JPS6251458A - Ink jet printer - Google Patents

Abstract

PURPOSE:To improve productivity by providing one carrier mounted on the other carrier in a movable fashion to enable the performance of a printing head alone to be checked. CONSTITUTION:A belt 14 which drives a printing head 10 is fixed to an electrode carrier 13, and if the belt 14 is driven, the electrode carrier 13 moves from left to right and hits a contact member 16 fitted to a nozzle carrier 12 with screws. If the belt 14 is pulled to the right under this state, the nozzle carrier 12 moves from left to right by means of the electrode carrier 13. In this case, an upper deflection electrode 5 deflects toward the left of a lower deflection electrode 4, so that ink particles 2 are directed to the left. Consequently, the character gradient generated resultantly faces toward the right, because the printing head 10 prints moving from left to right. Thus characters are printed vertically, and when characters printed in the forward operation inclines toward either left or right, they are adjusted by rotating a lever 18. As a result, it is possible to check the gradient correction performance with the printing head 10 alone and improve productivity.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention/fi A charge amount control type that can correct the printing inclination during forward and backward movements by shifting the relative position between the deflection electrode and the nozzle during forward and backward movements. It relates to inkjet printers.

[Background of the invention]

It is well known that in charging sound controlled inkjet printers, the inclination directions of printed characters are opposite between forward and reverse, resulting in a decrease in print quality.

Various methods and devices for correcting such printing inclination have been proposed. In Japanese Patent Application No. 60-1+'1172, the present applicant proposed a correction method by automatically changing the position of one of a pair of deflection electrodes during forward and backward movements. In this application, an electrode carrier on which one deflection electrode is mounted, and a nozzle carrier on which a nozzle, a charging electrode, and the other deflection electrode are mounted are arranged side by side on guide shafts provided in the width direction of the paper. For this reason, the tilt correction performance could only be checked in the assembled state as a pre/print head, and could not be checked as a single print head. Therefore, assembly, inspection, repair, etc. before and after checking are complicated, resulting in poor productivity.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inkjet printer that eliminates the drawbacks of the prior art described above and allows performance checks of the print head alone, thereby improving productivity.

[Summary of the invention]

The present invention focuses on the fact that the reason for the poor productivity in the above-mentioned application is that the electrode gear carrier and the nozzle carrier are arranged side by side on the guide shaft, and makes it possible to move one carrier to the other carrier. By installing
The configuration has been devised so that it is possible to check the performance of the print head alone. The present invention will be described below with reference to the drawings showing embodiments.

[Embodiments of the invention]

Two guide members 11 are provided at the front and rear along the front surface of the paper 7, and are supported by the side plate 15.

A nozzle carrier 12 on which the nozzle 1, charging electrode 3, upper deflection electrode 5, etc. are mounted is slidably mounted on the guide member 11. - The electrode carrier 13 carrying the lower deflection electrode 4 is slidably attached to the nozzle carrier 12 via a bearing 21 and a slide shaft 22 attached to the nozzle carrier 12. 1 to 5 show the printing state in the past when the print head 10, which is composed of the nozzle carrier 12, electrode carrier 13, etc., runs from the left side of the paper 7 to the right side, and FIG. , 3rd
As shown in the figure, the nozzle carrier 12 and the electrode carrier 3
and are in contact on the right side, and a play t is maintained on the left side. Conversely, in the case of return, the nozzle carrier 12 and the electrode carrier 13 are in a positional relationship such that they come into contact on the left side and maintain a play t on the right side.

Hereinafter, the character tilt correction mechanism will be specifically explained from the operation of each part. First, the operation of each part in the former case where the print head 10 prints while moving from left to right will be explained. A belt 14 that drives the printing pad 10 by a head feed motor (not shown) is fixed to the electrode carrier 13.
When the belt 14 is driven in the direction of the arrow in FIG. 2, the electrode carrier 13 moves from left to right, and the electrode carrier 1
The right end surface of No. 3 abuts against the end surface of the contact member 16 which is threadedly fitted onto the nozzle carrier 12. In this state, belt 14
When the nozzle carrier 12 is pulled to the right, the nozzle carrier 12 is pushed to the right by the electrode carrier 13 via this contact member 14, and in conjunction with the movement of the electrode carrier 13, the nozzle carrier 1
2 moves from left to right. In this way, print head 1
When 0 is printed from left to right, as shown in FIG. 21 and the lower deflection electrode 4 which is grounded through the guide member 11, the deflection electric field is tilted to the left in FIG. 4, and the ink droplets 2 receive a force from the deflection electric field in this direction during printing. It now has a velocity component that points to the left. On the other hand, since the printing pad 11 performs printing while moving from left to right, the ink droplets 2 have a rightward velocity component.

In this embodiment, since printing is performed while scanning the matrix from the bottom to the top, the direction of the character inclination that is likely to occur is to the right because the print head 10 prints while moving from left to right. On the other hand, the direction of the character inclination caused by the inclination of the deflection electric field is to the left,
These two cancel each other out, and the characters actually printed become vertical. In this embodiment, manufacturing variations in the upper and lower deflection electrodes 5.4, etc. are unavoidable. Therefore, in this example,
A mechanism is added to adjust the amount of character inclination correction in the forward and backward directions, and to explain the former case using FIGS. The member 16 has a structure that allows it to move from side to side by rotating. A leaf spring-like lever 18 made of sheet metal is fixed to the contact member 16. One end of the lever 8 fits into a groove 25 of a head cover 17 that is removably attached to the nozzle carrier 12, and the contact member 16 is held in place. Always bias the contact member 16 in the right direction.

The nozzle carrier 12 is fixed to the nozzle carrier 12 without any looseness in the left and right direction, and is designed to not easily rotate when the print head 10 moves.

Now, if the characters printed in the past were tilted to the left, when the lever 18 is rotated in the direction indicated as right of the head cover 17 in FIG. 5, the contact member 16 moves to the left.
Since the amount of rightward deviation of the lower deflection electrode 4 with respect to the upper deflection electrode 5 is reduced, the amount by which the direction of the deflection electric field is tilted to the left is alleviated, and the characters are corrected vertically. Of course, if the characters printed in the past were tilted to the right, lever 18
is rotated to the left in FIG. 5 to adjust the amount of character slant correction. Note that during printing, the relative positions of the upper and lower deflection electrodes 5.4 must not be changed, and in particular, it is necessary for the nozzle carrier 12 to accurately follow the left and right movement of the electrode gear rear 13.

In this embodiment, the nozzle carrier 12 and the electrode carrier 13 are constructed as separate members, and the nozzle carrier 12 on which the upper deflection electrode 5 is mounted via the head cover 17 is attached to the guide member 11, and the nozzle carrier 12 is slid onto the nozzle carrier 12. Since the attached electrode carrier 13 is driven by the belt 14, the relative positions of the upper and lower deflection electrodes 5.4 do not change for the following reasons. For example, print head 10
When printing while moving from left to right, when the belt 14 drives the electrode carrier 13 from left to right at a constant speed, the nozzle carrier 12 is also pushed through the contact member 16. As the nozzle carrier 12 moves from left to right, a frictional force is generated between the nozzle carrier 12 and the guide member 11, and a frictional force acts from right to left on the nozzle carrier 12 while it is running. The electrode carrier 13 and the nozzle carrier 12 can be maintained in a secure state of contact at the end surface of the contact member 16.

Furthermore, in this embodiment, since the relatively light electrode carrier 13 is driven by the belt 14 and the heavy nozzle carrier 12 is moved by the electrode carrier 13,
The right-to-left frictional force that the nozzle carrier 12 receives from the guide member 11 is relatively large, and the nozzle carrier 12 stably contacts the electrode carrier 13 via the contact member 16. Further, a coupling means (for example, a magnet and an adsorbing metal) having a force sufficiently smaller than the frictional force generated between the nozzle carrier 12 and the guide member 11 may be provided between the nozzle carrier 12 and the electrode carrier 13. good.

The case in which the print head 10 moves from left to right has been described above, but below, the case in which the print head 10 turns back and moves backward from right to left will be described below. When the print head 10 approaches the turning point, the head feeding motor decelerates and the electrode carrier 13 moves toward the belt 14.
to slow down through. On the other hand, since the nozzle carrier 12 has inertia, it moves faster than the electrode carrier 13, and when the print head 10 is traveling from left to right at a constant speed, the dimension t maintained on the left side of the electrode carrier 13 is It gradually becomes smaller and eventually becomes 0, and the nozzle carrier 12 collides with the electrode carrier 12 via the contact member 19. belt 1
When the driving direction of the electrode carrier 13 by 4 is reversed almost at this point of collision and the electrode carrier 13 starts to accelerate from right to left, the nozzle carrier 12Fi contact member 19
The electrode carrier 13 starts to accelerate from right to left through the electrode carrier 13. During this acceleration, the nozzle carrier 12 is pressed against the electrode carrier 13 via the end surface of the contact member 19 by the inertia force directed from left to right and the frictional force generated between the guide member 11 and directed from left to right. Actually, 1-2
Although the nozzle carrier 12 vibrates from side to side due to repeated collisions and repulsions, it attenuates by the time the electrode carrier 13 reaches a constant speed and does not adversely affect printing. In this way, the electrode carrier 13 and the nozzle carrier 12 come into contact with each other at the end surface of the contact member 19, and the right side surface of the electrode carrier 13 and the contact member 1
When a constant speed is reached while maintaining a gap of dimension t between the printer and the printer 6, printing will begin soon. Therefore, in the case of returning, when looking from the nozzle 1 toward the paper 7, the upper deflection electrode 5 is shifted to the right with respect to the lower deflection electrode 4, so the character inclination is changed for the same reason as in the previous case. It can be corrected. Adjustment of the correction amount of the character inclination is carried out by operating the lever 20 in the same way as the lever 18 was operated in the previous case and moving the contact member 19 in the case of returning. The levers 18 and 19 are completely independent, and each has a structure in which the forward and backward character inclinations can be adjusted independently.

In this embodiment, the structure is such that the electrode carrier 13 is driven by a belt 14 and the nozzle carrier 12 follows, but a structure may also be adopted in which the nozzle carrier 12 is driven by a belt or the like and the electrode carrier 13 follows this. . However, in this case, the scanning direction of the characters needs to be from top to bottom, contrary to the present embodiment.

Further, in this embodiment, the lower deflection electrode 4 is mounted on the electrode carrier 13, the upper deflection electrode 5 and the nozzle 1, etc. are mounted on the nozzle carrier 12, and the electrode carrier 13 is mounted on the belt 1.
4, the upper deflection electrode 5 is mounted on an electrode carrier 13, the lower deflection electrode 4 and nozzle 1 are mounted on a nozzle carrier 12, and the nozzle carrier 12 or electrode carrier 13 is driven by a belt 14. You can also use it as

However, in this case, the scanning direction of the characters needs to be from top to bottom, contrary to the present embodiment.

In addition, in this embodiment, the lower deflection electrode 4 is grounded,
Although a high voltage is applied to the upper deflection electrode 5, a high voltage may be applied to the lower deflection electrode 4 and the upper deflection electrode 5 may be grounded.

Furthermore, vibration-proofing rubber or the like may be provided at the collision portion between the one-electrode carrier 13 and the contact member 16.19 to absorb the vibration of each carrier 12.13 at the folded portion of the print head 10. Further, a collision detector may be provided on at least one of the nozzle carrier 12 and the electrode carrier 13 to detect a collision, and the head feeding motor may be controlled based on the detection result to make the head travel more smoothly.

As described above, according to the embodiment of the present invention, since the electrode Φ year 13 is slidably mounted on the nozzle carrier 12, it is possible to check the tilt correction performance of the print head 10 alone, increasing productivity. was able to improve significantly.

〔Effect of the invention〕

According to the present invention, it is possible to correct the printing inclination during forward and backward movement, and it is also possible to check the inclination correction performance of the print head alone, which facilitates assembly, inspection, and repair, and improves productivity. I was able to figure it out.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the print head of an inkjet printer of the present invention, FIG. 2 is a sectional view taken along the line f-1 in FIG. 1, and FIG. 3 is a sectional view taken along the single layer line in FIG. 1. , FIG. 4 is a sectional view taken along the line T in FIG. 1, and FIG. 5 is a side view of FIG. DESCRIPTION OF SYMBOLS 1... Nozzle, 2... Ink particle, 3... Charging electrode, 4... Lower deflection electrode, 5... Upper deflection electrode, 7
... paper, 10 ... print head, 11 ... guide member, 12 ... nozzle carrier, 13 ... electrode carrier, 14 ... belt, 16.19 ... contact member. Name of patent applicant Hitachi Koki Co., Ltd.

Claims (1)

[Scope of Claims] 1. Ink particles ejected from a nozzle are charged by a charging electrode according to printed information, and a pair of upper and lower deflection electrodes are used to deflect the ink particles according to the amount of charge of the particles, and the nozzle and the charging electrode , and an inkjet printer that prints by reciprocating a carrier on which one of the deflection electrodes is mounted along a guide member provided in the width direction of a recording medium, wherein the carrier is connected to an electrode carrier on which one of the deflection electrodes is mounted and a carrier on which one of the deflection electrodes is mounted; It consists of a nozzle carrier carrying the nozzle, a charging electrode, and the other deflection electrode, and either the electrode carrier or the nozzle carrier is attached to the guide member so as to be reciprocally movable, and the other carrier is attached to the guide member. The carrier is slidably mounted with play in the direction of reciprocating movement, and a driving means is provided for reciprocating either the electrode carrier or the nozzle carrier so as to change the position of the play between forward and backward movements. An inkjet printer characterized by having a configuration capable of correcting printing inclination during forward and backward operations. 2. The inkjet printer according to claim 1, wherein the carrier driven by the driving means is the other carrier mounted on one carrier mounted on the guide member. 3. The inkjet printer according to claim 2, wherein the one carrier is reciprocated via the other carrier. 4. A patent claim characterized in that the one carrier is shaped to straddle the other carrier in the reciprocating direction, and a contact member for regulating the position of play is provided on at least one of the opposing sides of the carrier. The inkjet printer according to item 2 of the range. 5. Claim 4, characterized in that the contact member is movable back and forth in a reciprocating direction, and the amount of play can be adjusted to adjust the amount of character inclination correction.
Inkjet printer as described in section.