Abstract: The invention relates to persistent screens where the image to be stored is stored in a layer (3) which contains as an active substance an illuminable luminophor (5) and which is tinted to increase the picture sharpness. The luminophor (5) is a rather small quantity of organic and/or inorganic UV luminophor material. In this connection, it has been found to be desirable to at least reduce the light loss caused by the tinting. To this end, the invention avoids dispersions of the scanning beam (14) in the persistence layer (3) during scanning by admixing to the luminophor (5) an UV luminophor (6) as well as an optical brightener (7). It has also been found appropriate to apply the persistence layer (3) on a substrate (2), such as a polyester foil, which is tinted with a substance that absorbs the light of the scanning beam (14) used for illuminating the layer (5). Such a screen utilizing the inventive principles is particularly useful in medical technology applications.

Abstract: An x-ray image storage screen for use in converting x-ray images into video pictures by the use of applied heat, such as a laser beam, has an active substance for the storage layer which is an alkaline earth-mixed halogen system having the formula BaF.sub.2 (Br, Cl):Eu:Sr, with barium fluoride (BaF.sub.2) comprising 0.6 mol, and the barium chloride (BaCl.sub.2) and the barium bromide (BaBr.sub.2) comprising the remaining 0.4 mol, preferably in equal portions, and wherein the activator europium (Eu) does not exceed 10.sup.-4 g-atom and the activator strontium (Sr) does not exceed 10.sup.-2 g-atom.

Abstract: Improved x-ray fluorescent screens include a fluorescent layer having luminescent material bound with a lacquer binding agent characterized by pronounced hydrophilic properties. A preferred binding agent is pure urea-formaldehyde resin which solidifies with heat through a polycondensation reaction. Additives, such as alkyd resins, epoxy resins, polyacrylate resins, nitrocellulose, vinyl chloride copolymers, or polyvinyl butyral can be added to the binding agent. The binding agent prevents agglomerations of the luminescent material crystals so that a more uniform emission of light occurs.

Abstract: Luminescent crystals of the activated rare-earth oxybromide type are coated with a layer of a double salt metal lanthanum sulfate, such as aluminum-lanthanum sulfate or an alkali-lanthanum sulfate, so as to stabilize the resultant luminescent material against humidity without adversely effecting the luminescence capability of such material. The humidity-stabilized luminescent materials of the invention are useful in luminescent coatings or the like employed in medical x-ray diagnoses for intensification of radiation effects on radiographic exposure films. Such intensification coatings generally are incorporated within x-ray intensifier foils.

Abstract: This invention relates to an improvement in an arrangement for ammonia feed in copying equipment with several switchable adsorption vessels, for instance four or five vessels, containing an adsorbent, at least one adsorption vessel of which in each case, the adsorbent of which is not saturated with ammonia, is charged with ammonia-containing air extracted from a developing chamber before this air leaves the copying equipment as cleaned exhaust air, and at least one adsorption vessel of which after saturation of the adsorbent can be regenerated by heating, and means whereby the liberated ammonia can be fed to the developing chamber.Each adsorption vessel can be connected via respective means to a line for the air extracted from pre-chambers of the developing chamber. The respective means are actuated according to a step-by-step switch unit. Furthermore, each adsorption vessel includes a gas outlet which can be either connected to the developing chamber or to an exhaust air line.

Abstract: This invention relates to an improvement in an apparatus for ammonia feed in copying equipment with a cold trap, for freezing out ammonia and water from air extracted from the immediate vicinity of a developing chamber, in particular from pre-chambers, together with a rectifying column for releasing ammonia from the frozen-out ammonia-water mixture and recycling the gaseous ammonia into the developing chamber, the improvement comprising heat exchanger means,With two heat-conducting channels adjacent each other through which the extracted air flows counter-currently, a cold source inSaid heat exchanger means, said source being at a transition position between said channels and surrounded thereby, heat source meansAdapted to heat said heat exchanger means, outlet means on said heat exchanger means, means connecting said outlet means on said heat exchanger means to said rectifying column, and means connecting said rectifying column to said developing chamber.

Abstract: This invention relates to a process for conducting ammonia in a diazo copying machine which comprises passing ammonia-containing exhaust air by first conduit means from a developing station of said copying machine through a cooled heat exchanger in which the ammonia and water is frozen out, then heating said heat exchanger to a temperature at which the water and the ammonia are liquified, passing the mixture of liquified water and liquified ammonia to a releasing station, adding fresh ammonia water to the liquified water and to the liquified ammonia, passing it together with the liquified water and liquified ammonia in the releasing station counter-currently to vapor produced by a vapor-generating means, and conducting the gaseous ammonia to the developing station, said process employing two heat exchangers, the first heat exchanger through which the exhaust air is passed being cooled and the second heat exchanger being heated for liquifying the ammonia and water frozen out during the preceding process step,

Abstract: An apparatus for developing photosensitive material with a gaseous medium comprising a housing having a developing chamber therein, at least one rotor in said developing chamber, said rotor extending over substantially the entire width of material to be developed and being mounted at a distance of about 0.05 to 20 mm from the material to be developed, a device for introducing gaseous developer medium between the rotor and the interior walls of said chamber, and a device for passing material to be developed through the apparatus, whereby it contacts said gaseous developer medium.

Abstract: A luminescent material which is stimulable or excitable through the intermediary of X-rays for the emission of photographically effective light, and which consists of activated lanthanum oxide halogenide. A portion of the lanthanum is replaced by lead and/or thalium in the luminescent material. Thereby, at a reduced afterglow there are obtained crystals with an approximately spherical shape, so that the granularity, as well as the afterglow are reduced.

Abstract: An apparatus for producing a gaseous developer medium for diazo-type material having a distillation column through which fluid developer solution and vapor pass counter-currently. An outlet on the distillation column is connected to a developing chamber. An inlet on the distillation column serves for feeding developer solution therein. The apparatus further includes a vapor generator connected to the distillation column by a direct conduit.