JPH10278301A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink jet recorder in which sealing force of a recording head, and the like, can be selected by an arrangement wherein a capping means regulates the pressing force of a plurality of springs against the recording head and a pressure regulating means interlinked with the pressing force regulates the air pressure being supplied to an ink cartridge. SOLUTION: A cap holder 35 is provided with a substantially quadrantal cam follower 40 in the center and fixed, at one end thereof, to an elongated hole in a frame through a shaft 41 so that the cap holder 35 can be moved in the horizontal direction and turned and urged constantly to the upper side of a recording head through a coil spring 42. When power is turned on, a cam 50 is turned to raise a pin 53 to the uppermost end and the pin 53 is engaged with a pawl 52 turned to the cam 50 side through a solenoid 51 upon turn on power. Consequently, a lever 48 is released from a shaft 37 and deenergized by a strong spring and the pawl 54a of a lock lever 54 is retracted from a recess in a carriage 1 as the lever 48 is turned thus unlocking the carriage 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type recording apparatus in which an ink jet type recording head is mounted on a carriage, an ink cartridge is mounted on a box, and ink is supplied from the ink tank to the recording head via a tube. Related to the device.

[0002]

2. Description of the Related Art An ink jet recording apparatus is equipped with an ink jet recording head for ejecting ink droplets by a pressure generating means on a carriage, and performs printing while receiving ink supply from an ink tank. With an ink cartridge on the carriage
Attempts have been made to simplify the structure. On the other hand, with the improvement of the performance of the ink jet recording head, the dot density has increased dramatically, enabling color printing with natural colors, and further improving print quality. Efforts are being made to make it as small as possible. As one of the means, a method has been proposed in which an emulsion or sugar is contained in ink to form an ink droplet on a recording medium. In the ink having such a film forming property, there is a high possibility that the flow of the ink to the recording head is obstructed by a porous body which is inevitably required for the on-carriage type cartridge. As shown in / 31335, the ink jet recording head and sub tank are mounted on the carriage, the ink cartridge is pressurized with air, the ink of the ink cartridge is supplied to the sub tank after passing through the recording head, and the ink remains on the recording head. Air bubbles and high-density ink near the nozzle opening are forcibly discharged to the sub-tank, and the thickened ink in the sub-tank is mixed with the ink supplied from the ink cartridge to reduce the density to a level suitable for printing. Is supplied to the recording head to perform printing.

[0003]

If the ink having such a film forming property is left in a non-printing state, an ink film is naturally formed at the nozzle opening, and the ink film functions as a lid. Within a period of about 8 hours, the ink film can be removed by pressure-feeding the ink to the recording head, and printing can be performed.

However, even if a small amount of ink leaks in the capped state, and if left in this state for a long period of time, the ink solidifies and it becomes difficult to separate the cap member. Must be sealed.

When the air bubbles discharged to the sub-tank are discharged to the outside via the gas selectable valve, it is necessary to seal the print head with a pressure that does not cause ink to leak from the print head. When the recording head is rubbed by the cap member for maintenance, to reduce the wear of the surface treatment material of the nozzle plate as much as possible,
It is necessary to press the cap member with an extremely weak pressure.

On the other hand, when ink is supplied from the ink cartridge to the recording head or the sub-tank, a relatively high pressure is required to remove the ink film formed at the nozzle opening or to discharge air from the sub-tank. However, since two types of pressures, that is, a relatively low pressure that does not affect the meniscus of the nozzle opening, are required, the air supply mechanism is required when at least four types of cartridges are required, such as in color printing. There is a problem of complexity.

The present invention has been made in view of such a problem, and an object of the present invention is to supply ink from an ink cartridge to a sub-tank by passing it through a recording head, and to pass ink from the sub-tank through the recording head. To provide a recording apparatus having a unitized capping mechanism and an air supply system suitable for an ink supply system for causing ink to flow back into a cartridge.

[0008]

According to the present invention, there is provided a subtank mounted on a carriage which moves in parallel with a platen and an ink jet recording head, and the recording head provided outside the carriage. An ink cartridge that communicates with a tube, an air pump that supplies air for discharging ink to the ink cartridge via a pressure adjusting unit, and a capping unit that seals a nozzle opening of the recording head outside a print area of the carriage. In an ink jet recording apparatus for supplying the ink of the ink cartridge to the sub-tank through the recording head and flowing the ink back from the sub-tank to the cartridge via the recording head, the capping means may include a plurality of springs. The above mentioned Pressing force is adjusted relative to the head,
Further, the pressure adjusting means adjusts the pressure of the air supplied to the ink cartridge in conjunction with the pressing force of the capping means.

[0009]

The pressing force can be adjusted only by selecting a plurality of springs by using the cam as the point of action, and the recording head is released from the capping means by adjusting the pressure of the pressure adjusting means in conjunction with the cam. In this case, air at a pressure necessary for removing air bubbles from the sub tank by being sealed by the capping means at a medium pressure is automatically selected.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a first embodiment of the present invention. 1 and 2 show an embodiment of an ink jet recording apparatus according to the present invention. A carriage 1 is supported by a guide member 2, connected to a carriage drive motor 4 via a timing belt 3, and a platen 5 is provided. It is configured to reciprocate in parallel to.

The carriage 1 receives a plurality of ink jet recording heads 6, 7, 8, 9 in this embodiment on the side facing the platen 5, and receives ink from an ink supply unit 10 described later. Are mounted.

One end of each of the sub-tanks 11 to 14 is connected to ink cartridges 15, 16, 17, and 18, which will be described later, and ink tubes 20, 21, 22, and 22 which are colored in a similar color to the ink supplied to the recording head. 23 are connected.

At the home position of the carriage 1, a unit 28 in which a capping member 25, an air pump 26, and a pressure adjusting valve 27, which will be described later, are incorporated in a frame is arranged. In the drawing, reference numeral 29 denotes a cassette for stocking the recording paper 30, and reference numeral 31 denotes an idle pulley provided at one end of the frame 32.

The recording apparatus having the above-described configuration is used for the ink pack 1 of the ink cartridge 15 as shown in FIG.
The tube 20 connects the ink supply port 15b of the recording head 6 to the ink outflow port 6a of the recording head 6, and the sub tank 11 is connected to the other ink outflow port 6b.

On the other hand, the pressurized space 15c of the ink cartridge 15 is supplied with air from an air pump 26 via a pressure adjusting valve 27 capable of setting a pressure in two levels, which will be described later.

With such a flow path configuration, air is supplied to the pressurized space 15c of the cartridge 15 so that the ink bag 15a
Is pressed, the ink in the ink bag 15a
From the ink outlet 6a located below the print head 6 through the common ink chamber and pressure generating chamber in the print head to the sub-tank 11 from the other ink outlet 6b.
Flow into

Due to the flow of ink, bubbles remaining in the common ink chamber and the pressure generating chamber are discharged to the sub tank 11. When the ink in the sub tank 11 is replenished and the pressure in the space in the sub tank 11 increases, only air is released from the air release valve 11a to the atmosphere. When the sub-tank 11 is filled with ink up to the ink full state, a signal is output from the ink full sensor 11b, the air pump 26 stops, and the air vent valve 11a closes.

The ink in the sub tank 11 is supplied to the recording head 6.
The ink flows back to the ink cartridge 15 through the recording head 6 via the tube 20 by the water head pressure based on the height difference between the ink cartridge 15 and the ink cartridge 15. When the backflow to the ink cartridge 15 proceeds and the amount of ink in the sub tank 11 decreases,
Since the incempty sensor 11c outputs a signal, the air pump 26 operates and the ink cartridge 15
Then, the ink is again supplied to the sub tank 11 via the recording head 6, and the supply of air from the air pump 26 is stopped when the ink becomes full.

The reciprocating circulation between the sub-tank 15 and the ink cartridge 15 via the recording head 6 is repeated so that the above-mentioned ink replenishment is performed each time the ink in the sub-tank 11 flows backward and decreases. Is performed to maintain the density of the ink at an optimum value for printing.

Next, the unit 28 will be described. The cap member 24 elastically contacting the nozzle openings of the recording heads 6 to 9 is made of a silicon rubber having chemical resistance, and is arranged in accordance with the arrangement pitch of the nozzle opening rows of the recording heads 6 to 9 as shown in FIG. A plurality of protrusions 2 so as to match
4a, 24a,... And tongues 24b, 24b extending downward to guide ink to the center of the concave portion between the convex portions 24a.
And ribs 24c, 24c on both sides to keep the convex region as flat as possible.

The cap member 24 is detachably mounted on a surface of a support 38 provided on a shaft 37 constantly biased toward the recording head 6 by a spring 36 on a cap holder 35 described later.

The cap holder 35 is formed by forming a substantially quarter cam floor 40 at the center thereof, and has one end attached to a long hole of the frame by a shaft 41 so as to be able to move and rotate in the horizontal direction. And is constantly urged upward by the coil spring 42 on the recording head side.

The cam follower 40 is provided with a first cam 43, and the cap holder 3 is rotated by rotation of the cam 43.
5 is moved vertically and horizontally. A second cam 45 is fixed to the shaft 44 of the first cam 43, and presses the other end of the coil spring 46 having one end fixed to the cap holder 35.

On the other hand, the recording head is fixed to a shaft 47,
A cap member pressing lever 48 rotatably provided on the frame via the shaft selectively contacts the support member 38 and presses the cap member 24 with a strong pressure of the coil spring 49.

The other end of the lever 48 is provided with a pin 53 which is in contact with a half-moon-shaped cam 50 and is engaged with a claw 52 which is lifted upward by the bias of a solenoid 51.

On the side facing the carriage 1, there is provided a lock lever 54 in which a claw 54a is constantly urged downward by a spring (not shown), and is engaged with a lever 55 which is rotated by a shaft 47 fixed to the lever 48. I agree.

When the power is turned on, the cam 50 rotates to raise the pin 53 to the uppermost end, and the pin 52 is rotated by the solenoid 51 which is energized by turning on the power. 53 is engaged (FIG. 4 (b)). As a result, the lever 48 separates from the shaft 37 and is released from the urging force by the strong spring 49, and the pawl 54a of the lock lever 54 retreats from the concave portion 1a of the carriage 1 due to the rotation of the lever 48, thereby locking the carriage 1. Unraveled.

In this state, the tip 43a of the first cam 43
Is located away from the cam floor 40, the cap holder 35 is positioned at a fixed position above the recording head by the spring 42 (FIG. 6 (I)). In this state, the tip 45a of the second cam 45 presses the spring 46,
The cap member 24 is pressed against the recording head 6 with a force determined by the elasticity of the spring 46, for example, about 400 grams. Therefore, even if the ink cartridges 15 to 18 are pressurized at such a pressure that bubbles in the sub tanks 11 to 14 can be eliminated, ink leakage from the recording heads 6 to 9 can be prevented.

When the second cam 45 is separated from the spring 46 by the rotation of the shaft 44 (FIG. 6 (II)), the cap member 24 is pressed with a small pressure by only the spring 36 provided on the shaft 37, for example, about 100 grams. The recording heads 6 to 9 are pressed.

When the shaft 44 further rotates, the first cam 4
The lower surface 40a of the cam follower 40 is pressed by the third side surface 43b. In this state, the cap member 24 has the front end surface of the convex portion 24a elastically contacting the nozzle plate of the recording head 6 and the rear end swingably supported by the shaft 37, so that the cap member 24 is parallel to the nozzle plate surface. It moves downward (FIG. 6 (III)). Due to the lowering of the cap member 24, the convex portion 24a of the cap member 24 which receives the pressing force of the spring 36 rubs the recording heads 6 to 9 without abrading the processing layer.

Further, when the first cam 43 rotates, its tip 43a contacts the lower surface of the cam floor 40, and the upper end of the cap member 24 contacts the lower end of the recording head 6 while receiving the pressing force of the spring 36 ( FIG. 7 (I)). In this state, the air pump 26 is operated to operate the ink cartridge 1.
When the ink is supplied to the recording head 6 from 5 to the sub-tank 11 becomes full or more of the ink, obstacles that cause clogging of the nozzle opening, such as ink residue at the nozzle opening, can be discharged together with the ink.

The ink that has flowed out of the recording head 6 flows through the area of the cap member 24 where the convex portion 24a is formed, and is guided by the lower tongue piece 24b to be used as the waste ink tank 5.
Fall to 6.

When the first cam 43 is further rotated, the tip of the cap holder 35 is further lowered, while the cap member 24 receives the low pressing force of the spring 36 and the upper slope 2 is pressed.
The recording head 4d moves downward on the recording head side while making contact with the lower end of the recording head 6, and projects forward from the nozzle plate surface of the recording head (FIG. 7 (II)). In this process, the ink that has flowed out due to the ink ejection capability recovery operation and adhered to the lower ends of the recording heads 6 to 9 m is formed on the upper slope 2 of the cap member 24.
It is scraped at 4d.

Further, when the cam 43 rotates and moves to the lower rear end of the cam follower 40, the cap holder 35 is pushed backward against the spring 42 and retreats. A constant gap ΔG1 is formed from the surface (FIG. 7 (III)).

When the cam 43 is further rotated at the stage when the ink ejection capability recovery operation is completed, the cap holder 35 is rotated.
While pushing the back of the cam follower (FIG. 8 (I)).
Reaches a stable point 40b formed on the rear end wall of the cap holder 35, a fixed gap ΔG2 is formed between the cap holder 35 and the recording head 6, and a horizontal posture is secured to enable printing (FIG. 8 ( II)).

Then, since the operating rod 58a of the limit switch 58 falls into the concave portion 511a of the cam 57 provided on the shaft 44, a signal is output from the limit switch. This signal is output to a control device (not shown) so that a printing routine can be started.

When the cam 43 further rotates, the tip 43a of the first cam 43 separates from the cam follower 40a, so that the cap holder 35 is pulled up by the spring 42.
As a result, the cap member 24 moves up to a position corresponding to the recording head 6, and when the shaft 44 further rotates in this state, the second cam 45 presses the spring 46.
Returning to the state (I), the cap member 24 is pressed with a moderate pressure of the spring 46 to seal the recording head 6.

In this state, when the power is turned off, the solenoid 51 is deenergized, the claw 52 retreats and the pin 53 becomes free, and the lever 48 is lowered by the urging force of the spring 49, as shown in FIG. In this state, the cap member 24 is pressed against the recording head 6 by a strong force of the spring 49, and the lock lever 54 engages with the concave portion 1a of the carriage 1 to lock the carriage 1.

Thus, even if a large head pressure acts on the recording head between the recording heads 6 to 9 and the sub-tank 11 due to the posture of the recording apparatus due to movement or the like, ink leakage from the recording head 6 or carriage 1 Inadvertent movement is surely prevented.

On the other hand, as shown in FIGS. 3, 9, and 10, the pressure regulating valve 26 has a donut-shaped pressure regulating chamber 61 on one side surface of the base 60 and an atmosphere opening port 62 in the center. The open surface of the pressure regulating chamber 61 is sealed with a diaphragm 63 to form a valve section. The diaphragm 63 has a central region rotatably supported at one end by a shaft 64 and a spring 66 fixed at one end to a lever 65 having a limited opening angle, and one end rotatable by the shaft 64. And a lever 68 constantly biased toward the diaphragm side by a spring 67 bridged between the frame and the frame 67, and is resiliently pressed against the atmosphere opening port 62.

The lever 68 has one end connected to the other end of a lever 70 which is advanced and retracted by a cam 69 fixed to the shaft 44. The lever 68 is moved in accordance with the operation of the capping mechanism.
Is moved so that the urging force of the spring 67 can be selectively applied and released.

The pressure regulating chamber 61 is provided with a plurality of, in this embodiment, four, outlets 71, 72, 73, 74, and a valve 75, which is opened and closed by cams 90, 91, 92, 93 described later,
Tubes 79, 80, 81, via 76, 77, 78,
82, the ink cartridges 15, 16, 17, 18
Are connected to the pressure chambers 15c, 16c, 17c and 18c. These tubes 79 to 82 are colored so as to be similar to the ink colors of the ink cartridges 15 to 18, respectively.

The valve bodies 75a to 78a of the valves 75 to 78 are constantly urged in the valve opening direction by springs, and each of the operating rods has a spring 86 via one arm of an independent L-shaped lever 83. 87, 88, 89 constantly urge in the valve closing direction.

A cam floor is formed at the tip of the other arm of the lever 83, and the entire circumference is equally divided into 32 regions by a modified sine curve to form four cam plates 90 having concave portions at predetermined positions. , 91, 92, and 93 are fixed to the rotating shaft 94 with their phases shifted from each other, and as shown in Table 1, simultaneous opening and closing of all valves, simultaneous opening of three valves, simultaneous opening of two valves, It is configured to realize 16 types of opening / closing patterns that enable opening of a valve and opening of one valve.

[0045]

[Table 1]

With such a configuration, the sub-tank 11,
The ink is supplied to all of the sub-tanks 11 to 10 at the same time, and the supply of the ink to all the sub-tanks 11 to 10 is stopped.
Even when signals are simultaneously output from the 0 ink full sensor and the ink end sensor, it is possible to respond by selecting the rotation position of the cam.

The air pump 26 is configured as a diaphragm pump, and is driven by a cam mechanism 101 that receives power from a drive source via a train wheel 100.

When the cap member 24 is pressed by the second lever 45 and the recording head 6 is sealed at a medium pressure by the spring 46, as shown in FIG.
Has moved to the carriage side, the diaphragm 63
Is pressed against the atmosphere opening port 62 by a strong pressure of the spring 67.

Therefore, the cam plates 90, 91, 92, 93
When the valves 75 to 78 are opened, high-pressure air is supplied to the ink cartridges 15 to 18 so that ink does not leak from the nozzle openings and the sub tanks 11 to 1
Ink 4 can be supplied with a pressure sufficient to eliminate air bubbles.

On the other hand, when the recording head 6 is in a state where the cap member 24 is unsealed, the cam fixed to the shaft 44 for driving the first and second levers 43 and 45 as shown in FIG. The lever 70 is retracted to the pressure adjusting valve side by 69, and the pressing force of the spring 67 is received by the lever 70, so that the diaphragm 63 is pressed to the atmosphere opening port 62 by a weak pressure of the spring 66. Therefore, it is possible to pressurize the ink cartridges 7 to 10 with a pressure that can cope with ink consumption in the recording head 6 by printing.

[0051]

As described above, in the present invention,
A subtank and an ink jet recording head mounted on a carriage that moves parallel to the platen, an ink cartridge that communicates with the recording head outside the carriage by a tube, and supplies ink discharge air to the ink cartridge via a pressure adjusting unit An air pump, capping means for sealing the nozzle opening of the recording head outside the printing area of the carriage, and supplying ink from the ink cartridge to the sub-tank through the recording head, and supplying ink from the sub-tank to the cartridge via the recording head. In the ink jet recording apparatus, the pressing force of the capping means against the recording head is adjusted by the urging forces of a plurality of springs, and the pressure adjusting means adjusts the pressure of the air supplied to the ink cartridge in conjunction with the pressing force of the capping means. Tones Since so as to, it is possible to select a sealing force only in the recording head be selected by cam action point a plurality of springs, the supply pressure of ink to the sub tank.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of an ink jet recording apparatus of the present invention.

FIG. 2 is a side view of the recording device.

FIG. 3 is a diagram showing an embodiment of an ink supply system of the recording apparatus.

FIGS. 4A and 4B are views showing an embodiment of a capping mechanism of the above apparatus in a state where a recording head is sealed and a printable state, respectively.

FIG. 5 is a perspective view showing one embodiment of a cap member of the same capping device.

FIGS. 6 (I) to (III) are explanatory views showing a process of moving from a state of ink supply to a sub-tank to a state where a rubbing operation is possible, among operations of the capping mechanism.

FIGS. 7 (I) to (III) are explanatory views showing a process in which the cap member moves to the lowermost end from the ink ejection capability recovery operation in the operation of the capping mechanism.

FIGS. 8 (I) to (II) are explanatory views showing a process of moving the capping mechanism to a printable state in the operation of the capping mechanism.

FIGS. 9A and 9B are a top view and a side view, respectively, showing an embodiment of the pressure adjusting valve of the recording apparatus in a state set to a high pressure state.

FIGS. 10A and 10B are a top view and a side view, respectively, showing an embodiment of the pressure adjusting valve of the recording apparatus in a state where the pressure adjusting valve is set to a low pressure state.

[Explanation of symbols]

 Reference Signs List 1 carriage 5 platen 6-9 ink jet recording head 7-10 sub tank 15-18 ink cartridge 24 cap member 26 air pump 27 pressure regulating valve 35 cap holder 40 cam follower 43 first cam 45 second cam 36, 46, 49 cap Member pressing spring 48 Cap member pressing lever 50 Cap member pressing lever lifting cam 51 Solenoid 52 Claw 54 Carriage claw

Claims (8)

[Claims] An ink jet recording head mounted on a carriage that moves in parallel with a platen; an ink cartridge that communicates with the recording head outside the carriage by a tube; An air pump that supplies air for discharging ink, a capping unit that seals a nozzle opening of the recording head outside a printing area of the carriage, and supplies ink from the ink cartridge to the sub tank through the recording head. Further, in an ink jet recording apparatus for causing ink to flow backward from the sub tank to the cartridge via the recording head, the capping means adjusts the pressing force on the recording head by the urging force of a plurality of springs, and adjusts the pressure. The means is the key An ink jet recording apparatus in conjunction with the pressing force of the mappings means for adjusting the pressure of air supplied to the ink cartridge. 2. The capping means, wherein a cap member is attached via a first spring to an upper portion of a cap holder having one end supported by a long hole, and a lower portion of the cap holder is stronger than the first spring. A second spring is provided, and the first spring can be biased by a lever biased by a third spring stronger than the second spring.
2. An ink jet recording apparatus according to claim 1, wherein said cam is movable in the vertical and horizontal directions, and said second cam is interlocked with said first cam so as to press said second spring. . 3. The ink jet recording apparatus according to claim 2, wherein a claw that engages with the carriage is provided at an end of the holder in conjunction with the lever. 4. The lever is held at a position separated from the first spring by electromagnetic means which is constantly urged in a power-on state, and a third lever is provided when power supply is cut off.
The ink jet recording apparatus according to claim 2, wherein the first spring is elastically contacted with the first spring by the urging force of the spring. 5. The recording apparatus according to claim 5, wherein the cap member has a slope portion whose upper end is receded from the recording head, and moves while contacting the lower end of the recording head following the movement of the holder. The ink jet recording apparatus according to claim 2, wherein the ink is scraped. 6. The pressure regulating valve according to claim 3, wherein a valve that constantly separates the pressure regulating chamber from the atmosphere communication port is pressed against the atmosphere communication hole.
And a fourth spring which is released by the third cam interlocking with the first cam and which can be released from the urging force and which is stronger than the third spring. The ink jet recording apparatus according to claim 2, wherein 7. The ink jet recording apparatus according to claim 6, wherein the pressure regulating valve is connected to the ink cartridge via a tube opened and closed by a cam plate. 8. The ink jet recording apparatus according to claim 7, wherein the tube is colored in a color similar to ink.