JP3143820B2 - Charge deflection type liquid jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for charging ink particles ejected from a liquid ejecting nozzle, and deflecting the charged ink particles by a deflecting electrode to land on a recording medium. The present invention relates to a charge-deflection type liquid jet recording apparatus for performing recording on a recording medium.

[0002]

2. Description of the Related Art In a charged deflection type liquid jet recording apparatus, printing is generally performed while a recording medium is conveyed to a fixed liquid jet head. In recent years, there has been a problem that print image quality deteriorates due to an increase in the transport speed of a recording medium. As a technique for solving such a problem, for example, as described in Japanese Utility Model Application Laid-Open No. 56-171240, the mounting angle of the deflection electrode is changed,
There is known a technique of correcting the inclination of a print line by changing the direction of an electric field and giving a speed in a conveying direction of a recording medium to a subsequent ink particle.

[0003]

However, in the above-mentioned prior art, a control circuit for controlling the electric field and controlling the speed of the recording medium in the transport direction is newly required, and the configuration of the recording apparatus becomes complicated. There is a disadvantage of doing so.

In the prior art, no consideration is given to a method of determining a correction amount from an actual distortion amount of a print result. Furthermore, the prior art does not consider any solution to the print distortion caused by the change in the ink particle velocity depending on the amount of deflection. For this reason, for example, when the printing medium is transported at a high speed of 300 m / min or more, it is not easy to reduce the printing distortion.

SUMMARY OF THE INVENTION An object of the present invention is to provide a charged deflection type liquid jet recording apparatus capable of reducing printing distortion during high-speed conveyance of a recording medium without complicating the apparatus configuration.

[0006]

In order to achieve the above object, the present invention provides an ejection nozzle for ejecting ink particles, a charging electrode for charging the ejected ink particles, and an electrostatic field for charging the charged ink particles. A deflection electrode for deflecting the flight direction of the ink particles when flying in the air, and charging the deflected ink particles to land on the recording medium to perform recording on the recording medium; In the recording apparatus, the flying direction of the ink particles having a deflected amount among the ink particles deflected by the deflecting electrode is directed to the surface of the recording medium .
As intersecting vertically into the injection nozzle, Oyo the charging electrode
And an ink jet head comprising the deflection electrode or
At least one of the recording media is inclined.
The number of ink particles from the deflection electrode and its deflection
Detecting means for detecting the amount, and detecting results from the detecting means.
Tilt angle display means for displaying the tilt angle based on the
It is a digit .

[0007]

[0008]

The present invention also provides a charging / deflection type liquid jet recording apparatus having the above-described configuration, wherein reading means for optically reading a recording result recorded on the recording medium, and reading the recording result from the read result. with determining skewness is further one provided with the tilt angle adjusting means for adjusting the pre Ki傾 oblique angle to reduce the skewness, the.

Further, according to the present invention, there is provided a charged-deflection type liquid jet recording apparatus having the above-described configuration, wherein a detecting means for detecting the number of ink particles from the deflecting electrode and the amount of deflection thereof, and a detection result from the detecting means. the inclination angle adjusting means for adjusting the pre Ki傾 oblique angle based in which was further provided.

[0011]

According to the above construction, the flying distance of the ink particles having the minimum deflection amount is slightly longer than that of the prior art, but the flying distance of the ink particles having the maximum polarization amount can be greatly reduced. For this reason, even if the recording medium is conveyed at a high speed, the printing distortion can be minimized. In this case, if the deflecting unit deflects the ink particles also in the transport direction of the recording medium, the printing distortion can be suppressed more effectively.

The number of ink particles and the amount of inclination are detected by the detecting means, and the results are statistically processed, whereby the flying direction of the ink particles having the intermediate deflection amount or the inclination angle of the recording medium can be determined. It can be displayed on the display means.

The recording result recorded on the recording medium is optically read by the reading means. If the read recording result is distorted, the inclination angle adjusting means sets the flying direction of the ink particles having an intermediate deflection amount. or by adjusting the recording medium, it sets a tilt oblique angle to the optimum value. In this case, without reading the recording result recorded on the recording medium, the detecting unit detects the quantity and the inclination amount of the ink particles, and based on the detection result, the flying direction of the ink particles in the middle of the deflection amount or the recording medium. adjust,
It may be set to tilt oblique angle to the optimum value.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a charged deflection type liquid jet recording apparatus of the present invention. In the drawing, a nozzle 1 ejects pressurized ink 2 pressurized at a predetermined pressure by a pressurizing source (not shown). At this time, the pressurized ink 2 in the nozzle 1
Due to the vibration of the electrostrictive element 4, the vibration of which is controlled by the excitation amplifier 3, particles are regularly formed after being ejected from the nozzle 1.

The ink particles 5 are charged to a predetermined value in a charging electrode 7 of which voltage is controlled by a character signal generating circuit 6, and furthermore, a deflection electrode to which a predetermined voltage is applied by a high voltage power supply 8. During the flight in the electrostatic field in 9, a deflection force corresponding to the charged electric charge is received, and the beam is deflected upward in the figure.
The deflected ink particles 5 land on the recording medium 10 conveyed in the direction perpendicular to the paper surface of the drawing, and form an image on the recording medium 10.

The ink particles 5 to which no charge is applied go straight without being deflected in the deflection electrode 9, are collected by the gutter 11, and are reused. In the figure, reference numeral 12 denotes the nozzle 1,
1 shows a liquid jet head cover including an electrostrictive element 4, a charging electrode 7, a deflecting electrode 9, a gutter 11, and the like.

In the charged deflection type liquid jet recording apparatus having the above-described configuration, when printing is performed on the recording medium 10, the amount of charge at the charging electrode 7 is changed so that the ink droplet landing position Do when the deflection amount is the minimum. Thus, the ink particles 5 can be landed at a predetermined position between the ink droplet landing position Dn and the maximum deflection amount.

In the present embodiment, the recording medium 10 is applied to the liquid ejecting head cover 12 such that the ink particles having an intermediate deflection amount land vertically on the recording medium 10, that is, land at the ink particle landing position Di. It is installed at an angle to it. The ink droplet landing position Di is positioned between the ink droplet landing position ink droplet Do when the deflection amount is minimum and the ink droplet landing position ink droplet Dn when the deflection amount is maximum, and the flying distance of the ink particle is minimized. The position is determined. If the angle between the ink particle flight path when the deflection amount is intermediate and the ink particle flight path when the deflection amount is minimum is α, this angle α becomes the head mounting angle. Note that the recording medium 10 may be fixed and the liquid ejecting head cover 12 may be installed to be inclined with respect to the recording medium 10, or both the recording medium 10 and the liquid ejecting head cover 12 may be relatively inclined. May be installed.

In general, the liquid jet head cover 12 is mounted so that its end face, that is, the face facing the recording medium 10 is substantially perpendicular to the flight path of the ink droplet when the deflection amount is the minimum. Therefore, in this embodiment,
The end surface of the liquid jet head cover 12 and the recording surface of the recording medium 10 form an angle α.

The liquid jet head cover 12 is provided for improving the operability of the operator and ensuring safety, and does not relate to the performance of the present charge-deflection type liquid jet recording apparatus.

FIG. 2 shows a schematic configuration of a conventional charge deflection type liquid jet recording apparatus for comparison. In the prior art, the angle formed between the recording medium 10 and the liquid ejecting head cover 12 with respect to the deflection direction of the ink particles 5 is not particularly considered. The recording medium 10 is set so as to be substantially perpendicular to the flight path of the ink particles.

The liquid ejecting head cover 12 is attached so that the end face thereof is substantially perpendicular to the flight path of the ink droplet when the deflection amount is the minimum, and the end face of the liquid ejecting head cover 12 and the recording medium 10 Is substantially parallel to the recording surface.

FIG. 3 shows the velocity distribution of ink particles in one line in the deflection direction of the conventional charge deflection type liquid jet recording apparatus.
It is desirable that the velocity distribution of the ink particles be substantially constant regardless of the amount of deflection. However, in an actual charged deflection type liquid jet recording apparatus, as shown in FIG. 3, the speed of ink particles having a large deflection amount decreases due to electrostatic interference between the charging electrode 7, the deflection electrode 9, and the ink particles. It exhibits such a velocity distribution.

FIG. 4 shows an example of printing for one line in the deflection direction, which is printed by a conventional charge deflection type liquid jet recording apparatus.
Since the velocity distribution in the deflecting direction is as shown in FIG. 3, when printing is performed over one line in the deflecting direction by the conventional charge deflecting type liquid jet recording apparatus, as shown in FIG. An image having an arcuate shape like the dot position 15 according to the technique is obtained. The image warpage amount δ at this time increases as the transport speed v of the recording medium 10 increases. For this reason, in high-speed printing, the image quality is extremely deteriorated.

In order to improve the speed distribution, it is necessary to optimize the shapes of the charging electrode 7 and the deflecting electrode 9 and to manufacture and control them with high accuracy, which is not preferable because it increases the cost.

Therefore, in this embodiment, as shown in FIG. 1, the flying direction of the ink particles having the intermediate deflection amount is such that the flying direction of the ink particles having the intermediate deflection amount intersects perpendicularly with the recording surface of the recording medium 10. Alternatively, by inclining the recording medium relatively, the flying distance of the ink particles having a large amount of deflection whose speed is decreasing is reduced, and the image warpage amount δ is reduced.

FIG. 5 shows the relationship between the head mounting angle α and the image warpage amount δ. Here, the head attachment angle α is the angle between the flight path of the ink particles when the deflection amount is intermediate and the flight path of the ink particles when the deflection amount is minimum, or the angle between the end face of the liquid jet head cover 12 and the recording medium 10. This is the angle made with the recording surface.

FIG. 5 shows that the image warpage amount δ decreases as the head mounting angle α increases from 0. In addition, the image warpage amount δ is 3 when the head mounting angle α is 3
It has been found that it becomes smaller in the range of 0 to 60 degrees, and becomes minimum around 45 degrees. For this reason, the head mounting angle is preferably set to 30 degrees to 60 degrees. In high-speed printing in which the transport speed of the recording medium 10 is high,
It was confirmed that it is better to set the head mounting angle to 45 degrees.

Next, a mounting device to which a liquid ejecting head including the nozzle 1, the electrostrictive element 4, the charging electrode 7, the deflecting electrode 9, the gutter 11, the liquid ejecting head cover 12, and the like is attached will be described with reference to FIG. As shown in FIG. 6, the liquid ejecting head 20 is fixed to a head slide table 22 which is slidable on a head support table 21 in a direction in which ink particles are ejected (left and right directions in the figure). The relative positional relationship between the head support 21 and the head slide 22 is adjusted using a slide clamper 23 attached to the head support 21. The head support 21 is held by a support guide 25 via a rotary elbow 24 that is rotatable in the ink particle deflection direction. The support guide 25 is held on a head support column 27 which is installed upright on the floor surface by a table 26.

The rotation amount of the rotary elbow 24 corresponds to the head mounting angle α in FIG. 5, and can be adjusted to a predetermined rotation angle by using the rotary elbow clamper 28. Further, the height position of the support guide 25 can be adjusted within the range of the height of the head support support 27 using the support guide clamper 29.

The column guide 25 is provided with a swivel elbow 30 rotatable in a plane parallel to the recording surface of the recording medium, so that the liquid ejecting head 20 can rotate in a plane parallel to the recording surface. Has become. Then, the rotation angle of the liquid ejecting head 20 in a plane parallel to the recording surface of the recording medium is adjusted to a predetermined angle using the swing elbow clamper 31.

The use of the above-described mounting device makes it possible to mount the liquid ejection head 20 at a predetermined printing position at a predetermined head mounting angle α. Note that the amount of movement or the amount of rotation of the head slide base 22, the rotating elbow 24, and the swinging elbow 30 can be controlled by a power source such as a stepping motor.

Next, an adjusting jig for adjusting the head mounting angle of the liquid ejecting head mounted on the mounting device of FIG. 6 will be described with reference to FIGS. 7 and 8. FIG. As shown in FIG. 7, a mounting angle adjustment arm support section 40 is fixed to the liquid ejecting head 20 near a position where the deflection start point between the deflecting electrodes 9 is projected on the liquid ejecting head cover 12. The two mounting angle adjusting arms 41 and 42 are rotatably and slidably supported by the mounting angle adjusting arm support portion 40.

Since the character height in the deflection direction is determined in advance, the deflection amount and the liquid ejection head 20
The distance between the recording medium 10 and the recording medium 10 is determined, so that the flying distance of the ink particles having the minimum deflection amount and the flying distance of the ink particles having the maximum deflection amount when a predetermined head mounting angle α is given from the printing and recording conditions. The distance and the flight angle can be obtained.

The distance display scales 43 and 44 displayed on the mounting angle support arms 41 and 42, and the liquid based on the obtained flight distance of the ink particles having the lowest deflection amount and the flight distance and the flight angle of the ink particles having the highest deflection amount. Using the angle display scale 45 displayed on the ejection head 20, the mounting angle support arms 41, 42 indicate the landing positions of the ink particles with the minimum deflection amount and the ink particles with the maximum deflection amount, respectively, so as to indicate the landing positions. , 42 are fixed.

When mounting the liquid jet head 20,
The liquid ejecting head 20 is arranged such that the mounting angle support arms 41 and 42 come into contact with each other at a position on the recording medium 10 where printing is to be performed.
Should be installed.

FIG. 8 shows another embodiment of the adjusting jig. In the present embodiment, the distance display scale 43 displayed on the mounting angle support arm 41 and the angle display scale 45 displayed on the liquid ejecting head 20 are determined based on the flying distance and the flying angle of the ink particles having the minimum flying distance. The mounting angle support arm 41 is used to indicate the landing position of the ink particles having the minimum flight distance by using the mounting angle support arm 41.
Is fixed.

Further, in this embodiment, the mounting angle support arm 41 is provided so that the mounting operation can be performed stably.
A contact pad 46 is provided at the leading end of the recording medium 10 so as to contact the recording surface of the recording medium 10 with a predetermined area. When the liquid ejecting head 20 is installed, the liquid ejecting head 20 may be attached so that the contact pad 46 comes into contact with the recording position of the recording medium 10.

FIG. 9 shows a line type ink droplet in which a light receiving element and a light emitting element are arranged in the vicinity of the liquid ejection port of the liquid ejection head cover 12 in the direction of deflection of the ink particle in the charged deflection type liquid ejection recording apparatus shown in FIG. Detection sensor 50
Is provided.

With the above configuration, the output signal from the excitation amplifier 3 and the charging signal generation circuit 6 and the output signal from the line type ink particle detection sensor 50 are combined to obtain the amount of ink particle deflection and the line amount. The average velocity of the ink particles up to the type ink particle detection sensor 50 can be obtained. As a result, the correction coefficient of the amount of charge on the charging electrode 7 and the head mounting angle α can be calculated.

The ink particle detection sensor 50 can be constituted by one light receiving element by being mounted above the ink particle deflection direction. In addition, the light receiving element and the light emitting element can be arranged to face the flight path of the ink particles. Further, the calculated head mounting angle α may be displayed to the operator.

FIG. 10 is a configuration diagram when the above-mentioned charged deflection type liquid jet recording apparatus is installed in a recording system. The liquid jet head 20 is fixed to a head support column 27, and controls signals of the electrostrictive element 4 and the charging electrode 7 and the pressure ink 2.
Is supplied from the controller 60. Then, a packing material 62 as a recording medium placed on the belt conveyor 61
Is transported as the belt conveyor 61 moves. The position of the packing material 62 is detected by a printing medium position detecting device 63 fixed to a side plate of the belt conveyor 61, and an output signal thereof is sent to the controller 60.

Based on the output signal of the printing medium position detecting device 63, a control command is given from the controller 60 to the liquid ejecting head 20 so as to perform printing at a predetermined recording position, and the liquid ejecting head 20 is described with reference to FIG. The operation prints a predetermined image 64 on the packing material 62.

When the liquid ejecting head 20 has the structure shown in FIG. 9, the correction amount is determined by the controller 6 based on the output of the ink particle detection sensor 50 at the time of initial distortion correction.
The operator can evaluate the image quality by displaying it on the display unit of “0” and save the trouble of making correction. The correction can be automated by employing a configuration in which each elbow of the head support column 27 is rotated by a power source such as a stepping motor.

FIG. 11 is a diagram showing another embodiment of the recording system. In this embodiment, an image capturing sensor 65 is provided in addition to the configuration shown in FIG. When the image capturing sensor 65 is provided in this manner, the head mounting angle α can be automatically adjusted, and power can be saved.

FIG. 12 shows the liquid jet head of FIG.
9 is a flowchart showing an operation after the system is started up when installed in the recording system of FIG. After starting the system, if the correction mode is selected in step 100, the process proceeds to step 101; otherwise, the process proceeds to step 110. When the correction mode is selected, the image capture sensor 65 is operated in step 101, and the ink particle detection sensor 50 is operated in step 102. Then, in step 103, a predetermined correction pattern is printed.

Next, in step 104, the ink particles at the time of printing the correction pattern are detected by the ink particle detection sensor 50, and the velocity distribution and the amount of distortion of the ink particles are measured from the result. Then, in step 105, the correction coefficient of the amount of charged electric charge and the head mounting angle are calculated from the measurement result in step 104, the correction is performed in step 106, and a correction pattern based on the correction is printed in step 107.

The printed correction pattern is stored in step 10
At step 8, the image is read by the image capturing sensor 65, and at step 109, it is determined whether the read print result is within a predetermined distortion limit. If it is within the distortion limit, the printing operation is executed in step 110 using the correction pattern in step 107 as a normal pattern. If it is not within the distortion limit in step 109, the process proceeds to step 104, where the processing from step 104 to step 108 is executed, and the above processing is repeated until the processing converges within the distortion limit.

[0049]

As described above, according to the present invention,
Since the flying distance of the ink particles having the maximum deflection amount can be reduced, printing distortion can be suppressed even when the recording medium is conveyed at high speed. In this case, if the deflection direction of the ink particles is also deflected in the transport direction of the recording medium, the printing distortion can be suppressed more effectively when the recording medium is transported at a high speed.

Further, if the quantity or deflection of ink particles from the deflection electrode is detected, or the recording result recorded on the recording medium is read optically, the results are used to determine the intermediate deflection amount. it is possible to relatively adjust the ink particle flying direction or a recording medium, it is possible to set the tilt oblique angle automatically.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a charged deflection type liquid jet recording apparatus of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional charged deflection type liquid jet recording apparatus.

FIG. 3 is a diagram showing a velocity distribution of ink particles for one row in a deflection direction according to the related art.

FIG. 4 is a diagram showing an example of printing for one row in a deflection direction printed by a conventional technique.

FIG. 5 is a diagram showing a relationship between a head mounting angle α and an image warpage amount δ.

FIG. 6 is a configuration diagram of a supporting device that supports the charged deflection type liquid jet recording apparatus of the present invention.

FIG. 7 is a configuration diagram of a jig for adjusting a head attachment angle.

FIG. 8 is a view showing an alternative of a jig for adjusting a head mounting angle.

FIG. 9 is a configuration diagram when a line sensor is attached to the charged deflection type liquid jet recording apparatus of the present invention.

FIG. 10 is a configuration diagram when installed in a recording system of a charged deflection type liquid jet recording apparatus of the present invention.

FIG. 11 is another configuration diagram when installed in the recording system of the charged deflection type liquid jet recording apparatus of the present invention.

FIG. 12 is a flowchart illustrating an operation after system startup when the liquid ejecting head of FIG. 9 is installed in the recording system of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle 2 Pressurized ink 3 Excitation amplifier 4 Electrostrictive element 5 Ink particle 6 Charge signal generation circuit 7 Charging electrode 8 High voltage power supply 9 Deflection electrode 10 Recording medium 11 Gutter 12 Liquid ejection head cover 20 Liquid ejection head 21 Head support 22 Head Slide base 23 Slide clamper 24 Rotating elbow 25 Support guide 26 Base 27 Head support support 28 Rotating elbow clamp 29 Support guide clamper 30 Swing elbow 31 Swing elbow clamper 40 Mounting angle adjusting arm support 41, 42 Mounting angle adjusting arm 43, 44 Distance display scale 45 Angle display scale 46 Contact pad 50 Ink particle detection sensor 60 Controller 61 Belt conveyor 62 Packing material 63 Print medium position detection 64 Image 65 Image capture sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-120757 (JP, A) JP-A-54-48239 (JP, A) JP-A-60-21276 (JP, A) JP-A-58-58 171969 (JP, A) JP-A-60-204375 (JP, A) JP-A-54-133337 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/075

Claims (6)

(57) [Claims] 1. An ejection nozzle for ejecting ink particles, a charging electrode for charging the ejected ink particles, and a deflecting electrode for deflecting the flight direction of the ink particles when the charged ink particles fly in an electrostatic field. A charged-deflection type liquid jet recording apparatus for recording on a recording medium by landing ink particles whose flight direction is deflected on a recording medium, wherein the deflection of the ink particles deflected by the deflection electrode is performed. as the flying direction of the amount between the ink particles intersect vertically into the surface of the recording medium, the injection nozzle, the charging electrode and the
An ink jet head having a deflection electrode or
With tilting the at least one of the recording medium, detecting means for detecting the quantity and amount of deflection of the ink particles from the deflection electrodes, the <br/> pre Ki傾 oblique angle based on a detection result from the detecting means A charge deflecting type liquid jet recording apparatus, comprising: an inclination angle display means for displaying. 2. The charged deflection type liquid jet recording apparatus according to claim 1 , wherein said tilt angle display means simultaneously displays a correction amount of the tilt angle with respect to an optimum value. apparatus. 3. The charged deflecting liquid jet recording apparatus according to claim 1 , wherein the detecting means is a line sensor provided between the deflecting electrode and the recording medium. Deflection type liquid jet recording device. 4. An ejection nozzle for ejecting ink particles, a charging electrode for charging the ejected ink particles, and a deflection electrode for deflecting the flight direction of the ink particles when the charged ink particles fly in an electrostatic field. A charged-deflection type liquid jet recording apparatus for recording on a recording medium by landing ink particles whose flight direction has been deflected onto a recording medium, wherein the deflection of the ink particles deflected by the deflection electrode is performed. as the flying direction of the amount between the ink particles intersect vertically into the surface of the recording medium, the injection nozzle, the charging electrode and the
An ink jet head having a deflection electrode or
While inclining at least one of the recording media, reading means for optically reading a recording result recorded on the recording medium, and determining the skewness of the recording result from the read result, to reduce before Symbol
Charged deflection type liquid jet recording apparatus characterized by comprising a tilting angle adjusting means for adjusting the tilt oblique angle, a. 5. An ejection nozzle for ejecting ink particles, a charging electrode for charging the ejected ink particles, and a deflecting electrode for deflecting the flight direction of the ink particles when the charged ink particles fly in an electrostatic field. A charged-deflection type liquid jet recording apparatus for recording on a recording medium by landing ink particles whose flight direction has been deflected onto a recording medium, wherein the deflection of the ink particles deflected by the deflection electrode is performed. as the flying direction of the amount between the ink particles intersect vertically into the surface of the recording medium, the injection nozzle, the charging electrode and the
An ink jet head having a deflection electrode or
With tilting the at least one of the recording medium, detecting means for detecting the quantity and amount of deflection of the ink particles from the deflection electrodes, the <br/> pre Ki傾 oblique angle based on a detection result from the detecting means A charge deflecting type liquid jet recording apparatus, comprising: a tilt angle adjusting means for adjusting. 6. The method of claim 1, 4, a charged deflection type liquid jet recording apparatus according to any one of 5, prior Ki傾 oblique angles charged deflection type liquid jet recording, which is a 30 to 60 degrees apparatus.