Liquid discharging head

A liquid discharging head includes: a first individual channel array constructed of individual channels aligned in a first direction; and a second individual channel array constructed of individual channels aligned in the first direction. The second individual channel array is arranged side by side to the first individual channel array in a second direction orthogonal to the first direction. Each of the individual channels includes: a nozzle, at least two pressure chambers communicating with the nozzle and arranged in the first direction, and a connecting channel connecting the nozzle and the at least two pressure chambers. The connecting channel has one end in a third direction communicating with the at least two pressure chambers, and the other end in the third direction communicating with the nozzle.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent Application No. 2020-080746, filed on Apr. 30, 2020, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

Field of the Invention

The present disclosure relates to a liquid discharging head provided with two individual channel arrays each of which is constructed of a plurality of individual channels.

Description of the Related Art

Japanese Patent Application Laid-open No. 2002-086714 discloses a head (liquid discharging head) in which individual channels each including one nozzle opening (nozzle) and one cavity part (pressure chamber) are arranged in two arrays.

SUMMARY

In Japanese Patent Application Laid-open No. 2002-086714, the individual channels are densely arranged and the width of the pressure chamber is small. In this case, it is impossible to stably discharge or eject a liquid requiring a large discharge pressure (highly viscous ink, special glossy ink, etc.).

Therefore, in order to stably discharge the liquid as described above, the inventor of the present disclosure has devised a configuration in which each of individual channels includes a nozzle, at least two pressure chambers, and a connecting channel connecting the nozzle and the at least two pressure chambers with each other. By this configuration, a large discharge pressure by a plurality of pieces of the pressure chamber can be applied in each of the individual channels, and the liquid can be stably discharged.

However, in a case that the above-described configuration is applied to the head of Japanese Patent Application Laid-open No. 2002-086714, the following problem might occur. For example, in each of the two individual channel arrays, in a case that two pressure chambers which are included in the plurality of pressure chambers and which are adjacent to each other in a direction in which the two individual channel arrays extend (first direction) are connected by the connecting channel, and a nozzle is arranged at the center of the two pressure chambers in the first direction, a nozzle belonging to one of the two individual channel rows and a nozzle belonging to the other of the two individual channel rows are not aligned in the first direction at an equal spacing distance therebetween. In this case, any imbalance or deviation might occur in the arrangement of dots formed on a recording medium, and the image quality might be lowered.

An object of present disclosure is to provide a liquid discharging head which is capable of suppressing any lowering in the image quality even in a case that the above-described configuration is applied.

According to an aspect of present disclosure, there is provided a liquid discharging head including:

a first individual channel array which is constructed of a plurality of individual channels aligned in a first direction; and

a second individual channel array which is constructed of a plurality of individual channels aligned in the first direction, the second individual channel array being arranged side by side to the first individual channel array in a second direction orthogonal to the first direction,

wherein each of the individual channel includes: a nozzle; at least two pressure chambers communicating with the nozzle and arranged side by side in the first direction; and a connecting channel connecting the nozzle and the at least two pressure chambers, the connecting channel having one end, in a third direction which is orthogonal to the first direction and the second direction, communicating with the at least two pressure chambers and the other end in the third direction communicating with the nozzle, and

a plurality of nozzles belonging to the first individual channel array and a plurality of nozzles belonging to the second individual channel array are arranged side by side at an equal spacing distance therebetween in the first direction.

DESCRIPTION OF THE EMBODIMENTS

First Embodiment

First, an explanation will be given about an overall configuration of a printer100provided with a head1relating to a first embodiment of present disclosure, with reference toFIG.1.

The printer100includes a head unit1xprovided with 4 pieces of the head1, a platen3, a conveying mechanism4, and a controller5.

A paper (paper sheet)9is placed on an upper surface of the platen3.

The conveying mechanism4has two roller pairs4aand4bwhich are arranged so as to sandwich the platen3therebetween in a conveyance direction. In a case that a conveying motor (not depicted in the drawings) is driven by control of the controller5, the two roller pairs4aand4brotate in a state that the paper9is sandwiched therebetween, thereby conveying the paper9in the conveyance direction.

The head unit1xis elongated in a paper width direction (a direction which is orthogonal to both of the conveyance direction and a vertical direction) and is of a line system in which an ink is ejected or discharged from a nozzle22(seeFIGS.2to4) with respect to the paper9in a state that a position of the head unit1xis fixed. Each of the four heads1is long in the paper width direction and the four heads1are arranged in a staggered manner in the paper width direction.

The controller5includes a ROM (Read Only Memory), a RAM (Random Access Memory) and an ASIC (Application Specific Integrated Circuit). The ASIC executes a recording processing, etc., in accordance with a program stored in the ROM. In the recording processing, the controller5controls a driver IC and a conveying motor (both of which are not depicted in the drawings) of each of the heads1based on a recording instruction (including image data) inputted from an external apparatus such as a PC, etc., and records an image on the paper9.

Next, the configuration of each of the heads1will be explained, with reference toFIGS.2to4.

As depicted inFIG.3, the head1has a channel substrate11, an actuator substrate12, and a protective member13.

The channel substrate11is constructed of eight plates11ato11hwhich are stack on one another in the vertical direction and which are joined to one another. The plates11ato11hare made of, for example, a resin (e.g., LCP: liquid crystal polymer) or a metal (e.g., SUS: stainless steel). A through hole forming a channel is formed in each of the plates11ato11h. The channel includes a plurality of individual channels20, a first common channel31, a second common channel32and a linking channel33.

As depicted inFIG.2, the plurality of individual channels20are arranged in a staggered manner in the paper width direction (first direction) so as to form two rows or arrays (first individual channel array20A and second individual channel array20B). Each of the first and second individual channel arrays20A and20B is constructed of a plurality of individual channels20aligned in the first direction. The first individual channel array20A and the second individual channel array20B are arranged side by side in a direction parallel to the conveyance direction (second direction: a direction which is orthogonal to the first direction).

Each of the first common channel31and the second common channel32extends in the first direction and are arranged side by side in the second direction; the first and second common channels31and32sandwich the plurality of individual channels20therebetween in the second direction. The first common channel31communicates with the plurality of individual channels20belonging to the first individual channel array20A. The second common channel32communicates with the plurality of individual channels20belonging to the second individual channel array20B.

The linking channel33extends in the second direction and links or connects an upper end part which is substantially at the center in the first direction of the first common channel31and an upper end part which is substantially at the center in the first direction in the second common channel32to each other. An ink supply port30is provided on an upper part at the center in the second direction in the linking channel33. A tube communicating with a sub tank (not depicted in the drawings) is attached to the ink supply port30.

The sub tank communicates with a main tank which stores the ink, and stores the ink supplied from the main tank. The ink in the sub tank is supplied from the ink supply port30to the linking channel33by driving of a pump (not depicted in the drawings) under the control of the controller5. The ink supplied to the linking channel33is branched or divided to one side in the second direction (left side inFIG.2) and the other side in the second direction (right side inFIG.2). The ink branched to the one side in second direction flows into a substantially center part in the first direction in the first common channel31, flows in first common channel31toward each of one side in the first direction (an upper side inFIG.2) and the other side in the first direction (a lower side inFIG.2), and is supplied to the plurality of individual channels20belonging to the first individual channel array20A. The ink branched to the other side in the second direction flows into a substantially central part in the first direction in the second common channel32, flows in the second common channel32toward each of one side (the upper side inFIG.2) and the other side (the lower side inFIG.2) in the first direction, and is supplied to the plurality of individual channels20belonging to the second individual channel array20B.

As depicted inFIG.2, each of the plurality of individual channels20includes: one nozzle22, two pressure chambers21(a first pressure chamber21aand a second pressure chamber21b), one connecting channel23, two narrow-width channels24aand24b, and two wide-width channels25aand25b.

In the following, the above-described elements included in each of the plurality of individual channels20will be explained.

The two pressure chambers21(first pressure chamber21aand second pressure chamber21b) have a substantially rectangular shape which is long in the second direction in a plane which is orthogonal to a vertical direction (third direction: a direction orthogonal to the first direction and the second direction); the two pressure chambers21are arranged side by side in the first direction. The connecting channel23is connected to one end in the second direction of the first pressure chamber21a, and the narrow-width channel24ais connected to the other end in the second direction of first pressure chamber21a. The connecting channel23is connected to one end in the second direction of the second pressure chamber21b, and the narrow-width channel24bis connected to the other end in the second direction of the second pressure chamber21b.

The narrow-width channels24aand24bhave a width which is smaller than a width (length in the first direction) of the first and second pressure chambers21aand21b, and function as a throttle. Each of the narrow-width channels24aand24bextends in the second direction from one end in the first direction (upper end inFIG.2) of one of the first and second pressure chambers21aand21bcorresponding thereto.

The wide-width channels25aand25bhave a width which is substantially same as the width (length in the first direction) of the first and second pressure chambers21aand21b. The wide-width channels25aand25bare arranged at respective positions each of which is coincident, in the first direction, with the position of one of the first and second pressure chambers21aand21bcorresponding thereto.

The narrow-width channel24aand the wide-width channel25aare arranged side by side with respect to the first pressure chamber21ain the second direction. The narrow-width channel24ais arranged between the first pressure chamber21aand the wide-width channel25ain the second direction.

The narrow-width channel24band the wide-width channel25bare arranged side by side with respect to the second pressure chamber21bin the second direction. The narrow-width channel24bis arranged between the second pressure chamber21band the wide-width channel25bin the second direction.

The narrow-width channel24aand the wide-width channel25aare arranged, in the second direction, between the first common channel31and the first pressure chamber21aof (belonging to) the first individual channel array20A. These narrow-width channel24aand wide-width channel25acommunicate the first common channel31with the first pressure chamber21aof (belonging to) the first individual channel array20A.

The narrow-width channel24band the wide-width channel25bare arranged, in the second direction, between the first common channel31and the second pressure chamber21bof (belonging to) the first individual channel array20A. These narrow-width channel24band wide-width channel25bcommunicate the first common channel31with the second pressure chamber21bof (belonging to) the first individual channel array20A.

The narrow-width channel24aand the wide-width channel25aare arranged, in the second direction, between the second common channel32and the first pressure chamber21aof (belonging to) the second individual channel array20B. These narrow-width channel24aand wide-width channel25acommunicate the second common channel32with the first pressure chamber21aof (belonging to) the second individual channel array20B.

The narrow-width channel24band the wide-width channel25bare arranged, in second direction, between the second common channel32and the second pressure chamber21bof (belonging to) the second individual channel array20B. These narrow-width channel24band wide-width channel25bcommunicate the second common channel32with the second pressure chamber21bof (belonging to) the second individual channel array20B.

As depicted inFIG.3, the first and second pressure chambers21aand21b, the narrow-width channels24aand24b, and the wide-width channels25aand25bare constructed of through holes formed in the plate11e(in other words, recessed parts formed in a stacked body of a vibration plate12a(to be described later on) and the plate11e).

As depicted inFIGS.3and4, the connecting channel23is constructed of through holes formed in the plates11fand11g, and connects the two pressure chambers21(first pressure chamber21aand second pressure chamber21b) and the nozzle22with one another. That is, in each of the plurality of individual channels20, the two pressure chambers21(first pressure chamber21aand second pressure chamber21b) communicate with one nozzle22via the connecting channel23. The connecting channel23has one end (upper end)23xin the third direction communicating with the first and second pressure chambers21aand21band the other end (lower end)23yin the third direction communicating with the nozzle22. The connecting channel23extends along the third direction from the one end23xto the other end23yin the third direction. The connecting channel23communicates with the first and second pressure chambers21aand21band the nozzle22, but does not communicate with any other parts or elements which are different from the first and second pressure chambers21aand21band the nozzle22.

As depicted inFIG.2, the connecting channel23is T-shaped (shape of a letter “T”) in the plane orthogonal to the third direction, and has a rectangular part23textending in the first direction over one ends in the second direction of respective two pressure chambers21(first pressure chamber21aand second pressure chamber21b), corresponding to the connecting channel23, and a projected part23pprojecting from the rectangular part23tin the second direction toward a side away from the first and second pressure chambers21aand21band provided with the nozzle22in a lower surface thereof.

As depicted inFIG.4, the connecting channel23has an inverted trapezoidal shape in a cross-section orthogonal to the second direction (a cross section along the first direction and the third direction). The nozzle22is located at a center between the two pressure chambers21(first pressure chamber21aand second pressure chamber21b) in the first direction.

As depicted inFIGS.3and4, the nozzle22is constructed of a through hole formed in the plate11h, and is opened in a lower surface of the channel substrate11.

Here, the plate11hcorresponds to a “first plate” of present disclosure, and the plate11gcorresponds to a “second plate” of the present disclosure. As depicted inFIG.3, the plate11gis stack in the third direction with respect to the plate11h, and has a through hole constructing a part of the other end23yof the connecting channel23. The through hole of the plate11gis covered with the plate11h.

The other end23y(the bottom part of the connecting channel23) is divided into two areas in the second direction, and includes a first area R1which is defined by the plate11hand a second area R2which is arranged side by side with respect to the first area R1in the second direction and which is defined by the plate11g. The first area R1is positioned at a location below the second area R2.

In the second direction, whereas the plate11ghas a length which is same as the six plates11ato11fpositioned at a location above the plate11g, the plate11his shorter than the other plates11ato11g. The length in the second direction of the plate11his approximately same as a length in the second direction of a partition wall W between the pressure chamber21of the first individual channel array20A and the pressure chamber21of the second individual channel array20B. The length in the second direction of the partition wall W is, for example, in a range of 2 mm to 4 mm.

The individual channels20of such a configuration as described above are arranged in the first direction at an equal spacing distance therebetween in each of the individual channel arrays20A and20B (seeFIG.2).

Specifically, as depicted inFIG.2, in each of the first individual channel array20A and the second individual channel array20B, a set of two pressure chambers21aand21bconstructing each of the plurality of individual channels20are arranged side by side in the first direction, and a plurality of pieces of the pressure chamber21are arranged side by side in the first direction at an equal spacing distance therebetween. A center-to-center distance Da in the first direction between two pressure chambers21which are adjacent to each other in the first direction in the first individual channel array20A and a center-to-center distance Db in the first direction between two pressure chambers21which are adjacent to each other in the first direction in the second individual channel array20B are a same distance which is a first distance D1. The first distance D1is, for example, in a range of 20 μm to 100 μm.

The plurality of pressure chambers21belonging to the first individual channel array20A are arranged to be shifted in first direction, by the first distance D1, with respect to the plurality of pressure chambers21belonging to the second individual channel array20B. Specifically, as depicted inFIG.2, among the plurality of pressure chambers21belonging to the second individual channel array20B, one pressure chamber21located at one end in the first direction (upper end inFIG.2) does not overlap in the second direction with any one of the plurality of pressure chambers21belonging to the first individual channel array20A, and each of the remaining pressure chambers21overlaps in the second direction with one of the plurality of pressure chambers21belonging to the first individual channel array20A. Among the plurality of pressure chambers21belonging to the first individual channel array20A, one pressure chamber21located at the other end in the first direction (lower end inFIG.2) does not overlap in the second direction with any one of the plurality of pressure chambers21belonging to the second individual channel array20B, and each of remaining pressure chambers21overlaps in the second direction with any one of the plurality of pressure chambers21belonging to the second individual channel array20B.

Each of the nozzles22belonging to the first individual channel array20A is arranged at the other side in the second direction (right side inFIGS.2and3) with respect to one of the plurality of pressure chambers21belonging to the first individual channel array20A. Each of the nozzles22belonging to the second individual channel array20B is arranged at the one side in the second direction (left side inFIGS.2and3) with respect to one of the plurality of pressure chambers21belonging to the second individual channel array20B. As depicted inFIG.2, the nozzles22belonging to the first individual channel array20A and the nozzles22belonging to the second individual channel array20B are alternately arranged in the first direction and between, in the second direction, the plurality of pressure chambers21belonging to the first individual channel array20A and the plurality of pressure chambers21belonging to the second individual channel array20B. These nozzles22are arranged in one array (row) along the first direction and at an equal spacing distance therebetween in the first direction. A center-to-center distance Dc in the first direction between two nozzles22which are included in the nozzles22and which are adjacent to each other in the first direction is the first distance D1which is same as the center-to-center distances Da and Db in the first direction between the pressure chambers21as described above.

The arrangement of the projected parts23pof the connecting channels23is same as that of the nozzles22. That is, as depicted inFIG.2, the projected parts23pof the connecting channels23belonging to the first individual channel array20A and the projected parts23pof the connecting channels23belonging to the second individual channel array20B are arranged alternately in the first direction and between, in second direction, the plurality of pressure chambers21belonging to the first individual channel array20A and the plurality of pressure chambers21belonging to the second individual channel array20B. These projected parts23pare arranged in the first direction in one array (row) and are arranged at an equal spacing distance therebetween in the first direction.

As depicted inFIG.3, the actuator substrate12is fixed to an upper surface of the plate11e, and includes a vibration plate12a, a common electrode12b, a plurality piezoelectric bodies12cand a plurality of individual electrodes12din this order from a lower part of the actuator substrate12.

The vibration plate12aand the common electrode12bare arranged in an entire area of the upper surface of the plate11eand cover all of the pressure chambers21formed in the plate11e. On the other hand, each of the plurality of piezoelectric bodies12cand each of the plurality of individual electrodes12dare provided on one of the plurality of pressure chambers21, and overlap with one of the plurality of pressure chambers21in the third direction.

The actuator substrate12further includes an insulative film12iand a plurality of wirings21e.

The insulative film12iis constructed of silicon dioxide (SiO2), etc., and covers a part, of the upper surface of the common electrode12b, which is not provided with the plurality of piezoelectric bodies12c, a side surface of each of the plurality of piezoelectric bodies12c, and upper surfaces of the plurality of individual electrodes12d. In the insulative film12i, a through hole is provided on a part, of the insulative film12i, which overlaps with each of the plurality of individual electrodes12din the third direction.

The plurality of wirings12eare formed on the insulative film12i. Each of the plurality of wirings12eis provided on one of the plurality of individual electrodes12d; a forward end of each of the plurality of wirings12eenters into the above-described through hole of the insulative film12, thereby allowing each of the plurality of wirings12eto be electrically connected with an individual electrode12dincluded in the plurality of individual electrodes12dand corresponding thereto. Each of the plurality of wirings12eis drawn to a center in the second direction of the actuator substrate12and is electrically connected to a wiring substrate (COF: Chip On Film, etc., not depicted in the drawings).

Although not depicted in the drawings, the wiring substrate has: a plurality of individual wirings which extend in the first direction and each of which is electrically connected to one of the plurality of wirings12e; and a common wiring electrically connected to the common electrode12b. The wiring substrate has a driver IC mounted thereon, and is connected to the controller5(seeFIG.1).

The driver IC generates a driving signal based on a control signal from the controller5(seeFIG.1) while maintaining the potential of the common electrode12bat the ground potential, and applies the driving signal to each of the plurality of individual electrodes12d. This causes the potential of each of the plurality of individual electrodes12dto change between a predetermined driving potential and the ground potential. In this situation, a part of the vibration plate12aand a part of each of the plurality of piezoelectric bodies12c(the parts being actuator12x) which are sandwiched between one of the plurality of individual electrodes12dand one of the plurality of pressure chambers21are deformed so as to project toward one of the plurality of pressure chambers21, thereby changing the volume of one of the plurality of pressure chambers21, applying pressure to the ink in one of the plurality of pressure chambers21, and causing the ink to be ejected or discharged from the nozzle22.

In a case that the ink is discharged from the nozzle22, the ink is supplied from the first common channel31or the second common channel32to each of the plurality of individual channels20. The ink supplied to each of the plurality of individual channels20flows through the wide-width channel25aor25band the narrow-width channel24aor24band then flows into each of the first and second pressure chambers21aand21b. The ink moves in the second direction inside the first and second pressure chambers21aand21b, moves to a lower side in the third direction through the connecting channel23, and is ejected or discharged from the nozzle22.

As depicted inFIG.3, the protective member13is adhered to an upper surface of the actuator substrate12. The protective member13has two recessed parts13xprovided on a lower surface thereof, and a through hole13ypenetrating therethrough in the third direction.

The two recessed parts13xextend in the first direction and are arranged side by side in the second direction. A plurality of actuators12xcorresponding to the first individual channel array20A are accommodated in one of the two recessed parts13x. A plurality of actuators12xcorresponding to the second individual channel array20B are accommodated in the other of the two recessed parts13x.

The through hole13yextends in the first direction at a center in second direction of the protective member13. The above-described wiring substrate (not depicted in the drawings) is arranged in the through hole13y.

Note that inFIG.4, the illustration of the protective member13and the plates11ato11clocated above the protective member13are omitted.

As described above, the foregoing configuration is applied to the head1according to the present embodiment. In the configuration, the plurality of individual channels20form each of the first individual channel array20A and the second individual channel array20B extending in the first direction; and each of the plurality of individual channels20includes: a nozzle22, at least two pressure chambers21(first pressure chamber21aand second pressure chamber21b), and a connecting channel23connecting the nozzle22and the at least two pressure chambers21(first pressure chamber21aand second pressure chamber21b). In this case, in the present embodiment, the plurality of nozzles22belonging to the first individual channel array20A and the plurality of nozzles22belonging to the second individual channel array20B are arranged side by side in the first direction, at the equal spacing distance therebetween (seeFIG.2). As a result, even in a case that the above-described configuration is applied, any imbalance or deviation does not occur in the arrangement of dots formed on the paper9, and any lowering in the image quality can be suppressed.

In each of the individual channel arrays20A and20B, the plurality of pressure chambers21are arranged side by side in the first direction at the equal spacing distance therebetween (seeFIG.2). In each of the individual channel arrays20A and20B, the center-to-center distance Da, Db in the first direction between the two pressure chambers21which are adjacent to each other in the first direction and the center-to-center distance Dc between the two nozzles22which are adjacent to each other in the first direction and which are a nozzle included in the plurality of nozzles22belonging to the first individual channel array20A and a nozzle included in the plurality of nozzles22belonging to the second individual channel array20B are the same first distance D1. The plurality of pressure chambers21belonging to the first individual channel array20A are arranged to be shifted in the first direction, by the first distance D1, with respect to the plurality of pressure chambers21belonging to the second individual channel array20B. Each of the plurality of individual channels20includes the one nozzle22, the two pressure chambers21which are adjacent to each other in the first direction (first pressure chamber21aand a second pressure chamber21b), and the connecting channel23. In each of the plurality of individual channels20, the one nozzle22is arranged at the center in the first direction between the two pressure chambers21(first pressure chamber21aand second pressure chamber21b). According to this configuration, the discharge pressure from the two pressure chambers21(first pressure chamber21aand second pressure chamber21b) is uniformly applied to the nozzle22, and the discharge is stabilized.

The plurality of nozzles22belonging to the first individual channel array20A and the plurality of nozzles22belonging to the second individual channel array20B are arranged, in the second direction, between the plurality of pressure chambers21belonging to the first individual channel array20A and the plurality of pressure chambers21belonging to the second individual channel array20B (seeFIG.2). In this case, the area occupied by the nozzles22in the second direction can be made small, as compared with a case in which the plurality of nozzles22belonging to the first individual channel array21A and the plurality of nozzles22belonging to the second individual channel array22B sandwich the plurality of pressure chambers22belonging to the first individual channel array20A and the plurality of pressure chambers22belonging to the second individual channel array20B in the second direction; and the size of the part constructing the nozzles22(in the present embodiment, the plate11h) can be made small in the second direction.

The plurality of nozzles22belonging to the first individual channel array20A and the plurality of nozzles22belonging to the second individual channel array20B are aligned in one array (row) along the first direction (seeFIG.2). In a configuration in which the nozzles22are not aligned in an array along the first direction (for example, a configuration in which the nozzles22are arranged in a staggered manner so as to form two arrays), in a case that dots extending linearly in the first direction are to be formed on paper9with the second direction as the conveyance direction, it is necessary to make a discharge timing of the ink from the nozzles22to be different between the individual channel arrays20A and20B. Further, in a case that paper9is conveyed while being inclined (skew) with respect to the conveyance direction due to any meandering etc., even in a case that the discharge timing is changed between the individual channel arrays20A and20B as described above, the landing position of the ink on the paper9is deviated from a desired position, and the image quality is lowered. In this respect, in present embodiment, since the nozzles22are arranged in one array along the first direction, the occurrence of the above-described problem can be suppressed.

The other end23yof the connecting channel23includes the first area R1defined by the plate11hand the second area R2arranged side by side with respect to the first area R1in the second direction and defined by the plate11g(seeFIG.3). In this case, the length in the second direction of the plate11hcan be shortened, thereby making it possible to reduce the cost of the material of plate11h.

The linking channel33linking the first common channel31and the second common channel32with each other is provided, and the ink supply port30which is common to the first and second common channels31and32is provided (seeFIG.2andFIG.3). In this case, it is easier to assemble a tube, etc., with respect to the ink supply port30than in a case that the ink supply port30is provided individually for each of the first common channel31and the second common channel32. In addition, the present embodiment is configured such that each of the plurality of individual channels20includes one nozzle22and two pressure chambers21(first pressure chamber21aand second pressure chamber21b), and the number of the nozzles22with respect to the pressure chambers21is small. However, a same liquid (the ink supplied from the common ink supply port30) is made to be discharged or ejected from the nozzles22of the two individual channel arrays20A and20B, thereby making it possible to suppress any lowering in the resolution.

Second Embodiment

Next, a second embodiment of the present disclosure will be explained, with reference toFIGS.5and6.

A head201according to the second embodiment (FIGS.5and6) is similar to the head1according to the first embodiment (FIG.2) in view of the point that the plurality of pressure chambers21are arranged side by side in the first direction at the equal spacing distance therebetween in each of the individual channel arrays20A and20B, and the point that the center-to-center distances Da and Db in the first direction between the two pressure chambers21which are adjacent to each other in the first direction in the individual channel arrays20A and20B, respectively, and the center-to-center distance Dc in the first direction between the two nozzles22which are adjacent in the first direction and which are a nozzle included in the plurality of nozzles22belonging to the first individual channel array20A and a nozzle included in the plurality of nozzles22belonging to the second individual channel array20B are the same distance which is the first distance D1.

Here, in the first embodiment (FIG.2), the plurality of pressure chambers21belonging to the first individual channel array20A are arranged to be shifted in the first direction, by the first distance D1, with respect to the plurality of pressure chambers21belonging to the second individual channel array20B. On the other hand, in the second embodiment (FIG.5andFIG.6), the plurality of pressure chambers21belonging to the first individual channel array20A are arranged to be shifted, in the first direction, by a second distance D2(a distance which is half the first distance D1), with respect to the plurality of pressure chambers21belonging to the second individual channel array20B. That is, in first embodiment (FIG.2), a shift amount in the first direction of the pressure chambers21between the two individual channel arrays20A and20B is the first distance D1which is same as the center-to-center distances Da and Db in the first direction between the pressure chambers21in the individual channel arrays20A and20B, respectively, whereas the shift amount in the second embodiment (FIG.5andFIG.6) is the second distance D2which is half the center-to-center distances Da and Db (=D1).

Further, the head201according to the second embodiment (FIGS.5and6) is similar to the head1according to the first embodiment (FIG.2) in view of the point that each of a plurality of individual channels220includes one nozzle22, two pressure chambers21which are adjacent to each other in the first direction (first pressure chamber21aand second pressure chamber21b), and a connecting channel23.

Here, in first embodiment (FIG.2), in each of the plurality of individual channels20, one nozzle22is arranged at the center between the two pressure chambers21(first pressure chamber21aand second pressure chamber21b) in first direction. In contrast to this, in the second embodiment (FIGS.5and6), one nozzle22is arranged at a position which is shifted by a third distance D3(a distance which is quarter (¼) the first distance D1) with respect to a center O between the two pressure chambers21(first pressure chamber21aand second pressure chamber21b) in the first direction in each of the plurality of individual channels220. The direction in which the nozzles22are shifted is different between the first individual channel array20A and the second individual channel array20B. Specifically, in each of the plurality of individual channels220belonging to the second individual channel array20B, one nozzle22is located at one side in the first direction (an upper side ofFIGS.5and6) with respect to the center O between the two pressure chambers21; and in each of the plurality of individual channels220belonging to the first individual channel array20A, one nozzle22is arranged at the other side in the first direction (a lower side ofFIGS.5and6) with respect to the center O between the two pressure chambers21.

Further, in the first embodiment (FIG.2andFIG.3), the linking channel33links or connects the upper end part which is substantially at the center in the first direction in the first common channel31with the upper end part which is substantially at the center in the first direction in the second common channel32. In contrast to this, in the second embodiment (FIG.5), the linking channel33links one end in the first direction (an upper end ofFIG.5) in the first common channel31and one end in the first direction (an upper end ofFIG.5) in the second common channel32. In the second embodiment (FIG.5), the linking channel33is at a height level which is same with the first and second common channels31and32, and is positioned at one side in the first direction (the upper side ofFIG.5) with respect to the first and second common channels31and32.

In the second embodiment, an ink supplied from the ink supply port30to the linking channel33is branched (split) into one side (left side inFIG.5) and the other side (right side inFIG.5) in the second direction. The ink branched into the one side in the second direction flows into one end in the first direction in the first common channel31, flows toward the other side (lower side inFIG.5) in the first direction in the first common channel31, and is supplied to the plurality of individual channels220belonging to the first individual channel array20A. The ink branched into the other side in the second direction flows into one end in the first direction in the second common channel32, flows toward the other side (lower side inFIG.5) in the first direction in the second common channel32, and is supplied to the plurality of individual channels220belonging to the second individual channel array20B.

As described above, according to the second embodiment (FIG.5), the head201can be manufactured by using an existing part, as the part constructing the plurality of pressure chambers21(a part having the configuration in which the plurality of pressure chambers21are arranged side by side in the first direction at the equal spacing distance therebetween in each of the individual channel arrays20A and20B; and the plurality of pressure chambers21belonging to the first individual channel array20A are arranged to be shifted in the first direction, by the second spacing distance D2, with respect to the plurality of pressure chambers21belonging to the second individual channel array20B: the plate11einFIG.3), and by appropriately changing the part constructing the nozzles22and the connecting channels23(plates11fto11hinFIG.3). Accordingly, there is no need to prepare a new part as the part constructing the pressure chambers21, and the cost can be reduced.

The shift amount in the first direction (second distance D2) by which the pressure chambers21are shifted between the two individual channel arrays20A and20B is smaller than the shift amount in the first embodiment (first distance D1inFIG.2) (seeFIG.5). As a result, an area occupied by the pressure chambers21in the first direction can be made small, thereby making it possible to make the size of the part constructing the pressure chambers21to be small in the first direction.

Furthermore, in the second embodiment, the linking channel33is at the height level which is same as the first and second common channels31and32. Therefore, the thickness (length in the third direction) of the channel substrate11can be made small, as compared with the first embodiment wherein the linking channel33and the first and second common channels31and32are at different height levels, respectively (seeFIG.3).

Third Embodiment

Next, a third embodiment of present disclosure will be explained, with reference toFIG.7.

In the first embodiment (FIG.3), the connecting channel23is constructed of the through holes formed in the two plates11fand11g, and the other end23yof the connecting channel23includes the first area R1defined by the plate11hwhich is one of the two plates11fand11gand the second area R2arranged side by side with the first area R1in the second direction and defined by the plate11gin which the holes constructing the nozzles22are formed. In contrast, in the third embodiment (FIG.7), a connecting channel23is constructed of a through hole formed in one plate311f, and all the area of the other end23yof the connecting channel23is defined by a plate311gin which the through holes forming the nozzles22are formed.

In a head301(FIG.7) according to the third embodiment, a channel substrate311is constructed of plates11ato11esimilar to those in the first embodiment (FIG.3), the plate311fsubstituted for the two plates11fand11gin the first embodiment, and the plate311gsubstituted for the plate11hin the first embodiment.

In the third embodiment, the plate311gcorresponds to the “first plate” of the present disclosure, and the plate311fcorresponds to the “second plate” of the present disclosure. The plate311fis stack in the third direction with respect to the plate311g, and has the through hole constructing the connecting channel23. The through hole of the plate311fis covered with the plate311g.

In the second direction, the plate311fhas a length which is same as those of the five plates11ato11epositioned above the plate311f, whereas the plate311gis shorter than the other plates11ato11eand311f. The length in the second direction of the plate311gis, for example, in a range of 3 mm to 5 mm.

As described above, according to the third embodiment (FIG.7), by adopting the configuration wherein the connecting channel23is constructed of the through hole in the plate311f, and all the area of the other end23yof the connecting channel23is defined by the plate311g, it is possible to easily form the connecting channel23by, for example, the etching, etc.

Fourth Embodiment

Next, a fourth embodiment of present disclosure will be explained, with reference toFIG.8.

In the head1of the first embodiment (FIG.2), the connecting channel23is T-shaped (shape of a letter “T”) in the plane orthogonal to the third direction, and has the rectangular part23textending in the first direction over the one ends in the second direction of the respective two pressure chambers21(first pressure chamber21aand second pressure chamber21b), among the plurality of pressure chambers21, corresponding to the connecting channel23, and the projected part23pprojecting from the rectangular part23tin the second direction to the side away from the first and second pressure chambers21aand21band having the nozzle22provided in the lower surface thereof. In contrast to this, in a head401of the fourth embodiment (FIG.8), a connecting channel23has no projected part23pin the plane orthogonal to third direction, and has only a rectangular part23textending in the first direction over one ends in the second direction of respective two pressure chambers21(first pressure chamber21aand second pressure chamber21b), among the plurality of pressure chambers21, corresponding to the connecting channel23, and the nozzle22is arranged in the center of the rectangular part23t.

Further, in the head1of the first embodiment (FIG.2), the plurality of nozzles22belonging to the first individual channel array20A and the plurality of nozzles22belonging to the second individual channel array20B are arranged in one array along the first direction. In contrast to this, in the head401of the fourth embodiment (FIG.8), a plurality of nozzles22belonging to the first individual channel array20A are arranged in one array along the first direction; and a plurality of nozzles22belonging to the second individual channel array20B are arranged in one array along the first direction, to be adjacent, in the second direction, to the array of the nozzles22of the first individual channel array20A. That is, in the head401of the fourth embodiment (FIG.8), the plurality of nozzles22belonging to the first individual channel array20A and the plurality of nozzles22belonging to the second individual channel array20B are arranged in a staggered manner in the first direction as a whole, and are arranged in two rows in the first direction.

According to the fourth embodiment (FIG.8), although the fourth embodiment is different from the first embodiment in view of the above-described point, the fourth embodiment has a configuration similar to that of the first embodiment (FIG.2), except for the above-described point, thereby making it possible to obtain effects similar to those obtained in the first embodiment (FIG.2).

Fifth Embodiment

It is also possible to apply the present disclosure to a liquid discharging head of the circulation type. A head501according to a fifth embodiment of present disclosure, which is a head of the circulation type, will be explained with reference toFIGS.9and10. Note that a same reference numeral is affixed to a configuration, of the head501, which is same as that in the head1, and any explanation therefor is omitted as appropriate.

As depicted inFIGS.9and10, the head501is provided with a first common supply channel131fand a first common return channel131r, instead of the first common channel31; and a second common supply channel132fand a second common return channel132r, instead of the second common channel32. The first common supply channel131fand the first common return channel131rare arranged to be side by side in the conveyance direction. Similarly, the second common supply channel132fand the second common return channel132rare arranged to be side by side in the conveyance direction. A first ink supply port131xis formed at a central part in the paper width direction of the first common supply channel131f, and a first ink recovery port131yis formed at a central part in the paper width direction of the first common return channel131r. Similarly, a second ink supply port132xis formed at a central part in the paper width direction of the second common supply channel132f, and a second ink recovery port132yis formed at a central part in the paper width direction of the second common return channel132r. The first ink supply port131xand the second ink supply port132xcommunicate with a non-illustrated sub tank via a non-illustrated tube and a non-illustrated pump. The first ink recovery port131yand the second ink recovery port132ycommunicate with the non-illustrated sub tank via a non-illustrated tube.

As depicted inFIGS.9and10, the second common supply channel132fcommunicates with a pressure chamber21bvia a supply channel134f. The supply channel134fextends from a lower part in the second common supply channel132fto the upstream side in the conveyance direction, extends further to the upper side and communicates with the pressure chamber21b. Note that although not depicted inFIG.10, the first common supply channel131fand the pressure chamber21aalso communicate with each other by a supply channel which is similar to the supply channel134f.

As depicted inFIGS.9and10, the first common return channel131rcommunicates with a pressure chamber21avia a return channel133r. The return channel133rextends from a lower part in the first common return channel131rto the downstream side in the conveyance direction, extends further to the upper side and communicates with the pressure chamber21a. Note that although not depicted inFIG.10, the second common return channel132rand the presser chamber21balso communicate with each other by a return channel which is similar to the return channel133r.

By the driving of the pump, the ink in the sub tank is supplied to the second common supply channel132fvia the second ink supply port132x. The ink inside the second common supply channel132fflows through the supply channel134fand is supplied to the pressure chamber21b. The ink supplied to the pressure chamber21bflows to the connecting channel23and a part of the ink is discharged from the nozzle22. The ink which is not discharged from the nozzle22flows toward a pressure chamber21acommunicating with the same connecting channel23as the pressure chamber21bvia the non-illustrated return channel. The ink inside the pressure chamber21aflows toward the second common return channel132rvia the non-illustrated return channel. Then, the ink inside the second common return channel132ris recovered to the inside of the sub tank, via the second ink recovery port132y. In such a manner, the ink supplied from the second common supply channel132fflows through the pressure chamber21b, the pressure chamber21aand flows into the second common return channel132r.

Similarly, by the driving of the pump, the ink in the sub tank is supplied to the first common supply channel131fvia the first ink supply port131x. The ink inside the first common supply channel131fflows through the non-illustrated supply channel and is supplied to the pressure chamber21b. The ink supplied to the pressure chamber21bflows to the connecting channel23and a part of the ink is discharged from the nozzle22. The ink which is not discharged from the nozzle22flows toward a pressure chamber21acommunicating with the same connecting channel23as the pressure chamber21b. The ink inside the pressure chamber21aflows to the first common return channel131rvia the return channel133r. Then, the ink inside the first common return channel131ris recovered to the inside of the sub tank, via the first ink recovery port131y. In such a manner, the ink supplied from the first common supply channel131fflows through the pressure chamber21b, the pressure chamber21aand flows into the first common return channel131r.

In such a manner, by generating a flow of the ink from the first common supply channel131ftoward the first common return channel131r, and a flow of the ink from the second common supply channel132ftoward the second common return channel132r, the ink does not remain in the vicinity of the nozzle22for a long period of time. Due to this, it is possible to prevent any increase in the viscosity of the ink in the vicinity of the nozzle22.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to or restricted by the above-described embodiments, and various design changes can be made within the scope of the claims.

The plurality of nozzles belonging to the first individual channel array and the plurality of nozzles belonging to the second individual channel array may sandwich the plurality of pressure chambers belonging to the first individual channel array and the plurality of pressure chambers belonging to the second individual channel array therebetween in the second direction.

Provided that the plurality of nozzles belonging to the first individual channel array and the plurality of nozzles belonging to the second individual channel array are arranged side by side in the first direction at the equal spacing distance therebetween, it is allowable to appropriately change the center-to-center distance between the two pressure chambers which are adjacent to each other in the first direction in each of the individual channel arrays and/or the shift amount in the first direction between the (two) pressure chambers belonging to the two individual channel arrays, respectively.

In the first individual channel array and/or the second individual channel array, a nozzle which is not arranged side by side in the first direction, at an equal spacing distance, with respect to other nozzles may be present. That is, the present disclosure is not limited to such a configuration that all the nozzles belonging to the first individual channel array and the second individual channel array are arranged side by side (aligned) in the first direction at the equal spacing distance therebetween; it is allowable that at least a part of the nozzles are arranged side by side in the first direction at the equal spacing distance therebetween.

As the shift amount in the first direction of pressure chambers between the two individual channel arrays, the first distance D1and the second distance D2are exemplified in the first embodiment and the second embodiment, respectively; however, pressure chambers, as an object of the shift amount, are pressure chambers corresponding to the respective nozzles which are arranged side by side in the first direction at the equal spacing distance therebetween. That is, in the first individual channel array and the second individual channel array, there may be a pressure chamber which does not correspond to the above-described shift amount.

For example, it is allowable that, inFIG.2, all the pressure chambers21belonging to the first individual channel array20A are arranged to be shifted by an amount corresponding to “first distance D1×2n (n: natural number)+first distance D1” in the first direction with respect to all the pressure chambers21belonging to the second individual channel array20B. In this case, although a certain part of the nozzles22, among the plurality of nozzles22belonging to the second individual channel array20B, which is located at one end in the first direction (upper side inFIG.2) is not arranged side by side in the first direction at the equal spacing distance, with respect to other nozzles22, the remaining (other) nozzles22are arranged side by side in the first direction, at the equal spacing distance therebetween, thereby making it possible to obtain the effects of the present disclosure.

Further, it is allowable that, for example, inFIG.5, all the pressure chambers21belonging to the first individual channel array20A are arranged to be shifted by an amount corresponding to a “first distance D1×2n (n: natural number)+second distance D2” in first direction with respect to all the pressure chambers21belonging to the second individual channel array20B. In this case, although a certain part of the nozzles22, among the plurality of nozzles22belonging to the second individual channel array20B, which is located at one end in the first direction (upper side inFIG.2) is not arranged side by side in the first direction at the equal spacing distance, with respect to other nozzles22, the remaining (other) nozzles22are arranged side by side in the first direction, at the equal spacing distance therebetween, thereby making it possible to obtain the effects of the present disclosure.

The present disclosure is not limited to the configuration wherein the common liquid supply port is provided with respect to the first common channel and the second common channel; it is allowable that individual liquid supply ports are provided with respect to the respective first and second common channels.

The number of the individual channel array may be not less than 3 (three).

Although the number of the nozzle belonging to each of the plurality of individual channels is one in the above-described embodiment, the number may be not less than 2 (two).

Although the number of pressure chamber belonging to each of the plurality of individual channels is two in the above-described embodiment, the number may be not less than 3 (three).

The liquid discharging head is not limited to being of the line-type, and may be of a serial-type (a system in which the liquid is ejected or discharged from the nozzles to a discharge object while the liquid discharging head is moving in a scanning direction parallel to the paper width direction).

The discharge object is not limited to paper (paper sheet) and may be, for example, cloth (fabric), a substrate, etc.

The liquid discharged or ejected from the nozzles is not limited to the ink, and may be an arbitrary liquid (e.g., a treating liquid which causes a component in the ink to aggregate or precipitate), etc.

The present disclosure is not limited to the printer, and is also applicable to a facsimile machine, a copying machine, a multi-functional peripheral, etc. The present disclosure is also applicable to a liquid discharging head used for an application different from the recording of an image (for example, a liquid discharging apparatus which discharges or ejects a conductive liquid onto a substrate to thereby form a conductive pattern on the substrate).