Non-contact non-destructive latent image scanner

A method for detecting and recording the information resulting from a latent image residue place on a surface, comprising the steps of:

• a) focusing a latent image scanner comprising a three-color laser-diode interferometry thickness gauge on the spot of the surface where a latent image is located;
• b) measuring the height of the latent image residue on the surface at said spot;
• c) recording the height measurement and location coordinates of the spot by a computer;
• d) moving the focus of said latent image scanner to new coordinates on an X-Y plane of the surface in a predetermined manner by moving an X-Y mechanical translator associated with said latent image scanner;
• and
• e) repeating steps a through d so as to detect and record the height information at least a portion of the latent image residue.

A method for detecting and recording information resulting from a latent image residue place on a surface, comprising the steps of:

• a) focusing a latent image scanner comprising a three-color laser-diode interferometry profiler on the spot of the surface where a latent image is located;
• b) measuring the height of the latent image residue on the surface at said spot;
• c) recording the height measurement and location coordinates of the spot by a computer;
• d) moving the focus of said latent image scanner to new coordinates on an X-Y plane of the surface in a predetermined manner by moving an X-Y mechanical translator associated with said latent image scanner;
• and
• e) repeating steps a through d so as to detect and record the height information of at least a portion of the latent image residue.

A latent image scanner comprising:

• a) means for focusing an image scanner on a spot of a surface where a latent image is located;
• b) means for measuring the height of the latent image residue on the surface of said spot;
• c) means for recording the height measurement and location coordinates of the spot;
• and
• d) means for controlling the movement of the focus of said image scanner in a predetermined manner, so as to focus, measure and record the height of at least a portion of the latent image residue, wherein the means for measuring the height of the residue is a three-color laser-diode interferometer.