JPH0527416A - Image transfer device with wiping roller - Google Patents

Abstract

PURPOSE:To facilitate mounting and dismounting of an image forming material and to obviate the generation of the mis-registration occurring in the image forming material by providing an image forming material affixing device for holding the image forming material on the surface of an impression cylinder and a wiping roller for bringing this material into tight contact with the surface of the impression roller. CONSTITUTION:A partly notched part 3 is provided on the impression cylinder 1 and a sheet receiving part 4 is installed in the notched part 3. A magnet sheet 5 is so installed as to cover a part of the sheet receiving part 4 and the surface of the impression cylinder in the direction reverse from the arrow of the partly notched part 3 to hold the image forming material 6 between the sheet receiving part 4, a part of the surface of the impression cylinder and the magnet sheet 5. The wiping roller 10 is brought into contact with the surface of the magnet sheet 5 holding the image forming material 6 on the surface of the impression cylinder 1. The contact position of the wiping roller 10 and the magnet sheet 5 at the time of affixing the image forming material is so set that the contact point between the wiping roller 10 and the magnet sheet 5 is brought on the surface of the impression cylinder on the side where the image forming material 6 is held.

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 sheet receiving portion provided with a forming material impregnating device 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 installed in a partially cutout portion provided on the surface of the impression cylinder, and the sheet. A magnet sheet covering the receiving portion and the surface of the impression cylinder near the sheet mounting direction of the cutout portion, and the ironing roller contacts the magnet sheet on the surface of the impression cylinder near the sheet attachment direction of the cutout portion. Is it free To provide an image transfer apparatus comprising.

The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view of an image transfer apparatus including an impression cylinder 1 for applying an image forming material and a transfer cylinder 2 for applying an image receptor such as paper. FIG. 2 shows a partially enlarged sectional 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 has a length such that its tip does not extend outside the circumferential surface of the impression cylinder 1. This is because the surface of the sheet receiving portion 4 or the transfer cylinder 2 is not damaged when the impression cylinder 1 and the transfer cylinder 2 rotate. When the image forming material is attached, the impression cylinder 1 is rotated in the direction of the arrow shown on the impression cylinder. The magnet sheet 5 is installed so as to hang over a part of the surface of the impression cylinder in the direction opposite to the arrow shown in the impression cylinder of the sheet receiving part 4 and the partial cutout part 3, and the sheet receiving part and a part of the surface of the impression cylinder. The image forming material 6 is held between it and the magnet sheet. The magnet sheet 6 may be rotatably attached via a pin joint (not shown) to the front portion of the partially cutout portion in the direction of rotation of the impression cylinder (the direction of the arrow of the impression cylinder). This is for facilitating the operation of holding the image forming material with the magnet sheet.

The sheet receiving portion 4 may be a pin bar 8 having at least one pin 7 in the axial direction of the impression cylinder (FIG. 2). The use of the pin bar 8 has the advantage of facilitating the alignment of the image forming material by fitting the pin holes provided in the image forming material into the pins of the pin bar. At this time, there is an advantage that the magnet sheet 5 is also provided with a pin hole corresponding to the pin of the pin bar, and the pin hole is fitted into the pin of the pin bar, whereby the installation position of the magnet sheet can be easily set. The sheet receiving portion 4 and the pin bar 8 are formed of a material that attracts the magnet sheet, such as iron, but the impression cylinder 1 does not necessarily have to be formed of a material that attracts the magnet sheet. By giving the magnet sheet appropriate hardness and flexibility,
The image forming material may be held on the surface of the impression cylinder by the force received by the sheet receiving portion 4.

On the surface of the impression cylinder 1, an ironing roller 10 is placed on the magnet sheet 5 holding the image forming material 6. The contact position of the ironing roller 10 and the magnet sheet 5 when the image forming material is attached is the ironing roller 10
The contact point with the magnet sheet 5 is set to the surface of the holding-side impression cylinder of the image forming material 6. When the contact point of the ironing roller 10 comes between the sheet receiving portion 4 and the surface of the impression cylinder at the time of applying the image forming material, the material is misaligned at the initial stage of applying the image forming material, which may cause misregistration. Absent. Further, the ironing roller 10 is attached to the magnet sheet 5
If it is brought into direct contact with a position where no image is formed, that is, the surface of the impression cylinder, it causes misregistration due to misalignment of the image forming material in the vertical direction or generation of wrinkles due to a raised portion of the image forming material. The contact pressure of the ironing roller 10 with the magnet sheet is appropriately adjusted by a spring or a guide (both not shown) or the like, or by its own weight. When the ironing roller 10 is not in use, it can be moved to a position away from the impression cylinder by means such as a guide rail (not shown) provided on the frame of the image transfer device. It is necessary for facilitating work or image transfer work. As the ironing roller 10, one that is covered with a heat resistant resin such as silicone rubber and that has an appropriate frictional force with the image forming material is used.

The impression cylinder 1 may be provided with another cutout portion 11 in front of the partial cutout portion 3 (in the direction of the arrow) so as to be inside the circumferential surface of the impression cylinder 1. preferable. This is to prevent the image receptor (not shown) gripping clamp 12 installed on the transfer cylinder 2 from being damaged or the surface of the impression cylinder being damaged when the impression cylinder 1 and the transfer cylinder 2 are rotated.

The operation of the image transfer device of the present invention will be described below. The upper side of the image forming material 6 is the sheet receiving portion 4.
Then, the magnet sheet 5 is placed so as to cover the sheet receiving portion 4 and the surface of the impression cylinder which is the holding side of the image forming material. By holding the image forming material with the magnet sheet, the image forming material is pressure-bonded to the sheet receiving portion or the pin bar on the surface. For this reason, the tensile force applied when the image forming material is wound around the impression cylinder is applied to the entire surface of the image forming material, and the partial expansion of the image forming material, especially the partial expansion near the pin hole is prevented. There is no misalignment, and the image forming material can be installed with high registration accuracy.

When the pin bar 8 is adopted as the sheet receiving portion 4, a pin hole of the image forming material 6 having a pin hole at a position corresponding to the pin 7 of the pin bar 8 is fitted into the pin 7.
Then, the pin hole of the magnet sheet is fitted into the pin 7.
The use of the pin bar 8 is preferable because the installation positions of the image forming material and the magnet sheet can be easily set.

After the image forming material and the magnet sheet are installed, the ironing roller 10 is brought into contact with the magnet sheet 5. Then, the impression cylinder is rotated in the direction of the arrow, and the image forming material is wound around the impression cylinder while being brought into close contact with the surface of the impression cylinder by the ironing roller, and then the lower side of the image forming material is attached to the lower side holding device. The lower side holding device is not particularly limited in its means such as an adhesive tape provided on the surface of the impression cylinder along the axial direction, or a clamp provided at another cutout portion of the impression cylinder. The adhesive tape is generally preferably used because the image-forming material adhered to the surface of the impression cylinder by the ironing roller 10 is fixed to the surface of the impression cylinder without requiring any other operation.

Since the image forming material is made of a soft material, the image forming material is lifted or the like in the vicinity of the partial cutout portion 3 and the surface of the impression cylinder in the reverse direction of the arrow shown on the impression cylinder.
By fixing this with the magnet sheet 5 and the ironing roller 10, the image forming material is evenly adhered to the surface of the impression cylinder over the entire width, so that the image forming material is wound around the impression cylinder without causing a deviation in register accuracy due to partial lifting or the like. Taken.

The image-forming material 6 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 operation with the protective film attached. To do. Then, the magnet sheet 5 is removed, the protective film is removed, and then the magnet sheet 5
Then, the image forming material having no protective film is pressure-bonded to the sheet receiving portion 4 again.

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 partially enlarged 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 5 magnet sheet 10 Ironing roller

Claims (2)

[Claims] 1. A nip between an impression cylinder and a transfer cylinder, comprising an impression cylinder to which an image forming material is attached and a transfer cylinder to which an image receptor is attached, the image being formed on a photosensitive layer of the image forming material. And an image forming material applying 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 by the transfer device. And an ironing roller for bringing the upper side holding device into close contact with the surface of the impression cylinder, and the upper side holding device is provided with a sheet receiving portion installed in a partial cutout portion provided on the surface of the impression cylinder, and the sheet receiving portion and the cutout portion A magnet sheet that covers the surface of the impression cylinder near the sheet mounting direction, and the ironing roller can contact the magnet sheet on the surface of the impression cylinder near the sheet mounting direction of the cutout portion when the image forming material is attached. Special to be Image transfer device to collect. 2. The image transfer apparatus according to claim 1,
The sheet receiving portion is a pin bar having at least one pin installed in the axial length direction of the impression cylinder in a partially cutout portion provided on the surface of the impression cylinder, and the magnet sheet is provided at a position corresponding to the pin. An image transfer device having a pin hole for holding an image forming material.