JPH05193154A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To disperse load torque at the time of pressing so as to make a driving motor small in size, light in weight, and reduce the cost thereof, by changing at every tube a timing at a time that a pressure roller presses or releases each tube. CONSTITUTION:A tube pump 4 is provided as a recovering tube pump for sucking or pressurizing by deforming four tubes 3 communicating with an outlet 52 of each record head 1 with a pressure roller 7. A timing at a time that the pressure roller 7 presses each tube 3 or a timing at a time that the pressure roller 7 is released from the state pressing each tube 3 is varied at every tube 3. When a fill-in occurs at the outlet 52 of the record head 1, a sucking recovery operation of each record head 1 is performed at a non-recording position.

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 functions such as a printer, a copying machine, and a facsimile, or a recording device used as an output device of a composite type electronic device including a computer, a word processor, etc. An image is recorded on a recording material (recording medium) such as a plastic thin plate. The recording device can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type and the like depending on the recording type.

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 unit (generally mounted on a carriage) that moves along the material, and a predetermined amount of paper is fed (conveyed material to be recorded) after one line of recording is completed, After that, the operation of recording (main scanning) the image of the next row is repeated on the recording material that has stopped again, thereby recording the entire recording material. On the other hand, in a line type recording apparatus that records only by sub-scanning in the conveyance direction of the recording material, the recording material is set at a predetermined recording position and the
After recording for one line, the paper is fed by a predetermined amount (recording material is conveyed), and then the recording of the next row is collectively performed. Be done.

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 and
High-definition images can be recorded at high speed, plain paper can be recorded without requiring special processing, running costs are low, and the non-impact method reduces noise, and multicolor It has an advantage that it is easy to record a color image using ink. Above all, the line type apparatus using the line type recording means in which a large number of ejection openings are arranged in the paper width direction can further speed up the 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 (ejection 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 and processed paper (paper with punch holes for perforations, paper with perforations, paper of arbitrary shape, etc.) have been required to be used.

In the above ink jet recording apparatus,
A recovery pump is provided to maintain the normal ink ejection state of the recording unit (recording head) or to recover the normal ink ejection state when the ejection port is clogged. A recovery means is used that sucks ink from the ejection port by pressure. In addition, as the recovery pump, a tube pump that generates a negative pressure by utilizing a volume change in a flexible tube may be used. This tube pump has an advantage that it has a simple structure and can form a small-sized and lightweight pump at low cost.

12 and 13 are longitudinal sectional views showing the structure of the tube pump, FIG. 12 shows a state where the tube is crushed, and FIG. 13 shows a state where the tube is crushed. 12 and 13, first,
The opening of the cap 2 is brought into contact with the ejection port forming surface 51 of the recording head 1 to seal the ejection port 52. A tube 3 is connected to a through hole on the back surface of the cap 2, and the tube 3 extends to a tube pump 4. The tube pump 4 has a structure in which a guide roller 6 is rotatably supported by a pump base 5 and a pressure roller 7 is rotatably supported by the guide roller 6. That is, the shaft 8 of the pressure roller 7 for pressing the tube 3 is rotatably supported by the guide roller 6, and the shaft 9 of the guide roller 6 is rotatably supported.
It is rotatably supported by. The pump base 5 is provided with a groove 10 concentric with the shaft 9 of the guide roller 6, and the tube 3 is mounted in the groove 10. Further, the other end (downstream end) of the tube 3 has a waste ink processing member 1 for storing the ink sucked from the ejection port 52.
1 is arranged.

In the above structure, when the guide roller 6 is rotated in the direction of arrow a by a driving means (not shown), the pressure roller 7 on the guide roller 6 contacts the tube 3 at the X position in FIG. Press. The tube 3 is crushed until the inner space of the pressing portion becomes zero. When the guide roller 6 further rotates in the direction of arrow a from this state,
The pressure roller 7 rotates in the direction of arrow a (revolves) while rotating (driven) in the direction of arrow b while the tube 3 is crushed.
To do. Then, when the pressure roller 7 reaches the Y position shown in FIG. 13, the pressure roller 7 is temporarily stopped. At this time, the negative pressure generated by the volume change in the tube 3 crushed by the pressure roller 7 between the X position and the Y position acts on the ejection port 52 of the recording head 1, and the ink is sucked from the ejection port 52. To be sucked out. The sucked ink is sequentially sent to the waste ink processing member 11 side.

[0009]

When a plurality of recording heads 1 are used such as a color ink jet recording apparatus, a plurality of tubes 3 are provided corresponding to the number of recording heads 1 and guides are provided. A plurality of pressure rollers 7 are arranged on the roller 6 corresponding to the number of tubes 3. In the conventional ink jet recording apparatus using a plurality of recording heads, in order to give an equal suction force to each recording head 1, the distances from the recording heads 1 of the tubes 3 to the X position and the Y position are made equal. It is necessary to mount each pressurizing roller 7 on the guide roller 6 so as to enter and exit the tube 3 at the same timing.

However, in such a conventional configuration, in order to reduce the size and weight of the entire apparatus and reduce the cost, the drive source for pump drive and the drive source for paper feed or the drive source for carriage drive are the same. Drive source (motor)
In the case of the above, when the pressure roller 7 presses the tube 3 or when the pressure roller 7 is released from the state in which the pressure roller 7 presses the tube 3, the motor is out of step or the paper is fed due to torque fluctuation. The accuracy becomes unstable, or the unevenness of the recorded image occurs in the carriage scanning direction.
The quality of the recorded image sometimes deteriorated.

Further, in the conventional example, the pressure roller 7 presses the tubes 3 at the same timing for each tube 3. However, at such a timing of the conventional example, since the torque required for driving the pump is maximized at the moment when the pressure roller 7 presses the tube 3, if the number of tubes 3 and the number of pressure rollers 7 increase, The pump driving torque is increased by the amount of torque (MAX torque) generated at the moment when the increased number of pressurizing rollers 7 press the tubes 3, which requires a large motor and increases the cost. There were also challenges.

The present invention has been made in view of such prior arts, and an object of the present invention is to reduce the load torque when the pressure roller presses these tubes even when a plurality of tubes are used. By dispersing the drive motor, it is possible to reduce the size and weight of the drive motor and reduce the cost.Furthermore, by dispersing the torque fluctuation at the moment of pressing the tube or at the moment of releasing the tube from the pressed state, the torque change up to the maximum torque can be achieved. Can be performed gradually, and by eliminating the step-out of the motor, the pump drive source can be shared with the paper feed drive source and carriage drive source without causing unevenness in paper feed accuracy and unevenness in main scanning operation. It is an object of the present invention to provide an ink jet recording apparatus that can achieve the above-mentioned features and can reduce the size and weight of the recording apparatus and reduce the cost.

[0013]

SUMMARY OF THE INVENTION According to the present invention, in an ink jet recording apparatus for recording by ejecting ink from a recording means to a recording material, a plurality of tubes communicating with a discharge port of the recording means are deformed by a pressure roller. A recovery tube pump that sucks or pressurizes with each is provided, and the timing when the pressure roller presses each tube or the timing when the pressure roller releases from the state of pressing each tube is changed for each tube. With the configuration, the above object is achieved.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a configuration of a main part of an embodiment of an ink jet recording apparatus to which the present invention is applied. In the inkjet recording apparatus of FIG. 1, the recording material 12 is intermittently fed in a predetermined direction by a transport (sub-scanning) mechanism, and recording is performed while moving the recording means 1 in the direction intersecting with the direction (main scanning). It is configured.

In FIG. 1, a recording material 12 made of paper or a plastic thin plate is conveyed in the direction of arrow A by a paper feeding device (not shown) and fixed to a bottom plate 13 by an upper guide 14.
And is guided between the lower guide 15. Further, the recording material 12
Is guided in the traveling direction by both guides 14 and 15, and enters between a pair of transport rollers composed of a transport roller (sub-scanning roller) 16 and a transport driven roller (sub-scanning driven roller) 17. The pair of conveying rollers 16 and 17 are rotationally driven by a conveying motor 18. The recording material 12 is carried out onto the platen 19 fixed to the bottom plate 13 by drivingly controlling the pair of conveying rollers 16 and 17, and the platen 19 is conveyed.
While being supported by the paper ejection roller 20 and the paper ejection driven roller 21
The sheet reaches the space between the pair of paper discharge rollers, and the conveyance is temporarily stopped there. The paper discharge roller pairs 20 and 21 are driven by the carry motor 18 in synchronization with the carry roller pairs 16 and 17.

A paper discharge guide 22 is supported on the bottom plate 13, and the pair of paper discharge rollers 20 and 21 are used to form an arrow A.
The recording material 12 conveyed in the direction is ejected from the paper ejection guide 22.
It is discharged to the outside of the device body while being guided by. Aluminum particles having a grain size of 1000 to 2000 are adhered to the surfaces of the transport roller 16 and the paper discharge roller 20, and the driven rollers 17 and 21 are baked with chloroprene rubber. Therefore, it is possible to convey the recording material 12 with a high conveying force and with high accuracy.

A main scanning rail (guide rail) 2 is provided above the platen 19 in parallel with the axial direction of the transport roller 16.
3 is fixed. The recording means 1 is a carriage 24
The carriage 24 is mounted on the bearing portion 2 of the carriage 24.
The guide rail 23 is inserted through the guide rail 5, and is movable along the guide rail 23. The recording means 1 mounted on the carriage 24 in this embodiment is composed of a plurality of (four) recording means using different inks, and in the case of full color recording, for example, black, cyan, magenta, yellow. 4 colors of ink are used. Also,
Each recording means (recording head) 1 of the present embodiment is of a cartridge type in which an ink tank and a recording portion (ink ejection portion) are integrated, and each of them is positionably mounted on a carriage 24 in a replaceable manner.

An ink ejecting portion (ejection port forming surface) is provided below each recording means 1, and a plurality of ejection ports are formed in the ink ejecting portion in a direction intersecting with the moving direction of the carriage 24. Has been done. Each ink ejecting section is arranged so as to eject ink toward the platen 19 side through the opening at the bottom of the carriage 24.

The recording means (recording head) 1 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 1 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 means (recording head) 1.
In FIG. 2, a plurality of ejection openings 52 are formed at a predetermined pitch on the ejection opening formation surface 51 that faces the recording material 12 with a predetermined gap (for example, about 0.5 to 2.0 mm). Each liquid path 5 that connects the common liquid chamber 53 and each discharge port 52
Electrothermal converters (heat generating resistors, etc.) 55 for generating energy for ejecting ink are arranged along the wall surface of No. 4. In this example, the recording head 1 is mounted on the carriage 24 in such a positional relationship that the ejection ports 52 are arranged in a direction intersecting the moving direction (main scanning direction) of the carriage 24. In this way, the corresponding electrothermal converter 55 is driven (energized) based on the image signal or the ejection signal to cause the ink in the liquid path 54 to film-boil, and the pressure generated at that time causes the ink to be ejected from the ejection port 52. A recording unit (recording head) 1 is configured.

In FIG. 1, a carriage motor (main scanning motor) 26 as a drive source for reciprocating the carriage 24 is fixed to the main body of the apparatus (side plate thereof, etc.). A motor pulley 27 is fixed to the rotation shaft of the carriage motor 26 and can rotate integrally with the rotation shaft. An idler pulley 28 is axially supported on the opposite side of the motor pulley 27, and a main scanning belt (carriage drive belt) 29 is stretched between the motor pulley 27 and the idler pulley 28. The carriage 24 uses the carriage drive belt 29.
And is reciprocally driven by the rotation of the carriage motor 26.

A home position HP of the carriage 24 is set at a position outside the recording area (or the platen 19) within the movement range of the carriage 24. In the vicinity of the home position HP, a cap 2 made of a rubber-like elastic material capable of sealing (capping) the ejection port forming surface of each recording head 1 is arranged. Further, in the vicinity of the cap 2, the ejection port 52 of each recording head 1 is provided.
A recovery device 30 is provided for eliminating defective ejection due to clogging of the paper. The recovery device 30 is configured so that the ejection port forming surface 51 is closed by the cap 2 and each ejection port 5 is closed.
2 is configured to generate a negative pressure and suck out foreign matters such as bubbles, adhered ink, and dust from the ejection port 52 together with the ink.

A roller (not shown) is rotatably supported on the lower portion of the carriage 24, and the roller rolls on the upper surface of the recording material 12 on the platen 19 so that each recording head 1 The distance between the ejection port forming surface 51 and the recording surface of the recording material 12 is always regulated to be constant. Further, since the cap 2 is disposed near the home position HP of the carriage 24, the platen 19 cannot be extended to the home position HP. Therefore, when the carriage 24 moves toward the home position HP, the rollers of the carriage 24 are disengaged from the platen 19. Therefore, at a position outside the platen 19, the carriage 24 rides on a guide plate (not shown) provided in the recovery device 30 via the rollers.

During the recording operation, the carriage motor 26 moves the carriage 24 and the recording head 1 is driven in accordance with an image signal, so that the platen 19 is moved.
Ink is ejected onto the recording material 12 stopped above to form an image for one line (main scanning). When the recording for one line is completed, the pair of conveying rollers 16 and 17 are rotated by a predetermined amount to convey the recording material 12 by a predetermined amount (for example, an amount corresponding to the height of one line) (sub scanning), and the carriage 24 again. And the recording head 1 is driven to perform recording (main scanning) of the next row. Thereafter, by repeating these main scanning and sub scanning alternately, an image is recorded on the entire recording material 12.
Then, when the rear end of the recording material 12 is detected by a sensor (not shown) arranged at a predetermined position, the recording operation is ended, and the recording material 12 is rotated by rotation of the pair of discharge rollers 20 and 21.
Is discharged to the outside of the apparatus main body along the paper discharge guide 22.

Each of the four recording means 1 comprises an ink tank portion in which yellow, magenta, cyan and black inks are stored and an ink ejection portion (recording head portion) for ejecting these inks. The section is connected to each ink ejecting section. Then, in accordance with each color-separated image signal, the four color inks are ejected from each ink ejection section (recording head section), and these four colors are superposed to form a full-color image. Note that the recording material 12 is not only fed from the paper feeding device, but also when the operator causes the recording material to enter the abutting portion of the pair of discharge rollers 20 and 21 and reversely rotates the transport motor 18. A method (manual feeding) in which the sheet is once conveyed from the paper discharge side into the sheet feeding device and then fed from the sheet feeding device again can be adopted.

The cap 2 is a discharge port 52 of the recording means 1.
The inside of the nozzle is kept in a wet state to prevent the ejection port 52 from being clogged due to ink drying or ink sticking. In addition, the tube pump 4 (FIGS. 3 to 6) in the recovery device 30 connected to each cap 2 is
When the cap 2 is driven in a state where the ejection port forming surface 51 is closed, impurities such as bubbles, adhered ink, and dust generated inside the ejection port 52 are sucked and removed together with the ink, and ejected. It is to eliminate defects.
In the inkjet recording apparatus of FIG. 1, the ink sucking operation from the ejection ports 52 of the plurality (four in the illustrated example) of the recording heads 1 is configured to convert the rotational driving force into a negative pressure in the recovery device 30. Multiple (4 in the example shown)
A tube pump 4 having a tube 3 (see FIGS. 3 to 6)
By driving.

Between the recording area (platen 19) and the cap 2, a rubber-like material for wiping and removing foreign matters (adhered matters) such as ink droplets and dust adhered to the ejection port forming surface 51 of each recording head 1. A cleaning member 33 formed of an elastic blade is arranged. This cleaning member 33
Is held by a holder 34 and is driven by a drive source (not shown).
It is configured such that it can be driven between a protruding position where it can slide on the ejection port forming surface 51 and a retracted position which is separated from the ejection port forming surface 51.

FIG. 3 shows a tube pump 4 to which the present invention is applied.
4 is a schematic vertical sectional view showing an embodiment of the present invention, FIG. 4 is a bottom view taken along line 4-4 in FIG. 3, and FIG. 5 is line 5 in FIG.
FIG. 6 is a partial front view seen from −5, and FIG. 6 is a schematic vertical sectional view showing an operation of the tube pump 4 of FIG. 3. The tube pump 4 shown in FIGS. 3 to 6 includes the recording means (recording head) 1
Is a recovery tube pump that performs suction or pressurization by deforming a plurality of (four) tubes 3 communicating with the discharge port 52 of the pressurizing roller 7 when the pressurizing roller 7 presses each tube 3. Or the timing when the pressurizing roller 7 is released from the state of pressing the tubes 3 is different for each tube 3. Then, when the ejection port 52 of the recording head 1 is clogged (when there is a possibility of occurrence), each recording head 1 at the non-recording position (for example, the home position HP).
Suction recovery operation is performed.

3 to 6, at the non-recording position, the opening of the cap 2 is connected to the ejection port forming surface 5 of the recording means 1.
1, and the discharge port 52 is sealed. A flexible tube 3 is connected to a through hole formed in the back portion of the cap 2, and the tube 3 extends toward the tube pump 4 side.
The tube pump 4 includes a pump base 5 and guide rollers 6
Is rotatably supported, and a pressure roller 7 is rotatably supported on the guide roller 6. In the present embodiment, as shown in FIGS. 4 and 5, the cap 2, the tube 3, the pressure roller 7, and the axis of the pressure roller 7 correspond to the number (4) of the recording means (recording heads) 1. Four support structures are provided for each.

A detailed description will be given below. 3 to 6, the shaft 35 of the guide roller 6 is provided with a bearing 36,
It is rotatably attached to the pump base 5. An E-shaped retaining ring 37 is attached as a retainer for the bearing 36. The pressure roller 7 for pressing the tube 3 is rotatably supported by fitting a shaft 38 of the pressure roller 7 into a roller bearing 39. The roller bearing 39 is attached to the hole 42 formed in the guide roller 6 with the compression spring 41 attached to the vertical axis 40, and positioned and fixed by the E-shaped retaining ring 43. At this time, the pressure roller 7 is
A force in the direction of pressing the tube 3 is applied by the compression spring 41.

The positioning of the roller bearing 39 is performed by the positioning pin 44 provided on the roller bearing 39.
Is performed by being guided by the guide groove 45 provided in the guide roller 6 and by being guided by the guide hole 42 of the guide roller 6 on the vertical axis 40 described above. In this case, in order to make the space of the tube pump 4 as small as possible, as shown in FIG. 5, the heights of the positioning pins 44 are alternately changed so that the guide pins 45 overlap each other. There is.

A guide roller 6 is attached to the pump base 5.
An arcuate groove 48 concentric with the shaft 35 is formed. The pump base 5 is attached to the base 46 of the apparatus main body in such a posture that the opening of the arc-shaped groove 48 is on the lower side. The reason is that the pump base 5 is provided with a cover function and the pump operating portion is covered with the pump base 5 to prevent the user from touching the pump operating portion. This is to prevent foreign matter from entering the pump operating unit. The tube 3 is fixed while being sandwiched in tube fixing grooves 47 formed on the front side and the rear side of the guide roller 6 of the pump base 5. The end of the tube 3 on the downstream side (the side opposite to the cap 2) is connected to a waste ink processing member 11 for storing the ink sucked from the ejection port 52 by suction.

In FIG. 6, a gear 31 for driving the tube pump 4 is provided on the shaft 49. On the other hand, a driven gear 32 is fixed to the shaft 35 of the guide roller 6, and the drive gear 31 meshes with the driven gear 32. When the drive gear 31 is rotationally driven in the direction of arrow e,
The rotational driving force is transmitted to the driven gear 32, and the guide roller 6 is rotationally driven in the direction of arrow a. And
When the pressure roller 7 is in contact with the tube 3, the pressure roller 7 is also rotated (driven) in the direction of arrow b in FIG. The shaft 49 is equipped with a quinte 64 for preventing the drive gear 31 from coming off.

In the above structure, when the drive gear 31 is rotationally driven by the drive source (not shown), the guide roller 6 is rotationally driven in the arrow a direction via the driven gear 32. As the shaft 49 on which the drive gear 31 is provided, for example,
Conveying rollers 16 for conveying the recording material 12 (paper feeding)
It is possible to use the shaft shown in FIG. 1 or a shaft that rotates in synchronization with the shaft (a part of the transport system). Further, rotation of other rotating parts of the recording apparatus such as the drive system of the carriage 24 or rotation of the drive source can be used.

When the guide roller 6 rotates in the direction of the arrow a, the pressure roller 7 axially supported by the guide roller 6 is integrated with the tube fixing groove 47 on the recording head 1 side (upstream side) of the pump base 5. It contacts the formed roller guide portion 65. This state is indicated by the position Z in FIG. At this time, the pressure roller 7 is guided to the roller guide portion 65.
The arrow f is rotated while being driven (rotated) in the direction of the arrow b.
The pressure roller 7 moves to a position where the tube 3 is being pressed.

When the guide roller 6 further rotates in the direction of the arrow a, the pressure roller 7 presses the tube 3 while rotating (rotating) in the direction of the arrow b, and moves to the position X in FIG.
While moving to, the tube 3 is pressed and crushed until the tube inner space of the pressing portion becomes zero. When the pressure roller 7 moves (revolves) from the position Z to the position X, the pressure roller 7 is guided by the roller guide 65 while pressing and deforming the tube 3 to compress the compression spring 41 (FIG. 5). Move in the direction of the arrow (direction of arrow f). Therefore, the position Z
From the position to the position X, the drive torque of the tube pump 4 increases.

The tube fixing groove 47 has a shape in which the groove width increases near the roller guide portion 65. This is to prevent the reaction force of the tube 3 crushed by the pressure roller 7 from being transmitted to the pressure roller 7 side at the point where the pressure roller 7 starts to contact the tube 3. That is, as shown in FIG. 4, the groove width j of the tube fixing groove 47 near the roller guide portion 65 is larger than the width i when the tube 3 is pressed by the pressure roller 7. However, since the roller guide portion 65 has a function of guiding the pressure roller 7, the groove width j near the roller guide portion 65 is set so that the pressure roller 7 does not fall into the fixed groove 47. It is narrower than the thickness (width) of the pressure roller 7.

As the guide roller 6 rotates, the pressure roller 7
When is further rotated (revolved) from position X in the direction of arrow a,
The pressure roller 7 moves while rotating (spinning) following the direction of the arrow b while the tube 3 is crushed. And Figure 3
Pause at position Y in the middle. At this time, a negative pressure is generated at the ejection port 52 of the recording unit (recording head) 1 due to the volume change in the tube 3 crushed by the pressure roller 7 between the position X and the position Y, and the recording head 1 A suction operation is performed to suck ink from the ink. When the suction operation is completed and the guide roller 6 is further rotated in the direction of the arrow a, the pressure roller 7 has the roller guide portion 66 on the downstream side (the waste ink processing member 11 side).
And gradually separate from the tube 3 along. The movement of the pressure roller 7 at this time is substantially opposite to the movement when the tube 3 comes into contact with the tube 3, and the pressure roller 7 is released from the state in which the tube 3 is pressed. At this time, since the pressurizing roller 7 is released from the pressed state of the tube 7, a phenomenon in which the drive torque of the tube pump 4 instantaneously decreases occurs.

By the negative pressure suction operation described above, ink is sucked from the ejection port 52 of the recording head 1, and the sucked ink is sequentially passed through the tube 3 to the waste ink processing member 11.
And is stored in the waste ink processing member 11.
In addition, the series of operations described above, as shown in FIG.
The sensor protrusion 67 provided on the guide roller 6 is detected by passing through the sensor 68 provided on the pump base 5, and the pressure roller 7 is positioned based on the detection result.

Therefore, in the present embodiment, the timing when the plurality of pressure rollers 7 press the corresponding tubes 3 and / or the state where the plurality of pressure rollers 7 press the corresponding tubes 3 are released. The tube 3 is configured to have different timings. Next, a plurality of pressure rollers 7 (7 _a , 7 _b , 7 _c ,
A configuration will be described in which the timing when 7 _d ) presses each tube 3 and the time when the tube 3 is released from the pressed state are different.

In FIG. 5, the stopper portion (stopper portion of the vertical axis 40) of the roller bearing means 80 for axially supporting the pressure roller 7, that is, the E-shaped retaining ring 43 to the shaft 3 of the pressure roller 7.
The distance to the bearing center 8, the pressure roller 7 _a, 7 _b, 7
_c, a different value for each 7 _{d, i.e., h a <h b <h} c
<H _d is set. In this embodiment, it is all set to an outer diameter equal to the value of each pressure roller 7 _a to _7-d. Therefore, the distance H from the stopper portion of the roller bearing means 80 of each pressure roller 7 to the tip of the pressure roller 7
Is different for each pressure roller 7. That is, in this embodiment, as shown in FIG. 5, the press roller 7 _a, 7 _b,
Against 7 _c, 7 _d, the distance from the stopper portion to the pressure roller tip is _{H a <H b <H c} H7 d.

FIG. 7 is a schematic partial enlarged view showing respective operation timings when the plurality of pressure rollers 7 enter the roller guide portion 65. In FIG. 7, each tube 3
Is t, the gap between the pressure roller 7 and the roller guide portion 65 is set to 2t or less in order that the pressure roller 7 presses the tube 3 to make the inner volume of the tube zero. There is a need. Further, since the tube 3 is crushed to have twice or less the wall thickness, a rapid reaction force acts on the pressure roller 7.

In FIG. 7, lines D _a , D _b , D _c , D _d
Indicates the locus of the tip of each pressure roller when a plurality of pressure rollers 7 _a , 7 _b , 7 _c , 7 _d move in the direction of arrow a, and points E _a , E _b , E _c , E _d is each trajectory D _a , D _b , D _c ,
The intersection of D _d and the line (trajectory) F with the gap 2t from the roller guide portion 65 is shown. These intersections E _a , E _b ,
As indicated by E _c and E _d , the pressure rollers 7 _a , 7 _b and 7
The timing at which _c and 7 _d receive the reaction force from the tube 3 (timing at which the maximum reaction force starts) is different for each pressure roller 7. Therefore, each pressure roller 7 _a
7 _d also be helped increase in pump driving torque generated by receiving the reaction force from the tube 3, the pressure roller 7 _a to 7-
It will be distributed for each _d .

[0044] Further, the press roller 7 _a to _7-d is tube 3
Timing (point) to release from pressing state
Similarly, the pressure roller is different for each pressurizing roller. Therefore, it is possible to disperse the fluctuation of the pump drive torque generated when the tube pressure is released. In this way, since the peak point of torque fluctuation is different (shifted) for each tube 3, it is possible to significantly reduce the maximum load torque applied to the drive motor as compared with the case where the peak points of torque fluctuation are the same. .. Further, it becomes possible to gradually change the torque until the pump drive torque becomes maximum.

It should be noted that in order to make the suction strength acting on the ejection port 52 the same in all the recording heads 1, the cap 2
From the pressure roller 7 to the point where the pressure roller 7 presses and deforms the tube 3 to start the pump operation (intersection points E _{a to} E _{d in} FIG. 7) are set to be the same for all tubes 3. There is.

According to the embodiment described above, when the plurality of tubes 3 communicating with the ejection ports 52 of the plurality of recording heads 1 are crushed and deformed by the pressure roller 7, the ink is sucked from each recording head 1. The timing when the pressure roller 7 presses each tube 3 and the timing when the pressure roller 7 is released from the state of pressing each tube 3 are changed (shifted) for each tube 3. Even when the ink is sucked from the plurality of recording heads 1 by the plurality of tubes 3, the load torque when the pressure roller 7 presses the tubes 3 is dispersed to reduce the size and weight of the drive motor and reduce the cost. The maximum negative load can be obtained by dispersing the torque fluctuation at the moment when the tube 7 is pressed or when the tube 3 is released from the pressed state. It is possible to gradually change the torque up to the torque, and by eliminating the step-out of the motor, the drive source of the tube pump 4 is driven to feed the paper without causing unevenness in the paper feeding accuracy or unevenness in the main scanning operation. It is also possible to use it as a power source and a carriage drive source, which makes it possible to reduce the size and weight of the recording apparatus and reduce the cost.

In the above-described embodiment, as a method for shifting the timing when each pressure roller 7 presses the tube 3 and the timing when the pressure roller 7 is released from the pressed state, the pressure is applied from the stopper portion of the roller bearing means 80. Pressure roller 7 _a ~
7 is adopted a method of changing the distance h _a to h _d until the bearing center axis 38 of _d, however, as shown in FIG. 8,
The plurality of pressure rollers 7 _a , 7 _b and their roller bearing means 80 have the same size, and the guide roller 6 for supporting them.
The contact portion of the shape may be configured to change each pressing roller 7 _a, 7 _b. As shown in FIG. 8, the pressure roller 7 _a
By increasing the abutting portions of the side by a distance G, be shorter by G than the distance H _b of the distance H _a to the tip portion of the pressurizing roller 7 _a to the distal end of the pressure roller 7 _b it can. That is, it is possible to achieve the same effects as the above-described embodiment while maintaining the relationship such as H _b = H _a + G.

Further, as shown in FIG. 9, the pressing roller 7 _a and the pressing roller 7 _b have the same abutting portion of the guide roller 6 and the roller bearing means 80, and the pressing roller 7 _a and 7 _b have the same size and shape.
_a, 7 by varying the outer diameter of _b, it is possible to achieve the same effects as those in the previous embodiment. That is,
As shown in FIG. 9, if the radius of the pressure roller 7 _a is J _a , the radius of the pressure roller 7 _b is J _b, and J _b −J _a = G, then the case of the embodiment of FIG. Similarly, the same effect can be achieved while maintaining the relationship of H _b = H _a + G.

[0049] Further, the pressure roller _{7 a, 7 b, 7 c} , 7 d
10, the abutting portions of the roller bearing means 80 and the guide roller 6 have the same shape, and as shown in FIG. 10, the roller guide portion 65 (or the roller guide portion 65) (or the roller guide portion) is formed from the center of the arc-shaped roller guide portion 48 of the pump base 5. The distance to the part 66) m _a ,
By changing m _b , m _c , and m _d , it is possible to achieve the same effects as those in the above-described embodiments.
That is, as shown in FIG. 10, 65 _a a roller guide portion for pressure roller 7 _a, 65 a roller guide portion for pressing roller 7 _{b b,} the roller guide portion for pressing roller 7 _c 6
5 _c, the roller guide portion for pressure roller 7 _d and 65 _d. Then, from the center of the arc-shaped roller guide portion 48, the roller guide portion _{65 a, 65 b, 65 c} , 65 a distance to each _d m _a, m _b, m _c, and m _d, for example, m _a
<M _b <m _c <roller guide portion 6 so as to be in the relationship of m _d
Each pressure roller 7 _a by forming a 5, 7 _b, 7 _c,
The timing when 7 _d presses the tube 3 can be changed (shifted).

[0050] Furthermore, as shown in FIG. 11, the roller guide portion 65 is the same size and shape in each pressure roller 7 _a to _7-d, by shifting the relative position of each pressure roller 7 _a to _7-d Also, it is possible to achieve the same effect as that of each of the above-described embodiments. That is, as shown in FIG. 11, the pressure roller 7 from the center of the shaft 35 of the guide roller 6 _a to _7-d
The distance to the tip is the same size (dimension N), and the pressure roller _{7 a, 7 b, 7 c} , 7 ( center of the shaft 38) the center of rotation of _{d K a, K b, K} c, K _d is displaced in a predetermined relative positional relationship. Even with such a configuration, each pressure roller 7
_a to _7-d can be different timings when pressing the tube 3 (deviated).

In the above embodiment, the ink jet recording apparatus using a plurality of recording means 1 for recording with different color inks has been described as an example. However, the present invention is not limited to a plurality of recording means and a plurality of inks. If the inkjet recording device is equipped with a suction tube, it is similarly applied to other devices such as an inkjet recording device for gradation recording using a plurality of recording means for recording with inks of the same color but different densities. It is possible to achieve the same effect.

Further, in the above-mentioned embodiment, the serial type recording apparatus in which the recording means 1 is mounted on the carriage 24 has been described as an example, but the present invention is the whole or a part of the recording material 12 in the width direction. The present invention can be similarly applied to a line type recording apparatus which uses a line type recording means having a length to cover the above and performs recording only by sub-scanning, and similar effects can be obtained. Further, the recording unit 1 is a cartridge type in which an ink ejection unit (recording head) and an ink tank unit are integrated, or an ink ejection unit (recording head unit) and an ink tank unit are separately provided. The same effects can be achieved regardless of the structure of the recording means, such as those connected by means of the like.

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.

Regarding 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 continuous type, but especially 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 Unexamined Patent Publication No. 123670/1984, which 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 are disclosed. 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 surely and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording 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, etc., 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 and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. 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 that 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 described 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 the form of the ink jet recording apparatus according to the present invention, besides 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 transmission / reception function. It may be in the form of the above.

[0063]

As is apparent from the above description, according to the present invention, in an ink jet recording apparatus for recording by ejecting ink from the recording means to the recording material, a plurality of tubes communicating with the ejection ports of the recording means are provided. A recovery tube pump that performs suction or pressurization by deforming with a pressure roller is provided, and the timing when the pressure roller presses each tube or when the pressure roller is released from the state of pressing each tube. Since the timing of is changed for each tube, even when using multiple tubes, the load torque when the pressure roller presses these tubes is dispersed to reduce the size and weight of the drive motor and reduce the cost. The torque at the moment of pressing the tube or at the moment of releasing the tube from the pressed state By distributing the dynamic, it can be carried out gradually torque change up torque,
By eliminating the step-out of the motor, the pump drive source can be shared with the paper feed drive source and carriage drive source without causing unevenness in the paper feed accuracy and unevenness in the main scanning operation, and the recording device is compact and lightweight. Provided is an ink jet recording apparatus which can achieve cost reduction and cost reduction.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a main configuration 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 vertical cross-sectional view showing the configuration of an embodiment of the tube pump according to the present invention.

FIG. 4 is a bottom view of the tube pump taken along line 4-4 in FIG.

5 is a partial front view of the tube pump taken along line 5-5 in FIG.

FIG. 6 is a schematic partially cutaway side view for explaining the operation of the tube pump of FIG.

FIG. 7 is a schematic explanatory view showing details of the tube pressing operation of the pressure roller in the embodiment of the tube pump to which the present invention is applied.

FIG. 8 is a partial front view showing a main part configuration of another embodiment of the tube pump to which the present invention is applied.

FIG. 9 is a partial front view showing a main part configuration of still another embodiment of the tube pump to which the present invention is applied.

FIG. 10 is a partially enlarged explanatory view showing a main part configuration of another embodiment of the tube pump to which the present invention is applied.

FIG. 11 is a partially enlarged explanatory view showing a main part configuration of still another embodiment of the tube pump to which the present invention is applied.

FIG. 12 is a schematic side view showing a state at the time of starting tube pressing of the tube pump for suction recovery.

FIG. 13 is a schematic side view showing a state of the tube pump for suction recovery when the tube pressing is completed.

[Explanation of symbols]

 1 Recording Means (Recording Head) 2 Cap 3 Tube 4 Tube Pump 5 Pump Base 6 Guide Roller 7 Pressurizing Roller 11 Waste Ink Treatment Member 12 Recording Material 16 Conveying Roller 18 Conveying Motor 19 Platen 20 Paper Ejecting Roller 23 Guide Rail 24 Carriage 26 Carriage Motor 30 Recovery Device 31 Drive Gear 32 Driven Gear 35 Shaft (Guide Roller) 38 Shaft (Pressure Roller) 39 Roller Bearing 40 Vertical Axis (Roller Bearing Means) 41 Compression Spring 42 Fitting Hole (Vertical Axis) 43 E Type Retaining ring (stopper part) 44 Positioning pin 46 Device body base 47 Tube fixing groove 48 Arcuate groove 49 Pump drive shaft 51 Discharge port forming surface 52 Discharge port 55 Electrothermal converter 65 Coro guide part 66 Coro guide part 68 Sensor 80 Roller bearing means A Recording material conveying direction Rotation direction of guide roller b Rotation direction of pressure roller E Point at which pressure roller crushes tube H Distance to tip of pressure roller in roller bearing means m Distance from center of guide roller of roller guide section K Pressure roller Rotation center

Claims (3)

[Claims] 1. In an ink jet recording apparatus for recording by ejecting ink from a recording means to a recording material, suction or pressurization is performed by deforming a plurality of tubes communicating with a discharge port of the recording means with pressure rollers. Inkjet recording characterized by providing a tube pump for recovery and changing the timing when the pressure roller presses each tube or the timing when the pressure roller releases from the state of pressing each tube for each tube apparatus. 2. 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 for ejecting ink. 3. The ink jet recording apparatus according to claim 2, 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. ..