Patent ID: 6094279
Filing Date: 2000-07-25
Classification: G11B

Abstract:
A process for integrating data in visually non-perceptible form into a reflective image formed by an array of points of different light absorptivities by means of a machine-readable agent having some perceptible amount of light absorptivity, comprising the steps of:(a) determining a target level of light absorptivity for each of said image points prior to forming said reflective image;(b) determining an amount of printing agent that must be deposited over each image point to attain said target level of light absorptivity;(c) selecting a group of said array of points to form an optical code;(d) redetermining said amount of printing agent for each of said array of points by subtracting some or all of the first determined amount of printing agent for each selected point such that said target level of light absorptivity will be attained when said machine-readable agent is deposited onto each selected point;(e) depositing a printing agent over said array of points to form said reflective image, and(f) depositing said machine-readable agent onto a selected group of said array of points to form an optical code representative of said data that is machine readable but visually imperceptible.