Patent Description:
A certain publicly known printing apparatus is provided with a plurality of head units which are aligned along a conveying direction of a sheet (paper sheet). Each of the head units is provided with a casing, a plurality of heads, a liquid supplying device configured to supply a UV ink containing an infrared curing agent to the plurality of heads, and a control substrate. The plurality of heads, the liquid supplying device and the control substrate of each of the plurality of head units are arranged in the inside of the casing. <CIT> discloses a printing apparatus.

The viscosity of the UV ink greatly varies or changes depending on a change in the temperature. Accordingly, from the viewpoint of avoiding the occurrence of any unsatisfactory discharge or ejection in the head(s), it is desired to make the temperature of a space around the heads and the liquid supplying device to be constant so as to maintain the temperature of the UV ink at a constant temperature. In view of this, since the control substrate generates a heat accompanying with the driving of the head(s), the control substrate needs to be cooled by using a fan, etc. In the above-described printing apparatus, the liquid supplying device and the heads each including the UV ink which needs to be maintained at the constant temperature and the control substrate requiring the cooling are arranged in the same casing. Therefore, there is such a fear that the temperature of the space around the heads and the liquid supplying device might vary or fluctuate accompanying with the cooling of the control substrate. In a case that the temperature of the space around the heads and the liquid supplying device varies, there is such a fear that the temperature of the UV ink might vary and a discharge state (ejection state) of the head(s) might vary.

An object of the present disclosure is to provide a technique of suppressing any variation or fluctuation in the temperature of the ink due to the cooling of the control substrate.

According to an aspect of the present disclosure, there is provided a head assembly as defined in appended claim <NUM>.

In the above-described configuration, the rigid substrate having the power source mounted thereon is arranged in the first space defined by the first member; and the tank configured to store the ink, the plurality of tubes forming an ink channel, the heater configured to warm or heat the ink, and the plurality of flexible substrates are arranged in the second space defined by the second member. The first space and the second space are partitioned from each other by the relay substrate. Since the airflow port configured to take the outside air thereinto is formed in the first member, it is possible to cool the power source of the rigid substrate by taking the outside air thereinto. The first space and the second space, however, are partitioned from each other by the relay substrate, thereby making it possible to suppress any variation or fluctuation in the temperature in the second space which would be otherwise caused due to any inflow of the air of the first space into the second space. With this, it is possible to suppress any effect of the variation in the temperature in the first space to the temperature in the second space, while cooling the first space with the outside air. Further, it is possible to electrically connect, to the relay substrate, the other end of each of the plurality of flexible substrates and the connector of the rigid substrate. With this, it is possible to connect the first space and the second space electrically, while shutting off the first space and the second space from each other thermally.

In the following, a printing apparatus <NUM> according to an embodiment of the present disclosure will be explained, based on the drawings. In <FIG>, a conveying direction of a recording medium <NUM> corresponds to a front-rear direction of the printing apparatus <NUM>. Further, a width direction of the recording medium <NUM> corresponds to a left-right direction of the printing apparatus <NUM>. Furthermore, a direction orthogonal to the front-rear direction and the left-right direction, namely, a direction perpendicular to the sheet surface in <FIG> corresponds to an up-down direction of the printing apparatus <NUM>. Note that the left-right direction is an example of a "first direction" of the present embodiment, and the front-rear direction (conveying direction) is an example of a "second direction" of the present embodiment.

As depicted in <FIG> and <FIG>, the printing apparatus <NUM> is provided with a platen <NUM>, three line head assemblies <NUM> (an example of a "head assembly" of the present disclosure), two conveying rollers 5A and 5B, a controller <NUM>, five ink reservoirs <NUM>, etc., which are accommodated in a casing <NUM>. Note that in <FIG> and <FIG>, only one reservoir <NUM> is depicted so as to simplify the drawings.

As depicted in <FIG> and <FIG>, a recording medium <NUM> is placed on an upper surface of the platen <NUM>. The three line head assemblies <NUM> are arranged, at a location above the platen <NUM>, so as to face (to be opposite to) the platen <NUM>. An ink is supplied from the ink reservoir <NUM> to each of the line head assemblies <NUM>. The structure of each of the line head assemblies <NUM> will be explained later on. Note that the three line head assemblies <NUM> are fixed to an arch frame <NUM> so that the three line head assemblies <NUM> are arranged along the front-rear direction (the conveying direction of the recording medium <NUM>). As depicted in <FIG>, the arch frame <NUM> has an arch shape, and the three line head assemblies <NUM> are arranged so that the three line head assemblies <NUM> are inclined with respect to a horizontal plane at mutually different angles.

As depicted in <FIG> and <FIG>, the two conveying rollers 5A and 5B are arranged, respectively, on the rear side and the front side of the platen <NUM>. The two conveying rollers 5A and 5B are driven by a non-illustrated motor. As depicted in <FIG>, the recording medium <NUM> is fed from a feeding roll 4A around which the recording medium <NUM> is wound in a roll shape, and is wound by a winding roll 4B. For example, it is allowable to use roll paper (roll paper sheet) as the recording medium <NUM>. Rotating shafts 4C and 4D, which are rotated by a non-illustrated motor, are attached to the feeding roll 4A and the winding roll 4B, respectively. These two rotating shafts 4C and 4D and the two conveying rollers 5A and 5B cooperate so as to feed the recording medium <NUM> from the feeding roll 4A, to convey the recording medium <NUM> toward the downstream side in the conveying direction (frontward) so that the recording medium <NUM> passes on the platen <NUM>, and to cause the recording medium <NUM> to be wound by the winding roll 4B. The two rotating shafts 4C and 4D and the two conveying rollers 5A and 5B are an example of a "conveyor" of the present disclosure.

As depicted in <FIG>, each of the line head assemblies <NUM> is provided with a line head <NUM> having a plurality of heads <NUM> (<NUM> pieces of the head <NUM> in the present embodiment). The plurality of heads <NUM> construct two head rows (head arrays) which are arranged in the front-rear direction. Each of the head rows includes <NUM> pieces of the head <NUM> which are arranged in the left-right direction. Positions in the front-rear direction of the five heads <NUM> arranged in the left-right direction are same. Note that, however, in the following explanation, the phrase that "the positions are same" does not mean that the positions are same in a strict sense; rather, the phrase intends to mean that the positions are same within a manufacturing error and an attaching error. Note that the positions in the left-right direction of the heads <NUM> included in the two head rows are shifted from one another. Namely, <NUM> pieces of the head <NUM> are arranged in a staggered manner.

A lower surface 11b of each of the heads <NUM> is a nozzle surface in which a plurality of nozzles 11a are formed. As depicted in <FIG>, the plurality of nozzles 11a of each of the heads <NUM> are arranged in a row form along the left-right direction which is the longitudinal direction of the line head <NUM> (line head assembly <NUM>) to thereby construct two nozzle rows. Note that although an intra-head channel is formed in the inside of each of the heads <NUM>, the shape, etc., of the intra-head channel will be described later on.

As described above, the ten heads <NUM> in each of the line head assemblies <NUM> (line heads <NUM>) form the two head rows. As described above, each of the ten heads <NUM> has the two nozzle rows. Since it is possible to discharge or eject different color inks from the respective nozzle rows, each of the ten heads <NUM> is capable of ejecting two color inks, at most. A white ink is supplied from one of the five ink reservoirs <NUM> to ten heads <NUM> of a line head assembly <NUM> which is arranged on the rearmost side (arranged closest to the upstream side in the conveying direction) among the three line head assemblies <NUM>. The white ink is usable for underlayer printing. A yellow ink and a magenta ink are supplied, respectively, from two of the five ink reservoirs <NUM> to ten heads <NUM> of a line head assembly <NUM> which is arranged second from the rear side (second from the upstream side in the conveying direction) among the three line head assemblies <NUM>. The yellow ink is ejected from a nozzle row which is arranged on the rear side (the upstream side in the conveying direction) among the two nozzle rows; and the magenta ink is ejected from a nozzle row which is arranged on the front side (the downstream side in the conveying direction) among the two nozzle rows, of each of the heads <NUM>. A cyan ink and a black ink are supplied, respectively, from two of the five ink reservoirs <NUM> to ten heads <NUM> of a line head assembly <NUM> which is arranged on the frontmost side (arranged closest to the downstream side in the conveying direction) among the three line head assemblies <NUM>. The cyan ink is ejected from a nozzle row which is arranged on the rear side (the upstream side in the conveying direction) among the two nozzle rows; and the black ink is ejected from a nozzle row which is arranged on the front side (the downstream side in the conveying direction) among the two nozzle rows, of each of the heads <NUM>. In the present embodiment, the inks are ejected from the three line head assemblies <NUM> which are arranged in the conveying direction in an order of a light (pale) color ink to a deep color ink from the upstream side toward the downstream side in the conveying direction, as described above. Note that in the present embodiment, each of the white ink, the yellow ink, the magenta ink, the cyan ink and the black ink is an UV-curable ink. The viscosity of the UV-curable ink varies or changes greatly depending on the temperature. In order to avoid any unsatisfactory ejection, it is necessary to maintain the viscosity of the ink within an appropriate range. For this purpose, it is necessary to maintain the temperature of the UV-curable ink at an appropriate temperature.

The controller <NUM> is provided with a FPGA (Field Programmable Gate Array), an EEPROM (Electrically Erasable Programmable Read-Only Memory), a RAM (Random Access Memory), etc. Note that the controller <NUM> may be provided with a CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit), etc. The controller <NUM> is connected to an external apparatus <NUM> such as a PC, etc., to be capable of data communication, and controls the respective parts or components of the printing apparatus <NUM> based on print data transmitted from the external apparatus <NUM>.

The controller <NUM> controls the motor driving the rotating shafts 4C and 4D and the motor driving the conveying rollers 5A and 5B so as to causes the two conveying rollers 5A and 5B to convey the recording medium <NUM> in the conveying direction. Further, the controller <NUM> controls the three line head assemblies <NUM> so as to eject the ink(s) from the nozzles 11a toward the recording medium <NUM>. With this, an image is printed on the recording medium <NUM>.

Next, the structure of the line head assembly <NUM> will be explained, with reference to the drawings. Note that since the three line head assemblies <NUM> has a same structure, the explanation will be made regarding one of the line head assemblies <NUM>. As described above, the three line head assemblies <NUM> are arranged so as to be inclined with respect to the horizontal plane at the mutually different angles, respectively. However, in order to simplify the explanation, in the following description, the direction(s) is (are) defined on the premise that the line head assemblies <NUM> are arranged perpendicularly on the horizontal plane. As depicted in <FIG>, each of the line head assemblies <NUM> is mainly provided with: a first casing <NUM>, a second casing <NUM>, a line head <NUM> including ten heads <NUM>, ten rigid substrates <NUM>, ten flexible substrates <NUM>, a fan <NUM>, a relay substrate <NUM>, a tank <NUM>, a heater <NUM>, and a plurality of tubes <NUM> connecting the heads <NUM> with the tank <NUM>. Note that in <FIG>, five flexible substrates <NUM> among the ten flexible substrates <NUM> are depicted.

As depicted in <FIG> and <FIG>, the first casing <NUM> is arranged to be superposed above the second casing <NUM>. The first casing <NUM> defines, in the inside thereof, a first space S1, and the second casing <NUM> defines, in the inside thereof, a second space S2. Note that in <FIG> and <FIG>, a lateral surface on the front side and a lateral surface on the rear side of each of the first casing <NUM> and the second casing <NUM> are removed so that the first space S1 and the second spaced S2 are easily seen. Note that the left-right direction corresponds to a depth direction of the first casing <NUM> and the second casing <NUM>, and the front-rear direction corresponds to a width direction of the first casing <NUM> and the second casing <NUM>. The depth direction is orthogonal to both of the up-down direction and the width direction.

As depicted in <FIG>, the first casing <NUM> has a substantially rectangular parallelepiped shape. A top plate <NUM> defining the upper surface of the first casing <NUM> is provided with a first grip <NUM>. A airflow port <NUM> is opened in a side wall 102R on the right side of the first casing <NUM>. The fan <NUM> is attached to the airflow port <NUM>. As will be described later on, the fan <NUM> is capable of feeding airflow (air) in an aligning direction (the left-right direction, the depth direction) of the rigid substrates <NUM>. Further, an opening <NUM> is formed in the lower surface of the first casing <NUM>.

The second casing <NUM> has such a shape that two rectangular parallelepipeds of which heights are mutually different are combined, and has, for example, a substantially shape of a letter "L" as seen from the front-rear direction. The upper surface of the second casing <NUM> has a first top plate 201a, a second top plate 201b which is arranged on the right side and on the upper side of the first top plate 201a, and a connecting wall 201c which links the first top plate 201a and the second top plate 201b and extends in the up-down direction. The connecting wall 201c expands in the width direction (front-rear direction) and the up-down direction, and is orthogonal to the depth direction (left-right direction). An opening <NUM> is formed in the first top plate 201a. Note that an opening area of the opening <NUM> formed in the lower surface of the first casing <NUM> and an opening area of the opening <NUM> formed in the first top plate 201a of the second casing <NUM> are approximately same. In a case that the first casing <NUM> is arranged to be overlaid on the upper surface of the second casing (the first top plate 201a) from thereabove, the two openings <NUM> and <NUM> overlap with each other in the up-down direction.

A second grip 208a is provided on a side wall <NUM> on the left side of the second casing <NUM>, and a third grip 208b is provided on the second top plate 201b of the second casing <NUM>. An electric power input port <NUM>, four ink ports <NUM> and a set of cooling water ports <NUM> are provided on a side wall 202R on the right side of the second casing <NUM>. The set of cooling water ports <NUM> are each a port for circulating a cooling water for colling the heads <NUM>. A non-illustrated piezoelectric actuator provided in the inside of each of the heads <NUM> generates heat accompanying with being driven. Accordingly, in a case that the head <NUM> is not sufficiently cooled, any unevenness in the temperature occurs in the head <NUM>, due to which any difference in the viscosity occurs, in some cases, between a certain nozzle 11a and another nozzle 11a. In such a case, even in a case that a driving signal of a same waveform is inputted, there is such a fear that any difference in the size might arise between an ink droplet of the ink ejected from the certain nozzle 11a and an ink droplet of the ink ejected from the another nozzle 11a, in some cases, and which might lead to any lowering in the print quality. In view of this, in the present embodiment, the cooling water is introduced from the set of cooling water ports <NUM> so as to cool the heads <NUM>. A non-illustrated electric power cable from a non-illustrated external power source is connected to the electric power input port <NUM>. The four ink ports <NUM> has a first ink supply port 222f, a second ink supply port 223f, a first ink discharge port 222d, and a second ink discharge port 223d. The first ink supply port 222f and the first ink discharge port 222d construct a pair, and are connected to a same ink reservoir <NUM> (see <FIG>). Namely, a same ink flows in the pair of the first ink supply port 222f and the first ink discharge port 222d. The first ink supply port 222f and the first ink discharge port 222d are connected, respectively, to a first supply port <NUM> and a first discharge port <NUM> of the tank <NUM> (see <FIG>). The second ink supply port 223f and the second ink discharge port 223d construct another pair, and are connected to a same ink reservoir <NUM> (see <FIG>). Namely, a same ink flows in the pair of the second ink supply port 223f and the second ink discharge port 223d. Note that it is not necessarily indispensable that the ink flowing in the pair of the first ink supply port 222f and the first ink discharge port 222d and the ink flowing in the pair of the second ink supply port 223f and the second ink discharge port 223d are same; for example, the inks may be different from each other. Further, the second ink supply port 223f and the second ink discharge port 223d are connected, respectively, to a second supply port <NUM> and a second discharge port <NUM> of the tank <NUM> (see <FIG>).

As depicted in <FIG> and <FIG>, since the four ink ports <NUM> are arranged on the lower side of the power source input port <NUM>, in a case that the ink leaks from the ink port(s) <NUM> and drips downward, there is no such a fear that the ink might adhere to the electric power input port <NUM>. With this, it is possible to prevent any shortage which would be otherwise caused by any dirtying of and the adhesion of the ink to the electric power input port <NUM>.

As depicted in <FIG>, the relay substrate <NUM> is attached to the second casing <NUM> so as to close the opening <NUM>, formed in the first top plate 201a of the second casing <NUM>, from therebelow. An upper surface of the relay substrate <NUM> is exposed from the opening <NUM> of the first casing <NUM>, and the upper surface of the relay substrate <NUM> closes the opening of the first casing <NUM>. Namely, the relay substrate <NUM> closes both of the opening <NUM> in the lower surface of the first casing <NUM> and the opening <NUM> in the upper surface of the second casing <NUM>. With this, the upper surface of the relay substrate <NUM> defines a part of the first space S1 and the lower surface of the relay substrate <NUM> defines a part of the second space S2.

As depicted in <FIG>, the relay substrate <NUM> is provided with <NUM> pieces of a first connector <NUM>, <NUM> pieces of a second connector <NUM> and a power source connector <NUM>. The power source connector <NUM> is arranged at a right end of the relay substrate <NUM>. As described above, the power source input port <NUM> is provided on the side wall 202R on the right side of the second casing <NUM>. As depicted in <FIG>, the power source connector <NUM> of the relay substrate <NUM> and the power source input port <NUM> are connected by a power source cable <NUM>. Further, the ten first connectors <NUM> are arranged on the upper surface, of the relay substrate <NUM>, which is exposed in the first space S1. In other words, the ten first connectors <NUM> are arranged on the upper surface, of the relay substrate <NUM>, facing the first space S1. The ten first connectors <NUM> are arranged in two rows in the front-rear direction (width direction). Each of the rows of the first connectors <NUM> includes <NUM> pieces of the first connector <NUM> arranged in the left-right direction (depth direction). Namely, an extending direction (row direction) of the row of the first connectors <NUM> is parallel to the depth direction (left-right direction). The ten second connectors <NUM> are arranged on the lower surface, of the relay substrate <NUM>, which is exposed in the second space S2. In other words, the ten second connectors <NUM> are arranged on the lower surface, of the relay substrate <NUM>, facing the second space S2. The ten second connectors <NUM> are also arranged in two rows in the width direction (front-rear direction); and each of the rows of the second connectors <NUM> includes <NUM> pieces of the second connector <NUM> arranged in the depth direction (left-right direction). Namely, an extending direction (row direction) of the row of the second connectors <NUM> is parallel to the depth direction (left-right direction). Note that the upper surfaced of the relay substate <NUM> corresponds to a "first surface" of the relay substrate of the present disclosure, and the lower surface of the relay substate <NUM> corresponds to a "second surface" of the relay substrate of the present disclosure.

The relay substrate <NUM> is provided with a non-illustrated wiring connecting each of <NUM> pieces of the first connector <NUM> to one of <NUM> pieces of the second connector <NUM>. With this, the second connectors <NUM> arranged on the lower surface of the relay substrate <NUM> and the first connectors <NUM> arranged on the first surface of the relay substrate <NUM> are electrically connected. Further, the relay substrate <NUM> has a non-illustrated electrical source wiring connecting the power source connector <NUM> and the ten first connectors <NUM> and a non-illustrated electrical source wiring connecting the power source connector <NUM> and the ten second connectors <NUM>. With this, the relay substrate <NUM> is capable of supplying the electric power from the non-illustrated external power source to a device, etc., connected to each of the first connectors <NUM> and the second connectors <NUM>. Note that the non-illustrate external power source is different from a power source <NUM>, of the rigid substrate <NUM>, which will be described later on.

As depicted in <FIG> and <FIG>, <FIG> pieces of the rigid substrate <NUM> are arranged in the first space S1. As depicted in <FIG>, each of the rigid substrates <NUM> is a rectangular substrate having a first surface 110a and a second surface 110b, and is a head controlling substrate configured to drive and control the head <NUM>. Each of the rigid substrates <NUM> has a connector <NUM>, a power source <NUM> and a plurality of circuit elements <NUM> which are mounted thereon. The power source <NUM> and a part of the plurality of circuit elements <NUM> are mounted on the first surface 110a of the rigid substrate <NUM>. Remaining circuit elements <NUM>, included in the plurality of circuit elements <NUM>, are mounted on the second surface 110b which is a rear surface of the first surface 110a. Note that all of the plurality of circuit elements <NUM> are not of a same kind, and the plurality of circuit elements <NUM> includes a plurality of kinds of circuit element.

The power source <NUM> mounted on the first surface 110a of each of the rigid substrates <NUM> is a power source element configured to generate a driving signal of a non-illustrated piezoelectric actuator included in the head <NUM>. The power source <NUM> is not mounted on the second surface 110b of each of the rigid substrates <NUM>; circuit elements configured to process a high speed signal are mounted on the second surface 110b, as the plurality of circuit elements <NUM>. A height of the power source <NUM> mounted on the first surface 110a of each of the rigid substrates <NUM> is higher than a height of one of the plurality of circuit elements <NUM> mounted on the second surface 110b of each of the rigid substrates <NUM>. Note that the term "height" described herein represents a height from each of the first surface 110a and the second surface 110b in a normal direction perpendicular to the rigid substrate <NUM> (parallel to the front-rear direction in <FIG>).

The connector <NUM> is arranged on a lower end of each of the rigid substrates <NUM>, and is inserted into each of the first connectors <NUM> of the relay substrate <NUM>. With this, the rigid substrates <NUM> are fixed so as to stand perpendicularly with respect to the relay substrate <NUM> (see <FIG>). As described above, since the first connectors <NUM> are aligned in the two rows, the rigid substrates <NUM> are also arranged to be aligned in two rows. As depicted in <FIG>, the rigid substrates <NUM> are arranged in the two rows, with rigid substrates <NUM> in one row and rigid substrates <NUM> in the other row being arranged back to back such that the first surfaces 110a each having the power source <NUM> mounted thereon do not face one another in the width direction (front-rear direction). Namely, in two rigid substrates <NUM>, which are included in the ten rigid substrates <NUM> and which face or are opposite to each other in the width direction (front-rear direction), the second surfaces 110b thereof on which only the circuit elements <NUM> having the height lower than the height of the electric source <NUM> are mounted face each other. Further, regarding the two rigid substrates <NUM> facing each other in the width direction (front-rear direction), a distance L1 in the front-rear direction between the rigid substrate <NUM> on the front side and a lateral surface on the front side of the casing <NUM> and a distance L2 in the front-rear direction between the rigid substrate <NUM> on the rear side and a lateral surface on the rear side of the casing <NUM> are each greater than a distance L3 in the front-rear direction between the two rigid substrates <NUM> facing each other in the width direction (front-rear direction).

As described above, the fan <NUM> is capable of feeding wind or airflow in the aligning direction of the rows of the rigid substrates <NUM> (the depth direction, the left-right direction). Since the direction in which the airflow is fed is a direction parallel to the first surface 110a and the second surface 110b of each of the rigid substrates <NUM>, the rigid substrates <NUM> do not hinder the flow of the airflow. Accordingly, it is possible to feed the air flow fed from the fan <NUM> up to the back (inner part) of the first casing <NUM>, along the aligning direction of the rows of the rigid substrates <NUM> (the depth direction, the left-right direction), thereby making it possible to efficiently cool the <NUM> pieces of the rigid substrate <NUM>.

The above-described distances L1 and L2 each correspond to the distance between the first surface 110a having the power sources <NUM> mounted thereon and the lateral surface of the first casing <NUM>, and the above-described distance L3 corresponds to the distance between the second surfaces 110b on each of which the power source <NUM> is not mounted. As described above, since the distances L1 and L2 are greater than the distance L3, it is possible to send the airflow efficiently to the power sources <NUM> of which heat generating amount is great, and to cool the power sources <NUM>.

Next, members arranged in the second space S2 will be explained. The lower surface of the relay substrate <NUM> is exposed in the second space S2 of the second casing <NUM>. Further, the line head <NUM> including the ten heads <NUM>, the ten flexible substrates <NUM>, the tank <NUM>, the heater <NUM>, and the plurality of tubes <NUM> connecting the heads <NUM> and the tank <NUM> are arranged in the second space S2.

One end of each of the flexible substrates <NUM> is connected to one of the second connectors <NUM> of the relay substrate <NUM>. Further, the other end of each of the flexible substrates <NUM> is connected to one of the heads <NUM>. Note that, as described above, the second connectors <NUM> of the relay substrate <NUM> are electrically connected to the first connectors <NUM> arranged on the upper surface of the relay substrate <NUM>, and further that the first connectors <NUM> are electrically connected to the connectors <NUM> of the rigid substrates <NUM>. Namely, the rigid substrates <NUM>, each of which is a head controlling substrate configured to drive and control one of the heads <NUM>, is connected to one of the heads <NUM> via the relay substrate <NUM> and one of the flexible substrates <NUM>. With this, each of the rigid substrates <NUM> is capable of transmitting a control signal with respect to one of the heads <NUM>, such as the driving signal with respect to the non-illustrated piezoelectric actuator of one of the heads <NUM>, via the relay substrate <NUM> and one of the flexible substrates <NUM>.

As depicted in <FIG>, the tank <NUM> is arranged in the second space S2 at a location below the relay substrate <NUM>. The tank <NUM> has a shape of a substantially rectangular parallelepiped which is long in the left-right direction. As depicted in <FIG>, the tank <NUM> is mainly provided with: a top plate <NUM>, an upper seal rubber <NUM>, a tank body <NUM>, a lower seal rubber <NUM>, a bottom plate <NUM> and the plurality of tubes <NUM>. The tank body <NUM> is formed of a resin, and can be formed, for example, by an injection molding. The top plate <NUM> and the bottom plate <NUM> may be formed of a resin or a metallic material. The top plate <NUM> is fixed to an upper part of the tank body <NUM>, in a state that the top plate <NUM> sandwiches the upper seal rubber <NUM> between the top plate <NUM> and the tank body <NUM>. Further, the bottom plate <NUM> is fixed to a lower part of the tank body <NUM>, in a state that the bottom plate <NUM> sandwiches the lower seal rubber <NUM> between the bottom plate <NUM> and the tank body <NUM>. The top plate <NUM> and the bottom plate <NUM> are screwed to the tank body <NUM> by a plurality of screws <NUM>. Note that as depicted in <FIG>, one piece of the head <NUM> is provided with a first supply port <NUM>, a first discharge port <NUM>, a second supply port <NUM> and a second discharge port <NUM>. As will be described later on, two ink circulating routes corresponding to the two nozzle rows, respectively, are provided on the head <NUM> (see <FIG> and <FIG>). As depicted in <FIG>, one end of the one of the ink circulating routes is connected to the first supply port <NUM>, and the other end of the one of the ink circulating routes is connected to the first discharge port <NUM>. Further, as depicted in <FIG>, one end of the other of the ink circulating routes is connected to the second supply port <NUM>, and the other end of the other of the ink circulating routes is connected to the second discharge port <NUM>. The tank <NUM> and one piece of the head <NUM> are connected to each other by four pieces of the tube <NUM>. Among the four tubes <NUM>, a first tube <NUM> is communicated with the first supply port <NUM>, a second tube <NUM> is communicated with the first discharge port <NUM>, a third tube <NUM> is communicated with the second supply port <NUM> and a fourth tube <NUM> is communicated with the second discharge port <NUM>. Since the tank <NUM> is connected to <NUM> pieces of the head <NUM>, the tank <NUM> is connected to <NUM> pieces of the tube <NUM>. However, in order to simplify the drawing, the number of the tube <NUM> connected to the tank <NUM> is reduced in the illustration of <FIG>.

As depicted in <FIG> and <FIG>, a first supply channel <NUM>, a first discharge channel <NUM>, a second supply channel <NUM> and a second discharge channel <NUM> are formed in the tank body <NUM>. Note that these four channels each extend in the left-right direction. Further, these four channels are arranged side by side in the front-rear direction. Note that these four channels are arranged, from the rear side toward the front side in the front-rear direction, namely, from the upstream side toward the downstream side in the conveying direction, in an order of the first supply channel <NUM>, the first discharge channel <NUM>, the second discharge channel <NUM> and the second supply channel <NUM>. Note that in <FIG> and <FIG>, only a part of each of the first supply channel <NUM>, the first discharge channel <NUM>, the second supply channel <NUM> and the second discharge channel <NUM> is depicted so that the length in the left-right direction of the tank <NUM> becomes (appears) to be short, in order to simplify the drawings.

A first supply port <NUM> communicating with the first supply channel <NUM>, a first discharge port <NUM> communicating with the first discharge channel <NUM>, a second discharge port <NUM> communicating with the second discharge channel <NUM>, and a second supply port <NUM> communicating with the second supply channel <NUM> are provided on a side wall 413R on the right side of the tank body <NUM>.

Next, an ink channel formed in the inside of the tank <NUM> will be explained in further detail. As depicted in <FIG> and <FIG>, the first supply channel <NUM> has a first basal supply channel <NUM>, and <NUM> pieces of a first branched supply channel <NUM> which are branched from the first basal supply channel <NUM> at a location below the first basal supply channel <NUM>. The ten first branched supply channels <NUM> correspond to the ten heads <NUM>, respectively. Note that in <FIG>, only a part of each of the first supply channel <NUM>, the first discharge channel <NUM>, the second supply channel <NUM> and the second discharge channel <NUM> is depicted so that the length in the left-right direction of the tank <NUM> becomes (appears) to be short, in order to simplify the drawings, in a similar manner regarding <FIG> and <FIG>. Further, in <FIG>, only a part of the ten first branched supply channels <NUM> is depicted. One end 452a of each of the first branched supply channels <NUM> is connected to the first basal supply channel <NUM>, and the other end 452b of each of the first branched supply channels <NUM> is connected to one of the tubes <NUM>.

As depicted in <FIG> and <FIG>, the first discharge channel <NUM> has a first basal discharge channel <NUM>, and <NUM> pieces of a first branched discharge channel <NUM> which are branched from the first basal discharge channel <NUM> at a location below the first basal discharge channel <NUM>. The ten first branched discharge channels <NUM> correspond to the ten heads <NUM>, respectively. Note that in <FIG>, only a part of the ten first branched discharge channels <NUM> is depicted so as to simplify the drawing. One end 462a of each of the first branched discharge channels <NUM> is connected to the first basal discharge channel <NUM>, and the other end 462b of each of the first branched discharge channels <NUM> is connected to one of the tubes <NUM>.

As depicted in <FIG> and <FIG>, the second supply channel <NUM> has a second basal supply channel <NUM>, and <NUM> pieces of a second branched supply channel <NUM> which are branched from the second basal supply channel <NUM> at a location below the second basal supply channel <NUM>. The ten second branched supply channels <NUM> correspond to the ten heads <NUM>, respectively. Note that in <FIG>, only a part of the ten second branched supply channels <NUM> is depicted so as to simplify the drawing. One end 472a of each of the second branched supply channels <NUM> is connected to the second basal supply channel <NUM>, and the other end 472b of each of the second branched supply channels <NUM> is connected to one of the tubes <NUM>.

As depicted in <FIG> and <FIG>, the second discharge channel <NUM> has a second basal discharge channel <NUM>, and <NUM> pieces of a second branched discharge channel <NUM> which are branched from the second basal discharge channel <NUM> at a location below the second basal discharge channel <NUM>. The ten second branched discharge channels <NUM> correspond to the ten heads <NUM>, respectively. Note that in <FIG>, only a part of the ten second branched discharge channels <NUM> is depicted so as to simplify the drawing. One end 482a of each of the second branched discharge channels <NUM> is connected to the second basal discharge channel <NUM>, and the other end 482a of each of the second branched discharge channels <NUM> is connected to one of the tubes <NUM>.

As depicted in <FIG>, the first supply port <NUM>, the first discharge port <NUM>, the second supply port <NUM> and the second discharge port <NUM> are arranged in the upper surface of each of the heads <NUM>. The first supply port <NUM> and the first discharge port <NUM> are arranged in the left-right direction, and the first supply port <NUM> is arranged on the left side of the first discharge port <NUM>. The second supply port <NUM> and the second discharge port <NUM> are arranged in the left-right direction, and the second supply port <NUM> is arranged on the right side of the second discharge port <NUM>. Further, the pair of the first supply port <NUM> and the first discharge port <NUM> is arranged on the rear side of the pair of the second supply port <NUM> and the second discharge port <NUM>.

Corresponding to the above-described arrangement of the first supply port <NUM>, the first discharge port <NUM>, the second supply port <NUM> and the second discharge port <NUM> in the upper surface of each of the heads <NUM>, the other end 452b of each of the first branched supply channels <NUM>, the other end 462b of each of the first branched discharge channels <NUM>, the other end 472b of each of the second branched supply channels <NUM> and the other end 482b of each of the second branched discharge channels <NUM> are arranged in a similar manner, as depicted in <FIG>. Namely, the other end 452b of each of the first branched supply channels <NUM> and the other end 462b of each of the first branched discharge channels <NUM> are arranged in the left-right direction, and the other end 472b of each of the second branched supply channels <NUM> and the other end 482b of each of the second branched discharge channels <NUM> are arranged in the left-right direction.

As described above, corresponding to that the ten heads <NUM> are arranged in the staggered manner so as to form the two head rows extending in the left-right direction, the set of the other end 452b of each of the first branched supply channels <NUM>, the other end 462b of each of the first branched discharge channels <NUM>, the other end 472b of each of the second branched supply channels <NUM> and the other end 482b of each of the second branched discharge channels <NUM>, which corresponds to one head <NUM>, are also arranged in a staggered manner so as to form two rows extending in the left-right direction. Namely, the set of the other end 452b of each of the first branched supply channels <NUM>, the other end 462b of each of the first branched discharge channels <NUM>, the other end 472b of each of the second branched supply channels <NUM>, and the other end 482b of each of the second branched discharge channels <NUM>, which corresponds to one head <NUM>, are arranged at positions overlapping, respectively, with the first supply port <NUM>, the first discharge port <NUM>, the second supply port <NUM> and the second discharge port <NUM> of the head <NUM>, in the up-down direction.

Next, the shape of the first branched supply channel <NUM> will be explained, with reference to the drawings. Note that since the second branched supply channel <NUM> has a shape which is symmetrical to the first branched supply channel <NUM> with respect to a line X in <FIG>, any detailed explanation for the second branched supply channel <NUM> will be omitted.

In the following explanation, the first basal supply channel <NUM>, the first basal discharge channel <NUM>, the second basal supply channel <NUM> and the second basal discharge channel <NUM> are collectively referred to as "basal channels". As depicted in <FIG>, the first basal supply channel <NUM> is arranged rearmost among the four basal channels. As depicted in <FIG>, five first branched supply channels <NUM> extend frontward from the first basal supply channel <NUM>. Note that each of the first branched supply channels <NUM> bends leftward at an intermediate part thereof, and then extends frontward again. As depicted in <FIG>, each of the first branched supply channels <NUM> extends frontward as if crawling under the first basal discharge channel <NUM>. Note that an upper surface 452U of each of the first branched supply channels <NUM> is inclined further downward as approaching closer to the other end 452b. Note that an inclination angle of the upper surface 452U with respect to the horizontal plane is greater than an inclination angle of the nozzle surface of each of the line head assemblies <NUM> with respect to the horizontal plane which is defined in a case that the line head assemblies <NUM> are attached to the arch frame <NUM>. Therefore, even in a case that the line head assemblies <NUM> are attached to the arch frame <NUM> so that each of the line head assemblies <NUM> is inclined with respect to the horizontal plane, the upper surface 452U of the first branched supply channel <NUM> is inclined further downward as approaching closer to the other end 452b.

Next, the shape of the first branched discharge channel <NUM> will be explained, with reference to the drawings. Note that since the second branched discharge channel <NUM> has a shape which is symmetrical to the first branched discharge channel <NUM> with respect to the line X in <FIG>, any detailed explanation for the second branched discharge channel <NUM> will be omitted.

As depicted in <FIG>, the first basal discharge channel <NUM> is arranged second rearmost among the four basal channels. As depicted in <FIG>, five first branched discharge channels <NUM> extends frontward from the first basal discharge channel <NUM>. As depicted in <FIG>, each of the first branched discharge channels <NUM> extend frontward as if crawling under the second basal discharge channel <NUM>. Note that an upper surface 462U of each of the first branched discharge channels <NUM> is inclined further downward as approaching closer to the other end 462b. Note that an inclination angle of the upper surface 462U with respect to the horizontal plane is greater than the inclination angle of the nozzle surface of each of the line head assemblies <NUM> with respect to the horizontal plane which is defined in a case that the line head assemblies <NUM> are attached to the arch frame <NUM>. Therefore, even in a case that the line head assemblies <NUM> are attached to the arch frame <NUM> so that each of the line head assemblies <NUM> is inclined with respect to the horizontal plane, the upper surface 462U of each of the first branched discharge channels <NUM> is inclined further downward as approaching closer to the other end 462b.

Further, as depicted in <FIG>, the five first branched discharge channels <NUM> extend rearward from the first basal discharge channel <NUM>. As depicted in <FIG>, each of the first branched discharge channels <NUM> extends rearward as if crawling under the first basal supply channel <NUM>. Note that the upper surface 462U of each of the first branched discharge channels <NUM> is inclined further downward as approaching closer to the other end 462b. Note that the inclination angle of the upper surface 462U with respect to the horizontal plane is greater than the inclination angle of the nozzle surface of each of the line head assemblies <NUM> with respect to the horizontal plane which is defined in a case that the line head assemblies <NUM> are attached to the arch frame <NUM>. Therefore, even in a case that the line head assemblies <NUM> are attached to the arch frame <NUM> so that each of the line head assemblies <NUM> is inclined with respect to the horizontal plane, the upper surface 462U of each of the first branched discharge channels <NUM> is inclined further downward as approaching closer to the other end 462b.

Next, connection between the tank <NUM> and the heads <NUM> will be explained. Although not depicted in the drawings, the other end 452b of each of the first branched supply channels <NUM> and the first supply port <NUM> of one of the heads <NUM> is connected by the tube <NUM>. Similarly, the other end 462b of each of the first branched discharge channels <NUM> and the first discharge port <NUM> of one of the heads <NUM> is connected by the tube <NUM>. The other end 472b of each of the second branched supply channels <NUM> and the second supply port <NUM> of one of the heads <NUM> is connected by the tube <NUM>. The other end 482b of each of the second branched discharge channels <NUM> and the second discharge port <NUM> of one of the heads <NUM> is connected by the tube <NUM>. As described above, the other end 452b of each of the first branched supply channels <NUM>, the other end 462b of each of the first branched discharge channels <NUM>, the other end 472b of each of the second branched supply channels <NUM> and the other end 482b of each of the second branched discharge channels <NUM> which corresponds to one piece of the head <NUM> are arranged, respectively, at positions overlapping in the up-down direction with the first supply port <NUM>, the first discharge port <NUM>, the second supply port <NUM> and the second discharge port <NUM>, respectively, of the head <NUM>. With this, it is possible to provide the connection in a state that the tubes <NUM> are extended so as not to cross one another, which in turn allows usage of tubes <NUM> of a same length.

In the present embodiment, since the UV-curable ink is used, it is necessary to maintain the temperature of the ink at a predetermined temperature. Accordingly, each of the line head assemblies <NUM> in the present embodiment is provided with the heater <NUM> configured to warm or heat the ink in the inside of the tubes <NUM> connecting the tank <NUM> and the head <NUM>. As depicted in <FIG>, the heater <NUM> is provided at a position overlapping with the tubes <NUM> in the front-rear direction. As the heater <NUM>, it is allowable to use, for example, a carbon heater which generates heat by supplying an electric current to a carbon sheet. Note that in order to warm the ink inside the tank <NUM> in advance, it is also possible to provide, for example, a sheet-shaped heater in the lower surface of the tank <NUM>.

Next, the ink circulating routes will be explained, with referenced to <FIG> and <FIG>. At first, an explanation will be given about an ink circulating route included in the ink circulating routes and corresponding to one of the two nozzle rows included in the head <NUM>, with reference to <FIG>. As depicted in <FIG>, the ink reservoir <NUM>, the first ink supply port 222f and the first ink discharge port 222d of the second casing <NUM> are fluidly connected via the ink circulating mechanism <NUM>. Note that the ink circulating mechanism <NUM> is a publicly known ink circulating system provided with a pump, a valve, an exhaust valve, etc., and any detailed explanation therefor will be omitted. By the ink circulating mechanism <NUM>, the ink supplied from the ink reservoir <NUM> flows toward the first ink supply port 222f of the second casing <NUM>. Further, the ink flows from the first ink supply port 222f of the second casing <NUM> toward the first supply channel <NUM> of the tank <NUM>, and passes through the tube <NUM> from the other end 452b of each of the first branched supply channels <NUM> of the first supply channel <NUM>, and flows into the first supply port <NUM> of the head <NUM>. A first supply manifold 14f, the plurality of pressure chambers 11p, the plurality of nozzles 11a and a first return manifold 14r are formed, as the intra-head channel, in the inside of the head <NUM>. The first supply manifold 14f and the first return manifold 14r are provided commonly with respect to the plurality of pressure chambers 11p. The plurality of pressure chambers 11p and the plurality of nozzles 11a correspond to one another in one-to-one basis. The ink supplied from the first supply port <NUM> flows from the first supply manifold 14f into the plurality of pressure chambers 11p. In a case that the non-illustrated piezoelectric actuator is driven so as to apply a discharge pressure (ejecting pressure) to a certain pressure chamber 11p as one of the plurality of pressure chambers 11p, an ink droplet of the ink is discharged or ejected from a nozzle 11a, among the plurality of nozzles 11a, communicating with the certain pressure chamber 11p. The ink which has not been discharged from the nozzle 11a is fed to the first return manifold 14r, passes through the first discharge port <NUM> and the tube <NUM> and flows into the first discharge channel <NUM> of the tank <NUM>. The first discharge channel <NUM> of the tank <NUM> is connected to the first ink discharge port 222d of the second casing <NUM>. The ink inflowed into the first discharge channel <NUM> passes through the first ink discharge port 222d and flows toward the ink reservoir <NUM>. In such a manner, the ink can be circulated.

Next, an explanation will be given about an ink circulating route included in the ink circulating routes and corresponding to the other of the two nozzle rows included in the head <NUM>, with reference to <FIG>. As depicted in <FIG>, the ink reservoir <NUM>, the second ink supply port 223f and the second ink discharge port 223d of the second casing <NUM> are fluidly connected via the ink circulating mechanism <NUM>. By the ink circulating mechanism <NUM>, the ink supplied from the ink reservoir <NUM> flows toward the second ink supply port 223f of the second casing <NUM>. Further, the ink flows from the second ink supply port 223f of the second casing <NUM> toward the second supply channel <NUM> of the tank <NUM>, and passes through the tube <NUM> from the other end 472b of the second branched supply channel <NUM> of each of the second supply channels <NUM>, and flows into the second supply port <NUM> of the head <NUM>. A second supply manifold 15f, the plurality of pressure chambers 11p, the plurality of nozzles 11a and a second return manifold 15r are formed, as the intra-head channel, in the inside of the head <NUM>. The second supply manifold 15f and the second return manifold 15r are provided commonly with respect to the plurality of pressure chambers 11p. The plurality of pressure chambers 11p and the plurality of nozzles 11a correspond to one another in one-to-one basis. The ink supplied from the second supply port <NUM> flows from the second supply manifold 15f into the plurality of pressure chambers 11p. In a case that the non-illustrated piezoelectric actuator is driven so as to apply a discharge pressure (ejecting pressure) to a certain pressure chamber 11p as one of the plurality of pressure chambers 11p, an ink droplet of the ink is discharged or ejected from a nozzle 11a, among the plurality of nozzles 11a, communicating with the certain pressure chamber 11p. The ink which has not been discharged from the nozzle 11a is fed to the second return manifold 15r, passes through the second discharge port <NUM> and the tube <NUM> and flows into the second discharge channel <NUM> of the tank <NUM>. The second discharge channel <NUM> of the tank <NUM> is connected to the second ink discharge port 223d of the second casing <NUM>. The ink inflowed into the second discharge channel <NUM> passes through the second ink discharge port 223d and flows toward the ink reservoir <NUM>. In such a manner, the ink can be circulated.

The line head assembly <NUM> is provided with the ten rigid substrates <NUM> each having the power source <NUM> mounted thereon, the ten heads <NUM>, the tank <NUM>, the plurality of tubes <NUM>, the heater <NUM>, the ten flexible substrates <NUM>, the relay substrate <NUM>, the first casing <NUM> having the airflow port <NUM> formed therein, and the second casing <NUM>. The first space S1 is formed in the first casing <NUM>, and the second space S2 is formed in the second casing <NUM>. The first space S1 is arranged above the second space S1, and the relay substrate <NUM> is arranged, in the up-down direction, between the first space S1 and the second space S2. The ten rigid substrates <NUM> are arranged in the first space S1, and the tank <NUM>, the heater <NUM>, the plurality of tubes <NUM>, and the plurality of flexible substrates <NUM> are arranged in the second space S2. The relay substrate <NUM> partitions the first space S1 and the second space S2 from each other.

Since the rigid substrates <NUM> each having the power source <NUM> mounted thereon are required to be cooled, the rigid substrates <NUM> are arranged in the first space S1 inside the first casing <NUM> in which the airflow port <NUM> is formed. In contrast, the members including the ink of which temperature is required to be maintained to be constant (the heads <NUM>, the tubes <NUM> and the tank <NUM>) and the heater <NUM> required for performing the temperature adjustment are arranged in the second space S2 inside the second casing <NUM>. Here, since the first space S1 and the second space S2 are partitioned from each other by the relay substrate <NUM>, any inflow or entering, to the second space S2, of the air in the first space S21 into which the outside air is taken via the airflow port <NUM> is suppressed. With this, any variation or fluctuation in the temperature of the second space S2, in which the temperature is adjusted by the heater <NUM>, is suppressed. Such a configuration is particularly useful for a case of using, as the ink, a UV-curable ink of which temperature is greatly required to be maintained to be constant.

The first connectors <NUM> and the second connectors <NUM> are provided on the relay substrate <NUM>. With this, it is possible to easily connect the rigid substrates <NUM> arranged in the first space S1 and the flexible substrates <NUM> arranged in the second space S2 electrically to one another, while suppressing any entering of the air in the first space S1 into the second space S2.

The opening <NUM> is formed in the lower surface of the first casing <NUM> and the opening <NUM> is formed in the upper surface of the second casing <NUM>. The opening <NUM> and the opening <NUM> are overlapped with each other in the up-down direction. In the present embodiment, the relay substrate <NUM> is attached to the upper surface of the second casing <NUM> so that the relay substrate <NUM> closes the opening <NUM> in the upper surface of the second casing <NUM> from therebelow. By arranging the relay substrate <NUM> in such a manner, it is possible to easily close the opening <NUM> and the opening <NUM>. Note that it is also allowable to attach the relay substrate <NUM> to the lower surface of the first casing <NUM> so that the relay substrate <NUM> closes the opening <NUM> from thereabove. Since the opening <NUM> and the opening <NUM> are overlapped with each other in the up-down direction, the relay substrate <NUM> is capable of closing the opening <NUM> and the opening <NUM> also in this case. Note that the rigid substrates <NUM> are arranged to extend upward while passing through the opening <NUM>. Namely, a part of each of the rigid substrates <NUM> is arranged in the inside of the first space S1. By arranging the rigid substrates <NUM> in such a manner, the power source <NUM>, which is mounted on each of the rigid substrates <NUM> and which is expected to generate the heat, can be arranged easily in the first space S1.

The above-described embodiment disclosed herein is exemplary in all the points, and is not restrictive or limiting. All the respective configurations indicated in the embodiment are not essential, and any change and/or omission may be made in each of the configuration, as necessary.

In the above-descried embodiment, the first casing <NUM> and the second casing <NUM> are configured to be separable from each other. Accordingly, it is possible to remove the first casing <NUM> as necessary. As described above, the first grip <NUM> is provide on the top plate <NUM> of the first casing <NUM>. A user is capable of separate the first casing <NUM> and the second casing <NUM> from each other, by lifting the first casing <NUM> upward while grasping the first grip <NUM>. For example, since each of the rigid substrates <NUM> includes the power source <NUM>, a frequency at which any failure or trouble occurs therein is higher than another substrate (for example, the relay substrate <NUM>). In a case that there is any failure in the rigid substrate <NUM>, it is possible to repair the rigid substrate <NUM> by removing the first casing <NUM> including the rigid substrate <NUM> from the second casing <NUM>. The present disclosure, however, is not limited to such an aspect. For example, as depicted in <FIG> and <FIG>, a line head assembly 10A according to the present disclosure may have a casing <NUM>. The casing <NUM> has a first frame part <NUM> defining the first space S1, a second frame part <NUM> defining the second space S2, and a lid <NUM> arranged above the first frame part <NUM>. The first frame part <NUM> and the second frame part <NUM> are not configured to be separable from each other. The first frame part <NUM> is an example of a "first member" of the present disclosure, and the second frame part <NUM> is an example of a "second member" of the present disclosure. Note that the first frame part <NUM> corresponds to the first casing <NUM> as described above, and the second frame part <NUM> corresponds to the second casing <NUM> as described above. Among the configurations provided on the first frame part <NUM> and the second frame part <NUM>, same reference numerals are affixed to any configurations which are common to those of the first casing <NUM> and the second casing <NUM>, and any explanation therefor will be omitted. Further, since the members arranged in the two spaces S1 and S2 are similar to those of the above-described line head assembly <NUM>, same reference numerals are affixed to any configurations which are common to those in the line head assembly <NUM>, and any explanation therefor will be omitted.

As depicted in <FIG>, the first frame part <NUM> is a frame member having a substantially rectangular parallelepiped shape. The first frame part <NUM> has a bottom surface 510D, a side wall 510R on the right side and a side wall <NUM> on the left side which extend upward respectively from both ends in the left-right direction of the bottom surface 510D, and an upper surface 510U. An opening <NUM> is formed in the bottom surface 510D. Further, another opening <NUM> is formed in the upper surface 510U. An airflow port <NUM> is formed in the side wall 510R on the right side of the first frame part <NUM>. Similarly to the first casing <NUM>, the fan <NUM> is attached to the airflow port <NUM>. An electric power input port <NUM> is provided in the side wall 510R on the right side, at a location below the airflow port <NUM>.

The second frame part <NUM> is a frame member having a substantially rectangular parallelepiped shape. The second frame part <NUM> has a bottom surface 520D, a side wall 520R on the right side and a side wall <NUM> on the left side which extend upward respectively from both ends in the left-right direction of the bottom surface 520D, and an upper surface 520U. The side wall 520R on the right side of the second frame part <NUM> is continued to the side wall 510R on the right side of the first frame part <NUM>. The side wall <NUM> on the left side of the second frame part <NUM> is continued to the side wall <NUM> on the left side of the first frame part <NUM>. Similarly to the second casing <NUM>, four ink ports <NUM> and a set of cooling water ports <NUM> are provided on the side wall 520R on the right side.

The upper surface 520U of the second frame part <NUM> and the bottom surface 510D of the first frame part <NUM> correspond to an upper surface and a lower surface of a same plate member. Accordingly, the above-described opening <NUM> opens also in the upper surface 520U of the second frame part <NUM>.

As depicted in <FIG>, a relay substrate 300A is attached to the upper surface 520U of the second frame part <NUM> so that the relay substrate 300A closes the opening <NUM> from therebelow. Since the relay substrate 300A has a similar configuration to that of the above-described relay substrate <NUM>, except that a power source connector 303A is arranged on the upper surface (a same surface on which the first connectors <NUM> are provided), any explanation therefor will be omitted. As depicted in <FIG>, the power source connector 303A is connected to the power source input port <NUM>.

Also in such a configuration, the first space S1 and the second space S1 are partitioned from each other by the relay substrate 300A, it is possible to suppress any inflow of the air in the first space S1, which is required to be cooled by air cooling, into the second space S2. With this, it is possible to suppress any variation or fluctuation in the temperature, in the second space S2, which is required to be maintained at a constant temperature.

Note that the lid <NUM> is firmly fixed to the upper surface 510U of the first frame part <NUM>, with a screw, etc. As depicted in <FIG>, the lid <NUM> is arranged so as to cover the opening <NUM> from thereabove. By removing the lid <NUM>, it is possible to expose the opening <NUM>. As described above, since each of the rigid substrates <NUM> includes the power source <NUM>, a frequency at which any failure or trouble occurs therein is higher than another substrate (for example, the relay substrate 300A). In the line head assembly 10A, however, by removing the lid <NUM>, it is possible to expose the opening <NUM> so that the user can access to the space S1 from the opening <NUM>. With this, it is possible to easily exchange the rigid substrate <NUM> arranged in the space S1, without separating the first frame part <NUM> from the second frame part <NUM>.

In the above-described embodiment, the number of the line head assembly <NUM> is <NUM> (three). The present disclosure, however, is not limited to such an aspect. The number, arrangement, etc., of the line head assembly <NUM> may be appropriately changed. Similarly, the number, the arrangement, etc., of the head <NUM> included in one piece of the line head <NUM> may be appropriately changed. Further, the number, arrangement, etc., of the nozzle 11a included in each of the heads <NUM> may also be appropriately changed. Furthermore, in the embodiment, although the controller <NUM> is provided on the printing apparatus <NUM>, the present disclosure is not limited to or restricted by such an aspect. For example, it is allowable to provide the controller <NUM> on the line head assembly <NUM>.

In the above-described embodiment, the recording medium which is wound in a roll shape (for example, rolled paper or rolled paper sheet) is used as the recording medium <NUM>. However, the present disclosure is not limited to or restricted by such an aspect; it is allowable to use a recording medium <NUM> of an appropriate shape and material, as necessary. In the embodiment, the structure, shape, material, etc., of the tank <NUM> may be changed as appropriate. For example, in the embodiment, the tank <NUM> is connected to the ten heads <NUM>. The present disclosure, however, is not limited to such an aspect. For example, it is allowable that the tank <NUM> is divided into three parts or portions, and that the divided three parts are connected, respectively, to four heads <NUM>, four heads <NUM> and two heads <NUM>. Further, the printing apparatus <NUM> of the above-described embodiment is provided with the three line head assemblies <NUM> and is configured to discharge the five color inks which are the white ink, cyan ink, magenta ink, yellow ink and black ink. The present disclosure is not limited to such an aspect; it is allowable that the printing apparatus <NUM> is configured to discharge an ink of an appropriate color. Further, in the embodiment, the UV-curable ink is used. The present disclosure, however, is not limited to such an aspect; it is allowable to use an ink different from the UV-curable ink (for example, a water-based ink, a pigment ink, etc.).

Claim 1:
A head assembly comprising:
a rigid substrate (<NUM>) including a connector and on which a power source (<NUM>) is mounted;
a plurality of heads (<NUM>);
a tank (<NUM>) configured to store an ink which is to be supplied to the plurality of heads;
a plurality of tubes (<NUM>) each fluidically connecting the tank and one of the plurality of heads;
a heater (<NUM>) configured to warm the ink in the tank and in the plurality of tubes;
a plurality of flexible substrates (<NUM>) each including an end electrically connected to one of the plurality of heads;
a relay substrate (<NUM>) to which the other end of each of the plurality of flexible substrates and the connector of the rigid substrate are electrically connected;
a first member (<NUM>) defining a first space (S1) and including an airflow port configured to take an outside air thereinto; and
a second member (<NUM>) defining a second space (S2) which is arranged on one side in a first direction with respect to the first space,
wherein the rigid substrate is arranged in the first space,
wherein the tank, the heater, the plurality of tubes and the plurality of flexible substrates are arranged in the second space,
wherein the relay substrate is arranged between the first space and the second space in the first direction, and partitions the first space and the second space from each other;
wherein the relay substrate includes a first connector (<NUM>) electrically connected to the connector of the rigid substrate, and a plurality of second connectors (<NUM>) each of which is electrically connected to the other end of one of the plurality of flexible substrates; and
wherein the first connector of the relay substrate is arranged in a first surface, of the relay substrate, defining the first space (S1) and wherein the plurality of second connectors of the relay substrate are arranged in a second surface, of the relay substrate, defining the second space.