JPS61239984A - Mapping method for forming image to plain paper and device thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming method using the image forming sheet described in US Pat. No. 44,399,209. More specifically, the present invention relates to a method of forming an image on plain paper.

US Patent 44.3 by Mead Corporation
No. 99,209 describes a transfer imaging system in which an imaging sheet consisting of a support and a microcapsule layer containing a color former and a photosensitive composition is imagewise exposed to actinic radiation. This exposed sheet is then overlapped with a developer sheet and passed through a calendar nip. There, the microcapsules are destroyed, the contents of the microcapsules are image-transferred to the developing sheet, a reaction takes place, and an image is formed. Primarily, the photosensitive composition is a photocurable composition containing an ethylenically unsaturated compound and a photoinitiator, the color former is a substantially colorless electron donating compound, and the developer is an aromatic carbonaceous compound. It is an electron acceptor like an acid salt.

When the imaging sheet is imagewise exposed to actinic radiation, the internal phase of the microcapsules is hardened in the exposed areas.

The internal phase in the unexposed areas remains liquid and the internal phase in the areas receiving moderate exposure is moderately hardened.

Therefore, when a certain destructive force is applied to the exposed image forming sheet, the microcapsules in the non-exposed area are destroyed and the internal phase can be released. The microcapsules in the underexposed area are moderately destroyed and release the internal phase. In this way, the internal phase of the microcapsules is image-transferred to the developing sheet to obtain an image.

The transfer imaging system described in U.S. Pat.
Although designed to be useful, users must purchase two types of coated paper to reproduce images: an imaging sheet and a developer sheet. Of course, it is desirable to form the image on ordinary paper. Moreover, this finished image is obtained on chemically coated paper which is irritating to the skin and has an undesirable feel.

The main object of the present invention is to provide a mapping process in which an image is formed on plain paper.

It is a further object of the present invention to provide an imaging process for forming edges on plain paper that does not involve a tri-process or wet development operation step.

Yet another object is to provide a mapping process useful for forming full color images on paper.

The above and other objects of the present invention include imagewise exposing an imaging sheet comprising a support having a color-forming substance and a microcapsule layer containing a photosensitive composition to actinic radiation;
applying a certain destructive force to the microcapsules, bringing the paper sheet into contact with the imaging sheet so that the coloring substance is image-transferred to the paper sheet, separating the paper sheet from the imaging sheet, and removing the transferred coloring substance from the image-forming sheet. This can be accomplished by an imaging process consisting of contacting the surface of the paper containing a color-forming material with a developing material that reacts to form a visible image. The color-forming substance is preferably contained in microcapsules together with the photosensitive composition.

The microcapsules can be destroyed by contacting the imaging sheet and paper or separately according to the process described above. The former method is preferred because it is easy to process and can maximize the amount of color former transferred from the imaging sheet to the paper sheet. If the microcapsules are destroyed in separate steps and the color former is transferred to paper, a certain amount of the color former tends to be lost, making it difficult to obtain good image density.

According to one embodiment of the invention, a developer is provided on the surface of an imaging sheet having microcapsules and color forming material.

The developer is preferably provided in a single layer on the surface of the imaging sheet, mixed with the microcapsules, but alternatively, it is possible to provide the developer in a separate layer below the microcapsule layer.

When the developer is provided to the surface of the imaging sheet, the developer may be encapsulated. In this case, a liquid developer or developer solution is used. A solid developer, such as a developer resin, is supplied to the support layer in direct admixture with the microcapsules.

If there is developer present on the surface of the image 7, the image is formed by brief imagewise exposure of the sheet to actinic radiation, then application of a constant destructive force to the sheet, and further transfer to a plain paper surface. The developer and color forming material are transferred to the paper surface and begin the reaction.

According to another aspect of the invention, a full color image is formed by using an imaging sheet containing microcapsules having different sensitivities and each containing cyan, magenta, yellow and optionally black color generators. be done. In this process the color image is separated into red, green, blue and sometimes black components.

Each of the colors is then individually changed in radiation to which the photosensitive composition containing the auxiliary color former is sensitive. The imaging sheets are then subjected to imaging exposure to color-changing radiation, either sequentially or simultaneously.

The full color image gives a certain destructive force to the microcapsules,
The color forming agent is obtained on the surface of the paper sheet by a process of contacting the paper sheet and the imaging sheet and treating the surface of the paper where the color forming agent is transferred with the developer material as described above.

1-4 illustrate the imaging sheet process of the present invention.

FIG. 5 is an example of an imaging device useful in carrying out the process of the present invention.

FIG. 6 shows an apparatus for using the developer according to the invention.

FIG. 7 shows an apparatus for using developer from a bed of particles according to the invention.

FIG. 8 shows a magnetic brush useful for use with the developer according to the present invention.

"Microcapsule" as used herein refers to microcapsules with separate walls and binder 1
This refers to both the so-called open phase system microcapsules consisting of an internal phase and a diced version.

As used herein, "photosensitive composition" refers to a composition whose viscosity changes upon exposure to actinic radiation.

"Active radiation" means the entire electromagnetic spectrum, including ultraviolet radiation, infrared radiation, x-rays, and particle radiation such as ion beam radiation.

"Normal paper" is paper that is not coated with a developing material. This refers to Bonn 1 paper as well as plain paper that has been treated or produced using techniques that enhance the properties of the images obtained according to the present invention. It is preferred to use paper with minimal surface irregularities (roughness).

The cited U.S. patent/i64,399,209 includes:
Imaging sheets and microcapsules useful in the present invention include
The mechanism for selectively releasing color-forming substances is detailed. Further cited U.S. patent application No. 339,91
7 (January 18, 1982) and scrap 620.994 (
(June 15, 1984) describes an imaging sheet useful for forming full color images and a method of exposing the imaging sheet to obtain a full color image.

The present invention provides an image forming sheet useful for forming a transfer image onto a color developing sheet.
It is based on the discovery that it can alternatively be used to form images on paper by transferring a color-forming substance to paper and then treating the paper with a developing substance. It was discovered here that the color-forming substance is transferred from the image-forming sheet to the paper, and a sufficient amount of the color-forming substance is transferred to the surface of the paper and remains behind to react with the developer to form an image. .

A typical example of the imaging sheet used in the present invention is shown in FIG. The sheet αα consists of a support (preferably a thin plastic film) and a layer (14
Consists of 1. Microcapsules consist of diced versions of the internal phase forming separate walls or in a binder. In the former case, microcapsules are produced by methods such as core cell elution or polymerization. If the microcapsules have separate walls, they are attached to the support 0z by a binder or, in many cases, the wall-forming compound itself attaches the microcapsules to the support.

The microcapsules shown in FIG. is not included in the Minister of Home Affairs.

Rather, it is associated with the microcapsules in other ways, for example by incorporating the coloring substance into the capsule wall or in a continuous layer with the microcapsules.

In the latter case, the internal phase is designed to dissolve the color-forming substance so that it is released from the microcapsules and transferred to the paper. If the developer is present on the surface of the imaging sheet together with the color-forming material, steps must be taken to prevent the developer from reacting with the color-forming material. This problem is primarily solved by encapsulating one or both of the developer and the color former.

The photosensitive composition is a photocurable or photosoftening composition. In the former case, the transfer of the colored substance to the paper sheet upon exposure to light is inhibited or prevented. In the latter case, the exposure improves the transfer of the color-forming material to the paper sheet. The internal phase of FIG. 1 is a liquid, non-exposed, photocurable composition.

Representative examples of photosensitive compositions useful in the present invention are disclosed in US Pat. No. 1,64,399,209. A typical example of a photocurable composition is a composition containing trimethylolpropane triacetate and a photoinitiator.

Figure 2 shows the exposure of microcapsules. The exposed and non-exposed areas are separated by a fort mask CI'4) through which radiation (indicated by arrows) from a source not shown is selectively passed. The internal phase (2QA) of the microcapsules (16A) exposed to light is solidified, but the microcapsules (16B) exposed to light or underexposed are solidified.
The internal phase (20) remains liquid. Figure 2 is a simple illustration of exposure and shows the distribution of exposed and unexposed microcapsules on the surface of the imaging sheet. However, at moderate exposures, the internal phase is moderately hardened and a moderate amount of color-forming material is transferred to the plain paper. The area consists of a combination of exposed microcapsules, non-exposed microcapsules and intermediately exposed microcapsules.Thus, the image created according to the present invention shows that the microcapsules are destroyed depending on the degree of exposure and the internal phase is released. It is a product of combination.

Various imaging devices are used in the present invention to expose the imaging sheet. It is contemplated that the imaging process of the present invention may be used to copy computer-generated output and that some type of electronically controlled imaging device is used for this purpose. A typical example of such an electronic imaging device is US Pat. No. 4,229,095; 44
,367,946 ; and /164,406,521
A light valve imaging device of the type described. Additionally, cathode ray tubes and certain laser imaging devices can also be used to imagewise expose the imaging sheet according to the invention. Of course, Fort Mask is also used.

When producing full color images, a suitable exposure device is one that controls three or four different radiation bands emitted by a single or multiple radiation sources. For example, an I)unn or matrix camera is used to create electronic signals corresponding to the desired cyan, magenta and yellow (and possibly black) images. This outfoot allows common multiplexers to
Drives the electronic control device of the exposure apparatus, including the logic package and timing device. This exposure device emits radiation to which the microcapsules on the image-forming sheet are sensitive, thereby image-formingly exposing the image-forming sheet.

After exposure, the image-forming sheet is usually overlapped with paper as shown in FIG. 3, and then a certain destructive force is applied to the microcapsules.

This operation is conveniently carried out by passing the paper and imaging sheet together through a nip between a pair of pressure rollers. This destroys the unexposed and/or underexposed microcapsules (16B) and releases the internal phase. Upon contact with the paper, the internal phase is transferred to the paper, forming a latent image c34) in the form of unreacted color-forming substance.

FIG. 3 shows the most typical example of microcapsule rupture and transfer of color-forming material to the paper surface, where the paper comes into contact with an imagewise exposed imaging sheet when the capsules are ruptured. Images can also be formed by destroying the microcapsules and transferring the coloring material in separate steps.

For example, as described in U.S. Pat. No. 44,448,516, microcapsules are destroyed by bringing an image forming sheet into contact with the fibrous outer surface of a developing roll, and then the image forming sheet is overlapped with a paper sheet and pressure is applied to transfer the coloring substance. , a latent image in the form of unreacted chromogenic material can be formed.

When the plain paper is brought into contact with a developing substance after transfer, an image is developed due to the reaction between the color forming substance and the developer.

This operation is shown in FIG. That is, the paper is brought into contact with the rotating developer applicator brush.
421, the developing substance (4IO) moves to the surface of the paper and reacts with the coloring substance to form a color image (46).
, 448,516, or so-called magnetic brushes of the general type used in xerographic toners.

The developer is preferably a dry material that is spread or used on the surface of the paper containing the color-forming material.

However, in some applications, to facilitate the reaction between the developer and the color-forming material, and to facilitate the reaction between the color-forming material and the developing material, which is absorbed by the paper but does not come into contact with the completely dry developer material. It is desirable to use a developer in solution form. If the developer is used in liquid form, it is desirable to minimize the wetness of the paper and, if necessary, to dry the paper.

The latent image is developed by contacting the imaging sheet with a bed of developer material. This is the container (t) containing the dry developer material.
This is done by passing the This operating situation is shown in FIG. The free particle body α29) is placed in the tray (144), and the cylinder (146) is placed in the tray (144).
) is 1 due to the rotation of the shaft (147).
It is attached horizontally on the tray α44). The cylinder (046) is placed in such a way that the sector (148) around it is in contact with the free particle body α29).
146) is located in relation to the tray. The free particles consist of particles of solid developer material or a combination of developer material and a dispersant such as sand. A plain paper sheet α50) with a latent image is fixed in the cylinder (146) in such a way that the surface of the paper (150) is stamped with the latent image facing outward. The paper (150) is then processed by rotating the cylinder (146) to bring the surface of the paper (150) into contact with the free particle body (129). The operation of the embodiment shown in FIG. 6 can be made more efficient by vibrating the tray α44) during rotation of the cylinder. This vibration is indicated by the arrow (152).

Another embodiment of the apparatus for carrying out development according to the invention is shown in FIG. In this embodiment, the first cylindrical drum (15
4) is assigned for rotation around the horizontal axis α56). The second holding drum α (to) is the drum (1
54), and the paper α53) and developer particles (129: are located between the drums (153) and (154). The paper α53) is indicated by the arrow (162). Input port angled in direction of rotation (160)
It is inserted from the tram (154) surface by being inserted from the tram (154) surface. The paper (153) is held on the inner surface of the tram (151) by the second drum α (7), or the paper α5
3) can also be held inside the tram (154) by clamping parts.

As the dome α (6) rotates, the particles (130) of the free particle body (129) containing developer move over the surface of the paper α, 53) and develop a latent image thereon. The rotational speed of the first cylindrical drum (154) is set such that the particles (129) do not fall too quickly, i.e. so that they are not thrown into the drum and are not held inside the tram α54) by centrifugal force. limited. Rather, a rotation is selected in which the particles are returned to the bottom of the drum with a wave-shaped movement of the vibrator, such that the particles are partially carried inside the drum and then recirculated.

FIG. 8 is a cross-sectional view of an apparatus for developing a latent image using a magnetic brush according to the present invention. Magnetic brush (170
) consists of a stationary shirt ) (172) having at least one pair of magnets α7◇ fixed thereto. Shaft (1
72) is located within a cylindrical sleeve (176) which rotates clockwise in the illustrated embodiment as shown by arrow (178). The sleeve (176) has a reservoir or container (182) in axial alignment with the magnetic brush (170).
contacting a magnetically absorbing free particle body (1FD) containing developer therein; It should be noted that other designs of magnetic brushes hold a stationary outer sleeve and rotate the inner magnetic part to create a moving pile on the outer sleeve.

When the sleeve (176) is rotated, the particles (18) stand up in a tree-like or bristle-like shape and form a groove (184) on the outer surface of the sleeve (176).Sleeve α76
) The pile (184) made on top is indicated by the arrow (17B)
As shown, the sleeve (17) rotates clockwise, and the magnetic brush (17) is adjusted to have the length of the pile (188) by a trim blade or tractor blade (186), and the image forming sheet is A sheet of plain paper (194) containing the latent image is interlocked with a magnetic brush (170).
) passes through the pile (188) and comes into contact with the ξ pile,
The developer moves to the surface of the paper where it reacts with the latent image.

Paper can be placed in contact with a pile of magnetic brushes in a variety of ways. The carrier cylinder (190) according to this aspect of the invention comprises a magnetic brush (170).
) The cylinder (190) is mounted so as to rotate on an axis (192) parallel to the cylinder (190).
76) and the cylinder α (9). The carrier cylinder (190) is operated in the same or opposite direction to the direction of the moving pile on the magnetic brush (17).

However, the paper (
194) is the pile (188) on the magnetic brush α70)
The magnetic brush (17) rotates at a higher tangential speed than the cylinder (190) and moves in the same direction as the pile (18).
8) is preferably moved over the surface of the latent image-containing paper (194).

The paper (194) is fixed to the cylinder (19) by a sheet stabilizing device consisting of a clip (196) or preferably by a vacuum system known in the literature. Pile of 17 (18
If the cylinder (176) is rotated so as to be continuously recirculated to make particles (18), the particles (18) will return to the container (182) again. Therefore, as shown in the container (+s2) It is desirable to include a particle agitator, such as a stirrer (198).

Paper sheets can also be sprayed or coated with powdered or liquid developer using known methods.

It is sometimes desirable to heat the paper to accelerate development and improve image density. This treatment is performed either at the time of use or after use of the developer, depending on the method of use. Heating conditions are not particularly critical. 50-60
A treatment time of 1 to 5 seconds is sufficient.

According to another aspect of the invention, the imaging sheet shown in FIG. 1 can be modified to include a developing substance on the surface of the sheet of microcapsules containing a photosensitive composition.

This imaging sheet is used in a similar manner to the imaging sheet of Figure 1, except that the step of applying the developing material to the plain paper is performed at the same time as the transfer of the coloring material to the plain paper surface. .

The developing material is supplied to the surface of the imaging sheet either in the same layer as the microcapsules (ie, layer α4 in FIG. 1) or in another layer below the microcapsule layer. According to one embodiment of the invention, the developer material is mixed with microcapsules and coated on the support. A developer material according to another embodiment of the invention is packaged into microcapsules. When the microcapsules contain a photosensitive composition and a color developer, the release and transfer of the developer material is controlled by imagewise exposure of the imaging sheet to actinic radiation. When the developer is encapsulated, a liquid developer or a developer solution is used.

As mentioned above, microcapsules can also be destroyed using methods other than pressurization. For example, in other embodiments, microcapsules can be destroyed ultrasonically, by abrasion or by heating, as described in US Pat. No. 4,448,516. In the latter case, the microcapsules contain a drug that generates gas when heated above a predetermined temperature.

In the latter case, the process can also be carried out with the paper sheet and the surface of the imaging sheet either separately or in contact with each other. In order to best transfer the color-forming substance from the image-forming sheet to paper, it is preferable to bring the microcapsules into contact with the paper sheet and destroy them, as shown in FIG.

The process of the invention is carried out using plain bond paper. However, other types of paper can of course also be used. Suitable papers are those which have the property of retaining a sufficient amount of color former on the surface of the paper where they can react with the dry developer material. It is undesirable to use paper that is highly absorbent and has no affinity with the developer, and is impregnated with a coloring agent.

It will be apparent to those skilled in the art that various designs of equipment may be used to carry out the process of the present invention. Although it is preferred that exposure and development are carried out in one imaging device, it is also possible to design separate devices for each step.

An example of a device useful in the present invention is shown in FIG. The basic elements of the apparatus are a light nozzle exposure device (100), an exposure drum (102), a pressure roller (108), a transfer roll (ICB), a carrier drum (11), and a developer applicator (U2). There is a light valve exposure device (
100) for the operation of U.S. Patent A 4,229.
, 095. The light valve exposure device α0 exposes the image forming sheet αω as it rotates and passes through the device on the exposure ram (102). The light valve exposure device includes a radiation source (104), a group of light valves (10
6) and a lens (ios) for focusing the light valve group outputted to one piece of the imaging sheet αω (111).The radiation source (104) and the light valve group (106
) is controlled by a device not shown.

If a full color image is to be produced, the radiation source (104) must emit radiation that is sensitive to each set of microcapsules on the imaging sheet. This 1
is a group of light valves (10
6) and by using a radiation source that emits in combination with a tuned filter.

After exposure, the drum (102) is rotated so that the supplied plain paper is not brought into contact with the imaging sheet by contacting the drum in the nip between the drum (102) and the pressure roller (10B). The roller (108) applies sufficient pressure to the combined image forming sheet 008 paper (to) to form the sheet α.
Either the microcapsules of ω are destroyed and the color forming substance contained therein is image-transferred, or the microcapsules of the sheet (10) and the paper (to) are combined. In this way, a latent image is formed as shown in FIG. 3 above.

The paper (7) is peeled off from the P-ram (102) by a conventional device such as a peeler gate (not shown) and then fed to a pressure roller (108) and transferred to a carrier drum by a roll (109). α1, and the paper is sucked by vacuum or other methods.

As the drum (11) rotates, the paper (11) comes into contact with a developer brush (112). The brush transfers dry developer material from the container (114) to the sheet surface where it is deposited on the paper sheet (11). It reacts with color-forming substances on the surface to create a color image.Heating the drum (No. 11) accelerates development.

The speed at which the image is developed on paper C30 is a function of the amount of color forming material transferred to the surface of the paper, as well as the amount of developer material used on the sheet surface and the temperature of the sheet. To create a visible image, carrier rolls (11
0) It is necessary to bring the top paper into contact with the developer roll (112) and rotate it several times.

Approximately 1 minute is required for development using the developing roll shown in FIGS. 4 and 5. One way to shorten the development time is to use a number of development rolls side by side to supply developer to the surface of the image forming sheet. Increasing the number of developer rolls reduces development time proportionally.

As mentioned at the beginning, U.S. Patent A 4,399,20
The imaging sheet described in No. 9 is suitable for use in the present invention.

However, it would be desirable to improve the imaging sheet to facilitate copying of plain paper. In particular, it is desirable to use a large amount of color-forming substance in the inner phase of the microcapsules in order to supply a large amount of color-forming substance to the paper surface. This can be achieved by using a high concentration of color former in the microcapsules or by using larger microcapsules containing more internal phase. The internal phase of the microcapsules primarily used in the present invention contains about 0.5 to 20% by weight of a color-forming substance.

The developer used in the present invention is selected from materials commonly used for carbonless paper purposes. One of the most advantageous features of the present invention is that it functions entirely as a dry mapping process. One suitable developer is disclosed in U.S. Patent A3,8 by Oda et al.
It is a resin powder containing the aromatic carboxylic acid or its salt described in No. 64,146. More specifically, it is a resin powder containing 3,5-di(methylbenzyl)salcylate.

Other developers used in the present invention are acid clay, activated clay, acidic polymers such as phenol-formaldehyde resins, phenols such as P-cresol and P-octylphenol, 3.5-:)-t-butyl These include aromatic carboxylic acids such as salicylic acid and their salts. The developer can also be used in liquid form according to some embodiments of the invention, but in this case additional processing steps are required.

Although the method described above and the apparatus for carrying out the method constitute preferred aspects of the invention,
- It will be appreciated that the strength tree invention is not limited to these precise methods and apparatus types, and modifications may be made without departing from the scope of the invention. The scope of the invention is limited by the claims.

[Brief explanation of the drawing]

1 to 4 illustrate the imaging sheet process of the present invention. FIG. 5 is an example of an imaging device useful in carrying out the process of the present invention. FIG. 6 shows an apparatus for using the developer according to the invention. FIG. 7 shows an apparatus for using developer from a bed of particles according to the invention. FIG. 8 shows a magnetic brush useful for use with the developer according to the present invention. AJ?

Claims (1)

[Claims] 1. In an image forming method using an image forming sheet comprising a support having a color-forming substance and a microcapsule layer containing a photosensitive composition on the surface; image forming exposure of the image forming sheet to actinic radiation; applying a certain destructive force to the microcapsule layer; overlapping the microcapsule layer and an ordinary paper sheet and placing the imaging sheet and the ordinary paper in contact; The steps of applying the destructive force to the microcapsule layer and the step of bringing the image-forming sheet and the ordinary paper sheet into contact are performed such that the color-forming substance is image-transferred to the paper as a latent image. and applying a developing material to the surface of the plain paper to which the color-forming material has been transferred; and wherein the developing material reacts with the color-forming material to produce a visible image. An image forming method using an image forming sheet comprising a support having a color-forming substance and a microcapsule layer containing a photosensitive composition on the surface. 2. The method according to claim 1, wherein the photosensitive composition is a photocurable composition, and the color forming substance is encapsulated together with the photocurable composition in microcapsules having separate walls. . 3. The method according to claim 2, wherein the color-forming substance is a substantially colorless electron-donating compound, and the developing substance is an electron-accepting compound. 4. The method of claim 3, wherein the imaging sheet is placed in contact with the ordinary paper sheet before applying the constant destructive force to the microcapsule layer. 5. The method of claim 4, wherein the step of applying the constant destructive force to the microcapsule layer comprises bringing the imaging sheet and the ordinary paper sheet into contact and passing them through a calender pressure nip. . 6. The method according to claim 5, wherein the image-forming exposure step of the image-forming sheet comprises exposing the sheet to image-forming light using an electronic imaging device. 7. The method according to claim 6, wherein the electronic imaging device is a light valve imaging device. 8. The method according to claim 1, wherein the developing substance is a dry electron-accepting compound. 9. The method according to claim 8, wherein the developing substance is a resin powder. 10. The method according to claim 1, wherein the step of using the developing material comprises contacting the surface of the ordinary paper sheet containing the transfer coloring material with a fibrous roller containing the coloring material. Method. 11. The method of claim 1, wherein said paper retains a sufficient amount of said transfer color forming material on its surface to react with said developer material to produce a visible image. 12. The method of claim 4, wherein the method comprises the additional step of heating the paper to promote reaction between the color forming material and the developing material. 13. The method of claim 1, wherein the developing material is applied to the surface of the plain paper sheet by passing the plain paper sheet containing the coloring material through a particle body containing the developing material. . 14. The method of claim 1, wherein said developer material is applied to said plain paper sheet by means of a magnetic brush. 15. The developing substance is a liquid developing substance that is encapsulated and coexists on the surface of the image-forming sheet together with the microcapsules containing the photosensitive composition, and the developing substance and the color-forming substance coexist on the image-forming sheet. 3. A method according to claim 2, wherein the method is applied to the surface of the sheet of plain paper by transfer from. 16. The method of claim 15, wherein the developer is encapsulated in discrete walled microcapsules. 17. The method according to claim 16, wherein the microcapsules containing the developer further contain a photocurable composition. 18. An apparatus useful for forming an image on plain paper utilizing an imaging sheet comprising a support having a microcapsule layer containing a photosensitive composition and a color-forming material, the apparatus comprising: activating the imaging sheet; A device for image-forming exposure to radiation; a device for applying a certain destructive force to the microcapsule layer; a device for superimposing the image-forming sheet and ordinary paper; and a device for separating the paper sheet and the image-forming sheet. An apparatus useful for forming images on ordinary paper, comprising: an apparatus for applying a developing material to the surface of the paper sheet. 19. The developer coexists with the microcapsules containing the photosensitive composition on the surface of the image-forming sheet, and the developer is used together with the color-forming substance on the surface of the paper by transfer from the image-forming sheet. The method according to claim 2, which comprises: