JP2004330615A - Inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder capable of effectively collecting mists. <P>SOLUTION: An air suction duct 18 having an opening section 20 provided in the vicinity of a moving position of a carriage 12 is coupled with an air suction fan 24, and then an air between an ink ejection face 28A of a recording head 28 and a paper 30 is sucked by a negative pressure generated by the operation of the suction fan 24. When the inkjet recorder starts the printing operation, an ink droplet 36 is ejected from the ink ejection face 28A and an image is formed on the paper 30, ink mists consisting of fine droplets of the ink ejected together with the ink droplet 36 is created to be allowed to fly on a portion between the ink ejection face 28A and the paper 30. As the ink mists are unevenly distributed on the portion between the ink ejection face 28A and the paper 30 at a specific distance, a blade 22 provided to the opening section 20 of the suction duct 18 is rotated as shown by the oblique arrow in the drawing to control the suction air to be in the direction of the ink ejection face 28A so that the air in the region where the ink mists 38 are unevenly distributed is mainly sucked, and then the created ink mists 38 can be efficiently sucked to be collected. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inkjet recording device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, it has been known that, when an ink droplet is ejected from a recording head in an ink jet recording apparatus, the ink droplet is separated into a relatively large ink droplet called a main droplet and a small droplet called a satellite. Further, fine droplets (ink mist) smaller than the satellite may be formed.
[0003]
Smaller satellites with lower speeds are more susceptible to the effects of the surrounding airflow before they reach the paper from the printhead, and the main droplets reach the print paper and adhere to locations away from the dots where they were formed. Therefore, the image becomes dirty. Or, it may not reach the paper and float inside the recording device to contaminate the inside of the recording device.
[0004]
Further, mist smaller than the satellite does not reach the recording surface, and floats near the paper, and then contaminates the inside of the apparatus and the margins of the recording paper.
[0005]
Therefore, a mechanism for forcibly generating an airflow by a fan during printing and collecting a part of the floating satellite or mist to a filter or the like has been conventionally disclosed.
[0006]
A mechanism that controls the operation of a fan by moving the carriage in consideration of the influence of wind generated by the movement of the carriage that holds the recording head has also been disclosed (see, for example, Patent Document 1).
[0007]
However, the above method controls the direction of the air flow by controlling the operation of the fan according to the drive control signal of the carriage driving means, and efficiently sends wind by generating an air flow that does not oppose the air flow due to the movement of the carriage. No matter what the mist is collected, there is no disclosure of the relationship between the mist generation position and the moving speed of the carriage.
[0008]
However, the following was found from the results of detailed observations of the flow of airflow around the recording head when the carriage was scanned, the occurrence of mist, and the floating state when the carriage was scanned.
[0009]
That is, the mist that does not reach the paper separates from the trajectory of the main droplet from a place away from the recording head by a certain distance, depending on the size of the mist and the scanning speed of the carriage, and starts floating, not in a place very close to the recording head. .
[0010]
When the scanning speed of the carriage is low, the mist is generated near the surface of the sheet and continues to drift near the surface of the sheet. When the scanning speed of the carriage is high, the mist is generated at a position distant from the paper surface, that is, at a position close to the ink ejection surface of the recording head, and drifts at a position distant from the paper surface.
[0011]
For this reason, the location where the ink mist is generated and the location where the ink mist floats are different between the recording head and the paper surface depending on the carriage speed.
[0012]
Based on these observations, in order to efficiently collect ink mist, it is necessary to send air near the paper surface when the carriage scanning speed is low, and to send air near the recording head when the carriage scanning speed is high. It turned out that there is. That is, a desired effect cannot be obtained with the structure disclosed in Japanese Patent Application Laid-Open No. H11-150572, in which airflow is sent between the recording head ejection surface and the paper surface. Therefore, a structure for actively controlling the position of the airflow is required.
[0013]
[Patent Document 1]
JP-A-11-138776 (FIG. 1, pages 5 to 6)
[0014]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and has as its object to provide an ink jet recording apparatus that efficiently collects mist.
[0015]
Means for Solving the Invention
2. An ink jet recording apparatus according to claim 1, comprising: a recording head having nozzles for ejecting ink droplets onto recording paper to form an image; and a carriage for holding and moving the recording head. An airflow generating unit that is provided in the inkjet recording apparatus and generates an airflow between the recording head and a sheet; and a speed detection unit that detects a moving speed of the carriage. Airflow control means for responsively bringing the peak position of the airflow velocity closer to the ink ejection surface of the recording head.
[0016]
In the invention having the above-described structure, as the speed of the carriage detected by the speed detecting means increases, the velocity distribution of the generated air flow approaches the ink ejection surface, so that the position where the ink mist is generated / floated from the surface of the paper to the ink of the recording head. It is possible to cope with the phenomenon of approaching the ejection surface, and it is possible to efficiently collect the ink mist.
[0017]
An ink jet recording apparatus according to a second aspect is characterized in that the airflow control means controls the angle of the airflow generated by the airflow generation means.
[0018]
In the invention having the above configuration, the method of controlling the angle of the airflow can control the velocity peak position of the airflow with a simple structure.
[0019]
According to a third aspect of the present invention, there is provided an ink jet recording apparatus including a plurality of airflow generating means, wherein the airflow control means controls the speed of each airflow generated by the airflow generating means.
[0020]
According to the invention having the above configuration, it is possible to control the airflow more precisely than using a single fan to control the airflow.
[0021]
An ink jet recording apparatus according to a fourth aspect is characterized in that the airflow control unit controls the position of the airflow generated by the airflow generation unit.
[0022]
In the invention having the above configuration, the method of controlling the position of the airflow can accurately control the velocity peak position of the airflow.
[0023]
An ink jet recording apparatus according to a fifth aspect is characterized in that the speed detecting means detects a speed based on a carriage drive signal.
[0024]
In the invention having the above configuration, the speed of the carriage is detected by the carriage driving signal generated by the control board, so that the detection can be performed with a simple structure without adding a sensor or the like.
[0025]
An ink jet recording apparatus according to a sixth aspect is characterized in that the speed detecting means detects the speed based on a printing operation control signal.
[0026]
In the invention having the above configuration, the speed of the carriage is detected by a print operation control signal such as image quality selection, so that the detection can be performed with a simple structure without adding a sensor or the like.
[0027]
An ink jet recording apparatus according to a seventh aspect is characterized in that the speed detecting means detects a speed based on a carriage position detection signal.
[0028]
In the invention having the above configuration, the speed of the carriage is detected by the carriage position detection signal generated by the operation control sensor, so that the detection can be performed with a simple structure without separately adding a sensor or the like.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an ink jet recording apparatus according to the first embodiment of the present invention.
[0030]
As shown in FIG. 1, the ink jet recording apparatus 10 includes a carriage 12 held on a shaft 14 so as to be reciprocally movable, a recording head 28 held on the carriage 12 and ejecting ink droplets on paper 30 to form an image, An opening 20 is provided near the moving position of the carriage 12, and an intake duct 18 is provided to suck ink mist by a negative pressure generated by an intake fan 24.
[0031]
The recording head 28 reciprocates as shown by a white arrow while maintaining a certain distance D from the sheet 30, and the opening width of the opening 20 is substantially equal to the distance D.
[0032]
FIG. 2 is an enlarged view of the intake duct of the ink jet recording apparatus according to the first embodiment of the present invention.
[0033]
An intake duct 18 provided with an opening 20 in the vicinity of the movement position of the carriage 12 is connected to an intake fan 24, and a negative pressure generated by the operation of the intake fan 24 causes a space between the ink ejection surface 28 </ b> A of the recording head 28 and the paper 30. Aspirate air.
[0034]
The ink jet recording apparatus 10 starts a printing operation, and ink droplets 36 are ejected from nozzles (not shown) of the ink ejection surface 28A. When an image is formed on the paper 30, minute ink droplets ejected simultaneously with the ink droplets 36 are formed. An ink mist composed of small droplets is generated and floats between the ink ejection surface 28A and the paper 30.
[0035]
If the ink mist adheres to the paper 30, it causes image contamination, and if it adheres to the inside of the machine, it contaminates the inside of the machine. Further, if it adheres to a transport roller or the like, the paper 30 is further contaminated.
[0036]
In order to prevent the contamination by the ink mist, in the present invention, the air containing the ink mist is sucked from the vicinity of the paper 30 by the intake duct 18 as shown in FIG. 2 and the ink mist is removed by the filter 16 provided in front of the intake fan 24. to recover.
[0037]
At this time, the ink mist does not exist evenly between the ink ejection surface 28A and the paper 30 (distance D), but depends on the reciprocating movement speed (scanning speed) of the carriage 12 and the paper 30. Have been found to be skewed to a particular distance between them.
[0038]
That is, when the scanning speed of the carriage 12 is low as shown in FIG. 3, when the recording head 28 moves while discharging the ink droplets 36 in the direction of the oblique arrow, the generated ink mist 38 drifts near the paper 30 and The paper stays near the surface of the paper 30.
[0039]
Therefore, it is necessary to suck the air near the paper 30 in order to efficiently suck and collect the ink mist 38.
[0040]
Therefore, as shown in FIG. 2, the direction of intake is controlled by vanes 22 provided in the opening 20 of the intake duct 18, and the air generated in the region where the ink mist 38 is unevenly distributed is mainly focused on, thereby generating the ink generated. The mist 38 can be efficiently sucked and collected.
[0041]
The blade 22 is rotatably supported by a shaft 26 and can change its angle in the direction of the oblique arrow. The blades 22 are driven by a motor (not shown), and the driving amount, that is, the angle of the blades 22 is controlled according to the scanning speed of the carriage 12 (recording head 28).
[0042]
That is, as shown in FIG. 3, when the scanning speed of the carriage 12 is low, the ink mist 38 is drifting near the surface of the paper 30. If the ink mist 38 is directed toward the surface of the ink mist 30, the ink mist 38 can be efficiently sucked and collected.
[0043]
Conversely, when the scanning speed of the carriage 12 is high, as shown in FIG. 4, the ink mist 38 drifts in an area between the ink ejection surface 28A and the paper 30 near the ink ejection surface 28A, and the operation speed is low. And stagnates at a location distant from the paper 30
[0044]
Therefore, as shown in FIG. 2, the blades 22 provided in the opening 20 of the intake duct 18 are rotated as shown by oblique arrows, and the direction of intake is controlled in the direction of the ink discharge surface 28A, so that the ink mist 38 is unevenly distributed. The ink mist 38 generated can be efficiently sucked and collected by mainly sucking the air in the region where the ink mist is generated.
[0045]
FIG. 5 shows the relationship between the position of the air flow and the wind speed at this time.
[0046]
The vertical axis in FIG. 5 is the height H within the distance D from the surface of the paper 30 to the ink ejection surface 28A, and the horizontal axis is the wind speed V of the air flow.
[0047]
When the scanning speed of the carriage 12 is high, the peak position of the wind speed V is located at a position where the height H is high, as indicated by the graph connected by O, and when the scanning speed is low, the peak position of the wind speed V is detected, as indicated by the graph indicated by □ Is set at a position with a low height H close to the surface of the paper, and the generated ink mist can be efficiently sucked and collected.
[0048]
FIG. 6 shows another embodiment of the intake duct according to the present invention.
[0049]
As shown in FIG. 6, the inside of the intake duct 18 is divided into a plurality of sections, and each divided duct is provided with a dedicated intake fan 24.
[0050]
That is, the intake duct 18 is divided into 18A, 18B, and 18C from the opening 20, and the intake fans 24A, 24B, and 24C are provided respectively, and ON / OFF of the intake fans 24A, 24B, and 24C or the rotation speed is controlled. By controlling the wind speed balance of the intake ducts 18A, 18B, 18C, the wind speed distribution in the height direction of the opening 20 can be optimized according to the scanning speed of the carriage 12.
[0051]
In this embodiment, the intake duct 18 is divided into three parts, but it may be divided into four or more parts to finely control the wind speed distribution. Alternatively, the wind speed distribution may be simply controlled vertically in two parts.
[0052]
FIG. 7 shows another embodiment of the intake duct according to the present invention.
[0053]
As shown in FIG. 7, a belt 32 is provided in the intake duct 18 so as to close the opening 20, and a slit 34 is provided in the belt 32.
[0054]
The belt 32 is supported by two shafts 40 so that it can be wound up or down, and the shafts 40 are fitted and fixed in holes 42. The shaft 40 is driven by a motor (not shown), and the position of the slit 34 can be moved up and down as indicated by a white arrow by winding the belt 32 up and down.
[0055]
As a result, the opening of the intake port 20 of the intake duct 18 is limited to the position of the slit 34, so that the position of the slit 34 can be moved up and down by the winding operation of the belt 32 to control the peak position of the airflow. it can.
[0056]
That is, when the scanning speed of the carriage 12 is high, the belt 32 is wound up (in the direction of the ink ejection surface 28A), and the position of the slit 34 is brought close to the position where the ink mist 38 stays, that is, the ink ejection surface 28A. The peak position is brought closer to the position where the ink mist 38 stays, so that the ink mist 38 can be efficiently sucked and collected.
[0057]
When the scanning speed of the carriage 12 is low, the belt 32 is wound down (in the direction of the paper 30), and the position of the slit 34 is moved closer to the position where the ink mist 38 stays, that is, in the vicinity of the paper 30. By approaching the ink mist 38 staying position, the ink mist 38 can be efficiently sucked and collected.
[0058]
By the way, as a method of detecting the scanning speed of the carriage 12, a method dedicated to detecting the speed of the carriage 12 may be provided inside the ink jet recording apparatus 10 to directly detect the scanning speed of the carriage 12, but in this method, a dedicated sensor is provided. This is problematic in terms of cost and space efficiency.
[0059]
Therefore, in the present invention, the scanning speed of the carriage 12 can be calculated with a simple configuration by obtaining the driving speed of the carriage 12 based on the carriage driving signal for controlling the motor for driving the carriage 12 and using the driving speed instead of the actually measured value.
[0060]
Alternatively, the speed of the carriage 12 may be calculated by a print operation control signal of the ink jet recording apparatus 10. That is, since the scanning speed of the carriage 12 can be calculated from the state of the switch SW between the high image quality mode and the high speed mode, the scanning speed of the carriage 12 may be obtained from these print operation control signals.
[0061]
Alternatively, the scanning speed of the carriage 12 may be obtained based on a detection signal obtained from an existing carriage position detection unit that detects the home position of the carriage 12 and the like.
[0062]
【The invention's effect】
Since the present invention has the above configuration, an ink jet recording apparatus capable of efficiently collecting mist can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an ink jet recording apparatus according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view illustrating the ink jet recording apparatus according to the first embodiment of the present invention.
FIG. 3 is a side view schematically showing generation and stagnation of ink mist.
FIG. 4 is a side view schematically showing generation and stagnation of ink mist.
FIG. 5 is a diagram illustrating a relationship between a wind speed and a height for each carriage scanning speed.
FIG. 6 is a perspective view showing an intake duct according to a second embodiment of the present invention.
FIG. 7 is a perspective view showing an intake duct according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Ink jet recording apparatus 12 Carriage 18 Intake duct 20 Intake port 22 Blade 24 Intake fan 28 Recording head 28A Ink ejection surface 30 Paper 32 Belt 34 Slit 36 Ink droplet 38 Ink mist

Claims (7)

A recording head having a nozzle for ejecting ink droplets on recording paper to form an image,
A carriage for holding and moving the recording head, and an inkjet recording apparatus comprising:
Airflow generating means provided in the inkjet recording apparatus, for generating an airflow between the recording head and a sheet,
Speed detecting means for detecting a moving speed of the carriage,
An ink jet recording apparatus, comprising: an airflow control unit that brings a peak position of the velocity of the airflow closer to an ink ejection surface of the recording head according to an increase in a moving speed of the carriage. 2. The ink jet recording apparatus according to claim 1, wherein the airflow control unit controls an angle of an airflow generated by the airflow generation unit. 2. The ink jet recording apparatus according to claim 1, further comprising a plurality of airflow generators, wherein the airflow controller controls the speed of each airflow generated by the airflow generator. 2. The ink jet recording apparatus according to claim 1, wherein the airflow control unit controls a position of an airflow generated by the airflow generation unit. 5. An ink jet recording apparatus according to claim 1, wherein said speed detecting means detects a speed based on a carriage drive signal. 5. An ink jet recording apparatus according to claim 1, wherein said speed detecting means detects a speed based on a printing operation control signal. 5. An ink jet recording apparatus according to claim 1, wherein said speed detecting means detects a speed based on a carriage position detection signal.

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