JPS6040022B2 - Image forming method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming method and an image forming apparatus for forming an image using liquid ink according to facsimile information, output information from a computer, optical information, or the like.

Conventionally, image forming methods using liquid ink have been widely used, particularly in the field of data processing, as they enable vibration-free and noise-free printing devices. As a typical example, ink droplets are continuously ejected toward the recording material, and ink droplets that do not want to adhere to the recording material are prevented from flying toward the recording material during the flight process. There is a method of suppressing this and forming an image on a recording material according to the information signal. However, with the above configuration, ink droplets that fly only at minute intervals must be suppressed during the flying stage of the collection time, making accurate control according to information signals difficult, and limiting image accuracy. There is. In addition, the ink flow that suppresses flying water in the direction of the recording material is
A circulation mechanism is required for collection and reuse, which also has the drawback of increasing the size of the device. In addition, as another image forming method, a plurality of ink supply holes (nozzles) are arranged facing the recording material, and pin electrodes corresponding to each nozzle are independently provided on the back of the recording material to respond to information signals. There is a method of selectively applying a high voltage pulse between each nozzle and an electrode to cause ink to fly and form an image.

With this configuration, since accurate information signals can be applied to each nozzle, image accuracy is improved. Furthermore, since the ink droplets whose flying glue is to be suppressed are not caused to fly from the beginning, there is no need to circulate the ink, which has the advantage that the apparatus can be made smaller. However, in order to improve image accuracy, it is necessary to accurately match the corresponding positions of the nozzle and pin electrodes, but since both the nozzle jet opening and the pin electrode are minute, it is necessary to match the corresponding positions of the two. is extremely troublesome in terms of device configuration. Furthermore, even if the installation positions of the two hawks are slightly shifted, the image accuracy decreases. In addition, high voltage pulses must be applied to the pin electrodes, and if the nozzles are arranged in a high density, interactions between adjacent electrodes will occur, making it impossible to arrange the nozzles in a high density, which makes it difficult to obtain high-resolution images. There is a drawback that formation cannot be expected. Therefore, the present invention makes it possible to obtain high-resolution images by enabling low-voltage control of image formation, and at the same time, it is possible to avoid the troublesome task of precisely aligning the corresponding positions of the spout of a minute nozzle and the pin electrode. An object of the present invention is to provide an image forming method and an image forming apparatus that do not require any operations.

That is, the present invention achieves the above object by providing a screen-like member having a plurality of arranged through holes, and an electrode for selectively introducing ink into the through holes in each row. and the ink groove relative to each other, and selectively applying a voltage between the electrode and the ink in the ink domain according to the information signal to selectively introduce ink into the corresponding through hole. It is characterized by forming an image in the above-mentioned screen.

The present invention also provides a screen-like member having a plurality of arranged through-holes and a column electrode for selectively introducing ink into the through-holes in common for each row of through-holes; means for selectively applying a voltage between the column electrode and the ink in the ink domain in accordance with an information signal; and a counter electrode provided on the opposite side of the ink groove for continuously applying a voltage between the ink in the ink groove, and between the column electrode and the ink in the ink field. It is characterized by forming an image by selectively applying a voltage according to the information signal, selectively introducing ink into the corresponding through-hole, and making it adhere to the print medium.

Hereinafter, the present invention will be explained using the drawings.

FIG. 1 is a plan view showing the arrangement of essential parts of an embodiment of the present invention.

In the figure, 1 is a screen-like member having a large number of through holes 2 arranged at equal intervals. Further, on the surface thereof, linear electrodes 3 surrounding the through hole 2 and being insulated and isolated from each other are arranged in parallel stripes. Further, its surface is coated with an ink repellent layer such as tetrafluorethylene. Note that FIG. 2 is an enlarged sectional view of the screen-like member.

In the figure, 4 is an ink repellent layer. Further, the screen-like portion 1 is placed close to or in contact with the ink within the slot-like capillary groove 5 of the ink supply device 6.

Note that the capillary groove 5 is configured such that the liquid ink 7 is always supplied in a fixed amount by an automatic replenishing device or the like. moreover,
A pulse voltage is applied to each linear electrode according to image information. Note that this means uses a conventionally known means that simultaneously sends a voltage from a bias power supply and sends an image signal from a signal source according to image information, converts it into a pulse form with a pulse converter, and applies a pulse voltage. It is not particularly shown because it can be done. With the above-mentioned basic structure, the present invention moves the screen-like part 1 with respect to the capillary groove 5 of the ink supply combiner 6 so that its linear electrodes 3 intersect at right angles, and the capillary groove 5 has each linear shape. The electrode is configured so that one through hole corresponds to the electrode. Then, by applying a pulse voltage to each linear electrode according to the image information, ink 7 is sucked into the through hole corresponding to the capillary groove 5 according to the image information. Since the screen-like member 1 is moving in the direction of the arrow, new through holes correspond to the capillary grooves 5 one after another,
Ink 7 is sucked into the through hole according to the image information.
In the example shown in FIG. 3, by first applying a pulse voltage to the linear electrodes A, B, and E according to image information, the linear electrodes A, B, and B that are in contact with or close to the surface of the capillary groove 5, A strong fringe electric field appears only within the through hole surrounded by E, and the ink liquid is attracted into the opening by its electrostatic attraction. Since the screen-like member 1 is moving, when the through holes in the next row do not come into contact with the capillary grooves 5 again, but when they approach, a voltage pulse is again applied to the control electrodes C, D, F, and the same occurs. Ink is sucked into the through hole. By sequentially repeating this operation, an image is drawn on the screen-like member 1 according to the image information. In addition, in the figure, the blacked-out through holes are
It shows a through hole filled with ink. Further, at this time, a voltage is uniformly applied to the linear electrodes, but it goes without saying that the only through holes that upwardly suck ink are those that are close to or in contact with the capillary grooves 5. Further, the signal applied to the linear electrode is an aperture gate signal for controlling the suction of the liquid ink 7. Therefore, by synchronizing the movement of the screen-like member and the application of the aperture gate signal, ink corresponding to image information is filled into the through-holes of the screen-like member, thereby drawing an image.
In the present invention, the screen-like member may move continuously on the ink groove or may move intermittently at every step.

When the ink capillary grooves and the through holes are moved step by step, the correspondence between the ink capillary grooves and the through holes is more reliably achieved. Furthermore, it goes without saying that the screen-like member does not necessarily have to move at right angles to the ink capillary grooves. Furthermore, it is not limited to making one through hole correspond to an ink capillary groove from one linear electrode, but it is also possible to make a plurality of through holes correspond to an ink capillary groove and introduce ink into the plurality of through holes simultaneously. Also good.
Further, the ink capillary groove does not necessarily have to be capillary depending on the installation interval of the through holes. Here, in the present invention, an image formed on a screen-like member according to image information can be attached to a print medium by flying ink in a through hole, or can be transferred by contact with the print medium. It is something.

Examples thereof will be described below with reference to the drawings. Figure 4 shows
This example shows an example in which an image formed on a screen-like member is scattered onto a print medium using a counter electrode.

In the figure, reference numeral 9 denotes an ink capillary groove, which holds liquid ink 10 in contact with or in close proximity to a screen-like member 11.

A counter electrode 8 is arranged parallel to the screen material member 11 on the opposite side of the ink capillary groove 9, and a printing medium 12 is placed between the two 8 and 11. Then, the liquid ink 10 is grounded,
A voltage is continuously applied from the power supply device 13 between this and the counter electrode 8 . That is, in this embodiment, with the configuration described in FIG.
Ink is sucked into the through hole 1, and the ink sucked into the through hole is caused to fly up to the print medium 12 and adhere to the print medium by the electrostatic attraction of the counter electrode. As a result, an image corresponding to the image information is formed on the print medium. It goes without saying that the voltage applied to the counter electrode is set to a value that allows only the ink sucked into the through-holes to fly away, but does not allow the ink in the capillary grooves 9 to fly away. Further, the screen-like member 11 and the print medium 12 are moved in synchronization. Further, FIG. 5 shows an example in which an image formed on the screen-like member 14 is transferred onto the printing medium 15 by contact.

In this embodiment, with the configuration described in FIG. , to be transferred onto the print medium 15. Also in this embodiment, the screen-like member 14 and the printing medium 1
Of course, it is necessary to move 5 and 5 in synchronization with each other. In addition, in this example, an example was shown in which ink sucked into the through-hole of the screen-like member is transferred onto the printing medium almost simultaneously, but this is not limited to this example. The screen-like member on which the image has been formed is moved to a position away from the capillary groove 16 while holding the image, and then the screen-like member 14 and the printing medium 15 are brought into contact with each other, and the image on the screen-like member is transferred to the printing medium. It is also possible to transfer the image to No. 15. At this time, it has been experimentally confirmed that the ink once sucked into the through hole does not fall even if the screen-like member moves. Also,
In this embodiment, the counter electrode 17 may be arranged on the back surface of the print medium at the transfer position. By providing the counter electrode 17, the ink inside the through hole of the screen-like member 14 can be filled up with the printing medium 15 due to the electrostatic attraction from the counter electrode.
Definitely move upwards. Therefore, the image from the screen-shaped portion 14 is reliably reproduced on the print medium 15. Further, in the present invention, by using a counter electrode, low voltage control of image formation is possible.

As shown in FIG. 8, a counter electrode 29 is installed parallel to the screen-like member 28 on the opposite side of the ink groove.
A voltage is continuously applied from a power source 31 between the ink and the ink liquid. Thereby, the ink liquid is attracted into the through hole by the cooperation of electrostatic attraction from the counter electrode 29 and the control electrode 30 to which a voltage is applied according to the image information. With this configuration, only a low voltage is required to apply a voltage to the linear electrode, that is, low voltage control of image formation is possible. Therefore, there is less interference between the linear electrodes, and the through holes can be provided more densely. By providing the through holes more densely, the quality of the image can be easily improved. Furthermore, since an image is drawn by controlling a low bias voltage according to image information, the speed of image formation can be increased. Furthermore, since pulse conversion becomes easy, the device can be manufactured easily, inexpensively, and compactly. Note that the counter electrode 3
Needless to say, the voltage applied to 0 must be such that it alone cannot supply ink into the through holes. Note that an embodiment of an ink supply device that supplies ink to the capillary grooves will be shown using FIGS. 6 and 7.

In FIG. 6, 18 is a capillary groove. Reference numeral 19 denotes an ink supply device, which includes a cylinder container 20 and a piston 21.

In this configuration, when a pressing force is applied to the piston 21 in the direction of the arrow, the ink liquid rises into the capillary book 18. Here, by keeping the above-mentioned pressing force constant, the rise of the ink liquid into the capillary groove 18 can always be adjusted to a constant amount.

Note that by providing the ink repelling layer 22 on the upper surface of the capillary groove, ink liquid is prevented from overflowing from the capillary groove 18.

Furthermore, in the embodiment shown in FIG. 7, an ink supply roller 24 is provided within the ink supply device 23. The ink supply roller 24 raises the ink liquid in the ink supply device 23 into the capillary groove 25 while rotating in the direction of the arrow. By keeping the rotational speed of this roller 24 constant,
The rise of the ink liquid into the capillary groove 25 can always be adjusted to a constant amount. Note that 26 is an ink repellent layer;
7 is an ink supply port.

The surface of the roller 24 may be roughened or provided with grooves to help the ink liquid rise. 6th
According to the embodiment shown in FIGS. 7 and 7, ink can rise into the capillary structure even if the capillary groove wall is made of a hydrophobic substance. Furthermore, if the capillary groove walls are made of a foaming substance, there is an effect that the ink liquid is reliably broken from the loose capillaries during transfer or when the ink liquid is scattered. Note that if the ink liquid is made of a hydrophilic substance, it goes without saying that the ink liquid will rise into the capillary structure due to capillary phenomenon.
As described above in detail, the present invention moves a screen-like member with respect to the capillary grooves of an ink supply device so that the linear electrodes thereof intersect at right angles, and one opening from each linear electrode to the capillary grooves. Configure the holes so that they correspond.

Then, by applying a pulse voltage to each linear electrode according to the image information, ink is sucked into the through holes corresponding to the capillary grooves according to the image information, and an image is drawn on the screen-shaped part. be. By using linear electrodes as in the present invention, control of the electrodes can be extremely simplified compared to a method in which independent electrodes are provided for each through hole and each electrode is controlled by an information signal. Therefore, the causes of failure can be reduced, the frequency of failure occurrence can be reduced, and costs can be reduced. Further, in the present invention, by providing a counter electrode, low voltage control of the linear electrode can be performed. Therefore, there is less interference between the linear electrodes, and it is also possible to arrange the electrodes more densely. That is, the through holes can be arranged more densely, so the quality of the image can be improved. Furthermore, since an image is drawn by controlling a low bias voltage according to image information, high-speed image formation is possible. Furthermore, since pulse conversion becomes easy, the device can be manufactured easily, inexpensively, and compactly. Moreover, the liquid ink used in the present invention is not limited to ink with a high resistance value, and conductive ink can also be applied. In the electrostatic ink suction method, the ink that makes up one path in the circuit is also considered a resistor, and by being able to use conductive ink with a lower resistance value,
Responsiveness to information signals becomes more distant. for that,
Furthermore, the recording speed can be improved.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the arrangement of the present invention, FIG. 2 is a sectional view of the screen-like member, FIG. 3 is a plan view showing the arrangement of the present invention, and FIGS. 4 and 5 are 6 and 7 are cross-sectional views of an ink supply device, and FIG. 8 is a cross-sectional view showing an embodiment of the present invention. In the figure, 1...screen-like member, 2...
...Through hole, 3... Linear electrode, 4...
Ink repellent layer, 5... Capillary groove, 6...
Ink supply container, 7...Liquid ink, 8...
. . . Counter electrode, 9 . . . Ink capillary groove, 10.
...Liquid ink, 11, 14... Screen-like member, 12, 15... Printing medium, 13...
... Power supply device, 16, 18, 251 ... Capillary groove, 17 ... Counter electrode, 19, 23 ... Ink supply device, 20 ... Cylinder container, 21. ...
... Piston, 22, 26 ... Ink repellent layer, 24
... Ink supply loaf, 27 ... Ink supply combiner, 28 ... Screen-like member, 29
...Counter electrode, 30... Linear electrode, 3
1...Power supply. Figure 1 Figure 2 Figure 4 Figure 5 Figure 8

Claims (1)

[Scope of Claims] 1. A screen-like member having a plurality of arranged through-holes and having an electrode commonly provided in each row of through-holes for selectively introducing ink into the through-holes, and an ink groove; and selectively applying a voltage between the electrode and the ink in the ink groove in accordance with the information signal to selectively introduce ink into the corresponding through-hole to cause the screen to move. An image forming method comprising forming an image on a shaped member. 2. The image forming method according to claim 1, wherein the movement is performed step by step. 3. Between a screen-like member having a plurality of arranged through-holes and a column electrode commonly provided in each row of through-holes for selectively introducing ink into the through-holes, and the screen-like member. means for selectively applying a voltage between the column electrode and the ink in the ink groove in accordance with an information signal; and a counter electrode provided on the opposite side to connectively apply a voltage to the ink in the ink groove,
An image is formed by selectively applying a voltage between the column electrode and the ink in the ink groove according to the information signal, selectively introducing the ink into the corresponding through hole and making it adhere to the printing medium. An image forming apparatus characterized by: