Device for developing photographic film bases

Patent

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Details

354321, G03D 308

Patent

active

053271890

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

The invention relates to a device according to the preamble of claim 1.
Developing apparatus of this kind is widely used, e.g. in connection with so-called mini-labs in which, from negatives, copies in the three colors are exposed on to so-called CN copying material by means of specified copying light quantities. Copies forming part of a single order are generally cut off in strips and are passed through so-called automatic developing apparatus with a plurality of treatment tanks containing different fluids, which are adapted to the particular copying material. Thus, for example in the well-known color-negative-positive process, color developing, in a so-called color developer, is followed by treatment in a bleaching fixing bath and then a subsequent treatment by rinsing or in a stabilizing bath. The copies, then dried, are cut into individual pictures and are passed on for final processing stacked according to each order.
Such a process is only suitable for a particular type of original, i.e. for negatives, which are copied on to a special CN paper, or for positives, slides, which are copied on to a special CT paper. In the latter case, a constant double exposure is additionally necessary over the whole film base surface, in addition to a reverse developing device upstream and rinses.


SUMMARY OF THE INVENTION

In German Patent Application P 38 39 573 (=A-G 5456), a photographic reversing process is described in which both types of originals can be exposed on to the same type of copy material, but have to be treated differently according to the type of exposure. The object of the invention is therefore to make the developing process such that, according to the type of exposure, different developing processes can be carried out in one and the same device.
This object is achieved in a device of the type mentioned in the introduction and having the characterizing features of claim 1.
The additional treatment tank upstream of the color developer tank of conventional filling is provided with a black-and-white developer. According to the intended holding time, length of tank and speed of operation, all baths can also be arranged as a multiple tank. The negative material exposed with the positive picture is therefore subjected to a black-and-white development before immersion in the color developer. In the reversing process conventional hitherto, masking of the residual silver halide is necessary after black-and-white development, which is carried out by chemical means after rinsing in a special masking bath or by a so-called double exposure before color development. According to a preferred embodiment of the invention, this masking of the residual silver halide is effected by a so-called double exposure, which is carried out after a certain time inside the color developing tank. In this case, it is significant that this double exposure is not effective until a few seconds after insertion of the photographic material into the color developer. In this way, high and optimum maximum densities of the individual colors, i.e. a high color saturation, can be obtained.


BRIEF DESCRIPTION OF THE DRAWINGS

Further details and advantages of the device according to the invention will appear from the subclaims in connection with the description of an embodiment, which is explained with the aid of Figures, in which:
FIG. 1 shows a side view of a developing device according to the invention connected to a roller copying machine,
FIG. 2, a diagram of the first two treatment tanks of the developing apparatus according to FIG. 1 viewed from the side with optional bridging of the reverse developing tank,
FIG. 3, an alternative to the bridging of the reverse developing tank according to FIG. 2, and
FIG. 4, a further embodiment of an optionally effective bridging of the reverse developing tank.


DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, a developing device is shown in which the photographic material 13a from a roller copying machine 2 is passed through seven wet treatment tanks 3 to 9 consecut

REFERENCES:
patent: 3699869 (1972-10-01), Jensen
patent: 3785269 (1974-01-01), Morioka
patent: 4362376 (1982-12-01), Otani
patent: 4709913 (1987-12-01), Cagey

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