JPH08118681A - Ink jet recorder - Google Patents

Abstract

PURPOSE: To improve the reliability of an ink jet recorder and to reduce the driving power required for starting a plunger pump by reducing the contact area of the pump with the cylinder at the time of waiting except the suction operation, and preventing the fixing of the piston due to the ink thickening of the contact when it is left to stand for a long period. CONSTITUTION: The vicinity of the outer periphery of the piston 105 of the rubber elastic member of a negative suction type plunger pump 43 used for discharge failure recovering process is brought into contact with the protrusion 111a of a pump seal 110 deformation preventing washer 111 or the protrusion of the cylinder 103 to be deformed, thereby reducing the contact area with the inner periphery of the cylinder 103.

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, and an ink jet recording having a plunger pump for preventing defective ink ejection of the recording means. Regarding the device.

[0002]

2. Description of the Related Art A recording device having functions such as a printer, a copying machine and a facsimile, or a recording device used as an output device of a multifunction machine or a workstation including a computer, a word processor, etc., is a sheet or a plastic thin plate based on image information. Images (including characters and symbols) on recording materials (recording media) such as (sheets for OHP)
Is configured to record. The recording device can be classified into an ink jet type, a wire dot type, a heat sensitive type, a thermal transfer type, a laser beam type and the like depending on the recording system of the recording means used.

In a serial type recording apparatus which employs a recording system in which a 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 set. An image (including characters, symbols, etc.) is recorded by a recording unit (recording head) mounted on a carriage that moves (main scanning) along, and after one line of recording is completed, a predetermined amount of paper is fed (sub-scan). An image is recorded in a desired range of the recording material by repeating the operation of performing (scanning) and then recording (main scanning) the image of the next row. On the other hand, in a line type recording apparatus that records a recording material only in the sub-scanning direction in which the recording material is fed in the transport direction, the recording material is set at a predetermined recording position, and one line of recording is continuously performed at one time. A predetermined amount of paper feed (pitch feed) is performed, and an image is recorded on the entire recording material.

Among them, the ink jet type (ink jet recording apparatus) is a means for performing recording by ejecting ink from an ink jet recording means (recording head) onto a recording material, and it is easy to make the recording means compact and high definition. Image can be recorded at high speed, it can be recorded on plain paper without requiring special processing, the running cost is low, and it is a non-impact system, so there is less noise and more It has the advantage that it is easy to use and record color images. Above all,
The line type recording apparatus using the line type recording means in which a large number of ejection openings are arranged in the paper width direction can further increase the recording speed.

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 (ejection port arrangement), and to further reduce the size. Further, by utilizing the advantages of IC technology and micro processing technology, it is easy to make the recording means long and planar (two-dimensional), and it is also easy to make the recording means full-multi and high-density mounting. is there. On the other hand, there are various requirements for the material of the recording material, and in recent years, in addition to the ordinary recording material such as paper and resin thin plate, thin paper and processed paper (paper with punch holes for filing and perforation). Paper, paper of any shape, etc.)
It has been required to use such as.

The above-mentioned ink jet recording means (recording head) records an image by ejecting ink from minute ejection openings according to recording information to form flying ink droplets and attaching the ink droplets to a recording material. It is configured to do. In such an ink jet recording head, ejection failure (including non-ejection) may occur due to dryness and thickening of ink in the ejection port, intrusion of dust, generation of bubbles in the ink, and the like. In order to prevent or eliminate (recover) defects and maintain a stable ink ejection function in the recording head, a recovery system including an ink suction unit is provided.

Conventionally, a pump unit has been used as an ink suction means mounted in the recovery system of an ink jet recording apparatus, and a plunger pump has been mainly used as the pump unit. This plunger pump has a basic structure in which a piston (plunger) is slidably fitted in a cylinder, and is configured to generate a negative pressure suction force by relatively reciprocating the piston. There is. In the conventional plunger pump, the outer peripheral surface of the piston is always in close contact with the inner peripheral surface of the cylinder with a constant crushing amount both during suction (during operation) and during standby (during non-operation). .

[0008]

However, in the ink suction means of the conventional ink jet recording apparatus as described above, the ink adhering to the outer circumference of the piston increases in viscosity after being left for a long period of time, and the seal surface of the piston is always maintained. Since the pressure is applied, the piston may stick to the inner peripheral surface of the cylinder, which may significantly increase the driving force of the plunger pump. In particular, when a water-resistant ink is used as the ink, its nonvolatile components are large,
The above-mentioned fixation was easily generated.

The present invention has been made in view of the above technical problems, and an object of the present invention is, in an inkjet recording apparatus having a recovery mechanism provided with a negative pressure suction type plunger pump, other than suction operation. The contact area with the inner peripheral surface of the cylinder can be reduced by deforming the vicinity of the outer circumference of the piston during standby, thereby preventing sticking due to ink thickening at the contact part between the piston and cylinder when left for a long time. It is an object of the present invention to provide an inkjet recording apparatus that can be prevented and that can improve the reliability of the recording apparatus as a product and can simplify the recording apparatus by reducing the driving force required to start the plunger pump.

[0010]

According to a first aspect of the present invention, in an ink jet recording apparatus for recording by ejecting ink from a recording means to a recording material, a recovery mechanism for recovering or preventing defective ink ejection of the recording means. By providing a negative-pressure suction type plunger pump in the cylinder, and deforming the vicinity of the outer circumference of the piston for reciprocating in the cylinder of the plunger pump to generate negative pressure during standby other than suction operation, It achieves the purpose.

According to the invention of claims 2 to 8, in addition to the structure of claim 1, a projection is provided on a part of the member inside the plunger pump, and the projection is brought into contact with substantially the entire circumference of the piston. By this, the configuration that deforms the vicinity of the outer periphery of the piston,
The member inside the plunger pump is a fixed member for preventing the deformation of the seal member due to negative pressure, a protrusion is provided on a part of the inner surface of the cylinder of the plunger pump, and the protrusion abuts substantially the entire circumference of the piston. By deforming the vicinity of the outer circumference of the piston, by removing a part of the piston, by contacting the protrusion with a part of the piston in the vicinity of the outer periphery, by contacting the protrusion with a part of the piston The above object can be achieved more efficiently by providing a protrusion or by reducing the contact area with the inner peripheral surface of the cylinder by the deformation near the outer periphery of the piston.

[0012]

In the ink jet recording apparatus of the present invention constructed as described above, the contact area between the outer circumference of the piston and the inner circumference of the cylinder is reduced after the suction operation for sucking the ink from the discharge port of the recording means is completed. The adhesion due to the thickened ink is also reduced, and the sticking between the piston and the cylinder does not occur. Also, if you cut out a part of the piston,
The force required for deformation can be reduced by lightening,
This is effective for downsizing the device.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing an embodiment of an ink jet recording apparatus suitable for applying the present invention. FIG.
In the carriage 23, a head cartridge 20 constituting a recording means is replaceably mounted, and the head cartridge 20 has a structure in which a recording head 21 and an ink tank 22 are integrated. One end of the carriage 23 on the recording head 21 side is fitted to the lead screw 13 rotatably attached to the chassis 1 so as to be slidable in the axial direction, and the other end of the carriage 23 has a guide ( (Not shown) is provided. The guide is slidably engaged with a guide rail 2 formed on the chassis 1 in parallel with the axial direction of the lead screw 13. The carriage 23 is guided and supported so as to be capable of reciprocating in the axial direction thereof as the lead screw 13 rotates while always maintaining a constant posture.

In FIG. 1, a lead screw gear 24 is fixed to the left end of the lead screw 13, and a carriage motor 25 attached to the chassis 1.
A pinion gear 26 is fixed to the output shaft of the, and the lead screw gear 24 and the pinion gear 26 mesh with each other. FIG. 2 shows the lead screw 13 of the carriage 23.
FIG. 6 is a schematic vertical cross-sectional view showing a bearing engaging portion with respect to FIG. Figure 2
In the lead screw 13, a guide groove (guide groove) 27 is spirally formed at a predetermined pitch, and a lead pin 28 attached to a bearing portion 29 of the carriage 23 is provided.
Is fitted in the guide groove 27. Therefore, the carriage 23 reciprocates as the lead screw 13 rotates as the carriage motor 25 rotates forward and backward.

In FIG. 1, the recording head 21 is driven in synchronism with the reciprocating movement of the carriage 23, and ink is ejected in accordance with a recording signal, so that one line of recording is performed on the recording material 3. As the energy generation means for generating such ink ejection energy, an electromechanical energy converter such as a piezo element is used, a droplet is ejected by heat generated by irradiating an electromagnetic wave such as a laser, a heating resistor is used. For example, there is a device that heats ink by an electrothermal converter such as a heating element that it has and ejects the ink.

The recording head (recording means) 21 is an ink jet recording means for ejecting ink by utilizing heat energy, and has an electrothermal converter for generating heat energy. In addition, the recording head 21
Is to perform recording by ejecting ink from an ejection port by utilizing a pressure change caused by growth and contraction of bubbles due to film boiling caused by thermal energy applied by the electrothermal converter.

FIG. 3 shows the recording means (recording head) 21.
FIG. 3 is a partial perspective view schematically showing the structure of the ink ejection section of FIG. In FIG. 3, the ejection port surface 81 facing the recording material (recording paper or the like) 3 with a predetermined gap (for example, about 0.5 to 2.0 mm) ejects a plurality of ejections at a predetermined pitch. An electrothermal converter (heat-generating resistor, etc.) 8 for forming energy for ink ejection along the wall surface of each liquid passage 84 which has an outlet 82 and connects the common liquid chamber 83 and each ejection port 82.
5 are provided. In this example, the recording head 21
Are mounted on the carriage 23 in such a positional relationship that the ejection ports 82 are arranged in a direction intersecting the scanning direction of the carriage 23. 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 ink generated from the ejection port 82 is ejected by the pressure generated at that time. The recording head 21 is configured.

In FIG. 1, when one line of recording is performed by scanning (main scanning) of the carriage 23, the recording material 3 is conveyed by one line (paper feed) by the conveying means,
Record the next line at that position. The recording material 3 is conveyed by the conveyance roller 4 and the pinch roller 8 that is in pressure contact with the conveyance roller 4.
Rotation pair, discharge roller 7 and spur 6 that abuts on it
It is carried out by a rotating pair of.

Specifically, the ejection port surface 8 of the recording head 21
The recording material 3 having the recording surface facing 1 is pressed against the conveying roller 4 by the pinch roller 8, and the conveying roller 4 is appropriately rotated by the conveying motor 5, so that the recording material 3
To the recording position as needed. And after recording,
The recording material 3 is pressed against the discharge roller 7 by the spur 6, and the recording material 3 is discharged and conveyed outside the apparatus by the rotation of the discharge roller 7. The conveyance roller 4 and the discharge (paper discharge) roller 7 are driven by a conveyance motor (paper feed motor) 5, and the driving force thereof is transmitted by a reduction gear train 15.

FIG. 4 is an exploded perspective view schematically showing the left end portion of the lead screw 13 which constitutes a clutch mechanism for transmitting the driving force of the carriage motor 25 to the recovery system via the lead screw 13. In FIG. 4, an initial lock 30, a clutch plate 31, a clutch gear 32, and a return spring 33 are arranged at the left end portion of the lead screw 13. The initial lock 30 is fixed to the lead screw 13. The clutch gear 32 is fitted to the lead screw 13 so as to be slidable in the axial direction, and a part thereof enters the inside of the initial lock 30.

That is, the clutch gear 32 is formed with projections 34 at two asymmetrical positions on the circumference, and these projections 34 are opposed only in the axial direction to the recesses 35 formed in the initial lock 30 in the same phase. It is movably fitted. A flange 36 is provided on the end surface of the clutch gear 32 on the lead screw gear 24 side, and trigger teeth 38 for giving a rotation trigger to the control gear 37 are formed on the flange 36.

A gear is formed on the outer periphery of the control gear 37, and the position where the clutch gear 32 on the lead screw 13 meshes with the control gear 37 when the lead screw 13 is incorporated into the recovery system plate 39. Have a relationship. However, during the recording operation, in the control gear 37, a part of the outer periphery of the control gear that is cut out (a toothless portion) faces the clutch gear 32. It never meshes. A side gear 40 having several teeth is formed on the side surface of the toothless portion of the control gear 37. The side gear 40 meshes with the trigger teeth 38 of the clutch gear 32 and gives a rotation trigger to the control gear 37.

In FIG. 1, a recovery mechanism 41 is provided at a predetermined position (usually near the home position of the carriage 23) outside the recording area of the recording apparatus. FIG. 5 is a schematic perspective view of the recovery mechanism 41. In FIG. 5, the recovery mechanism 41 includes a cap 42, a plunger pump 43, and a control gear 37. The cap 42 is
This is for abutting the ejection opening surface 81 of the recording head 21 located at the home position to cap the ejection opening 82. The plunger pump 43 is a negative pressure suction type, and in the capping state, the inside of the cap 42 is set to a negative pressure to suck the ink from the ejection port 82 through the cap and send the ink to a waste ink reservoir (not shown). It is for.

The control gear 37 moves the cap 42 back and forth with respect to the ejection port surface 81, transmits the driving force to the plunger pump 43, and wipes the ink and foreign matter adhering to the ejection port surface 81. It constitutes a transmission mechanism section including a cam mechanism and a gear mechanism for operating the mechanism. This control gear 37
The rotational driving force of the carriage motor 25 is transmitted to the motor via the clutch gear 32 described above.

FIG. 6 shows a negative pressure suction type plunger pump 43.
FIG. 3 is a schematic vertical sectional view showing the first embodiment of FIG. In FIG. 6, a negative pressure is generated by reciprocating the piston 105 mounted on the plunger 104 along the inner surface of the cylinder 103, and the negative pressure sucks the ink from the ejection port 82 of the recording head 21. The discharge function of 82 can be restored. The piston 105 is formed of a rubber-like elastic body such as silicon rubber.

The piston 105 (plunger 104)
The reciprocating motion of is obtained by rotating the stroke gear 106 having the protrusion 106a that fits with the lead groove 104a provided in the plunger 104. further,
The rotational force of the stroke gear 106 is given by meshing with the above-mentioned control gear 37,
The source is the rotational driving force of the carriage motor 25.

The cap 42 can be closely contacted with and separated from the recording head 21, and its operation is executed by the cam of the control gear 37. Generally, the cap 42 is made of an elastic material having low gas permeability and excellent ink resistance, such as chlorinated butyl rubber. Pump seal (seal member)
Reference numeral 110 denotes an elastic seal member that is in close contact with the inner circumference of the cylinder 103 and the outer circumference of the plunger 104 and is provided to realize a closed space inside the pump.

The cap lever 107 is a member that relays the cap 42 and the inside of the cylinder 103, and has an ink flow path inside. In addition, the ink flow path,
On the way, cap lever seal 108 and SUS steel ball 109
The airtightness is secured between the ink suction port 103a of the cylinder 103 and the contact surface 42a of the cap 42 with the recording head 21. The pump washer 111 is a fixing member provided to prevent the pump seal 110 from being deformed by the negative pressure generated in the pump.

Therefore, as shown in a partially enlarged view in FIG. 6, the characteristic construction of the present embodiment is that the protrusion 111a provided on the pump washer (fixing member) 111 contacts the vicinity of the outer periphery of the piston 105 during standby. The contact is that the piston 105 is deformed. As a result, the contact area between the outer circumference of the piston 105 and the inner circumference of the cylinder 103 is reduced only during standby without impairing the sealing performance during the suction operation. Therefore, when left without using the pump, the thickened ink is prevented from sticking to the contact portion between the outer circumference of the piston 105 and the inner circumference of the cylinder 103. The protrusion 111a may be provided so as to abut the entire circumference of the piston 105, or may be provided only at a specific place where ink is likely to collect, depending on the installation and usage of the recording apparatus.

According to the embodiment described above, the negative pressure suction type plunger pump 43 is provided in the recovery mechanism 41 for recovering or preventing the ink ejection failure of the recording head 21, and the cylinder 103 of the plunger pump 43 is provided. 105 for reciprocating the piston to generate negative pressure
Since the vicinity of the outer periphery of the cylinder 103 is deformed during standby other than the suction operation to reduce the contact area with the inner peripheral surface of the cylinder 103, the piston 105 when left standing for a long time
It is possible to prevent sticking due to thickening of the ink at the contact portion between the cylinder 103 and the cylinder 103, improve the reliability of the inkjet recording device as a product, and simplify the recording device by reducing the driving force required to start the plunger pump 43. Can be realized.

FIG. 7 shows a negative pressure suction type plunger pump 43.
FIG. 6 is a schematic vertical sectional view showing a second embodiment of The feature of this embodiment is that the pump washer 11 in the first embodiment is used.
In place of the first projection 111a, the projection 103b formed on the inner surface of the cylinder 103 is used. The second embodiment of FIG. 7 differs from the first embodiment of FIG. 6 in this respect, but has substantially the same configuration in other points, and the corresponding portions are denoted by the same reference numerals, and their details will be described. The description is omitted.

The second embodiment shown in FIG. 7 is slightly inferior to the first embodiment in terms of assembling, but the pump washer 111 is made of a thin metal plate or the like due to the size limitation of the apparatus. This embodiment is particularly effective when it is difficult to form the protrusion. Also in this embodiment, as in the case of the above-described first embodiment, the vicinity of the outer periphery of the piston 105 of the plunger pump 43 of the suction recovery mechanism 41 is deformed during standby other than the suction operation, so that the inside of the cylinder 103 is not deformed. Since it is configured to reduce the contact area with the peripheral surface, it is possible to prevent sticking due to ink thickening at the contact portion between the piston 105 and the cylinder 103 when left for a long time, and as a product of an inkjet recording apparatus. It is possible to realize the improvement of reliability and simplification of the recording apparatus by reducing the driving force required for starting the plunger pump 43.

FIG. 8 shows a negative pressure suction type plunger pump 43.
It is a typical longitudinal cross-sectional view showing a piston 105 of the third embodiment of. The feature of this embodiment resides in that the piston 105 of the first or second embodiment described above is formed with the thinned portion 105a. The third embodiment of FIG. 8 is different from the above-described first or second embodiment in this respect, but has substantially the same configuration in other points, and corresponding portions are denoted by the same reference numerals, respectively. The detailed description of is omitted.

According to the third embodiment of FIG. 8, the meat removal 105
Since the rigidity of the piston 105 is reduced by a, the deformation of the piston 105 is facilitated. Therefore, the driving force required when the piston 105 is deformed can be reduced,
The effect that the miniaturization of the device can be achieved is obtained. Also in this embodiment, as in the case of the first and second embodiments described above, the piston 105 is not used during standby except for the suction operation.
Since the contact area with the inner peripheral surface of the cylinder 103 is reduced by deforming the vicinity of the outer periphery of the cylinder 103, it is possible to prevent sticking due to thickening of ink in the contact portion between the piston 105 and the cylinder 103 when left for a long period of time. Improvement of reliability as a product of inkjet recording device and plunger pump 4
It is possible to realize simplification of the recording apparatus by reducing the driving force required for starting the recording medium of No. 3.

FIG. 9 shows a negative pressure suction type plunger pump 43.
FIG. 11 is a schematic vertical sectional view showing a piston 105 of the fourth embodiment of the present invention. The feature of this embodiment is that the piston 105 is also provided with the projection 105b in the first or second embodiment. The protrusion 105b on the piston 105 side is the first
It is provided at a position corresponding to a portion of the pump washer 111 of the embodiment that contacts the protrusion 111a or the protrusion 103b of the cylinder 103 of the second embodiment. In this embodiment, the protrusion 111a of the pump washer 111 and the cylinder 103 are
This is effective when the protrusions 103b cannot be formed sufficiently. Further, a configuration in which this embodiment and the third embodiment of FIG. 8 are combined may be adopted.

The fourth embodiment of FIG. 9 is different from the above-mentioned first to third embodiments in the above points, but is substantially the same in other points, and the corresponding portions are designated by the same reference numerals. , And detailed description thereof will be omitted. According to the fourth embodiment of FIG. 9, as in the case of the above-described first to third embodiments, the vicinity of the outer periphery of the piston 105 is deformed during the standby state other than the suction operation to reduce the contact area with the inner peripheral surface of the cylinder 103. Since it is reduced, it is possible to prevent sticking due to thickening of ink at the contact portion between the piston 105 and the cylinder 103 when left for a long period of time, and it is possible to improve reliability as a product of the inkjet recording apparatus and to start the plunger pump 43. It is possible to realize simplification of the recording apparatus by reducing the required driving force.

In the above-mentioned embodiments, the case of the serial recording method in which the recording means (recording head) is moved in the main scanning direction has been described as an example, but the present invention is the whole width or a part of the recording material. The same can be applied to the case of the line recording method in which the line recording unit having a length covering the above is used to perform recording only in the sub-scan, and the same effect can be achieved. In addition to the inkjet recording apparatus that performs single-color recording, the present invention also provides a color inkjet recording apparatus that has one or a plurality of recording heads and records with inks of different colors, and gradations that use inks of the same color but different densities. The same can be applied to an inkjet recording apparatus, and further to an inkjet recording apparatus in which these are combined, and similar effects can be achieved.

Further, according to the present invention, the recording means is such that the recording means is a replaceable ink jet cartridge (head cartridge) in which the recording head portion and the ink storage portion are integrated, or the recording means is a permanent type. It can be similarly applied to the case where various forms are taken, and the same effect can be achieved.

The present invention can be applied to an ink jet recording apparatus that uses a recording means (recording head) using an electromechanical transducer such as a piezo element, but among them, thermal energy is used. Then, an excellent effect is brought about in an ink jet recording apparatus which uses a recording means of a method of ejecting ink. This is because such a system can achieve high density recording and high definition recording.

[0040]

As is apparent from the above description, according to the invention of claim 1, in the ink jet recording apparatus for recording by ejecting ink from the recording means to the recording material, the defective ink ejection of the recording means is recovered. Alternatively, a negative pressure suction type plunger pump is provided in the recovery mechanism for prevention, and the vicinity of the outer circumference of the piston for reciprocating the inside of the cylinder of the plunger pump to generate negative pressure is deformed during standby other than suction operation. Since it is configured, by deforming the vicinity of the outer circumference of the piston during standby other than the suction operation, it is possible to prevent sticking due to thickening of ink at the contact portion between the piston and the cylinder when left for a long period of time. It is possible to improve the reliability of the product and simplify the recording device by reducing the driving force required to start the plunger pump. An ink jet recording apparatus is provided.

According to the inventions of claims 2 to 8, in addition to the structure of claim 1, a projection is provided on a part of the member inside the plunger pump, and the projection is applied to substantially the entire circumference of the piston. A structure that deforms the vicinity of the outer circumference of the piston by contacting, a member inside the plunger pump is a fixing member for preventing deformation of the seal member due to negative pressure, and a protrusion on a part of the inner surface of the cylinder of the plunger pump Is provided, the protrusion is brought into contact with substantially the entire circumference of the piston to deform the vicinity of the outer periphery of the piston, a part of the piston is thinned out, and the protrusion contacts a part of the vicinity of the outer periphery of the piston. The contact area with the inner peripheral surface of the cylinder is reduced by the contacting structure, the structure in which a protrusion that contacts the protrusion is provided on a part of the piston, or the deformation near the outer periphery of the piston. With this configuration, the vicinity of the outer circumference of the piston is deformed more efficiently during standby other than the suction operation, so that sticking due to ink thickening at the contact portion between the piston and the cylinder when left for a long time can be prevented. (EN) Provided is an inkjet recording apparatus capable of improving the reliability of the recording apparatus as a product and simplifying the recording apparatus by reducing the driving force required for starting the plunger pump.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of an inkjet recording apparatus suitable for applying the present invention.

FIG. 2 is a schematic vertical sectional view showing a bearing engaging portion between a carriage and a lead screw in FIG.

FIG. 3 is a partial perspective view schematically showing the structure of an ink ejection portion of the recording means in FIG.

FIG. 4 is an exploded perspective view schematically showing a driving force transmission mechanism provided at a left end portion of the lead screw in FIG.

FIG. 5 is a schematic perspective view of the recovery mechanism in FIG.

FIG. 6 is a schematic vertical sectional view showing a first embodiment of a negative pressure suction type plunger pump used in the recovery mechanism of the inkjet recording apparatus according to the present invention.

FIG. 7 is a schematic vertical sectional view showing a second embodiment of the negative pressure suction type plunger pump used in the recovery mechanism of the inkjet recording apparatus according to the present invention.

FIG. 8 is a schematic longitudinal sectional view showing a piston of a third embodiment of a negative pressure suction type plunger pump used in the recovery mechanism of the ink jet recording apparatus according to the present invention.

FIG. 9 is a schematic longitudinal sectional view showing a piston of a fourth embodiment of a negative pressure suction type plunger pump used in a recovery mechanism of an inkjet recording apparatus according to the present invention.

[Explanation of symbols]

 1 Chassis 2 Guide Rail 3 Recording Material 4 Conveying Roller 5 Paper Feed Motor 7 Ejecting Roller 8 Pinch Roller 13 Lead Screw 20 Head Cartridge 21 Recording Means (Recording Head) 22 Ink Tank 23 Carriage 24 Lead Screw Gear 25 Carriage Motor 27 Guide Groove (Guidance Article) 28 Lead Pin 30 Initial Lock 31 Clutch Plate 32 Clutch Gear 37 Control Gear 39 Recovery System Plate 41 Recovery Mechanism 42 Cap 43 Plunger Pump (Negative Pressure Suction Means) 103 Cylinder 103b Protrusion 104 Plunger 105 Piston 105a Thickening 105b Protrusion 110 Pump seal (seal member) 111 Pump washer (fixing member) 111a Protrusion 81 Discharge port surface 82 Discharge port 84 Liquid path 85 Electrothermal conversion body

Claims (10)

[Claims] 1. In an inkjet recording apparatus for recording by ejecting ink from a recording means to a recording material, a negative pressure suction type plunger pump is provided in a recovery mechanism for recovering or preventing defective ink ejection of the recording means. An ink jet recording apparatus, characterized in that the vicinity of the outer circumference of a piston for reciprocating in a cylinder of the plunger pump to generate a negative pressure is deformed during standby other than suction operation. 2. The plunger pump according to claim 1, wherein a projection is provided on a part of a member inside the plunger pump, and the projection is brought into contact with substantially the entire circumference of the piston to deform the vicinity of the outer circumference of the piston. Inkjet recording device. 3. The ink jet recording apparatus according to claim 2, wherein the member inside the plunger pump is a fixing member for preventing the sealing member from being deformed by negative pressure. 4. The protrusion is provided on a part of the inner surface of the cylinder of the plunger pump, and the protrusion is brought into contact with substantially the entire circumference of the piston to deform the vicinity of the outer circumference of the piston. Inkjet recording device. 5. The ink jet recording apparatus according to claim 1, wherein a part of the piston is thinned. 6. The ink jet recording apparatus according to claim 2, wherein the protrusion is in contact with a part of the piston in the vicinity of the outer periphery thereof. 7. The ink jet recording apparatus according to claim 2, wherein a protrusion that comes into contact with the protrusion is provided on a part of the piston. 8. The ink jet recording apparatus according to claim 1, wherein the deformation in the vicinity of the outer periphery of the piston reduces the contact area with the inner peripheral surface of the cylinder. 9. The inkjet recording apparatus according to claim 1, wherein the recording means is an inkjet recording means including an electrothermal converter that generates thermal energy used for ejecting ink. 10. The ink jet recording apparatus according to claim 9, 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.