JPH02217249A - Image recording system and its device - Google Patents

Abstract

PURPOSE:To obtain a sharply recorded image at high resolution by transmitting image information for discharging ink held in a microorifices through the intermediary or ions transported in the air. CONSTITUTION:A positive high voltage is applied to a discharge wire 44 on the main unit 4 of a recording head to generate plus ions. At the same time, the plusions are transported to an ion discharge section 41 using a compressed air. A control signal corresponding to an image pattern is applied to each control electrode 45 in an ion discharge path 41 from a control circuit 46 in synchronization with the generation of ions. The plus ion is discharged to an area outside the main unit of the recording head from only the part corresponding to a recorded image. The discharged plus ion is sent flying to an ink-holding sheet, and the part where the plus ion is received of the ink-holding sheet 1 has an increased potential level. An electrostatic field is constantly generated due to a power supply 52 between the main unit of the head and a back electrode 51. Therefore, an electrostatic induction force acts on the ink I held in the sheet 1, so that the ink is sent flying to a recording sheet 3 to form a recorded image. Consequently, it is possible to form a sharply recorded image at high resolution using a simply constituted device, and ensure the stable performance of the device.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an image recording device that forms a recorded image by flying ink onto a recording sheet, and particularly relates to an image recording device that forms a recorded image by flying ink onto a recording sheet, and particularly relates to an image recording device that forms a recorded image by flying ink onto a recording sheet, and in particular, ink is retained in a film-like ink retaining member having fine holes. The present invention relates to a type of image recording method and apparatus in which ink is made to fly.

[Prior Art] Conventionally, as a recording method using a film-like sheet having an ink retention function in this type of image recording apparatus,
For example, as shown in FIG. 6, an ink i is applied to a film b having regular or irregular micropores a, and after the ink i is supplied to the micropores a, heat is generated according to an input signal. Heat generation 8 IIC is brought into contact with the ink i held in the micropore a, and the ink i is transferred from the micropore a of the film b to the recording sheet d by the energy generated by thermal expansion of the ink 1 or vaporization of the ink i due to the heating. A device that performs recording by flying it (Japanese Patent Application Laid-open No. 164838/1983) is known. In addition, as another example, as shown in FIG.
While the electrode array Q in which the groups are arranged is arranged in contact with each other,
A counter electrode f is arranged on the back side of the recording sheet d, and by applying a control signal according to image information between each electrode e of the electrode array Q and the counter electrode f, the ink facing the electrode e is Electrostatic energy is applied to i, and one ink surface and the counter electrode f
It is known that an electrostatic field corresponding to the image pattern is formed between the film b and the ink i to selectively fly from the micropores a of the film b to the recording sheet d by electrostatic attraction.

According to these recording methods, compared to the inkjet method, which also records images by ejecting and flying ink, there are many micro nozzles for ejecting ink and the ejected ink is deflected according to image information. This method eliminates the need for means, etc., greatly simplifies the device configuration, and is suitable for a simple image recording device.

[Problems to be Solved by the Invention] However, these conventional techniques have the following problems. In other words, in a device that adopts the former recording method,
Since the ink held in the micropores is directly heated by electricity, the ink tends to stick to the heat generating part, and the acting force generated by the thermal expansion or vaporization of the ink is diffused in a direction other than the direction in which the ink flies. becomes unstable,
While there is a problem in that mutual interference occurs between adjacent dots formed on the recording sheet, leading to deterioration in the quality of the recorded image, in the apparatus that adopts the latter recording method, the ink is placed adjacent to each other due to electrostatic induction. If it adheres between the electrodes,
This method has the problem that a short circuit may occur between the electrodes, which may damage the recording head. Furthermore, in both devices, the recording operation is performed while the film and the recording head (heat generating part or electrode array) are in contact with each other. When a region is formed, sufficient thermal energy or electrostatic attraction does not act on the ink held in this region, so the common problem is that the image formed on the recording sheet has image defects due to poor ink flight. There are also some problems.

The present invention was made in view of these problems, and
The purpose is to provide an image recording method and apparatus that can form a high-resolution, high-quality recorded IiI image with a simple device configuration and maintain stable performance.

[Means for Solving the Problems] In order to achieve the above object, the image recording method of the present invention discharges ink held in micropores formed in a film-like member according to image information, and records images on a recording sheet. In this method, ions are applied to the ink held in the micropores according to the image information, and an electrostatic field that passes through the film-like member is applied to the ink area to which the ions have been applied. is ejected from the micropores by electrostatic attraction based on the electrostatic field.

Further, the image recording apparatus of the present invention employing the above image recording method includes an ink holding sheet having a large number of fine holes, an ink supply means for supplying ink into the fine holes of the ink holding sheet, and an ink holding sheet having a large number of fine holes. A head body that applies ions to the ink held in the image according to image information, and an electrostatic field forming means that causes the ink area to which the ions have been applied to fly to the recording sheet. It is.

In such technical means, the film-like part, or rather the ink-retaining sheet, is a multi-Water film that retains ink.
i.9 The material may be selected as appropriate as long as it has micropores formed therein. Examples include synthetic resins made of polyimide, polyester, polyethylene terephthalate, etc.; however, from the viewpoint of durability, It is preferable to use a material that has good solvent resistance, abrasion resistance, and mechanical strength. or,
The thickness may be appropriately determined depending on the strength of the ink holding sheet itself, the ease with which the ink flies, the diameter of the micropores, etc., and is usually about several tens of micrometers. As the method for transporting the film-like member in the present invention, the structure may be modified as appropriate, such as a cartridge method in which the film-like member holding ink in advance is wound from one roll to the other. In consideration of problems such as flight failure due to ink coagulation, it is preferable to install an ink supply means to hold the ink immediately before the printing operation as shown in the second invention. In this case, an endless belt-shaped ink holding sheet is preferable. I eat it.

Further, as the ink supply means, an ink storage container is disposed in the moving path of the ink holding sheet formed in the shape of an endless belt, and the ink is held by impregnating the moving ink holding sheet with the ink in the container. The structure may be changed as appropriate, such as the one that supplies ink to the sheet or the one that applies ink directly to the ink holding sheet.

Furthermore, as long as the head main body is capable of selectively applying ions to each ink unit area formed by a plurality or a single fine hole corresponding to a recording pixel according to image information, the ion generating part may be used. The configuration and structure of the control unit for selective application, the conveyance means for applying the generated ions to the ink holding sheet, etc. may be changed as appropriate. Also, the spacing between the ink holding sheet and the ink holding sheet is 0.
It is preferable to set it to about 1 to 0.5all.

Further, the electrostatic field forming means uniformly generates an electrostatic attraction force to the extent that a unit area of ink that receives ions and causes a fluctuation in potential level flies from the micropores of the ink holding sheet to the recording sheet. If it is possible to do so, the structure may be changed in design as appropriate.

[Effect] Since the unit area of ink to which ions have been applied according to image information has a different potential level compared to other unit areas of ink to which ions have not been applied, The ink unit area to which the ions have been applied receives an electrostatic attraction force in the direction of the recording sheet, flies toward the recording sheet from the micropores of the ink holding sheet, and forms ink dots on the recording sheet.

[Example] Hereinafter, the image recording method of the present invention and its till will be explained in detail based on the accompanying drawings.

◎First Embodiment Figures 1 and 2 show a first embodiment of an image recording apparatus according to the present invention, and show an ink holding sheet 1 formed in the shape of an endless belt and movement of this ink holding sheet 1. An ink supply means 2 arranged in a path and an ink holding sheet 1
a head body 4 spaced apart inside the head body 4;
and an electrostatic field forming means 5 for forming an electrostatic field from the recording sheet 3 toward the recording sheet 3.

First, as shown in FIGS. 3 and 4, the ink holding sheet 1 is an endless belt-like film having a large number of micropores 11 over the entire surface, and is made of polyimide and has a thickness of about 25 μm. . The ink holding sheet 1 is rotatably hung around transport rolls 12, 13, and 14, and the head body 4 is disposed between the transport rolls 12, 14 to perform a recording operation. There is.

Further, the ink supply means 2 includes an ink container 21 disposed below the conveyance roll 14 and a pair of blades 22 provided on the downstream side in the rotational direction of the conveyance roll 14 and in contact with the ink holding sheet 1. The ink holding sheet 1 that is supported by the outer surface of the transport roll 14 and passes through is impregnated with the ink I filled in the ink container 21, and the ink I is supplied to the fine holes 11 of the ink holding sheet 1. Excess ink I adhering to the ink holding sheet 1 is removed by a blade 22.

Further, the head main body 4 includes a shield 43 in which an ion exhaust path 41 and a compressed air introduction path 42 are established, a discharge wire 44 disposed within the shield 43, and a pixel density in the ion exhaust path 41. A pair of control electrodes 45 are arranged according to the image information and a control signal is applied according to the image information.
They are arranged with a gap of m. By applying a high voltage to the discharge wire 44, a discharge occurs between the discharge wire 44 and the shield 43, generating ions, and the generated ions are discharged together with the air introduced from the compressed air introduction path 42. After being guided to the ion path 41, the ions selectively pass through the ion ejection path 41 depending on the presence or absence of an electric field generated by the control electrode 45, and are ejected from the head body 4. still,
Reference numeral 46 is a control circuit that applies a signal to the IIJ'n M pole 45 according to image information.

Further, the electrostatic field forming means 5 includes a rolled back electrode 5 for electrostatic induction, which is arranged at an appropriate distance from the ink holding sheet 1 and also functions as a transport support surface for the recording sheet 3.
1, and an electrostatic field forming power source 52 that is interposed between the head body 4 and the back electrode 51 and forms an electrostatic field directed from the head body 4 toward the back electrode 51 side.

The ink (2) contained in the ink container 21 has a viscosity of 1G CP8 or less and a surface tension of 102 dyn/c.
A material having an electric resistance of 1010 Ω or more and an electrical resistance of 1010 Ωα or more is used, and the optimum one is selected depending on the diameter of the micropores 11, the strength of the electrostatic field, the thickness of the ink holding sheet 1, the recording speed, etc.

In the image recording apparatus of this embodiment configured as described above, the recording operation is performed as follows.

First, a high positive voltage is applied to the discharge wire 44 of the head body 4 to generate platy ions, and the generated positive ions are conveyed to the ion discharge path 41 by compressed air. A control signal corresponding to the image pattern is applied from the control circuit 46 to each control electrode 45 in the ion ejection path 41 in synchronization with ion generation, and the positive ions passing through the ion ejection path 41 are removed from the portion corresponding to the recorded image. is discharged outside the head body 4. The discharged positive ions fly toward the ink holding sheet 1, and the potential level of the corresponding area of the ink holding sheet 1 that receives the positive ions increases. Head body 4 and back l! Since an electrostatic field is constantly formed between the pole 51 and the electrostatic field forming means 11152, based on this electrostatic field, an electrostatic charge is generated in the ink held on the ink holding sheet 1 corresponding to the portion where the potential level increases. The attractive force acts, and the ink I flies from the fine holes 11 toward the recording sheet 3 placed in front of the back electrode 51, and a recorded image is formed on the recording sheet 3. Along with this ink flying operation, the ink holding sheet 1 is conveyed by the conveying rolls 12, 13, and 14, and the ink holding sheet 1 holding the ink in the fine holes 11 is continuously placed at a position facing the head main body 4. Therefore, recorded images are sequentially formed on the recording sheet 3 according to the image signals. Further, the ink holding sheet 1 after the ink flying is sent to the ink container 21 by the transport rolls 12, 13, 14, and after the fine holes 11 are replenished with new ink I, it is transferred to the head body 4 Circulate to facing position.

In this embodiment, an electrostatic field for causing the ink I to fly was formed between the head body 4 and the back electrode 51, so that the positive ions discharged from the head body 4 were not affected by the conveying force of the compressed air. An electrostatic attraction force is also acting in one direction on the ink holding sheet, making the flight direction of the ions uniform, resulting in a structure that further suppresses mutual interference between adjacent dots when forming a recorded image. .

In this way, in the m-image recording apparatus of this embodiment, ions are applied to the ink l held on the ink holding sheet 1 to modulate its potential level, and static electricity is applied to the ink unit area whose potential level has been modulated. Image recording is performed based on the basic operating principle of causing the ink I to fly from the fine holes of the ink holding sheet 1 by applying an electric field.

Therefore, even if wrinkles occur in the ink holding sheet 1 and the distance between the head main body 4 and the ink holding sheet 1 changes slightly, the amount of ions applied from the head main body 4 to the ink I will not change. This prevents the ink I held on the ink holding sheet 1 from flying poorly, so that a stable recorded image is always formed.

Furthermore, since the force that causes the ink (■) to fly is the electrostatic attraction force in the direction of the recording sheet 3 due to the electrostatic field, the flying ink does not spread over a wide range and adhere to the recording sheet 3, and there is little mutual interference between adjacent dots. High resolution recorded images can be obtained.

In this embodiment, a case has been described in which an image is formed by simply applying the ink I to the recording sheet 3, but it goes without saying that means for drying the ink I may be provided as necessary.

In addition, in this embodiment, the case where the fine holes 11 of the ink holding sheet 1 and the recording pixels correspond one to one is explained as an example, but the diameter of the fine holes 11 is made smaller and the arrangement density is adjusted to the head body. By increasing the arrangement density of the ilJ m electrodes 45 provided in 4, a plurality of fine holes 1 are formed in one recording pixel.
1 can be made to correspond to each other, and it becomes easy to control the printing timing accompanying the rotation of the ink holding sheet.

◎Second Embodiment FIG. 5 shows a color image recording apparatus constructed using the image recording apparatus according to the present invention.

The color image recording apparatus in this embodiment has four image recording units arranged in parallel as in the first embodiment, and the ink containers 21 of each recording unit contain yellow O+, cyan, and Contains magenta and black ink.

Then, while continuously feeding the recording sheet 3 to each recording unit, by inputting image information corresponding to each color to each control circuit 44 in synchronization with the transport timing of the recording sheet 3, each color is displayed on the recording sheet 3. Images corresponding to the images are recorded one after another to obtain a full-color recorded image.

[Effects of the Invention] As described above, according to the image recording method and device of the present invention, image information for ejecting ink held in micropores is transmitted through ions carried in the air. By doing so, accurate image information is always transmitted to the ink, making it possible to obtain high-resolution, high-quality recorded images, and to create an image recording device that can demonstrate stable performance with a simple N41 configuration. Obtainable.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the recording principle of the image recording method according to the present invention, FIG. 2 is a schematic diagram showing a first embodiment of the image recording apparatus according to the present invention, FIG. 3 is a plan view showing an ink holding sheet, and FIG. FIG. 4 is an enlarged sectional view of part A in FIG. 3, fIs is a schematic diagram showing a second embodiment of the image recording device according to the present invention, and FIGS. 6 and 7 are recording methods used in the conventional image recording device. FIG. [Explanation of symbols] 1: Ink holding sheet 2: Ink supply means 3: Recording sheet 5: Electrostatic field forming means 51: Back electrode

Claims (2)

[Claims] (1) In an image recording method in which a recorded image is formed on a recording sheet by ejecting ink held in fine holes formed in a film-like member according to image information, the ink held in the fine holes is While applying ions in accordance with image information, an electrostatic field that passes through the film-like member is applied, and only the ink area to which the ions have been applied is ejected by electrostatic attraction based on the electrostatic field. Image recording method. (2) An ink retaining sheet having a large number of micropores, an ink supply means for supplying ink into the micropores of the ink retaining sheet, and an ink retaining sheet that supplies ions to the ink retained in each of the micropores according to image information. A head body for applying the ions, and an electrostatic field forming means that includes a back electrode facing the head body through the ink holding sheet and causes the ink area to which the ions have been applied to fly to the recording sheet. Image recording device.