Patents by Inventor Peter Verrept
Peter Verrept has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6136524Abstract: A light-sensitive silver halide photographic emulsion has been described, said emulsion comprising a colloidally stabilizing binder and {100} tabular silver halide grains containing at least 50 mole % of silver chloride, wherein at least 70% by number of all grains is provided by said tabular grains, exhibiting an average aspect ratio of at least 5 and an average equivalent circular grain diameter of at least 0.3 .mu.m, wherein said tabular grains have an average thickness of less than 0.25 .mu.m for at least 75% by number of all tabular grains.Type: GrantFiled: February 24, 1999Date of Patent: October 24, 2000Assignee: Agfa-Gevaert, N.V.Inventors: Peter Verrept, Ann Verbeeck, Frank Louwet
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Patent number: 6083678Abstract: A method has been described for preparing a light-sensitive silver halide photographic emulsion comprising performing at least three distinct precipitation steps in an aqueous medium into a reaction vessel, followed by desalting by means of flocculation and washing or by means of ultrafiltration, said emulsion comprising a colloidally stabilizing binder and {100} tabular silver halide grains containing at least 50 mole % of silver chloride, wherein at least 60% by number of all grains is provided by said tabular grains, and wherein said tabular grains exhibit an average aspect ratio of at least 2, an average thickness of at most 0.25 .mu.m with a variation coefficient of at most 0.25, and an average equivalent circular crystal diameter of 0.3 .mu.m or more with a variation coefficient of at most 0.Type: GrantFiled: October 9, 1998Date of Patent: July 4, 2000Assignee: Agfa-Gevaert, N.V.Inventors: Peter Verrept, Jan Cuypers
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Patent number: 6048096Abstract: An image-forming system for radiological imaging is described consisting of an intensifying screen comprising on a support at least one layer of a green-light emitting phosphor and, in operative association therewith, a prehardened light-sensitive photographic silver halide film material, comprising a support and on both sides thereof one or more hydrophilic colloid layers having monodisperse cubic silver chloroiodide grains with a mean crystal diameter of from 0.40 .mu.m up to 0.65 .mu.m or {111} tabular silver chloroiodide grains having an aspect ratio of from 5 to 20 and a tabularity from 20 to 200; wherein said grains have been spectrally sensitized in the green wavelength range and have been coated in a total amount of silver per sq.m. of from 6 g up to 8 g, expressed as an equivalent amount of silver nitrate per sq.m.; wherein in the image-forming system silver chloroiodide grains have been chemically sensitized with one or more selenide compound(s) generating silver selenide.Type: GrantFiled: February 24, 1998Date of Patent: April 11, 2000Assignee: Agfa-Gevaert, N.V.Inventors: Ann Verbeeck, Freddy Henderickx, Johan Loccufier, Peter Verrept
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Patent number: 6030762Abstract: A method has been found of preparing a silver halide emulsion comprising silver chlorobromoiodide or silver chloroiodide tabular grains with at least 75 mole % of chloride and from 0.1 up to 3 mole % of iodide, based on silver, further having {111} crystal faces, an average aspect ratio of at least 2:1, with at least 50%, more preferable at least 75% and still more preferable more than 90% of the total projected area of all grains being provided by said tabular grains and with a variation coefficient on sphere equivalent diameter (SED) of said grains being lower than 0.30, more preferably lower than 0.25 and most preferable from 0.05 up to at most 0.Type: GrantFiled: March 16, 1998Date of Patent: February 29, 2000Assignee: Agfa-Gevaert, N.V.Inventors: Peter Verrept, Ann Verbeeck
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Patent number: 6010840Abstract: A method has been described for preparing a gelatinous emulsion having grains rich in silver choride, wherein at least 70%, and more preferred 90%, of the total projected area of all grains is provided by {111} tabular grains having an average aspect ratio of more than 2:1, an average equivalent circular diameter of at least 0.3 .mu.m and an average thickness of from 0.05 to 0.25 .mu.Type: GrantFiled: January 19, 1999Date of Patent: January 4, 2000Assignee: Agfa-Gevaert, N.V.Inventors: Peter Verrept, Ann Verbeeck, Nadia Vermant, Frank Louwet
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Patent number: 5998083Abstract: An image-forming system for radiological imaging is disclosed said system consisting of an intensifying screen comprising on a support at least one layer of a green-light emitting phosphor and, in operative association therewith, a prehardened light-sensitive photographic silver halide film material, comprising a support and on both sides thereof one or more hydrophilic colloid layers, said layers being hardened to such an extent that their swelling degree is reduced to less than 200% after immersing said material for 2 minutes in demineralised water of 35.degree. C.; further comprising in at least one of said hydrophilic layers chemically ripened, monodisperse essentially cubic silver chloroiodide grains having a mean crystal diameter of from 0.40 mm up to 0.65 mm; wherein said grains have been spectrally sensitised in the wavelength range between 520 and 580 nm, have a maximum absorption between 540 and 500 nm and have been coated in a total amount of silver per sq.m.Type: GrantFiled: February 24, 1998Date of Patent: December 7, 1999Assignee: Agfa-Gevaert, N.V.Inventors: Ann Verbeeck, Freddy Henderickx, Dirk Vandenbroucke, Peter Verrept
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Patent number: 5989799Abstract: A radiographic screen/film combination or system has been provided comprising a duplitized film sandwiched between a pair of supporting or self-supporting X-ray intensifying screens, characterized in that i) said pair of supported or self-supporting X-ray intensifying screens essentially consists of luminescent phosphor particles emitting at least 50% and more preferably at least 80% of their emitted radiation in the wavelength range shorter than 380 nm, as e.g. a niobium and gadolinium doped, monoclinic M, yttriumtantalate (MYT) phosphor corresponding to formula IYTaO.sub.4 :Gd:Nb (I),ii) said film comprises {111} tabular silver halide grains rich in silver chloride, spectrally sensitive to irradiation in the said wavelength range shorter than 380 nm by the presence of at least one azacyanine dye as a spectral sensitizer.Type: GrantFiled: June 18, 1998Date of Patent: November 23, 1999Assignee: Agfa-Gevaert. N.V.Inventors: Ann Verbeeck, Peter Verrept, Paul Callant, Koenraad Caron
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Patent number: 5912108Abstract: A method has been disclosed of processing an image-wise exposed light-sensitive black-and-white silver halide photographic material comprising a support coated on one or both sides thereof with hydrophilic layers, wherein at least one of said layers comprises one or more emulsions having tabular silver halide crystals rich in silver chloride, said method comprising the steps of developing, fixing, rinsing and drying, further characterized in that said developing step proceeds in a black-and-white developer comprising one or more organic compounds inhibiting development, more preferably one or more benzotriazole compounds, and in that said developer is substantially free from bromide ions in favor of a low fog level, a high speed and a sufficiently high covering power of the developed tabular grains.Type: GrantFiled: December 16, 1997Date of Patent: June 15, 1999Assignee: Agfa-Gevaert, N.V.Inventors: Ann Verbeeck, Peter Verrept, Freddy Henderickx
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Patent number: 5885763Abstract: A method is disclosed of preparing of a photographic silver halide emulsion comprising precipitating in one or more precipitation steps in a reaction vessel, followed by desalting by means of flocculation and washing or by means of ultrafiltration, said emulsion comprising gelatin as a binder and {100} tabular silver halide grains containing at least 50 mole % of chloride, wherein at least 40% by number of all grains is provided by said tabular grains, and wherein said tabular grains exhibit an average aspect ratio of at least 2, an average thickness of at most 0.5 .mu.m, and an average equivalent circular crystal diameter of 0.3 .mu.m or more, characterized in that during said precipitation step(s) said gelatin binder present in said reaction vessel is substantially free of calcium ions and is oxidized to a degree in order to have a methionine content of at most 4000 ppm.Type: GrantFiled: October 23, 1997Date of Patent: March 23, 1999Assignee: AGFA-Gevaert, N.V.Inventors: Peter Verrept, Hieronymus Andriessen
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Patent number: 5840474Abstract: A method is disclosed for the preparation of tabular silver halide emulsion grains rich in chloride and showing (100) parallel major and an average aspect ratio of at least 2.0 in silica sol as protective colloid binder. Important parameters are the addition modalities of the silica sol and the ratio of its amount to the amount of a costabilizing onium compound.Type: GrantFiled: September 18, 1996Date of Patent: November 24, 1998Assignee: Agfa-Gevaert, N.V.Inventors: Hieronymus Andriessen, Peter Verrept
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Patent number: 5733715Abstract: A light-sensitive silver bromide or silver bromoiodide emulsion is provided, comprising silver bromide or silver bromoiodide tabular triangular grains, said tabular triangular grains having an average grain thickness of less than 0.3 .mu.m, an average crystal diameter of at least 0.6 .mu.m; an average aspect ratio of at least 2:1; a variation coefficient of less than 40%, said grains accounting for a total projective area of at least 30%; characterized in that the thickness ratio of triangular tabular grains to hexagonal tabular grains is from 1.3 to 0.7.Type: GrantFiled: July 15, 1996Date of Patent: March 31, 1998Assignee: Agfa-Gevaert, N.V.Inventors: Ann Verbeeck, Peter Verrept