Abstract:
The present invention concerns a radiographic system comprising at least one X-ray intensifying screen and a radiographic film which is sensitive to actinic radiation. The X-ray intensifying screen emits mainly ultraviolet radiation and the photosensitive film comprises a tabular-grain silver halide emulsion. Such a system enables very high quality radiographs to be obtained, even with a fast processing method.
Abstract:
The present invention concerns a method for preparing earth alkaline metal borates. The method comprises the steps of forming a mixture of an earth-alkaline metal alkoxide and a boron alkoxide, of hydrolysing this mixture to form a metal-borate precursor, and then coating the precursor onto a substrate and thermally treating it to form an inorganic film on the substrate. The method is especially useful to prepare beta barium borate layers which can serve in non-linear optical devices to produce second harmonics generation.
Abstract:
The invention relates to a method for preparing particles of metal oxide, as well as particles obtained by such method. The method consists in: precipitating a hydroxide, adding an inorganic compound such as a salt having a melting point lower than the oxide crystallization temperature, and heating the hydroxide and the salt at a high temperature. An oxide in the form of a fine powder is obtained, thus particularly allowing to perform thin conductive layers.
Abstract:
The device for supplying under pressure a photographic coating station is comprised of a first reservoir intended to receive a given volume of photographic emulsion, said reservoir being connected to an air reservoir whose pressure is maintained constant by appropriate means, the volume of said air reservoir being much larger than the volume of the first reservoir so as to absorb substantially the relative variations of pressure related to the emulsion volume variations. Application to the coating of photographic products.
Abstract:
PCT No. PCT/FR91/00775 Sec. 371 Date Apr. 6, 1993 Sec. 102(e) Date Apr. 6, 1993 PCT Filed Oct. 3, 1991 PCT Pub. No. WO90/07968 PCT Pub. Date Jul. 26, 1990.The present invention is a filtration method and device for separating particles of a suspension according to their mass. The invention includes a rotating uncloggable filter. The filter rotates inside of a stationery housing. Separation by particle size is achieved by adjusting the rotational speed of the filter. The filter is particularly useful for washing photographic suspensions.
Abstract:
In the field of photography, an interfacing device (10) is connected to a receiver unit by a first arrangement and to a feeder unit by a second arrangement. A driving roller (42) draws the photographic strip (153) out of the feeder unit so that it forms a loop (53) which triggers a control system (56) controlling the rotation speed of the motor (41). The device can be used for feeding a photographic film printer.
Abstract:
A dispenser (1) comprising a core (10) to which one end of a strip material (15) is attached with a leader (14). The core defines two parallel spindles, a first spindle (11) on which the leader is wound, and a second spindle (12) on which the strip material is wound. The two spindles are separated so that once the strip material has been completely unwound, said leader remains wound onto said first spindle and does not come out of the dispenser. The dispenser can be used for packaging light-sensitive products.
Abstract:
The invention relates to a pigment-receiving support for electrostatic transferral. The support comprises a transparent or non-transparent plastic base, and a receptive layer comprised of a surface-active agent and a hydrophilic binder, the titer of the surface-active agent being of at least 1mg/dm , and being at least twice that of the hydrophilic binder, and preferably over ten times that of the hydrophilic binder. Applications in producing overhead projector sheets or magnetography supports.
Abstract:
Very small iron-containing particles that are in the shape of facetted nodules. Such particles can be non-magnetic particles such as delta ferric oxide hydrate particles or magnetic particles such as magnetic iron oxide particles or metallic particles. Magnetic layers containing such magnetic particles combine excellent remanent magnetization with increased output signal level. The facetted nodular particles are prepared in a process in which (a) an aqueous solution of ferrous salt is added to an aqueous solution of alkaline hydroxide while avoiding substantial local excesses of the ferrous salt, and subjecting the ferrous salt solution to reducing conditions before or during its addition to the alkaline hydroxide solution and (b) the ferrous hydroxide particles are oxidized to delta ferric oxide hydrate particles in the presence of an iron complexing agent, for example, pyrogallol, that is capable of selectively forming ferric iron complexes that are soluble in the reaction medium. The use of the iron complexing agent in this process provides delta ferric oxide particles rather than alpha ferric oxide particles which are normally obtained in processes of this type. The delta ferric oxide hydrate particles are converted to facetted nodular magnetic particles by appropriate heat treatments.
Abstract:
The present invention concerns a process for obtaining a silver halide photographic emulsion which can be used in colour negative photographic processes. This emulsion comprises grains containing a silver chlorobromide core and a peripheral area with a high silver chlorobromide content, and is chemically and spectrally sensitised. This emulsion has improved sensitivity characteristics.