JP2017007322A - Liquid discharge head and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cool an electromechanical conversion element, a common external electrode and an individual liquid chamber without contact of the electromechanical conversion element and external electrode with cooling liquid.SOLUTION: A liquid discharge head 34 comprises: a nozzle plate 118 on which a nozzle 114 is formed; a channel plate 119 formed with an individual liquid chamber 115 communicating to the nozzle 114; a diaphragm 116 which seals at least a portion of the individual liquid chamber 115; and an electromechanical conversion element 110 which is provided on the side facing the individual liquid chamber 115 via the diaphragm 116, further comprises: an individual external electrode 121 for driving the electromechanical conversion element 110; and a common external electrode 120 of the plurality of electromechanical conversion elements 110. The common external electrode 120 is provided on the side facing the channel plate 119 via the diaphragm 116. A liquid channel 108 independently of the individual liquid chamber 115 is provided over the arrangement direction of the individual liquid chamber 115. A heat conductor 117 is interposed between the common external electrode 120 and the liquid channel 108.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a liquid discharge head and an image forming apparatus.

  In general, as an image forming apparatus that combines a printer, a facsimile machine, a copying machine, a plotter, or a plurality of these functions, for example, an ink jet equipped with a liquid discharge head (droplet discharge head) for discharging droplets of ink or the like There is a recording device.

  The liquid discharge head includes a nozzle that discharges a liquid droplet of ink or the like, a liquid chamber (individual liquid chamber) that communicates with the nozzle and stores a liquid, and PZT (lead zirconate titanate) as a piezoelectric body. A configuration including an electromechanical conversion element such as a piezoelectric element is known.

  In this piezo-type liquid discharge head, when a voltage is applied to the electromechanical transducer, the electromechanical transducer vibrates so as to deform the diaphragm that forms part of the wall of the liquid chamber. Due to this deformation, the liquid in the liquid chamber is pressurized and droplets can be ejected from the nozzle.

  In such a liquid ejection head, various types of liquid discharge heads are used to prevent deterioration of displacement characteristics due to heat generation during power supply to the electromechanical transducer and loss of piezoelectric characteristics, and to reduce variations in liquid ejection characteristics due to temperature distribution. The one provided with a suitable temperature adjusting means has been proposed.

  As a temperature adjusting means for the liquid discharge head, a technique is known in which a cooling liquid flow path is provided between the ink flow paths, and the temperature of the recording head is adjusted by adjusting the temperature of the liquid by flowing the liquid. .

  For example, in Patent Document 1, a plurality of grooves are formed side by side on one surface for the purpose of reducing and cooling temperature variations in an ink jet recording head, and at least a part of the side walls of the grooves is made of a piezoelectric material. The structure which becomes the board | substrate which becomes this, and also the structure by which the ink flow path and the liquid flow path are alternately arrange | positioned are disclosed by the some groove | channel.

  However, the technique disclosed in Japanese Patent Laid-Open No. 2004-228561 uses heat generated from electromechanical conversion elements and external electrodes (common external electrodes and individual external electrodes) that cause variations in ink discharge characteristics due to temperature distribution, as a cooling liquid. In the method of cooling by flowing the electromechanical conversion element and the external electrode are in contact with the liquid, the life of the head itself may be shortened.

  Further, it has not been sufficient to efficiently cool the electromechanical conversion element, the common external electrode serving as the maximum heat generation source, and the individual liquid chamber that affects the ink ejection characteristics.

  Therefore, the present invention provides a liquid discharge head capable of efficiently cooling the electromechanical conversion element, the common external electrode, and the individual liquid chamber without the electromechanical conversion element and the external electrode coming into contact with the cooling liquid. The purpose is to do.

  In order to achieve this object, a liquid discharge head according to the present invention includes a nozzle plate in which nozzles are formed, a flow path plate in which individual liquid chambers communicating with the nozzles are formed, and at least a part of the individual liquid chambers. A liquid ejection head comprising: a diaphragm for sealing the liquid; and an electromechanical conversion element provided on a side facing the individual liquid chamber via the vibration plate, wherein the individual external device that drives the electromechanical conversion element An electrode and a common external electrode of the plurality of electromechanical conversion elements, the common external electrode being provided on the side facing the flow path plate through the diaphragm, and extending in the arrangement direction of the individual liquid chambers A liquid flow path independent from the individual liquid chamber is provided, and a heat conductor is interposed between the common external electrode and the liquid flow path.

  According to the present invention, the electromechanical conversion element, the common external electrode, and the individual liquid chamber can be efficiently cooled without the electromechanical conversion element and the external electrode coming into contact with the cooling liquid.

1 is a perspective view showing an external appearance of an image forming apparatus. It is sectional drawing which shows the mechanism of an image forming apparatus. FIG. 2 is a top view illustrating a main configuration of the image forming apparatus. It is a perspective view which shows a liquid discharge head. It is a perspective view which shows the internal structure of a liquid discharge head. It is explanatory drawing which shows the flow-path structure of a liquid discharge head. It is A-A 'sectional drawing of FIG. It is explanatory drawing about supply of the liquid to a liquid discharge head. It is explanatory drawing about supply of the liquid to a liquid discharge head. FIG. 9 is another example of a cross-sectional view taken along the line A-A ′ of FIG. 6. FIG. 9 is another example of a cross-sectional view taken along the line A-A ′ of FIG. 6.

  Hereinafter, a configuration according to the present invention will be described in detail based on the embodiment shown in FIGS.

[First Embodiment]
(Image forming device)
FIG. 1 is a perspective view showing an appearance of the image forming apparatus according to the present embodiment. The image forming apparatus shown in FIG. 1 has an apparatus main body 1, a paper feed tray 2 for loading paper mounted on the apparatus main body 1, and a detachably mounted on the apparatus main body 1 to record (form) an image. And a paper discharge tray 3 for stocking the printed paper.

  Further, a cartridge loading for loading an ink cartridge that protrudes from the front surface to the front side of the apparatus main body 1 and is lower than the upper surface is provided at one end side of the front surface of the apparatus main body 1 (side of the paper supply / discharge tray section). The cartridge loading unit 4 has an operation / display unit 5 provided with operation buttons and a display.

  The cartridge loading section 4 includes a plurality of ink cartridges 10k each containing inks of different color materials, such as black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. 10c, 10m, and 10y (referred to as “ink cartridge 10” when colors are not distinguished) are inserted from the front side of the apparatus main body 1 toward the rear side and can be loaded, and on the front side of the cartridge loading unit 4 Has a front cover (cartridge cover) 6 that can be opened and closed when the ink cartridge 10 is attached and detached.

  Next, the mechanism of the image forming apparatus will be described with reference to FIGS. FIG. 2 is a schematic side view illustrating the outline of the mechanism, and FIG.

  As shown in FIG. 3, a carriage 33 is slidably held in a main scanning direction by a guide rod 31 and a stay 32 which are guide members horizontally mounted on the left and right side plates 21A and 21B, and a main scanning motor which is a driving means. 3 is moved and scanned in the direction indicated by the arrow in FIG. 3 (carriage main scanning direction) via the timing belt.

  On the carriage 33, a liquid ejection head 34 for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K) is main-scanned with a nozzle row composed of a plurality of nozzles. They are arranged in the sub-scanning direction orthogonal to the direction, and are mounted with the ink droplet ejection direction facing downward. The carriage 33 is equipped with a pressure damper mechanism 35 for suppressing pressure fluctuation due to the main scanning operation of the carriage 33.

  In the liquid discharge head, the ink stored in the sub-tanks 8k, 8c, 8m, and 8y (referred to as “sub-tank 8” when colors are not distinguished) arranged at predetermined positions via the ink supply tubes 36 of the respective colors. Supplied. The sub tank 8 is supplementarily supplied with ink of each color from the ink cartridge 10 of each color mounted in the cartridge loading unit 4. The cartridge loading unit 4 is provided with a supply pump unit 7 for feeding ink in the ink cartridge 10.

  An intermediate portion of the ink supply tube 36 is held by a holding member 37 on the front stay 29. Ink filling into the liquid ejection head 34 is performed by feeding the liquid by the circulation pump 143 in a state where the liquid ejection head 34 is capped by the cap 82 (82a to 82d). When the circulation pump 143 is driven, the air in the liquid discharge head 34 and the ink supply tube 36 is sent into the sub tank 8, and the liquid discharge head 34 and the ink supply tube 36 that have become negative pressure by this operation are filled with ink. It is. That is, the ink is circulated between the sub tank 8 and the liquid discharge head 34 via the ink supply tube 36.

  On the other hand, as shown in FIG. 2, the sheets 42 are separated one by one from the sheet stacking section 41 as a sheet feeding section for feeding the sheets 42 stacked on the sheet stacking section (pressure plate) 41 of the sheet feeding tray 2. A half paddle (feeding roller) 43 to be fed and a separation pad 44 made of a material having a large friction coefficient are provided opposite to the feeding roller 43, and this separation pad 44 is urged toward the feeding roller 43 side.

  A guide member 45 for guiding the paper 42, a counter roller 46, a transport guide member 47, and a tip pressurization are provided to feed the paper 42 fed from the paper feeding unit to the lower side of the liquid discharge head 34. A pressing member 48 having a roller 49 is provided, and a conveying belt 51 is provided as conveying means for electrostatically attracting the fed paper 42 and conveying it at a position facing the liquid ejection head 34.

  The conveyance belt 51 is an endless belt, and is configured to wrap around the conveyance roller 52 and the tension roller 53 and circulate in the belt conveyance direction (sub-scanning direction). Further, a charging roller 56 that is a charging unit for charging the surface of the transport belt 51 is provided. The charging roller 56 is disposed so as to come into contact with the surface layer of the transport belt 51 and to rotate following the rotation of the transport belt 51. The conveyance belt 51 rotates in the belt conveyance direction when the conveyance roller 52 is rotationally driven through timing by a sub-scanning motor that is a driving unit.

  Further, as a paper discharge unit for discharging the paper 42 recorded by the liquid discharge head 34, a separation claw 61 for separating the paper 42 from the transport belt 51, a paper discharge roller 62, and a paper discharge roller 63 are provided. In addition, a paper discharge tray 3 is provided below the paper discharge roller 62.

  A duplex unit 71 is detachably mounted on the back surface of the apparatus body 1. The duplex unit 71 takes in the paper 42 returned by the reverse rotation of the transport belt 51, reverses it, and feeds it again between the counter roller 46 and the transport belt 51. The upper surface of the duplex unit 71 is a manual feed tray 72.

  Further, as shown in FIG. 3, a maintenance / recovery mechanism 81 including a recovery means for maintaining and recovering the state of the nozzles of the liquid ejection head 34 is arranged in the non-printing area on one side of the carriage 33 in the scanning direction. ing.

  The maintenance / recovery mechanism 81 includes cap members (hereinafter referred to as “caps”) 82a, 82b, 82c, and 82d (hereinafter referred to as “caps 82” when not distinguished from each other) for capping each nozzle surface of the liquid ejection head 34. ), And a wiper blade 83 that is a blade member for wiping the nozzle surface, and an empty discharge receiver that receives droplets when performing an empty discharge that discharges droplets that do not contribute to recording in order to discharge thickened ink 84 and the like.

  Further, as shown in FIG. 3, when idle ejection is performed in the non-printing area on the other side in the scanning direction of the carriage 33 to eject liquid droplets that do not contribute to recording in order to discharge ink that has been thickened during recording or the like. An empty discharge receiver 88 for receiving the liquid droplets is arranged, and the empty discharge receiver 88 is provided with an opening 89 along the nozzle row direction of the liquid discharge head 34.

  In the image forming apparatus configured as described above, the sheets 42 are separated and fed one by one from the sheet feed tray 2, and the sheets 42 fed substantially vertically upward are guided by the guide member 45, and are conveyed to the conveyor belt 51 and the counter. It is sandwiched between the rollers 46 and conveyed, and further, the leading end is guided by the conveying guide member 47 and pressed against the conveying belt 51 by the leading end pressing roller 49, and the conveying direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately repeated with respect to the charging roller 56, that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 51 alternates, that is, in a sub-scanning direction that is a circumferential direction. , Plus and minus are alternately charged in a band shape with a predetermined width.

  When the sheet 42 is fed onto the conveyance belt 51 charged with the plus and minus alternately, the sheet 42 is attracted to the conveyance belt 51, and the sheet 42 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 51. The

  Therefore, by driving the liquid ejection head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped paper 42 to record one line, and the paper 42 is conveyed by a predetermined amount. Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 3.

  During printing (recording) standby, the carriage 33 is moved to the maintenance / recovery mechanism 81 side, and the liquid ejection head 34 is capped by the cap 82 to keep the nozzles moist, thereby preventing ejection failure due to ink drying. Further, a recovery operation is performed in which ink is sucked from the nozzles by a suction pump (referred to as “nozzle suction” or “head suction”) while the liquid ejection head 34 is capped by the cap 82, and the thickened ink and bubbles are discharged. Do. Further, an idle ejection operation for ejecting ink not related to recording is performed before the start of recording or during recording. Thereby, the stable ejection performance of the liquid ejection head 34 is maintained.

(Liquid discharge head)
FIG. 4 is a perspective view showing the appearance of the liquid ejection head 34 according to the present embodiment. FIG. 5 is a perspective view showing the internal configuration of the liquid ejection head 34 shown in FIG. FIG. 6 is an explanatory diagram showing a flow path configuration of the liquid ejection head 34.

  The liquid discharge head 34 includes a cover 102, a flexible printed circuit (FPC) 103, a heat sink 104, a housing 105, a first supply port 106, a second supply port 107, and a liquid flow path. 108, a drive IC 109, an electromechanical conversion element 110, a temperature monitoring element 111, a heater 112, a supply flow path 113, a nozzle 114, an individual liquid chamber 115, and the like.

  The cover 102 is an outer appearance cover of the liquid discharge head 34, and FIG. 5 shows a state in which a part thereof is removed for explanation of the internal configuration.

  A first supply port 106 serving as a liquid supply port to the supply flow channel 113 and a second supply port 107 serving as a liquid supply port to the liquid flow channel 108 are formed at both ends in the short direction of the housing 105. Has been.

  In the present embodiment, one second supply port 107 is formed between the two first supply ports 106, and a total of three supply ports are formed side by side in the short direction of the housing 105, for a total of 6 There are two supply ports.

  FIG. 6 is an explanatory diagram showing communication between two first supply ports 106, one second supply port 107, a supply channel 113, and a liquid channel 108. As shown in FIG. 6, each of the first supply ports 106 communicates with an independent supply channel 113, and the supply channel 113 extends along the longitudinal direction of the housing 105 and the longitudinal direction of the housing 105. It communicates with the individual liquid chamber 115 formed in parallel in the direction. The longitudinal direction of the housing 105 is the arrangement direction of the individual liquid chambers 115.

  As shown in FIG. 6, the second supply port 107 communicates with a liquid flow path 108 provided along the longitudinal direction of the housing 105. The liquid flow path 108 is provided between the two supply flow paths 113 in the short direction of the housing 105, is independent of the supply flow path 113 and the individual liquid chamber 115, and is not in communication.

  The first supply ports 106 are provided at both ends of the supply flow channel 113, and the second supply ports 107 are provided at both ends of the liquid flow channel 108. Since the first supply port 106 and the second supply port 107 are liquid flow paths, they are supplied from one side and discharged from the other side when the liquid is circulated.

  A plurality of individual liquid chambers 115 are provided in parallel in the vertical direction of the supply channel 113, and a nozzle 114 is formed on the other end side of the supply channel 113 with the communicating portion. The individual liquid chambers 115 and the nozzles 114 are formed by the two supply channels 113 with a predetermined shift in the longitudinal direction of the housing 105, and the two nozzle rows formed by the nozzles 114 are arranged in a staggered manner. The The liquid flow path 108 is provided between the two nozzle rows.

  In the present embodiment, two sets of two first supply ports 106 and one second supply port 107 shown in FIG. 6 are formed as shown in FIG. Four passages 113 and two liquid passages 108 are formed.

  The liquid discharge head 34 is not limited to two supply channels 113 and two sets of three channels each provided with one liquid channel 108 therebetween. There may be. Further, the configuration of the combination of the number of the supply channels 113 and the liquid channels 108 is not limited to the above example.

  The FPC 103 transmits electric signals from the host device, and is, for example, a stacked type FPC in which drive wirings are formed in a stacked shape. The FPC 103 is connected to a drive circuit board that includes a drive IC 109 that controls the drive of the electromechanical transducer 110.

  Based on the signal supplied from the drive circuit board, a voltage is applied to the electromechanical conversion element 110 and the electromechanical conversion element 110 is deformed, whereby the pressure in the individual liquid chamber 115 is increased, and the jet liquid (discharge liquid) ) Is discharged.

  Further, a heat radiating plate 104 that releases heat generated by the driving IC 109 to the outside of the head is provided at a position adjacent to the driving IC 109, and one end of the heat radiating plate 104 is exposed from the cover 102 to the outside of the liquid ejection head 34. Yes.

  In addition, a temperature monitoring element 111 is provided in the housing 105 as temperature detection means for measuring the temperature of the spray liquid. The temperature monitoring element 111 is connected to the FPC 103.

  In addition, a heater 112 is provided in the housing 105 as a heating means for heating the spray liquid.

  FIG. 7 is a cross-sectional view taken along line A-A ′ of FIG. 6. The liquid discharge head 34 seals a nozzle plate 118 on which nozzles 114 for discharging liquid are formed, a flow path plate 119 on which a plurality of individual liquid chambers 115 communicating with the nozzles 114 are formed, and one surface of the individual liquid chamber 115. And a jet liquid channel unit produced by stacking the diaphragm 116 to be stopped. Further, as shown in FIG. 7, the individual liquid chamber 115 and the liquid flow path 108 are adjacent to each other with the partition wall 119 a of the flow path plate 119 interposed therebetween. The central line of the liquid flow path 108 indicates a portion where the depth direction of the cross-sectional view is shifted.

  The jet liquid channel unit is held and fixed to the housing 105. The supply channel 113 includes an injection liquid channel unit and a housing 105, and the first supply port 106 supplies the injection liquid from the outside.

  In addition, the electromechanical conversion element 110 is joined to the surface of the spray liquid channel unit on the diaphragm 116 side, and the convex portion of the diaphragm 116 is pressed by the electromechanical conversion element 110 to transmit the pressure to the individual liquid chamber 115. ing. In addition, an individual external electrode 121 (dashed line portion in the drawing) for driving the electromechanical conversion element 110 and a common external electrode 120 (dotted line portion in the drawing) of the plurality of electromechanical conversion elements 110 are provided.

  A plurality of electromechanical conversion elements 110 are arranged corresponding to each nozzle row, and serve as pressure generation sources for liquid discharge from nozzles 114 arranged at high density. The common external electrode 120 is provided on the side facing the flow path plate 119 with the diaphragm 116 interposed therebetween.

  In the liquid ejection head 34 according to the present embodiment, a heat conductor 117 is provided between the common external electrode 120 and the liquid flow path 108. It is preferable that at least a part of the common external electrode 120 and the heat conductor 117 are in contact with each other.

  It is effective to configure the thermal conductor 117 with a material having a thermal conductivity better than that of the diaphragm 116. The heat conductor 117 is preferably made of an insulating material. For example, a liquid epoxy resin sealing material (for example, Rico Zima Inas (manufactured by Sumitomo Osaka Cement Co., Ltd.)) can be used. By using the insulating heat conductor 117, it is possible to prevent energization with the common external electrode 120. The heat conductor 117 is arranged along the liquid flow path 108 in the arrangement of the individual liquid chambers 115. It is preferable to be provided in substantially the entire longitudinal direction of the direction.

  Next, the supply of the ejection liquid (ink) to the liquid ejection head 34 and the supply of the liquid (cooling liquid) supplied to the liquid flow path 108 will be described with reference to FIG.

  As shown in FIG. 8, the liquid ejection head 34 is connected to an ejection liquid tank 124 (sub tank 8 in the example of FIG. 3) for supplying the ejection liquid.

  The ejection liquid is supplied from the ejection liquid tank 124 to the supply flow path 113 via the four first supply ports 106 of the liquid discharge head 34 via the supply path 123 (in the example of FIG. 3, the ink supply tube 36). . The jet liquid supplied to the supply flow path 113 is appropriately discharged from the nozzle 114.

  Further, the liquid is supplied from the jet liquid tank 124 to the liquid flow path 108 via the liquid path 122 and the two second supply ports 107 of the liquid discharge head 34. The liquid supplied to the liquid flow path 108 returns to the spray liquid tank 124 again from the second supply port 107 on the opposite side. That is, the liquid is configured to circulate.

  Here, in the example of FIG. 8, the liquid supplied to the liquid flow path 108 is the jet liquid supplied from the jet liquid tank 124.

  By circulating the same liquid as the spray liquid from the spray liquid tank 124 in the liquid flow path 108, it is possible to adjust the temperature with the spray liquid having the same temperature as the spray liquid tank 124.

  Next, with reference to FIG. 9, another example of the supply of the ejection liquid to the liquid discharge head 34 and the supply of the liquid supplied to the liquid flow path 108 according to the present embodiment will be described.

  As shown in FIG. 9, the liquid discharge head 34 is connected to an injection liquid tank 124 for supplying an injection liquid and a liquid tank 125 for supplying a liquid.

  The jet liquid is supplied from the jet liquid tank 124 through the supply path 123 to the supply flow path 113 through the four first supply ports 106 of the liquid discharge head 34.

  Further, the liquid is supplied from the liquid tank 125 through the liquid path 122 to the liquid flow path 108 through the two second supply ports 107 of the liquid discharge head 34. The liquid supplied to the liquid flow path 108 returns to the spray liquid tank 124 again from the second supply port 107 on the opposite side. That is, the liquid is configured to circulate.

  Here, in the example of FIG. 9, the liquid supplied to the liquid flow path 108 is different from the jet liquid supplied from the jet liquid tank 124. The liquid in this case is preferably a liquid having a specific heat higher than that of the jetting liquid (ink).

  By circulating a liquid having a high specific heat through the liquid flow path 108 and the liquid tank 125, in addition to being free from the influence of internal disturbance, it is possible to obtain a heat radiation characteristic by a liquid having a high specific heat.

  According to the liquid ejection head 34 according to the first embodiment described above, the liquid circulating through the liquid flow path 108 does not contact the electromechanical conversion element 110, the individual external electrode 121, and the common external electrode 120 at the maximum. It is possible to efficiently cool the individual liquid chamber 115 that affects the heat generation of the common external electrode 120 serving as a heat generation source and the ink ejection characteristics.

  In addition, by arranging the liquid flow paths 108 between the two rows of the individual liquid chambers 115, the arrangement of the two rows of the individual liquid chambers 115 can be cooled by the single liquid flow path 108. It has become.

[Second Embodiment]
Hereinafter, other embodiments of the liquid discharge head according to the present invention will be described. In addition, the description about the same point as the said embodiment is abbreviate | omitted suitably.

  FIG. 10 is another example of the A-A ′ sectional view of FIG. 6. The liquid discharge head 34 includes a nozzle plate 118 in which the nozzles 114 are formed, a flow path plate 119 in which a plurality of individual liquid chambers 115 are formed, and a vibration plate 116 that seals one surface of the individual liquid chambers 115. A jet liquid flow path unit manufactured as described above. Further, as shown in FIG. 10, the individual liquid chamber 115 and the liquid flow path 108 are adjacent to each other with the partition wall 119 a of the flow path plate 119 interposed therebetween.

  In addition, the electromechanical conversion element 110 is joined to the surface of the spray liquid channel unit on the diaphragm 116 side. In addition, an individual external electrode 121 (dashed line portion in the drawing) for driving the electromechanical conversion element 110 and a common external electrode 120 (dotted line portion in the drawing) of the plurality of electromechanical conversion elements 110 are provided.

  In the liquid ejection head 34 according to the present embodiment, the electromechanical conversion element 110 is fixed to the support 126 with the common external electrode 120 interposed therebetween. The electromechanical conversion element 110 and the support 126 are fixed with an adhesive (adhesive layer 128). The support 126 can release heat by transmitting the heat generated by the electromechanical conversion element 110 to the liquid flow path 108 through the support 126, the heat conduction member 127, the heat conductor 117, and the diaphragm 116 in this order. Further, it is preferable that the support 126 is provided along the liquid flow path 108 in substantially the entire region in the longitudinal direction of the individual liquid chambers 115 in the arrangement direction.

  In the first embodiment shown in FIG. 7, the opposite side of the diaphragm 116 across the liquid flow path 108 is a space between the electromechanical transducers 110, but in this embodiment, FIG. As shown in FIG. 5, a heat conducting member 127 is provided, and a diaphragm 116 facing the liquid flow path 108 and a support 126 are provided with the heat conducting member 127 interposed therebetween. In addition, it is preferable that the heat conducting member 127 is provided along the liquid flow path 108 in substantially the entire region in the longitudinal direction of the individual liquid chambers 115 in the arrangement direction.

  Various materials can be applied to the heat conducting member 127 without any limitation on rigidity or the like. For example, it is preferable to use a material such as aluminum having good thermal conductivity.

  A heat conductor 117 is preferably provided between the heat conducting member 127 and the diaphragm 116.

  Further, it is preferable that a heat conductor 117 is provided between the heat conductive member 127 and the support 126.

  FIG. 11 is another example of the A-A ′ sectional view of FIG. 6. As shown in FIG. 10, a part of the common external electrode 120 and the diaphragm 116 may be in contact with each other, but as shown in FIG. 11, between the common external electrode 120 and the diaphragm 116. In addition, a heat conductor 117 is preferably provided.

  According to the liquid ejection head 34 according to the second embodiment described above, the liquid circulating in the liquid flow path 108, the electromechanical conversion element 110, the individual external electrode 121, and the common external, as in the first embodiment. Heat generation of the common external electrode 120 and the individual liquid chamber 115 can be efficiently cooled without contacting the electrode 120.

  Further, by using the ink jet recording apparatus (image forming apparatus) including the liquid discharge head 34 according to the present embodiment described so far, an ink jet recording apparatus including the liquid discharge head 34 with high cooling efficiency and high quality is obtained. be able to.

  In addition, although an inkjet printer has been described as an example of the image forming apparatus, the present invention can also be applied to an inkjet copy, an inkjet fax, or a composite recording apparatus thereof. Further, the image forming apparatus includes both a serial type image forming apparatus and a line type image forming apparatus, unless otherwise limited.

  Further, in an ink jet recording apparatus, an image is formed by adhering ink droplets to a sheet by a liquid discharge head while conveying a medium. The medium here is also referred to as “paper”, but the material is not limited, and a recording medium, a recording medium, a transfer material, a recording paper, and the like are also used synonymously. The image forming apparatus means an apparatus for forming an image by ejecting liquid droplets on a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, or ceramic.

  The image formation is not only giving an image having a meaning such as a character or a figure to the medium but also giving an image having no meaning such as a pattern to the medium (simply ejecting a droplet). Also means. The ink is not limited to so-called ink, and is not particularly limited as long as it becomes a droplet when ejected. For example, the ink is a generic term for liquids including DNA samples, resists, pattern materials, and the like. Used as For example, in addition to an inkjet recording apparatus, the present invention can be applied to industrial manufacturing apparatuses such as a color filter manufacturing apparatus, a metal wiring manufacturing apparatus, a textile printing apparatus, and a DNA chip manufacturing apparatus using an inkjet technique.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

34 Liquid discharge head 102 Cover 103 Flexible printed circuit board 104 Heat sink 105 Housing
106 First supply port 107 Second supply port 108 Liquid channel 109 Drive IC
110 Electromechanical conversion element 111 Temperature monitoring element 112 Heater 113 Supply channel 114 Nozzle 115 Individual liquid chamber 116 Vibration plate 117 Thermal conductor 118 Nozzle plate 119 Channel plate 120 Common external electrode 121 Individual external electrode 122 Liquid path 123 Supply path 124 Injection liquid tank 125 Liquid tank 126 Support body 127 Heat conduction member 128 Adhesive layer

JP 2011-235480 A

Claims (10)

A nozzle plate on which nozzles are formed;
A flow path plate in which an individual liquid chamber communicating with the nozzle is formed;
A diaphragm for sealing at least a part of the individual liquid chamber;
An electromechanical conversion element provided on the side facing the individual liquid chamber via the diaphragm, and a liquid ejection head comprising:
An individual external electrode for driving the electromechanical transducer and a common external electrode for the plurality of electromechanical transducers;
The common external electrode is provided on the side facing the flow path plate through the diaphragm,
A liquid flow path independent of the individual liquid chambers is provided in the arrangement direction of the individual liquid chambers, and
A liquid discharge head, wherein a heat conductor is interposed between the common external electrode and the liquid flow path. A nozzle plate on which nozzles are formed;
A flow path plate in which an individual liquid chamber communicating with the nozzle is formed;
A diaphragm for sealing at least a part of the individual liquid chamber;
An electromechanical conversion element provided on the side facing the individual liquid chamber via the diaphragm, and a liquid ejection head comprising:
Comprising a support for fixing the electromechanical transducer,
A liquid flow path independent of the individual liquid chambers is provided over the arrangement direction of the individual liquid chambers,
The liquid ejection head, wherein the vibration plate seals at least a part of the liquid flow path, and a heat conduction member is interposed between the vibration plate and the support. An individual external electrode for driving the electromechanical transducer and a common external electrode for the plurality of electromechanical transducers;
The common external electrode is provided on the side facing the flow path plate through the diaphragm,
The part of the common external electrode is in contact with the diaphragm, or the common external electrode and the diaphragm are provided via a heat conductor. Liquid discharge head.   The liquid ejection head according to claim 3, wherein at least one of the heat conducting member, the support body, and the diaphragm is provided via the heat conductor.   The liquid discharge head according to claim 2, wherein the heat conducting member is made of aluminum.   The liquid ejection head according to claim 1, wherein the heat conductor has an insulating property.   The liquid discharge head according to claim 1, wherein the liquid flow path is provided between two rows of the individual liquid chambers.   The liquid discharge head according to claim 1, wherein the same liquid as the discharge liquid discharged from the nozzle is circulated in the liquid flow path.   The liquid discharge head according to claim 1, wherein a liquid having a specific heat higher than that of the discharge liquid discharged from the nozzle is circulated in the liquid flow path.   An image forming apparatus comprising the liquid ejection head according to claim 1.