JPH0786690B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is capable of forming an image by superimposing a single color or multiple colors utilizing the difference in the adhesiveness between the exposed and unexposed portions of the photosensitive layer, Further, the present invention relates to an image forming apparatus capable of forming an image suitable for a color press prepress proof or the like. More specifically, it relates to an image forming apparatus capable of easily peeling off a protective film of an exposed image forming material on an exposure cylinder.

[Prior Art] Conventionally, in the printing industry, a prepress proof has been used as a means for confirming the finish, color tone and the like of a final printed matter before printing. This prepress proof has an overlay method and a surprint method, and they are used properly according to the purpose of use.

In the overlay method, each transparent base film is provided with a photosensitive layer corresponding to each color separation (color separation) image, an image is formed on each base film by irradiation with active light and development, and then each base film is visually registered. And stack them. This method is affected by the reflected light from the superposed films, and thus has a drawback that the texture is significantly different from the actual printed matter.

The surprint method is, for example, US Pat.
As disclosed in Nos. 060024 and 3060025, a plurality of images formed on each photosensitive layer corresponding to each color separation image are sequentially transferred to a single image receptor to obtain a prepress proof. To form. Each photosensitive layer may be colored corresponding to each color-separated image, or each transferred image may be colored with powder color toner.

The system disclosed in U.S. Pat. No. 3060023 and the like is a system in which the photosensitive layer and the image receptor are planarly pressed and brought into close contact with each other, heated, and then peeled off. In this method, in which the photosensitive layer and the image receptor are planarly pressure-bonded and then peeled off, the reproduction of the transferred image becomes unstable unless the working conditions such as the peeling speed and direction are constant, and the transferred image Unevenness in reflection density, fine periodic patterns, and fine patterns with fine directionality are generated, and accuracy of color reproduction and the like is significantly reduced.

JP-A-59-97140 and JP-A-61-188537,
It discloses a proofing method applicable to both the overlay method and the surprint method. This proofing system prepares a color sheet 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 in which an image receiving layer and a protective film are laminated on a polyester support. The emulsion surface of the color sheet and the halftone negative image are brought into close contact with each other, exposed to form an image, and the unexposed portion is eluted with a mixed solution of sodium carbonate, butyl cellosolve and water. After drying, it can be used as overlay proofing. Since a developer is used, it is difficult to make it continuous.

In the case of use as a surprint proofing, the black image formed on the color sheet on the image receiving film is transferred to the image receiving film under the conditions of a temperature of 110 ° C., a pressure of 2 bar and a speed of 60 cm / min. Then, the image-receiving film is visually or punched to be registered, 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 mattized film is applied to complete the proofing sheet.

In the above method, the original image layer formed on the film on the protective film side of the color sheet is laminated so that the original image layer is in contact with the protective film, and exposed. After the exposure, the protective film is peeled off, and the image is formed by pressing it on the image receptor. Therefore, the formed image becomes a reverse image, and therefore it is necessary to transfer it again in order 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 and it is difficult to obtain an image with high accuracy. 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 becomes large and the image quality is deteriorated.

Simple proofing in which an image forming material having a photosensitive layer is used and transferred by a relief proof printing machine is also well known. That is,
This is a system in which an image receptor is placed on a paper platen of a proof printing machine, an exposed color sheet is held on an impression cylinder, and transferred while rotating the impression cylinder.

In any of the above methods, image exposure and transfer are
The image forming material and the original image are fixed and exposed on a table or the like by using a register pin or the like, and then transferred from the table or the like to a transfer device by hand.

In color proof, images are formed by repeating four colors, and registering and phase matching in the four colors are important for maintaining image quality. Conventionally, most of these registrations are made by a visual or pin type perforated film. It is difficult to say that these methods are sufficiently applicable, especially when it is desired to form a color image in a short time. That is, it is difficult to continuously perform each process such as exposure and transfer. Further, when the transfer to the image receptor is a manual method, the quality of the image formation depends on the experience and intuition of the operator, so that a good image cannot always be obtained.

The applicant of the present invention has disclosed that, in order to solve the problems of the prior art, in Japanese Patent Application No. 63-164987, Japanese Patent Application No. 63-164988, and Japanese Patent Application No. 63-164989, exposed and unexposed parts of a photosensitive layer are An image forming apparatus capable of forming an image by superimposing a single color or multiple colors utilizing the difference in adhesiveness between the two has been proposed.

For example, in the image forming apparatus proposed in Japanese Patent Application No. 63-164987, the light source for exposure is arranged on the inner side in the radial direction of the exposure cylinder formed of a light transmissive material, and the original image, the support and the photosensitive layer are formed on the exposure cylinder. This is a device in which protective films are laminated in this order, the protective film is peeled off after image exposure from the exposure cylinder side, and then the photosensitive layer is pressed onto the image receptor held by the transfer cylinder by nip pressure.

According to the above-mentioned proposed apparatus, it is possible to provide a prepress proof or a small amount of printed matter, which has substantially the same texture as that of the actual printed matter and is excellent in color reproduction accuracy, in a single transfer, and the image can be uniformly exposed and transferred. A forming device is provided.

[Problems to be Solved by the Invention] However, even in the above-mentioned image forming apparatus, in order to easily carry out the peeling of the protective film of the image-formed image forming material on the exposure cylinder, the image forming in the exposure cylinder is performed. It was necessary to use a particular material or a means for attaching the original image, or to use a protective film with a half cut beforehand. In addition, there is a problem that the photosensitive layer is wrinkled depending on the skill of the work of peeling off the protective film, and the image quality is deteriorated.

The present invention solves the above problems and provides an image forming apparatus in which peeling of a protective film is facilitated.

Further, the present invention provides an image forming apparatus capable of continuously producing a prepress proof and the like and capable of easily peeling off a protective film of an image forming material without being influenced by the skill of an operator.

[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 provided on the photosensitive layer side of the support. In an apparatus for image-exposing an image-forming material consisting of and an image to be exposed, and transferring a part or all of the unexposed portion to an image receptor, the apparatus has a cylindrical shape formed of a light-transmitting material or Semi-cylindrical exposure cylinder, exposure light source arranged inside or outside the exposure cylinder in a radial direction, transfer cylinder in proximity to or in contact with the exposure cylinder, and protective film or image of exposed image forming material on the exposure cylinder The apparatus is provided with a means for cutting the forming material in the axial direction of the exposure cylinder at the front end portion in the traveling direction of the image forming material or near the front end portion and the rear end portion in the traveling direction.

The apparatus of the present invention is an apparatus provided with a protective film peeling unit that peels the protective film of the image forming material cut by the cutting unit.

As the image forming material, various image forming materials such as a material for a dry method for forming an image by peeling development can be used. A material for a dry method by peeling development is preferable because the operation is simple and the operation can be 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 non-image area such as a UV lamp.

The exposure cylinder is preferably made of a material such as glass or acrylic resin that has excellent light transmittance and is stable against heat and the like. The exposure cylinder may be cylindrical or semi-cylindrical. When the exposure cylinder is cylindrical, the exposure light source is placed inside the exposure cylinder in the radial direction, and when it is semi-cylindrical, it is installed inside or outside the exposure cylinder in the radial direction. .

The transfer cylinder is preferably installed so that it can be brought into contact with the exposure cylinder and that the nip pressure between the transfer cylinder and the exposure cylinder can be adjusted. The transfer cylinder may be coated with an elastic material such as rubber in order to facilitate transfer of the image formed on the photosensitive layer of the image forming material held on the transfer cylinder to the image receptor.

The image forming material impregnating means installed on the exposure cylinder is provided with a large number of holes or grooves for vacuuming means in the material impregnating region of the cylinder or a part thereof, for example, a peripheral portion of the material impregnating region, to suck and fix the material A means for fixing the material on the surface of the exposure drum, such as a means for fixing, a means for fixing with double-sided adhesive tape, a means for fixing with static electricity, a means for mounting a plurality of clamps along the axial direction of the exposure cylinder, and a means for fixing with the clamps. Any means can be adopted if it exists. When a clamp or the like is used as the attachment means, the means is installed in a recess provided on the surface of the exposure cylinder, or a recess is provided in a portion of the transfer cylinder that comes into contact with the clamp, or the transfer cylinder is partially cut off in the tangential direction. The shape is preferable because it does not damage the surface of the body. Further, in the attachment means, the image forming material is accurately aligned and registered on the exposure cylinder and the transfer cylinder,
It is preferable that a pin bar or the like is also provided in parallel in order to ensure proper phase alignment.

The image receptor holding means installed on the transfer cylinder includes means for opening a large number of holes or the like in the area for holding the image receptor, means for sucking and fixing the receptor, means for fixing with a double-sided adhesive tape or static electricity, clamp, etc. Any means that can fix the body to the transfer cylinder may be used, but a pin bar or the like may be used to accurately align the image forming material with the image receptor and the phase matching when producing a color proof or the like. It is preferable to place them side by side. Further, a plurality of small-diameter rolls may be arranged in the vicinity of the outer peripheral surface of the transfer drum to bring the image receptor into close contact with the drum surface to prevent wrinkles and the like from occurring.

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

The image forming apparatus of the present invention includes a protective film of the exposed image forming material on the exposure cylinder or the image forming material, in the vicinity of the front end portion in the traveling direction of the image forming material, or in the vicinity of the front end portion and the rear end portion. The device is provided with a means for cutting in the axial direction of the impression cylinder.

When the protective film is cut in the vicinity of its end, the protective film generally floats in the tangential direction of the exposure cylinder, and the protective film is easily separated from the image forming material. Also, by cutting the vicinity of the end of the protective film gripped by the attachment means of the exposure cylinder, for example, the gripper, and then arranging the gripper to move inward or outward of the impression cylinder, You may make it promote the floating of the edge of the remaining part.

The means for cutting the protective film in the axial direction may cut along the axis of the exposure cylinder when the rotation of the exposure cylinder is stopped, and the exposure may be performed when cutting while rotating the exposure cylinder. The cutting direction may be inclined according to the peripheral speed of the body.

The cut portion of the protective film may be in the vicinity of the front end portion in the traveling direction of the image forming material, or in the vicinity of the front end portion and in the vicinity of the rear end portion. For example, when the image forming material adhering means of the exposure cylinder is a gripper at both the front end and the rear end, cutting is performed near the front end and the rear end. When both the front end and the rear end of the image forming material are adhesive tapes as the attachment means of the exposure cylinder, the protective film is cut in the region held by the adhesive tapes. It is not necessary to cut the protective film near the rear end. The image forming material may be cut. For example, this is the case where the attachment means of the exposure cylinder is provided with a hole or the like over the entire attachment area of the image forming material and sucks through the hole. In this case, the suction force is adjusted so that the suction force on the support is larger than the adhesive force between the protective film and the photosensitive layer.

In order to facilitate the separation of the protective film on the surface of the exposure cylinder, the protective film, the material of the support or the protective film should be made 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 photosensitive layer. Release treatment may be performed on the surface of the protective film.

The image forming apparatus of the present invention may further include a protective film peeling unit that peels the protective film in the image forming region cut by the cutting unit.

The peeling of the protective film depends on the type of attachment means of the exposure drum,
In some cases, the photosensitive layer on the support may be wrinkled to deteriorate the image quality. The protective film peeling means is provided with a roll that moves rotatably and reciprocally along the circumference of the exposure cylinder, so that a protective film cut on the roll and the end of which is lifted is attached, and the roll is protected by rotation. It is a device that moves the film along the circumference while winding it. A double-sided adhesive tape may be attached to the roll, and the protective film may be attached to the roll by bringing the roll into contact with the cut protective film.

As another protective film peeling means, the center of rotation is eccentric from the axis of the exposure drum on both side surfaces of the exposure drum so that the tip end approaches the circumferential surface of the exposure drum on one side of the swing when swinging. A swing arm is installed on the swing arm, and the swing arm is protruded at the tip of the swing arm in the direction of rotation of the exposure cylinder, and the protruding tip is inclined so as to be substantially the same as the circumferential surface of the exposure cylinder when contacting the exposure cylinder. It is also possible to provide a bar extending in the axial direction and to attach a temporary bonding means such as an adhesive tape to the tip end of the bar on the exposure drum side. A protective film, which is cut and whose end is lifted up, is attached to the temporary bonding means, and then the swing arm is swung in the direction opposite to the rotation direction of the exposure cylinder to peel off the protective film. Further, the center of rotation of the swing arm may be aligned with the center of rotation of the shaft, and at this time, a bar provided at the tip of the swing arm is installed so as to be rotatable on the circumferential surface side of the exposure drum.

The protective film is preferably peeled off at an acute angle with respect to the protective film surface, and in order to control the peeling angle constant, a guide plate may be installed between the tip end of the swing arm and the circumferential surface of the exposure drum.

It is preferable to provide heating means in the image receptor holding region of the transfer cylinder so that the image receptor can be heated to an appropriate temperature. This is because the transfer of the exposed photosensitive layer to the image receptor is smoothed, the transfer speed is improved, and the precision of reproducing a fine image is improved. The temperature of the body surface in the image receptor-attached region is 50 to 150 ° C, preferably about 60 to 110 ° C.

When it is necessary to perform post-exposure to increase the film strength of the image transferred to the image receptor, a light source installed inside the exposure cylinder or a light source installed outside the transfer cylinder in the radial direction is used. Exposure may be performed.

As the support, a material which is stable to heat, chemicals, light and the like and which transmits actinic rays is preferable. For example, cellulose acetate, polystyrene, polyvinyl chloride,
The film or sheet is made of polyethylene terephthalate, polycarbonate, polyimide, polypropylene or the like. In particular, a polyethylene terephthalate film or sheet is preferable because it is excellent in transparency, heat stability and dimensional stability.

These supports may be used as they are, or may be subjected to release treatment with an appropriate oil-repellent substance. Examples of the oil repellent substance include silicon resin and fluorine resin.

The photosensitive layer comprises (a) a photopolymerizable compound and a colorant, (b) a photopolymerizable compound, a thermoplastic resin and a colorant, and the like, and further includes a photopolymerization initiator, a thermal polymerization inhibitor, etc. You may use together.

As the photopolymerizable compound, at least one selected from monomers, oligomers and prepolymers is used.
A compound capable of plasticizing a thermoplastic resin at room temperature is preferable.

As the thermoplastic resin (organic polymer binder), a polymer which is thermoplastic and has no compatibility with the photopolymerizable compound and which does not have photopolymerizability can be used.

As the dye and / or pigment contained in the photosensitive layer, those known in the related art can be used. In general,
Dyes and pigments having hues of yellow, magenta, cyan, and black are desirable, and in addition, metal powder, white pigment, fluorescent pigment, and the like can be used. For color proof, yellow,
There are red, indigo, and black ink, and pigments or dyes matching these hues can be selected and used.

The film thickness of the photosensitive layer may be about 0.5 to 5 μm, and an appropriate coating amount varies depending on the dye and / or pigment contained, but 0.5 to 10 g / m ² is suitable.

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 releasing property of the polyethylene film itself may be used, or a releasing agent such as a fluorine resin or a silicone resin may be applied. It is preferable that the protective film is colored black or the like in order to prevent reflection of light from the exposure light source.

The image receptor used in the present invention includes art paper, coated paper,
Any base material such as high-quality paper and film can be appropriately selected.

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 including an exposure light source, an exposure cylinder, a transfer cylinder, a cutting means and a peeling means.

A laminate 11 in which the UV lamp 1 is arranged on the inner side in the radial direction of the exposure cylinder 3, and the image forming material 7 and the original image 9 are laminated on the exposure cylinder 3 in this order from the outer side with the protective film (black sheet) 5 side as the outer side.
To expose. A clamp 13 is provided on the surface of the exposure cylinder 3, and the laminate 11 is brought into close contact with the surface of the exposure cylinder by the clamp.

After the image exposure, the exposure cylinder is rotated to move the position of the image forming material, and the protective film of the image forming material held by the clamp 13 is cut by the cutter 15 near the clamp at the front end and the rear end in the rotation direction.
Is moved in the axial direction of the exposure cylinder and cut. When the protective film is cut while rotating the exposure cylinder, the cutter may be installed so that the moving direction of the cutter is inclined from the axis of the exposure cylinder.

After cutting the protective film, the exposure drum is rotated, and the front end of the cut protective film is a bar with a double-sided adhesive tape attached to the tip of the swing arm 16 installed with the center of rotation eccentric from the axis of the exposure drum. When the start point of 17 is reached, swing arm 16
Move the bar 17 in the direction of rotation of the exposure cylinder (clockwise in the figure) to contact the protective film, and then swing the bar in the direction opposite to the direction of rotation of the exposure cylinder (counterclockwise in the figure). , Separate the protective film. At this time, the exposure cylinder may be stopped, but peeling while rotating the exposure cylinder is preferable because the protective film can be rapidly peeled off. Guide plate 18
Has the function of controlling the peeling angle of the protective film within a predetermined range.

After peeling off the protective film 5, the exposure cylinder is rotated to transfer the image forming material 7 and the original image 9 with the exposed photosensitive layer to the exposure cylinder 3 and the transfer cylinder.
Introduced into the nip formed from 19 and.

The transfer cylinder 19 has a shape in which a part of the exposure cylinder that comes into contact with the clamp 13 is partially cut off in the tangential direction to eliminate contact between the clamp and the transfer cylinder at the nip. An image receptor 23 is held on the transfer cylinder by a double-sided adhesive tape 21. The image-forming material with the photosensitive layer exposed on the surface was introduced into the nip formed between the exposure cylinder and the transfer cylinder by rotation of the exposure cylinder and pressure-bonded to the image receptor 23 to form the photosensitive layer. Transfer the image to the image receiver. The transfer cylinder preferably releases contact with the exposure cylinder after the transfer is completed. It is preferable to provide a heating means (not shown) in the image receptor holding area of the transfer cylinder. UV inside the exposure cylinder is rotated by further rotating the transfer cylinder.
The transferred image is post-exposed by the lamp.

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 15 is fixed to the cutter base 24, and the cutter base is movably attached to a base 26 slidably attached to a base guide shaft 25. Pulleys 27 and 29 are installed at both ends of the pedestal guide shaft, a wire 31 is stretched around the pulley, and the pedestal 26 is fixed to one of the wires. By rotating the pulley 27 forward and backward, the wire is reciprocated, and the pedestal 26 is also reciprocated.
As shown in FIG. 3, the cutter base 24 is axially attached to the base 26 by the shaft 33, and one end of the spring 35 is fixed to the cutter base and the other end is fixed to the base. As shown in FIG. 4, an attestation 37 is installed on each of the pulleys 27 and 29 so that the cutter table 24 contacts the attestation 37 when the pedestal 26 moves to the pulley 27 or 29 side. To do.

When the pedestal 26 moves to the pulley 27 side, the cutter table 24 comes into contact with the ates 37 and is pushed up by the ates to raise the cutter table, and this state is maintained by the spring 35. Then, when the pedestal 26 moves to the pulley 29 side,
The cutter table comes into contact with the sword, and the cutter table is laid down. This state is maintained by the spring.

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

[Effect 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 easily, quickly, and stably, particularly in a surprint method using a printing paper.

The present invention can be applied not only to the overlay method, but also to printing a small number of copies of several hundreds.

According to the present invention, the quality of the transferred image obtained is good, a normal image can be obtained by one transfer, exposure-transfer (further, post-exposure) can be continuously carried out, and registration is easy. Therefore, there is a remarkable effect that a stable image can be obtained without depending on the experience and intuition of an expert.

In the image forming material composed of support / photosensitive layer / protective film, the thickness of the protective film is thicker than that of the support, and the light transmittance is often poor.

According to the present invention, since light is exposed from the support side, light is less diffused and scattered, and therefore a good prepress proof or printed matter can be provided.

According to the present invention, since the exposure cylinder and the transfer cylinder, which are light-transmissive, are the main components, a small space is required and the structure of the apparatus is relatively simple.

According to the present invention, by providing the protective film or the image forming material cutting means in the vicinity of the impression cylinder, there is provided an apparatus capable of easily peeling the protective film without preliminarily putting a half cut on the protective film.

According to the present invention, by providing the protective film peeling means in the vicinity of the impression cylinder, there is provided an apparatus capable of preventing the deterioration of the image quality due to the quality of the protective film peeling operation.

[Brief description of drawings]

FIG. 1 is a schematic side view of an image forming apparatus of the present invention,
2 is a schematic plan view showing the cutting means of the present invention, FIG. 3 is a partially enlarged plan view of the cutting means, and FIG. 4 is a schematic front view of the cutting means. DESCRIPTION OF SYMBOLS 1 ... UV lamp, 3 ... Exposure cylinder 5 ... Protective film, 7 ... Image forming material 9 ... Original image, 15 ... Cutter 16 ... Swing arm, 17 ... Bar 19 ... Transfer cylinder, 23 ... Image receptor

Claims (4)

[Claims] 1. An image forming material comprising 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 is laminated with an original image. Of a cylindrical or semi-cylindrical exposure cylinder formed by a light-transmissive material, and a radius of the exposure cylinder A light source for exposure disposed inside or outside in the direction, a transfer cylinder in proximity to or in contact with the exposure cylinder, and a protective film of the exposed image-forming material on the exposure cylinder or the image-forming material at the front end portion in the traveling direction of the image-forming material. Alternatively, the image forming apparatus is provided with means for cutting in the axial direction of the exposure cylinder near the front end and the rear end in the traveling direction. 2. The image forming apparatus according to claim 1, further comprising a protective film peeling unit that peels off the protective film in the image forming region cut by the cutting unit. 3. The protective film peeling means is a roll which is rotatable and movable in the circumferential direction of the exposure drum.
The image forming apparatus described. 4. The protective film peeling means comprises a swing arm that swings back and forth in the circumferential direction of the exposure drum, and a bar having a protective film temporary adhering means attached to the tip of the swing arm. 2. The image forming apparatus according to 2.