JP2009274418A - Fluid jetting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid jetting apparatus which can simply and inexpensively carry out moisture retention of nozzles. <P>SOLUTION: The fluid jetting apparatus is equipped with a jetting head 13 which has a jetting surface 21A where a plurality of the nozzles 17 for jetting a fluid are formed, an oil supplying means 50 which supplies an oil to the jetting surface 21A in a non-printing state of the jetting head 13, and an oil drawing means which makes the oil supplied to the jetting surface 21A by the oil supplying means 50 drawn into the nozzles 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluid ejecting apparatus.

  The fluid ejecting apparatus is an apparatus that includes an ejecting head capable of ejecting a fluid and ejects various fluids from the ejecting head toward a recording material or the like. As a typical fluid ejecting apparatus, for example, an ink jet recording head (hereinafter simply referred to as a recording head) is provided, and a recording paper is formed by using liquid ink (fluid) as ink droplets from nozzles of the recording head (ejection head). There is an ink jet recording apparatus that performs recording by forming dots by discharging and landing on a recording material such as a recording medium.

In such an ink jet recording apparatus, there is a possibility that ink ejection failure may occur due to the inside of the nozzle being dried in a non-printing state. Therefore, there is a technique for separating the components in the ink by leaving it alone and moisturizing the nozzle (see, for example, Patent Document 1).
JP-T-2002-529572

  However, since the above-described conventional technique is used as a humectant by separating the components in the ink, there is a problem that costs increase due to restrictions on the ink that can be used.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a fluid ejecting apparatus capable of simply and inexpensively moisturizing a nozzle.

  In order to solve the above problems, a fluid ejecting apparatus according to the present invention includes an ejecting head having an ejecting surface on which a plurality of nozzles ejecting fluid are formed, and oil is applied to the ejecting surface in a non-printing state of the ejecting head. Oil supply means for supplying, and oil drawing means for drawing the oil supplied to the ejection surface by the oil supply means into the nozzle.

  According to the fluid ejecting apparatus of the present invention, the oil supplied to the ejecting surface is drawn into the nozzle by the oil drawing means, so that the nozzle can be prevented from drying in the non-printing state. Further, it is possible to eliminate the need for a cap member that has been conventionally used to prevent nozzle drying, and to simplify the apparatus configuration.

Moreover, in the fluid ejecting apparatus, it is preferable that the oil supply means has an oil tank storing the oil, and the oil is supplied to the ejection surface by being immersed in the oil tank.
According to this configuration, by being immersed in the oil tank, for example, the oil can be easily and reliably supplied to the ejection surface regardless of the uneven shape of the surface.

Moreover, in the fluid ejecting apparatus, it is preferable that the oil supply unit includes a roller having an outer peripheral surface coated with the oil.
According to this configuration, the oil can be easily and reliably supplied to the entire ejection surface by rotating the outer peripheral surface of the roller in contact with the ejection surface.

In the fluid ejecting apparatus, it is preferable that the oil has substantially the same viscosity as the fluid ejected from the nozzle.
According to this configuration, since the viscosity of the oil is substantially the same as that of the fluid, it can be satisfactorily drawn into the nozzle or discharged from the nozzle.

In the fluid ejecting apparatus, it is preferable that the ejecting head is a line head.
In a long shape such as a line head, it is difficult to obtain good adhesion of a conventional cap member, and there is a possibility that prevention of drying of the nozzle may be insufficient. In contrast, the present invention uses oil supplied to the ejection surface with the inside of the nozzle as a moisturizing means. Since oil is a liquid, an oil film can be formed on the entire ejection surface regardless of the shape of the ejection surface.
Therefore, the present invention is particularly effective when applied to an elongated shape such as a line head to which a conventional cap member is difficult to apply.

  Hereinafter, an embodiment of a fluid ejection device according to the present invention will be described with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size. In this embodiment, an ink jet printer is exemplified as the fluid ejecting apparatus according to the invention.

FIG. 1 is a schematic configuration diagram of an ink jet printer (hereinafter, referred to as a printer 100) of the present embodiment, FIG. 2 is a plan view of a main part around a recording head, and FIG. It is.
As shown in FIGS. 1 and 2, the printer 100 includes a recording unit 10 that performs recording on the recording paper 12.

  The recording unit 10 ejects ink droplets to form a recording head 13 (ejection head) that forms an image on a recording paper 12 that is a fluid ejection target, a recording paper conveyance mechanism 14 that conveys the recording paper 12, and a recording head 13. An ink storage unit 15 that stores ink (fluid) to be supplied.

  The recording paper transport mechanism 14 includes a paper feed motor (not shown), a paper feed roller that is rotationally driven by the paper feed motor, and the like, and the recording paper 12 is fed in conjunction with a recording (printing / printing) operation. The recording head 13 can be sequentially fed so as to face the recording head 13.

  The ink storage unit 15 is disposed on one side of the printer main body 16 and supplies ink to a recording head 13 described later by an ink supply unit (not shown). The ink storage unit 15 supplies ink of colors corresponding to the respective colors (yellow (Y), magenta (M), cyan (C), black (K1: dye system), black (K2: pigment system)) of the printer 100. It has ink tanks 15Y, 15M, 15C, 15K1, and 15K2 for storage. The ink reservoir 15 and the recording head 13 communicate with each other via an ink supply unit (not shown).

  The recording head 13 is a so-called line head type recording head in which a number of nozzles are arranged over a length (maximum recording paper width W) exceeding at least one side of the maximum size recording paper 12 targeted by the printer 100. In the present embodiment, at least five printing sections 5Y, 5M, 5C, 5K1, and 5K2 corresponding to each color (Y, M, C, K1, and K2) are provided. Each printing unit 5Y, 5M, 5C, 5K1, and 5K2 has a nozzle row L (see FIG. 3) in which a large number of nozzles 17 for ejecting ink droplets are arranged and arranged. The formed area is the nozzle formation area 21B. The nozzle rows L are arranged in order along the conveyance direction of the recording paper 12. The nozzle row L is one line of nozzles 17 or a plurality of lines of nozzles 17, and the number of nozzles 17 and the number of lines are appropriately set. FIG. 3 shows an embodiment of the nozzle row L, and shows a plurality of lines by the nozzles 17. By increasing the number of lines, a wide range of recording can be performed at once, and the resolution of the image is also increased.

The recording head 13 is arranged such that the length direction corresponding to the maximum recording paper width W is perpendicular to the conveyance direction of the recording paper 12, and ink droplets are ejected from the nozzles 17 of each nozzle row L onto the recording paper 12. An image is recorded on the recording paper 12.
The ink supply means for communicating the ink storage unit 15 and the recording head 13 has a plurality of ink supply channels (not shown), and the respective ink tanks 15Y, 15M, 15C, 15K1, and 15K2 to the respective printing units 5Y. , 5M, 5C, 5K1, and 5K2.

  Furthermore, the printer 100 according to the present embodiment includes an oil supply unit 50 that supplies oil to the ejection surface 21A (see FIG. 4) of the recording head 13, and the oil supplied to the ejection surface 21A by the oil supply unit 50. And a suction mechanism 39 as oil pull-in means for pulling in.

  The oil supply means 50 and the suction mechanism 39 are for preventing the nozzle 17 from drying and preventing the ink from being thickened in the nozzle 17, and are used in a non-printing state in the recording head 13.

  The recording head 13 can be moved in the vertical direction by a head moving mechanism (not shown). More specifically, the recording head 13 can be moved in the vertical direction between the printing position and the maintenance position by a head moving mechanism.

  The printing position is a position where recording is performed by ejecting ink from the nozzle 17 of the recording head 13 to the recording paper 12, and is a position where the recording head 13 is relatively moved upward. The maintenance position is a position where a maintenance process is performed to keep the nozzle 17 of the recording head 13 moisturized by the oil supply means 50 and the suction mechanism 39, and the position where the recording head 13 is relatively moved downward. It is.

Hereinafter, the configuration of the recording head 13 will be described in detail with reference to FIG. FIG. 4 is a cross-sectional view showing a part of the recording head 13.
The recording head 13 includes a head body 18 and a flow path forming unit 22 including a vibration plate 19, a flow path substrate 20, and a nozzle substrate 21. The nozzles 17 that eject ink are formed on the nozzle substrate 21, and the lower surface of the nozzle substrate 21 is an ejection surface 21 </ b> A. The flow path forming unit 22 is a unit in which the diaphragm 19, the flow path substrate 20, and the nozzle substrate 21 are laminated and joined together with an adhesive or the like.

  The recording head 13 includes an accommodation space 23 formed inside the head body 18 and a drive unit 24 disposed in the accommodation space 23. The drive unit 24 includes a plurality of piezoelectric elements (fluid supply units) 25, a fixing member 26 that supports the upper end of the piezoelectric elements 25, and a flexible cable 27 that supplies a drive signal to the piezoelectric elements 25. The piezoelectric element 25 is provided so as to correspond to each of the plurality of nozzles 17.

  In addition, an internal flow path 28 that is formed inside the head body 18 and flows ink supplied from the ink tank via the ink supply flow path, and a flow path that includes the vibration plate 19, the flow path substrate 20, and the nozzle substrate 21. A reservoir 29 formed by the forming unit 22 and connected to the internal flow path 28, an ink supply port 30 formed by the flow path forming unit 22 and connected to the reservoir 29, and an ink formed by the flow path forming unit 22 A cavity 31 connected to the supply port 30 is provided. A plurality of cavities 31 are provided so as to correspond to the plurality of nozzles 17. Each of the plurality of nozzles 17 is connected to each of the plurality of cavities 31.

  The head body 18 is made of synthetic resin. The diaphragm 19 is obtained by laminating an elastic film on a metal support plate such as stainless steel. An island portion 32 to be joined to the lower end of the piezoelectric element 25 is formed at a portion corresponding to the cavity of the diaphragm 19. At least a part of the diaphragm 19 is elastically deformed according to the driving of the piezoelectric element 25. A compliance portion 33 is formed between the diaphragm 19 and the vicinity of the lower end of the internal flow path 28.

  In the flow path substrate 20, the reservoir 29, the ink supply port 30, and the cavity 31 that connect the lower end of the internal flow path 28 and the nozzle 17 have recesses for forming respective spaces. In the present embodiment, the flow path substrate 20 is formed by anisotropic etching of silicon.

  The nozzle substrate 21 has a plurality of nozzles 17 formed at a predetermined interval (pitch) in a predetermined direction. The nozzle substrate 21 of the present embodiment is a plate-like member formed of a metal such as stainless steel.

  The ink supplied from each ink tank through each ink supply channel flows into the upper end of the internal channel 28. The lower end of the internal flow path 28 is connected to the reservoir 29, and the ink that has flowed into the upper end of the internal flow path 28 from the ink tank via the ink supply flow path flows into the reservoir 29 after flowing through the internal flow path 28. Supplied. The ink supplied to the reservoir 29 is supplied to be distributed to each of the plurality of cavities 31 via the ink supply port 30.

  When a drive signal is input to the piezoelectric element 25 via the cable 27, the piezoelectric element 25 expands and contracts. As a result, the diaphragm 19 is deformed (moved) in a direction toward and away from the cavity. As a result, the volume of the cavity 31 changes, and the pressure of the cavity 31 containing ink changes. Ink is ejected from the nozzles 17 due to this pressure fluctuation.

  As described above, the piezoelectric element 25 of the present embodiment varies the pressure of the cavity 31 connected to the nozzle 17 based on the input drive signal in order to eject ink from the nozzle 17. Then, a desired image is formed on the recording paper 12 by the ink ejected from the nozzle 17.

  FIG. 5 is a diagram showing a schematic configuration in the oil supply means 50. As shown in FIG. 5, the oil supply means 50 includes an oil tank 50A in which oil is stored. The oil tank 50A is sized so that the entire ejection surface 21A of the recording head 13 can be immersed.

  As the oil stored in the oil tank 50A, alkanes having 7 or more carbon atoms, monohydric alcohols, dihydric or higher polyhydric alcohols, and derivatives of the above substances are used. An oil having 7 or more carbon atoms is suitable for the present invention because it does not dissolve in water. The oil has substantially the same viscosity as the ink ejected from the nozzle 17. This makes it possible to satisfactorily draw into the nozzle 17 or discharge from the nozzle 17 as described later.

  The recording head 13 in the non-printing state is lowered by a head moving mechanism (not shown), and the ejection surface 21A is immersed in the oil tank 50A of the oil supply means 50 as shown in FIG. Thereafter, the recording head 13 is pulled up from the oil tank 50A by the head moving mechanism. At this time, as shown in FIG. 6B, an oil film 53 is formed on the entire ejection surface 21A.

  Subsequently, the suction mechanism 39 shown in FIG. 1 is operated to place the ink supply path and the nozzle 17 in a negative pressure state. Thereby, the oil film formed on the ejection surface 21A is drawn into the nozzle 17 as shown in FIG. The printer 100 maintains a state in which oil is drawn into the nozzle 17 during non-printing. The oil adhering to the vicinity of the opening 17A of the nozzle 17 is held by surface tension. The oil drawn into the nozzle 17 in this way can prevent the printer 100 from drying in the non-printing state. Further, the oil drawn into the nozzle 17 prevents the ink in the nozzle 17 from being oxidized, and can also prevent problems such as a change in the color of the ink.

  When returning from such a non-printing state to a printing state, after the oil is discharged from each nozzle 17 of the recording head 13, the oil adhering to the ejection surface 21A is wiped by the wipe member. Furthermore, by performing the flushing operation to adjust the ink meniscus in the nozzles 17, the printer 100 is brought into a printable state.

  Incidentally, in the printer 100 according to the present embodiment, the recording head 13 is a so-called line head. Conventionally, when the cap member used for drying the nozzles of the recording head has a long shape such as a line head, good adhesion cannot be obtained, and the prevention of drying of the nozzles may be insufficient. It was.

  On the other hand, in this embodiment, oil is used as means for keeping the inside of the nozzle 17 moisturized. Since oil is a liquid, an oil film can be formed on the entire ejection surface 21A without depending on the shape of the ejection surface 21A. Therefore, oil can be drawn into all the nozzles 17 on the ejection surface 21A as described above. Therefore, according to the present embodiment, it is possible to reliably prevent the inside of the nozzle 17 from being dried even in a long head such as a line head that has conventionally been difficult to prevent the nozzle from drying. As described above, the present invention can obtain a particularly remarkable effect in the line head. Further, in the present embodiment, since the nozzle 17 is moisturized by drawing oil into the nozzle 17 as described above, a cap member that has been conventionally used to prevent the nozzle from drying is unnecessary. The device configuration can be simplified.

(Second Embodiment)
Next, a second embodiment of the printer will be described. In this embodiment, the shape of the oil supply means is different from that of the first embodiment, and the other configurations are the same. Therefore, the same configurations and members as those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted or simplified.

  FIG. 8 is a diagram showing a schematic configuration of the oil supply means 150 according to the present embodiment. The oil supply means 150 according to the present embodiment is mainly configured by an application roller 150A. The application roller 150A is immersed in an oil tank 151 in which oil is stored, so that oil is applied to the outer peripheral surface thereof. In the present embodiment, oil can be easily and reliably supplied to the entire ejection surface 21A by rotating the outer peripheral surface of the application roller 150A while being in contact with the ejection surface 21A. Also in this embodiment, the oil applied to the ejection surface by the application roller 150A forms an oil film on the entire ejection surface 21A without depending on the shape of the ejection surface 21A. The oil adhering to the vicinity of the opening 17A of the nozzle 17 is held by surface tension.

  Subsequently, as in the above embodiment, the suction mechanism 39 is operated to place the ink supply path and the nozzle 17 in a negative pressure state. Thereby, the oil film formed on the ejection surface 21 </ b> A is drawn into the nozzle 17. The printer 100 maintains a state in which oil is drawn into the nozzle 17 during non-printing. Thus, the oil drawn into the nozzle 17 can prevent the printer 100 from drying even in a non-printing state.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention. In the first and second embodiments, the suction mechanism 39 as oil drawing means for drawing the oil applied to the ejection surface 21A into the nozzle 17 is exemplified, but the present invention is not limited to this, and for example, the nozzle 17 Any structure that can bring the inside into a negative pressure state can be replaced.

  In the second embodiment, oil is applied to the ejection surface 21A by the application roller 150A, and then the oil is drawn into the nozzle 17 by the suction mechanism 39. However, the oil is applied to the ejection surface 21A by the application roller 150A. The oil may be drawn into the nozzle 17 by operating the suction mechanism 39 while applying the oil.

In the above embodiment, the fluid ejecting apparatus is embodied as an ink jet printer. However, the present invention is not limited to this, and fluid other than ink (a liquid material in which particles of functional material are dispersed, a flow such as a gel) The present invention can also be embodied in a fluid ejecting apparatus that ejects or discharges a shape.
For example, a liquid material injection device for injecting a liquid material in the form of dispersed or dissolved materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, and surface-emitting displays, and biochip manufacturing It may be a fluid ejecting apparatus that ejects a bio-organic matter used in the above, or a fluid ejecting apparatus that ejects a fluid that is used as a precision pipette as a sample.
In addition, transparent resin liquids such as UV curable resins to form fluid injection devices that inject lubricating oil onto precision machines such as watches and cameras, micro hemispherical lenses (optical lenses) used in optical communication elements, etc. May be a fluid ejecting apparatus that ejects a liquid onto the substrate, a fluid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate, or a fluid ejecting apparatus that ejects gel. Then, in any one of these fluid ejecting apparatuses, the present invention is applied if there is a possibility that the ejected fluid (liquid body, fluid body) may increase the viscosity due to, for example, drying or the like and cause ejection failure. be able to.

1 is a schematic configuration diagram of a printer. FIG. 2 is a plan view of a main part around a recording head. FIG. 3 is a plan view showing an ejection surface of a recording head. FIG. 3 is a diagram illustrating a detailed configuration of a recording head. It is a figure which shows schematic structure in an oil supply means. It is a figure for demonstrating the moisture retention operation | movement of a nozzle. It is a figure for demonstrating the state by which oil was drawn in in the nozzle. It is a figure which shows schematic structure of the oil supply means which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 ... Recording head (ejection head), 17 ... Nozzle, 21A ... Ejection surface, 39 ... Suction mechanism (oil drawing means), 50 ... Oil supply means, 50A ... Oil tank, 100 ... Printer (fluid ejection apparatus), 150 ... Oil Supply means, 150A ... coating roller (roller)

Claims (5)

An ejection head having an ejection surface on which a plurality of nozzles for ejecting fluid are formed;
Oil supply means for supplying oil to the ejection surface in a non-printing state of the ejection head;
An oil drawing device comprising oil drawing means for drawing the oil supplied to the jetting surface by the oil supply means into the nozzle.   The fluid ejecting apparatus according to claim 1, wherein the oil supply unit includes an oil tank that stores the oil, and the oil is supplied to the ejection surface by being immersed in the oil tank.   The fluid ejecting apparatus according to claim 1, wherein the oil supply unit includes a roller having an outer peripheral surface coated with the oil.   The fluid ejecting apparatus according to claim 1, wherein the oil has substantially the same viscosity as the fluid ejected from the nozzle.   The fluid ejecting apparatus according to claim 1, wherein the ejecting head is a line head.

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