JP2007245350A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure the stirring capability when stirring an ink by eliminating the time loss for opening and closing a valve by making a speed for closing the valve in the ink flowing path connecting an ink tank and a printer head a high speed mode when the ink tank is mounted while to prevent the inside of the recording device from being stained with the ink by suppressing the ink from flowing out from an ink supplying needle by making a speed for closing the valve a low speed mode when the ink tank is not mounted. <P>SOLUTION: The speeds for closing the valve in the supplying path are constituted of two kinds of fast and slow modes. The time loss is eliminated by closing the valve in the fast mode when the ink tank is mounted. Further, the valve is moved in the fast mode to obtain a desired mixing capacity when the ink is stirred. The valve is closed in the fast mode to prevent the ink from flowing out from the tank needle when the ink tank is not mounted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus that performs recording by ejecting ink onto a recording sheet, and more particularly to an ink supply system in the inkjet recording apparatus.

  Among recording methods such as printers, an ink jet recording method that records on recording paper by ejecting ink from nozzles (nozzles) is a low-noise non-impact recording method and can perform high-density and high-speed recording operations. In recent years, it has been widely adopted.

As the ink used in the ink jet recording apparatus, a dye-based or pigment-based aqueous ink containing an insoluble or hardly soluble colorant is generally used. When this water-based ink is used, the color material in the ink aggregates and settles with time, and dark ink is generated. Therefore, when printing is performed, the image quality is remarkably deteriorated. Therefore, in order to eliminate color material sedimentation, some conventional ink jet recording apparatuses are provided with stirring means. (For example, see Patent Document 1)
Hereinafter, an ink jet recording apparatus provided with a conventional stirring means will be described with reference to FIG. The ink tank 23 and the print head 24 are communicated with each other through an ink channel 26, and the ink channel 26 is filled with ink. In order to improve the ink discharge state from the print head 24 and prevent ink leakage from the nozzle 25, the print is made at a position higher by the height H than the ink level in the ink supply unit. The head 24 is arranged, and the inside of the print head 24 is in a state where the negative pressure corresponding to the height H head differential is maintained. Thereby, the nozzle 25 is maintained in a state where the ink is filled in a state where the meniscus is formed. In the middle of the ink flow path 26, a shut-off valve 21 and a stirring means 20 are provided. The stirring means 20 uses the volume change due to expansion and contraction to suck and discharge ink in the ink flow path 26. By operating the stirring means 20 in a state where the shutoff valve 21 is closed and the ink flow path 26 is shut off, the ink in the ink flow path 26 flows back to the ink tank side. The ink that has flowed backward blows out from the supply needle 22 into the ink tank, and agitates the ink tank.

In addition, in order to reduce the size of the apparatus, there is also an ink jet recording apparatus that has a stirring function by opening and closing the shut-off valve 21 in the configuration of the ink jet recording apparatus having the stirring means shown in FIG.
JP 2004-243667 A (page 15, FIG. 1)

  In the ink jet recording apparatus configured as described above, when the recording apparatus main body is tilted and the water head difference H between the print head and the ink tank collapses, the negative pressure in the print head cannot be maintained, the meniscus is broken, and ink leaks. May end up. Therefore, by closing the valve when the power is turned off, the ink is prevented from leaking from the print head even if the water head difference H collapses.

  In an ink jet recording apparatus in which a shutoff valve has a stirring function, in order to stir ink in an ink tank, ink is blown out from a supply needle by opening and closing the shutoff valve. For this reason, if the shutoff valve is closed with no ink tank attached, the ink will blow out from the supply needle and contaminate surrounding components. For example, when the power supply of the main body is turned off with the ink tank removed, ink blows out and stains surrounding components.

  As a means for preventing the ink from blowing out from the supply needle, there is a method of preventing the ink from blowing out by attaching a cover to the needle hole of the supply needle when the ink tank is removed. However, the cost is increased by adding a cover for the needle hole, and a buffer for storing ink corresponding to the volume change of the shut-off valve is required, resulting in the disadvantages of increased space and cost.

  As another approach, the ink tank can be removed only when necessary, such as when the ink tank is replaced, by locking the lid of the portion to which the ink tank is attached. When the user presses the ink tank replacement button, the shutoff valve is closed and then the lid is unlocked, preventing ink from blowing out from the supply needle due to closing the shutoff valve when the ink tank is not installed. be able to. However, even in this case, the user needs to press the ink tank replacement button to increase the space and cost by attaching the lid lock, and to remove the ink tank. I will.

  Therefore, in order to solve the above problems, in the present invention, a print head that performs recording by discharging ink onto a recording material, an ink tank that holds ink, a tank station that mounts the ink tank, and the ink tank In an ink jet recording apparatus having an ink flow path for guiding ink from the ink to the print head and a valve for blocking the flow of ink in the middle of the ink flow path, the valve is blocked at least at two modes or more. Features.

  In the ink jet recording apparatus of the present invention, when the ink tank is attached to the tank station, the valve shuts off at a high speed mode, and when the ink tank is not attached to the tank station, the valve The shut-off speed is a low speed mode.

  The ink jet recording apparatus of the present invention is characterized in that the ink in the ink tank is agitated by the shut-off operation of the valve.

  Furthermore, the ink jet recording apparatus of the present invention is characterized in that the high speed mode of the speed at which the valve is shut off is the same as the speed at which the valve is shut off when stirring the ink in the ink tank.

  Further, in the ink jet recording apparatus of the present invention, when the ink tank is attached to the tank station, the speed at which the valve is shut off is set to a high speed mode, and when the ink tank is not attached to the tank station, the valve The speed for shutting off is a low speed mode, and the speed for shutting off the valve when stirring the ink in the ink tank is a medium speed mode.

  Furthermore, the ink jet recording apparatus of the present invention is characterized in that the ink tank can always be attached and detached.

  According to the present invention, it is possible to prevent ink from being blown out from the ink supply needle and prevent surrounding parts from being soiled with ink without requiring cost increase or space increase such as addition of parts or securing of space. Can do.

Example 1
As a first embodiment, a case where the speed for shutting off the valve is provided in two modes will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the ink supply apparatus of the present invention.

  When the ink tank 1 is attached to the tank station 9, the ink supply needle 2 and the air communication needle 3 are stuck in the ink tank 1. The atmosphere communicating needle 3 is connected to the atmosphere through the atmosphere communicating path 5, and when ink is consumed by printing, air enters the ink tank 1 from here. The ink supply needle 2 is connected to the print head 10 by an ink flow path 4 in which a valve 6 is installed on the way. The print head 10 ejects ink by ejecting it from the ejection nozzle 11. After the ink is ejected, the capillary force of the ejection nozzle 11 causes the ink to be sucked up from the ink tank 1 at any time via the ink flow path 4, and the cycle of filling the ink into the ejection nozzle 11 is repeated.

  When the ink thickener is clogged in the discharge nozzle 11 or when the gas dissolved in the ink of the discharge nozzle 11 is accumulated to form bubbles, the recovery unit 18 is used to remove these. The recovery operation of the print head 10 is performed. The recovery unit 18 includes a cap 18a for capping the opening surface of the discharge nozzle 11 of the print head 10, and a suction pump 18b connected to the cap 18a. The suction pump 18b is driven in a state where the opening surface of the discharge nozzle 11 is capped with the cap 18a, and the ink in the discharge nozzle 11 is forcibly sucked to remove the ink thickener and excess bubbles from the discharge nozzle 11. Remove. In addition, when the above-described recovery method cannot completely remove the thickened substance and excess bubbles in the discharge nozzle 11, the suction pump 18a is driven with the valve 6 shut off, and the negative pressure in the print head 10 is reached. There is also a method of valve closing suction in which the valve 6 is in a communicating state after increasing the pressure, and ink is allowed to flow at once to remove thickened substances and excess bubbles in the discharge nozzle 11.

  The tank station 9 has an ink receiver 8 near the base of the ink supply needle 2, and an absorber 7 is installed at the bottom of the tank station 9. The ink receiver 8 is connected to the absorber 7, and the ink attached to the ink supply needle 2 flows from the ink receiver 8 to the absorber 7 when the ink tank 1 is detached.

  The tank station 9 is provided with detection means 12, and the detection means 12 detects whether the ink tank 1 is mounted on the tank station 9.

  Hereinafter, the operation / function of the valve 6 of this embodiment will be described with reference to FIG.

  The central portion of the valve 6 is pressed from above via the spring holder 14 by the spring 13, and the flow path 4 is shut off. A rotatable lever 15 is engaged with the upper portion of the spring holder 14, and the lever 15 is in contact with the cam 16. The cam 16 is rotated by the drive motor 17 and the lever 15 is pushed. When the lever 15 is pushed by the cam 16, the valve 6 is lifted against the biasing force of the spring 13, and the flow path 4 is brought into a communication state.

  The role of the valve 6 is as follows. The first is communication / blocking of the ink flow from the ink tank 1 to the print head 10 by opening and closing the valve 6. During printing, the valve 6 is kept in communication so that ink flows from the ink tank 1 to the print head 10. On the other hand, when the power of the main body is turned off or the printer is moving, the valve 6 is shut off so that ink does not flow so that ink does not leak.

  The second is used for stirring the ink in the ink tank 1 by utilizing the volume change due to the communication / blocking operation of the valve 6. As shown in FIGS. 3A and 3B, when the valve 6 is brought into the communication state, the ink flows and the ink is accumulated in the valve 6. Here, the ink flow path 4 has a difference in flow path resistance between the flow path 4a on the ink tank 1 side and the flow path 4b on the print head 10 side so that the flow path resistance is 4a << channel 4b. Therefore, when the valve 6 is in a communication state, ink in the ink tank is drawn from the flow path 4a having a small flow path resistance. Next, by shutting off the valve 6, the ink in the valve flows backward to the flow path 4 a, and the ink is ejected from the ink supply needle 2 into the ink tank 1. By repeating this operation, the ink in the ink tank 1 is stirred.

  In the present embodiment, the speed at which the valve 6 is shut off is set to two modes, a high speed mode and a low speed mode, and the two modes are selectively used depending on whether the ink tank 1 is attached or not attached to the tank station 9. The speed at which the valve 6 is shut off is changed by changing the rotational speed of the drive motor 17.

  When the ink tank 1 is mounted, the speed at which the valve 6 is shut off is set to the high speed mode. In this embodiment, the high speed mode for shutting off the valve 6 is the speed most efficient for stirring the ink. This speed is determined by the volume change amount of the valve 6, the capacity of the ink tank (ratio of the bottom area to the height), the flow path resistance of the flow path 4a, the viscosity of the ink used, and the like. Is a speed at which the valve 6 rotates once per second, that is, a speed at which the valve 6 communicates / cuts off once per second.

  By shutting off the valve 6 in the high speed mode, the above-described stirring ability is ensured and time loss during normal operation of the valve 6 is eliminated.

  When the ink tank 1 is not attached to the tank station 9, the valve 6 is shut off in the low speed mode. When the valve 6 is shut off as described above, the ink flows backward to the flow path 4a side of the ink flow path 4 by the volume change and is pushed out from the ink supply needle 2. At this time, since the speed at which the valve 6 is shut off is slow, the flow speed of the ink that flows backward is also slow. Therefore, the flow rate of the ink pushed out from the ink supply needle 2 is also slowed down. The low speed mode for shutting off the valve 6 is determined by the volume change amount of the valve 6, the flow path resistance of the flow path 4a, the ink viscosity, and the like. In this embodiment, the valve 6 is shut off at a speed at which the cam 16 rotates once in 10 seconds, that is, at a speed at which the valve 6 communicates / cuts off once every 10 seconds.

  Slowly pushed ink flows through the ink supply needle 2 to the ink receiver 8 (FIG. 4A). A narrow groove through which ink can flow from the ink receiver 8 toward the absorber 7 by capillary force is provided. The ink that has flowed to the ink receiver 8 flows through the above-described narrow groove by capillary force, and reaches the absorber 7 installed at the bottom of the tank station 9 (FIG. 4B). Thus, the ink pushed out from the ink supply needle 2 is held by the absorber 7.

  As described above, when the ink tank is installed by providing two modes for the speed at which the valve in the middle of the ink flow path is shut off, time is lost by shutting off the valve in the high speed mode. And a desired stirring ability is obtained. By shutting off the valve in the low speed mode when the ink tank is not installed, the ink supply needle is prevented from blowing out ink and contamination by ink inside the recording apparatus is prevented.

(Example 2)
As a second embodiment, a description will be given of a case in which the speed for shutting off the valve is provided in three modes. The basic configuration and operation of the recording apparatus are the same as those in the first embodiment.

  In the present embodiment, the speed at which the valve 6 is shut off can be switched between three modes: a high speed mode, a medium speed mode, and a low speed mode.

  First, the speed at which the valve 6 is shut off during normal operation when the ink tank is mounted is the high speed mode. In this embodiment, the speed is such that the valve 6 communicates / blocks once every 0.5 to 1 second. By shutting off the valve 6 in the high-speed mode, the operating time loss of the valve 6 during the valve closing suction, which is one of the recovery operations of the print head 10 described in the first embodiment, is eliminated, and the printer main body is first turned on. The print can be shortened.

  Next, the speed at which the valve 6 is shut off when the ink tank is stirred is set to the medium speed mode. As described in the first embodiment, the ink agitation draws ink by the communication of the valve 6 and blows out the ink by blocking. Therefore, if the speed at which the valve 6 is shut off (that is, the speed at which the valve 6 communicates) is too high, the ink will not catch up due to the viscosity of the ink, and the ink cannot be sufficiently drawn into the valve 6. In addition, the amount of ink blown out decreases, and the stirring efficiency decreases. On the other hand, if the speed at which the valve 6 is shut off is too slow, the ink blowing speed becomes slow and the stirring efficiency is lowered. Therefore, in this embodiment, the most efficient speed for stirring the ink is adopted as the medium speed mode. As with the first embodiment, the speed at which the valve 6 in the medium speed mode is shut off is the volume change amount of the valve 6, the capacity of the ink tank (the ratio of the bottom area to the height), the flow path resistance of the flow path 4a, and the use. In this embodiment, the speed is such that the valve 6 communicates / blocks once every 1 to 2 seconds.

  Finally, the speed at which the valve 6 shuts off when the ink tank is not attached is the low speed mode. As in the first embodiment, the valve 6 is shut off at a speed at which the valve 6 communicates / cuts off once every 10 seconds, depending on the volume change amount of the valve 6, the flow path resistance of the flow path 4a, the ink viscosity, and the like.

  As described above, by providing the three modes of the valve shut-off speed in the middle of the ink flow path, when the ink tank is installed, the valve is shut off in the high-speed mode, thereby reducing time loss. Is lost. Further, when the ink in the ink tank is agitated, a desired agitation ability is obtained by connecting / blocking the valve in a medium speed mode optimized for agitation of the ink. Further, when the ink tank is not installed, the valve is shut off in the low-speed mode, thereby suppressing the ejection of ink from the ink supply needle and preventing contamination by the ink inside the recording apparatus.

Sectional drawing which shows the ink supply system of the recording device which concerns on this invention Sectional view of the valve portion of the present invention Sectional view showing the state of stirring by the valve Sectional view showing the valve closed when the ink tank is not installed Sectional view showing a conventional ink supply system

Explanation of symbols

1 Ink tank 2 Ink supply needle 3 Atmospheric communication needle 4 Ink flow path
4a Channel A
4b Channel B
5 Atmospheric communication path 6 Valve 7 Absorber 8 Ink receiver 9 Tank station 10 Print head 11 Nozzle 12 Detection means 13 Spring 14 Spring holder 15 Lever 16 Cam 17 Drive motor 18 Recovery unit 18a Cap 18b Suction pump 20 Stirring means 21 Shut-off valve 22 Supply Needle 23 Ink tank 24 Print head 25 Nozzle 26 Ink flow path

Claims (6)

A print head that performs recording by discharging ink onto a recording material; an ink tank that holds ink; a tank station that mounts the ink tank; an ink flow path that guides ink from the ink tank to the print head; and In an ink jet recording apparatus having a valve for blocking the flow of ink in the middle of the ink flow path,
An ink jet recording apparatus characterized by providing at least two modes at which the valve is shut off. In item 1,
When the ink tank is attached to the tank station, the speed at which the valve is shut off is set to a high speed mode. When the ink tank is not attached to the tank station, the speed at which the valve is shut off is set to a low speed mode. An ink jet recording apparatus. In the first and second terms,
An ink jet recording apparatus, wherein the ink in the ink tank is agitated by the shut-off operation of the valve. In the first term, the second term, and the third term,
The high speed mode of the speed at which the valve is shut off is the same as the speed at which the valve is shut off when stirring the ink in the ink tank. In the first and third terms,
When the ink tank is attached to the tank station, the speed at which the valve is shut off is set to a high speed mode. When the ink tank is not attached to the tank station, the speed at which the valve is shut off is set to a low speed mode. An ink jet recording apparatus, wherein a speed at which the valve is shut off when stirring the ink in the tank is set to a medium speed mode. In the first term, the second term, the third term, the fourth term, and the fifth term,
An ink jet recording apparatus characterized in that an ink tank can always be attached and detached.

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