JP2007196455A - Head module, liquid ejecting head and liquid ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable it to sharply reduce the space which is needed for the electrical connection of a head module. <P>SOLUTION: A head module comprises two or more head chips 20 wherein an electrode to be electrically connected with a control substrate is mounted, a nozzle sheet 25 wherein a nozzle has been formed and two pieces of flexible wiring substrate 3 with wiring for electrically connecting the electrode of each head chip 20 with the connector of the control substrate. For each flexible wiring substrate 3, one end of the wiring is electrically connected with the electrode of each head chip 20, and the other end serves as an interposition terminal part 3b for the connector of the control substrate. The interposition terminal part 3b of each flexible wiring substrate 3 is arranged so as to be located at the position shifted mutually between each flexible wiring substrate 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a head module that is electrically connected to a control board using a wiring board and discharges liquid, and a liquid discharge head and a liquid discharge apparatus using the head module. The present invention relates to a technology that can greatly reduce the space required for secure connection.

  2. Description of the Related Art Conventionally, as an example of a liquid ejecting apparatus, a line head type ink jet printer in which nozzles for ejecting ink are arranged in a length corresponding to the width of a recording sheet is known. The head (liquid discharge head) used in such a line printer supports a single nozzle sheet having a size corresponding to the width of the recording paper with a rigid head frame, and a heating resistor is formed on the nozzle sheet. A head chip provided with a body (energy generating element) and a barrier layer for forming a liquid chamber around the heat generating resistor is accurately arranged corresponding to each line.

A line printer that corresponds to the width of the recording paper by such a head does not require a means for moving the head in the main scanning direction, so that vibration and noise are reduced and the printing speed can be significantly increased. .
On the other hand, however, if a problem occurs in the head due to partial damage of the nozzle sheet or defective head chip, the entire head is treated as a defective product. Therefore, it is difficult to control the quality of the head, resulting in inferior mass productivity. In addition, even if the head is partially broken, it is necessary to replace the entire head, which is inefficient and incurs high repair costs.

  Therefore, a modular head configured by combining a plurality of head modules has been proposed. That is, a head chip is arranged on a small nozzle sheet to form one head module, and a plurality of head modules are combined to form one head corresponding to the width of the recording paper. According to this modular head, production / quality control can be performed in units of head modules, so that it is possible to expect a reduction in the defect rate and a corresponding increase in mass productivity. Also, in terms of service, it is efficient and user friendly because only the defective head module needs to be replaced. Furthermore, since various sizes of heads can be easily provided by changing the arrangement and combination of the head modules, efficient design and manufacture are possible.

  However, in a modular head, the number of wires for applying an electric pulse for ejecting ink to the head chip increases. When the number of wirings increases, the wiring of the heads becomes complicated and the man-hours and labors in the manufacturing process and the assembly process increase and become complicated. In addition, problems such as erroneous connection of wires tend to occur.

Therefore, a head module is disclosed in which the number of wires from each head chip is reduced and connection to the outside is enabled by a smaller number of wires. In other words, this is a technique in which wiring from the head chip is partially shared by a flexible wiring board (see, for example, Patent Document 1).
JP 2003-34032 A

  Here, the flexible wiring board is one in which one end side of the wiring is electrically connected to the electrode of the head chip and the other end side is a terminal portion inserted into the connector of the control board. This flexible wiring board must be arranged for each head module. As a result, a large number of flexible wiring boards must be electrically connected. As a result, a space for installing other wiring and components may be taken away, and interference with other wiring and components may occur. It might be. In addition, if excess dimensions occur in the flexible wiring boards during connection, crosstalk may occur between the flexible wiring boards and the control board, unnecessary radiation may occur, and the signal waveform may be distorted. It becomes easy and it becomes a demerit in the improvement of the response frequency, and it causes malfunction.

Thus, many problems remain to connect a large number of flexible wiring boards to the control board with a simple configuration. If such a problem is left unattended, not only the efficiency of the modular head is impaired, but a combination of a plurality of head modules may be disadvantageous.
Therefore, the problem to be solved by the present invention is to greatly reduce the space required for the electrical connection of the head module while improving the productivity and assembly of the head.

The present invention solves the above-described problems by the following means.
According to a first aspect of the present invention, an energy generating element is disposed on a substrate, and a liquid chamber is formed around the energy generating element on a surface of the substrate on which the energy generating element is disposed. A plurality of head chips provided with electrodes for electrically connecting to the control board, a nozzle sheet on which nozzles for discharging the liquid in the liquid chamber are formed, and A plurality of wiring boards having wirings for electrically connecting the electrodes of the head chip and the connectors of the control board, and applying an ejection force to the liquid in the liquid chamber by the energy generating element; A head module that discharges liquid in the liquid chamber from the nozzle, wherein each wiring board has one end of the wiring electrically connected to the electrode of each head chip. The other end side is a terminal portion for the connector of the control board, and the terminal portions of the wiring boards are arranged so as to be shifted from each other between the wiring boards. It is characterized by.

  The invention according to claim 5, which is another aspect of the present invention, relates to a liquid discharge head using a plurality of head modules according to claim 1, and is still another aspect of the present invention. The invention of claim 8 relates to a liquid discharge apparatus using a plurality of head modules of the invention of claim 1.

(Function)
In each of the above inventions, each wiring board of the head module has one end of the wiring electrically connected to the electrode of each head chip, and the other end serving as a terminal portion for the connector of the control board. The parts are arranged so as to be shifted from each other between the wiring boards.
Therefore, when connecting the terminal portions of the respective wiring boards in the head module to the connectors of the control board, the terminal portions of the wiring boards do not interfere with each other, so that the connectors can be arranged efficiently.

  According to the present invention, even if a head (liquid ejection head) is configured by combining a plurality of head modules, a connector necessary for electrically connecting the terminal portion of each wiring board of the head module and the control board is provided. It becomes possible to arrange efficiently. Therefore, the space required for the electrical connection of the head module can be greatly reduced while improving the productivity and assembly of the head. In addition, no excessive dimension is generated in each wiring board, crosstalk is not generated between the flexible wiring boards and the control board, and unnecessary radiation is not generated, and signal waveform distortion can be prevented.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a liquid discharge head 1 according to an embodiment of the present invention, as viewed from the ink discharge surface side.
Here, the liquid discharge head 1 is used as a head mounted on a liquid discharge apparatus (in this embodiment, a color line inkjet printer). As shown in FIG. 1, the liquid ejection head 1 includes a head frame 2, a flexible wiring board 3 (corresponding to a wiring board in the present invention), and a plurality of head modules 10 including a plurality of head chips 20. It consists of and.

  In addition, in the plan view of FIG. 1, each head module 10 is connected in series in the longitudinal direction in the head module arrangement hole 2a, and is screwed to the head frame 2 by screws 5, and the two heads The module 10 covers one A4 width and prints one color. The two head modules 10 connected in series are provided in four stages (a total of eight), and four colors of Y (yellow), M (magenta), C (cyan), and K (black) are provided. A liquid discharge head 1 which is a line head is configured.

FIG. 2 is a cross-sectional view showing the periphery of the head chip 20 of the head module 10 in the liquid ejection head 1 shown in FIG.
As shown in FIG. 1, eight head chips 20 are provided in each head module 10, and each head chip 20 has a semiconductor substrate 21 made of silicon or the like as shown in FIG. And a heating resistor 22 deposited on one surface of the semiconductor substrate 21 (corresponding to the energy generating element in the present invention). As the energy generating element of the present invention, a heating element other than the heating resistor 22 (such as a heater), a piezoelectric element such as a piezo element, MEMS, or the like can be used.

  In addition, an electrode 23 is formed on the edge of the semiconductor substrate 21 that is on the same side as the surface on which the heating resistor 22 is formed and opposite to the edge on which the heating resistor 22 is formed. The heating resistor 22 and the electrode 23 are electrically connected via a conductor portion (not shown) formed on the semiconductor substrate 21.

  The electrode 23 and the wiring pattern 3a (corresponding to the wiring in the present invention) of the flexible wiring board 3 are connected (ACF connection) via the anisotropic conductive film 28, and the head chip 20 and the module frame 11 are connected. A resin 29 such as an epoxy resin is provided in the gap (opposite side of the flow path 27) to seal the anisotropic conductive film 28. This is because the structure around the head chip 20 (upper side in FIG. 2) is immersed in the ink in the buffer tank 12 when the head module 10 is used, so that the ink does not enter the live part and short-circuit. It is what I did. On the other hand, the outer edge of the nozzle sheet 25 and the outer edge of the flexible wiring board 3 are attached so as to be close to each other, but the gap is sealed with the resin 30 provided from the nozzle sheet 25 side.

  Furthermore, a barrier layer 24 and a nozzle sheet 25 are sequentially laminated on the surface of the head chip 20 on which the heating resistor 22 is formed. The barrier layer 24 forms a side wall of the ink liquid chamber 26 (corresponding to the liquid chamber in the present invention) and serves to bond the head chip 20 and the nozzle sheet 25 together. The barrier layer 24 is made of, for example, a photosensitive cyclized rubber resist or an exposure-curing dry film resist, and is laminated on the entire surface of the head chip 20 on which the heating resistor 22 of the semiconductor substrate 21 is formed. By removing unnecessary portions by a photolithographic process, it is formed in a substantially concave shape when viewed in plan so as to surround the vicinity of the three sides of the heating resistor 22.

  Furthermore, the nozzle sheet 25 is formed with a plurality of nozzles 25a, and is formed by, for example, an electroforming technique using nickel. The nozzle sheet 25 is more specifically configured so that the position of the nozzle 25a matches the position of the heating resistor 22, that is, the nozzle 25a faces the heating resistor 22, more specifically, the central axis of the nozzle 25a. The heating resistor 22 is bonded to the barrier layer 24 so that the center of the heating resistor 22 coincides when viewed in plan.

  The ink liquid chamber 26 is composed of the semiconductor substrate 21, the barrier layer 24, and the nozzle sheet 25 so as to surround the heating resistor 22. The ink liquid chamber 26 is filled with the ink to be ejected, and the ink is applied when the ink is ejected. It becomes a pressure chamber. The surface of the semiconductor substrate 21 on which the heat generating resistor 22 is formed constitutes the bottom wall of the ink liquid chamber 26, and the portion of the barrier layer 24 surrounding the heat generating resistor 22 in a substantially concave shape forms the side wall of the ink liquid chamber 26. The nozzle sheet 25 constitutes the top wall of the ink liquid chamber 26. The ink liquid chamber 26 communicates with a flow path 27 between the head chip 20 and the module frame 11.

One heating chip 22 is usually arranged on the one head chip 20 in units of 100. Then, each of the heating resistors 22 is selected in accordance with a command from a control board (not shown), and the ink in the ink liquid chamber 26 corresponding to the heating resistor 22 is ejected from the opposing nozzle 25a. . That is, if a short-time (for example, 1 to 3 μsec) pulse current is passed through the heating resistor 22 while the ink liquid chamber 26 is filled with ink, the heating resistor 22 is rapidly heated. As a result, a gas phase ink bubble is generated at a portion in contact with the heating resistor 22, and a certain volume of ink is pushed away by the expansion of the ink bubble (the ink boils). As a result, ink having a volume equivalent to the displaced ink is ejected from the nozzle 25a as ink droplets, and the ink droplets land on the photographic paper to form dots (pixels).
Next, a more detailed structure of the liquid ejection head 1 using the head module 10 and a plurality of head modules 10 will be described.

FIG. 3 is a plan view showing the module frame 11 of the head module 10 in the liquid ejection head 1 shown in FIG.
As shown in FIG. 3 (a), the module frame 11 is formed in a substantially rectangular shape when viewed in a plan view, and engaging portions 11a cut out in a substantially L shape at both left and right ends thereof. have. The module frame 11 is made of, for example, stainless steel having a thickness of about 0.5 mm. In the present embodiment, substantially rectangular head chip arrangement holes 11b are formed at eight locations. The head chip arrangement hole 11b has a hole shape slightly larger than the outer shape of the head chip 20 (see FIG. 2) so that the head chip 20 can be arranged completely inside.

  Further, the module frame 11 is formed with two mounting holes 11d for screwing and fixing to the head frame 2 shown in FIG. 1, and the head module 10 is attached to the head frame 2 through the mounting holes 11d. ing. Furthermore, a groove 11c (a hatched portion in FIG. 3A) is formed so as to surround a part of the outer edge portion of each head chip arrangement hole 11b. Then, an adhesive 14 is applied (printed) as shown in FIG. 3B to the area surrounded by the periphery of the head chip arrangement hole 11b and the groove 11c, and as shown in FIG. A nozzle sheet 25 in which a plurality of nozzles 25 a is formed is attached to the module frame 11. The area of the adhesive 14 has a size that substantially matches the outer edge of the nozzle sheet 25 when the nozzle sheet 25 is adhered. 11c enters and is absorbed by the groove 11c.

  Furthermore, by sticking the nozzle sheet 25, a part of the region of the head chip arrangement hole 11b is covered. The nozzle sheet 25 is formed to a minimum size necessary to be supported by the module frame 11, and when the nozzle sheet 25 is stuck on the head chip arrangement hole 11b, the head chip arrangement hole is formed. 11b and the size that exists only in the application range of the adhesive 14. That is, the nozzle sheet 25 is formed in the minimum necessary size so as to cover a necessary part of the region of the head chip arrangement hole 11b and to have a minimum adhesion area.

  Each nozzle 25a formed in such a nozzle sheet 25 is one in which a number of through holes corresponding to the number of heating resistors 22 in one head chip 20 shown in FIG. The hole is tapered so that the opening diameter gradually decreases as it approaches the ink ejection surface (the outer surface of the nozzle sheet 25). Further, the pitch between the nozzles 25a of the nozzle 25a row located in each head chip arrangement hole 11b is the same as the arrangement pitch of the heating resistors 22 of the head chip 20 (in the case of forming the head module 10 having a resolution of 600 dpi). , About 42.3 μm).

  Furthermore, the nozzle 25a row in each head chip arrangement hole 11b is drawn in parallel with the longitudinal direction of the module frame 11 when considering a line connecting the nozzle 25a row (a line passing through the center of each nozzle 25a). It is on the center line side of the module frame 11. Then, assuming that each head chip placement hole 11b is “N1”, “N2”, “N3”,..., “N8” in order from the left side, “N1”, “N3”, “N5”, and The rows of nozzles 25a in the “N7” -th head chip arrangement hole 11b are aligned on a straight line parallel to the center line, and the “N2”, “N4”, “N6”, and “N8” -th rows are arranged. The relationship is similar.

  Therefore, the nozzle 25a rows in the adjacent head chip arrangement holes 11b (for example, the nozzle 25a rows in the “N1” -th and “N2” -th head chip arrangement holes 11b) are two straight lines parallel to the center line. Align on top. In the present embodiment, eight head chip arrangement holes 11b are formed for one module frame 11, but even when more or fewer head chip arrangement holes 11b are formed, Try to satisfy the relationship.

  Then, the head chips 20 in which the barrier layers 24 (see FIG. 2) are stacked are arranged and fixed in a staggered manner in each head chip arrangement hole 11b. Thus, the head chip 20 on which the barrier layer 24 is formed is arranged in the head chip arrangement hole 11b, and the nozzle sheet 25 and the head chip 20 are bonded to each other, so that the nozzle sheet 25 on the head chip 20 side is bonded. The ink liquid chamber 26 is formed by the surface, the barrier layer 24, and the surface on which the heating resistor 22 of the head chip 20 is formed. Here, when the head chip 20 is placed in the head chip placement hole 11b, the head chip 20 is placed with an accuracy of about ± 1 μm, for example, so that the nozzle 25a is positioned directly below the heating resistor 22 of the head chip 20.

  By the way, in the state where the head chip 20 is adhered to the nozzle sheet 25, the electrode 23 of the head chip 20 is exposed to the outside without being hidden by the nozzle sheet 25. Therefore, in this exposed portion, the electrode 23 provided on the head chip 20 side and the flexible wiring board 3 are joined (electrically connected).

FIG. 4 is a perspective view showing the periphery of the head chip 20 of the head module 10 in the liquid discharge head 1 shown in FIG. 1, as viewed from the ink discharge surface side. In FIG. 4, a part of the flexible wiring board 3 is turned over for easy understanding of the drawing.
FIG. 5 is a plan view showing the head module 10 in the liquid discharge head 1 shown in FIG. 1, as viewed from the ink discharge surface side. In FIG. 5, the front side (ink ejection surface side) is the attachment surface side of the nozzle sheet 25, but for ease of understanding of the drawing, the head chip 20 attached from the opposite surface is shown. It is shown by a solid line (hatched part).

  As shown in FIG. 4, the flexible wiring board 3 is bonded to the module frame 11 on the ink ejection surface side. The flexible wiring board 3 is for electrically connecting the electrode 23 of the head chip 20 in the head chip arrangement hole 11b and a control board 4 (not shown) described later. It has a so-called sandwich structure that is sandwiched from both sides by, for example, and has flexibility. Then, as shown in FIG. 5, two flexible wiring boards 3 are attached to one head module 10. The head chips 20 are arranged in two rows of four, but in this embodiment, one flexible wiring board 3 is attached in each row, and as shown in FIG. One end side of the wiring pattern 3 a formed on the flexible wiring board 3 is bonded to the electrode 23 of the head chip 20.

  At this time, the nozzle sheet 25 and the flexible wiring board 3 are adjacently bonded and fixed on the module frame 11 so that the bonding of the electrode 23 is not easily released. However, since the cross-section of the wiring pattern 3a is exposed at the tip of the flexible wiring board 3 in the manufacturing process, there is a possibility of short-circuiting between the wiring patterns 3a when contacting the nozzle sheet 25. Therefore, the exposed surface (cross section) of the wiring pattern, which is the outer edge of the flexible wiring board 3, is brought close to the outer edge of the nozzle sheet 25, but there is a slight gap between the two, and the gap is formed in the resin 30 (see FIG. 2). ).

  On the other hand, as shown in FIG. 5, the other end side of the wiring pattern 3a of each flexible wiring board 3 is inserted into a connector 4a (not shown) of a control board 4 to be described later (a terminal part in the present invention). Equivalent). And the insertion terminal part 3b of each flexible wiring board 3 is arrange | positioned so that it may become a position mutually shifted between each flexible wiring board 3. FIG. That is, each flexible wiring board 3 has an asymmetric outer shape in the vertical and horizontal directions, but has the same shape and is arranged point-symmetrically with the insertion terminal portion 3b facing outward.

  As described above, the two flexible wiring boards 3 are arranged point-symmetrically on the ink ejection surface side of the head module 10. Further, a buffer tank 12 (see FIG. 2) is joined to the opposite side of the head module 10 so as to cover the upper part of the head chip 20.

6 is a plan view showing the head module 10 in the liquid ejection head 1 shown in FIG. 1, and is a view seen from the surface opposite to FIG.
Here, the buffer tank 12 is a tank for temporarily storing ink supplied from an ink cartridge (not shown), and one buffer tank 12 is provided for one head module 10. When viewed in the plan view shown in FIG. 6, the buffer tank 12 has a shape substantially equivalent to that of the module frame 11. As shown in FIG. The side wall and the top wall are formed to have the same thickness, and the cross section is formed in a substantially inverted concave shape. Therefore, a hollow ink flow path 27 (halftone dot portion in FIG. 2) is formed inside the buffer tank 12, and becomes a supply source of ink to the ink liquid chamber 26.

  When such a buffer tank 12 is mounted on the module frame 11, all the head chip arrangement holes 11b (see FIG. 5) are covered. As shown in FIG. 2, the inside of the buffer tank 12 and the ink liquid chamber 26 of each head chip 20 communicate with each other via a flow path 27 between the module frame 11 and the head chip 20. Thereby, the buffer tank 12 forms an ink flow path common to all the head chips 20 in the head module 10 and temporarily stores the ink to be supplied to the ink liquid chamber 26. In the present embodiment, the buffer tank 12 is also a rigid support member for fixing the module frame 11.

  Furthermore, one liquid discharge head 1 is formed by using a plurality of such head modules 10. That is, as shown in FIG. 1, a rigid head frame 2 is formed with a head module arrangement hole 2a, and eight head modules 10 are arranged in this head module arrangement hole 2a in this embodiment. (Two head modules 10 are connected in series, and the head modules 10 connected in series are arranged in four stages). Each head module 10 is screwed to the head frame 2 by screws 5 and positioned.

  At this time, as shown in FIG. 6, the two flexible wiring boards 3 arranged symmetrically with respect to each other with the insertion terminal portion 3 b facing outward are bent upward along the side surface of the buffer tank 12. That is, since each flexible wiring board 3 of the head module 10 has flexibility, it can be bent easily. Then, the head module 10 in a state in which each flexible wiring board 3 is bent is arranged in the head module arrangement hole 2a.

FIG. 7 is a plan view showing a state in which all the head modules 10 shown in FIG. 6 are arranged in the head module arrangement hole 2a of the head frame 2, and is a view seen from the surface opposite to FIG.
As shown in FIG. 7, each head module 10 disposed in the head module disposition hole 2 a has each flexible wiring board 3 bent along the side surface of the buffer tank 12, so that one head module 10 is Two flexible wiring boards 3 (hatched portions in FIG. 2) extend perpendicular to the paper surface.

  Each of the flexible wiring boards 3 extending vertically is in a state where the respective insertion terminal portions 3b are exposed, but the insertion terminal portions 3b are point-symmetric so as to be shifted from each other between the respective flexible wiring substrates 3. Is arranged. Therefore, even if all the head modules 10 are arranged in the head module arrangement hole 2a, as shown in FIG. 7, the insertion terminal portions 3b of the flexible wiring board 3 in each stage of the head module 10 interfere with each other. There is no.

  Further, as shown in FIG. 7, ink supply holes 12 a are formed in the top wall of each buffer tank 12. Ink is supplied into the buffer tank 12 from an ink cartridge (not shown) through the ink supply hole 12a. Furthermore, a control board 4 (not shown) that is screwed into the screw hole 2b of the head frame 2 is disposed on the top wall side of the buffer tank 12 so as to cover all the buffer tanks 12.

FIG. 8 is a plan view showing the control board 4 attached to the inside of the head frame 2 shown in FIG.
Here, the control board 4 is for controlling the ejection of ink and the like. In order to connect the insertion terminals 3b of the flexible wiring board 3 shown in FIG. A connector 4a having an openable / closable lid is provided. Further, in the vicinity of the connector 4a, a notch portion 4b through which the insertion terminal portion 3b of the flexible wiring board 3 is passed is formed.

  The connector 4a and the notch 4b are provided in each row corresponding to the two flexible wiring boards 3 of one head module 10 shown in FIG. Therefore, in total, there are 16 connectors 4a and 16 notches 4b corresponding to the two in-line × four-stage head modules 10. The two connectors 4a in each row are arranged side by side in the longitudinal direction of each module frame 11 (see FIG. 6), and are oriented in directions different from each other by 180 °.

  Further, the control board 4 has an opening 4c and a connection port 4d formed in a portion facing the ink supply hole 12a (see FIG. 7). Four openings 4c are formed corresponding to the central portion of the four-stage head module 10, and four connection ports 4d are provided corresponding to both ends of the four-stage head module 10, respectively. A total of eight are formed. The control board 4 is screwed to the screw hole 2b of the head frame 2 in the state shown in FIG. 7 by the screw hole 4e.

FIG. 9 is a plan view showing the liquid discharge head 1 shown in FIG. 1, and is a view seen from the surface opposite to FIG.
As shown in FIG. 9, the control board 4 is screwed to the head frame 2 by screws 6. At this time, the insertion terminal portion 3b of the flexible wiring board 3 having flexibility passes through the notch portion 4b of the control board 4 and comes out from the lower side to the upper side of the control board 4, and is connected to the connector 4a. Therefore, each head module 10 (see FIG. 1) is electrically connected to the control board 4 behind the flexible wiring board 3.

  Here, the two connectors 4a to which the two flexible wiring boards 3 of each head module 10 are connected are arranged side by side in the longitudinal direction of the module frame 11 (see FIG. 6) of the head module 10 as described above. It is connected to each connector 4a with the insertion terminal portions 3b of the two flexible wiring boards 3 facing inward. That is, in order to connect the insertion terminal portion 3b of the flexible wiring board 3 to the connector 4a, the insertion terminal portion 3b may be pinched with a finger, bent inward, and inserted into the connector 4a. Then, the insertion terminal portion 3b is easily inserted into the connector 4a, and the connection is completed.

  Further, all the ink supply holes 12 a of the buffer tank 12 shown in FIG. 7 are exposed to the outside without being hidden by the control board 4 by the openings 4 c and the connection ports 4 d of the control board 4. Therefore, if both ends of the U-shaped tube 13 and one end of the ink supply pipe 14 are inserted from the outside of the control substrate 4 for each stage of the buffer tank 12, ink is supplied to the buffer tank 12 of each stage. Become. Then, two buffer tanks 12 connected in series are used as one stage, and an A4-compatible line head is formed. By arranging two buffer tanks 12 arranged in series in four stages, Y, M, C, and K Thus, a color line head corresponding to the four colors (color) is formed. If the U-shaped tube 13 and the ink supply tube 14 are pulled out, each head module 10 can be removed while the control board 4 is screwed to the head frame 2.

  As described above, in the liquid ejection head 1 of the present embodiment, each head module 10 has two identical flexible wiring boards 3 having an asymmetric outer shape in the vertical and horizontal directions, and the two flexible wiring boards 3 are inserted. The terminal portions 3b are arranged symmetrically with respect to each other with the terminal portions 3b facing outward. Therefore, the flexible wiring boards 3 extending from the adjacent head modules 10 are connected at regular intervals in a very limited space of the control board 4 without overlapping in the connector 4a and the notch portion 4b of the control board 4. As a result, each flexible wiring board 3 can be inserted without taking up space for installing the wiring of the control board 4 and various mounting parts (capacitors, etc.) and without interfering with the wiring of the control board 4 and the mounting parts. The terminal portion 3 b can be connected to the connector 4 a of the control board 4.

  Further, when each head module 10 is arranged in the head module arrangement hole 2 a of the head frame 2, the flexible wiring board 3 necessary for connecting the insertion terminal portion 3 b of the flexible wiring board 3 to the connector 4 a of the control board 4 is used. Extra dimensions and useless space can be eliminated as much as possible, and crosstalk between the flexible wiring boards 3 and the control board 4, generation of unnecessary radiation, signal waveform distortion, and the like can be prevented. Furthermore, since the excessive dimension of the flexible wiring board 3 does not occur, the cost can be suppressed and the dimensions of the flexible wiring board 3 can be made uniform, so that the manufacturing efficiency of the liquid ejection head 1 is improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications as described below are possible, for example.
(1) In the present embodiment, each head module 10 has two identical flexible wiring boards 3 having asymmetric outer shapes in the vertical and horizontal directions, and the two flexible wiring boards 3 have the insertion terminal portions 3b on the outside. They are arranged symmetrically with respect to each other. However, the present invention is not limited to this, and a plurality of flexible wiring boards 3 having various shapes can be arranged as long as the insertion terminal portions 3b are shifted between the flexible wiring boards 3.

  (2) In this embodiment, the connectors 4 a of the control board 4 are arranged side by side in the longitudinal direction of the module frame 11 in each head module 10. In addition, the insertion terminal portion 3 b is connected to the connector 4 a of the control board 4 with the insertion terminal portion 3 b facing inward between the flexible wiring boards 3. However, the present invention is not limited thereto, and the connector 4a can be variously arranged, and the insertion terminal portion 3b can be connected toward the connector 4a (for example, toward the outside).

FIG. 2 is a plan view illustrating a liquid discharge head according to an embodiment of the present invention, as viewed from the ink discharge surface side. FIG. 2 is a cross-sectional view showing the periphery of a head chip of a head module in the liquid discharge head shown in FIG. 1. FIG. 2 is a plan view showing a module frame of a head module in the liquid ejection head shown in FIG. 1. FIG. 2 is a perspective view showing the periphery of a head chip of a head module in the liquid discharge head shown in FIG. 1, as viewed from the ink discharge surface side. FIG. 2 is a plan view showing a head module in the liquid ejection head shown in FIG. 1, as viewed from the ink ejection surface side. FIG. 6 is a plan view showing a head module in the liquid ejection head shown in FIG. 1, as viewed from the opposite side of FIG. 5. It is the top view which shows the state which has arrange | positioned all the head modules shown in FIG. 6 in the head module arrangement | positioning hole of a head frame, and is the figure seen from the surface on the opposite side to FIG. It is a top view which shows the control board attached to the inner side of the head frame shown in FIG. FIG. 2 is a plan view showing the liquid ejection head shown in FIG. 1, as viewed from the surface opposite to FIG. 1.

Explanation of symbols

1 Liquid ejection head 3 Flexible wiring board (wiring board)
3a Wiring pattern (wiring)
3b Insertion terminal (terminal part)
4 Control board 4a Connector 10 Head module 11 Module frame 11b Head chip placement hole 20 Head chip 21 Semiconductor substrate (board)
22 Heating resistor (energy generating element)
23 Electrode 24 Barrier layer 25 Nozzle sheet 25a Nozzle 26 Ink liquid chamber (liquid chamber)

Claims (8)

An energy generating element is disposed on the substrate, and a barrier layer for forming a liquid chamber around the energy generating element is provided on the surface of the substrate where the energy generating element is disposed, and the control substrate is electrically A plurality of head chips provided with electrodes for connection to
A nozzle sheet on which nozzles for discharging the liquid in the liquid chamber are formed;
A plurality of wiring boards having wiring for electrically connecting the electrodes of each of the head chips and the connector of the control board;
A head module that discharges the liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the liquid chamber by the energy generating element;
In each of the wiring boards, one end side of the wiring is electrically connected to the electrode of each head chip, and the other end side is a terminal portion for the connector of the control board,
The head module, wherein the terminal portions of the wiring boards are arranged so as to be shifted from each other between the wiring boards. The head module according to claim 1,
Each of the wiring boards is flexible. A head module. The head module according to claim 1,
Each of the wiring boards has the same shape, and is arranged symmetrically with respect to each other with the terminal portions of the wiring boards facing outward. The head module according to claim 1,
Each of the wiring boards has an asymmetric outer shape in the vertical and horizontal directions. Multiple head modules;
And a control board provided with a plurality of connectors for electrically connecting each of the head modules,
Each of the head modules
An energy generating element is disposed on the substrate, and a barrier layer for forming a liquid chamber around the energy generating element is provided on a surface of the substrate on which the energy generating element is disposed, A plurality of head chips provided with electrodes for connecting electrically,
A nozzle sheet on which nozzles for discharging the liquid in the liquid chamber are formed;
A plurality of wiring boards having wirings for electrically connecting the electrodes of the head chips and the connectors of the control board;
A liquid discharge head for discharging the liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the liquid chamber by the energy generating element;
Each wiring board of each head module has one end of the wiring electrically connected to the electrode of each head chip, and the other end serving as a terminal portion for each connector of the control board,
The liquid discharge head according to claim 1, wherein the terminal portions of the wiring boards are arranged so as to be shifted from each other between the wiring boards. The liquid ejection head according to claim 5, wherein
Each of the head modules includes a module frame in which a head chip arrangement hole for accommodating each of the head chips is formed,
The connectors of the control board are arranged side by side in the longitudinal direction of the module frames. The liquid ejection head according to claim 5, wherein
Each of the wiring boards of each of the head modules is connected to each of the connectors of the control board with the terminal portion facing inward. Multiple head modules;
And a control board provided with a plurality of connectors for electrical connection with each of the head modules,
Each of the head modules
An energy generating element is disposed on the substrate, and a barrier layer for forming a liquid chamber around the energy generating element is provided on a surface of the substrate on which the energy generating element is disposed, A plurality of head chips provided with electrodes for connecting electrically,
A nozzle sheet on which nozzles for discharging the liquid in the liquid chamber are formed;
A plurality of wiring boards having wirings for electrically connecting the electrodes of the head chips and the connectors of the control board;
A liquid discharge device that discharges the liquid in the liquid chamber from the nozzle by applying a discharge force to the liquid in the liquid chamber by the energy generating element;
Each wiring board of each head module has one end of the wiring electrically connected to the electrode of each head chip, and the other end serving as a terminal portion for each connector of the control board,
The liquid ejecting apparatus according to claim 1, wherein the terminal portions of the wiring boards are arranged so as to be shifted from each other between the wiring boards.

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