Hoechst Aktiengesellschaft

Agfa-gevaert Ag

Ajax International Machinery & Metal Works A/s

Eckehard Stein

Herbert Schroter

Peter Jessen Juergensen

Eberhard Schoernig

Peter Schwagler

Dorothee Griesch

Ullrich Dudder

An apparatus for developing radiation-sensitive, exposed printing forms into printing plates is disclosed. The apparatus has a developer pan in which a developer bath 2 is situated. The individual printing form runs through the developing station of this apparatus in a running-through plane. On both sides of the running-through plane there are a first pair of transport rollers, two brushing rollers with their counter-rollers and a second pair of transport rollers at the end of the developing station. Arranged between the first pair of transport rollers and the first brushing roller with its counter-roller, on the underside of the running-through plane, are guide rollers. A closed vessel, filled with developing solution, is connected via a developer circuit and a pump to the developer bath. In the vessel there are a temperature sensor and a measuring electrode for the electric conductivity of the developing solution. The temperature sensor and the measuring electrode are connected to a computer, so too is a sensor, which is arranged underneath a feeding table for the printing forms. Data, such as formats of the printing forms, characteristic lines of the specific conductivity of the developing solution for various printing form types, set temperature values and temperature coefficients for the conductivity of the developing solution, are stored in the computer. The computer is also connected to pumps for metered feeding of developing replenisher and water into the developer bath and to a cooling device as well as a heating device within the developer bath.

Process and apparatus for developing radiation-sensitive, exposed

An apparatus and a process for developing radiation-sensitive, exposed printing forms into printing plates is disclosed. The apparatus has a developer pan that contains a developer bath. Individual printing form runs through the developing station of this apparatus in a running-through plane. On each side of the running-through plane there is are a first pair of transport rollers, two brushing rollers with counter-rollers and a second pair of transport rollers at the end of the developing station. Guide rollers are arranged between the first pair of transport rollers and the first brushing roller with its counter-roller, on the underside of the running-through plane. A closed vessel, filled with developing solution, is connected via a developer circuit and a pump to the developer bath. The vessel contains a temperature sensor and a measuring electrode for the electric conductivity of the developing solution. The temperature sensor and the measuring electrode are connected to a computer, so too is a sensor, which is arranged underneath a feeding table for the printing forms. Data, such as formats of the printing forms, characteristic lines of the specific conductivity of the developing solution for various printing form types, set temperature values and temperature coefficients for the conductivity of the developing solution, are stored in the computer. The computer is also connected to pumps for metered feeding of developing replenisher and water into the developer bath and to a cooling device and a heating device within the developer bath.

In the developing station of a processing system for printing plates, a counter-roller is offset with respect to the brush roller in the plane of passage of the printing plates by a given distance 'a'. In another embodiment, the transport rollers are lowered by an amount 'b' with respect to the plane of passage which extends horizontally between the gap between the brush roller and the counter-roller.

Developing station of a processing system for printing plates

This invention relates to an improvement in the process for conducting ammonia in a developing apparatus for developing diazotype copying material, wherein exhaust air laden with gaseous ammonia and composed of the developer medium escaping from a developing chamber and air, is conducted in at least one absorption vessel countercurrently to water capable of absorbing ammonia; wherein the ammonia water of relatively low concentration thus obtained is conducted in an evaporator countercurrently to a stream of water vapor; and wherein the ammonia gas/water vapor mixture thus obtained is used for preparing the gaseous developer medium; the improvement comprising completely condensing the ammonia gas/water vapor mixture discharged from the evaporator to form ammonia water of a relatively high concentration; storing the ammonia water in an ammonia water supply tank; introducing the ammonia water discharged from the ammonia water supply tank, at a constant rate, into an evaporator which is in direct connection with the developing chamber; and passing the ammonia gas/water vapor mixture produced by evaporation from the evaporator into the developing chamber. The invention also relates to an apparatus for performing the process.

Process for conducting ammonia in a developing apparatus used for

This invention relates to a vaporizer for generating developer gas, containing ammonia, from aqueous ammonia for developing diazo copying material comprising a first vaporizer unit including a rectifying column and a column head, a gas outlet for taking off the developer gas and an inlet opening into the column head for feeding in aqueous ammonia, and a heatable, steam-generating sump vessel having a base and a residual water outlet, a second unit including a volatilizer with means for heating a base zone thereof, a residual water inlet opening in said base zone, a residual water line connecting said residual water inlet opening to said residual water outlet of said rectifying column, said residual water outlet of said rectifying column projecting upwardly in said sump vessel and having an orifice above the base thereof, said two units being arranged side by side with parallel axes in a single casing, a first connecting branch as said gas outlet for taking off the developer gas and a second connecting branch as the inlet for feeding in aqueous ammonia connected to said column head, a suction branch connected as a suction outlet on said volatilizer, said residual water outlet of said rectifying column, said first and second connecting branches of said vaporizer, said residual water inlet opening, and said suction branch of said volatilizer projecting from said casing, and said residual water connecting line having a section at a lower level than the base of the sump vessel and the base zone of the volatilizer.

Vaporizer for generating developer gas, containing ammonia gas, from

The invention relates to a vaporizer for generating developer gas, containing ammonia, from aqueous ammonia for developing diazo copying material, comprising a rectifying column with a transfer section, a substantially closed column head with a cover plate and a base plate, a first connecting branch for taking off the developer gas and a second connecting branch for feeding in aqueous ammonia opening into the column head, and a heated, steam-generating sump vessel at the foot of the transfer section, which includes a weir for liquids, which is located in the column head between the cover plate and the base plate below the connecting branches but above the transfer section, extends substantially over the entire cross-sectional area and has at least one passage orifice for liquid and at least one passage orifice for vapor.

This invention relates to an improvement in the process for the production of photocopies with two-component diazotype material which cannot be developed by the action of heat alone and which, during continuous passage through a photocopying machine, is first exposed imagewise to light emitted by a mercury lamp and is then exposed, for the purpose of development, to an ammonia/water mixture, in vapor form, in a development chamber, the improvement comprising employing light emitted from a gallium-modified or indium-modified mercury lamp for the imagewise exposure of the diazotype material, and exposing the diazotype material, which has been exposed to light, to an ammonia/water vapor mixture in the development chamber, said mixture in terms of vapor pressure being unsaturated and containing at most 25 per cent by weight of ammonia, at a temperature of about 105 to 120.degree. C and at a predetermined pressure. The invention also relates to an apparatus for performing the process.

Process and apparatus for the production of photocopies using

In a diazo copier, a first developing chamber for developing a diazo material employing an ammonia-containing vaporous developer, a second chamber adjacent an output aperture of the first developing chamber, a source of heat, and a suction device for drawing off developer escaping from the second developing chamber through an output aperture and for removing developer from the diazo material are provided. A rotatably mounted porous hollow roller means forms part of said suction device positioned in said second chamber and a suction duct means is connected to said roller means. A transport means which is not in heat-conducting connection with the source of heat is provided for bringing the copying material in contact with the hollow suction roller means.

Apparatus for developing a photosensitive material using a vaporous

This invention relates to an improvement in a copying apparatus, particularly a photoprinting apparatus, comprising an exposure station, a developing chamber, and an evaporator associated with the developing chamber, in which a developer composed of an ammonia/water mixture is virtually completely evaporated and over-heated at a temperature about 100.degree. C, preferably about 105.degree. C, and at a predetermined pressure, preferably atmospheric pressure, the apparatus further including, for dosage of the ammonia/water mixture, a feed pipe connected with the evaporator, a valve connected with the feed pipe, and a control unit connected with the valve, whereby the rate of feed of the ammonia/water mixture may be adapted to different operating conditions, the improvement comprising first switch means, actuatable by an original, positioned at an entrance for the original upstream of an exposure station in the feed direction of the apparatus. Second switch means, actuatable by a copying material, positioned at a delivery point of said copying material downstream of said developing chamber, control unit means electrically connected with said first and second switch means, said control unit being so constructed that after said first switch means has been switched to a first position by the original, the valve is first opened for a relatively long period of time, and the valve is then alternately opened and closed, in accordance with pulses, as long as the first or second switch means is maintained in its first switching position by one or more originals or one or more sheets of copying material, respectively, and said pulse-wise opening and closing of the valve is terminated only when neither the first nor the second switch means is maintained in its first switching position by an original or a sheet of copying material, respectively.

Copying apparatus, in particular photoprinting apparatus, comprising a

This invention relates to a method of exposure control in photographic printing apparatus for printing from originals made on different types of photographic material, the method comprising:

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Frankfurt-am-Main, Germany

Eckehard Stein