JP2011136460A - Liquid injection head and liquid injection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid injection head in which a heater is densely formed at each nozzle, and a means to control the heating timing of the heater corresponding to a nozzle opening according to discharge drive timing to discharge liquid from the nozzle opening. <P>SOLUTION: The liquid injection head is equipped with: a nozzle plate 14 in which a nozzle array composed of a plurality of nozzle openings 13 is formed; a flow path forming substrate 12 brought into contact with the nozzle plate 14, and having a plurality of pressure generating chambers 11 communicating with the plurality of nozzle openings 13 through nozzle communicating holes 24 as communicating paths, respectively, and formed in a nozzle array direction; and a heater 60 at least as one heater part brought into contact with the nozzle plate 14, and provided outside the flow path where the liquid flows in a position facing the plurality of pressure generating chambers 11, and heating inks as liquids in the plurality of pressure generating chambers 11. The heater 60 is formed over a nozzle array direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus.

  As an example of a liquid ejecting head, a liquid ejecting head including an actuator unit provided with a pressure generating element and a pressure generating chamber, for example, and ejecting a liquid such as ink from a nozzle opening provided in a nozzle plate in communication with the pressure generating chamber There is. In order to eject a highly viscous liquid using such a liquid ejecting head, it is necessary to increase the driving force of the pressure generating element by supplying a high voltage to the pressure generating element. Therefore, in Patent Document 1, a heater as a heating unit that reduces the viscosity of the liquid for each nozzle opening is provided, and a nozzle heating control unit that controls the heating timing by the heater according to the discharge driving timing for discharging the liquid from the nozzle opening. A liquid ejecting apparatus including the same has been proposed.

JP-A-2005-104135

  For example, in order to form a high-resolution image, the number of nozzle openings formed in the nozzle plate is increased. However, if the number of nozzle openings formed in the nozzle plate is increased, the nozzle openings must be formed in the nozzle plate at a high density. Therefore, as in Patent Document 1, there is a problem that it is not easy to form a heater with high density for each nozzle opening. In addition, there is a problem that it is not easy to construct means for controlling the heating timing of the heater corresponding to each nozzle opening in accordance with the ejection driving timing for ejecting liquid from each nozzle opening.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A nozzle plate in which a nozzle array including a plurality of nozzle openings is formed, and a plurality of pressure generation chambers that are in contact with the nozzle plate and communicate with each of the plurality of nozzle openings via communication passages, A flow path forming substrate formed in the nozzle row direction and the nozzle plate is provided at a position facing the plurality of pressure generation chambers and outside the flow path through which the liquid flows, and the liquid in the plurality of pressure generation chambers A liquid ejecting head, wherein the heating body portion is formed across the nozzle row direction.

  According to this configuration, at least one heating body part that is in contact with the nozzle plate, is provided at the position facing the pressure generation chamber and outside the flow path through which the liquid flows, and heats the liquid in the pressure generation chamber. As a result, the heat generated from the heating body portion can be conducted through the nozzle plate to increase the temperature of the liquid flowing through the nozzle opening, and the temperature of the liquid flowing through the pressure generating chamber can be increased. For this reason, it is possible to discharge a high viscosity liquid from the nozzle opening after reducing the viscosity. Further, at least one heating element is formed across the nozzle row direction. Therefore, the temperature of the liquid that passes through the plurality of nozzle openings formed in the liquid ejecting head and the liquid that flows through the plurality of pressure generation chambers can be increased by the heating body portion. Accordingly, it is only necessary to form at least one heating element in the liquid ejecting head, so that the heating element can be easily formed.

  Application Example 2 In the application example, a cavity is provided between the flow path forming substrate and the heating body portion in a direction orthogonal to a direction in which the pressure generating chamber and the heating body portion face each other. The liquid jet head.

  According to this configuration, the thermal conductivity in the direction orthogonal to the direction in which the pressure generating chamber and the heating body portion face each other is reduced by the cavity. As a result, the amount of heat generated in the heating body portion and conducted in the direction in which the pressure generation chamber and the heating body portion face each other increases, so that the temperature of the liquid in the pressure generation chamber can be further increased.

  Application Example 3 In the direction in which the pressure generating chamber and the heating body portion face each other, the heat generating member has higher thermal conductivity than the flow path forming substrate, and forms a part of the wall surface of the pressure generating chamber. The liquid ejecting head according to claim 1, further comprising a thermally conductive plate in contact with the body.

  According to this configuration, the thermal conductivity between the heating body portion and the pressure generating chamber is improved by the thermal conductive plate. Thereby, the heat generated from the heating body part can be conducted through the heat conductive plate to further increase the temperature of the liquid in the pressure generating chamber.

  Application Example 4 The apparatus further includes a liquid supply port communicating with the pressure generation chamber on the upstream side of the pressure generation chamber, and the viscosity of the liquid passing through the nozzle opening when the liquid is discharged from the nozzle opening. Is lower than the viscosity of the liquid passing through the liquid supply port.

  According to this configuration, when the liquid in the pressure generation chamber is about to be ejected, there is a liquid that is about to flow upstream of the pressure generation chamber and a liquid that is about to flow downstream of the pressure generation chamber. Since the liquid downstream of the pressure generating chamber has a lower viscosity than the liquid that is going to flow upstream of the pressure generating chamber, the liquid in the pressure generating chamber is more in the pressure generating chamber than the upstream side of the pressure generating chamber. It tries to flow to the nozzle opening side on the downstream side. Therefore, it becomes easy to discharge the liquid in the pressure generation chamber from the nozzle opening.

  Application Example 5 Liquid temperature for detecting the temperature of the liquid in the pressure generating chamber, including a temperature sensor and an energizing circuit unit that energizes the heating body unit and generates heat in the heating body unit. And a heating control unit that controls the energization circuit unit based on the temperature detected by the liquid temperature detection unit and controls a heat generation amount of the heating body unit. Liquid ejector.

  According to this configuration, the temperature range of the liquid in the plurality of pressure generating chambers formed in the liquid ejecting head can be adjusted. Therefore, it becomes easy to adjust the range of the viscosity of the liquid in the plurality of pressure generating chambers and to eject the highly viscous liquid from the nozzle opening. Therefore, the control means for heating the heating element can be easily constructed.

1 is a schematic perspective view of an ink jet printer. FIG. 3 is a cross-sectional view of a liquid jet head. FIG. 3 is a partial cross-sectional view of a liquid ejecting head. The fragmentary perspective view of the heater with which the nozzle plate was equipped. FIG. 2 is a block diagram showing an electrical schematic configuration of an ink jet printer. FIG. 9 is a cross-sectional view of a liquid jet head according to a second embodiment. FIG. 10 is a cross-sectional view of a liquid jet head according to a third embodiment. FIG. 9 is a cross-sectional view of a liquid jet head according to a fourth embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic perspective view of an ink jet printer (hereinafter referred to as “printer”) 1 as an example of a liquid ejecting apparatus of the present embodiment. The carriage 9 of the printer 1 is configured to be reciprocated in the main scanning direction D1 by being guided by the guide shaft 2 by the timing belt 3 driven by the carriage motor 6.

  The printer 1 includes a linear scale 4 in which slits at regular intervals are drawn in the main scanning direction D1, and a linear encoder including an optical system sensor (not shown) fixed to the carriage 9. The slit can be detected by the optical system sensor, and the position in the main scanning direction D1 can be detected.

  The recording paper P as a recording medium is conveyed in the sub-scanning direction D2 while being sandwiched between a paper feeding roller (not shown) driven by the paper feeding motor 7 and a freely driven roller (not shown).

  FIG. 2 is a cross-sectional view of an ink jet liquid ejecting head (hereinafter referred to as “liquid ejecting head”) 10. A liquid ejecting head 10 shown in FIG. 2 is mounted on the side of the carriage 9 in FIG. 1 that faces the recording paper P, and a black ink cartridge that supplies ink as liquid to the liquid ejecting head 10 on the upper side of the carriage 9 in the drawing. 5a and a color ink cartridge 5b are detachably loaded.

  The black ink cartridge 5a and the color ink cartridge 5b are filled with ink that is a highly viscous liquid such as ultraviolet curable ink. Ink is ejected from the liquid ejecting head 10 in the liquid ejecting direction D3 between the liquid ejecting head 10 reciprocating in the main scanning direction D1 and the platen 8 onto the recording paper P passing in the sub-scanning direction D2. It is the structure formed.

  As shown in FIG. 2, the liquid ejecting head 10 includes a flow path forming substrate 12 having a pressure generating chamber 11, a nozzle plate 14 in which a nozzle opening 13 communicating with the pressure generating chamber 11 is formed, and a flow path forming substrate. 12 includes a flow path unit 16 including a diaphragm 15 provided on a surface opposite to the nozzle plate 14. Furthermore, it has a piezoelectric element unit 18 having a piezoelectric element 17 provided in a region corresponding to the pressure generating chamber 11 on the vibration plate 15, and an accommodating portion 19 that is fixed on the vibration plate 15 and accommodates the piezoelectric element unit 18. And a case head 20.

  The nozzle plate 14 is formed with a nozzle row including a plurality of nozzle openings 13 in the sub-scanning direction D2 of FIG. The flow path forming substrate 12 is provided with a plurality of pressure generating chambers 11 partitioned by partition walls in the surface layer portion on one surface side so as to be aligned in the nozzle row direction corresponding to each nozzle.

  Ink is supplied to the outside of the row of each pressure generating chamber 11 via an ink introduction port 21 communicating with the black ink cartridge 5a and the color ink cartridge 5b as ink supply means outside the case head 20, and a plurality of pressures are supplied. A reservoir 22 serving as a common liquid chamber for the generation chamber 11 is provided so as to penetrate the flow path forming substrate 12 in the thickness direction. The reservoir 22 and each pressure generation chamber 11 communicate with each other via an ink supply port 23, and ink is supplied to each pressure generation chamber 11 from an ink supply unit via an ink introduction port 21 and the reservoir 22. . Of course, the reservoir 22 does not need to be formed on the flow path forming substrate 12. For example, the reservoir 22 is provided in the case head 20, and the ink supply port 23 described later is provided in the vibration plate 15. The chamber 11 may be in liquid communication.

  An ink supply port 23 (a kind of liquid supply port) is formed for each pressure generation chamber 11. Further, since the ink supply port 23 is formed with a cross-sectional area narrower than that of the pressure generation chamber 11, the ink supply port 23 plays a role of keeping the flow path resistance of the ink flowing from the reservoir 22 into the pressure generation chamber 11 constant. Further, a nozzle communication hole 24 is formed in each pressure generation chamber 11 on the end side opposite to the reservoir 22 of the pressure generation chamber 11 through the flow path forming substrate 12.

  Thus, in the present embodiment, each pressure generating chamber 11 is filled with ink by flowing ink from the reservoir 22 through the ink supply port 23 in the surface direction of the flow path forming substrate 12. That is, the flow path forming substrate 12 is provided with the pressure generating chamber 11, the reservoir 22, the ink supply port 23, and the nozzle communication hole 24.

  Such a flow path forming substrate 12 is made of a silicon single crystal substrate, and the pressure generating chamber 11 and the like provided on the flow path forming substrate 12 are formed by etching the flow path forming substrate 12. Of course, as the material for the flow path forming substrate 12, in addition to the silicon single crystal substrate, a metal material such as stainless steel or a resin material such as photosensitive resin may be used.

  The nozzle plate 14 is bonded to one surface side of the flow path forming substrate 12 via an adhesive 50, and each nozzle opening 13 is connected to each pressure generating chamber via a nozzle communication hole 24 provided in the flow path forming substrate 12. 11 communicates. On the other hand, the diaphragm 15 is bonded to the other surface side of the flow path forming substrate 12. Each pressure generating chamber 11 is defined by the diaphragm 15.

  The vibration plate 15 is formed of a composite plate of an elastic film 25 made of an elastic member such as a resin film and a support plate 26 made of, for example, a metal material that supports the elastic film 25, and the elastic film 25 side is It is joined to the flow path forming substrate 12 via an adhesive 51.

  In addition, an island portion 27 is provided in a region of the diaphragm 15 facing each pressure generating chamber 11, and the tip portion of the piezoelectric element 17 contacts the island portion 27. The tip of the piezoelectric element 17 is joined to the island 27 by an adhesive 28.

  In addition, in a region facing the reservoir 22 of the vibration plate 15, a compliance portion 29 configured by only the elastic film 25 is provided by removing the support plate 26 by etching. The compliance unit 29 absorbs the pressure change when the elastic film 25 of the compliance unit 29 is deformed when the pressure change in the reservoir 22 occurs, and plays a role of constantly maintaining the pressure in the reservoir 22. . Further, the diaphragm 15 is provided with an opening 30 so that the ink introduction port 21 and the reservoir 22 are in fluid communication.

  The piezoelectric element 17 is integrally formed in one piezoelectric element unit 18. That is, a piezoelectric element forming member 34 in which the piezoelectric material 31 and the electrode forming materials 32 and 33 are vertically sandwiched and laminated is formed to correspond to each pressure generating chamber 11. Each piezoelectric element 17 is formed by cutting into comb teeth.

  An inactive region that does not contribute to vibration of the piezoelectric element 17 (piezoelectric element forming member 34), that is, the base end side of the piezoelectric element 17 is fixed to the fixed substrate 35. In the present embodiment, the piezoelectric element unit 18 is configured by the piezoelectric element 17 (piezoelectric element forming member 34) and the fixed substrate 35. In the vicinity of the base end portion of the piezoelectric element 17, a circuit board 37 having a wiring 36 for supplying a signal for driving each piezoelectric element 17 is connected to the surface opposite to the fixed board 35.

  Such a piezoelectric element unit 18 is fixed in a state where the distal end portion of the piezoelectric element 17 is in contact with the island portion 27 of the diaphragm 15 as described above. For example, in this embodiment, the case head 20 is fixed on the diaphragm 15, and the piezoelectric element unit 18 is accommodated in the accommodating portion 19 of the case head 20, and the fixed substrate on which the piezoelectric element 17 is fixed. 35 is fixed to the case head 20 on the side opposite to the piezoelectric element 17. Specifically, a stepped portion 38 is provided in the accommodating portion 19 of the case head 20, and the fixed substrate 35 is bonded to the stepped portion 38 of the case head 20 with an adhesive 39.

  Further, a wiring board 41 provided with a plurality of conductive pads 40 to which the respective wirings 36 of the circuit board 37 are connected is fixed on the case head 20, and the housing portion 19 of the case head 20 is connected to the wiring board 41. 41 is substantially blocked. The wiring board 41 is formed with a slit-like opening 42 in a region facing the housing part 19 of the case head 20, and the circuit board 37 is drawn out of the housing part 19 from the opening 42 of the wiring board 41. It is.

  Moreover, the circuit board 37 which comprises the piezoelectric element unit 18 consists of chip-on-film (COF) in which the drive IC (not shown) for driving the piezoelectric element 17 was mounted in this embodiment, for example. Each wiring 36 of the circuit board 37 is connected to the electrode forming materials 32 and 33 constituting the piezoelectric element 17 by, for example, solder, anisotropic conductive material, or the like on the base end side. On the other hand, each wiring 36 is joined to each conductive pad 40 of the wiring board 41 on the tip side. Specifically, each wiring 36 is connected to the wiring board 41 in a state in which the tip of the circuit board 37 drawn out of the housing part 19 from the opening 42 of the wiring board 41 is bent along the surface of the wiring board 41. The conductive pads 40 are joined to each other.

  FIG. 3 is a partial cross-sectional view of the liquid ejecting head 10. As shown in FIG. 2 and FIG. 3, a heater 60 such as a film heater is used as a heating body portion in a region that does not become a liquid flow path of the flow path forming substrate 12 and faces the row of the pressure generation chambers 11. Is provided. The surface of the heater 60 on the vibration plate 15 side is connected to the flow path forming substrate 12 via an adhesive 61, and the surface of the heater 60 on the nozzle plate 14 side is connected to the nozzle plate 14 via an adhesive 50. Is done. Further, as shown in FIG. 3, the heater 60 is formed in a region facing the pressure generation chamber 11 of the flow path forming substrate 12, but is formed so as to extend to a region facing the ink supply port 23. Absent. As will be described later, this is because the liquid passing through the ink supply port 23 needs to have a higher viscosity than the liquid passing through the nozzle opening 13.

  FIG. 4 is a partial perspective view of the heater 60 provided in the nozzle plate 14, as viewed from the pressure generation chamber 11 side. As shown in FIG. 4, the heater 60 is formed over the nozzle row direction D4 in which the nozzle openings 13 are formed side by side.

  FIG. 5 is a block diagram illustrating an electrical schematic configuration of the printer 1. The printer 1 is schematically configured including a printer controller 70 and a print engine 100.

  The printer controller 70 includes an external interface (external I / F) 71 that exchanges data with an external device such as the host computer 200, a RAM 72 that stores various data, a control routine for various data processing, and the like. ROM 75, a control unit 73 that controls each unit, an oscillation circuit 74 that generates a clock signal CK, a drive signal generation circuit 76 that generates a drive signal COM to be supplied to the head drive circuit unit 101, and a dot pattern An internal interface (internal I / F) 77 for outputting data, drive signals, and the like to the head drive circuit unit 101 is provided.

  The RAM 72 is used as a reception buffer, an intermediate buffer, an output buffer, and a work memory (not shown). Print data from the host computer 200 is temporarily stored in the reception buffer, intermediate code data is stored in the intermediate buffer, and dot pattern data is expanded in the output buffer.

  In addition to controlling each unit, the control unit 73 receives print data from the host computer 200 through the external I / F 71, converts the print data into intermediate code data, and converts the intermediate code data into dot pattern data.

  The control unit 73 outputs the dot pattern data to the head drive circuit unit 101 through the internal I / F 77. This dot pattern data is constituted by print data obtained by decoding (translating) gradation data.

  The control unit 73 supplies a latch signal, a channel signal, and the like to the head drive circuit unit 101 based on the clock signal CK from the oscillation circuit 74. The latch pulse and channel pulse included in these latch signal LAT and channel signal CH define the supply timing of each pulse constituting the drive signal.

  The drive signal generation circuit 76 is controlled by the control unit 73 and generates a drive signal for driving the piezoelectric element 17. The drive signal generating circuit 76 discharges ink as ink droplets (a type of droplet) from the nozzle opening 13 (see FIG. 2), and forms ejection dots on the recording paper P, and the nozzle opening 13 It is configured to generate a drive signal COM that includes a fine vibration pulse for agitating the ink by slightly vibrating the free surface of the exposed ink, that is, the meniscus.

  Next, the configuration of the print engine 100 will be described. The print engine 100 includes a carriage motor 6, a drive circuit unit 107 for driving the carriage motor 6, a paper feed motor 7, a drive circuit unit 108 for driving the paper feed motor 7, a linear encoder 110, and the linear encoder 110. A counting circuit 109 for counting the output encoder pulses, a head driving circuit 101 for driving the piezoelectric element 17 provided in the liquid ejecting head 10, and a pressure generating chamber 11 of the liquid ejecting head 10 are heated. The pressure generating chamber heating unit 114 and the liquid temperature detecting unit 111 for detecting the temperature of the ink in the pressure generating chamber 11 are configured.

  The control unit 73 acquires the value obtained by counting the encoder pulses from the counting circuit unit 109, and can recognize the scanning position of the carriage 9 (liquid ejecting head 10) in the main scanning direction D1.

  The head drive circuit unit 101 includes a shift register (SR) 102, a latch 103, a decoder 104, a level shifter (LS) 105, and a switch 106. The dot pattern data SI output from the printer controller 70 is serially transmitted to the shift register 102 in synchronization with the clock signal CK from the oscillation circuit 74. The dot pattern data SI is 2-bit data. For example, the dot pattern data SI is represented by gradation information representing four recording gradations (ejection gradations) including non-recording (fine vibration), small dots, medium dots, and large dots. It is configured. Specifically, non-printing is represented by gradation information “00”, small dots are represented by gradation information “01”, medium dots are represented by gradation information “10”, and large dots are represented by gradation information “11”.

  A latch 103 is electrically connected to the shift register 102. When a latch signal (LAT) from the printer controller 70 is input to the latch 103, the dot pattern data in the shift register 102 is latched. The dot pattern data latched by the latch 103 is input to the decoder 104. The decoder 104 translates 2-bit dot pattern data to generate pulse selection data. This pulse selection data is constituted by associating each bit with each pulse constituting the drive signal COM. Then, supply or non-supply of the ejection drive pulse to the piezoelectric element 17 is selected according to the contents of each bit, for example, “0” and “1”.

  The decoder 104 outputs pulse selection data to the level shifter 105 when receiving the latch signal (LAT) or the channel signal (CH). In this case, the pulse selection data is input to the level shifter 105 in order from the upper bit. The level shifter 105 functions as a voltage amplifier. When the pulse selection data is “1”, the level shifter 105 outputs an electric signal boosted to a voltage capable of driving the switch 106, for example, a voltage of about several tens of volts. The pulse selection data “1” boosted by the level shifter 105 is supplied to the switch 106. The drive signal COM from the drive signal generation circuit 76 is supplied to the input side of the switch 106, and the piezoelectric element 17 is connected to the output side of the switch 106.

  The pulse selection data controls the operation of the switch 106, that is, the supply of the drive pulse in the drive signal to the piezoelectric element 17. For example, during the period when the pulse selection data input to the switch 106 is “1”, the switch 106 is in a connected state, and the corresponding ejection drive pulse is supplied to the piezoelectric element 17, and the waveform of this ejection drive pulse is Following this, the potential level of the piezoelectric element 17 changes. On the other hand, during the period when the pulse selection data is “0”, the level shifter 105 does not output an electrical signal for operating the switch 106. For this reason, the switch 106 is in a disconnected state, and the ejection drive pulse is not supplied to the piezoelectric element 17.

  The decoder 104, the level shifter 105, the switch 106, the control unit 73, and the drive signal generation circuit 76 that perform such an operation function as an ejection control unit, and based on the dot pattern data SI, eject drive pulses from the drive signal. Is selected and applied (supplied) to the piezoelectric element 17. As a result, the piezoelectric element 17 expands or contracts in accordance with the voltage change of the ejection drive pulse, and the pressure generation chamber 11 (see FIG. 2) expands or contracts as the piezoelectric element 17 expands and contracts, thereby generating dot pattern data. An amount of ink droplets corresponding to the gradation information constituting SI is ejected from the nozzles.

  The pressure generation chamber heating unit 114 includes a heater 60 as a heating unit provided in the liquid ejecting head 10, and an energization circuit unit 115 that energizes the heater 60 and causes the heater 60 to generate heat.

  The liquid temperature detection unit 111 includes a thermistor (not shown) as the temperature sensor 113 and a detection circuit unit 112 that detects a signal output from the thermistor. The thermistor is provided in, for example, the nozzle plate 14 or the flow path forming substrate 12 in the vicinity of the pressure generating chamber 11 in FIG. 3, and the ink in the pressure generating chamber 11 is passed through the nozzle plate 14 or the flow path forming substrate 12. Detect temperature. The viscosity of the ink discharged from the nozzle opening 13 needs to be a constant viscosity that is easy to discharge. In order to control the speed and amount of the liquid ejected using the meniscus of the nozzle opening 13, it is not good that the viscosity is too low. However, the viscosity of the liquid flowing into the pressure generating chamber 11 is not constant depending on the use environment and the injection frequency. Moreover, there is a correlation between viscosity and temperature.

  Therefore, the heating control unit 78 detects the temperature in the pressure generation chamber 11 by the liquid temperature detection unit 111 including the temperature sensor 113 and the detection circuit unit 112, thereby grasping the viscosity in the pressure generation chamber 11 and energizing. The energization amount output from the circuit unit 115 is controlled, and the heat generation amount generated from the heater 60 is controlled.

  The heating control unit 78 includes a control program stored in the ROM 75, and functions when the control unit 73 reads out the control program from the ROM 75 and executes it in the RAM 72.

  As described above, the liquid ejecting head 10 provided in the printer 1 according to the present embodiment is in contact with the nozzle plate 14 in which the nozzle row including the plurality of nozzle openings 13 is formed and the nozzle plate 14. A plurality of pressure generating chambers 11 communicating with each other through a nozzle communication hole 24 as a communication path are in contact with the flow path forming substrate 12 formed in the nozzle row direction D4 and the nozzle plate 14 and face the plurality of pressure generating chambers 11. And a heater 60 as at least one heating body section that heats ink as liquid in the plurality of pressure generation chambers 11, and the heater 60 is formed across the nozzle row direction D4. Yes.

  According to this configuration, the heat generated from the heater 60 is conducted through the nozzle plate 14 to increase the temperature of the ink flowing through the nozzle opening 13, and the temperature of the ink flowing through the pressure generating chamber 11 can be increased. Therefore, it is possible to eject ink that is a highly viscous liquid from the nozzle openings 13. Further, at least one heater 60 is formed over the nozzle row direction D4. Therefore, the temperature of the ink that passes through the plurality of nozzle openings 13 formed in the liquid ejecting head 10 and the ink that flows in the plurality of pressure generation chambers 11 can be increased by the heater 60. Accordingly, since at least one heater 60 may be formed in the liquid ejecting head 10, the heater 60 can be easily formed.

  In addition, an ink supply port 23 serving as a liquid supply port communicating with the pressure generation chamber 11 is provided upstream of the pressure generation chamber 11. The heater 60 is not provided at a position where the ink supply port 23 faces the nozzle plate 14. For this reason, the temperature of the ink flowing in the pressure generating chamber 11 provided with the heater 60 at a position facing the nozzle plate 14 and passing through the nozzle opening 13 is higher than the temperature of the ink passing through the ink supply port 23. Therefore, when ink is ejected from the nozzle opening 13, the viscosity of the ink passing through the nozzle opening 13 is lower than the viscosity of the ink passing through the ink supply port 23.

  According to this configuration, when the pressure in the pressure generation chamber 11 is generated as a result of the driving of the piezoelectric element 17 serving as the pressure generation element, the ink in the pressure generation chamber 11 is more than the upstream side of the pressure generation chamber 11. Since it tends to flow toward the nozzle opening 13 which is relatively downstream of the pressure generating chamber 11, it becomes easy to discharge the ink in the pressure generating chamber 11 from the nozzle opening 13.

  In addition, the printer 1 described in the present embodiment includes the liquid ejecting head 10, the energization circuit unit 115 that energizes the heater 60 as the heating body unit to generate heat, and the thermistor as the temperature sensor 113. The liquid temperature detection unit 111 that detects the temperature of the liquid in the pressure generation chamber 11 and the energization circuit unit 115 are controlled based on the temperature detected by the liquid temperature detection unit 111 to control the amount of heat generated by the heater 60. A heating control unit 78.

  According to this configuration, the temperature range of the ink in the plurality of pressure generating chambers 11 formed in the liquid ejecting head 10 can be adjusted. Therefore, it becomes easy to adjust the range of the viscosity of the ink in the plurality of pressure generating chambers 11 and eject the high viscosity ink from the nozzle opening 13. Therefore, a control means for heating the heater 60 can be easily constructed.

(Second Embodiment)
In the second embodiment, a liquid ejecting head in which a cavity is provided between the flow path forming substrate 12 and the heater 60 will be described. FIG. 6 is a cross-sectional view of the liquid jet head 10a in the second embodiment.

  In the liquid jet head 10a of FIG. 6, a cavity 62 is provided on the reservoir 22 side of the heater 60 and a cavity 63 is provided on the nozzle communication hole 24 side of the heater 60 in a direction intersecting the liquid jet direction D3. The cavities 62 and 63 prevent heat from the heater 60 from being transmitted in the direction intersecting the liquid ejection direction D3. That is, in the heater 60 and the flow path forming substrate 12, the thermal conductivity in the direction intersecting with the liquid ejecting direction D3 can be made lower than the thermal conductivity in the liquid ejecting direction D3.

  Accordingly, the ratio of the amount of heat transmitted in the liquid ejecting direction D3 out of the amount of heat generated by the heater 60 increases, so that the temperature of the ink in the pressure generation chamber 11 further increases.

  Other configurations in the present embodiment are the same as those described in the first embodiment.

(Third embodiment)
In the second embodiment, cavities are provided on both sides of the heater 60 in the direction intersecting with the liquid ejecting direction D3. In the third embodiment, a liquid ejecting head in which a cavity is provided on one side of the heater 60 will be described. FIG. 7 is a cross-sectional view of the liquid jet head 10b according to the third embodiment.

  As shown in FIG. 7, in the direction crossing the liquid ejecting direction D <b> 3, the cavity 62 is provided on the reservoir 22 side of the heater 60, and no cavity is provided on the nozzle communication hole 24 side of the heater 60.

  Thereby, the thermal conductivity from the heater 60 to the nozzle communication hole 24 side is higher than the thermal conductivity from the heater 60 to the reservoir 22 side. As a result, the temperature of the ink flowing in the nozzle communication hole 24 becomes higher than the temperature of the ink flowing in the reservoir 22.

  Thereby, when ink is ejected from the nozzle opening 13, the viscosity of the ink passing through the nozzle opening 13 is lower than the viscosity of the ink passing through the reservoir 22. Accordingly, the ink in the pressure generation chamber 11 tends to flow toward the nozzle opening 13 on the downstream side of the pressure generation chamber 11 rather than the reservoir 22 side positioned on the upstream side of the pressure generation chamber 11. It becomes easy to discharge from 13.

  Other configurations in the present embodiment are the same as those described in the first embodiment.

(Fourth embodiment)
In the fourth embodiment, a liquid jet head including a heat conductive plate on the heater 60 side of the pressure generation chamber 11 will be described. FIG. 8 is a cross-sectional view of the liquid jet head 10c in the fourth embodiment.

  A heat conductive plate 64 is provided on the heater 60 side of the pressure generating chamber 11 of the liquid jet head 10c of FIG. The thermal conductive plate 64 has higher thermal conductivity than silicon forming the flow path forming substrate 12, and is formed of, for example, a member such as stainless steel or nickel, and constitutes a part of the wall surface on the heater 60 side in the pressure generation chamber 11. To do.

  Thereby, the heat conductivity between the heater 60 and the pressure generating chamber 11 is improved by the heat conductive plate 64. Thereby, the heat generated from the heater 60 can be conducted through the heat conductive plate 64 to further increase the temperature of the ink flowing in the pressure generating chamber 11.

  In the present embodiment, as described with reference to FIG. 7, the cavity 62 is provided on the reservoir 22 side of the heater 60 to reduce the thermal conductivity from the heater 60.

  Other configurations in the present embodiment are the same as those described in the first embodiment.

  In the first to fourth embodiments, the liquid ejecting heads 10, 10a, 10b, and 10c are each provided with one heater 60, but may be provided with a plurality of heaters whose longitudinal direction is the nozzle row direction D4.

  In the first to fourth embodiments, the printer including the liquid ejecting head in which the nozzle row in the sub-scanning direction D2 that the recording paper P conveys has been described. However, the nozzle row in the main scanning direction D1 is described. The present invention is also applied to a printer including a liquid ejecting head in which is formed.

  In the first to fourth embodiments, the ink jet liquid ejecting head that forms an image on the recording paper P has been described as an example of the liquid ejecting head. However, the liquid ejecting head is used for manufacturing a color filter such as a liquid crystal display. The present invention is also applied to color material ejection heads, organic EL displays, electrode material ejection heads used for electrode formation such as FEDs (field emission displays), bioorganic matter ejection heads used for biochip production, and the like.

  DESCRIPTION OF SYMBOLS 1 ... Inkjet printer 10, 10a, 10b, 10c ... Liquid ejecting head, 11 ... Pressure generating chamber, 12 ... Flow path forming substrate, 13 ... Nozzle opening, 14 ... Nozzle plate, 24 ... Nozzle communication hole, 60 ... Heater 62, 63 ... cavity, 64 ... heat conductive plate, 78 ... heating control part, 111 ... liquid temperature detection part, 115 ... energization circuit part, D4 ... nozzle row direction.

Claims (5)

A nozzle plate formed with a nozzle row composed of a plurality of nozzle openings;
A plurality of pressure generating chambers that are in contact with the nozzle plate and communicate with each of the plurality of nozzle openings via communication passages, and a flow path forming substrate formed in the nozzle row direction;
At least one heating body portion that is in contact with the nozzle plate and is located at a position facing the plurality of pressure generation chambers and outside the flow path through which the liquid flows, and heats the liquid in the plurality of pressure generation chambers. ,
The liquid ejecting head according to claim 1, wherein the heating body portion is formed in the nozzle row direction. The liquid ejecting head according to claim 1,
A liquid ejecting head, wherein a cavity is provided between the flow path forming substrate and the heating body portion in a direction orthogonal to a direction in which the pressure generating chamber and the heating body portion face each other. The liquid ejecting head according to claim 1 or 2,
Heat that has higher thermal conductivity than the flow path forming substrate in a direction in which the pressure generation chamber and the heating body portion face each other, forms a part of the wall surface of the pressure generation chamber, and is in contact with the heating body portion A liquid ejecting head comprising a conductive plate. The liquid ejecting head according to any one of claims 1 to 3,
A liquid supply port communicating with the pressure generation chamber is further provided on the upstream side of the pressure generation chamber,
The liquid ejecting head according to claim 1, wherein when the liquid is discharged from the nozzle opening, the viscosity of the liquid passing through the nozzle opening is lower than the viscosity of the liquid passing through the liquid supply port. The liquid jet head according to any one of claims 1 to 4,
An energizing circuit section for energizing the heating body section and generating heat in the heating body section;
A liquid temperature detector having a temperature sensor and detecting the temperature of the liquid in the pressure generating chamber;
A liquid ejecting apparatus comprising: a heating control unit that controls the energization circuit unit based on the temperature detected by the liquid temperature detection unit and controls a heat generation amount of the heating body unit.

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