JPH04220352A - Electrostatic sucking type ink jet recording device - Google Patents

Abstract

PURPOSE:To keep uniformly the density of ink at positions of a group of recording electrodes by always feeding fresh ink in an ink tank to the recording electrodes regardless of whether the recording electrodes are used ones or new ones. CONSTITUTION:An ink tank 9 is provided separately from a fixing area of a group of recording electrodes 16, while an ink carrier member 21 is provided so as to be movable between the interior of the tank 9 and the group of recording electrodes 16. The member 21 is driven by a drive means 17 to attach ink 25 in the tank 9 to the member 21, thereby continuously feeding the ink to the electrodes 16 located on the moving route of the member 21.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic suction type ink jet recording apparatus.

0002

[Prior Art] Various inkjet recording systems have been developed for ejecting ink, but recently a slitjet recording device, shown in Fig. 8, has been developed that ejects ink from slits rather than so-called nozzles. . An ink tank 2 is integrally formed in the head 1, and the inside of the ink tank 2 communicates with a slit-shaped ink discharge port 3 formed at the front end of the head 1.

[0003] The slit-shaped ink discharge port 3 has 8 ink/m
Recording electrodes 4 are arranged at m. A voltage is applied between this recording electrode 4 and a counter electrode 6 on the back side of the recording paper 5. A roller 7 for feeding the recording paper 5 is fixed to the counter electrode 6.

When a voltage is applied between the recording electrode 4 and the counter electrode 6, the ink on the recording electrode 4 is charged, and this charged ink is generated between the recording electrode 4 and the counter electrode 6. Due to the action of the electric field, the ink is attracted toward the counter electrode 6 and flies, and the ink is recorded on the recording paper 5.

[0005]

[Problems to be Solved by the Invention] In the slit jet recording device shown in FIG. 8, the ink discharge port, that is, the slit portion, and the ink tank are in communication, so that ink is always accumulated in the slit portion. ing. In actual printing, since the slit part has a used part and an unused part, there was a defect that the ink density was non-uniform within the slit part. The present invention aims to eliminate the above-mentioned defects.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention makes ink placed on a group of recording electrodes fly by a potential difference between the recording electrodes and a counter electrode facing the recording electrodes. In an electrostatic suction type inkjet recording device configured to perform recording on a recording paper disposed between a group of recording electrodes and a counter electrode, an ink tank disposed at a position away from the recording electrode group, and an inside of the ink tank are provided. The ink transporting member includes an ink transporting member movably disposed with a moving path between the recording electrode group and the recording electrode group, and a driving means for driving the ink transporting member.

[0007]

[Operation] By moving the ink conveying member, ink in the ink tank is continuously conveyed onto the recording electrode.

[0008] Therefore, the ink in the ink tank is continuously conveyed even onto unused recording electrodes, and the ink does not remain on unused recording electrodes. Ink is supplied without interruption without any distinction, and the ink on the recording electrode group is maintained at a uniform density as a whole.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be explained in detail below with reference to embodiments shown in the accompanying drawings. In FIG. 1, reference numeral 8 denotes a case body of an electrostatic suction type inkjet recording apparatus, and an ink tank 9 is disposed at the bottom of the case body. A sheet feed roller 10 is disposed within the ink tank 9 and is rotatably supported by the tank 9.

Head partitions 12 and 13 forming a chamber 11 are provided at the upper part of the main body 8, and a fan 14 for creating a mechanical gas is disposed within the chamber 11. The fan 14 is fixed to the partition wall 12.

A substrate 15 is provided at the bottom of the partition wall 12, and a large number of recording electrodes 16 are fixedly arranged in parallel at regular intervals on the substrate 15. A slit-shaped opening, that is, an ink discharge port, is formed between the front end of the substrate 15 and the partition wall 13.

A sheet driving roller 18 is rotatably supported on the main body 8 and is connected to an output shaft of a motor 17 fixedly attached to the main body 8. Reference numerals 19 and 20 indicate sheet feed rollers, which are rotatably supported by the main body 8.

Reference numeral 21 denotes an ink conveying member, which includes the sheet feeding rollers 10, 19, 20 and the sheet driving roller 1.
It is made up of an endless flexible porous sheet stretched over 8 sheets.

In the ink conveying member 21, a large number of holes 22 for ink adhesion are formed in a matrix, and each hole 22
The interval on one line is set to be the same as the interval between each electrode 16 of the group of recording electrodes 16.

A slit is formed in the partition wall 12 and the tank 9 to form a moving path for the ink conveying member 21. One of the slits of the ink tank 9 is provided with a blade 23 made of a rubber plate.
, 24 are arranged facing each other with a predetermined gap therebetween, and the ink conveying member 21 is inserted between the blades 23 and 24. The blades 23 and 24 are for regulating the amount of ink 25 in the ink tank 9 that adheres to the ink transport member 21 to a predetermined amount.

A moving path of the ink conveying member 21 between the sheet driving roller 18 and the sheet feeding roller 20 faces the opening of the chamber 11. A slit-shaped opening 26 is formed in the main body 8 at a position facing the chamber opening.

Reference numeral 27 denotes a platen roller which is rotatably supported on the main body of the printer (not shown) in conjunction with a rotary drive device, and faces the opening 26 in parallel with a predetermined distance therebetween.

A shaft-shaped counter electrode 28 is fixedly provided at the center of the platen roller 27 so as to face the group of recording electrodes 16 . Reference numeral 29 denotes recording paper, which is supported by a recording paper feeding mechanism (not shown) provided in the main body of the printer. The recording paper 29 is supported by the paper feeding mechanism so as to be in contact with the platen roller 27 and move vertically upward between the platen roller 27 and the opening 26.

Next, the operation of this embodiment will be explained. When the ink transport member 21 moves at a predetermined speed counterclockwise along the sheet feed rollers 10, 20, and 19 in FIG. An appropriate amount is attached to the recording electrode 21 and transported to the tip of the recording electrode 16 group.

Drive circuits for supplying voltage pulses to the recording electrodes 16 are provided one by one for all the recording electrodes 16 in order to improve the recording speed. In this example, 8d
ot/mm and effective recording width of 200 mm, 1600 pieces are required per recording head. In this example, commercially available I
The recording pulse voltage was set to 300V.

A voltage is applied between the recording electrode 16 and the opposing electrode 28 on the back side of the recording paper 29. When the ink 25 adhering to the ink adhesion hole 22 moves to the front of the recording electrode 16 as shown in FIG.

This ink 25 is charged by the potential difference between the recording electrode 16 and the counter electrode 28, and this charged ink 25
5 is attracted towards the opposite electrode 28 due to the action of the electric field generated between the recording electrode 16 and the opposite electrode 28, and the recording paper 2
Fly towards 9.

When voltages are applied to adjacent recording electrodes 16 at the same time, since the ink 25 is electrically charged, a Coulomb repulsive force acts between the ejected ink 25, which corresponds to the recording image forming position on the recording paper 29. The position of the recording electrode 16 may shift.

Therefore, the distance between the recording electrodes 16 that are driven at the same time is such that the displacement of the recording image forming position can be ignored.

Next, an embodiment using an ink supply roller as the ink conveyance member will be described with reference to FIGS. 4 and 5.

Reference numeral 30 denotes a drive shaft linked to the rotation drive device, and is rotatably supported on both side walls of an ink tank 31 provided in the head case body (not shown). An ink transport member 32 consisting of an ink supply roller is fixedly installed around the drive shaft 30.

The lower circumferential surface of the ink conveying member 32 is disposed within the ink tank 31, and the upper circumferential surface thereof is located above the ink tank 31. A predetermined number of recording electrodes 33 are attached to a substrate 34 fixed to the ink tank 31 in a horizontal row. The recording electrodes 33 are arranged in a horizontal line facing the circumferential surface of the ink transporting member 32 located above the ink tank 31 with a slight gap therebetween.

27 is a platen roller facing the recording electrode 33 group, 28 is a counter electrode, and 35 is the recording electrode 3 group.
A blade consisting of a rubber plate arranged on the upstream side of the third group, 2
9 is recording paper.

In the above configuration, the ink conveying member 3
The ink 25 in the ink tank 31 adhering to the surface of the ink tank 31 is left in an appropriate amount by the blade 35 due to the rotation of the ink transport member 32 in the counterclockwise direction in FIG. recording electrode 33 by
carried into position.

When a voltage is applied between the recording electrode 33 and the counter electrode 28, an ink meniscus is formed in the ink 25 located on the recording electrode 33, and particles of the ink 25 fly toward the recording paper 29, causing recording. will be held.

Another embodiment will be described below with reference to FIGS. 6 and 7. In this embodiment, an ink supply roller provided with a large number of ink adhesion holes is used as the ink conveyance member.

Reference numeral 36 denotes an ink tank fixedly attached to the case body (not shown), and bearings 37 and 38 erected on the case body are arranged on both sides of the ink tank.

39 is a fan for creating a meniscus;
It is fixed to the shaft body 40. Both ends of the shaft body 40 are rotatably supported by the bearings 37 and 38.

Reference numeral 41 denotes an ink conveying member consisting of a hollow ink supplying roller, and a number of holes 42 for ink adhesion are transparently provided in the peripheral wall of the ink conveying member.

The shaft body 40 is inserted into a hole formed in the center of both side walls of the ink conveying member 41 via a ball bearing.
The ink conveying member 41 is rotatably supported around the shaft body 40 . The fan 39 is disposed within the hollow portion of the ink transport member 41.

A lower portion of the ink conveying member 41 is disposed within the ink tank 36.

A substrate 4 is mounted on the front wall of the ink tank 36.
3 is fixedly installed on the substrate 43, and the ink conveying member 41
A large number of recording electrodes 43 are fixedly provided facing the peripheral surface of the recording electrode 43, and the arrangement interval of each electrode 44 of the recording electrode 43 group and the arrangement interval of the ink adhesion holes 42 on one line of the ink transport member 41 are the same. It is set.

The air outlet 39a of the fan 39 faces the recording electrode 44 group.

Reference numeral 45 denotes a ring-shaped gear fixed to the side wall of the ink conveying member 41, and the gear 45 is loosely fitted onto the shaft 40.

A drive gear 47 is fixed to the output shaft of a drive motor 46 fixed to the case body via a bracket, and the drive gear 47 meshes with the gear 45.

A blade 48 is fixed to the front wall of the ink tank 36, located upstream of the recording electrode 44, and the ink scraping action of the blade 48 removes the ink adhering to the ink adhesion holes 42. The amount is regulated to an appropriate level.

In FIG. 6, 27 is a platen roller, and 28 is a platen roller.
is a counter electrode, and 29 is a recording paper.

In the above-described configuration, when the ink transport member 41 is rotated in the direction of the arrow in FIG. 6 by driving the drive motor 46, the ink 25 in the ink tank 36 adheres to the ink adhesion hole 42 and reaches the recording electrode. Transported to Group 44.

The ink 25 distributed to the group of recording electrodes 44 forms an ink meniscus due to the wind from the fan 39, and also flies toward the recording paper 29 due to the potential difference between the recording electrodes 44 and the counter electrode 28, thereby causing recording. Recording is performed on paper 29.

[0045]

As described above, the present invention has a structure in which an appropriate amount of ink is always supplied to the recording electrodes by the ink conveying member, so that the ink concentration is constant and printing quality can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an inkjet head.

FIG. 2 is a partially cutaway external view of an inkjet head.

FIG. 3 is a side sectional view of the inkjet head.

FIG. 4 is an external view showing a second example of an inkjet head.

FIG. 5 is a side view showing a second embodiment of the inkjet head.

FIG. 6 is an external view showing a third embodiment of an inkjet head.

FIG. 7 is a front view showing a third example of an inkjet head.

FIG. 8 is an external view showing a conventional inkjet head.

[Explanation of symbols]

1 Head 2 Ink tank 3 Ink discharge port 4 Recording electrode 5 Recording paper 6 Counter electrode 7 Roller 8 Case body 9 Ink tank 10 Sheet feed roller 11 Chamber 12 Partition wall 13 Partition wall 14 Fan 15　Substrate 16 Recording electrode 17 Motor 18 Sheet drive roller 19 Sheet feed roller 20 Sheet feed roller 21 Ink transport member 22 hole 23 Blade 24 Blade 25 Ink 26 Opening 27 Platen roller 28 Counter electrode 29 Recording paper 30 Drive shaft 31 Ink tank 32 Ink transport member 33 Recording electrode 34 Board 35 Blade 36 Ink tank 37 Bearing 38 Bearing 39 Fan 40 Shaft body 41 Ink transport member 42 hole 43 Board 44 Recording electrode 45 Gear 46 Drive motor 47 Drive gear 48 Blade

Claims (1)

[Claims] 1. Ink placed on a group of recording electrodes is ejected by a potential difference between the recording electrode and a counter electrode facing the recording electrode, and is recorded on a recording paper disposed between the recording electrode and the counter electrode. The electrostatic suction type inkjet recording apparatus includes an ink tank disposed at a position away from the recording electrode group, and a movement path between the inside of the ink tank and the recording electrode group. An electrostatic suction type inkjet recording apparatus comprising: an ink conveying member movably arranged; and a driving means for driving the ink conveying member.