Abstract: A composition and a method and an apparatus for using the composition for secure thermal ink jet printing on a substrate. The thermal ink jet ink composition is clear and is invisible to an unaided human eye in visible light when printed on the substrate.

Abstract: A method and substrate for printing information wherein at least one coating is applied to a substrate, the coating having a colorformer leucodye and at least one color activator. The colorformer leucodye and at least one activator react when heated to exhibit a chromic change of at least one of a color change visible in normal light and a fluorescence visible only in ultraviolet light. The at least one coating is heated with at least one laser beam to effect the chromic change at selected points to thereby print information.

Abstract: A composition and a method and an apparatus for using the composition for secure thermal ink jet printing on a substrate. The thermal ink jet ink composition is clear and is invisible to an unaided human eye in visible light when printed on the substrate.

Abstract: A method for authenticating a textile product, wherein a colorless composition is applied to at least one portion of at least one thread of the textile product. The composition comprises one of a pair of a colorformer and an activator which react when mixed to produce a spectral response. The textile product is authenticated as genuine by applying the other of the pair of the colorformer and activator to at least one portion of the at least one thread to produce the spectral response. The textile product may be a thread or a woven label.

Abstract: A method and substrate for printing information wherein at least one coating is applied to a substrate, the coating having a colorformer leucodye and at least one color activator. The colorformer leucodye and at least one activator react when heated to exhibit a chromic change of at least one of a color change visible in normal light and a fluorescence visible only in ultraviolet light. The at least one coating is heated with at least one laser beam to effect the chromic change at selected points to thereby print information.

Abstract: A method for authenticating a textile product, wherein a colorless composition is applied to at least one portion of at least one thread of the textile product. The composition comprises one of a pair of a colorformer and an activator which react when mixed to produce a spectral response. The textile product is authenticated as genuine by applying the other of the pair of the colorformer and activator to at least one portion of the at least one thread to produce the spectral response. The textile product may be a thread or a woven label.

Abstract: A latent image printing method and apparatus uses a substrate with one main surface having a covering comprising one of a first pair of a color developer and color former dye defining a background color in conjunction with the one main surface, wherein the color developer and the color former dye react when mixed to produce a first spectral response which is visible relative to the background color and a continuous coating over the covering which is non-porous with respect to the other of the pair and solvent-resistant to the other of the pair. The coating above selected portions of the covering corresponding to a desired latent image is removed.

Abstract: A latent image printing method and apparatus uses a substrate with one main surface having a covering comprising only one of a first pair of a color developer and color former dye in at least one selected latent imaging area defining a background color in conjunction with the one main surface, wherein the color developer and the color former dye react when mixed to produce a first spectral response which is visible relative to the background color and a continuous coating over the covering which is non-porous with respect to the other of the pair and solvent-resistant to the other of the pair. The coating above selected portions of the covering corresponding to a desired latent image is removed.

Abstract: A latent image printing method and apparatus uses a substrate with one main surface having a covering comprising one of a first pair of a color developer and color former dye defining a background color in conjunction with the one main surface, wherein the color developer and the color former dye react when mixed to produce a first spectral response which is visible relative to the background color and a continuous coating over the covering which is non-porous with respect to the other of the pair and solvent-resistant to the other of the pair. The coating above selected portions of the covering corresponding to a desired latent image is removed.

Abstract: A latent image printing method and apparatus uses a substrate with one main surface having a covering comprising one of a first pair of a color developer and color former dye defining a background color in conjunction with the one main surface, wherein the color developer and the color former dye react when mixed to produce a first spectral response which is visible relative to the background color and a continuous coating over the covering which is non-porous with respect to the other of the pair and solvent-resistant to the other of the pair. The coating above selected portions of the covering corresponding to a desired latent image is removed.

Abstract: A security marking method and composition wherein a first marking is applied to a surface of a substrate with a mixture of a printing medium and a first composition, wherein the first marking is visible to an unaided human eye and is indistinguishable from a marking applied with the printing medium alone, to an unaided human eye when illuminated by visible light or ultraviolet light. A second composition is added either with the mixture or thereafter, wherein the second composition is reactable with the first composition to fluoresce and wherein the fluorescing is only visible to an unaided human eye when illuminated by ultraviolet light.

Abstract: A latent image printing method and apparatus uses a substrate with one main surface having a covering comprising one of a first pair of a color developer and color former dye defining a background color in conjunction with the one main surface, wherein the color developer and the color former dye react when mixed to produce a first spectral response which is visible relative to the background color and a continuous coating over the covering which is non-porous with respect to the other of the pair and solvent-resistant to the other of the pair. The coating above selected portions of the covering corresponding to a desired latent image is removed.

Abstract: A latent image printing method and apparatus uses a substrate with one main surface having a covering comprising only one of a first pair of a color developer and color former dye in at least one selected latent imaging area defining a background color in conjunction with the one main surface, wherein the color developer and the color former dye react when mixed to produce a first spectral response which is visible relative to the background color and a continuous coating over the covering which is non-porous with respect to the other of the pair and solvent-resistant to the other of the pair. The coating above selected portions of the covering corresponding to a desired latent image is removed.

Abstract: A security marking method comprises marking a portion of the substrate by applying a first marking fluid which is invisible to a unaided eye when illuminated by both visible light and ultraviolet light and activating the marked portion by applying a second marking fluid thereon. The second marking fluid is reactable with the first marking fluid to be invisible to an unaided human eye when illuminated by visible light and fluorescent when illuminated by ultraviolet light. The invention also includes the composition comprising the first and second marking fluids.

Abstract: A method for protecting against duplication of a document with a color copier comprises providing a background color on a document having an average reflectance value and printing on the background with a contrast color having a spectral characteristic which modulates the average reflectance value by no more than 5% and has an average value equal to the average reflectance value. The contrast color is printed with a printing medium that allows activation by a rub and reveal action or by application of intense light.

Abstract: A method for protecting against duplication of a document with a color copier and a security substrate comprises providing a background color on a document having an average reflectance value and printing on the background with a contrast color having a spectral characteristic which modulates the average reflectance value by no more than 5% and has an average value equal to the average reflectance value. The contrast color is printed with a printing medium including one of a colorformer leucodye and an activating phenolic resin. The other of the colorformer leucodye and the activating phenolic resin is to the printing medium on the document later to verify that the document is an original.

Abstract: A detecting or monitoring device for laser radiation is able to oeprate at room temperature and employs a thin film of semi-conductor material of non-centrosymmetric lattice structure having a substantial crystallographic texture; thin film may suitably be tellurium in a film thickness of 1 to 100 .mu.m, supported on a substrate of single crystal silicon.

Abstract: Paper is provided with resistance to photocopying or transmission by telefacsimile by spatial spectral modulation of the paper reflectance at a specific single or preferably multiple frequencies. Such paper has a colored pattern of at least two colors repeating in at least one dimension of a face of a paper with at least one frequency in the range of from about 0.5 to about 50 times per cm. The colors contrast with black or similar dark color to permit black or similar dark colored information to be visible readable when applied to the colored pattern. The colors also cooperate with such information to provide a document resistant to photocopying and transmission by telefacsimile.

Abstract: A method for protecting against duplication of a document with a color copier comprises providing a background color on a document having an average reflectance value and printing on the background with a contrast color having a spectral characteristic which modulates the average reflectance value by no more than 5% and has an average value equal to the average reflectance value. The contrast color is printed with a printing medium that allows activation by a rub and reveal action or by application of intense light.