Patent Document ID: 8768013
Application ID: 13286895
Patent Status: 1

Claim One:
1. A method of calibrating a geometric model of a fingerprint imaging system, the geometric model defining geometry of reflective and/or refractive surfaces associated with optical elements within the fingerprint imaging system at which light is reflected or refracted, the geometric model including a plurality of surface parameters that specify relative physical positions of reflective and/or refractive surfaces within the fingerprint imaging system in relation to other reflective and/or refractive surfaces within the fingerprint imaging system in three-dimensional space, the method comprising: capturing an image of a predetermined target with the fingerprint imaging system, the target including distinguishing points provided at predetermined positions on the target; measuring positions of the distinguishing points in the captured image of the target; comparing the measured positions of the distinguishing points in the captured image to positions of distinguishing points predicted according to the geometric model of the fingerprint imaging system; and adjusting the surface parameters of the geometric model that specify the relative physical positions of reflective and/or refractive surfaces associated with optical elements in the fingerprint imaging system based on the comparison between the measured positions of the distinguishing points and the predicted positions of the distinguishing points without mechanically adjusting the relative physical positions of the refractive and/or reflective surfaces of the optical elements.