JPH03230967A - Ink transfer device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a transfer device, and particularly to an ink transfer device that directly transfers ink to transfer paper in accordance with a print signal.

[Prior art and its problems]

2. Description of the Related Art Conventionally, so-called inkjet type devices have been known as devices that print on paper using liquid ink. This device prints an image on paper using an inkjet that ejects liquid ink, and prints the image by moving a nozzle linearly as the paper moves. However, since the inkjet performs reciprocating linear motion, it takes a long time to print one screen.

Therefore, in order to perform high-speed printing with liquid ink, a multi-nozzle method using multiple nozzles is used even in the same inkjet method. If this device is used, the printing processing time can be reduced to some extent, but on the other hand, a large number of precise nozzles are required, which increases the cost of the device.

Furthermore, since a fine nozzle is used, the ink tends to clog the nozzle, and to eliminate this problem, it is necessary to use ink with low clay content. However, low clay inks bleed easily (making it difficult to create high-quality images).

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned conventional drawbacks, it is an object of the present invention to provide an ink transfer device that can perform high-speed transfer processing and obtain high-quality transferred images.

[Key points of the invention]

According to the present invention, the above-mentioned object includes: an ink drum whose surface is coated with ink and a predetermined potential is applied; a helical electrode body which is disposed opposite to the ink drum and has a helical electrode formed on its surface and rotates at a predetermined speed; It has a spiral electrode body and a plurality of divided electrodes formed between the ink drum, and by setting the spiral electrode and the divided electrodes to a predetermined potential according to a print signal, the ink surface and the predetermined potential are set between the ink drum and the divided electrodes. This is achieved by providing an ink transfer device that selectively transfers ink to sheets of paper conveyed at intervals.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a sectional view of the ink transfer device of this embodiment. In the figure, an ink transfer device 1 includes a paper feed roller 2, a pair of conveyance rollers 3, a conveyance guide plate 4, a transfer section 5, and a conveyance belt 6. The transfer section 5 includes a screw pole (hereinafter referred to as SP roll) 7, It is composed of a control electrode film 8, an ink drum 9, an ink box 10, an ink roller 11, and an ink cleaner 12. Further, a paper feed cassette 13 loaded with paper P is installed below the paper feed roller 2, and a paper discharge tray 14 is formed on the side of the ink transfer device l.

The transport roll pair 3 includes a transport roll 3a and a transport roller 3b, rotates in the direction of the arrow at a predetermined timing, and transports the paper P. The conveyance guide plate 4 is a guide section that guides the paper P to the transfer section 5, and is made of an insulating material. The conveyor belt 6 is a so-called air suction belt that rotates in the direction of the arrow and conveys the paper P having ink adhered to the underside thereof while sucking it upward without causing ink to adhere to the belt, as will be described later.

On the other hand, ink 15 is stored within the ink box 10, and this ink 15 adheres to the surface of an ink roller 11 also disposed within the ink box 10. The ink roller 11 is configured to rub against the circumferential surface of the ink drum 9. The ink drum 9 is configured to be rotatable in the direction of the arrow,
The configuration is such that ink is applied to the circumferential surface by sliding friction with the ink roller 11. Further, a blade 1 extending from the end of the ink box 10 is provided on the circumferential surface of the ink drum 9.
0' are formed close to each other and regulate the ink applied to the circumferential surface of the ink drum 9 to a predetermined layer thickness. Furthermore, a cleaner 12 is provided to rub against the ink drum 9, and is configured to remove ink that has not been transferred to the paper P, as will be described later.

FIG. 3 is a cross-sectional view of the SP roll 7. The SF30-roll 7 has a structure in which a spiral electrode 7b is embedded in a base 7a, and rotational force is transmitted to the shaft 7c of the SP roll 7 from a rotational drive mechanism (not shown). Further, as shown in the figure, the spiral electrodes 7b are arranged parallel to each other at predetermined intervals, which will be described in detail later.

Figure 1 shows the SP roll 7 and ink drum 9 near the transfer position.
FIG. 2 is a diagram showing an arrangement configuration of a control electrode film 8 and an electric circuit configuration. The spiral electrode 7b of the SP roll 7 is connected to ground. Further, an electrode 9a is disposed on the inner periphery of the ink drum 9, and a voltage v1 is applied from a power source 16. Further, the control electrode film 8 is formed with segment electrodes 8a and mask electrodes 8b as control electrodes.

This segment electrode 8a is connected to the common terminal (2) of the switch S, and the mask electrode 8b is connected to the power source 16. The switch S is turned on and off in accordance with a signal output from a control circuit (not shown) based on the print signal.

Further, the terminal (2) of the switch S is connected to the ground, and the terminal (2) is connected to the power source 17. Therefore, when the switch S is switched to the terminal ■ side (assuming that the switch S is on at this time), the segment electrode 8a is at the ground level, and when the switch S is switched to the terminal ■ side, the segment electrode 8a is at the ground level. (Assume that switch S is off at this time)
, voltages v and +V2 are applied to the segment electrodes 8a.

A plan view of the control electrode film 8 is shown in FIG. 4 to explain the structure of the control electrode film 8 in detail. In addition, Fig. 5 is A of Fig. 4.
-A' sectional view. As shown in both figures, the control electrode film 8 is composed of a segment electrode 8a, a mask electrode 8b, and an insulating material 8c, and the mask electrode 8b is formed on the side facing the ink drum 9. The segment electrode 8a and the mask electrode 8b each extend to one side end of the control electrode fill 8 and form terminals 8a' and 8b', respectively.

The segment electrode 8a is connected to the switch S via this terminal 8a' as described above, and the mask electrode 8b is connected to the power source 16 via the mask terminal 8b'. Further, the segment electrode 8a and the mask electrode 8b have an opening 8a" having a predetermined width in the sub-scanning direction shown by arrow C.
8b'' is formed. This opening 8a'' is a portion where the segment electrode 8a is not formed, and the opening 8b'' is a portion where the segment electrode 8a is not formed.
'' is a portion where the mask electrode 8b is not formed.

Further, the opening 8a" is narrower than the opening 8b", and is configured to narrow down the electric field formed between the spiral electrode 7b and the electrode 9a, which will be described later.

On the other hand, as shown in FIGS. 1 and 4, the openings 8a", 8
bn is configured to be inclined with respect to the main scanning direction (the axial direction of the ink drum 9). This is a configuration for transferring ink in parallel to the main scanning direction even if the paper P moves in the sub-scanning direction (convex direction) while a voltage is applied to one segment electrode 7b, as will be described later. .

FIG. 6 particularly shows the segment electrode 8a and mask electrode 8b.
It is a diagram illustrating the formation state of openings 8a'' and 8b'' in which no .
The figure further shows in detail the arrangement of the opening 8a and the spiral electrode 7b. Here, it is assumed that the SP roll 7 rotates in the direction of arrow A and moves upward in the paper of the figure. The moving direction of the paper (sub-scanning direction, convex direction) is opposite to this direction, and the axial direction of the ink drum 9 (
(main scanning direction) is the direction of the arrow in the figure. Spiral electrode 7b
moves in the main scanning direction as the SP roll 7 rotates.

Further, LSP shown in the same figure indicates the pitch of the spiral electrode 7b in the main scanning direction, and in the case of this embodiment, it is configured to process dot printing on one segment electrode 8a and mask electrode 8b7-. Therefore, Lsp is −DS (however, Ds indicates the size of the driver 1). Further, as shown in the figure, while the spiral electrodes 7b intersect with the respective openings 8a'' (openings 8b''), a pulse signal instructing the switch S to turn on or off is sequentially output from a control circuit (not shown). , printing processing is performed. During this time, the paper P moves in the direction of the arrow, so that the first print position (for example, D+) and the last print value W (D+') are shifted by one dot (Ds). Therefore, in order to compensate for this printing position deviation in advance, in this embodiment, the segments 8a and mask electrodes 8b (openings 8a", 8b") are rotated counterclockwise with respect to the main scanning direction, as shown in the figure. It is arranged at an angle θ-.

If this angle θ- is the clockwise inclination angle of the spiral electrode 7b with respect to the main scanning direction, θ and P, then the LSE shown in the figure is expressed as Lsp Dscot θSP. therefore,
tanθ1 is DS/LSE and DS/(Lsp
Dscot θSP). Now, by substituting -DS into the above-mentioned LSP-, tanθ- is (Kcot
θ5p)-', therefore, the openings 8a'' and 8b'' are formed by tilting by this angle.

The ink transfer device 1 configured as described above transfers the paper P.
When the transfer process is performed, the ink 15 in the ink box 10 is transferred as the ink drum 9 and ink roller 11 rotate.
is applied to the ink roller 11 and further applied to the ink drum 9. Thereafter, the ink on the ink drum 9 is regulated to a constant layer thickness by the blade 10' and transported to the transfer position (the space between the ink drum 9 and the spiral electrode 70b via the openings 8a'' and 8b''). be done. At this time, the paper P is also carried out from the paper feed cassette 13 by the paper feed roller 2, and
The image reaches the transfer position via the conveyance guide plate 4.

For example, switch S is turned on according to the print signal (switch S
When the common terminal (2) is located on the terminal (2) side, the spiral electrode 7b and the segment electrode 8a are at the ground level. Further, a voltage v1 is applied by a power source 16 between the electrode 9a of the ink drum 9 and the spiral electrode 7b. For this reason, the picture electrode 7b
An electric field is formed between the ink drum 9a and 9a, and the ink 15 on the ink drum 9 is attracted toward the paper P and adsorbed to the lower surface of the paper P as shown in FIG.

On the other hand, when the switch S is off (when the common terminal ■ of the switch S is located on the terminal ■ side), the spiral electrode 7b is at the ground level as described above, but the segment electrode 8a is connected to the power supply 16.
and voltage v1+v2 from 17 are applied. Further, the voltage Vl is applied to the electrode 9a of the ink drum 9 in the same manner as described above. Therefore, the voltage Vl + V2 applied to the segment 8a is lower than the voltage vI applied between the picture electrodes 7b and 9a.
is higher, so no electric field is formed from the ink drum 9 in the direction of the paper P. Therefore, at this time, the ink drum 9
The upper ink is not transferred to the paper P.

Paper P according to the on/off of the switch S during the transfer operation mentioned above.
Ink is sequentially transferred onto the paper P, but the opening 8a'' is formed at an angle θ as described above, and the angle is different from the paper P.
Since the ink transfer speed corresponds to the moving speed in the direction of the arrow, the ink transfer position on the paper P is transferred parallel to the main scanning direction.

The paper P on which ink has been transferred in accordance with the print signal as described above is discharged to the paper discharge tray 14 by the conveyor belt 6.

As described above, when the above transfer process is sequentially executed for each line by the ink transfer device 1 having the configuration of this embodiment, the paper P
The image transferred thereon does not shift in the sub-scanning direction, resulting in a transferred image of excellent quality.

Furthermore, it can transfer at a higher speed than conventional inkjet methods.

FIGS. 8 and 9 are diagrams explaining other embodiments of the present invention.

In this embodiment, an SP roll and a control electrode film are arranged inside an ink drum. That is, as shown in FIG. 8, an SP roll I9 is disposed on a part of the inner circumference of the ink drum 21 with a control electrode film 18 interposed therebetween. Further, a bias electrode 20 is disposed directly above the ink drum 21 on which the control electrode film 18 and the SP roll 19 are disposed. Further, the paper P is conveyed between the ink drum 21 and the bias electrode 20. The other configuration is the same as that shown in FIG. 2 described above, and ink 15 is stored in the ink box 10, and the ink roller 11 is also arranged at the same position as in the previously described embodiment. .

FIG. 9 is a diagram showing a state when ink is transferred to paper P by the ink transfer device having the above configuration.

As in the previous embodiment, as the ink drum 2I and ink roller 11 rotate in the direction of the arrow, the ink box 10
The ink 15 inside is applied to the ink drum 21 and conveyed to the transfer position. At this time, a voltage 1 is applied between the bar 3 ear-swimming pole 20 and the spiral electrode 19b, and the switch S is turned on and off according to the print signal, thereby controlling transfer/non-transfer of the ink 15 to the paper P. .

For example, when the switch S is on, the voltage applied to the segment electrode 18b is set to the ground level, and the electric field shown in the figure is formed to transfer the ink 15 on the ink drum 21 to the paper P. Further, when the switch S is off, the voltage of the segment electrode 18b is set to Vl+V2 as described above, thereby preventing the formation of an electric field and preventing the ink 15 on the ink drum 21 from being transferred to the paper P.

Also in this embodiment, since the opening 18'' formed in the control electrode film 18 is tilted counterclockwise by an angle θ with respect to the main scanning direction as described above, the paper P
The transfer position of the upper ink 15 is parallel to the main scanning direction.

Therefore, also in the case of this embodiment, the image quality is excellent and high-speed transfer processing is possible.

In this embodiment, a roll 4 with a spiral electrode 7b embedded therein as shown in FIG. 3 was used as the SP roll, but for example, a spiral electrode 7 as shown in FIG.
An old SP roll having a structure in which b' is protruding may also be used.

〔Effect of the invention〕

As described above in detail, according to the present invention, it is possible to obtain a transferred image with extremely excellent print quality without performing skewed image transfer onto paper as in the conventional method.

Furthermore, it is possible to provide an ink transfer device with improved transfer speed compared to conventional ink transfer devices.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main parts of an ink transfer device according to an embodiment, FIG. 2 is a diagram showing the overall configuration of an ink transfer device according to an embodiment, FIG. 3 is a cross-sectional view of an sp roll, and FIG. 4 is a control electrode. A plan view of the film, Fig. 5 is a cross-sectional view of the control electrode film, Fig. 6 is a diagram that does not show the arrangement relationship between the spiral electrode and the opening of the control electrode film in the SP old roll unfolded state, and Fig. 7 is a diagram showing the opening of the control electrode film. FIG. 8 is a configuration diagram of an ink transfer device of another embodiment, and FIG. 9 is a diagram of an ink transfer device of another embodiment. FIG. 10 is a diagram showing a modification of the old SP roll. 1... Ink transfer device, 2... Paper feed roller, 3... Conveyance roll, 4... Conveyance guide plate, 5... Transfer section, 6... Conveyance belt, 7.19...・SP old roll 7a... Base body, 7b... Spiral electrode, 8.18... Control electrode film, 8a, 18a... Segment electrode, 8b... Mask electrode, 8a'', 8b''...・Opening portion, 9.21... Ink drum, 10... Ink box, 11... Ink roller, 12... Ink cleaner, 13... Paper feed cassette, 14... Paper output tray 15 ...Ink, 16.17...Power supply, S... Switch.

Claims (1)

[Scope of Claims] 1) An ink drum whose surface is coated with ink and a predetermined potential is applied; a helical electrode body that is placed opposite to the ink drum and has a helical electrode formed on its surface and rotates at a predetermined speed; It has a plurality of divided electrodes formed between an electrode body and the ink drum, and by setting the spiral electrode and the divided electrodes to a predetermined potential according to a print signal, a predetermined distance from the ink surface is created between the ink drum and the divided electrodes. An ink transfer device that selectively transfers ink to a sheet of paper that is conveyed while holding a paper. 2) When the angle between the axial direction of the ink drum and the divided electrode is θ_W, and the angle between the axial direction of the ink drum and the spiral electrode is θ_S_P, tan θ_W=(
2. The ink transfer device according to claim 1, wherein K-cotθ_S_P)^-^1 (where K is an arbitrary integer).