JPH0266552A - Image forming device - Google Patents

Abstract

PURPOSE:To facilitate the peeling off of a protecting film from an exposed image forming material and to improve picture quality by cutting the forward or backward end in the advancing direction of the protecting film of the exposed image forming material moving to a pressure barrel or the material itself in the axial direction of the pressure barrel. CONSTITUTION:The device is provided with an exposing barrel 3, an exposing light source 1 arranged outside the radial direction of the exposing barrel 3, and the pressure barrel 15 close to or in contact with the exposing barrel 3. Moreover the device is provided with a means 17 cutting the forward or backward end in the advancing direction of the protecting film 8 for the exposed image forming material 5 moving onto the pressure barrel 15, or the material itself, in the axial direction of the pressure barrel 15. The device is also provided with protecting film peeling means 19 and 21 peeling off the protecting film 8 in an image forming area cut by the cutting means 17. Thus, the peeling off of the protecting film 8 can be facilitated to produce a prepress proof, etc., continuously.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a prepress proof for color proofing by superimposing monochrome or multicolors using the difference in adhesiveness between exposed and unexposed areas of a photosensitive layer. The present invention relates to an image forming apparatus capable of forming an image suitable for use as an image forming apparatus.

More specifically, the present invention relates to an image forming apparatus that allows easy removal of a protective film from an exposed image forming material and does not impair image quality.

[Prior Art] Conventionally, in the field of printing industry, prepress blues have been used as a means for checking the finish, color tone, etc. of final printed matter before printing. There are overlay and subprint methods for this bripress proof, each of which is used depending on the purpose of use.

In the overlay method, each transparent base film is provided with a photosensitive layer corresponding to the image (color separation), an image is formed on each base film by irradiation with actinic rays and development, and then each base film is registered by visual inspection, etc. and overlap. This method has the disadvantage that the quality of the printed material is significantly different from that of actual printed matter because it is affected by the reflected light from each superimposed film.

For example, the server printing 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 toner.

The method disclosed in U.S. Patent No. 3,060,023, etc. is as follows:
This is a method in which a photosensitive layer and an image receptor are brought into close contact with each other in a two-dimensional manner under pressure, 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 plane and then peeled off, 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-uniformity in the reflection density of the transferred image results in fine periodic patterns and even fine directional patterns, resulting in a significant decrease in the accuracy of color reproduction, etc.

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 subprint 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 halftone negative are brought into close contact, exposed to light to form an image, and the unexposed areas are eluted with a mixture of soda carbonate, butyl cellosolve, and water. After drying, it can be used as an overlay proofing method.

Since a developer is used, continuous processing is difficult.

When used as a sub-print proofing method, the ink image formed on the above color sheet is placed on the image-receiving film at a temperature of 110'C, a pressure of 2 bar, and a speed of 60°C.
The image is transferred to an image-receiving film at a speed of m/min. Next, registration is performed visually or by punching on this image-receiving film, and a cyan image is transferred. The above operation is repeated in the order of magenta and yellow to obtain a color image.

The obtained color image is transferred to an image receptor, which is a transfer target. To reduce the gloss of the transferred image, a matte film is applied to complete the proofing sheet.

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 formed image becomes 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. Further, in order to obtain a normal image by one transfer, it is necessary to expose the film having the original image layer so that the film side is 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.

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 moved from the table or the like to the transfer device.

In color bluefing, images are created by repeating four colors (a turtle formation), and the registration and phase alignment of these four colors is important to maintain image quality. Conventionally, most of these registrations were done visually or by the bin method. Hole punching (using Nafilm) These methods cannot be said to be adequate methods, especially when it is desired to form a color image in a short period of time. Continuous processing is difficult.Furthermore, when the transfer to the image receptor is performed manually, the quality of the image formation depends on the operator's experience and intuition, so it is not always possible to produce good images.

The applicants of the present application have proposed Japanese Patent Application No. 63-164984 and Japanese Patent Application No. 63-164 to solve the problems of the prior art.
No. 164985 and Japanese Patent Application No. 63-164986 propose an image forming apparatus capable of forming images by superimposing monochrome or multicolor images by utilizing the difference in tackiness between exposed and unexposed areas of a photosensitive layer. Na.

For example, in the image forming apparatus proposed in Japanese Patent Application No. 63-164985, 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 exposed image forming material is attached to the exposure cylinder. The image-forming material is introduced into a nip formed by an impression cylinder and transferred onto the impression cylinder, and then, after peeling off the protective film, it is introduced into a nip formed by an exposure cylinder to which an image receptor is attached and an impression cylinder. This device presses the image formed on the photosensitive layer onto the image receptor using nip pressure.

According to the above-mentioned proposed device, it is possible to provide a bristle press blue or a small amount of printed matter with almost the same texture as the actual printed matter and excellent color reproduction accuracy in one transfer, and exposure and transfer can be performed uniformly and easily. An image forming apparatus is provided.

[Problems to be Solved by the Invention] However, even in the above-mentioned image forming apparatus, in order to easily implement the protective film ill M on the impression cylinder, a specific method is required for applying the image forming material to the impression cylinder. It was necessary to use a protective film with a half cut in advance.

Furthermore, depending on the skill level of the protective film removal operation, wrinkles may appear in the photosensitive layer, resulting in a problem of deterioration of image quality.

The present invention solves the above problems and provides an image forming apparatus in which a protective film can be easily peeled off.

Further, the present invention provides an image forming apparatus that can continuously create prepress blueprints and the like, and can provide uniform and good image quality regardless of the level of skill of the operator.

[Means for Solving the Problems] The image forming apparatus of the present invention comprises a support, a photosensitive layer formed on one surface of the support, and a protective film provided on 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 a part or all of the unexposed area to an image receptor, the apparatus comprising an exposure cylinder, and disposed outside the exposure cylinder in the radial direction. an exposure light source, an impression cylinder that is close to or in contact with the exposure cylinder, and a protective film of the exposed image-forming material transferred onto the impression cylinder, or the image-forming material near the front end in the traveling direction of the image-forming material; The apparatus includes means for cutting the impression cylinder in the axial direction near the front end and near the rear end.

Furthermore, the image forming apparatus of the present invention is an apparatus further comprising a protective film peeling means for peeling off the protective film of the image forming area cut by the cutting means.

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 may be used as long as it can cure the photosensitive layer corresponding to the U-clamp 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 applying means for adhering the image forming material to the exposure cylinder is a means for suctioning and fixing the material by providing a large number of holes, grooves, etc. for a vacuum means in the material applying area of the cylinder. , means for fixing with double-sided adhesive tape, means for fixing using static electricity, means for attaching a clamp bar along the axial direction of the exposure cylinder and fixing with said bar, gripper cylinders used in impression cylinders and intermediate cylinders of printing presses, etc. Any means can be used as long as it can fix the material on the surface of the image forming material on the surface of the impression cylinder. The structure must be such that when the material is held, it can 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. In addition, it is preferable that the attachment means also include a bin bar or the like in order to accurately position the image forming material on the exposure cylinder and the impression cylinder and to ensure proper registration and phase alignment. A plurality of small-diameter rolls may be arranged near the outer circumferential surface to bring the image forming material and/or image receptor into close contact with the cylinder surface, and to rub the image forming material and/or the image receptor by ε to prevent the occurrence of wrinkles and the like.

The image forming material holding means for holding the exposed image forming material placed on the impression cylinder is a 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 a double-sided adhesive. Any means capable of fixing the image forming material to the impression cylinder, such as fixing with tape or electrostatic means, may be used. 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.

The image forming apparatus of the present invention further includes an image receptor attaching means for attaching an image receptor to the exposure cylinder, and the image-exposed photosensitive layer on the impression cylinder is transferred to the attached image receptor by the means. It's okay. 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. Alternatively, a transfer cylinder may be provided that can freely contact the impression cylinder, and the image-exposed photosensitive layer may be transferred to an image receptor attached to the transfer cylinder.

In the image forming apparatus of the present invention, a common transfer cylinder having a radius larger than that of an exposure cylinder and an impression cylinder is provided on the impression cylinder side, a plurality of combinations of exposure cylinders and impression cylinders are arranged around the common transfer cylinder, and a plurality of combinations of exposure cylinders and impression cylinders are arranged around the common transfer cylinder. It can also be applied to a device for transferring an image-exposed photosensitive layer on an impression cylinder to an attached image receptor.

The image forming apparatus of the present invention transfers the protective film of the exposed image forming material transferred from the exposure cylinder onto the impression cylinder or the image forming material near the front end in the traveling direction of the image forming material, or near the front end and the rear end of the image forming material. This device is equipped with means for cutting in the axial direction of the impression cylinder near the section.

When the protective film is cut near its ends, the protective film generally rises in the tangential direction of the impression cylinder, making it easier to separate the protective film from the image forming material. Also, cutting the vicinity of the end of the protective film held by the holding means of the impression cylinder, such as a gripping claw,
Next, the gripping claw may be configured to move inward or outward of the impression cylinder to help lift the edge of the remaining portion of the protective film.

The means for cutting the protective film in the axial direction may be such as to cut along the axis of the impression cylinder when the rotation of the impression cylinder is stopped, or along the axis of the impression cylinder when cutting is performed while the impression cylinder is rotating. The cutting direction may be inclined in accordance with the circumferential speed of the cylinder.

The cut portion of the protective film may be near the front end in the direction of movement of the image forming material, or near the front end and near the rear end. If both are gripping claws, cut near the front end and near the rear end. When the holding means of the impression cylinder is an adhesive tape for both the front end and the rear end of the image forming material, the protective film is cut within the area held by the adhesive tape. There is no need to cut the protective film near the rear end.

The imaging material may also be cut. For example, when the holding means of the impression cylinder has holes or the like over the entire holding area of the image forming material, the image forming material is sucked from the applicant. In this case, the suction force is adjusted so that the suction force against the support is greater than the adhesive force between the protective film and the photosensitive layer.

Further, it is preferable to appropriately select the material of the protective film, the support, or the material of the photosensitive layer so that the adhesive force between the photosensitive layer and the protective crotch is weaker than the adhesive force between the photosensitive layer and the support. A release treatment may be applied to the surface of the protective film.

The image forming apparatus of the present invention may further include a protective film peeling means for peeling off the protective film of the image forming area cut by the cutting means.

Peeling off of the protective film, depending on the type of holding means for the impression cylinder, may in some cases reduce the quality of the image, which does not cause wrinkles or the like on the photosensitive layer on the support.

The protective film peeling means installs a roll that can rotate freely and move forward and backward along the circumference of the impression cylinder, attaches a cut protective film with raised ends to the roll, and rotates the roll to protect the film. This is a device that moves the membrane along its circumference while winding it up. The protective film may be attached to the roll by attaching double-sided adhesive tape to the roll and bringing the roll into contact with the cut protective film.

Another method for removing the protective film is to set the center of rotation eccentrically from the axis of the impression cylinder on both sides of the impression cylinder so that when the cylinder is swung, the tip approaches the circumferential surface of the impression cylinder on one side of the swing. A swing arm is installed on the swing arm, and the impression cylinder has a swing arm that projects from the tip of the swing arm in the direction of rotation of the impression cylinder, and whose protruding tip is inclined so that it is almost flush with the circumferential surface of the impression cylinder when it comes into contact with the impression cylinder. It is also possible to provide a bar extending in the longitudinal direction of the axis of the bar and attach temporary adhesive means such as adhesive tape to the tip of the bar on the compression side. The protective film with the cut ends raised is attached to the temporary adhesive means, and the swing arm is then swung in a direction opposite to the direction of rotation of the impression cylinder to peel off the protective film.

Further, the rotation center of the swing arm may be made to coincide with the rotation center of the axis, and in this case, a bar provided at the tip of the swing arm is installed so as to be able to rotate toward the circumferential surface of the impression cylinder.

It is preferable that the protective film be peeled off at an acute angle to the surface of the protective film, and in order to control the peeling angle to be constant, a guide plate may be installed between the tip of the swing arm and the circumferential surface of the impression cylinder.

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 drum surface in the image receptor attachment area is 50 to 150°C, preferably 60 to 1
The temperature is about 10°C.

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 blue or printed matter, the original image used in the present invention is a film made for a single color (image mask) or a transparent polyethylene terephthalate film with functions such as color separation, with light-shielding paper fixed. The image mask may be a color-separated image mask if a multicolored color proof or print is to be obtained.

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,
Films or sheets made of polyethylene terephthalate, polycarbonate, 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 an appropriate oil-repellent substance. Examples of the bowl oil-based substance include silicone resins and fluororesins.

The photosensitive layer consists of (a) a photopolymerizable compound and a coloring agent, (b) a photopolymerizable compound, a thermoplastic resin, a colorant, etc., and further contains a photopolymerization initiator, a thermal polymerization inhibitor, 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 the photopolymerizable compound 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 hues of yellow, magenta, cyan, and black are desirable, and metal powders, white pigments, fluorescent pigments, etc. can also be used.

For color proofing, there are yellow, red, indigo, and ink, and pigments or dyes that match these hues can be selected and used.

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

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.

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, an impression cylinder, a cutting means, and a peeling means. 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 exposure cylinder is provided with a gripper 11 for attaching an image forming material in a concave portion 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. The original may be peeled from the exposure f& stack and then introduced into the nip.

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. The protective film 8 of the image forming material is cut in the axial direction of the impression cylinder by a cutter 17 near the gripping claw 12 side. When cutting with a cutter with the impression cylinder stopped, the cutting direction may be along the axis of the impression cylinder; when cutting with a cutter while the impression cylinder continues to rotate, the cutting direction may be tilted in accordance with the circumferential speed of the impression cylinder. Just let it happen. Then, by rotating the gripper by swinging the arm, the remaining end of the protective film is lifted up.

The impression cylinder was further rotated, and the raised end of the protective film reached the starting point of the bar 21 to which the double-sided adhesive tape was attached, which was attached to the tip of the swing arm 19, which was installed with the rotation center eccentric from the axis of the impression cylinder. At this time, the bar is moved in the direction of rotation of the impression cylinder (clockwise in the diagram) to contact the protective film, and then the bar is swung in the direction opposite to the rotation direction of the impression cylinder (counterclockwise in the diagram) to protect the film. Separate the membrane. At this time, the guide plate 22 functions to control the peeling angle of the protective film within a predetermined range. 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 an arm-equipped gripper 12 and an adhesive tape 13.

The protective 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 second knob 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) are provided in the image receptor application area during the exposure period.The exposure cylinder is preferably further rotated and the transferred image is post-exposed by a U-lamp.

FIG. 2 is a plan view of a cutter showing an embodiment of the cutting means of the present invention, FIG. 3 is a partially enlarged plan view showing the operation of the cutter, and FIG. 4 is a front view of the cutter. The cutter 17 is fixed to the cutter base 23, and the cutter base is attached to the base guide shaft 23.
It is movably attached to a pedestal 25 which is slidably attached to the pedestal 25. Two pulleys 27 are installed at both ends of the pedestal guide shaft, a wire 31 is stretched across the pulleys, and the pedestal 25 is fixed to one of the wires. By rotating the pulley 27 in the normal and reverse directions, the wire is reciprocated, and along with the reciprocation, the pedestal 25 is also reciprocated. As shown in FIG. 3, the cutter stand 23 is fixed to the stand 1iffi 25 by a shaft 33, one end of the spring 35 is fixed to the cutter stand, and one end of the spring 35 is fixed to the stand. As shown in FIG.
The cutter base 23 is installed so that it comes into contact with the cutter base 37 when the cutter base 5 moves in the direction of the pulley 27 or 291.

When the base 25 moves to the pulley 27 side, the cutter base 2
3 comes into contact with the attachment 37, and the cutter table is pushed up by the attachment, and the cutter table is in an upright state.
5 is maintained. Next, when the base 25 moves toward the 1-lie 29 side, the cutter base comes into contact with the ate, and the cutter base is in a lying state, and this state is maintained by the spring.

By providing the cutting means as described above, it is possible to cut only the protective film of the image forming material or the image forming material. Further, the cutting edge of the cutter may be a rotating blade, and its shape can be arbitrarily selected.

[Effects of the Invention] According to the present invention, color proofs having the same quality as 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 performed continuously, and registration is easy. Therefore, it has the remarkable effect that stable images 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 often thicker than the support and has poor light transmittance.

According to the present invention, since light is exposed from the support side, there is little diffusion or scattering of light, and therefore it is possible to provide a good prepress blue or printed matter.

According to the present invention, it is relatively easy to register the image forming material and the image receptor by attaching them to the exposure cylinder,
Therefore, color proofs or printed matter without misregistration can be provided.

According to the present invention, by providing the protective film or the image forming material cutting means near the impression cylinder, an apparatus is provided that can easily peel off the protective film without making a half cut in the protective film in advance.

According to the present invention, by providing a protective film peeling means in the vicinity of the impression cylinder, there is provided an apparatus that can prevent image quality from deteriorating due to the quality of the protective film peeling operation.

[Brief explanation of the drawing]

The first section is a schematic side view of the image forming apparatus of the present invention,
2 is a plan view showing the cutting means of the present invention, and FIG. 3 is a partially enlarged plan view of the cutting means 1. FIG. 4 is a front view of the cutting means and a side view showing a half-cut state of the edge of the protective film. 1...UV lamp 5...Image forming material 9...Original picture 17...Cutter 19...Swing arm

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 side of the support is used as an original image. In a device that performs image exposure by laminating a photosensitive drum and transferring a part or all of the unexposed area to an image receptor, the device includes an exposure cylinder, an exposure light source disposed radially outside of the exposure cylinder, and an exposure cylinder. impression cylinders in close proximity or contact;
and the protective film of the exposed image forming material transferred onto the impression cylinder or the image forming material in the axial direction of the impression cylinder near the front end in the traveling direction of the image forming material, or near the front end and near the rear end. An image forming apparatus comprising a cutting means. 2. The image forming apparatus according to claim 1, further comprising a protective film peeling means for peeling off the protective film of the image forming area cut by the cutting means. 3. The apparatus according to claim 2, wherein the protective film peeling means is a roll that freely moves forward and backward and rotatably in the circumferential direction of the impression cylinder. 4. The protective film peeling means comprises a swing arm that swings forward and backward in the circumferential direction of the impression cylinder, and a bar having protective film temporary adhesion means attached to the tip of the swing arm. Device.