1. Field of the Invention
The present invention relates to a liquid jet head for discharging liquid from nozzles to form images and characters on a recording medium or to form a thin film material, and also relates to a liquid jet apparatus using the liquid jet head.
2. Description of the Related Art
In recent years, an ink jet system liquid jet head has been used for creating characters and graphics by discharging ink droplets onto a recording sheet or the like, or to forming a pattern of a functional thin film by discharging a liquid material onto a surface of an element substrate. In the ink jet system, ink or a liquid material is supplied from a liquid tank to the liquid jet head through a supply tube, and the ink is loaded into small spaces formed in the liquid jet head. In response to a drive signal, the volume of the small spaces is instantaneously reduced to discharge liquid droplets from nozzles communicating to grooves.
On a surface of the flexible substrate 53 on the piezoelectric substrate 52 side, there are formed wiring electrodes 61 for supplying the drive signal to the drive electrodes 59. As indicated by the arrows of
In the conventional example illustrated in
Further, in order to form the extension electrodes 86 on the back surface side of the piezoelectric ceramic substrate 81 as illustrated in
The present invention has been made in view of the above-mentioned circumstances, and it is therefore an object of the present invention to provide a liquid jet head which can be manufactured by a simple manufacturing method and is easy to downsize.
A liquid jet head according to the present invention includes: an actuator substrate including: a plurality of grooves, which are arranged in parallel in a surface of the actuator substrate ranging from a front end thereof to a vicinity of a rear end thereof while being spaced apart from one another through an intermediation of partition walls; drive electrodes, which are arranged on side surfaces of each of the partition walls; and electrode terminals, which are electrically connected to the drive electrodes and arranged on the surface of the actuator substrate in the vicinity of the rear end thereof; a cover plate, which is bonded to the surface of the actuator substrate and closes upper openings of the plurality of grooves to form a plurality of channels; and a flexible substrate, which is bonded to the surface of the actuator substrate in the vicinity of the rear end thereof, and includes wiring electrodes electrically connected to the electrode terminals, in which the plurality of channels include: a discharge channel for discharging liquid; and a dummy channel that does not discharge the liquid, the discharge channel and the dummy channel being arranged alternately with each other, in which the electrode terminals include: a first electrode terminal, which is electrically connected to two drive electrodes each arranged on a side surface on the discharge channel side, of both side surfaces of each of two partition walls constituting the discharge channel; and a second electrode terminal, which is electrically connected to a drive electrode arranged on a side surface of one of the two partition walls of the discharge channel on the dummy channel side, and a drive electrode arranged on a side surface of another one of the two partition walls on the dummy channel side, and in which the wiring electrodes include: a common wiring electrode, which electrically connects the first electrode terminal corresponding to the discharge channel, and another first electrode terminal corresponding to another discharge channel; and a plurality of individual wiring electrodes, which are electrically and individually connected to the second electrode terminal corresponding to the discharge channel and a second electrode terminal corresponding to the another discharge channel.
Further, in each of the discharge channel and the another discharge channel, a first connection point, at which the first electrode terminal is electrically connected to the common wiring electrode, is situated closer to the front end than a second connection point, at which the second electrode terminal is electrically connected to one of the plurality of individual wiring electrodes.
Further, the first connection point and the second connection point are opposed to each other along a longitudinal direction of the discharge channel.
Further, the common wiring electrode is situated closer to an outer periphery of the flexible substrate than the plurality of individual wiring electrodes.
Further, the common wiring electrode intersects the second electrode terminal; and in the intersection therebetween, an insulating film for preventing short-circuit is interposed.
Further, a groove constituting the discharge channel extends from the front end of the actuator substrate to a position on the rear end side short of a position at which the electrode terminals are arranged, and a groove constituting the dummy channel extends from the front end of the actuator substrate to the rear end thereof.
A liquid jet apparatus according to the present invention includes: any one of the above-mentioned liquid jet heads; a moving mechanism for reciprocating the liquid jet head; a liquid supply tube for supplying liquid to the liquid jet head; and a liquid tank for supplying the liquid to the liquid supply tube.
The liquid jet head according to the present invention includes: an actuator substrate including: a plurality of grooves, which are arranged in parallel in a surface of the actuator substrate ranging from a front end thereof to a vicinity of a rear end thereof while being spaced apart from one another through an intermediation of partition walls; drive electrodes, which are arranged on side surfaces of each of the partition walls; and electrode terminals, which are electrically connected to the drive electrodes and arranged on the surface of the actuator substrate in the vicinity of the rear end thereof; a cover plate, which is bonded to the surface of the actuator substrate and closes upper openings of the plurality of grooves to form a plurality of channels; and a flexible substrate, which is bonded to the surface of the actuator substrate in the vicinity of the rear end thereof, and includes wiring electrodes electrically connected to the electrode terminals. Further, the plurality of channels include: a discharge channel for discharging liquid; and a dummy channel that does not discharge the liquid, the discharge channel and the dummy channel being arranged alternately with each other. The electrode terminals include: a first electrode terminal, which is electrically connected to two drive electrodes each arranged on a side surface on the discharge channel side, of both side surfaces of each of two partition walls constituting the discharge channel; and a second electrode terminal, which is electrically connected to a drive electrode arranged on a side surface of one of the two partition walls of the discharge channel on the dummy channel side, and a drive electrode arranged on a side surface of another one of the two partition walls on the dummy channel side. The wiring electrodes include: a common wiring electrode, which electrically connects the first electrode terminal corresponding to the discharge channel, and another first electrode terminal corresponding to another discharge channel; and a plurality of individual wiring electrodes, which are electrically and individually connected to the second electrode terminal corresponding to the discharge channel and a second electrode terminal corresponding to the another discharge channel. With this structure, the number of wiring electrodes on the flexible substrate can be reduced substantially by half as compared to the number of electrode terminals on the actuator substrate. Accordingly, the wiring electrodes can be formed on the flexible substrate with ease and connection between the electrode terminals and the wiring electrodes is facilitated.
In the accompanying drawings:
A liquid jet head of the present invention includes an actuator substrate having a plurality of grooves formed in a surface thereof, a cover plate bonded to the surface of the actuator substrate, and a flexible substrate for supplying a drive signal to the actuator substrate. The actuator substrate includes the plurality of grooves, which are arranged in parallel in the surface of the substrate ranging from its front end to the vicinity of its rear end while being spaced apart from one another through the intermediation of partition walls, drive electrodes, which are formed on side surfaces of each partition wall, and electrode terminals, which are electrically connected to the drive electrodes and arranged on the surface of the actuator substrate in the vicinity of the rear end. The cover plate closes upper openings of the plurality of grooves formed in the surface of the actuator substrate to forma plurality of channels arranged in parallel. The flexible substrate is bonded to the substrate surface of the actuator substrate in the vicinity of the rear end, and includes wiring electrodes electrically connected to the above-mentioned electrode terminals formed on the actuator substrate.
The plurality of channels arranged in parallel include discharge channels for discharging liquid and dummy channels that do not discharge liquid, the discharge channels and the dummy channels being arranged alternately with each other. The electrode terminals formed in the vicinity of the rear end of the actuator substrate include first electrode terminals and second electrode terminals. The first electrode terminal is electrically connected to two drive electrodes arranged on side surfaces on the discharge channel side, of the side surfaces of two partition walls constituting the discharge channel. The second electrode terminal is electrically connected to a drive electrode arranged on a side surface of one of the partition walls of the discharge channel on the dummy channel side, and a drive electrode arranged on a side surface of the other partition wall on the dummy channel side.
Each partition wall is made of a piezoelectric material. In this case, the entire actuator substrate may be made of the piezoelectric material, or only the partition wall part may be made of the piezoelectric material. The partition wall may produce a large electrostrictive effect when the partition wall is subjected to polarization processing in a direction of the normal of the actuator substrate surface, for example. In this case, the entire partition wall may be subjected to the polarization processing in the direction of the normal, or the polarization direction may be inverted at substantially half the height of the partition wall. Then, the drive signal is supplied to the first electrode terminal and the second electrode terminal to symmetrically deform both the partition walls constituting the discharge channel with the discharge channel set as the center of symmetry. Accordingly, the volume of the discharge channel changes to discharge liquid loaded inside from a nozzle communicating to the discharge channel. In general, the first electrode terminal is connected to a GND and the drive signal is supplied to the second electrode terminal so that the actuator substrate is driven.
The wiring electrodes formed on the flexible substrate include a common wiring electrode and individual wiring electrodes. The common wiring electrode electrically connects in common a first electrode terminal corresponding to one discharge channel and a first electrode terminal corresponding to another discharge channel. The individual wiring electrodes are electrically and individually connected to the second electrode terminals corresponding to the respective discharge channels.
Therefore, in a case where n (n is a positive integer) discharge channels are provided in the actuator substrate, in order to drive those discharge channels, 2n electrode terminals are provided in total, that is, n first electrode terminals and n second electrode terminals. On the other hand, n+1 wiring electrodes only need to be formed on the flexible substrate, for example, one common wiring electrode and n individual wiring electrodes. In other words, according to the liquid jet head of the present invention, the number of wiring electrodes to be formed on the flexible substrate side can be reduced greatly as compared to the number of the electrode terminals formed on the actuator substrate side, and wiring density on the flexible substrate side can be halved substantially. Accordingly, the wiring electrodes can be formed on the flexible substrate with ease, and further, connection between the electrode terminals and the wiring electrodes is facilitated.
In each discharge channel, when a connection point at which the first electrode terminal on the actuator substrate side is electrically connected to the common wiring electrode on the flexible substrate side is defined as a first connection point and a connection point at which the second electrode terminal on the actuator substrate side is electrically connected to the individual wiring electrode on the flexible substrate side is defined as a second connection point, the first connection point is situated closer to the front end of the actuator substrate than the second connection point. With this structure, the pitch of the connection points in the arrangement direction of the respective channels can be increased, with the result that the connection process is facilitated and connection failure can be reduced.
The first connection point and the second connection point may be arranged so as to be opposed to each other along the longitudinal direction of the discharge channel. With this structure, large intervals can be secured for the wiring electrodes and the connection points between adjacent discharge channels, which suits to arrangement of the wiring electrodes with higher density.
The common wiring electrode maybe formed so as to be situated closer to an outer periphery of the flexible substrate than the individual wiring electrode. This structure eliminates the need to form the common wiring electrode between the individual wiring electrodes, with the result that the minimum pitch of the wiring electrodes can be set substantially equal to the pitch of the first electrode terminals. Accordingly, the wiring electrodes can be formed on the flexible substrate with ease and, at the same time, yields of the connection process can be increased. The common wiring electrode has a larger amount of current flowing therethrough than the individual wiring electrode, but a voltage drop due to wiring resistance can be suppressed by increasing the wiring width of the common wiring electrode irrespective of the electrode width and electrode pitch of the individual wiring electrodes.
Further, an insulating film for preventing short-circuit is interposed in an intersection at which the common wiring electrode intersects each second electrode terminal. As a result, the short-circuit can be prevented. The insulating film at the above-mentioned intersection may be arranged on the common wiring electrode side, or may be arranged on the second electrode terminal side. This structure enables the electrode wiring to be laid only on one side of the flexible substrate, which contributes to cost reduction. Hereinbelow, specific description is given with reference to the accompanying drawings.
(First Embodiment)
As illustrated in
The actuator substrate 2 is formed as follows. A surface of a piezoelectric substrate is cut with a dicing blade to form the plurality of grooves 6 arranged in parallel. Subsequently, a photosensitive resin sheet is attached to the surface of the piezoelectric substrate, and a pattern is formed through exposure and development. Subsequently, a conductive film is deposited onto the surface of the piezoelectric substrate and the side surfaces of the partition walls 7 by an oblique deposition, and then the photosensitive resin sheet is removed by a lift-off method. As a result, the drive electrodes 9 are formed on the side surfaces of each partition wall 7 and the electrode terminals 10 are formed on the surface 15.
The cover plate 4 includes a liquid supply cell 12 for allowing liquid to flow in, and slits 13 penetrating from a bottom surface of the liquid supply cell 12 to a back surface of the cover plate 4. The cover plate 4 is bonded to the surface of the actuator substrate 2 with adhesive so that the surface of the actuator substrate 2 in the vicinity of the rear end RE is exposed and the slits 13 communicate to upper opening portions of every other grooves 6. The cover plate 4 closes the upper openings of the grooves 6 to form channels. The channels include discharge channels C capable of supplying the liquid from the liquid supply cell 12 through the slits 13, and dummy channels D that do not communicate to the liquid supply cell 12 and hence do not supply the liquid, the discharge channels C and the dummy channels D being arranged alternately with each other. The nozzle plate 5 includes nozzles 14 communicating to the discharge channels C, and is bonded to the actuator substrate 2 and the cover plate 4 at the front end FE.
The electrode terminals 10 include first electrode terminals 10a and second electrode terminals 10b. The first electrode terminal 10a is connected to two drive electrodes 9 formed on side surfaces of two partition walls 7 on the discharge channel side, the partition walls 7 constituting the discharge channel C. The second electrode terminal 10b is connected to a drive electrode 9 formed on a side surface of one of the partition walls 7 on the dummy channel D side, the partition walls 7 constituting the discharge channel C, and a drive electrode 9 formed on a side surface of the other partition wall 7 on the dummy channel D side. In other words, in each discharge channel C, the first electrode terminal 10a extends from an end portion of the discharge channel C to a position short of the rear end RE, while the second electrode terminal 10b extends from both end portions of the dummy channels D situated on both sides of the discharge channel C and surrounds the first electrode terminal 10a in an inverted C shape. Then, the flexible substrate 3 is bonded to the surface 15 in the vicinity of the rear end RE.
Referring to
The flexible substrate 3 includes a common wiring electrode 11a and a plurality of individual wiring electrodes 11b. The common wiring electrode 11a is electrically connected to the first electrode terminal 10a corresponding to the discharge channel C1 via a first connection point 16a, and is connected to a GND. The other first electrode terminals 10a corresponding to the other discharge channels C2 to C4 are similarly connected to the common wiring electrode 11a through the other first connection points 16a. The individual wiring electrodes 11b are electrically connected to the second electrode terminals 10b through second connection points 16b corresponding to the discharge channels C1 to C4.
For example, in a case of driving the discharge channel C1, a drive signal is supplied to a terminal Ta. Then, an electric field is applied to upper half portions of the partition wall 71 and the partition wall 72 in their thickness direction to cause slip distortion in the thickness direction. As a result, the partition wall 71 and the partition wall 72 are deformed in a “dogleg” shape with reference to a bending point defined at substantially half the height of the partition wall 71 and the partition wall 72. With this structure, the volume of the discharge channel C1 changes to discharge the liquid loaded inside from the nozzle 14. Also in a case of driving the other discharge channels C2 to C4, drive signals are supplied via terminals Tb to Td to the drive electrodes 9 on the dummy channel D2 side to the dummy channel D5 side. The drive electrodes 9 on the discharge channel C1 side to the discharge channel C4 side are set at the GND level, and hence, even if conductive liquid is employed, no drive signal leaks through the liquid.
Referring to
The first electrode terminals 10a and the second electrode terminals 10b are formed on the surface 15 of the actuator substrate 2 in the vicinity of the rear end RE. The first electrode terminal 10a is electrically connected to the drive electrodes 9 formed on both the side surfaces of the discharge channel C1. The second electrode terminal 10b is electrically connected to the two drive electrodes 9 formed on the side surfaces of the dummy channels D1 and D2 on the discharge channel C1 side, the dummy channels D1 and D2 being situated on both sides of the second electrode terminal 10b. On the surface 15, the second electrode terminal 10b surrounds the first electrode terminals 10a in an inverted C shape.
The common wiring electrode 11a and the individual wiring electrodes 11b are formed on the surface of the flexible substrate 3 on the actuator substrate 2 side. The common wiring electrode 11a is arranged so as to surround the individual wiring electrodes 11b along an outer periphery of the flexible substrate 3. The common wiring electrode 11a is electrically connected to the first electrode terminal 10a corresponding to the discharge channel C1 at the first connection point 16a. The first electrode terminals corresponding to the other discharge channels are similarly connected in common to the common wiring electrode 11a at the other first connection points. The individual wiring electrode 11b is electrically connected to the second electrode terminal 10b corresponding to the discharge channel C1 at the second connection point 16b. The second electrode terminals corresponding to the other discharge channels are similarly electrically connected at the other second connection points. The first connection point 16a is situated closer to the front end FE than the second connection point 16b.
With this electrode structure, the number of wiring electrodes on the flexible substrate 3 can be reduced substantially by half as compared to the number of electrode terminals on the actuator substrate 2. Accordingly, the wiring electrodes can be formed on the flexible substrate with ease. Further, the pitch of the connection points 16 in the arrangement direction of the respective channels, that is, the direction orthogonal to the grooves 6, is increased, which facilitates the connection process for connecting the first electrode terminals 10a and the second electrode terminals 10b to the common wiring electrode 11a and the individual wiring electrodes 11b, respectively. Further, the common wiring electrode 11a is arranged along the outer periphery of the flexible substrate 3 so as to surround the individual wiring electrodes 11b. Accordingly, even in a case where the number of discharge channels C is increased and the wiring density of the individual wiring electrodes 11b is higher, the electrode width of the common wiring electrode 11a can be set freely irrespective of the wiring pitch of the individual wiring electrodes 11b. As a result, the voltage drop due to the resistance of the common wiring electrode 11a can be suppressed.
The second connection point 16b may be arranged closer to the rear end RE than the first connection point 16a as long as the second connection point 16b is situated on the second electrode terminal 10b. In this case, the length of the second electrode terminal 10b in the direction orthogonal to the channel direction equals a sum of the width of one groove 6 and the thickness of two partition walls 7. Accordingly, the strictness with the alignment accuracy required in aligning the individual wiring electrodes 11b to the second electrode terminals 10b is eased, with the result that the connection failure can be reduced and the connection process is facilitated. Further, when the first connection point 16a and the second connection point 16b are arranged so as to be opposed to each other along the longitudinal direction of the discharge channel C as illustrated in
It is noted that the common wiring electrode 11a is formed on the flexible substrate 3 along the outer periphery of the flexible substrate 3, but the present invention is not limited thereto. For example, the common wiring electrode 11a may be arranged between two individual wiring electrodes 11b, or may be formed only along the outer periphery on one side. Further, the wiring electrodes 11 are formed on the surface of the flexible substrate 3 on the actuator substrate 2 side, but the present invention is not limited thereto. For example, the common wiring electrode 11a is formed on a surface of the flexible substrate 3 on a side opposite to the actuator substrate 2 side, and the common wiring electrode 11a is electrically connected to the first electrode terminals 10a at the first connection points 16a through a penetration electrode penetrating the flexible substrate 3. With this structure, a short-circuit is prevented with ease through the interposition of the flexible substrate 3 in the intersection at which the common wiring electrode 11a intersects each second electrode terminal 10b. Further, the flexible substrate 3 may be provided separately for the individual wiring electrodes and for the common wiring electrode. This structure eliminates the need to arrange the common wiring electrode around the individual wiring electrodes, with the result that the contour of each flexible substrate 3 can be reduced and a compact flexible substrate 3 may be formed as a whole.
Further, lead zirconate titanate (PZT) ceramics are used for the actuator substrate 2, and each partition wall 7 is subjected to the polarization processing in the direction of the normal of the substrate surface. The partition wall 7 may have a chevron structure, or the electrodes may be formed on upper half portions or lower half portions of the partition wall 7, the upper half portion and the lower half portion being distinguished at substantially half the height of the partition wall 7. For the cover plate 4, the same material as that for the actuator substrate 2 is used, and for the nozzle plate 5, a polyimide film is used. However, the present invention is not limited to those materials, and needless to say, other materials may be used instead.
The chevron structure mentioned herein has a characteristic in the actuator substrate and hence the structure of the actuator substrate is different from that illustrated in
(Second Embodiment)
The first and second electrode terminals 10a and 10b are formed on the surface 15 of the actuator substrate 2 in the vicinity of the rear end RE, and the second electrode terminal 10b is arranged so as to surround the first electrode terminal 10a. The common wiring electrode 11a and the individual wiring electrodes 11b are formed on the surface of the flexible substrate 3 on the actuator substrate 2 side, and the common wiring electrode 11a is formed along the periphery of the flexible substrate 3 so as to surround the individual wiring electrodes 11b. The common wiring electrode 11a is electrically connected to the first electrode terminal 10a corresponding to the discharge channel C1 at the first connection point 16a through an anisotropic conductive film (not shown). The other first electrode terminals corresponding to the other discharge channels are similarly connected to the common wiring electrode 11a. The individual wiring electrode 11b is electrically connected to the second electrode terminal 10b corresponding to the discharge channel C1 at the second connection point 16b closer to the rear end RE than the first connection point 16a through an anisotropic conductive film (not shown).
In this structure, the common wiring electrode 11a inevitably intersects the second electrode terminals 10b in plan view. Therefore, insulating layers 17 are interposed in the intersections between the common wiring electrode 11a and the second electrode terminals 10b corresponding to the respective discharge channels, to thereby prevent the short-circuit between the common wiring electrode 11a and the second electrode terminals 10b.
An insulating film is used as the insulating layer 17. The insulating layer 17 may be attached at each intersection to the flexible substrate 3 side or the actuator substrate 2 side. Further, the insulating film as the insulating layer 17 may be formed so as to cover the surface of the second electrode terminal 10b or the common wiring electrode 11a at the intersection.
(Third Embodiment)
Referring to
The circuit board 19 has the drive ICs 20 mounted on its surface, and is bonded to the flexible substrate 3 at its end portion on a side opposite to the actuator substrate 2. The circuit board 19 has wires (not shown) on its surface, and one end of each wire is electrically connected to the drive IC 20 while the other end is electrically connected to the common wiring electrode 11a or the individual wiring electrode 11b on the flexible substrate 3. In other words, the drive signals generated by the drive ICs 20 are transmitted to the electrode terminals 10 on the actuator substrate 2 through the wiring electrodes 11 on the flexible substrate 3, and supplied to the drive electrodes 9 of the respective channels. Note that, the structures of the actuator substrate 2, the cover plate 4, and the nozzle plate 5, and the layout of the electrode terminals 10 and the wiring electrodes 11 are the same as those of the first embodiment or the second embodiment, and detailed description thereof is therefore omitted herein.
The common wiring electrode 11a is electrically connected to the first electrode terminal 10a corresponding to the discharge channel C1 at the first connection point 16a through an anisotropic conductive film (not shown). The first electrode terminals corresponding to the other discharge channels are similarly connected to the common wiring electrode 11a. The individual wiring electrode 11b is electrically connected to the second electrode terminal 10b corresponding to the discharge channel C1 at the second connection point 16b through an anisotropic conductive film (not shown). The second electrode terminals corresponding to the other discharge channels have the same structure. The individual wiring electrodes 11b are electrically independent of one another.
The first connection point 16a is situated closer to the front end FE than the second connection point 16b. The insulating layer 17a serving as a cover layer is arranged so as to cover the surface of the common wiring electrode 11a in a part closer to the front end FE than the first connection points 16a. Further, an insulating layer 17b is formed on the surface of the flexible substrate 3 in a part between the actuator substrate 2 and the circuit board 19 to protect the surfaces of the wiring electrodes 11. Because the insulating layer 17a serving as the cover layer is arranged between the second electrode terminals 10b and the common wiring electrode 11a, the short-circuit between the second electrode terminals 10b and the common wiring electrode 11a can be prevented even in a case where the end portion of the flexible substrate 3 on the front end FE side is pressed from above.
In
(Fourth Embodiment)
As illustrated in
The common wiring electrode 11a on the flexible substrate 3 is electrically connected to the first electrode terminal 10a on the actuator substrate 2 corresponding to the discharge channel C1 at the first connection point 16a. The first electrode terminals 10a corresponding to the other discharge channels are similarly electrically connected to the common wiring electrode 11a. The individual wiring electrode 11b on the flexible substrate 3 is electrically connected to the second electrode terminal 10b on the actuator substrate 2 corresponding to the discharge channel C1 at the second connection point 16b. For the other discharge channels C, the corresponding individual wiring electrodes 11b have the same wiring structure.
Further, the insulating layers 17 are interposed between the common wiring electrode 11a and the drive electrodes 9 formed on the side surfaces of the dummy channels D. With this structure, the short-circuit between the common wiring electrode 11a and the drive electrodes 9 formed on the side surfaces of the dummy channels D is prevented. Note that, the insulating layer 17 for preventing the short-circuit may be arranged on the upper surface of the common wiring electrode 11a, or may be arranged at the electrode intersection on the actuator substrate 2 side. Instead of arranging the insulating layer 17 only at the intersection part, as described in the third embodiment, the insulating layer 17 may be arranged so as to cover the entire surface of the common wiring electrode 11a in a part closer to the front end FE than the first connection points 16a.
(Fifth Embodiment)
The liquid jet apparatus 30 includes a moving mechanism 43 for reciprocating liquid jet heads 1 and 1′ according to the present invention described above, liquid supply tubes 33 and 33′ for supplying liquid to the liquid jet heads 1 and 1′, respectively, and liquid tanks 31 and 31′ for supplying the liquid to the liquid supply tubes 33 and 33′, respectively. The liquid jet heads 1 and 1′ are each constituted by the liquid jet head 1 according to the present invention. Specifically, the liquid jet heads 1 and 1′ each include: an actuator substrate having a plurality of grooves arranged in parallel in a surface thereof and partition walls each for spacing adjacent grooves apart from each other; a cover plate covering the grooves and bonded to a surface of the actuator substrate; and a nozzle plate including nozzles communicating to the grooves and bonded to an end surface of the actuator substrate. The actuator substrate includes discharge channels for discharging liquid droplets and dummy channels that do not discharge liquid droplets, the discharge channels and the dummy channels being arranged alternately with each other. On the surface of the actuator substrate 2 in the vicinity of the rear end RE, first electrode terminals and second electrode terminals are arranged. The first electrode terminal is connected to drive electrodes formed on side surfaces of the discharge channel, and the second electrode terminal is connected to drive electrodes formed on side surfaces of the dummy channels on the discharge channel side. The first electrode terminal is situated closer to the front end than the second electrode terminal. On the flexible substrate, a common wiring electrode and individual wiring electrodes are arranged. The common wiring electrode is electrically connected to the first electrode terminals through first connection points, and the individual wiring electrodes are electrically connected to the second electrode terminals through second connection points.
Specific description is given below. The liquid jet apparatus 30 includes: a pair of transport means 41 and 42 for transporting a recording medium 34 such as paper in a main scanning direction; the liquid jet heads 1 and 1′ for discharging liquid onto the recording medium 34; pumps 32 and 32′ for pressing the liquid stored in the liquid tanks 31 and 31′ to supply the liquid to the liquid supply tubes 33 and 33′, respectively; and the moving mechanism 43 for moving the liquid jet heads 1 and 1′ to perform scanning in a sub-scanning direction orthogonal to the main scanning direction.
The pair of transport means 41 and 42 each extend in the sub-scanning direction, and include a grid roller and a pinch roller that rotate with their roller surfaces coming into contact with each other. The grid roller and the pinch roller are rotated about their shafts by means of a motor (not shown) to transport the recording medium 34 sandwiched between the rollers in the main scanning direction. The moving mechanism 43 includes a pair of guide rails 36 and 37 extending in the sub-scanning direction, a carriage unit 38 capable of sliding along the pair of guide rails 36 and 37, an endless belt 39 to which the carriage unit 38 is connected and thereby moved in the sub-scanning direction, and a motor 40 for revolving the endless belt 39 through pulleys (not shown).
The carriage unit 38 has the plurality of liquid jet heads 1 and 1′ placed thereon, and discharges four kinds of liquid droplets, such as yellow, magenta, cyan, and black. The liquid tanks 31 and 31′ store liquid of corresponding colors, and supply the liquid through the pumps 32 and 32′ and the liquid supply tubes 33 and 33′ to the liquid jet heads 1 and 1′, respectively. The liquid jet heads 1 and 1′ discharge the liquid droplets of the respective colors in response to a drive signal. By controlling the timing to discharge the liquid from the liquid jet heads 1 and 1′, the rotation of the motor 40 for driving the carriage unit 38, and the transport speed of the recording medium 34, an arbitrary pattern can be recorded on the recording medium 34.
With this structure, the number of wiring electrodes on the flexible substrate can be reduced as compared to the number of electrode terminals on the actuator substrate, and the wiring density can be halved substantially. Accordingly, the wiring can be laid on the flexible substrate with ease and, at the same time, yields of the connection can be increased.
Number | Date | Country | Kind |
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2010-124353 | May 2010 | JP | national |
Number | Name | Date | Kind |
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20090315957 | Koseki | Dec 2009 | A1 |
Number | Date | Country |
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2130678 | Sep 2009 | EP |
09029977 | Feb 1997 | JP |
Number | Date | Country | |
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20110292115 A1 | Dec 2011 | US |