Abstract: A compact-sized fingerprint imaging device includes an optical plate for creating a fingerprint pattern at a finger field on the optical plate. The fingerprint pattern is illuminated with light from an illuminating tool to create imaging light rays. A small thickness of the optical plate, and hence of the fingerprint imaging device, is possible due to a design that includes an array of microreflectors covering a part of the optical plate, the microreflectors being distributed along a base surface. The imaging light rays from the fingerprint pattern that are reflected by the array of microreflectors are received by an imaging lens that projects an image of the fingerprint pattern to an image sensor.

Abstract: An imaging device includes an optical plate made of an optically transparent material and forming a surface for receiving a finger. The imaging device includes a light source and an imaging system. The light source is positioned to illuminate the finger receiving surface. The imaging system is positioned to receive light collected from the finger receiving surface and to form an image of a fingerprint pattern of the finger based on the received light. To reduce a thickness of the optical plate, the optical plate may have an index of refraction less than 1.49. In another design to reduce the thickness of the optical plate, the optical plate may have an index of refraction less than the index of refraction of finger skin. The optical plate may be made of a silicone material.

Abstract: A fingerprint imaging device includes an optical plate and an imaging system. The optical plate includes an optically-transparent base having a first surface covered with an array of microstructures and a coating deposited on the first surface for receiving a finger. To enable fingerprint imaging, the coating has an index of refraction that is different from the index of refraction of the base.

Abstract: A fingerprint imaging device includes an optical plate having a finger receiving surface for creating an image of a fingerprint pattern. The fingerprint pattern is illuminated with light from an illuminating tool to create imaging light rays. The imaging light rays from the fingerprint pattern are received by an imaging lens that projects an image of the fingerprint pattern to an image sensor. Another light source is provided to project a light beam onto finger receiving surface. This light source is used to determine whether an object on the finger receiving surface is real or fake.