Patent Description:
Inkjet printers and inkjet plotters that utilize an inkjet recording method are known as printing apparatuses. A liquid discharge head for discharging liquid is mounted in printing apparatuses using such an inkjet method. In addition, in such a liquid discharge head, a plurality of driver ICs are mounted on the same flexible substrate (see, for example, Patent Document <NUM>).

Patent Document <NUM>: <CIT>
Moreover, <CIT> discloses an ink jet head including an ejection unit including first nozzles arranged along a line, second nozzles arranged parallel to the first nozzles, a first actuator configured to cause ink to be ejected from the first nozzles, and a second actuator configured to cause ink to be ejected from the second nozzles, a first drive circuit configured to drive the first actuator, a second drive circuit configured to drive the second actuator, and a casing, wherein the casing has a first space on a first side of the casing and a second space on a second side of the casing that is opposite to the first side, and wherein the first drive circuit is housed in the first space and the second drive circuit is housed in the second space.

The present invention provides a liquid discharge head according to claim <NUM>, a liquid discharge head according to claim <NUM>, a recording device according to claim <NUM>, a recording device according to claim <NUM>, and a recording device according to claim <NUM>. Preferred embodiments are described in the dependent claims.

Embodiments of a liquid discharge head and a recording device disclosed in the present application will be described in detail below with reference to the accompanying drawings. The disclosure is not limited by the following embodiments.

Inkjet printers and inkjet plotters that utilize an inkjet recording method are known as printing apparatuses. A liquid discharge head for discharging liquid is mounted in printing apparatuses using such an inkjet method.

A piezoelectric method is another method for discharging liquid from a liquid discharge head. In a liquid discharge head that uses such a piezoelectric method, a part of a wall of an ink channel is bent and displaced by a displacement element to mechanically pressurize and discharge the ink in the ink channel.

In addition, in order to drive such a piezoelectric element, a plurality of driver ICs are provided at the liquid discharge head. Furthermore, in the liquid discharge head, these plurality of driver ICs are mounted at the same flexible substrate.

However, in the existing liquid discharge head, the large amount of heat is generated from the driver ICs at the time of operation. This leads to an increase in thermal interference between driver ICs adjacent to each other, which may cause unstable operation of the driver ICs.

In view of the situation described above, it is expected to achieve a liquid discharge head and a recording device that can overcome the problem described above and can reduce the thermal interference between driver ICs adjacent to each other.

First, a description will be given on an overview of a printer <NUM> that is one example of a recording device according to an embodiment, with reference to <FIG> and <FIG>. <FIG> and <FIG> are explanatory views of the printer <NUM> according to the embodiment.

Specifically, <FIG> is a schematic side view of the printer <NUM> and <FIG> is a schematic plan view of the printer <NUM>. The printer <NUM> according to the embodiment is, for example, a color inkjet printer.

As illustrated in <FIG>, the printer <NUM> includes a paper feed roller <NUM>, guide rollers <NUM>, an applicator <NUM>, a head case <NUM>, a plurality of conveying rollers <NUM>, a plurality of frames <NUM>, a plurality of liquid discharge heads <NUM>, conveying rollers <NUM>, a dryer <NUM>, conveying rollers <NUM>, a sensor <NUM>, and a collection roller <NUM>. The conveying rollers <NUM> are examples of a conveyor.

The printer <NUM> includes a controller <NUM> that controls the paper feed roller <NUM>, the guide rollers <NUM>, the applicator <NUM>, the head case <NUM>, the plurality of conveying rollers <NUM>, the plurality of frames <NUM>, the plurality of liquid discharge heads <NUM>, the conveying rollers <NUM>, the dryer <NUM>, the conveying rollers <NUM>, the sensor <NUM>, and the collection roller <NUM>.

By landing droplets on the printing sheet P, the printer <NUM> records images and characters on the printing sheet P. The printing sheet P is an example of a recording medium. The printing sheet P is rolled on the paper feed roller <NUM> prior to use. In this state, the printer <NUM> conveys the printing sheet P from the paper feed roller <NUM> to the inside of the head case <NUM> via the guide rollers <NUM> and the applicator <NUM>.

The applicator <NUM> uniformly applies a coating agent over the printing sheet P. With surface treatment thus performed on the printing sheet P, the printing quality of the printer <NUM> can be improved.

The head case <NUM> houses the plurality of conveying rollers <NUM>, the plurality of frames <NUM>, and the plurality of liquid discharge heads <NUM>. The inside of the head case <NUM> is formed with a space separated from the outside except for a part connected to the outside such as parts where the printing sheet P enters and exits.

If necessary, the controller <NUM> controls at least one of controllable factors of the internal space of the head case <NUM>, such as temperature, humidity, and barometric pressure. The conveying rollers <NUM> convey the printing sheet P to the vicinity of the liquid discharge heads <NUM>, inside the head case <NUM>.

The frames <NUM> are rectangular flat plates, and are positioned above and close to the printing sheet P conveyed by the conveying rollers <NUM>. As illustrated in <FIG>, the frames <NUM> are positioned such that the longitudinal direction of the frames <NUM> is orthogonal to the conveyance direction of the printing sheet P. Furthermore, the plurality of (e.g., four) frames <NUM> are located inside the head case <NUM> along the conveyance direction of the printing sheet P.

Note that, in the following description, a direction in which a printing sheet P is transferred is also referred to as a "sub scanning direction," and a direction orthogonal to this sub scanning direction and parallel to the printing sheet P is also referred to as a "main scanning direction".

Liquid, for example, ink, is supplied to the liquid discharge heads <NUM> from a liquid tank (not illustrated). Each liquid discharge head <NUM> discharges the liquid supplied from the liquid tank.

The controller <NUM> controls the liquid discharge heads <NUM> based on data of an image, characters, and the like to discharge the liquid toward the printing sheet P. The distance between each liquid discharge head <NUM> and the printing sheet P is, for example, approximately <NUM> to approximately <NUM>.

The liquid discharge heads <NUM> are fixed to the frame <NUM>. For example, the liquid discharge heads <NUM> are fixed to the frame <NUM> at both end portions in the longitudinal direction. The liquid discharge heads <NUM> are positioned such that the longitudinal direction of the liquid discharge heads <NUM> is orthogonal to the conveyance direction of the printing sheet P.

That is, the printer <NUM> according to the embodiment is a so-called line printer in which the liquid discharge heads <NUM> are fixed inside the printer <NUM>. Note that the printer <NUM> according to the embodiment is not limited to a line printer and may also be a so-called serial printer.

A serial printer is a printer employing a method of alternately performing operations of recording while moving the liquid discharge heads <NUM> in a manner such as reciprocation in a direction intersecting (e.g., substantially orthogonal to) the conveyance direction of the printing sheet P, and conveying the printing sheet P.

As illustrated in <FIG>, a plurality of (e.g., five) liquid discharge heads <NUM> are fixed to one frame <NUM>. <FIG> illustrates an example in which three liquid discharge heads <NUM> are located on the forward side and two liquid discharge heads <NUM> are located on the rear side, in the conveyance direction of the printing sheet P. Further, the liquid discharge heads <NUM> are positioned without their centers overlapping in the conveyance direction of the printing sheet P.

The plurality of liquid discharge heads <NUM> positioned in one frame <NUM> form a head group 8A. Four head groups 8A are positioned along the conveyance direction of the printing sheet P. The liquid discharge heads <NUM> belonging to the same head group 8A are supplied with ink of the same color. As a result, the printer <NUM> can perform printing with four colors of ink using the four head groups 8A.

The colors of the ink discharged from the respective head groups 8A are, for example, magenta (M), yellow (Y), cyan (C), and black (K). The controller <NUM> can print a color image on the printing sheet P by controlling each of the head groups 8A to discharge the plurality of colors of ink onto the printing sheet P.

Note that a surface treatment may be performed on the printing sheet P, by discharging a coating agent from the liquid discharge heads <NUM> onto the printing sheet P.

Furthermore, the number of the liquid discharge heads <NUM> included in one head group 8A and the number of the head groups 8A provided in the printer <NUM> can be changed as appropriate in accordance with printing targets and printing conditions. For example, if the color to be printed on the printing sheet P is a single color and the range of the printing can be covered by a single liquid discharge head <NUM>, only a single liquid discharge head <NUM> may be provided in the printer <NUM>.

The printing sheet P thus subjected to the printing process inside the head case <NUM> is conveyed by the conveying rollers <NUM> to the outside of the head case <NUM>, and passes through the inside of the dryer <NUM>. The dryer <NUM> dries the printing sheet P after the printing process. The printing sheet P thus dried by the dryer <NUM> is conveyed by the conveying rollers <NUM> and then collected by the collection roller <NUM>.

In the printer <NUM>, by drying the printing sheet P with the dryer <NUM>, it is possible to suppress bonding between the printing sheets P rolled while being overlapped with each other, and rubbing between undried liquid at the collection roller <NUM>.

The sensor <NUM> includes a position sensor, a speed sensor, a temperature sensor, and the like. Based on information from the sensor <NUM>, the controller <NUM> can determine the state of each part of the printer <NUM> and control each part of the printer <NUM>.

In the printer <NUM> described above, the printing sheet P is the printing target (i.e., the recording medium), but the printing target in the printer <NUM> is not limited to the printing sheet P, and a roll type fabric or the like may be the printing target.

Furthermore, instead of directly conveying the printing paper P, the printer <NUM> may have a configuration in which the printing sheet P is put on a conveyor belt and conveyed. By using the conveyor belt, the printer <NUM> can perform printing on a sheet of paper, a cut cloth, wood, a tile, or the like as a printing target.

Furthermore, the printer <NUM> may discharge a liquid containing electrically conductive particles from the liquid discharge heads <NUM>, to print a wiring pattern or the like of an electronic device. Furthermore, the printer <NUM> may discharge liquid containing a predetermined amount of liquid chemical agent or liquid containing the chemical agent from the liquid discharge heads <NUM> onto a reaction vessel or the like to produce chemicals.

The printer <NUM> may also include a cleaner for cleaning the liquid discharge heads <NUM>. The cleaner cleans the liquid discharge heads <NUM> by, for example, a wiping process or a capping process.

The wiping process is, for example, a process of using a flexible wiper to rub a second surface 21b (see <FIG>) of a channel member <NUM> (see <FIG>), which is an example of a surface of a portion from which a liquid is discharged, thereby removing the liquid attached to the second surface 21b.

The capping process is performed as follows, for example. First, a cap is provided so as to cover the second surface 21b of the channel member <NUM> which is an example of the portion from which the liquid is discharged (this action is referred to as capping). This action forms a substantially sealed space between the second surface 21b and the cap.

The discharge of liquid is then repeated in such a sealed space. Consequently, it is possible to remove a liquid having a viscosity higher than that in the normal state, foreign matter, or the like that has clogged a discharge hole <NUM> (see <FIG>).

Next, the configuration of the liquid discharge head <NUM> according to the embodiment will be described with reference to <FIG> is an exploded perspective view illustrating a schematic configuration of the liquid discharge head <NUM> according to the embodiment.

The liquid discharge head <NUM> includes a head body <NUM>, a wiring portion <NUM>, a housing <NUM>, and a pair of heat dissipation plates <NUM>. The head body <NUM> includes the channel member <NUM>, a piezoelectric actuator substrate <NUM> (see <FIG>), and a reservoir <NUM>.

Note that, in the following description, for the purpose of convenience, a direction in which the head body <NUM> is provided in the liquid discharge head <NUM> is referred to as "downward," and a direction in which the housing <NUM> is provided relative to the head body <NUM> is referred to as "upward".

The channel member <NUM> of the head body <NUM> has a substantially flat plate shape, and includes a first surface 21a (see <FIG>), which is one main surface, and the second surface 21b (see <FIG>) located at an opposite side from the first surface 21a. The first surface 21a has an opening 61a (see <FIG>), and a liquid is supplied into the channel member <NUM> from the reservoir <NUM> through the opening 61a.

A plurality of the discharge holes <NUM> (see <FIG>) used to discharge a liquid onto the printing sheet P are located at the second surface 21b. Furthermore, a channel through which a liquid flows from the first surface 21a to the second surface 21b is formed inside the channel member <NUM>. Details of the channel member <NUM> will be described later.

The piezoelectric actuator substrate <NUM> is located on the first surface 21a of the channel member <NUM>. The piezoelectric actuator substrate <NUM> includes a plurality of displacement elements <NUM> (see <FIG>). In addition, the piezoelectric actuator substrate <NUM> is electrically connected to the flexible substrate <NUM> of the wiring portion <NUM>. The piezoelectric actuator substrate <NUM> will be described in detail later.

The reservoir <NUM> is disposed on the piezoelectric actuator substrate <NUM>. The reservoir <NUM> includes an opening 23a at both end portions thereof in the main scanning direction. The reservoir <NUM> has a channel therein, and is supplied with a liquid from the outside through the opening 23a. The reservoir <NUM> has a function of supplying the liquid to the channel member <NUM> and a function of storing the liquid to be supplied.

The wiring portion <NUM> includes the flexible substrate <NUM>, a wiring board <NUM>, a plurality of driver ICs <NUM>, a pressing member <NUM>, and an elastic member <NUM>. The flexible substrate <NUM> has a function of transferring a predetermined signal sent from the outside to the head body <NUM>. Note that, as illustrated in <FIG>, the liquid discharge head <NUM> according to the embodiment includes two flexible substrates <NUM>.

Each of the flexible substrates <NUM> has one end portion electrically connected to the piezoelectric actuator substrate <NUM> of the head body <NUM>. The other end portion of the flexible substrate <NUM> is drawn upward so as to be inserted into an opening 23b of the reservoir <NUM>, and is electrically connected to the wiring board <NUM>.

This enables the piezoelectric actuator substrate <NUM> of the head body <NUM> and the outside to be electrically connected. Details of the flexible substrate <NUM> will be described later.

The wiring board <NUM> is located above the head body <NUM>. The wiring board <NUM> has a function of distributing a signal to the plurality of driver ICs <NUM>.

The plurality of driver ICs <NUM> are provided at one main surface of the flexible substrate <NUM>. As illustrated in <FIG>, in the liquid discharge head <NUM> according to the embodiment, two driver ICs <NUM> are provided on each flexible substrate <NUM>. Note that, in the embodiment, the number of driver ICs <NUM> provided on each flexible substrate <NUM> is not limited to two.

The driver IC <NUM> drives the piezoelectric actuator substrate <NUM> of the head body <NUM> on the basis of a signal transmitted from the controller <NUM> (see <FIG>). With this configuration, the driver IC <NUM> drives the liquid discharge head <NUM>.

The pressing member <NUM> has a substantially U-shape in a cross-sectional view, and is configured to press the driver ICs <NUM> on the flexible substrate <NUM> toward the heat dissipation plate <NUM> from the inner side. With this configuration, the embodiment enables heat generated when the driver IC <NUM> drives to be efficiently dissipated to the heat dissipation plate <NUM> on the outer side.

The elastic member <NUM> is disposed so as to be in contact with an outer wall of a pressing portion, which is not illustrated, of the pressing member <NUM>. With the elastic member <NUM> being provided, it is possible to reduce the likelihood of the pressing member <NUM> causing breakage of the flexible substrate <NUM> at the time when the pressing member <NUM> presses the driver ICs <NUM>.

The elastic member <NUM> is made of, for example, double-sided foam tape or the like. In addition, for example, by using a non-silicon-based thermal conductive sheet for the elastic member <NUM>, it is possible to improve the heat dissipating property of the driver IC <NUM>. Note that the elastic member <NUM> does not necessarily have to be provided.

The housing <NUM> is disposed on the head body <NUM> so as to cover the wiring portion <NUM>. This enables the wiring portion <NUM> to be sealed with the housing <NUM>. The housing <NUM> is made of, for example, a resin or a metal or the like.

The housing <NUM> has a box shape elongated in the main scanning direction, and includes a first opening 40a and a second opening 40b at side surfaces opposed in the sub scanning direction. The first opening 40a and the second opening 40b are examples of an opening. In addition, the housing <NUM> includes a third opening 40c at a lower surface, and includes a fourth opening 40d at an upper surface.

One of the heat dissipation plates <NUM> is disposed on the first opening 40a so as to close the first opening 40a. The other of the heat dissipation plates <NUM> is disposed on the second opening 40b so as to close the second opening 40b.

The heat dissipation plates <NUM> are provided so as to extend in the main scanning direction, and are made of a metal, an alloy, or the like having a high heat dissipating property. The heat dissipation plates <NUM> are provided so as to be in contact with the driver ICs <NUM>, and have a function of dissipating heat generated by the driver ICs <NUM>.

The pair of heat dissipation plates <NUM> are each fixed to the housing <NUM> with a screw that is not illustrated. Thus, the housing <NUM> to which the heat dissipation plates <NUM> are fixed has a box shape in which the first opening 40a and the second opening 40b are closed and the third opening 40c and the fourth opening 40d are open.

The third opening 40c is provided so as to be opposed to the reservoir <NUM>. The flexible substrate <NUM> and the pressing member <NUM> are inserted into the third opening 40c.

The fourth opening 40d is provided in order to insert a connector (not illustrated) provided on the wiring board <NUM>. It is preferable that a portion between the connector and the fourth opening 40d be sealed using resin or the like. This makes it possible to suppress entry of a liquid, dust, or the like into the housing <NUM>.

Furthermore, the housing <NUM> includes thermal insulation portions 40e. The thermal insulation portions 40e are respectively provided so as to be adjacent to the first opening 40a and the second opening 40b, and are provided so as to protrude outward from side surfaces of the housing <NUM> that are opposed to each other in the sub scanning direction.

In addition, the thermal insulation portions 40e are formed so as to extend in the main scanning direction. That is, the thermal insulation portions 40e are located between the heat dissipation plates <NUM> and the head body <NUM>. By providing the housing <NUM> with the thermal insulation portions 40e in this manner, it is possible to suppress transfer of heat generated by the driver ICs <NUM> through the heat dissipation plates <NUM> to the head body <NUM>.

Note that the liquid discharge head <NUM> may further include a member other than the member illustrated in <FIG>.

Next, the configuration of the head body <NUM> according to the embodiment will be described with reference to <FIG>. <FIG> is an enlarged plan view of the head body <NUM> according to the embodiment. <FIG> is an enlarged view of a region surrounded by a dot-dash line illustrated in <FIG>. <FIG> is a cross-sectional view taken along line A-A in <FIG>.

As illustrated in <FIG>, the head body <NUM> includes the channel member <NUM> and the piezoelectric actuator substrate <NUM>. The channel member <NUM> includes a supply manifold <NUM>, a plurality of pressurizing chambers <NUM>, and a plurality of discharge holes <NUM>.

The plurality of pressurizing chambers <NUM> are connected to the supply manifold <NUM>. The plurality of discharge holes <NUM> are each connected to corresponding one of the plurality of pressurizing chambers <NUM>.

Each of the pressurizing chambers <NUM> opens to the first surface 21a (see <FIG>) of the channel member <NUM>. Furthermore, the first surface 21a of the channel member <NUM> has an opening 61a that communicates with the supply manifold <NUM>. In addition, a liquid is supplied from the reservoir <NUM> (see <FIG>) through the opening 61a to the inside of the channel member <NUM>.

In the example illustrated in <FIG>, the head body <NUM> has four supply manifolds <NUM> located inside the channel member <NUM>. Each of the supply manifolds <NUM> has a long thin shape extending along the longitudinal direction (that is, in the main scanning direction) of the channel member <NUM>. At both ends of the supply manifold <NUM>, the opening 61a of the supply manifold <NUM> is formed on the first surface 21a of the channel member <NUM>.

In the channel member <NUM>, a plurality of pressurizing chambers <NUM> are formed so as to expand two-dimensionally. As illustrated in <FIG>, each of the pressurizing chambers <NUM> is a hollow region having a substantially diamond planar shape with corner portions being rounded. The pressurizing chamber <NUM> is open at the first surface 21a of the channel member <NUM>, and is closed by the piezoelectric actuator substrate <NUM> being bonded to this first surface 21a.

The pressurizing chambers <NUM> form a pressurizing chamber row arrayed in the longitudinal direction. The pressurizing chambers <NUM> in two adjacent pressurizing chamber rows are arranged in a staggered manner between the two pressurizing chamber rows. In addition, one pressurizing chamber group includes four pressurizing chamber rows connected to one supply manifold <NUM>. In the example illustrated in <FIG>, the channel member <NUM> includes four pressurizing chamber groups.

Furthermore, relative arrangements of the pressurizing chambers <NUM> within individual pressurizing chamber groups are configured in the same manner, and the pressurizing chamber groups are arranged in a manner such that they are slightly shifted from each other in the longitudinal direction.

The discharge holes <NUM> are disposed at positions of the channel member <NUM> other than a region that is opposed to the supply manifold <NUM>. That is, the discharge holes <NUM> do not overlap with the supply manifold <NUM> in a transparent view of the channel member <NUM> from the first surface 21a side.

Furthermore, in a plan view, the discharge holes <NUM> are disposed within a region in which the piezoelectric actuator substrate <NUM> is mounted. One group of such discharge holes <NUM> occupies a region having approximately the same size and shape as the piezoelectric actuator substrate <NUM>.

Then, the displacement element <NUM> (see <FIG>) of a corresponding piezoelectric actuator substrate <NUM> is caused to be displaced, thereby discharging droplets from the discharge hole <NUM>.

As illustrated in <FIG>, the channel member <NUM> has a layered structure in which a plurality of plates are layered. These plates include a cavity plate 21A, a base plate 21B, an aperture plate 21C, a supply plate 21D, manifold plates 21E, 21F, and <NUM>, a cover plate <NUM>, and a nozzle plate 21I arranged in this order from the upper surface of the channel member <NUM>.

A large number of holes are formed in these plates. The thickness of each of the plates is approximately <NUM> to approximately <NUM>. With this configuration, the holes can be formed with high accuracy. The individual plates are layered while aligned with respect to each other such that these holes communicate with each other to form a predetermined channel.

In the channel member <NUM>, the supply manifold <NUM> and the discharge hole <NUM> communicate through an individual channel <NUM>. The supply manifold <NUM> is located on the second surface 21b side within the channel member <NUM>, and the discharge hole <NUM> is located at the second surface 21b of the channel member <NUM>.

The individual channel <NUM> includes a pressurizing chamber <NUM> and an individual supply channel <NUM>. The pressurizing chamber <NUM> is located at the first surface 21a of the channel member <NUM>. The individual supply channel <NUM> serves as a channel that connects the supply manifold <NUM> and the pressurizing chamber <NUM>.

In addition, the individual supply channel <NUM> includes a reduction portion <NUM> having a width narrower than other portions. The reduction portion <NUM> has a width narrower than other portions of the individual supply channel <NUM>, and hence, has a high channel resistance. In this manner, when the channel resistance of the reduction portion <NUM> is high, pressure occurring at the pressurizing chamber <NUM> is less likely to escape to the supply manifold <NUM>.

The piezoelectric actuator substrate <NUM> includes piezoelectric ceramic layers 22A and 22B, a common electrode <NUM>, an individual electrode <NUM>, a connecting electrode <NUM>, a dummy connecting electrode <NUM>, and a front surface electrode <NUM> (see <FIG>).

The piezoelectric actuator substrate <NUM> has the piezoelectric ceramic layer 22A, the common electrode <NUM>, the piezoelectric ceramic layer 22B, and the individual electrode <NUM> layered in this order.

Both of the piezoelectric ceramic layers 22A and 22B each extend over the first surface 21a of the channel member <NUM> so as to extend across the plurality of pressurizing chambers <NUM>. The piezoelectric ceramic layers 22A and 22B each have a thickness of approximately <NUM>. For example, the piezoelectric ceramic layers 22A and 22B are made of a lead zirconate titanate (PZT)-based ceramic material having ferroelectricity.

The common electrode <NUM> is formed over substantially the entire surface in a surface direction of a region between the piezoelectric ceramic layer 22A and the piezoelectric ceramic layer 22B. That is, the common electrode <NUM> overlaps with all the pressurizing chambers <NUM> in the region that is opposed to the piezoelectric actuator substrate <NUM>.

The thickness of the common electrode <NUM> is approximately <NUM>. For example, the common electrode <NUM> is made of a metal material such as a Ag-Pd based material.

The individual electrode <NUM> includes a body electrode 72a and an extraction electrode 72b. The body electrode 72a is located in a region of the piezoelectric ceramic layer 22B that is opposed to the pressurizing chamber <NUM>. The body electrode 72a is slightly smaller than the pressurizing chamber <NUM>, and has a shape substantially similar to that of the pressurizing chamber <NUM>.

The extraction electrode 72b is drawn out from the body electrode 72a to be outside the region that is opposed to the pressurizing chamber <NUM>. The individual electrode <NUM> is made of, for example, a metal material such as a Au-based material.

The connecting electrode <NUM> is located on the extraction electrode 72b, and is formed to have a convex shape with a thickness of approximately <NUM>. The connecting electrode <NUM> is electrically connected to an electrode provided at the flexible substrate <NUM> (see <FIG>). The connecting electrode <NUM> is made of, for example, silver-palladium, including glass frit.

The dummy connecting electrode <NUM> is located on the piezoelectric ceramic layer 22B and is positioned so as not to overlap with various electrodes such as the individual electrode <NUM>. The dummy connecting electrode <NUM> connects the piezoelectric actuator substrate <NUM> and the flexible substrate <NUM>, and increases the connection strength.

Furthermore, the dummy connecting electrode <NUM> makes uniform the distribution of the contact positions between the piezoelectric actuator substrate <NUM> and the piezoelectric actuator substrate <NUM>, and stabilizes the electrical connection. The dummy connecting electrode <NUM> is preferably made of a material equivalent to that of the connecting electrode <NUM>, and is preferably formed in a process equivalent to that of the connecting electrode <NUM>.

The front surface electrode <NUM> illustrated in <FIG> is formed on the piezoelectric ceramic layer 22B and at a position that does not interfere with the individual electrode <NUM>. The front surface electrode <NUM> is connected to the common electrode <NUM> through a via hole formed in the piezoelectric ceramic layer 22B.

With this configuration, the front surface electrode <NUM> is grounded and maintained at the ground electric potential. The front surface electrode <NUM> is preferably made of a material equivalent to that of the individual electrode <NUM>, and is preferably formed in a process equivalent to that of the individual electrode <NUM>.

A plurality of the individual electrodes <NUM> are individually electrically connected to the controller <NUM> (see <FIG>) via the flexible substrate <NUM> and wirings, in order to individually control the electric potential. By setting the individual electrode <NUM> and the common electrode <NUM> to have different electric potentials, and applying an electric field in the polarization direction of the piezoelectric ceramic layers 22A, the portion of the piezoelectric ceramic layer 22A to which the electric field is applied operates as an activation section distorted due to a piezoelectric effect.

In other words, in the piezoelectric actuator substrate <NUM>, portions of the individual electrode <NUM>, the piezoelectric ceramic layer 22A, and the common electrode <NUM> that are opposed to the pressurizing chamber <NUM> function as the displacement element <NUM>.

In addition, unimorph deformation of the displacement element <NUM> results in the pressurizing chamber <NUM> being pressed and a liquid being discharged from the discharge hole <NUM>.

Next, a drive procedure of the liquid discharge head <NUM> according to the embodiment will be described. The individual electrode <NUM> is set to be a higher electric potential (hereinafter, also referred to as a high electric potential) than the common electrode <NUM> in advance. Then, each time a discharge request is made, the individual electrode <NUM> is once set to be the same electric potential (hereinafter, referred as a "low electric potential") as the common electrode <NUM>, and then is again set to the high electric potential at a predetermined timing.

With this configuration, at the timing when the individual electrode <NUM> changes to the low electric potential, the piezoelectric ceramic layers 22A and 22B return to their original shapes, and the volume of the pressurizing chamber <NUM> increases to be higher than the initial state, that is, higher than the state of the high electric potential.

At this time, negative pressure is applied to the inside of the pressurizing chamber <NUM>. Thus, a liquid in the supply manifold <NUM> is sucked into the interior of the pressurizing chamber <NUM>.

After this, the piezoelectric ceramic layers 22A and 22B deform so as to protrude toward the pressurizing chamber <NUM> at the timing when the individual electrode <NUM> is again set to the high electric potential.

In other words, the inside of the pressurizing chamber <NUM> has a positive pressure as a result of a reduction in the volume of the pressurizing chamber <NUM>. Thus, the pressure of the liquid within the pressurizing chamber <NUM> rises, and droplets are discharged from the discharge hole <NUM>.

In other words, in order to discharge droplets from the discharge hole <NUM>, the controller <NUM> supplies a drive signal including pulses based on the high electric potential to the individual electrode <NUM> using the driver IC <NUM>. It is only necessary to set the pulse width to an acoustic length (AL) that is a length of time when a pressure wave propagates from the reduction portion <NUM> to the discharge hole <NUM>.

With this configuration, when the inside of the pressurizing chamber <NUM> changes from the negative pressure state to the positive pressure state, the pressures under both of the states are combined, which makes it possible to discharge the droplets with higher pressure.

In addition, in a case of gray scale printing, the gray scale is expressed based on the number of droplets continuously discharged from the discharge hole <NUM>, that is, the amount (volume) of droplets adjusted based on the number of times the droplets are discharged. Thus, the droplets are discharged a number of times corresponding to the designated gray scale to be expressed, through the discharge hole <NUM> corresponding to the designated dot region.

In general, when the liquid discharge is continuously performed, an interval between the pulses that are supplied to discharge the droplets may be set to the AL. Due to this, a period of a residual pressure wave of pressure generated in discharging the droplets discharged earlier matches a period of a pressure wave of pressure to be generated in discharging droplets to be discharged later.

Thus, the residual pressure wave and the pressure wave are superimposed, whereby the droplets can be discharged with a higher pressure. Note that in this case, the speed of the droplets to be discharged later is increased, and the impact points of the plurality of droplets become close.

Next, details of the flexible substrate <NUM> according to the embodiment will be described with reference to <FIG>. <FIG> is a perspective view used to explain the structure of the flexible substrate <NUM> according to the embodiment and the vicinity of the flexible substrate <NUM>. Note that a wiring layer 31b (see <FIG>) formed within the flexible substrate <NUM> or various types of elements on the wiring board <NUM> or the like are not illustrated in <FIG>.

The flexible substrate <NUM> has a shape that gradually bifurcates and tapers toward the upper direction. That is, the flexible substrate <NUM> includes two protruding portions 31p each protruding upward. In addition, the flexible substrate <NUM> includes a lower portion 31u electrically connected to the piezoelectric actuator substrate <NUM> (see <FIG>) of the head body <NUM> (see <FIG>).

In addition, the tip portion of the protruding portion 31p of the flexible substrate <NUM> that serves as a connector insertion portion 31t is inserted into a connector 32a provided at the wiring board <NUM>. Furthermore, inserting the connector insertion portion 31t inserted into the connector 32a allows the flexible substrate <NUM> and the wiring board <NUM> to be electrically connected.

The plurality of driver ICs <NUM> are mounted at a position lower than each of the plurality of connector insertion portions 31t of the flexible substrate <NUM>. The pressing member <NUM> is provided at a side of the flexible substrate <NUM> opposite from a side where the driver ICs <NUM> are mounted. In addition, the pressing member <NUM> is used to press the driver ICs <NUM> from the inner side toward the heat dissipation plate <NUM> (see <FIG>). Note that the position where the driver ICs <NUM> are mounted is not limited to the position lower than the connector insertion portion 31t.

In addition, a slit <NUM> is formed between the protruding portions 31p adjacent to each other at the flexible substrate <NUM>. Details of this slit <NUM> will be described later.

<FIG> is a schematic view of a cross-section at or around the connector insertion portion 31t of the flexible substrate <NUM> according to the embodiment. At or around the connector insertion portion 31t, the flexible substrate <NUM> includes a base substrate 31a, the wiring layer 31b, a cover layer 31c, and a reinforcing plate 31d.

The base substrate 31a is composed of an insulation body (for example, a resin material or the like) having flexibility. The wiring layer 31b is formed at a front surface of the base substrate 31a, and is composed of an electroconductive body (for example, a metal or the like). With this wiring layer 31b, a desired wiring pattern is formed at the flexible substrate <NUM>.

The cover layer 31c is formed at a front surface of the base substrate 31a so as to cover the wiring layer 31b. The cover layer 31c is provided to protect the wiring layer 31b.

The reinforcing plate 31d is a member for reinforcing the vicinity of the connector insertion portion 31t at the flexible substrate <NUM>. The reinforcing plate 31d is disposed at a back surface of the base substrate 31a, and is made out, for example, of resin such as glass epoxy, composite, polyetherimide, polyimide, or polyester; or a metal such as stainless steel, aluminum, or an alloy thereof.

<FIG> is a diagram used to explain the entire configuration of the flexible substrate <NUM> according to the embodiment. Note that, in <FIG>, positions of the corresponding connectors 32a are illustrated with the long dashed short dashed lines.

As illustrated in <FIG>, the flexible substrate <NUM> includes a plurality of (two in <FIG>) the protruding portions 31p configured to protrude in the same direction. These protruding portions 31p protrude in an inserting direction T of the connector insertion portion 31t.

In addition, since the flexible substrate <NUM> has flexibility and the widths of the protruding portions 31p are configured to be reduced, the flexible substrate <NUM> has a shape that makes it easy to insert the connector insertion portions 31t into the connectors 32a at the time of insertion.

Furthermore, in the embodiment, the slit <NUM> is formed between protruding portions 31p adjacent to each other at the flexible substrate <NUM>. Such a slit <NUM> is formed so as to extend from a side (the upper side in <FIG>) from which the protruding portions 31p protrude at the flexible substrate <NUM> and in a direction (the downward direction in <FIG>) opposite to the direction in which the protruding portions 31p protrude.

With this configuration, it is possible to easily deform not only the protruding portions 31p but also the vicinity of the slit <NUM> at the time of inserting the connector insertion portions 31t into the connectors 32a. Thus, the flexible substrate <NUM> according to the embodiment has a shape that makes it easy to insert the connector insertion portions 31t into the connectors 32a at the time of insertion.

Here, in the embodiment, the slit <NUM> extends up to a region between the driver ICs <NUM> adjacent to each other on the same main surface of the flexible substrate <NUM>. That is, the slit <NUM> is formed so as to separate adjacent driver ICs <NUM> from each other.

With this configuration, it is possible to lengthen the heat transfer path from one driver IC <NUM> to another driver IC <NUM> at the flexible substrate <NUM>. Thus, the embodiment makes it possible to reduce the thermal interference between the driver ICs <NUM> adjacent to each other.

Furthermore, in the embodiment, it is preferable that the slit <NUM> is formed at the center between protruding portions 31p adjacent to each other. If the slit <NUM> is formed at a decentered position between the protruding portions 31p adjacent to each other, the protruding portion 31p disposed closer to the slit <NUM> can be easily deformed to the vicinity of the slit <NUM>, whereas the protruding portion 31p disposed further away from the slit <NUM> is difficult to be deformed to the vicinity of the slit <NUM>.

However, in a case of the embodiment, the slit <NUM> is formed at the center between the protruding portions 31p adjacent to each other. This makes it possible to evenly deform both of the protruding portions 31p to the vicinity of the slip <NUM>. Thus, with the embodiment, it is possible to evenly insert the individual connector insertion portions 31t.

In addition, in the embodiment, it is preferable that a shank <NUM> that protrudes in the width direction of the protruding portion 31p is provided at a side portion of the protruding portion 31p adjacent to the connector insertion portion 31t. Note that, in the example in <FIG>, two shanks <NUM> are provided at one side portion.

In the embodiment, by holding the shank <NUM> to insert the connector insertion portion 31t into the connector 32a, it is possible to more easily insert the connector insertion portion 31t into the connector 32a.

As illustrated in <FIG>, a large number of the wiring layers 31b illustrated with the dashed lines are formed at the flexible substrate <NUM>. Note that, for the purpose of facilitating understanding, the number of the wiring layers 31b are illustrated in <FIG> in a reduced manner.

For example, a plurality of the wiring layers 31b that extend toward the connector insertion portion 31t are formed from a center portion of the upper portion of the driver IC <NUM>. In addition, a plurality of the wiring layers 31b that extend toward the lower portion 31u of the flexible substrate <NUM> are formed from the lower portion of the driver IC <NUM>.

Furthermore, from portions other than the center portion of the upper portion of the driver IC <NUM>, a plurality of the wiring layers 31b that extend toward the lower portion 31u of the flexible substrate <NUM> are formed in a diverted manner so as to avoid the driver IC <NUM>.

In addition, a wiring layer 31ba that is the wiring layer 31b disposed closest to the slit <NUM> extends from the slit <NUM> side of the upper portion of the driver IC <NUM> so as to avoid the driver IC <NUM> and pass through the vicinity of the slit <NUM> toward the lower portion 31u of the flexible substrate <NUM>.

<FIG> is an enlarged view illustrating the configuration of the flexible substrate <NUM> according to the embodiment, and is a diagram used to explain a positional relationship between the slit <NUM> and the wiring layer 31ba at the flexible substrate <NUM>.

As illustrated in <FIG>, in the embodiment, the width of the slit <NUM> is substantially equal throughout the entire region, and falls in a range, for example, of approximately <NUM> to <NUM>. In addition, the slit <NUM> extends so as to be along the inserting direction T of the connector insertion portion 31t.

In the embodiment, it is preferable that the width of the slit <NUM> is equal to or more than a predetermined value (for example, <NUM>). In a case where the width of the slit <NUM> is less than the predetermined value, flexible substrates <NUM> at both sides of the slit <NUM> are excessively close to each other when the vicinity of the slit <NUM> is deformed to insert the connector insertion portion 31t, which results in a possibility that these flexible substrates <NUM> at both sides are rubbed with each other.

However, in a case of the embodiment, since the width of the slit <NUM> is set to be equal to or more than the predetermined value, it is possible to suppress a failure occurring due to rubbing, with each other, of the flexible substrates <NUM> at both side of the slit <NUM>.

Furthermore, in the embodiment, it is preferable that the wiring layer 31ba of the flexible substrate <NUM> includes a portion 31bb extending along the slit <NUM>. With this configuration, it is possible to enhance the rigidity of the flexible substrate <NUM> in the vicinity of the slit <NUM>.

In addition, in the embodiment, it is preferable that the wiring layer 31ba of the flexible substrate <NUM> is disposed so as to surround a tip portion 31sa of the slit <NUM>. This makes it possible to enhance the rigidity of the vicinity of the tip portion 31sa of the slit <NUM> at the flexible substrate <NUM>.

Thus, with the embodiment, it is possible to prevent the flexible substrate <NUM> from being torn when the vicinity of the slit <NUM> is deformed.

Furthermore, in the embodiment, the pressing member <NUM> is exposed from the slit <NUM> to the heat dissipation plate <NUM>. For this reason, by bringing the pressing member <NUM> exposed from the slit <NUM> into direct contact with the heat dissipation plate <NUM>, it is possible to favorably transfer, to the heat dissipation plate <NUM>, the heat transferred from the driver IC <NUM> to the pressing member <NUM>. Thus, with the embodiment, it is possible to favorably dissipate the heat generated from the driver IC <NUM>.

Various modification examples of the flexible substrate <NUM> according to the embodiment will be described with reference to <FIG>. <FIG> is an enlarged view illustrating a configuration of the flexible substrate <NUM> according to a first modification example of the embodiment. Note that, in the various variations below, redundant explanations are omitted, with parts that are the same as those in the embodiment described above denoted by the same reference numerals.

As illustrated in <FIG>, in the flexible substrate <NUM> according to the first modification example, the slit <NUM> has a shape differing from that in the embodiment. Specifically, the tip portion 31sa of the slit <NUM> according to the first modification example has a rounded shape, in line with a first aspect of the present invention.

In this manner, by making the tip portion 31sa of the slit <NUM> have a rounded shape, it is possible to disperse the stress acting on the tip portion 31sa of the slit <NUM> at the time when the vicinity of the slit <NUM> is deformed.

Thus, with the first modification example, it is possible to prevent the flexible substrate <NUM> from being torn at the time when the vicinity of the slit <NUM> is deformed. Note that the example in <FIG> gives an example in which the tip portion 31sa of the slit <NUM> has a circular shape. However, the shape of the tip portion 31sa is not limited to the circular shape, and may be an elliptical shape.

In addition, in the first modification example, in line with the first aspect of the present invention, the wiring layer 31ba of the flexible substrate <NUM> extends so as to be in contact with an imaginary circle C concentric with the rounded shape formed at the tip portion 31sa of the slit <NUM>. That is, in the first modification example, the wiring layer 31ba of the flexible substrate <NUM> has a portion 31bc that extends so as to be in contact with this imaginary circle C.

With this configuration, it is possible to lengthen the distance from the tip portion 31sa of the slit <NUM> to the wiring layer 31ba, which makes it possible to suppress a failure (for example, short circuit of the wiring layer 31ba) occurring as a result of the slit <NUM> and the wiring layer 31ba being close to each other.

<FIG> is an enlarged view illustrating the configuration of the flexible substrate <NUM> according to a second modification example of the embodiment. As illustrated in <FIG>, the slit <NUM> according to the second modification example is configured such that the width of a base end portion 31sb is wider than the width of portions other than the base end portion 31sb and the tip portion 31sa.

With this configuration, at the time when the vicinity of the slit <NUM> is deformed, it is possible to prevent the flexible substrates <NUM> at both sides of the base end portion 31sb that is more largely deformed, from being rubbed with each other. Thus, with the second modification example, it is possible to suppress a failure occurring due to rubbing, with each other, of the flexible substrates <NUM> at both side of the base end portion 31sb.

Note that the example in <FIG> gives an example in which the width of the slit <NUM> changes stepwise from the base end portion 31sb toward the tip portion 31sa. However, the change in the width of the slit <NUM> is not limited to the stepwise manner.

<FIG> is an enlarged view illustrating the configuration of the flexible substrate <NUM> according to a third modification example of the embodiment. In the example in <FIG>, the width of the slit <NUM> gradually reduces from the base end portion 31sb to a predetermined location, and the width of the slit <NUM> is substantially equal from the predetermined location to the vicinity of the tip portion 31sa.

Even with such a shape, at the time when the vicinity of the slit <NUM> is deformed, it is possible to prevent the flexible substrates <NUM> at both sides of the base end portion 31sb that is more largely deformed, from being rubbed with each other. Thus, with the third modification example, it is possible to suppress a failure occurring due to rubbing, with each other, of the flexible substrates <NUM> at both sides of the base end portion 31sb.

Furthermore, in the third modification example, all the internal angles of the slit <NUM> other than the tip portion 31sa can be each set to be an obtuse angle. This makes it possible to disperse the stress acting on the slit <NUM> at the time when the vicinity of the slit <NUM> is deformed.

Thus, with the third modification example, it is possible to prevent the flexible substrate <NUM> from being torn at the time when the vicinity of the slit <NUM> is deformed.

<FIG> is an enlarged view illustrating the configuration of the flexible substrate <NUM> according to a fourth modification example of the embodiment. In the example in <FIG>, the width of the slit <NUM> gradually reduces from the base end portion 31sb to the vicinity of the tip portion 31sa.

Even with such a shape, at the time when the vicinity of the slit <NUM> is deformed, it is possible to prevent the flexible substrates <NUM> at both sides of the base end portion 31sb that is more largely deformed, from being rubbed with each other. Thus, with the fourth modification example, it is possible to suppress a failure occurring due to rubbing, with each other, of the flexible substrates <NUM> at both sides of the base end portion 31sb.

In addition, in the fourth modification example, all the internal angles of the slit <NUM> other than the tip portion 31sa can be each set to be an obtuse angle. This makes it possible to disperse the stress acting on the slit <NUM> at the time when the vicinity of the slit <NUM> is deformed.

Thus, with the fourth modification example, it is possible to prevent the flexible substrate <NUM> from being torn at the time when the vicinity of the slit <NUM> is deformed.

<FIG> is an enlarged view illustrating the configuration of the flexible substrate <NUM> according to a fifth modification example of the embodiment. Note that, in <FIG>, hatching is applied to a portion where the reinforcing plate 31d is provided in the vicinity of the slit <NUM>.

As illustrated in <FIG>, the flexible substrate <NUM> according to the fifth modification example includes the reinforcing plate 31d at the periphery of the portion where the slit <NUM> extends, in line with a first alternative of a second aspect of the present invention. This makes it possible to prevent the flexible substrate <NUM> from being broken from the periphery of the portion where the slit <NUM> extends.

Furthermore, the flexible substrate <NUM> according to the fifth modification example includes the reinforcing plate 31d at the periphery of the tip portion 31sa of the slit <NUM>, in line with a second alternative of the second aspect of the present invention. This makes it possible to prevent the flexible substrate <NUM> from being broken from the periphery of the tip portion 31sa of the slit <NUM>.

Note that the example in <FIG> gives an example in which the reinforcing plate 31d is provided at both the periphery of the region where the slit <NUM> extends and the periphery of the tip portion 31sa of the slit <NUM>. However, it may be possible that the reinforcing plate 31d is provided only at either one of them.

In particular, by providing the reinforcing plate 31d only at the periphery of the tip portion 31sa of the slit <NUM>, it is possible to prevent breakage starting from the periphery of the tip portion 31sa of the slit <NUM> where stress is more likely to concentrate and the possibility of breakage is relatively high, and it is also possible to reduce the amount of usage of the reinforcing plate 31d.

In addition, in the fifth modification example, no wiring layer 31b is provided at a portion of the flexible substrate <NUM> where the reinforcing plate 31d is provided, in line with the second aspect of the present invention. This makes it possible to prevent the wiring layer 31b from being broken at the time when a portion of the flexible substrate <NUM> that corresponds to the slit <NUM> is stamped out together with the reinforcing plate 31d to form the slit <NUM>.

<FIG> is a diagram used to explain the entire configuration of the flexible substrate <NUM> according to a sixth modification example of the embodiment. The embodiment illustrated in <FIG> or the like gives an example in which two protruding portions 31p are provided at one flexible substrate <NUM>. However, the number of the protruding portions 31p provided at one flexible substrate <NUM> is not limited to two.

For example, in a case where the resolution of the liquid discharge head <NUM> is set to be high, more driver ICs <NUM> are necessary. Thus, there may be a case where the number of the protruding portions 31p needs to be equivalent to these driver ICs <NUM>.

For example, as illustrated in <FIG>, in a case where four driver ICs <NUM> are mounted to one flexible substrate <NUM>, four protruding portions 31p that correspond to the four driver ICs <NUM> are formed.

In this manner, even in a case where three or more (four in <FIG>) protruding portions 31p are formed at one flexible substrate <NUM>, it is only necessary that a plurality of the slits <NUM> (three in <FIG>) that have been described above are formed between the protruding portions 31p adjacent to each other.

With this configuration, at the time when all the connector insertion portions 31t are inserted into the connectors 32a, it is possible to easily insert these connector insertion portions 31t.

In addition, since it is possible to lengthen the heat transfer path from one driver IC <NUM> to another driver IC <NUM> at the flexible substrate <NUM>, it is possible to reduce the thermal interference between the driver ICs <NUM> adjacent to each other.

<FIG> is a diagram used to explain the entire configuration of the flexible substrate <NUM> according to a seventh modification example of the embodiment. Note that, in <FIG>, the positions of the corresponding connectors 32a are illustrated with the long dashed short dashed lines.

As illustrated in <FIG>, the flexible substrate <NUM> includes a plurality of the protruding portions 31p (two in <FIG>) configured to protrude in the same direction. These protruding portions 31p protrude in the inserting direction T of the connector insertion portion 31t.

Furthermore, in the seventh modification example, a through hole 31e is formed between the protruding portions 31p adjacent to each other at the flexible substrate <NUM>. Such a through hole 31e is formed so as to extend from a side (the upper side in <FIG>) from which the protruding portions 31p protrude and in a direction (downward direction in <FIG>) opposite to the direction in which the protruding portions 31p protrude.

However, unlike the slit <NUM>, the through hole 31e does not reach the same side as the side from which the protruding portions 31p protrude at the flexible substrate <NUM>. That is, the through hole 31e is closed with respect to the same side as the side from which the protruding portions 31p protrude at the flexible substrate <NUM>.

Furthermore, in the seventh modification example, the through hole 31e extends up to a region between the driver ICs <NUM> adjacent to each other on the same main surface of the flexible substrate <NUM>. That is, the through hole 31e is formed so as to separate adjacent driver ICs <NUM> from each other.

With this configuration, it is possible to lengthen the heat transfer path from one driver IC <NUM> to another driver IC <NUM> at the flexible substrate <NUM>. Thus, with the seventh modification example, it is possible to reduce the thermal interference between the driver ICs <NUM> adjacent to each other.

<FIG> is an enlarged view illustrating the configuration of the flexible substrate <NUM> according to the seventh modification example of the embodiment, and is a diagram used to explain a positional relationship between the through hole 31e and the wiring layers 31ba at the flexible substrate <NUM>.

As illustrated in <FIG>, in the seventh modification example, the width of the through hole 31e is substantially equal throughout the entire region, and falls in a range, for example, of approximately <NUM> to <NUM>. In addition, the through hole 31e extends so as to be along the inserting direction T of the connector insertion portion 31t.

In the seventh modification example, it is preferable that the width of the through hole 31e is equal to or less than a predetermined value (for example, <NUM>). If the width of the through hole 31e is greater than this predetermined value, there is a possibility that the through hole 31e and the wiring layer 31ba interfere with each other.

However, in the seventh modification example, since the width of the through hole 31e is set to be equal to or less than the predetermined value, it is possible to suppress a failure resulting from the through hole 31e and the wiring layer 31ba interfering with each other.

In addition, in the seventh modification example, it is preferable that the wiring layer 31ba of the flexible substrate <NUM> includes the portion 31bb extending along the through hole 31e. This makes it possible to enhance the rigidity of the flexible substrate <NUM> in the vicinity of the through hole 31e.

Note that, unlike the slit <NUM> that has been described above, the planar shape of the through hole 31e may be configured such that neither an end portion 31ea nor an end portion 31eb has a rounded shape, as illustrated in <FIG>. Furthermore, unlike the slit <NUM> that has been described above, the reinforcing plate 31d is not always necessary to be provided at the periphery of the end portions 31ea and 31eb at the through hole 31e.

This is because, since the through hole 31e is closed to the side surface of the flexible substrate <NUM>, there is no possibility that stress concentrates on the through hole 31e even at the time when the flexible substrate <NUM> is deformed.

Furthermore, in the seventh modification example, a portion extending from the through hole 31e to the pressing member <NUM> is exposed to the heat dissipation plate <NUM>. Thus, by causing the pressing member <NUM> exposed from the through hole 31e to be brought into direct contact with the heat dissipation plate <NUM>, it is possible to favorably transfer, to the heat dissipation plate <NUM>, the heat transferred from the driver IC <NUM> to the pressing member <NUM>. Thus, with the seventh modification example, it is possible to favorably dissipate the heat generated from the driver IC <NUM>.

Although embodiments of the present disclosure are described above, the present disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the scope of the appended claims. For example, the embodiment described above gives an example in which the shank <NUM> is provided in the vicinity of the connector insertion portion 31t of the protruding portion 31p. However, the shank <NUM> may not be necessarily provided.

As described above, the liquid discharge head <NUM> according to the embodiment includes the head body <NUM>, the plurality of driver ICs <NUM>, the flexible substrate <NUM>, and the wiring board <NUM>. The head body <NUM> includes the discharge hole <NUM> configured to discharge a liquid. The plurality of driver ICs <NUM> control drive of the head body <NUM>. The plurality of driver ICs <NUM> are mounted at the flexible substrate <NUM>, and the flexible substrate <NUM> is electrically connected to the head body <NUM>. The wiring board <NUM> includes the plurality of connectors 32a. In addition, the flexible substrate <NUM> includes the plurality of protruding portions 31p configured to protrude in the same direction and each including a tip portion (connector insertion portion 31t) to be inserted into corresponding one of the plurality of connectors 32a, and also includes the slit <NUM> formed between the protruding portions 31p adjacent to each other and extending up to a region between the driver ICs <NUM> adjacent to each other. This makes it possible to reduce the thermal interference between the driver ICs <NUM> adjacent to each other. Furthermore, since the slit <NUM> is provided between the protruding portions 31p, it is possible to improve operability of each of the protruding portions 31p.

In addition, in the liquid discharge head <NUM> according to the embodiment, the wiring layer 31ba of the flexible substrate <NUM> includes the portion 31bb extending along the slit <NUM>. With this configuration, it is possible to enhance the rigidity of the flexible substrate <NUM> in the vicinity of the slit <NUM>.

Furthermore, in the liquid discharge head <NUM> according to the embodiment, the tip portion 31sa of the slit <NUM> has a rounded shape. This makes it possible to prevent the flexible substrate <NUM> from being torn at the time when the vicinity of the silt <NUM> is deformed.

Furthermore, in the liquid discharge head <NUM> according to the embodiment, the wiring layer 31ba of the flexible substrate <NUM> extends so as to be in contact with the imaginary circle C concentric with the rounded shape formed at the tip portion 31sa of the slit <NUM>. This makes it possible to suppress a failure (for example, short circuit of the wiring layer 31ba or the like) occurring as a result of the slit <NUM> and the wiring layer 31ba being close to each other.

Furthermore, in the liquid discharge head <NUM> according to the embodiment, the wiring layer 31ba of the flexible substrate <NUM> is disposed so as to surround the tip portion 31sa of the slit <NUM>. This makes it possible to prevent the flexible substrate <NUM> from being torn at the time when the vicinity of the silt <NUM> is deformed.

Furthermore, in the liquid discharge head <NUM> according to the embodiment, the flexible substrate <NUM> includes the reinforcing plate 31d at the periphery of a portion where the slit <NUM> extends, in line with the first alternative of the second aspect of the present invention. This makes it possible to prevent the flexible substrate <NUM> from being broken from the periphery of the portion where the slit <NUM> extends.

Furthermore, in the liquid discharge head <NUM> according to the embodiment, the flexible substrate <NUM> includes the reinforcing plate 31d at the periphery of the tip portion 31sa of the slit <NUM>, in line with the second alternative of the second aspect of the present invention. This makes it possible to prevent the flexible substrate <NUM> from being broken from the periphery of the tip portion 31sa of the slit <NUM>.

Furthermore, in the liquid discharge head <NUM> according to the embodiment, the flexible substrate <NUM> is configured such that the wiring layer 31b is not provided at a portion where the reinforcing plate 31d is provided, in line with the second aspect of the present invention. This makes it possible to prevent the wiring layer 31b from being broken at the time when a portion of the flexible substrate <NUM> that corresponds to the slit <NUM> is stamped out together with the reinforcing plate 31d to form the slit <NUM>.

Furthermore, in the liquid discharge head <NUM> according to the embodiment, the slit <NUM> is formed at the center between the protruding portions 31p adjacent to each other. This makes it easy to equally insert the individual connector insertion portions 31t.

Furthermore, in the liquid discharge head <NUM> according to the embodiment, the slit <NUM> is configured such that the width of the base end portion 31sb is wider than the width of the portion other than the base end portion 31sb and the tip portion 31sa. This makes it possible to prevent the flexible substrates <NUM> at both side of the base end portion 31sb from being rubbed with each other.

Furthermore, the liquid discharge head <NUM> according to the embodiment includes the head body <NUM>, the plurality of driver ICs <NUM>, the flexible substrate <NUM>, and the wiring board <NUM>. The head body <NUM> includes the discharge hole <NUM> configured to discharge a liquid. The plurality of driver ICs <NUM> control drive of the head body <NUM>. The plurality of driver ICs <NUM> are mounted at the flexible substrate <NUM>, and the flexible substrate <NUM> is electrically connected to the head body <NUM>. The wiring board <NUM> includes the plurality of connectors 32a. In addition, the flexible substrate <NUM> includes the plurality of protruding portions 31p configured to protrude in the same direction and each including the tip portion (connector insertion portion 31t) to be inserted into corresponding one of the plurality of connectors 32a, and also includes a through hole 31e formed along a protruding direction of the protruding portions 31p and extending up to a region between the driver ICs <NUM> adjacent to each other. This makes it possible to reduce the thermal interference between the driver ICs <NUM> adjacent to each other.

In addition, the recording device (printer <NUM>) according to the embodiment includes the liquid discharge head <NUM> described above, the conveying unit (conveying roller <NUM>) configured to convey a recording medium (printing sheet P) to the liquid discharge head <NUM>, and the controller <NUM> configured to control the plurality of driver ICs <NUM> of the liquid discharge head <NUM>. This makes it possible to achieve the printer <NUM> in which thermal interference between the driver ICs <NUM> adjacent to each other is reduced.

In addition, the recording device (printer <NUM>) according to the embodiment includes the liquid discharge head <NUM> described above, and the applicator <NUM> configured to apply the coating agent on a recording medium (printing sheet P). With surface treatment thus performed on the printing sheet P, the printing quality of the printer <NUM> can be improved.

In addition, the recording device (printer <NUM>) according to the embodiment includes the liquid discharge head <NUM> described above, and the dryer <NUM> that dries a recording medium (printing sheet P). With this configuration, it is possible to suppress the bonding between the printing sheets P rolled while being overlapped with each other, and rubbing of undried liquid, in the collection roller <NUM>.

Claim 1:
A liquid discharge head (<NUM>) comprising:
a head body (<NUM>) comprising a discharge hole (<NUM>) configured to discharge a liquid;
a plurality of driver ICs (<NUM>) configured to control drive of the head body (<NUM>);
a wiring board (<NUM>) comprising a plurality of connectors (32a); and
a flexible substrate (<NUM>) at which the plurality of driver ICs (<NUM>) are mounted, the flexible substrate (<NUM>) being electrically connected to the head body (<NUM>) and comprising:
a plurality of protruding portions (31p) configured to protrude in a same direction and each including a tip portion (31sa) to be inserted into a corresponding one of the plurality of connectors (32a); and
a slit (<NUM>) formed between adjacent protruding portions (31p) of the plurality of protruding portions (31p) and extending up to a region between the driver ICs (<NUM>) adjacent to each other,
characterised in that
a tip portion (31sa) of the slit (<NUM>) has a rounded shape, and
a wiring layer of the flexible substrate (<NUM>) extends and is in contact with an imaginary circle concentric with a rounded shape formed at the tip portion (31sa) of the slit (<NUM>).