JPS6317621B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid jet recording device that is simple and compact, has stable printing against external forces such as vibration, impact, and tilt, and has high reliability.

One of the characteristics of a liquid jet recording apparatus is that an open system supply mechanism as shown in FIG. 1 is possible in principle. That is, in a system in which a recording (so-called ink) liquid is filled from a tank (liquid storage tank) 103 having a vent hole 104 to a recording head 101 via a supply path 102 so that the pressure inside the tank is always maintained at atmospheric pressure. In response to an electrical signal applied to the recording head 101, the amount of recording liquid ejected as a droplet 105 from the tip (ejection orifice) of the head section 101 can be gradually replenished to the tip of the head 101 due to the surface tension of the liquid. However, when such a system method is applied to various recording devices, various problems arise.
First, when the main body of the apparatus is tilted, there is a certain distance from the tank 103 to the tip of the head 101, so there is a height difference (water level difference) between the tank 103 and the discharge orifice, and the recording liquid formed at the discharge orifice is The meniscus may retreat in the direction of the supply path, or conversely, liquid may leak from the discharge orifice. Therefore, if the meniscus recedes, it is possible to recover by applying pressure from the tank 103 side, but if it leaks, the inside of the device will be contaminated with liquid. The above-mentioned tilting often occurs when the device is being transported and moved, and frequently occurs in, for example, desk-top calculators, small typewriters, and the like. Therefore, if the meniscus receding recovery operation had to be performed every time it was moved, or if the internal liquid leaked, it would not be a practical product.

Further, when vibrations, shocks, etc. are applied, phenomena such as liquid leakage due to the tilting of the device and receding of the meniscus are accelerated. That is, when external stress such as vibration or shock is applied to the main body of the device or the supply path 102, the meniscus in the discharge orifice is easily broken due to this stress, and droplets are discharged to the outside or the meniscus retreats. do.
At this time, if the device is tilted, that is, if there is a difference in water level, the meniscus once broken will not easily recover and may leak continuously to the outside, or may retreat in the supply path to a position where it can maintain an equilibrium state. or This vibration/shock usually occurs frequently,
This is particularly the case with devices that perform recording by moving the recording head 101 back and forth relative to the recording medium.

Another important problem to be solved is that when recording by moving the above-mentioned recording head back and forth at high speed on a recording medium such as paper, as in a small printer,
The supply path 102 follows the movement of the head 101 and swings around a certain point on the side of the tank 103 as a fulcrum. At this time, the liquid contained in the supply path 102 is influenced by centrifugal force, and the greater the mass of the liquid contained in the supply path 102 or the faster the speed of reciprocating movement, the greater the applied centrifugal force. If this centrifugal force overcomes the holding force of the meniscus, the liquid will flow out from the discharge orifice without applying a print signal to the recording head 101. This will inevitably stain the device and the recording medium with liquid, which is a fatal defect in practice.

In order to avoid such inconvenient phenomena associated with the reciprocating movement of the recording head during recording, for example,
USP 3953862, USP 3967286, USP 4095237, etc. describe a liquid ejecting device having a structure in which a recording head section and a tank section (liquid storage tank section) move integrally. In order to solve the above-mentioned inconvenience, the liquid ejecting devices described in these documents not only have a structure in which the recording head section and the liquid storage tank section are moved integrally, but also have a structure in which the recording head section and the liquid storage tank section are moved together. During reciprocating movement, the liquid in the liquid storage tank vibrates due to acceleration and deceleration, resulting in the liquid leaking from the vent provided in the liquid storage tank or air getting mixed into the liquid. Therefore, improvements are being made to prevent this.

However, the liquid jet device having the structure described in these prior art includes a liquid chamber where the driving force for the liquid jet of the recording head is generated;
Since the positional relationship with the liquid level in the liquid storage tank is random, the liquid discharge becomes unstable due to a drop in the liquid level in the liquid storage tank, and the liquid supply to the liquid chamber is smooth and speedy. Since a part of the liquid supply path from the liquid storage tank to the liquid chamber is located below the bottom of the liquid storage tank, there is a high probability that the supply path will become clogged. In some cases, it is difficult to repair, and there are some points that could be improved.

It is understood that it is very difficult to apply the open system supply mechanism which is possible in principle to an actual recording apparatus due to practical problems.

On the other hand, there is a liquid jet recording device having a so-called closed system supply mechanism. That is, as shown in FIG. 2, a pressurizing mechanism 205 is provided in the tank portion 203, and by opening and closing a valve 206 provided in the supply path 202, the reduced amount of liquid discharged from the head 201 is replenished. Alternatively, the tank 203 is similar to the tank 103 in FIG. 1, and has a structure in which the internal pressure is equal to the outside pressure, and a special pressurizing mechanism is not provided, but a pressurizing mechanism is provided in the valve 206 instead. It is something that The valve 206 is opened and closed in response to a signal from a liquid amount detector such as a pressure sensor provided near the head 201 or in the supply path 202. Since the system from valve 206 to head 201 can be considered as a closed system, the problems that occur in the open system described above are considerably reduced. However, as can be understood from the simple explanation in FIG. 2, this closed system supply mechanism requires a complicated mechanism and is quite costly, and does not take advantage of its characteristics.

As a result of analyzing the problems with the open system supply mechanism described above, the present inventors were able to develop a liquid jet recording device with a very simple structure and sufficient printing stability and reliability for practical use. be.

A main object of the present invention is to provide a liquid jet recording device that improves the drawbacks of conventional liquid jet recording devices.

Another object of the present invention is to provide a liquid jet recording device that is simple and compact, has print stability against external forces such as vibration, impact, and tilt, and is highly reliable.

Still another object of the present invention is to provide a liquid jet recording device that can always provide a stable liquid supply even during high-speed recording and can perform recording in response to recording signals faithfully and reliably. .

The liquid jet recording device of the present invention that achieves the above object includes a plurality of orifices arranged in a direction different from the scanning direction of the carriage for ejecting liquid, and a thermal energy connected to the orifices to eject the liquid. a heat acting part that acts on the liquid;
A supply channel having an inner diameter of 0.3 mm to 2 mm for supplying liquid to the heat acting part, and coupled to at least a portion of the heat acting part in a coupling relationship capable of supplying thermal energy to the liquid in the heat acting part. a recording head comprising an electric/thermal converter; a liquid storage tank connected to the head so that the liquid therein is supplied to the heat application section from an inlet at the end of the supply path; an external electrical connection means for supplying an electric signal for driving the electric/thermal converter to the electric/thermal converter; comprising a built-in structure, the external electrical connection means being electrically connected to the main body when the structure is disposed in the carriage, and
Each of the heat acting parts is arranged at a height where the liquid in the liquid storage tank can be supplied by capillary force, and an orifice located above and at the top of the end of the supply path and the end of the supply path. The difference in height from the entrance of the section is 120 mm or less.

The liquid jet recording device of the present invention having the above-mentioned configuration eliminates the problems of conventional liquid jet recording devices, has a very simple configuration, and
It has sufficient printing stability and reliability.

Further, the liquid jet recording device of the present invention is compact, has print stability against external forces such as vibration and impact, and has high reliability.

Furthermore, the liquid jet recording apparatus of the present invention can always stably supply liquid even during high-speed recording, and can perform recording in response to recording signals faithfully and reliably.

In addition, as in the present invention, the inner diameter of the supply path for supplying the liquid in the liquid storage tank to the heat acting part of the recording head is
By setting the diameter to 0.3 mm to 2 mm, even if the device is rotated vertically or tilted, problems such as liquid leaking from the discharge orifice or the meniscus retreating and not returning to its original state can be effectively eliminated.

The present invention is characterized by the above-mentioned points, and was achieved as a result of conducting experiments as described below as an example in detail and considering them from various viewpoints.

The resistance force against the water level pressure caused by the inclination in a liquid jet recording device and the acceleration of the liquid in the supply path when the recording head of the device moves back and forth is the meniscus holding force in the discharge orifice and the capillary tube in the head or supply path. It can be seen as a progressive force.

In a liquid jet recording device, as mentioned above, the necessity of meniscus holding force is important, but the capillary advancing force in the liquid supply path up to the discharge orifice is also important. This is because even if the meniscus retreats due to the inclination of the device, if the capillary advancement force is large, when the water level returns to normal, the liquid can be moved to the discharge orifice by the capillary force, eliminating the need for recovery operations by other means. It is.

This meniscus retention force and capillary advancement force are determined by the diameter of the orifice provided at the tip of the recording head, the degree of restriction of the liquid flow path up to the orifice, the critical surface tension of the material forming the orifice, and the surface tension of the liquid used. It is determined by the correlation with viscosity.

The meniscus retention force and capillary advancement force can be considered in a model similar to the capillary upward force in the field of surface chemistry.

The height at which a liquid rises in a capillary tube due to capillarity is generally expressed as:

H=γ2cosθ/rρg H: Height of rise γ: Surface tension of liquid ρ: Density of liquid r: Capillary radius θ: Contact angle g: Acceleration of gravity This formula can actually be applied only to ideal systems. Qualitatively, however, it can be seen that when γ and ρ of the liquid are constant, θ is small (that is, the critical surface tension γc of the wall material is larger than γ), and the smaller γ is, the larger H becomes. This is because the material of the orifice part has a high critical surface tension such as glass or metal, and it can be said that the smaller the diameter, the greater the meniscus retention force. In addition, if the pipe diameter of the flow path and supply path in the head up to the orifice is small, and the distance to the tank containing the liquid is short, even if the meniscus recedes for some reason, it will be immediately resolved. He should be back. Conversely, even if an impact force is applied under a condition where the water level pressure changes in a way that causes a leak, such as when the orifice part is at the bottom, the liquid will jump out from the orifice only when the impact force is applied. , there is no continuous leakage.

The present invention was made against the above background, and as a result of various experiments and studies, basically the height difference between the recording liquid level in the recording head section and the liquid storage tank section, and the length of the liquid supply path were determined as follows. This is based on the finding that the above-mentioned problems can be solved by limiting the method as described in detail in . In order to more effectively achieve the object of the present invention, the recording head section and the liquid storage tank section are constructed as an integrated structure, and the structure is such that the recording head section and the liquid storage tank section can be mounted on a moving carriage.

Hereinafter, the present invention will be explained in detail using one of the experimental examples, but the present invention is not limited to the scope described below.

In order to achieve the present invention, the present inventors conducted various basic studies such as capillary rising force, meniscus retention force when the device is tilted, and meniscus retention force against acceleration. The recording head model used for this study has a structure as shown in the schematic assembly diagrams in FIGS. It is created by aligning and bonding a recess forming the common liquid chamber 526 and a grooved plate 525 provided with a groove forming the liquid discharge part 509 in a predetermined manner. In the figure, a recording head 501 having nine orifices 522-1 to 522-9 for ejecting liquid is shown as an example in which characters to be recorded are composed of 9×7 dots.
The invention is not limited thereto, but applies to any recording head having one or more ejection orifices.

The dimensions of the recording head used in the experiments shown below are as follows: the orifice size is 50 .mu.x50 .mu., the groove pitch is 125 .mu., the inner diameter of the supply pipe 511 is 0.6 mm, and the length is 18 mm. Also, the surface tension of the recording liquid used
It has a viscosity of 45dyne/cm and 3cps.

First, the capillary rising force of various tubes was measured and found to be 45 mm for a 0.6 mm glass tube, 16 mm for a polyethylene tube, and 0 mm for a Teflon tube. Also, in the case of a combination of pure water and glass tube, 58mm
It was hot. Furthermore, when a polyethylene pipe of the same diameter is connected to the end of the supply line pipe 706 of a recording head similar to that shown in FIGS. 5a to 5c, and the meniscus retention force is measured, the liquid level in the liquid storage tank is measured. Meniscus regression and liquid leakage did not occur until the water level difference was up to 100 degrees. However, when this device was subjected to light vibrations, liquid leakage and meniscus regression occurred at a water level difference of 60 mm. Furthermore, in order to measure the holding force of the meniscus against acceleration, the recording head with the polyethylene tube was mounted on a rotary acceleration generator in the arrangement shown in the figure as shown in Figure 3, and the holding force of the meniscus against the recording liquid content and tangential acceleration was measured. was measured. Third
In the figure, 301 is a rotary acceleration generator,
Rotate in the direction of arrow A. 302 is a recording head;
304 is a polyethylene pipe, and 305 is a liquid filling its entire path. The central axis of the discharge orifice 303 is defined as the tangential direction to the rotation direction, and the length of the liquid filled in the supply path along the direction in which centrifugal force acts is defined as l.

FIG. 4 shows the results when measured as described above. In the figure, the area is a part where stable ejection is possible, and the area is a part where liquid leakage or meniscus regression is severe and stable ejection cannot be performed. The holding force against the gravitational acceleration G at the recording head (portion l') is extremely large at 140G, but if there is liquid in the supply path (portion l), an acceleration corresponding to this mass is added, and l but 1.5G at 80mm
Liquid leakage occurred. This results in liquid leaking from the ejection orifice 303 even when no recording signal is applied to the recording head 302 when the supply path 1 is moved at high speed in accordance with the movement of the recording head 302.

Based on the above considerations, when using a supply pipe with an inner diameter of about 0.6 mm, the height difference between the discharge orifice and the liquid level, in other words, the height difference between the discharge orifice and the suction port at the end of the supply system. As long as the distance was kept below 50 mm, there was almost no liquid leakage or receding of the meniscus, no matter what condition the device was left on an incline, or even when subjected to vibrations or shocks. In addition, the supply path connecting the recording head and liquid storage tank was constructed so that it moved together with the recording head, so that no liquid leaked from the discharge orifice during recording, even when extremely large accelerations were applied. . This in principle makes an open system supply mechanism virtually possible. In order to apply these basic points to an actual recording system, the recording head section and the liquid storage tank section may be integrated.

FIG. 5 shows one preferred embodiment of a liquid jet recording apparatus having an integrated structure of a recording head and a liquid storage tank, which satisfies the basic requirements for achieving the objects of the present invention.

Figure 5a is a schematic perspective view of the recording device, Figure 5b
is a schematic cross-sectional view when cut along the dashed-dotted line OP,
Figure 5c is a schematic assembly of the recording head section, Figure 5d
is a schematic partial cross-sectional view taken along the dashed-dotted line XY.

In the liquid jet recording device 500 shown in FIGS. 5a, b, c, and d, some of the dimensions and sizes of each part are exaggerated for ease of viewing. In particular, the recording head 501 is intentionally exaggerated. Although it is shown enlarged, it is actually smaller than the liquid storage tank section 502.

The apparatus 500 shown in FIG.
A recording head section 501 is electrically and liquid-supplied connected and housed at a predetermined position on the upper end of the cartridge 2, and is mounted on a carriage 503, so that the recording head section 501 and the liquid storage tank section 502 are integrated. scan axis 5
It is designed to be able to move back and forth on 04.

In this example embodiment, the recording head unit 50
1 has a structure that is removable from the liquid storage tank 502 so that the recording head 501 can be replaced. However, the recording head 501 and the liquid storage tank 502
It is also possible to have a structure in which these are fixedly installed. 50
Reference numeral 5 denotes a pressing means, which is made of an elastic material such as rubber, has a ventilation hole 506 in the center, and has a liquid storage tank section 502.
It has a function of manually discharging liquid from the orifice portion 507 by pressurizing the inside. Such a pressing means 505 is, for example, an orifice portion 5.
07 or the supply path in the recording head section 501 is clogged due to contamination with dirt or drying of the liquid used, the pressing means 505 is pressed with a cover over the ventilation hole 506 to close the liquid storage tank section. By pressurizing the inside of 502, clogging can be removed. FIG. 5b shows a schematic cross-sectional view taken along the dashed line OP in FIG. 5a. The recording head section 501 includes an orifice section 507 consisting of nine orifices provided at the tip of the recording head section 501 for ejecting liquid.
A liquid discharge part in which electrothermal converters, which are means for generating thermal energy that is the driving force for discharging liquid from 07, are mechanically coupled to a flow path provided in a number corresponding to the number of orifices. 509, supplying liquid to each flow path of the liquid discharge part 509,
It consists of a common liquid chamber 510 provided to prevent so-called back waves from each flow path, and a supply line pipe 611 for supplying the liquid in the liquid storage tank 502 to the common liquid chamber 510.

In the figure, the liquid discharge part 509 has nine flow paths, each flow path is provided with an orifice at its tip, and is a place where the thermal energy generated by the electrothermal converter acts on the liquid. It has a certain heat acting part.
An orifice that communicates with the heat acting section located at the highest position in the heat acting section, that is, the heat acting section located above and at the top of the nine flow paths in the figure, and an inlet at the end of the supply path. The recording head section 501 and the liquid storage tank section 502 are arranged so that the difference in height is 120 mm or less.
is designed and manufactured. An air removal hole is provided in the upper part of the common liquid chamber 510 for removing air to the outside when air enters the common liquid chamber 510, and is normally closed with an air removal hole plug.
Further, electrical signals for driving the nine electric/thermal converters provided in the recording head section 501 are transmitted through a connector 512 connecting the recording head section 501 and the liquid storage tank section 502 and a drive circuit provided externally. It is input to each electricity/thermal transducer through a connector 513 which is an electrical connection means to be electrically connected to.

A supply pipe 51 that is part of the recording head section 501
1 is introduced into the liquid storage tank section 502 from the recording head main body, and the liquid in the liquid storage tank section 502 is guided into the recording head main body, and is fixed by the wall 514 of the liquid storage tank section 502. vibration,
It is designed so that it does not move due to shock. In this implementation system, the supply pipe 511 had an inner diameter of 0.6 mm.
Reference numerals 515 and 516 each indicate a vent hole in the liquid storage tank section 502, and function to always keep the pressure inside the liquid storage tank section 502 equal to the outside pressure.

Reference numeral 516-1 denotes a liquid replenishment part located directly below the vent hole 515, which is made of an elastic material such as thin rubber. By inserting the tip into the liquid replenishing part 516-1 through the ventilation hole 515, liquid replenishment can be performed.

In the liquid storage tank section 502 shown in FIG. Even if there is a mechanical shock due to force from another party or a shock during return during high-speed reciprocating recording, the ventilation hole 515
Therefore, there is no leakage of liquid outside the device.

Each heat acting part of the liquid discharge part 509 and the common liquid chamber 51
In order to enable the liquid in the liquid storage tank 502 to be smoothly and speedily supplied only by capillary force, an orifice at the uppermost part of the liquid discharge part 509 and a liquid inlet 517 at the terminal end of the supply pipe 511 are used. Height difference L
The recording head section 501 and the liquid storage tank section 502 are designed so that the length is set as defined below,
It is better if it is manufactured in one piece.

That is, L is parallel to the free surface of the liquid in the liquid storage tank section 502 and passes through the center point of the distal end surface of the terminal end of the supply pipe 511, and is defined as the distance L ₁ from the straight line passing through the center point of the orifice. device 500
Instead of being mounted on the carriage 503 in the state shown in the figure and recording is executed, for example, it is grounded on the surface of the carriage where the connector 513 is provided, and the initial discharge direction of the liquid discharged from the orifice is controlled by gravity. If you turn it in the opposite direction, it will clog.
When recording is carried out by being mounted on the carriage 503 so that the free surface of the liquid in the liquid storage tank 502 is parallel to the wall surface of the device 500 where the connector 513 is provided, the distance L is equal to L in the figure. ₂ .

In the present invention, this L is determined by designing and manufacturing a wide variety of recording heads, conducting experiments as described above, and determining the capillary rising force, meniscus holding force, and droplet ejection characteristics obtained as a result. Based on detailed analysis and study of data regarding the relationship between

That is, when using a recording liquid with a surface tension of 40 to 60 dyne/cm, the inner diameter of the supply pipe 511 should be 0.3 to 2.0 dyne/cm.
In mm, L is 120 mm or less.

Furthermore, preferably, the inner diameter of the supply pipe 511 is
The inner diameter of the supply pipe 511 is set to 0.5 to 0.8 mm, and L is set to 50 mm or less. By setting L within such a range, even if the device 500 is rotated vertically or tilted,
No liquid leaks from the discharge orifice or the meniscus recedes and does not recover. The lower limit of L is usually about 20 mm due to the capacity of the liquid stored in the liquid storage tank 502, mounting problems when incorporating it into the main body of the liquid jet recording device, and problems with the speed of reciprocating movement. Ru. For example, when the inner diameter of the supply pipe 511 is around 0.6 mm, extremely good droplet exposure characteristics can be obtained by setting L to 50 mm or less, especially 40 mm or less.

A liquid jet recording device having a structure similar to that shown in FIG. 6 was left with the orifice portion 507 facing upward or downward, but no liquid leaked from the orifice or the meniscus receded. The inner diameter of the supply pipe of this device is 0.6 mm, L.
is 50mm, and the surface tension of the recording liquid used is
It was 48dyne/cm. Furthermore, when we checked for leakage due to tangential acceleration, there was no leakage up to 140G, proving that it is extremely stable in practical terms.

As described above, the apparatus of the present invention allows an open system supply mechanism to be effectively applied to an actual recording system. In other words, even under various conditions such as vibration, impact, and tilt, problems such as non-discharge of liquid, meniscus retreat, and liquid leakage can be prevented, and stable discharge and recording reliability are greatly improved. It is.

Next, regarding the recording head section 501, FIGS.
This will be explained in detail.

The recording head section 501 has a predetermined size and corresponds to a substrate 518 on the surface of which nine electrothermal transducers 519-1 to 519-9 are provided at a pitch, and corresponding positions of the electrothermal transducers 519. Nine grooves 522-1 to 522-9 provided and a common liquid chamber recess 52 that communicates with the grooves and forms a common liquid chamber 510.
6. Position the grooved plate 525 in which the air removal hole 523 and the liquid introduction hole 524 connecting the supply pipe 511 and the common liquid chamber 510 are machined with predetermined dimensions as desired. It is assembled by pasting. A supply pipe 511 having a predetermined inner diameter is fitted into the liquid introduction hole 524 .

The air removal hole 523 is normally closed with an air removal hole plug 508 except when removing air.

On the surface of the substrate 518, a common electrode 520 is provided for supplying an external drive signal to the electric/thermal converter.
Nine selection electrodes 521-1 to 521-9 are provided.

FIG. 5d is a schematic partial cross-sectional view taken along the dashed line XY shown in FIG. 5a.

The recording head section 501 includes the substrate 5 on which the electrothermal transducer 519 is provided as described above.
An orifice 527 and a liquid discharge portion 528 are formed by bonding the grooved plate 525, which has a predetermined number of grooves of a predetermined width and depth at a predetermined linear density, to the surface of the recess 18 so as to cover it. It has a similar structure. In the case of the recording head section 501 shown in the figure, the orifice 5
Although shown as having a plurality of recording heads 27, the present invention is of course not so limited, and is also within the scope of the present invention in the case of a single orifice recording head.

The liquid discharge part 528 has an orifice 527 for discharging liquid droplets at its terminal end, and an electrothermal converter 519.
It has a heat acting part 529 where the thermal energy generated by the liquid acts on the liquid to generate bubbles and cause a sudden change in state due to expansion and contraction of the volume.

The heat acting portion 529 is located above the heat generating portion 530 of the electrothermal converter 519, and has a heat acting surface 531 that contacts the liquid of the heat generating portion 530 as its bottom surface.

The heat generating section 530 includes a lower layer 532 provided on the substrate 518, a heat generating resistor layer 533 provided on the lower layer 532, and an upper layer 534 provided on the heat generating resistor layer 533. Heat generating resistance layer 5
33 is provided with electrodes 520 and 521 on its surface for supplying electricity to the layer 533 to generate heat. The electrode 520 is an electrode common to each heat generating section of the liquid discharging section, and the electrode 521 is a selection electrode for selectively generating heat in each heat generating section of the liquid discharging section. It is located along the road.

The upper layer 534 isolates the heating resistance layer 533 from the liquid in the liquid discharge part 528 in order to chemically and physically protect the heating resistance layer 533 from the liquid used, and also connects the electrodes 520 and 521 through the liquid. The heating resistance layer 533 has a protective function of preventing short-circuiting.

The upper layer 534 has the above-mentioned functions, but the heating resistance layer 533 has liquid resistance and
In addition, if there is no risk of an electrical short circuit between the electrodes 520 and 521 through the liquid, it is not necessarily necessary to provide it, and the electrothermal transducer may be designed to have a structure in which the liquid comes into direct contact with the surface of the heating resistance layer 533. It's okay.

The lower layer 532 mainly has a heat flow control function. That is, when ejecting droplets, the heating resistance layer 533
The heat generated in the heat generating resistor layer 5 becomes clogged after the droplet is ejected, so that the proportion of the heat generated in the heat generating part 529 is conducted as much as possible to the heat acting part 529 side rather than to the substrate 518 side.
After the power to 33 is turned off, the heat acting part 5
29 and the heat generating section 530 quickly reaches the substrate 5.
18 side to rapidly cool the liquid and generated bubbles in the heat acting part 529.

The device shown in FIG. 5 shows a basic structure showing the requirements of the present invention, and it is advantageous in practice to add various mechanisms. The important thing is to provide a liquid-containing member with continuous micropores near the end of the supply pipe. As an embodiment of such an example, as shown in FIG.
4 or as shown in FIG.
Examples of methods include arranging 03.

In the case of FIG. 7, the liquid inlet 706 at the terminal end 705 of the supply line pipe 704 constituting the recording head section
is inserted into the interior of the liquid-containing member 703, and the supply pipe 704 is fixed therein.

In the device shown in FIG. 7, the liquid containing member 703 is disposed only on the bottom surface 702 of the liquid storage tank 701; It is good to accommodate.

As described above, one of the effects of providing the liquid containing member at the liquid introduction port of the supply line pipe is as follows.

In other words, if the device is left in an inclined state where the amount of liquid stored in the liquid storage tank is small, the liquid may not come into contact with the liquid inlet of the supply line pipe. Even if the liquid contained in the liquid containing member is sufficiently retained, there is no problem in printing for a short time, and even if the liquid is left in the above state for a long time, air bubbles may be mixed in when the liquid containing member returns to its normal position. This has the advantage of not causing any trouble to the next printing operation.

Furthermore, by appropriately setting the diameter of the internal pores, this liquid-containing member can also function as a filter for preventing air bubbles and dust from entering. The liquid-containing member is preferably made of a polymeric material from the viewpoint of handling and the ability to arbitrarily select various shapes, pore diameters, porosity, etc. Such materials include various materials such as polyethylene, polypropylene, polymethyl methacrylate, copolymers of methyl methacrylate and acrylonitrile, polyvinyl alcohol, polyurethane, and synthetic rubber. In order to improve retention and prevent air bubbles from being mixed in, it is desirable to use a material that has a high affinity with the liquid used for recording.

In addition, it is desirable that the porosity be high in order to increase the ability to contain and retain liquid, but in the present invention, it is usually
30-90%, preferably 30-70% can be effectively utilized. The average pore diameter is usually 5 to 600 microns, and if it is to be used to prevent air bubbles and dust from entering, it is preferable to have a diameter smaller than the orifice diameter.

According to the present invention, it has a very simple structure and has sufficient printing stability and reliability for practical use. More specifically, it is simple and compact, and can print against external forces such as vibration, impact, and tilt. It is stable and
A highly reliable liquid jet recording device can be provided. Further, according to the present invention, it is possible to provide a liquid jet recording apparatus that is capable of always stably supplying liquid even during high-speed recording and that can perform recording in response to recording signals faithfully and reliably.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are principle explanatory diagrams of an open system and a closed system supply mechanism of a liquid jet recording device, respectively.
FIG. 3 is a schematic diagram for explaining the measurement system according to the present invention, and FIG. 4 is a diagram showing the results of the measurement. Figures 5a, b, c, and d show an example of a preferred embodiment of the recording device of the present invention, in which a is a schematic perspective view, b is a cross-sectional view taken along a dashed-dotted line OP, and c is a
A schematic assembly diagram of the recording head section 501, d is a partial cross-sectional view taken along the dashed line XY, and FIGS. 6 and 7 are partial views showing other embodiments of the present invention. 101, 201...recording head, 102, 202
... Supply channel, 103, 203 ... Tank, 104 ... Vent hole, 105, 204 ... Droplet, 205 ... Pressure mechanism, 206 ... Valve, 301 ... Rotary acceleration generator,
302...recording head, 303...orifice, 30
4... Polyethylene pipe, 305... Liquid, 500... Liquid jet recording device, 501... Recording head portion, 502
...liquid storage tank section, 503...carriage, 504...scanning axis, 505...pressing means, 506...ventilation hole, 50
7... Orifice part, 508, 515, 516... Air removal plug, 509... Liquid discharge part, 510... Common liquid chamber, 511... Supply path pipe, 512, 513... Connector, 514... Wall, 517... Liquid inlet, 518 …
Substrate, 519... Electric/thermal converter, 520... Common electrode, 521... Selection electrode, 522... Groove, 523... Air removal hole, 524... Liquid inlet, 525... Grooved plate, 526... Common liquid chamber recess, 527 ... Orifice, 528 ... Liquid discharge part, 529 ... Heat action part, 53
0...Heat generation part, 531...Heat action surface, 532...Lower layer, 533...Heating resistance layer, 534...Upper layer, 60
1,704...Supply line pipe, 602,705...Terminal end, 603,706...Liquid inlet, 604,703
...liquid containing member, 702...bottom surface.

Claims (1)

[Claims] 1. A plurality of orifices for discharging liquid arranged in a direction different from the scanning direction of the carriage, and a portion communicating with the orifices and applying thermal energy to the liquid for discharging the liquid. A certain heat acting part,
A supply channel having an inner diameter of 0.3 mm to 2 mm for supplying liquid to the heat acting part, and coupled to at least a portion of the heat acting part in a coupling relationship capable of supplying thermal energy to the liquid in the heat acting part. a recording head comprising an electric/thermal converter; a liquid storage tank connected to the head so that the liquid therein is supplied to the heat application section from an inlet at the end of the supply path; an external electrical connection means for supplying an electric signal for driving the electric/thermal converter to the electric/thermal converter; comprising a built-in structure, the external electrical connection means being electrically connected to the main body when the structure is disposed in the carriage, and
Each of the heat acting parts is arranged at a height where the liquid in the liquid storage tank can be supplied by capillary force, and an orifice located above and at the top of the end of the supply path and the end of the supply path. A liquid jet recording device characterized by a height difference of 120 mm or less from the entrance of the part. 2. The liquid jet recording device according to claim 1, wherein the inlet of the end portion of the supply path is sealed with a liquid-containing member. 3 The liquid containing member has an average pore diameter of 5 to 600 μm.
The liquid jet recording device according to claim 2, having micropores with a porosity of 30 to 90%. 4. The liquid jet recording device according to claim 1, wherein the bottom surface of the liquid storage tank section is inclined.