An ink-jet recording apparatus includes an ink supplying member which has an ink storage section, an exhaust section, and a space portion formed between the ink storage section and the exhaust section, an ink-jet head, and two flexible flat cables (FPC) which are drawn in mutually opposite directions from the ink-jet head. One FPC is wired by passing along a side of the ink supplying member, opposite to the exhaust section, and the other FPC is wired by passing through the space portion. Since the FPC is wired avoiding the ink supplying member and the exhaust section, it is possible to eliminate adhering of ink to the FPC, and to eliminate a waste of FPC wiring. Moreover, it is possible to reduce a cost, and to uniformize electrical characteristics of the two flexible flat cables.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent Application No. 2006-133688 filed on May 12, 2006, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ink-jet recording apparatus which carries out recording by jetting an ink, and particularly to an ink-jet recording apparatus in which, an ink-jet head and an circuit board are connected by a flexible flat cable (FFC, flexible print circuit (FPC)), and an ink supplying member is arranged between the ink-jet head and the circuit board.

2. Description of the Related Art

As an ink-jet head applicable to an ink-jet recording apparatus, an ink-jet head which includes a cavity portion having nozzles formed in a surface (front surface) facing a recording medium, and ink channels formed therein, an actuator which selectively applies a jetting pressure to the ink inside the cavity portion, and a FFC which transmits a driving signal which is to be supplied to this actuator has hitherto been known. As it has been disclosed in FIG. 2 and FIG. 3 of US2005/140741A1 (corresponds to Japanese Patent Application Laid-open No. 2005-178306), such ink-jet head is fixed to a head holder, and mounted on the ink-jet recording apparatus.

In recent years, for dealing with a high-speed printing and/or high-density printing, there has been a tendency of increasing the number of nozzles (or nozzle rows) of the ink-jet head. In an ink-jet recording apparatus described in US2005/140741A1, for increasing the number of nozzle rows, two recording heads are arranged in parallel in a front surface of a head holder. Two FFCs (FPCS) are drawn from each recording head, in mutually opposite directions, and the FFCs are connected to a circuit board at a position at which the FFCs face mutually, the circuit board being fixed to a rear-surface side of the head holder.

An ink tank which supplies an ink from an ink cartridge to the recording head is mounted between the recording head and the printed circuit substrate in the head holder of the ink-jet recording apparatus described in US2005/140741A1. The ink tank is formed to be substantially rectangular parallelepiped shaped (cuboid). The two FFCs which are drawn in the mutually opposite directions from each recording head pass along a side of the ink tank from a front-surface side of the head holder, and reach the printed circuit board on the rear-surface side of the head holder. The two FFCs are wired to be bilaterally symmetrical in a side view.

In FIG. 4 of Japanese Patent Application Laid-open No. 2005-125636, a damper unit which also functions as an ink tank for storing an ink, and an exhaust valve means (unit) which removes air bubbles from the damper unit are connected integrally. Since the exhaust valve means removes the air bubbles included in the ink of the damper unit, it is possible to prevent from occurring a jetting defect due to mixing of the air bubbles in the ink-jet head.

SUMMARY OF THE INVENTION

In an ink-jet recording apparatus described in US2005/140741A1, instead of the ink tank, when the damper unit and the exhaust valve unit described in the Japanese Patent Application Laid-open No. 2005-125636 are mounted on the head holder, it is not possible to draw around the two FFCs to be bilaterally symmetrical in a side view. This is because, the exhaust valve unit is connected to the side surface of the damper unit described in Japanese Patent Application Laid-open No. 2005-125636.

Concretely, in Japanese Patent Application Laid-open No. 2005-125636, one recording head is arranged on a front surface of the damper unit, and further, the exhaust valve means is connected to the damper unit such that the exhaust valve unit is projected sideward. Therefore, as in a case described above, when two FFCs to be connected to two recording heads are wired to a rear-surface side of the head holder, the FFCs are drawn to a side of the damper unit on which the exhaust valve unit is arranged. One FFC is longer than the other FFC which is drawn to an opposite side of the side of the damper unit on which the exhaust valve unit is arranged. This is because one FFC runs along the side of the exhaust valve means opposite to the damper unit. Therefore, there are problems that a cost of the FFCs becomes high, and that electrical characteristics of one FFC do not match with those of the other FFC.

Moreover, in this case, since the exhaust valve unit is covered by the FFC, there is a possibility of occurrence of an electrical short circuit when an ink, which is discharged at the same time when air bubbles are discharged from an outer opening end provided to the exhaust valve unit, is adhered to the FFC and flows to a terminal portion. Moreover, there is a problem that it becomes difficult to control a discharge of the air bubbles by opening and closing the exhaust section.

The present invention is made in view of the abovementioned circumstances. An object of the present invention is to realize a reduction of cost and uniformization of electrical characteristics of the FFCs by preventing from adhering to the FFC the ink discharged along with the discharge of the air bubbles from an exhaust section, and/or eliminating a waste of wiring of the FFCs, in an ink-jet recording apparatus which includes a head holder in which an ink-jet head and an ink supplying member having a damper unit and an exhaust valve unit, and two FFCs which are wired from a front-surface side of the head holder to an circuit board of a rear-surface side.

According to a first aspect of the present invention there is provided an ink-jet recording apparatus which jets droplets of an ink onto a recording medium, including

an ink-jet head which selectively jets the droplets of the ink, including a cavity unit in which a cavity and a plurality of nozzles which communicate with the cavity are formed, and an actuator which applies a jetting pressure to the ink in the cavity;

a circuit board on which an electric circuit which is electrically connected to the actuator is formed, the circuit board being arranged on the ink-jet head on a side opposite to the nozzles;

an ink supplying unit which is arranged between the ink-jet head and the circuit board, the ink supplying unit including an ink storage section which stores the ink to be supplied to the ink-jet head, an exhaust section which is connected to the ink storage section to remove air bubbles generated in the ink stored in the ink storage section, and a space formed in the ink supplying unit penetrating therethrough from a side of the ink-jet head of the ink supplying member up to the circuit board, the space being formed between the ink storage section and the exhaust section; and

two flexible flat cables which connect the actuator and the circuit board, the flexible flat cables including a first flexible flat cable which is wired to pass along a side, of the ink storage section, opposite to the exhaust section, and a second flexible flat cable which is drawn from the actuator to the other side, of the ink storage section, opposite to the first flexible flat cable to be wired to pass through the space.

According to the first aspect of the present invention, from among the two FFCs which are arranged in parallel, to be drawn in mutually opposite directions, one FFC passes through a space portion formed between the exhaust section and the ink storage section of the ink supplying member, and the other FFC passes along a side of the ink storage chamber (section) on the opposite side of the space portion, and each of the FFCs is connected to the circuit board. Therefore, it is possible to match a length of the two FFCs. Accordingly, it is possible to prevent unevenness in electrical characteristics of the two FFCs, and to reduce a cost of members by decreasing the length of the cables.

The ink-jet recording apparatus of the present invention, may further include a head holder which is substantially box shaped and which holds the ink-jet head, the ink supplying unit, and the circuit board, the ink-jet head and the circuit board being held so as to overlap with each other in a plan view. The exhaust section may have an outer opening which is opened to outside of the ink supplying unit, at a side opposite to the ink storage section with respect to the second flexible flat cable.

In the ink-jet head, since the ink supplying member and the circuit board are held by the head holder, it is possible to fix easily the ink supplying member and the circuit board. Since the outer opening of the exhaust section opens to an outside at a side of the second FFC, opposite to the ink storage chamber, even when the ink is discharged with the air bubbles from the exhaust section, the ink is not adhered to the FFC, and it is possible to avoid a short-circuit accident due to adhering of the ink to the FFC.

The ink-jet recording apparatus of the present invention may further include an exhaust valve which is provided on the exhaust section, and which connects and disconnects an outside of the ink supplying unit and the ink storage section through the outer opening; and an operating mechanism which is provided outside of the head holder, and which operates the exhaust valve.

According to the ink-jet recording apparatus of the present invention, since the outer opening of the exhaust section opens on the outside of the second FFC, on the opposite side of the ink storage section, it is possible to open and close more easily the exhaust vale which opens and closes with respect to the outside of the outer opening, by an operation of the operating mechanism, and to discharge appropriately to the outside the air bubbles accumulated in the ink storage section. As a result, it is possible to prevent an occurrence of a discharge defect caused due to mixing of the air bubbles of the ink storage section into the ink-jet head.

The ink-jet recording apparatus of the present invention may include further a suction mechanism which is provided outside of the head holder, which is detachable from the outer opening of the exhaust section, and which sucks air bubbles from the ink storage section when the suction unit is in closely contact with the outer opening.

Since the outer opening of the exhaust section is opened on the outer side of the second FFC, on the opposite side of the ink storage chamber (section), it is possible to bring in close contact and detach the suction mechanism with and from the outer opening of the exhaust section, and to discharge assuredly the air bubbles accumulated in the ink storage section.

In the ink-jet recording apparatus of the present invention, the flexible flat cables (the first FFC and the second FFC) may have a belt shape, and the space may be formed as a slit of which cross section corresponds to a cross section of the belt shaped flexible flat cables.

Since the space is formed as a slit of which cross section corresponds to a cross section of the belt shaped FFC, it is possible to provide the space without increasing remarkably a size of the entire ink supplying member.

In the ink-jet recording apparatus of the present invention, the ink supplying member may include a connecting portion connecting the ink storage chamber and the exhaust section, the connecting portion partially overlapping in a plan view with an extending area in which the second flexible flat cable is extended in a longitudinal direction thereof, and which has a width at a position, of the second flexible flat cable, at which the second flexible flat cable is drawn from the actuator; and the second flexible flat cable is formed to be belt shaped, which is shifted at an intermediate portion or at an end portion in a width direction of the second flexible flat cable to avoid the connecting portion.

The intermediate portion, in a longitudinal direction, of the FFC or the end portion of the FFC is formed in advance to be shifted in the direction of width, according to a relationship between a width of the FFC at a position drawn from the actuator and the connecting portion between the exhaust section and the ink storage section in the ink supplying member, it is possible to connect the second FFC which passes through the space portion to the circuit board without being twisted or bent in between the longitudinal direction.

In the ink-jet recording apparatus of the present invention, the flexible flat cables may include a plurality of cables connected in a longitudinal direction of the cables.

Since the first FFC and/or the second FFC includes the cables connected in the longitudinal direction, for example, it is possible to divide the cables as cables to be connected to the actuator, and cables to be connected to the circuit board. In this case, at the time of handling the ink-jet head singly, it is possible to carry out work operation without the cables to be connected to the circuit board not being connected. In other words, since it is possible to shorten a length of the FFC at the time of handling the ink-jet head singly, it is possible to reduce a possibility of detachment of the FFC, and the actuator, and a damage of the FFC.

In the ink-jet recording apparatus of the present invention, each of the flexible flat cables may have a flat portion which is joined to the actuator, and a flexible portion which is continuous to the flat portion and on which a chip circuit which drives the actuator is mounted. The head holder may have a bottom plate in which the ink-jet head is fixed to one surface thereof, and in which slit holes each for drawing the flexible portion of one of the flexible flat cables toward a rear-surface side of the bottom plate are formed for the flexible portions respectively; and a plurality of heat sinks which is disposed on a side of the other surface of the base plate, and which makes a contact with the chip circuit disposed on the flexible portion, the heat sinks corresponding to the flexible flat cables and guiding the flexible portion of the flexible flat cables to the circuit board. A heat sink, among the heat sinks, corresponding to the second flexible flat cable may be provided along the space.

Since two heat sinks are provided on the rear-surface side of the base plate of the head holder, one heat sink corresponding to each flexible portion of the flat and flexible portion drawn in the mutually opposite directions from the actuator, and raised on the rear-surface side of the base plate of the head holder, it is possible to make the chip circuit of the flexible portion release heat efficiently, due to each heat sink. Moreover, since each FFC is guided up to the circuit board, along the heat sink, it is possible improve a wiring strength of the FFC.

In the ink-jet recording apparatus of the present invention, the actuator may have a first actuator and a second actuator, and one end of the first FFC may be connected to the first actuator, and one end of the second FFC may be connected to the second actuator. In this case, since the ink-jet recording apparatus has a plurality of actuators, it is possible to improve a nozzle density.

In the ink-jet recording apparatus of the present invention, the first flexible flat cable and the second flexible flat cable may have mutually different shapes. In this case, since the first FFC and the second FFC have mutually different shapes, it is possible to adjust according to a wiring route of each FFC.

In the ink-jet recording apparatus of the present invention, the first flexible flat cable and the second flexible flat cable may have shifted portions shifted toward one side in a width direction of the flexible flat cables respectively, and the shifted portion of the second flexible flat cable may be shifted to an extent greater than that of the shifted portion of the first flexible flat cable. In this case, since the shifted portion which is substantially shifted is formed on the second FFC which is wired through the space portion, it is possible to connect the second FFC which is wired through the space portion to the circuit board without being twisted or bent in between in the longitudinal direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A basic embodiment of the present invention will be described below with reference to the accompanying diagrams.FIG. 1shows an ink-jet recording apparatus100to which the present invention is applied. It is possible to use the ink-jet recording apparatus100of this embodiment not only as a printer alone, but also as printer in a multi function device (MFD) which is provided with functions such as a printer function, a copier function, a scanner function, a facsimile function and the like. The ink-jet recording apparatus100includes: a main-body frame2; two guide shafts (a rear guide shaft6and a front guide shaft7) which are provided in parallel along a main scanning direction (Y direction) inside the main-body frame; an ink-jet head1which is provided inside the main-body frame2and which performs recording by jetting an ink on to a paper PA which is a recording medium; a carriage3on which the ink-jet head1is mounted and which travels along the main scanning direction (Y direction); ink supply sources5a,5b,5c, and5d(5ato5d) which are arranged inside the main-body frame; and an ink supply tube14which connects the ink supply sources5ato5dand the ink-jet head1.

The carriage3is slidably mounted on the rear guide shaft6and the front guide shaft7. The carriage3is capable of reciprocating in the main scanning direction (Y direction), by a carriage driving motor17which is arranged at a rear-right side in the main-body frame2, and a timing belt18which is an endless belt. In the main-body frame2, the ink supply sources (ink tanks)5ato5dare arranged, and the ink supply sources5ato5dsupply an ink to the ink-jet head1via the ink supply tubes14. The ink-jet recording apparatus100of this embodiment is provided with the ink supply sources5ato5dwhich supply inks of four colors (black, yellow, magenta, and cyan) (refer toFIG. 1).

The paper PA is transported horizontally along a lower-surface side of the ink-jet head1(direction A inFIG. 1), along a secondary scanning direction (X direction) which is orthogonal to the scanning direction (Y direction). The ink is jetted in a downward direction to perform printing, on to the paper PA from nozzles4(refer toFIG. 5) of the ink-jet head1which moves in the main scanning direction (Y direction).

An ink receiving section20is arranged at one side (left side ofFIG. 1in this embodiment) of an inner portion of the main-body frame (flushing position), on a farther outer side than the paper PA which is transported, and a maintenance unit21is arranged at the other side of the inner portion of the main-body frame (head stand-by position). Accordingly, the ink-jet head1jets the ink periodically, at a flushing position, during a recording operation in order to prevent the blocking of the nozzles. This ink is received at the ink receiving section20. Moreover, a cleaning of the ink-jet head1such as wiping a nozzle surface of the ink-jet head1by the maintenance unit21, and a recovery process for sucking the ink and the air bubble for each color in coordination with an exhaust section25which will be described later are carried out at the head stand-by position.

A head holder8is mounted on the carriage3. As shown inFIG. 2, the head holder8has a substantially box shape opened at an upper surface, and a recess5bis formed to be opening downward, in a lower-surface of a bottom plate8aof the head holder8. The ink-jet head1having a substantially flat shape is accommodated in the recess5b. At this time, a surface of the ink-jet head1in which the nozzles4open is exposed in a downward direction from the head holder8. The ink-jet head1is fixed by an adhesive to the bottom plate5awith a predetermined gap such that the ink-jet head1is almost parallel to the lower-surface of the bottom plate5awhich is a ceiling surface of the recess5b. In the description, a surface of the ink-jet head1in which the nozzles open is called as a front surface or a lower surface, and another surface opposite to the front surface (lower surface) is called as a rear surface or an upper surface.

An circuit board22having a stiffness is fixed to a rear-surface side of the head holder8, bridging two opposite sides of the opening in the upper surface of the head holder8. An electric circuit is formed on this circuit board22, and is arranged at a position on the rear-surface side of the head holder8, overlapping the ink-jet head1, in a plan view. The circuit board22is connected to the ink-jet head1via FFCs (FPCs)12L and12R which will be described later, and is also connected to a control substrate on a main-body side which is arranged inside the main-body frame2, via a FFC which is not shown in the diagram. An ink supplying member (ink supplying unit)23is mounted on an upper-surface side of the bottom plate8aof the head holder8, between the ink-jet head1and the circuit board22(refer toFIG. 2). The ink supplying member23temporarily stores the ink supplied via the ink supply tube14(14ato14d), and supplies to the ink-jet head1.

The ink-jet head1includes a cavity unit10in which a plurality of nozzles4and an ink channel are formed; a piezoelectric actuator11which applies a pressure to the ink in the cavity unit10to selectively jet the ink from the nozzles4; and the FFC12L (first FFC) and the FFC12R (second FFC) each transmitting a driving signal to the piezoelectric actuator11: and these components are arranged in stacked form.

As shown inFIG. 3, in this embodiment, two piezoelectric actuators11are stacked side by side in the Y direction on a rear surface of one cavity unit10. The FFCs12L and12R are stacked on the piezoelectric actuators11, respectively, and the two FFCs are drawn in mutually opposite directions along the Y direction. Moreover, a reinforcing frame15is stacked on the rear surface of the cavity unit10to surround the two piezoelectric actuators11integrally.

As shown inFIG. 4, 10 nozzle rows arranged at a predetermined interval in the Y direction are formed in the cavity unit10of the ink-jet head1(refer toFIG. 3). Each of the nozzle rows has a plurality of nozzles4aligned in the X direction (secondary scanning direction) of the carriage3. Four nozzle rows among the ten nozzle rows correspond to a black ink (Bk), and two nozzle rows, among the ten nozzle rows, each correspond to a magenta ink (M), a cyan ink (C), and a yellow ink (Y). In this embodiment, ink colors are assigned to the ten nozzle rows in an order of cyan, cyan, yellow, black, black, black, black, yellow, magenta, and magenta, from a left side inFIG. 4.

Similar to a disclosure in Japanese Patent Application Nos. 2002-67312 and 2001-219560, as shown inFIG. 3, eight ink intake ports13which are opening on one end side in the X direction on an upper surface of the cavity unit10are formed. The ink which is supplied individually to each of the ink intake ports13from ink outflow ports41ato41dof an ink storage section24is distributed to a large number of pressure chambers71via each of the manifold chambers70. The cavity unit10selectively jets the ink from each of the nozzles4communicating with one of pressure chambers71(refer toFIG. 4) by driving of the piezoelectric actuator11corresponding to the one of the pressure chambers71.

The FFCs12L and12R are belt shaped. At one end thereof, a flat portion12awhich is joined in a stacked form on an upper surface of the piezoelectric actuator11is formed, and at the other end, a flexible portion12bwhich is in continuity with the flat portion12ais formed. A chip circuit12cwhich drives the piezoelectric actuator11is mounted on the flexible portion12b(refer toFIG. 2,FIG. 5, andFIG. 6). Each of the FFCs12L and12R of this embodiment has a first cable121which is to be connected to the piezoelectric actuator11, and a second cable122which is to be connected to the circuit board22, and the first cable121and the second cable122are connected in a longitudinal direction.

As shown inFIGS. 5 and 6, the first cable121has a flat portion12a, and a plurality of terminal electrodes12dformed on a surface of the flat portion12afacing the piezoelectric actuator11, for connecting electrically to the piezoelectric actuator11. These terminal electrodes12dare connected to a common electrode and an operating portion of the piezoelectric actuator11corresponding to the pressure chambers71. The flexible portion12bof the first cable121is shorter than the flexible portion12bof the second cable122. The chip circuit12cis mounted on the flexible portion12bof the first cable121, and a connecting terminal12efor connecting to the second cable122is provided at an end portion of the flexible portion12bof the first cable121, on an opposite side of the flat portion12a.

The second cable122is flexible entirely, and includes a flexible portion12bwhich is longer than the flexible portion12bof the first cable121. A connecting terminal12ffor connecting to the first cable121is formed at one end of the flexible portion12bof the second cable122, and a connecting terminal12gfor connecting to a connector12hon the circuit board22is formed at the other end of the flexible portion12bof the second cable122. A shape of the FFC12will be described later.

As shown inFIG. 2, two slits80through which the flexible portion12bof the FFCs12L and12R are pierced from a front-surface side to a rear-surface side are formed in the bottom plate8aof the head holder8. Each of the slits80is long in the X direction, and the two slits80are formed at an interval in the Y direction. A heat sink82is fixed on an upper-surface side of the bottom plate8aof the head holder8adjacent to the two slits80. The heat sink82is a metallic member having a favorable thermal conductivity, which is formed by bending such that bottom and side surfaces of the heat sink form a shape of an English alphabet L in a side view, the bottom surface being parallel to the bottom plate8aof the head holder8, and the side surface being parallel to a side wall of the head holder8facing the Y direction.

The flexible portions12bof the FFCs12L and12R are passed between the bottom plate8aand the bottom surface of the heat sink82, and the chip circuit12cthermally contacts with the bottom surface of the heat sink82upon being pushed by a rubber elastic body81. Accordingly, heat generated in the chip circuit12cis released by the heat sink82. Moreover, as shown inFIG. 2, the connecting terminal12eof the first cable121and the connecting terminal12fof the second cable122are connected at a position toward a lower-end portion of a side surface of the heat sink82. The second cable122is guided to the circuit board22, which is positioned at the rear-surface side of the head holder8, along the side surface of the heat sink82.

The reinforcing frame15is a flat member which reinforces the cavity unit10. The reinforcing frame15is formed of a material (for example, a metallic plate of stainless steel) having a stiffness superior to a stiffness of the cavity plate10, and has an outer shape slightly larger than the cavity unit10. By stacking the reinforcing frame15to surround the piezoelectric actuator11, along the rear surface of the cavity unit10, a deformation and a distortion of the cavity unit10which is thin and flat shaped are prevented. Eight connecting holes15afor connecting the ink intake port13of the cavity unit10, and the ink outflow ports41ato41dof the ink storage section24which will be described later are arranged side by side at one end portion of the reinforcing frame15in the X direction.

Next, the ink supplying member23will be described below. In the ink supplying member23, the ink storage section (ink tank)24and the exhaust section (air exhaust unit)25are connected integrally. An inside of the ink storage section24is divided into a plurality of ink chambers27to30, and the ink storage section24stores the inks in these ink chambers according to the color of the ink. The exhaust section25removes bubbles accumulated in the ink storage section24. The exhaust section25is connected to the ink storage section24by a connecting portion24awhich will be described later.

The ink outflow ports41ato41dof each of the ink chambers27to30are provided at one side, in the X direction, of the bottom surface of the ink storage section24. The ink outflow ports41ato41dare connected to the ink intake port13of the ink-jet head1via an elastic sealing member (not shown in the diagram) and the connecting holes15aof the reinforcing frame15, on an inner side of an opening (not shown in the diagram) which is formed through the bottom plate8a. Accordingly, the ink of each color is supplied independently from the ink chambers27to30to each of the ink intake ports13of the ink-jet head1.

The connecting portion24aof the ink storage section24and the exhaust section25is arranged on a side of the ink storage section24(one side in X direction) where the ink outflow ports41ato41dare provided. The connecting portion24ais extended in the Y direction from the ink storage section24. A space26in the form of a slit corresponding to a cross-section of a belt shape of the FFC12R is formed in an area of the ink supplying member23, between the ink storage section24and the exhaust section25. The space26is pierced from a front surface side to a rear-surface side of the ink supplying member23, and is formed as a notch extending from the other side in the X direction, in a plan view. In detail, as shown inFIG. 7, at a position where the FFC12R is drawn from the piezoelectric actuator11, the FFC12R has a portion which overlaps partly in a plan view with the connecting portion24a. In other words, at the position of drawing from the piezoelectric actuator11, a part in the X direction (width direction) of the FFC12R overlaps with a part in the X direction (width direction) of the connecting portion24a. The space26may not be formed only in the form of a notch in a plan view, but may be formed in the form of a long hole in a plan view according to the requirement.

The ink-jet head1has the two FFCs12L and12R. The FFC12R, drawn toward a side where the exhaust section25is provided, rises up upon passing through the space26formed in the area of the ink supplying member26between the exhaust section25and the ink storage section24, and the FFC12L rises up upon passing along a side of the ink storage section24opposite to the exhaust section25. The FFCs12L and12R are connected at a position facing the circuit board22which is arranged on the rear-surface side. Accordingly, since a distance of drawing around becomes short, as compared to a case when passed along an outer side of the exhaust section25, it is possible to make a length of the FFC12R same as a length of the FFC12L.

Both of the two FFCs12L and12R are extended to connect from a connecting position with the piezoelectric actuator11up to a connecting position with the circuit board22. For avoiding a contact with the circuit board22and the connecting portion24aof the ink supplying member22, the FFCs12L and12R are formed to be belt shaped having an inclined portion (a shifted portion) appropriately, in the width direction.

In this embodiment, in the FFC12L (in particular, the second cable122) passing along the side of the ink supplying member23, opposite to the exhaust section25(left side inFIG. 2), a shifted portion122Ls which is inclined (shifted) by only L1is formed in the width direction (X direction), with respect to the flat portion12a(with respect to a drawing position from the piezoelectric actuator11). As shown inFIG. 7, the shifted portion122Ls of the FFC12L is formed at a position passing through a notch22aon a left side portion of the circuit board22for avoiding an interference with a side edge in the width direction of the FFC12L and an outer edge of the notch22afacing the side edge of the FFC12L.

On the other hand, in the FFC12(in particular, the second cable122) drawn on a side of the ink supplying member23, toward the exhaust section25(right side inFIG. 2), and wired through the space26, as shown inFIG. 6, a shifted portion122Rs which is shifted by only L2which is greater than L1is formed in the width direction (X direction), with respect to the flat portion12a(with respect to a drawing position from the piezoelectric actuator11). The shifted portion122Rs is formed for avoiding an interference with a side edge in the width direction of the FFC12R and the connecting portion24aof the ink supplying member22.

Next, a detailed structure of the ink supplying member23which is applicable to this embodiment will be described below by with reference toFIGS. 8A,8B, and9. However, a structure of an inside of the ink supplying member23described below is an example, and it is not intended to restrict to this structure.

The ink supplying member23has an upper case31, a lower case32, and two flexible films33and34. As it will be described later, the ink storage section24and the exhaust section25are formed by the upper case31, the lower case32, and two flexible films33and34. The flexible films33and34are made of a synthetic resin, and are impermeable with respect to air and liquid. The ink chambers27to30according to each color are provided to the ink storage section24, and each of the ink chambers27to30is partitioned by a main partition wall35and secondary (sub) partition walls36and37.

The lower case32has an opening (aperture) portion which is formed so as to open a substantial portion of a lower surface of the lower case32, the main partition wall35which is parallel to the opening portion, and formed integrally to the opening portion with a predetermined interval, and the secondary partition wall36which is formed integrally to the main partition wall35to rise from an upper surface of the main partition wall35(refer toFIG. 2andFIG. 9). The upper case31includes the secondary partition wall37which is formed at a position corresponding to a position at which the secondary partition wall36of the lower case32is extended upward (refer toFIG. 8A).

The flexible film33is adhered to cover the opening portion of the lower case32on a lower surface of the ink storage section24, and the flexible film34is adhered to cover the exhaust section25and the ink storage section24of the upper case31, spreading over the exhaust section25and the ink storage section24.

The ink chamber27for the black ink (Bk) includes a first chamber27awhich is formed between the flexible film33and a lower surface of the main partition wall35in the lower case32, a second chamber27bwhich is partitioned by the secondary partition wall36on an upper surface of the main partition wall35of the lower case32, and a third chamber27cwhich is demarcated by the secondary partition wall37in the upper case31. An upper surface of the third chamber27cis covered by the flexible film34.

The ink chamber28for the cyan ink (C), the ink chamber29for the magenta ink (M), and the ink chamber30for the yellow ink (Y) include first chambers28a,29a, and30apartitioned by the secondary partition wall37in the upper case31respectively, and second chambers28b,29b, and30bpartitioned by the secondary partition wall36on the upper surface of the main partition wall35in the lower case respectively. An upper surface of the first chambers28a,29a, and30ais covered by the flexible film34.

Passage holes39which make communicate the first chambers28a,29a, and30afor the color inks (cyan, magenta, and yellow) and the second chambers28b,29b, and30b, and an air hole40which makes communicate the second chamber27bfor the black ink and the third chamber27c, are made in a bottom wall38of the upper case31.

As shown inFIG. 8BandFIG. 9, the ink outflow ports41ato41dwhich make the ink flow out to the ink-jet head1, are positioned side by side on a lower surface of the second chambers27bto30bfor each color, and are opened in a downward direction, at a position extended in a downward direction farther than the flexible film33.

As shown inFIG. 8BandFIG. 9, ink supply tubes14ato14dfrom the ink supply sources (ink tanks)5ato5dare connected to ink inflow ports47ato47dprovided at one end of the ink supplying member27(opposite side of the ink inflow ports41ato41din a plan view). The black ink (Bk) flows into the first chamber27afrom the ink inflow port47athrough a recess passage48, and flows into the second chamber27bthrough a passage42. As shown inFIGS. 5A,8B, and9, the other color inks (cyan, magenta, and yellow) flow from the ink inflow ports47bto47d, through the recess passage48and a communicating passage49(formed such that the upper case32and the lower case31are connected), into the first chambers28ato30aformed in the upper case31. After that, the inks flow into the second chambers28bto39bformed in the lower case32through a communicating hole39.

A pressure fluctuation (pressure change, pressure wave) in each ink is absorbed (relaxed) by the flexible films33and34facing respectively. The ink supplying member23is fixed to the head holder8, between the flexible film33and the bottom plate8aof the head holder8. A gap for a deformation (A gap to accommodate a deformation) of the flexible film33has been secured between the flexible film33and the base plate Ba of the head holder8.

In the ink storage section24of such structure, air bubbles included in the ink are accumulated upon separation to float on an upper side of each of the second chambers27bto30b. Since an amount (the number) of air bubbles increases gradually, it is necessary to discharge the accumulated air bubbles to an outside. As shown inFIG. 8A, a plurality of exhaust holes53which communicate with an upper portion of each of the second chambers27bto30bis formed to penetrate the upper case31, at positions corresponding to an upper side of each of the ink outflow ports41ato41d. Each of the exhaust holes53communicates with an end portion of an exhaust passage51which is formed independently as a recess (which is formed as a grove) in the upper surface of the upper case31. The exhaust passage51is extended in the Y direction along the communicating portion24a, and is connected to a passage hole56of the exhaust section25. An upper surface of the passage hole56and the exhaust passage51is covered by the flexible film34.

Exhaust holes53for the cyan ink (C), the yellow ink (Y), and the magenta ink (M) respectively are formed to cut through a cylindrical member (not shown in the diagram) which is suspended inside each of the second chambers28bto30b, from the upper case31. When the air bubbles are discharged from the exhaust holes53as it will be described later, a predetermined amount of the air o is remained at the upper portion of each of the second chambers28bto30b. The predetermined amount corresponds to a height of the cylindrical member (corresponds to a volume of a space in the cylindrical member). In the exhaust holes53, a predetermined amount of air is secured by providing the third chamber27c. However, the exhaust hole53for the black ink may also be formed similarly as the exhaust hole53for the inks of other colors.

As shown inFIG. 8A, four passage holes56corresponding to the ink of each color, are formed in the exhaust section25. The passage holes56are long in a vertical direction and open vertically. As shown inFIG. 2, a large diameter portion56ais formed in an upper half of each passage hole56, and a small diameter passage56bis formed in a lower half of each passage hole56. A lower end of the small diameter passage56bis opened to an outside at almost the same plane as an opening (aperture) plane of the nozzles4of the ink-jet head1. An exhaust valve57is inserted into the large diameter portion56a, and a valve rod58of a small diameter which is pierced through the small diameter passage56bis formed integrally in the exhaust valve57. A packing59such as an O-ring for sealing, which is fitted on the valve rod58, is arranged at a lower-end surface side of the exhaust valve57. A lower end of the valve rod58is extended up to an area near an outer opening end of the small diameter passage56b. The exhaust valve57is always pushed in downward direction by a spring mechanism60such as a coiled spring which is provided inside the large diameter portion56a. In this state, the packing59is pushed to a bottom surface of the large diameter portion56aof the passage hole56, and the vale is in a closed state.

The maintenance unit21includes a cap member76which covers an opening (aperture) surface of the nozzles4of the ink-jet head1such that the opening surface can be opened and closed, and a plurality of small cap members72which cover individually an outer opening end of the exhaust section25, in other words, an outer opening end of each small diameter passage56b, such that the outer opening end can be opened and closed. When the carriage3has moved to a stand-by position (right-end position inFIG. 1), both the cap members76and72are made to ascend by a vertical movement mechanism73such that the both cap members76and72make a close contact with the opening surface of the nozzles4and the outer opening end of the exhaust section26(25), similarly as a known maintenance unit. At the time of moving the carriage3to another position, the both cap members76and72are made to descend to be isolated (separated) from the surface thereof.

Each of the small cap members72has a projection72a(operating mechanism) which is projected farther than the small cap member72. When the projection72amakes a close contact with the outer opening end of the exhaust section25, the projection72apushes up the valve rod58resisting a bias force of a spring means60. Accordingly, the packing59is released from an inner bottom portion of the large diameter portion56a, and the valve is in an open state. Moreover, each small cap member72is connected to a suction pump74which is a suction mechanism, via a common channel, and by driving the suction pump74, the air bubbles accumulated in the second chambers27bto30bof each ink chamber are sucked and discharged collectively.

Moreover, the cap member76is connected to the suction pump74similarly as the known maintenance unit, and by driving the suction pump74, the ink which is thickened, and impurities are sucked and removed.

The cap member76and the small cap member72are selectively connected to the suction pump by a switching valve75. The cap member76and the small cap member72make a close contact with the outer opening end of the exhaust section25and the opening (aperture) surface of the nozzles4at the same time, by the vertical movement mechanism73. Only ink suction from a nozzle22, or only discharge of the air bubbles in the second chambers27bto30bmay be carried out separately. Or, the discharge of the air bubbles in each of the second chambers27bto30bmay be carried out individually by making each of the projections72ato be independently movable. Moreover, instead of the suction operation of the suction pump74as described above, by applying a positive pressure to the ink from a side of the ink tank5, the ink which is thickened and impurities may be removed by pushing from the nozzle22, and the air bubbles in the second chambers27bto30bmay be discharged. Or, the suction operation and applying the positive pressure to the ink may be used together in combination.

In the ink-jet recording apparatus100of the abovementioned structure, the exhaust section25may be arranged integrally side by side at a side portion of the ink storage section24in the ink supplying member23which is mounted on the head holder8. Since the space26is formed between the ink storage section24and the exhaust section25, it is possible to connect the FFC12R of the ink supplying member23, which is drawn toward the exhaust section25, to the circuit board22through the space portion26. Accordingly, it is possible to match the length of the FFC12R with the length of the FFC12L of the ink supplying member, which is drawn toward the side opposite to the exhaust section25. Therefore it is possible to suppress an unevenness in electrical characteristics of the two FFCs12L and12R. Moreover, it is possible to shorten a wiring length of the FFCs, and to reduce a cost of the FFCs12L and12R.

Moreover, since the outer opening end of the exhaust section25opens at a position away from the FFC12R, it is possible to separate (disengage) easily the small cap member72and the projection72afrom the outer opening end of the exhaust section25without a fear of interference of the FFC12R with the small cap member72and the projection72a. Moreover, there is no fear that the ink discharged along with the air bubbles from the outer opening end of the exhaust section25causes an electric short-circuit of the terminals of the FFC.

Moreover, a shifted portion in which a central axis of the cable is shifted in the width direction is formed in a middle portion in the longitudinal direction of the FFC12R, such that the FFC12R passing through the space26does not make a contact with the connecting portion24abetween the ink storage section24and the exhaust section25. Therefore, the FFC12R is not required to be twisted or bent to pass through the space portion26, and wiring becomes easy.

In this embodiment, the portion in between the FFC12R (the middle portion of the FFC12R) is shifted. However, the other end of the FFC12R, on the side of the circuit board22may be shifted in the width direction according to a positional relationship of the piezoelectric actuator11and the circuit board22in a plan view.

Moreover, in the FFCs12L and12R, since the two cables namely the first cable121and the second cable122are connected in the longitudinal direction, it is possible to handle the ink-jet head with a short cable length without connecting the first cable121and the second cable122in a manufacturing process prior to fixing the ink-jet head1to the head holder8. Consequently, a fear that the cable is hung during the operation is reduced, and it is possible to prevent the FFC12from getting disconnected electrically, and detached from the piezoelectric actuator11.