JP2005028844A - Ink jet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet recording device capable of suitably radiating heat generated at an ink jet recording head. <P>SOLUTION: In the ink jet recording device 10 which is provided with an ink jet recording head 32 with a heating element and a metal 36 for heat radiation; a carriage 12 which has an ink jet recording head 32 mounted thereon and reciprocates in an orthogonal direction with a direction where a recording medium 60 is conveyed; and positioning parts 52 and 54, formed on the carriage 12, with which the metal part 36 comes into contact, a part of the carriage 12 including at least the positioning parts 52 and 54 is constituted of a heat conductive material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus that records an image (including characters, hereinafter the same) by ejecting ink droplets onto a recording medium such as paper, and more specifically, an ink jet recording head (hereinafter simply referred to as “recording head”). It is related with the means to improve the heat dissipation in.

  Conventionally, an inkjet recording head is mounted on a carriage that reciprocates in a direction orthogonal to the recording medium conveyance direction, and conveyance of the recording medium at a predetermined pitch and carriage reciprocation (scanning of the recording head) are alternately performed. 2. Description of the Related Art Inkjet recording apparatuses that record (form) an image based on desired image data on a recording medium by ejecting ink droplets from the nozzles of the inkjet recording head while repeating are known.

  In such an ink jet recording apparatus, in recent years, it has been desired to increase the speed of continuous printing with a color image (increase in the number of prints per unit time). Increasing the speed, increasing the length of the recording head (in the recording medium conveyance direction) (increasing the number of nozzles), and increasing the scanning speed of the recording head are progressing. There is also a demand for higher quality print quality.

  However, as the printing frequency is increased and the printing quality is improved, the recording head is heated to eject ink, which increases the amount of heat generated by the recording head, resulting in a decrease in printing performance. Needless to say, there is a possibility that the print quality may be deteriorated and the ink jet recording apparatus may be broken. Even if the scanning speed of the recording head is increased, there is a concern about the alignment position shift between the recording heads of black, cyan, magenta, and yellow, and the deterioration of the printing quality due to vibration during scanning. There are concerns about the impact of shortening the service life of the product.

  Therefore, conventionally, an air gap opening in the main scanning direction is provided at a predetermined position of the carriage that holds the recording head, and the carriage moves in the main scanning direction so that air is passed through the air gap to cool the recording head. (For example, refer to Patent Document 1), a metal base plate as a heat sink attached to the recording head has been increased in size (increased surface area).

However, increasing the size of the base plate causes an increase in the weight of the recording head and an increase in the number of man-hours for processing the base plate, and there are concerns about an increase in cost and an increase in the size of the ink jet recording apparatus. In addition, it is conceivable to attach a vibration absorber between the carriage and the recording head with respect to the vibration of the recording head. However, there is a concern that the cost is increased, the carriage structure is complicated, and the inkjet recording apparatus is enlarged. The
JP 2002-144540 A

  Therefore, the present invention provides an ink jet that can suitably dissipate heat generated in a recording head without increasing the size and cost even if the printing frequency is increased or the printing quality is improved. An object is to obtain a recording apparatus.

  In order to achieve the above object, an inkjet recording apparatus according to claim 1 of the present invention includes an inkjet recording head having a heating element and a metal part for heat dissipation, and the inkjet recording head. An ink jet recording apparatus comprising: a carriage that reciprocates in a direction perpendicular to a conveyance direction of a recording medium; and a positioning unit that is formed on the carriage and contacts the metal unit. It is characterized in that the part is made of a heat conductive material.

  According to the first aspect of the present invention, since at least a part of the carriage including the positioning portion with which the heat radiating metal portion provided on the ink jet recording head is made of the heat conductive material, the heat generated from the ink jet recording head is The metal part is transmitted to the carriage through the positioning part, and is radiated from the carriage. Therefore, heat dissipation of the ink jet recording head is performed efficiently.

  According to another aspect of the present invention, there is provided an ink jet recording apparatus having a heating element and provided with a metal part for heat dissipation, and the ink jet recording head mounted thereon, in a direction orthogonal to the conveyance direction of the recording medium. In an ink jet recording apparatus comprising: a carriage that is inserted into a laid shaft and reciprocally moves; and a positioning portion that is formed on the carriage and contacts the metal portion, at least a portion through which the shaft is inserted from the positioning portion A part of the carriage including the above is composed of a heat conductive material.

  In the invention of claim 2, since at least a part of the carriage including the position where the heat-dissipating metal part provided on the ink jet recording head comes into contact with the part through which the shaft is inserted is made of a heat conductive material, The heat generated from the ink jet recording head is propagated from the metal part to the carriage via the positioning part and further to the shaft. That is, since heat is radiated by both the carriage and the shaft, the ink jet recording head is radiated more efficiently.

  Furthermore, the ink jet recording apparatus according to claim 3 is the ink jet recording apparatus according to claim 1 or 2, wherein the heat conducting material is an alloy containing magnesium as a component.

  In the invention of claim 3, since the heat conductive material is an alloy containing magnesium, the positioning portion can be processed with high accuracy. Further, since the weight can be reduced as compared with other metals and vibration absorption is excellent, there is no problem that the ink jet recording head is displaced due to vibration. Therefore, high-definition printing is possible.

  The ink jet recording apparatus according to claim 4 is the ink jet recording apparatus according to claim 1 or 2, wherein the heat conducting material is a resin in which metal powder is mixed with polyphenylene sulfide.

  In the invention of claim 4, since the heat conducting material is a resin in which metal powder is mixed with polyphenylene sulfide, it has heat dissipation properties and the carriage can be reduced in weight.

  According to a fifth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to fourth aspects, a ceramic sheet is provided in addition to a part of the carriage made of the heat conductive material. It is characterized by.

  In the invention of claim 5, by providing a ceramic sheet in addition to the portion made of the heat conductive material, heat can be released from that portion. Therefore, heat dissipation of the ink jet recording head is performed more efficiently.

  According to the present invention, it is possible to efficiently perform heat dissipation in the ink jet recording head.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on examples shown in the drawings. First, the outline of the inkjet recording apparatus 10 will be described first, and then the main part according to the present invention will be described. The recording medium will be described as recording paper 60. In FIG. 1, a direction perpendicular to the transport direction of the recording paper 60 in the inkjet recording apparatus 10 is represented by an arrow M as a main scanning direction, and a transport direction is represented by an arrow S as a sub-scanning direction.

  As shown in FIG. 1, the ink jet recording apparatus 10 includes a carriage 12 on which an ink jet recording head 32 (ink jet recording unit 30) described later is mounted. A pair of brackets 14 project from the upstream side (hereinafter simply referred to as “upstream side”) of the carriage 12 in the conveyance direction of the recording paper 60, and the brackets 14 are provided with circular openings 14A. ing. A shaft 20 installed in the main scanning direction is inserted through the opening 14A.

  Further, a drive pulley (not shown) and a driven pulley (not shown) constituting the main scanning mechanism 16 are disposed at both ends in the main scanning direction, and wound around the driving pulley and the driven pulley, A part of the timing belt 22 that travels in the main scanning direction is fixed to the carriage 12. Therefore, the carriage 12 is supported so as to be reciprocally movable in the main scanning direction, and its moving speed is set to a high speed of about 1.0 m / sec.

  Further, the ink jet recording apparatus 10 is provided with a paper feed tray 26 in which recording papers 60 before image printing are bundled and placed above the paper feed tray 26 by an ink jet recording head 32. A paper discharge tray 28 is provided for discharging the recording paper 60 on which is printed. A sub-scanning mechanism 18 including a transport roller and a discharge roller that transport the recording paper 60 fed one by one from the paper feed tray 26 in the sub-scanning direction at a predetermined pitch is provided. The ink jet recording apparatus 10 is provided with a control panel 24 for performing various settings during printing.

  As shown in FIG. 2, the ink jet recording unit 30 includes an ink jet recording head 32 and an ink tank 34 that supplies ink to the head, and its lower surface (hereinafter referred to as “ink ejection surface”). The nozzles of the ink jet recording head 32 provided on the carriage 12 are mounted on the carriage 12 so as to face the recording paper 60. Therefore, the ink jet recording head 32 ejects ink droplets from the nozzles onto the recording paper 60 while moving in the main scanning direction by the main scanning mechanism 16, thereby recording an image on a predetermined band region.

  When one movement in the main scanning direction is completed, the recording paper 60 is conveyed by a predetermined pitch in the sub scanning direction by the sub scanning mechanism 18, and the ink jet recording head 32 is again moved in the main scanning direction (the direction opposite to the above). The image is recorded on the next band area while moving to, and an image based on the image data is recorded on the recording paper 60 by repeating such an operation a plurality of times.

  In the inkjet recording apparatus 10 configured as described above, as shown in FIGS. 3 to 5, the carriage 12 has four storages for storing the inkjet recording units 30 of black, cyan, magenta, and yellow in a replaceable manner. A chamber 40 is provided. Each storage chamber 40 includes a left side wall 42 of the carriage 12, a right side wall 44, and three side walls 46 that divide the storage chamber 40 at equal intervals. An opening 40A for exposing a nozzle provided on the 32 ink ejection surface is formed. A lock lever 48 is provided in the upper part of each storage chamber 40 so as to be rotatable in the vertical direction after the respective inkjet recording units 30 are stored and fixed so that the inkjet recording units 30 are not detached.

  The side wall 46 and the right side wall 44 urge each ink jet recording unit 30 in one of the main scanning directions (the illustrated one presses the right side surface portion of the ink jet recording unit 30 to urge leftward. A leaf spring 50 is attached as an urging means. Two positioning members 52 and 54 are provided at the lower ends of the left side wall 42 and the side wall 46 so as to protrude at a predetermined interval (separated from the upstream side and the downstream side). The positioning members 52 and 54 are flat projections formed integrally with the carriage 12, and are made of a metal base plate 36 (see FIG. 2) attached to the lower portion of each inkjet recording unit 30, that is, the left side surface portion of the inkjet recording head 32. Is in contact with the plane (hereinafter referred to as “reference plane”).

  The surfaces of the metal base plate 36 that come into contact with the reference surfaces of the positioning members 52 and 54 are formed in a flat shape so that they can contact with the reference surface with high accuracy. Accordingly, the ink jet recording head 32 (ink jet recording unit 30) can be positioned and placed in each storage chamber 40 of the carriage 12 with high accuracy.

  The base plate 36 is configured to assemble a chip (not shown) having a heating element for ink ejection to the ink jet recording head 32, and a heat sink for radiating heat generated in the recording head 32 (chip). Also serves as a role. That is, the heat generated in the recording head 32 (chip) propagates to the base plate 36 and is radiated. As shown in FIG. 2, a manifold 38 for connecting the chip and the ink tank 34 is provided on the right side surface portion of each inkjet recording head 32.

  Further, in the carriage 12, a lower portion D (see FIG. 4) including at least the positioning members 52 and 54 in contact with the base plate 36 to the bracket 14 through which the shaft 20 is inserted is composed of a metal containing magnesium, that is, a magnesium alloy. Has been. Here, the lower portion D refers to a portion configured to form a path for heat propagation from the positioning members 52 and 54 to the bracket 14. Therefore, as shown in the figure, the entire upper end portion 14B of the bracket 14 does not have to be in the side view, and the shape of the portion is appropriately changed in design.

  That is, it is only necessary that at least a part (lower part D) of the carriage 12 is made of a magnesium alloy, and the upper part U including the lock lever 48 may be made of a magnesium alloy (an abbreviation of the carriage 12). The whole may be composed of a magnesium alloy), or may be composed of a resin material such as ABS or PC. When the upper portion U is made of a resin material, the upper portion U may be combined with the lower portion D made of metal by insert molding or an assembling means (not shown). It goes without saying that if a part (upper portion U) of the carriage 12 is made of a resin material, the carriage 12 can be reduced in weight.

  Here, the magnesium alloy is naturally superior in thermal conductivity (heat dissipation performance) to the resin material. Specifically, for example, the thermal conductivity of a resin material such as ABS or PC is 0.2 W / m · k, whereas the thermal conductivity of magnesium is 72 W / m · k. For this reason, as indicated by arrows in FIGS. 4 and 5, heat generated in the ink jet recording head 32 and propagated to the base plate 36 is propagated to the carriage 12 through the positioning members 52 and 54 to be dissipated. Heat propagates from the carriage 12 to the shaft 20 via the bracket 14 and is radiated.

  Further, when the upper portion U of the carriage 12 is made of a resin material, it is preferable to attach a thin film ceramic sheet to an appropriate portion thereof. The thermal conductivity of the ceramic sheet is 156 W / m · k. If the ceramic sheet is attached in a state where it is in contact with a lower part D made of a magnesium alloy, the heat transmitted to the lower part D of the carriage 12 is transferred. It can be propagated to the ceramic sheet and can be dissipated from it.

  Further, the carriage 12 may be made of a heat-dissipating resin material instead of the magnesium alloy. The heat-dissipating resin material is a resin material in which a metal powder filler is mixed based on polyphenylene sulfide (PPS), and its thermal conductivity is 20 W / m · k. Therefore, heat can be radiated as well as the above magnesium alloy and ceramic sheet. In this case, since substantially the entire carriage 12 is made of a resin material, the weight can be reduced as compared with the carriage 12 using a magnesium alloy for a part (lower part D) as described above.

  Next, the operation of the inkjet recording apparatus 10 as described above will be described. First, the black, cyan, magenta, and yellow inkjet recording units 30 are mounted in the four storage chambers 40 formed in the carriage 12, respectively. At this time, since each inkjet recording unit 30 is urged leftward by the urging force of each leaf spring 50, the base plate 36 attached to the left side surface thereof comes into contact with the reference surfaces of the positioning members 52 and 54. , Positioned accurately.

  Thereafter, printing is performed by the ink jet recording head 32. At this time, heat generated in the recording head 32 (chip) propagates to the base plate 36 and is radiated. Further, since the lower part D including at least the positioning members 52 and 54 to the bracket 14 of the carriage 12 is made of a magnesium alloy (or a resin material having heat dissipation properties), the heat transmitted to the base plate 36 Propagated to the carriage 12 via 52 and 54 and also radiated from the carriage 12.

  Furthermore, since the heat transmitted to the carriage 12 is transmitted from the carriage 12 to the shaft 20 via the bracket 14, the heat is also radiated from the shaft 20. Therefore, the heat radiation efficiency (cooling efficiency) in the ink jet recording head 32 can be remarkably improved as compared with the conventional case, and the problems caused by the temperature rise of the recording head 32 (chip) during continuous ejection can be reduced. Needless to say, if substantially the entire carriage 12 is made of a magnesium alloy (or a resin material having heat dissipation properties), the heat dissipation efficiency (cooling efficiency) is further improved.

  Further, even if the upper portion U of the carriage 12 is made of a resin material such as ABS or PC, heat can be radiated therefrom by attaching a ceramic sheet thereto. That is, if a part of the ceramic sheet is in contact with the lower part D and stuck to the resin material part, the heat propagated to the lower part D propagates from the lower part D to the ceramic sheet, and from there Heat is dissipated. Therefore, heat can be radiated even in the resin material portion having low thermal conductivity (0.2 W / m · k), and the heat radiation efficiency (cooling efficiency) in the ink jet recording head 32 can be reduced. It is possible to increase to substantially the same level as in the case of a resin material having a property.

  As described above, the heat generated in the ink jet recording head 32 (chip) is actively dissipated (cooled) by the carriage 12 that contacts the base plate 36 via the positioning members 52 and 54 and further propagates to the shaft 20. Thus, heat is actively radiated from the shaft 20. For this reason, the size (volume and surface area) of the base plate 36 can be reduced (the base plate 36 can be made compact). That is, it is sufficient that the base plate 36 has only the chip and the manifold 38 portion. Further, when the heat is released (cooled) by contacting the base plate 36 as described above, the temperature can be lowered more efficiently than the conventional method such as air cooling.

  In addition, magnesium is lighter than other metals (specific gravity is about 2/3 of aluminum and 1/4 of iron) and has low cutting resistance and is easy to process. Therefore, the carriage 12 can be lightened. At the same time, the positioning members 52 and 54 can be processed with high accuracy. In addition, since magnesium has a higher resistance to deformation than other metals, the deformation of the carriage 12 and the displacement of the inkjet recording head 32 due to impact, temperature change, aging, etc. can be minimized.

  Further, since magnesium has better vibration / impact energy absorption characteristics than other metals, vibration applied to the inkjet recording head 32 that prints while reciprocating in the main scanning direction can be reduced as much as possible. Therefore, it is possible to improve the holding performance for holding the ink jet recording unit 30 (ink jet recording head 32) positioned in the carriage 12 (housing chamber 40) at an optimum position, and to improve the printing performance. Thereby, high-definition printing can be realized.

  As described above, in any case, the ink jet recording apparatus 10 of the present embodiment can satisfactorily dissipate heat in the ink jet recording head 32. However, the ink jet recording apparatus 10 is limited to recording images (including characters) on the recording paper 60. Is not to be done. That is, the recording medium is not limited to paper, and the liquid to be ejected is not limited to ink. For example, it is industrially useful to create color filters for displays by discharging ink onto polymer films or glass, or to form bumps for component mounting by discharging solder in a welded state onto a substrate. It is included in all droplet ejecting apparatuses used.

Partially broken schematic perspective view of an ink jet recording apparatus Schematic perspective view of inkjet recording unit Schematic perspective view of a carriage incorporating an ink jet recording unit Schematic perspective view of a carriage incorporating an ink jet recording unit Schematic plan view of a carriage incorporating an ink jet recording unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inkjet recording device 12 Carriage 20 Shaft 30 Inkjet recording unit 32 Inkjet recording head 34 Ink tank 36 Base plate 40 Storage chamber 50 Leaf spring 52 Positioning member 54 Positioning member 60 Recording paper (recording medium)

Claims (5)

An ink jet recording head having a heating element and provided with a metal part for heat dissipation;
A carriage on which the ink jet recording head is mounted and reciprocating in a direction orthogonal to the conveyance direction of the recording medium;
A positioning portion formed on the carriage and in contact with the metal portion;
In an inkjet recording apparatus comprising:
An inkjet recording apparatus, wherein at least a part of a carriage including the positioning portion is made of a heat conductive material. An ink jet recording head having a heating element and provided with a metal part for heat dissipation;
A carriage on which the inkjet recording head is mounted and reciprocatingly inserted through a shaft extending in a direction perpendicular to the conveyance direction of the recording medium;
A positioning portion formed on the carriage and in contact with the metal portion;
In an inkjet recording apparatus comprising:
An ink jet recording apparatus, wherein a part of a carriage including at least a portion from the positioning portion to a portion through which the shaft is inserted is made of a heat conductive material.   The inkjet recording apparatus according to claim 1, wherein the heat conductive material is an alloy containing magnesium as a component.   3. The ink jet recording apparatus according to claim 1, wherein the heat conductive material is a resin obtained by mixing polyphenylene sulfide with metal powder.   5. The ink jet recording apparatus according to claim 1, wherein a ceramic sheet is provided in addition to a part of the carriage made of a heat conductive material.

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