Signalling means for enhancing the performance of automatic fingerprint identification systems by reducing system response to non-fingerprint-like regions within an image field pattern of interest. A two dimensional generalized sequency analyzer, such as a fast Fourier transform machine, responsive to a binary coded image signal identifies discrete frequency terms occurring within a selected bandwidth corresponding to a spatial frequency region of interest, associated with a fingerprint image. Logic means, responsive to the sequency analyzer, further identifies the relative energy levels of the bandwidth-limited spectral content of the binary coded image signal to signal the identity of a non-fingerprint-like region within the scanned image.

Non-fingerprint region indicator

An apparatus and method for acquiring an image of a patterned object such as a fingerprint including a light refracting device, a focusing lens, and a light source. The light refracting device can, for example, be a prism and includes an imaging surface, a light receiving surface and a viewing surface. Incident light from the light source is projected through the light receiving surface and reflected off a surface other than the imaging surface. This reflected light is then projected onto the imaging surface to create an image of the patterned object from substantially all scattered light through the viewing surface. The lens is placed adjacent to the viewing surface to focus the light on an image sensor.

High contrast, low distortion optical acquisition system for image capturing

An improved incoherent optical processor fingerprint identification apparatus employs a rotatable grating for inspecting the ridge orientations in a plurality of preselected finite sample areas of a fingerprint. A detector array including a plurality of detectors each related to a discrete sampled area is disposed to receive an image of the fingerprint filtered by the rotating grating. An incoherent light source and a lens and retroreflective prism assembly function in cooperation with the grating to produce an image thereof superposed on the grating itself such that minimum light is propagated to the detector array in the absence of an input fingerprint pattern whereas, in the presence of a fingerprint pattern, light is diffracted thereby to be filtered by the grating for supply to the detectors. Maximum light may occur at each detector under a condition of spatial alignment of the grating lines with the ridge lines of the related sampled area whereby the time interval between a reference orientation of the grating and the instant of maximum light at each detector may be converted to equivalent electrical signals uniquely representative of a particular fingerprint pattern. The signal to noise factor of the optical system is significantly improved by the use of a novel grating element having plural reflecting and transmitting stripes, with optically absorbing stripes interposed between them.

Spurious signal removal in optical processor fingerprint identification apparatus

Apparatus for use with an autocorrelation technique for characterizing fingerprints includes an imaging device for providing an image of a fingerprint. The image so produced is then utilized by a microprocessor in order to generate an autocorrelation pattern for statistical comparison with stored data so as to determine whether the image of the fingerprint under test is derived from the fingerprint representated by the stored data.

Method and apparatus for fingerprint characterization and recognition using auto correlation pattern

A system for inspecting a specimen, such as a semiconductor wafer that uses a laser light source for providing a beam of light. The beam is applied to a traveling lens acousto-optic device having an active region and responsive to an RF input signal to selectively generate plural traveling lenses in the active region. The traveling lens acousto-optic device is operative to receive the light beam and generate plural flying spot beams, at the respective focus of each of the generated traveling lenses. A light detector unit, having a plurality of detector sections, each detector section having a plurality of light detectors and at least one multi-stage storage device operative to receive in parallel an input from the plurality of light detectors, is used to generate useable scan data. Information stored in each of the storage devices is serially read out concurrently from the multiple stages.

Wafer defect detection system with traveling lens multi-beam scanner

A fingerprint identification apparatus utilizing coherent optical processing techniques wherein the ridge line orientation in a plurality of preselected finite areas of the fingerprint is inspected by means of a rotating spatial slit filter disposed in the Fourier transform plane of an optical processor for sequentially selecting distinct components of the Fourier transform for transmission to the image plane of the processor whereat a plurality of photodetectors are disposed each corresponding to a discrete sample area. The time delay between a reference orientation of the slit filter and the occurrence of peak light at each detector is noted and a proportional analog or digital representation thereof is generated for storage and subsequent comparison with similarly obtained signals representative of a fingerprint presented for identification.

Coherent optical processor fingerprint identification apparatus

An electro-optical data storage system and method of operation thereof comprising the means and steps, respectively, for selectively recording and reading data stored in any of a plurality of tandemly disposed photoplastic plates. Data is recorded on each plate by uniformly charging a selected plate, exposing the selected plate to a data beam which modulates the charge to produce a charge pattern representative of the data, briefly heating the plate to a softened condition to develop the charge pattern as a deformation image on the photoplastic surface, and converting the deformation image to a latent image by briefly reheating the plate to a greater degree than used for developing the deformation image. The data stored in any plate is read out by uniformly recharging and again reheating a selected plate to reconstitute the latent image as a deformation image which modulates a beam propagating through the plate so that the stored data is imparted to the beam for readout.

Stacked photoplastic data storage system

A holographic apparatus for recording digital data comprising a recording medium and means for producing coherently related reference and signal beams in combination with a plurality of phase modulators disposed across the path of the signal beam and each responsive to a discrete bit of the digital data to be recorded. In the absence of electrical excitation applied to the modulators, the entire signal beam would normally interfere with the reference beam to produce high intensity interference fringes. Application of electrical energy representative of discrete digital bits, however, to one or more of the modulators causes the associated portions of the signal beam to be varied in phase such that interference thereof with the reference beam is substantially weakened whereby upon illumination of the developed hologram for readout only the unmodulated parts of the signal beam are reproduced.

Mahon D Mc

Papers

Coherent optical processor fingerprint identification apparatus

Stacked photoplastic data storage system

Phase modulation holographic data recording apparatus