JPH0527418A - Image transfer device with tray - Google Patents

Abstract

PURPOSE:To provide the image transfer device having an image forming material affixing device which facilitates in mounting and dismounting of an image forming material and does not generate the mis-registration occurring in the image forming material. CONSTITUTION:This device has the image forming material affixing device for holding the top side and bottom side of the image forming material on the surface of an impression cylinder 1 over the entire region in the transverse direction, a tray 7 for charging the image forming material, and a wiping roller 11 for bringing the image forming material into tight contact with the surface of the impression cylinder. A top side holding device consists of a sheet receiving part 4 installed in a partly notched part 3 provided on the surface of the impression cylinder and a magnet sheet 9 holding the image forming material between the sheet receiving part and the surface of the impression cylinder near the notched part. The tray for inserting the image forming material is so disposed that the front end of the tray exists near the front end of the magnet sheet 9 on the surface of the impression cylinder at the time of affixing the image forming material. The wiping roller is so installed as to come into contact with the impression cylinder on the magnet sheet on the surface of the impression cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image transfer device. More specifically, the present invention relates to an image transfer device equipped with an image forming material affixing device that allows easy attachment and detachment of the image forming material and does not cause misregistration due to the image forming material.

[0002]

2. Description of the Related Art Recently, an image forming material in which a photosensitive layer is coated on one surface of a support is imagewise exposed, and then the image formed on the photosensitive layer is exposed to a paper or the like generally under heating. One-color or multi-color prepress proofs suitable for proof printing to be transferred to the image receptor have been prepared.

When an image receptor such as paper is heated in advance and a photosensitive layer of an image forming material is pressure-bonded to the image receptor to transfer the image formed on the photosensitive layer onto the paper, one sheet of paper is used. Four
In the case of color printing, four color images are transferred in an overlapping manner. In this case, if wrinkles or the like occur when the image forming material is attached to the impression cylinder, misalignment occurs in the images of the second and subsequent colors that are overprinted, and it is not possible to obtain a beautiful printed matter suitable for the purpose of proof printing.

The image-forming material used in the present invention comprises a support, a photosensitive layer formed on one surface of the support, and a protective film. As the support and the protective film, a thin film or sheet made of a material such as cellulose acetate, polystyrene, polyvinyl chloride, polyethylene terephthalate is used. Since the support and the protective film are made of such a soft material, they have a characteristic that wrinkles and the like are likely to occur when they are attached to the impression cylinder.

As an apparatus for producing the above-mentioned prepress proof, an impression cylinder having an image forming material attached thereto and a transfer cylinder having an image receiving member attached thereto are arranged so that the photosensitive layer of the image forming material and the image receiving member face each other. An apparatus has been generally proposed in which both cylinders are brought into contact with each other and the image formed on the photosensitive layer is transferred to an image receptor at a nip between the cylinders. In such a device, as a device for attaching an image forming material in an impression cylinder, a soft sheet-like material such as a conventional image forming material can be easily attached and detached, and wrinkles or the like are not generated,
Although there has been a strong demand for the development of a device for maintaining a high registration accuracy, a device satisfying such a demand has not yet been developed.

[0006]

SUMMARY OF THE INVENTION The present invention provides an image transfer device such as a device for making a prepress proof, in which a soft sheet-like material such as an image-forming material is excellent in register accuracy and can be attached to the sheet-like material. An object of the present invention is to provide an image transfer device equipped with an image forming material attachment device that can be easily removed.

[0007]

SUMMARY OF THE INVENTION The present invention comprises an impression cylinder having an image forming material attached thereto and a transfer cylinder having an image receptor attached thereto, and an image forming member formed on a photosensitive layer of the image forming material is provided with an impression cylinder. And a transfer cylinder for transferring the image to an image receptor, the transfer device holding the upper side and the lower side of the image forming material across the width direction on the impression cylinder surface. A forming material impregnating device, an image forming material charging tray, and an ironing roller for bringing the image forming material into close contact with the surface of the impression cylinder. The upper side holding device is a partial cutout portion provided on the surface of the impression cylinder. And a magnet sheet for holding the image forming material between the sheet receiving portion and the impression cylinder surface in the vicinity of the cutout portion, the image forming material charging tray being the tray. Of the magnet on the surface of the impression cylinder. It arranged to be positioned near the tip of the bets, ironing roller, providing the tray with the image transfer device which comprises installed to be brought into contact with the impression cylinder on the magnetic sheet on the impression cylinder surface.

The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic sectional view of an image transfer apparatus of the present invention including an impression cylinder 1 on which an image forming material is attached and a transfer cylinder 2 on which an image receptor such as paper is attached. FIG. 2 shows a partial perspective view of the impression cylinder 1. The impression cylinder 1 is partially provided with a cutout portion 3, and the sheet receiving portion 4 is installed in the cutout portion. The sheet receiving portion 4 is installed so that its tip does not extend outside the circumferential surface of the impression cylinder. This is to avoid damage to the surface of the transfer cylinder or the sheet receiving portion due to the rotation of the impression cylinder 1 and the transfer cylinder 2. As shown in FIG. 2, the sheet receiving portion 4 may be a pin bar 6 having at least one pin 5 in the axial direction of the impression cylinder 1. The pin bar 6 is preferable in that the position of the image forming material on the impression cylinder can be easily set.

The tray 7 is rotatable about a fulcrum 8, and when the image forming material is placed on the sheet receiving portion 4, the tip end of the tray 7 on the impression cylinder side is inclined toward the impression cylinder side. After the upper side of the image forming material (not shown) placed on the tray 7 is placed at a predetermined position of the sheet receiving portion 4, the image forming material is held by the magnet sheet 9. The magnet sheet 9 holds the image forming material between the sheet receiving portion 4 and the surface of the impression cylinder located in the vicinity of the partial cutout portion 3. The tip end of the magnet sheet 9 on the tray side is the pressure of the tray 7. The width should not overlap with the tip of the trunk. The sheet receiving portion 4 is formed of a material that attracts the magnet sheet 9, for example, iron, but the impression cylinder 1 does not necessarily have to be formed of a material that attracts the magnet sheet 9. The image forming material may be held on the surface of the impression cylinder by the force received by the sheet receiving portion 4 by giving the magnet sheet 9 appropriate hardness and flexibility. As shown in FIG. 2, the magnet sheet 9 has a partial cutout 3
The pin joint 10 is attached to the front part in the direction of rotation of the impression cylinder indicated by the arrow
You may install so that it can rotate via.

After holding the image forming material by the magnet sheet 9, the ironing roller 11 is brought into contact with the magnet sheet on the magnet sheet 9 on the surface of the impression cylinder. At this time, the squeezing roller 11 does not come into contact with the tray 7, but is preferably near the tray 7. If an unnecessary distance is provided between the ironing roller 11 and the tray 7,
The image forming material easily floats between the magnet sheet 9 and the tray 7 and easily causes misregistration due to wrinkles or the like. The ironing roller 11 is installed at a position away from the impression cylinder when the ironing roller is not in use by means of a roller (not shown) such as a roller provided on the shaft of the roller and a guide rail provided on the frame of the transfer device. It is preferable to keep it because the transfer operation is facilitated. The contact pressure between the ironing roller 11 and the magnet sheet 9 is appropriately adjusted by its own weight or by an elastic member such as a spring so as to prevent the image forming material from wrinkling due to the magnitude of the pressure.

The adhesive tape 12, preferably a double-sided adhesive tape, is preferably installed on the surface of the impression cylinder below the tray 7 and near the tip of the tray along the axial direction of the impression cylinder. In order to avoid damage to the attachment means such as a clamp 13 for attaching an image receptor (not shown) provided on the surface of the transfer cylinder 2 or the surface of the impression cylinder due to contact between the impression cylinder 1 and the transfer cylinder 2, It is preferable to provide another notch 14 that is recessed inward of the circumferential surface of the impression cylinder at the front of the notch 3 of the impression cylinder 1 in the arrow direction.

The ironing roller 11 is attached to the magnet sheet 9
After making contact with the top, the impression cylinder 1 is rotated in the direction of the arrow shown on the impression cylinder. The image forming material passes over the adhesive tape 12 while being brought into close contact with the surface of the impression cylinder by the ironing roller 11, and is fixed by the adhesive tape. Further, by continuing the rotation of the impression cylinder 1, an image forming material attachment means such as an adhesive tape 12 provided on the surface of the impression cylinder at the lower side of the image forming material or a clamp (not shown) provided in another notch 14 Hold by.

The operation of the image transfer apparatus of the present invention will be described below. The tray 7 is rotated about the fulcrum 8 and the tip end of the tray 7 on the impression cylinder side is inclined toward the impression cylinder side. The upper side of the image forming material placed on the tray 7 is placed at a predetermined position of the sheet receiving portion 4. Next, the magnet sheet 9 is placed near the tray 7 so that the sheet receiving portion 4 and the magnet sheet do not overlap with the tray 7.
As shown in FIG. 2, when the pin bar 6 is used as the sheet receiving portion, a pin hole is made at a position corresponding to the pin 5 of the pin bar in advance and the image forming material is set.
Then, the magnet sheet 9 is rotated to fit the pin hole 15 of the sheet into the pin 5 of the pin bar. By holding the image forming material with the magnet sheet, the image forming material is pressure-bonded to the sheet receiving portion 4 or the pin bar 6 on the surface. Therefore, the tensile force applied when the image forming material is wound around the impression cylinder 1 is applied to the entire width of the image forming material, and the partial extension of the image forming material, especially the partial extension near the pin hole is prevented. The image forming material can be installed with high registration accuracy without misalignment. Use of the pin bar 6
It is preferable in that the image forming material can be easily set at a predetermined position.

Then, the ironing roller 11 is brought into contact with the magnet sheet 9 on the surface of the impression cylinder. When the ironing roller comes into direct contact with the image forming material instead of the magnet sheet, it causes wrinkles and the like due to lifting of the image forming material, and it is not possible to obtain a beautiful printed matter with excellent registration accuracy.

The ironing roller 11 is attached to the magnet sheet 9
Then, the impression cylinder 1 is rotated in the direction of the arrow. When the adhesive tape 12 is provided, the image forming material is pressure-bonded to the adhesive tape 12. Since the image forming material is made of a soft material, the image forming material may float up near the tip of the magnet sheet. By fixing this with the adhesive tape 12, the image forming material is evenly adhered to the surface of the impression cylinder over the entire width, so that there is no deviation in the registration accuracy due to partial lifting or the like. In order to effectively prevent the tray 7 from contacting the image forming material, it is preferable to provide rolling means such as rollers on both sides of the tip.

Further, the impression cylinder 1 is rotated in the direction of the arrow, and the lower side portion of the image forming material is pressure-bonded to the adhesive tape provided in the vicinity of the other cutout portion 14 of the impression cylinder 1 in the arrow direction. Alternatively, the image forming material is held by another clamp (not shown) installed in the other cutout portion 14. The image-forming material is composed of a support, a photosensitive layer and a protective film. Generally, the material image-formed by image exposure is attached to the impression cylinder 1 by the above-mentioned operation with the protective film attached. Then, the magnet sheet 9 is removed, the protective film is removed, and then the magnet sheet 9 is installed again so that the image forming material without the protective film is pressure-bonded to the sheet receiving portion 4 or the pin bar 6.

In a multi-color, for example, four-color prepress proof, since the four-color image-forming material is transferred onto one image receptor, for example, paper, it is easy to attach and remove the image-forming material, and the registration accuracy is high. The device attached to the impression cylinder is
It is very important, and the image transfer device of the present invention meets such a demand.

[0018]

According to the present invention, there is provided an image transfer device in which an image forming material can be easily attached and detached and which can be attached to an impression cylinder with high registration accuracy.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an image transfer device.

FIG. 2 is a partial perspective view of an image attachment device for an impression cylinder.

[Explanation of symbols]

1 impression cylinder 2 transfer cylinder 3 Notch 4 sheet receiving part 6 pin bar 7 trays 9 Magnet sheet 11 Ironing roller

Claims (4)

[Claims] 1. A nip between an impression cylinder and a transfer cylinder, which comprises an impression cylinder to which an image forming material is attached and a transfer cylinder to which an image receptor is attached, for forming an image on a photosensitive layer of the image forming material. And an image forming material affixing device for holding the upper side and the lower side of the image forming material over the entire width direction on the impression cylinder surface. A material charging tray and an ironing roller for bringing the image forming material into close contact with the surface of the impression cylinder, and the upper side holding device includes a sheet receiving portion installed in a partial cutout portion provided on the surface of the impression cylinder. And a magnet sheet for holding the image forming material between the sheet receiving portion and the impression cylinder surface in the vicinity of the cutout portion, and the image forming material charging tray has a tip end of the tray when the image forming material is attached. Part on the surface of the impression cylinder An image transfer device with a tray, which is arranged so as to be located in the vicinity of the leading end of the roller and is provided with an ironing roller so as to come into contact with the impression cylinder on the magnet sheet on the surface of the impression cylinder. 2. The image transfer apparatus according to claim 1,
The upper side holding device further includes an adhesive tape provided on the surface of the impression cylinder near the tip of the magnet sheet along the axial direction, and the tip of the tray for charging the image forming material has the adhesive tape and the magnet sheet. An image transfer device with a tray, which is arranged so as to be located between and. 3. The image transfer device according to claim 1,
An image transfer device with a tray, wherein the sheet receiving portion is a pin bar having at least one pin in the axial direction of the impression cylinder, and the magnet sheet is provided with pin holes at positions corresponding to the pins. 4. The image transfer apparatus according to claim 1,
An image transfer device with a tray, wherein the tray for charging the image forming material is provided with rolling means for rolling the surface of the impression cylinder on both sides of the tray front end portion.