration plate <NUM> is a metallic plate which has a substantially rectangular shape in a plan view, and is formed of an iron-based alloy such as stainless steel, a copper-based alloy, a nickel-based alloy, or a titanium-based alloy, etc. The upper surface of the vibration plate <NUM> having the electric conductivity is arranged on the side on which the lower surface of the piezoelectric body <NUM> is located. Accordingly, the upper surface of the vibration plate <NUM> is capable of functioning also as the common electrode. The vibration plate <NUM> as the common electrode is connected to a ground wiring of a driver IC <NUM> (see <FIG>) which drives the actuator unit <NUM>, and is maintained to be the ground potential at all times. Note that it is not necessarily indispensable that the vibration plate <NUM> is the metallic plate; for example, it is allowable that the vibration plate <NUM> is formed of a piezoelectric material which is same as that forming the piezoelectric body <NUM>, and that a metallic film as the common electrode is formed on the upper surface of the vibration plate <NUM>.

The piezoelectric body <NUM> is formed of a piezoelectric material composed primarily of lead zirconate titanate (PZT) which is a solid solution of lead titanate and lead zirconate and which is a ferroelectric substance. The piezoelectric body <NUM> is polarized in a thickness direction (up-down direction) at least at an area facing the pressure chamber 12a (a part sandwiched between the individual electrode <NUM> and the vibration plate <NUM>). In the present embodiment, a layer of the piezoelectric body (piezoelectric layer) which is formed continuously across the plurality of pressure chambers 12a is formed on the upper surface of the vibration plate <NUM>. It is allowable, however, that <NUM> pieces of an independent (separate) piezoelectric body <NUM> are provided, each corresponding to one of the <NUM> pieces of the pressure chamber 12a.

As depicted in <FIG>, each of the individual electrodes <NUM> is arranged at an area, of the upper surface of the piezoelectric body <NUM>, which faces one of the pressure chambers 12a. Each of the individual electrodes <NUM> is electrically connected to the driver IC <NUM> (see <FIG>) mounted on a non-illustrated flexible wiring (COF), via a signal line <NUM> (see <FIG>). As depicted in <FIG>, the driver IC <NUM> is electrically connected to the controller <NUM>. The driver IC <NUM> applies a driving pulse signal to the individual electrode <NUM> of the driving element <NUM>, based on a signal transmitted from the controller <NUM>. With this, the driver IC <NUM> applies either one of a predetermined driving potential and the ground potential selectively to each of the individual electrodes <NUM>.

Next, an explanation will be given about an action of the driving element <NUM> of the actuator unit <NUM> at a time of ink discharge (ink ejection). In a case that the predetermined driving potential is applied from the driver IC <NUM> to a certain individual electrode <NUM> included in the individual electrodes <NUM>, a potential difference is generated between the certain individual electrode <NUM> to which the driving potential is applied and the vibration plate <NUM> as the common electrode and maintained at the ground potential. With this, an electric field in the thickness direction is generated at the part, of the piezoelectric body <NUM>, sandwiched between the certain individual electrode <NUM> and the vibration plate <NUM>. The direction of the electric filed is parallel to the polarization direction of the piezoelectric body <NUM>. Accordingly, due to this electric field, an area (active area), of the piezoelectric body <NUM>, which faces the certain individual electrode <NUM> contracts in a plane direction orthogonal to the thickness direction. Here, the vibration plate <NUM> which is on the lower side of the piezoelectric body <NUM> is fixed to the channel unit <NUM>. Accordingly, accompanying with the active area, of the piezoelectric body <NUM>, which is positioned on the upper surface of the vibration plate <NUM> contracting in the plane direction, a part of the vibration plate <NUM> which covers the pressure chamber 12a is deformed so as to project toward the pressure chamber 12a (unimorph deformation, see <FIG>). In this situation, since the volume inside the pressure chamber 12a is reduced, the pressure of the ink inside a certain pressure chamber 12a, among the pressure chambers <NUM>, corresponding to the certain individual electrode <NUM> is increased, thereby discharging the ink from a nozzle 11a, among the nozzles 11a, communicating with the certain pressure chamber 12a.

Next, an explanation will be given about the schematic electric configuration of the ink-jet printer <NUM>, with reference to <FIG>. The controller <NUM> is electrically connected to each of the heads <NUM>. The controller <NUM> is mainly provided with a CPU (Central Processing Unit) <NUM>, a ROM (Read Only Memory) <NUM>, a RAM (Random Access Memory) <NUM>, and a non-volatile memory <NUM>. The ROM <NUM> stores a program(s), a variety of kinds of data, etc., with which the CPU controls a variety of kinds of operations. The RAM <NUM> is used as a memory area configured to temporarily store data, signal, etc., to be used by the CPU <NUM> for executing the program, or is used as a work space for executing data processing. It is allowable to use, as the non-volatile memory <NUM>, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory). Note that it is allowable to use a MPU (Microprocessor Unit) or a FPGA (Field Programmable Gate Array), rather than using the CPU <NUM>.

As depicted in <FIG>, each of the heads <NUM> has a FPGA <NUM> and the driver IC <NUM>, in addition to the actuator unit <NUM> including the <NUM> driving elements <NUM>. The FPGA <NUM> is connected to the drive IC <NUM> by a wiring <NUM> for control signal. Further, the driver IC <NUM> is connected to each of the driving elements <NUM> by a wiring <NUM> for driving signal.

In a case that the controller <NUM> receives image data from the external apparatus <NUM>, the FPGA <NUM> outputs a control signal via the wiring <NUM> for control signal, under the control by the controller <NUM>, the driver IC <NUM> generates a driving signal for driving the actuator unit <NUM> based on the control signal inputted from the FPGA <NUM>, and outputs the generated driving signal to the actuator unit <NUM> via the wiring <NUM> for driving signal.

Further, a certain driving element <NUM>, among the driving elements <NUM>, is driven based on the driving signal supplied from the driver IC <NUM>, the ink is thereby discharged from a certain nozzle 11a, among the nozzles 11a, corresponding to the certain driving element <NUM>, in an amount corresponding to the driving signal.

Furthermore, the controller <NUM> is electrically connected to a conveying motor <NUM>, and controls the driving of the conveying motor <NUM> to thereby control the conveyance of the medium M by the conveying rollers 5A and 5B. Moreover, the controller <NUM> is electrically connected to the driving motor <NUM>, and controls the driving of the driving motor <NUM> to thereby control the movement of the head bar <NUM> in the wiping direction via the pinion gear <NUM>.

Next, the maintenance system <NUM> provided on the ink-jet printer <NUM> according to the present embodiment will be explained.

As depicted in <FIG>, <FIG> and <FIG>, the rack gear <NUM> extends in the wiping direction. The rack gear <NUM> is arranged in the inside of the casing <NUM> (see <FIG>). As depicted in <FIG>, teeth meshing or engaging with the pinion gear <NUM> are formed in the lower surface of the rack gear <NUM>. As depicted in <FIG>, a length in the wiping direction of the rack gear <NUM> is longer than a length in the wiping direction of an area, of the head bar <NUM>, in which the ten heads <NUM> are arranged (hereinafter referred to as a "head arrangement area").

As depicted in <FIG>, the guide <NUM> extends in the wiping direction, and is arranged in the inside of the casing <NUM>. As depicted in <FIG>, the guide <NUM> is arranged at a location below the rack gear <NUM> and the head holder <NUM>. Guide grooves 85A are formed in side surfaces, respectively, which are on the both sides in the conveying direction of the guide <NUM>. A cross sectional shape of each of the guide grooves <NUM> is substantially rectangular, and each of the guide grooves 85A extends in the wiping direction (direction perpendicular to the sheet surface of <FIG>). Note that as depicted in <FIG>, a length in the wiping direction of the guide <NUM> is also longer than the length in the wiping direction of the head arrangement area in the head bar <NUM>.

The maintenance base <NUM> has a shape of a rectangular parallelepiped. As depicted in <FIG>, a length in the conveying direction of the maintenance base <NUM> is longer than a length in the conveying direction of the head arrangement area in the head bar <NUM>. Further, as depicted in <FIG>, a pinion gear <NUM> which protrudes rearward is provided on a side surface on one side in the conveying direction (rear side) of the head holder <NUM>, and the driving motor <NUM> connected to a rotation shaft 83A of the pinion gear <NUM> is fixed to the inside of the maintenance base <NUM>. As depicted in <FIG>, the rotation shaft 83A of the pinion gear <NUM> extends in the conveying direction, and teeth meshing with the teeth of the rack gear <NUM> are formed in a circumferential surface of the pinion gear <NUM>. Further, an engaging block <NUM> is provided on a location, in the lower surface of the head holder <NUM>, which is on the one side in the conveying direction (rear side). The engaging block <NUM> engages with the guide grooves 85A of the guide <NUM>, while the pinion gear <NUM> meshes or engages with the rack gear <NUM>, thereby supporting the head holder <NUM>. Note that the positions in the up-down direction of the rack gear <NUM>, the guide <NUM> and the head holder <NUM> can be adjusted to a wiping position and to a retreating (retracting) position, by a non-illustrated lifting and lowering mechanism. The wiping position is a position at which an upper end <NUM> of the wiper <NUM> (to be described later on) is located above the nozzle surface 41A (nozzle formation area 41B) of the head <NUM>. The retreating position is a position at which the upper end <NUM> of the wiper <NUM> is located below the nozzle surface 41A (nozzle formation area 41B) of the head <NUM>.

As depicted in <FIG>, the two wipers <NUM> are attached to the upper surface of the maintenance base <NUM>. Each of the two wipers <NUM> includes a member which is integrally formed by an EPDM rubber (a wiper body <NUM>, a base part <NUM> and a projection <NUM> which will be described later on). The EPDM rubber has the hardness of not less than <NUM> degrees, and has a property which is less likely to swell by the ink. The shape of each of the two wipers <NUM> will be described later on. As depicted in <FIG> and <FIG>, positions in the wiping direction of the two wipers <NUM> are shifted from each other. Specifically, a wiper <NUM> (hereinafter referred to as a "wiper 100A") included in the two wipers <NUM> and arranged on the upstream side in the conveying direction is arranged to shift to the one side in the wiping direction (to the left side, leftward) with respect to a wiper <NUM> (hereinafter referred to as a "wiper 100B") included in the two wipers <NUM> and arranged on the downstream side in the conveying direction. Further, as depicted in <FIG>, the wiper 100A is attached to the upper surface of the maintenance base <NUM> so that the nozzle formation area 41B of each of the five heads <NUM> on the upstream side in the conveying direction (front side) is positioned between the both ends in the conveying direction of the wiper 100A. Similarly, the wiper 100B is attached to the upper surface of the maintenance base <NUM> so that the nozzle formation area 41B of each of the five heads <NUM> on the downstream side in the conveying direction (rear side) is positioned between the both ends in the conveying direction of the wiper 100B.

In a case that the pinion gear <NUM> rotates in normal and reverse directions in accordance with the driving of the driving motor <NUM>, the head holder <NUM> thereby moves in a reciprocal manner along the rack gear <NUM> and the guide <NUM> in the wiping direction. The head holder <NUM>, the driving motor <NUM>, the pinion gear <NUM>, the rack gear <NUM> and the guide <NUM> correspond to a "driving part" of the present invention. As will be described later on, in a state that the head holder <NUM> is moved to the maintenance position by the non-illustrated liftin-lowering mechanism, the head holder <NUM> is moved toward the right side in the wiping direction, thereby making it possible to perform a wiping operation of wiping the ink adhered to the nozzle formation area 41B of the head <NUM>. In this situation, as depicted in <FIG>, the upper end <NUM> (see <FIG>) of the wiper 100A successively makes contact with the nozzle formation areas 41B of the respective five heads <NUM> on the upstream side in the conveying direction, and wipes off the ink adhered to the nozzle formation areas 41B. Similarly, the upper end <NUM> (see <FIG>) of the wiper 100B successively makes contact with the nozzle formation areas 41B of the respective five heads <NUM> on the downstream side in the conveying direction, and wipes off the ink adhered to the nozzle formation areas 41B. Namely, each of the wiper 100A and the wiper 100B is capable of wiping a plurality of pieces of the nozzle formation area 41B which is aligned in the wiping direction. In the maintenance system <NUM> of the present invention, since each of the wipers <NUM> is capable of wiping the plurality of pieces of the nozzle formation area in such a manner, it is possible to wipe the plurality of nozzle formation areas efficiently, and to shorten the time required for the maintenance.

Next, the shape of the wiper <NUM> will be explained, with reference to <FIG>, <FIG>, <FIG>. As depicted in <FIG>, the wiper <NUM> is provided with a wiper body <NUM>, a base part <NUM>, two projections <NUM> and a fixing member <NUM> (see <FIG>, <FIG>). The wiper body <NUM> is a plate-like member elongated in the conveying direction. The wiper body <NUM> has a thickness in the wiping direction which becomes thinner further toward the upper side. A plurality of grooves <NUM> extending in the up-down direction is formed in a surface <NUM> (hereinafter referred to as a "first surface <NUM>") on the one side in the wiping direction (left side) of the wiper body <NUM>. A plurality of grooves <NUM> extending in the up-down direction and a plurality of grooves <NUM> extending in the conveying direction are formed in a surface <NUM> (hereinafter referred to as a "second surface <NUM>") on the other side in the wiping direction (right side) of the wiper body <NUM>. Stepped parts <NUM> of which height in the up-down direction is lower than the upper end <NUM> are formed, respectively, on both sides in the conveying direction of the upper end <NUM> of the wiper body <NUM>. The upper end <NUM> is an example of a "first area" of the present invention, and the stepped parts <NUM> are each an example of a "second area" of the present invention. In a case that the wiper <NUM> is at the wiping position, the upper end <NUM> makes contact with the nozzle surface <NUM> of the head <NUM>, and the stepped parts <NUM> make contact with the nozzle cover <NUM> of the head <NUM>, as will be described later on.

As depicted in <FIG>, the base part <NUM> is provided on a lower end of the first surface <NUM> of the wiper body <NUM>. The thickness (length in the wiping direction) of the base part <NUM> is greater than the thickness of the wiper body <NUM>. A projecting part <NUM> which projects in the up-down direction is formed at a central part in the conveying direction of the base part <NUM>.

As depicted in <FIG>, two projections <NUM> which project toward the other side (right side) in the wiping direction are formed in the second surface <NUM> of the wiper body <NUM>. In the present embodiment, the two projections <NUM> are arranged in the conveying direction with a spacing distance therebetween so that an inner side end in the conveying direction of each of the two projections <NUM> is located at a position which is same as one of the ends on the both sides in the conveying direction of the upper end <NUM> of the wiper body <NUM> (see <FIG>). In other words, each of the two projections <NUM> projects, in the second surface <NUM> of the wiper body <NUM>, from one of the stepped parts <NUM> toward the other side in the wiping direction (right side). Each of the projections <NUM> has a base <NUM> having a substantially rectangular parallelepiped shape and extending perpendicularly from the second surface <NUM>, and a supporting part <NUM> which spreads downward from a lower end of the base <NUM>. Note that an upper surface 131a of the base <NUM> is flush with one of the stepped parts <NUM> of the wiper body <NUM>. As will be described later on, in a case that the wiper <NUM> is at the wiping position, the upper surface 131a of the base <NUM> makes contact with the nozzle cover <NUM> of the head <NUM>. The upper surface 131a of the base <NUM> is an example of a "contact surface" of the present invention.

As depicted in <FIG>, a thickness in the conveying direction of the base <NUM> is greater than a thickness in the conveying direction of the supporting part <NUM>. An upper end of the supporting part <NUM> is continuously connected to a lower end of the base <NUM>, and a left end of the supporting part <NUM> is continuously connected to the second surfaced <NUM> of the wiper body <NUM>. A lower end of the supporting part <NUM> is located at a position lower than the center in the up-down direction of the second surface <NUM>. The supporting part <NUM> has a trapezoidal shape as seen in the conveying direction, and a length in the wiping direction of the supporting part <NUM> becomes longer further downward from the lower end of the base <NUM>. Further, a length in the up-down direction of the supporting part <NUM> becomes shorter as separating further away from the second surface <NUM> of the wiper body <NUM> toward the right side.

As depicted in <FIG>, a width L1 in the conveying direction of the upper end <NUM> of the wiper body <NUM> is greater than a length L2 in the conveying direction of the nozzle formation area 41B of each of the heads <NUM>, and is slightly smaller than an inner width L3 of the nozzle cover <NUM>. Accordingly, in a case that the wiper <NUM> is positioned at the wiping position, the upper end <NUM> of the wiper body <NUM> is capable of making contact with the nozzle surface 41B, without interfering with the nozzle cover <NUM>. Further, the width L1 in the conveying direction of the upper end <NUM> of the wiper body <NUM> is greater than the length L2 in the conveying direction of the nozzle formation area 41B of each of the heads <NUM>. Accordingly, during the wiping operation, the upper end <NUM> of the wiper body <NUM> is capable of wiping the entirety of the nozzle formation area 41B. Furthermore, a depth l in the up-down direction of the stepped parts <NUM> is substantially same as a height H in the up-down direction of the nozzle cover <NUM>. Moreover, as described above, the upper surface 131a of the base <NUM> is flush with the stepped parts <NUM> of the wiper body <NUM>. Accordingly, in the case that the wiper <NUM> is positioned at the wiping position, the stepped parts <NUM> of the wiper body <NUM> and the upper surface 131a of the base <NUM> are capable of making contact with the nozzle cover <NUM>. Further, a width L4 in the conveying direction of the stepped parts <NUM> and a width L5 in the conveying direction of the upper surface 131a of the base <NUM> are greater than a length L6 in the conveying direction of the nozzle cover <NUM>. Accordingly, at the time of the wiping, the stepped parts <NUM> and the upper surface 131a of each of the projections <NUM> are capable of wiping the entirety of the nozzle cover <NUM>.

The fixing member <NUM> is a member configured to fix the wiper body <NUM> to the maintenance base <NUM>. As depicted in <FIG>, the fixing member <NUM> is provided with a first member <NUM> and a second member <NUM> which are fixable to the first member <NUM>. Note that the first member <NUM> is fixed to the maintenance base <NUM> (see <FIG>). As depicted in <FIG>, the first member <NUM> is a member having a cross section which is substantially a shape of a letter "L", and elongated in the conveying direction. Two projecting bars <NUM> and <NUM> extending in the conveying direction are formed in a surface on the right side in the wiping direction of the first member <NUM>. The projecting bar <NUM> is positioned above the projecting bar <NUM>, and the projecting bars <NUM> and <NUM> are arranged with a spacing distance in the up-down direction. The projecting bar <NUM> is formed to have a discontinued gap <NUM> at a part in the conveying direction thereof. As depicted in <FIG>, it is possible to fix the wiper body <NUM> to the fixing member <NUM> by causing the base member <NUM> provided on the lower part of the wiper body <NUM> to be sandwiched between the first member <NUM> and the second member <NUM> in a state that the base part <NUM> is inserted between the two projecting bars <NUM> and <NUM>. Since the base part <NUM> is inserted between the two projecting bars <NUM> and <NUM>, there is no fear that the wiper body <NUM> might be deviated in the up-down direction. Further, although not depicted in the drawings, the projecting part <NUM> of the base part <NUM> engages with the gap <NUM> provided on the projecting bar <NUM>. With this, there is not such a fear that the wiper body <NUM> might be deviated in the conveying direction.

Next, the deformation of the wiper <NUM> during the wiping operation will be explained, with reference to <FIG>.

As depicted in <FIG> in a dotted line, in a case that the wiper body <NUM> and the projection <NUM> do not make contact with the lower surface of the head <NUM>, the wiper body <NUM> stands vertically with respect to the maintenance base <NUM> so that the wiper body <NUM> is parallel to the up-down direction. A length L in the up-down direction (hereinafter referred to as a height L) of the wiper body <NUM> is greater than the distance in the up-down direction between the maintenance base <NUM> and the nozzle surface 41A of the head <NUM>. In the case that the wiper body <NUM> do not make contact with the lower surface of the head <NUM>, the wiper body <NUM> and the head <NUM> overlap with each other in the up-down direction by an amount corresponding to a length LAP. Namely, the upper end <NUM> of the wiper body <NUM> is located above the nozzle surface 41A of the head <NUM> by the length LAP. In this situation, a length of a part, which is included in the wiper body <NUM> and which does not overlap with the head <NUM> in the up-down direction, can be expressed as: length L - LAP. Note that the distance in the up-down direction between the upper end <NUM> of the wiper body <NUM> and the projection <NUM> is referred to as a distance l. As described above, since the upper surface 131a of the projection <NUM> and the stepped parts <NUM> are flush with each other, the distance l corresponds to the depth in the up-down direction of the stepped parts <NUM> (see <FIG>).

As depicted in a solid line in <FIG>, in a case that the upper end <NUM> of the wiper body <NUM> makes contact with the nozzle surface 141A, the wiper body <NUM> is deformed to be inclined by an angle <NUM> toward the other side in the wiping direction (right side), as compared with the case that the upper end <NUM> of the wiper body <NUM> does not make contact with the nozzle surface 141A. Note that the angle θ1 can be expressed as: θ1 = arccos ((L-LAP)/L)[rad]. Note that since the projection <NUM> projects perpendicularly from the wiper body <NUM> toward the other side in the wiping direction (right side), the projection <NUM> does not make contact with the lower surface of the head <NUM> in a case that the upper end <NUM> of the wiper body <NUM> makes (is making) contact with the nozzle surface 41A. In other words, in a case that the wiper body <NUM> makes (is making) contact with the nozzle surface 31A of the head <NUM> and is thereby (being) deformed, the projection <NUM> does not hinder the wiper body <NUM> from being deformed.

Here, such a case is presumed that the projection <NUM> is not provided on the wiper <NUM>. In a case that the wiper <NUM> moves, with respect to the head <NUM>, toward the one side in the wiping direction (left side) and that the upper end <NUM> of the wiper body <NUM> is separated from the nozzle surface 41A, the wiper body <NUM> is abruptly restored to a parallel state in which the wiper body <NUM> is parallel to the up-down direction. Namely, the wiper body <NUM> is consequently restored to be inclined by the angle θ1 toward the one side in the wiping direction (left side). In this situation, there is such a fear that the ink which has been wiped from the nozzle surface 41a by the wiping operation and adhered to the first surface <NUM> of the wiper body <NUM> might be scattered in the surrounding due to the abrupt restoration of the wiper body <NUM>.

In view of this, the projection <NUM> is provided on the wiper <NUM> in the present embodiment. In this case, as depicted by the solid line in <FIG>, in the case that the wiper <NUM> moves, with respect to the head <NUM>, toward the one side in the wiping direction (left side) and that the upper end <NUM> of the wiper body <NUM> is separated from the nozzle surface 41A, the projection <NUM> makes contact with the lower surface of the head <NUM> (for example, the lower surface of the nozzle cover <NUM>) before the wiper body <NUM> becomes to be parallel to the up-down direction. With this, in an instant that the upper end <NUM> of the wiper body <NUM> is separated from the nozzle surface 41A, the wiper body is restored toward the one side in the wiping direction (left side) only by an angle θ2 (θ2 < θ1), rather than by the angle θ1. Here, the angle θ2 can be expressed as: θ2 = arccos ((L-l)/L)[rad]. Further, provided that a distance along the projection <NUM> between the wiper body <NUM> and a contact point between the projection <NUM> and the head <NUM> in the case that the projection <NUM> makes contact with the lower surface of the head <NUM> is expressed as "X", the X can be expressed as: X = L sin θ2. The distance X corresponds to a height of the projection <NUM> from the wiper body <NUM> which is required in a case of determining the height L of the wiper body <NUM>, the overlap LAP in the up-down direction between the wiper body <NUM> and the nozzle surface 41A of the head <NUM> and the distance l in the up-down direction between the upper end <NUM> of the wiper body <NUM> and the projection <NUM>.

In a case that the wiper <NUM> moves further toward the one side in the wiping direction (left side) with respect to the head <NUM> and that the projection <NUM> is separated from the lower surface of the head <NUM>, the wiper body <NUM> is restored toward the one side in the wiping direction (left side) further only by an angle θ3 (θ3 = θ1 - θ2). With this, the wiper body <NUM> is restored to the state of being parallel to the up-down direction. In such a manner, the wiper body <NUM> is restored gradually in the two phases after the upper end <NUM> of the wiper body <NUM> is separated from the nozzle surface 41A. With this, occurrence of such a situation that the ink which has been wiped from the nozzle surface 41a by the wiping operation and adhered to the first surface <NUM> of the wiper body <NUM> is scattered in the surrounding due to the abrupt restoration of the wiper body <NUM> is lowered.

Note that according to the calculation by the inventors, it is found out that in a case that the height L of the wiper body <NUM> is <NUM>, the overlap LAP in the up-down direction between the wiper body <NUM> and the nozzle surface 41A of the head <NUM> is <NUM>, and the distance l in the up-down direction between the upper end <NUM> of the wiper body <NUM> and the projection <NUM> is <NUM>, the angle θ1 is <NUM>°, the angle θ2 is <NUM>° and the angle θ3 is <NUM>°; and that the required height X of the projection <NUM> from the wiper body <NUM> is <NUM>. Further, it is found out that in a case that the height L of the wiper body <NUM> is <NUM>, the overlap LAP in the up-down direction between the wiper body <NUM> and the nozzle surface 41A of the head <NUM> is <NUM>, and the distance l in the up-down direction between the upper end <NUM> of the wiper body <NUM> and the projection <NUM> is <NUM>, the angle θ1 is <NUM>°, the angle θ2 is <NUM>° and the angle θ3 is <NUM>°; and that the required height X of the projection <NUM> from the wiper body <NUM> is <NUM>. Furthermore, it is found out that in a case that the height L of the wiper body <NUM> is <NUM>, the overlap LAP in the up-down direction between the wiper body <NUM> and the nozzle surface 41A of the head <NUM> is <NUM>, and the distance l in the up-down direction between the upper end <NUM> of the wiper body <NUM> and the projection <NUM> is <NUM>, the angle θ1 is <NUM>°, the angle θ2 is <NUM>° and the angle θ3 is <NUM>°; and that the required height X of the projection <NUM> from the wiper body <NUM> is <NUM>. In such a manner, it is found out that by fixing the height X of the wiper body and by changing the value of the overlap LAP in the up-down direction between the wiper body <NUM> and the nozzle surface 41A of the head <NUM>, the angles θ1 and θ2 change as described above.

In the above-described embodiment, the head <NUM> has the lower surface including the nozzle surface 41A in which the nozzles 11a are opened. The wiper <NUM> is configured to make contact with the nozzle surface 41A of the head <NUM> and to wipe the nozzle surface 41A. The head holder <NUM>, the driving motor <NUM>, the inion gear <NUM>, the rack gear <NUM> and the guide <NUM> are collectively referred to as the driving part. By using the driving part, it is possible to move the head holder <NUM> (head <NUM>) so that the wiper <NUM> moves toward the one side in the wiping direction (left side) relative to (with respect to) the head <NUM> in the state that the wiper <NUM> makes contact with the nozzle surface 41A. Note that the present invention is not necessarily limited to a configuration wherein the head <NUM> moves in the wiping direction in the state that the wiper <NUM> is fixed. It is allowable that the wiper <NUM> is configured to move in the wiping direction in a state that the head <NUM> stands still, or that both of the head <NUM> and the wiper <NUM> are configured to move in the wiping direction.

The wiper <NUM> is provided with the wiper body <NUM> having the upper end <NUM> which is a wiping part configured to wipe the nozzle surface 41A, and the projection <NUM> which projects from the wiper body <NUM> toward the other side in the wiping direction (right side). After the upper end <NUM> of the wiper body <NUM> is separated from the end part on the one side in the wiping direction (left side) of the nozzle surface 41A, the projection <NUM> makes contact with the lower surface of the head <NUM> (the lower surface of the nozzle cover <NUM>).

After the upper end <NUM> of the wiper body <NUM> is separated from the end part on the one side in the wiping direction (left side) of the nozzle surface 41A, the projection <NUM> makes contact with the lower surface of the head <NUM> (the lower surface of the nozzle cover <NUM>), which in turn suppress occurrence of such a situation that the deformation of the wiper body <NUM> is restored all at once. With this, the restoring speed of the wiper body <NUM> is suppressed to thereby suppress the occurrence of such a situation that the ink which has been wiped from the nozzle surface 41a by the wiping operation and adhered to the first surface <NUM> and the upper end <NUM> of the wiper body <NUM> is scattered in the surrounding due to the abrupt restoration of the wiper body <NUM>. By providing the projection <NUM> as described above on the wiper <NUM>, the restoring force of the wiper body <NUM> is suppressed. Accordingly, there is no need to provide a member which is different from the wiper <NUM> separately so as to suppress the restoring force of the wiper body <NUM>, and to suppress the manufacturing cost. Further, since the projection <NUM> is formed in the second surface <NUM> on the other side in the wiping direction (right side), the projection <NUM> does not affect the deformation of the wiper body <NUM> in a case that the wiper body <NUM> wipes the nozzle surface 41A. Accordingly, even in a case that the projection <NUM> is formed so as to suppress the restoring force of the wiper body <NUM>, there is not such a fear that the wiping performance of the wiper <NUM> might be lowered.

In the above-described embodiment, the wiper body <NUM> and the projection <NUM> are produced by being integrally formed. With this, it is possible to suppress the increase in the manufacturing cost of the wiper <NUM>.

In the above-described embodiment, the projection <NUM> is provided with the upper surface 131a of the base <NUM> which extends perpendicularly from the second surface <NUM> on the other side in the wiping direction (right side) of the wiper body <NUM>, and makes contact with the lower surface of the nozzle cover <NUM> of the head <NUM>. With this, it is possible to wipe the lower surface of the nozzle cover <NUM> by using the upper surface 131a of the base <NUM> of the projection <NUM>.

In the above-described embodiment, the supporting part <NUM> is provided on the projection <NUM>, at the location below the base <NUM>. The upper end of the supporting part <NUM> is continuously connected to the lower end of the base <NUM>, and the left end of the supporting part <NUM> is continuously connected to the second surface <NUM> of the wiper body <NUM>. The supporting part <NUM> has a shape of trapezoid as seen in the conveying direction, and the length in the wiping direction of the supporting part <NUM> becomes longer further downward from the lower end of the base <NUM>. By adopting such a configuration, it is possible to support the base <NUM> of the projection <NUM> more stably by the supporting part <NUM>.

In the above-described embodiment, the wiper body <NUM> has the upper end <NUM> as the wiping part configured to wipe the nozzle surface 41A and the first surface <NUM>. Accordingly, the ink wiped from the nozzle surface 41A by the wiping operation adheres to the first surface <NUM> of the wiper body <NUM>. Since the plurality of grooves <NUM> extending in the up-down direction is formed in the first surface <NUM> of the wiper body <NUM>, it is possible to move the ink adhered to the first surface <NUM> downward via the plurality of grooves <NUM>. With this, it is possible to suppress the occurrence of such a situation that the ink adhered to the first surface <NUM> is scattered in the surrounding in a case that the deformation of the wiper body <NUM> is restored.

In the above-described embodiment, the two projections <NUM> which project from the second surface <NUM> of the wiper body <NUM> are provided on the wiper <NUM>. The two projections <NUM> are arranged with the spacing distance in the conveying direction orthogonal to the wiping direction. Since the two projections <NUM> are provided on the wiper <NUM> in such a manner, it is possible to wipe two location at a time by using the two projections <NUM>.

Further, the two projections <NUM> make contact with the nozzle cover <NUM>, rather than making contact with the nozzle surface 41A in the lower surface of the head <NUM>. With this, it is possible to wipe the nozzle cover <NUM> at the same time with the wiping of the nozzle surface 41A, rather than wiping only the nozzle surface 41A.

In the above-described embodiment, the wiper body <NUM> has the upper end <NUM> making contact with the nozzle surface 41A at the time of the wiping, and the stepped parts <NUM> of which height in the up-down direction is lower than that of the upper end <NUM>. At the time of the wiping, the stepped parts <NUM> make contact with the nozzle cover <NUM> which covers the nozzle surface 41A from therebelow. With this, it is possible to perform wiping for the nozzle surface 41A and the nozzle cover <NUM> at a time during the wiping.

In the present embodiment, in a case that the wiper <NUM> moves toward the one side in the wiping direction (left side) relative to the head <NUM> and that the upper end <NUM> of the wiper body <NUM> is separated from the nozzle surface 41A, the projections <NUM> make contact with the lower surface of the nozzle cover <NUM> before the wiper body <NUM> becomes to be parallel to the up-down direction. In this case, since the projections <NUM> do not collide against the nozzle surface 41A, there is not a fear that the projections <NUM> might damage the nozzle surface 41A.

In the present embodiment, the plurality of grooves <NUM> extending in the up-down direction and the plurality of grooves <NUM> extending in the conveying direction are formed in the second surface <NUM> of the wiper body <NUM>. The plurality of grooves <NUM> has the effect of moving the ink adhered to the second surface <NUM> downward, similarly to the plurality of grooves <NUM>. Further, by providing the plurality of grooves <NUM> on the second surface <NUM>, it is possible to make the wiper body <NUM> to be easily deformable.

In the present embodiment, the two projecting bars <NUM> and <NUM> which are configured to fit to the base part <NUM> of the wiper <NUM> are formed in the fixing member <NUM>. Further, the projecting bar <NUM> of the fixing part <NUM> is provided with the gap <NUM> configured to fit to the projecting part <NUM> of the base part <NUM> of the wiper <NUM>. Since the base part <NUM> is inserted between the two projecting bars <NUM> and <NUM>, there is no such a fear that that the wiper body <NUM> might be deviated in the up-down direction. Further, since the projecting part <NUM> of the base part <NUM> engages with the gap <NUM> formed in the projecting bar <NUM>, there is not such a fear that the wiper body <NUM> might be deviated in the conveying direction.

In the present embodiment, each of the first surface <NUM> and the second surface <NUM> of the wiper body <NUM> is a broad wide surface expanding in the conveying direction and the up-down direction. The thickness in the wiping direction of the wiper body <NUM> becomes thinner further upward. Further, the two projections <NUM> are arranged to be apart in the both sides in the conveying direction of the second surface <NUM>. Each of the projections <NUM> has the base <NUM> and the supporting part <NUM>. The lower end of the supporting part <NUM> is located below the center in the up-down direction of the second surface <NUM> of the wiper body <NUM>. Further, the length in the conveying direction of each of the projections <NUM> is greater than the thickness in the conveying direction of the wiper body <NUM>.

Also in such a case, since after the upper end <NUM> of the wiper body <NUM> is separated from the end part on the one side in the wiping direction (left side) of the nozzle surface 41A, the projections <NUM> make contact with the lower surface of the head <NUM> (the lower surface of the nozzle cover <NUM>), it is possible to suppress occurrence of such a situation that the deformation of the wiper body <NUM> is restored all at once. This suppresses the occurrence of such a situation that the ink which has been wiped from the nozzle surface 41A by the wiping operation and adhered to the first surface <NUM> and the upper end <NUM> of the wiper body <NUM> is scattered in the surrounding due to the abrupt restoration of the wiper body <NUM>. Further, by providing the projections <NUM> as described above on the wiper <NUM>, the restoring force of the wiper body <NUM> is suppressed. Accordingly, there is no need to provide a member which is different from the wiper <NUM> separately so as to suppress the restoring force of the wiper body <NUM>, and thus it is possible to suppress the manufacturing cost. Further, since the projections <NUM> are formed in the second surface <NUM> on the other side in the wiping direction (right side), the projections <NUM> do not affect the deformation of the wiper body <NUM> in a case that the wiper body <NUM> wipes the nozzle surface 41A. Accordingly, even in a case that the projections <NUM> are formed so as to suppress the restoring force of the wiper body <NUM>, there is no such a fear that the wiping performance of the wiper <NUM> might be lowered.

In the foregoing, the embodiment of the present invention has been explained. The present invention, however, is not limited to or restricted by the above-described embodiment; various kinds of change can be made to the present invention within the range described in the claims. In the following, a modification of the above-described embodiment will be explained.

In the above-described embodiment, the wiper body <NUM>, the base part <NUM> and the projections <NUM> of the wiper <NUM> are integrally formed of the EPDM rubber. The present embodiment, however, is not limited to or restricted by this. For example, it is allowable to form the wiper body <NUM>, the base part <NUM> and the projections <NUM> of a perfluoro fluorine rubber, rather than forming the wiper body <NUM>, the base part <NUM> and the projections <NUM> of the EPDM rubber. Further, it is not necessarily indispensable that the wiper body <NUM>, the base part <NUM> and the projections <NUM> are integrally formed; it is allowable to form the wiper body <NUM>, the base part <NUM> and the projections <NUM> by combining separate (individual) members. Furthermore, although the hardness of the wiper member <NUM> is preferably not less than <NUM> degrees, it is not necessarily indispensable that the hardness of the wiper body <NUM> is not less than <NUM> degrees.

In the above-described embodiment, although the two pieces of the projection <NUM> are provided, the present invention is not necessarily limited to such an aspect. For example, it is allowable that the number (quantity) of the projection <NUM> may be <NUM> (one), or not less than <NUM>. Further, the position in the conveying direction of the projection <NUM> may also be changed as appropriate.

In the above-described embodiment, although the upper surface 131a of the base <NUM> of the projection <NUM> and the stepped part <NUM> are formed to be flush with each other with respect to the up-down direction, the present invention it not limited to such an aspect. For example, it is allowable that the projection <NUM> is arranged so that the upper surface 131a is located below the stepped part <NUM>. Further, in the above-described embodiment, the upper surface 131a of the base <NUM> and the stepped part <NUM> are configured to make contact with the nozzle cover <NUM> and to wipe the nozzle cover <NUM>. The present invention, however, is not limited to such an aspect. For example, it is not necessarily indispensable that the nozzle cover <NUM> is provided on the head <NUM>. In such a case, it is allowable that the stepped part <NUM> is not provided, and that the upper surface 131a of the base <NUM> is configured to make contact with the nozzle surface 41A.

In the above-described embodiment, although the ink-jet printer <NUM> is provided with one piece of the head bar <NUM>, the number (quantity) of the head bar <NUM> may be plural. Note that the number of the head <NUM> provided on the head bar <NUM> is not limited to <NUM> (ten). Further, the number of the nozzle 11a opened in the nozzle surface 41A, the number of the nozzle row, and the number of the nozzle 11a forming each of the nozzle rows are not limited to the numbers, respectively, as described above. Furthermore, it is also possible to change the number and the arrangement of the individual channel <NUM> and the driving element <NUM> as appropriate, in accordance with the number and the arrangement of the nozzle 11a.

It is allowable that the position at which the wiper 110A is attached is not shifted in the wiping direction with respect to the position at which the wiper 100B is attached. Namely, in the maintenance base <NUM>, the attachment position of the wiper 100A and the attachment position of the wiper 100B may be aligned in the wiping direction.

In the above-described embodiment, although the wiper 100A and the wiper 100B are provided as the separate members, the present invention is not limited to this. For example, the wiper 100A and the wiper 100B may be formed or molded as one member by connecting an end part on the one side in the conveying direction (end of the rear side) of the wiper 100A and an end part on the other side in the conveying direction (end part on the front side) of the wiper 100B are connected by a connecting part.

In the above-described embodiment, the head holder <NUM> is supported by the rack gear <NUM> and the guide <NUM> which are arranged on the one side in the conveying direction (rear side) with respect to the head holder <NUM>, the present invention in not limited to this. For example, it is allowable to further provide a guide extending in the wiping direction on the other side in the conveying direction (front side) with respect to the head holder <NUM>, and to support an end part on the other side in the conveying direction of the head holder <NUM> with this guide. In this case, it is also allowable to provide, on the end part on the other side in the conveying direction on the lower surface of the head holder <NUM>, a roller which is slidable along the added guide.

Further, it is allowable to arrange an absorbing member, for example such as a sponge, etc., configured to absorb the ink adhered to the first surface <NUM> of the wiper body <NUM>, on the fixing member <NUM> of the wiper <NUM>.

In the above-described embodiment, the channel unit <NUM> of each of the heads <NUM> is provided with the actuator unit <NUM> having the <NUM> driving elements <NUM> corresponding, respectively to the <NUM> individual channels <NUM>. The present invention, however, is not limited to such an aspect. For example, it is allowable to provide, on the channel unit <NUM>, a heater configured to bump the ink inside each of the individual channels <NUM> so as to discharge the ink from the nozzle 11a, instead of the actuator unit <NUM>.

Claim 1:
A liquid discharge apparatus (<NUM>) comprising:
a head (<NUM>) including a lower surface including a nozzle surface (41A) in which a nozzle (11a) is opened;
a wiper (<NUM>) configured to make contact with the nozzle surface (41A) of the head (<NUM>) and to wipe the nozzle surface (41A); and
a driving part (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) configured to drive at least one of the wiper (<NUM>) and the head (<NUM>) so as to cause the wiper (<NUM>) to move relative to the head (<NUM>) toward one side in a wiping direction in a state that the wiper (<NUM>) makes contact with the nozzle surface (41A),wherein
the wiper (<NUM>) includes:
a wiper body (<NUM>) including a wiping part (<NUM>) configured to wipe the nozzle surface (41A), the wiper body (<NUM>) having a plate shape and including a surface (<NUM>) expanding in a first direction and a second direction orthogonal to the first direction, and a thickness in a third direction orthogonal to the first direction and the second direction; and
a projection (<NUM>) projecting from the wiper body (<NUM>) toward the other side in the wiping direction,
after the wiping part of the wiper body (<NUM>) is separated from an end part on the one side in the wiping direction of the nozzle surface (41A), the projection (<NUM>) is configured to make contact with the lower surface of the head (<NUM>), and
in a case that the wiper body (<NUM>) makes contact with the nozzle surface (41A), the wiper body (<NUM>) is configured to be deformed to be inclined toward the other side in the wiping direction,
characterized in that the projection projects from the surface in the third direction.