JP6205849B2 - Print head unit and printing apparatus - Google Patents

Description

  The present invention relates to a print head unit and a printing apparatus for performing printing by discharging a liquid onto a recording medium.

  Conventionally, an inkjet head described in Patent Document 1 is known as an inkjet head that records a desired image by discharging a liquid such as ink onto a recording medium. In the ink jet head, ink is transferred from the ink chamber to the nozzle, and the transferred ink is ejected from the nozzle as droplets. The amount of ink droplets ejected from the nozzles is controlled by a drive circuit provided on the head substrate of the ink head. In the head substrate of this conventional ink head, a drive circuit is arranged inside the head substrate.

  Conventionally, an inkjet printing apparatus having a plurality of piezo-type inkjet heads that pressurize ink in an ink chamber by displacement of a piezoelectric actuator using a piezoelectric actuator (piezo element) and eject ink droplets from nozzles is known. . When driving the piezoelectric actuator, it is necessary to apply a relatively high driving voltage. For this reason, in many cases, the head substrate of the ink jet head is provided with a drive IC for supplying a drive voltage to the piezoelectric actuator. The amount of ink droplets ejected from the nozzles is controlled by driving the piezoelectric actuator in accordance with the drive voltage from the drive IC.

JP 2000-218803 A

  Since the head substrate is connected to other components that control the drive circuit, the surface of the head substrate may be flat with few irregularities in relation to the arrangement of the head substrate and wiring components connected to the head substrate. desirable. In order to reduce unevenness on the surface of the head substrate, it is conceivable to embed the drive IC in the head substrate. However, a drive IC that supplies a drive voltage to the piezoelectric actuator generates a large amount of heat in nature. Since the inside of the head substrate has poor heat dissipation compared to the head substrate surface, if the heat radiation from the drive IC is not sufficient, the operation of the drive IC may become unstable or the drive IC may be damaged. It was.

  It is an object of the present invention to provide a print head unit and a printing apparatus that improve the heat dissipation of a drive IC embedded in a head substrate.

  A print head unit according to a first aspect of the present invention includes a discharge unit having a discharge port capable of discharging a liquid, and a piezoelectric actuator that is driven according to a drive voltage and controls a discharge amount of the liquid discharged from the discharge unit. A driving IC having a voltage circuit for controlling the driving voltage; a head substrate in which the driving IC is embedded between a plurality of stacked substrates; and a plan view in at least one surface of the head substrate. In the head substrate surface, a metal layer disposed in a region overlapping with a region where the driving IC is embedded, and a thickness direction of the head substrate from the driving IC side embedded in the head substrate to the metal layer And a heat transfer portion in which a heat transfer layer made of a heat conductive material is formed on the inner peripheral surface of the through hole.

  In the print head unit according to the first aspect, the heat generated from the drive IC embedded in the head substrate is transferred from the side where the drive IC is disposed through the heat transfer section that passes between the drive IC and the metal layer. It is possible to dissipate heat to the metal layer formed on the surface. Therefore, it is possible to prevent the liquid ejection failure from occurring in the print head unit due to damage to the drive IC due to heat or malfunction.

  The print head unit may include a heat radiating member standing in a direction away from the surface of the metal layer in a region where the metal layer is disposed on the head substrate surface. The metal layer may have a contact area that contacts the heat radiating member, and the heat transfer section may be disposed in the contact area.

  In this case, the print head unit conducts heat generated from the drive IC embedded in the head substrate to the metal layer through a heat transfer portion that passes between the drive IC and the metal layer, and further transfers the conducted heat from the metal layer. It is possible to dissipate heat to the heat radiating member. Here, since the heat radiating member is provided so as to be in contact with the region where the heat transfer portion of the metal layer is disposed, the heat conducted from the drive IC to the metal layer can be effectively radiated to the heat radiating member. For this reason, the print head unit can improve the heat dissipation of the drive IC embedded in the head substrate. In addition, it is possible to prevent a liquid ejection failure from occurring in the print head unit due to damage or malfunction of the drive IC due to heat.

The print head unit may include a liquid flow path that guides the liquid supplied to the discharge unit to the discharge port. The liquid flow passage may be arranged at a position between the position of said discharge port of said metallic layer.

Depending on the liquid such as ink supplied to the ejection unit, there is a possibility that it will boil and deteriorate when heated. There is a possibility that liquid ejection failure may occur due to clogging of the ejection port due to boiling or altered liquid. In order to prevent boiling and deterioration of the liquid in the discharge port, the discharge port is preferably disposed at a position away from the drive IC that may generate heat and the metal layer to which heat generated from the drive IC is conducted. By disposing the liquid channel at a position between the position of the discharge port and the position of the metal layer , the distance between the metal layer and the discharge port can be separated. Therefore, it is possible to prevent the occurrence of liquid discharge failure due to boiling and alteration of the liquid in the discharge port.

The liquid channel may include a supply port that supplies a liquid to the discharge unit, and a liquid storage unit that stores the liquid supplied from the supply port to supply the discharge port. The supply port may be disposed at a position between the position of said discharge port of said metallic layer.

In this case, by disposing the liquid supply port between the metal layer and the discharge port, the liquid flow path is disposed between the metal layer and the discharge port, so that the distance between the metal layer and the discharge port is increased. be able to. In addition, since the supply port serving as the entrance of the liquid flow path is disposed at a position between the position of the metal layer and the position of the discharge port , the liquid guided from the supply port to the discharge port via the liquid storage portion In addition, it is possible to prevent the occurrence of defective liquid discharge due to boiling and alteration due to heat from the driving IC and the metal layer.

  The discharge unit may have a discharge surface on which a plurality of the discharge ports are formed. The head substrate may be provided substantially vertically upward with respect to the ejection surface. The liquid storage unit may be disposed above the discharge surface and provided on the same side as the discharge surface with respect to the head substrate. The supply port may be disposed above a position where the liquid storage unit is disposed.

  In this case, the head substrate is provided substantially vertically upward with respect to the ejection surface. In addition, the liquid reservoir is disposed above the ejection surface, and the supply port is disposed above the liquid reservoir. Since the liquid flow path is arranged between the metal layer provided on the surface of the head substrate and the discharge port, the distance between the metal layer and the discharge port can be pulled up and down. In addition, it is possible to prevent the occurrence of liquid discharge failure due to the liquid led from the supply port to the discharge port through the liquid storage unit being boiled and altered by the heat from the driving IC and the metal layer.

  A printing apparatus according to a second aspect of the present invention supports a plurality of print head units according to any one of claims 1 to 5, and performs main scanning with respect to a print medium with respect to each of the plurality of print head units. A printing apparatus including a carriage that moves relative to a direction, wherein the head substrate provided in the print head unit is disposed so that the surface thereof is substantially parallel to the main scanning direction. And

  In the printing apparatus according to the second aspect, the ejection unit of the print head unit is moved relative to the print medium in the main scanning direction by the carriage. Here, the surface of the head substrate provided in the print head unit is disposed substantially parallel to the main scanning direction. For this reason, when the carriage is driven, the surface of the head substrate disposed in the print head unit moves relative to the print medium in substantially parallel to the main scanning direction. Therefore, the air in the vicinity of the head substrate surface is easily moved in the main scanning direction, and the heat radiation effect to the outside of the metal layer disposed on the head substrate surface is enhanced. Therefore, the heat dissipation of the drive IC embedded in the head substrate can be improved. Thereby, it is possible to prevent the print quality from being deteriorated due to the drive IC being damaged by heat or causing malfunction.

  The head substrate may be attached to one end side of the print head unit. The carriage includes a set of two print head units arranged so that the one end sides of the print head unit face each other, and the set print head unit is a sub-substantially orthogonal to the main scanning direction. You may support at least 1 set substantially parallel to a scanning direction. The metal layer may be disposed on the surface of the surface of the head substrate that faces the other end side opposite to the one end side.

  In this case, since the print head units are arranged back to back so that one end sides face each other, the space required for mounting a plurality of print head units on the carriage is reduced, and the enlargement of the carriage is suppressed. Can do. In addition, a metal layer is disposed on the surface of the head substrate facing the other end side opposite to the one end side facing the set of print head units, on the surface of the head substrate. When the carriage is driven, the air near the head substrate surface moves more easily on the head substrate surface facing the other end side than on the head substrate surface facing the one end side, which is the side facing a set of print head units. , Heat is hard to stay. Therefore, it is possible to improve the heat dissipation of the drive IC embedded in the head substrate while arranging the print head unit in a compact manner. Thereby, it is possible to prevent the print quality from being deteriorated due to the drive IC being damaged by heat or causing malfunction.

1 is a perspective view illustrating an overall configuration of a printing apparatus 30. FIG. 3 is a front view of the printing apparatus 30. FIG. 3 is a plan view of the printing apparatus 30. FIG. FIG. 4 is a perspective view showing an arrangement relationship between a platen 39 and a carriage 34. 3 is a perspective view of a carriage 34 that supports a print head unit 35. FIG. 4 is a bottom view showing a schematic configuration of a carriage 34. FIG. 3 is a perspective view of a print head unit 351. FIG. 3 is a block diagram showing an electrical configuration of the printing apparatus 30. FIG. 4 is a plan view showing a first layer P1 of a head substrate 241. FIG. 5 is a plan view showing a second layer P2 of the head substrate 241. FIG. 4 is a plan view showing a third layer P3 of the head substrate 241. FIG. 5 is a plan view showing a fourth layer P4 of the head substrate 241. FIG. 5 is a plan view showing a fifth layer P5 of the head substrate 241. FIG. 6 is a plan view showing a sixth layer P6 of the head substrate 241. FIG. 4 is a partial cross-sectional view of the head substrate 241 showing the structure of the head substrate 241. FIG. FIG. 6 is a partial cross-sectional view of the head substrate 241 showing heat radiation fins 261 that come into contact with the metal layer 401 on the surface of the head substrate 241.

  An embodiment of the present invention will be described with reference to the drawings. First, a schematic configuration of the printing apparatus 30 will be described with reference to FIGS. The printing apparatus 30 is connected to a personal computer (hereinafter referred to as a PC) 1 (see FIG. 8 described later). A user creates print data to be printed on a recording medium by operating the PC 1, and the PC 1 has a function of transmitting the created print data to the printing apparatus 30 via a cable. The printing apparatus 30 has a function of executing a printing process in which liquid (for example, ink) is ejected to the print head 20 (see FIG. 6 described later) based on the print data transmitted from the PC 1. The lower left side and upper right side in FIG. 1 are the front side and the back side of the printing apparatus 30, respectively. An upper left direction and a lower right direction in FIG. 1 are a left direction and a right direction of the printing apparatus 30, respectively, and an up and down direction in FIG. 1 is an up and down direction of the printing apparatus 30. The printing apparatus 30 includes a rectangular box-shaped casing 31.

  A guide rail 33 extends in the left-right direction at approximately the center in the front-rear direction of the casing 31 and above a platen 39 described later. The carriage 34 is supported by the guide rail 33 so as to be movable along the guide rail 33 in the main scanning direction that is the left-right direction of the housing 31. The carriage 34 supports a print head unit 35 as a general concept including a plurality of print head units 351 to 358 (see FIG. 5 described later). By driving a main scanning motor 46 provided near the right end of the guide rail 33, the carriage 34 moves along the guide rail 33 in the main scanning direction. At this time, as shown in FIG. 3, a pair of rollers 500 and 500 respectively provided at the front end portion of the carriage 34 travel on the upper surface of the horizontal member 152 provided in the horizontal direction of the casing 31. The carriage 34 has a pair of left and right protruding cylindrical guide engaging portions 341 engaged with the guide rail 33 and the pair of rollers 500 and 500 traveling on the upper surface of the horizontal member 152. It can be reciprocated along the guide rail 33 (see FIG. 1, FIG. 3, FIG. 4 and FIG. 5 described later). The carriage 34 is fixed to a drive belt 101 that is stretched along the main scanning direction, and the carriage 34 moves in the main scanning direction when the main scanning motor 46 drives the driving belt 101. In FIG. 5, a felt 153 is provided to remove foreign matters on the horizontal member 152 when the rollers 500 and 500 move on the horizontal member 152. Hereinafter, when the print head units 351 to 358 are collectively referred to, or when any of them is not specified, the print head units 351 to 358 are referred to as print head units 35.

  The printing apparatus 30 is an ink jet printer that can eject liquid onto a recording medium. In the present embodiment, the liquid is ink, and the printing apparatus 30 can print on a recording medium using each ink of cyan, yellow, magenta, black, and white. Eight ink cartridges (not shown) that contain each ink are mounted on the left side surface of the printing apparatus 30. The four ink cartridges contain color inks of cyan, magenta, yellow, and black, and the remaining four ink cartridges contain white ink. Each ink cartridge is connected to a flexible ink supply tube 321 (see FIG. 7), and the ink is led out from each ink cartridge, and each ink supply tube 321 (see FIG. 7) is connected. To the print head 20 of each color (see FIG. 6). In addition, a maintenance mechanism is provided at the position where the carriage 34 has moved to the left end of the guide rail 33, which includes a suction pump (not shown), etc., and performs so-called purging or the like that prevents clogging of the nozzle 21 (see FIG. 6). It has been.

  A pair of guide rails 37 extend in the front-rear direction at a substantially central lower portion in the left-right direction inside the housing 31. The pair of guide rails 37 are respectively supported on the base portion 5 raised in the vertical direction of the casing 31 and can be moved in the front-rear direction (sub-scanning direction) along the guide rail 37 on the upper portion of the base portion 5. A platen support base 38 is supported. A replaceable platen 39 is fixed to the upper end of a column that is vertically raised substantially at the center of the platen support 38.

  The platen 39 is a substantially rectangular plate whose longitudinal direction is the front-rear direction of the housing 31 in plan view, and is used for horizontally placing a recording medium made of a fabric such as a T-shirt on the upper surface thereof. is there. The tray 4 supported by the platen support base 38 receives the sleeve of the T-shirt when the user places the T-shirt or the like on the platen 39, so that the sleeve or the like becomes the bottom surface of the housing 31. It is for protecting it from falling. A sub-scanning motor 47 (see FIG. 8) is provided at the rear end of the platen drive mechanism 6 provided with a guide rail 37 for moving the platen support 38. The platen support 38 is moved along the guide rail 37 in the sub-scanning direction that is the front-rear direction of the housing 31 by driving the sub-scanning motor 47. Although not shown in detail, an operation panel 51 (see FIG. 8) for operating the printing apparatus 30 is provided at a position immediately before the right side of the casing 31 with a display 49 (see FIG. 8). Yes.

  The printing apparatus 30 can form pixel rows (dot rows) in the main scanning direction by causing the print head 20 (see FIG. 6) to eject ink while moving the print head unit 35 in the main scanning direction. When the scanning in the main scanning direction is completed, the printing apparatus 30 moves the platen support base 38 on which the platen 39 is supported in the sub-scanning direction, and then forms a pixel row in the main scanning direction again. The printing apparatus 30 repeatedly performs the above operation according to the print data, thereby forming a plurality of pixel rows on the recording medium and performing printing.

  As described above, the printing apparatus 30 according to the present embodiment moves the carriage 34 in the main scanning direction and moves the platen 39 in the sub-scanning direction, so that the carriage 34 is placed on the platen 39 (the platen 39). Moved relative to the printed print medium). However, the printing apparatus 30 only needs to be able to move the carriage 34 relative to the platen 39, and the specific movement method is not limited to the method of the present embodiment. That is, when the platen 39 is moved in the main scanning direction and the carriage 34 is moved in the sub-scanning direction, when only the platen 39 is moved in the main scanning direction and the sub-scanning direction, only the carriage 34 is moved in the main scanning direction and the sub-scanning direction. It is possible to adopt a method of moving to.

  A detailed configuration of the print head unit 351 will be described with reference to FIG. Although FIG. 7 shows only the print head unit 351 as an example, the other seven print head units 352 to 358 (see also FIG. 5 and the like) have the same configuration.

  The print head unit 351 includes a base plate 271 whose longitudinal direction is the front-rear direction (see FIGS. 1 and 4) in a state where the print head unit 351 is supported by the carriage 34. The base plate 271 is a substantially rectangular plate. In addition, the upper right and lower left of FIG. 7 are the one end side and the other end side in the longitudinal direction of the base plate 271, respectively. Hereinafter, one end side in the longitudinal direction of the base plate 271 is simply referred to as “one end side”, and the other end side in the longitudinal direction of the base plate 271 is simply referred to as “other end side”. The base plate 271 is provided substantially horizontally below the print head unit 351 when installed on the carriage 34. A print head 201 for discharging ink is provided below the base plate 271. A nozzle surface 22 on which a plurality of nozzles 21 are formed is provided on the bottom surface of the print head 201 (see FIG. 6 described later). The nozzle surface 22 is a substantially horizontal plane. A base end attaching portion 291 is provided on one end side of the base plate 271. Further, a tip mounting portion 281 is provided on the other end side of the base plate 271. The other seven print head units 352 to 358 also have base plates 272 to 278 similar to the base plate 271, respectively.

  On one end side of the base plate 271, a head substrate 241, which is a multilayer printed circuit board on which electrical components such as various IC chips are mounted, is held by a vertically long arm 251, and a nozzle surface on the bottom surface of the print head 201. 22 (see FIG. 6) is vertically erected upward. Although details will be described later, a head drive IC 431 (see FIG. 8) including a voltage circuit for controlling a drive voltage for driving the piezoelectric actuator 441 (see FIG. 8) is embedded in the head substrate 241. That is, the head substrate 241 is a multilayer substrate in which a plurality of substrates are stacked, and a head driving IC 431 is disposed between the stacked substrates. The head substrates 242 to 248 of the other seven print head units 352 to 358 also have head drive ICs 432 to 438 similar to the head drive IC 431, respectively (see FIG. 8).

  A metal layer 401 is disposed on one side of the surface of the head substrate 241 in the middle in the vertical direction. The metal layer 401 is a part of a circuit pattern provided on the surface of the head substrate 241. The metal layer 401 is patterned into a predetermined shape on the surface of the head substrate 241. Although details will be described later, the metal layer 401 is provided on the surface of the head substrate 241 in order to dissipate heat generated from the head driving IC 431 embedded in the head substrate 241 to the outside of the head substrate 241. When the print head unit 351 is supported by the carriage 34 together with the other print head units 352 to 358, the print head units 351 are arranged so as to face each other with their one ends facing each other (see FIG. 5 described later). At this time, the head substrate 241 is positioned above the nozzle surface 22 (see FIG. 6) with the surface of the surface on which the metal layer 401 is disposed facing the other end side opposite to the one end side. Standing vertically. Further, a heat radiating fin 261 in which a large number of metal thin plates for cooling are arranged with a narrow gap in the lateral direction is provided at the middle portion in the vertical direction of the head substrate 241. Although details will be described later, the radiation fins 261 are fixed to the arm 251 and the head substrate 241 in a state of being in contact with the metal layer 401. The head substrates 242 to 248 of the other seven print head units 352 to 358 also have metal layers 402 to 408 similar to the metal layer 401, respectively. The metal layers 402 to 408 are provided with heat radiation fins 262 to 268 similar to the heat radiation fins 261, respectively.

  In the print head 201, 128 ejection channels for ejecting ink are provided. In the present embodiment, as an actuator of the print head 201, a piezoelectric actuator using a piezo element having a characteristic of changing its volume when a voltage is applied as a driving energy source is used. Each ejection channel is provided with a piezoelectric actuator 441 (see FIG. 8) that is driven by a drive voltage from a voltage circuit provided in a head drive IC 431 (see FIG. 8) embedded in the head substrate 241 individually. On the bottom surface of the print head 201, a nozzle surface 22 on which 128 fine nozzles 21 are formed is provided (see FIG. 6). Then, corresponding to each ejection channel, the piezoelectric actuator 441 is controlled so that ink is ejected downward from the nozzle 21 formed on the nozzle surface 22 of the print head 201 and printing on the recording medium is performed. The print heads 202 to 208 of the other seven print head units 352 to 358 also have piezoelectric actuators 442 to 448 similar to those of the print head 201, respectively (see FIG. 8).

  Further, the print head unit 351 includes a flow path section 211 on the base plate 271. The flow path unit 211 is connected to the print head 201 provided below the base plate 271, and supplies ink supplied from the ink cartridge (not shown) to the print head 201 of the print head unit 351. It is a member that forms an ink flow path. The flow path unit 211 includes a supply port 231 and an ink tank 221. The ink tank 221 is disposed on the base plate 271 of the print head unit 351. The ink tank 221 is a part capable of storing the ink supplied from the ink cartridge via each ink supply tube 321. A supply port 231 for supplying ink to the ink tank 221 is provided above the ink tank 221. The ink stored in the ink tank 221 is supplied to the print head 201. The ink tank 221 is disposed on the other end side with respect to the head substrate. The nozzle surface 22 on the bottom surface of the print head 201 is also arranged on the other end side with respect to the head substrate, similarly to the ink tank 221.

  The metal layer 401 described above is disposed at a position above the supply port 231 on the surface of the head substrate 241. For this reason, the flow path portion 211 including the supply port 231 and the ink tank 221 is disposed between the metal layer 401 and the nozzle 21 (see FIG. 6) formed on the nozzle surface 22 in the vertical direction.

  A detailed configuration of the carriage 34 will be described with reference to FIGS. 5 and 6. As shown in FIG. 5, the carriage 34 supports a total of eight print head units 351 to 358, four each on the front and rear sides. A lower portion of the carriage 34 is opened. Print heads 201 to 208 are provided below the plurality of print head units 351 to 358, respectively. Nozzle surfaces 22 on which 128 fine nozzles 21 are formed are respectively provided on the bottom surfaces of the print heads 201 to 208 (see FIG. 6). As described above, the nozzle surface 22 is a substantially horizontal plane. Each of the plurality of nozzles 21 is formed on the nozzle surface 22. In FIG. 6, the number of nozzles 21 smaller than the actual number is shown for the sake of simplicity. The ink supplied from the ink cartridge (not shown) to each of the plurality of print heads 201 to 208 is ejected downward from the nozzle 21 by driving of the piezoelectric actuators 441 to 448 (see FIG. 8) provided in the ejection channel. Is done.

  The print head 201 is cyan (C), the print head 202 is magenta (M), the print head 203 is yellow (Y), the print head 204 is black (K), and the print heads 205 to 208 are white (W) inks. Is discharged. That is, the carriage 34 is a general concept printing including print heads 201 to 208 that eject inks of cyan (C), magenta (M), yellow (Y), black (K), and white (W). A head 20 is provided at the bottom. Therefore, the printing apparatus 30 can perform printing by discharging both white ink and color ink onto a recording medium. In the present embodiment, the white ink is ejected over the entire or part of the area where printing is performed as a background in printing such as when the color of the print medium is dark before the color ink is ejected. That is, the white ink is a pretreatment ink. The color ink is used to draw a pattern or the like in the area after the white ink is ejected over the entire area or a part where the printing is performed. That is, the color ink is a post-processing ink. The white ink is also used as post-processing ink for drawing a pattern or the like. Therefore, the printing apparatus 30 can perform various printing regardless of the color of the recording medium. Hereinafter, when the print heads 201 to 208 are collectively referred to, or when any of them is not specified, the print head 20 is referred to.

  Further, regarding the pre-processing ink and the post-processing ink, depending on the print image, the pre-processing color ink may not necessarily be ejected after the pre-processing white ink is ejected. More specifically, there may be a region where only pre-processing white ink is ejected or a region where only post-processing color ink is ejected. In this embodiment, white ink is used as pre-processing ink, and color ink is used as post-processing ink. However, combinations of pre-processing ink and post-processing ink, types of ink, and the like are as follows. It can be changed as appropriate and is not limited to the case of this embodiment.

  Of the eight print head units 351 to 358 supported by the carriage 34, four print head units 351 to 354 are provided on the front side of the printing apparatus 30 (see FIGS. 1 and 3). The remaining four print head units 355 to 358 are provided on the rear side. At that time, the print head units 351 to 354 and the print head units 355 to 358 are arranged so as to be back to back with each other facing one end side (see FIGS. 4 and 5). The two print head units back-to-back in this way (the print head unit 351 and the print head unit 355, the print head unit 352 and the print head unit 356, the print head unit 353 and the print head unit 357, and the print head unit 354). And the print head unit 358), each of which is arranged in the main scanning direction. The carriage 34 supports four sets of the print head units in the above set in the longitudinal direction substantially parallel to the sub-scanning direction. When the print head units 351 to 358 are mounted on the carriage 34 as described above, the nozzle surfaces 22 of the print heads 201 to 208 formed below the base plates 271 to 278 are mounted on the platen 39 when printing is performed. It is arranged opposite to the placed recording medium.

  The respective surfaces of the head substrates 241 to 248 provided in the print head unit 35 are arranged so as to be substantially parallel to the main scanning direction when supported by the carriage 34. Therefore, when the carriage 34 is moved in the main scanning direction by driving the main scanning motor 46 (see FIG. 8), the surfaces of the head substrates 241 to 248 are also substantially parallel to the main scanning direction with respect to the print medium. Move relatively.

  Note that the printing apparatus 30 of the present embodiment only needs to include at least one set of print head units 35, and the type and number of the print head units 35 are not limited to the examples illustrated in FIGS. For example, the number of print head units 35 corresponding to the white ink may be only one instead of four, or a part of a plurality of print head units 35 corresponding to the white ink are mounted on the carriage 34. Printing may be performed using As for color ink, three print head units 35 corresponding to three colors other than black (cyan, magenta, yellow) may be provided, or any one of cyan, magenta, yellow, and black. One piece corresponding to may be provided. A print head unit 35 corresponding to ink other than cyan, magenta, yellow, and black (for example, gold, silver, etc.) may be provided.

  The electrical configuration of the printing apparatus 30 will be described with reference to FIG. The printing apparatus 30 includes a CPU 40 that controls the printing apparatus 30. A ROM 41, a RAM 42, a head drive unit 43, a motor drive unit 45, a display control unit 48, an operation processing unit 50, and a USB interface 52 are connected to the CPU 40 via a bus 55.

  The ROM 41 stores a control program for controlling the operation of the printing apparatus 30, initial values, and the like. The RAM 42 temporarily stores various data such as print data received from the PC 1. The head drive unit 43 is connected to the head drive ICs 431 to 438, and controls the drive voltage for driving the piezoelectric actuators 441 to 448 in the voltage circuit of each head drive IC 431 to 438. Then, by applying the generated drive voltage to the piezoelectric elements of the piezoelectric actuators 441 to 448, the piezoelectric actuators 441 to 448 provided in the ejection channels of the print heads 201 to 208 are driven. The motor driving unit 45 drives a main scanning motor 46 that moves the carriage 34 in the main scanning direction, and a sub scanning motor 47 that moves the platen support 38 on which the platen 39 is fixed in the sub scanning direction. The display control unit 48 controls display on the display 49 in accordance with an instruction from the CPU 40. The operation processing unit 50 detects an operation input to the operation panel 51. The USB interface 52 connects the printing apparatus 30 to an external device such as the PC 1. The PC 1 creates print data and transmits the created print data to the printing apparatus 30 via the USB interface 52. The main body of the printing apparatus 30 is provided with a power source for supplying power to the print head unit 35. A predetermined voltage and current are applied from the power source to the voltage circuits of the head driving ICs 431 to 438. The

  A detailed configuration of the head substrate 241 included in the print head unit 351 will be described with reference to FIGS. Although the head substrate 241 is described as an example, the same applies to the head substrates 242 to 248 provided in the other seven print head units 352 to 358, respectively.

  The head substrate 241 is a multilayer substrate in which a plurality of substrates are stacked. In a multilayer substrate, conductor layers and insulating resin layers are alternately laminated. In the head substrate 241 of this embodiment, six copper layers L1 to L6 are employed as a plurality of conductor layers constituting the multilayer substrate. Further, five resin layers M1 to M5 are employed as the plurality of resin layers constituting the multilayer substrate. In this specification, the layer in which the copper layer L1 is formed on the surface of the resin layer M1 is referred to as a first layer P1. A layer in which the copper layer L2 is formed on the surface of the resin layer M1 is referred to as a second layer P2. The layer in which the copper layer L3 is formed on the surface of the resin layer M3 is referred to as a third layer P3. The layer in which the copper layer L4 is formed on the surface of the resin layer M3 is referred to as a fourth layer P4. The layer in which the copper layer L5 is formed on the surface of the resin layer M5 is referred to as a fifth layer P5. The layer in which the copper layer L6 is formed on the surface of the resin layer M5 is referred to as a sixth layer P6 (see FIG. 15). In addition, on each surface of the actual first layer P1 to sixth layer P6, a wiring pattern is formed by each of the copper layers L1 to L6. However, in FIGS. The copper layers L1 to L6 other than the layer 401 are not shown.

  The head substrate 241 includes a first layer P1 that is a first outermost layer and a sixth layer P6 that is a second outermost layer on a side different from the first layer P1. A second layer P2 is provided on the inner layer side of the first layer P1. A fifth layer P5 is provided on the inner layer side of the sixth layer P6. A third layer P3 is provided on the inner layer side of the second layer P2 with the resin layer M2 interposed therebetween. A fourth layer P4 is provided on the inner layer side of the fifth layer P5 with the resin layer M4 interposed therebetween. The metal layer 401 is disposed on the copper layer L1 formed on the surface of the first layer P1 among the first layer P1 that is the first outermost layer and the sixth layer P6 that is the second outermost layer ( (See FIGS. 9 and 15).

  The copper layer L5 formed on the surface of the fifth layer P5 is a conductor layer inside the head substrate 241. The copper layer L5 is provided with a head drive IC mounting region 404 that is a region where the head drive IC 431 is mounted (see FIG. 13). A head driving IC 431 is mounted in the head driving IC mounting region 404, and the head driving IC 431 is embedded in the head substrate 241 (see FIG. 15).

  A general-purpose driver IC is used as the head driving IC 431 mounted on the copper layer L5 of the fifth layer P5. The piezoelectric actuator 441 provided in the ejection channel in the print head 201 is an actuator using a piezoelectric element having a characteristic that the volume changes when a voltage is applied as a driving energy source. In order to drive an actuator using a piezo element, it is necessary to apply a relatively high voltage (for example, a voltage exceeding 100 V) to the piezo element. For this reason, in many cases, a dedicated driver IC for applying a driving voltage is indispensable for an actuator using a piezoelectric element. Also in this embodiment, a head drive IC 431 that supplies a drive voltage to the piezoelectric actuator 441 is provided on the head substrate 241. On the other hand, when the head substrate 241 is provided in the print head unit 351, the surface of the head substrate 241 is less uneven due to the arrangement of the head substrate 241 in the print head unit 351 and the wiring components connected to the head substrate 241. Desirably flat.

  For this reason, in this embodiment, the head drive IC 431 is embedded by being embedded in the head substrate 241. Specifically, the resin layer M2, the third layer P3, the fourth layer P4, and a part of the resin layer M4 are selectively removed to form a cavity 403 inside the head substrate 241 (see FIG. 15). ). A head driving IC 431 is accommodated in the formed cavity 403. FIGS. 11 and 12 show a state in which a part of the third layer P3 and the fourth layer P4 is removed in order to form the cavity 403 inside the head substrate 241. FIG.

  The metal layer 401 in the copper layer L1 on the surface of the first layer P1 is disposed in a region overlapping the head drive IC mounting region 404 in which the head drive IC 431 is mounted in the copper layer L5 of the fifth layer P5 in plan view. (See FIGS. 9 and 13). As shown in FIG. 9, the metal layer 401 is provided with a large number of heat transfer sections 60 arranged in a matrix. Each heat transfer section 60 has a through-hole 61 formed so as to penetrate from the head driving IC 431 side embedded in the head substrate 241 to the surface of the first layer P1 which is the first outermost layer of the head substrate 241; It is comprised by the heat-transfer layer 62 formed in the internal peripheral surface of the through-hole 61 (refer FIG. 15). Each through hole 61 penetrates through the head substrate 241 in the thickness direction together with the metal layer 401 disposed on the copper layer L1 on the surface of the first layer P1. That is, the through hole 61 is provided so as to penetrate through the first layer P1 and the second layer P2. A heat transfer layer 62 is formed on the inner peripheral surface of each through hole 61. The heat transfer layer 62 is made of a heat conductive material, and is in contact with the surface of the head driving IC 431 housed in the cavity 403 and the metal layer 401 disposed on the copper layer L1.

  The head drive IC 431 that supplies a drive voltage to the piezoelectric actuator 441 has a voltage circuit and generates heat when energized. Since the head drive IC 431 is embedded at an intermediate position between the plurality of stacked head substrates 241, the heat transfer section 60 as described above is configured in consideration of heat dissipation from the head drive IC 431. Heat from the head drive IC 431 is reliably conducted to the metal layer 401 through the air in the through hole 61 and the heat transfer layer 62 around the air, and the conducted heat is transferred from the metal layer 401 to the head substrate 241. Is dissipated outside. That is, the heat transfer unit 60 is a thermal via having a function of conducting heat generated from the head driving IC 431 to the metal layer 401 on the surface of the head substrate 241.

  In the present embodiment, in order to effectively radiate the heat conducted from the head driving IC 431 to the metal layer 401 through the heat transfer unit 60 to the outside of the head substrate 241, the metal radiating fins 261 are provided on the metal layer 401. Is provided. The heat radiating fins 261 are erected in a direction away from the surface of the metal layer 401 while being in contact with the metal layer 401 (see FIGS. 7 and 16). On the metal layer 401, a contact region 402 that is a region in contact with the radiation fin 261 is provided (see FIG. 9). The large number of heat transfer units 60 described above are provided in the contact region 402. For this reason, the heat conducted from the head driving IC 431 to the metal layer 401 can be radiated more reliably to the outside of the head substrate 241. Therefore, the heat conducted to the metal layer 401 through the heat transfer section 60 is reliably conducted to the heat radiating fins 261. Therefore, the head substrate 241 of this embodiment has a heat radiating property from the embedded head driving IC 431. It is extremely excellent. The heat transfer section 60 also functions as a vent hole through which air passes through each through hole 61 constituting each heat transfer section 60.

  The metal material that can be used for the metal layer 401 is not particularly limited. In the present embodiment, copper is adopted as the metal material constituting the metal layer 401. Copper is particularly preferable as a metal material employed in the metal layer 401 because copper has excellent thermal conductivity and can reliably dissipate heat conducted from the head driving IC 431 to the outside of the head substrate 241. In addition to copper, for example, aluminum, indium, tin, lead, silver, zinc, or the like can be used as the metal material constituting the metal layer 401. Even if the metal layer 401 is composed of a conductive material obtained by combining two or more of these metals. Good. In order to protect the surface of the metal layer 401 and prevent rust, the surface of the metal layer 401 may be subjected to flash plating with gold or the like. In the present embodiment, the metal layer 401 is disposed only on the copper layer L1 formed on the surface of the first layer P1, which is the first outermost layer of the head substrate 241, but the second outermost layer is disposed. A metal layer may also be disposed on the copper layer L6 formed on the surface of the sixth layer P6 that is the surface layer. By disposing the metal layer 401 on both surfaces of the head substrate 241, the heat dissipation of the head drive IC 431 embedded in the head substrate 241 can be further improved.

  In the present embodiment, the shape of each through-hole 61 in a plan view is circular, but is not limited to this, and may be a polygon such as an ellipse or a quadrangle. The method for forming the through hole 61 is not particularly limited, and examples thereof include drilling, routering, punching, and laser processing. Moreover, as a heat conductive material which comprises the heat transfer layer 62, various heat conductive materials are employable, For example, the same material as the constituent material of the metal layer 401 can be used. Although the formation method of the heat-transfer layer 62 is not specifically limited, For example, methods, such as metal plating, vapor deposition, and sputtering, are mentioned.

  In the present embodiment, the radiating fins 261 are fixed to the arm 251 and the head substrate 241 in a state of being in contact with the contact region 402 of the metal layer 401. The fixing method of the heat radiation fin 261 is not particularly limited, and various fixing methods such as a method using adhesion, a method using welding, a method using screws, and a method using clips can be employed.

  As described above, according to the print head unit 351 according to the present embodiment, the head substrate 241 is a multilayer substrate in which a plurality of layers from the first layer P1 to the sixth layer P6 are stacked. A copper layer L5 on the fifth layer P6, which is the inner layer of the head substrate 241, is provided with a head driving IC mounting region 404 that is a region where the head driving IC 431 is mounted. By mounting the head driving IC 431 in the head driving IC mounting area 404, the head substrate 241 embeds the head driving IC 431 therein. A metal layer 401 is disposed on the copper layer L1 on the first layer P1, which is the outermost layer of the head substrate 241. The metal layer 401 has a through hole 61 formed so as to reach the surface of the first layer P1 from the head driving IC 431 side embedded in the head substrate 241, and a transmission formed on the inner peripheral surface of the through hole 61. A heat transfer section 60 constituted by the heat layer 62 is provided. Therefore, the print head unit 351 according to the present embodiment can dissipate heat conducted from the head driving IC 431 embedded in the head substrate 241 to the metal layer 401. Therefore, it is possible to prevent the ink ejection failure from occurring in the print head unit 351 due to the drive IC 431 being damaged by heat or malfunctioning.

  The print head unit 351 conducts heat generated from the head drive IC 431 embedded in the head substrate 241 to the metal layer 401 through the heat transfer section 60 penetrating between the head drive IC 431 and the metal layer 401. Heat can be further dissipated from the metal layer 401 to the radiation fins 261. Here, since the heat radiation fin 261 is provided so as to contact the contact region 402 provided with a large number of heat transfer portions 60 in the metal layer 401, the heat conducted from the head driving IC 431 to the metal layer 401 is effective. Therefore, heat can be radiated to the heat radiation fin 261. For this reason, the print head unit 351 can improve the heat dissipation of the head drive IC 431 embedded in the head substrate 241. In addition, it is possible to prevent ink ejection failure from occurring in the print head unit 351 due to damage or malfunction of the drive IC 431 due to heat.

  Some liquids such as ink supplied to the print head 201 may boil and deteriorate when heated. There is a possibility that liquid ejection failure may occur due to clogging of the nozzle 21 caused by boiling or altered liquid. In order to prevent boiling and alteration of the liquid in the nozzle 21 of the print head 201, the nozzle 21 is preferably arranged at a position away from the head driving IC 431 that generates heat. By disposing a flow path portion 211 that is an ink flow path when supplying the print head 201 between the nozzle 21 and the metal layer 401, the distance between the metal layer 401 and the nozzle 21 can be separated. Therefore, it is possible to prevent the occurrence of liquid discharge failure due to boiling and alteration of the liquid in the nozzle 21.

  The flow path unit 211 includes a supply port 231 and an ink tank 221. By disposing the supply port 231 between the metal layer 401 and the nozzle 21, the flow path portion 211 is disposed between the metal layer 401 and the nozzle 21, so that the distance between the metal layer 401 and the nozzle 21 is separated. be able to. In addition, since the supply port 231 serving as the entrance of the flow path section 211 is disposed between the metal layer 401 and the nozzle 21, the liquid guided from the supply port 231 to the nozzle 21 through the ink tank 221 is transferred to the head. It is possible to prevent the occurrence of liquid ejection failure due to boiling and alteration due to heat from the driving IC 431 and the metal layer 401.

  The head substrate 241 is provided substantially vertically upward with respect to the nozzle surface 22 provided on the bottom surface of the print head 201. An ink tank 221 is disposed above the nozzle surface 22, and a supply port 231 is disposed above the ink tank 221. Since the channel portion 211 is disposed between the metal layer 401 provided on the surface of the head substrate 241 and the nozzle 21 formed on the nozzle surface 22, the distance between the metal layer 401 and the nozzle 21 is set in the vertical direction. Can be pulled apart. Further, it is possible to prevent the occurrence of liquid ejection failure due to the liquid that is guided from the supply port 231 to the nozzle 21 through the ink tank 221 boiled and deteriorated by the heat from the head driving IC 431 and the metal layer 401.

  In the printing apparatus 30, the print head 20 of the print head unit 35 is moved relative to the print medium by the carriage 34 in the main scanning direction. Here, the respective surfaces of the head substrates 241 to 248 provided in the print head unit 35 are arranged so as to be substantially parallel to the main scanning direction when supported by the carriage 34. For this reason, when the carriage 34 is moved in the main scanning direction by driving the main scanning motor 46, the surfaces of the head substrates 241 to 248 also move relative to the print medium substantially in parallel with the main scanning direction. Therefore, the air in the vicinity of the respective surfaces of the head substrates 241 to 248 can easily move in the main scanning direction, and the heat radiation effect to the outside of the metal layers 401 to 408 disposed on the respective surfaces of the head substrates 241 to 248. Will increase. Therefore, the printing apparatus 30 can improve the heat dissipation of the head drive IC 431 embedded in the head substrate 241. As a result, it is possible to prevent a decrease in print quality due to the drive IC 431 being damaged by heat or causing a malfunction.

  The print head unit 35 includes two print head units (print head unit 351 and print head unit 355, print head unit 352 and print head unit 356, print head unit 353 and print head unit 357, print head unit 354 and print head unit. 358) as a set, each one end side is opposed to each other, and they are arranged back to back. Therefore, it is possible to reduce the space required when attaching the plurality of print head units 35 to the carriage 34 and to prevent the carriage 34 from becoming large. Further, among the respective surfaces of the head substrates 241 to 248 provided in the print head unit 35, the respective head substrates 241 to 248 facing the other end side opposite to the one end side facing the pair of print head units 35. Metal layers 401 to 408 are respectively disposed on the surface. The main scanning motor 46 is driven by the surfaces of the head substrates 241 to 248 facing the other end rather than the surfaces of the head substrates 241 to 248 facing the one end facing the pair of print head units 35. Thus, when the carriage 34 is moved in the main scanning direction, the air in the vicinity of each surface of the head substrates 241 to 248 is easy to move, and heat is not easily trapped. Therefore, the printing apparatus 30 can improve the heat dissipation of the head drive ICs 431 to 438 embedded in the head substrates 241 to 248 while arranging the print head unit 35 in a compact manner. As a result, it is possible to prevent a decrease in print quality due to the drive IC 431 being damaged by heat or causing a malfunction.

  The nozzle 21 in the present embodiment corresponds to the “ejection port” of the present invention. The print head 20 corresponds to the “ejection unit” of the present invention. The piezoelectric actuator 441 corresponds to the “piezoelectric actuator” of the present invention. The head drive IC 431 corresponds to the “drive IC” of the present invention. The head substrate 241 corresponds to the “head substrate” of the present invention. The metal layer 401 corresponds to the “metal layer” of the present invention. The through hole 61 corresponds to the “through hole” of the present invention. The heat transfer layer 62 corresponds to the “heat transfer layer” of the present invention. The heat transfer section 60 corresponds to the “heat transfer section” of the present invention.

  The heat radiation fin 261 corresponds to the “heat radiation member” of the present invention. The contact area 402 corresponds to the “contact area” of the present invention. The channel portion 211 corresponds to the “liquid channel” of the present invention. The supply port 231 corresponds to the “supply port” of the present invention. The ink tank 221 corresponds to the “liquid reservoir” of the present invention. The nozzle surface 22 corresponds to the “ejection surface” of the present invention.

  In addition, this invention is not limited to said embodiment, A various change is possible. For example, the head substrate 241 is not limited to being configured by alternately stacking six copper layers L1 to L6 and five resin layers M1 to M5, and four copper layers and three resin layers are alternately arranged. It may be constituted by being laminated, or may be constituted by alternately laminating eight or more copper layers and seven or more resin layers. The layer on which the head driving IC 431 is mounted is not limited to the copper layer L5 of the embodiment, and the head driving IC 431 may be embedded in the head substrate 241.

  The shape of the heat radiation fin 261 is not limited to the shape of the above embodiment, and a plate-shaped heat radiation plate or the like may be used. The heat radiation fin 261 may be in contact with the entire surface of the metal layer 401.

  The liquid supplied to the print head unit 35 is not limited to the ink of the embodiment. For example, instead of the pretreatment ink, a processing agent for improving the fixing of the ink and a color ink as a posttreatment liquid are used. May be. For example, in discharging printing, a discharging agent may be used instead of the pre-processing ink, and discharging ink may be used instead of the post-processing ink. That is, the liquid that can be ejected by the print head 20 may be any liquid that has properties such as viscosity that can be ejected from the print head 20. Therefore, the liquid is not limited to ink but may be a chemical agent such as a decoloring agent.

  In the above description, the case where the present invention is applied to the printing apparatus 30 for a fabric such as a T-shirt has been described as an example. However, the present invention is not limited to this, and the present invention is not limited to this. The present invention may be applied. In this case, the same effect can be obtained.

20 Print head 21 Nozzle 22 Nozzle surface 30 Printing device 35 Print head unit 46 Main scanning motor 60 Heat transfer section 61 Through hole 62 Heat transfer layer 211 Flow path section 221 Ink tank 231 Supply port 241 Head substrate 261 Heat radiation fin 401 Metal layer 402 Contact area 431 Head drive IC
441 Piezoelectric actuators L1-L6 Copper layer

Claims (7)

A discharge part having a discharge port capable of discharging a liquid;
A piezoelectric actuator that is driven in accordance with a drive voltage and controls a discharge amount of liquid discharged from the discharge unit;
A drive IC comprising a voltage circuit for controlling the drive voltage;
A head substrate in which the driving IC is embedded between a plurality of stacked substrates;
A metal layer provided on at least one surface of the head substrate and disposed in a region overlapping the region where the driving IC is embedded in the head substrate surface in plan view;
A heat transfer having a through hole penetrating from the side of the driving IC embedded in the head substrate to the metal layer in the thickness direction of the head substrate, and configured by a thermally conductive material on an inner peripheral surface of the through hole A print head unit comprising: a heat transfer portion on which a layer is formed. In the region where the metal layer on the surface of the head substrate is disposed, a heat dissipating member is provided standing in a direction away from the surface of the metal layer,
The metal layer has a contact area that contacts the heat dissipation member,
The print head unit according to claim 1, wherein the heat transfer section is disposed in the contact area. A liquid flow path for guiding the liquid supplied to the discharge unit to the discharge port;
The liquid flow path, the print head unit according to claim 1 or 2, characterized in that it is arranged at a position between the position of said discharge port of said metallic layer. The liquid flow path includes a supply port for supplying liquid to the discharge unit, and a liquid storage unit for storing the liquid supplied from the supply port to the discharge port,
The supply port, the print head unit according to claim 3, characterized in that it is arranged at a position between the position of said discharge port of said metallic layer. The discharge part has a discharge surface on which a plurality of the discharge ports are formed,
The head substrate is provided substantially vertically upward with respect to the ejection surface,
The liquid storage portion is disposed above the ejection surface and is provided on the same side as the ejection surface with respect to the head substrate.
The print head unit according to claim 4, wherein the supply port is disposed above a position where the liquid storage unit is disposed. A printing system comprising a carriage that supports a plurality of print head units according to any one of claims 1 to 5 and moves the ejection portions of the plurality of print head units relative to a print medium in a main scanning direction. A device,
The printing apparatus according to claim 1, wherein the head substrate provided in the print head unit is disposed such that a surface of the head substrate is substantially parallel to the main scanning direction. The head substrate is attached to one end side of the print head unit,
The carriage is a set of two print head units arranged so that the one end sides of the print head units face each other, and the set print head units are substantially orthogonal to the main scanning direction. Support at least one set substantially parallel to the sub-scanning direction,
The printing apparatus according to claim 6, wherein the metal layer is disposed on a surface of the head substrate that faces the other end side opposite to the one end side.

Images