JP3170380B2 - Inkjet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer, and more particularly to an ink jet printer which performs printing by reciprocating a recording head in a main scanning direction.

[0002]

2. Description of the Related Art Such an ink jet printer which performs printing by reciprocating a recording head in a main scanning direction, as shown in FIGS. 1 and 2 of JP-A-57-24283, is known. A recording head movable in the scanning direction and an ink tank for supplying ink to the recording head are separately provided, and a structure in which these are connected by an elongated tube is disclosed in JP-A-3-101954 to 101972. As shown in the figure, there is known a recording head having a structure in which an ink tank is integrally formed with a recording head.

[0003]

In the former structure, the tube connected to the recording head is generally elongated so as not to hinder the movement of the recording head.
For this reason, there is a drawback that the piping work is complicated and a large-scale pump device is required.

[0004] In the latter structure, the above-mentioned problem is solved. However, when the ink in the ink tank is used up, each expensive recording head needs to be replaced, and the running cost is high. Having. Furthermore, the print head is larger (generally several times) by the amount of the ink tank than a single print head, and the moving space in which the print head moves is increased. Since this moving space becomes a dead space in which other components and the like cannot be mounted, there is a disadvantage that the entire apparatus becomes large. Further, there is a disadvantage that the energy required for reciprocating the recording head also increases because the weight of the recording head increases. In particular, in a color printer using three or four colors of ink, these disadvantages are remarkably exhibited.

[0005]

According to the first aspect of the present invention, there is provided a recording head having a discharge nozzle, a flow path communicating with the discharge nozzle, and an ink supply port for guiding ink to the flow path from outside. Inkjet having a recording head moving means for reciprocating a head in a main scanning direction, and an ink tank having an ink supply port at a position opposed to an ink supply port of the recording head moved to a predetermined position by the recording head moving means. In the printer, the ink supply port and the ink supply port are connected, and the ink in the ink tank is transferred to the recording head via the ink supply port and the ink supply port by a pump operation .

According to the second aspect of the present invention, an ink-impregnated member for generating a capillary phenomenon is provided in a flow path from the ink supply port to the discharge nozzle.

According to the third aspect of the present invention, there is provided an ink transfer means driven by a connecting operation of a connecting means for connecting the ink supply port and the ink supply port which are opposed to each other. According to the fourth aspect of the present invention, a printhead having a discharge nozzle, a flow path communicating with the discharge nozzle, and an ink supply port for guiding ink from the outside to the flow path, and reciprocates the printhead in the main scanning direction. In an ink jet printer comprising a recording head moving means and an ink tank for supplying ink to the recording head, the ink tank is located in the ink jet printer, and is arranged separately from the recording head moving means, When the recording head reciprocates by the recording head moving means, ink is supplied from the ink tank to the recording head by a pump operation when the recording head is at the home position.

[0008]

According to the first aspect of the present invention, the recording head is reciprocated in the main scanning direction by the recording head moving means to perform the printing, and the ink is supplied to the recording head at a predetermined position. It is performed from. That is, when the recording head is moved to a predetermined position by the recording head moving means, the ink supply port and the ink supply port are connected at this position by the connection means. Then, the ink is transferred from the ink tank to the recording head via the ink supply port and the ink supply port by the ink transfer means and supplied. When the ink supply is completed, the connection between the ink supply port and the ink supply port is released, and the recording head is reciprocated in the main scanning direction by the recording head moving means again to perform the printing.

According to the second aspect of the invention, the ink replenished from the ink replenishment port by the capillary action of the ink impregnated member is guided to the discharge nozzle.

According to the third aspect of the present invention, the transfer means is driven by the connection operation between the ink supply port and the ink supply port by the connection means, and ink is supplied. Claim
According to the invention described in Item 4, the ink tank is moved to the recording head.
Since it is not mounted on the moving means,
Small and light weight, and
And can be driven with low power
Can be configured to reduce the consumption of the entire printer
Less power is required.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the ink jet printer according to the present embodiment includes guide rollers 2 sequentially arranged downstream from a paper storage unit on which a paper roll 1 is placed.
A paper transport path 6 for transporting the paper 1 a is formed by the guide roller 3, the drive roller 4, and the pressing roller 5 pressed against the drive roller 4. The drive roller 4
Is connected to a transport motor 9 via a pulley 7 and a timing belt 8, and the rotational force of the transport motor 9 is transmitted.

A platen plate 10 is provided between the guide rollers 2 and 3 along the back side of the paper transport path 6. The platen plate 10 is provided with a large number of small holes (not shown), and the sheet 1a is sucked by a fan (not shown) provided on the back surface of the platen plate 10 so that the sheet 1a is brought into close contact with the platen plate 10.

A recording head 11 is arranged to face the platen plate 10. This recording head 11
Is mounted on a carrier 13 via a recording head base 12. This carrier 13 is a carrier shaft 14
And movably attached to the guide rail 15. The carrier shaft 14 and the guide rail 15 are arranged so that their axial directions are parallel to the platen plate 10 and perpendicular to the feeding direction of the paper 1a (main scanning direction). And the carrier 1
Reference numeral 3 is connected to a drive motor 18 via a timing belt 16 and a pulley 17. That is, a recording head moving means 19 for reciprocating the recording head 11 in the main scanning direction by the carrier 13, the carrier shaft 14, the guide rail 15, the timing belt 16, the pulley 17, and the driving motor 18 is formed. In this embodiment, the recording head moving means also functions as a connecting means. In this ink jet printer, one end side of the moving range of the recording head moving means 19 is set as a home position, and the recording head 11 is made to stand by at the home position at the time of non-irradiation. The recording head 11 is connected to a recording head control unit (not shown) by a flexible cable 11a so as not to hinder the reciprocating movement.

Here, as shown in FIG. 2, the recording head 11 has a plurality of ejection nozzles 2 for ejecting ink at its tip.
0 is formed, and a common liquid chamber 21 for supplying ink to the discharge nozzle 20 is formed at the rear end of the discharge nozzle 20. This common liquid chamber 21 is provided for all the discharge nozzles 2
It communicates with 0. Here, the capacity of the common liquid chamber 21 is not limited to this, but in this embodiment, the capacity is such that about 20 A4 sheets can be printed. An ink supply port 22 for supplying ink from outside to the common liquid chamber 21 is formed in the recording head 11 in the main scanning direction. As shown in FIG. 3, an elastic cap 23 having a radial cut is attached to the ink supply port 22. The elastic cap 23 is made of fluorine rubber or the like in consideration of elasticity and corrosion resistance to ink. The common liquid chamber 21 of the recording head 11 is filled with a polyurethane foam 24 which is an ink-impregnated member. The polyurethane foam 24 may be a member that generates another capillary phenomenon. And the common liquid chamber 2
A filter 25 is provided between the nozzle 1 and the discharge nozzle 20. The filter 25 is preferably made of stainless steel mesh or the like. The recording head 11 is of a thermal ink jet type, and the ejection nozzle 20
A heating element 26 is provided therein.

An ink tank 27 for supplying ink to the recording head 11 is located at a home position which is one end of the moving range of the recording head 11 as shown in FIG. As shown in FIGS. 4 and 5, the ink tank 27 has a cylindrical ink supply port 28 projecting from the recording head 11 at a position facing the ink supply port 22. And this ink tank 2
7, the recording head 1 is provided at an intermediate portion thereof as shown in FIG.
A bellows portion 27a that contracts in the moving direction of the first member 1 is formed. This bellows portion 27a is used as ink transfer means.
Further, an air introduction hole 29 for introducing air from the outside to the inside of the ink tank is formed in an upper portion of the ink tank 27. A check valve 30 is provided in the air introduction hole 29, and the flow from the inside of the ink tank toward the outside is stopped.

In such an arrangement, in this ink jet printer, the recording head 11 is reciprocated within the printing range in the main scanning direction by the driving motor 18, and the paper 1a is fed by the driving roller 4 to sequentially print. Shooting is performed. Here, in the recording head 11, the heating element 26 in the discharge nozzle 20 generates heat, thereby generating bubbles in the ink. The rapid expansion of the bubbles causes the ink droplets to flow from the tip of the discharge nozzle 20 to the paper 1.
It is gushing toward a. Then, the ejected amount of ink is replenished from the common liquid chamber 21 into the discharge nozzle 20.

When the printing is performed as described above, the ink in the common liquid chamber 21 is gradually consumed. For this reason, this ink jet printer performs an ink replenishing operation for replenishing the recording head 11 with ink as appropriate. Hereinafter, the ink supply operation will be described. First, drive motor 1
8 to move the recording head 11 to the home position. When the recording head 11 moves to the home position, the ink supply port 22 of the recording head 11 and the ink supply port 28 of the ink tank 27 that face each other are connected with this movement. At this time, the drive motor 18
The recording head 11 is pressed against the ink tank 27 by the above driving force, so that the bellows 27a of the ink tank 27 contracts due to this pressing force. Then, this ink tank 27
Is changed, the ink in the ink tank 27 flows into the common liquid chamber 21 through the ink supply port 28 and the ink supply port 22, and is supplied. The ink supply port 22
The elastic cap 23 provided on the
And the cut is opened. The ink tank 27 that has contracted once is released from the pressed state by the movement of the recording head 11 and the bellows portion 2.
The volume returns to the original volume by the self-restoring force of 7a. At this time,
The check valve 30 is opened and air corresponding to the volume of ink supplied to the recording head 11 flows into the ink tank 27 from the air inlet 29. The elastic cap 23 provided in the ink supply port 22 closes the cut when the ink supply port 28 is separated, thereby preventing intrusion of dust and the like. The ink supply to the recording head 11 is performed by repeating the above ink supply operation from once to a plurality of times.

As described above, according to this embodiment, since the recording head 11 and the ink tank 27 are provided separately, the recording head 11 reciprocated by the recording head moving means can be reduced in size and weight. The moving space of the recording head 11, which is a dead space, can be reduced, and the entire apparatus can be reduced in size. Further, since the recording head 11 is lightweight, the current consumption of the drive motor 18 can be reduced, and the battery life and the like can be extended. Further, since piping of a long tube is not required, assembly can be facilitated. Further, since the ink tank 27 is contracted by the driving force of the driving motor 18 for moving the recording head 11 to the home position and the pump is operated, ink can be supplied without providing a special pump. Further, in the present embodiment, since the polyurethane foam 24 is provided in the common liquid chamber 21, each discharge nozzle 2 is formed by the capillary phenomenon of the polyurethane foam 24.
Ink can be satisfactorily spread to zero, and it is possible to prevent an ejection error caused by air being mixed into the ejection nozzle 20. Further, since the filter 25 is provided between the common liquid chamber 21 and the discharge nozzle 20, clogging of the discharge nozzle 20 can be prevented. In the present embodiment, the ink supply port 22 and the ink supply port 28 are connected when the recording head 11 is at the home position at the time of printing standby or when the printer is stopped. Mixing can be prevented.

In this embodiment, the ink supply port 22 is pressed against the ink supply port 28 by moving the recording head 11 side.
The connection is not limited to this. For example, the ink tank 27 is driven and moved by a solenoid or the like (connection means) and the ink supply port 28 is moved to the ink supply port 22 of the recording head 11 located at the home position. Press on
You may make it connect. In this embodiment, the ink supply port 22 and the ink supply port 28 are opposed to each other in the main scanning direction. However, the present invention is not limited to this, and may be in any direction. Further, in the present embodiment, the ink supply port 28 is formed integrally with the ink tank 27, but the present invention is not limited to this. The ink tank and the supply port are separately provided, and the pipe and the tube or the supply port and the ink tank are provided. The connection may be made by a flow path formed in a holder or the like for holding.

Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those described in the above embodiment are denoted by the same reference numerals, and detailed description is omitted. In this embodiment, an ink tank 31 is provided instead of the ink tank 27 of the above embodiment. As shown in FIG. 6, the ink tank 31 has a cylindrical ink supply port 32 projecting from the recording head 11 at a position facing the ink supply port 22. Then, a tapered taper shaft 33 serving as an ink transfer means is penetrated from the inside of the ink tank 31 to the ink supply port 32. This taper shaft 3
Reference numeral 3 denotes an ink supply port which is urged outward by a spring 34 in the ink tank 31 so that its own taper fits with a tapered portion 32 a formed on the inner peripheral portion of the ink supply port 32. 32 is closed. The tip of the tapered shaft 33 protrudes from the tip of the ink supply port 32.

In such a configuration, the recording head 11
Next, an ink supply operation for supplying ink from the ink tank 31 will be described. First, the recording head 11 is moved to the home position by being driven by the drive motor 18. And
When the recording head 11 moves to the home position, the ink supply port 22 of the ink tank 31 and the ink supply port 32 of the ink tank 31 that are opposed to each other are connected with this movement. At this time, the tip of the tapered shaft 33 projecting from the tip of the ink supply port 32 abuts on the recording head 11, and the tapered shaft 33 is pushed into the ink tank 31. Therefore, the ink that has been pushed in by the tapered shaft 33 is pushed out of the ink tank 31, flows into the common liquid chamber 21 through the ink supply port 32 and the ink supply port 22, and is supplied. Then, when the recording head 11 moves, the pushed-in taper shaft 33 returns to the position before being pushed by the urging force of the spring 34. At this time, the check valve 30 is opened and the air corresponding to the ink volume supplied to the recording head 11 flows into the ink tank 31 from the air inlet 29. The above-described ink supply operation is repeated once to a plurality of times to supply ink to the recording head 11.

[0022]

According to the first aspect of the present invention, there is provided a recording head having a discharge nozzle, a flow path communicating with the discharge nozzle, and an ink supply port for guiding ink from outside to the flow path.
A recording head moving means for reciprocating the recording head in the main scanning direction, and an ink tank having an ink supply port at a position facing the ink supply port of the recording head moved to a predetermined position by the recording head moving means. In the ink jet printer, the ink supply port and the ink supply port are connected, and the ink in the ink tank is transferred to the recording head by a pump operation via the ink supply port and the ink supply port. Therefore, the recording head and the ink tank can be separated from each other, and the recording head can be made smaller. Therefore, the moving space of the recording head can be reduced, and the apparatus can be downsized. Because it can be made lighter, the energy required to reciprocate the recording head can be reduced. In addition, since only the ink tank can be replaced, the running cost can be reduced, and the ink supply port and the ink supply port do not need to be connected by a tube or the like at the time of assembling, so that they can be easily assembled. And the like.

According to the second aspect of the present invention, since the ink impregnated member for generating the capillary phenomenon is provided in the flow path from the ink supply port to the discharge nozzle, the ink supply port is formed by the capillary phenomenon of the ink impregnated member. Ink can be satisfactorily guided from the nozzles to the discharge nozzles, and it is possible to prevent an ejection error caused by air being mixed into the discharge nozzles.

According to the third aspect of the present invention, since the ink transfer means is driven by the connection operation of the connection means for connecting the ink supply port and the ink supply port which are opposed to each other, the drive for driving the ink transfer means is provided. Means can be omitted, and there are effects that the size of the device can be reduced and the cost can be reduced. According to the invention described in claim 4, the ink
Since the tank is not mounted on the print head moving means,
The head moving means can be made very small and lightweight,
Therefore, it can be driven by a small motor with low power.
The entire printer can be made compact,
In addition, the effect that the power consumption of the whole printer is small
Having.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall configuration of a first embodiment of the present invention.

FIG. 2 is a plan side view showing a recording head.

FIG. 3 is a perspective view showing a recording head.

FIG. 4 is a longitudinal sectional side view showing a connection state between an ink tank and a recording head.

FIGS. 5A and 5B are explanatory views showing a connection state between an ink supply port of a recording head and an ink supply port of an ink tank. FIG. 5A is a perspective view showing a separated state, and FIG.

FIG. 6 is a longitudinal sectional side view showing a connection state between an ink tank and a recording head according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Recording head 19 Recording head moving means and connection means 20 Discharge nozzle 22 Ink supply port 24 Ink impregnated member 27, 31 Ink tank 27a, 33 Ink transfer means 28, 32 Ink supply port

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takesada Hirose 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Tetsuro Hirota 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Hideki Otsuki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-5-238016 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B41J 2/175

Claims (4)

(57) [Claims] 1. A print head having a discharge nozzle, a flow path communicating with the discharge nozzle, and an ink supply port for guiding ink from the outside to the flow path, and a print head movement for reciprocating the print head in the main scanning direction. And an ink tank having an ink supply port at a position opposed to the ink supply port of the recording head moved to a predetermined position by the recording head moving means, wherein the ink supply port and the ink supply port are provided. And the ink in the ink tank is pumped to the recording head through the ink supply port and the ink supply port .
Jet printer, characterized in that the transport Ri. 2. The ink jet printer according to claim 1, wherein an ink impregnating member for generating a capillary phenomenon is provided in a flow path from the ink supply port to the discharge nozzle. 3. An ink transferring means driven by a connecting operation of a connecting means for connecting an ink supply port and an ink supply port which are opposed to each other.
The ink-jet printer as described. 4. A printhead having a discharge nozzle, a flow path communicating with the discharge nozzle, and an ink supply port for guiding ink from the outside to the flow path, and a printhead movement for reciprocating the printhead in the main scanning direction. Means and an ink tank comprising an ink tank for supplying ink to the recording head, wherein the ink tank is located in the ink jet printer, and is arranged separately from the recording head moving means, and the recording head is An ink jet printer characterized in that ink is supplied from the ink tank to the recording head by a pump operation when the recording head is moved back and forth by the recording head moving means when the recording head is located at a home position.