JPH11268256A - Ink jet recorder and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance wettability of a hydrophilic ink to a recording face while suppressing scattering of solvent from a projecting surface of an ink drop by humidifying between a recording head and the recording face at the time of ejecting the ink drop. SOLUTION: At the time of recording on the upper surface 20 of a package by ejecting a drop D of hydrophilic ink from a recording head 16, humidifying air W is fed gently between the recording head 16 and the upper surface 20 of a package in order to keep the atmospheric humidity at 40%. The humidifying air W prevents scattering of solvent from the surface of the ink drop D and enhances wettability at ink by humidifying the upper surface 20 of a package. Consequently, even when the upper surface 20 of a resin package exhibiting low affinity for hydrophilic ink is printed with hydrophilic ink, the ink drop D hitting on the upper surface 20 of a package is not separated resulting in high quality recording with hydrophilic ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet recording method and an ink jet recording apparatus. More specifically, the present invention relates to a technique for optimizing an atmosphere between a recording head and a recording surface of a medium.

[0002]

2. Description of the Related Art In an ink jet recording apparatus such as an ink jet printer, a carriage 11 is driven by a pulse motor 1 via a timing belt 12 as shown in FIG.
3 and is guided by the guide member 14 so that the recording paper 1
5 is configured to reciprocate in the paper width direction. In the example shown in FIG. 5B, the carriage 11 has an ink jet recording head 16 attached to the lower surface of the carriage 11, the surface facing the recording paper 15. Also, as can be seen from FIGS. 5A and 5B,
The recording head 16 receives ink replenishment from an ink cartridge 17 mounted on the carriage 11 and ejects ink droplets D onto the recording paper 15 in accordance with the movement of the carriage 11 to form dots. To print images and text.

[0003] Here, since the recording paper 15 itself has a hydrophilic property and has an ink absorbing property,
As the ink used in the inkjet recording apparatus,
High-quality recording can be performed by using a hydrophilic ink in which a solvent such as water or a hydrophilic organic solvent is blended with a pigment or a dye.

[0004]

The ink jet recording apparatus has such advantages that recording can be performed on a medium in a non-contact manner. Also suitable for recording. Therefore, if an inspection number can be recorded in an IC package by an ink jet method, which is conventionally performed by silk printing or the like, a plate is not required, which is convenient. However, since the IC package is made of plastic, the affinity with the hydrophilic ink is originally poor, and the ink does not absorb the ink. Therefore, when the recording is performed using the hydrophilic ink, the adhesion and the fixability of the ink are poor, and the ink is blurred. And the like, and good-looking printing may not be performed. Therefore, there is a method of adjusting the composition of the ink to the material of the medium.However, the ink is required to have various characteristics such as long-term storage properties, and it is necessary to consider the effect on the environment. .

[0005] Therefore, an object of the present invention is to improve the atmosphere at the time of recording so that high-quality recording can be performed with hydrophilic ink even on a recording surface that is not familiar with hydrophilic ink. An object of the present invention is to provide an ink jet recording method and an ink jet recording apparatus which can be used.

[0006]

According to the present invention, there is provided an ink jet recording method for recording on a recording surface of a medium by discharging ink droplets of hydrophilic ink from a recording head. When the ink droplets are ejected onto the recording surface, the space between the recording head and the recording surface of the medium is humidified.

The inventors of the present invention have repeatedly conducted experiments for stably performing high-quality recording with hydrophilic ink on a surface that does not absorb ink. The new finding that humidity, which was not a problem, greatly affects the quality of recording. That is, when recording with hydrophilic ink on a surface that does not absorb ink, if the humidity between the recording head and the recording surface of the medium is low, ink droplets that have landed on the recording surface will be discharged. It was found that the particles were separated into beads in the above manner, and that not only the adhesion and the fixability after recording were reduced, but also blurring and the like occurred. Therefore, in the present invention, by humidifying the space between the recording head and the recording surface of the medium and keeping the humidity at or above a certain level, while suppressing the scattering of the solvent from the surface of the ejected ink droplets,
Increases wettability between the recording surface and the hydrophilic ink. Therefore,
Since ink droplets that have landed on the recording surface do not separate in a ball shape, it is possible to perform high-quality recording with good ink adhesion and fixability. Further, since drying of the nozzles can be suppressed by humidification, clogging of the nozzles can be prevented, and ejection of ink droplets can be maintained in a good state. Therefore, the same effect as capping the recording head can be obtained.

As described above, when humidifying the space between the recording head and the recording surface of the medium, the space between the recording head and the recording surface of the medium is, for example, an atmosphere having a relative humidity of 40% or more. To

In the present invention, to humidify the space between the recording head and the recording surface of the medium, for example, humidified air is supplied between the recording head and the recording surface of the medium.

According to the present invention, high-quality recording can be performed with a hydrophilic ink even on a recording surface that is not familiar with the hydrophilic ink. Therefore, the recording surface of a medium that does not have ink absorbency. Alternatively, high-quality recording can be performed on a recording surface of a medium made of resin, such as an IC package.

In such an ink jet recording method, for example, a pressure generating chamber communicating with a nozzle opening and a diaphragm constituting a wall surface of the pressure generating chamber are deformed in an out-of-plane direction to expand and contract the pressure generating chamber. An ink jet recording apparatus having, on a carriage, a recording head having a pressure generating element for ejecting an ink droplet of hydrophilic ink from the nozzle opening to the recording surface of the medium by causing the recording head to record on the medium. It can be implemented by providing a humidifying device that humidifies the space between the surfaces.

[0012] In the present invention, it is preferable that the air outlet of the humidifier is formed on the carriage. With this configuration, even if the carriage moves, the space between the recording head and the recording surface of the medium can be reliably humidified. In addition, the apparatus can be made smaller and simpler than when the recording head and the air outlet of the humidifier are formed on separate carriages.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet recording apparatus to which the present invention is applied will be described with reference to the drawings.

(Overall Configuration) FIG. 1 is an external view of an ink jet recording apparatus to which the present invention is applied, FIGS. 2A and 2B are perspective views showing the configuration inside the recording apparatus main body, and a recording head, respectively. It is explanatory drawing which shows a structure of a periphery.

As shown in FIG. 1, the ink jet recording apparatus 1 of the present embodiment has a plurality of I
It is for recording an inspection number or the like on each package upper surface 20 of C2, and has a recording apparatus main body 10 and a tray transport table 3 for transporting the tray TR in the direction shown by the arrow A.

As shown in FIG. 2A, inside a recording apparatus main body 10 of the ink jet recording apparatus 1, a carriage 11 is driven by a pulse motor 13 via a timing belt 12.
And is guided by the guide member 14 to reciprocate in the width direction of the tray TR. FIG. 2 (B)
As shown in FIG. 2, an ink jet recording head 16 is mounted on the surface of the carriage 11 facing the tray TR, in the example shown in FIG.

2 (A) and 2 (B), the recording head 16 receives ink supply from an ink cartridge 17 mounted on the carriage 11, and moves the tray TR together with the movement of the carriage 11. The ink droplets D are ejected onto the package upper surface 20 of each of the ICs 2 arranged above to form dots, and an inspection number or the like is printed on the package upper surface 20 of each of the ICs 2. In the non-printing area of the ink jet recording apparatus 1, a capping device 18 is configured to seal the nozzle openings of the recording head 16 during a pause, and to discharge ink from the recording head 16 during a flushing operation performed during a printing operation. Drop D is received. Capping device 18
A cleaning device 19 is arranged in the vicinity of, and the cleaning device 19 is configured to wipe off the ink residue adhering thereto by wiping the surface of the recording head 16 with a blade or the like.

(Structure for Improving Recording Quality) In the ink jet recording apparatus 1 configured as described above, since the recording paper is hydrophilic, it is compatible with the hydrophilic ink. When an inspection number is printed on the package upper surface 20 of the IC 2 with a hydrophobic ink, the IC package is made of resin, so that the package upper surface 2 is hydrophobic when viewed from recording paper and has no ink absorption.
A value of 0 indicates poor compatibility with the hydrophilic ink. The hydrophilic ink referred to here is not only a water-soluble ink in which the solvent is water alone, but also a water-soluble ink using an organic solvent having high compatibility with water as a solvent, or such an organic solvent and water. It refers to a water-soluble ink or the like using a mixture as a solvent.

Therefore, in the present embodiment, as shown in FIG. 2B, when recording is performed on the package upper surface 20 of the IC 2 by discharging ink droplets D of hydrophilic ink from the recording head 16, The humidified air W is gently supplied between the IC 2 and the package upper surface 20 to reduce the humidity of the atmosphere to 4%.
Keep above 0%. Further, the humidified air W humidifies the package upper surface 20 to increase the ink wettability. Therefore, even when printing with the hydrophilic ink on the package upper surface 20 of the resin IC 2 that is not familiar with the hydrophilic ink,
Since the ink droplets D that have landed on the package upper surface 20 do not separate, high-quality recording of a test number or the like can be performed using hydrophilic ink. Therefore, unlike silk printing,
A plate for each inspection date is not required, and it is easy to handle a large number of varieties in small quantities. The reason why the recording quality is improved by maintaining the relative humidity between the recording head 16 and the package upper surface 20 of the IC 2 at, for example, 40% or more is considered to be that the package upper surface 20 is humidified to enhance ink wettability. Further, although the discharged ink droplet D lands on the package upper surface 20 in a short time, since the ink droplet D is extremely small, if the solvent scatters from the surface of the ink droplet D before landing on the package upper surface 20, , Package top surface 20
The wettability between the recording head 16 and the package upper surface 20 of the IC 2 is reduced by, for example,
It is considered that keeping it at 0% or more can prevent the solvent from scattering from the surface of the ink droplet D before landing on the package upper surface 20.

In order to carry out such an ink jet recording method, the ink jet recording apparatus 1 of the present embodiment includes:
A humidifier 70 for humidifying the space between the recording head 16 and the package upper surface 20 of the IC 2 is configured. The humidifying device 70 includes a humidified air generating chamber 72 and an ultrasonic vibrator 7 that generates ultrasonic water vapor by applying ultrasonic waves to water stored therein.
3 and the steam generated in the humidified air generating chamber 72 is supplied to an air supply pipe 7.
The humidifying air blower 77 is attached to the carriage 11 so as to communicate with the air supply tube 74. The air supply tube 74 is formed of a flexible tube, and can follow the movement of the carriage 11.

Here, the humidified air outlet 71 is opened near the recording head 16 mounted on the carriage 11, and the position of the humidified air outlet 71 is in the printing direction (arrow) as viewed from the recording head 16. B), that is, the preceding position when viewed from the recording head 16. In addition, the humidified air blowing pipe 77 is connected to the carriage 1.
1, the air outlet 71 is connected to the recording head 16 and I
It faces between the package upper surface 20 of C2.

In the ink jet recording apparatus 1 thus configured, the humidified air outlet 71 is provided between the recording head 16 and the package upper surface 20 of the IC 2.
, The relative humidity between the recording head 16 and the package upper surface 20 of the IC 2 is maintained at 40% or more, and the package upper surface 20 is automatically humidified. The air outlet 71 of the humidifier 70 is
Since the recording head 16 is provided on the carriage 11, the space between the recording head 16 and the package upper surface 20 of the IC 2 is always reliably humidified even when the carriage 11 moves. Therefore, the ink droplets D ejected from the recording head 16 do not scatter the solvent from the surface until the ink droplets D land on the package upper surface 20, and the landed package upper surface 20 is in a humidified state. , Even if the ink is hydrophilic,
Will be well established. Therefore, according to the inkjet recording apparatus 1 of the present embodiment, high-quality recording can be performed.

The recording head 1 is humidified to
Since the drying of the nozzle 6 can be suppressed, clogging of the nozzle can be prevented, and the ejection of the ink droplet D can be maintained in a good state. Therefore, the same effect as capping the recording head 16 can be obtained.

Further, the air outlet 7 of the humidifier 70
1 is a carriage 11 on which a recording head 16 is mounted.
The recording head 16 and the humidifying device 7
The apparatus can be made smaller and simpler than in the case where the zero air outlet 71 and the carriage are separately provided.

The humidified air blow-out tube 77 connects the air blow-out port 71 on the carriage 11 to the recording head 1.
6 and the package upper surface 20 of the IC 2, it is possible to print while humidifying when the carriage 11 moves in either direction. With this configuration, humidification can be performed under exactly the same conditions when the carriage 11 moves in any direction.

(Configuration of Recording Head 16) FIG. 3 is a sectional view showing the configuration of the recording head 16. As shown in FIG.

As shown in FIG. 3, in the recording head 16,
A nozzle opening 111 is formed in the nozzle plate 110,
In the flow path forming plate 112, a through hole that partitions the pressure generating chamber 113, a through hole or a groove that partitions two ink supply ports 114 communicating on both sides with the pressure generating chamber 113, and these ink supply ports 114 are respectively provided. A through-hole that defines two common ink chambers 115 that communicate with each other is formed. Diaphragm 1
Reference numeral 16 is made of an elastically deformable thin plate, abuts against the tip of a piezoelectric vibrator PZT (pressure generating element) such as a piezo element, and is fixed to the nozzle plate 110 in a liquid-tight manner with the flow path forming plate 112 interposed therebetween. , The flow path unit 118.

The base 119 is formed with an accommodation chamber 120 for accommodating the piezoelectric vibrator PZT so that it can vibrate, and an opening 121 for supporting the flow path unit 118, and exposing the tip of the piezoelectric vibrator PZT from the opening 121. The piezoelectric vibrator PZ
T is fixed by a fixed substrate 122. In addition, base 119
With the island portion 116a of the vibration plate 116 in contact with the piezoelectric vibrator PZT, the recording head 16 is assembled by fixing the channel unit 118 to the opening 121.

With such a configuration, the piezoelectric vibrator PZT
When the pressure generation chamber 113 expands due to contraction, the ink in the common ink chamber 115 flows into the pressure generation chamber 113 via the ink supply port 114. When the piezoelectric vibrator PZT expands and the pressure generating chamber 113 contracts after a lapse of a predetermined time,
The ink in the pressure generating chamber 113 is compressed and the nozzle opening 11
An ink droplet is ejected from 1.

(Control System of Inkjet Recording Apparatus) FIG.
The configuration of a control system included in the inkjet recording apparatus will be described with reference to FIG.

In FIG. 4, the ink jet recording apparatus 1
The control device 60 is configured to receive a print command signal and print data from the host and receive a print voltage signal from the print head drive circuit 3 and a head selection circuit 32.
0, and also controls the carriage drive circuit 33 and the like to execute the printing operation. The control device 60
Controls the humidifying operation of the humidifying device 70 described with reference to FIG. Further, the control device 60 causes the flashing to be performed based on the time measurement data of the timer
The recording head 16 is cleaned.

In the recording head driving circuit 30, the driving voltage generating circuit 31 is configured to generate a trapezoidal wave having a voltage value necessary for discharging ink droplets from the nozzle openings 111. Further, the head selection circuit 32 selectively applies the drive voltage of the drive voltage generation circuit 31 to the piezoelectric vibrator PZT corresponding to the print data by controlling the transistor T. The timer means 34 includes a print timer 3
5, a pause timer 36 and a power-off timer 38. The print timer 35 is a timer for measuring the duration of the printing operation, and is started from the start of printing and reset by a flushing operation. The pause timer 36 is backed up by a secondary power supply to be described later so as to be able to measure time even after the main power supply SP is turned off, and when the printing operation is stopped and the recording head 16 is sealed by the capping device 18, Timing is started and reset when printing starts. The power-off timer 38 is connected to the power-on detecting means 3.
9, the timer is started from the time point when the power switch SW is detected to be turned off, and is output after the time required for sealing the recording head 16 by the capping device 18 has elapsed, and the relay 40 is deenergized to send the signal to the device. The supply of the main power SP is cut off. The main power supply SP also supplies power to the humidifying device 70 described with reference to FIG.

(Other Embodiments) In the ink jet recording apparatus 1, the humidity between the recording head 16 and the package upper surface 20 of the IC 2 is monitored, and as a result of the monitoring, the relative humidity is lower than a predetermined level. Only the humidification between the recording head 16 and the package upper surface 20 of the IC 2 is performed, and when the relative humidity is equal to or higher than a predetermined level, the humidification between the recording head 16 and the package upper surface 20 of the IC 2 is stopped. You may comprise.

In the above embodiment, the humidified air outlet 71 is formed on the carriage 11.
The humidified air outlet 71 may be formed on a moving body separate from the carriage 11 as long as it can humidify the space between the carriage 11 and the package upper surface 20 of the IC 2.

Further, the medium on which recording is performed by the ink jet recording apparatus 1 of the above embodiment is not limited to an IC package, but includes various resin molded products, metal products, paper having a resin coating on the surface, and the like.

[0036]

As described above, in the ink jet recording method and the ink jet recording apparatus to which the present invention is applied, the atmosphere in which the ink droplets fly is humidified.
Water does not scatter from the ink droplet surface, and the landed recording surface is in a humidified state. Therefore, it is possible to perform high-quality recording with the hydrophilic ink even on a material that is not familiar with the hydrophilic ink. Further, since drying of the nozzles can be suppressed by humidification, clogging of the nozzles can be prevented, and ejection of ink droplets can be maintained in a good state. Therefore, the same effect as capping the recording head can be obtained.

[Brief description of the drawings]

FIG. 1 is an external view of an inkjet recording apparatus to which the present invention is applied.

FIGS. 2A and 2B are perspective views each showing a main part in a main body of an ink jet recording apparatus to which the present invention is applied;
FIG. 3 is an explanatory diagram showing an enlarged view of the vicinity of a recording head.

FIG. 3 is a cross-sectional view illustrating a configuration of a recording head used in the inkjet recording apparatus illustrated in FIG.

FIG. 4 is a block diagram of a control system and a drive system included in the inkjet recording apparatus shown in FIG.

FIGS. 5A and 5B are a perspective view showing a main part in a main body of a conventional ink jet printing apparatus, and an enlarged explanatory view showing the vicinity of a print head.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 inkjet recording device 2 IC (medium) 3 tray transport table 10 recording device main body 11 carriage 16 recording head 20 package surface (recording surface) 30 recording head drive circuit 70 humidifying device 71 humidified air outlet 72 humidified air generating chamber 73 super Sonic vibrator 74 Air supply tube 75 Blower 77 Humidified air blow-out tube D Ink droplet W Humidified air TR Tray

Claims (7)

[Claims] 1. An ink jet recording method for performing recording on a recording surface of a medium by discharging ink droplets of hydrophilic ink from a recording head, comprising:
An ink jet recording method comprising humidifying a space between the recording head and a recording surface of the medium. 2. The apparatus according to claim 1, wherein the relative humidity between the recording head and the recording surface of the medium is 40% by humidifying the recording head and the recording surface of the medium.
An ink jet recording method characterized by having the above atmosphere. 3. The ink jet recording method according to claim 1, wherein the humidification is performed by supplying humidified air between the recording head and a recording surface of the medium. 4. The method according to claim 1, wherein
The recording surface of the medium is a surface having no ink absorbency. 5. The method according to claim 1, wherein
The recording surface of the medium is made of a resin, and is an ink jet recording method. 6. A pressure generating chamber communicating with a nozzle opening, and a diaphragm constituting a wall surface of the pressure generating chamber being deformed in an out-of-plane direction to expand and contract the pressure generating chamber, thereby causing a medium from the nozzle opening to expand. An ink jet recording apparatus having, on a carriage, a recording head provided with a pressure generating element for ejecting ink droplets of hydrophilic ink onto a recording surface of the recording medium, wherein humidification between the recording head and the recording surface of the medium is performed. An ink jet recording apparatus comprising the apparatus. 7. The ink jet recording apparatus according to claim 6, wherein the air outlet of the humidifier is formed on the carriage.