text: In photographic processing apparatus, different processing solutions are contained in separate tanks, the material being processed as it passes from one tank to another through the required processing stages. This means that the apparatus needs to have a separate tank for each solution which is required for a particular process--for example, a tank for each of the developer, bleach, fix (or combined bleach/fix) and wash stages, the material being processed making contact with the air as it passes from one tank to the next.
  Moreover, such processing apparatus usually comprises more than one washing stage and hence there is a requirement for a separate wash tank for each of the washing stages. As a result, such processing apparatus tend to be large and cumbersome.
  U.S. Pat. No. 3,824,616 describes an automatic film processor which comprises a plurality of treatment tanks and a transport system for transporting a sheet of film through the tanks in succession. In this processor, the film sheet enters the air as it crosses over from one tank to another. A guide structure is provided between adjacent tanks to guide the film sheet as it passes through the air between the adjacent tanks. The film sheet is processed with its emulsion surface outermost. A positive air pressure is produced adjacent the interior of the guide structure to urge the sheet of film away therefrom to minimize faulty processing and scratching of the emulsion surface of the film sheet.
  Although U.S. Pat. No. 3,824,616 describes a processor which overcomes the problem of the film sheet making contact with the guide structure as it crosses over from one tank to the next, the processor is still large and requires several separate tanks.
  GB-A-1 292 004 discloses a compact processor in which the processing tanks are nested within one the other. The processor comprises a first container mounted on a support and a second container positioned within the first container but spaced therefrom to define a processing tank therebetween. One processing solution is contained in the processing tank defined by the walls of the two containers, and a second different processing solution is contained in the second container. A cross-over arrangement is provided so that the material being processed can pass from the first container and the solution contained therein into the second container and the solution contained therein. In the cross-over arrangement, the material being processed makes contact with the air. It is also possible to introduce material directly into the second container for processing without it having to pass initially through the first container.