JPH0215260A - Method and device for forming image - Google Patents

Abstract

PURPOSE:To obtain in one transfer a prepress proof, which has almost the same quality as an actual printed matte and also has excellent color- reproducibility, or a small amount of printed matters by composing the device, which transfers an unexposed part onto an image receiving body, of an exposure light source, an exposure drum, and a pressure drum coming into press-contact with the exposure drum. CONSTITUTION:A UV lamp 1 is placed radially outside the exposure drum 3; an image forming material 5 and the laminated body of an original 9 are exposed; the exposure drum 3 has a gripping pawl 11 for the image forming material in its recessed part, and also has an adhesive tape 13 for the image receiving material. The exposure drum 3 is then rotated so that a laminated body, comprised of the image forming material 5 and original 9, is drawn between the exposure drum 3 and pressure drum 15 creating a nip; as it does so, the pressure drum 15 is provided with a gripping pawl 12 having an arm whereby the image forming material is held; and also a protective film 8, attached inside the forming material 5, is floated by the pawl 12 to be removed from the material 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an image that can be formed by superimposing monochrome or multicolor images by utilizing the difference in tackiness between exposed and unexposed areas of a photosensitive layer. The present invention relates to a forming apparatus and an image forming method. More specifically, the present invention relates to an image forming apparatus and an image forming method capable of obtaining a transfer material similar to a printed matter as a prepress proof for color proofing or the like.

[Prior Art] Conventionally, in the field of printing industry, prepress proofing has been used as a means for checking the finish, color tone, etc. of final printed matter before printing. There are two types of prepress proofing methods: overlay method and zaprint method, each of which is used depending on the purpose of use.

In the overlay method, a photosensitive layer corresponding to each color separation (color separation) image is provided on each transparent Heath film, an image is formed on each Heath film by irradiation with actinic rays and development, and then each Heath film is registered by eye or the like. and overlap them. This method has the disadvantage that it is affected by the reflected light from the stacked films, so the actual printed matter has a thicker texture (,71).

For example, the print method is described in US Pat. No. 3,060,023.
No. 3,060,024, and No. 3,060,025, a plurality of images formed on each photosensitive layer corresponding to each color separation image are sequentially transferred to a single image receptor. It forms a prepress blueprint.

Each photosensitive layer may be colored to correspond to each color separation image, or each transferred image may be colored with powder Color I.

US! The method disclosed in IN Patent No. 3,060,023, Mei MH, etc. is a method in which a photosensitive layer and an image receptor are brought into close contact with each other under pressure in a plane, heated, and then peeled off.

In this method, in which the photosensitive layer and the image receptor are brought into close contact with each other under pressure in a two-dimensional manner and then peeled off bitangentially, if the working conditions such as the speed and direction of peeling are not constant, the reproduction of the transferred image will become unstable. , non-uniform reflection density of the transferred image, fine periodic patterns, and even fine directional patterns are produced, and the accuracy of color reproduction etc. is significantly reduced.

JP-A No. 59-97140, JP-A No. 61-1885
No. 37 discloses a proofing method that is applicable to both the overlay method and the print method.

In this proofing method, a color sheet is prepared in which a release layer, a colored photosensitive layer, and a protective film are sequentially laminated on a polyester support, and an image-receiving film is prepared in which an image-receiving layer and a protective film are laminated on a polyester support. , the emulsion side of the color sheet and the half 1 to 1 negative are brought into close contact, exposed to light to form an image, and the unexposed areas are eluted with a mixture of carbonic acid sorter, butyl cellosolve, and water. After drying, it can be used as an overlay blue ink.

Since a developing solution is used, continuous processing is difficult.

When using the ink as a black ink using the black printing method, apply the ink image formed on the color sheet to the image-receiving film at a temperature of 1]0°C, a pressure of 2 bar, and a speed of 6.
Transfer to an image-receiving film under conditions of 0 cm/m j n. Registration is then performed visually or by punching to this image-receiving film, and a cyan image is transferred. The above operation is repeated for magenta and yellow in this order to obtain a color image.

The obtained color image is transferred to an image receptor, which is a transfer target. In order to reduce the gloss of the transferred image, a matte film is applied (=J) to complete Blue Finixy 1~.

In the above method, an original image layer formed on a film is laminated on the protective film side of the color sheet so that the original image layer is in contact with the protective film, and then exposed. After exposure, the protective film is peeled off and an image is formed by pressing onto an image receptor. Therefore, since the image formed is a reverse image, another transfer is necessary to obtain a normal image. In this case, since a protective film is interposed between the original image layer and the photosensitive layer, light is diffused, making it difficult to obtain a highly accurate image. In addition, in order to produce a normal image in one transfer, it is necessary to expose the film with the film side having the original image layer in contact with the protective film.

In this case, since the film having the original image layer and the protective film are interposed between the original image layer and the photosensitive layer, there is a drawback that light diffusion due to exposure increases and image quality deteriorates.

Simple proofing is also well known, in which an image forming material having a photosensitive layer is used and transferred by a letterpress proofing press. That is,
In this method, the image receptor is placed on the paper surface plate of the proof printing machine, the exposed color sheet is held on the impression cylinder, and the image is transferred while the impression cylinder rotates.

[Problems to be Solved by the Invention] In any of the above methods, image exposure and transfer are
The image forming material and the original image are fixed on a table or the like using register pins, exposed, and then manually transferred from the table or the like to a transfer device.

In color proofing, image formation is performed repeatedly in four colors, and registration and phase alignment of the four colors are important for maintaining image quality. Conventionally, these registers have been mostly determined visually or by drilling holes using a film. These methods cannot be said to be fully applicable, especially when it is desired to form a color image in a short period of time. That is, it is difficult to perform continuous processing of each process such as exposure and transfer. When the transfer to the step '#J image receptor is performed manually, the quality of the image formation depends on the operator's experience and intuition, and it is not always possible to produce good images.

An object of the present invention is to provide an image forming apparatus and an image forming method that can provide a prepress proof or a small amount of printed matter with almost the same texture as an actual printed matter and excellent color reproduction accuracy in one transfer.

A further object of the present invention is to provide an image forming apparatus and an image forming method that can uniformly and easily perform exposure and transfer.

A further object of the present invention is to provide an image forming apparatus and an image forming method that can continuously create prepress proofs and the like.

[Means for Solving the Problems] The image forming apparatus of the present invention includes a support, a photosensitive layer formed on one surface of the support, and a protective film attached to the photosensitive layer side of the support. An apparatus for laminating an image forming material with an original image, exposing it to light, and transferring part or all of the unexposed area to an image receptor, the apparatus being in contact with an exposure light source, an exposure cylinder, and the exposure cylinder. an exposure cylinder, an exposure light source is disposed radially outside the exposure cylinder, an image forming material attachment means and an image receptor attachment means are provided on the exposure cylinder, and the image forming material is attached to the surface of the exposure cylinder. This is a device equipped with means for holding the

As the image-forming material, various image-forming materials can be used, such as dry method materials that form images by peel development. A dry method material using peel development is preferable because the operation is simple and continuous.

As the light source for exposure, any light source such as a UV lamp may be used as long as it can cure the photosensitive layer corresponding to the non-image area.

It is preferable that the impression cylinder is installed so that it can freely contact the exposure cylinder and adjust the nip pressure between it and the exposure cylinder.

The impression cylinder is preferably coated with an elastic material such as rubber in order to facilitate the transfer of the image formed on the photosensitive layer of the image forming material held on the impression cylinder to the image receptor.

The image forming material attachment means includes a means for suctioning and fixing the material by providing a large number of holes or swamps for vacuum means in the material attachment area of the body, a means for fixing the material using double-sided adhesive tape, and a means for fixing it using static electricity. The clamp bar can be attached along the axial direction of the exposure cylinder by means of fixing it with the bar, or by any means that can fix the material on the surface of the cylinder, such as a gripper used in the impression cylinder or intermediate cylinder of a printing press. However, between nips or gaps (hereinafter referred to as nips) can also be adopted.
When the material is held by the image forming material holding means of the impression cylinder, it is necessary to have a structure that allows the material to be separated from the exposure cylinder. Further, when a clamp bar or the like is used as the attachment means, it is preferable to install the means radially inward from the barrel surface in order to avoid damaging the barrel surface. Preferably, the attachment means also includes a pin bar or the like for accurately positioning the image forming material on the exposure cylinder and the impression cylinder and ensuring appropriate registration and phase alignment.

The image forming material holding means installed on the impression cylinder includes means for sucking and fixing the material by opening a large number of holes etc. in the area for holding the image forming material, and means for fixing the image forming material using double-sided adhesive tape or electrostatic means. Any means that can fix the image forming material to the impression cylinder may be used, but it is more preferable to use gripping claws in order to smoothly transfer the image forming material from the exposure cylinder to the impression cylinder. It is also possible to use a gripper and a suction means or an adhesive tape as the attachment means, and to use a gripper as the holding means. Alternatively, a plurality of small-diameter rolls may be arranged near the outer peripheral surface of the exposure cylinder and/or impression cylinder to bring the image forming material and/or image receptor into close contact with the cylinder surface to prevent the occurrence of wrinkles, etc. good.

In order to separate the protective film on the surface of the impression cylinder and hold the image forming material on the impression cylinder, the protective film is protected so that the adhesive force between the photosensitive layer and the protective film is weaker than the adhesive force between the photosensitive layer and the support. It is preferable to appropriately select the material of the film, the support, or the photosensitive layer. A release treatment may be applied to the surface of the protective film. Also,
A cut is made in the axial direction of the impression cylinder near the tip of the protective film in the direction of travel.
is inserted, the protective film is gripped by a holding means such as a gripping claw of the impression cylinder, and then the gripping claw is moved inside the impression cylinder, whereby the remaining edge of the protective film is lifted up, This end portion may be fixed by hand or by fastening means installed near the outer periphery of the impression cylinder so that the protective film separates as the impression cylinder rotates.

The image forming apparatus of the present invention is an apparatus in which the exposure cylinder is further provided with image receptor attachment means, and the image-exposed photosensitive layer on the impression cylinder is transferred to the image receptor attached to the image receptor attachment means. Alternatively, the image receptor may be attached to the exposure cylinder by an image forming material attachment means of the exposure cylinder, and the image formed on the photosensitive layer on the impression cylinder may be transferred to the image receptor.

It is preferable to provide a heating means in the image receptor attachment area of the exposure cylinder so that the image receptor can be heated to an appropriate temperature. This is to smoothen the transfer of the exposed photosensitive layer to the image receptor, improve the transfer speed, and improve the reproduction accuracy of fine images. The temperature of the body surface in the image receptor attachment area is 50 to 150°C, preferably 60 to 11°C.
The temperature is about 0°C.

Embodiments of the apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic side view of an image forming apparatus of the present invention, which includes an exposure light source, an exposure cylinder, and an impression cylinder.

A UV lamp 1 is arranged radially outside the exposure cylinder 3 and exposes the stack of the image forming material 5 and the original image 9. The original picture is
When forming a monochrome image, a single positive or negative film may be used, and when forming a multicolor image, a color-separated positive or negative film is used.

The exposure cylinder is provided with grippers 11 for attaching an image forming material to four parts of the exposure cylinder, and an adhesive tape 13 for attaching an image receptor. The gripping claws 11 may be those commonly used for changing grips on impression cylinders or intermediate cylinders of printing presses.

The exposure cylinder is rotated to introduce a stack of image forming material 5 and original image 9 into a nip formed by exposure cylinder 3 and impression cylinder 15. After exposure, the original image may be peeled off from the laminate and then introduced between the nips.

The impression cylinder 15 is provided with an arm-equipped gripper 12 in an image forming material holding area on the surface of the impression cylinder, and holds the image forming material introduced by the gripper. A half-cut is provided in the protective film 8 near the tip in the direction of rotation of the impression cylinder, and the image forming material including the edge of the protective film is held by the gripping claw, and the remaining protection is lifted up by the rotation of the gripping claw due to the swing of the arm. Separate the protective membrane by grasping the edges of the membrane. The separated protective film is wound up by a winding roller 16. The image forming material from which the protective film on the impression cylinder has been separated is held on the surface of the impression cylinder by the arm gripping claws 12 and the holding roll 17.

The M retaining film held on the impression cylinder is separated and the image forming material with the photosensitive layer exposed on the surface is introduced into a nip formed between the impression cylinder and the exposure cylinder by rotation of the impression cylinder, The adhesive tape 13 installed on the exposure cylinder is pressed onto an image receptor 18 attached to the exposure cylinder, and the image formed on the photosensitive layer is transferred to the image receptor. It is preferable that the impression cylinder is released from contact with the exposure cylinder after the transfer is completed. Preferably, heating means (not shown) is provided in the image receptor attachment area of the exposure cylinder. Preferably, the exposure cylinder further rotates and the transferred image is post-exposed by the U-clamp.

FIG. 2 shows that a half cut is made in the edge 19 of the protective film of the image forming material 5, which consists of the support 6, the photosensitive layer 7, and the protective film 8, and the end of the protective film held by the gripper of the impression cylinder. Edge 1
9 and the remaining protective film 20 are cut or separated. This facilitates separation of the protective film from the photosensitive layer on the impression cylinder surface. At this time, it is preferable to perform a mold release treatment on the photosensitive layer side of the protective film. FIG. 3 shows a state in which a half cut is made in one edge of the protective film 8, and a portion of the remaining protective film 20 is overlapped with the edge. As a result, only the edge portion is held by the gripper of the impression cylinder, and the remaining protective film can be easily separated.

In the image forming method of the present invention, in the image forming apparatus of the present invention, an image forming material and an original image are laminated and attached in this order to an exposure cylinder with a protective film on the exposure cylinder side, and the image-exposed laminate or image forming material is exposed. By rotating the cylinder, the laminate or image forming material is introduced between the nip formed by the exposure cylinder and the impression cylinder, and after the impression cylinder holds the laminate or the image forming material and the protective film is peeled off, the exposure cylinder with the image receptor attached thereto is inserted into the nip formed by the exposure cylinder and the impression cylinder. A method of transferring an image formed on an image-forming material to an image receptor by introducing the image-forming material into a nip formed from a cylinder.

Image receptors used in the present invention include art paper, coated paper,
Any suitable base material such as high-quality paper or film can be selected.

When obtaining a single-color prepress proof or printed matter, the original image used in the present invention is an image obtained by fixing a light-shielding paper to a film made for a single color (image mask) or a transparent polyethylene terephthalate film that functions as a color-separating shade. It may be a mask, or a color-separated image mask if a multicolored color proof or print is to be obtained.

The image forming material used in the present invention usually consists of a support and a photosensitive layer formed on one side of the support.

As the support, a material that is stable against heat, chemicals, light, etc. and transmits actinic rays is suitable. For example, cellulose acetate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate,
It is a film or sheet made of polyimide, polypropylene, etc. In particular, polyethylene terephthalate films or sheets are preferred because they have excellent transparency, thermal stability, and dimensional stability.

These supports may be used as they are, or may be subjected to mold release treatment with a suitable oil-based substance. Examples of oil-repellent substances include silicone resins and fluororesins.

The one-day photosensitive layer consists of (a) a photopolymerizable compound and a colorant, (b) a photopolymerizable compound, a thermoplastic resin, a colorant, etc., or a photopolymerization initiator, a thermal polymerization inhibitor, etc. etc. may be used together.

As the photopolymerizable compound, at least one selected from monomers, oligomers, and prepolymers is used.

Preferably, it is a compound that can plasticize a 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.

As the dye and/or pigment to be contained in the photosensitive layer, conventionally known dyes and/or pigments can be used. in general,
Dyes and pigments having yellow, magenta, cyan, and black hues are suitable, and metal powders, white pigments, fluorescent pigments, etc. can also be used.

For color proofing, there are yellow, red, indigo, and ink, and use pigments or dyes that match these hues. You can choose and use it.

The thickness of the photosensitive layer may be about 0.5 to 5 .mu.m, and the appropriate coating thickness varies depending on the dye and/or pigment contained, but it is suitably 0.5 to 10 g/m@2.

Examples of the protective film used in the present invention include polyethylene film, polyethylene terephthalate film, and acetate film. When the protective film is a polyethylene film, the mold releasability of the polyethylene film itself may be used, or a mold release agent such as fluororesin or silicone resin may be applied.

The present invention will be explained below with reference to Examples. In the examples, parts do not indicate parts by weight, and % does not indicate weight %.

Example 1 Diaryl isophthalate prepolymer (Daisort Isotap Mn4500 manufactured by Osaka Soda Co., Ltd.)
0) 21.23 parts dipentaerythritol hexaacryle-1-D PHA (manufactured by Nippon Kayaku Co., Ltd. 708 parts addition polymerization initiator Hensophenone 05 parts 4,4 bis-ethylaminobenthophenone (EAB Hodogaya Chemical Co., Ltd.) ) made
0.17 parts hydroquinone 0001
Part car phone black MA-7 (manufactured by Mitsubishi Chemical Industries, Ltd.)
A photosensitive layer liquid having a composition of 5.0 parts toluene, 38.0 parts, and 400 parts of methyl ethyl ketone was prepared.

This photosensitive layer liquid is applied to biaxially stretched polyethylene terephthalate).
・Coat the film (thickness: 12 μm) so that the dry coating film becomes 2.4 μm, and then coat the coated surface with a polyethylene film (protective film) having half-cuts 1 to 1 on the edges as shown in Figure 2. ) was added to obtain an image forming material.

Using this image forming material, in the apparatus shown in FIG. 1, the image forming material, a positive film, and art paper were each attached to an exposure cylinder, and exposure and transfer were performed. Do not separate the protective film by hand on the impression cylinder surface.

The resulting transferred image was clear.

The speed of feeding the image forming material and the art paper between the nips was 50 cm/min, the linear pressure was 4 kg/cm, and the surface temperature of the exposure cylinder on the art paper side was 100°C.

Example 2 Instead of the carbon black used in Example 1, Lionol Yellow FGI 310, Carmine 7BFG4412, and Lionol Blue FG7330 were used to prepare photosensitive layer solutions.

The photosensitive layer solution was applied to a polyethylene terephthalate film in the same manner as in Example 1, and a polyethylene film was attached to obtain an image forming material. First, a color-separated positive film corresponding to Lionol Yellow FG1310 was layered on the laminate, exposed using the apparatus shown in FIG. 1, and transferred over the transferred image obtained in Example 1. Next, repeat the above operation for the remaining two colors to produce a color proof in which halftone images are formed in the order of black, cyan, magenta, and yellow. The operating method is the same as in Example 1.

-l so The resulting color proof was clear.

[Effects of the Invention] According to the present invention, a color proof having a texture equivalent to that of an actual printed matter can be provided simply, quickly, and stably, especially in the sub-printing method using printing paper.

The present invention is not only applicable to overlay methods, but also to printing in small print runs of up to several hundred copies.

According to the present invention, the quality of the obtained transferred image is good, a normal image can be obtained with one transfer, exposure and transfer (and post-exposure) can be carried out continuously, and registration is easy. Therefore, a remarkable effect is achieved in that a stable image can be obtained without relying on the experience or intuition of a skilled person.

In image forming materials consisting of a support/photosensitive layer/protective film, the protective film is thicker than the support and often has poor light transmittance.

According to the present invention, since exposure is performed from the support side, there is less light diffusion and scattering, and therefore good prepress proofs or printed materials can be provided.

According to the present invention, since the image forming material and the image receptor are attached to the exposure cylinder, registration is relatively easy;
Therefore, color proofs or printed matter without misregistration can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of an image forming apparatus of the present invention,
FIG. 2 and FIG. 3 are side views showing a half-cut state of the edge portion of the protective film.

Claims (1)

[Scope of Claims] 1. An image forming material consisting of a support, a photosensitive layer formed on one side of the support, and a protective film attached to the photosensitive layer side of the support is used as an original image. An apparatus for laminating and image-exposing and transferring part or all of the unexposed area to an image receptor, the apparatus comprising an exposure light source, an exposure cylinder, and an impression cylinder in contact with the exposure cylinder, the exposure light source is arranged on the outside of the exposure cylinder in the radial direction, the exposure cylinder is provided with an image forming material attachment means and an image receptor attachment means, and the impression cylinder is provided with a means for holding the image forming material attached to the surface of the exposure cylinder. image forming apparatus. 2. In the image forming apparatus according to claim 1, the image forming material and the original image are laminated and attached in this order to the exposure cylinder with the protective film on the exposure cylinder side, and the image-exposed laminate or image forming material is applied by rotation of the exposure cylinder. The laminate or image forming material is introduced between the nip formed by the exposure cylinder and the impression cylinder, the impression cylinder holds it, the protective film is peeled off, and then the image receptor is attached to the exposure cylinder and the impression cylinder. An image forming method comprising transferring an image formed on an image-forming material to an image receptor by introducing the image-forming material into a nip formed in the image-forming material.