The present invention relates to an image recording apparatus of the the which employs a photo- and pressure-sensitive heat-developable material which is composed of a substrate and a layer formed on the substrate from a material which is photosensitive and which enables a latent image thereon to be developed by heat and the developed image to be fixed by application of pressure. The invention also is concerned with an image recording method which makes use of such a photo- and pressure-sensitive heat-developable material.
An image recording material employing microcapsules containing a photosensitive composition has been known. An example of such a recording material is disclosed in Japanese Kokai No. 179,836/1982. This recording material has a substrate which carries capsules made of a synthetic polymeric resin and containing a vinyl compound, a photopolymerization initiator and a coloring precursor.
In recording an image, using this recording material, the material is first exposed so that the microcapsules are hardened in conformity with the form of the image. Then, as the recording material is pressed, the microcapsules which have not been hardened are ruptured so as to release the coloring agent precursor, thus forming a color image. This image recording system provides a high quality of the recorded image with a dry-type simple processing, but suffers from a disadvantage in that the photosensitivity is much smaller as compared with the system which makes use of silver halide.
Under this circumstance, the present applicant has proposed, in the specification of Japanese Kokai No. 275,742/1986, a novel recording material which has a high photosensitivity and which ensures a high quality of the recorded image with a simple dry-type process. This recording material is a photo- and pressure-sensitive heat-developable material constituted by a carrier and a layer formed on the surface of the carrier, the layer containing at least a photosensitive silver halide, reducing agent, polymerizable compound and a color image forming substance, wherein the polymerizable compound and the color image forming substance are confined in common microcapsules.
An image recording method which makes use of this photo- and pressure-sensitive heat-developable material is disclosed in the specification of Japanese Kokai No. 278,849/1986 filed by the same applicant. According to this method, the heat-developable material is first exposed so that a latent image is formed thereon in conformity with the image to be recorded. Then, the material is heated for development so that the polymerizable compound in the area where the latent image exists is polymerized to produce a polymeric compound, thus thermally setting the microcapsules. Then, the material is superposed on an image receiving material having an image receiving layer capable of receiving the color image forming substance, and is pressed to the image receiving material so that at least part of the microcapsules having no latent image is ruptured so as to transfer the color image forming substance to the image receiving material, thereby forming an image on the latter.
In order to obtain a clear image by the transfer of the heat-developed image from the photo- and pressure-sensitive heat-developable material to the image receiving material, it is essential that the heat-developable material be pressed uniformly onto the image receiving material under a given condition.