material and the image receiving material from each other. In the thermal developing image forming apparatus, a photosensitive element coated on the photosensitive material is imagewise exposed to form a latent image. The photosensitive material is then overlapped with an image receiving material, and the materials are pressed under heat between a rotating drum and an endless belt pressed on the rotating drum, whereby diffusible dyes are released from the photosensitive material in an image part and transferred to the image receiving material. Thereafter, the materials are detached from each other to form a color image on the image receiving material.
In general, a recording material having an image forming layer on only one surface thereof (single sided photosensitive film) is used in the method of recording a latentand there is no necessity of heating from both surfaces of the material.
In the method, in which a subject is placed between an X-ray tube and a recording material, and a latent image is recorded on the recording material with an X-ray transmitted through the subject, a recording material having image forming layers on both sides of a support (double sided photosensitive film) is used. The double sided photosensitive film is housed, upon imaging, in a cassette with fluorescent intensifying screens disposed on both front and back surfaces thereof. The fluorescent intensifying screen emits fluorescent light upon irradiating with an X-ray. The double sided photosensitive film is exposed with the fluorescent light.
In the case where a recording material having image forming layers on both surfaces is applied to