JPH0976532A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent ink sucked from the nozzles of an ink jet head by a priming mechanism from overflowing to the periphery and entering the pump of the priming mechanism. SOLUTION: At the time of priming, a priming action by which ink in the nozzles of an in jet head and a cap covering them is sucked into a negative pressure space 35 is performed by closing an ink drip hole 40 of the negative pressure space 35 by operating a cover 42 toward a closing direction by an opening and closing mechanism 45 and by maintaining the negative pressure space 35 in a negative pressure condition by a pump. During a predetermined period other than that for priming, the ink drip hole 40 of the negative pressure space 35 is opened by operating the cover 42 into an opening direction by the opening and closing mechanism 47, ink in the negative pressure space 35 is dropped from the ink drip hole 40 to a waste ink reservoir 54. The waste ink reservoir 54 must be widely open in the top and reduce the cubic capacity by evaporating recovered ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printer having a function of preventing clogging of nozzles of an inkjet head.

[0002]

2. Description of the Related Art In an ink jet printer in which ink is ejected from an ink jet head, if a non-printing state is continued for a long time, ink in the nozzle of the ink jet head is dried and clogging occurs. Various inkjet printers having a priming mechanism for sucking ink that has dried and clogged in the nozzle have been considered.

For example, in a serial type ink jet printer in which a carriage on which an ink jet head is mounted is moved along a platen, at least a capping mechanism and a priming mechanism are provided at a position outside the print area of the carriage, as shown in FIG. The maintenance station 100 is provided, and the cap 101 of the maintenance station 100 is connected to the ink tank 103 via the tube 102, the suction side of the pump 104 and the ink tank 103 are connected by the tube 105, and the carriage is installed at the maintenance station 100. When moved to a position facing 100, the nozzle of the inkjet head is sealed with the cap 101, and in this state, the pump 104 is driven to suck the ink in the cap 101 and the nozzle and Eliminating the clogging, the recovered ink is that the recovered used in the ink tank 103.

In this conventional example, the pump 104 is driven by utilizing the rotational force of the rotary shaft 107 of the paper feed motor 106. That is, the pump 104 has the rotating shaft 107.
Has an operating rod 109 that is rotatably fitted to an eccentric roller 108 fixed to the end of the rod, and a diaphragm (not shown) that oscillates due to the swinging motion of the operating rod 109. Generate pressure.

[0005]

As shown in FIG. 6, since the ink tank 103 is hermetically closed, the ink collected inside does not come into contact with the outside air, so it is difficult to vaporize, and the volume of the collected ink does not decrease. As a result, the collected ink exceeds the capacity of the ink tank 103 and the ink tank 103
And the tube 105 may overflow. A seal member 11 is provided between the ink tank 103 and the tube 105.
Even if 0 is inserted, it is impossible to completely prevent the ink from flowing out, and sometimes ink flows to the pump 104, which may cause the pump 104 to malfunction. Further, even if the ink tank 103 is regularly replaced, the amount of ink in the ink tank 103 must be constantly detected, and the replacement work of the ink tank 103 is troublesome.

[0006]

According to the first aspect of the present invention,
A capping mechanism that covers the nozzle of the inkjet head with a cap during non-printing, a negative pressure space that has an ink dropping port that is opened and closed by a lid and that is connected to the cap, and the suction side of the pump are connected. Provided with a priming mechanism for sucking ink in the nozzle in a state of being covered with the cap, an opening / closing mechanism that maintains the lid body in a closed state during priming and opens the lid body in a predetermined period other than priming, The ink jet printer is provided with a waste ink reservoir having a part of an ink receiving portion facing the lower side of the ink dropping port and spreading in a plane direction and having an open upper surface in a wide range. Therefore, when the lid is closed by the opening / closing mechanism to drive the pump during priming, the negative pressure space becomes negative pressure, and the ink in the nozzle and the cap is sucked into the negative pressure space. During a predetermined period other than the time of priming, when the lid is opened by the opening / closing mechanism, the ink sucked into the negative pressure space is dripped from the ink dropping port to the waste ink reservoir. Since the upper surface of the waste ink reservoir is wide open, the ink vaporizes.

A second aspect of the present invention is the ink jet printer according to the first aspect of the present invention, which is provided with an opening / closing mechanism that interlocks with the sheet feeding operation. Therefore, it is not necessary to separately provide a driving device to drive the opening / closing mechanism.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. Although only one side is shown, a plurality of guide shafts 2 are installed on opposite side plates 1,
A carriage 3 is slidably fitted on these guide shafts 2. The carriage 3 has a platen 4
An ink cartridge 8 composed of an ink jet head 6 having a nozzle 5 facing each other and an ink tank 7 is detachably mounted.

The carriage 3 is driven beyond the printing area to the non-printing area, and the paper feed motor 9 is provided in the non-printing area. A drive gear 11 is fixed to one end of a rotating shaft 10 of the paper feed motor 9, and a platen gear 12 is fixed to an end of the platen 4. The drive gear 11 and the platen gear 12 are composed of a plurality of gears 13, 1.
They are connected by 4.

Further, a frame 16 is fixed to a support 15 which holds the paper feed motor 9, and the frame 1
6, two shafts 1 parallel to the guide shaft 2
A slider 19 having a protruding piece 18 protruding toward the guide shaft 2 is slidably fitted to these shafts 17. The slider 19 is urged toward the support 15 by a spring 20. Further, the slider 19 has a cap 21 for covering the nozzle 5.
Are held slidably in a direction orthogonal to the moving direction of the carriage 3. Further, the frame 16 is formed with a guide groove 23 into which a roller 22 rotatably provided on the lower surface of the cap 21 is fitted. This guide groove 23
Is inclined toward the guide shaft 2 side from the right end toward the central portion, and is formed into a substantially "V" shape parallel to the guide shaft 2 from the central portion toward the left end. As a result, the roller 22 moves along the guide groove 23 when the slider 19 reciprocates, so that the cap 2
1 approaches or separates from the guide shaft 2.

That is, the slider 1 is pushed by the carriage 3 moving out of the printing area to move leftward and is returned rightward by the urging force of the spring 20.
9, the cap 21 movably held by the slider 19 in a direction orthogonal to the moving direction thereof, and the guide groove 23 for guiding the roller 22 provided in the cap 21 form a capping mechanism 24. Has been formed.

Next, an ink tank 25 fixed to a base plate described later is arranged near the left side plate 1 and a pump 26 is fixed to the support 15. A tube 27, one end of which is connected to the cap 21, is inserted into a notch 28 formed in the frame 16, and a tip 27 a of the tube 27 is connected to the ink tank 25. Although not shown, the pump 26 is of a type in which a suction force is generated by an amplitude operation of a diaphragm. The suction pipe 29 and the ink tank 25 are connected by a tube 30, and the exhaust pipe 31 is opened to the atmosphere. ing. Further, the pump 26 has an operating rod 32, one end of which is connected to a diaphragm inside thereof, and an end portion of the operating rod 32 has an end portion of the rotating shaft 10 of the paper feed motor 9.
Is rotatably fitted to an eccentric roller (not shown) fixed to the other end. Further, one end of a U-shaped tube clamp 33 which holds the tube 27 is fixed to a side surface of the slider 19 on the side plate 1 side. A negative pressure space 35 (see FIGS. 1 and 2) is formed inside the ink tank 25.

The tube 27 connected to the cap 21, the ink tank 25 connected to the tube 27, the pump 26 connected to the ink tank 25 via the tube 30, and the slider. A priming mechanism 36 that sucks the ink in the nozzle 5 of the inkjet head 6 is formed by the tube clamp 33 that crushes the tube 27 between 19 and the left end of the frame 16. The operation of the priming mechanism 36 will be described in detail later.

As shown in FIGS. 1 and 2, a plurality of bosses 38 are provided upright on the base plate 37 constituting the bottom of the casing of the ink jet printer of this embodiment, although only one is shown. The ink tank 25 is attached to the boss 38 with a screw 39. An ink dropping port 40 projecting laterally is formed in the lower part of the ink tank 25, and a lid 42 having a seal member 41 in contact with the ink dropping port 40 is rotatably attached to a base plate 37 by a spindle 43. Is held. This lid 42
Is urged by a compression spring 44 in a direction to close the ink dropping port 40.

An opening / closing mechanism 45 for opening / closing the lid 42 is provided. The opening / closing mechanism 45 includes a lever 47 rotatably held by the base plate 37 via a support shaft 46, and a protrusion 49 formed on a part of the outer periphery of the auto sheet feed cam 48 and interfering with the lever 47. It is formed by. That is, from the state shown in FIG.
When the auto seat feed cam 48 rotates clockwise, the lever 47 is pushed by the protrusion 49 and rotates counterclockwise around the support shaft 46, and the lid 42 moves, as shown in FIG. The ink dropping port 40 is opened by being pushed by the lower end of the shaft and rotating clockwise about the support shaft 43. Further, the lever 47 has a tension spring between the pin 50 erected at the tip and the pin 51 erected on the base plate 37 so that the lever 47 returns to the vertical posture as shown in FIG. 52 is stretched.

The auto seat feed cam 48 is
Although not shown, the sheet feed tray of the auto sheet feeder is pressed to the sheet feed position by the protrusion 49 to start sheet feeding. Further, the paper feed motor 9 drives the platen 4 and the pump 26 by rotation in one direction, and drives the paper feed roller and the pump 26 of the above-described auto sheet feeder by rotation in the other direction.

Further, at the bottom of the base plate 37, there is a waste ink reservoir 54 having a part of an ink receiving portion 53 facing below the ink dropping port 40 and spreading in a plane direction and having an open upper surface. Has been formed. The waste ink reservoir 54 is provided with an ink absorbing material 55.
A rib 56 is formed in the waste ink reservoir 54, but the waste ink reservoir 54 is continuous without being partitioned by the rib 56.

In such a configuration, the state shown in FIG. 3 is a state in which the carriage 3 is located in the print area. Printing is performed by causing ink to fly from the nozzles 5 of the inkjet head 6 onto the recording paper on the platen 4 while the carriage 3 moves in the printing area. In this way, when the carriage 3 is located in the print area, the slider 19 is kept stopped on the side of the support 15 by the pressure of the spring 20. In this state, since the roller 22 at the lower end of the cap 21 is located at the right end of the guide groove 23,
Retract to a position where the distance from the guide shaft 2 is the maximum. The stop position of the carriage 3 when printing is not performed or when the power is turned off is the capping position shown in FIG.

That is, as shown in FIG. 4, when the carriage 3 moves to the left capping position, the protruding piece 18 is pressed against the carriage 3, so that the slider 19 works with the cap 21 against the pressure of the spring 20. Move to the side plate 1 side. At this time, since the roller 22 of the cap 21 moves along the inclined portion of the guide groove 23, the cap 21 advances toward the guide shaft 2 and covers the nozzle 5. Thereby, drying of the ink in the nozzle 5 is prevented, and clogging due to the ink residue is prevented.

However, when the nozzle 5 is clogged with a low occurrence frequency, the user can perform priming as necessary. This is done by operating a priming key (not shown) to move the carriage 3 to the priming position on the side plate 1 side and drive the paper feed motor 9 as shown in FIG. More specifically, in the process in which the carriage 3 moves from the capping position shown in FIG. 4 to the priming position shown in FIG. 5, the roller 22 moves in the horizontal portion of the guide groove 23.
The relative position of the nozzle 5 and the cap 21 does not change. In this state, the end of the tube clamp 33 contacts the left side of the frame 16 so that the tube clamp 33 clamps and crushes the tube 27. When the paper feed motor 9 is rotated, the operating rod 32
The pump 26 is driven by the operation of. At this time, the suction side tube 27 is clamped by the tube clamp 33 and maintained in the closed state, so that a negative pressure is generated on the suction side of the pump 26. Then, the paper feed is executed, and when the carriage 3 is moved to the right capping position again,
The slider 19 returns to the right side together with the cap 21 by the pressure of the spring 20, and the tube clamp 33 separates from the left side of the frame 16 to release the tube 27 from the held state.
Due to the negative pressure in the negative pressure space 35, the ink in the nozzle 5 is sucked out through the cap 21. The sucked ink is collected in the ink tank 25.

For printing, as shown in FIG.
In the process in which the carriage 3 moves away from the projecting piece 18 and moves to the printing area, the slider 19 moves together with the cap 21 to the right side of the support 15 by the pressure of the spring 20.
At this time, since the roller 22 moves to the right end of the guide groove 23, the cap 21 is separated from the nozzle 5.

As described above, every time the auto sheet feeder is driven to feed the sheet to the platen 4, the lever 47 is rotated by the protrusion 49 of the auto sheet feed cam 48 as shown in FIG. The lid 42 is rotated in the opening direction to open the ink dropping port 40, so that the ink collected in the negative pressure space 35 of the ink tank 25 is dropped from the ink dropping port 40 to the ink receiving portion 53. Since the waste ink reservoir 54 including the ink receiving portion 53 is formed at the bottom portion of the housing such as the base plate 37 having a large area, the ink storage capacity can be increased to several times that of the ink tank 25. Moreover, since the upper surface of the waste ink reservoir 54 is open over a wide area, the ink collected inside comes into contact with the outside air and is vaporized, so that the capacity is reduced. Therefore, the ink does not overflow from the waste ink reservoir 54 even if it is left until the life of the inkjet printer is exhausted. This eliminates the need to replace the ink tank 25,
In addition, it is possible to prevent ink from entering the pump 26. Further, since the opening / closing mechanism 45 is interlocked with the sheet feeding operation of the automatic sheet feeder, it is not necessary to separately provide a driving device to drive the opening / closing mechanism 45.

The negative pressure space between the cap 21 and the pump 26 is not limited to the negative pressure space 35 formed inside the ink tank 25, and for example, the cap 21.
It may be a pipeline connecting the pump 26 and the pump 26. In this case, an ink dropping port is formed in a part of the conduit.

[0024]

According to the invention described in claim 1, a negative pressure space connected to the cap has a capping mechanism for covering the nozzles of the ink jet head with a cap during non-printing, and an ink dropping port opened and closed by the lid. And a suction side of a pump are connected to each other, and a priming mechanism for sucking ink in the nozzle in a state where the nozzle is covered with the cap is provided, and the lid is kept closed during the priming and a predetermined time other than the priming is provided. During this period, an opening / closing mechanism for opening the lid and a waste ink reservoir having an ink receiving portion facing the lower side of the ink dropping port partially extending in the plane direction and having an open upper surface are provided. Therefore, when the lid is closed by the opening / closing mechanism during priming to drive the pump, the negative pressure space becomes negative pressure, so the ink in the nozzle is sucked into the negative pressure space. It is possible to eliminate the clogging of the nozzle by. Also, during a predetermined period other than during priming, when the lid is opened by the opening / closing mechanism, the ink sucked into the negative pressure space can be dripped from the ink dropping port to the waste ink reservoir, and this waste ink reservoir has a wide upper surface. Since the ink is vaporized, it is possible to vaporize the ink and reduce the volume, and thus it is possible to reliably avoid a state where the ink overflows from the waste ink reservoir and a state where the ink enters the pump of the priming mechanism.

According to the second aspect of the present invention, since the opening / closing mechanism interlocked with the sheet feeding operation is provided, the opening / closing mechanism can be opened / closed by using the driving mechanism of the sheet feeding device without separately using the driving mechanism. .

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a side view showing a state in which a portion of a section is a cross section and an ink dropping port is closed by a lid together with a waste ink reservoir.

FIG. 2 is a side view showing, together with a waste ink reservoir, a state in which an ink dropping port is opened in a part of a cross section.

FIG. 3 is a plan view showing a printed state.

FIG. 4 is a plan view showing a capping operation of a nozzle.

FIG. 5 is a plan view showing a priming operation of a nozzle.

FIG. 6 is a perspective view showing a configuration of a conventional maintenance station.

[Explanation of symbols]

 4 Platen 5 Nozzle 6 Inkjet Head 21 Cap 24 Capping Mechanism 26 Pump 35 Negative Pressure Space 36 Priming Mechanism 40 Ink Dripping Port 42 Lid 45 Opening / Closing Mechanism 53 Ink Receptor 54 Waste Ink Reservoir

Claims (2)

[Claims] 1. An ink jet head arranged opposite to a platen, a capping mechanism for covering a nozzle of the ink jet head with a cap when not printing, and an ink dropping port opened and closed by a lid and connected to the cap. A priming mechanism that connects the negative pressure space and the suction side of the pump and sucks ink in the nozzle with the nozzle covered by the cap, and keeps the lid closed during priming. For a predetermined period other than the above, an opening / closing mechanism that opens the lid, and a waste ink reservoir that partially has an ink receiving portion that faces below the ink drop opening and that spreads in the plane direction and has an open upper surface in a wide range An ink jet printer comprising: 2. The ink jet printer according to claim 1, further comprising an opening / closing mechanism that interlocks with a paper feeding operation.