JP2006069055A - Ink tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid inconvenience due to erroneous mounting of a plurality of ink tanks.
In an ink tank having an ink path for leading ink to the outside, an ink path blocking valve disposed in the ink path of the ink tank, and a magnetic attraction for blocking the ink path blocking valve An ink tank comprising: an urging force expression means using force.
[Selection] Figure 3

Description

  The present invention relates to an ink tank used in an ink jet printer used for image output manufacturing, copy manufacturing, and the like.

  The number of ink tanks installed in an ink jet printer is basically four colors of black, cyan, magenta, and yellow. However, since photographic prints have been widely used, it has been increasing. In particular, in recent years, with the spread of pigment inks, the number of ink tanks for gray, sepia, blue, green, orange, pink, red, and many other ink colors has increased. However, as the number of ink tanks mounted on an ink jet printer increases, the color of the ink tanks makes it difficult to know where to place them, and the number of misplacements increases.

  Generally, ink tanks are designed not to be mounted incorrectly, but they are designed so that the mounting shape of the ink tank matches the mounting side and the mounting side, and those that come off may not be mounted. This is a mechanical attachment preventing means. However, the types of ink differ slightly depending on the characteristics of the print head of each printer, and it is no exaggeration to say that there are an unlimited number of types.

  In particular, there are many types of ink, such as the type of ink used, such as viscosity characteristics and the type of dye (the same color has a slightly different density and color, or a mixture of dye pigments). There must be a tank.

  As described above, it is obvious that the necessary type amount cannot be satisfied by the compatibility confirmation by the mechanical shape. Also, in Japanese Patent Publication No. 6-65494, for such compatibility confirmation, a magnet is arranged, and an ink path is opened by a magnetic repulsive force with a magnet provided in the ink jet printer main body to prevent color mixing. There is a method, but this method has a problem that the magnet valve body vibrates during distribution and scrapes the wall surface to generate foreign matter. In addition, a magnet array facing the color ink tank must be arranged in the printer body or head, which is economically disadvantageous because a large space is required and the number of magnets is increased. Japanese Patent Laid-Open No. 05-301350 has a purpose of preventing color mixing, but the ink path disposed on the ink jet printer main body side is opened and closed by the lateral movement of the valve body of the magnet to prevent ink leakage. Technology is also introduced. However, this technique cannot realize the necessary magnetic force compared to the weight and shape of the valve body. That is, the magnetic force cannot reach a sufficient distance because the range covered by the magnetic moment decreases in inverse proportion to the square of the distance. In addition, since there is no shielding member on the ink tank side, the problem that all the ink inside the ink tank mixes colors due to color mixing and becomes unusable once installed is not solved.

Similarly, a technique for controlling the supply of ink by opening and closing the air communication hole using a solenoid valve is disclosed in Japanese Patent Application Laid-Open No. 07-290721. This may also prevent ink leakage. However, if they are installed incorrectly, it is impossible to prevent color mixing of the entire ink by mutual diffusion between the inks. If the ink path is connected, the ink is mixed until all the densities are constant by mutual diffusion, and thus the color mixture cannot be stopped by this method. A technique which has been further improved to prevent mixing is disclosed in Japanese Patent Application Laid-Open No. 08-118671. This method is a method of controlling opening and closing of both the air communication hole and the ink supply port with a magnet. However, a spring is used as the valve body biasing force expression means mounted on the ink tank. With this spring biasing member, there is a problem that a sufficient distance for the movement of the valve body cannot be realized with a small amount of electric power.
Japanese Examined Patent Publication No. 6-65494 JP-A-5-301350 JP 7-290721 A JP-A-8-118671 JP-A-11-286121

  Therefore, generally used is to mount a small IC chip in an ink tank and confirm this conformity by electrical bonding. However, this also has a problem. The reason is that a general ink tank is a negative pressure type, the inside of the ink tank is set lower than atmospheric pressure, and the ink supply port of the ink tank and the ink receiving port of the inkjet head are in liquid contact. Due to the configuration, when different types of ink come into contact with each other, diffusion occurs between the inks, resulting in a problem that the inks are mixed. In order to avoid such problems, it is necessary to adopt a structure in which the ink does not mix even when the ink tank is bonded to the inkjet head.

  Accordingly, as a result of intensive studies, the inventors have devised a pressure supply type ink tank using an electromagnetic valve as disclosed in JP-A-11-286121. However, in this method, since the electromagnetic valve is mounted in each ink tank, the cost of the ink tank is increased, and there is an economical disadvantage.

  Therefore, the inventor further studied diligently and arrived at a new idea as described below.

The present invention improves the following improvement points.
(1) Since it is a solenoid valve, it requires a lot of electric power to open due to the urging force generated by the spring.
(2) In order to use this power efficiently, it is necessary to form a closed magnetic path around the open valve body with a high permeability soft magnetic material, which is economically disadvantageous in terms of parts processing, materials, etc. is there.
(3) Because it is a pressurized ink tank, it is necessary to pay attention to the leakage of ink when it is damaged, and the housing must be strengthened.
(4) A mounting terminal is required at the mounting portion for each ink color of the inkjet head, which is economically disadvantageous.
(5) In addition, the valve body must be made smaller due to the driving force, which increases the force with which the valve body pushes the valve seat. It is necessary to partially use expensive rubber such as fluorine rubber for the valve body.
(6) Since the urging force expressing member is a spring, it is not possible to take a sufficient movement distance of the valve body. Therefore, expensive electromagnetic stainless steel had to be used.

  In order to avoid the above necessary improvement points, the present inventor has conducted studies and has come to find the following solutions. Specifically, it is as shown below.

  In an ink tank provided with an ink path for leading ink to the outside, an ink path blocking valve disposed in the ink path of the ink tank and a magnetic attraction force for blocking the ink path blocking valve body are used. And an urging force expressing means.

  The ink tank of the present invention is not a pressure supply type, but a negative pressure supply type, and does not completely block the mutual contact of ink, but the path is artificially blocked by a valve body. Is the method. In other words, a slight gap or hole of about 1 to 5 μm may be opened, but it takes time to completely mix colors, and after the ink tank has been installed, the printer checks the installation status of all the tanks once and mixes the colors. It is to make it a mechanism that is detected before proceeding rapidly.

  In this way, by installing the blocking part in the ink path, it is possible to prevent a sudden color mixture of ink even if there is a slight gap in the blocking part.

  As a method of forming a blocking portion in this ink path, a method using electromagnetic force is adopted, but this time it is not a complete blocking portion, so a soft magnetic material and a ferromagnetic material valve are combined and arranged, and In order to develop the electromagnetic force, it was decided to use powerful electromagnetic force expression means installed on the ink jet printer main body side. Moreover, since it is not necessary to use a closed magnetic circuit around the valve body arranged in the ink tank by doing in this way, the valve body can be opened and closed with a simple configuration. That is, the opening / closing mechanism can be configured with a simple structure without forming a closed circuit with high permeability.

  Next, in long-term logistics vibration and storage, the valve body forms a blocking part more stably so that the internal valve body does not scrape the tank side wall due to abnormal vibration, and various movements can also occur due to serial movement of the head. Therefore, it is necessary to temporarily fix the valve body by a method other than gravity. In order to realize this, the present inventor made the valve body in a state of giving a slightly weak magnetization of about 200 to 1000 gauss using a ferromagnetic material. In this case, the ink supply path of the tank can be blocked by adhering to the biasing force expressing member made of the soft magnetic material or the paramagnetic material arranged on the lower wall of the tank by its own magnetic force. it can. Of course, depending on the output of the magnetism generating means arranged in the printer body, the biasing force generating member can reverse the magnetic direction, so that the repulsive force is generated by the magnetic force and the valve body is moved. Thus, the ink path can be changed from blocking to opening. If the magnetic generation of the magnetic generating means arranged in the ink jet printer is stopped, the biasing force expressing member will generate a magnetic attractive force with the valve body depending on the magnetism of the valve body, The ink path can be blocked, and the ink path can be opened and closed arbitrarily by an external signal.

  The above-described means is an economical means that can prevent color mixing of the ink of the present invention.

  In addition, if the ink is a pigment ink, the ink may sink if stored for a long time or left for a long time. As a result, the inventors have found a method of generating a flow inside the ink tank and preventing the ink from settling by this flow. That is, every time the head operates serially, each time the valve body passes over the magnetism generating means installed in the main body, it moves up and down to generate a flow inside the ink tank. If this operation is not desired, it is sufficient that the magnetic force is not generated in the magnetism generating means.

  Further, when detecting the remaining amount of ink at the same time, in the configuration of the present invention, due to the buoyancy of the ink, the valve body does not operate when the ink runs out, that is, the valve body cannot be operated under gravity. It becomes possible to do.

  The presence or absence of ink can be detected by detecting this up / down motion by a change in impedance due to opening / closing of a magnetic sensor, coil, or closed magnetic circuit.

  This function also exhibits new utility. For example, if the valve element does not operate for some reason, it can be determined that the ink tank is defective, and if there is no change in impedance, the valve element sticks to the ceiling of the ink tank housing wall. Since it is possible to detect problems such as whether or not the ink tank is caught or where there is no ink, it is possible to determine whether the ink tank is good or not based on whether or not this signal changes.

  As a matter of course, since it is shipped after checking that there is a signal change at the time of shipment, it is judged that the fact that no change in impedance is found means that there is no ink.

  In the ink tank to which the present invention is applied, by disposing the ink path blocking means 5 ′ in the ink path 4 between the ink supply port 3 and the ink storage unit 9, the ink tank 100 is erroneously attached. It becomes possible to prevent complete color mixing of the ink 1.

  Furthermore, by arranging the ink path blocking means as close to the ink supply port 3 as possible, the amount of color mixing when the ink 1 is installed can be reduced.

  In addition, when the ink 1 is a raw ink tank or the like, the flow of the ink 1 is generated in the ink storage unit 9 ′ by the periodic operation of the valve body 5 using the blocking means, so that the ink 1 is settled and separated. Can be prevented.

  Furthermore, when the ink 1 is consumed and the ink 1 runs out, the remaining amount of ink can be detected from the change in operation of the valve body 5. Further, the urging force expressing means 7 ′ of the valve body 5 is not used as a dynamic urging force expressing method such as a spring, but is set as the urging force expressing means 7 ′ based on magnetic attraction force. Can be lowered.

  As described above, the method and configuration of the present invention are an epoch-making method in preventing color mixing in the ink tank 100 and stabilizing the characteristics of the ink 1 for a long period of time, and the effect is great.

  The details described above will be described below in detail with reference to the explanatory diagrams.

  FIG. 1 is a schematic perspective view showing a basic preferred configuration of the present invention.

  FIG. 2 is a cross-sectional perspective view taken along line A-A ′ of FIG. 1. FIG. 3 is a schematic cross-sectional view of FIG. 2 with the magnetic generating means 250 added for easy understanding.

  Inside the ink tank housing 11, an ink bag 9 that stores the ink 1 and an ink path 4 that guides the ink 1 to the ink supply port 3 are arranged. An ink supply pressure contact body 31 as shown in FIG. 3 is generally arranged at the ink supply port 3 of the ink tank 100. This member has a cylindrical shape made of a bundle of polypropylene fibers, and has a function of supplying ink by capillary force in the direction of the fibers. In the middle of the ink passage 4, a shut-off drive chamber 6 and a valve body 5 that shuts off the passage are arranged. The valve body 5 can move up and down in the shut-off drive chamber 6 along the path to open and close the passage. The urging force generating means 7 ′ for blocking the passage is the weight of the valve body 5, that is, gravity. However, when the ink tank is mounted with a slight inclination, a gap is generated or the blocking is performed. A large gap is generated by leaning on the side wall of the closed drive chamber 6. Further, the valve body 5 may vibrate due to vibration during distribution, and the side wall may be scraped unnecessarily to generate dust or foreign matter in the ink.

  Of course, it is needless to say that scraped scraps are floating in the ink as waste and there is a high concern about causing defects. Therefore, as described above, the urging force expressing member 7 made of a soft magnetic material is arranged at a position below the valve body 5. In this way, due to the self-magnetic force of the valve body 5, the valve body 5 and the biasing force expressing member 7 generate an attractive force and are relatively temporarily coupled. By disposing the casing wall 11 'of the ink tank in the middle, concerns such as reaction (corrosion) between the valve body 5 made of a ferromagnetic material and the ink can be avoided.

  A coil 8 is wound above the valve body 5 and is operated by the magnetic force of the printer body. The inductance of the coil 8 changes as the valve body moves and approaches the coil 8. However, a slight current flowing through this coil appears as a change in impedance. This is a mechanism that can detect the presence or absence of ink.

  In this way, the ink supply path 4 in the ink tank 100 can be opened and closed.

  The ink storage unit 9 ′ does not hold the negative pressure with an ink absorber such as a sponge, but is configured as an ink bag 9 that is pulled by a weak spring 10 to generate a negative pressure. A schematic perspective view thereof is shown in FIG. When one end of the spring spring is fixed to the central portion of the side surface of the ink bag and the other end is fixed to the side surface of the ink tank housing 11, the ink bag 9 contracts as shown in FIG. State), the spring spring 10 extends, and a negative pressure is generated by the tensile force. FIG. 4 shows only the ink bag 9 as a whole in FIG. 2 for easy understanding. FIG. 5 is a schematic perspective explanatory view showing a state in which the ink 1 is consumed and the ink bag 9 is contracted. It can be seen that the spring 10 extends to generate a negative pressure accordingly.

  Of course, the spring spring 10 may be a rubber, a leaf spring, or a bending spring. In short, any spring can be used as long as it can deform the ink bag 9 and can generate a negative ink pressure due to a tensile force at that time.

  In this way, when the ink 1 is consumed, the negative pressure rises, so that air enters the joints on the ink supply port 3, the inkjet pudding, and the head 210 on the continuous side, and the valve body 5 Air enters a certain part. In this case, the valve body 5 does not receive the buoyancy of the ink 1 and therefore does not respond to electromagnetic driving on the main body side.

  As a result, the sensor coil 8 is configured such that a predetermined impedance change is not seen and the absence of the ink 1 is detected. In this way, the circulation of the ink is alienated by the shutoff valve body 5 disposed in the ink path 4 between the supply port 3 of the ink tank 100 and the ink 1 storage unit.

  Due to this operation, ink mixing (color mixing) does not proceed to a certain extent, and complete ink color mixing can be prevented.

  The valve body 5 is made of a material such as ferrite, Ni-iron, or an alloy. However, since the valve body 5 is disposed in the ink 1, elution of the valve body material into the ink 1 is required. When this is eluted, there is a concern that even if the amount is small, a foreign matter commonly called kogation is generated in the heating element of the ink jet head or cavitation destruction is caused. Therefore, it is desirable to coat the surface of the valve body 5 with a noble metal plating or an organic tree that does not elute into the ink 1. In the piezo head, it is determined that such a process is not necessary, but since there is a concern about nozzle clogging, it is better to coat the valve body 5 by any method.

  Further, when the printer 200 is stopped without performing printing, if it is desired to prevent the sedimentation of the pigment ink, the ink tank is placed at a position closest to the magnetism generating means 250 as shown in FIG. If the movement is performed and the magnetism generating means 250 is caused to generate magnetism or the magnetism generation is stopped, the valve body 5 is vibrated up and down in the shut-off drive chamber 6 so as to be shown in the ink bag 9. -3, it is possible to generate the flow 15 of the ink 1 as shown in -3. As a result, a flow is generated in the ink bag 9, and the sedimentation and separation of the ink 1 can be prevented.

  For this operation, it is better not to use a spring for the biasing force generating means 7 'as shown in FIG. 3, and a paramagnetic or soft magnetic material is disposed in the ink tank 100 and used as the biasing force expressing member 7. good. The reason for this is that if the means for expressing the dynamic biasing force such as a spring is displaced according to Hooke's law, the biasing force increases in proportion to the displacement. In other words, in the case of a configuration in which it is difficult to assemble a closed magnetic field circuit as in this example, a large amount of electric power is required to drive the valve body 5, and thus a gap that allows the ink 1 to flow sufficiently is formed. , About 10W power is required.

  However, since the power allowed for these drivings is at most about 5 W or less, the printer 200 cannot be realized. In addition, as described above, when the urging force spring is not used, the function as a valve body does not appear well in the case of distribution or when the printer 200 is inclined at an angle, etc., and dust is worn due to wear on the wall surface. It becomes easy to generate unnecessary items. Therefore, if a material having no remanent magnetization such as Ni-iron, iron (pure), or ferrite is disposed on the opposite side of the valve body 5, the valve body 5 is attached to the paramagnetic material by its own magnetic force. The ink flow path 4 can be blocked by urging the force-expressing body 7 with a magnetic attractive force.

  Here, as a specific preferred example, a winding coil 252 of 30 μmφ is wound 3000 to 6000 times around a square iron-silicon alloy 251 having a cross-sectional area of 7 mm square and a length of 14 mm as the magnetism generator 250. Thus, the magnetic generation means 250 was obtained. Next, magnetic stainless steel having a thickness of 0.25 mm and a side of 7 mm was used for the soft magnetic urging force expressing means 7. In addition, the valve body 5 arranged at the corresponding position was made of iron ferrite having a residual magnetization of 800 gauss and having a side of 10 mm and a thickness of 0.5 mm with a polyimide coating of 2 to 10 μm on the surface. Further, the wall of the ink tank casing 11 ′ having a thickness of 0.25 mm is disposed between the valve body 5 and the biasing force developing member 7. This is because the wall surface of the ink tank member is desired to be continuous so that the ink does not flow out. The thickness of the other part of the member of the ink tank 100 is 0.8 mm to 1.5 mm in terms of strength. Compared to this, it can be seen that 0.25 mm is thinner than other parts. This is because the magnetic attractive force and repulsive force do not work well unless the thickness is reduced in this way.

  FIG. 6 shows a schematic cross-sectional view when the ink tank 100 is mounted on the inkjet head 210. Ink supplied from the pressure contact member 31 disposed at the outlet of the ink tank 100 in the drawing is further supplied from the ink liquid chamber 86 in the ink jet head 210 to the ink jet ejection element 87 via the filter 84. Thereafter, ink jet droplets are ejected by the operation of the ink jet ejection element. FIG. 7 shows a schematic perspective configuration diagram when the inkjet head 210 is mounted on the inkjet printer 200. For explanation, only one ink tank 100 is mounted on the inkjet head 210. It is a well-known fact that an image is recorded on the paper 150 while the inkjet head 210 moves left and right by serial scanning. In the middle of printing, the ink-jet head 210 moves to the position of the magnetism generating means 250, and when the position is just opposite to the position of the magnetic passage hole 253 arranged in each ink-jet head 210, the magnetism generating means 250 is driven. As a result, the valve body 5 is driven. In FIG. 7, for the sake of explanation, two magnetism generating means 250 are arranged. However, the magnetism generating means 250 can be adjusted as appropriate, and may be one or the number of ink tanks 100 may be arranged. Further, the connection terminal 81 of the ink presence / absence detection sensor 8 is connected to the connection terminal 81 ′ disposed on the inkjet head 210, and a signal is sent to the main body of the inkjet printer 200.

  The gap between the biasing force expressing member 7 and the magnetic generating member 250 was 0.25 mm to 0.3 mm. Although it is desirable to make contact if possible, the magnetism generating means 250 is fixed to the printer main body 200. On the other hand, since the ink tank 100 moves serially, it is difficult to arrange it so as to contact. It is.

  When a voltage of 10 V and a current of 0.03 A (30 μA) were applied to the winding coil 252, the valve element 5 opened the ink path 4 in the ink. Further, when the ink was consumed by printing and air entered the driving chamber of the valve body 5, the movement of the valve body 5 did not occur. Naturally, the impedance of the coil for detecting the ink remaining amount did not change.

  The dimensions and characteristic values are only a part of the examples of the present invention, and the dimensions and characteristic values can be changed in a timely manner in the usage situation. In addition, if the ink 1 is configured to absorb the ink in an ink absorber such as a sponge and dispose it negatively without using the raw ink tank 100 or the like, the ink flow into the ink bag 9 as described above. There is no need to make.

1 is a schematic perspective view of a preferred embodiment of the present invention. FIG. 2 is a schematic perspective view taken along the line A-A ′ of FIG. 1 as an example of a preferred embodiment of the present invention. FIG. 3 is a schematic cross-sectional view for explaining a driving situation by providing a magnetic driving means in FIG. 2. FIG. 3 is a schematic cross-sectional perspective view for explanation of giving an overall image of an ink bag and applying a negative pressure to the ink bag. In FIG. 4, it is a schematic cross-sectional perspective view for showing a state when ink is consumed. It is a cross-sectional schematic diagram when an example of an ink tank is mounted on an inkjet head. It is a schematic perspective explanatory view of an example of an ink jet printer equipped with an ink jet head equipped with an ink tank. (For explanation, only one ink tank is mounted.)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ink 3 Ink supply port 4 Ink path 4a, 4b Ink outlet from ink bag 5 Valve body 6 Valve body drive chamber 7 Energizing force member 8 Magnetic detection sensor coil 9 Ink bag 10 Negative pressure generating spring 11 Ink tank housing Body 11 ′ Thin ink tank casing 15 Ink flow 31 Ink connection pressure contact body 51 Ink tank lid 52 Latch lever 81 Detection sensor connection terminal portion 82 Inkjet head holder 83 Inkjet ejection element 84 Filter 89 Shaft hole of inkjet head 91,92 Ink bag outlet component 93 Ink bag mutual adhesive portion 100 Ink tank 150 Paper 200 Inkjet printer 210 Inkjet print head 241,242 Shaft 243 Paper feed roller shaft 244 Paper feed low Over 250 magnetic generating element 251 winding coil 253 magnetic passage hole solenoid core 252 magnetic generator for the magnetic field generator

Claims (6)

In an ink tank having an ink path for leading ink outside,
An ink comprising: an ink path blocking valve disposed in an ink path of the ink tank; and an urging force expressing means using a magnetic attraction force to block the ink path shielding valve. tank.   The ink tank according to claim 1, wherein the ink path shielding valve body is a ferromagnetic body and has a spontaneous magnetic force.   3. The urging force expressing member generates the urging force by generating a magnetic attraction force with the valve body by the magnetic force of the ink path shielding valve body. 4. Ink tank.   The ink tank according to claim 3, wherein the urging force expression member is disposed at a position spatially closest to the valve body in a configuration capable of blocking / opening an ink path.   The biasing force expressing member reverses its magnetic direction by magnetism generating means arranged in the ink jet printer and develops a magnetic repulsive force, thereby moving the valve body in position and opening an ink path. The ink tank according to claim 4, wherein the ink tank is a member capable of.   The ink tank according to any one of claims 1 to 5, wherein the ink tank has a detection configuration capable of detecting the presence or absence of ink by a change in a position of the valve body.

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