Method and apparatus for printing on passports and the like

Method for printing on documents in booklet form;

• such as passports and other identification documents, which comprises the following steps:
• 1) providing a set of signals defining an image to be printed;
• 2) providing a temporary substrate having two faces;
• 3) providing a transparent substrate having a front and a rear face;
• 4) for each color comprised in said image to be printed:
• (a) causing a laser beam to impinge on a metal cylinder in a pattern controlled by said signals, whereby electrostatically to charge a surface of said cylinder at selectively predetermined spots;
• (b) passing said electrostatically charged cylinder close enough to a reservoir of coloring matter in powder form, having said color to be printed, for the coloring matter to be electrostatically attracted to said selectively predetermined spots and form thereon the pattern which said color forms in said images;
• (c) passing said temporary substrate in contact with said cylinder whereby said pattern is deposited on one face thereof;
• (d) repeating said operations (a) to (c) for all of said each color whereby, to form said image;
• said temporary substrate being substantially non-absorbent and non-adhesive, or at least considerably less adhesive and less absorbent for said coloring matters than said transparent substrate;
• 5) provisionally setting said image without an application of pressure;
• 6) placing one face of said temporary substrate in contact with said rear face of said transparent substrate;
• 7) transferring said image from said temporary substrate to said rear face of said transparent substrate, whereby said image is applied to said transparent substrate rear face and the image is visible through said transparent substrate from said front face thereof and is visible in reverse from said rear face;
• 8) providing a final substrate, that is intended to carry the image, said final substrate having a front face;
• 9) juxtaposing said transparent substrate to said final substrate with said rear face of said transparent substrate in contact with said front face of said final substrate;
• and
• 10) laminating the juxtaposed said transparent substrate and said final substrate, permanently to bind them, said image being enclosed between said two substrates and visible from said front face of said transparent substrate as if printed on said final substrate.