Eastman-Kodak Company

Other

Richard F Davis

Robert E Dickerson

Susan K Mroczek

David J Steklenski

Anthony Adin

Stephen A Hershey

A blue-sensitive radiographic silver halide film comprises a silver halide emulsion layer comprising predominantly tabular silver halide grains that have an aspect ratio of at least 15, a grain thickness of at least 0.1 &mgr;m, and comprise at least 90 mol % bromide and up to 4 mol % iodide, based on total silver halide. Substantially all of the iodide is present in an internal localized portion of the tabular silver halide grains that excludes the surface of the grains. The tabular silver halide grains are dispersed in a hydrophilic polymeric vehicle mixture comprising at least 0.5% of oxidized gelatin, based on the total dry weight of the polymeric vehicle mixture in the emulsion layer. The tabular silver halide grains are spectrally sensitized using a combination of spectral sensitizing dyes to provide increased speed and reduced dye stain. The dyes have maximum J-aggregate absorptions on the tabular silver halide grains of from about 380 to about 500 nm, wherein the maximum J-aggregate absorption of one spectral sensitizing dye is from about 20 to about 50 nm lower in wavelength than the maximum J-aggregate absorption of the second spectral sensitizing dye.

Blue spectrally sensitized film for radiography, imaging assembly and method

A blue-sensitive, radiographic silver halide film comprises a silver halide emulsion layer comprising predominantly tabular silver halide grains that have an aspect ratio of at least 15, a grain thickness of at least 0.1 &mgr;m, and comprise at least 90 mol % bromide and up to 4 mol % iodide, based on total silver halide. Substantially all of the iodide is present in an internal localized portion of the tabular silver halide grains that excludes the surface of the grains. The tabular silver halide grains are dispersed in a hydrophilic polymeric vehicle mixture comprising at least 0.5% of oxidized gelatin, based on the total dry weight of the polymeric vehicle mixture in the emulsion layer.

Blue-sensitive film for radiography and imaging assembly and method

A blue-sensitive, radiographic silver halide film comprises a silver halide emulsion layer comprising predominantly tabular silver halide grains that have an aspect ratio of at least 15, a grain thickness of at least 0.1 &mgr;M, and comprise at least 90 mol % bromide and from about 0.5 to about 2.75 mol % iodide, based on total silver halide. Substantially all of the iodide is present in an internal localized portion of the tabular silver halide grains that excludes the surface of the grains. The tabular silver halide grains are dispersed in a hydrophilic polymeric vehicle mixture comprising at least 0.5% of oxidized gelatin, based on the total dry weight of the polymeric vehicle mixture in the emulsion layer. In addition, the tabular grain emulsion includes a mercapto-substituted benzothiazole, benzoxazole, or benzimidazole to provide desired image tone and processability.

Blue-sensitive film for radiography with desired image tone

A radiographic silver halide film has reduced yellow dye stain by including a blend of tabular silver halide grains in the emulsion layers. The blend of grains includes blue-sensitive tabular silver halide grains that have an aspect ratio of at least 15, a grain thickness of at least 0.1 &mgr;m, and comprise at least 90 mol % bromide and up to 4 mol % iodide, based on total silver halide. Substantially all of the iodide is present in an internal localized portion of the tabular silver halide grains that excludes the surface of the grains. The blend also includes green-sensitive tabular silver halide grains that have an aspect ratio of at least 20, a grain thickness of at least 0.07 &mgr;m, and comprise at least 90 mol % bromide, up to 1.5 mol % chloride, and up to 1.5 mol % iodide, based on total silver halide. The molar ratio of silver in the blue-sensitive silver halide grains to the silver in the green-sensitive silver halide grains is from about 2:1 to about 6:1. The tabular silver halide grains are dispersed in a hydrophilic polymeric vehicle mixture comprising at least 0.5% of oxidized gelatin, based on the total dry weight of the polymeric vehicle mixture in the emulsion layer.

Blue-sensitive film for radiography with reduced dye stain

An imaging assembly includes a blue-sensitive, radiographic silver halide film comprises a silver halide emulsion layer comprising predominantly tabular silver halide grains that have an aspect ratio of at least 15, a grain thickness of at least 0.1 &mgr;m, and comprise at least 90 mol % bromide and up to 4 mol % iodide, based on total silver halide. The tabular silver halide grains are dispersed in a hydrophilic polymeric vehicle mixture comprising at least 0.5% of oxidized gelatin. The film is used in combination with one or more intensifying screens that absorb X-radiation and emit radiation having a wavelength of from about 300 to about 500 nm. In many embodiments, the intensifying screens include a &ldquo;blue-light&rdquo; emitting alkaline earth fluorohalide phosphor dispersed in a binder on a support.

Radiographic imaging assembly with blue-sensitive film

A method and device for detecting and/or photographing unregulated light flash events such as lighting strikes and muzzle flashes during both daylight and night time conditions is disclosed. The present device utilizes a photodiode sensor in conjunction with a photoresistor to control feedback gain of a transimpedance amplifier thereby providing non-linear amplification and therein constant sensitivity to detect an unregulated, omni-directional flash of light and produce an output signal that is input to an analog comparator circuit whereat a predetermined threshold level is set to prevent false triggering of the isolation relays and/or camera shutter. The output from the comparator circuit is input to a timer circuit to produce a signal of sufficient duration to trigger the isolation relay(s) and/or camera shutter. The output signal from the timer circuit is sent to an isolation relays and/or an infrared coded pulse generator depending on the features of the particular associated equipment in order to release the camera shutter or to protect an electronic or electrical device from the damaging effects of the lightning return stroke. In an alternative embodiment the functions of the comparator circuit, the timer circuit and the coded pulse generator are carried out by a programmable logic device such as a mixed signal processor with analog, digital, real time clock and non-volatile RAM capability wherein the lightning event processing functions are incorporated into the program code. In a further embodiment, the coupling circuit is tuned wherein motion of an object is detected. In yet a further embodiment, multiple photosensor arrays are utilized in conjunction with non-linear amplification and computing means to determine the location of flash events and to control associated equipment.

Non-linear flash and lightning detection device

A method and device for detecting and photographing unregulated light flash events such as lighting strikes during both daylight and night time conditions is disclosed by detecting the initiation of the lightning stepped leader event of the immediate lightning flash for photographic and detecting activities. The present device utilizes a photodiode sensor in conjunction with a photoresistor to control feedback gain of a transimpedance amplifier to detect an unregulated, omni-directional flash of light and produces an output signal that is input to an analog comparator circuit where a predetermined threshold level is set to prevent false triggering of the isolation relay(s) and/or camera shutter. The output from the comparator circuit is input to a timer circuit to produce a signal of sufficient duration to trigger the isolation relay(s) and/or camera shutter. The output signal from the timer circuit is sent to isolation relays and/or an infrared coded pulse generator depending on the features of the particular camera in order to release the camera shutter or to protect an electronic or electrical device from the damaging effects of the lightning return stroke. In an alternative embodiment the functions of the comparator circuit, the timer circuit and the coded pulse generator are carried out by a programmable logic device such as a mixed signal processor with analog, digital, real time clock and non-volatile RAM capability wherein the lightning event processing functions are incorporated into the program code. The device circuitry is incorporated into a compact enclosure which can be mounted directly onto the camera or, or in the alternative integrated into the camera housing.

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Rochester, NY, United States of America

Richard F Davis