JPH0524357A - Image transfer device with heating device - Google Patents

Abstract

PURPOSE:To uniformize the temp. distribution over the surface of a transfer cylinder by forming a thin aluminum plate on the surface thereof and mounting a plane heater inside the transfer cylinder in an image transfer device adapted to transfer the image of an image forming material formed on a photosensitive layer onto an image receiver by a nip provided on the side of an impression cylinder and the transfer cylinder. CONSTITUTION:The image transfer device is provided with an impression cylinder (not shown) having an image forming material attached thereto and a transfer cylinder 2 having an image receiver (not shown) attached thereto and the image formed on a photosensitive layer of the image forming material by the image exposure is transferred onto the image receiver under heat by a nip formed between the impression cylinder and the transfer cylinder 2, In such an image transfer device, a thin aluminum plate 9 is provided on the surface of the transfer cylinder 2 to eliminate the out-of-register due to the surface irregularities of the image receiver and form a beautiful multicolor transfer image. A plane heater 16 is also mounted inside the transfer cylinder 2 to distribute a uniform temp. over the entire surface of the transfer cylinder and solve the trouble of an uneven image transfer due to the differences in the temp.

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 with a heating device. More specifically, the present invention relates to an image transfer device with a heating device in which the transfer drum surface is smoothed and the temperature distribution of the transfer drum surface is uniform.

[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 heated to form an image receptor such as paper. BACKGROUND ART Single-color or multi-color prepress proofs suitable for proof printing to be transferred to a printer have been created.

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 such 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.

When an image receptor such as paper is heated in advance and the photosensitive layer of the 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 the surface of the transfer drum to which the image receptor is attached is uneven, wrinkles and the like are likely to occur on the image receptor attached to the transfer drum, and misregistration occurs in the second and subsequent images overprinted. It is not possible to obtain a beautiful printed material suitable for the purpose of proof printing.

In transferring the image formed on the photosensitive layer by imagewise exposure to the image receptor, it is necessary to uniformly heat the image receptor in order to obtain a beautiful transferred image.

However, it is complicated and difficult to always keep the surface of the transfer cylinder smooth as required because complicated work such as polishing is required. Further, there has been a strong demand for the development of a heating device for keeping the temperature of the transfer drum surface uniform, but a device satisfying such a demand has not yet been developed.

[0007]

SUMMARY OF THE INVENTION The present invention provides an image transfer device such as a device for producing a prepress proof, by achieving a simple smoothing of the transfer drum surface and a uniform temperature distribution, thereby producing a beautiful printed matter. It is an object of the present invention to provide an image transfer device capable of obtaining the above.

[0008]

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. In a device for transferring to the image receptor under heating at a nip between the transfer cylinder and the transfer cylinder, the transfer cylinder is such that an aluminum thin plate is lapped around the surface of the cylinder main body, and a planar heater is provided on the inner surface of the cylinder main body. Provided is an image transfer device with a heating device which is mounted.

The present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of an image transfer apparatus of the present invention, FIG. 2 is a perspective view showing a method of surrounding an aluminum thin plate on a transfer cylinder, and FIG. 3 is a peripheral view of the aluminum thin plate on the transfer cylinder. The perspective view which shows the mounting method and the installation state of the planar heater is shown.

The image transfer apparatus of the present invention comprises an impression cylinder 1 to which an image forming material (not shown) is attached and a transfer cylinder 2 to which an image receptor (not shown) is attached. The means for attaching the image forming material and the image receptor is not particularly limited, and conventionally known means, for example, various means such as a clamp, an adhesive tape, and vacuum suction can be appropriately adopted. In the case of FIG. 1, in the impression cylinder 1, the magnet sheet 3 and the adhesive tape 4 are used.
Shows an example in which the upper side and the lower side of the image forming material are respectively held, and in the transfer cylinder 2, an example in which the image receptor is held by the clamp 5 is shown. The image formed by imagewise exposure on the photosensitive layer of the image-forming material is transferred to the image receptor under heating at a nip formed between the impression cylinder and the transfer cylinder. The irregularities on the surface of the transfer cylinder become irregularities on a thin image receptor such as paper, which makes it difficult to obtain a beautiful transferred image. Further, when trying to obtain a multicolor transfer image, misalignment due to the unevenness of the image receptor occurs, so that a beautiful multicolor transfer image cannot be obtained. The present invention solves the above problems by mounting a thin aluminum plate on the surface of the transfer drum. Further, the present invention has solved the surface roughness of an aluminum thin plate caused by use by providing a simple aluminum thin plate circumscribing device. The aluminum thin plate is 0.1 to 1 mm, preferably 0.2 to
Those having a thickness of 0.5 mm are preferably used. The thinner the aluminum thin plate, the easier it is to wind, the better the adhesion to the surface of the body of the body, and the better the heat conductivity. However, if it is too thin, problems occur in strength, which is not preferable.

2 and 3 show an aluminum thin plate circumscribing device. As shown in FIG. 2, a partial cutout 6 is provided on the surface of the transfer cylinder 2, and a positioning pin 8 is provided on the side surface 7 of the partial cutout along the axial direction of the transfer cylinder.
Holders 10 and 11 are screwed to both ends of the aluminum thin plate 9 with bolts 12 along the axial direction. The aluminum thin plate and the holder are provided with through holes 13 and through holes 14 for screwing the tension adjusting bolts at positions corresponding to the positioning pins 8. As shown in FIG. 3, the positioning pin 8 is inserted into the through holes 13 on the upper side and the lower side of the aluminum thin plate 9. Then, the tension adjusting bolt 15 is screwed into the through hole 14 so that the projecting end of the bolt 15 is projected from the holder 11 so as to hit the side surface 7 of the partially cutout portion 6. By adjusting the length of protrusion of the tension adjusting bolt from the holder 11, the degree of tension of the thin aluminum plate 9 circumferentially attached to the surface of the transfer cylinder 2 is adjusted.

FIG. 3 shows a state in which the sheet heater 16 is mounted on the inner surface of the transfer cylinder 2. The sheet heater 16 is a sheet-shaped heater covered with heat-resistant rubber or the like. The sheet heater 16 is mounted by a sheet heater retainer 17 having a diameter slightly smaller than the inner surface of the transfer cylinder 2.

The operation of the image transfer device with a heating device of the present invention will be described below. In the apparatus of the present invention, the thin aluminum plate 9 is inserted into the holders 10 and 11 through the positioning pin through hole 13 and then the tension adjusting bolt 15 is inserted into the through hole 14 of the tension adjusting bolt. The aluminum plate is closely attached to the surface of the transfer cylinder 2 by screwing. Further, the sheet heater 16 is brought into close contact with the inner surface of the transfer cylinder 2 by screwing the bolt 18 of the sheet heater retainer 17. When the sheet heater is installed on the outer surface of the transfer cylinder, the sheet heater has a pressure at the time of transfer, which shortens the life of the heater. However, the apparatus of the present invention has such a problem. Never. Further, since the aluminum thin plate is in close contact with the surface of the transfer drum, the temperature distribution on the entire surface of the transfer drum becomes uniform, and uneven transfer due to the size of the temperature does not occur. Furthermore, since the thin aluminum plate can be easily attached and detached, the surface of the transfer drum can always be kept in a smooth state, so that it is possible to easily prevent the occurrence of uneven transfer due to the unevenness of the surface of the transfer drum.

[0015]

According to the present invention, there is provided an image transfer device with a heating device, which can easily smooth the surface of the transfer cylinder and uniformize the temperature distribution on the surface. Further, according to the present invention, there is provided an image transfer device with a heating device capable of quickly and easily mounting and removing a thin aluminum plate on the surface of the transfer drum and a planar heater on the inner surface of the transfer drum.

[Brief description of drawings]

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

FIG. 2 is an explanatory view of a transfer cylinder with an aluminum thin plate.

FIG. 3 is an explanatory view showing a mounting state of an aluminum thin plate and a sheet heater.

[Explanation of symbols]

1 impression cylinder 2 transfer cylinder 6 partial cutouts 9 Aluminum thin plate 10 Holder 11 Holder 15 Sheet heater

Claims (3)

[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. In the apparatus for transferring the image to the image receptor under heating by means of, the transfer cylinder is characterized in that a thin aluminum plate is circumferentially attached to the surface of the main body of the transfer cylinder, and a planar heater is attached to the inner surface of the main body of the transfer cylinder. Image transfer device with heating device. 2. The image transfer apparatus according to claim 1,
Around the aluminum thin plate, the transfer cylinder is provided with a partially cutout portion having a positioning projection, and both ends of the aluminum thin plate are provided with a holder along the axial direction of the transfer cylinder.
A through hole that penetrates the aluminum thin plate and the holder is provided at a position corresponding to the positioning protrusion and the tension adjusting bolt, and the positioning protrusion is inserted into the positioning through hole of the aluminum thin plate and the holder, and then tension is applied. An image transfer device with a heating device, characterized in that the tension of an aluminum thin plate is adjusted with an adjusting bolt and is attached to a transfer cylinder. 3. The image transfer device according to claim 2,
An image transfer device with a heating device, in which the holder comprises two holders that sandwich an aluminum thin plate from the upper surface and the lower surface.