Latent fingerprint detection
First Claim
1. A device for detecting a latent fingerprint on a substrate, the device comprising:
- an illumination source that emits illumination at a VUV (vacuum ultra-violet) wavelength range to illuminate an area on the substrate, wherein the illumination source is configured to cause the substrate to fluoresce providing visible spectrum contrast against the fingerprint which does not fluoresce; and
a visible-spectrum imaging device that captures an image of the illuminated fingerprint contrasted against the fluorescing substrate;
wherein the illumination source comprises a broad-spectrum light source and a waveband filtering device that filters all but the VUV illumination waveband out of the broad-spectrum generated by the broad-spectrum light source;
wherein the waveband filtering device comprises a first mirror in optical communication with the broad-spectrum light source and a second mirror in optical communication with the first mirror;
wherein the first and second mirrors both being wedge-shaped mirrors, each having a wedge angle that creates total internal reflection with respect to any light reflected from a back surface of the mirror; and
wherein the first and second mirrors both being equipped with a VUV dielectric coating on a front reflecting surface such that each mirror reflects only the VUV illumination waveband from its front reflecting surface.
1 Assignment
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Accused Products
Abstract
Systems, devices, and methods for detecting a contaminant on a substrate are discussed herein. Variations of such systems, devices, and methods may include one or more illumination sources that emit illumination at one or more desired wavelength ranges to illuminate one or more areas on the substrate; where the desired wavelength range is one that is absorbed by the contaminant while causing the substrate to fluoresce. Such fluorescence may be detected with a visible-spectrum detector, which will also detect the contaminant as a darker contrast area against the fluorescence. In some variations, an illumination source includes a broad-spectrum light source and a waveband filtering device that filters all but the desired illumination waveband out of the broad-spectrum light generated by the broad-spectrum light source.
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Citations
16 Claims
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1. A device for detecting a latent fingerprint on a substrate, the device comprising:
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an illumination source that emits illumination at a VUV (vacuum ultra-violet) wavelength range to illuminate an area on the substrate, wherein the illumination source is configured to cause the substrate to fluoresce providing visible spectrum contrast against the fingerprint which does not fluoresce; and a visible-spectrum imaging device that captures an image of the illuminated fingerprint contrasted against the fluorescing substrate; wherein the illumination source comprises a broad-spectrum light source and a waveband filtering device that filters all but the VUV illumination waveband out of the broad-spectrum generated by the broad-spectrum light source; wherein the waveband filtering device comprises a first mirror in optical communication with the broad-spectrum light source and a second mirror in optical communication with the first mirror; wherein the first and second mirrors both being wedge-shaped mirrors, each having a wedge angle that creates total internal reflection with respect to any light reflected from a back surface of the mirror; and wherein the first and second mirrors both being equipped with a VUV dielectric coating on a front reflecting surface such that each mirror reflects only the VUV illumination waveband from its front reflecting surface. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A device for detecting a latent fingerprint on a substrate, the device comprising:
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an illumination source that emits collimated illumination at a mid-wave or long-wave infra-red illumination to illuminate an area on the substrate, wherein the illumination source is configured to cause the substrate to fluoresce providing visible spectrum contrast against the fingerprint which does not fluoresce, wherein the latent fingerprint remains untreated with any chemicals or contrast agents prior to illumination; and an infra-red imaging device that captures an image of the illuminated fingerprint contrasted against the substrate; where the collimated infra-red beam source is capable of providing illumination to a target more than ten feet away from the illumination source for latent fingerprint detection; and
where the imaging device is co-located with the infra-red beam source. - View Dependent Claims (8, 9)
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10. A device for detecting a latent fingerprint on a substrate, the device comprising:
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an illumination source that emits illumination at a VUV (vacuum ultra-violet) wavelength range to illuminate an area on the substrate, wherein the illumination source is configured to cause the substrate to fluoresce providing visible spectrum contrast against the fingerprint which does not fluoresce; and a visible-spectrum imaging device that captures an image of the illuminated fingerprint contrasted against the fluorescing substrate; where the illumination source includes a broad-spectrum light source and a waveband filtering device that filters all but the VUV illumination waveband out of the broadspectrum generated by the broad-spectrum light source; the waveband filtering device including a first optical element in optical communication with the broad-spectrum light source and a second optical element in optical communication with the first optical element; the first and second optical elements both being equipped with a VUV dielectric coating on a reflecting surface such that each optical element reflects only the VUV illumination waveband from the reflecting surface; and the first and second optical elements both being configured to remove light not reflected by the reflecting surface from the output illumination. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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Specification