JPH10264493A - Double printing device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To efficiently produce a small number to a large number of multi-colored prints at a low running cost without causing perforation defects, wrinkles, and conveyance defects during plate making of heat-sensitive stencil paper. Provided is a dual printing apparatus which is excellent in ink drying property of printed matter and does not show off or strike through. SOLUTION: A liquid discharging means for transferring a light-to-heat conversion material so as to reproduce an image on a heat-sensitive stencil sheet, a light irradiation means for irradiating the heat-sensitive stencil sheet with visible light or infrared light to make a plate, A cylindrical plate cylinder; a heating means for heating the stencil printing ink, which reversibly changes from a solid state to a liquid state, in the plate cylinder; and supplying the ink to the inner peripheral surface of the plate cylinder in contact with the inner peripheral surface. A squeegee means, and a pressing mechanism for pressing at least one of the plate cylinder and the printing paper to bring the stencil printing ink into close contact with the printing paper via the heat-sensitive stencil sheet, further comprising a liquid discharging means. The light-to-heat conversion material and / or the colorant are configured so that an image can be printed directly on printing paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple printing apparatus which not only can efficiently print a small number to a large number of printed matter by two printing methods, but also has excellent ink drying properties and little set-off.

[0002]

2. Description of the Related Art A heat generating means such as a thermal head for generating image information obtained by converting images such as characters, figures and photographs into electric signals as dot-like heat is formed by melting and perforating a thermoplastic resin film of a heat-sensitive stencil sheet. The method of making a stencil, wrapping the heat-sensitive stencil paper around a plate cylinder containing the stencil printing ink, and passing the stencil printing ink through the perforated portion of the stencil printing paper to transfer it to the printing paper is a digital printing with high speed printing and low running cost It is already popular as a machine.

[0003]

However, in this digital printing press, when making a thermosensitive stencil sheet, a perforation defect occurs due to uneven pressing pressure of the stencil sheet against the thermal head, and wrinkles are formed on the stencil sheet. In some cases, or poor transport.

Further, the conventional digital printing machine is useful for obtaining a large number of the same printed matter, but it is rather expensive when a small number of printed matter is required.

[0005] From such a background, it is conceivable to incorporate a thermal recording paper or a thermal transfer recording paper into a printing machine in order to obtain a small number of printed matters. There is a drawback that the operation becomes complicated by preparing both of them.

[0006] In addition, when a small number of printed materials are obtained using one kind of plain paper, printing is performed by an electrophotographic method, and when a large number of printed materials are obtained, stencil printing can be performed using a heat-sensitive stencil sheet. Although an apparatus has been proposed, there is a disadvantage that the entire system is expensive and large.

On the other hand, in order to obtain a color print in a digital printing machine, a plate cylinder containing stencil printing ink must be prepared for each color. A complicated operation of replacing the plate cylinder for each printing is required, and there is a disadvantage that work efficiency is deteriorated.

The stencil emulsion ink generally used in the prior art requires a long time for drying. When the printed paper is held immediately after printing, the ink may transfer to the hand, Overlapping printed paper and the like during continuous printing causes ink set-off, and there is a problem that these phenomena are remarkable particularly on postcard paper having poor ink permeability. The reason is that the drying of the emulsion ink is performed only by the penetration of the oil phase component and the evaporation of the water phase component. In addition, the viscosity of the emulsion ink changes depending on the ambient temperature. For example, when the temperature is high, the ink is softened, and the ink leaks, leaks aside or leaks from the bottom (the end of the base paper wound around the plate cylinder). (A phenomenon in which ink leaks from the ink).

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to prevent the occurrence of poor perforation, wrinkles, or poor conveyance during the stencil making of heat-sensitive stencil paper, and to reduce the number of multicolor sheets from a small number to a large number. It is an object of the present invention to provide a multiple printing apparatus which can efficiently obtain a printed material at a low running cost, has excellent ink drying properties of a stencil-printed printed material, and can prevent set-off or strike-through.

[0010]

According to the present invention, an object of the present invention is to discharge a photothermal conversion material contained in a liquid onto a heat-sensitive stencil sheet in accordance with image information previously converted into an electric signal. Liquid discharging means for transferring the light-to-heat conversion material so as to reproduce an image based on the image information, and irradiating the heat-sensitive stencil sheet to which the light-to-heat conversion material has been transferred with visible light or infrared light to form the heat-sensitive stencil sheet Beam irradiation means for perforating and making a stencil, an ink-permeable cylindrical plate cylinder which winds the heat-sensitive stencil sheet around its outer peripheral surface and rotates around its own central axis, and reversibly changes from a solid state to a liquid state Heating means for heating the phase-change stencil ink in the plate cylinder,
Squeegee means for supplying the ink to the peripheral surface while being in contact with the inner peripheral surface of the plate cylinder, and in a state where the printing paper moves in synchronization with the rotation of the plate cylinder, the plate cylinder and the printing paper Is pressed and brought into close contact with each other, and the stencil printing ink in a liquid state supplied to the inner peripheral surface of the plate cylinder is transferred to the printing paper via the perforated heat-sensitive stencil sheet. And a pressing mechanism. The liquid discharging means further comprises a liquid ejecting unit, wherein the photothermal conversion material and / or the coloring agent contained in the liquid is printed on the printing paper in accordance with image information previously converted into an electric signal. And a direct printing device on which an image based on the image information can be printed directly.

That is, in the duplex printing apparatus of the present invention, in the conventional rotary stencil printing apparatus, a liquid containing a light-to-heat conversion material is discharged from the liquid discharging means onto the heat-sensitive stencil sheet as a stencil printing method of the heat-sensitive stencil sheet. A first step of transferring the light-to-heat conversion material to the heat-sensitive stencil sheet, and irradiating the heat-sensitive stencil sheet with visible light or infrared light to selectively perforate a portion of the heat-sensitive stencil sheet to which the light-to-heat conversion material has transferred. The first feature is that a method including the second step is employed.

As such a liquid discharging means, for example, 1
10 to 2000 pieces per inch (10 to 2000 dpi)
An ejection head made of a nozzle, a slit, a porous material, a porous film, or the like having an opening portion is connected to a piezoelectric element, a heating element, a liquid sending pump, or the like, and the liquid containing the photothermal conversion material is used as an electrical signal of a character image. The device is configured to discharge intermittently or continuously, that is, in the form of dots or lines.

In the first step, for example, the discharge head slightly separated from the heat-sensitive stencil sheet is moved in parallel with the heat-sensitive stencil sheet, and the liquid is discharged from the discharge head in accordance with image information previously converted into an electric signal. The liquid discharging device is controlled so as to be discharged onto the heat-sensitive stencil sheet, the liquid transferred to the heat-sensitive stencil sheet is evaporated, and the image is formed as a solid adherent mainly composed of the light-to-heat conversion material. It can be implemented by reproducing it on the surface.

[0014] In the second step, the heat-sensitive stencil sheet to which the light-to-heat conversion material has been transferred is irradiated with visible light or infrared light.
Since the light-to-heat conversion material absorbs light and generates heat, as a result, the thermoplastic resin film of the heat-sensitive stencil sheet is melt-punched,
Heat-sensitive stencil paper can be directly made. This irradiation with visible light or infrared light can be easily performed using a xenon lamp, a flash lamp, a halogen lamp, an infrared heater, or the like.

As described above, in the printing apparatus of the present invention, it is not necessary to bring the stencil sheet into contact with any object such as a manuscript or a thermal head at the time of plate making, and it is sufficient that the heat-sensitive stencil sheet alone is exposed to visible light or infrared light. In addition, no wrinkles are generated on the stencil sheet during stencil making.

In the present invention, the first step and the second step may be performed before the heat-sensitive stencil sheet is applied to the plate cylinder, or after the heat-sensitive stencil sheet is applied to the plate cylinder. You may go. In particular, since the printing apparatus of the present invention uses an ink which reversibly changes its phase from a solid state to a liquid state, the heat-sensitive stencil sheet is applied to a plate cylinder before the ink is heated and fluidized by a heating means. It is convenient to perform plate making in a state. That is, when the ink in the cylindrical plate cylinder is in a solid state and the ink on the outer peripheral surface of the cylindrical plate cylinder is still in a solid state, even if the heat-sensitive stencil sheet is wound around the cylindrical plate cylinder, An air layer is interposed in the gap between the heat-sensitive stencil sheet and the heat-sensitive stencil sheet, and therefore has a substantial heat insulating effect. Therefore, when the light-to-heat conversion material is irradiated with visible light or infrared light at the site to which the light-to-heat conversion material has been transferred, the heat energy obtained by the light-to-heat conversion is stored in the thermoplastic resin film, and as a result, the thermoplastic resin film becomes a high temperature and is efficiently melt-plated. .

On the other hand, in a stencil printing machine using a liquid ink at room temperature, when a heat-sensitive stencil sheet is wound around a cylindrical plate cylinder, the gap between the outer peripheral surface of the plate cylinder and the heat-sensitive stencil sheet is filled with the liquid ink. The gap is filled and no air layer is formed in the gap. Therefore, even if visible light or infrared light is applied to the part where the light-to-heat conversion material has been transferred in this state, the heat energy obtained by the light-to-heat conversion is diffused from the thermoplastic resin film toward the liquid ink, and as a result, the thermoplastic resin The melt perforation may be insufficient without increasing the temperature of the resin film.

Further, in the apparatus according to the present invention, the liquid discharging means discharges the photothermal conversion material and / or the coloring agent contained in the liquid onto the printing paper in accordance with the image information previously converted into an electric signal. Has a second feature in that a dual printing apparatus capable of printing an image based on the image information directly thereon and capable of printing by two methods, stencil printing and ink jet printing, is provided. .

In the case of such a double printing apparatus, the liquid discharging means changes the direction of the heat-sensitive stencil sheet and the direction of the printing paper and selectively puts the light-to-heat conversion material and / or light on both.
Alternatively, a single discharge head capable of discharging a colorant may be provided, and a discharge head capable of discharging a photothermal conversion material on a heat-sensitive stencil sheet and a colorant on a printing paper may be provided. The ejection heads may be separately provided. Also, in order to enable multicolor printing, the liquid discharging means is provided with a plurality of discharge heads capable of discharging a colorant on a printing paper, and each of the discharge heads discharges a colorant having a different color tone. Multicolor printing may be performed, and the liquid discharge unit may include a single discharge head that can discharge a plurality of colorants of different colors on the printing paper. .

As described above, according to the duplex printing apparatus of the present invention, when printing a large number of sheets, the light-to-heat conversion material and / or the colorant are discharged from the liquid discharge means onto the heat-sensitive stencil sheet and are irradiated by the light irradiation means. When stencil printing is performed and stencil printing is performed and a small number of printings are performed, the photothermal conversion material and / or
Alternatively, printing can be easily performed by directly discharging the coloring agent onto the printing paper. Accordingly, by preparing one type of printing paper and a heat-sensitive stencil sheet in the printing apparatus and controlling the liquid discharge means in the printing apparatus, both small-number printing and large-number printing are efficiently performed. be able to. Further, it is also possible to perform a multi-color printing by superposing and discharging a photothermal conversion material and / or a colorant from a liquid discharging unit on a stencil-printed printing paper. Further, the frequent use of black printing is performed by stencil printing, and the infrequently used printing of red, blue and yellow is performed directly on the printing paper to improve the efficiency of multicolor printing.

The photothermal conversion material used in the present invention may be any material capable of converting light energy to heat energy, and is a material having a high photothermal conversion efficiency, for example, carbon black, silicon carbide, silicon nitride, and the like. In addition to inorganic pigments such as metal powders and metal oxides, organic pigments and organic dyes are included. Examples of carbon black include furnace black, channel black, lamp black, acetylene black, oil black, and the like. Among the organic dyes, those exhibiting large light absorption in a specific wavelength range, such as anthraquinone-based, phthalocyanine-based, cyanine-based, squarylium-based, and polymethine-based dyes, are preferable.

The colorant used in the present invention may be the same as the light-to-heat conversion material when the light-to-heat conversion material has a color tone. For example, carbon black, phthalocyanine blue, Victoria blue, brilliant carmine 6B, Organic or inorganic pigments such as permanent red F5R, rhodamine lake B, benzidine yellow, Hanza yellow, naphthol yellow, titanium oxide, calcium carbonate, and dyes such as azo type, anthraquinone type, quinacridone type, xanthene type and acridine type. No.

The liquid containing the photothermal conversion material and the colorant may be an aliphatic hydrocarbon, an aromatic hydrocarbon,
Solvents such as alcohols, ketones, esters, ethers, aldehydes, carboxylic acids, amines, low-molecular-weight heterocyclic compounds, oxides, water, etc., specifically, hexane, heptane, octane, benzene , Toluene, xylene, methyl alcohol, ethyl alcohol,
Isopropyl alcohol, n-propyl alcohol, butyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, glycerin, acetone, methyl ethyl ketone, ethyl acetate, propyl acetate,
Ethyl ether, tetrahydrofuran, 1,4-dioxane, formic acid, acetic acid, propionic acid, formaldehyde,
Acetaldehyde, methylamine, ethylenediamine,
Examples include dimethylformamide, pyridine, ethylene oxide and the like. These liquids can be used alone or in combination, and it is preferable that these liquids evaporate quickly after being discharged from the liquid discharging means onto the heat-sensitive stencil paper. In addition, the liquid, if necessary, dyes, pigments, fillers,
It may contain a binder, a curing agent, a preservative, a wetting agent, a surfactant, a pH adjuster, and the like.

Thus, the photothermal conversion material and / or the colorant are appropriately dispersed or mixed in the liquid in a form capable of being discharged from the liquid discharge means, thereby preparing a heat-sensitive stencil sheet making composition or a colorant composition. can do.

The heat-sensitive stencil sheet used in the present invention may be any stencil made of a thermoplastic resin film alone, as long as the light-to-heat conversion material transfers to at least one surface thereof and can be melt-punched by the heat generated by the light-to-heat conversion material. Even for base paper,
Any stencil sheet including a thermoplastic resin film and a porous support laminated thereon may be used.

As such a thermoplastic resin film, for example, polyethylene, polypropylene, polyvinyl chloride,
A film made of a resin component such as polyvinylidene chloride, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyurethane, polycarbonate, polyvinyl acetate, acrylic resin, and silicone resin is used. These resin components may be used alone or as a mixture or as a copolymer. The thickness of the thermoplastic resin film is suitably 0.5 to 50 μm, preferably 1 to 50 μm.
２０20 μm. If the thickness of the film is less than 0.5 μm, the handleability and strength are inferior. If the thickness exceeds 50 μm, a large amount of heat energy is required for perforation, which is not economical.

Examples of the porous support include natural fibers such as manila hemp, pulp, mitsumata, mulberry, and Japanese paper; synthetic fibers such as polyester, nylon, vinylon, and acetate;
Thin paper, nonwoven fabric, screen gauze and the like using metal fibers, glass fibers or the like alone or as a mixture. The basis weight of these porous supports is preferably in the range of 1 to ²⁰ g / m ² , more preferably in the range of 5 to 15 g / m ² . 1g /
If it is less than m ² , the strength as a base paper will be weak, and if it exceeds 20 g / m ² , the ink permeability during printing may be poor. Further, the thickness of the porous support is preferably in the range of 5 to 100 μm, more preferably in the range of 10 to 50 μm. If the thickness is less than 5 μm, the strength as a base paper will be weak, and if it exceeds 100 μm, the ink permeability during printing may be poor.

The heat-sensitive stencil sheet used in the present invention has a liquid absorbing layer laminated on the surface from which the liquid is discharged in order to prevent bleeding of the liquid discharged on the surface and to promote drying of the liquid. It is preferable that when irradiating a light beam to perforate the stencil sheet, perforation faithful to image information can be performed and a sharp image can be obtained.

The liquid absorbing layer is provided on the outermost surface of the heat-sensitive stencil sheet, and is preferably formed as a resin layer which is irradiated with light during stencil making and melt-punched in the same manner as the above-mentioned thermoplastic resin film. Any material may be used as long as it prevents the liquid to be spread in the planar direction and fixes the photothermal conversion material on the stencil paper. Preferably, the liquid absorbing layer is made of a material having a high affinity for the liquid used. For example, if the liquid is aqueous, use a polymer compound such as polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl pyrrolidone, ethylene-vinyl alcohol copolymer, polyethylene oxide, polyvinyl ether, polyvinyl acetal, and polyacrylamide. be able to. These resin components may be used alone or as a mixture or as a copolymer. Further, if the liquid is an organic solvent, for example,
High molecular compounds such as polyethylene, polypropylene, polyisobutylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinyl acetate, acrylic resin, polyamide, polyimide, polyester, polycarbonate, and polyurethane can be used. These resin components may be used alone or as a mixture or as a copolymer.

Further, the liquid absorbing layer may contain organic or inorganic fine particles. Examples of such fine particles include organic fine particles such as polyurethane, polyester, polyethylene, polystyrene, polysiloxane, phenol resin, acrylic resin, and benzoguanamine resin.Also, talc, clay, calcium carbonate, titanium oxide, aluminum oxide, oxide Examples include inorganic fine particles such as silicon and kaolin.

The liquid absorbing layer can be obtained by applying a liquid obtained by mixing the above-mentioned polymer compound and, if necessary, the above-mentioned fine particles to a heat-sensitive stencil sheet by a coating means such as a gravure coater or a wire bar coater and then drying. Can be.

The third feature of the printing apparatus of the present invention resides in that the stencil printing ink supplied into the cylindrical plate cylinder is an ink which reversibly changes from a solid state to a liquid state at a certain temperature. Having. This ink becomes a liquid ink having a certain viscosity by the heating means at the time of stencil printing, so that it can be transferred to the printing medium through the perforated portion of the stencil sheet. Further, the liquid ink transferred onto the printing medium instantaneously undergoes a phase change during transportation to become a solid ink, so that the ink can be fixed to the printing medium in a short time. Therefore, even if the printed matter printed by the method of the present invention is touched by hand immediately after printing, the hand is not stained with ink, and no set-off occurs even when continuous printing is performed. Further, since the ink used in the present invention does not penetrate into the inside of the printing medium, the strike-through of the ink does not occur. Further, according to the present invention, since the ink instantaneously changes from a liquid state to a solid state on a printing medium, the printing medium such as a film or a metal as well as a normal printing paper or a postcard paper having poor ink permeability. Can also be printed.

The stencil printing ink used in the present invention has a phase change temperature of 30 to 150 ° C., preferably 40 to 120 ° C.
It is desirable that the printing ink be in a temperature range of ° C.
Here, the solid state means a state in which the printing ink has lost its fluidity to the extent that it does not adhere even when touched, and the liquid state means
A state in which the fluidity is higher than the solid state, preferably a state in which the printing ink has a viscosity such that the printing ink can flow out from the perforated portion of the stencil paper, and the phase change temperature of the printing ink means that the ink is in the solid state. Keep the maximum temperature means. If the phase change temperature is too low, the internal temperature of the printing apparatus and the
If the temperature is lower than 0 ° C., the ink becomes fluidized, and as a result, the printing apparatus is soiled, and side leakage and tail leakage are likely to occur.
On the other hand, if the phase change temperature is higher than 150 ° C., a large-scale heating means is required to change the phase of the ink from a solid to a liquid. The change takes a long time, and the waiting time until printing is lengthened.

The stencil printing ink used in the present invention is 3
It can be obtained by mixing a colorant with a reversible phase change component that reversibly changes phase from a solid state to a liquid state in a temperature range of 0 to 150 ° C, preferably 40 to 120 ° C. It can be obtained by melting a target phase change component and mixing it with a colorant and, if necessary, a dispersant.

As the reversible phase change component, for example, components such as waxes, fatty acid amides, fatty acid esters, resins, etc., specifically, carnauba wax, microcrystalline wax, polyethylene wax, montan wax, paraffin wax, Candelilla wax, shellac wax, oxidized wax, ester wax,
Beeswax, wood wax, whale wax, stearamide, lauramide, behenamide, caproamide, palmitamide, low molecular weight polyethylene, polystyrene,
α-methylstyrene polymer, vinyl toluene, indene, polyamide, polypropylene, acrylic resin, alkyd resin, polyvinyl acetate, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, and the like.

Examples of the colorant include organic or inorganic pigments such as furnace carbon black, lamp black, cyanine blue, lake red, cyanine green, titanium oxide and calcium carbonate, and azo, anthraquinone and quinacridone pigments. Dyes.

As the above-mentioned dispersant, anionic, cationic and nonionic dispersants can be used, and examples thereof include sorbitan fatty acid esters, fatty acid monoglycerides and quaternary ammonium salts.

The stencil printing ink used in the present invention can be in the form of oil-based ink and W / O emulsion ink. When the ink is in the form of an oil-based ink, the reversible phase change component, the colorant, and, if necessary, the dispersant may be dissolved and mixed. In the case of a W / O emulsion ink, the reversible phase change component, the colorant, and the dispersant are dissolved and mixed, and the aqueous phase component is added thereto with stirring to emulsify. After cooling, W
/ O type solid phase change ink is obtained. The coloring agent may be contained in the aqueous phase component.

At the time of printing, the stencil printing ink is heated to a temperature not lower than its phase change temperature to be in a liquid state.
It is desirable that the heating is performed to the extent of 0 to 1,000,000 cps, preferably 100 to 100,000 cps. If the viscosity of the ink at the time of printing is lower than 10 cps, the viscosity of the ink is too low and the ink easily leaks from between the printing apparatus and the end of the stencil sheet. Penetrates rapidly from the surface of the printing paper into the inside, and strikethrough occurs. If the viscosity of the ink at the time of printing is higher than 1,000,000 cps, it is difficult for the ink to pass through the perforated stencil sheet, the print density is reduced, and printing unevenness occurs.

As the cylindrical plate cylinder of the present invention, those used in ordinary rotary stencil printing machines such as metal drums having ink-permeable holes on the peripheral surface can be used. The peripheral surface of the drum can be formed using a porous member such as a metal fiber, a synthetic fiber, a metal porous body, and a polymer porous body, which is used in an ordinary stencil printing apparatus.

The printing apparatus according to the present invention further comprises a heating means for heating the stencil printing ink supplied into the plate cylinder; and a heating means for inscribing the inner peripheral surface of the plate cylinder to apply the ink to the peripheral surface of the plate cylinder. And squeegee means for supplying the squeegee.

The heating means may directly heat the stencil printing ink, or may heat the squeegee means and heat the printing ink by the heat generated by the squeegee means. . The heating means may be either a contact type or a non-contact type, and specific examples thereof include a nichrome wire heater, a planar heater, a ceramic heater, a conductive carbon heater, an electromagnetic induction heater,
Examples include an infrared heater, a halogen lamp, a xenon lamp, and a microwave heater.

The heating means is preferably arranged to heat the squeegee means preferentially over the ink in order to improve the heating efficiency of the stencil printing ink and to speed up printing. The means may be provided near or in contact with the squeegee means, or the heating means may be incorporated in or integrated with the squeegee means.

The squeegee means of the present invention is provided so as to be inscribed in the inner peripheral surface of the plate cylinder, and acts to push out the ink phase-changed from solid to liquid by the heating means to the outside of the plate cylinder. I do. Therefore, the squeegee means of the present invention needs to be sufficiently heated during printing. Such a squeegee means can be usually formed of a heat-resistant member made of a rigid or elastic body such as a metal roller, a metal pipe, a plastic blade, and a plastic belt.

Thus, according to the present invention, the perforated heat-sensitive stencil sheet is wound around the outer peripheral surface of an ink-permeable cylindrical plate cylinder that rotates around its own central axis, similarly to the conventional rotary stencil printing apparatus. And the stencil ink is melted by the heating means. Then, in a state where the printing paper moves in synchronization with the rotation of the plate cylinder, with the aid of a pressing mechanism that presses at least one of the printing cylinder and the printing paper to bring them into close contact with each other, the squeegee means As a result, the printing ink supplied to the inner peripheral surface of the plate cylinder passes through the plate making section of the stencil sheet and is transferred to the printing paper, thereby achieving stencil printing.

This pressing mechanism may be, for example, a press roller provided outside the plate cylinder and opposed to the plate cylinder and pressing the outer peripheral surface thereof. Alternatively, the pressing mechanism may be provided on the inner peripheral surface of the flexible plate cylinder. A squeegee roller or blade that inscribes and expands the plate cylinder outward and presses the plate cylinder against a paper cylinder provided to face the outside of the plate cylinder may be used. May also be used as the squeegee means. By such a pressing mechanism, when the ink in the liquid state is passed from the perforated portion of the stencil sheet made by stencil and the ink is transferred onto the printing paper, the stencil paper and the printing paper are moved by 0.01.
To 10 kg / cm ^2, pressing preferably a pressure of 0.05~5kg / cm ^2, 0.001~10 seconds, preferably printing in time of 0.005 seconds. When the pressure is low and the time is short, it is difficult for the ink in the liquid state to pass through the perforated stencil sheet, so that the amount of transferred ink on the printing paper is small, and the print density is low and the printed matter may be uneven. On the other hand, if the pressure is high and the time is long, the amount of ink passing from the stencil printing paper increases, and therefore the amount of ink transferred on the printing paper increases, which may result in blurred or blurred printed matter. Breakthrough and set-off are also likely to occur. Therefore, in the printing apparatus of the present invention, it is possible to obtain a good printed matter by increasing the time when the pressure is low and shortening the time when the pressure is high.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on specific examples with reference to the drawings, but the present invention is not limited to the specific examples.

Referring to FIG. 1, the plate making mechanism of the heat-sensitive stencil sheet in the apparatus of the present invention will be described. FIG. 1A shows a heat-sensitive stencil sheet 13 having a three-layer structure composed of a liquid absorbing layer 21, a thermoplastic resin film 22, and a porous support 23. The liquid absorbing layer 21 of the heat-sensitive stencil sheet 13 is shown in FIG.
A droplet of the liquid 26 containing the photothermal conversion material is ejected as a character image from the ejection head 25 of the liquid ejection means,
As shown in FIG. 1B, the photothermal conversion material 28 is transferred onto the heat-sensitive stencil sheet 13.

Next, as shown in FIG. 1C, a visible light or infrared light 31 is applied to the image portion where the light-to-heat conversion material 28 of the stencil sheet is transferred and fixed by using a light irradiation means 30 provided with a light reflecting plate 29. Irradiation, only the portion of the fixed photothermal conversion material 28 generates heat, and as shown in FIG.
1 and the thermoplastic resin film 22 are melted to form perforations 32, and plate making is performed.

Next, the mechanism of stencil printing in the printing apparatus of the present invention will be described with reference to a specific example shown in FIG. In FIG. 2, reference numeral 5 denotes a cylindrical plate cylinder of the present invention, the outer peripheral surface of which is formed of a porous member. A heat-sensitive stencil sheet 13 made as shown in FIG. 1 is wound on the outer peripheral surface of the plate cylinder 5 by a known method. A squeegee means 51 made of a metal pipe is provided in the cylindrical plate cylinder 5,
The plate cylinder 5 is arranged so as to be rotatable about an axis parallel to the central axis of the plate cylinder 5 and in contact with the inner peripheral surface of the plate cylinder 5, and is rotated in the same direction as the rotation of the plate cylinder 5 when the plate cylinder 5 rotates. You. In the squeegee means 51, a heating means 52 comprising a halogen lamp is provided so as to actively heat the metal pipe, and the light pipe 53 can efficiently heat the metal pipe. When the outer periphery of the squeegee means 51 reaches the phase change temperature of the ink 54 used for printing, the ink 54 changes from a solid state to a liquid state. As a result, it is pushed outward from the inner peripheral surface of the plate cylinder 5.

Here, the printing paper 14 sent in synchronization with the rotation of the plate cylinder 5 is pressed by the press roller 6 provided outside the plate cylinder 5 so as to face the squeegee means 51. When the ink 54 is pressed against the heat-sensitive stencil sheet 13 on the outer periphery of the printing paper 1
Transfer to 4 The transferred ink instantly becomes a temperature lower than the phase change temperature on the printing paper, and the solid ink 55 is formed.
Established as.

Next, a multiple printing apparatus according to the present invention will be described based on a specific example shown in FIG. FIG. 3 is a side view schematically showing the internal structure of the printing apparatus according to the present invention, in which a plate cylinder 5 is disposed inside a housing C. The plate cylinder 5 has the same configuration as that shown in FIG. 2, and a rotatable metal pipe in contact with the inner peripheral surface thereof is provided as squeegee means 51 therein. The squeegee means 51 has a heating means 52 comprising a halogen lamp therein, and is heated positively by the lamp. The heated squeegee means 51 serves to heat and fluidize the phase-changeable ink in the plate cylinder 5 and to push the ink out of the plate cylinder 5 when the plate cylinder 51 rotates. Immediately below the plate cylinder 5, there is provided a press roller 6 arranged at a position facing the metal pipe of the squeegee means 51 and capable of moving up and down so as to come into contact with and separate from the outer peripheral surface of the plate cylinder 5. . A part of the outer peripheral surface of the plate cylinder 5 is provided with an openable / closable clamp means 55 for clamping one end of the stencil sheet wound on the outer peripheral surface of the plate cylinder 5.

The plate cylinder 5 rotates counterclockwise in the figure when stencil printing is performed, and a sheet feeding table 8 for printing paper 14 is provided on the left side of the case C in the figure, and above the sheet feeding table 8. A paper feed mechanism 11 is provided which has a configuration in which an endless belt is stretched over a pair of rollers for feeding out the printing papers 14 one by one in the direction of the plate cylinder 5. A paper feed timing roller comprising a pair of upper and lower rollers for feeding the discharged printing paper 14 between the plate cylinder 5 and the press roller 6 in synchronization with the rotation of the plate cylinder 5 during printing.
12a is arranged. On the right side of the plate cylinder 5 in FIG.
A discharge roller composed of a pair of upper and lower rollers for transporting the printed paper 15 printed and fed between the printer and the press roller 6 to a paper discharge table 9 disposed on the right side of the housing C in the drawing.
12b is provided.

In FIG. 3, a lid S is provided above the casing C, and the image sensor 1 is mounted on the back side of the lid S. A document feed roller 19 is provided, and a document is supplied between the document feed roller 19 and the image sensor 1 from the outside of the lid S to read an image of the document, and read image information converted into an electrical signal. Have been able to. A roll-shaped heat-sensitive stencil sheet 13 is accommodated in the casing C below the document feed roller 19 so as to be rotatable around an axis by a suitable stencil sheet accommodating means. A stencil feed roller 10 comprising a pair of vertically opposed rollers is provided for transporting the thermosensitive stencil sheet in the direction. On the opposite side of the plate cylinder 5, there is provided a plate discharging box 7 for discharging used stencils. Further, the plate cylinder 5 and the base paper supply roller 10
A cutter 20 for cutting the heat-sensitive stencil sheet when the transfer of the heat-sensitive stencil sheet for one plate to the plate cylinder 5 is completed is provided.

According to the present invention, in the printing apparatus shown in FIG. 3, in order to discharge the light-to-heat conversion material onto the heat-sensitive stencil sheet, for example, the discharge head of the liquid discharge means may be replaced by a discharge head 2a as shown in FIG. The stencil sheet 13 can be arranged toward the stencil sheet in the vicinity of the stencil sheet transport path A up to the plate cylinder 5, and can be arranged toward the plate cylinder 5 like the discharge head 2b shown in the drawing. Can also.

In the printing apparatus shown in FIG. 3, in order to make a stencil sheet by perforating a stencil sheet, for example, a light beam irradiating means is used. Can be arranged toward the stencil sheet in the vicinity of the stencil sheet transport path A up to the stencil sheet, or can be arranged toward the plate cylinder 5 like the light beam irradiation means 4b shown in the figure.

Further, in the printing apparatus shown in FIG. 3, in order to print an image directly on the printing paper 14, the discharging head of the liquid discharging means is connected to the plate cylinder of the printing paper transport path B like the discharging head 3a shown in FIG. 5 can be arranged toward the printing paper at the downstream side, and can also be arranged toward the printing paper at the upstream side of the plate cylinder 5 in the printing paper transport path B as shown in the discharge head 3b shown. .

In the printing apparatus shown in FIG. 3, the liquid discharging means may be provided with one or both of the discharging heads 2a and 2b for making a heat-sensitive stencil sheet. It is sufficient to provide both or one of 3a and 3b.For example, if the discharge head 2b can be turned in the direction of the plate cylinder and the printing paper, the heat-sensitive stencil sheet can be formed with only a single discharge head 2b. Performs plate making and direct printing on printing paper.

In the printing apparatus shown in FIG. 3, in order to print directly from an original, the original is inserted below the lid S, and while the original is fed by the original feed roller 19, the image is read by the image sensor 1 and the electric signal is read. By controlling the movement of the ejection head and the ejection of the liquid based on the image information, an image can be reproduced on a stencil sheet or printing paper. Further, the image can be reproduced by controlling the operation of the ejection head directly from the personal computer based on the image information stored in the personal computer (not shown).

When printing a small number of sheets on the printing paper 14,
The plate cylinder 5 and the press roller 6 are separated from each other, and the printing paper 14 on the paper feed table 8 is fed by the paper feed mechanism 11 and the paper feed timing roller 12a.
While the paper is being conveyed by the paper discharge rollers 12b, the liquid discharge means discharges a liquid containing a colorant and / or a photothermal conversion material directly from the discharge head 3a or 3b shown in FIG. The printing is performed in such a manner that printing is performed, and the printed paper 15 is stocked on the paper discharge tray 9.

To perform color printing on the printing paper 14,
What is necessary is just to provide a plurality of ejection heads in the liquid ejection unit, and control so that a colorant having a different color tone is ejected onto the printing paper 14 from each of them. For example, two colors can be printed by discharging colorants having different tones from the discharge heads 3a and 3b.

When printing a large number of sheets on the printing paper 14,
While the heat-sensitive stencil 13 is sent to the plate cylinder 5 by the transport roller 10, the liquid discharging means discharges a liquid containing a photothermal conversion material onto the stencil 13 from the illustrated discharge head 2a to reproduce an image. Then, visible light or infrared light is irradiated from the light irradiation means 4a to perforate the stencil sheet 13 to make a plate, wind it around the plate cylinder 5, and make a plate. This perforation may be performed by irradiating visible light or infrared light from the light beam irradiation means 4b after winding the stencil sheet 13 around the plate cylinder 5.
Further, since the heat-sensitive stencil sheet of the present invention can be made in a non-contact manner, for example, after wrapping the heat-sensitive stencil sheet 13 around the plate cylinder 5 to form a plate, the phase change ink in the plate cylinder 5 is changed from a solid state to a liquid state by heating. Before the state, the liquid containing the photothermal conversion material is applied to the plate cylinder 5 from the discharge head 2b to form the stencil paper 1
The stencil sheet 13 may be perforated to make a stencil by controlling the liquid ejection means so as to reproduce the image by discharging onto the stencil 3, and then irradiating visible light or infrared light from the light irradiation means 4b.

The plate cylinder 5 on which the perforated stencil sheet 13 has been formed on the outer peripheral surface rotates counterclockwise in the figure around the axis thereof and at the same time has the squeegee means 51 heated by the heating device 52 on the inner peripheral surface. The stencil printing ink phase-changed from a solid to a liquid is supplied, and the printing paper 14 conveyed by the paper feed mechanism 11 and the timing roller 12a in synchronization with the rotation thereof is fed by the press roller 6 to the plate cylinder 5 To transfer the stencil printing ink that has passed through the perforated portion of the stencil sheet 13 to the printing paper 14 for printing. Then, the printing paper 14 is transported to the paper output table 9 by the paper output rollers 12b, and the ink is dried. The printed paper 15 is stocked.

In order to obtain a printed matter obtained by performing both direct printing and stencil printing with a liquid containing a colorant on the same printing paper, the printing paper 14 is pressed against the plate cylinder 5 by a press roller 6 and the printed matter is pressed. In addition to the stencil printing obtained, the printing paper 1
4 is obtained by performing direct printing from the ejection means 3a or 3b. Here, during stencil printing, a single ejection head that moves to the position of the illustrated ejection head 2a during direct printing and at the position of the illustrated ejection head 3a during direct printing is provided, or at the time of stencil printing, A single ejection head that can be turned in the direction of the ejection head 2b and that can be turned so as to face the illustrated ejection head 3b in the case of direct printing may be provided. This is convenient for obtaining a printed material of in this case,
The printing order is, for example, either direct printing or stencil printing is performed on the printing paper 14 and stocked as the printed paper 15 on the paper discharge tray 9, and this paper 15 is again transferred to the paper feed tray 8.
After placing on the printing paper, the other printing may be performed.
Before and after the stencil printing is performed by the plate cylinder 5 on the stencil 5, the discharge heads 3a and / or
Or, if printing is performed directly from 3b, the printing paper 14
Stencil printing and direct printing can be performed during one process of being sent to the paper discharge table 9 from the printer.

[0065]

According to the present invention, it is not necessary to bring the heat-sensitive stencil sheet into contact with any object such as a manuscript or a thermal head at the time of plate making, and the heat-sensitive stencil sheet need only be exposed to visible light or infrared light. No wrinkles or poor conveyance occur.

When printing a large number of sheets, stencil printing can be performed, and when printing a small number of sheets, printing can be performed directly on printing paper. It is sufficient to prepare printing paper and heat-sensitive stencil paper in the same manner as described above, and efficient printing can be performed at low running cost with one small printing apparatus.

Further, since a phase change ink which is reversibly changed from a solid to a liquid by heating is used, a clear printed matter having no set-off or strike-through of the printed matter can be obtained. Further, since the ink instantaneously changes from a liquid state to a solid state on a printing medium, it can be printed not only on ordinary printing paper but also on a plastic film, a metal plate or the like.

Further, it is also possible to perform direct printing by superimposing on stencil-printed printing paper to perform multi-color printing and multi-color printing, and to cope with color printing.

[Brief description of the drawings]

FIG. 1A is a side sectional view schematically showing a state in which a liquid containing a photothermal conversion material is discharged from a liquid discharge means toward a liquid absorbing layer of a heat-sensitive stencil sheet, and FIG. It is a side cross-sectional view schematically showing a state in which the material has been transferred to the heat-sensitive stencil paper, (c) is a side cross-sectional view schematically showing a state in which the light-to-heat conversion material is irradiated with light rays to the transferred heat-sensitive stencil paper. ,
(d) is a side sectional view schematically showing a state of a heat-sensitive stencil sheet made by irradiating a light beam.

FIG. 2 is a side view schematically showing a specific example of a plate cylinder of the printing apparatus of the present invention and its periphery.

FIG. 3 is a side view schematically showing an internal structure of a specific example of the multiple printing apparatus according to the present invention.

[Description of Signs] C Casing S Lid A A stencil sheet transport path B Printing paper transport path 1 Image sensors 2a, 2b, 3a, 3b Discharge heads 4a, 4b Light beam irradiation means 5 Plate cylinder 6 Press roller 7 Plate discharge box 8 Feeding Paper table 9 Paper discharge table 10 Raw paper supply roller 11 Paper feed mechanism 12a Paper feed timing roller 12b Paper discharge roller 13 Heat sensitive stencil paper 14 Print paper 15 Printed paper 19 Original feed roller 20 Cutter 21 Liquid absorption layer 22 Thermoplastic resin film 23 Porous support 25 Discharge head of liquid discharge means 26 Light-heat conversion material-containing liquid 28 Light-heat conversion material 29 Light reflection plate 30 Light irradiation means 31 Visible light or infrared light 32 Perforation 51 Squeegee means 52 Heating means 53 Light beam 54 Ink 55 Clamp means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B41J 2/21 B41J 3/04 101Z B41N 1/24 102 101A

Claims (6)

[Claims] 1. A photothermal conversion material contained in a liquid is discharged onto a heat-sensitive stencil sheet according to image information previously converted into an electric signal, and an image based on the image information is reproduced thereon. A liquid discharge unit for transferring the light-to-heat conversion material, a light beam irradiation unit for irradiating the heat-sensitive stencil sheet to which the light-to-heat conversion material has been transferred with visible light or infrared light, and perforating the heat-sensitive stencil sheet to make a plate; An ink-permeable cylindrical plate cylinder that rotates around its own central axis by winding a base paper around its outer peripheral surface, and a stencil printing ink that reversibly changes phase from a solid state to a liquid state is heated in the plate cylinder. A heating unit, a squeegee unit that inscribes the ink on the inner peripheral surface of the plate cylinder and supplies the ink to the peripheral surface, and a state in which printing paper moves in synchronization with the rotation of the plate cylinder. Less with the printing paper Pressing either one of them to bring them into close contact with each other, and transferring the stencil printing ink in a liquid state supplied to the inner peripheral surface of the plate cylinder to the printing paper via the perforated heat-sensitive stencil sheet. And a liquid ejecting unit, wherein the liquid discharging unit is configured to print the photothermal conversion material and / or the coloring agent contained in the liquid on printing paper in accordance with image information previously converted into an electric signal. A multiple printing apparatus adapted to discharge and directly print an image based on the image information thereon. 2. The liquid discharge means, wherein the direction of the heat-sensitive stencil sheet and the direction of the printing paper are changed to selectively discharge the light-to-heat conversion material and / or the colorant onto both of them. 2. The multiple printing apparatus according to claim 1, further comprising: a discharge head. 3. The liquid discharge means includes a plurality of discharge heads capable of discharging the colorant on the printing paper, and performs multicolor printing by discharging the colorants having different colors from the discharge heads. The duplex printing apparatus according to claim 1, wherein the printing apparatus is capable of performing the printing. 4. The heat-sensitive stencil sheet is a heat-sensitive stencil sheet comprising a thermoplastic resin film and a liquid absorbing layer laminated thereon, wherein the light-to-heat conversion material is discharged onto the liquid absorbing layer, 2. The duplex printing apparatus according to claim 1, wherein the heat-sensitive stencil sheet is made by perforating the thermoplastic resin film with the light beam irradiating means. 3. 5. The duplex printing apparatus according to claim 1, wherein said heating means heats said squeegee means, and said ink is heated by heat generated by said squeegee means. 6. The duplex printing apparatus according to claim 1, wherein the stencil printing ink reversibly changes its phase from a solid state to a liquid state at a temperature of 30 to 150 ° C.