Photography – Fluid-treating apparatus – Photographic medium or cartridge sensing
Reexamination Certificate
2002-06-05
2003-02-04
Rutledge, D (Department: 2851)
Photography
Fluid-treating apparatus
Photographic medium or cartridge sensing
C396S569000
Reexamination Certificate
active
06513995
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a method of processing photographic material and to the production of images from film or digital image files. For example, the invention includes the production of photographic print images using a photographic material such as Ektacolor™ Paper. It is concerned particularly with processing using a development stage in which development is carried out with developer applied to the surface of the processed material in an imagewise manner. The invention also relates to a method of determining a required exposure for producing the image.
BACKGROUND OF THE INVENTION
Photographic prints are typically made using materials, which are exposed imagewise and processed through a set of chemical processing solutions. Processing of photographic materials in automatic processing equipment is normally carried out using tanks of solution through which the processed material is passed. The solutions are modified as they carry out the chemical processes. The effect of this modification is compensated for by replenishment of the tanks with replenisher solutions, which add chemicals to replace those that have been used during processing. Care has to be taken to replenish tank solutions accurately so that the chemical concentrations are maintained at a constant level to ensure consistent performance.
Solution is lost from the tanks when the processed photographic material leaves the tank. Also, the replenisher solutions are added to the tanks in larger quantities than are removed with the processed material thus producing liquid effluent. Chemical by-products introduced by the chemical reactions occurring during processing are removed from the tank by the liquid effluent and also by the solution that is carried out of the tank with the processed material.
Single-Use processing systems involving the use of small volumes of processing solution have been described (see for example Research Disclosure Sep. 1997, p638 ). In some examples, these involve the application of processing solutions to the surface of the photographic materials in a way that results in a uniform amount of solution being applied i.e. when the material is being developed, a layer of uniform thickness of developer is applied over the material. The uniform application of developer to the surface of color negative paper using ink-jet methods has been described in, for example, European Patent Application No. 94201050.5. U.S. Pat. No. 3,869,288 describes the separate application of developer components by spraying droplets onto the surface of the photographic material being processed. U.S. Pat. No. 5,200,302 describes a method of processing involving coating photographic material with developer to produce a film of processing solution of a thickness at most 20 times that of the dry gel thickness of the material.
A problem with uniform application of processing solution, such as developer, is that this results in low-density areas of the image being treated with the same amount of chemical as maximum density areas. This results in inefficient chemical use and possibly to the production of higher than required image density in minimum density areas.
To address this, image information is used to control the amount of processing solution applied so that it is applied in an imagewise manner, as described in, for example, U.S. Pat. No. 5,701,541. In this example, high silver papers are used and processed involving bleaching and fixing to remove silver and silver halide followed by washing to remove all the soluble chemicals left in the coating including developing agent from the developer and the dissolved silver halide.
Imagewise application of developer also enables easier removal of the materials dissolved in the solution from the coating of the photographic material such as color developing agent. This is because, in addition to less excess developer being used in total, the excess is normally greater in low density areas where less is used in the formation of image density and where the removal of all the developer components is more important. This is significant when the development is carried out using coating or spraying rather than a deep tank method since the concentrations of processing solution are usually higher. It is also particularly important when the stages after development are short or involve low rates of replenishment which may lead to unacceptable build-up of developer components. In some examples, silver removal stages are omitted altogether in which case there is no opportunity to remove or redistribute the developer applied in the developer stage.
In addition, where uniform application of developer is used the response of the photographic material to the image exposure (resulting in image dye formation), is known. However, when the amount of solution, or the composition of the solution or solutions applied varies according to the image, the response of the photographic material to the image exposure also varies. Where less dye is needed, less solution needs to be provided but then the rate and extent of dye formation is reduced. As a result, the process itself reduces the image density in these areas, which is undesirable. In such a situation, it is likely that compared with a process using uniform application of processing solution the image resulting from an imagewise application of solution is higher in contrast, which is clearly undesirable.
Problem to be Solved by the Invention
A system and method is required to provide the advantages of a simple, chemically efficient, low or zero-effluent process with fully satisfactory photographic performance.
It is further desirable to provide a method of stabilizing the image against long-term modification by retained chemicals which involves minimal washing or other means of removal of retained chemicals.
Reducing the amount of developer applied, according to the anticipated density required can result in reduced response to the image exposure during the development process. This can increase the contrast of the image and if too little developer is applied can even result in loss of image information in low density regions. Both effects are clearly undesirable. It is therefore necessary to find a way to provide high quality images using a process involving image-wise developer application and benefiting from process simplicity, efficient use of process chemicals and low levels of effluent.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a method for processing light sensitive photographic material, in which an image is exposed onto the photographic material. At least one developer is applied to the material in an imagewise manner wherein the amount of developer applied at any point depends on the image density to be produced at that point. The exposure is controlled to account for the response of the photographic material to the amount of developer applied.
Preferably, the exposure is controlled such that the combination of exposure and the amount of developer applied produces a predetermined image density at that point. In one example, the predetermined image density is substantially equivalent to that produced by processing of an exposed image in a non-imagewise manner.
Preferably, the exposure is controlled using digitally controlled scanning of the image onto the photographic material. Alternatively, a mask, which may be digitally generated, is used to control the exposure.
Preferably, the developer is applied to the photographic material using a fluid-jet applicator.
According to a second aspect of the present invention, there is provided a method of determining a required exposure for creating an image on photographic material in accordance with the method of the first aspect of the present invention. Initially, a value of exposure on a desired sensitometry relationship for a non-imagewise development process is selected.
As a second step the value of image density to which the selected value of exposure corresponds is identified. Finally, from a sensitometry relati
Evans Gareth B.
Fyson John R.
Hewitson Peter
Eastman Kodak Company
Rutledge D
Sales Milton S.
LandOfFree
Method of processing photographic material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of processing photographic material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of processing photographic material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3133319