JPH0976527A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording apparatus cleaning an ink emitting orifice by a simple structure without discarding ink. SOLUTION: When a recording head 31 is slid left and right to perform recording, an arm 31-6 is energized by a distortion spring 38 to be revolved centering around a fulcrum 31-7 and a cap 31-4 is moved to a position 31-4' enabling recording by an ink emitting surface 31-3. When the ink emitting surface 31-3 is cleaned, the recording head 31 is moved to the right and a cap 31-4 is pushed by a push member 34-3 to cover and hermetically close the ink emitting surface 31-3 and a roller arm 43 is engaged with a pump driving pawl 34-1. The roller arm 43 is rotationally driven by the pump driving pawl 34-1 and the rollers 44 of both ends thereof press a loop like ink passage under pressure to rotate and the ink sucked from the ink emitting surface through the suction end 41a of an ink passage 41 and the head cap 31-4 is returned to an ink tank 31-1 from a sending-out end 41b.

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, and more particularly to an ink jet recording apparatus for circulating ink so that ink on an ink ejection surface of a recording head does not solidify.

[0002]

2. Description of the Related Art Conventionally, in an ink jet type recording apparatus, various measures have been taken in order to prevent clogging of ink discharge ports (printing nozzles).

FIG. 4 is a perspective view schematically showing a conventional ink jet recording apparatus. As shown in the figure, in this ink jet recording apparatus, the print head 1 has a carriage 2
And is opposed to the platen roller 3. The carriage 2 is slidably held by the shaft 5 and is engaged with the toothed belt 6a. The toothed belt 6a is
When the motor 7 rotates in both the forward and reverse directions, it is rotationally driven in the forward and reverse directions via a gear described later. As a result, the print head 1 prints characters and the like on the paper 4 while sliding along the platen 3 in the left-right direction (main scanning direction) of the paper 4 indicated by the double-headed arrow A in the figure. The platen 3 is driven by the motor 8 to sequentially feed the paper 4 in the vertical direction (sub-scanning direction),
As a result, printing by the print head 1 proceeds line by line. A head cleaning device 9 is arranged at the right end of the platen 3. This head cleaning device 9 has a cleaning port 9-1.
The cleaning port 9-1 faces the ink ejection port of the print head 1 when the print head 1 is at the home position at the right end. At this time, the ink ejection port of the print head 1 is engaged with the cleaning device 9 by the cleaning port 9-1 as required, and the cleaning of the ink ejection port is executed.

FIG. 5 is a diagram showing the engagement relationship between the print head 1 and the head cleaning device 9 at the home position. As shown in the figure, the carriage 2 holds the ball screw 6b held on the shaft 5 (the toothed belt 6a of FIG. 4 has the same function as the ball screw 6b of FIG. 4 for simplification of illustration).
It is driven to move to the home position. At this time, if it is a predetermined cleaning time, the head cleaning device 9 starts the cleaning operation based on an appropriate instruction. The head cleaning device 9 includes an engagement cap 10, a discharge pipe 11, a pump 12, a waste ink container 13, and the like. The engagement cap 10 is connected to one end of the discharge pipe 11, and is engaged with the ink ejection port 1-1 of the print head 1 by the cap driving member 15. The pump 12 accommodates the middle part of the discharge pipe 11 as a perfect circular loop 11-1, and rotates the rotor 16 around the center of the loop 11-1.
It has. The rotor 16 rotates by holding rollers 17 at both ends thereof, and the rollers 17 are the loops 1 of the discharge pipe 11.
Rotate while pressing 1-1 from inside. By this rotation, a vacuum is formed in the discharge pipe 11 on the side connected to the engaging cap 10, and the print head 1 is placed in the discharge pipe 11.
Ink is sucked from the ink ejection port 1-1 through the engagement cap 10. This ink is sequentially sent through the discharge pipe 11 to become the waste ink 18 and is discharged to the waste ink container 13. The waste ink container 13 is eventually taken out from the head cleaning device 9, and the waste ink reservoir 18-1 inside is discarded. The rotational drive of the rotor 16 is transmitted from the drive shaft gear 7-1 of the motor 7 shown in FIG. 4 via the drive gear 21, the planet gears 22, the idle gear 23, and the rotor gear 24. The planetary gear 22 is arranged so as to move up and down as shown by a double-headed arrow B in the figure, and when the cleaning of the print head 1 is completed, it moves downward and meshes with the gear 25. The gear 25 transmits the drive to the ball screw 6b via an unillustrated ohmic gear or the like.

[0005]

However, in the above-described cleaning of the print head, the engagement cap that engages with the ink ejection port of the print head is arranged in the head cleaning device fixed to the main body of the device. , In order for the engagement cap to engage with the print head without causing ink leakage, it is necessary to accurately position the print head that has moved to the home position, and this control requires advanced technology. Therefore, there is a problem in that there are large design restrictions.
Further, there is also known one in which a pump drive system such as the waste ink container 13, the pump 12 and the motor 7 is arranged on the carriage side. In this case as well, the engagement cap is fixed to the apparatus main body side and fixed. There is a problem that it is more difficult to engage the ejecting pipe that is installed with the ejected ink container that moves together with the carriage, and the structure becomes complicated in order to ensure this engaging relationship. Further, since the motor 7 is provided on the carriage side, the configuration becomes more complicated. Further, in each case, since it is premised that the ink sucked from the print head for cleaning is discarded, there is a problem that the ink is consumed more than the actual amount used for printing. In that case, there is also a problem in that the volume of the entire waste ink container is increased and the miniaturization of the apparatus main body is hindered.

An object of the present invention is to clean an ink discharge port with a simple structure, and further, it is not necessary to discard ink.
An object of the present invention is to provide an inkjet recording device including a cleaning device.

[0007]

The structure of the ink jet recording apparatus according to the present invention will be described below. According to the present invention, as described in claim 1, a recording head that ejects ink to perform recording on a sheet, an ink containing unit, a position that covers the ink ejection surface of the recording head, and retreat from the position can perform recording. To the position, a biasing means for biasing the cap means in the position direction enabling the recording, an ink flow path provided between the cap means and the ink containing means, and A carriage that includes a pump unit that engages with the ink flow path and is movable in a direction intersecting the sheet transport direction; and a cap unit that is provided at a non-recording position of the apparatus main body and the carriage moves to the non-recording position. Engaging means for engaging the cap means to move the cap means to a position covering the ink ejection surface, and engaging with the pump means to form an ink flow from the in ejection surface to the ink containing means. And a driving means for driving.

The ink containing means is, for example, an ink tank for supplying ink to the recording head as described in claim 2, and for example, as described in claim 3, ink flowing out from the ink ejection surface is collected. Configured as a waste ink container.

Thus, the ink ejection port can be cleaned with a simple structure.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a front view schematically showing the configuration of the main part of an inkjet recording apparatus according to an embodiment. FIG. 1A shows the recording head 31, the slide shaft 32, the drive ball screw 33, and the pump drive unit 34 of the inkjet recording apparatus. The recording head 31 of this embodiment is configured as a cartridge that can be attached to and detached from a carriage (not shown), and the ink tank 31-
1, a head body 31-2, an ink ejection surface 31-3, and the like, and includes a head cap 31-4 and a pump 31-5. The slide shaft 32 includes a device body base 35.
The drive ball screw 33 is also held by the apparatus main body base 35 and is driven in both forward and reverse directions by being engaged with a rotation drive mechanism (not shown). Thus, the carriage, that is, the recording head 31 is configured to slide in the left-right direction indicated by the double-headed arrow C in the drawing (hereinafter, with respect to the movement of the carriage, the recording head 3 will be used instead of the carriage).
This will be described as a movement of 1. ). Although not shown in the figure, in order to support the recording sheet facing the ink ejection surface 31-3 of the recording head 31, a platen is provided directly below the structure of FIG. It is arranged so as to face the recording head 31.

The pump drive section 34 is composed of a pump drive claw 34-1, a claw drive gear 34-2, a cap pushing member 34-3, etc., and the slide shaft 32, the carriage and the right end of the recording head 31. Is similarly held and disposed on the apparatus main body base portion 35 for holding the.

FIG. 2B is an enlarged view of the engagement positional relationship between the recording head 31 and the pump drive section 34. The figure
In (b), illustration of the cap pushing member 34-3 is omitted. As shown in FIG. (B), the head cap 31-4 of the recording head 31 is held by the cap arm 31-6,
The cap holding end of the cap arm 31-6 rotates about the fulcrum 31-7. A torsion spring 38 is engaged with the cap arm 31-6. While the recording head 31 is driven by the driving ball screw 33 and slides left and right to perform the recording operation (see FIG. (A)), the cap arm 31-6 moves to the position shown in FIG. Rotate to the right position indicated by the broken line (the state shown in Figure (a)). As a result, the head cap 31-4 is attached to the ink ejection surface 3 indicated by the solid line in the figure.
A position 31-4 'at which the ink ejection surface 31-3 indicated by the broken line in FIG.
Move to. That is, in the state of the head cap 31-4 shown by the solid line in FIG. 2B, the recording head 31 is driven by the drive ball screw 33 to move to the right as shown by the arrow E in FIG. As far as the position of the drive unit 34, the same figure (a)
The state is shown in which the ink ejection surface 31-3 is pressed by the cap pressing member 34-3 and the ink ejection surface 31-3 is sealed from the outside air.

As described above, the head cap 31-4 is
Ink ejection surface (recording surface) 31-3 as shown in FIG.
And a position which is retracted from this position and enables recording by the ink ejection surface 31-3 as shown in FIG.

When the recording head 31 further moves to the right from the above state, the pump drive claw 34- of the pump drive section 34-
1 engages with the roller arm 43 of the pump 31-5 of the recording head 31 shown in FIG. After this, the claw drive gear 3
4-2 is driven by the drive connecting gear 35-1 to rotate the pump drive claw 34-1.

FIG. 3C is a side view of the recording head 31 (viewed from the arrow D in FIG. 1B). As shown in FIG. 3C (see also FIGS. 1A and 1B), the suction end 41a of the ink flow path 41 is connected to the head cap 31-4. The ink flow path 41 is made of a pipe member having appropriate elasticity, and an extension portion from the suction end 41a is a pump 31-5.
A loop is formed in the inside of the ink tank 31-1 from the upper part of the ink tank 31-1 and the other end serves as a delivery end 41b.
Has been introduced within. A roller arm 43 is rotatably arranged in the loop of the ink flow path 41 of the pump 31-5.

In FIG. 2 (a), the pump drive claw 34- is shown on the left side.
1 shows an enlarged perspective view of the tip of FIG.
-1 and an enlarged sectional view of the pawl drive gear 34-2. Further, FIGS. 1B and 1C are enlarged views of the FF ′ cross sectional view of FIG. 1C. 2 (a), (b), and (c) are the same as those shown in FIGS. 1 (a), (b), and (c). , (c) are assigned the same numbers.

The configuration will be further described below with reference to FIGS. 2 (a), 2 (b) and 2 (c), and FIG. 1 (a) and FIG.
The operation will be described with reference to (b) and (c) again. Fig. 2 (a)
As shown in FIG.
-2 are connected to each other by a square sleeve (token), and the tip of the square sleeve of the pawl drive gear 34-2 is the rear side of the pump drive pawl 34-1. It fits inside the sleeve and is connected by a square sleeve connection. A spiral spring 37 is fitted and arranged in the sleeve of the pump driving pawl 34-1, so that the pawl driving gear 34-2 causes the pump driving pawl 34-1 to move to the left direction, that is, the recording head 31 direction.
In the event of a collision, it is configured to have an appropriate buffering force and be supported so as to be able to project and retract. The sandwiching claw width a of the pump driving claw 34-1 shown in the left perspective view of FIG. 7C corresponds to the width of the roller arm 43 of the pump 31-5.

As shown in FIG. 2 (b) (see also FIG. 1 (c)), the pump 31-5 is provided on the side surface of the ink tank 31-1 so as to project integrally with the ink tank 31-1. Has an annular edge 42 that forms an ink flow path 41 in the edge 42.
Are accommodated in a loop shape, and a roller arm 43 is rotatably provided at the central portion. Pump rollers 44 are respectively arranged at both ends of the roller arm 43, and the peripheral surfaces thereof are in pressure contact with the loop-shaped ink flow path 41.

When the recording head 31 moves to the head cleaning position at the right end shown in FIG. 1A, the tip end of the pump driving claw 34-1 of the pump driving unit 34 (FIG. 2A) is located at the center of the roller arm 43. (See) presses. If the pressing position is incorrect, the pump drive claw 34-1 will be recessed into the square sleeve coupling portion against the biasing force of the spiral spring 37, and the pump drive claw 34-1
When the holding claw width a of the pump driving claw 34-1 matches the arm width of the central portion of the roller arm 43 due to the rotation of the pump driving claw 34-1, the pump driving claw 34-1 projects by the biasing force of the spiral spring 37 and engages with the roller arm 43. To meet.

By this engagement, the roller arm 43 is driven by the pump driving claw 34-1 and rotates in the clockwise direction shown by the arrow in FIG. 1 (c), so that the pump roller 44 moves in the ink flow path 41. While pressing (Fig. 1 (c), Fig. 2)
(Refer to (b)) By rotating, the ink in the ink flow path 41 is handled in the rotation direction of the roller arm 43.

As a result, ink is ejected from the ink ejection surface 31-3 shown in FIG. 1A through the head cap 31-4 as shown in FIG. 2C as shown by the arrow G in the figure. The ink is sucked to the suction end 41a of the ink flow path 41. By this suction, the ink, dirt, dust, or the like, the density of which has risen above a predetermined density due to drying or the like, is removed from the ink ejection surface 31-3 of the recording head 31, and the ink ejection surface 31-3 is cleaned.

The sucked ink is sequentially handled in the loop-shaped ink flow passage 41, that is, is sent out by the pump 31-5, and is recirculated from the sending end 41b of the ink flow passage 41 to the ink tank 31-1. .

Although not shown in the drawing, an appropriate filtering member is provided in the upper portion of the ink tank 31-1 to filter the ink flowing back from the delivery end 41b of the ink flow path 41 to remove impurities. , And merges with the lower ink storage section.
Therefore, the ink tank 31-1 has both the original function of the ink tank for supplying the ink to the head body 31-2 and the function of the waste ink container for collecting the ink flowing out from the ink ejection surface 31-3.

In the above embodiment, a loop-shaped ink flow path 41 is used as a pump integrally attached to the recording head.
It uses a pump roller that rotates while pressing against
The pump is not limited to this, and may be any pump as long as it can be configured integrally with the recording head and has a small shape.

FIG. 3 is a diagram showing a screw pump as another example of the pump. The same figure (a) is a front view of the recording head, the same figure (b) is a side view as seen from the side that engages with the pump drive part, and the same figure (c) is the H part of the pump part of FIG. FIG. 1 (a), (b) and (c), the same components as those shown in FIGS. 1 and 2 are designated by the same reference numerals. Also, the cap arm 31-6
Illustration of the torsion spring 38 that is locked to is omitted. Furthermore,
In FIGS. 3A, 3B, and 3C, the recording head 31 has the pump driving unit 3
4 (see FIGS. 1 (a), 1 (b), and 1 (c)).

The screw pump 45 shown in this example is integrally mounted on the front surface of the ink tank 31-1 of the recording head 31, as shown in FIGS. 3 (a), (b) and (c). In the screw pump 45, the screw shaft 45-2 to which the helical screw 45-1 is fixed has its both ends attached to the ink tank 3
The bearing 45-3 is rotatably supported by the bearings 45-3 provided on both sides of the front surface of the 1-1. Pump drive unit 3 of screw shaft 45-2
The end portion in the side direction of the ink tank 31-1 that engages with No. 4 is
It projects more than the bearing 45-2, and the extreme end is formed into a slightly flat square shaft 45-4. The angular shaft 45-4 engages with the pump driving pawl 34-1 of the pump driving unit 34, and the screw shaft 45-2 is rotationally driven. In this way, since the end of the rotary shaft of the screw pump 45 that engages with the pump drive unit 34 is arranged along the front wall of the recording head 31,
In this case, the pump drive claw 34-1 of the pump drive unit 34
2 is arranged at a position moved to the front of the drawing (upward in the drawing) in FIG. 1A, as compared with the case of the configuration of FIG.

On the other hand, the ink flow path 41 extends from the suction end 41a connected to the head cap 31-4 to the ink tank 31.
The intermediate portion up to the delivery end 41b connected to the upper part of -1 is arranged in a straight line in front of the ink tank 31-1, and the helical screw 45-1 causes the contact plate 45-5 to move.
It is pressed against the ink tank 31-1 via. Patch 4
5-5 is made of a flexible and elastic member similar to the tube of the ink flow channel 41, and protects the ink flow channel 41 so that the helical screw 45-1 does not directly contact the ink flow channel 41. .

The above-mentioned screw shaft 45-2 is engaged with the pump drive portion 34 and is rotationally driven to rotate the helical screw 45-.
1 is the counterclockwise direction indicated by the arrow J in FIG.
In FIG. 3 (a), (b), (c), the ink in the ink flow path 41 is drawn from the suction end 41a when the arrow J is rotated in the clockwise direction (as viewed from the reverse oblique direction in FIG. 3C). It is sucked in the direction of the screw pump 45 shown by K, is sent out by the sending end 41-6 to the upper direction of the ink tank 31-1 shown by the arrow L, and is recirculated into the ink tank 31-1 as in the case of FIG. .

In the above embodiment, the recording head 31 is explained as a cartridge which can be attached to and detached from the carriage. However, for example, an ink replenishing port is provided in the ink tank 31-1 so that ink can be replenished to form an integral body with the carriage. It may be used as a permanent part of.

Further, each component constituting the recording head 31 may be fixed to or detachable from the carriage as a separate unit. For example, the head body 31-2, the ink tank 31-1, the ink circulation member (head cap 31-
4, the pump 31-5, the cap arm 31-6, the return arm 38, and the ink flow path 41) are each a separate unit, and only the ink tank 31-1 can be replaced, or the ink tank 31-1 and the ink circulation member are replaced. Various variations such as possible are conceivable.

Further, in the above embodiment, the ink tank 31-1 has been described as a desirable structure having a function of the waste ink container, but the upper part of the tank may be isolated as the ink discharge chamber and the lower part of the tank may be isolated as the ink supply chamber.

[0032]

As described above, according to the present invention,
Since the cap means for covering the ink ejection surface of the recording head, the pump means, and the waste ink container are arranged on the carriage side, and the pump driving means is arranged on the apparatus main body side, the cleaning device can be made compact and the ink delivery. Since the end does not come into contact with or separate from the external waste ink container, there is no inconvenience such as ink leaking or smearing out from the part coming into contact with the waste ink container, and therefore a comfortable environment for use can be formed. . Further, since the ink tank is also used as the waste ink container, the ink is circulated into the ink tank without being discarded, so that the waste of the ink is eliminated, and therefore the running cost is reduced and the cost is reduced. Further, since the waste ink container is unnecessary, the recording apparatus can be downsized, and therefore the apparatus price is reduced and the utilization is increased.

[Brief description of drawings]

FIG. 1A is a front view schematically showing a configuration of a main part of an ink jet recording apparatus according to an embodiment, and FIG. 1B is an enlarged view showing an engagement positional relationship between a recording head and a pump driving unit. FIG. 3C is a side view of the recording head (view from the arrow D in FIG. 1B).

FIG. 2 (a) is an enlarged perspective view of a tip portion of a pump driving pawl and an enlarged sectional view of a pump driving pawl and a pawl driving gear, (b) and (c).
[Fig. 2] is an enlarged arrow view of the FF 'section of Fig. 1 (c).

3A and 3B are views showing a screw pump as another example of the pump, in which FIG. 3A is a front view of a recording head, FIG. 3B is a side view engaging with a pump drive portion thereof, and FIG. FIG. 7 is a view of the pump section of FIG.

FIG. 4 is a perspective view schematically showing a conventional inkjet recording device.

FIG. 5 is a diagram showing an engagement relationship between a conventional print head and a head cleaning device.

[Explanation of symbols]

 1 Print Head 1-1 Ink Discharge Port 2 Carriage 3 Platen Roller 4 Paper 5 Shaft 6a Toothed Belt 6b Ball Screw 7, 8 Motor 7-1 Drive Shaft Gear 9 Head Cleaning Device 9-1 Cleaning Port 10 Engagement Cap 11 Discharge Pipe 11-1 loop 13 waste ink container 15 cap drive member 16 rotor 17 roller 18 waste ink 18-1 waste ink pool 21 drive gear 22 planetary gear 23 idle gear 25 gear 31 recording head 31-1 ink tank 31-2 head body 31-3 Ink ejection surface 31-4 Head cap 31-4 'Head cap retracted position 31-5 Pump 31-6 Cap arm 31-7 Support point 32 Slide shaft 33 Drive ball screw 34 Pump drive part 34-1 Pump drive claw a Claw width 34-2 Claw drive gear 3 4-3 Cap Pushing Member 35 Device Main Body Base 35-1 Drive Transmission Gear 36 Connection Part 37 Spiral Spring 38 Torsion Spring 41 Ink Flow Path (Elastic Pipe) 41a Suction End 41b Delivery End 42 Edge 43 Roller Arm

Claims (3)

[Claims] 1. A recording head that ejects ink to perform recording on a sheet, an ink containing unit, a position that covers the ink ejection surface of the recording head, and a position that enables recording by retracting from the position. Movable cap means, urging means for urging the cap means in a position direction in which the recording is possible, an ink flow path provided between the cap means and the ink containing means, and the ink flow path A carriage that is movable in a direction intersecting with the sheet conveying direction, and a pump unit that is engaged with the carriage unit; and a cap unit that is provided at a non-recording position of the apparatus main body and moves when the carriage moves to the non-recording position. Engaging means that engages with the cap means to move the cap means to a position that covers the ink ejection surface, and drive means that engages with the pump means to form an ink flow from the ink ejection surface to the ink containing means. An ink jet recording apparatus characterized by comprising: means, a. 2. The ink jet recording apparatus according to claim 1, wherein the ink containing means is an ink tank that supplies ink to the recording head. 3. The ink jet recording apparatus according to claim 1, wherein the ink containing means is a waste ink container that collects ink flowing out from the ink ejection surface.