JPH0369939A - Image forming device - Google Patents

Abstract

PURPOSE:To suppress the occurrence of wrinkles at the time of separating by making the width of a superposing nip roller larger than a range where a latent image is formed and smaller than a part where solvent for forming an image is stuck. CONSTITUTION:A heat developable photosensitive material 16 conveyed from an exposing part is held between a conveying roller pair 25 as shown by an arrow and conveyed to a water application part 26. The side part of the photosensitive material 16 is guided by a guide 63 to contact with an applying roller 64 and the water being the solvent for forming the image is applied to the photosensitive material 16. Then, it is held between a conveying roller pair 27 and conveyed to the superposing roller 48. Therefore, the applying roller 64 does not abut on the side part of the photosensitive material 16 but the water is applied at least to the range where the image is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus that overlaps a photosensitive material on which a latent image is formed and an image-receiving material and transfers the image to the image-receiving material.

[Conventional technology]

As an image forming material in which an image is formed by overlapping a photosensitive material and an image-receiving material as described above, for example, a heat-developable photosensitive material is well known. Pages 242-255 of Salt Photography Edition (published by Corona Publishing in 1982), Page 40 of Video Information published in April 1978, Neblett's Handbook of Photography and Reprography (Ne
brett's Handbook of Photo
graphy and reprography> 7th edition (7th Bd,) Van Nostrand Reinhold Company - (Van No5trand
Reinhold Company), pages 32-33.

As for the method of obtaining a color image by heat development, a mobile dye is released in an image form by heating, and this mobile dye is transferred to a dye-fixing material (image-receiving material) having a mordant using a solvent such as water. transfer to a dye-fixing material using a high boiling point organic solvent; transfer to a dye-fixing material using a hydrophilic thermal solvent built into the dye-fixing material; A method of transferring the dye to a dye-receiving material such as a support has been proposed.

Specifically, as an apparatus for carrying out this type of image forming method, as disclosed in Japanese Patent Application Laid-open No. 59-75247, a color image is formed on a heat-developable photosensitive material using an exposure head in an exposure section. After exposing the photothermographic material to light, an image forming solvent such as water is applied to the photothermographic material using a roller, and this is sent to the thermal development section, where the image receiving material is brought into close contact with the photothermographic material after heat development and transferred to the transfer section. An image forming apparatus has been proposed which thermally transfers an image to an image receiving material in a transfer section.

Furthermore, an apparatus has been proposed in which a heat-developable photosensitive material and an image-receiving material are superimposed to simultaneously perform development and transfer.

[Problem to be solved by the invention]

In the image forming solvent application section of the image forming apparatus described above, the photothermographic material is coated with a roller before being conveyed. The side portions of this material that are not involved in imaging are used for transport guides, and therefore no imaging solvent is applied to these side portions.

Further, the heat-developable photosensitive material and the image-receiving material are brought into close contact with each other with a certain amount of nip pressure.

When heating for development or transfer is performed here, on the image surface where the image forming solvent is sufficiently applied, there is not much evaporation of the image forming solvent, so almost no adhesive force is generated. The image forming solvent tends to evaporate in the side areas, and furthermore, the image forming solvent is dispersed in the coating boundary area, resulting in a low coating density, and the adhesive force between the photothermographic material and image receiving material tends to increase It becomes the amount of solvent.

At this time, when these two materials are peeled off after being brought into close contact with each other with a certain amount of nip pressure as described above, the adhesion strength differs greatly between the image forming surface part and the side part. There is a problem in that the force is concentrated in the area, causing wrinkles in the material and uneven density.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide an image forming apparatus that smoothly peels off a photosensitive material and an image-receiving material, suppresses the occurrence of wrinkles, and prevents the occurrence of density unevenness. .

[Means and effects for solving the problems] The above object of the present invention is to apply an image forming solvent to at least one of a photosensitive material or an image receiving material on which a latent image has been formed, and to overlap the materials with a nip roller, In an image forming apparatus that transfers an image to an image-receiving material, this is achieved by a configuration in which the width of the overlapping nip roller is larger than the image forming area and smaller than the area to which the image forming solvent is attached.

In other words, by making the width of the overlapping nip roller larger than the latent image formation range and smaller than the area to which the image forming solvent is attached, as described above, the image forming solvent is dispersed, the coating density is low, and the materials tend to adhere to each other. It is possible to suppress the nip pressure at the side portions, which weakens the adhesive force at these side portions and reduces the difference between the adhesive force at the image surface portion, thereby suppressing the occurrence of wrinkles during peeling.

The image forming apparatus to which the present invention is applied may be configured to apply an image forming solvent to either the photothermographic material or the image receiving material, or may be configured to apply the image forming solvent to both materials. You can.

The photosensitive material and image-receiving material used in the present invention develop, transfer, and develop a latent image obtained by imagewise exposure in the presence of an image-forming solvent.
Any type of material may be used as long as a visible image can be obtained by processing such as fixing.

For example, photosensitive materials include heat-developable photosensitive materials,
U.S. Patent No. 4.430.415, U.S. Patent No. 4.483.9
No. 14, No. 4.500.626, No. 4.503.
No. 137, JP-A-59-154445, JP-A No. 59-16
No. 5054, No. 59-180548, No. 59-218
No. 443, No. 60-120356, No. 61-8825
No. 6, No. 61-238056, etc.

The above-mentioned heat-developable photosensitive material basically consists of photosensitive silver halide, a binder, a dye-providing compound, a reducing agent (
In some cases, the dye-donating substance also serves as a reducing agent), and if necessary, organic silver salts and other additives can be contained.

The heat-developable photosensitive material may be one that gives a negative image or one that gives a positive image when exposed to light. There are two types of methods for producing positive images: a direct positive emulsion as a silver halide emulsion (a method using a nucleating agent, and a method using a light fogging method).
Either a method using a dye-donating compound or a method using a dye-donating compound that emits a positively diffusible dye image can be adopted.

There are various methods for transferring diffusible dyes, such as transferring to a dye fixing layer using an image forming solvent such as water, transferring to a dye fixing layer using a high boiling point organic solvent, and transferring to a dye fixing layer using a hydrophilic thermal solvent. A method of transferring the dye to a dye fixing layer having a dye-receiving polymer using the thermal diffusivity or sublimation of a diffusible dye has been proposed.
It can be any of them.

In addition, as the image forming solvent used for the above diffusion transfer,
For example, there is water, and this water includes not only so-called pure water but also water in the widely customary sense. Alternatively, a mixed solvent of pure water and a low boiling point solvent such as methanol, DMF, acetone, or diisobutyl ketone may be used. Furthermore, a solution containing an image formation accelerator, an antifoggant, a development stopper, a hydrophilic heat solvent, etc. may also be used.

[Embodiment]

Hereinafter, one embodiment of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention.

A magazine 14 is disposed on the machine base 12 of the image forming apparatus 10, and a roll-shaped photothermographic material 16 is housed within the magazine 14.

The photothermographic material 16 is pulled out from its outer periphery, cut into a predetermined length by a cutter 18, and then wound around the outer periphery of a rotating drum 20 in the direction of arrow A. The exposure drum 22 corresponds to the outer periphery of this rotating drum 20.
is arranged, rotates the rotating drum 20 at high speed,
An image is exposed onto the wound photothermographic material 16.

After exposure, the photothermographic material 16 is transferred to the rotating drum 20 in the reverse direction.
In the direction of arrow B>, the scraper 24 scrapes the rotating drum 20.
The sheet is peeled off from the substrate and further conveyed by a pair of conveying rollers 25 and 27. Conveyance roller pair 25.27
is mechanically connected to a step motor (not shown) as a driving means, and is rotated by the step motor.

A water application section 26 is provided between the pair of conveyance rollers 25 and the pair of conveyance rollers 27 on the conveyance path of the photothermographic material 16 . A coating roller 64 rotated by an AC motor (not shown) is disposed in the water coating section 26, and the photothermographic material 16 is transferred to the coating roller 64 while being conveyed.
Water as an image forming solvent is applied by contacting the substrate.

The heat-developable photosensitive material 16 coated with water is transferred to the heat-developable transfer section 28.
It is now being sent to.

In the thermal development transfer section 28, a heating drum 34 and an endless pressure belt 36 serving as pressure contact means are arranged. Further, a halogen lamp 38 is disposed inside the heating drum 34, and the outer peripheral surface of the heating drum 34 is heated to about 90° C. by the halogen lamp 38.

The endless crimping belt 36 is wrapped around rollers 37, 39, 41.
．． 43, and its endless outer side is pressed against the outer peripheral surface of the heating drum 34. The winding roller 37 is mechanically connected to a step motor (not shown), and is rotated by the drive of this step motor. The photosensitive material 16 is pinched and conveyed and thermally developed.

Near the part where the endless pressure belt 36 is wound around the roller 37, a rubber overlapping roller 48 is placed so as to be pressed against and in contact with the outer peripheral surface of the heating drum 34. This overlapping roller 48 is also mechanically connected to a step motor (not shown), and is rotated by the drive of this step motor.

The image-receiving material 32 sent to the thermal development transfer section 28 is transferred by a superimposing roller 48 placed in pressure contact with the outer peripheral surface of the heating drum 34 (between the superimposing roller 48 and the outer peripheral surface of the heating drum 34). The heat-developable photosensitive material 16 is superimposed on the heating drum 34 and the endless pressure belt 36.
It is designed to be supplied between.

The heat-developable photosensitive material 16 is heated while being conveyed in a superimposed state with the image-receiving material 32 in the heat-developable transfer section 28, and the image is transferred to the image-receiving material 32 along with heat development, and an image is obtained on the image-receiving material 32. It looks like this.

A peeling plate 80 is disposed on the side of the thermal development transfer section 28 . The peeling plate 80 has a distal end close to the outer circumferential surface of the heating drum 34, moves together with the heating drum 34, engages with the photothermographic material 16 located inside, and transfers the photothermographic material 16 into an image. The material 32 is peeled off from the outer periphery of the heating drum 34.

A pair of separation rollers 50 are arranged below the peeling plate 80 and correspond only to both ends of the image receiving material 32 in the width direction.
Furthermore, a conveyor belt 52 is wound around the separation roller 50. This conveyor belt 52 engages only at both ends of the image receiving material 32 in the width direction, and transfers the image receiving material 32 to the photothermographic material 1.
6 and is bent and transported.

This separation roller 50 is mechanically connected to a step motor (not shown), and is rotated by the drive of this step motor.

The separated image-receiving material 32 is dried by a heater 54 and then sent onto a take-out tray 56 formed at the top of the machine stand 12.

On the other hand, the separated photothermographic material 16 is conveyed by a pair of conveying rollers 58 and sent to a waste photosensitive material storage box 59. This conveyance roller pair 58 is also mechanically connected to a step motor (not shown).
It is rotated by a step motor.

Next, the operation of this embodiment will be explained.

FIG. 2 is a perspective view of the water application section.

The photothermographic material 16 conveyed from the exposure section is held between a pair of conveyance rollers 25 as shown by the arrow, and then conveyed to the water application section 26 . Then, the side portion of the photothermographic material 16 is guided by a guide 63, comes into contact with a coating roller 64, is coated with water, which is an image forming solvent, is held between a pair of conveying rollers 27, and is conveyed to an overlapping roller 48. Ru.

Therefore, although the application roller 64 does not come into contact with the side portions of the photothermographic material 16, water is applied to at least the area where an image is to be formed. Here, FIG. 3 shows a state in which the photothermographic material 16 and the image-receiving material 32 are overlapped, and are conveyed in the direction of the arrow. Here, the coating range is equivalent to the image forming range indicated by the dotted line S.

FIG. 4(a) shows the water application distribution along line Y--Y in FIG. The application range of the dotted line S is x t-x
The range is 2. Note that Xo is the width of the photothermographic material 16. As you can see here, the water is applied over the area x, -x
It is also dispersed and distributed in the side portions of the heat-developable photosensitive material 16, which are other than 2. The adhesive force with the image-receiving material 32 tends to be strongest in the range of both end portions where the amount of water distribution decreases.

FIG. 5 is a perspective view of the heating drum.

Here, the overlapping roller 48 is pressed against the heating drum 34 with a constant pressure by a pressing member (not shown). Then, the overlapping roller 48 and the heating drum 3
4 shows a state in which a photothermographic material 16 and an image receiving material 32 are sandwiched between them. In this way, the width of the overlapping roller 48 is narrower than the width of the photothermographic material 16 at least in the range that covers the image forming area, and the side portions of the photothermographic material 16 are pressed by the overlapping roller 48. Never.

The pressure distribution in this situation is shown in FIG. 4(b). With such a pressure distribution, the photothermographic material 16 and the image receiving material 32, which have the water application distribution shown in FIG. Within this range, the clamping pressure can be reduced, and strong adhesion between the photothermographic material 16 and the image-receiving material 32 can be prevented.

In this way, it is more effective to set the width of the overlapping roller 48 as close to the width of the image boundary as possible within a range where changes in pressure do not affect the image surface.

[Effects of the Invention] According to the present invention, the overlapping rollers have a width larger than the image forming area and smaller than the area to which the image forming solvent is attached, as described above, particularly within a range where changes in pressure do not affect the image forming surface. By making the width as close to the image boundary as possible, it is possible to suppress the nip pressure in the area where the image forming solvent is dispersed and the amount of coating is small and the materials tend to adhere to each other. The difference in adhesive strength between the side portion and the side portion becomes smaller, and wrinkles can be prevented from forming when peeled off.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of the image forming apparatus, Fig. 2 is a schematic perspective view of the water application section, Fig. 3 is a diagram showing a superimposed state of a photothermographic material and an image receiving material, and Fig. 4 (a). ) is a diagram showing the water application distribution along the line Y-Y, FIG. 4(b) is a diagram showing the pressure distribution along the line Y-Y, and FIG. 5 is a perspective view of the heating drum. Codes in the figure: 10 Image forming device 16 Heat-developable photosensitive material 25.2
7-Transport roller pair 26-Water application section 28 Heat development transfer section 32/image receiving material 34/heating drum 36 Endless pressure belt
46 Conveying roller pair 48 - Overlapping roller 62 Tray 63 - Guide 64 Water application roller Fig. 1 ■ Fig. 2 Fig. 3 Fig. 4

Claims (1)

[Claims] In an image forming apparatus that applies an image forming solvent to at least one of a photosensitive material or an image-receiving material on which a latent image has been formed, and superimposes the same using a nip roller, and transfers the image to the image-receiving material, the width of the overlapping nip roller is An image forming device whose width is larger than the image forming area and smaller than the area to which the image forming solvent is attached.