JPH04369558A - Ink tank, ink jet head cartridge having ink tank, and ink jet device - Google Patents

Abstract

PURPOSE:To prevent air penetrating when an ink tank is attached or detached from going to an ink bag side by a method wherein a slit intercepting means is provided inside a tank or in a passage continuously connecting a pressure regulating means to a recording head discharging ink. CONSTITUTION:A recording head part 500 and an ink tank part 250 are so constructed as to be capable of being attached or detached and when ink in an ink tank is gone, the ink tank is so constructed as to be capable of being exchanged. A joint part 200 of the recording head part side, a joint part 210 of the tank side, and an ink bag 300 are made of a flexible bag. As the ink in the ink tank 250 decreases by consumption of the ink by discharge of the ink from the recording head part 500, the ink bag 300 is deflated, and pressure in the ink tank part 250 is kept constant.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink tank for storing ink, an ink jet cartridge configured by connecting the tank to a recording head for ejecting ink, and an ink jet device in which the cartridge is detachably attached. be.

[Background Art] Conventionally, a method for storing ink in an inkjet cartridge (hereinafter sometimes abbreviated as IJC) in which a recording head section and a tank section are integrated is disclosed in US Pat. A method of impregnating a porous body with ink, as disclosed in Japanese Patent Publication No. 87242/1982, is known.

However, in these methods, the ink is impregnated into a porous material such as a sponge, which results in poor volumetric efficiency.Furthermore, as the ink in the tank decreases, negative pressure increases, causing unusable ink to accumulate in the tank. The problem is that a considerable amount remains, making it difficult to increase the capacity of the tank.

On the other hand, in order to increase the volumetric efficiency, it is preferable to directly store the raw ink, but one method for this is to use a rubber blender as disclosed in US Pat. There is a way to store ink inside.

However, in this method, there is a problem that the ink in the tank oscillates due to the movement of the carriage, causing pressure fluctuations with respect to the recording head, and it is difficult to increase the capacity of the tank. Also, as the amount of ink in the tank decreases,
There was also the problem that because the negative pressure increased, a considerable amount of unusable ink remained in the tank.

[0006] In order to solve these problems, the present inventors have proposed a pressure regulating means which has a very simple structure and also has a valve function for stably supplying and shutting off liquid. In other words, by providing a pressure regulating means in the ink tank that also has a valve function and is made of an elastic member with a slit that is closed in a steady state and opens at a certain pressure differential, the pressure of the liquid applied to the nozzle can be maintained at a certain level. This makes it possible to control and supply ink to the recording head within the range of . More specifically, it has a valve function in which when the difference between internal and external pressure exceeds a certain value, the wall deforms and the slit opens, and below a certain pressure difference, the wall restores itself and the slit opens. A partition wall made of an elastic member is provided inside an ink tank (hereinafter referred to as a slit blender) or in the middle of an ink flow path.

[0007] This has made it possible to perform stable ink ejection using a large-capacity ink tank. If a large-capacity ink tank becomes possible as described above, the ink tank separated type in which the recording head section and the ink tank section are separated is very preferable since it brings about advantages such as a reduction in running costs. In particular, the use of a slit blender has made it possible to increase the ratio of the amount of ink stored in the entire ink tank, making it possible to store a large amount of ink in a small ink tank. This enables a type where the recording head and ink tank are integrated on the printer for printing, and unlike conventional separate types, the ink tank is fixed inside the printer body relative to the recording head. This makes it possible to provide an ink tank that is much simpler and lower cost than the type that connects the two with a tube.

[0008]

[Problems to be Solved by the Invention] However, in the case of an integral traveling type ink tank separated type, it is impossible for the pressure on the recording head side and the ink tank side to be exactly the same when installing and removing the ink tank. The ink will flow to the lower pressure side through the connecting pipe that connects the two. At this time, if there is air in the connecting pipe or the like, there is a risk that air may enter the ink tank. At this time, if air enters the ink tank and enters the print head side through the connecting pipe that connects the ink tank part and the print head part, and eventually reaches the nozzle part of the print head, it will be called non-ejection. A problem will occur.

In addition, especially when the negative pressure on the recording head side is 0 or a little negative pressure and there is a lot of air on the recording head side, the pressure inside the slit blade will rapidly reduce the negative pressure. There is a possibility that the air from the recording head side will be drawn in in the direction of decrease, and the force will cause the air to enter through the slit blender into the ink bag that mainly stores ink in the ink tank section. If air enters the ink bag, there is a problem that ink may leak from the nozzle portion when the bag is pressurized due to expansion of the air due to environmental changes such as high temperatures.

[0010] Air entering the recording head side as described above can be removed by a recovery pump provided in the printer body, but air entering the ink bag in the main tank through a slit blender can be removed. Air must be prevented because it cannot be easily removed because it adheres between the ink bags or is obstructed by the slits of the slit blender.

[0011]

[Means for Solving the Problems] The present invention has been proposed to solve these problems, and is a slit blocker that has a very simple structure and stably prevents air from entering through the slits. The purpose is to propose a means to perform the action.

The present invention has been proposed to achieve the above-mentioned object, and includes an ink tank equipped with an ink supply section that stores ink and supplies ink. In the state it is occluded,
A partition wall made of an elastic member has a slit that opens in response to a predetermined differential pressure, and is arranged in a region between the partition wall and the ink supply section so that the slit can be shielded by a pressure change in the region. It is characterized by having a shielding means.

[0013] Furthermore, the recording device is constructed by integrating a recording device for discharging ink and an ink tank storing ink to be supplied to the recording device, and records an image by forming ink dots on a recording member. In an inkjet cartridge that is removably mounted on an inkjet recording device, the cartridge is configured such that the recording means and the ink tank can be brought into contact with and separated from each other, and an ink supply section to the recording means in the ink tank is provided with an inkjet cartridge. The partition wall is made of an elastic member and has a slit that is closed in a steady state and opens in response to a predetermined differential pressure. The invention is characterized by comprising a shielding means arranged to be capable of shielding.

[0014] The present invention further includes a support member for mounting and supporting an inkjet cartridge which is integrally formed with a recording means for discharging ink and an ink tank storing ink to be supplied to the recording means, and a support member for mounting and supporting an inkjet cartridge which is integrally configured with a recording means for discharging ink and an ink tank storing ink to be supplied to the recording means; In the inkjet recording apparatus, the cartridge is configured such that the recording means and the ink tank can be brought into contact with and separated from each other, and the cartridge is configured such that the recording means and the ink tank can be brought into and out of contact with each other. The ink supply section to the recording means has a partition wall made of an elastic member having a slit that is closed in a steady state and opens in response to a predetermined pressure difference, and in an area between the partition wall and the ink supply section. , further comprising a shielding means arranged to be able to shield the slit due to pressure changes within the region.

[0015] As described above, the slit blocker made of an elastic member is configured to block the slit of the pressure regulating means when the pressure is above a controlled pressure, and not to affect the function of the pressure regulating means when the pressure is below the controlled pressure. By providing the means in the area between the ink supply section in the ink tank and the slit blender, it is possible to prevent air from entering the slit blender, and even if air does enter, it will not go to the ink bag. It can be possible to prevent

[0016]

Embodiments will be described in detail below with reference to the drawings. Figure 1,
2 shows a first embodiment of a slit blender according to the present invention, and FIG. 1 shows a slit blender attached to an ink tank according to the present invention, a mounting base for attaching the same, and a slit cutoff valve. FIG. 2 shows an ink tank section of an inkjet head cartridge in which a recording head section and an ink tank section are configured separately.
The figure shows the slit blader installed.

In FIGS. 1 to 4, 100 is a slit blade made of an elastic material having a hardness of about 15° to 70° (JISA), more preferably an elastic material having a hardness of 25° to 50°. Specifically, silicone rubber,
SBR/BRIR/EPM/EPDM/butyl rubber, chloroprene rubber, urethane rubber, fluororubber, nitrile rubber, acrylic rubber, polysulfide rubber, ethylene rubber, fluorosilicone rubber, SEP rubber (thin-cone modified ethylene propylene rubber), etc. are preferably used. Can be used.

Furthermore, since these materials come into contact with the ink in the ink tank, they must not contain any substances that would change the physical properties of the ink (surface tension, viscosity, etc.) or dissolve into the ink. At the same time, it is necessary that the physical properties of these materials do not change due to the ink.

Reference numeral 110 denotes a slit, and 120 a mounting base on which the slit blender is attached.The mounting base has a shape that follows the outer circumferential shape of the blender base, and is oval in this example.

Furthermore, a slit cutoff valve 130 is provided on the upper surface of the slit blader mounting base of the mounting base 120. This slit cutoff valve 130 prevents air that enters when the ink tank is attached and detached from going to the ink bag side.

Specifically, if the pressure on the ink tank section 250 side is lower than the pressure on the print head section 500 side, when the ink tank 250 is installed, the print head section 500 side and the ink tank section 250 may be connected. The ink and air on the recording head section 500 side are drawn in through the connecting pipe 200, which causes the pressure inside the slit blender 100 to rapidly decrease. At this time, the slit blader 100 is deformed by the force of retraction to the extent that it expands further than the restored state. In this case, ink and air may enter the ink bag 300 that mainly stores ink in the ink tank section 250 through the slit 110 at the tip of the slit blender 100. However, at this time, the tip 132 of the slit cutoff valve 130 succumbs to the pressure of drawing ink and air and moves toward the slit 110, just blocking the slit. Therefore, even if air comes in at this time, it will not enter the ink bag through the slit 110.

After this, when the pressure on the recording head section 500 side and the ink tank section 250 side becomes equal, the tip part 132 of the slit cutoff valve 130 returns to the predetermined position, so that the normal valve function of the slit 110 is not affected. The configuration is such that it has no effect.

In this embodiment, the slit blade 1
There is normally a gap of 0.5 mm between the slit 110 of the 00 and the tip 132 of the slit cutoff valve 130.

[0024] At this time, the positive pressure for the slit shutoff valve 130 to shut off the slit 110 is preferably 0 mm or more, more preferably +30 mm or more.

In this embodiment, an elastic material is used for the slit cutoff valve 130, such as silicone rubber, SBR, etc.
BRIR/EPM/EPDM/butyl rubber, chloroprene rubber, urethane rubber, fluororubber, nitrile rubber, acrylic rubber, polysulfide rubber, ethylene rubber, etc. are suitable. It goes without saying that similar effects can also be obtained by using a mechanically controlled valve in one direction.

However, since these materials come into contact with the ink in the ink tank, they must not contain any substances that would change the physical properties of the ink (surface tension, viscosity, etc.) or dissolve into the ink. At the same time, it is also necessary that the physical properties of these materials do not change due to the ink.

Further, it is preferable that the tip portion 132 of the slit cutoff valve 130 has a thinner wall thickness than the other portions, since the response is excellent. In this example, the thickness of the tip is 0.1 m.
m, and the other portions were 0.3 mm.

The slit blender 100 is mounted on a mounting base 120 such that the slit 110 of the slit blender 100 and the long axis of the ellipse of the mounting base 120 form a right angle. As a result, a difference in tension is generated on the side wall of the slit blender in the long axis direction and the short axis direction of the ellipse of the mounting base 120 to which the slit blender is attached, and the crushing of the blender allows the slit to be opened smoothly. However, this angle is not limited to this even if it is slightly deviated as long as it is within the range of 0 to 55 degrees.

FIG. 2 is a diagram of an ink cartridge according to this embodiment using the slit blender of the present invention. Figure 2
, the recording head section 500 and the ink tank section 250
It has a removable structure, so it can be replaced when the ink in the ink tank runs out. 20
0 is a connection part on the recording head side, and 210 is a connection part on the tank side. An ink bag 300 is made of a flexible bag, and as the ink in the ink tank 250 decreases due to ink consumption due to ink ejection from the recording head 500, the ink bag 300 deflates.
The pressure within 50 remains constant. 180 is a sub-tank room.

In this embodiment, the slit blender is placed inside the ink tank section 250 and separated between the sub-tank chambers 180. In this state, the slit 110 is closed. At this time, the slit blader 100 is in a completely restored state as shown in FIG. 1, or in a slightly collapsed state, and the liquid pressure applied to the nozzles of the recording head section 500 is below +30 mm water head. . Therefore,
In this state, a balanced relationship between the meniscus holding force of the ejection port and the internal pressure of the ink tank is maintained, so that ink does not easily leak from the nozzle due to changes in temperature, pressure, vibration, etc.

From this state, as the recording head discharges droplets and the ink in the sub-tank chamber 180 is consumed and reduced, the pressure in the sub-tank chamber 180 decreases, and the slitted blender 100 collapses through the connection part. .

[0032] In this way, when the difference between the pressure inside the sub-tank chamber 180 and the pressure inside the ink bag 300 exceeds a certain value,
As the slit blender 100 itself collapses, the slit 110 at the tip opens as shown in FIG. The pressure gradually decreases. Sub tank chamber 180 and ink bag 3
As the differential pressure within 00 decreases, ink flows out to the slit blender 100 side, the slit blender 100 gradually recovers from its collapse, and the slit 110 closes. At this time, the pressure in the sub-tank chamber 180 becomes more negative than that in the ink bag 300. Therefore, during printing, the state shown in FIGS. 2 and 3 changes. In the steady state, slit 1 of the slit blader 100
This is the state shown in FIG. 2 in which 10 is closed. On the other hand, even when suction is temporarily applied from the nozzle using a suction pump or the like, the pressure difference between the sub-tank chamber 180 and the ink bag 300 becomes large, as during printing, so the slit 110 opens and then returns to a steady state. In order to obtain stable ink droplets, the recording head section 5
The ink pressure applied to 00 is preferably about +30 to -200 mm water head. More preferably, the water head is in the range of 0 to -100 mm, and the pressure in the sub-tank chamber 180 must be controlled. In order to obtain such conditions, the material (hardness) and shape of the slit blader 100, the slit 11
It is necessary to design the shape etc. of 0.

FIG. 4 shows a state in which the recording head section 500 and the ink tank section 250 are separated.

FIG. 5 is a schematic diagram of an ink jet recording apparatus IJRA to which the ink cartridge of the present invention is applied. Here, the carriage HC is connected to a threaded groove 500 of a lead screw 5004 that rotates via drive force transmission gears 5011 and 5009 in conjunction with the forward and reverse rotations of the drive motor 5013.
The carriage HC engaged with the carriage 5 has a pin (not shown) and is reciprocated in the directions of arrows a and b. Carriage H
An inkjet head cartridge 400 is attached to C. A paper pressing plate 5002 presses the paper against the platen 5000 in the moving direction of the carriage. 5007 and 5008 are photocouplers, which are home position detection means for confirming the presence of the lever 5006 of the carriage in this area and switching the rotational direction of the motor 5013. 5016 is a member that supports a cap member 5022 that caps the front surface of the recording head;
5015 is a suction means for sucking the inside of this cap,
Suction recovery of the recording head is performed through the opening 5023 in the cap. 5017 is a cleaning blade, 5019 is a member that allows this blade to move in the front and back direction,
These are supported by a main body support plate 5018. Needless to say, the blade is not of this type, but a well-known cleaning blade can be applied to this example. Also, 50
12 is a lever for starting suction for suction recovery;
It moves with the movement of the cam 5020 that engages with the carriage, and the driving force from the drive motor is controlled by known transmission means such as clutch switching.

These capping, cleaning, and suction recovery operations are configured so that the desired processes can be performed at the corresponding positions by the action of the lead screw 5005 when the carriage HC is positioned in the home position side area. Any of these can be applied to this example as long as the desired operation is performed at a known timing.

In particular, the present invention is an inkjet recording system that includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink, and uses the thermal energy to generate a thermal energy. This provides excellent effects in recording heads and recording apparatuses that cause changes in the state of ink.

For its typical configuration and principle, see, for example, US Pat. Nos. 4,723,129 and 4,740.
Preferably, it is carried out using the basic principles disclosed in the '796 specification. This method is the so-called on-demand type.
It can be applied to any continuous type, but
In particular, in the case of on-demand type, the electrothermal transducer placed in correspondence with the sheet holding the liquid (ink) or the liquid path is heated rapidly to a temperature that corresponds to the recorded information and exceeds nucleate boiling. By applying at least one drive signal that provides a rise, the electrothermal transducer generates thermal energy that causes film boiling on the thermally active surface of the recording head, resulting in a liquid ( This is effective because it can form air bubbles within the ink. The growth and contraction of these bubbles causes the liquid (ink) to be ejected through the ejection opening.
Form at least one drop. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, making it possible to eject liquid (ink) with particularly excellent responsiveness. This pulse-shaped drive signal is described in U.S. Pat. No. 4,463,359 and U.S. Pat.
The one described in the specification of No. 62 is suitable. Further, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

In addition to the configuration of the recording head as disclosed in the above-mentioned specifications, in addition to the combination configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path), U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44 disclose a configuration in which the action portion is arranged in a bending region.
A configuration using the specification of No. 59600 is also included in the present invention. In addition, Japanese Patent Application Laid-open No. 123670 of 1982 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 138461 of 1981, which discloses a configuration in which a discharge portion corresponds to a discharge portion.

Furthermore, a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus can be produced by combining a plurality of recording heads as disclosed in the above-mentioned specification. Either a configuration that satisfies the length or a configuration as a single recording head formed integrally may be used, but the present invention can more effectively exhibit the above-mentioned effects.

In addition, a replaceable chip-type recording head that is attached to the apparatus main body enables electrical connection with the apparatus main body and ink supply from the apparatus main body, or a print head that is integrated into the print head itself. The present invention is also effective when a cartridge type recording head is used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. Specifically, these are:
Capping means, cleaning means, pressure or suction means, preheating means for the recording head using an electrothermal transducer or another heating element, or a combination thereof, and ejection other than recording. It is also effective to perform stable recording. Furthermore, the recording mode of the recording device is not limited to a recording mode in which only the mainstream color such as black is used, but the recording head may be configured integrally or by a combination of two or more, but it is also possible to use multiple colors of different colors or mixed colors. The present invention is also extremely effective for devices equipped with at least one full color image.

[0042]

As explained above, in a liquid storage tank having a pressure adjusting means made of an elastic member having a slit that is closed in a steady state and opens at a certain difference or more, the pressure inside the tank or the pressure A slit in the pressure adjusting means is provided in a flow path connecting the adjusting means and a recording head that discharges ink, so that a slit in the pressure adjusting means is blocked at a pressure higher than a controlled pressure, and the function of the pressure adjusting means is not affected at a pressure lower than the controlled pressure. By providing the slit blocking means configured as described above, it has become possible to prevent the air that enters when the ink tank is attached or detached from going to the ink bag side.

As a result, even when an ink tank containing air contained in an ink bag is stored/left at a high temperature, there is a problem of pressurization due to the expansion of the air contained in the ink bag and the resulting ink leakage. This significantly improves the performance of liquid storage tanks that use raw ink.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a slit blader and a slit isolation valve in a first embodiment of the present invention.

FIG. 2 is a sectional view of an ink tank equipped with a slit cutoff valve according to a first embodiment of the present invention assembled into an ink cartridge (slit closed state).

FIG. 3 is a sectional view (slit open state) of an ink tank equipped with a slit cutoff valve according to a first embodiment of the present invention assembled into an ink cartridge.

FIG. 4 is a cross-sectional view of the ink tank equipped with the slit cutoff valve according to the first embodiment of the present invention in a state separated from the ink cartridge (slit closed state).

FIG. 5 is a perspective view of an inkjet recording apparatus with a recording head and separate ink tank type using the present invention.

[Explanation of symbols]

Reference Signs List 100 Slit blender 110 Slit 120 Mounting stand 130 Slit cutoff valve 132 Tip portion 180 Sub-tank chamber 200 Connection portion on the recording head side 210 Connection portion on the tank side 250 Ink tank portion 300 Ink bag 400 Inkjet head cartridge 500
Recording head section

Claims (7)

[Claims] [Claim 1] A recording device that discharges ink and an ink tank that stores ink to be supplied to the recording device are integrated, and an image is recorded by forming ink dots on a recording member. In an inkjet cartridge that is removably mounted on an inkjet recording device, the cartridge is configured such that the recording means and the ink tank can be brought into contact with and separated from each other, and an ink supply section to the recording means in the ink tank is provided with an inkjet cartridge. The partition wall is made of an elastic member and has a slit that is closed in a steady state and opens in response to a predetermined differential pressure. An inkjet cartridge characterized by comprising a shielding means arranged to be able to shield the inkjet cartridge. 2. The inkjet cartridge according to claim 1, wherein the partition wall functions as a pressure adjustment means for adjusting the holding pressure of ink with respect to the recording means. 3. The recording means ejects ink using thermal energy, and includes an electrothermal conversion element for generating thermal energy. inkjet cartridge. 4. A support member that mounts and supports an inkjet cartridge integrally comprising a recording means for discharging ink and an ink tank storing ink to be supplied to the recording means; In the inkjet recording apparatus, the cartridge is configured such that the recording means and the ink tank can be brought into contact with and separated from each other, and the cartridge is configured such that the recording means and the ink tank can be brought into and out of contact with each other. The ink supply section to the recording means has a partition wall made of an elastic member having a slit that is closed in a steady state and opens in response to a predetermined pressure difference, and in an area between the partition wall and the ink supply section. . An inkjet recording apparatus comprising: a shielding means arranged to be able to shield the slit by a pressure change in the area. 5. The inkjet recording apparatus according to claim 4, wherein the partition wall functions as a pressure adjustment means for adjusting the holding pressure of ink with respect to the recording means. 6. The recording means ejects ink using thermal energy, and includes an electrothermal conversion element for generating thermal energy. inkjet recording device. 7. An ink tank equipped with an ink supply section that stores ink and supplies ink, wherein the ink supply section of the ink tank has an elastic slit that is closed in a steady state and opens when a predetermined differential pressure is applied. The invention is characterized in that it has a partition wall made up of a member, and a shielding means arranged in a region between the partition wall and the ink supply section so as to be able to shield the slit by a pressure change in the region. ink tank.