GB2293025A - Photographic processing apparatus - Google Patents

Abstract

It is known that reducing the volume of a processing tank will increase the turnover of processing solution in that tank. A kit for reducing the volume of a processing tank comprises a plurality of blocks (14, 16, 18, 20) which can either be assembled in situ or external to the processing tank and subsequently inserted therein. The blocks preferably have 4 columns (34, 54) between which a central column (40, 60) of the block above fits. <IMAGE>

Description

PHOTOGRAPHIC PRO PROCESSING APPARATUS Field of the Invention The present invention relates to photographic processing apparatus and is more particularly concerned with such apparatus where it is desired to reduce the volume of the processing solution in at least one processing tank.

Background of the Invention It is well known to process photographic materials in web and sheet form by passing the material through a photographic processor which comprises a plurality of processing stages, for example, developer, bleach, bleach-fix, wash, and stabiliser stages etc. The material is processed in each stage by the processing solutions retained in that particular part of the processor. In such apparatus, the material being processed is substantially immersed in the solution in each of the processing stages. As a result, the volumes of processing solutions used tend to be large - often at least 40 or 50 litres.

It is also known to process photographic materials using low volumes of solution - typically less than 1 litre and preferably around 100ml. Such arrangements are described in published European patent applications EP-A-0 515 454, EP-A-0 532 558, EP-A-0 546 136, EP-A-0 553 172, EP-A-0 614 545 and others. In processing apparatus in which low volumes of processing solutions are utilised, unstable processing chemistry can be employed, for example, redox amplification (RX) chemistry.

EP-A-0 562 401 discloses an arrangement for a photographic processor in which the volumes of processing solution utilised are reduced. The processor is of conventional size, that is, having large tank volumes, but in which lower volumes of processing solutions are utilised. The processing bath for each processing stage comprises a plurality of processing tanks. Each processing bath contains upper and lower guide rollers over which the photographic material to be processed is transported, each of the lower rollers being located in a respective one of the processing tanks. The material is alternately dipped into a processing tank and processing solution retained therein in the bath and not dipped so that the time for which the material is dipped in processing solution is not more than 50% of the total time in that particular processing bath.

Problem to be solved by the Invention When the volume of processing solution in a processing tank is reduced, there is dead space in the tank. It is often required to fill that dead space by adding shaped blocks. These blocks are often difficult to use as each type of processor requires blocks of specific shapes and sizes which may be difficult to insert into the processing tank when a processing rack located therein.

Furthermore, such blocks tend to be very heavy if they are required to displace large volumes of solution. If these blocks are lighter than the solution they replace, they will tend to float and not have the effect of reducing the volume of the processing tank.

Summary of the Invention It is therefore an object of the present invention to provide a flexible arrangement for filling the dead space in a processing tank in which a reduced volume of processing solution is utilised.

In accordance with one aspect of the present invention, there is provided a method of reducing tank volume for a processing tank in a multi-stage process wherein reduced volumes of processing chemistry are utilised, characterized in that a plurality of block elements are used to fill dead space in the processing tank.

In accordance with another aspect of the present invention, there is provided a kit for reducing the volume in a processing tank, the kit comprising a plurality of block elements of different shapes and sizes which are interlockable to form a unit for filling dead space in the processing tank.

Advantageous Effect of the Invention By this arrangement, the block elements can be built in situ inside the processing tank or can be formed into a unit for subsequent insertion into the processing tank.

Additionally, the unit can be constructed inside a plastic bag or container which is evacuated and sealed when the desired shape has been attained for a particular processing tank. This provides a relatively smooth surface which is less liable to retain old processing solution and which is easier to clean.

Moreover, each individual block element is light and easy to handle, and assembly and disassembly is straightforward and convenient.

Brief Description of the Drawings For a better understanding of the present invention, reference will now be made, by way of example only, to the accompanying drawings in which: Figure 1 is a schematic diagram of a processing tank which has its volume reduced in accordance with the present invention; Figure 2 is a plan view of one embodiment of a block element for use in the processing tank shown in Figure 1; Figure 3 is a sectioned side elevation of the block element shown in Figure 2; Figure 4 is a plan view of a second embodiment of a block element for use in the processing tank shown in Figure 1; Figure 5 is a sectioned side elevation of the block element shown in Figure 4; Figure 6 is a sectioned end elevation of the block elements shown in Figures 2 and 4; and Figure 7 illustrates the locking arrangement for two block elements.

Detailed Description of the Invention In Figure 1, a processing tank 10 is shown schematically. The tank 10 comprises a processing rack 12 mounted in the centre of the tank 10. Either side of the processing rack 12 is a block 14, 16 for reducing the volume of solution in the tank 10.

Additional blocks 18, 20 are provided below the processing rack 12 and inside the rack 12 respectively.

In accordance with the present invention, the blocks 14, 16, 18, 20 are made from block elements 30, 50 which are similar to 'Lego' (Registered Trade Mark) blocks as shown in Figures 2 to 8.

Figures 2 and 3 illustrate a block element 30 which is of generally cuboid with a length which is twice as long as its width. Top surface 32 of block element 30 is provided with eight cylindrical columns 34. Undersurface 36 has a recess 38 which includes two further cylindrical columns 40 formed in recess 38. Columns 40 are designed to engage with columns on the top surface of another block element. Block element 30 also includes a weight portion 42.

Figures 4 and 5 illustrate a block element 50 which is similar to block element 30 but having a width which is the same as its length. Top surface 52 of block element 50 is provided with four cylindrical columns 54. Undersurface 56 has a recess 58 which includes a further cylindrical column 60 formed in recess 58. Column 60 is designed to engage with columns on the top surface of another block element.

Block element 50 also includes a weight portion 62.

Figure 6 illustrates a cross-sectioned view through block elements 30 and 50.

Figure 7 illustrates how two block elements are fitted together. Column 40, 60 in respective recess 38, 58 of respective block element 30, 50 fits between four of columns 34 (block element 30) or columns 54 (block element 50) when one block element is pushed, in the direction indicated by the dotted arrows, on to another block element.

Although block elements 30, 50 are described as having respective weight portions 42, 62, it may be the case that only some of these elements include weight portions.

By pressing the block elements 30, 50 together, blocks 14, 16, 18, 20 as shown in, and described with reference to, Figure 1 can be made up.

Once suitably shaped unit has been made using block elements 30, 50 for a particular processing tank, the outside of the unit can be coated with a good sealant to prevent processing liquid entering any interstices formed in the unit.

Alternatively, the unit can be sealed in a shrink-wrap or vacuum-pack container if required.

Other suitably shaped block elements may also be provided to assist in the construction of an appropriately shaped unit.

It is possible to construct the blocks 14, 16, 18, 20 in situ, each block element being inserted into the processing tank as required.

As an alternative to the block elements 30, 50 described above, blocks 14, 16, 18, 20 (Figure 1) may be solid or hollow. If the blocks are hollow, they can be filled with water to weight them down, the water being pumped out when the blocks are to be removed. If filled with water, the water could be heated to assist with the temperature control for the process. Alternatively, the blocks could be filled with replenisher materials.

Instead of blocks, the volume in the processing tank can be taken up by suitably placed and secured inflatable membranes.

Claims (3)

CLAIMS:

1. A method of reducing tank volume for a processing tank in a multi-stage process wherein reduced volumes of processing chemistry are utilised, characterized in that a plurality of block elements are used to fill dead space in the processing tank.

2. A kit for reducing the volume in a processing tank, the kit comprising a plurality of block elements of different shapes and sizes which are interlockable to form a unit for filling dead space in the processing tank.

3. A kit according to claim 2, wherein the block elements are shaped like 'Lego' blocks.