JP3347493B2 - Ink jet device - 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 apparatus having a line head in which a plurality of head units each having a plurality of discharge ports for discharging liquid are arranged.

[0002]

2. Description of the Related Art In addition to an output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, or a facsimile apparatus having a transmission / reception function, an ink jet apparatus which can be applied to a textile printing apparatus, etc. A line head having a plurality of head units in which a plurality of ejection ports for ejecting liquids such as dyes (hereinafter collectively referred to as ink) is provided. Has a print width corresponding to the width of the print medium, it is possible to perform desired printing on the print area only by transporting the print medium such as recording paper or cloth. In addition, since the line head is fixed, the mechanism is simple and the number of movable parts can be reduced, so that noise and vibration can be reduced. The required time can be greatly reduced.

However, in such an ink jet apparatus, it is difficult to manufacture a long line head with high reliability and at a low cost. Therefore, conventionally, a plurality of ejection ports for ejecting ink are formed. In many cases, a pseudo line head in which a plurality of head units are arranged while being shifted up and down is substituted.

[0004] In the above-described ink jet apparatus, if the ejection openings are clogged with bubbles or dust, or if the ink that has become highly viscous due to evaporation of water remains, ink ejection failure occurs. In order to eliminate such ink ejection failure, a method of collectively sucking and recovering the entire line head and an independent recovery unit provided for each head unit constituting the line head are provided. A method is known in which only the unit is selectively suction-recovered.

[0005]

According to the method of collectively recovering the entire line head of an ink jet apparatus when an ink discharge failure occurs, a recovery action works on all the discharge ports, so that a large amount of ink is wasted. Will be consumed.

In this respect, in a method of providing independent recovery means for each head unit constituting a line head and selectively recovering by suction only the head unit in which an ejection failure has occurred, ink consumption is minimized. However, it is necessary to provide recovery means of a number corresponding to the number of head units, and there are many mechanical restrictions in terms of an increase in the number of parts, installation space, and the like, and the manufacturing cost is greatly increased.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to efficiently and inexpensively eliminate defective ink ejection of a line head having a plurality of head units each having a plurality of ejection openings for ejecting liquid. An object of the present invention is to provide an ink jet device.

[0008]

[0009]

According to the present invention, there is provided an ink jet apparatus comprising: a line head in which a plurality of head units each having a plurality of discharge ports for discharging liquid are arranged in a staggered manner; A plurality of suction ports arranged in a staggered manner that can face each other, a plurality of communication pipes having one end communicating with the plurality of suction ports, and a row communicating with the other end of each of the plurality of communication pipes. A head cap having a plurality of connection ports arranged in a row, and a discharge failure of liquid from the discharge ports formed in any of the head units movably provided so as to communicate with any of the connection ports. And recovery means for recovering each of the head units. Here, a positioning unit for identifying the position of the recovery unit with respect to the head cap may be further provided so that an arbitrary head unit and the recovery unit can face each other. Also, the recovery means
A slider that is attached to the head cap movably along the arrangement direction of the connection ports and can communicate with any connection port;
A suction pump connected to the slider and capable of recovering a defective discharge of liquid from a discharge port formed in the head unit for each head unit may be provided.

[0010]

[0011]

According to the present invention, at the time of test printing for confirming that the liquid is normally discharged from all the discharge ports of the line head, the identification code corresponding to each head unit is printed together. The head unit having the ink ejection failure is identified by its identification code.

The position of the recovery means with respect to the connection port of the head cap is set by using the positioning means based on the identification code, so that the connection port connected to the head unit in which the ink ejection failure has occurred and the recovery port are connected. The recovery operation of the head unit is performed by directly facing the means.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the present invention is applied to an ink jet recording apparatus will be described in detail with reference to FIGS.

As shown in FIG. 1 showing a schematic structure of a main part of an ink jet recording apparatus according to this embodiment and FIG. 2 in which a line head and a head cap are extracted and enlarged, a line head 12 incorporated in a housing 11 is The main part is constituted by a plurality of head units 13 (14 units in the illustrated example) each having a plurality of ejection ports formed on the front surface, and these head units 13 correspond to a range corresponding to the entire width in the width direction of a recording medium (not shown). Are arranged in a staggered manner vertically.

A head cap 14 which can face the front of the line head 12 is held reciprocally in a direction opposite to the line head 12 with respect to a cap bracket 15 extending in the width direction of the recording medium.
An actuator 16 that can move the head cap 14 in the direction facing the line head 12 is provided between the head bracket 4 and the cap bracket 15. That is, by operating the actuator 16, the head cap 14 can be brought into close contact with the line head 12, and conversely, the head cap 14 can be separated from the line head 12.

The cap bracket 15 is connected at one end in the width direction to a wire 19 wound around a pulley 18 which is driven by a cap elevating motor 17 installed in the housing 11 and is guided via a guide device (not shown). The head cap 14 is moved up and down with respect to the housing 11 between a recovery work position facing the front surface of the line head 12 and a standby position shown in FIG.

Incidentally, between the housing 11 and the wire 19,
A tension adjusting member 20 for appropriately holding the tension of the wire 19 is provided.

A head cap 1 is provided at the upper end of the housing 11.
A pair of head cap rising end detection sensors 21 and 22 for setting a recovery work position which is a rising end of the head 4 is provided. At the lower end of the housing 11, a head cap lowering edge detection sensor 23 for setting a standby position which is a lowering edge of the head cap 14 which does not hinder the recording operation during a recording operation of the ink jet recording apparatus is provided. ing. These head cap rising end detection sensors 2
In this embodiment, a photocoupler is used as each of the headcaps 1 and 22 and the head cap lowering end detection sensor 23. A light-shielding dog plate 24 that blocks the optical path of the rising end detection sensors 21 and 22 and blocks the optical path of the head cap falling end detection sensor 23 at the standby position of the head cap 14 is mounted.

FIG. 2 and FIG. 3 showing the disassembled structure of the head cap 14 in this embodiment, and FIG. 4 showing the appearance of the head cap 14 on the side facing the line head 12.
As shown in FIG.
Is a positioning knob which is slidably engaged with the outer cover 26 having an elongated hole 25 formed along the width direction of the recording medium along the elongated hole 25 of the outer cover 26 and operated by an operator. 27, a partition plate 29 housed in the outer cover 26 and having connection ports 28 corresponding to the number of the head units 13 formed at predetermined intervals along the elongated holes 25, and the outer cover 26 sandwiching the partition plate 29. , And a main part is constituted by the press plate 30 which can face the line head 12.

A slider 32 is connected to the positioning knob 27 via an O-ring 31 in sliding contact with the partition plate 29. An opening (not shown) communicating with a suction pump (not shown) through a suction pipe 33 connected to a positioning knob 27 is formed on the distal end surface of the slider 32 surrounded by an O-ring 31 facing the partition plate 29. Have been. A plurality (four in the illustrated example) of suction pockets 35 each having a suction port 34 capable of directly facing the head unit 13 of the line head 12 are provided inside the holding plate 30 vertically along the width direction of the recording medium. The suction pockets 35 and the connection ports 28 of the partition plate 29 are in communication with each other via a communication pipe 36. Further, a seal packing 37 surrounding each suction port 34 is protrudingly provided on the distal end surface of the holding plate 30. These seal packings 37 are formed of an elastic elastic material such as rubber, and when the head cap 14 moves toward the line head 12 at the recovery operation position, the head cap 14 is compressed and deformed so as to surround each head unit 13. And the suction port 34 of the suction pocket 35 communicate with each other in a liquid-tight manner.

On the other hand, the outer cover 26 is provided with an identification code R corresponding to a unique number assigned to each head unit 13 in advance, and in this embodiment, reference numerals 1 to 14 are shown in FIG. The number is assigned to the head unit 13. When the pointer 38 provided on the positioning knob 27 is aligned with the mark L of each identification code R, the suction pocket 35 which can face the head unit 13 corresponding to the identification code R coincides with the suction pocket 35. Knob 27
The positions of the marking lines L corresponding to the identification codes R are set so that the suction pipes 33 communicate with each other.

On the other hand, when performing test printing for confirming normal ejection of the line head 12, according to a procedure previously incorporated in a controller (not shown) in the housing 11, the above-described printing pattern shown in FIG. The identification code R of the head unit 13 and the corresponding identification code R are printed together. As this print pattern, any pattern may be used as long as normal discharge of all the discharge ports of each head unit 13 can be confirmed. In the present embodiment, the corresponding identification code R is printed on the upper side of the print pattern of each head unit 13 from 1 to 14 in order from the right side in FIG.

The identification code R of each head unit 13
As a matter of course, it is naturally possible to adopt other characters other than the numbers as in the present embodiment.

When a printing failure occurs during use of the ink jet recording apparatus, a test pattern shown in FIG. 5 is printed. Then, it is ascertained in which head unit 13 of the identification code R the printing failure has occurred. Next, the cap lifting / lowering motor 17 is driven to raise the head cap 14 from the standby position to the recovery work position together with the cap bracket 15 via the wire 19. Then, at this recovery work position, the actuator 16 is further driven to advance the head cap 14 toward the line head 12, and each head unit 13 and the suction port 34 of the suction pocket 35 are made liquid-tight via the seal packing 37. Communicate. Thereafter, the operator aligns the pointer 38 of the positioning knob 27 with the mark L of the identification code R corresponding to the identification code R of the head unit 13 in which printing has failed, and drives a suction pump (not shown) to perform printing. Suction pocket 3 for ink or the like from the ejection opening of defective head unit 13
5, suction port 34 and communication pipe 36, connection port 28 of partition plate 29, O-ring 31, opening of slider 32, communication pipe 3
Then, the head unit 13 is subjected to a recovery process by sucking and discharging the ink through the nozzles 3 in order.

As described above, ink is sucked only from the head unit 13 in which a discharge failure has occurred, and the cause of the failure is removed. Therefore, a suction pump used with a low capacity is sufficient. Unnecessarily wasting ink from the head unit 13 that is not in use can be prevented.

After the recovery process is completed, the actuator 16 is again driven in the reverse direction to separate the head cap 14 from the line head 12, and the cap lifting motor 17 is driven in the reverse direction to move the head cap 14 to the recovery work position. To the standby position.

The present invention includes a means (for example, an electrothermal conversion element or a laser beam) for generating thermal energy as energy used for performing ink ejection, particularly in an ink jet system. The present invention provides excellent effects in an ink jet head or an ink jet apparatus of a type in which a change in the state of ink is caused by energy. According to such a method, it is possible to achieve higher density and higher definition of the print.

The typical configuration and principle are described, for example, using the basic principle disclosed in US Pat. No. 4,723,129 and US Pat. No. 4,740,796. What is performed is preferred. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to a sheet or ink path holding ink. Applying at least one drive signal to the electrothermal transducer that provides a rapid temperature rise exceeding nucleate boiling corresponding to the print information, thereby generating heat energy in the electrothermal transducer and causing the thermal action of the inkjet head This is effective because film boiling occurs on the surface, and as a result, bubbles in the ink corresponding to the drive signal one-to-one can be formed. The ink is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubbles are performed immediately and appropriately, so that the ink ejection with particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in U.S. Pat. Nos. 4,463,359 and 4,345,262 are suitable. It should be noted that U.S. Pat. No. 4,313,124 relating to the invention relating to the rate of temperature rise of the heat acting surface.
If the conditions described in the specification are adopted, more excellent printing can be performed.

The structure of the ink jet head may be a combination of a discharge port, an ink path, and an electrothermal transducer (a linear liquid flow path or a right-angle liquid flow path) as disclosed in the above-mentioned respective specifications. U.S. Pat. No. 4,558,333, which discloses a configuration in which the heat acting portion is arranged in a bending region.
No. 4,459,600 are also included in the present invention. In addition, Japanese Patent Application Laid-Open No. Sho 59-1 discloses a configuration in which a common slit is used as a discharge section of an electrothermal transducer for a plurality of electrothermal transducers.
No. 23670, and Japanese Patent Application Laid-Open No. 59-1 discloses a configuration in which an opening for absorbing a pressure wave of thermal energy is made to correspond to a discharge portion.
The effect of the present invention is effective even in a configuration based on Japanese Patent No. 38461. That is, according to the present invention, printing can be performed reliably and efficiently regardless of the form of the inkjet head.

Further, the present invention can be effectively applied to a full line type ink jet head having a length corresponding to the maximum width of a print medium on which an ink jet apparatus can print. Such an ink jet head may have a configuration that satisfies the length by a combination of a plurality of ink jet heads or a configuration as a single integrally formed ink jet head.

In addition, even in the case of the serial type as described above, an ink jet head fixed to the apparatus body,
Alternatively, a replaceable chip-type ink jet head that can be electrically connected to the device main body and supplied with ink from the device main body by being attached to the device main body, or an ink tank is provided integrally with the ink jet head itself The present invention is also effective when a cartridge type ink jet head is used.

Further, it is preferable to add a discharge recovery means for the ink jet head, a preliminary auxiliary means, and the like as the constitution of the ink jet apparatus of the present invention since the effect of the present invention can be further stabilized. If these are specifically mentioned, capping means for the ink jet head, cleaning means, pressurizing or suction means,
Preheating means for performing heating using an electrothermal conversion element, a heating element different from this, or a combination thereof, and preliminary discharging means for performing discharging different from printing can be used.

The type and number of ink jet heads to be mounted are, for example, not only one provided for a single color ink but also a plurality of inks having different print colors and densities. A plurality may be provided. That is, for example, the print mode of the ink jet apparatus is not limited to the print mode of only the mainstream color such as black, and may be either an integrated ink jet head or a combination of a plurality of ink jet heads. The present invention is also very effective for an apparatus provided with at least one of the full-color print modes using mixed colors.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink in a liquid state may be used. In addition, in order to positively prevent the temperature rise due to thermal energy by using the energy of the state change of the ink from the solid state to the liquid state, or to prevent the ink from evaporating, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy such as the one in which the ink is liquefied by the application of the heat energy in accordance with the print signal and the liquid ink is ejected, and the one which already starts to solidify when reaching the print medium, etc. The present invention can also be applied to a case where an ink that liquefies for the first time is used. In such a case, the ink is held in a state of being held as a liquid or solid substance in the concave portion or through hole of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, a configuration in which the electrothermal conversion element is opposed to the electrothermal conversion element may be adopted. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition to the above, the form of the ink jet apparatus according to the present invention can be used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. May be adopted.

[0036]

[0037]

According to the present invention, the recovery means for recovering the liquid discharge failure from the discharge port formed in the head unit for each head unit is held movably with respect to the connection port of the head cap. Since the positioning means for identifying the position of the recovery means with respect to the connection port of the head cap is provided, the connection port communicating with the head unit having a discharge failure is directly opposed to the recovery means, and the discharge failure is extremely reduced. It can be resolved easily and quickly. In addition, the pump used for the recovery means can be reduced in capacity and the liquid is not sucked from the normal head unit, so that wasteful consumption of the liquid can be suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a main part in a see-through state in an embodiment in which the present invention is applied to an ink jet recording apparatus.

FIG. 2 is a perspective view in which an inkjet head and a head cap in the embodiment shown in FIG. 1 are extracted and enlarged.

FIG. 3 is an exploded perspective view of a part of a head cap in the embodiment shown in FIGS. 1 and 2;

FIG. 4 is a perspective view of the appearance of the head cap in the embodiment shown in FIGS.

FIG. 5 is a cutaway view showing an example of a print pattern of a test print according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Housing 12 Line head 13 Head unit 14 Head cap 15 Cap bracket 16 Actuator 17 Cap raising / lowering motor 18 Pulley 19 Wire 20 Tension adjusting member 21, 22 Head cap rising end detection sensor 23 Head cap falling end detection sensor 23 24 Dog plate 25 Slot 26 Outer cover 27 Alignment knob 28 Connection port 29 Partition plate 30 Press plate 31 O-ring 32 Slider 33 Suction tube 34 Suction port 35 Suction pocket 36 Communication tube 37 Seal packing 38 Pointer L Marking line R Identification code

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/18 B41J 2/185

Claims (3)

(57) [Claims] A line head in which a plurality of head units each having a plurality of ejection ports for ejecting liquids are arranged in a staggered manner, and a line head is arranged in a staggered manner capable of directly facing the head units.
A plurality of suction ports arranged in
A plurality of communication pipes each communicating with the suction port, and
Are arranged in a line to communicate with the other end of the communication pipe
A head cap having a plurality of connection ports, and a discharge failure of liquid from the discharge ports formed in any of the head units provided movably so as to communicate with any of the connection ports. An ink jet apparatus comprising: a recovery unit that can recover each head unit. 2. The apparatus according to claim 1, further comprising positioning means for identifying a position of said recovery means with respect to said head cap so that any said head unit and said recovery means can face each other. An inkjet device according to item 1. Wherein said recovery means includes a slider capable of communicating with any of the connection ports attached to the head cap movably along the direction of arrangement of the prior SL connection port, the head connected to the slider ink jet apparatus according to claim 1 or claim 2, characterized in that have a suction pump capable of recovering the ejection failure of the liquid from the discharge port formed in the unit for each individual of the head unit.