JP2008093847A - Inkjet head equipped with drying preventing ability at its tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head equipped with a nozzle drying preventing mechanism which has no possibility of drying a nozzle even when an ink with an extremely rapid drying is used and normally performs delivering from the first delivery even when the delivery is performed again from a resting state as an industrial application by preventing the nozzle from drying, especially suppressing advancing of drying the nozzle within an imaging region. <P>SOLUTION: The drying of the ink from the nozzle is suppressed by making the neighborhood of a delivering hole under a solvent atmosphere. A nozzle for exclusive use for an ink drying preventing liquid is formed independently from a use for delivering the ink. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates not only to a printer for PC, which is a kind of information processing apparatus, but also to an ink jet recording apparatus that has recently been remarkably applied for industrial use such as device manufacturing, and in particular, stably without drying a nozzle portion having a small aperture The present invention relates to an ink jet recording apparatus having a mechanism for ejecting ink. An ink jet recording apparatus that directly ejects ink onto a recording medium is not limited to the recording medium, and has developed significantly in recent years from the viewpoint of high speed and low noise. In addition, the head is the core of the ink jet recording apparatus. Ensuring the reliability of the company is also gaining importance.

  In recent years, along with the development of the information processing industry, characteristics such as image quality and resolution required for printers have rapidly advanced, and even in an ink jet recording apparatus which is one of the typical methods of printers, the nozzle diameter is very small. Advances in technology such as computerization and drive control have enabled the required high-quality drawing. However, with the miniaturization of the nozzle diameter, various problems such as an increase in ink concentration due to drying of the ink solvent and bubbles in the ink have become more prominent. Such a state lowers the original drawing accuracy and is a big problem in terms of ensuring reliability.

As means for solving the above-mentioned problems, there is means for adding an anti-drying agent such as urea, thiourea, ethylene urea, or ethylene glycol to the ink itself. However, since impurities are added to the ink itself, there is a problem in a later process. In some cases, it may not be possible to add some inks. On the other hand, as a means for preventing drying on the apparatus side, when the ink jet head reaches a non-drawing region, there is a method of covering the nozzle with a nozzle cap to shut off the outside air, but there is a problem with the airtightness of the nozzle cap, It is insufficient as a drying prevention method. In another method, ink is ejected to a non-recording area to prevent drying, or by sucking ink through a nozzle cap, thereby removing ink in an abnormal state such as viscosity increase or mixing of microbubbles. There are also methods such as this, but since these methods discard a large amount of ink, there remains a problem in terms of cost. Therefore, in Japanese Patent Laid-Open No. 6-336018, in order to reduce consumption of ink to be sucked in order to prevent nozzle clogging, the ink is driven to come into contact with and separate from the nozzle before sucking ink from the nozzle. By connecting the nozzle cap to the decompression chamber connected to the negative pressure generating means, covering the nozzle with the nozzle cap when not drawing, and maintaining the inside of the decompression chamber and the nozzle cap in a negative pressure state by the negative pressure generating means There is a method in which the ink meniscus is moved inside the nozzle to activate it in a fluid state even if the ink is solidified in the nozzle. By using this method, it is possible to obtain a sufficient effect with a consumer printer. However, when using ink with extremely fast drying in industrial applications that have been developed in recent years, the cap must be removed. In the time until drawing starts, the ink suction effect is lost, and in reality, it is necessary to take measures such as preliminary ink ejection in a non-drawing area. JP-A-11-157090 has a sponge made of a fibrous or porous material in a non-drawing region and a backup device made of a non-volatile fluid impregnated in the sponge, and this device can be pressed against or separated from the nozzle part. A method has been proposed in which the nozzle portion is surrounded by a non-volatile fluid during pressure contact to prevent drying. However, this method is also insufficient for industrial use, for the same reason as described above.
JP-A-6-336018 Japanese Patent Laid-Open No. 11-157090

  As described above, various methods for solving various problems such as undischarge due to nozzle drying and misalignment have been proposed. However, any of these methods is still insufficient for industrial use. This is the provision of a method for preventing nozzle drying when each of the above-described methods is in a non-drawing area. With extremely fast drying ink as used in industrial applications, the head draws from the non-drawing area. This is because drying progresses in the time from moving to the region and actually starting drawing, resulting in ejection failure.

  In order to deal with such a problem, a means of replacing a defective head has been taken, but since the cost has been increased, a means for avoiding this is required.

  Accordingly, an object of the present invention is to prevent drying of the nozzle, particularly by suppressing the progress of nozzle drying in the drawing area, so that it is possible to pause without drying the nozzle even when using extremely fast ink as an industrial application. It is an object of the present invention to provide a head provided with a nozzle drying prevention mechanism that allows normal discharge from the first shot even when re-discharge is performed from the state.

  Such an object can be achieved by the following configuration. That is, the present invention has a mechanism for preventing ink drying in the nozzles by making the vicinity of the ink discharge port a solvent atmosphere in an ink jet recording apparatus that performs drawing on a recording medium by ejecting ink from the nozzles. Inkjet recording apparatus characterized by the above.

  2. The ink jet recording apparatus according to claim 1, further comprising a nozzle into which an ink drying prevention liquid for preventing ink drying in the nozzle is injected, in addition to the nozzle into which ink is injected. is there.

  Furthermore, the present invention is the ink jet recording apparatus according to claim 2, wherein a solvent of ink discharged onto the recording medium is used as the ink drying preventing liquid.

  As described above, by employing the head having the ink drying prevention capability according to the present invention, it is possible to provide a highly reliable ink jet recording apparatus that is free from defects such as ejection failure and twist due to ink drying. It was.

  Further, by using this inkjet recording apparatus for industrial purposes, the yield on the recording medium side (device parts, etc.) can be improved.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a head configuration diagram of an ink jet recording apparatus according to the present invention. The ink jet head 1 has a piezoelectric element 6, an ink nozzle 31, an ink drying preventing liquid nozzle 41, and an orifice plate 2. The piezoelectric element 6 is made of a lead zirconate titanate ceramic material. The orifice plate is made of a metal such as polyimide or Ni, and the discharge port side is water-repellent treated with a Teflon (registered trademark) material or the like. The nozzles are alternately arranged for ink and for ink drying prevention liquid, and form a line in a straight line. FIG. 2 shows the head shown in FIG. 1 cut along a plane (a-b plane) in which a common flow path is formed. The inkjet head 1 has an ink manifold 7 for supplying ink and an ink drying preventing liquid to each nozzle. As shown in the figure, the common flow path is divided into an ink flow path 3 and an ink drying prevention liquid flow path 4, and the amount of discharge liquid and the like can be adjusted respectively. In the figure, reference numerals 31 and 41 denote receptacles for feeding ink from the tank and ink drying prevention liquid into the respective common flow paths.

  In this proposal, the energy generating means is a piezoelectric element, but it is not particularly limited as long as it does not affect the ink and the ink drying prevention liquid, such as bubble generation by a heating element.

  As for the nozzle arrangement, as described above, in addition to the alternating arrangement, both liquids are divided in units of columns as shown in FIG. 3, and further, the arrangement is staggered in units of columns as shown in FIG. However, it is not limited to these.

  FIG. 6 is a schematic diagram showing a state in which ink is ejected from a head in which nozzles are alternately arranged. Ink is ejected from the ink nozzle, and the ink drying preventing liquid is filled in the ink drying preventing liquid nozzle to the vicinity of the ejection opening. It should be noted that the effect of preventing ink drying can be enhanced by making the meniscus surface always at a certain position by, for example, driving the ink drying preventing liquid nozzle with a unique piezoelectric element.

  FIG. 5 shows a head to which an ink drying prevention mechanism is attached so as to surround the ink discharge port array 33. As an ink drying prevention mechanism, a sponge made of a fibrous or porous material is impregnated with a highly volatile ink drying prevention liquid. The ink drying prevention liquid is sequentially supplied to the sponge. . As described above, the ink drying prevention mechanism is not particularly limited as long as it is a means capable of setting the solvent atmosphere in the vicinity of the ejection port and not affecting the ejection performance, in addition to forming a dedicated nozzle. Not.

  The ink drying preventing liquid is not particularly limited as long as it is a material that suppresses the drying speed of the ink, but it is preferable to use an ink solvent in consideration of the influence on the ink.

  An ink jet head in which the energy generation source of the nozzle arrangement shown in FIG. 1 is a piezoelectric element was produced.

  Next, the following ink and ink drying preventing liquid were prepared.

R ink C.I. I. Acid orange 148: 3.5 parts by weight C.I. I. Acid red 289: 0.5 part by weight Diethylene glycol: 30 part by weight Isopropyl alcohol: 20 part by weight Ion exchange water: 40 part by weight The above curing component: 6 part by weight G ink C.I. I. Acid yellow 23: 2 parts by weight Zinc phthalocyanine sulfoamide: 2 parts by weight Diethylene glycol: 30 parts by weight Isopropyl alcohol: 20 parts by weight Ion-exchanged water: 40 parts by weight The above curing component: 6 parts by weight B ink C.I. I. Direct blue 199: 4 parts by weight Diethylene glycol: 30 parts by weight Isopropyl alcohol: 20 parts by weight Ion-exchanged water: 40 parts by weight Curing component: 6 parts by weight Ink drying preventing liquid Mixed solution of diethylene glycol and isopropyl alcohol The above ink and ink drying prevention The liquid was supplied to each of the ink jet heads prepared above, and the ink was sucked to the head discharge port.

  Next, using an ink jet recording apparatus provided with the head, ink was applied to a pixel-corresponding portion of the transparent substrate on which the black matrix was formed. At this time, various drive controls were performed on the ink drying prevention liquid to correct the meniscus position. In the middle, the discharge was paused several times, but when discharging again, there was no problem such as twisting or discharge failure, stable discharge was performed, and the color filter created was observed with an optical microscope. It was confirmed that there was no problem.

1 is a head configuration diagram of an ink jet recording apparatus according to the present invention. FIG. 1 is a configuration diagram of an ink manifold in a head of an ink jet recording apparatus according to the present invention. 4 is a nozzle arrangement configuration example of an ink jet recording apparatus according to the present invention. 4 is a nozzle arrangement configuration example of an ink jet recording apparatus according to the present invention. 4 is a nozzle arrangement configuration example of an ink jet recording apparatus according to the present invention. FIG. 3 is a diagram illustrating a state where ink is being discharged from the ink jet recording apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet head 2 Orifice plate 3 Ink common channel 31 Ink receiving port 32 Ink nozzle 33 Ink ejection port 4 Ink drying preventing liquid common channel 41 Ink drying preventing solution receiving port 42 Ink drying preventing nozzle 43 Ink drying preventing Liquid outlet 5 Sponge 6 Piezoelectric element 7 Ink manifold

Claims (3)

  An ink jet recording apparatus that performs drawing on a recording medium by ejecting ink from a nozzle, and has a mechanism for preventing ink drying in the nozzle by setting a solvent atmosphere in the vicinity of the ink discharge port Recording device.   2. The ink jet recording apparatus according to claim 1, further comprising a nozzle into which an ink drying preventing liquid for preventing ink drying in the nozzle is injected, in addition to the nozzle into which ink is injected.   3. The ink jet recording apparatus according to claim 2, wherein an ink solvent discharged onto the recording medium is used as the ink drying preventing liquid.

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