Abstract: Small mechanical devices fabricated from semiconductor substrates called micro-electromechanical systems (MEMS) are used in the telecommunications industry for various purposes, such as switching and attenuation. Typically a small mirror or arm is moved into or out of the optical path of a beam of light to redirect of attenuate the signal. The present invention relates to a drive circuit for a MEMS device that converts a low voltage source into a higher more useful voltage pulse. The present invention also relates to an optically powered MEMS device utilizing the aforementioned drive circuit. Moreover, the drive circuit according to the present invention can be used to generate a single exponentially decaying pulse that can both generate an actuation force and a braking force for the MEMS device.

Abstract: Small mechanical devices fabricated from semiconductor substrates called micro-electromechanical systems (MEMS) are used in the telecommunications industry for various purposes, such as switching and attenuation. Typically a small mirror or arm is moved into or out of the optical path of a beam of light to redirect of attenuate the signal. The present invention relates to a drive circuit for a MEMS device that converts a low voltage source into a higher more useful voltage pulse. The present invention also relates to an optically powered MEMS device utilizing the aforementioned drive circuit. Moreover, the drive circuit according to the present invention can be used to generate a single exponentially decaying pulse that can both generate an actuation force and a braking force for the MEMS device.

Abstract: 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.

Abstract: A non-minutia method and apparatus for comparing a reference fingerprint image to a candidate fingerprint image are disclosed. During enrollment of a reference image, a unique reference set of data is generated in a reference coordinate system by placing a group of line segments on the reference image. A collection of constraints is used for defining the subspace for each line of the reference group. A similar set of candidate line segments is constructed on the candidate fingerprint image in a candidate coordinate system. A candidate set of data is determined and then compared with the reference set of data using translation and rotation of the coordinate systems. Tolerances of the comparison are also provided for.