EP0093337B1 - Photographic registration process - Google Patents

Description

The invention relates to a photographic recording method in which a latent luminescent image is produced in a photographic recording material by imagewise exposure. The luminescence image generated in this way is, according to the invention, scanned photoelectively by means of luminescence spectroscopic methods and recorded electronically. If the photographic recording material contains luminescent images which correspond to different colors of light, the luminescent signals obtained in a photoselective manner can be used to produce color images.

It is known to use the luminescence of chemical compounds for image or information recording. A distinction can be made here between methods that use silver-containing recording materials and those that do without silver.

In the so-called "silver-free" processes, for example, non-luminescent compounds are converted into luminescent compounds by imagewise exposure to high-energy radiation. The image information recorded in this way can be made visible in the form of luminescence radiation by irradiation with longer-wave light which stimulates the luminescence (DE-A 1 949 605, DE-A 2 240 554, DE-A 2 446 700).

Disadvantages of these methods are the light instability of the luminescent compounds produced by the irradiation when scanning the latent image with the excitation radiation and the low wavelength selectivity during recording, since short-wave energy-rich radiation in the wavelength range from 200 to for converting the non-luminescent compounds into luminescent compounds 400 nm is required.

Image recording methods in which silver-containing recording materials are used include those in which the contained luminescent compounds serve only for the reproduction ("read out") of information previously recorded in a silver halide emulsion layer (GB-A 1 129 285, GB-A 1 174131) , and those in which the luminescent compounds play an essential role in the actual image recording, for. B. as an energy converter in the recording of high-energy radiation in silver halide emulsion layers (US-A 2511 462) or in the production of copies (US-A 2 865 744) as a photosensitive substance. In the latter copying process, the luminescent compound (sensitizer) loses its luminescent ability imagewise depending on the exposure. The luminescence image excited with blue light can then be imaged on a panchromatic recording material in order to produce a duplicate of the original. Because of the low sensitivity - the generation of the luminescence image requires a multiple of the exposure that would be required for a sufficient exposure of the silver halide - this method is only suitable for copying, but not for recording purposes.

In addition, other methods are known according to which an image recording already produced can be converted into luminescence images by toning methods or printing methods (EP-A 0 012 010, US T 893 003). According to US-A4104 519, a generated silver image is scanned with an X-ray beam and the X-ray fluorescence signal is recorded electronically.

• 1. Unzureichende Empfindlichkeit für sichtbares Licht
• 2. Unzureichende Selektivität für bestimmte Spektralbereiche.

The known methods have one or more of the following disadvantages:

• 1. Insufficient sensitivity to visible light
• 2. Inadequate selectivity for certain spectral ranges.

The invention has for its object to provide a highly sensitive photographic recording method with which light of certain spectral ranges can be selectively recorded and with which multicolored images can be produced with simultaneous selective recording of light of different spectral ranges.

The invention relates to a photographic recording method in which a latent luminescence image is produced by imagewise exposure of a light-sensitive photographic recording material, characterized in that a photographic recording material which contains light-sensitive silver halide and at least one luminescent compound in at least one layer is imagewise exposed and developed, wherein in at least one layer a silver image and a latent luminescence image superimposed thereon are generated, and that the image information contained in the latent luminescence image is optionally photo-selectively scanned by means of a luminescence spectroscopic method and in the form of monochrome after diffusion transfer of the latent luminescence image to a separate, preferably silver and silver halide-free image-receiving sheet Luminescence signals are recorded electronically.

In the recording method according to the invention, a light-sensitive photographic material with one or more light-sensitive silver halide emulsion layers, which contains luminescent compounds embedded in the silver halide emulsion layer or layers, is first exposed and developed imagewise. The silver halide is the actual light-sensitive substance. It can be (spectrally) unsensitized and therefore have its sensitivity mainly in the short-wave part of the visible spectrum or in the longer-wave UV or by adding spectral sensitizers for the longer-wave Parts of the visible spectrum should be sensitized. In the method of the present invention, the silver halide is assigned at least one luminescent compound. This can be one of the spectral sensitizers mentioned or also another luminescent compound which does not need to have any spectral sensitizing properties. A number of examples of luminescent compounds are listed in Example 1.

It was found that the luminescence density of the luminescent compound is imagewise modified by the image-wise exposure and subsequent development, so that a latent luminescence image (mostly opposite gradation) is superimposed on the silver image produced during development. This latent luminescence image can be made visible by excitation with colored light of a suitable wavelength. At least two causes are responsible for the formation of the latent luminescence image. This phenomenon is based in part on the imagewise deletion of the luminescence of the luminescent compound, which is present at least initially in a uniform distribution, by the silver image produced during development. On the other hand, in some cases a latent luminescence image is still retained even if the image silver has been removed, e.g. B. by treatment with a bleaching or bleach-fixing bath (color processing).

The latent luminescence image generated during development can be queried by luminescence spectroscopic methods (DE-A 3 038 908), for example by scanning the developed recording material with a sharply focused monochrome light beam of a wavelength suitable for the excitation of the luminescence and the luminescence radiation triggered thereby by means of suitable optoelectronic ones Converter (photo detectors) is detected. The luminescence signals are converted point by point or line by line into electronic pixel signals and, if necessary, electronically recorded after electronic processing (amplification, reversal). Electronic recording is understood to mean the use of electronic means for the immediate production of a visible image (video image, hard copy) or for storing the image information in order to generate such a visible image at a desired later point in time.

The method according to the invention thus comprises two essential sub-steps, namely firstly the production of the latent luminescent image and secondly the conversion of the latent luminescent image into electronic image signals.

In the first sub-step of the method, a photographic recording material with at least one light-sensitive silver halide emulsion layer and at least one luminescent compound contained therein is exposed imagewise and subjected to processing which comprises at least one treatment step in which a silver image is formed (development). This can be, for example, treatment in an aqueous developer bath in a conventional black and white or color processing operation. The presence of color couplers or other color images in the recording material or in the (color) developer bath is possible, but is not a prerequisite for the method according to the invention. To stabilize the developed silver image and protect against post-exposure, it is expedient to give the development treatment a fixing or stabilizing treatment, if necessary after intermediate washing. B. in a conventional fixer or bleach-fix, to follow, in which the undeveloped silver halide is washed out of the recording material or converted into non-photosensitive silver compounds. Such a fixation treatment can be dispensed with, e.g. B. if the second essential sub-step of the process (generation of the electronic image signals) immediately follows the development without the freshly developed recording material previously actinic light, z. B. daylight is exposed. A change in the image information of the silver image by the excitation light used in the scanning can be accepted under certain circumstances, since it can generally only have an effect after the electronic image signal has already been obtained (and stored).

Since the entirety of the measures of the first essential sub-step of the method according to the invention (generation of the latent luminescence image) can be identical to the entirety of the measures of conventional black-and-white or color processing steps - provided that the recording material used contains at least one luminescent compound in at least one silver halide emulsion layer, which is generally the case (e.g. spectral sensitizers), the method according to the invention in principle offers the possibility of copying, enlarging or video images of black and white or color images produced in a conventional manner by means of the second essential sub-step via the electronic recording of the image information to create.

One of the advantages of the method according to the invention is, however, that because of the extraordinarily high sensitivity of the luminescence method (detection limit approx. 10 -16 mot - cm -2), only extremely small amounts of substance of luminescent compound and silver halide are required. The greatest gradual signal change in luminescence can be found in the “shadows”, ie in the areas of the image in which, due to the low exposure during development, only a small amount of image silver or image color density has been developed. With higher optical densities, the differentiation in the luminescence decreases noticeably and the luminescence density asymptotically approaches a lower limit. Recordings are therefore particularly suitable for the method according to the invention materials with low silver application. This can move in a wide range and z. B. per layer from 0.02 to 30.0 g AgN0 _{3 /} m ² . However, silver coatings of (per layer) less than 0.2 g AgN0 _{3 /} m ^{2 are} preferred. The luminescent compound is present in a much lower concentration. Depending on the luminescence quantum yield of the luminescent compound, their concentration is between 10- ⁶ and 10- ² mol / mol AgNOa. The use of such small amounts of substance for a photographic recording process only appears possible in that the highly sensitive silver halide system (amplification factor approx. 10 ⁶ ) is combined with the highly sensitive luminescence method, which leads to a further amplification.

Another significant advantage of the recording method according to the invention lies in its photoselectivity, i. H. the selectivity for certain sub-areas of the spectrum or for certain wavelengths of light. This is based on the one hand on the fact that the photoselectivity of the silver halide system (by spectral sensitization) is used in a known manner for the primary recording (first essential sub-step of the method), and on the other hand on the fact that the for the generation of the electronic image signals (in the second essential sub-step of the method) used luminescent radiation occurs only in limited sub-regions of the spectrum. The combination of the first essential sub-step of the method with the second essential sub-step of the method thus results in an advanced overall method on the basis of the photoselectivity thereby made possible. Since the spectral position of the luminescence density maximum is a parameter that is characteristic of the respective luminescence-capable connection, it is even possible to distinguish between a plurality of luminescence-capable connections present next to one another on the basis of their different luminescence wavelength when generating the electronic image signals. This further opens up the possibility, in an advanced manner, of recording colored, also multicolored images with the aid of the method according to the invention. For this purpose, it is only necessary to assign different luminescent compounds to different silver halide emulsions of different spectral sensitivity contained in the same recording material, which only need to differ in their luminescence wavelength. It proves to be particularly favorable that these requirements are already met in many cases by the spectral sensitizers used for the spectral sensitization. Experience has shown that these compounds are in agreement with regard to the spectral position of the sensitization maximum and the luminescence density maximum, since the sensitizing (I band) are usually identical to the luminescent excited molecular states. Because of their double function, spectral sensitizers are therefore the luminescent compounds which are preferably used according to the invention. In addition, other non-spectrally sensitizing luminescent compounds are also possible, which can be used instead of the spectral sensitizers or, if necessary, additionally, for. B. optical brighteners.

A color photographic recording material with three comparatively low-silver silver halide emulsion layers of different spectral sensitivity is suitable, for example, for the recording of a multicolor image by the method of the present invention. The silver application of the individual layers can be so low that no silver image or only a slightly visible silver image is developed during normal development. For example, silver applications of (per layer) less than 0.2 g AgNOs m ^{2 are possible.} One of the layers contains, for example, a red sensitizer, e.g. B. RS-6, another a green sensitizer, e.g. B. GS-1, and the third is either due to intrinsic sensitivity or due to the presence of a blue sensitizer, e.g. B.BS-2, mainly sensitive to blue light (formulas of the sensitizer dyes - see Example 1). Instead of the blue sensitizer, the latter layer can also contain another luminescent compound, which should have its spectral luminescence maximum at a wavelength of less than 500 nm if possible. This recording material preferably contains neither a color coupler nor any other color former. In addition to its low silver application, such a recording material is in principle comparable to a known coupler-free color film, with which color images can be produced in a laborious chromogenic processing process comprising several development steps and several intermediate exposures. In the present case, however, the silver application of the individual layers is too low to produce a sufficient color density when processed in the chromogenic processing method mentioned.

If the recording material described is exposed imagewise, e.g. B. in a conventional photographic camera, then first in the three silver halide emulsion layers according to the respective spectral sensitivity and exposure to light of the appropriate wavelength (blue, green, red) the corresponding partial images in the form of latent silver images. The corresponding silver images are generated from this by simple development processing, e.g. B. using a conventional black and white developer bath. However, any other development treatment is also possible by means of which a latent silver image is converted into a real silver image. The invention makes use of the knowledge that a corresponding latent luminescence image of opposite gradation is superimposed on each of the silver images produced in this way. That means e.g. B. when using the mentioned sensitizers BS-2, GS-1 and RS-6 that in the blue-sensitive layer registered partial image is superimposed on a latent luminescence image with maximum intensity at the emission wavelength Ae = 490 nm (BS-2); a latent luminescence image of emission wavelength _A e = 520 nm (GS-1) is superimposed on the partial image registered in the green-sensitive layer and a latent luminescence image of emission wavelength λe = 689 nm (RS-6) is superimposed on the partial image registered in the red-sensitive layer. By scanning with monochrome light of suitable excitation wavelengths Aa, the individual latent luminescence (partial) images are queried simultaneously or successively point by point or line by line, ie excited to luminescence and converted into electronic image signals in accordance with the measured luminescence density. The partial images, which are discussed here, are not color images in the actual sense, but rather color separations of the colored original to be assigned to different spectral ranges, from which multi-color images of the original can be reconstructed using additive or subtractive methods.

The advantage associated with such a recording material or its use for the method according to the invention is obvious. The low silver application, the simple layer structure (no stress on the layer by color couplers or oil formers) and the simple processing have a favorable effect on the costs. The layer thickness of the individual layers and of the entire layer structure can be kept low, which benefits the sharpness. Because of the high sensitivity of the process, fine-grain silver halide can be used, which also has a beneficial effect on sharpness. Exposure in a conventional camera is possible, and finally multi-color images can be recorded.

As layer supports for the photographic recording material used in the process according to the invention, not only the usual transparent support materials come into question, but also advantageously highly scattering, in particular opaque support materials, e.g. B. paper, especially superficially hydrophobic paper such as polyethylene-laminated paper, or pigmented plastic films (white cello). The multiple scattering caused by the scattering base has a favorable effect in the method of the present invention, because this significantly increases both the absorption and the emission probabilities of the luminescent compounds.

Suitable light-sensitive emulsions are emulsions of silver bromide or mixtures thereof, optionally with a low content (for example up to 10 mol-0 / o) of silver iodide in one of the commonly used natural or synthetic hydrophilic binders, preferably gelatin. Fine-grain emulsions are used with advantage, such as. B. with an average grain size up to 0.5 microns, however, coarser emulsions can also be used. The emulsions can be chemically sensitized in a known manner, e.g. B. by sulfur ripening or addition of precious metal compounds, especially gold, platinum, palladium or iridium compounds.

As spectral sensitizers such. B. the usual mono- or polymethine dyes in question, such as acidic or basic cyanines, hemicyanines, streptocyanines, merocyanines, oxonols, hemioxonols, styryl dyes or other, also tri- or polynuclear methine dyes, for example rhodacyanines or neocyanines. Such sensitizers are described, for example, in F. M. Hamer's work "The Cyanine Dyes and Related Compounds", (1964) Interscience Publishers John Wiley and Sons.

The spectral sensitizers or also the other luminescent compounds used according to the invention are expediently added to the ready-to-pour silver halide emulsions in dissolved or dispersed form.

In the present method, it is important that the spectral sensitizer used or also the other luminescent compound remains in the layer in sufficient concentration after coating and processing. Surprisingly, it turns out that the concentration of spectral sensitizer normally remaining in the layer during normal processing is large enough to form a usable latent luminescence image. In contrast to conventional photographic processes (e.g. black and white), in which, in the interest of achieving colorless layers, such sensitizing dyes are used which can be easily removed from the layers during processing, it has a favorable effect in the process according to the invention if the dyes remain as largely as possible in the recording material during processing. Sensitizing dyes with low solubility are therefore preferably used in aqueous processing baths.

The luminescence spectra of layers which contain silver halide and a sensitizing dye generally have, in addition to the luminescence signal of the monomeric dye, a further signal, usually at longer wavelengths, which is attributable to the silver halide dye aggregate. The latter generally disappears when the silver halide is removed from the layer by fixing, while the former usually occurs to an increased extent on the fixed recording material, ie in the absence of silver halide. It is therefore generally advisable to follow the development step not only for reasons of image stabilization, but also for the purpose of increasing the luminescence density, by means of which a silver halide-free latent luminescence image is obtained. So the developed latent Lumines zenzbild be subjected to a fixing treatment in the usual way to remove the remaining silver halide or else be transferred to a silver halide-free image receiving layer by diffusion transfer.

In the present context, the expression “latent image” refers to an invisible image that has been obtained on the basis of an imagewise exposure and that can be converted into a visible image by suitable additional measures.

A "latent silver image" is therefore an imagewise distribution of development nuclei in this layer, which is obtained by imagewise exposure of a silver halide emulsion layer. Because of the low concentration of the development nuclei, such an image is normally not visible, but can be converted into a visible (real) silver image by development.

A "latent luminescent image" also denotes an invisible record of a previous imagewise exposure, in this case a record obtained by imagewise exposure and development of a recording material containing light-sensitive silver halide and a luminescent compound associated therewith in a layer. This latent luminescence image is only made temporarily visible in the case of excitation by light of a suitable wavelength. The latent luminescence image can be an imagewise distribution of a luminescent compound, or else a uniform distribution of the luminescent compound on which a silver image is superimposed in the same layer.

The scanning of the latent luminescence image obtained and conversion of the luminescence signals into electronic image signals is carried out in such a way that the developed recording material or the image-receiving layer with the latent luminescence image contained therein is scanned line by line with a light beam of a wavelength suitable for the excitation of the luminescence. Suitable excitation light is, for example, laser light or light from a lamp monochromator unit. The wavelength of the excitation light is expediently chosen so that a luminescent compound of the latent luminescence image is specifically excited for maximum luminescence. For example, a triple of the following lasers is suitable for the excitation of the sensitizers mentioned:

The variety of available Ar or Kr laser lines enables extensive adjustment to a given sensitizer triple.

The luminescence radiation of the individual pixels is converted into electronic signals by means of suitable photodetectors, which can be stored or used directly to control devices for temporary image reproduction (television tube) or for the production of permanent images (image copy, enlargement). Suitable photodetectors are, for example, photodiodes, several of which can be integrated into a so-called photodiode array or into a photodiode array. The latent luminescence image to be scanned is, for example, imaged line by line onto a photodiode line with the aid of a tilting mirror system, each image point of the image line being imaged onto a specific photodiode of the photodiode line. With simultaneous excitation of all pixels of an image line, all photodiodes of the photodiode row are thus addressed simultaneously and each individual photodiode supplies the electronic image signal of the image point imaged on it. The individual photodiodes of the photodiode line can also be addressed in succession if the pixels of the image line to be scanned are excited to luminescence in succession. However, it is also possible for the individual pixels of an image line to be scanned one after the other with the aid of optical deflection means, e.g. B. another mirror or an oscillating light guide arrangement (fiber optics) on a single photodiode or photomultiplier, so that the photodetector supplies the image signals of the individual pixels of an image line in succession.

The desired high resolution of the images to be recorded by the method according to the invention is achieved by keeping the image points of the latent luminescence image to be as small as possible. This happens e.g. B. in that either using a sharply focused excitation light beam, for. B. in the form of a laser beam always only a small point, ie a very narrow area, is excited to luminescence, or by the fact that if the excitation light is not focused and correspondingly larger areas are simultaneously excited to luminescence, smaller ones from this Sub-areas corresponding to pixels by means of suitable optical means, e.g. B. selected by microscope objectives. In any case, a corresponding electronic signal, the amplitude of which is a measure of the measured luminescence density, is assigned to each individual pixel. The line-by-line scanning of the latent luminescence image can also be carried out using the so-called »spiral scan« method. Here, the original, in this case the developed photographic recording material with the latent luminescence image, is clamped onto a rotatably mounted drum and set in rapid rotation. Excitation and photo detector units for one or more of each in the Developed recording material existing luminescent connections are firmly mounted on a movable carriage that can be moved parallel to the axis of rotation and is shifted exactly by the width of an image line during one revolution.

The image information obtained in the form of electronic signals is either used directly for controlling suitable image display devices or previously processed in a known manner by means of electronic aids (eg computers) and possibly stored. Electronic processing is understood to mean measures which, using electronic means, serve for amplification, image reversal, gradation change and improvement of the signal-to-noise ratio. Such measures are known.

Likewise, methods are known with which electronic image signals are converted into visible images, e.g. B. in television pictures (DE-A 2,908 533, DE-A 2 912 667) or in top view or see-through pictures on an opaque or transparent substrate (DE-A 2 040665, DE-A 2 043 140, US-A 3 842 195 , D EA 3 033 892).

The invention is explained below using the examples and the figures.

• Fig. 1 eine Transportvorrichtung zur iumineszenzspektroskopischen Abtastung eines Probestreifens.
• Fig. 2 eine Lumineszenzdichtekurve von Perylen in einer Silberchloridbromidemulsion nach Auszugsbelichtung (U 449) und Schwarzweißverarbeitung.
• Fig. 3 Silberdichtekurven und (normierte) Lumineszenzdichtekurven von blau-, grün- bzw. rotsensibilisierten Einzelschichten; Auszugsbelichtung und Schwarzweißverarbeitung.
• Fig. 4 Colorumkehrfilm ohne Kuppler; Auszugsbelichtung (U 531 und L 599) und Schwarzweißverarbeitung.
• Fig. 5 Colorumkehrfilm ohne Kuppler; Emissionsproduktspektrum.
• Fig. 6 Grünsensibilisierte Einzelschichten; Auszugsbelichtung (U 531) und Schwarzweißverarbeitung.
• Fig. 7 Grünsensibilisierte Einzelschichten ; Emissionsproduktspektren; Konzentrationsreihe.
• Fig. 8 Grünsensibilisierte Einzelschichten; Auszugsbelichtung (U 531) und Schwarzweißverarbeitung; Konzentrationsreihe.
• Fig. 9 Colorpapier;
  Auszugsbelichtung und Schwarzweißverarbeitung.
• Fig. 10 Colorpapier;
  Weißbelichtung und Schwarzweißverarbeitung.
• Fig. 11 Lumineszenzdichtekurve von GS-1;
  Auszugsbelichtung (U 531) und Colorverarbeitung.
• Fig. 12 Colorpapier;
  Auszugsbelichtung (U 449) und Colorverarbeitung.
• Fig. 13 Colorpapier;
  Auszugsbelichtung (U 531) und Colorverarbeitung.
• Fig. 14 Colorpapier;
  Auszugsbelichtung (L 622) und Colorverarbeitung.
• Fig. 15 Colorpapier;
  Weißbelichtung und Colorverarbeitung.
• Fig. 16 Colorpapier;
  Emissionsproduktspektrum.
• Fig. 17 Emissionsproduktspektren von GS-1
  in einer Silberschicht nach unterschiedlicher Bleichfixierung.

It shows

• Fig. 1 shows a transport device for iuminescence spectroscopic scanning of a test strip.
• 2 shows a luminescence density curve of perylene in a silver chloride bromide emulsion after pull-out exposure (U 449) and black and white processing.
• 3 silver density curves and (normalized) luminescence density curves of blue, green or red-sensitized individual layers; Separate exposure and black and white processing.
• Fig. 4 color reversal film without coupler; Separate exposure (U 531 and L 599) and black and white processing.
• 5 color reversal film without coupler; Emission product range.
• 6 green-sensitized individual layers; Separate exposure (U 531) and black and white processing.
• 7 green-sensitized individual layers; Emission product spectra; Concentration series.
• 8 green-sensitized individual layers; Separation exposure (U 531) and black and white processing; Concentration series.
• Fig. 9 color paper;
  Separate exposure and black and white processing.
• Fig. 10 color paper;
  White exposure and black and white processing.
• Fig. 11 Luminescence density curve of GS-1;
  Extraction exposure (U 531) and color processing.
• Fig. 12 color paper;
  Extract exposure (U 449) and color processing.
• Fig. 13 color paper;
  Extraction exposure (U 531) and color processing.
• Fig. 14 color paper;
  Extract exposure (L 622) and color processing.
• 15 color paper;
  White exposure and color processing.
• Fig. 16 color paper;
  Emission product range.
• Fig. 17 emission product spectra of GS-1
  in a silver layer after different bleach fixation.

The color filters used are identified by one of the letters U and L together with a three-digit number.

U denotes a band pass filter. The number indicates the mean of the wavelengths at which the transparency is half of its maximum. L denotes an edge filter with a sharp absorption edge in the visible area, which is permeable to longer waves. The three-digit number indicates the wavelength of the intersection of the abscissa with the straight line, which is determined by the points with the density 2 and 0.3 of the absorption curve of the edge filter. Further information on color filters can be found in the publication "Filters for Photography", 1st edition 1973, Agfa-Gevaert AG.

example 1

• 1. Perylen (445)
• 2. 2,7-Bis-dimethylamino-9,9-dimethylanthracen-10-on (445)
• 3. 4,6-Dimethyl-7-(N-ethylamino)-coumarin (450)
• 4. 3-Nitro-N,N-dimethylanilin (524)
• 5. Coumarin 153 [CAS Reg. No. 53518-18-6] (540)
  
• 6. Kresylviolett [CAS Reg. No. 10510-54-0] (628)
  

Each of the luminescent compounds mentioned below (spectral sensitizers and non-sensitizing compounds) was dissolved in methanol, a silver chloride bromide emulsion (56.6 g AgN0 ₃ per kg crude emulsion) was added in an amount of 2 mg substance per 1 g AgNOs. The wavelength of the maximum luminescence density [nm] is given in brackets:

• 1. Perylene (445)
• 2. 2,7-bis-dimethylamino-9,9-dimethylanthracen-10-one (445)
• 3. 4,6-dimethyl-7- (N-ethylamino) coumarin (450)
• 4. 3-nitro-N, N-dimethylaniline (524)
• 5. Coumarin 153 [CAS Reg. 53518-18-6] (540)
  
• 6. Cresyl violet [CAS Reg. No. 10510-54-0] (628)
  

• 7. Weißtöner der Formel: (408/420).
  
• 8. Rhodamin 6G [CAS Reg. No. 989-38-8] (560/572)
  
• 9. Rhodamin B [CAS Reg. No. 81-88-9] (568/580)
  
• 10. BS-1 (BS = Blausensibilisator) (438/448)
  
• 11. BS-2 (480/490)
  
• 12. GS-1 (GS=Grünsensibilisator) (512/520)
  
• 13. GS-2(511/523)
  
• 14. GS-3 (514/522)
  
• 15. RS-1 (RS=Rotsensibilisator) (575/585)
  
• 16. RS-2 (560/570)
  
• 17. RS-3 (600/610)
  
• 18. RS-4 (667/677)
  
• 19. RS-5 (670/680)
  
• 20. RS-6 (679/689)
  

In the following compounds, two wavelengths [nm] are given in parentheses, the first relating to the absorption and the second relating to the luminescence of the emission product spectra. The term “emission product spectrum” denotes the product of the absorption spectrum and the emission spectrum and is explained in DE-A 3 038 908.

• 7. White tones of the formula: (408/420).
  
• 8. Rhodamine 6G [CAS Reg. No. 989-38-8] (560/572)
  
• 9. Rhodamine B [CAS Reg. No. 81-88-9] (568/580)
  
• 10. BS-1 (BS = blue sensitizer) (438/448)
  
• 11. BS-2 (480/490)
  
• 12. GS-1 (GS = green sensitizer) (512/520)
  
• 13. GS-2 (511/523)
  
• 14. GS-3 (514/522)
  
• 15.RS-1 (RS = red sensitizer) (575/585)
  
• 16.RS-2 (560/570)
  
• 17.RS-3 (600/610)
  
• 18. RS-4 (667/677)
  
• 19. RS-5 (670/680)
  
• 20.RS-6 (679/689)
  

The mixture was then diluted with twice the amount of 5% gelatin solution and cast onto a layer support with a silver coating (AgNO ₃ ) between 0.77 and 0.85 g / m ² . In almost all cases (exception: No. 7), a paper coated with polyethylene was used as the substrate.

For No. 7 (optical brightener) Klarcello was used as a layer support.

• Entwickler I - 1,5 min
  
  auffüllen mit Wasser auf 1000 ml
• Wässerung -1 min
• Fixierung -5 min
  
  auffüllen mit Wasser auf 1000 ml
• Wässerung -10 min

A sample of each of the recording materials thus obtained was exposed to blue light (pull-out filter U 449) behind a step wedge (Δ D / step = 0.15) and exposed to black and white development at 22 ° C. as follows:

• Developer I - 1.5 min
  
  make up to 1000 ml with water
• Watering -1 min
• Fixation -5 min
  
  make up to 1000 ml with water
• Watering -10 min

The luminescence densities at the specified wavelengths of the luminescence density maximum were determined on the sample strips thus obtained by scanning the sample strips with an excitation beam a and the luminescence emission being registered automatically. A transport device according to FIG. 1 served as a continuous measuring device for test strips.

Fig. 1 shows a transport device with a roll-off device 1 and a roll-up device 2 for the test strip 3. Between the roll devices 1, 2, guide rollers 4 are arranged and between the guide rollers 4 there is the measuring plate 5 with a device for pressing the test strip 3 flat Measuring plate 5 is provided with a measuring window 6, onto which the light beam of excitation a is directed, which generates the emission beam on the test strip 3. The roller device 1, 2 is driven in the direction of the arrow in the usual way with a synchronous motor (not shown).

The transport device with the sample strip used was placed in a device for luminescence measurement, which essentially consisted of a light source, two double monochromators, an excitation radiation measuring device, a transmission measuring device and an emission detector, e.g. B. FLUOROLOG, computer controlled emission spectrometer from SPEX, USA.

The excitation beam a struck the test strip 3 with an excitation light spot 2.5 mm wide and 10 mm high. The excitation and emission wavelengths were set to the maximum intensity of the luminescent radiation of the compound in question and the test strip 3 was measured at this setting.

Fig. 2 is a typical measurement curve, which was obtained by this measurement method using the example of compound 1 (perylene). The spectral flux density (luminescence density) unit ΦΔe, λ = photons - s- ^{1 is shown} . m ^-1 . cm ^2. sr- ¹ ,
as ordinate over the length I of the test strip as the abscissa. The numbers refer to the numbering of the wedge steps (width b = 6.35 mm) in the direction of increasing blackening. The silver coating was 0.83 g AgN0 _{3 /} m ^2. The excitation light had a wavelength λa = 433 nm with a bandwidth Δλa = 5 nm. The luminescence radiation was measured at λe = 445 nm with a bandwidth of 2 nm.

Example 2

Blue, green and red-sensitized silver chloride bromide emulsions were each cast onto a layer of polyethylene-coated paper with a silver coating of 0.4 g AgNO _{3 /} m ² . These were common black and white emulsions that contained no coupler or other color former. The sensitizers were at a concentration of 10 ⁴ moles per mole Contain silver halide. The recording materials were exposed behind a step wedge and behind the pull-out filters (U 449, U 531, L 622) corresponding to the respective sensitization and, as described in Example 1, subjected to a black and white development.

In Fig. 3, for the three separation exposures blue (U 449), green (U 531) and red (L 622), the silver densities D (right ordinate; positive increase) and the corresponding (normalized) luminescence densities Φ _D (left ordinate; negative Increase) as a function of the exposure log H.

Example 3

The process was tested on a commercially available multilayer color reversal film without an embedded coupler (KODACHROME 25). A first and a second sample after the exposure exposure were processed green (U 531) or red (L 599) behind a step wedge (wedge constant Δ _D / step = 0.15) in black and white as described in Example 1.

The silver densities D (right ordinate) obtained and the corresponding normalized luminescence densities Φ _D (left ordinate) are shown in FIG. 4 as a function of the exposure log H (same representation as in FIG. 3).

A third sample of the above-mentioned color reversal film was subjected to the black and white processing described in Example 1 without exposure. A fourth sample was examined for comparison in the unprocessed state. The so-called emission product spectra (product of absorption and luminescence spectra) of these two samples are shown in FIG. 5 (recorded in the emission spectrometer FLUOROLOG from SPEX, USA). The wavelength of the excitation radiation λa is offset from the wavelength of the registered emission ie by Δλ = λe-λa = 8 nm after shorter wavelengths and was varied with the spectral bandwidth Δλa = 5 nm synchronously with λe while maintaining the distance Δλ over the entire spectral range (Δλ _e = 2 nm). Curve 1 (spectrum of the unprocessed sample) shows the luminescence signals of the green sensitizer GS at 514 nm and the red sensitizer RS at 578 nm. In addition, the signals of the dye aggregates appearing only in the presence of silver halide are present at 550 nm (GS) and 654 nm (RS). These latter signals are missing in curve 2 (spectrum of the processed sample).

Example 4

Using a silver-rich silver halide emulsion containing 2.14-10 ⁴ moles of green sensitizer GS-2 per mole of silver halide, several recording materials with different silver coatings in the range of 0.02 to 30 g AgN0 _{3 /} m ² were produced. For this, the described emulsion diluted with different amounts of a 5% gelatin solution and poured onto a layer of polyethylene-coated paper.

In Fig. 6 the luminescence densities and the silver densities are shown, which on the recording materials with the silver coatings 0.02 and 0.76 g AgNOa / m ² after exposure to green light (extraction filter U 531) behind a grayscale wedge and black and white processing (as described in Example 1) were determined (same representation as in Fig. 3).

Measurement conditions:

Normierungsfaktor K_e (GS

• 0,02 g AgNO₃/m², K_e(GS) = 4,83 . 10⁴
• 0,76 g AgN0₃/m², K_e (GS) = 9,94 . 10⁴

Standardization factor K _e (GS

• 0.02 g AgNO ₃ / m ² , K _e (GS) = 4.83. 10 ⁴
• 0.76 g AgN0 ₃ / m ² , K _e (GS) = 9.94. 10 ⁴

Example 5

Increasing amounts of green sensitizer GS-1 (1: 250 in methanol) were added to a silver chloride bromide emulsion. The emulsion samples thus obtained were each individually. Pour onto a layer of polyethylene-coated paper (wet layer thickness 38 µm). The silver application of all samples was between 0.78 and 0.8 g AgN0 _{3 /} m ^2. The emission product spectra of the green sensitizer GS-1 are shown in FIG. 7 for the samples given below.

In Fig. 8, the silver densities and the luminescence densities after green separation exposure (U 531) and black and white processing (as in Example 1) for the samples 2 (curves 2; right ordinate scale D and Φ _D ) and 7 (curve 7; left) Ordinate scale D and Φ _D ) shown (otherwise as in Fig. 3).

Sample 2

Sample 7

Measurement conditions

Example 6

• 1. blauempfindliche Schicht mit Gelbkuppler
• 2. Schutzschicht
• 3. grünempfindliche Schicht mit Purpurkuppler
• 4. Schutzschicht
• 5. rotempfindliche Schicht mit Blaugrünkuppler
• 6. Schutzschicht

A multi-layer color photographic recording material made of an opaque substrate (COLORPAPIER) was produced by applying the following layers in the order given to a paper substrate coated on both sides with polyethylene.

• 1. blue-sensitive layer with yellow coupler
• 2nd protective layer
• 3. Green-sensitive layer with a purple coupler
• 4. Protective layer
• 5. Red-sensitive layer with cyan coupler
• 6. Protective layer

• blauempfindliche Schicht - 3,2 - 10^-4 mol BS-1
• grünempfindliche Schicht - 3,1 - 10-⁴ mol GS-1
• rotempfindliche Schicht - 1,2 - 10-⁴ mol RS-4

The light-sensitive layers contained a silver bromide emulsion with a silver coating of 0.5 g AgN0 _{3 /} m ² and a spectral sensitizer for the respective part of the spectrum, in the following amounts, based on 1 mol AgN0 ₃ :

• blue-sensitive layer - 3.2 - 10 ^-4 mol BS-1
• green sensitive layer - 3.1 - 10- ⁴ mol GS-1
• red sensitive layer - 1,2 - 10- ⁴ mol RS-4

Exposure was carried out behind a step wedge (ΔD / step = 0.1) and with blue, green, red or white light (pull-out filter U 449, U 531, L 622 or daylight filter). The exposed recording material was then subjected to black and white processing as described in Example 1. The silver densities D and the luminescence densities Φ _D for the separation exposures blue (U 449), green (U 531) and red (L 622) are shown in FIG. 9.

Measurement conditions - as in example 2.

mit Φ_D=Dmax der Schwarzweiß- (bzw. Farb-)entwicklung, betragen:

The normalization factors

with Φ _D = Dmax of black and white (or color) development, amount to:

The silver densities and the luminescence densities of the individual layers for daylight (white light) exposure are correspondingly shown in FIG. 10.

Example 7

• Entwickler Il - 3,5 min
  
  • auffüllen mit Wasser auf 1000 ml,
  • einstellen auf pH 10,2.
• Bleichfixierbad - 1,5 min
  
  • auffüllen mit Wasser auf 1000 ml;
  • einstellen auf pH 7.
• Wässerung -3 min.

The color paper described in Example 6 is subjected to color processing at 33 ° C. as follows after exposure to daylight or extract (as in Example 6).

• Developer Il - 3.5 min
  
  • make up to 1000 ml with water,
  • adjust to pH 10.2.
• Bleach-fix bath - 1.5 min
  
  • make up to 1000 ml with water;
  • adjust to pH 7.
• Watering -3 min.

A test strip of this material, which had been exposed and processed with green light (pull-out filter U 531) in the manner specified, was carried out in accordance with the method given in Example 1 in an emission spectrometer (FLUOROLOG) with the aid of a transport device according to FIG. 1 at a constant feed rate of 1 cm - s ^-1 and scanned with an excitation beam spot 2.5 mm wide and 10 mm high.

Measurement conditions:

The measurement curve obtained is shown in FIG. 11 (representation as in FIG. 2). With increasing exposure, i.e. H. the luminescence density drops sharply with increasing wedge stage number. Outside the 30 wedge steps, which corresponds to the unexposed background, the luminescence density has the same maximum value as in the »veil« (wedge steps 1 to 10).

• Gelb - kurzgestrichelte Linie
• Purpur - langgestrichelte Linie
• Blaugrün - ausgezogene Linie

12 to 15 show the measurement results for the pull-out exposures blue (FIG. 12), green (FIG. 13) and red (FIG. 14) and for daylight exposure (FIG. 15). The same representation was chosen as in FIG. 3, but instead of the silver gradations the corresponding color gradations are shown, as follows:

• Yellow - dashed line
• Purple - long dashed line
• Teal - solid line

• BS - Kreuz
• GS - Kreis
• RS - Punkt

The curves of the luminescence densities are signed as follows: (Signing = measuring points)

• BS - cross
• GS circle
• RS point

Measurement conditions:

The normalization factors K _e were:

In Fig. 16, the emission spectrum of the unexposed, unprocessed COLORPAPER (curve 1) is compared with that of the unexposed, but color-processed COLORPAPER (curve 2). The spectral photon flux density ΦΔ _e , λ is plotted against the emission wavelength (measurement conditions as in FIG. 5). The short-wave band A at 418 nm belongs to the optical brightener (compound no. 7) from the paper base. The bands at 448 nm and 475 nm are luminescence signals from the blue sensitizer BS-1, the latter (475 nm) only occurring in the presence of silver halide, ie in unprocessed material. The green sensitizer GS-1 luminesces at 520 nm and the red sensitizer RS-4 at 677 nm.

Example 8

A "black noodle" (gelatin with finely divided black silver) mixed with 1.5 - 10- ⁴ mol GS-1 / mol Ag was poured onto a polyethylene-coated paper base. The silver coating was 0.67 g Ag / m ^2.

The emission product spectra of the green sensitizer GS-1 are shown in FIG. 17 for the samples of different bleach fixation specified below (see Example 7).

This shows that the luminescence of the green sensitizer is clearly extinguished even with the smallest amounts of silver.

Measurement conditions

Example 9

gelöst in Methanol, versetzt und auf einer polyethylenbeschichteten Papierunterlage vergossen. Der Silberauftrag betrug 0,7 g AgN0_3/m².A 1.76 - 10 ^-4 mol GS-1 / mol of AgNO _3-sensitized silver chlorobromide emulsion without coupler was with4 - 10- ³ and 4 - 10- ² mol / mol AgN0 ₃ magenta dye of the following formula

dissolved in methanol, mixed and cast on a polyethylene-coated paper base. The silver coating was 0.7 g AgN0 _{3 /} m ² .

The material was exposed behind a step wedge and behind the pull-out filters U 449 and U 531 and subjected to color processing as described in Example 7.

The processed samples show that only in the exposed areas of the step wedge - and here gradually increasing with the exposure - both in the intrinsic sensitivity range of the silver halide (U 449 excerpt exposure) and in the sensitized spectral range (U 531 excerpt exposure) of the purple dye together with the silver is bleached, while the unexposed background remains purple.

Claims (11)

1. A photographic recording process, in which a latent luminescence image is produced by the image-wise exposure of a photosensitive photographic recording material, characterised in that a photographic recording material which contains photosensitive silber halide and at least one compound capable of luminescence in at least one layer is exposed image-wise and developed whereby a silver image and a latent luminescence image superimposed on the silver image are produced, and the image information contained in the latent luminescence image is scanned photoselectively by a luminescence spectroscopic process and is recorded electronically in the form of monochrome luminescence signals.

2. A recording process according to claim 1, characterised in that

- a silver image is produced, by image-wise exposure and development, in at least one layer of a photographic recording material, which layer contains silver halide and at least one compound capable of luminescence, in uniform distribution, by which silver image (in the event of excitation) the luminescence of the compound capable of luminescence is weakened image-wise,

- the silver image is scanned by a monochrome light beam of a wavelength suitable for exciting luminescence, and

- the image information in the form of the luminescence thus excited is detected quantitatively by an opto-electronic transducer device, is converted into electronic image signals and is recorded electronically.

3. A process according to claim 2, characterised in that the electronic image signals are used as input signals for an apparatus for the production of visible images.

4. A process according to claim 2, characterised in that at least one spectral sensitization dye is used as the compound capable of luminescence.

5. A process according to claim 2, characterised in that, after development and before the silver image is scanned by an exciting light beam, the photographic recording material is treated with a means for removing the remaining silver halide.

6. A process according to claim 2, characterised in that a photographic recording material having an opaque substrate is used.

7. A process according to claim 2, characterised in that

- a photographic recording material having at least three silver halide emulsion layers of differing spectral sensitivity is used, each of which layers contains a compound capable of luminescence, the compounds capable of luminescence differing from each other in that they are excited to luminescence by light from different partial regions of the spectrum,

- the photographic recording material is exposed imagewise and developed, a partial image corresponding to the respective spectral sensitivity being produced in the form of a silver image in each of the silver halide emulsion layers, by which partial image (in the event of excitation) the luminescence of the compound capable of luminescence contained in this layer is weakened,

- each partial image is scanned by a monochrome light beam of a wavelength suitable for the excitation of the luminescence of the corresponding compound capable of luminescence, and

- the image information of each partial image in the form of the luminescence thus excited is detected quantitatively by an opto-electronic transducer device, is converted into electronic image signals and is recorded electronically.

8. A process according to claim 7, characterised in that the electronic image signals from each of the partial images are used as input signals for an apparatus for the production of a monochrome visible partial image of another colour and a multi-coloured image is produced by the combination of the differently coloured partial images.

9. A process according to claim 7, characterised in that partial images of the primary colours blue, green and red are recorded by using a photographic recording material having a blue-, a green- and a red-sensitized silver halide elumsion layer.

10. A colour coupler-free, colour-photographic recording material having a blue-sensitized, a green- sensitized and a red-sensitized silver halide emulsion layer, characterised in that each of the silver halide emulsion layers contains a spectral sensitization dye and a silver application corresponding to from 0,02 to 0,2 g AqNOs/m?·.

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