JPH03209448A - Image forming device - Google Patents

Abstract

PURPOSE:To carry out an uniform image exposure without having irregularity by providing a partition perpendicular to an exposing barrel and having the inclination of 0-80 deg. angle in the rotational direction of the exposing barrel at every prescribed intervals in parallel, between the exposing barrel and a light source. CONSTITUTION:The protective film face of an image forming material 10 is brought into contact with the surface of the exposing barrel 1, and the emulsion face of a silver salt film 11 is stuck on the image forming material so as to face the exposing barrel side. Furthermore, a polyethylene terephthalate film 12 is additionally stuck to the exposing drum 1 through the use of a jig for sticking such as a pin bar thereon. The light source 4, a light shielding cylinder 5 for preventing the leakage of light 5, and the partition 6 uniformizing an optical path in a light shielding cylinder and intensity distribution are arranged. The partition 6 is provided perpendicular to the exposing barrel 1, with the inclination of 0-80 deg. angle in the rotational direction, and in parallel, at every prescribed intervals. Thus, an uniform image exposure without having irregular ity is carried out.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a 5-image forming apparatus, and more specifically, to a difference in tackiness between an exposed area and an unexposed area of a photosensitive layer. The present invention relates to an image forming apparatus that is capable of creating a transfer material that is completely similar to a printed material as a prepress proof by using an image forming material that uses monochrome or multicolor superimposition.

(Prior Art) Conventionally, in the printing industry, it has been generally known to use one-proof printing or pre-press proofing as a means of checking one color tone of the final printed matter before printing. ing.

Prepress proofing has the advantage of being able to predict the final printed product without using printing ink, and can be used with overlay or subprinting methods depending on the final image quality and various objectives in the plate-making and printing processes. etc. are used accordingly.

In the overlay method, a photosensitive layer containing a coloring material corresponding to each color separation mask is placed on a transparent base film, and the film and mask are brought into close contact with each other, exposed, and developed, and the respective films are overlapped to perform calibration.

Nowadays, new methods that do not use a developing solution or developing gas are being considered, such as in Japanese Patent Application Laid-Open No. 63-188088, but this method requires the use of transmitted light, so it is low cost but The delicate two-color balance and gradation are impaired from the beginning, and it is not possible to judge the final finish of the printed matter as a reflective object.

Unlike the overlay method, the subprint method provides a hard copy, so its utility value is high.

For example, as described in U.S. Pat. be.

Also, 1 Japanese Patent Publication No. 59 97410, 61-1
There is also a prepress proof that can be used for both the overlay method and the subprint method as described in Japanese Patent No. 88537. The advantage of this method is that depending on the purpose of use, if you want to change simple text, etc., you can use TiN recognition with just the overlay, and if you want to obtain a hard copy of changes in subtle color parts such as patterns, this method can be used. It has great versatility in that it only needs to be transferred to a transfer target. however.

This method has the disadvantage of creating a poor working environment because it requires a developing process using an organic solvent. Furthermore, regarding the images obtained.

Although it is possible to transfer to any transfer object, a photosensitive transparent intermediate layer is interposed between the transfer object and the colored photosensitive layer.
The object to be transferred and the colored photosensitive layer are adhered to each other. Due to the presence of this layer, one reflected light is diffusely reflected, resulting in a finish that is quite different from the actual printed matter, and the density of the obtained transfer tends to be lower than that of the actual printed matter.

Furthermore, since the thickness of the photosensitive layer that is transferred remains constant, it is stable as a photosensitive material, but since it is not possible to change the tone as a prepress proof, the result is a finish that differs from the actual printed matter. It ends up.

(Problems to be Solved by the Invention) An exposure cylinder that first performs one-image exposure, at least one exposure light source disposed outside the exposure cylinder in the radial direction, a blanket cylinder that can be detached from the exposure cylinder, and a blanket cylinder that is detachable from the exposure cylinder; The inventors have invented an image forming apparatus equipped with a printing cylinder, and have discovered an apparatus and method that do not have the above-mentioned drawbacks, that is, can form images that closely resemble printed matter. In this apparatus, an exposure cylinder holds an image forming material and an original image, and a light source placed near the exposure cylinder performs exposure, and the exposed image forming material is transferred to a blanket cylinder.

Transfer is performed by applying heat and pressure to a direct image receptor such as paper held on the exposure cylinder or printing cylinder (removable from the blanket cylinder).
This is an apparatus or method that can reproduce a color image by repeatedly exposing and transferring four colors.

The transfer material obtained using this image forming apparatus reproduces the exact same image and texture as the actual printed material because there is no layer such as an adhesive layer between the printing material and the image forming material. have already been discovered. Also.

JP-A-63-147154, JP-A-63-14716
Materials described in Publication No. 2 and the like are suitable.

However, when the light source attached to this device is a rod-shaped lamp, it is difficult to obtain parallel light rays, so the image may be distorted at the side edges, and the light intensity distribution may vary in the length direction of the lamp. Therefore, uniform image exposure in the axial direction of the exposure cylinder is difficult. That is, the lamp intensity is strong at the center of the lamp length, and weak at both ends of the lamp. Therefore, if an image-forming material with uniform exposure sensitivity is determined to have the appropriate sensitivity at the center of the lamp, both ends of the image-forming material will be insufficiently cured, causing a so-called fog phenomenon.On the other hand, if the appropriate sensitivity is determined at both ends of the lamp, This results in overexposure at the center of the lamp, resulting in unnecessary image distortion. In addition, to simply achieve a uniform exposure intensity distribution, it is possible to use a point light source, but the distance between the irradiated surface and the light source must be quite large, and the light intensity is weak, so it is necessary to use a point light source for image exposure. It had drawbacks such as being quite time consuming.

Considering these various conditions, it would be better to use a rod-shaped lamp with a strong light intensity, but a method was needed to make the light intensity uniform without weakening it.

[Structure of the invention]

(Means for Solving the Problems) The present invention comprises a support, a photosensitive layer formed on one side of the support, and a protective film provided on the photosensitive layer as necessary. An exposure cylinder for image forming an image by laminating an image forming material with an original image and transferring a part or all of the unexposed area to an image receptor;
In an image forming apparatus comprising at least one exposure light source disposed radially outside an exposure cylinder, a blanket cylinder detachable from the exposure cylinder, and optionally a printing cylinder, there is provided a light source between the exposure cylinder and the light source. , is an apparatus in which partition plates are provided in parallel at predetermined intervals, perpendicular to the exposure cylinder and inclined at an angle of 0° to 80° in the rotational direction of the exposure cylinder, and furthermore, the partition plates are black. , and an image forming apparatus in which the light source is a rod-shaped light source arranged tangentially parallel to the exposure cylinder.

This relates to a device for creating transfers on image receptors such as paper that have the same print density as ordinary printed matter, and when using a rod-shaped lamp as the image exposure light source, it is possible to adjust the distribution in the lamp axis direction without reducing the light intensity. The purpose is to provide a device for aligning.

With this device, it is possible to obtain a texture that is no different from that of ordinary printed matter, that is, a reflection density and gloss window equivalent to that of ordinary printed matter. Therefore, the transfer material obtained using this method is completely equivalent to a normal printed matter as a prepress proof, and is close to the ideal.

The apparatus of the present invention will be explained with reference to two drawings. FIG. 1 shows a schematic side view of the device of the invention.

In the apparatus shown in FIG. 1, the exposure cylinder 1. Blanket cylinder 2° Printing cylinder 3. This device includes a light source 4. First, an image forming material and an original image are fixed to the exposure cylinder 1 using a pin bar means, a vacuum means, a mounting bracket, etc., and exposed using a light source 4. After exposure, remove the original image and transfer the image-forming material to a blanket cylinder using metal fittings, adhesive tape, etc. If there is a protective film, remove the protective film so that the photosensitive layer of the image-forming material becomes the outermost surface. Transfer is performed while rotating the image receptor twice in the nip between the blanket cylinder 2 held by the printer and the printing cylinder 3 holding the image receptor. When forming a color image, four colors are transferred repeatedly.

Although FIG. 1 discloses an apparatus using three cylinders, it is also possible to use two cylinders. For example, it is also possible to perform exposure with an exposure cylinder, transfer the image forming material to a blanket cylinder after the exposure, hold an image receptor on the exposure cylinder, and perform transfer between the exposure cylinder and the blanket cylinder.

FIG. 2 is a side view showing the exposure state of the exposure cylinder 1. Image exposure is performed by passing light (usually ultraviolet rays) from a light source 4 through a light-shielding tube 5. A partition plate 6 is provided on the side of the light-shielding cylinder 5 closer to the exposure cylinder. The partition plates 6 are arranged perpendicularly to the exposure cylinder 1 and parallel to the rotation direction or inclined at an angle of 0 to 80 degrees and parallel to each other at predetermined intervals.

FIG. 3 shows the exposure cylinder 1. Light source 4. Light-shielding tube5. FIG. 6 is a perspective view of a portion of a partition plate 6. FIG.

The imaging material that can be used in the present invention essentially consists of a transparent support, one or more photosensitive layers, and a protective film.

As this transparent support, a material which is stable against heat, chemical light, etc., and which sufficiently transmits actinic light is suitable. Examples include films or sheets of cellulose acetate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate, polypropylene, and the like.

As a protective film, polyethylene film is rigid and
It is preferable in terms of oxygen permeability, expansion/contraction rate, surface smoothness, adhesion, releasability, etc.

Further, the transparent support or the protective film may be subjected to conductive treatment in order to remove static electricity generated when the protective film is peeled off.

Examples of materials that can be applied to the photosensitive layer of the image forming material of the present invention include:

(a) A photopolymerizable compound and a colorant (sometimes no colorant is included) (b) A photopolymerizable compound, a thermoplastic resin, a colorant, etc.; Polymerization accelerators, thermal polymerization inhibitors, resin plasticizers, pigment dispersants, etc. are used in combination.

Photopolymerizable compounds include monomers and polymers.

At least one selected from prepolymers is applied.

The photopolymerizable compound is not particularly limited, but preferably one that can plasticize the thermoplastic resin at room temperature.

As the thermoplastic resin (organic polymer binder), a thermoplastic, non-photopolymerizable polymer that has excellent compatibility with photopolymerizable compounds can be used. For example, polyvinyl chloride,
Poly(meth)acrylic acid ester epoxy resins, polyurethane resins, cellulose derivatives (e.g. ethyl cellulose, cellulose acetate).

nitrocellulose), vinyl chloride/vinyl acetate copolymer, polyamide resin, polyvinyl acetate resin, diallyl phthalate resin, butadiene-acrylonitrile copolymer, etc. These thermoplastic materials can be used depending on the required physical properties. It may contain one kind or two or more kinds.

The colorant applied to the photosensitive layer is an organic pigment.

Dye 1 Conventionally used dyes and pigments such as carbon blank can be used. It is also possible to mix several dyes and pigments to obtain the required hue.

The pigment or dye added to the photosensitive layer is suitably 5 to 50% of the total solid content, more preferably 5 to 50% of the total solid content.

7 to 20% is preferred.

The method of using the image forming material having the above composition is as follows:
The transparent support side of the image forming material and the image surface of the mask original plate are brought into close contact, image exposure is carried out from the mask side, the mask original plate is then removed, and the protective film is removed, and the photosensitive layer and the transfer target are placed between nip rolls using heat, pressure, speed, etc. By appropriately setting the transfer conditions and performing transfer, it is possible to obtain a transferred material with a texture that is not exactly different from ordinary printed matter.

The present invention will be described in more detail below with reference to Examples, but the present invention is not limited thereto. Example "Central part" refers to parts by weight.

Example 1 A photosensitive layer solution having the following composition was prepared.

Diallylisophthalate prepolymer 22 parts (manufactured by Daiso Co., Ltd.) KAYARAD-DPHA 7 parts (manufactured by Nippon Kayaku Co., Ltd.) Benzophenone (manufactured by Daiichi Kasei Co., Ltd.) 0.5 parts E
AB (manufactured by Hodogaya Chemical Co., Ltd.) o, 2nd part MA
-7 (manufactured by Mitsubishi Kasei Corporation) Part 3 R-52
(Manufactured by Hoechst Japan Co., Ltd.) 1 part methyl ethyl ketone 40 parts toluene
10 parts xylene
10.3 parts of this photosensitive layer solution was added to a polyethylene terephthalate film (thickness 1
2μ) to a dry film thickness of 25μ.

The colored photosensitive layer formed on the transparent support and the protective film were laminated together using a laminator so as to be in contact with each other to obtain 9 image forming materials.

As shown in FIG. 2, the protective film surface of the image forming material 10 is brought into contact with the surface of the exposure cylinder 1, and the emulsion surface of the silver halide film 11 with a halftone dot area ratio of 50% is exposed onto the image forming material. Paste it so that it faces the body side, and then apply a layer of 200mm thick from above.
A polyethylene terephthalate film I2 of μ was attached to the exposure cylinder 1 using a sticking jig such as a pin bar.

Light source 4, light shield tube 5 for preventing light leakage. A partition plate 6 is arranged at the position shown in the figure to make the optical path and intensity distribution uniform in the light-shielding tube. After attaching the image forming material to the exposure cylinder I in this way, a rod-shaped lamp with a lamp length of 75 cm and a lamp tube diameter of 16 mm was turned on, and the exposure cylinder was rotated for a distance of 10.200 m.
Actinic light of j/cm2 was applied. The polyethylene terephthalate film 12 and the original positive mask 11 were peeled off, the image forming material 10 was transferred to the blanket cylinder 2, and the protective film was peeled off.

Next, transfer was performed using the printing cylinder 3 holding the coated paper and the blanket cylinder 2. The conditions were: coated paper, Pearl Coat (manufactured by Mitsubishi Paper Mills, Ltd.) and the image forming material from which the protective film had been removed were brought into close contact, the pressure was 4 kgf/cm, and the passing speed was 3.
When the photosensitive layer was transferred at a nip between rollers at a rate of 5 cm/min and a roller surface temperature of 90° C., the thickness of the photosensitive layer in the unexposed area was 2.0 μm. Incidentally, the reflection density of the solid portion transferred onto the coated paper was 1.5. Another 50%
When looking at the difference in the rope point in the axial direction of the exposure cylinder, the difference was 50% at the center of the lamp and 50.2% at both ends of the lamp.

(Measurements were made by Macbeth, RD-914).
Furthermore, seven partition plates were arranged perpendicularly to the exposure cylinder and parallel to the rotating direction of the exposure cylinder. The length of the partition plate was 9 cm, the width was 11 cm, and the interval between the two was 10 cm.

Example 2 When the partition plate of the image forming apparatus of Example 1 was tilted at 60 degrees with respect to the rotational direction of the exposure cylinder and image exposure was performed as in Example 1 and printing was performed, the thickness of the photosensitive layer in the unexposed area was 2. .0μ was transferred. The reflection density of the dark area transferred onto coated paper is 1.
5 (measured by Macbeth, RD-914).

Furthermore, when we looked at the difference in the 50% halftone area in the axial direction of the exposure cylinder, we found that it was 50% at the center of the lamp and 50.1% at both ends of the lamp.
This enabled uniform image exposure with no unevenness in the width direction.

Example 3 When the partition plate of the image forming apparatus of Example 1 was tilted at 45 degrees with respect to the rotational direction of the exposure cylinder and image exposure was carried out as in Example 1 and printing was performed, the thickness of the photosensitive layer in the unexposed area was 2. .0μ was transferred. The reflection density of the solid area transferred onto coated paper is 1.
5 (measurement was made by Macbeth, RD-
914).

Furthermore, when looking at the difference in the 50% halftone area in the axial direction of the exposure cylinder, the difference was 49.6% at the center of the lamp and 50.6% at both ends of the lamp.
At 1%, uniform image exposure without unevenness was achieved in the width direction.

Example 4 The partition plate of the image forming apparatus of Example 1 was painted black to prevent diffuse reflection, and the image was exposed and printed as in Example 1 at an angle of 45 degrees with respect to the direction of rotation of the exposure cylinder. The thickness of the photosensitive layer in the unexposed area was 2.0 μm. The reflection density of the solid area transferred onto the coated paper was 4°1.5 (measured using Macbeth, RD914).
by).

Furthermore, when we looked at the difference in the 50% halftone area in the axial direction of the exposure cylinder, we found that it was 49.7% at the center of the lamp and 50.7% at both ends of the lamp.
At 3%, uniform image exposure without unevenness was achieved in the width direction.

It was also observed that by making the partition plate black, unnecessary light leakage was reduced.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic side view of an image forming apparatus, and FIG. 2 is an exposure cylinder. A side view of the light source, light-shielding cylinder, etc., and Figure 3 shows the exposure cylinder and light source. A perspective view of a light-shielding tube, etc. is shown, respectively. In the figure, knee exposure cylinder, 2-blanket cylinder, 3-printing cylinder,
4-light source, 5-shading cylinder, 6-partition plate are shown, respectively.

Claims (1)

[Claims] 1. An image forming material consisting of a support, a photosensitive layer formed on one side of the support, and a protective film provided on the photosensitive layer if necessary, A device that performs image exposure by laminating an original image and transfers a part or all of the unexposed area to an image receptor, the device comprising: an exposure cylinder that performs image exposure; In an image forming apparatus equipped with one exposure light source, a blanket cylinder that is detachable from the exposure cylinder, and, if necessary, a printing cylinder, between the exposure cylinder and the light source, there is a A device characterized in that partition plates are provided parallel to each other at predetermined intervals and are inclined at an angle of 0° to 80° in the direction of rotation. 2. The image forming apparatus according to claim 1, wherein the partition plate is black. 3. The image forming apparatus according to claim 1 or 2, wherein the light source is a rod-shaped light source arranged tangentially parallel to the exposure cylinder.