초록 ▼

A fingerprint identifying device includes a transparent prism having a fingerprint receiving face, a fingerprint viewing face at an acute angle to the fingerprint receiving face, two opposed parallel faces perpendicular to the fingerprint receiving face and a further light-absorbing face generally o

A fingerprint identifying device includes a transparent prism having a fingerprint receiving face, a fingerprint viewing face at an acute angle to the fingerprint receiving face, two opposed parallel faces perpendicular to the fingerprint receiving face and a further light-absorbing face generally opposite to the fingerprint viewing face. A light source in the form of a bank of LEDs is provided for transmitting light into the prism. A light diffuser is provided for light transmitted from the light source such that in operation diffused light is transmitted into the prism through both of the parallel faces and against the fingerprint receiving face to provide substantially uniform illumination of a finger contacting the fingerprint receiving face, a fingerprint image being visible through the fingerprint viewing face. Preferably, the bank of LEDs is disposed at the two opposed parallel faces adjacent to the fingerprint receiving face. It is also preferred if the light source extends above the plane of the fingerprint receiving face to illuminate the edges of a finger from outside of the prism.

대표청구항 ▼

[ We claim:] [1.] An apparatus for identifying fingerprints, comprising:transparent prism means having a fingerprint receiving face, a fingerprint viewing face at an acute angle to the fingerprint receiving face, two opposed parallel faces perpendicular to the fingerprint receiving face and a furthe

[ We claim:] [1.] An apparatus for identifying fingerprints, comprising:transparent prism means having a fingerprint receiving face, a fingerprint viewing face at an acute angle to the fingerprint receiving face, two opposed parallel faces perpendicular to the fingerprint receiving face and a further light-absorbing face generally opposite to the fingerprint viewing face,light source means for transmitting light into the prism, andlight diffuser means for diffusing light transmitted from the light source,such that in operation diffused light is transmitted into the prism through both of the parallel faces and against the fingerprint receiving face to provide substantially uniform illumination of a finger contacting the fingerprint receiving face, a fingerprint image being visible through the fingerprint viewing face, the light source being located adjacent both of the parallel faces and extending beyond a plane of the fingerprint receiving face, whereby some of the light is directed directly against a finger contacting the fingerprint receiving face, the remainder of the light being transmitted into the prism through the parallel faces.