摘要:
The present invention is directed to a method of forming a positive image in a photothermographic element comprising a potentially negative-working emulsion wherein fog density development is imagewise inhibited in exposed areas of the image upon thermal development. In one embodiment of the invention, a density-inhibiting agent is released during thermal development which agent inhibits the thermal development of unexposed silver salts in the exposed areas relative to the unexposed areas. The method preferably comprises imagewise exposing the film with a non-solarizing amount of radiation/energy to form a latent image and thermally developing the latent image in a single development step to produce a positive image in the element. The present invention is also directed to a photothermographic element that can be used in the present process in which a positive image characterized by high speed and discrimination is formed when exposed and thermally heated above 150° C.
摘要:
The present invention is directed to a method of forming a positive image in a photothermographic element comprising a potentially negative-working emulsion wherein fog density development is imagewise inhibited in exposed areas of the image upon thermal development, the element further comprising a developer or precursor thereof and an oxidized developer scavenging agent to accelerate development by removing oxidized developer as it is formed during the thermal development step. In one embodiment of the invention, in which a density-inhibiting agent is released during thermal development that inhibits the thermal development of unexposed silver salts in the exposed areas relative to the unexposed areas, the method comprises imagewise exposing the film with a non-solarizing amount of radiation/energy to form a latent image and thermally developing the latent image in a single development step to produce a positive image in the element. The present invention is also directed to a photothermographic element that can be used in the present process in which a positive image characterized by high speed and discrimination is formed when exposed and thermally heated above 150° C.
摘要:
The present invention is directed to a method of forming a positive image in a photothermographic film exposed by electrons in a transmission electron microscope to form a latent image in the film. The photothermographic film has at least one imaging layer comprising a potentially negative-working emulsion, but wherein thermal development of unexposed silver salts in exposed areas relative to unexposed areas is inhibited when thermally developing the imagewise exposed assembly, thereby producing a positive image. The present invention is also directed to the processing of the photothermographic film in which a positive image characterized by high speed and discrimination is formed in the film when heated above 150° C.
摘要:
Communications between an RFID interrogator and an RFID transponder require that no more than one transponder be present in the reading range of the interrogator and transmitting into motion at any given time. If multiple transponders are in the field, then a collision between the return signals of the transponders occurs, rendering the signals unreadable. A method to resolve the collisions and allow for accurate transmission of each transponder's data is given. This method is especially effective over other methods when the transponder is a read-only type of device, whereby there is no communications interrogator on board the read-only transponder.
摘要:
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.It has been observed that faster rates of development, relatively thinner tabular grains under comparable conditions of preparation, increased contrast and improvements in speed-granularity relationships can be realized when (1) the tabular grains contain less than 10 mole percent iodide and (2) the surface chemical sensitization sites include epitaxially deposited silver halide protrusions of a face centered cubic crystal lattice structure of the rock salt type forming epitaxial junctions with the tabular grains, the protrusions (a) being restricted to those portions of the tabular grains located nearest peripheral edges of and accounting for less than 50 percent of the {111} major faces of the tabular grains, (b) containing a silver chloride concentration at least 10 mole percent higher than that of the tabular grains, and (c) including a higher iodide concentration than those portions of the tabular grains extending between the {111} major faces and forming epitaxial junctions with the protrusions.A photographic element is disclosed in which an ultrathin tabular grain emulsion as described above is coated over an emulsion layer intended to record visible light.
摘要:
The invention is generally accomplished by providing a tabular-grain silver halide emulsion in which at least 50 percent of the total grain projected area is accounted for by tabular grains having a mean diameter of at least 0.6 micrometer and a spacing between at least two parallel twin planes of less than about 0.011 micrometer. In a preferred form, at least 90 percent of the total grain projected area is accounted for by the tabular grains of the invention having a mean diameter of at least 0.6 micrometer and a spacing between at least two parallel twin planes of less than 0.012 micrometer.
摘要:
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.In further improving photographic performance by incorporating a photographically useful dopants, it has been observed that iridium placed in the ultrathin tabular grains and a shallow electron trapping site providing dopant placed in the silver halide protrusions can together increase photographic speed and reduce high intensity reciprocity failure.
摘要:
A radiographic element for medical diagnostic imaging is disclosed comprised of a transparent support and first and second silver halide emulsion layer units coated on opposite sides of the film support, each emulsion layer unit being comprised of a silver iodohalide tabular grain emulsion containing less than 5 mole percent iodide, based on silver. An improvement in speed in relation to granularity is obtained by the presence of tabular grains having {111} major faces, containing a maximum surface iodide concentration along their edges, and a lower iodide concentration within their corners than elsewhere along their edges.
摘要:
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.Improved sensitivity is observed when the surface chemical sensitization sites include silver halide protrusions of a face centered cubic crystal lattice structure forming epitaxial junctions with the tabular grains and having a higher overall solubility than at least that portion of the tabular grains forming epitaxial junctions with the protrusions and a sensitivity enhancing combination of dopants are contained in the silver halide grains including a first sensitivity enhancing dopant capable of providing shallow electron trapping sites and a second sensitivity enhancing selenium dopant. To further enhance sensitivity, one of the sensitivity enhancing dopants is restricted to the tabular grains while the other is restricted to the silver halide epitaxy.
摘要:
An improved spectrally sensitized ultrathin tabular grain emulsion is disclosed in which 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 grains, are spectrally sensitized and improved by employing in forming the surface chemical sensitization sites at least one silver salt epitaxially located on the tabular grains. A photographic element is disclosed comprised of a support, a first silver halide emulsion layer coated on the support and sensitized to produce a photographic record when exposed to specular light within the minus blue visible wavelength region of from 500 to 700 nm, a second silver halide emulsion layer capable of producing a second photographic record coated over the first silver halide emulsion layer to receive specular minus blue light intended for the exposure of the first silver halide emulsion layer, the second silver halide emulsion layer being capable of acting as a transmission medium for the delivery of at least a portion of the minus blue light intended for the exposure of the first silver halide emulsion layer in the form of specular light, wherein the second silver halide emulsion layer is comprised of the improved spectrally sensitized ultrathin tabular grain emulsion of the invention.