An image-forming device includes a source of radiation (20), e.g. UV, a means such as a liquid-crystal cell (1) for modulating this radiation according to the image to be formed, and an output means (11) towards which the modulated radiation is directed and whose reflective or absorptive properties are altered when it receives the radiation. A suitable material for the output means is a photochromic material which changes colour under the influence of UV. Such a display can be made easily visible in strong ambient light. The output means can also be made removable, the device then acting as a printer.