JP2722289B2 - Ink jet recording apparatus and recovery apparatus for the recording apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is an ink jet recording apparatus 及 for recording by discharging ink from recording means to a recording material
And a recovery device used for the recording 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 composite electronic device or a workstation including a computer and a word processor, etc., is based on image information. It is configured to record an image on a recording material (recording medium) such as a plastic thin plate. The recording apparatus can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type and the like according to a recording method.

In a serial type recording apparatus employing a serial scanning system in which a main scanning is performed in a direction crossing a conveying direction (sub-scanning direction) of a recording material, the recording material is set at a predetermined recording position, and then the recording is performed. An image is recorded (main scanning) by recording means (generally mounted on a carriage) moving along the material, and after a recording of one line is completed, a predetermined amount of paper is fed (conveyance of the recording material), Thereafter, the operation of recording (main scanning) the image of the next row on the recording material stopped again is repeated, so that the recording of the entire recording material is performed. On the other hand, in a line type recording apparatus that records only by sub-scanning in the transport direction of the recording material, the recording material is set at a predetermined recording position,
After the recording for the row is performed, a predetermined amount of paper feed (conveyance of the recording material) is performed, and further, the operation of collectively recording the next row is repeated, thereby recording the entire recording material. It is.

Among the above recording apparatuses, an ink jet recording apparatus (ink jet recording apparatus) performs recording by discharging ink from a recording means (recording head) onto a recording material. Easy,
High-definition images can be recorded at high speed, recording can be performed on plain paper without special processing, running costs are low, and the non-impact method reduces noise, and It has advantages such as easy recording of a color image using ink. Above all, a line-type apparatus using a line-type recording means in which a large number of discharge ports are arranged in the paper width direction can further increase the recording speed.

[0005] In particular, an ink jet type recording means (recording head) for discharging ink by using thermal energy,
Through a semiconductor manufacturing process such as etching, vapor deposition, sputtering, etc., an electrothermal converter, an electrode,
By forming the liquid path wall, the top plate, and the like, it is possible to easily manufacture a device having a high-density liquid path arrangement (discharge 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 plates (OHP
Etc.), thin paper and processed paper (paper with perforated holes for perforation, perforated paper, paper of any shape, etc.) have come to be required.

In the above ink jet recording apparatus,
A recovery pump is provided to maintain a normal ink ejection state of the recording means (recording head), or to eliminate clogging of the ejection openings and to restore a normal ink ejection state when clogging occurs. Then, a recovery means (recovery device) for sucking ink from the discharge port by the negative pressure of the pump is used. Further, a tube pump that generates a negative pressure by utilizing a change in volume in a flexible tube may be used as the recovery pump. This tube pump has the advantage that the structure is simple, and a low-cost, small-sized and light-weight pump can be constructed.

FIGS. 8 and 9 are longitudinal sectional views showing the structure of a conventional tube pump. FIG. 8 shows a state where the crushing of the tube is started, and FIG. 9 shows a state where the crushing of the tube is completed. 8 and 9, 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 pump base 5
The guide roller 6 is rotatably supported, and a pressure roller 7 is rotatably supported on 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 by the pump base 5. The pump base 5 is formed with a groove 10 concentric with the shaft 9 of the guide roller 6, and the tube 3 is mounted in the groove 10. At the other end (downstream end) of the tube 3, a waste ink processing member 11 for storing ink sucked from the discharge port 52 is disposed.

In the above configuration, 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 is moved to the X position in FIG.
And presses the tube 3. The tube 3 is crushed until the internal 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 (revolves) in the direction of arrow a while rotating (following rotation) in the direction of arrow b with the tube 3 crushed. Then, when the pressure roller 7 comes to the Y position shown in FIG. At this time, a negative pressure generated by a volume change in the tube 3 crushed by the pressure roller 7 between the X position and the Y position acts on the discharge port 52 of the recording head 1,
Ink is sucked (sucked out) from the ejection port 52.
The sucked ink is sequentially sent to the waste ink processing member 11 side.

[0009]

However, in the above conventional example, when another driving source such as a driving source for conveying a recording material is used as a pump driving source, the driving direction of the other driving source is correct. May use both inversion and inversion,
When the guide roller 6 in FIG. 8 is driven in the reverse rotation direction indicated by the arrow f, the ink discharged from the recording head 1 by suction during the forward rotation drive and the waste ink processing member 11
If the ink that has not reached the inside of the tube 3 remains in the tube 3, a phenomenon occurs in which the ink flows backward to the cap 2 side, and the ink overflows from the cap 2 or the waste ink is formed on the discharge port forming surface in the capping state. However, there is a problem that ink is adhered, or a waste ink is mixed into the ejection port, resulting in a recording failure.

As a countermeasure against the above-mentioned inconvenience, after the suction operation,
In order to move the sucked ink toward the waste ink processing member 11 as much as possible, there is a method in which the guide roller 6 is rotated in the direction of arrow a in a non-capping state. However, in this method, the waste ink processing member 11 is
When the guide roller 6 is disposed at a position away from the guide roller 6, it is necessary to rotate the guide roller 6 in the direction of the arrow a considerably much.
The disadvantage is that the recovery operation becomes very long. In addition, if a dedicated driving source is used as the driving source of the tube pump 4 and the rotation direction of the driving source is limited to one direction, the backflow phenomenon of the ink can be solved, but the cost increases and the apparatus becomes larger. There was an inconvenience.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned disadvantages of the related art, and an object of the present invention is to prevent the backflow of ink with a simple structure, to improve the image quality, and to provide a reverse pump. An object of the present invention is to provide an ink jet recording apparatus provided with a suction pump for recovering discharge performance, which can improve the durability of a tube and the reliability of a pump by eliminating rotation.

[0012]

SUMMARY OF THE INVENTION The present invention relates to an ink jet recording apparatus for performing recording by discharging ink from a recording means to a recording material and a recovery apparatus used for the recording apparatus.
A tube pump that generates a negative pressure for recovering the discharge port by deforming a tube communicating with the discharge port of the recording unit with a pressure roller, and generates a driving force for driving the tube pump. A one-way clutch provided between the drive source and the tube pump and the drive source, for transmitting the drive force from the drive source only in a direction in which a negative pressure is applied to the discharge port with respect to the tube pump; The above object is achieved by adopting a configuration having the following.

According to another aspect of the present invention, in addition to the above configuration, a transport roller is disposed between the drive source and the tube pump, a clutch spring is wound around the transport roller shaft, and one end of the clutch spring is connected to the transport roller shaft. When the transfer roller rotates in a direction that generates a negative pressure at the discharge port, the clutch spring is tightened to transmit the driving force to the tube pump, and the transfer roller rotates in the opposite direction. In this case, the above-described object is achieved more efficiently by adopting a configuration in which the clutch spring is loosened and the driving force is not transmitted to the tube pump.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an essential configuration of an embodiment of an ink jet recording apparatus to which the present invention is applied. The ink jet recording apparatus shown in FIG. 1 intermittently feeds a recording material 12 in a predetermined direction by a transport (sub-scanning) mechanism, and performs recording while moving (main scanning) the recording unit 1 in a direction crossing the direction. It is configured.

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

A paper discharge guide 22 is supported on the bottom plate 13, and is driven by an arrow A by the paper discharge roller pair 20, 21.
The recording material 12 conveyed in the direction
Is discharged out of the apparatus main body while being guided by. The transport roller 16 and the paper discharge roller 20 have aluminum particles having a particle size of 1000 to 2000 adhered to their surfaces, and chloroprene rubber is baked on each of the driven rollers 17 and 21. Therefore, the recording material 12 can be conveyed with a high conveying force and with high accuracy.

A main scanning rail (guide rail) 2 is provided on the upper rear side of the platen 19 in parallel with the axial direction of the transport roller 16.
3 is fixed. The recording means 1 includes a carriage 24
The carriage 24 is mounted on its bearing 2
The guide rail 23 is inserted through 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. In the case of full-color recording, for example, black, cyan, magenta, yellow 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 section (ink ejection section) are integrated, and each is positioned and mounted on a carriage 24 in a replaceable manner.

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

The recording means (recording head) 1 is an ink jet recording means for discharging ink using thermal energy, and is provided with an electrothermal converter for generating thermal energy. Further, the recording head 1 includes:
The recording is performed by discharging ink from the discharge ports by utilizing a pressure change generated by growth and shrinkage of bubbles caused by film boiling caused by the heat energy applied by the electrothermal transducer.

FIG. 2 is a partial perspective view schematically showing the structure of the ink ejection section of the recording means (recording head) 1.
In FIG. 2, a plurality of discharge ports 52 are formed at a predetermined pitch on a discharge port forming surface 51 facing the recording material 12 with a predetermined gap (for example, about 0.5 to 2.0 mm). And each liquid path 5 that communicates the common liquid chamber 53 and each discharge port 52.
An electrothermal converter (heat generating resistor or the like) 55 for generating energy for ink ejection is provided along the wall surface of No. 4. In this example, the recording head 1 is mounted on the carriage 24 in such a manner that the ejection openings 52 are arranged in a direction intersecting with the moving direction (main scanning direction) of the carriage 24. In this manner, the corresponding electrothermal transducer 55 is driven (energized) based on the image signal or the ejection signal to cause the ink in the liquid passage 54 to boil, and the ink is ejected from the ejection port 52 by the pressure generated at that time. Recording means (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 apparatus main body (a side plate thereof). A motor pulley 27 is fixed to a rotation shaft of the carriage motor 26 and can rotate integrally with the rotation shaft. An idler pulley 28 is 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. Carriage 2
The carriage 4 is coupled to the carriage drive belt 29, and is reciprocated by the rotation of the carriage motor 26.

A home position HP of the carriage 24 is set at a position within the moving range of the carriage 24 and outside the recording area (or the platen 19). In the vicinity of the home position HP, a rubber-like elastic material cap 2 capable of sealing (capping) the ejection port forming surface of each recording head 1 is provided. In the vicinity of the cap 2, the ejection openings 52 of each recording head 1 are provided.
There is provided a recovery device 30 for resolving a discharge failure due to clogging or the like. The recovery device 30 is configured such that each of the discharge ports 5
2 is configured to generate a negative pressure to suck out foreign matter such as air bubbles, fixed ink, dust, etc., together with the ink from the discharge port 52.

In the ink jet recording apparatus shown in FIG. 1, the operation of sucking ink from the ejection port 52 is performed by the recovery device 30.
This is performed by driving a tube pump 4 (FIGS. 3 and 4) configured to convert the rotational driving force into a negative pressure. The tube pump 4 is configured to be rotationally driven by a rotational driving force of the transport roller 16 via a one-way clutch (FIG. 3) and gears 31 and 32. The tube pump 4 will be described later with reference to FIGS.

A roller (not shown) is rotatably supported at the lower part 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 is rotated. 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 provided 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 in the direction of the home position HP, the rollers of the carriage 24 come off the platen 19. Therefore, at a position off the platen 19, the carriage 24 rides on a guide plate (not shown) provided on the recovery device 30 via the rollers.

In the recording operation, the carriage 24 is moved by the carriage motor 26 and the recording head 1 is driven in accordance with the 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 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-scan), and the carriage 24 is returned again. Then, the recording head 1 is driven to perform recording (main scanning) of the next row. Hereinafter, an image is recorded on the entire recording material 12 by alternately repeating the main scanning and the sub-scanning.
Then, when the trailing end of the recording material 12 is detected by a sensor (not shown) arranged at a predetermined position, the recording operation is terminated, and the rotation of the discharge roller pair 20, 21 causes the recording material 12 to rotate.
Along the paper discharge guide 22 to the outside of the apparatus main body.

Each of the four recording means 1 comprises an ink tank section in which yellow, magenta, cyan, and black inks are stored, and an ink discharge section (recording head section) for discharging these inks. The unit is connected to each ink ejection unit. The four colors of ink are ejected from each ink ejection unit (recording head unit) in accordance with each color-separated image signal, and these four colors are overlapped to form a full-color image. The recording material 12 is not only fed from the paper feeding device, but also allows the operator to cause the recording material to enter the abutting portion of the pair of discharge rollers 20 and 21 and to rotate the transport motor 18 in the reverse direction. A method (manual feed) in which the paper is once conveyed from the paper discharge side into the paper feeding device and then fed again from the paper feeding device is also adopted.

The cap 2 is provided at the discharge port 52 of the recording means 1.
Is kept wet to prevent clogging of the discharge port 52 due to ink drying or ink fixation. The tube pump 4 (FIGS. 3 and 4) in the recovery device 30 connected to each cap 2 is connected to each cap 2, and the discharge port forming surface 5 is connected to each cap 2.
By driving the nozzle 1 in a sealed state, impurities such as air bubbles, fixed ink, dust and the like generated inside the discharge port 52 are sucked and removed together with the ink, and the discharge failure is eliminated.

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

FIG. 3 is a plan view of the tube pump according to one embodiment of the present invention, FIG. 4 is a longitudinal sectional view of the tube pump of FIG. 3, and FIG. 5 is an operation of the tube pump of FIGS. 6 is a longitudinal sectional view showing FIG.
FIG. 7 is a partial cross-sectional view taken along line -6 in FIG.
FIG. 7 is a front view of the one-way clutch as viewed from 7. When clogging occurs or is likely to occur in the ejection port 52 of the recording unit (recording head) 1, the suction recovery operation is performed at the non-recording position (normally the home position HP).

3 to 5, in the non-printing position, the opening of the cap 2 is
1 and the outlet 52 is sealed. A flexible tube 3 is connected to a through hole formed in the back of the cap 2, and the tube 3 extends toward the tube pump 4.
The tube pump 4 is provided with guide rollers 6 on a pump base 5.
Is rotatably supported, and a pressure roller 7 is rotatably supported by the guide roller 6. In this embodiment, as shown in FIG. 3, the cap 2, the tube 3, the pressure roller 7, the support structure of the pressure roller 7, and the like correspond to the number (four) of the recording means (recording heads) 1. Are provided four each.

Hereinafter, a specific description will be given. In FIGS. 3 to 6, the shaft 35 of the guide roller 6 is
It is rotatably attached to the pump base 5. An E-shaped retaining ring 37 is mounted as a stopper for the bearing 36. The pressure roller 7 for pressing the tube 3 is rotatably supported by fitting a shaft 38 to a roller bearing 39. The roller bearing 39 is attached to a hole 42 formed in the guide roller 6 with a compression spring 41 attached to a longitudinal axis 40, and is positioned and fixed by an E-shaped retaining ring 43. At this time, the pressure roller 7
The compression spring 41 applies a force in the direction of pressing the tube 3.

The positioning of the roller bearing 39 is performed by positioning pins 44 provided on the roller bearing 39.
Is guided by the guide groove 45 provided in the guide roller 6 and the above-described longitudinal axis 40 is guided by the guide hole 42 of the guide roller 6. In this case, in order to make the space of the tube pump 4 as small as possible, as shown in FIG. 6, a configuration is adopted in which the heights of the positioning pins 44 are alternately changed so as to overlap in the respective guide grooves 45. I have.

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

3, 5 and 5, a coil-shaped clutch spring 61 and the gear (drive gear) 31 are mounted on a shaft 49 at the end of the transport roller 16 (FIG. 1) in a fitted state. Have been. The drive gear 31 is rotatably supported by a shaft 49, and the clutch spring 61 is connected to the protrusion 6 of the drive gear 31.
2 regulates the thrust direction. The inner diameter of the clutch spring 61 is smaller than the outer diameter of the shaft 49, and has an appropriate amount of interference. When the transport roller 16 rotates in the direction of the arrow e, the clutch spring 61 acts on the shaft 49 in the tightening direction and rotates together with the transport roller 16 in the direction of the arrow e. In this case, the end of the clutch spring 61 (the portion bent in an L-shape as shown in FIG. 7) abuts against the stopper 63 of the drive gear 31 so that the transport roller 1
6 is transmitted to the drive gear 31. This rotational driving force is transmitted to a gear (a driven gear fixed to the shaft 35 of the guide roller 6) 32 meshing with the driving gear 31, and the pressure roller 7 is moved in the direction of the arrow a in FIGS. (The normal rotation direction).

On the other hand, when the transport roller 16 rotates in the direction of arrow k, the clutch spring 61 acts on the shaft 49 of the transport roller 16 in the slack direction. At this time, the torque at which the transport roller 16 and the clutch spring 61 slip is not zero, and there is a slight idling torque. This idling torque is a torque when the shaft 49 starts slipping with respect to the clutch spring 61 when rotating in the loosening direction. Therefore, when the transport roller 16 rotates in the direction of arrow k, if the torque for rotating the tube pump 4 in the reverse direction (rotation in the direction opposite to the arrow a in FIGS. 4 and 5) is larger than the idling torque, the clutch spring As the shaft 61 and the shaft 49 slip, the rotational driving force of the transport roller 16 is not transmitted to the drive gear 31, and therefore, the reverse driving force is not transmitted to the pressure roller 7. In this embodiment, the torque for rotating the tube pump 4 in the reverse direction is set to be larger than the idling torque, and the driving force in the reverse direction is not transmitted to the pressure roller 7. Thus, the clutch spring 6
1 constitutes a one-way clutch. In addition,
The shaft 49 is provided with a lock 64 that prevents the drive gear 31 from coming off.

In the above configuration, when the transport roller 16 is driven to rotate in the paper feed direction during recording (forward direction indicated by arrow e) by the transport motor 18 (FIG. 1), the drive gear 3 is driven.
The guide roller 6 is rotationally driven in the direction of arrow a via the first gear 1 and the driven gear 32. In this embodiment, the transport roller 1
Although the rotation of the guide roller 6 is transmitted to the guide roller 6, the rotational force of the guide roller 6 may be obtained from another roller of the recording material conveying system, another rotating unit of the recording apparatus, or a driving source. When the guide roller 6 rotates in the direction of arrow a,
The pressure roller 7 pivotally supported by the guide roller 6 forms a tube fixing groove 4 on the recording head 1 side (upstream side) of the pump base 5.
7 comes into contact with the roller guide 65 formed integrally with the roller 7. This state is indicated by a position Z in FIG. At this time, the pressure roller 7 is guided (guided) by the roller guide portion 65,
It moves in the direction of arrow f while being driven and rotated (rotated) in the direction of arrow b, and moves to the position where the pressure roller 7 is pressing the tube 3.

When the guide roller 6 further rotates in the direction of arrow a, the pressure roller 7 comes into contact with the tube 3 at the position X in FIG. And crush it until the space inside the tube 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 has moved in the direction of arrow f to a position where the tube 3 has already pressed the tube 3 at the position Z. The increase in pressure acting on the pressure roller 7 at the position X is suppressed within a certain range. Rather, the pressure roller 7 gradually presses the tube 3 along the roller guide portion 65, and the pressure roller 7
The fluctuation of the torque applied to the transport roller 16 when the contact is made can be made very small.

The tube fixing groove 47 has such a shape that 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 tube 3 at the portion where the groove width is small (portion of the groove width h) near the roller guide portion 65.
Is preferably larger than the outer diameter of the wide portion i when the tube 3 is pressed by the pressure roller 7. However, in this case, since the function of the roller guide 65 is also provided, the width h of the arc-shaped groove needs to be smaller than the thickness g of the pressure roller 7.

With the rotation of the guide roller 6, the pressure roller 7
Is further rotated (revolved) in the direction of arrow a from position X,
The pressure roller 7 moves while being driven (rotated) in the direction of arrow b while the tube 3 is crushed. And FIG.
Pause at middle position Y. At this time, a negative pressure is generated in the discharge port 52 of the recording means (recording head) 1 due to a volume change in the tube 3 crushed by the pressure roller 7 between the position X and the position Y, and A suction operation for sucking ink from the printer is performed. When the suction is completed, the guide roller 6
Is further rotated in the direction of arrow a, the pressure roller 7 gradually moves away from the tube 3 along the roller guide 66 on the downstream side (on the waste ink processing member 11 side). At this time, the movement of the pressure roller 7 is substantially opposite to the movement when the pressure roller 7 contacts the tube 3 described above. Therefore, the pressure roller 7 is
The torque fluctuation when releasing from the state where is pressed can also be made very small.

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

In the embodiment shown in FIGS. 3 to 7, a one-way clutch comprising the clutch spring 61 is provided on the shaft 49 of the transport roller 16, so that when the transport roller 16 rotates forward in the direction of arrow e, , The rotational force is transmitted to the guide roller 6 to perform the above-described suction operation.
When the transport roller 16 rotates in the reverse direction of the arrow k, its rotational force is not transmitted to the drive gear 31, and the guide roller 6 does not rotate. Therefore, the reverse rotation driving force is not transmitted to the pressure roller 7, and the reverse flow phenomenon of the ink in the tube 3 as described in the conventional example does not occur.

As described above, even when the transport roller 16 reverses in the direction of arrow k, a slight idling torque is generated between the clutch spring 61 and the shaft 49. In the present embodiment, the home position of the pressure roller 7 is set in the non-pressure area of the tube 3 and the idling torque of the clutch spring 61 is set to 40.
The driving torque in the reverse rotation direction of the tube pump 4 (the driving torque when the pressure roller 7 enters the tube 3) is set to 250 to 650 g-cm. That is, when the transport roller 16 rotates in the reverse direction of the arrow k, the pressure roller 7 rotates (revolves) to a position where it contacts the tube 3, but the pressure roller 7 protrudes into the tube 3 more than the idling torque. Since the torque at the time is greater, the pressure roller 7 remains stopped at this position. Therefore,
A positive pressure for causing the ink in the tube 3 to flow backward to the recording head 1 is not generated. At this time, the clutch spring 61 is in a slip state with respect to the shaft 49.

According to the embodiment described above, the tube 3
In the configuration in which the tube pump 4 performs suction recovery by utilizing the deformation of the above, and the drive source of the tube pump 4 rotates forward and backward, the tube 3 is pressed only at the time of normal rotation when suction negative pressure is generated in the recording head. Since the driving force is transmitted to the pressurizing roller 7 to be deformed, the backflow of the ink in the tube pump 4 is prevented, so that the ink overflows from the cap 2 and the ink adheres or discharges to the discharge port forming surface 51. It is possible to improve the quality of the recorded image by eliminating waste ink from entering the outlet 52.
Further, since there is no reverse rotation drive, the rotation amount of the tube pump 4 can be reduced, and the durability of the tube 3 and the reliability of the pump can be improved. further,
By using a spring clutch as a one-way mechanism for preventing reverse rotation drive, a simple and lightweight one-way mechanism could be obtained.

In the above-described embodiment, the case where the tube pump 4 is driven by the rotational force of the conveying roller 16, that is, the case where the tube pump 4 is driven by the same driving source as the recording material conveying system has been described. Is, for example, a carriage motor for serial scanning the printhead,
The driving may be performed using another driving source in the recording apparatus. Also in that case, a one-way mechanism is provided between the drive source and the tube pump 4.

In the above-described embodiment, the clutch spring 6
Although the case of using the one-way mechanism using 1 has been described, other types of clutches may be used as long as they have a one-way function. Furthermore, an electromagnetic clutch, a ratchet, or the like may be used as long as the driving force is transmitted only to the tube pump 4 in the normal rotation direction. In the above-described embodiment, the shaft 49 of the transport roller 16 is used.
Although the configuration having the one-way mechanism has been described, this one-way mechanism may be disposed in the pump 4 and may be disposed anywhere in the drive transmission mechanism from the drive source to be used to the pressurizing roller 7. Good.

In the above-described embodiment, an ink jet recording apparatus for color recording using a plurality of recording means 1 for recording with inks of different colors has been described as an example. The same applies regardless of the number of recording means, such as an ink jet recording apparatus for monochromatic recording, or an ink jet recording apparatus for gradation recording using a plurality of recording means for recording with the same color and different density inks. It is possible to achieve the same effect.

In the above-described embodiment, the serial type recording apparatus in which the recording means 1 is mounted on the carriage 24 has been described as an example. However, the present invention is applied to 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 printing apparatus that prints only by sub-scanning using a line-type printing unit having a length covering the above-described range, and the same effect can be obtained. Further, as the recording means 1, in addition to a cartridge type in which an ink discharge section (recording head) and an ink tank section are integrated, an ink discharge section (recording head section) and an ink tank section are separately provided, and these are used as ink supply tubes. Regardless of the configuration of the recording means, such as a configuration in which the recording means are connected with each other, 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, for example, a recording means (recording head) using an electromechanical transducer such as a piezo element. The present invention brings about an excellent effect in an ink jet recording apparatus of a type in which ink is ejected. According to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described, for example, in US Pat. Nos. 4,723,129 and 4,740.
Preferably, this is done using the basic principles disclosed in US Pat. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling to an electrothermal transducer arranged corresponding to the sheet or liquid path in which Then, heat energy is generated in the electrothermal transducer, and the film is boiled on the heat acting surface of the recording means (recording head). As a result, air bubbles in the liquid (ink) can be formed one-to-one corresponding to the driving signal. It is valid.

The liquid (ink) is ejected through the ejection opening by the growth and shrinkage of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, US Pat.
Those described in 463359 and 4345262 are suitable. Incidentally, US Pat. No. 4,431,131 of the invention relating to the temperature rise rate of the heat acting surface.
If the conditions described in the specification of JP-A No. 24 are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,558,333 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 459600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal transducer for a plurality of electrothermal transducers, and an aperture for absorbing pressure waves of thermal energy. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, the 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 medium (recording medium) on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head. In addition, even with the serial type printer as in the above example, the recording head fixed to the main unit or attached to the main unit enables electrical connection with the main unit and supply of ink from the main unit. The present invention is also effective when a replaceable chip type print head or a cartridge type print head having an ink tank provided integrally with the print head itself is used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like provided as a configuration of the printing apparatus in the present invention, since the effects of the present invention can be further stabilized. If you list these specifically,
For the recording head, a capping unit, a cleaning unit, a pressurizing or suctioning unit, a preheating unit using an electrothermal transducer or another heating element or a combination thereof, and a discharge other than recording. Performing the preliminary ejection mode is also effective for performing stable printing.

The types and the number of recording heads to be mounted are, for example, not only one provided for a single color ink but also a plurality of inks having different recording colors and densities. May be provided in plurality. That is, for example, as the recording mode of the recording apparatus, not only the recording mode of only the mainstream color such as black,
The recording head may be formed integrally or by a combination of a plurality of recording heads, but the present invention is also extremely effective for an apparatus provided with at least one of multiple colors of different colors or full color by mixing colors.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or below and which softens or liquefies at room temperature, or an ink jet ink In general, in the method, the temperature of the ink itself is adjusted within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. What is necessary is just to be liquid. in addition,
Whether to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or use ink that solidifies in a standing state to prevent evaporation of the ink In any case, the ink is liquefied by the application of the heat energy according to the recording signal, and the liquid ink is ejected,
The present invention is also applicable to a case where an ink having a property of being liquefied for the first time by thermal energy, such as an ink which starts to solidify when it reaches a recording medium, is used.

The ink in such a case is disclosed in
As described in JP-A-56847 or JP-A-60-71260, a form in which the liquid sheet or the solid sheet is opposed to the electrothermal converter while being held as a liquid or solid substance in the concave portion or through hole of the porous sheet. It 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, the form of the ink jet recording apparatus according to the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. And the like.

[0058]

As is apparent from the above description, according to the present invention, there is provided an ink jet recording apparatus for performing recording by discharging ink from a recording means to a recording material and a recovery apparatus used in the recording apparatus. A tube pump for generating a negative pressure for recovering the discharge port by deforming a tube communicating with the discharge port with a pressure roller, and a driving source for generating a driving force for driving the tube pump A one-way clutch provided between the tube pump and the drive source, for transmitting a driving force from the drive source only in a direction in which a negative pressure is applied to the discharge port with respect to the tube pump; With a simple configuration, it is possible to prevent the backflow of ink and improve the image quality, and eliminate the reverse rotation of the pump to reduce the tube Recovery device used in the inkjet recording apparatus and the recording apparatus provided with a suction pump for discharge performance recovery can improve the reliability of durability and pump is provided.

According to another aspect of the present invention, in addition to the above structure,
A configuration in which a one-way clutch is provided between the tube pump and its drive source, or a transport roller is disposed between the drive source and the tube pump, a clutch spring is wound around a transport roller shaft, and one end of the clutch spring is provided. Abuts a part of the gear on the conveying roller shaft, and when the conveying roller rotates in a direction to generate a negative pressure at the discharge port, the clutch spring is tightened to transmit a driving force to the tube pump, and the conveying roller is rotated in reverse. In the case of rotation in the direction, the clutch spring is loosened so that the driving force is not transmitted to the tube pump, so that the above-mentioned effect can be achieved more efficiently.

[Brief description of 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.

FIG. 2 is a partial perspective view schematically illustrating a structure of an ink ejection unit of a recording unit in FIG.

FIG. 3 is a plan view showing a configuration of an embodiment of a suction recovery device according to the present invention.

FIG. 4 is a longitudinal sectional view of the suction recovery device of FIG. 3;

FIG. 5 is a schematic longitudinal sectional view showing the operation of the suction recovery device of FIG. 3;

FIG. 6 is a partial cross-sectional view taken along line 6-6 in FIG.

FIG. 7 is a front view of the one-way mechanism as viewed from line 7-7 in FIG. 3;

FIG. 8 is a longitudinal sectional view showing a state at the time of starting a suction operation of the conventional suction recovery device.

9 is a longitudinal sectional view showing a state at the end of the suction operation of the suction recovery device of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording means (recording head) 2 Cap 3 Tube 4 Tube pump 5 Pump base 6 Guide roller 7 Pressure roller 11 Waste ink processing member 12 Recording material 16 Transport roller 18 Transport motor 19 Platen 20 Discharge roller 23 Guide rail 24 Carriage 26 Carriage motor 30 Recovery device 31 Drive gear 32 Driven gear 39 Roller bearing 40 Vertical axis 41 Compression spring 47 Tube fixing groove 48 Arc-shaped groove 49 Conveying roller shaft 51 Discharge port forming surface 52 Discharge port 55 Electrothermal converter 61 Clutch Spring 65 Roller guide section 66 Roller guide section 68 Sensor

Claims (6)

(57) [Claims] 1. An ink jet recording apparatus for performing recording by discharging ink from a discharge port of a recording means to a recording material, wherein a tube communicating with the discharge port of the recording means is deformed by a pressure roller. A tube pump that generates a negative pressure for performing recovery of the tube pump, a drive source that generates a driving force for driving the tube pump, and a tube pump that is provided between the tube pump and the drive source. An ink jet recording apparatus comprising: a one-way clutch for transmitting a driving force from the driving source only in a direction in which a negative pressure acts on the discharge port. 2. A transfer roller is disposed between the drive source and the tube pump, a clutch spring is wound around the transfer roller shaft, and one end of the clutch spring abuts against a part of a gear on the transfer roller shaft. When the transport roller rotates in a direction to generate a negative pressure at the discharge port, the clutch spring is tightened to transmit the driving force to the tube pump, and when the transport roller rotates in the opposite direction, the clutch spring is loosened. 2. The ink jet recording apparatus according to claim 1, wherein no driving force is transmitted to the tube pump. 3. An ink jet recording apparatus according to claim 1, wherein said recording means is an ink jet recording means provided with an electrothermal transducer for generating thermal energy used for discharging ink. apparatus. 4. An ink jet recording apparatus according to claim 3, wherein said recording means discharges the ink from a discharge port using film boiling generated in the ink by thermal energy generated by the electrothermal transducer. . 5. A recovery device used in an ink jet recording apparatus for performing recording by discharging ink from a discharge port of a recording means to a recording material, wherein a tube communicating with the discharge port of the recording means is deformed by a pressure roller. A recovery tube pump for generating a negative pressure for recovering the discharge port, a drive source for generating a driving force for driving the tube pump, and a drive source between the tube pump and the drive source. A one-way clutch for transmitting a driving force from the driving source only in a direction in which a negative pressure is applied to the discharge port with respect to the tube pump;
A recovery device for an inkjet recording device, comprising: 6. A conveyance roller is provided between the drive source and the tube pump, a clutch spring is wound around a conveyance roller shaft, and one end of the clutch spring is abutted against a part of a gear on the conveyance roller shaft. When the transport roller rotates in a direction to generate a negative pressure at the discharge port, the clutch spring is tightened to transmit the driving force to the tube pump, and when the transport roller rotates in the opposite direction, the clutch spring is loosened. 6. The recovery device according to claim 5, wherein the driving force is not transmitted to the tube pump.