JPH05246045A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To certainly prevent absorbed ink from again flowing backward to a capping means by providing a flow resistance means composed of an air permeable high-molecular polymer in the ink passage between the capping means and a pump means. CONSTITUTION:A recovery device is constituted so that a capping means 22 is brought into close contact with the emitting orifice forming surface of a recording head and a pump means 23 is driven through a piston shaft 43 to generate negative pressure in the capping means 22 to suck ink from an emitting orifice and the ink is drawn in the pump means 23 through an ink passage 68 to be sent to the ink absorbing body in a cylindrical feed roller through an ink pipe 25 and a flow resistance means 73 is formed in the ink passage 68 formed to a cap lever 60 by an insert member 7 composed of an air permeable high-molecular polymer. An ink back flow phenomenon is generated by the force acting at the time of the forward movement of a piston 57 and the force due to the change of the position energy caused by the posture change or movement of the pump means 23 but the pressure applied to the ink by this force is far smaller than the resistance value of the flow resistance means 73.

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 for recording by ejecting ink from a recording means onto a recording material.

[0002]

2. Description of the Related Art A recording device having a function such as a printer, a copying machine, a facsimile, or a recording device used as an output device such as a composite electronic device including a computer and a word processor, a workstation, etc. An image is recorded on a recording material (recording medium) such as a plastic thin plate.
The recording apparatus is an ink jet type according to a recording method,
It can be classified into a wire dot type, a thermal type, a laser beam type and the like.

In a serial type recording apparatus which employs a serial scan system in which main scanning is performed in a direction intersecting a conveying direction (sub-scanning direction) of a recording material, the recording material is set at a predetermined recording position and then the recording material is recorded. An image is recorded (main scanning) by a recording device mounted on a carriage that moves along the material, and a predetermined amount of paper is fed (conveyed material to be recorded) after the recording for one line is completed, and then again. The recording of the entire recording material is performed by repeating the operation of recording (main scanning) the image of the next row on the recording material that has stopped. On the other hand, in a line type recording apparatus that records only by sub-scanning in the conveying direction of the recording material, the recording material is set at a predetermined recording position, and one line of recording is collectively performed, and then a predetermined amount is recorded. The paper is fed (pitch feed), and the recording of the next line is collectively performed, whereby the entire recording material is recorded.

Among the above recording apparatuses, an ink jet type recording apparatus (ink jet recording apparatus) performs recording by ejecting ink from a recording means (recording head) onto a recording material, and the recording means can be made compact. Easy, high-definition images can be recorded at high speed, plain paper can be recorded without special processing, running cost is low, and non-impact method reduces noise. In addition, it is easy to record a color image using multicolor inks. Among them, the line type using a full multi type recording means in which a large number of ejection openings are arranged in the paper width direction can further speed up recording.

In particular, an ink jet type recording means (recording head) for ejecting ink by utilizing heat energy,
Through the semiconductor manufacturing process such as etching, vapor deposition, and sputtering, the electrothermal converter formed on the substrate, the electrode,
By forming the liquid passage wall, the top plate and the like, it is possible to easily manufacture a liquid discharge device having a high-density liquid passage arrangement (discharging port arrangement), and to further reduce the size. On the other hand, there are various requirements for the material of the recording material,
In recent years, ordinary recording materials such as paper and resin thin plate (OHP)
Etc.), thin paper or processed paper (paper with bunch holes for filing, perforated paper, paper of any shape, etc.) has been required to be used.

[0006] In general, the above-mentioned ink jet recording apparatus is equipped with a recovery device for removing the thickened ink and dust adhering to the ejection port of the recording head to maintain or recover a stable ink ejection function. This recovery device has a capping unit for preventing ink from drying at the ejection port of the recording head and a pump unit for sucking ink from the ejection port. The capping means and the pump means are connected by a flow path member such as a tube member made of polyethylene or a passage member in which a passage is formed,
The negative pressure generated by the pump unit is configured to suck the ink from the ejection port via the capping unit and the flow path member. As the pump means, for example, a plunger type is used.

[0007]

However, in the above-mentioned conventional recovery device, the ink sucked from the capping means by the negative pressure of the pump means and flowing through the flow path member moves the pump means (piston movement). There is a possibility that it may flow back toward the discharge port in conjunction with (movement etc.). For example,
In the backward stroke of the piston, there is a case where the ink to be discharged to the outside of the cylinder loses to the flow path resistance of the discharge system and flows back from the ink suction port of the cylinder to the capping means side. When such a backflow phenomenon occurs, the grease in the pump means is carried to the ejection port of the recording head and mixed in with the ink before ejection, which causes a problem that the recording quality is extremely deteriorated, or the recording head and the cap ( In some cases, there is a problem that ink leaks from between the contact surface with the capping means).

The present invention has been made in view of the above technical problems, and an object of the present invention is to reliably prevent the ink once sucked into the pump means from flowing back to the capping means side again. An object of the present invention is to provide an ink jet recording apparatus capable of improving the performance and reliability of products by eliminating deterioration of recording quality and ink leakage.

[0009]

SUMMARY OF THE INVENTION According to the present invention, recording is performed by ejecting ink from a recording unit onto a recording material, and defective ink ejection of a capping unit for sealing an ejection port of the recording unit and the recording unit is prevented. In the ink jet recording apparatus having the pumping means for achieving the above, the above object is achieved by providing the flow resistance means in the ink flow path between the capping means and the pumping means.

In addition to the above construction, another invention of the present invention is as follows:
The flow resistance means is a breathable polymer, the flow resistance means is an orifice member or a weir member, or the flow resistance means is formed by the roughness of the inner wall surface of the ink flow path. In addition, the above-mentioned object can be achieved more efficiently by adopting a configuration in which the roughness of the inner wall surface has a directionality.

[0011]

According to the above construction, the flow resistance means composed of a polymer, an orifice, a weir, or a rough inner wall surface is provided in the ink flow path between the capping means (cap) and the pump means (pump unit). Since the ink is once passed through the flow resistance means by the strong negative pressure of the pump means, the ink does not flow backwards by overcoming the resistance force of the flow resistance means even if pressure due to the return operation of the pump means acts. become unable. As a result, deterioration of recording quality and ink leakage due to backflow of ink to the recording head side are eliminated, and the performance and reliability of the recording apparatus are improved.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same reference numerals indicate the same or corresponding portions. FIG. 1 is a schematic perspective view showing the configuration of the essential parts of an embodiment of an inkjet recording apparatus to which the present invention is applied. In FIG. 1, an ink jet cartridge 4 having a structure in which a recording head (recording device) 2 and an ink tank 3 are integrated is replaceably mounted on a carriage 1. One end of the carriage 1 on the recording head 2 side is fitted to a lead screw 6 rotatably attached to the chassis 5 so as to be slidable in the axial direction. On the other hand, a guide roller 7 is pivotally supported on the other end of the carriage 1.

A guide rail 8 parallel to the lead screw 6 is formed on the chassis 5, and the guide roller 7 of the carriage 1 is slidably fitted on the guide rail 8. The lead screw 6 is formed with a lead groove 9 having a predetermined pitch in a spiral shape, and the carriage 1 is provided with an engagement protrusion 11 which is fitted into the lead groove 9 by a pressing elastic member 10 such as a leaf spring. Has been.
A drive belt 15 is wound around a pulley 12 fixed to the left end of the lead screw 6 in the figure and a pulley 14 fixed to an output shaft of a drive motor 13.
The lead screw 6 is rotated by the forward / reverse rotation of the drive motor 13.
Can be driven to rotate forward and backward.

In this way, the carriage 1 is movably guided and supported by the lead screw 6 and the guide rail 8, and the drive motor 13 rotates the lead screw 6 in the forward and reverse directions, so that the arrow A direction and the reverse direction thereof are obtained. It is configured to move back and forth.
Recording material 16 made of recording paper or plastic thin plate
Is fed (sub-scanning = conveyed) by a conveying roller 18 (shown by a chain double-dashed line in FIG. 1) that rotates by receiving a rotational driving force from the conveying motor 17.

The recording head (recording means) 2 is an ink jet recording means for ejecting ink by utilizing heat energy, and is provided with an electrothermal converter for generating heat energy. Further, the recording head 2 is
Recording is performed by ejecting ink from the ejection port by utilizing the pressure change caused by the growth and contraction of bubbles caused by film boiling caused by the heat energy applied by the electrothermal converter.

FIG. 2 is a partial perspective view schematically showing the structure of the ink ejection portion of the recording head 2. In FIG. 2, a plurality of ejection openings 82 are formed at a predetermined pitch on the ejection opening forming surface 81 that faces the recording material 16 with a predetermined gap (for example, about 0.5 to 2.0 mm). Common liquid chamber 83
An electrothermal converter (heat-generating resistor, etc.) 85 for generating energy for ejecting ink is provided along the wall surface of each liquid passage 84 that communicates with each ejection port 82. In this example, the inkjet cartridge 4 is mounted on the carriage 1 in such a positional relationship that the ejection openings 82 of the recording head 2 are arranged in a direction intersecting with the moving direction (main scanning direction) of the carriage 1. In this way, the corresponding electrothermal converter 85 is driven (energized) based on the image signal or the ejection signal to cause the ink in the liquid passage 84 to film-boil, and the pressure generated at that time causes the ink to be ejected from the ejection port 82. Recording means (recording head) 2 is configured.

In FIG. 1, the conveying roller 18 for conveying the recording material 16 through a position facing the ejection port forming surface 81 of the recording head 2 has a hollow cylindrical shape, and both ends of the conveying roller 18 are formed. Side plate 1 on the left side of the chassis 5 in the figure
It is rotatably supported by 9 and a side plate 20 on the right side in the figure. Further, the inner space of the transport roller 18 communicates with the outside air. A recovery device 21 for recovering the ink ejection function of the recording head 2 by removing clogging of the ejection port 82 of the recording head 2 is provided on the left side of the conveyance roller 18 in the figure. The recovery device 21 includes a cap (capping means) 22 for sealing the ejection port forming surface 81 of the recording head 2. This cap 22
Is movable in the front-back direction, and the cap 2
By sealing the ejection port 82 with 2, it is possible to prevent the ink from drying or adhering to the ejection port 82.

In addition to the cap (capping means) 22, the recovery device 21 generates a negative pressure inside the cap 22 while the discharge port forming surface 81 is sealed (capped) to generate a negative pressure from the discharge port 82. Pump unit (pump means) 23 for forcibly sucking out ink
And a transmission mechanism portion 24 for moving the cap 22 back and forth (contact and separation) with respect to the discharge port forming surface 81 and transmitting a driving force to the pump unit 23. The pump unit (pump means) 23 may have a well-known structure including a piston and a cylinder,
The ink is sucked from the ejection port 82, and the sucked ink is discharged from the inside of the cap 22 into an ink flow path (described later).
The ink is sucked through and is sent to the waste ink pipe 25. In addition, the transmission mechanism section 24 includes the cap 2
It is composed of a cam and a gear mechanism for moving 2 forward and backward or transmitting a driving force to the pump unit 23, and is driven by transmitting the rotational driving force of the lead screw 6 via the clutch gear 26.

The clutch gear 26 is axially slidably attached to the left end portion of the lead screw 6 via a rotation preventing mechanism such as a spline groove.
7 is always urged rightward in the figure (toward the carriage 1 side). When the carriage 1 moves in the direction of arrow A and the pressing portion 28 provided integrally with the carriage 1 presses the right side surface of the clutch gear 26 in the direction of arrow A, the clutch gear 26 resists the spring 27. Then, it moves and meshes with the timing gear 29 of the transmission mechanism section 24. When the clutch gear 26 and the timing gear 29 mesh with each other in this way, the rotational force of the lead screw 6 is transmitted to the timing gear 29, and the timing gear 29
Is rotated in the direction of arrow B, the transmission mechanism portion 24 is driven.

Further, the lead groove 9 of the lead screw 6
Has a shape such that the discharge port forming surface 81 stops at a position facing the cap 22 while the clutch gear 26 transmits the rotational force of the lead screw 6 to the transmission mechanism portion 24 (the lead is zero at the end portion). Has a shape). When the capping means (cap) 22 is brought into close contact with the ejection port forming surface 81 by the transmission mechanism section 24 and the pump means (pump unit) 23 is driven, ink is sucked from the ejection port 82 into the cap 22 and the cap 22 is discharged. The ink inside is sucked into the pump unit 23 through the ink flow path, and the waste ink pipe 2 is further discharged from the pump unit 23.
5 and is absorbed in the ink absorber 30 in the carrying roller 18.

In FIG. 1, the hollow cylindrical carrier roller 18 is rotatably supported by the carrier roller 18.
Inside, there is provided a thin cylindrical covering member 31 made of a plastic material such as polyethylene or EVA. The covering member 31 is fixed to the portion of the pump unit 23 at its left end in the drawing and fixed to the side plate 20 at its right end in the drawing. The ink absorber 30
Is a cotton-like material such as polyester and is filled inside the covering member 31. The waste ink pipe 25 connected to the pump unit 23 is inserted into the ink absorber 30 along the central axis of the covering member 31 by a predetermined length. The covering member 31 has openings 32 formed at desired plural positions for communicating the inside with the outside air.

FIG. 3 is an exploded perspective view showing the construction of the essential parts of the first embodiment of the recovery device 21. In FIG. 3, on the outer surface of the cylinder 41 of the pump means (pump unit) 23, there is formed a cap lever receiver 45 into which a lever seal 44 described later is fitted and held. At the position of the cap lever receiver 45 of the cylinder 41, an ink flow path (opening) 46 communicating with the inside of the cylinder 41 is formed.
The waste ink pipe 25 is integrally formed at the rear end of the cylinder 41, and the front end of the waste ink pipe 25 is inserted into the ink absorber 30 provided in the transport roller 18. Has been done. The waste ink pipe 25 is filled with a cotton-like cylinder absorber 47 such as polyester for transferring the waste ink stored in the cylinder 41 to the ink absorber 30.

A cylinder cap 48 is press-fitted and fixed to the front end opening of the cylinder 41. Cylinder cap 4
A lever guide 49 is formed at a position facing the cap lever receiver 45 on the outer peripheral portion of 8. A piston seal 50 fitted in the cylinder 41 is attached to the piston shaft 43. The diameter of the central opening of the piston seal 50 is set to be slightly smaller than the outer diameter of the piston shaft 43, and the piston seal 50 is mounted so that it can frictionally slide on the piston shaft 43 under a predetermined tightening force. Has been done. In this case, the sliding frictional force with the piston shaft 43 may be reduced by applying a lubricating coating to the surface of the piston seal 50.

The piston shaft 43 is integrally formed with a part of the operating shaft 51, a part of the piston retainer 52, a part of the piston receiver 53, and a part of the connecting shaft 54. An axial groove 55 that serves as an ink flow path is formed. Further, a groove-shaped detent 56 is formed on the portion of the piston shaft 43 on the operating shaft 51. Then, between the piston retainer 52 and the piston receiver 53 of the piston shaft 43 (portion of the connecting shaft 54),
A piston 57 made of rubber-like elastic material such as NBR is attached. The outer diameter of this piston 57 is the cylinder 41
Is formed larger than the inner diameter of the piston 57 by a predetermined amount.
Is adapted to reciprocally slide in an appropriately compressed state when inserted into the inner diameter of the cylinder 41. A piston pressing roller 58 and a piston return roller shaft 59 are rotatably attached to the left end of the piston shaft 43 in the figure.

In FIG. 3, the cylinder cap 48 is
The cap lever 60 is held by the lever guide 49 and the lever seal 44 fitted in the cap lever receiver 45. This cap lever 60 has
A rotary shaft 61, an ink guide portion 62, a lever guide portion (not shown) and the like are provided. A seal portion 64 that is in close contact with the tube portion 63 formed on the back surface of the cap 22 is provided at the tip of the cap lever 60. Also,
Engaging portions 67 with which hooks (claws) 66 formed on both sides of the cap holder 65 engage are formed on both sides of the tip end portion of the cap lever 60. Further, the cap lever 60 is provided with an ink flow path 68 which passes through the inside of the cap lever from the seal portion 64, is bent at a substantially right angle in the middle thereof, and passes through the center of the ink guide portion 62 to open to an end face thereof. ing.

The cap lever 60 has a rotating shaft 6
1 is fitted into the hole 69 of the lever guide 49, and the ink guide portion 62 is fitted to the cap lever receiver 45.
It is held by being press-fitted into the recessed hole portion 70 of the lever seal 44 held therein. The lever seal 44 has an ink flow path (not shown) for communicating an ink flow path 68 opening in the ink guide portion 62 and an ink flow path (opening) 46 formed in the cylinder 41.
Are formed.

The cap holder 65 is provided with an opening 71 for mounting the cap 22.
The capping means (cap) 22 has the tube portion 63 formed on the back surface thereof in the cap holder 65.
The tube portion 6 while being inserted into the opening 71 of
3 is attached in a state in which the tip portion of 3 is in close contact with the seal portion 64 of the cap lever 60. A suction port 72 is formed inside the cap 22, and the suction port 72 communicates with a central hole (opening) of the tube portion 63 through an ink flow path (not shown) formed in the cap 22. The tube portion 63 communicates with the ink flow path 68 of the cap lever 60.

As described above, the capping means 22 is brought into close contact with the discharge port forming surface 81, and the pump means 23 is driven through the piston shaft 43 to generate a negative pressure inside the capping means 22 to discharge the discharge port 82. Ink is sucked from the capping means 22, the sucked ink is sucked into the pump means 23 (in the cylinder 41) through the ink flow path (ink flow path 68, etc.), and the ink is passed through the waste ink pipe 25. A recovery device 21 that operates so as to be delivered into the absorber 30 is configured.

Therefore, in the recovery device 21 shown in FIG. 3, the ink flow path 68 formed inside the ink flow path between the capping means 22 and the pump means 23, that is, the ink flow path 68 formed in the cap lever 60 in the illustrated example. The flow resistance means 73 is provided inside. Further, in the first embodiment of FIG. 3, the flow resistance means 73 includes the insert 7 inserted in the ink flow path 68, that is, the insert 7 such as a breathable polymer which causes energy loss of the ink flow.
It is composed of four.

According to such a recovery device 21, at the time of the suction recovery operation, the large negative pressure of the pump means 23 causes the ink sucked from the ejection port 82 into the capping means 22 to be vigorously sucked, and the cap lever 60. It is introduced into the pump means 23 through the flow resistance means 73 therein (in this embodiment, an insert 74 such as a polymer). On the other hand, the ink is transferred from the pump means 23 to the capping means 22.
The phenomenon of backflowing toward the side tends to occur due to a force acting when the piston 57 returns (returns), a force due to a change in potential energy due to a posture change or a movement of the pump means 23, or the like. However, the pressure applied to the ink by the force that causes such backflow is much smaller than the resistance value of the flow resistance unit 73. Therefore, in the recovery device 21, once the ink sucked from the capping means 22 passes through the flow resistance means 73, the ink cannot overcome the resistance of the flow resistance means 73 and flow backward. Therefore, according to the above-described embodiment, it is possible to improve the performance and reliability of the inkjet recording apparatus by eliminating the deterioration of recording quality and ink leakage due to the backflow of the sucked ink.

FIG. 4 is a schematic partial perspective view showing a partially broken-away main structure of a second embodiment of a recovery device 21 in an ink jet recording apparatus to which the present invention is applied. In this embodiment, the flow resistance means 7 provided in the ink flow path 68.
3 is composed of an orifice member 75 and a weir member 76 mounted in the ink flow path 68. That is, the orifice member 75 and the dam member 76 are configured to give a desired energy loss to the ink flow between the capping means 22 and the pump means 23. The other parts of this embodiment have substantially the same configuration as in the first embodiment of FIG.

Even with the configuration shown in FIG. 4, the same effect of preventing ink backflow as in the case of the embodiment shown in FIG. 3 can be obtained, and an ink jet recording apparatus without deterioration of recording quality and ink leakage can be obtained. It was In the embodiment shown in FIG. 4, the orifice member 75 and the weir member 76 are mounted one by one. However, it is possible to mount only one or a plurality of the orifice member 74 or only one weir member 75. One or a plurality of them may be mounted, and the number of orifice members 75 and weir members 76 may be appropriately selected and mounted, and various combinations can be implemented. Also, the same effect as in the case of FIG. 3 was obtained.

FIG. 5 is a schematic partial perspective view showing a partially broken-away main structure of a recovery device 21 in an ink jet recording apparatus to which the present invention is applied. In this embodiment, the flow resistance means 7 provided in the ink flow path 68.
3 is configured by roughening the inner wall surface of the ink flow path 68, that is, by making the inner wall surface rough so as to give a desired resistance to the ink flow. The other parts of this embodiment have substantially the same configuration as in the first embodiment of FIG. As described above, each of the above-mentioned configurations can be achieved by the structure in which the inner wall surface of a part or the whole of the ink flow path connecting the capping means 22 and the pump means 23 is made rough so as to give a desired energy loss to the ink flowing in the ink flow path. As in the case of the embodiment, it is possible to prevent the backflow of the ink, and it is possible to obtain the ink jet recording apparatus in which the recording quality is not deteriorated and the ink does not leak.

In the embodiment of FIG. 5, the roughness of the inner wall surface of the ink flow path 68 may be provided with directivity. For example, a relatively high resistance force is exerted in the flow direction, but a relatively low resistance force is exerted in the direction orthogonal to the flow.
A rough surface may be formed in a desired pattern.

FIG. 6 is a schematic partial perspective view showing a partially broken-away main structure of a recovery device 21 in an ink jet recording apparatus to which the present invention is applied. In this embodiment, the flow resistance means 7 provided in the ink flow path 68.
3 is a valve function member 77 mounted in the ink flow path 68.
It is composed by. As the valve function member 77, for example, a valve holding member that is normally held at a small opening (or closed) position by a spring biasing force and whose opening is increased by static pressure when ink flow occurs is used. You can As for the form of the valve function member, an arbitrary mechanism can be used. The other parts of this embodiment have substantially the same configuration as in the first embodiment of FIG.

According to the fourth embodiment of FIG. 6 as well, the same operation and effect as in the above-mentioned respective embodiments can be obtained, and a desired energy loss can be given to the ink flow between the capping means 22 and the pump means 23. As a result, backflow of ink was prevented, and an ink jet recording apparatus without deterioration of recording quality and ink leakage was obtained.

Although the flow resistance means 73 is provided in the ink flow path 68 of the cap lever 60 in the first to fourth embodiments of FIGS. 3 to 6, the flow resistance means 73 is used. The disposition position can be selected at any position as long as it is within the ink flow path between the capping means 22 and the pump means 23. Also, the number of flow resistance means 73 can be arbitrarily selected. According to each of the embodiments described above, by providing the resistance means 73 exhibiting a desired flow resistance in the ink flow path connecting the capping means 22 and the pump means 23, the ink once sucked to the pump means 23 side is removed. Since the backflow is prevented from returning to the capping means 22 again, the recording quality is degraded and the capping means 22
This prevents ink from leaking from the product, improving product performance and reliability.

In each of the above-described embodiments, the ink jet recording apparatus using one recording head (recording means) 2 is described as an example, but the present invention is not limited to a plurality of recording heads using different color inks. Even if the number of recording heads and the inks used are different, such as an inkjet recording apparatus using the recording heads described above, or an inkjet recording apparatus for gradation recording using a plurality of recording heads recording with inks of the same color but different densities. It can be applied and can achieve the same effect.

In each of the above-mentioned embodiments, the recording head 2
Although the description has been given by taking as an example a serial type ink jet recording apparatus in which the carriage is mounted on the carriage 1, the present invention uses a line type recording head having a length that covers the whole or a part of the recording material in the width direction. The same can be applied to the line type ink jet recording apparatus that records only by scanning, and the same effect can be obtained. Further, as the recording head (recording means), in addition to a cartridge type integrated with an ink tank, a configuration in which the recording head is separated from the ink tank and connected by an ink supply tube, etc. However, the same can be applied and the same effect can be achieved.

The present invention can be applied to an ink jet recording apparatus using a recording means (recording head) using an electromechanical transducer such as a piezo element, but among them, thermal energy is used. In this way, an excellent effect can be obtained in an ink jet recording apparatus of the type that ejects ink. This is because such a system can achieve high density recording and high definition recording.

With regard to its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
This is preferably done using the basic principles disclosed in US Pat. No. 7,967. This method can be applied to both the so-called on-demand type and the continuous type, but particularly in the case of the on-demand type, a liquid (ink) is used.
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path holding the Since the electrothermal converter generates heat energy to cause film boiling on the heat acting surface of the recording means (recording head), as a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal. It is valid.

Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection openings 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 this pulse-shaped drive signal, US Pat.
Those described in US Pat. Nos. 4,633,359 and 4,345,262 are suitable. Incidentally, US Pat. No. 43131 of the invention relating to the rate of temperature rise of the heat acting surface.
If the conditions described in No. 24 are adopted, even more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection 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 and US Pat. No. 4, which disclose a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of 459600 is also included in the present invention. In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 138461/1984, which discloses a configuration in which the above is associated with the discharge portion. That is, according to the present invention, recording can be reliably 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 material (recording medium) which can be recorded by the recording apparatus. Such a recording head may have a configuration that fills the length by combining a plurality of recording heads or a configuration as one recording head integrally formed. In addition, even with the serial type as in the above example, it is possible to electrically connect to the device body or supply ink from the device body by mounting it on the recording head fixed to the device body or on the device body. The present invention is also effective when a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, and the like, which are provided in the present invention as a configuration of the recording apparatus, because the effects of the present invention can be further stabilized. If these are specifically mentioned,
Capping means, cleaning means, pressurizing or suctioning means, electrothermal converter or other heating element or preheating means by a combination thereof, and ejection different from recording are applied to the recording head. Performing the preliminary ejection mode is also effective for stable recording.

Regarding the type or 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. And a plurality of them may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode only for mainstream colors such as black,
The recording head may be integrally configured or a combination of a plurality of recording heads may be used. However, the present invention is extremely effective for an apparatus having at least one of a mixed color of different colors or a full color of mixed colors.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and softens or liquefies at room temperature, or an ink jet. In the method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. Any liquid may be used. in addition,
Whether the temperature rise due to thermal energy is positively used as the energy for changing the state of the ink from the solid state to the liquid state, or the ink that solidifies when left standing for the purpose of preventing ink evaporation is used. In any case, the ink is liquefied by applying the thermal energy according to the recording signal and the liquid ink is ejected,
The present invention is also applicable to the case of using an ink which has a property of being liquefied only by thermal energy, such as one which has already started to solidify when it reaches the recording medium.

The ink in such a case is disclosed in JP-A-54-54.
As described in JP-A-56847 or JP-A-60-71260, a mode in which it is held as a liquid or a solid in a concave portion or a through hole of a porous sheet and faces the electrothermal converter. May be 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 a form of the ink jet recording apparatus according to the present invention, in addition to the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. And the like may be used.

[0050]

As is apparent from the above description, according to the present invention, recording is performed by ejecting ink from the recording means to the recording material, and recording is performed with a capping means for sealing the ejection port of the recording means. In the ink jet recording apparatus having pump means for preventing defective ink ejection of the means, the flow resistance means is provided in the ink flow path between the capping means and the pump means. Provided is an ink jet recording apparatus capable of surely preventing the ink sucked into the ink from flowing back to the capping means side, and improving the performance and reliability of the product by eliminating the deterioration of recording quality and ink leakage. ..

According to another aspect of the present invention, in addition to the above configuration,
The flow resistance means is a breathable polymer, the flow resistance means is an orifice member or a weir member, or the flow resistance means is formed by the roughness of the inner wall surface of the ink flow path. Moreover, since the roughness of the inner wall surface is made directional, an inkjet recording apparatus capable of achieving the above effect more efficiently is provided.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a configuration of a main part of an embodiment of an inkjet recording apparatus to which the present invention is applied.

FIG. 2 is a partial perspective view schematically showing the structure of an ink ejection portion of the recording means in FIG.

FIG. 3 is a partially cutaway exploded perspective view showing a configuration of a first embodiment of a recovery device in an inkjet recording device to which the present invention has been applied.

FIG. 4 is a partially cutaway perspective view showing a main part of a second embodiment of a recovery device in an inkjet recording device to which the present invention has been applied.

FIG. 5 is a partially cutaway perspective view showing essential parts of a third embodiment of a recovery device in an inkjet recording apparatus to which the present invention has been applied.

FIG. 6 is a partially cutaway perspective view showing an essential part of a fourth embodiment of a recovery device in an inkjet recording apparatus to which the present invention has been applied.

[Explanation of Codes] 1 Carriage 2 Recording Head (Recording Means) 3 Ink Tank 4 Inkjet Cartridge 5 Chassis 6 Lead Screw 9 Lead Groove 11 Engagement Protrusion 13 Drive Motor 15 Drive Belt 16 Recording Material 17 Conveying Motor 18 Conveying Roller 21 Recovery Device 22 Capping Means (Cap) 23 Pump Means (Pump Unit) 24 Transmission Mechanism 25 Waste Ink Tube 30 Ink Absorber 31 Covering Member 41 Cylinder 43 Piston Shaft 45 Cap Lever Receptor 46 Ink Flow Path 48 Cylinder Cap 57 Piston 60 Cap Lever Reference numeral 65 Cap holder 68 Ink flow path 73 Flow resistance means 74 Breathable insert such as high molecular polymer 75 Orifice member 76 Weir member 77 Valve function member 81 Discharge port forming surface 82 Discharge port 85 Electrothermal converter

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B41J 2/185 8306-2C B41J 3/04 102 R

Claims (7)

[Claims] 1. A capping means for ejecting ink from a recording means to a recording material for recording, a capping means for sealing an ejection port of the recording means, and a pump means for preventing defective ink ejection of the recording means. An ink jet recording apparatus having the above, wherein flow resistance means is provided in an ink flow path between the capping means and the pump means. 2. The ink jet recording apparatus according to claim 1, wherein the flow resistance means is a breathable polymer. 3. The ink jet recording apparatus according to claim 1, wherein the flow resistance means is an orifice member or a weir member. 4. The ink jet recording apparatus according to claim 1, wherein the flow resistance means is formed by the roughness of the inner wall surface of the ink flow path. 5. The ink jet recording apparatus according to claim 4, wherein the roughness of the inner wall surface has a directivity. 6. The inkjet recording apparatus according to claim 1, wherein the recording unit is an inkjet recording unit including an electrothermal converter that generates thermal energy used to eject ink. 7. The ink jet recording apparatus according to claim 6, wherein the recording unit ejects the ink from the ejection port by utilizing film boiling generated in the ink by the thermal energy generated by the electrothermal converter. .