JP2005246903A - Inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance operation stability by suppressing the occurrence of a malfunction, that is, an abnormality in the ejection amount and ejection speed of ink, caused by a rise in the temperature of the ink in the recording head 6, without causing the upsizing of an apparatus, in the inkjet recorder which is equipped with the recording head 6 and a holder case 1 equipped with the recording head. <P>SOLUTION: A first hermetic space 31 is formed between the recording head 6 and a bottom part 5 of the holder case 1, and a second hermetic space 32, which is isolated from the hermetic space 31, is formed in one side part 7 of the holder case 1. A piezoelectric actuator 20, which is electrically connected to a cable 40, is arranged in the space 31, and an IC chip 41 on the cable 40 is arranged in the hermetic space 32. A wiring passage ranging from the hermetic space 31 to the hermetic space 32 is hermetic in a state that the cable 40 is arranged. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus including a recording head that records ink on a recording medium (for example, paper) by ejecting ink from a nozzle on the front surface, and a holder case on which the recording head is mounted.

  2. Description of the Related Art Conventionally, piezoelectric ink jet recording apparatuses are provided with a recording head for recording on a recording medium such as paper by ejecting ink from nozzles on the front surface.

  As an example of this type of recording head, in Patent Document 1, a piezoelectric actuator is joined to the back surface of the recording head, and a flexible flat cable is joined to the back surface of the piezoelectric actuator for electrical connection with an external device. The configuration is described.

  In Patent Document 1, a recording head is attached from below to a bottom plate of a substantially box-shaped holder case that opens upward. A protective cover is placed on the front surface of the recording head. The flexible flat cable extends from the gap between the bottom plate and the protective cover and is wired along the side plate of the holder case.

  A heat radiating member (heat sink) made of a metal plate is attached to the side plate of the holder case from the outside. Between the side plate and the heat radiating member, a driving circuit for driving a piezoelectric actuator attached to a midway portion of the flexible flat cable is disposed in close contact with the heat radiating member.

  A gap between the outer periphery of the protective cover and the bottom plate of the holder case and a gap between the outer periphery of the protective cover and the outer periphery of the heat dissipation member are sealed with a sealant. Moreover, the clearance gap between the outer periphery of a thermal radiation member and the side plate of a holder case is also sealed with the sealing agent.

According to this configuration, the piezoelectric actuator and the drive circuit are housed in a sealed state in a gap space surrounded by the holder case, the protective cover, and the heat dissipation member. This prevents ink, paper dust, dust and the like from adhering to the piezoelectric actuator and drive circuit.
Japanese Patent Laying-Open No. 2003-80793 (see FIG. 6)

  By the way, in the piezoelectric inkjet recording apparatus, the drive circuit on the flexible flat cable generates heat due to frequent driving of the recording head during printing. This heat is usually released to the outside through a heat dissipating member in close contact with the drive circuit.

  However, in the configuration of Patent Document 1, the gap space on the piezoelectric actuator (recording head) side communicates with the gap space on the drive circuit side, and the positional relationship between the printhead and the drive circuit is close. When the amount of heat generation is excessive and heat radiation by the heat radiating member cannot be sufficiently performed, the heat generated in the drive circuit may be transmitted to the recording head.

  As a result, the ink temperature in the recording head rises and the viscosity of the ink decreases, so that the ink discharge amount increases more than the set amount or the discharge speed becomes too fast. There is a possibility that the amount and the discharge speed cannot be obtained. For this reason, there was room for improvement from the viewpoint of operational stability and the like.

  As a measure for solving this problem, it is conceivable to simply increase the size of the heat dissipating member. However, this is not preferable because it is contrary to the recent demand for a compact recording head (and thus an ink jet recording apparatus).

  SUMMARY OF THE INVENTION Accordingly, it is a technical object of the present invention to provide an ink jet recording apparatus that solves the above-described problems and has improved operational stability without causing an increase in the size of the apparatus.

  In order to solve this technical problem, an invention according to claim 1 is an inkjet including a recording head for recording on a recording medium by discharging ink from a nozzle on the front surface, and a holder case to which the recording head is fixed. In the recording apparatus, an actuator that imparts ejection energy to the ink and a flexible flat cable that is electrically connected to the actuator are attached to the back surface of the recording head, and the flexible flat cable has a longitudinal middle portion. Has a drive circuit for driving the actuator, and a first sealed space is formed between the recording head and the bottom at the bottom of the holder case, and at the side of the holder case. Has a second sealed space spaced apart from the first sealed space, and the first sealed space includes the flange. The actuator electrically connected to the kibble flat cable is disposed, and the drive circuit on the flexible flat cable is disposed in the second sealed space, and the second sealed from the first sealed space. The wiring path leading to the space is sealed with the flexible flat cable disposed.

  According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the holder case has a heat radiating member for radiating heat of the drive circuit, and the heat radiating member opens the second sealed space. It constitutes at least a part of the side part to be defined.

  According to a third aspect of the present invention, in the inkjet recording apparatus according to the second aspect, the drive circuit on the flexible flat cable is sandwiched between a side portion of the holder case and the heat radiating member. It is in close contact with the heat dissipating member.

  According to a fourth aspect of the present invention, in the ink jet recording apparatus according to the third aspect, an elastic member is disposed in the second sealed space between the drive circuit and a side portion of the holder case, and the drive The circuit is pressed against the heat radiating member by the elastic member.

  A fifth aspect of the present invention is the ink jet recording apparatus according to any one of the second to fourth aspects, wherein the carriage is reciprocally movable in a direction perpendicular to a transport direction of the recording medium on which the holder case is mounted and transported. The heat dissipating member constitutes the outermost wall located on the outermost side of the holder case, and the wide surface thereof is disposed so as to be parallel or perpendicular to the moving direction of the carriage.

  According to the configuration of claim 1, the actuator electrically connected to the flexible flat cable is housed in a first sealed space formed at the bottom of the holder case, and the drive circuit on the flexible flat cable is It is stored in a second sealed space formed on the side of the holder case. And the wiring channel | path from the said 1st sealed space to the said 2nd sealed space is sealed in the state which has arrange | positioned the flexible flat cable.

  Accordingly, the inside of the first and second sealed spaces is maintained in an airtight state in which no gas or liquid enters or exits from the outside, so that foreign matters such as ink enter the first and second sealed spaces. Can be suppressed. Thereby, there is an effect that it is possible to eliminate a failure caused by the adhesion of the foreign matter such as an electrical short-circuit accident at a connection portion between the actuator and the flexible flat cable.

  On the other hand, since the first and second sealed spaces are separated from each other in the holder case, the heat generated by the drive circuit enclosed in the second sealed space is transmitted through the holder case and the like. Thus, it is difficult to reach the recording head on the first sealed space side. As a result, it is possible to remarkably suppress the occurrence of problems such as abnormal ink discharge amount and discharge speed due to an increase in the ink temperature in the recording head, and without increasing the size of the heat radiating member, There is an effect that the operational stability can be improved.

  If comprised like Claim 2, the said 2nd sealed space will be demarcated by making the heat radiating member for radiating the heat | fever of the said drive circuit into at least one part of the side part of the said holder case. In other words, the heat radiating member plays a role like a lid cover that defines the second sealed space in the side portion of the holder case. Thus, the holder case can be configured compactly without losing the heat radiation function of releasing the heat generated in the drive circuit to the outside, and the entire inkjet recording apparatus can be downsized. Play.

  According to the configuration of claim 3, since the drive circuit on the flexible flat cable is sandwiched between the side of the holder case and the heat dissipation member, the drive circuit is in close contact with the heat dissipation member. The heat generated by the circuit can be reliably transmitted to the heat radiating member. Therefore, it is possible to efficiently dissipate heat to the air outside the holder case, and there is an effect of contributing to stable driving of the driving circuit.

  The fourth aspect of the present invention further embodies the configuration of the third aspect. If comprised in this way, the said drive circuit can be closely_contact | adhered to the said heat radiating member by utilizing the elastic restoring force of the elastic member arrange | positioned between the said drive circuit and the side part of the said holder case. Therefore, although it is a simple structure, there exists an effect of contributing to the improvement of the heat dissipation effect from the said heat radiating member to the exterior.

  According to the fifth aspect of the present invention, the holder case is mounted on a carriage that can reciprocate in a direction orthogonal to the conveyance direction of the recording medium. Therefore, when recording (printing) on the recording medium, As the carriage reciprocates, the holder case and the heat dissipation member also move along the reciprocating direction. Then, since an air flow is formed around the outer surface of the heat radiating member, the heat radiating member is efficiently cooled by receiving the air flow, and the heat radiating effect from the heat radiating member to the outside is further improved. There is an effect.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 9 show a first embodiment of an ink jet printer to which the present invention is applied. 1 is a perspective view of an ink jet printer, FIG. 2 is a perspective view of a printer head, FIGS. 3 and 4 are exploded perspective views of the printer head, FIG. 5 is a sectional side view taken along line VV in FIG. FIG. 7 is an exploded perspective view of the recording head, FIG. 8 is an exploded perspective view of the cavity unit, and FIG. 9 is a partially enlarged exploded perspective view of the cavity unit.

  An ink jet printer P to which the present invention is applied includes, for example, an ink cartridge 61 filled with four color inks of cyan, magenta, yellow, and black, and a printer head 63 for recording on paper 62 as a recording medium. A carriage 64 on which the ink cartridge 61 and the printer head 63 are mounted, and a direction (main scanning direction, hereinafter referred to as X direction) perpendicular to the conveyance direction of the paper 62 (sub scanning direction, hereinafter referred to as Y direction). Drive unit 65, a platen roller 66 that extends in the reciprocating direction of the carriage 64 and that corresponds to the recording area by the printer head 63, and a purge device 67 (see FIG. 1). reference).

  The drive unit 65 is disposed at the lower end portion of the carriage 64 and extends in parallel with the platen roller 66, the guide plate 72 is disposed at the upper end portion of the carriage 64 and extends in parallel with the carriage shaft 71, and the carriage Between the shaft 71 and the guide plate 72, two pulleys 73 and 74 disposed at both ends of the carriage shaft 71 and a timing belt 75 wound around the pulleys 73 and 74 are configured.

  The carriage 64 joined to the timing belt 75 is linearly reciprocated while being supported by the carriage shaft 71 and the guide plate 72 by the rotational driving force of one pulley 73 that rotates according to the driving of the motor 76. It is configured.

  The paper 62 conveyed in the Y direction (sub-scanning direction) from a paper supply unit (not shown) is introduced between the platen roller 66 and the printer head 63 and ejected from the printer head 63 as will be described later. After a predetermined recording (printing) is performed, the paper is discharged.

  The purge device 67 is provided on the side of the platen roller 66 so as to face the printer head 63 when the printer head 63 is at the reset position. The purge device 67 includes a purge cap 81 that abuts against an opening surface of the nozzle 11a so as to cover a plurality of nozzles 11a (details will be described later) in the printer head 63, a pump 82 and a cam 83, and an ink storage unit. 84 and a cap 85.

  When the printer head 63 is at the reset position, the printer head 63 can be recovered by sucking the defective ink containing bubbles or the like accumulated inside the printer head 63 with the pump 82 driven by the cam 83. it can. The sucked defective ink is stored in the ink storage section 84.

  The cap 85 is provided at a position opposite to the platen roller 66 in the purge device 67. This covers a plurality of nozzles 11a (details will be described later) of the printer head 63 returned to the reset position when recording (printing) is completed in order to prevent ink from drying.

  A wiper member 86 is disposed adjacent to the purge device 67 at a position on the platen roller 66 side in the purge device 67. The wiper member 86 wipes the nozzle surface of the printer head 63 as the carriage 64 moves, and is formed in a spatula shape. When wiping the nozzle surface, the wiper member 86 protrudes upward, and when the nozzle surface is not wiped, it retracts downward.

  As shown in FIGS. 2 to 4, the printer head 63 includes two recording heads 6 that perform recording on a sheet 62 by ejecting ink from nozzles 11 a on the front surface (the upper surface in FIGS. 2 and 4 and the lower surface in FIG. 3). , 6 (head unit) and a synthetic resin holder case 1 (head holder) to which both the recording heads 6, 6 are mounted.

  The holder case 1 has a substantially box shape opened upward. This open space with an upward opening is a mounting portion 3 for mounting the ink cartridge 61. Ink is recorded from each ink cartridge 61 mounted on the mounting section 3 via ink supply passages 4a to 4d (details will be described later) for each color connected to the ink discharge section (not shown). It is supplied to the head 6.

  First, the configuration of the recording head 6 will be described with reference to FIGS.

  The recording head 6 includes a cavity unit 10 configured by laminating a plurality of metal plates, and a plate-type piezoelectric actuator 20 joined to the back surface (upper surface) of the cavity unit 10 via an adhesive or an adhesive sheet. And a flexible flat cable 40 lap-joined on the back surface (upper surface) of the piezoelectric actuator 20 for electrical connection with an external device.

  As shown in FIG. 8, the cavity unit 10 has a structure in which five thin metal plates of a nozzle plate 11, two manifold plates 12, 12, a spacer plate 13 and a base plate 14 are overlapped with an adhesive, respectively. Yes. In the first embodiment, except for the nozzle plate 11 made of synthetic resin, each of the plates 12 to 14 is made of a 42% nickel alloy steel plate and has a thickness of about 50 μm to 150 μm. The nozzle plate 11 is made of synthetic resin such as polyimide and has a thickness of about 50 μm to 100 μm. Each of the plates 11 to 14 has a substantially rectangular shape in plan view that is long in the Y direction (sub-scanning direction) (see FIGS. 7 and 8).

  In the nozzle plate 11, a large number of nozzles 11 a for discharging ink having a minute diameter (in the embodiment, about 25 μm) are formed at minute intervals according to the resolution at the time of printing. The plurality of nozzles 11a are arranged in two rows in a staggered arrangement along the Y direction (sub-scanning direction).

  The upper and lower manifold plates 12 and 12 and the spacer plate 13 are provided with a large number of through-holes 17 communicating with the nozzles 11a corresponding to the arrangement pattern of the nozzles 11a. In the upper and lower manifold plates 12, 12, ink passages 12 a, 12 b are formed so as to extend along both sides of the row of through holes 17.

  However, the ink passage 12b of the lower manifold plate 12 is recessed so as to open only to the upper surface side of the lower manifold plate 12 (see FIG. 8). The ink passages 12 a and 12 b are sealed by overlapping and joining the spacer plate 13 to the upper manifold plate 12.

  A large number of narrow pressure chambers 16 extending in the short side direction (X direction) are formed in the base plate 14 so as to penetrate in the plate thickness direction. These pressure chambers 16 are arranged in two rows in a staggered manner along the long side direction (Y direction) of the base plate 14 so as to correspond to the arrangement pattern of the nozzles 11a.

  As shown in FIG. 9, when the longitudinal reference lines 14a and 14b parallel to the staggered nozzle rows are set, the tip 16a of the left pressure chamber 16 is positioned on the right longitudinal reference line 14a, and the right pressure The tip 16a of the chamber 16 is located on the left longitudinal reference line 14b. As can be seen from this, the pressure chambers 16 on both the left and right sides are alternately arranged so as to extend in opposite directions.

  The front end 16a of each pressure chamber 16 communicates with each nozzle 11a of the nozzle plate 11 through a through hole 17 formed in the spacer plate 13 and the upper and lower manifold plates 12 and 12.

  On the other hand, the other end 16 b of each pressure chamber 16 communicates with the ink passages 12 a and 12 b of the upper and lower manifold plates 12 and 12 through the flow holes 18 formed on both sides of the row of the through holes 17 in the spacer plate 13. doing. The other end 16b of each pressure chamber 16 is recessed so as to open only on the lower surface side of the base plate 14 (see FIG. 9).

  As shown in FIGS. 7 and 8, two ink supply ports 19 are provided along the short side direction (X direction) at one end on the short side of the base plate 14 and the spacer plate 13 so as to correspond to the upper and lower positions. It is formed to line up. Each of the ink supply ports 19 communicates with one end portion of the ink passages 12a and 12b positioned below in a plan view as viewed from the stacking direction.

  A filter 29 made of synthetic resin or the like for removing dust in the ink supplied from the ink cartridge 61 is fixed to the upper surfaces of both ink supply ports 19, 19 in the base plate 14 with an adhesive.

  In the above configuration, the ink flowing into the cavity unit 10 from the ink cartridge 61 is supplied to the ink passages 12 a and 12 b from the ink supply ports 19 and 19 of the base plate 14 and the spacer plate 13. Next, the ink in the ink passages 12a and 12b is distributed into the pressure chambers 16 through the flow holes 18, and then driven in the pressure chambers 16 by driving the piezoelectric actuator 20 (details will be described later). From the through hole 17 to the nozzle 11 a corresponding to the pressure chamber 16.

  In the first embodiment, since different colors are supplied from the ink cartridge 61 to the ink supply ports 19 and the ink passages 12a and 12b corresponding thereto in the two recording heads 6 and 6, each recording head. Corresponding one color ink is ejected from each nozzle 11a row of the nozzle plate 11 in FIG.

  On the other hand, the piezoelectric actuator 20 has a structure in which a plurality of piezoelectric sheets are laminated. As described in JP-A-4-341851, the pressure chambers in the cavity unit 10 are provided on the upper surface of the lowermost piezoelectric sheet among the piezoelectric sheets and the upper surface of the odd-numbered piezoelectric sheet counted upward from the piezoelectric sheet. Narrow individual electrodes (not shown) are formed at locations corresponding to 16.

  A common electrode (not shown) common to the plurality of pressure chambers 16 is formed on the upper surface of the even-numbered piezoelectric sheets from the bottom. On the upper surface of the uppermost piezoelectric sheet (top sheet), an individual surface electrode 21 electrically connected to each individual electrode, and a common surface electrode 22 electrically connected to the common electrode, Is provided.

  The plate-type piezoelectric actuator 20 having such a configuration is laminated and fixed to the cavity unit 10 such that each individual electrode of the piezoelectric actuator 20 corresponds to each pressure chamber 16 of the cavity unit 10.

  On the surface on the back surface (upper surface) side of the piezoelectric actuator 20, various wiring patterns (not shown) in the flexible flat cable 40 are electrically connected to the surface electrodes 21 and 22 by heating and pressing the flexible flat cable 40. To be joined.

  Each flexible flat cable 40 is a strip having flexibility. An IC chip 41 as a drive circuit for driving the piezoelectric actuator 20 is attached to a wide surface in the middle of the longitudinal portion of the flexible flat cable 40 (see FIGS. 3, 4 and 6). The other end of the flexible flat cable 40 is detachably connected to a control board (not shown) arranged in the ink jet printer P.

  In the above configuration, when a voltage is applied between any one of the individual electrodes of the piezoelectric actuator 20 and the common electrode corresponding thereto, the piezoelectric longitudinal effect is applied to the portion (active portion) corresponding to both electrodes. As a result, distortion in the stacking direction occurs, and the internal volume of the pressure chamber 16 with respect to any individual electrode changes. At this time, if the polarization direction of the piezoelectric sheet sandwiched between both electrodes and the direction of the applied electric field are the same, the piezoelectric actuator 20 is distorted so as to extend in the stacking direction, and the ink in the pressure chamber 16 is discharged from the nozzle 11a. It is ejected in the form of droplets (predetermined recording (printing) is performed).

  Next, the structure of the holder case 1 and the mounting structure of the recording head 6 with respect to the holder case 1 will be described with reference to FIGS.

  The holder case 1 is an injection molded product made of a synthetic resin material such as polyethylene or polypropylene, and is formed in a substantially box shape with an open top surface. Four ink cartridges 61 are configured to be attachable and detachable from above in an open space with an upward opening that becomes the mounting portion 3 of the ink cartridge 61.

  At one end of the mounting portion 3 in the sub-scanning direction (Y direction), ink supply passages 4 a, 4 b, 4 c, 4 d connected to ink discharge portions (not shown) of the respective ink cartridges 61 are provided at the bottom of the holder case 1. 5 is formed so as to communicate with the lower surface (outer surface) of 5 (see FIG. 3). These ink supply passages 4a to 4d are arranged so as to be aligned along the main scanning direction (X direction). An annular packing or O-ring (not shown) made of an elastic material such as rubber is provided on the outer periphery of each ink supply passage 4a to 4d to prevent ink leakage when connected to the ink discharge portion of each ink cartridge 61. Is fitted.

  The bottom part 5 of the holder case 1 is formed in a horizontal shape so as to protrude downward from the mounting part 3. On the lower surface side (outer surface side) of the bottom portion 5, a head support portion 8 for fitting two recording heads 6 in parallel is formed in a downward opening shape.

  At one end of the head support 8 in the sub-scanning direction (Y direction), openings 45 (four in the first embodiment) communicating with the ink supply paths 4a to 4d are formed. A fitting groove 46 having a substantially elliptical shape in plan view is formed in the outer periphery of the two adjacent openings 45 and 45 so as to surround both the openings 45 and 45. In each of the fitting grooves 46, an annular packing 47 made of an elastic material such as rubber is fitted in order to prevent ink leakage when connected to the ink supply port 19 of the recording head 6.

  The bottom 5 has slit-shaped first cable holes 52 (two in the first embodiment) for pulling out the flexible flat cable 40 fixed to each recording head 6 into the mounting portion 3, and a head support. A plurality of adhesive flow holes 55 for fixing the recording heads 6 and 6 are formed in 8 (see FIGS. 3 and 4).

  The dimension in the narrow width direction of each first cable hole 52 is set larger than the thickness of the IC chip 41 portion in the flexible flat cable 40. That is, the dimension in the narrow width direction of each first cable hole 52 is set to a size that allows the IC chip 41 portion of the flexible flat cable 40 to pass through.

  The plurality of flow holes 55 are arranged in three rows along the sub-scanning direction (Y direction) so that the long side portions of the recording head 6 can be fixed at appropriate intervals (see FIG. 4). ). In the first embodiment, the pouring hole 55 formed in the substantially central portion in the X direction of the head support portion 8 is formed wide so as to straddle the back surfaces of the two recording heads 6 and 6 arranged side by side. (See FIG. 5).

  In a state where the two recording heads 6 are arranged on the head support portion 8 so that each piezoelectric actuator 20 is positioned in the head support portion 8, the flexible flat cable 40 is pulled out from the first cable hole 52 into the mounting portion 3. (See FIG. 6).

  The recording heads 6 and 6 are fixed to the head support portion 8 of the holder case 1 by filling the respective injection holes 55 of the bottom portion 5 with the adhesive 58 from the mounting portion 3 side (open space side) and curing it. Yes. Each first cable hole 52 through which the flexible flat cable 40 is inserted is sealed (sealed) with an adhesive 58 (which may be a simple sealing agent).

  The outer circumferences of the recording heads 6 and 6 are sealed and fixed with an adhesive 58 to the head support portion 8 of the holder case 1. In other words, the adhesive 58 is disposed all around the gap between the outer periphery of the recording heads 6 and 6 and the inner peripheral wall of the head support 8 and between the opposing long sides of the recording heads 6 and 6. Is filled over. Therefore, the space surrounded by the bottom 5 (head support 8) of the holder case 1 and the recording heads 6 and 6 is a first hermetic housing in which the piezoelectric actuator 20 is accommodated with the flexible flat cable 40 pulled out. A space 31 is formed.

  As shown in FIGS. 4 and 6, on the outer surface of the one side portion 7 in the sub-scanning direction (Y direction) in the holder case 1 (the outer surface of the one side portion 7 located on the side opposite to the ink supply paths 4 a to 4 d). Is formed so that the storage portion 9 for storing the IC chip 41 on the flexible flat cable 40 opens outward.

  The upper and lower horizontal plate portions 9a and 9b in the storage portion 9 are formed in a stepped shape so that the lower horizontal plate portion 9b protrudes outward in a side view than the upper horizontal plate portion 9a. On the upper surface of the lower horizontal plate portion 9b, a recessed groove 9c for fitting a lower edge portion of the heat radiating member 60 described later extends along the X direction at a location outside the upper horizontal plate portion 9a in plan view. Is formed.

  In one side portion 7 having the storage portion 9, slit-like second cable holes 53 (in the first embodiment, two locations) for drawing each flexible flat cable 40 drawn into the mounting portion 3 into the storage portion 9. ) Is formed (see FIGS. 3 and 6). In the first embodiment, the first cable hole 52 in the bottom portion 5 in the holder case 1, the mounting portion 3 that is an open space having an upward opening shape, and the second cable hole 53 in the one side portion 7 on the storage portion 9 side. The wiring passage described in the claims is configured.

  The dimension in the narrow width direction (X direction) of each second cable hole 53 is set larger than the thickness of the IC chip 41 portion in the flexible flat cable 40 as in the case of the first cable hole 52. Two elastic members 42 made of rubber or the like are fixed to the outer surface (inside the storage portion 9) of the side portion 7 on the storage portion 9 side so as to be arranged at appropriate intervals along the X direction (see FIGS. 4 and 4). (See FIG. 6).

  The storage portion 9 has a substantially rectangular plate-like heat dissipation member 60 that is long in the X direction so as to close the outward opening in a state where the flexible flat cables 40 are drawn upward one by one from the second cable holes 53, 53. Is attached.

  The heat dissipating member 60 is for releasing heat generated in the IC chip 41 as a drive circuit to the outside. The heat dissipation member 60 of the first embodiment is made of a metal plate such as aluminum having high heat dissipation efficiency (high thermal conductivity). In the first embodiment, the heat dissipation member 60 constitutes the outermost wall located on the outermost side of the holder case 1. The wide surface extends parallel to the main scanning direction (X direction, movement direction of the carriage 64).

  An IC chip 41 on the flexible flat cable 40 is sandwiched between the inner surface of the heat dissipation member 60 and the elastic member 42. In the first embodiment, the heat radiating member 60 is attached to the storage portion 9 with the IC chip 41 on the flexible flat cable 40 brought into contact with the inner surface side of the heat radiating member 60 pressed against the elastic member 42 in the storage portion 9. Thus, the IC chip 41 is brought into close contact with the inner surface of the heat radiating member 60 using the elastic restoring force of the elastic member 42.

  The lower edge portion of the heat radiating member 60 is sealed and fixed with an adhesive 58 in a state of being fitted into the recessed groove 9c of the lower horizontal plate portion 9b. Each flexible flat cable 40 is drawn further upward (outside of the storage portion 9) from between the upper end portion on the inner surface side of the heat radiating member 60 and the front end surface of the upper horizontal plate portion 9 a in the storage portion 9. The gap through which each flexible flat cable 40 is inserted is sealed with an adhesive 58 that bonds the heat radiating member 60 and the storage portion 9 together. Each second cable hole 53 is also sealed with an adhesive 58 (which may be a simple sealing agent) in a state where the flexible flat cable 40 is inserted.

  Therefore, the space surrounded by the one side portion 7 (storage portion 9) of the holder case 1 and the heat radiating member 60 is the second sealed space in which the IC chip 41 is stored with the flexible flat cable 40 disposed. 32. As a result, the first and second sealed spaces 31 and 32 of the holder case 1 are disposed with the upward opening-shaped open space (mounting portion 3) in which the ink cartridge 61 is mounted interposed therebetween.

  According to the above configuration, each of the casting holes 55 in the bottom portion 5, each of the first cable holes 52, the gap between the outer periphery of both the recording heads 6 and 6 and the inner peripheral wall of the head support portion 8, and both the recording heads 6 and 6. By filling the gap 58 between the opposing long sides with the adhesive 58, a space surrounded by the bottom 5 of the holder case 1 and the recording heads 6 and 6 is formed in the first sealed space 31. Therefore, the piezoelectric actuator 20 located on the back side of the cavity unit 10 is housed in the first sealed space 31 in an airtight state where gas and liquid do not enter and exit from the outside.

  Moreover, in the part spaced apart from the 1st sealed space 31, between the lower edge part of the thermal radiation member 60 and the lower horizontal board part 9b of the accommodating part 9, the upper end part of the thermal radiation member 60, and the upper horizontal board part 9a of the accommodating part 9 By filling the second cable holes 53 with an adhesive, a space surrounded by one side 7 of the holder case 1 and the heat radiating member 60 is formed in the second sealed space 32. The IC chip 41 on the flexible flat cable 40 is housed in the second sealed space 32 in an airtight state in which no gas or liquid enters or leaves the outside.

  As a result, foreign matters such as ink, paper dust, and dust cannot enter the first and second sealed spaces 31 and 32, so that it is possible to reliably prevent such foreign matters from adhering to the piezoelectric actuator 20 and the IC chip 41. it can. Therefore, it is possible to eliminate failures caused by the adhesion of foreign matters such as an electrical short circuit accident at the connecting portion between the piezoelectric actuator 20 and the flexible flat cable 40 and a failure of the IC chip 41.

  Moreover, when the second sealed space 32 is formed, the heat generated by the IC chip 41 is released to the outside by using the heat radiating member 60 made of a metal plate as a lid cover that closes the opening of the storage unit 9. The holder case 1 can be made compact without impairing the heat dissipation function. This makes it possible to reduce the size of the printer head 63 and thus the entire apparatus.

  On the other hand, the first and second sealed spaces 31 and 32 of the holder case 1 are separated from each other in a sealed state via an open space (mounting portion 3) having an upward opening in which the ink cartridge 61 is mounted. 2 The heat generated in the IC chip 41 enclosed in the sealed space 32 is, for example, a synthetic resin holder case 1 having a lower thermal conductivity than that of the metal (heat dissipating member 60) or the outside air in the open space (mounting portion 3). , It becomes difficult to reach the recording head 6 on the first sealed space 31 side.

  In addition, since the second sealed space 32 is adjacent to the open space (mounting portion 3) with the one side portion 7 of the holder case 1 sandwiched therebetween, the heat generated in the IC chip 41 is transferred via the heat dissipation member 60. Not only can it escape to the air outside the printer head 63, it can also escape to the air in the open space (mounting portion 3) located on the opposite side of the heat radiating member 60. Thereby, the heat dissipation effect to the outside of the printer head 63 can be enhanced, and the possibility that the heat generated in the IC chip 41 is transmitted to the recording head 6 on the first sealed space 31 side can be further suppressed. On the other hand, in the first sealed space 31, when the piezoelectric actuator 20 is driven in response to a signal from the IC chip 41, the piezoelectric actuator 20 itself also generates heat. Due to the heat generated at this time, the temperature distribution in the first sealed space 31 becomes uniform, and the temperature difference between the recording heads 6 is also reduced. Therefore, the ink ejection characteristics of the recording head 6 itself are made uniform.

  Therefore, it is possible to remarkably suppress the occurrence of problems such as abnormal ink discharge amount and discharge speed due to an unnecessarily high ink temperature in the recording head 6, and to make the temperature distribution of the recording head 6 itself uniform. Is effective, and the operational stability of the ink jet recording apparatus can be improved without increasing the size of the heat dissipating member 60. In addition, since the cooling efficiency of the IC chip 41 is improved, the IC chip 41 can be driven stably.

  Furthermore, since the IC chip 41 on the flexible flat cable is in close contact with the heat radiating member 60 by being sandwiched between the elastic member 42 and the heat radiating member 60 in the housing portion 9, the heat generated by the IC chip 41 is dissipated. The member 60 can be reliably transmitted. As a result, heat can be efficiently radiated to the air outside the printer head 63, contributing to stable driving of the IC chip 41.

  In the first embodiment, the IC chip 41 is attached to the heat radiating member 60 by using the elastic restoring force of the elastic member 42 fixed to the outer surface (inside the storage portion 9) of the one side portion 7 on the storage portion 9 side. Therefore, it is possible to contribute to the improvement of the heat dissipation effect from the heat radiating member 60 to the outside while having a simple configuration.

  In addition, since the holder case 1 of the first embodiment is mounted on the carriage 64 that can reciprocate in the main scanning direction (X direction), the carriage 64 reciprocates during recording (printing) on the paper 62. The holder case 1 and the heat dissipation member 60 also move along the X direction. Then, an air flow is always formed around the outer surface (wide surface) of the heat radiating member 60 while the carriage 64 is reciprocating, so that the heat radiating member 60 receives the air flow. And is cooled efficiently. Therefore, this point also contributes to the improvement of the heat dissipation effect from the heat dissipation member 60 to the outside.

  The wide surface of the heat radiating member 60 in the first embodiment extends in parallel to the main scanning direction (X direction, movement direction of the carriage 64). For example, the recording heads 6 and 6 are arranged to extend long in the X direction. And it is also possible to form the 2nd sealed space 32 in the one side part of the X direction in the holder case 1, and to make the wide surface of the heat radiating member 60 orthogonal to an X direction. In this case, as the carriage 64 reciprocates in the main scanning direction (X direction), the wide surface of the heat radiating member 60 faces the wind and is cooled by receiving the wind. Very expensive.

  FIGS. 10-13 has shown 2nd Embodiment which is another example of the structure of a holder case. FIG. 10 is a plan view of the printer head as viewed from the back side (upper surface side), FIG. 11A is a side view of the recording head attached to the support frame, and FIG. FIG. 12 is an exploded perspective view of the recording head, and FIG. 13 is a sectional side view taken along line XIII-XIII in FIG.

  The printer head 63 'according to the second embodiment includes a recording head 6' configured to eject four colors of ink, a support frame 50 'disposed on the back side of the recording head 6', and the support head 50 '. A synthetic resin holder case 1 ′ (head holder) to which a recording head 6 ′ is mounted via a frame 50 ′ is provided.

  Also in the case of the second embodiment, the open space of the upwardly open substantially box-shaped holder case 1 ′ is a mounting portion 3 ′ for mounting the ink cartridge 61 ′. Ink is supplied from the ink cartridge 61 ′ mounted on the mounting portion 3 ′ to the recording head 6 ′ via an ink supply sleeve 44 ′ (details will be described later) for each color.

  The recording head 6 'is a long type that is long in the Y direction (sub-scanning direction). For this reason, the holder case 1 ′ to which the recording head 6 ′ is attached is also configured to be long in the Y direction (sub-scanning direction) (see FIGS. 10 and 11).

  As shown in FIG. 12, the recording head 6 ′ includes a plurality of metal plate laminated cavity units 10 ′, a plate-type piezoelectric actuator 20 bonded to the back surface (upper surface) of the cavity unit 10 ′, The piezoelectric actuator 20 includes a flexible flat cable 40 that is lap-joined to the back surface (upper surface) of the piezoelectric actuator 20 for electrical connection with an external device.

  Although not shown in detail, the nozzle rows formed on the front side of the recording head 6 'are arranged in four rows in a staggered manner along the Y direction (sub-scanning direction). These four nozzle rows are divided into two in the middle in the Y direction, and each of the two rows is divided into four sets. The two rows and one set of nozzle groups correspond to each of four colors of ink filled in the ink cartridge 61 '.

  Four (a total of eight) ink supply ports 19 ′ are formed along the short side direction (X direction) at both longitudinal ends on the back side of the recording head 6 ′. These eight ink supply ports 19 'are divided into a total of four sets, with two adjacent ones as one set. The set of two ink supply ports 19 'corresponds to each of the four colors of ink filled in the ink cartridge 61'. On the upper surface of a set of two adjacent ink supply ports 19 ′, filters 29 ′ (four in total) made of synthetic resin for removing dust in the ink supplied from the ink cartridge 61 ′ are adhesive. It is fixed with.

  Further, on the four filters 29 ', substantially cylindrical sleeves 44' project from the ink cartridge 61 'in order to receive ink supply (FIGS. 10 and 11 (a) and (b)). )reference).

  Each sleeve 44 'has a large-diameter portion 44a' having a large outer diameter at the lower portion and a small-diameter portion 44b 'having a small outer diameter at the upper portion. An ink passage is formed inside each sleeve 44 '. The lower end surface of the large-diameter portion 44a ′ is firmly joined to the corresponding filter 29 ′ with an epoxy resin or the like. An annular packing or O-ring (not shown) made of an elastic material such as rubber is provided on the outer periphery of the small-diameter portion 44b 'in order to prevent ink leakage when connected to an ink discharge portion (not shown) of the ink cartridge 61'. Z)).

  As shown in FIGS. 11 (a) and 11 (b), the support frame 50 'is made of metal and has a substantially rectangular opening 56, which is also long in the Y direction, at the center of a substantially rectangular flat plate that is long in the Y direction. ′ Has a perforated shape. On the front surface side (lower surface side) of the support frame 50 ′, a step portion 57 ′ that surrounds the outer peripheral side of the opening 56 ′ is formed (see FIG. 13).

  The recording head 6 ′ is bonded and fixed to the stepped portion 57 ′ of the support frame 50 ′ with an adhesive 58 ′ so that the portion of the piezoelectric actuator 20 is accommodated in the opening 56 ′. Accordingly, the opening 56 'of the support frame 50' is closed by the recording head 6 '. The two flexible cables 40 and the four sleeves 44 ′ attached to the back surface (upper surface) of the recording head 6 ′ are drawn upward from the opening 56 ′.

  On the other hand, the piezoelectric actuator 20 is the same as that of the first embodiment. However, since the cavity unit 10 'has a long shape in the Y direction, the two piezoelectric actuators 20 and 20 include the cavity unit 10'. Are fixed side by side along the long side direction (Y direction) (see FIG. 12). Also, flexible flat cables 40 and 40 are joined to the two piezoelectric actuators 20 and 20, respectively.

  Next, the structure of the holder case 1 ′ and the mounting structure of the recording head 6 ′ with respect to the holder case 1 ′ will be described with reference to FIG.

  A head support portion 8 'for fitting the recording head 6' through a support frame 50 'is formed in a downward opening shape at the bottom portion 5' of the holder case 1 'having a substantially box shape with an upper opening. Further, a slit-shaped first cable hole 52 ′ for drawing out the flexible flat cable 40 fixed to the recording head 6 ′ into the mounting portion 3 ′ and a rear surface of the recording head 6 ′ protrude from the bottom 5 ′. Insertion holes 54 'and 54' (two locations in the first embodiment) into which the sleeves 44 '(four in the first embodiment) are inserted, and an adhesive for fixing the support frame 50' in the head support portion 8 ' Are formed (see FIGS. 10 and 13).

  The dimension in the narrow width direction (X direction) of the first cable hole 52 ′ is set larger than the thickness of the IC chip 41 portion in the flexible flat cable 40. The insertion holes 54 ′ and 54 ′ are formed in a substantially elliptical shape in plan view at both ends on the short side of the bottom 5 ′. Two sleeves 44 'and 44' adjacent to each other on the short side of the recording head 6 'are inserted into one insertion hole 54'. The plurality of casting holes 55 ′ are arranged in two rows along the left and right long sides (Y direction) of the bottom portion 5 ′.

  In a state where the recording head 6 'is arranged on the head support portion 8' so that the support frame 50 'is sandwiched between the bottom portion 5' of the holder case 1 'and the recording head 6', the insertion holes 54 ', Two sleeves 44 'are inserted through 54'. Two flexible flat cables 40 are drawn out from the first cable hole 52 '.

  The support frame 50 ′ is formed on the head support portion 8 ′ of the holder case 1 ′ by filling each casting hole 55 ′ in the bottom portion 5 ′ with the adhesive 58 ′ from the mounting portion 3 ′ side (open space side) and curing it. It is fixed. The first cable hole 52 'through which the flexible flat cable 40 is inserted is sealed (sealed) with an adhesive 58' (which may be a simple sealing agent).

  The outer periphery of the support frame 50 'to which the recording head 6' is fixed is sealed and fixed to the head support portion 8 'of the holder case 1' with an adhesive 58 '(which may be a simple sealant). That is, the adhesive 58 ′ is filled in the gap between the outer periphery of the support frame 50 ′ and the inner peripheral wall of the head support portion 8 ′. Therefore, in the space surrounded by the bottom 5 '(head support 8') of the holder case 1 ', the recording head 6' and the support frame 50 ', the piezoelectric actuator 20 is in a state where the flexible flat cable 40 is pulled out. A first sealed space 31 'is housed.

  As shown in FIG. 13, a storage portion 9 ′ for storing the IC chip 41 on the flexible flat cable 40 opens upward in one side portion 7 ′ of the holder case 1 ′ that is open upward and substantially box-shaped. Is formed.

  A slit-like second cable hole 53 'is formed in the partition wall 9a' near the mounting portion 3 'in the storage portion 9'. In the second embodiment, the first cable hole 52 ′ in the bottom 5 ′, the mounting part 3 ′, and the second cable hole 53 ′ in the partition wall 9 a ′ in the storage part 9 ′ are provided in the holder case 1 ′. The wiring passages described in 1) are configured.

  An elastic member 42 ′ made of rubber or the like is fixed to the inner bottom surface of the storage portion 9 ′. The storage portion 9 ′ has a heat radiation that is long in the Y direction and substantially in the shape of a letter in cross section so as to close the upward opening in a state where the two flexible flat cables 40 are drawn upward from the second cable hole 53 ′. A member 60 'is attached. The heat radiating member 60 'of the second embodiment is also made of a metal plate such as aluminum.

  The IC chip 41 on the flexible flat cable 40 is sandwiched between the lower extending portion 60b 'of the heat radiating member 60' and the elastic member 42 '.

  A space between the lower surface of the upper horizontal portion 60a 'of the heat radiating member 60' and the upper end surface of the partition wall 9a 'of the storage portion 9' is sealed and fixed with an adhesive 58 '. A flexible flat cable 40 is drawn upward (outside the storage portion 9 ′) from between the corner portion 60 c ′ of the heat radiating member 60 ′ and the inner surface of the outer wall 9 b ′ of the storage portion 9 ′. The gap through which the flexible flat cable 40 is inserted is sealed with an adhesive 58 ′ that bonds the heat radiating member 60 ′ and the storage portion 9 ′. The second cable hole 53 'is also sealed with an adhesive 58' (which may be a simple sealing agent) with the flexible flat cable 40 inserted.

  A space surrounded by one side 7 '(housing portion 9') of the holder case 1 'and the heat radiating member 60' is a second sealed space 32 'in which the IC chip 41 is housed. Accordingly, also in the second embodiment, the first and second sealed spaces 31 ′ and 32 ′ of the holder case 1 ′ sandwich the open space (mounting portion 3) having an upward opening in which the ink cartridge 61 ′ is mounted. Is arranged in. Other configurations are the same as those of the first embodiment.

  According to the above configuration, the gaps between the outer peripheries of the casting holes 55 ′, the first cable holes 52 ′ and the support frame 50 ′ of the bottom 5 ′ and the inner peripheral wall of the head support 8 ′ in the holder case 1 ′. By filling the adhesive 58 ′, a space surrounded by the bottom 5 ′, the recording head 6 ′, and the support frame 50 ′ is formed in the first sealed space 31 ′. And between the lower surface of the upper horizontal part 60a 'of the heat radiating member 60' and the upper end surface of the partition wall 9a 'of the storage part 9', the corner part 60c 'of the heat radiating member 60' and the outer wall 9b 'of the storage part 9'. By filling the second cable hole 53 ′ with an adhesive between the inner surface and the space surrounded by the housing portion 9 ′ of the holder case 1 ′ and the heat radiating member 60 ′, the flexible flat cable 40 is arranged. In the installed state, it is formed in the second sealed space 32 '. In addition, the first and second sealed spaces 31 ′ and 32 ′ are separated from each other in a sealed state via an open space (mounting portion 3 ′) having an upward opening. Therefore, also in the case of 2nd Embodiment, there exists an effect similar to 1st Embodiment.

  The present invention is not limited to the illustrated embodiment, and can be embodied in various forms. For example, a holder case having an open space with an upward opening, a head support portion and a recording head that form a first sealed space, a storage portion that forms a second sealed space, a heat radiating member, and the like have various appearances other than those described above. Can be embodied in shape. The support frame 50 'is not an essential component for the present invention.

  The configuration and number of the recording heads 6 and 6 ′ are arbitrary. The cavity unit 10 of the recording head 6 may be a ceramic material in addition to a metal material. Furthermore, the actuator of the ink jet recording apparatus according to the present invention may be a piezoelectric actuator of a type different from the piezoelectric actuator 20 described above, or discharges ink from the nozzle 11a by vibrating the diaphragm covering the back of the pressure chamber by static electricity. The structure to be made may be sufficient.

  Further, in the above-described embodiment, the configuration is such that the printer head 63 (63 ′) having the recording head 6 (6 ′) and the holder case 1 (1 ′) is mounted on the frame-shaped carriage 64. You may make itself play the role of the holder case 1 (1 '). That is, the recording head 6 (6 ′) and the heat radiating member 60 (60 ′) can be directly attached to the carriage 64 to function as the holder case according to the present invention.

  When the flexible flat cable 40 is wired in the wiring path extending from the first sealed space 31 (31 ′) to the second sealed space 32 (32 ′), the middle portion of the flexible flat cable 40 has the mounting portion 3 (3 ′). You may let it pass along the outer surface side of holder case 1 (1 '), without letting it pass.

  The present invention can also be applied to a tube supply type inkjet recording apparatus that supplies ink from an ink tank disposed in a main body to a recording head mounted on a carriage via a tube. In this case, on the mounting portion of the holder case (carriage), for example, a bubble storage portion (damper portion) for storing bubbles in the ink flow path from the ink tank to the nozzle is mounted as the component described in the claims. It will be.

1 is a perspective view of an ink jet printer to which the present invention is applied. It is a perspective view of the printer head in a 1st embodiment. It is a disassembled perspective view of a printer head. It is a disassembled perspective view of the printer head when the nozzle side is turned up. FIG. 5 is a side cross-sectional view taken along line VV in FIG. 2. FIG. 6 is a side sectional view taken along line VI-VI in FIG. 2. FIG. 3 is an exploded perspective view of a recording head. It is a disassembled perspective view of a cavity unit. It is a partial expansion disassembled perspective view of a cavity unit. It is the top view which looked at the printer head in 2nd Embodiment from the back side (upper surface side). (A) is a side view of the state in which the recording head is attached to the support frame, and (b) is a plan view of the state in which the recording head is attached to the support frame as seen from the back side. FIG. 3 is an exploded perspective view of a recording head. It is XIII-XIII seeing side sectional drawing of FIG.

Explanation of symbols

P Inkjet printer 1, 1 'Holder case 3, 3' Mounting section as open space 5, 5 'Bottom 6, 6' Recording head 7, 7 'One side 8, 8' Head support 9, 9 'Storage 9a Upper horizontal plate portion 9b Lower horizontal plate portion 9a 'Partition wall 9b' Outer wall 10, 10 'Cavity unit 11a Nozzle 20 Piezoelectric actuator 31, 31' First sealed space 32, 32 'Second sealed space 40 Flexible flat cable 41 Drive circuit IC chip 42, 42 'elastic member 52, 52' first cable hole 53, 53 'second cable hole 55, 55' casting hole 58, 58 'adhesive 60, 60' heat radiation member 60a 'upper horizontal part 60b ′ Lower extension portion 60 c ′ Corner portion 61, 61 ′ Ink cartridge as part 62 Paper as recording medium 3, 63 'printer head 64 the carriage

Claims (5)

An ink jet recording apparatus comprising: a recording head that records ink on a recording medium by discharging ink from a front nozzle; and a holder case to which the recording head is fixed,
An actuator that applies ejection energy to the ink and a flexible flat cable that is electrically connected to the actuator are attached to the back surface of the recording head, and the actuator is driven in the middle part of the flexible flat cable. While having a drive circuit to
A first sealed space is formed at the bottom of the holder case between the recording head and the bottom, and a second sealed space separated from the first sealed space is formed at the side of the holder case. Formed,
The actuator electrically connected to the flexible flat cable is disposed in the first sealed space, and the drive circuit on the flexible flat cable is disposed in the second sealed space,
An ink jet recording apparatus, wherein a wiring passage extending from the first sealed space to the second sealed space is sealed in a state where the flexible flat cable is disposed. The holder case has a heat radiating member for radiating heat of the drive circuit,
The ink jet recording apparatus according to claim 1, wherein the heat radiating member constitutes at least a part of the side portion defining the second sealed space.   The said drive circuit on the said flexible flat cable is closely_contact | adhered to the said heat radiating member by being clamped between the side part of the said holder case, and the said heat radiating member, It was described in Claim 2 characterized by the above-mentioned. Inkjet recording device. In the second sealed space, an elastic member is disposed between the drive circuit and the side of the holder case,
4. The ink jet recording apparatus according to claim 3, wherein the drive circuit is pressed against the heat radiating member by the elastic member. A carriage that is reciprocally movable in a direction orthogonal to a conveyance direction of the recording medium to which the holder case is mounted and conveyed;
The heat dissipating member constitutes an outermost wall located on the outermost side of the holder case and is arranged so that a wide surface thereof is parallel or perpendicular to a moving direction of the carriage. 4. The ink jet recording apparatus described in any one of 4 above.

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