JP2006224433A - Ink injecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink injecting method which prevents the leakage of ink from a nozzle or the color mixing from occurring at the time of a pressurization type ink injection such as a needle puncture or at the time of the re-injection, and also, stabilizes the state of ink (bubbles) in a liquid chamber by stopping the ink by a filter at the time of an initial ink injection. <P>SOLUTION: The ink injection is performed while pressurizing the nozzle by a gas from the face side or pressurizing the filter through the nozzle at the time of the ink injection. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for injecting ink into an ink jet recording cartridge used in an ink jet recording apparatus, which performs recording by ejecting ink from a recording head onto a recording medium.

  The ink jet recording apparatus is a so-called non-impact recording type recording apparatus, and has a feature that noise is hardly generated at the time of recording, and high-speed recording and recording on various recording media are possible. For this reason, the ink jet recording apparatus is widely adopted as an apparatus that bears a recording mechanism such as a printer, a copier, a facsimile machine, and a word processor.

  As a typical ink ejection method in a recording head mounted on such an ink jet recording apparatus, a method using an electromechanical transducer such as a piezo element or the like, heats ink by irradiating electromagnetic waves such as a laser. There are known ones that discharge ink droplets by the action of the above, or those that heat ink by an electrothermal conversion element having a heating resistor and discharge ink drops by the action of film boiling.

  Among these, an ink jet recording head using an electrothermal conversion element is provided with an electrothermal conversion element in a recording liquid chamber, and supplies heat energy to the ink by supplying an electric pulse as a recording signal thereto to generate heat, Recording is performed on a recording medium by ejecting an ink liquid from a minute ejection port using the bubble pressure when the recording liquid is foamed (at the time of boiling) caused by the phase change of the recording liquid. An ink jet recording head using an electrothermal conversion element generally includes a nozzle having an ejection opening for ejecting ink droplets, an ink flow path for supplying ink to the nozzle, and a common liquid chamber. Yes.

  In addition, the ink jet recording head is a tank replacement type in which the ink tank and the ink jet recording head part are detachable, or a form of an ink jet recording cartridge in which the ink jet recording head part and an ink container part containing ink are integrated. There is. Inkjet recording cartridges in which the inkjet recording head unit and ink container unit are integrated can be replaced with each other when the head is old, so that the durability and reliability of the head itself can be set to be somewhat low. In addition, various products are provided to constantly provide new heads to users.

  Next, a general ink jet recording cartridge will be described with reference to FIG. 7 and an ink jet recording apparatus shown in FIG.

  A general ink jet recording apparatus will be described with reference to FIG.

  FIG. 6 is a schematic view showing an ink jet recording apparatus, in which ink jet recording cartridges 601 and 602 are positioned on a carriage 603 and mounted so as to be replaceable. In this conventional example, the ink jet recording cartridges 601 and 602 are a black cartridge that discharges black ink and a color cartridge that discharges yellow, magenta, and cyan color inks, respectively. The carriage 603 is provided with an electrical connection section for meeting external signal input terminals of the ink jet recording cartridges 601 and 602 and transmitting an electrical signal to each ejection section.

  The carriage 603 is guided and supported in the reciprocating movement direction along a guide shaft 604 extending in the main scanning direction and installed in the apparatus main body. The carriage 603 is driven by a main scanning motor 605 via driving mechanisms such as a motor pulley 606, a driven pulley 607, and a timing belt 608, and its position and movement are controlled. A home position sensor 609 is provided on the carriage 603. This makes it possible to know the position of the shielding plate 610 when the home position sensor 609 on the carriage 603 passes.

  A recording medium 611 such as a printing paper or a plastic thin plate is separated and fed one by one from the auto sheet feeder 614 by rotating a pickup roller 613 from a paper feeding motor 612 via a gear. Further, by the rotation of the transport roller 614, the transport roller 614 is transported (sub-scanned) through a position (print unit) facing the discharge port surfaces of the ink jet recording cartridges 601 and 602. The conveyance roller 614 is performed via a gear by the rotation of the LF roller 615.

  At this time, the determination as to whether the recording medium 611 has been fed and the confirmation of the cue position at the time of feeding are performed when the recording medium 611 passes through the paper end sensor 616. Further, the paper end sensor 616 is also used to finally determine the current recording position from the actual rear end where the rear end of the recording medium 611 is actually located.

  Note that the back surface of the recording medium 611 is supported by a platen (not shown) so as to form a flat print surface in the print unit. In this case, the ink jet recording cartridges 601 and 602 mounted on the carriage 613 are held so that their discharge port surfaces protrude downward from the carriage 603 and are parallel to the recording medium 611 between the two sets of transport rollers. ing.

  The ink jet recording cartridges 601 and 602 are mounted on the carriage 603 so that the arrangement direction of the ejection ports in each ejection section intersects the scanning direction of the carriage 603 described above, and ink is ejected from these ejection ports. Make a record.

  Next, a general ink jet recording cartridge will be described with reference to FIG.

  In this conventional example, a color cartridge for performing printing by discharging yellow, magenta, and cyan inks will be described as an example.

  In FIG. 7, reference numeral 601 denotes an ink jet recording cartridge, and reference numeral 702 denotes an ink jet recording chip portion. The ink jet recording chip is a heater as an energy generating element for converting electric energy into heat energy and ejecting ink. It consists of a substrate with wiring for transmitting electrical energy supplied from an inkjet recording device, a nozzle plate with a flow path for supplying ink to the heater and an ink discharge port for discharging ink. ing.

  In this conventional example, one inkjet recording chip 702 has ejection port arrays 703, 704, and 705 for ejecting three colors of yellow, magenta, and cyan.

  Reference numeral 706 denotes an electric wiring tape for transmitting an electric signal from the ink jet recording apparatus to the ink jet recording chip 702, and an electric signal is input from the ink jet recording apparatus via an external signal input terminal 707.

  The electrical wiring tape 706 and the inkjet recording chip 702 are electrically connected to the electrical wiring tape 706 at two end faces of the inkjet recording chip 702, and the electrical connection portion is covered with a sealing material 708 and protected from ink. Has been.

The ink supplied to the inkjet recording chip 702 is stored in an ink storage unit (not shown) for holding and storing each color ink partitioned by a case unit 709 and a lid 710. An ink absorber for holding ink is stored in the ink storage portion. In addition, a filter is provided in the ink supply path portion for supplying ink to the ink jet recording head portion provided in the case 709 so that foreign matter does not enter the ink discharge port provided in the ink jet recording chip 702. Yes.
JP 10-44463 A

  The problem to be solved by the present invention is to supply ink from an ink container to an ink jet recording chip when the ink is injected into the ink container while injecting the ink into the ink jet recording cartridge as described above. Ink may enter halfway through the ink supply path. As a result, bubbles may remain more easily in the ink flow path than when there is no ink at the time of subsequent ink recovery.

  In addition, even when the ink jet recording cartridge is used once and the ink in the ink container is used up, if the ink jet recording chip portion 702 is still usable, the ink absorber provided in the case 709 can be reused. In some cases, ink is injected and reused. In general, ink re-injection is performed by injecting an ink from an ink injection port provided in the lid 710 of the ink jet recording cartridge into an ink absorber in the case 709 by inserting a needle into the ink absorber.

  At the time of the injection, if the ink in the case is in a pressurized state for some reason, such as the ink injection speed is too high, the ink discharge port arrays 703, 704, and 705 provided in the ink jet recording chip 702 are re-injected. In some cases, ink leaks from the ejection port array corresponding to the ink color.

  As described above, when ink leaks from the ink ejection port array and the leaked ink touches the ink ejection port array of another color, the ink of the other color ink ejection port array is in the case. Since the negative pressure of a certain ink absorber is applied, there is a problem that the leaked ink is drawn into the ink discharge port array and color mixing occurs.

  In addition, when ink leakage occurs in an ink jet recording cartridge containing monochromatic ink, if the ink leaks, the ink is dripped, and the case portion of the ink jet recording cartridge, the ink refilling device, and the user's surroundings The environment may be polluted.

  The present invention has been made paying attention to the above points, and prevents ink leakage and color mixing from the nozzles when pressurized ink injection such as needle sticking or re-injection, and at the initial ink injection. An object of the present invention is to provide an ink injection method that stops ink with a filter and stabilizes the ink (bubble) state in the liquid chamber.

The present invention has been made in view of the above problems,
Inkjet recording chip comprising an ink container containing ink and an ink absorber for holding the ink, energy generating means for ejecting ink supplied from the ink container, and an ink ejection port for ejecting ink An ink injection method for injecting ink into an ink jet recording cartridge, comprising: injecting ink by pressurizing an ink discharge port portion for discharging ink toward the inside of the ink jet recording cartridge at the time of ink injection Method,
In the case of injecting ink into an ink jet recording cartridge, it is provided in the ink flow path through the ink discharge port by applying pressure from the ink discharge port provided in the ink jet recording chip. Pressurized pressure is also applied to the filter section, and the ink is stopped by the filter section when ink is injected, making it difficult to enter the ink flow path freely. At this time, the pressurizing pressure needs to be weaker than the meniscus force of the filter. This is because when the pressure is higher than the meniscus force of the filter, bubbles enter the ink container from the filter portion.

  In addition, when the ink is reinjected into the ink jet recording cartridge, a pressure is applied to the ink ejection port array provided in the ink jet recording chip so that the ink in the case is in a pressurized state for some reason during the ink reinjection. However, ink leakage from the ink discharge port array is very unlikely to occur.

  In addition, it is important that this pressurizing pressure be weaker than the meniscus force of the ink discharge port array. If it is greater than the meniscus force, bubbles will enter the ink jet recording cartridge from the ink discharge port array. .

  Furthermore, the re-ink injection method while pressurizing the ink injection port array is effective when re-injecting ink into an ink jet recording cartridge containing a plurality of colors of ink, and can prevent color mixing due to ink dripping as described above. It becomes possible.

  Inkjet recording chip comprising an ink container containing ink and an ink absorber for holding the ink, energy generating means for ejecting ink supplied from the ink container, and an ink ejection port for ejecting ink When ink is injected into an ink jet recording cartridge equipped with an ink absorber, the ink is injected by pressurizing the filter through the ink discharge port (ink) or the discharge port, so that the pressure of the ink to be injected etc. Even when the ink held in the ink is in a pressurized state, it prevents halfway ink inflow into the ink flow path, and also at the time of ink re-injection where ink is present in the ink flow path, An ink jet recording car that can prevent ink leakage from the ink discharge port, It is possible to prevent ridges and re-ink injectors from being soiled, and even in an ink jet recording cartridge containing multiple colors of ink, ink dripping can prevent ink color mixing in the ink jet recording chip, and reliability can be improved. It is possible to provide a high ink injection method.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a schematic view showing a state where ink is re-injected into an ink jet recording cartridge according to a first embodiment of the present invention. In the case surrounded by a tank case 101 and a lid 102 of the ink jet recording cartridge 111. An ink absorber 103 is provided.

  Further, the tank case 101 is provided with an ink supply path 105 for supplying ink held by the ink absorber 103 to the ink jet recording chip 106, and an upper part of the ink supply path 105 is shown in FIG. As shown, a filter 104 is provided. The ink absorber 103 holding the ink is in pressure contact with the filter 104 at an appropriate amount, so that the ink held on the ink absorber 103 without ink shortage is supplied to the ink jet recording chip 106.

  The lid 102 is provided with an ink inlet 112 for injecting ink, and is normally closed with a label (not shown) or the like to prevent evaporation of ink in the ink jet recording cartridge 111. When the ink is refilled, the label is removed and the refilling is performed.

  Reference numeral 108 denotes an ink injector, and the ink injector 108 includes an ink injection needle 107. The ink injection needle 107 is inserted into the ink absorber 103 from the ink injection port 112, and the ink injector The ink is pressurized and pushed out from the tip of the ink injection needle 107 to inject ink. An arrow 110 indicates the direction in which the ink exits at this time. Generally, in consideration of the ink distribution of the ink absorber 103, the ink is injected from the vicinity of the filter 104 provided in the ink supply path 105.

  When such ink injection is performed, since the ink is injected under pressure, a pressurizing pressure is applied to the ink 113 in the ink passage 105, and further, the ink passage provided in the ink jet recording chip 106 is applied. The pressure applied to the existing ink is also transmitted. This pressure becomes even stronger, for example, when the ink injection speed is increased to increase the number of ink injection processes.

  At this time, the periphery of the ink jet recording chip 109 is sealed with a cap 109 so as to prevent the ink from leaking from an ink discharge port (not shown) provided in the ink jet recording chip 106 due to the ink injection pressure. This gas is pressurized to prevent ink leakage from the ejection port.

  Next, the meniscus state of the ink discharge port provided in the inkjet recording chip will be described with reference to the drawings.

  FIG. 2 shows the state of the ink in the vicinity of the ejection port when an appropriate negative pressure is applied to the ink by the ink absorber provided in the ink jet recording cartridge, and 201 is a flow path member. There is a φd circular hole from which ink is ejected. A hole of φd (this portion becomes the discharge port) is filled with ink 202, and a meniscus 203 is formed by the surface tension. The meniscus shape at this time is formed toward the inside of the discharge port because the negative pressure of the ink absorber is applied as described above.

  The ink meniscus force at this time is obtained by the following equation.

P = 4γ / d − Formula (1)
P: meniscus force (dyn / cm ² ) γ: ink surface tension (dyn / cm) d: discharge port diameter (cm)

For example, when the ink surface tension is 30 (dyn / cm) and the discharge port diameter is 0.002 (cm),
P = 4 × 30 / 0.002 = 6 × 10 ⁴ (dyn / cm)
It becomes.

  As can be seen from the above equation, the meniscus force of the ink is determined by the shape (diameter) of the ink discharge port and the physical property value (surface tension) of the ink.

  Next, the ink meniscus state when the ink is pressurized will be described with reference to FIG.

  In the same configuration as in FIG. 2, since the ink is in a pressurized state, as shown by 302 in FIG. 3, the ink meniscus protrudes from the flow path member.

  Theoretically, the meniscus force at this time should be the value calculated by the above equation (1), but the ink discharge port portion provided in the actual ink jet recording chip has its ridge 401 as shown in FIG. In many cases, the shape is not ideal, such as an R shape. If R is attached to the ridge portion 401, when the ink forms a meniscus at that portion, it is the same as the case where the discharge port diameter φd in the formula (1) is increased, and the meniscus force is ideal. It will drop more.

  Further, there may be a case where foreign matter 403 such as thickened ink or paper dust adheres to the surface (face surface) portion of the ink jet recording chip, and if the foreign matter 403 comes into contact with the ink 202, a meniscus cannot be formed, This may cause ink leakage.

Therefore, as described in the first embodiment of the present invention, since the ejection port provided in the ink jet recording chip is weak against the pressure applied from the ink holding member side and it is necessary to prevent ink leakage, At the time of injection, an ink jet recording chip having such an ink discharge port is preferably pressurized from the discharge port side as shown in FIG. 1, and the discharge port diameter and ink of the example shown in this embodiment were used. In the case of the pressurization, if the pressurization is performed at a pressure smaller than 6 × 10 ⁴ (dyn / cm), there is no problem such as bubbles entering the ink flow path through which the ink provided in the ink jet recording chip passes. Ink-jet recording cartridges that contain ink of a single color to prevent ink leakage, stains on the cartridge housing due to ink dripping, dirt on the re-ink injection device, Ink jet recording cartridges containing ink can further prevent color mixing between different colors, and enables re-ink injection with high reliability.

  Some ink jet recording chips provided in the ink jet recording cartridge include discharge ports having a plurality of types of discharge port areas in order to discharge a plurality of discharge amounts as shown in FIG. In this embodiment, an ejection port array for ejecting three types of inks of yellow, magenta, and cyan is provided, and ejection ports 501, 2pl for ejecting 5 pl of ink are ejected for each color. The inkjet recording chip provided with the discharge outlet 502 was used. In such a case, re-injection can be performed without impairing reliability by applying pressure from the cap in accordance with the meniscus force of the larger discharge port area.

  Further, use an inert gas such as nitrogen as the gas for pressurizing the ink in the cap, or provide a filter in the path of the pressurized gas so that foreign matter is not mixed with the pressurized gas. Thus, there is no fear that the ink jet recording chip is contaminated by the pressurized gas at the time of reinking, and further reliable reinking is possible.

  Also at the time of initial ink injection into the ink jet recording cartridge, as shown in the first embodiment, an ink injection needle is inserted into an ink absorber provided in an ink container, and ink is injected from there. As shown in FIG. 5, the ink 113 enters the halfway end in the ink flow path 105, and a large bubble 801 remains in the ink flow path 105. In order to remove the bubbles in the subsequent ink recovery, complicated recovery conditions and a large suction pressure are required.

  Therefore, in this embodiment, as shown in FIG. 9, the ink jet recording chip 106 is provided with a pressure applied from the cap 109 in the absence of ink in the ink flow path 105 during the initial ink injection. Pressurizing pressure is applied to the filter 104 through the ink discharge port. If ink is injected in such a state, the ink is pushed at the filter 104 and the ink 113 hardly enters the ink flow path 105.

In this embodiment, the filter 104 is a sintered filter obtained by sintering metal (SUS). The meniscus force of the filter used in this example is 5 × 10 ⁴ (dyn / cm), but the pressurizing pressure from the cap 109 is kept smaller than this force. By performing such an ink injection method, it is possible to perform ink injection with no air bubbles entering the ink container, no ink entering the ink flow path 105, and a simple recovery operation. It becomes.

Schematic diagram of a state where re-ink injection is performed according to the first embodiment of the present invention. Schematic diagram showing the meniscus state near the normal ink ejection port Schematic diagram showing the meniscus state in the vicinity of the ejection opening when the ink in the ink jet recording cartridge is in a pressurized state Enlarged view of the vicinity of the discharge port in FIG. The schematic diagram which showed the arrangement | sequence of the discharge outlet concerning 2nd Example of this invention Schematic diagram showing a conventional inkjet recording apparatus Schematic diagram showing a conventional inkjet recording cartridge Schematic diagram showing the state of conventional ink injection Schematic diagram showing ink injection according to the third embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Tank case 102 Cover 103 Ink absorber 104 Filter 105 Ink flow path 106 Inkjet recording chip 107 Ink injection needle 108 Ink injector 109 Cap 110 Arrow representing ink flow 111 Inkjet recording cartridge 112 Ink injection hole 113 Ink 201 flow path Member 202 Ink 203 Meniscus 301 Meniscus 401 Discharge port ridge line (R)
402 Meniscus 403 Foreign object 501 Ink ejection port (for 5 pl)
502 Ink ejection port (for 2 pl)
601 Inkjet recording cartridge 602 Inkjet recording cartridge 603 Carriage 604 Guide shaft 605 Main scanning motor 606 Motor pulley 607 Driven pulley 608 Timing belt 609 Home position sensor 610 Shield plate 611 Recording medium 612 Paper feed motor 613 Pickup roller 614 Transport roller 615 LF roller 616 Paper end sensor 702 Inkjet recording chip 703 Discharge port array 704 Discharge port array 705 Discharge port array 706 Electrical wiring tape 707 External signal input terminal 708 Sealing material 709 Case 710 Cover 801 Foam

Claims (7)

  Inkjet recording chip comprising an ink container containing ink and an ink absorber for holding the ink, energy generating means for ejecting ink supplied from the ink container, and an ink ejection port for ejecting ink And an ink injection method into an ink jet recording cartridge provided with a filter in an ink supply path from the ink container to the ink jet recording chip. When ink is injected, an ink discharge port for discharging the ink is ejected by gas. An ink injection method characterized by injecting ink by applying pressure to the inside of a recording cartridge.   The ink injection method according to claim 1, wherein the pressurizing pressure is weaker than a meniscus force of the filter.   2. The ink injection method according to claim 1, wherein the pressurizing pressure at the time of ink injection is weaker than the meniscus force of the ink generated at the ink discharge port.   4. The ink injection method according to claim 1, wherein the ink injection is re-ink injection into an ink jet recording cartridge into which ink has been injected at least once.   5. The ink injection method according to claim 1, wherein the ink jet recording cartridge ejects a plurality of colors of ink.   The ink jet recording cartridge has discharge ports with different discharge port areas for discharging a plurality of types of discharge amounts of ink, and the pressurizing pressure is weaker than a meniscus having a larger discharge port area. The ink injection method according to any one of 1, 3, 4, and 5.   The ink injection method according to claim 1, wherein the gas used to pressurize the discharge port of the ink jet recording cartridge is an inert gas.