JP2007223129A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To permit the obtainment of a good printing result by suppressing a blower to dry inks on a printing surface from blowing up wasteful ink mists and dust. <P>SOLUTION: The blower communicates with an electromagnetic valve controlled so as to open and close by a controller, and performs the start and stop of blowing by the opening and closing of the electromagnetic valve and is connected to a head portion carrying an inkjet head. During printing, the controller controls printing mediums so as to deliver them in a prescribed direction, so as to move the head portion in the direction intersecting the printing mediums, to discharge an ink from the head portion, to perform printing on the printing mediums and dry the ink sticking to the printing surfaces of the printing mediums by wind jet from the blower. The controller controls the electromagnetic valve so as to stop the blower from blowing when the head portion is in a waiting position and is moving toward a prescribed printing area, so as to put the blower into a blowing state when the head portion enters the printing area and so as to stop the blower from blowing when the head portion finishes printing to the printing medium. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing apparatus that prints on a print medium with an ink ejection type print head and that dries ink drops placed on the print medium with a blower.

When printing with an ink jet printer, there is a problem of drying of ink adhering to the medium. There is no problem as long as the ink is a combination of a printing medium and ink that easily penetrates the ink. However, when printing on a printing medium such as a resin or plastic that hardly penetrates the ink, the ink is fixed mainly by evaporation of the ink solvent. Is called. Therefore, it takes a long time to fix the ink, and the promotion of the ink fixing is a big problem. Usually, since the ink is only evaporated to the air on the print medium, the evaporation is not promoted easily, and when the printing is performed in a closed space surrounded by a cover, Since the air on the print medium does not move, the ink fixing is not promoted. 2. Description of the Related Art Conventionally, a recording apparatus that performs printing after blowing air containing ink mist or evaporated solvent staying in the vicinity of a printing medium before printing with a blower provided on both sides of the recording head is known (for example, Patent Document 1). There is also known an ink jet apparatus in which a gas blowing device is attached to an ink jet head, gas is constantly blown out toward the substrate surface, and solvent vapor evaporated from ink droplets on the substrate is blown off (see, for example, Patent Document 2).
Japanese Patent Laying-Open No. 2005-212323 JP 2001-341296 A

In normal control in which a blower is attached to the head unit to promote drying of ink on the printing surface, the blower is always used in a blown state. It is good when the air is blown on the print medium, but when the air is blown when the air is not necessary, for example, when the head portion is moved to a purge area where ink is discharged or a place outside the print area. In other words, mist and dust will be scattered around the printing device. In addition, when a fan or the like is used as a blower, rotation itself does not stop immediately even if driving is stopped, so that it is not suitable for on / off control of blower.
The main object of the present invention is to solve the above problems.
Also, if a strong wind is blown directly against the printing medium immediately after printing, the ink is blown directly onto the ink before it is dried (fixed), so the ink flows in the blowing direction and drying is accelerated in that state. May result in poor print results. Further, if the air ejected from the blower is dirty, the printing result may be adversely affected. When air is blown on the print medium to promote the evaporation of ink, it is desirable to blow air as close to the print medium as possible in order to increase the efficiency of the spray effect. For example, in the case of a structure in which a hole is formed in a tube as disclosed in Japanese Patent Application Laid-Open No. 2001-341296 of the above Patent Document 2, there is no problem if the air is blown obliquely downward, but the air is blown in parallel to the printing surface. The lower part of the tube is always under the tube hole. Moreover, not only in this structure, but considering that a hole is provided in an object and the air is blown in parallel to the printing surface, the lower surface portion of the air blowing port necessarily exists. Therefore, in a printing apparatus using an inkjet head, since the distance between the paper surfaces with the printing medium is very small, it is physically impossible to project an object below the head portion. It is very difficult to move only air in parallel in the lower part.
In addition, when using a blower in the vicinity of the head section with inkjet, the printing method discharges minute droplets of ink, so the air flow during printing has a subtle effect on the flying ink, and printing. May be adversely affected. Therefore, it is desirable to prevent the wind from flowing under the head part if possible.
Another object of the present invention is to solve the above problems.

To achieve the above object, according to the present invention, in a printing apparatus provided with a blower device that promotes drying of ink after printing on a head unit, the blower of the blower device is stopped only at a designated place in the head unit scanning direction. In order to perform this, a blower control mechanism is provided that controls the blower and the blower stop by the moving position of the head unit in the scanning direction during the printing operation.
The present invention also provides a print medium transport mechanism for transporting a print medium in a predetermined direction, a head portion on which an ink jet head is mounted, and the head portion reciprocates between a print area and a print area. A head unit moving mechanism, a controller, and a blower connected to the head unit that communicates with an electromagnetic valve that is controlled to be opened and closed by the controller, and performs blowing and stopping by opening and closing the electromagnetic valve, Under the control of the controller, the print medium is sent in a predetermined direction, while the head unit is moved in a direction crossing the print medium, and ink is ejected from the head unit toward the print surface of the print medium to print the print medium. An ink jet printer that prints on the surface and blows air from the blower to dry the ink adhering to the print surface of the print medium. Thus, when the head unit is in the standby position and during movement from the standby position toward a predetermined print area, the air blower is stopped and when the head unit enters the print area, the air blower is turned off. The controller controls the solenoid valve so that the air blower is stopped and the air blower is stopped when the head unit finishes printing on the print medium.
The present invention also has a support surface for supporting the print medium, a print medium transport mechanism for transporting the print medium in a predetermined direction, a head portion on which the inkjet head is mounted, and the head portion within the print area. A head unit moving mechanism for reciprocating between a print area and a standby position in a direction orthogonal to the transport direction of the print medium, a controller, and an electromagnetic valve controlled to open and close by the controller, Blowing and stopping are performed by opening and closing, and a blowing device connected to a side portion on the rear side with respect to the print movement direction of at least the head portion in the both sides of the head portion, and under the control of the controller, While feeding the print medium in a predetermined direction, the head unit is moved in a direction across the print medium, and ink is ejected from the head unit toward the print surface of the print medium, An ink jet printing apparatus that performs printing on a character medium, wherein the blower device includes an air nozzle that blows air toward the printing surface, and the Coanda effect is provided at the bottom of the blower device. A wall surface that generates a horizontal airflow in a direction substantially perpendicular to the ink ejection direction toward the direction away from the adjacent head portion, on the lower side of the blower. When in the standby position and during the movement from the standby position toward the predetermined print area, the air blower is stopped from blowing, and when the head unit enters the print area, the air blower is brought into the air blowing state. When the printing on the print medium is finished, the controller controls the solenoid valve so that the blower stops air blowing.
Further, the invention is characterized in that the print area is a predetermined area wider than a print medium defined by a print medium support surface that supports the print medium.
In the present invention, the print area is an area defined by a print medium, and the air blowing is performed only on the print medium.
Further, the present invention is characterized in that the blower device is attached to both sides of the head portion.
Moreover, this invention provides the air circulation hole which supplies the air drawn in into the said horizontal airflow from the upper direction between the said head part and the said air blower.
According to the present invention, a shielding member is provided between the head unit and the blower to prevent negative pressure due to the horizontal air current from reaching the lower part of the head unit.
Moreover, the present invention is characterized in that the horizontal air flow is jetted from substantially the entire longitudinal direction of the blower.
In the present invention, a filter for removing dirt from the air is disposed in the air supply path of the blower.
Moreover, this invention makes the direction of the horizontal airflow ventilated from the said air blower substantially parallel with respect to the moving direction of the said head part.
Moreover, this invention makes the direction of the horizontal airflow ventilated from the said air blower slanted with respect to the moving direction of the said head part.

Since the present invention controls the two states of air blowing and air blowing stop with the movement of the head part, it is possible to suppress the rising of wasteful ink mist or dust outside the printing area, so that good printing The result can be obtained.
Further, according to the present invention, since the horizontal airflow is sent from the air blower in a direction substantially perpendicular to the ink ejection direction, the airflow does not directly affect the ink immediately after printing. Ink does not flow in the blowing direction and drying is not accelerated in this state.
In addition, since the horizontal air flow generation unit is provided at the bottom of the blower, the horizontal air flow can be easily brought close to the printing surface. In addition, since the filter acts on the gas to be blown, it is possible to prevent the ink after printing from being adversely affected.
In the invention of claim 11, by providing the air blowing device obliquely, the air can be influenced not only immediately after printing but also on the ink after the printing medium after printing is conveyed. In addition, since an air supply area is provided between the head unit and the blower so that air can flow from other than under the head unit, the influence of the airflow from the blower under the head unit can be further reduced. Good printing results can be obtained.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory diagram showing a schematic configuration of an inkjet printing apparatus according to the present invention, and the inkjet printing apparatus includes a Y-axis rail 2 that extends in the Y-axis direction and is horizontal to the floor surface. The Y-axis rail 2 is installed on the body (not shown) of the ink jet printing apparatus. A head portion 4 is connected to the Y-axis rail 2 via a carriage 6 so as to be capable of reciprocating along the longitudinal direction of the Y-axis rail 2.

On the substrate of the head unit 4, ink discharge nozzles of a plurality of inkjet print heads are arranged in the same plane in the opening of the bottom of the head unit 4. A platen 8 (mounting plate) is supported by the machine body below the Y-axis rail 2. A gap (not shown) extending in a direction parallel to the Y-axis rail 2 is formed in the platen 8, and a conveying plate 10 is orthogonal to the Y-axis rail 2 as shown in FIG. A driving roller 12 for conveying in the X-axis direction is rotatably arranged.

The drive roller 12 is linked to an X-axis drive mechanism including a motor controlled by a controller. On the extended plane of the platen 8 in a direction perpendicular to the longitudinal direction of the Y-axis rail 2, there are provided a plurality of conveying plate guide auxiliary mechanisms 14 and 16 made of rollers arranged in parallel. A plurality of pressure rollers 18 are supported on the Y-axis rail 2 side so as to be movable up and down via roller support members corresponding to the drive rollers 12. The head unit 4 is provided with an object detection sensor (not shown) that detects the print medium 20 on the transport plate 10.

  In the scanning movement path along the Y-axis rail 2 of the head unit 4, as shown in FIG. 5, a home position (the position at which the head unit 4 waits at a position deviating from the printing area on the platen 8). A standby position) is provided, and at the home position, a purge box 22 for performing maintenance of the nozzles of the inkjet head, for example, idle ejection of ink and cleaning of the nozzles, is disposed. When the head unit 4 is waiting at the home position, capping to the nozzle is also performed so that the ink in the nozzle does not dry.

Blowers 24 and 25 are attached to both sides of the head portion 4 via a connecting body 23 so as to be positioned in the front and rear of the print movement direction along the Y-axis rail 2. As shown in FIG. 4, the air blowers 24 and 25 are provided with an air nozzle 26 formed in a thin space perpendicular to the support plane of the platen 8 that is horizontal to the floor surface inside the apparatus main body 28. The high pressure air is supplied to the air nozzle 26 from a high pressure chamber inside the apparatus main body 28. The air nozzle 26 a of the air nozzle 26 opens at the bottom of the apparatus main body 28.

On the bottom wall surface of the apparatus main body 28, the flow of compressed air injected perpendicularly to the support plane of the platen 8 or the conveying plate 10 or the print plane of the print medium 20 from the air outlet 26a of the air nozzle 26 is subjected to the Coanda effect. As a result, a curved surface 30 and a parallel surface 32 are formed to change in a direction that is horizontal to the support plane of the platen 8 or the conveyance plate 20 or the print plane of the print medium 20 and opposite to the direction toward the head unit 4. Yes. The air outlet 26a is in contact with the upper part of the curved surface. The connecting body 23 between the blower devices 24 and 25 and the head part 4 is formed with an air circulation hole 35 for supplying the air above the blower devices 24 and 25 to the lower side of the blower devices 24 and 25. . FIG. 1 shows an air supply mechanism for supplying air to the blowers 24 and 25.

This air supply mechanism includes a pneumatic pump 34 (compressor) disposed on the airframe side, electromagnetic valves 36, 38, and 40 that open and close an air passage as necessary, and a filter 42 that removes dust in the air. , And a regulator 44 that adjusts the air pressure to be constant, and these are connected by a tube. The tubes 46 and 48 connected to the respective output ports of the solenoid valves 38 and 40 are connected to the air inlets of the device main bodies 28 of the corresponding blower devices 24 and 25 via a connector and are pumped from the pump 34. Air is configured to be supplied to the high-pressure chamber in the apparatus main body 28 via the electromagnetic valves 38 and 40. As shown in FIG. 7, the air blowers 24 and 25 send a horizontal air current from substantially the entire longitudinal direction of the apparatus main body 28. In this embodiment, the horizontal air current sending range is substantially the same as the print width of the head unit 4. Of course, the horizontal air current sending range, that is, the width of the air nozzle 26 may be larger than the print width.

The printing apparatus includes a controller, and the controller controls the driving units such as the driving roller 12, the head unit 4, the air supply mechanism, and the head unit moving mechanism to perform printing on the printing medium 20 on the transport plate 10. Thus, the printing program and the blower control program are stored in the storage device of the controller.
Next, the printing operation of the printing apparatus will be described.

  A plate-shaped print medium 20 is set on the conveyance plate 10, and the print medium 20 is sandwiched between the drive roller 12 and the pressure roller 18 together with the conveyance plate 10 as shown in FIG. 3. In this state, under the control of the controller, the drive roller 12 is intermittently rotated counterclockwise in FIG. 3, and the print medium 20 is fed leftward in FIG. On the other hand, under the control of the controller, the head unit 4 is fed along the Y-axis rail 2 in a direction perpendicular to the transport direction of the print medium 20 and from the nozzles of the inkjet head mounted on the head unit 4 to the platen. 8 or ink is ejected to the support plane of the transport plate 10 or the print plane of the print medium 20, and printing is performed on the print medium 20 on the transport plate 20. In carrying out the present invention, the present invention is not particularly limited to a printing apparatus using a conveyance plate. A printing apparatus that performs printing on a normal roll paper or cut paper as a printing medium or a rotary drum structure as a platen. It is possible to use various types of printing apparatuses, and the present invention is not particularly limited to the configuration of the printing apparatus illustrated.

  During the printing, as shown in FIG. 1, the blower 24 on the rear side with respect to the moving direction of the head unit 4 is driven by the control of the controller. The air jetted from the air outlet 26 a of the air nozzle 26 of the blower 24 is parallel to the support plane or the print plane of the print medium 20 by the curved surface 30 and the parallel plane 32 formed on the wall surface of the apparatus body 28. And a horizontal airflow H that flows above the print surface of the print medium 20 in a direction opposite to the direction of movement of the head unit 4.

The horizontal airflow H generates a negative pressure in the vicinity of the air outlet 26a. The negative pressure acts as a suction force for drawing air from the air circulation hole 35 provided between the head portion 4 and the apparatus main body 28. To do. Thereby, it is possible to suppress the influence of the negative pressure accompanying the generation of the horizontal airflow H from reaching the lower side of the head portion 4, and the air below the head portion 4 is sucked by the horizontal airflow by the blower 24. The airflow is not generated. As shown in FIG. 2, the horizontal air flow H generated on the printing plane promotes the evaporation of the solvent (solvent) of the ink immediately after printing, and the time required for solidifying the ink is shortened.

In addition to the configuration of the air circulation hole 35, the blowers 24 and 25 and the head are used as means for preventing the air flow from being generated below the head portion 4 due to the negative pressure accompanying the generation of the horizontal air flow H. A shielding member (not shown) such as a partition may be provided between the unit 4 and the unit 4.
Next, the control operation of the blower by the controller will be described with reference to the flowchart shown in FIG.

  When the printing apparatus enters the printing mode, the head unit 4 starts to move leftward in FIG. 5 along the Y-axis rail 2 from the standby position (purge area) shown in FIG. Step 1). At this time, the pump 34 is in a power-on state. Further, under the control of the controller, the solenoid valve 36 is “open” and the solenoid valves 38 and 40 are both “closed”. In FIG. The front blower 24 and the rear blower 25 are both stopped.

Next, the head unit 4 moves above the print medium 20 and scans the print medium 20 with an object detection sensor. As a result, the controller recognizes the position of the print medium 20 (step 2). Next, the head unit 4 moves to the right along the Y-axis rail 2 in FIG. 5, returns to the standby position outside the print area, and stops at that position (step 3) (see FIG. 5A). . When the head portion 4 is in the standby position stop state, the output ports of the solenoid valves 38 and 40 are both kept closed.

Next, the head unit 4 starts moving from the standby position toward the print medium 20 in the left direction from the standby position in FIG. 5 while maintaining the blower stopped state (step 4) (FIG. 4). 5B). Next, as shown in FIG. 5C, the head unit 4 ejects ink on the printing medium 20 and starts a printing operation on the printing plane of the printing medium 20. Simultaneously with the start of the printing operation, the controller opens the output port of the electromagnetic valve 38 and puts the blowing device 25 on the rear side in the blowing state with respect to the printing movement direction of the head unit 4 (step 5).

At this time, the blowing device 24 on the front side remains in the blowing stopped state with respect to the printing movement direction of the head unit 4. During printing, when the head unit 4 moves to the right along the Y-axis rail 2 as shown in FIGS. 1 and 2 while ejecting ink on the print medium 20, the controller controls the solenoid valve 38. The output port of the solenoid valve 40 is closed, the output port of the solenoid valve 40 is opened, the rear blower 24 is selected with respect to the print movement direction of the head unit 4, the blower 24 is brought into a blower state, and the front blower is blown. The device 25 is set to a blown stop state. When printing on the printing medium 20 is completed, the controller stops the ink ejection operation of the head unit 4 (step 6).

At this time, the controller closes both the electromagnetic valve 36 or the electromagnetic valves 38 and 40, and puts the air blowers 24 and 25 into the air supply stop state. Next, the controller determines whether there is print data in the memory with the solenoid valve 36 or both the solenoid valves 38 and 40 closed (step 7). When returning and starting the printing operation and judging negative, the head unit 4 is moved to the standby position with the solenoid valve 36 or both the solenoid valves 38 and 40 closed, and stopped at the standby position ( Step 8) The printing operation is completed.

In FIG. 1, the head unit 4 performs printing only in one direction in the bidirectional movement in FIG. 1, and does not perform printing in the other direction. In this case, it is only necessary to provide a blower device on the side of the head unit 4 that is located rearward with respect to the printing movement direction, and it is not necessary to provide a blower device on both sides of the head unit 4. Further, during printing in step 5, even if both the solenoid valves 38 and 40 are set to “open” and the air blowing devices 24 and 25 on both sides of the head unit 4 are in the air blowing state, the effect of promoting ink on the printing surface can be obtained. .

In the embodiment shown in FIG. 1, the air blowers 24 and 25 on both sides of the head portion 4 have the same structure, and the left and right connecting bodies 35 that connect these to the head portion 4 have the same structure. Used, both sides of the head part 4 are symmetrical in FIG. In the above embodiment, as shown in FIG. 7, the longitudinal direction of the apparatus main body 28 is set parallel to the conveyance direction of the print medium 20, and the blowing direction of the blowing devices 24 and 25 is set to the moving direction of the head unit 4. However, as shown in FIG. 8, the longitudinal direction of the apparatus main body 28 is inclined with respect to the conveyance direction of the print medium 20, and the blowing direction of the blowing devices 24 and 25 is set with respect to the moving direction of the head unit 4. May be inclined. In FIG. 8, the blowing direction of the blowing device 25 is indicated by an arrow. With this configuration, as shown in FIG. 8, the air blower 25 at the rear of the head unit 4 with respect to the print scanning movement direction in the left direction in the drawing (when the head unit 4 scans in the right direction, the air blower 24 ) Can influence not only the ink immediately after printing but also the ink after the printing medium 20 after printing is conveyed.

It is explanatory drawing of the inkjet printing apparatus which concerns on this invention. It is explanatory drawing of an inkjet printing apparatus. It is explanatory drawing of an inkjet printing apparatus. It is explanatory drawing of an inkjet printing apparatus. It is operation | movement explanatory drawing of an inkjet printing apparatus. It is a flowchart which shows operation | movement of an inkjet printing apparatus. It is a plane explanatory view of an ink jet printer. It is a plane explanatory view showing other embodiments of an ink jet printer.

Explanation of symbols

2 Y-axis rail 4 Head unit 6 Carriage 8 Platen 10 Transport plate 12 Drive roller 14 Transport plate guide assist mechanism 16 Transport plate guide assist mechanism 18 Pressure roller 20 Print medium 22 Purge box 24 Blower device 25 Blower device 26 Air nozzle 26a Air Jet port 28 Device body 30 Curved surface 32 Parallel surface 34 Pneumatic pump 35 Air flow hole 36 Solenoid valve 38 Solenoid valve 40 Solenoid valve 42 Filter 44 Regulator 46 Tube 48 Tube

Claims (12)

In a printing device provided with a blower that promotes drying of ink after printing on the head unit, during the printing operation, the blower of the blower device is blown and the blower is stopped only at the specified location in the head unit scanning direction. A printing apparatus comprising a blowing control mechanism for controlling blowing and blowing stop according to a moving position of the head portion in the scanning direction. A print medium transport mechanism for transporting the print medium in a predetermined direction, a head section equipped with an inkjet head, and a head section movement for reciprocating the head section from the standby position to the print area and within the print area A mechanism, a controller, and a blower connected to the head unit that communicates with an electromagnetic valve that is controlled to be opened and closed by the controller, and that is blown and stopped by opening and closing the electromagnetic valve, and is controlled by the controller, While feeding the print medium in a predetermined direction, the head portion is moved in a direction crossing the print medium, ink is ejected from the head portion toward the print surface of the print medium, and printing is performed on the print surface of the print medium. And an ink jet printing apparatus that blows out air from the blower and dries the ink adhering to the print surface of the print medium. When the head portion is in the standby position and during movement from the standby position toward the predetermined print area, the air blower is stopped from blowing, and when the head portion enters the print area, the air blower is in the air blowing state. The printing apparatus according to claim 1, wherein the controller controls the electromagnetic valve so that the air blower is stopped when the head unit finishes printing on the print medium. A print medium transport mechanism having a support surface for supporting the print medium, for transporting the print medium in a predetermined direction, a head portion on which an ink jet head is mounted, the head portion within the print area, and the print area and the standby position. A head portion moving mechanism for reciprocating the print medium in a direction orthogonal to the conveyance direction of the print medium, a controller, and an electromagnetic valve controlled to be opened and closed by the controller. A blower connected to at least one of the two side portions of the head portion that is on the rear side with respect to the print movement direction of the head portion, and the print medium is predetermined by the control of the controller. While moving in the direction, the head portion is moved in a direction crossing the print medium, ink is ejected from the head portion toward the print surface of the print medium, and printing is performed on the print medium. In the ink jet printing apparatus, the blower includes an air nozzle that blows air toward the printing surface, and the air blown from the compressed air nozzle is bent at a right angle by the Coanda effect at the bottom of the blower. A wall surface for generating a horizontal air flow in a direction substantially perpendicular to the ink ejection direction, which is directed to a direction away from the adjacent head unit, on the lower side of the blower, and the head unit is in the standby position. During the movement from the standby position toward the predetermined print area, the air blower is stopped and when the head unit enters the print area, the air blower is brought into the air blow state, and the head unit is moved to the print medium. The printing apparatus is characterized in that the controller controls the solenoid valve so that the blower is stopped when the printing is finished. The printing apparatus according to claim 3, wherein the print area is a predetermined area wider than a print medium defined by a print medium support surface that supports the print medium. The printing apparatus according to claim 3, wherein the print area is an area defined by a print medium, and the air blowing is performed only on the print medium. The printing apparatus according to claim 3, wherein the blower is attached to both sides of the head portion. The printing apparatus according to claim 3, wherein an air circulation hole for supplying air drawn into the horizontal airflow from above is provided between the head unit and the blower. The printing apparatus according to claim 3, wherein a shielding member is provided between the head unit and the blower to prevent negative pressure due to the horizontal airflow from reaching the lower part of the head unit. . The printing apparatus according to claim 3, wherein the horizontal air current is ejected from substantially the entire longitudinal direction of the blower. The printing apparatus according to claim 3, wherein a filter for removing dirt on the air is disposed in an air supply path of the blower. The printing apparatus according to claim 3, wherein a direction of a horizontal air flow blown from the blower is substantially parallel to a moving direction of the head unit. The printing apparatus according to claim 3, wherein a direction of a horizontal air flow blown from the blower is inclined with respect to a moving direction of the head unit.

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