Print head unit, print head, and control board

Abstract

To provide a print head that can be controlled even with high current. [Solution] A print head that receives a drive signal from a drive circuit and ejects liquid, comprising a connection portion to which a card edge of a printed circuit board that supplies the drive signal to the print head is connected, and the drive signal is supplied from the printed circuit board connected to the card edge via the connection portion.

Description

Technical Field

[0001] The present invention relates to a print head unit, a print head, and a control board.

Background Art

[0002] Research and development have been conducted on liquid ejecting apparatuses that eject liquid onto a recording medium such as printing paper to form an image on the recording medium.

[0003] In relation to this, there is known a liquid ejecting apparatus in which a control board that supplies a drive signal to a print head and a flexible board of the print head are connected via an FFC (Flexible Flat Cable) connector, a BtoB connector, or the like (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problem to be Solved by the Invention

[0005] However, in the liquid ejecting apparatus as described in Patent Document 1, it is difficult to increase the rated current of the connector, and as a result, it may be difficult to supply a large current to the print head.

Means for Solving the Problem

[0006] One aspect of the print head according to the present disclosure is a print head that ejects liquid upon receiving supply of a drive signal from a drive circuit, comprising: a connection portion to which a card edge of a control board that supplies the drive signal to the print head is connected, wherein the drive signal is supplied from the control board connected via card edge connection through the connection portion.

[0007] Furthermore, one embodiment of the control board according to the present disclosure is a control board having a drive circuit and supplying a drive signal from the drive circuit to a print head, a printed circuit board electrically connected to the print head, and a card edge connected to the connection portion of the print head. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an example of the schematic configuration of printer 1000. [Figure 2] Figure 1 is a schematic exploded perspective view of the inkjet recording head 100. [Figure 3] This figure shows a schematic exploded perspective view of the print head unit 30 shown in Figure 2. [Figure 4] This is a cross-sectional view of the main parts illustrating the print head unit 30 and the cover case 40. [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below with reference to the drawings. Note that, in order to make the explanation easier to understand, some parts of the drawings have been omitted or some components have been exaggerated.

[0010] The following description will explain the print head according to the embodiment, using the inkjet recording head 100 as an example of a print head, and will also explain the liquid ejection device according to the embodiment, using the printer 1000 as an example of an image recording device which is a liquid ejection device. Figure 1 shows an example of the schematic configuration of printer 1000. In Figure 1, the X direction indicates the main scanning direction in which the carriage 104 moves. Also in Figure 1, the Y direction indicates the sub-scanning direction in which the recording medium P is transported. Also in Figure 1, the Z direction is perpendicular to the X and Y directions.

[0011] In the example shown in Figure 1, the printer 1000 includes an inkjet recording head 100, a motor 103, a carriage 104, a carriage movement mechanism 105, a platen roller 106, and an ink cartridge 107.

[0012] The inkjet recording head 100 is mounted on the recording medium P side of the carriage 104 and sprays ink as droplets onto the surface of the recording medium P. The recording medium P side of the carriage 104 is the lower surface in the Z direction in Figure 1. The carriage movement mechanism 105 includes a timing belt 108, a drive pulley 111, a driven pulley 112, and a motor 109. The timing belt 108 is locked to the carriage 104 and is stretched between the drive pulley 111 and the driven pulley 112. The drive pulley 111 is connected to the output shaft of the motor 109. Therefore, when the motor 109 is activated, the carriage 104 is guided by the guide rod 110 installed on the printer 1000 and moves back and forth in the X direction, which is the main scanning direction.

[0013] The platen roller 106 receives driving force from the motor 103 and moves the recording medium P in the Y direction, which is the sub-scanning direction. The ink cartridge 107 stores ink and is detachably mounted on the carriage 104. The ink cartridge 107 supplies ink to the inkjet recording head 100. Ink is an example of the liquid that the inkjet recording head 100 ejects onto the recording medium P, and any colored liquid other than ink may be used.

[0014] In this configuration, the printer 1000 can record images or the like on recording paper or the like by moving the carriage 104 back and forth in the X direction using the carriage movement mechanism 105, and while transporting the recording medium P in the Y direction using the platen roller 106, spraying ink as droplets from the inkjet recording head 100 attached to the carriage 104.

[0015] Figure 2 is a schematic exploded perspective view of the inkjet recording head 100 shown in Figure 1. Figure 2 also shows the X direction of the main scanning direction, the Y direction of the sub-scanning direction, and the Z direction which is perpendicular to the X and Y directions. In the example shown in Figure 2, the inkjet recording head 100 includes a mounting plate 10, a case head 20, a print head unit 30, and a cover case 40. The print head unit 30 is positioned at the bottom of the case head 20. The print head unit 30 is then housed in the cover case 40. Although only one print head unit 30 and one cover case 40 are depicted, a configuration combining multiple units is also possible.

[0016] The mounting plate 10 has a needle 11 that guides ink from the ink cartridge 107 shown in Figure 1, a filter 12 that filters the ink, and the like. The case head 20 also has a case head side board 13 for connecting the flexible circuit board 37, which will be described later.

[0017] The case head side board 13 is a printed circuit board (PCB) electrically connected to the print head unit 30 and functions as a control board that supplies drive signals to the print head unit 30. For this reason, the case head side board 13 is provided with a drive circuit (not shown) that generates drive signals to be supplied to the print head unit 30. Furthermore, the case head side board 13 is the printed circuit board that is closest to the print head unit 30 in terms of current path among the printed circuit boards electrically connected to the print head unit 30.

[0018] The case head-side substrate 13 is electrically connected to the print head unit 30 via a relay substrate that performs relay connection. The relay substrate may be any substrate as long as it can electrically connect the case head-side substrate 13 and the print head unit 30. For this reason, the relay substrate is omitted in FIG. 2. Note that the case head-side substrate 13 may be configured to be electrically connected directly to the print head unit 30 without going through the relay substrate. As described above, the case head-side substrate 13 is electrically connected to the print head unit 30. Therefore, a drive signal is supplied to the print head unit 30 from the case head-side substrate 13.

[0019] The case head-side substrate 13 has a card edge 21 that is card-edge-connected to a relay substrate that relays the electrical connection between the print head unit 30 and the case head-side substrate 13. Accordingly, the relay substrate is provided with a connection portion to which the card edge 21 is connected. Note that, in a case where the case head-side substrate 13 is directly connected to the print head unit 30 without the relay substrate interposed therebetween, the print head unit 30 includes a connection portion to which the card edge 21 is connected. In this case, the case head-side substrate 13 is card-edge-connected to the print head unit 30 via the card edge 21.

[0020] On the front surface and the back surface of the card edge 21, connection terminals that are card-edge-connected to the connection portion of the relay substrate or the connection portion of the print head unit 30 are provided. At least a part of the connection terminals of the card edge 21 may be configured to be gold-plated or may be configured not to be gold-plated. Further, at least a part of the connection terminals of the connection portion of the relay substrate, or at least a part of the connection terminals of the connection portion of the print head unit 30 may be configured to be gold-plated or may be configured not to be gold-plated.

[0021] Further, the card edge 21 is provided at an end portion of the case-head-side substrate 13. In the example shown in Fig. 2, the card edge 21 is provided at the end portion on the positive X-direction side among the end portions of the case-head-side substrate 13. Further, the card edge 21 may be configured integrally with the case-head-side substrate 13, or may be configured separately from the case-head-side substrate 13.

[0022] The ink jet recording head 100 is connected via the card edge 21 to the case-head-side substrate 13 and the relay substrate or print head unit 30 through card edge connection. Therefore, compared with a case where the case-head-side substrate 13 is connected to the relay substrate or print head unit 30 via an FFC (Flexible Flat Cable) connector or the like, control can be performed even with a large current. In addition, compared with connection via an FFC connector or the like, card edge connection provides more stable contact between contacts, and can reduce the occurrence of short circuits, incorrect insertion, and the like.

[0023] Fig. 3 is a schematic exploded perspective view of the print head unit 30 shown in Fig. 2. Fig. 4 is a cross-sectional view of essential parts for explaining the print head unit 30 and a cover case 40. Figs. 3 and 4 also respectively show the X direction as the main scanning direction, the Y direction as the sub-scanning direction, and the Z direction orthogonal to the X direction and the Y direction. In Figs. 3 and 4, the print head unit 30 has a nozzle plate 31 at a position facing the recording medium P shown in Fig. 1. A plurality of nozzle openings 310 for ejecting ink are formed in the nozzle plate 31. Each of the plurality of nozzle openings 310 is provided at a pitch corresponding to the dot formation density. Ink is ejected from the print head unit 30 by being discharged from each nozzle opening 310. The nozzle opening 310 is an example of a discharge portion. A flow path forming substrate 32 for supplying ink to the nozzle plate 31, a vibration plate 33, a reservoir plate 34, and a compliance substrate 35 are stacked on the nozzle plate 31.

[0024] The channel-forming substrate 32 is provided with through holes that form a pressure generating chamber 320, an ink supply path 321 that communicates with the pressure generating chamber 320, and a communication passage 322. The cross-sectional shape of the pressure generating chamber 320 in the X direction is rectangular. In Figures 3 and 4, the X direction is the width direction perpendicular to the Y direction, which is the longitudinal direction of the inkjet recording head 100. The pressure generating chamber 320 is formed to be long in the X direction, which is the width direction of the inkjet recording head 100. For this reason, in the following explanation, the X direction may be referred to as the longitudinal direction of the pressure generating chamber 320. The cross-sectional shape of the pressure generating chamber 320 in the X direction is not limited to rectangular; it may be other shapes, such as a trapezoid.

[0025] Furthermore, a communication passage 322 is formed in the longitudinally outer region of the pressure generating chamber 320 of the flow path forming substrate 32. The communication passage 322 and each pressure generating chamber 320 are connected via an ink supply passage 321, which serves as a liquid supply passage provided in each pressure generating chamber 320. The ink supply passage 321 is formed with a narrower width than the pressure generating chamber 320, thereby maintaining a constant flow resistance for the ink flowing from the communication passage 322 into the pressure generating chamber 320.

[0026] The diaphragm 33 is laminated on the flow path forming substrate 32 and constitutes part of the pressure generating chamber 320. A piezoelectric element 36 that exhibits flexural vibration when a voltage is applied is formed on the diaphragm 33. In Figure 3, the piezoelectric element 36 comprises a lower electrode 360 ​​grounded by a common electrode, a piezoelectric body 361, and an upper electrode 362 as an individual electrode. The piezoelectric elements 36 are formed on the surface of the diaphragm 33 opposite to the pressure generating chamber 320, with the diaphragm 33 in between, so as to cover the pressure generating chamber 320, and are arranged in rows in the direction of the nozzle row corresponding to each pressure generating chamber 320.

[0027] For the lower electrode 360, for example, metals such as platinum and iridium, or metal oxides such as lanthanum nickelate (LNO) and strontium ruthenate (SrRuO) can be used. For the upper electrode 362, for example, metals such as platinum and iridium can be used. These electrodes can be formed by sputtering, vapor deposition, or the like.

[0028] Lead zirconate titanate can be used as the piezoelectric element 361. As a method for manufacturing the piezoelectric 361 film, a so-called sol-gel method can be used, in which a so-called sol, in which a metal-organic substance is dissolved and dispersed in a catalyst, is applied and dried to gel, and then fired at a high temperature to obtain a piezoelectric 361 film made of a metal oxide. Furthermore, the method for manufacturing the piezoelectric material 361 film is not limited to the sol-gel method, but may also be the MOD (Metal-Organic Decomposition) method, for example. Also, the method for manufacturing the piezoelectric material 361 film is not limited to these liquid-phase methods, but may also be the method for manufacturing the piezoelectric material 361 film using a deposition method such as sputtering.

[0029] The nozzle plate 31, the channel forming substrate 32, and the diaphragm 33 are made of ceramic plates such as alumina and zirconia. The nozzle plate 31, the channel forming substrate 32, and the diaphragm 33 are connected by integral firing. Conductive ceramics are used for the diaphragm 33. Insulating ceramics are used for the nozzle plate 31 and the channel forming substrate 32. The diaphragm 33 is grounded. Grounding of the diaphragm 33 can be done via the printer 1000. Since the diaphragm 33 is conductive and grounded, it can be used as a common electrode for the piezoelectric element 36. In this embodiment, the diaphragm 33 can be used as the lower electrode 360. Conductive ceramics can be made by dispersing conductive particles in insulating ceramics such as alumina or zirconia. For example, silicon particles can be used as the conductive particles.

[0030] The nozzle plate 31, the channel forming substrate 32, and the diaphragm 33 can be integrally fired by the following method. For example, the green sheet is subjected to processing such as cutting and punching to form the necessary through holes, etc., thereby forming the sheet-like precursors of the nozzle plate 31, the flow path forming substrate 32, and the diaphragm 33. The green sheet is an unfired sheet material. Then, by stacking and firing each sheet-like precursor, the sheet-like precursors are integrated to form a single ceramic sheet. In this case, since each sheet-like precursor is fired as a single unit, no special bonding treatment is required. Furthermore, the integrated firing of each sheet-like precursor can also provide high sealing performance at the joint surfaces of each sheet-like precursor.

[0031] In Figure 4, the reservoir plate 34 has a piezoelectric element holding portion 340 for protecting the piezoelectric element 36, and a through hole that forms a reservoir portion 341 communicating with the communication passage 322, and is bonded to the diaphragm 33. The communication passage 322 and the reservoir portion 341 together are called a manifold. A compliance substrate 35 is bonded to the side of the compliance substrate 35 opposite to the side bonded to the diaphragm 33. The region of the compliance substrate 35 corresponding to the reservoir portion 341 is composed of a flexible film 352 that absorbs pressure fluctuations generated in the manifold.

[0032] In the example shown in Figure 3, the flexible substrate 37 is connected to the lower electrode 360 ​​and upper electrode 362 of the piezoelectric element 36 through the reservoir plate 34 and the compliance substrate 35. A COF (Chip On Film) substrate can be used for the flexible substrate 37. The flexible circuit board 37 is electrically connected to the case head side board 13, which is located on the case head 20 shown in Figure 2, via an intermediate board, and power is supplied from the case head side board 13 to the flexible circuit board 37. A drive circuit 370 is mounted on the flexible circuit board 37, which controls the selective supply of drive signals from the case head side board 13 shown in Figure 2 to the piezoelectric element 36. In other words, the drive circuit provided on the case head side board 13 also supplies a selection signal to the drive circuit 370 to select which of the multiple nozzle openings 310 from which ink will be ejected.

[0033] In the inkjet recording head 100, when voltage is applied to the piezoelectric vibrator, the piezoelectric element 36 flexes and vibrates, and this vibration causes ink to be ejected from the nozzle opening 310 of the nozzle plate 31.

[0034] According to the embodiments described above, the following effects can be obtained. (1) The inkjet recording head 100 is connected to the relay board or print head unit 30 via a card edge connection, and can therefore be controlled even by high currents.

[0035] (2) Since the inkjet recording head 100 is connected to the relay board or print head unit 30 via a card edge connection, the occurrence of short circuits, incorrect insertions, etc. can be reduced.

[0036] (3) The charge accumulated on the insulating nozzle plate 31 flows through the ink filling the pressure generating chamber 320 from the nozzle opening 310 and reaches the diaphragm 33. The charge that reaches the diaphragm 33 escapes through the diaphragm 33 because the diaphragm 33 is made of conductive ceramics and the diaphragm 33 is grounded. Therefore, the inkjet recording head 100 can suppress damage to the drive circuit 370 due to the inflow of accumulated charge.

[0037] (4) The inkjet recording head 100 uses the diaphragm 33 as the ground-side lower electrode 360, so there is no need to form a new electrode, resulting in a simple structure and ease of manufacture.

[0038] (5) The inkjet recording head 100 has a flow channel forming substrate 32 made of ceramics, a diaphragm 33, and a nozzle plate 31 which are fired together as a single unit. This reduces positional displacement between the flow channel forming substrate 32, the diaphragm 33, and the nozzle plate 31 due to thermal shrinkage, making assembly easier.

[0039] (6) A printer 1000 having the effects of (1) to (5) can be obtained.

[0040] In addition to the embodiments described above, various other modifications are possible. For example, the channel-forming substrate 32 may be made of conductive ceramics. In this case as well, the lower electrode 360 ​​and the diaphragm 33 can be used as common electrodes.

[0041] In the example described above, the case where the liquid ejection head is an inkjet recording head 100 was explained. However, the liquid ejection head of the present invention can also be used, for example, as a colorant ejection head used in the manufacture of color filters for liquid crystal displays, an electrode material ejection head used in electrode formation for organic EL displays, FEDs (surface-emitting displays), etc., or a bio-organic material ejection head used in the manufacture of biochips.

[0042] Although the printer 1000 has been described above as an example of a liquid ejection device according to the present invention, the liquid ejection device according to the present invention can also be used industrially. In this case, the liquid (liquid material) to be ejected can be various functional materials adjusted to an appropriate viscosity with a solvent or dispersion medium. In addition to image recording devices such as the exemplified printer, the liquid ejection device of the present invention can also be suitably used as a colorant ejection device used in the manufacture of color filters for liquid crystal displays, a liquid material ejection device used in the formation of electrodes and color filters for organic EL displays, FEDs (surface-emitting displays), electrophoretic displays, etc., and a bioorganic material ejection device used in the manufacture of biochips.

[0043] Furthermore, the items listed above may be combined in any way.

[0044] <Note> [1] A print head unit that receives a drive signal from a drive circuit and ejects liquid, comprising a connection portion to which a card edge of a control board that supplies the drive signal to the print head unit is connected, and the drive signal is supplied from the control board connected to the card edge via the connection portion. [2] The print head unit according to [1], wherein at least one of the connection terminals on the card edge and the connection terminals that connect to the connection terminals on the card edge at the connection portion are gold-plated. [3] The print head unit according to [1] or [2], wherein the front and back surfaces of the card edge are provided with connection terminals that are connected to the connection portion of the card edge. [4] The print head unit according to any one of [1] to [3], wherein the print head unit has a plurality of ejection parts for ejecting liquid, and the connection part receives a selection signal from the control board via the card edge to select which of the plurality of ejection parts to eject the liquid from. [5] A print head comprising a print head unit described in any one of items [1] to [4], and the control board. [6] A control board having a drive circuit and supplying a drive signal from the drive circuit to a print head unit, wherein the control board is electrically connected to the print head unit and has a card edge that is connected to the connection part of the print head unit, or a card edge that is connected to a relay board that relays the electrical connection between the print head unit and the control board.

[0045] Although embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may be modified, replaced, deleted, etc., as long as it does not deviate from the gist of this disclosure. [Explanation of Symbols]

[0046] 10…Mounting plate, 11…Needle, 12…Filter, 13…Case head side substrate, 20…Case head, 21…Card edge, 30…Print head unit, 31…Nozzle plate, 32…Flow path forming substrate, 33…Diaphragm, 34…Reservoir plate, 35…Compliance substrate, 36…Piezoelectric element, 37…Flexible substrate, 40…Cover case, 100…Inkjet recording head, 103…Motor, 104…Carriage, 105…Carriage 106…Platen roller, 107…Ink cartridge, 108…Timing belt, 109…Motor, 110…Mounted guide rod, 111…Drive pulley, 112…Driven pulley, 310…Nozzle opening, 320…Pressure generating chamber, 321…Ink supply path, 322…Connecting passage, 340…Piezoelectric element holder, 341…Reservoir, 352…Membrane, 360…Lower electrode, 361…Piezoelectric body, 362…Upper electrode, 370…Drive circuit, 1000…Printer

Claims

1. A print head unit that receives a drive signal from a drive circuit and ejects liquid, The control board that supplies the drive signal to the print head unit has a connection section to which the card edge is connected, The drive signal is supplied from the control board connected to the card edge via the aforementioned connection portion. Printhead unit.

2. At least one of the connection terminals on the card edge and the connection terminals that connect to the card edge at the connection portion is gold-plated. The print head unit according to claim 1.

3. The front and back surfaces of the card edge are provided with connection terminals that are connected to the connection portion of the card edge. The print head unit according to claim 1.

4. The print head unit has a plurality of ejection sections for ejecting liquid, The connection part receives a selection signal from the control board via the card edge to select which of the plurality of dispensing parts to dispense the liquid from. The print head unit according to claim 1.

5. A print head unit according to any one of claims 1 to 4, The control board and, A print head equipped with a print head.

6. A control board having a drive circuit and supplying a drive signal from the drive circuit to a print head unit, This is a printed circuit board that is electrically connected to the print head unit. The card edge is connected to the connection portion of the print head unit, or to a relay board that relays the electrical connection between the print head unit and the control board, Control board.

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