Abstract: A labeling method for marking a product with invisible information. The label includes a removable laminate formed from a light transmissive layer, and a light transmissive adhesive that detachably affixes the label to a product. The label includes an invisible marker that contains information, detectable by light of selected wavelength. The amount of marker selected is sufficient to allow information in the marker to be detected only when the laminate is affixed over a surface with a selected optical background. The label laminate is removed from the surface of the product and affixed to a surface having the selected optical background and is exposed to light that renders the information in the marker detectable. The method allows covert information in the label laminate to be reliably detected and read with the use of minimal quantities of marker material.

Abstract: An apparatus for authenticating security markers includes a laser or LED for illuminating the security marker; a detector for detecting an optical response from the security marker; an element for changing a temperature of the laser or LED to vary the wavelength of radiation produced by the LED; a detector for detecting changes in the optical response from the security marker as the wavelength of the radiation changes; a microprocessor for comparing the optical response profile from the security marker as it varies with changes in wavelength to a reference profile; and authenticating the security marker if the optical response profile matches the reference profile.

Abstract: A method for authenticating security markers includes preparing a security marker with at least two or more optically active compounds; applying the security marker to an article to be authenticated; illuminating the security marker with radiation; detecting the optical response of the security marker; and wherein the two or more optically active compounds have a complementary response to different wavelengths of the illuminating radiation.

Abstract: A method for authenticating security markers includes illuminating the security marker with a laser, detecting an optical response from the security marker, changing a temperature of the laser to vary the wavelength of radiation produced by the laser; detecting changes in the optical response from the security marker as the wavelength of the radiation changes, comparing the optical response profile from the security marker as it varies with changes in wavelength to a reference profile; and authenticating the security marker if the optical response profile matches the reference profile.

Abstract: A method of eliminating background noise from a system for authenticating security markers includes capturing an image of a background of the security marker; illuminating the security marker; capturing a plurality of images of the optical response of the security marker; averaging the plurality of optical response images; smoothing the background image; and subtracting the smoothed background image from the average of the plurality of optical response images.

Abstract: A method to deactivate a security measure includes applying a first covert optically active security marker to a product or document; completing a transaction for the product or document; and applying a second optically active security marker to the product or document which indicates completion of the transaction.

Abstract: An apparatus for eliminating background noise from a security marker authenticating system including a first sensor for capturing an image of a background of the security marker; a light source for illuminating the security marker; the first sensor or a second sensor or both captures a plurality images of the optical response of the security marker; a computer which averages the plurality of optical response images; the computer smoothes the background image; and the computer subtracts the smoothed background image from the average of the plurality of optical response images.

Abstract: A method for authenticating security markers includes capturing an image of a region of interest on a product with a camera; storing image data in a two-dimensional array on a microprocessor; counting a number of pixels at or above a predetermined brightness level in the image data with the microprocessor to determine a first score; establishing an area within the image; counting a number of pixels within the area to determine a second score; calculating a ratio of the second score to the first score; and if the ratio is above a predetermined threshold the security marker is authenticated.

Abstract: A method for detecting authorized security markers includes capturing an image of a region of interest on a product with a camera; storing image data in a two-dimensional array on a microprocessor; counting a number of pixels at or above a predetermined brightness level in the image data with the microprocessor to determine a first score; eroding the image data; counting the pixels which remain at or above the predetermined brightness level after erosion to determine a second score; calculating a ratio of the second score to the first score; and producing a first authentication signal if the ratio meets a first predetermined criteria.

Abstract: An article comprises one or more porous particles. Each porous particle comprises a polymer that provides a continuous solid phase including an external particle surface, and first and second discrete pores that are isolated from each other and dispersed within the continuous solid phase. The porous particle further comprises a first marker material present in the first discrete pores, and a second marker material that is detectably different from the first marker material and is present within the second discrete pores. The marker materials can provide a means for identifying documents, clothing, or other articles as genuine, and providing a detectable security system.

Abstract: A security marker material comprising emissive particles selected from at least two groups with different size distributions and the size distributions satisfy the formula: [(x?z)2/(Sx2+Sz2)]1/2>1 wherein x and z are the volume-weighted mean equivalent-spherical diameters of the two particle distributions and Sx and Sz are the standard deviations of the same two distributions.

Abstract: A security marker material comprising emissive particles selected from at least two groups with different size distributions and the size distributions satisfy the formula: [(x?z)2/(Sx2 +Sz2)]1/2 >1 wherein x and z are the volume-weighted mean equivalent-spherical diameters of the two particle distributions and Sx and Sz are the standard deviations of the same two distributions. The emissive materials are placed in or on an item. The emissive materials are excited with electromagnetic radiation in one or more specified spectral bands. The electromagnetic radiation is detected in one or more spectral bands from the emissive materials in an image-wise fashion. The attributes of the image are analyzed and characterized and are compared to authentication criteria to determine the authenticity of the marked item.

Abstract: A security marker material comprising emissive particles and the emissive particles can be grouped into at least two groups with different size distributions and the size distributions satisfy the formula: [(x?z)2/(Sxs+Sz2)]1/2>1 where x and z are the volume-weighted mean equivalent-spherical diameters of the two particle distributions and Sx and Sz are the standard deviations of the same two distributions. The security marker material is part of a security system and authentication is based on criteria which include responses related to marker size and size distribution. This invention provides a less expensive method of generating a more complex, difficult-to-replicate security code.

Abstract: A labeling method for marking a product with invisible information. The label includes a removable laminate formed from a light transmissive layer, and a light transmissive adhesive that detachably affixes the label to a product. The label includes an invisible marker that contains information, detectable by light of selected wavelength. The amount of marker selected is sufficient to allow information in the marker to be detected only when the laminate is affixed over a surface with a selected optical background. The label laminate is removed from the surface of the product and affixed to a surface having the selected optical background and is exposed to light that renders the information in the marker detectable. The method allows covert information in the label laminate to be reliably detected and read with the use of minimal quantities of marker material.

Abstract: A silver halide emulsion comprising radiation sensitive silver halide grains exhibiting a face centered cubic crystal lattice structure containing a hexacoordination complex of an iridium ion in which at least half of the coordination sites in the hexacoordination complex are provided by halogen or pseudohalogen ligands, and at least one coordination site is provided by a ligand comprising a azole ring containing a chalcogen atom and a nitrogen atom, wherein the azole ring is substituted at the 5-position with a halide ion. The invention provides emulsions containing with a preferred class of iridium dopants which are especially useful for improving reciprocity performance in silver halide emulsions with minimal or no impact on other aspects of photographic performance. These dopants give a superior balance of reciprocity and other photographic properties compared to other iridium dopants exemplified in the prior art.

Abstract: A radiation-sensitive emulsion is disclosed comprised of cubic silver iodochlorobromide grains comprising 0.25 to about 1.5 mol % iodide, 1 to about 25 mol % chloride, and from about 73.5 to 98.75 mol % bromide, each based on total silver in the emulsion, wherein the grains have an average equivalent circular diameter of greater than 0.6 micrometers and contain from 10−7 to 10−3 mole per silver mole of a metal ion coordination complex dopant of Formula (I) in an internal region of the grains formed after 10 percent and before 95 percent of the total grain silver has been precipitated: [ML6]n  (I) wherein n is zero, −1, −2, −3 or −4, M is a filled frontier orbital polyvalent metal ion, other than iridium, and L6 represents bridging ligands which can be independently selected, provided that at least four of the ligands are anionic ligands, and at least one of the ligands is a cyano ligand or a ligand more electronegative than a cyano ligand.

Abstract: The invention provides a radiation-sensitive silver halide emulsion comprisingsilver halide grains including tabular grains(a) having {111} major faces(b) containing greater than 70 mole percent bromide, based on silver,(c) accounting for greater than 90 percent of total grain projected area,(d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m,(e) exhibiting an average thickness of less than 0.07 .mu.m, and(f) having latent image forming chemical sensitization sites on the surfaces of the tabular rains, anda spectral sensitizing dye adsorbed to the surfaces of the tabular grains,wherein the surface chemical sensitization sites include at least one silver salt epitaxially located on said tabular rains and wherein said grains further comprise a mercapto compound represented by Formula III ##STR1## where R.sup.1 is an aliphatic or aromatic radical containing up to 20 carbon atoms.

Abstract: A chemically and spectrally sensitized ultrathin tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (e) exhibiting an average thickness of less than 0.07 .mu.m.It has been observed that increased speed and contrast as well as improvements in speed-granularity relationships can be realized when the surface chemical sensitization sites include epitaxially deposited silver halide protrusions forming epitaxial junctions with the tabular grains, the protrusions (a) being located on up to 50 percent of the surface area of the tabular grains, (b) having a higher overall solubility than at least that portion of the tabular grains forming epitaxial junctions with the protrusions, and (c) forming a face centered cubic crystal lattice.

Abstract: A chemically and spectrally sensitized ultrathin tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide and at least 0.25 mole percent iodide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (e) exhibiting an average thickness of less than 0.07 .mu.m.

Abstract: A chemically and spectrally sensitized tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide and at least 0.25 mole percent iodide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (f) exhibiting an average thickness in the range of from less than 0.3 .mu.m to at least 0.07 .mu.m.