JPH0615842A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To provide an ink jet recording apparatus enhanced in ink use efficiency and having an inexpensive ink supply pressure control mechanism. CONSTITUTION:The interior of a carriage 15 is held to a predetermined pressure range of 40-0mumAq by an air discharge valve 13 and an air taking-in valve 12. The tube 28 provided in the carriage 15 and connecting an ink jet recording head 26 and an ink bag 31 is deformed by the peripheral pressure thereof and the peripheral pressure is applied to supplied ink. By this constitution, the pressure of the ink supplied to the ink jet recording head 26 is always held to -40-0mmAq.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink supply mechanism in the ink jet recording apparatus.

[0002]

2. Description of the Related Art Conventionally, in an ink supply system of an ink jet recording apparatus, in order to stabilize the ejection performance of a recording head and prevent ink from leaking from an ink ejection port or the like, a container storing ink more than the ink ejection port is used. The ink liquid level is arranged at a low position, whereby the pressure of the ink supplied to the recording head is controlled to be low. In such a case, the arrangement of the ink tank with respect to the recording head is naturally restricted.

As a structure for controlling the ink supply pressure to solve this restriction, a structure using a porous body such as a sponge in the ink storage container is known. That is, the ink is retained in the porous body by utilizing the capillary force of the porous body,
This holding force controls the pressure of the ink supplied to the recording head.

[0004]

However, in order to stabilize the ejection performance of the recording head and prevent ink leakage, it is necessary to use a porous body having a relatively high density. For this reason, the amount of ink that can be filled with respect to the volume of the ink container is reduced by the bulk of the porous body.
Further, as the amount of ink in the ink tank decreases, the capillary force of the porous body relatively increases, and the pressure for supplying ink to the recording head relatively decreases. As a result, the ink remains held by the porous body and cannot be used. Therefore, there is a problem in that the usage efficiency of the volume of ink that can be actually used decreases.
Further, since the porous body is discarded together with the ink tank after use, the cost becomes high and the environment is adversely affected.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to increase the efficiency of ink use, and to provide an ink jet recording apparatus having an inexpensive ink supply pressure control mechanism.

[0006]

In order to achieve such an object, an ink jet recording apparatus of the present invention ejects the ink in an ink jet recording apparatus that ejects ink onto a recording medium to perform recording. A recording head, an ink storage container for supplying the ink to the recording head, a pipe member connecting the recording head and the ink storage container, and a container surrounding the pipe member and provided with a valve. And the pipe member can be deformed by the pressure of the gas in the container.

The ink jet recording apparatus of the present invention is an ink jet recording apparatus for ejecting ink onto a recording medium for recording, and a recording head for ejecting the ink, and for supplying the ink to the recording head. It is characterized in that it has an ink bag and a container surrounding the ink bag and provided with a valve, and the ink bag can be deformed by the pressure of gas in the container.

[0008]

According to the present invention, a tube member which can be deformed by the pressure in the ink storage container is provided between the recording head for ejecting ink and the ink storage container for supplying ink to the recording head. As a result, the pressure of the ink applied to the recording head can be kept constant.

[0009]

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

Embodiment 1 FIG. 1 is a perspective view of an ink jet recording apparatus according to a first embodiment of the present invention.

In the figure, reference numeral 15 designates a carriage provided with an air intake valve 12 for taking in air from the outside of the ink supply system and an air exhaust valve 13 for exhausting air out of the ink supply system. The valves 12 and 13 are configured by a Mylar (registered trademark) sheet, silicone oil is applied to the sheet and the peripheral surface of the opening of the carriage 15, and the difference between the air pressure in the carriage 15 and the atmospheric pressure is described above. Opens and closes the valve. In this example,
Although two valves are arranged on the upper surface of the carriage 15, the valve may be installed at any position on the carriage 15.

The carriage 15 is fixed by a mechanism (not shown), and the carriage 15 is a guide shaft 1.
It is provided so as to be reciprocable along 4, 16.

In FIG. 1, 17 is a carriage 15.
A carriage motor for scanning the carriage along the guide shafts 14 and 16, and a wire 18 for transmitting the driving force of the carriage motor 17 to the carriage 15. A feed motor 19 is connected to the feed roller 50 via the transmission mechanism 20 to convey a recording medium (not shown).

Further, as will be described later, the carriage 15 having an ink jet recording head 26 in a part thereof returns to the home position if necessary, and is capped by the cap 23 of the recording head recovery device 22. Further, when moving to the home position, the blade 25 provided on the blade holding member 24 removes water droplets, dust, and the like attached to the ejection port surface.

FIG. 2 is a schematic sectional view taken along the line AA of FIG.

An ink jet recording head 26 is fixed in the carriage 15 closed by the valve 13 (12). The inkjet recording head 26 and the fitting portion 29A of the carriage 15 are connected by a tube 28. The fitting portion 29A is fitted with the fitting portion 29B provided on the ink tank cartridge 27 as the ink tank cartridge 27 is mounted. An ink bag 31 is provided in the ink tank cartridge 27,
The mouth of the ink bag 31 is connected to the fitting portion 29B.

The tube 28 extending from the ink jet recording head 26 to the fitting portion 29A is formed of a deformable flexible member, and is flexible enough to be deformed according to the change of the air pressure in the carriage 15. Have.

In the above structure, the valve 13 is configured to operate when the difference between the pressure inside the carriage 15 and the outside air pressure is about 0 mmAq to discharge the air inside the carriage 15, and the valve 12 is The operation is performed when the difference between the pressure inside the carriage 15 and the outside air pressure is about 40 mmAq, and the outside air is taken in. This allows the carriage 1
The pressure in 5 is always kept at about -40 mmAq to 0 mmAq.

For example, when the temperature inside the carriage 15 rises and the air inside the carriage 15 expands and the pressure rises, the air discharge valve 13 operates and the difference in air pressure inside and outside the carriage 15 becomes zero. On the other hand, when the air inside the carriage 15 cools and the air inside the carriage 15 contracts and the pressure drops, the air intake valve 12 operates. As a result, the difference between the pressure inside the carriage 15 and the outside air pressure of the carriage 15 does not exceed 40 mmAq. When the air pressure in the carriage 15 is low, it is needless to say that the air pressure in the carriage 15 is lower than the outside air pressure so that the outside air is taken in and the pressure difference is kept within a negative pressure within a predetermined range. .

In the above structure, if the air pressure of the carriage 15 is adjusted by controlling the temperature inside the carriage 15 using a heater or the like, more precise control will be performed. The air pressure in the carriage 15 described in this embodiment is the same as the ink bag 3 that stores the ink 30.
1 varies depending on the position at which the ink tank cartridge 27 accommodating 1 is installed and the ejection performance of the inkjet recording head 26 used. Furthermore, the pressure of ink is 0 to − in a normal inkjet recording head.
Although the negative pressure is about 150 mmAq, it can be controlled by a valve using the negative pressure depending on the case.

The tube 2 provided in the carriage 15
Since No. 8 has sufficient flexibility so that the ink 31 in the tube 28 becomes equal to the pressure in the carriage 15, the pressure of the ink in the tube 28 and the air pressure in the carriage 15 are the same. Therefore, the inkjet recording head 2
The pressure applied to 6 is controlled to a negative pressure of -40 mmAq to 0 mmAq. Therefore, the ejection performance of the inkjet recording head 26 can be stabilized, and ink leakage from the ejection port can be prevented.

In this embodiment, the case where the means for controlling the ink pressure is provided on the carriage 15 has been described. However, the above-mentioned means is provided in the middle of the tube 28 connecting the ink jet recording head 26 and the ink tank cartridge 27. A space closed by a valve (not shown) having the same function as that of the illustrated carriage 15 may be provided. However, in this case, the tube 28 needs to be rigid in a portion other than the space closed by the valve so as not to be affected by the change in the atmospheric pressure. If not configured as described above, the tube 28 will be deformed by the atmospheric pressure, and the pressure applied to the inkjet recording head 26 will fluctuate.

Embodiment 2 FIG. 3 is a schematic sectional view of an ink supply system showing a second embodiment of the present invention.

A tube 28 for supplying ink for connecting the ink jet recording head 26 and the ink tank cartridge 27 is formed with a flexible member 33 having sufficient flexibility to be deformed by external pressure. Then, a part or all of the flexible member 33 is replaced by the elastic member 3
Cover with 4. In this case, however, the tube 28 must be made of a material that is rigid enough not to be deformed by the pressure of the outside air except for the portion made of the flexible member 33. If not configured in this way, pressure is applied to the tube 28 exposed to the outside air, the ink pressure of the inkjet recording head 26 fluctuates, and ejection performance and ink leakage occur, which is not preferable.

At the stage of manufacturing the ink jet recording head 26, the pressure inside the closed system covered with the elastic member 34 is set so as to obtain an appropriate ink pressure.
Here, when the temperature in the closed system rises and the air pressure increases, the elastic member 34 deforms outward so as to cancel the increase in the pressure, while the temperature in the closed system drops and the air pressure increases. When it decreases, the elastic member 34 deforms inwardly so as to cancel the contraction of the pressure.

By selecting the elastic member 34 satisfying such conditions, the air pressure in the closed system can be always maintained at the initial set pressure. The elastic member 34 applies a pressure of -40 mmAq to 0 mmA to the inkjet recording head 26.
What is controlled to be q may be used.

Embodiment 3 FIG. 4 shows a third embodiment of the present invention and is a schematic exploded sectional view taken along the line AA of FIG.

In the ink tank cartridge 27, an ink bag 31 in which the ink 30 is stored is housed.
The ink bag 31 is made of a sufficiently flexible material.

In this embodiment, the ink jet recording head 26 and the ink bag 31 in the ink tank cartridge 27 are connected via the fitting portion 35, and the ink jet recording head 26 and the ink tank cartridge 27 are connected.
Is integrated, but may be removable.

The carriage 15 is provided with an air intake valve 12 and an air exhaust valve 13.

Here, the ink tank cartridge 27 and the carriage 15 have a positioning pin 36 and a positioning hole 3.
7, the fitting member 38 on the carriage 15 causes the ink tank cartridge 27 to move.
The side shutter member 39 is pressed. By this,
The hollow portion 42 in the ink tank cartridge 27 and the hollow portion 41 in the carriage 15 communicate with each other. This state is shown in FIG. With this configuration, the air pressure inside the ink tank cartridge 27 is controlled by the valve 12,
Controlled by 13.

Also in this case, as in the first embodiment, the difference between the pressure of the hollow portion 41 in the carriage 15 and the pressure of the outside air is 0 mm.
Set the valve 13 to discharge air at about Aq,
On the other hand, the valve 12 is set so that the air is taken in when the difference between the pressure of the hollow portion 42 in the ink tank cartridge 27 and the pressure of the outside air is about -40 mmAq.

The valves 12, 1 so as to operate in this manner
With the configuration 3, the air pressure in the ink tank cartridge 27 is appropriately controlled, and the force applied to the ink bag 34 can be kept within a predetermined pressure range.

Therefore, the pressure for supplying the ink 30 in the ink bag 31 to the ink jet recording head can be properly maintained.

(Others) The present invention is particularly provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink even in the ink jet recording system. The present invention brings about excellent effects in a recording head and a recording apparatus of the type in which the state of ink is changed by the heat energy. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the main body of the apparatus or the ink from the main body of the apparatus is electrically connected to the main body of the apparatus by being attached to the main body of the apparatus. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, etc. because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping unit, a cleaning unit, a pressure or suction unit for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying thermal energy such as ink that is liquefied by applying thermal energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as the form of the ink jet recording apparatus of the present invention, besides the one used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and further a facsimile apparatus having a transmitting / receiving function It may be a form or the like.

[0044]

As described above, a pipe member which can be deformed by the pressure in the ink storage container between the recording head for ejecting the ink and the ink storage container for supplying the ink to the recording head. By providing the, the pressure of the ink applied to the recording head can be maintained constant.

Therefore, it is possible to provide an ink jet recording apparatus with good ink use efficiency.

[Brief description of drawings]

FIG. 1 is a perspective view of an inkjet recording apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional view according to the first embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view according to the second embodiment of the present invention.

FIG. 4 is a schematic exploded sectional view according to a third embodiment of the present invention.

FIG. 5 is a schematic sectional view according to a third embodiment in which a cartridge and a carriage are mounted.

[Explanation of symbols]

 12 Air intake valve 13 Air discharge valve 14 Guide shaft 15 Carriage 16 Guide shaft 17 Carriage motor 18 Wire 19 Feed motor 20 Transmission mechanism 22 Recording head recovery device 23 Cap 24 Blade holding member 25 Blade 26 Inkjet recording head 27 Ink tank Cartridge 28 Tube 29A, 29B Fitting part 30 Ink 31 Ink bag 33 Flexible member 34 Elastic member 35 Fitting part 36 Positioning pin 37 Positioning hole 38 Fitting member 39 Shutter member 41 Hollow part 42 Hollow part 50 Feed roller

Claims (6)

[Claims] 1. An ink jet recording apparatus for ejecting ink to a recording medium for recording, a recording head for ejecting the ink, an ink storage container for supplying the ink to the recording head, It is characterized in that it has a pipe member connecting the recording head and the ink storage container, and a container surrounding the pipe member and provided with a valve, and the pipe member can be deformed by the pressure of gas in the container. Inkjet recording device. 2. An ink jet recording apparatus for ejecting ink to a recording medium for recording, a recording head for ejecting the ink, an ink bag for supplying the ink to the recording head, and the ink bag. And an ink container surrounding the container, the ink bag being deformable by the pressure of the gas in the ink container. 3. The ink jet recording apparatus according to claim 1, wherein the valve takes in air from the outside of the container when the pressure inside the container is lower than the atmospheric pressure by a predetermined value or more. 4. The ink jet recording apparatus according to claim 1, wherein the valve discharges from the inside of the container to the outside when the pressure inside the container is higher than the atmospheric pressure by a predetermined value or more. 5. The ink jet recording apparatus according to claim 1, wherein the tube member is made of an elastic member. 6. The ink jet recording apparatus according to claim 1, wherein the ink is used to generate bubbles in the ink by utilizing thermal energy, and the ink is ejected based on the generation of the bubbles. Inkjet recording device.