FR2491224A1 - METHOD FOR MANUFACTURING A NETWORK OF INTERCALE MICRO-CELLS AND NETWORK THUS OBTAINED - Google Patents

Abstract

THE INVENTION RELATES TO A METHOD FOR MANUFACTURING A NETWORK OF INTERCAL MICROCELLS. A SUPPORT 102 SEEN IN SECTION, INCLUDING MICROCELLS 108 SEPARATED BY SIDE WALLS 110, IS COVERED WITH AN ELIMINABLE MEDIA, PARTICULARLY WITH A MEMBRANE 104, WHICH CLOSES THE MICROCELLS. THE MEMBRANE OF A FIRST SET OF MICROCELLS IS SELECTIVELY REMOVED, IN ORDER TO ALLOW SELECTIVE MODIFICATION OF THE CONTENTS OF THE FIRST SET OF MICROCELLS, WITHOUT MODIFYING AT THE SAME TIME THE CONTENT OF A SECOND SET OF MICROCELLS. APPLICATION IN PHOTOGRAPHY, THE DESCRIBED STRUCTURE LIMITING THE LATERAL DIFFUSION OF THE IMAGE AND, IN PARTICULAR, IN COLOR PHOTOGRAPHY BY IMAGE TRANSFER.

Description

The present invention relates to a method of manufacturing networks of

  microcells and the networks obtained by this process. The invention relates more particularly to a method of manufacturing networks useful in photography. Belgian Patent 881,513 discloses an image forming product comprising a support which contains open microcell networks on one of the faces of the support. The photographic products described in Belgian Pat. No. 881,513 contain, in various configurations, a network of microcells in which one, two or, generally, three sets of microcells are arranged to form a network of intercalated microcells. According to one embodiment of the invention, three sets of microcells are interposed, each set containing a different imaging component, a subtractive primary imaging component (e.g., yellow, magenta). or blue-green), or an additive primary imaging component (ie, blue, green or red). Preferably, each microcell of each set is arranged such that it is in close proximity to at least one microcell of each of the other two sets. The microcells are of such size that they are not easily visible to the naked eye, and the fact that these microcells are interposed helps the oei to fuse the adjacent dye images of the various sets of micro cells into one. color image. According to a preferred embodiment of Belgian Pat. No. 881,513, blue-green, magenta and yellow dyes or precursors of these dyes, whose mobility can be varied, are associated with immobilized dyes or pigments red, green and blue, respectively, each being present in one of three sets of microcells and the microcells being coated with a silver halide panchromatic emulsion layer. By exposing the silver halide emulsion layer through the microcells and by development, a negative image can be formed in primary additive colors and the blue-green, magenta and cyan dyes can be transferred to a layer. receiver, in order to obtain a positive image in primary subtractive colors. A technique described in the aforesaid Belgian patent for filling the microcells in order to form a network of intercalated microcells consists in first filling the microcells with a sublimable substance. A laser beam is directed on the microcells forming a first set, in order to sublimate the substance initially filling the first set of microcells. The microcells thus emptied 2491224 2 can then be filled, by any appropriate technique, with a first imaging component. The method is repeated for the second set of microcells, which are thus filled by a second imaging component. The process may be repeated again with the third set of microcells to be filled, although laser beam processing is not necessary in this case. Although the process described in Belgian Pat. No. 881,513 is useful for differentially filling the microcells of a network of intercalated microcells, it is desirable to avoid the use of sublimable substances. It is also desirable to have a process that requires less energy to empty the microcell assemblies, but avoids the risk of only partial filling of the microcells. Finally, it is desirable to have a process which offers the possibility of initially filling the microcells with one or more non-sublimable substances, which are intended to remain permanently in some of the microcells. The present invention offers these advantages relative to those described in Belgian Pat. No. 881,513. The method according to the invention consists in forming, in a support comprising a first and a second face, a planar array of microcells open on the first face and selectively modifying the content of a first set of microcells with respect to a second intercalated set of microcells. This process is characterized by selectively modifying the contents of the microcells by placing, in a position adjacent to the first face, a removable means for closing both the first and second set of microcells, and in that the closure means of the first set of microcells is selectively removed to selectively modify the contents of the first set of microcells without at the same time changing the contents of the second set of microcells. In the accompanying drawings, FIG. 1A is a plan elevation of the support; Fig. 1B is a sectional view of the product of Fig. 1A taken along line 1B of Fig. 1A; Figures 2 and 3 are sectional views of other supports;

  Fig. 4A is a plan elevation of a multi-colored filter element; Fig. 4B is a sectional view of the product of Fig. 4A taken along line 4B of Fig. 4A; Figs. 5A to 5D are sectional views illustrating the successive steps of constructing a multicolor filter element; and Fig. 6 is a sectional view of a color image transfer element obtained according to the invention. The drawings are schematic in nature. Since the individual micro-cells are too small to be seen with the naked eye, the microcells and the elements containing them are greatly enlarged. The depth of the microcells is also exaggerated relative to the thickness of the supports, which is generally at least 50 to 500 times greater. For the implementation of the invention, a support comprising a network of microcells is used. The support and its microcells can be similar to those described in Belgian Pat. No. 881,513. FIGS. 1A and 1B schematically represent a preferred variant of a support according to the present invention. The support comprises two substantially parallel main faces 104 and 106. In this support, there are formed microcells 108, open on the first face of the support. These micro-cells are delimited by a network of side walls 110 which form part of the lower part 112 of the support, which means that the side walls 110 and the lower part 112 of the support are in one piece; thus, the support plays the role of barrier between adjacent cells. The lower part of the support defines the bottom 114 of each micro-cell. The dashed line 120 delimits an elementary pattern containing a single microcell. The remainder of the support shown is formed by elementary patterns substantially identical to the pattern delimited by the dashed line 120. The supports according to the present invention may exhibit differences in their geometric configurations and structures. FIG. 2, for example, schematically represents a sectional view of a support 202 comprising a first main face 204 and a second face 206, substantially parallel to the first face. A microcell 208 is open on the first side. The support comprises a large number of identical repeating patterns. The support forms the side walls and the bottom of the microcells 208. These walls are curved and are easier to manufacture by certain techniques, such as etching; they furthermore make it possible, in case of need, to redirect the radiation of exposure towards the inside of the microcells for photographic dele- ciations. FIG. 3 represents an elementary pattern of a support 300. This support comprises a first element 302 with a first face 304 and a second substantially parallel face 306; a second support member 2491224 X 4 308 is applied to the first, with an aperture 310 for each microcell. This second element has an outer face 312. The walls of the opening 310 in the second element of the support and the first face of the first support element define a microcell. The support is formed by the repetition of the elementary pattern shown. The micro-cells are arranged on the support according to a predetermined arrangement in order to form a network. It is generally desirable and most efficient to generate micro-cells so that they are aligned along at least one of the plane axes of the support surface. For example, with hexagonal-shaped micro-cells (preferably used for networks consisting of three sets of micro-cells differing in the content of the microcells), there is an alignment of the microcells along three axes of the surface of the support forming between them angles of 600. Preferably, the microcells form a regular network. It is possible, however, to vary the spacing of adjacent microcells to allow alterations in visual effects or for other purposes. Although FIG. 1A represents microcells having the form of regular hexagons, these microcells may be in the form of polygons, circles or ellipses or any other configuration. The supports described above are only examples of possible configurations. According to one variant, the microcells can be of maximum depth. In another variation, a relatively deformable support member may be applied to a second, relatively non-deformable and embossed support member. Seen in section, such a support differs from the support 300 in that a thinned portion of the second element of the support 308 extends below the mesocells, the second support element not being open as shown. For color photographic products, it is preferred to use microcells

  hexagonal, as described in more detail below. It is also desirable to apply on the supports described above layers for modifying their surface characteristics. For example, one or more thin layers of substratum may be applied to one side of the support to the microcells so as to coat the walls of the microcells without filling them. Such layers can be used to improve the adhesion of the substances to be introduced into the microcells, to increase or decrease radiation reflection or for other purposes. Although, in all of the figures, one of the faces of the support is flat, it may have other configurations. For example, separate microcell networks may be open on each support face. Depending on the applications, the microcells of these distinct networks may be aligned or not oriented relative to each other. The face which is represented plane may also be lenticular. In a preferred form, the projective area of the lenticules may correspond to the projective area of the patterns 120. For photographic applications, it is frequently desirable to form elements containing two or three distinct sets of intercalated microcapsules. These sets may contain, for example, blue, green, and red interposed filter segments, and the blue, green, and red pigments or dyes forming the filters are each contained in a separate set of microcells. The separate sets of microcells may also contain image-forming photosensitive substances, each of which is sensitive to a different region of the visible spectrum. Thus the sets of microcells may contain blue, green and red sensitive silver halide emulsions, each emulsion being contained in a distinct set of microcells. In another form, the three sets of microcells may contain primary subtractive image-forming dyes or precursors of such dyes, i.e., blue-green, magenta and yellow image-forming dye precursors or dyes precursors. The microcells may also contain combinations of filter substances, photosensitive substances and image forming substances. To illustrate a specific application of the microcellular supports, FIGS. 4A and 4B show a multi-color filter element 400. The filter element is constituted by a support 102 comprising a large number of identical hexagonal microcells 108. The sidewalls 110 separating the adjacent microcells are dyed to reduce light transmission, while the underlying portions 112 of the carrier, which form the bottom of the microcells, are substantially transparent. As shown, the multicolor filter element comprises red, green and blue filters, represented by R (red), G (green), B (blue). The filter segments belong respectively to a first, second and third set of microcells forming an interleaved network. The multi-color filter element 400 may be used to obtain color images by an additive process, as described in British Patent Specification No. 15,027, United States Patent Specification No. 1,003,720, and in US Pat. James' Theory of the Photographic Process, 2nd Edition, 5 Macmillan, 1977, p. 335. By exposing a panchromatic photosensitive substance through the multicolour filter, for example a panchromatic silver halide emulsion, it is possible to form a color image. For example, a negative color image can be obtained using a negative silver halide emulsion by examining this emulsion after photographic exposure and development through the multicolour filter. likewise obtain a positive image in color using a positive-direct photographic emulsion. The intercalated microcell array shown is particularly advantageous visually, since each filter segment is surrounded by an equal number of segments of each of the other two filter elements. In this way, the eye can easily merge the separated filter segments laterally as it looks at an image. In addition, copying through a multicolor negative image formed by the filters and an image-forming photosensitive substance to form a positive color image is facilitated by the spatial relationship of the distinct sets of microcells. Of course, network filter segments may have other configurations. For example, instead of being intercalated as shown, the blue, green, and red filter segments can form distinct rows of microcells. So, a

  A row of filter segments of one color may be interposed between two rows of filter segments of the two other additive primary colors. It is also possible to obtain filter networks in which the different filter elements comprise unequal numbers of microcells. For example, we know that the human eye gets most of its information from the green region of the spectrum. The red region of the spectrum gives a smaller amount of information and the lowest amount of information is obtained by the blue region of the spectrum. U.S. Patent No. 3,971,065 discloses an intercolored multicolor filter array in which the green segments occupy half of the total area of the grating, the red and blue segments each occupy one-half of the remaining area of the grating. network. Such filters can be obtained by the process of the present invention, if desired. It is desirable to make filters in which the filter elements or filter segments interspersed have the smallest possible dimensions. However, the lateral diffusion of the substances forming the various filter elements imposes a limit on the size of these elements and makes it difficult to obtain small filter elements. For example, when dyes from adjacent segments mix together, undesirable color changes may occur. As indicated in Belgian Pat. No. 881,513, it has been recognized that lateral diffusion can be prevented by placing the filtering substances in microcells. The side walls 110 of the support 102 form a physical barrier which prevents the lateral diffusion and mixing of the filtering substances. The present invention provides an improved process for the selective introduction of substances into intercalated sets of microcells. We must hold. the fact that the supports shown in the figures are considerably enlarged and that there are distortions of the relative proportions. More particularly, the microcells are generally greatly enlarged. In reality, the microcells are of dimenions such that they are not easily visible to the naked eye and, in general, it is only possible to see the microcells with the aid of a microscope. In general, the method of the present invention is applicable to the formation of elements containing, in a first set of microcells, a first substance or a first combination of substances and, in at least one other intercalated set of microcells, a different substance or a different combination of substances. Figures 5A to 5D illustrate the application of the method of the invention to the manufacture of an element containing three intercalated sets of microcells each containing a different substance or a different combination of substances. In FIG. 5A, the support 102 is shown in the form described above for obtaining a multicolour filter element 400. A membrane 502 is shown adjacent to the first face 104 of the support. The membrane covers and closes the microcells 108 of the support. The membrane comprises an organic polymer or is entirely formed by such a polymer and this membrane is thin compared to the side walls 110 of the support. Preferably, the thickness of the membrane is of the order of about 5 to 50% of that of the side walls. The microcells initially preferably contain an easily removable thermal insulator such as air, but these microcells can initially contain any readily removable substance. To form the membrane and place it in the position shown in FIG. 5A, any suitable conventional technique may be used. In most cases, however, the membrane has a thickness of 0.2 to 1 μm, so that many techniques useful for forming thick membranes can not be used to form the membrane 502. In a preferred embodiment, the membrane is formed by casting a solution of a film-forming polymer in a volatile solvent on the surface of a liquid contained in a reservoir. This liquid is such that the polymer 10 is not easily soluble, it is for example water. The film freezes at least partially by evaporation of the solvent. To protect the film from any disturbances, it is possible to place on the film, if desired, a floating frame. & Slowly moving the support 102, in the tank, to the surface of the water, it is possible to set up the membrane on the first face of the support, without affecting the integrity of the membrane. The element is left for a while, so that traces of water in the microcells can evaporate. The small thickness of the membrane allows air and water vapor to diffuse through this membrane, so that after a while,

  obbient 20 an element as shown in Figure 5A which comprises only air in the cell. If desired, to obtain the casting surface, the water can be replaced by other liquids which are volatile or highly heat-conducting. In another embodiment, the support can simply be applied to the dry top surface of the cast membrane on the surface of a liquid such that the first face of the support is in contact with the membrane. The next step of the process is to selectively open the microcells intended to form one of the sets of interleaved microcells. Any suitable technique can be used in this regard, but it is preferred to use radiation which is directed onto the membrane to open the microcell assembly. One of the techniques described in Belgian Pat. No. 881,513 may be used, for example, the use of masks. In a preferred technique, a laser beam can be used which is sequentially directed to the microcells forming a set of intercalated microcells. Known laser scanning techniques, such as those described in U.S. Patent Nos. 3,732,796 and 3,864,697 and US Patent Publication No. 3,098,860, may be used for this purpose. two laser beams are used. One of the laser beams has sufficient intensity to achieve the desired alteration of the membrane covering the microcells. The second laser beam is used only to accurately position the first laser beam and may be of different wavelength and lower intensity. The first and second laser beams are separated in the plane of the membranes by a precisely determined distance. By using a photodetector to receive light transmitted through the carrier by the second laser or reflected by the carrier, it can be determined when a microcell or sidewall is aligned with the second laser beam. In the preferred embodiment shown, in which the bottom walls of the carrier are substantially transparent and the sidewalls are dyed, any appreciable change in light intensity perceived by the photodetector is a function of the relative position of the carrier and the laser beam. In other cases, differences in reflection or refraction between the bottom and the side walls forming the microcells can provide the information to the photodetector. Once the position of the second laser beam respectively at a microcell has been determined, the position of the first laser beam respectively at one microcell can also be fixed, since the spacing between the lasers and the center-to-center distances of the microcells are known. Depending on the desired array and exposure accuracy, tracking with the second laser beam can be performed before exposing each microcell with the first laser beam, or only at the beginning of the exposure of a set of microcells. or at specified intervals, for example before exposing each row of microcells of a set. When a first scan has been performed by the first laser beam, the support comprises a set of open microcells and the remaining intercalated microcell assemblies are not or substantially unaffected. Instead of sequentially exposing the microcells by a laser beam as indicated, exposure can be performed through a mask. Laser beam scanning has the advantages of eliminating the need for mask preparation and alignment with respect to the microcells prior to opening a set of microcells. When the energy from a laser beam or other source reaches the membrane in one or more ranges corresponding to a microcell or set of microcells, the membrane is heated locally. It is preferable that the radiant energy selectively reaches that portion of the membrane located at or near the center of the underlying microcell. Since the membrane is extremely thin, its heat capacity is low, i.e., very little heat energy is required to raise its temperature. Thus, a laser beam, for example, can easily raise the temperature of the organic membrane to its decomposition point in the region above a microcell. Since the thickness of the membrane is not greater than half that of the side walls, and is generally much smaller, the sidewalls do not have as high a temperature rise as that of the membrane. brane, even when the membrane and the support are formed of the same substance. Being thicker, the side walls have a capacity

  heat, which slows down their temperature rise. In addition, if the radiant energy is confined to the region near the center of the underlying microcell, the heat can be conducted laterally through the membrane to the sidewalls, but because it is very thin , the membrane is an inefficient thermal conductor. The selective thermal destruction of the membrane can be enhanced by forming the support of a more heat stable substance so that if the membrane and the support reach the same temperature, the membrane will be selectively destroyed. It is particularly intended according to the invention to use in combination a source of radiant energy and a membrane such that the membrane effectively absorbs radiant energy. The film-forming polymer composition can be modified by incorporating an ultraviolet absorbing compound, a dye or an infra-red absorbing compound. On the other hand, once the membrane is in place, it can be applied to it a substance increasing the absorption. For example, the membrane may receive a lamp black deposit, passing it over a flame, to increase its absorption of radiant energy. In addition to increasing the absorption of radiant energy by the membrane, a support which is relatively non-absorbing in the spectral region of the radiant energy may be selected. From the foregoing, it appears that, by selectively acting on the regions of the membrane covering a set of micro-cells, it is possible to selectively open a set of micro-cells, without affecting the sets of microcells. adjacent and without 2491224 damage the media. Then, by any suitable technique, all the open microcells can be filled without filling the remaining micro-cells. This is illustrated in Figure 5B, in which the membrane 502 has been modified by aperture-forming 504 corresponding to an underlying set of microcells. By way of illustration, the set of open microcells is represented by a substance forming filter segments B of blue color. To fill the set of open microcells, a technique is preferably used which gives rise to very low physical stresses on the membrane. For example, in the form illustrated, an aqueous solution of blue dye or a suspension of blue pigment may be introduced into the open microcell assembly while exerting only very slight stresses on the remainder of the membrane. After evaporation of the water, the blue dye or blue pigment remains in the open microcell set. The filling may be repeated, if desired, until the desired optical density of blue dye or pigment is obtained in the open microcells. This technique can be used with any substance or combination of substances that it is desired to introduce into the microcells and with any compatible volatile liquid. By appropriate choice of substances and liquids, successive layers can be deposited in the cells, if desired. According to another embodiment, the filling substance may be in the form of fine particles which are gently deposited by brushing in the microcells. Of course, the particles have average diameters significantly less than the width of the microcells. If desired, the particles can be melted in the microcells. For example, many particulate substances simply melt when held in high humidity conditions. The fusion can also be obtained by a slight heating. In Fig. 5C, a second set of intercalated microcells is shown open and filled to form green filter segments G. For this second set of microcells, the techniques described above can be used to open and fill the first set of microcells, but using a green filter substance. At this stage of the process, only the small segments 506, covering the third set of interposed microcells, remain of the original membrane. To fill the third set of microcells, the techniques described above can be used to open and fill the first and second set of microcells, but using a red filter material. The product obtained as shown in FIG. 5D is the multi-color filter element 400. It is obvious that the last set of microcells can be filled by a larger number of techniques than the first and second set of microcells. To open the last set of microcells, it is not necessary that the techniques used to remove the membrane be-really selective.For example, in the mode

  In the illustrated embodiment, it is not necessary for the radiant energy to act selectively on the membrane segments 506, since the membrane can be fully de-treated when the last set of microcells is opened. That is, the element shown in FIG. 5C can be uniformly exposed to radiant energy to destroy membrane segments 506. In another embodiment, the remaining membrane segments can be removed by applying against these remaining segments. a support on which they adhere more strongly than on the first side 104. One can use for this purpose, any of the usual techniques of transfer by laminating. It is not even necessary to remove the membrane segments 506 before filling. By using filling techniques that are, by themselves, capable of destroying the membrane segments, the opening and filling phases of the last set of microcells can be combined. For example, by coating with the doctor blade of the element shown in FIG. 5C, with a red filter substance, the segments of the membranes can subside in the underlying microcells, leaving room for the substance Red filter also enters the third set of microcells. The above microcell filling technique is particularly suitable for applications in which each set of microcells, except the last one, must be substantially completely filled. Thus, after opening and filling the first set of microcells, any substance to be introduced into another set of microcells can not enter the first set, since the substance filling these microcells prevents another substance from being able to enter. enter. In many applications, any small amount of material likely to be deposited above the first set of filled microcells during the filling of the second set or any subsequent set may be neglected. The possible superficial deposition may also be eliminated, by gently abrading the first face 104 of the support after all the microcells have been filled. For example, the face 104 of the carrier may be wiped, or polished by a doctor blade, to remove any substances above those contained in the microcells. Another embodiment is particularly suitable for only partially filling the microcells or for maintaining a high degree of separation between the substances that are placed in the separate sets of microcells. Once the first set of microcells is open and partially filled to the desired ratio, a second membrane is placed on the first side of the support. If desired, the first membrane can be completely removed before the second membrane is put in place, for example by film-coating or by the destruction techniques described above. When the membranes are relatively thin, so that the multiple layers of membrane can still be selectively destroyed by heat without damaging the side walls of the support, one can set up the second membrane on the first membrane which is then open. The first and second membranes are then selectively destroyed in the regions above the second set of microcells so that these microcells can be at least partially filled by the formed openings. If a third membrane is used, it can be put in place following the same techniques and considerations as for the first and second membranes. It is generally preferred that the last set of microcells is opened by selectively acting on the overlying membrane or membranes, thereby preserving the closure of the sets of microcells which have been previously at least partially filled. Depending on the desired applications, any remaining membrane, after the last set of microcells has been selectively filled in the desired proportion, may be left in place, destroyed or transferred to a separate support as described above. According to a variant of the differential filling method of the microcell assemblies described above, it is possible to introduce into all the microcells, before their closure by a membrane, at least one substance which remains permanently in at least one set interleaved microcells. The membrane enclosing the microcells is removed by one of the techniques described above in all regions except those corresponding to the set of microcells in which the substantially present substance is intended to remain. The substance initially present is

  5 then removed from the open microcells. For example, a soluble substance can be removed by simply bringing the element into contact with a solvent, spraying a solvent or immersing in a solvent. After at least one set of microcells has been emptied, a second substance or combination of substances is introduced into the set of empty microcells. The general method described above can be illustrated by reference to the manufacture of the multicolored filter element 400. An eliminable blue filter substance, for example a blue filter dye, which can be used, is initially introduced into the microcells 108 of the support 102. dissolved. The microcells are then closed by a membrane 502 and the element is then similar to that of FIG. 5A, but the microcells each contain a blue filter substance. Then, by one of the selective membrane removal techniques described above, the second and third sets of intercalated microcells are opened which are intended to contain respectively a green filter substance and a red filter substance. 506-like membrane segments then only cover the microcells in which the filter material must remain incorporated. The element can be contacted with a solvent of the blue filter substance, which can be removed from the second and third sets of open microcells. The second and third sets of microcells can then be filled, at least partially, with a dissolvable green filter material, and the second and third sets of microcells are closed by a second membrane. The segments of the first membrane may be removed or, preferably, left in place since they do not interfere with the subsequent phases of the process. By proceeding as before, the second membrane portions above the third set of microcells can be selectively removed and the green filter substance of the third set of microcells removed. The second membrane remains intact in the regions closing the first and second sets of microcells, and the blue and green filter substances remain in these microcells. The red filter substance can then be introduced into the third set of microcells. It should be noted that since the membranes protect the microcells in which the desired substance is to remain incorporated, the microcells containing the green and blue substances may be wholly or only partially filled with substance without modification of the process. It is immaterial whether the red filter material is soluble or wholly or partially fills the third set of microcells, since this has no effect on the process steps. After filling the third set of microcells in the desired proportion, any portion of the membrane that remains in place, depending on the application for which the element is intended, can be removed, if desired. Since air is an exceptionally good thermal insulator, it is preferred that the microcells be only partially filled with the blue and green filter substances so as to leave in the microcells an air gap which separates the filter substances from the cells. membranes. However, if the filter substances are good heat insulators, the increase in laser energy required to act on fully filled microcells can be tolerated. With the multi-color filter element 400 described above, a panchromatic image forming substance can be used in the form of a continuous layer applied on a separate support, this layer not being integral with the filter element and being only juxtaposed with it during exposure and visual examination. In another form, the image forming panchromatic substance may form a separate continuous layer, applied to the first face of the support. According to yet another alternative, the image forming panchromatic substance can be in each of the microcells, so that the filtering substances are placed between the imaging substance and the radiation source used for the exposure. According to a preferred embodiment, a mordant is placed on the bottom walls of the microcells and the filter substances are dyes immobilized by the mordant and, therefore, placed adjacent the bottom walls of the microcells. The imaging substance may be mixed with the filter substance. When the imaging substance is mixed with the filter substance, it is preferred to incorporate a blue-sensitive imaging substance in the microcells containing the blue filter substance, a

  A green-sensitive imaging substance in the microcells containing the green filter substance and a red-sensitive imaging substance in the microcells containing the red filter substance. The three image-forming substances can be introduced with the filter substances as described above, except that the image-forming substances should be protected against exposure to actinic radiation. The use of dyes or primary sub-tractive dye precursors in interleaved microcell arrays is illustrated in Figure 6. This figure shows a photographic element 600 for obtaining transfer color images. The transporous support 602, the microcells 608 and the walls 610 may be identical to those of the element 400, described above. The microcells contain filter substances and image-forming photosensitive substances as described above. In addition, each of the microcells contains a primary subtractive dye precursor, which may have a mobile form and an immobile form as a dye or dye precursor. The microcells R, the microcells G and the micro-cells B contain, respectively, blue-green, magenta and yellow mobile dye precursors. The carrier 602 forms, with the contents of the microcells, an image-forming portion of the photographic element. The photographic element shown in FIG. 6 corresponds to a preferred embodiment, according to which a red-sensitive silver halide emulsion is present in the microcells R, a green-sensitive silver halide emulsion is present in the microcells G and a blue-sensitive silver halide emulsion is present in the microcells B, each emulsion being mixed with a primary additive filter material and a complementary primary subtractive dye precursor. The image-receiving part of the photographic product consists of a transparent support or complementary sheet 650 carrying a dye immobilization layer 652, then a reflective spacing layer 654 which preferably is white. and finally a silver receiving layer 656, which contains a silver precipitating agent. In a preferred embodiment of a composite photographic product, the image forming portion and the image receiving portion are placed face to face and joined by their edges. After exposure, a frangible capsule, not shown, releases a treatment solution. A gap 658 is shown between the image forming and image receiving portions to indicate the location of the post-exposure processing solution. The treatment solution contains a silver halide solvent. A silver halide developer is incorporated in the treatment solution or located so that it is contacted with the treatment solution when it is released from the frangible capsule. The developer (or combination of developers) can be incorporated into the silver halide emulsions. The photographic product 600 is preferably a positive-effect image transfer system. In such a system, the silver halide emulsions are preferably negative and the dye precursors have a positive effect, although direct positive emulsions and negative dye precursors also produce a dye transfer system. positive image. The photographic product is exposed at 600 through the transparent support 602. The red, green and blue filters do not interfere with the imagewise exposure, since in each case they only absorb outside the region. of the spectrum to which the emulsion with which they are associated is sensitive. However, the filters may have a useful function and protect the emulsions from exposure outside the desired region of the spectrum. For example, when the emulsions exhibit appreciable natural sensitivity to blue, the red and green filters absorb the light so that the red and green sensitive emulsions are not impressed by the blue light. By releasing the treatment solution between the image forming element and the image receiving element of the product, the development of the silver halides occurs in the microcells containing the exposed silver halides. The development of silver halides in a microcell results in a selective immobilization of the present dye precursor which is initially mobile. In a preferred form, the dye precursor is both immobilized and converted to a primary subtractive dye of a hue complementary to that of the filter. The residual mobile dye precursor, under

  dye form or precursor form, migrates through the silver receiving layer 656 and through the reflection and spacing layer 604 to the dye immobilization layer 652. By passing through the silver receiving layer and the spacer layer, the primary subtractive dye precursors or dyes are free to diffuse laterally and do so effectively. Referring to Figure hA, it can be seen that each microcell containing a particular primary subtractive dye precursor is surrounded by microcells containing precursors of the other two primary subtractive dyes. Thus, lateral scattering results in an overlap of dye ranges transferred into the dye immobilization layer of the receptor element, when a dye or mobile dye precursor is transferred from adjacent microcells. When three primary subtractive dyes overlap in the receiver element, black image areas are formed and, when no dye is present, white areas due to reflection by the spacer layer are observed. When two of the primary subtractive dyes overlap on the receiver element, a primary additive image range is formed. Thus, it can be seen that a multicolored positive image can be formed which can be seen through the transparent medium 650. This positive transfer image is an image in the place. In the product for color photography 600, the risk of unwanted interimage effects due to the migration of the oxidized developer is significantly reduced, compared with the usual photographic products comprising superimposed color-forming layers, since the sidewalls of the oxidized developer are substantially reduced. support element prevent direct lateral migration between adjacent microcells. Nevertheless, in some systems, the oxidized developer may be movable and may migrate with the moving dye or mobile dye precursor to the receiving member and migrate in the opposite direction to an adjacent microcell. In order to minimize undesired immobilization of the dye or dye precursor prior to its transfer into the mordant layer of the receiving member, it is preferred to incorporate into the silver receiving layer 656 a developer trap. oxide. Since the treatment solution contains a silver halide solvent, the undeveloped silver halide remaining in the microcells is dissolved and can diffuse to the adjacent silver receiving layer. Dissolved money is physically developed in the receiving layer of money. Solubilization and transfer of the silver halide out of the microcells has the effect of limiting the direct or chemical development of the silver halide in the microcells. It is well known that prolonged contact between the silver halide and the developer under conditions of development (eg high pH) can result in increased levels of haze. Dissolution and transfer of the silver halide involves a mechanism which terminates the development of the silver halide in the microcells. In this way, the production of the oxidized developer is stopped and the immobilization of the dye in the microcells is also stopped. There is therefore a very simple mechanism to stop the development of the silver halide and the immobilization of the dye. In addition to the positive color image obtained by transfer, a useful negative color image is obtained. In microcells in which the development of the silver halide has occurred, an immobilized primary subtractive dye is present. This immobilized image-forming dye produces, with the primary additive filter material, a noticeable absorption in the visible spectrum, which imparts a high neutral density to these microcells. For example, when an immobilized blue-green dye is formed in a microcell also containing a red filter, it is clear that the blue-green filter dye absorbs the red light while the red filter absorbs in blue and green. The developed silver, present in the microcell, also increases the neutral density. In microcells in which the development of silver halide has not occurred, the mobile dye precursor, before or after dye conversion, has migrated to the receptor element. The only color present is then that supplied by the filter. It is advantageous, in order to reduce the minimum density, to use silver receiving layer 656 to halt the development of the silver halide, as described above, rather than resorting to other processes of stopping development. Yes

  the imaging element 600 of the photographic product 600 is separated from the image receiving element, the imaging element itself forms a negative image in primary additive colors. This negative image may be used for transmission or reflection prints in order to obtain positive color images at the location, for example enlargements, hard copies and slides, by conventional photographic techniques. . The above description of photographic product 600 illustrates the use of initially mobile subtractive primary dye precursors as well as primary additive filter substances and red, green and blue sensitive silver halide emulsions. , in interleaved microcell networks. In other photographic products for obtaining transfer color images, the microcells can contain the silver halide precipitating agent and panchromatic silver halide emulsions can be layered, in order to cover the other products contained in the microcells. The precursors of primary subtractive dyes may initially be mobile or immobile. In addition, the dye precursors may be replaced by mobile or immobile primary subtractive dyes which may undergo imagewise mobility changes. In this case, it is preferred to place the primary subtractive dyes in the microcells in such a way that the exposure radiation reaches the halide before the dye, thereby avoiding concurrent absorption and any resulting decrease in sensitivity. According to another variant, the hue of the preformed image-forming dyes may be modified so that these dyes do not compete with the silver halide for the absorption of the light to which it is sensitive. the silver halide present in the same microcell. By contact with the treatment solution, the dyes can come back to the desired color again. If it is not desired to have an additive image retained in color, the primary additive filter substances may not be incorporated in the microcells, in the cases where the silver halide of each set of microcells is sensitive only to one of the blue, green and red regions of the spectrum. If it is not desired to obtain a color image by transfer, layer 652 can be replaced by layer 656, so that a transferred silver image can be observed, all dyes or subtractive primary dye precursors. Of course, if no color image or transferred silver image is desired, the image receiving element of the photographic material can be removed, as can the dye or precursor. of primary subtractive dye. It therefore appears that a large number of substances can be used to form interleaved micro-cell arrays, useful even for a specific application such as color photography. The following are preferred systems for obtaining transfer color images, which may be made according to the present invention. According to one embodiment, the photographic product 600 may contain (1) in a first set of microcells, a blue dye or filter pigment and an initially colorless, yellow dye-forming coupler, mobile; (2) in a second set of intercalated microcells, a green filter dye or pigment and an initially colorless, magenta dye-forming coupler, and (3) in a third set of intercalated microcells, a dye or a red filter pigment and a coupler initially colorless blue-green dye trainer, mobile. In a preferred form, a silver halide negative panchromatic emulsion is applied above the microcells (not shown in FIG. 6). Layer 656 contains a silver precipitating agent and an oxidized developer trap. The reflection and spacing layer 654 may be a usual layer containing titanium oxide. The immobilization layer 652 of the dye contains a substantially immobile oxidizing agent. The photographic product 600 is exposed imagewise through the transparent support 602. A treatment composition containing a color developing agent and a silver halide solvent is then released and spread uniformly in the space 658. L The silver halide is developed in the exposed areas, forming an oxidized chromogenic developer which couples with the present dye-forming coupler with the formation of a stationary dye. The dye or pigment filter, the immovable dye formed and the silver developed all increase

  together the optical density of the microcells that are exposed. In the unexposed areas, the unexposed silver halide is dissolved by the silver halide solvent and migrates to layer 656, where it is reduced to silver. The oxidized developer, produced during the reduction of the silver halide to silver, immediately undergoes cross-oxidation with the oxidized developer trap, which is present with the silver precipitating agent in layer 656. At the same time, the mobile coupler migrates out of the microcells that have not been exposed. The movable coupler does not react with the oxidized color developer in layer 656 since any traces of oxidized color developing agent preferentially react with the oxidized developer trap. The coupler thus migrates, unaffected, through layer 656 and penetrates the reflection and spacing layer 654. Due to the thickness of this layer, the movable coupler can migrate laterally to some extent. Upon reaching the immobilization layer 652, the coupler reacts with the oxidized color developer 1. The oxidized color developer is uniformly produced in this layer by interaction of the oxidizing agent with the color developing agent. Due to the lateral diffusion in the spacer layer, superimposed immobile dye images, yellow, magenta and blue-green, are formed in the immobilization layer and can be observed as a multicolored image through the transparent support. (or complementary sheet) `650, the layer 654 providing a white reflective background. Since only the dye or filter pigment remains in the unexposed microcells, the carrier 602 forms a negative in additional primary colors. To illustrate another embodiment, a photographic product as described above may be modified by replacing initially colorless, dye-forming mobile couplers with initially mobile developing dyes. The hue of the developing dyes is modified so that the developing dye present in the microcells containing the red, green and blue filter substances does not initially absorb light in the red, green and blue regions of the spectrum, respectively. The dye mordant, as well as an oxidant, may be present in the dye immobilization layer 652. Since the dye-image-forming substance 30 itself is a silver halide developer, a customary activator solution may be used, preferably containing an electron transfer agent. The other characteristics may be identical to those described for the previous embodiment. After imagewise exposure and release of the activator solution, the developing dye reacts with the exposed silver halide to form an immobile primary subtractive dye which is complementary to the primary additive filter material in the exposed micro-cell. . Thus, the optical density of the exposed microcells 2491224 23 is increased and a color negative primary additive image can be formed in the carrier 602 by the filter substances. The development of the silver halide is terminated by transfer of the dissolved silver halide as previously described. In the unexposed areas, the unoxidized developing dye migrates to the immobilization layer 652, where it is immobilized to form a positive color image. During the treatment, the hue of the developing dyes is modified, so that they form primary subtractive dyes complementary to that of the primary additive filter substances with which they are initially associated in the microcells. That is, the microcells containing red, green and blue filter substances contain developing dyes which ultimately form blue-green, magenta and yellow dye images. The color changes can be achieved by the high pH of the treatment, they can also be obtained by etching or by combining the image dye receptor element with a complexing agent. Instead of using modified dye developing dyes as described above, initially mobile leuco dye derivatives in combination with electron transfer agents can be used to obtain similar results. . Since the leuco-derivatives are initially colorless, it is not necessary to change the hue to avoid competing absorption of light during exposure. The leuco dye derivatives are converted to primary subtractive image-forming dyes by oxidation in the dye immobilization layer.

  Instead of using initially mobile dyes or dye precursors, as described above, it is possible to employ initially immobile substances. Benzisoxazolones which are precursors of hydroxylamine type compounds, dye liberators, are preferably used. By cross-oxidation in the microcells with the oxidized electron transfer agent, produced by development of the exposed silver halide, the release of the mobile dye is prevented. The release of the mobile dye occurs in the ranges in which the silver halide is not exposed and in which there is no production of oxidized electron transfer agent. Preferably, the hue of the dye image-forming compounds is initially modified to avoid competing absorption during imagewise exposure. The mordant immobilizes the dyes in the layer 652. In this embodiment, the presence of an oxidant is not necessary in this layer 602. Each of the embodiments described above used compound formers dye image with positive effect. To illustrate an embodiment using negative-effect dye image-forming compounds, a first set of microcells 608 may contain a blue dye or filter pigment, a silver precipitating agent, and a liberating compound. oxidation-reduction dye, containing a yellow dye whose hue is modified to avoid absorption in the blue region of the spectrum, prior to treatment. Similarly, a second set of intercalated microcells contains a green filter dye or pigment, the silver precipitating agent, and a redox dye-releasing compound containing a modified hue magenta dye, and a third set of intercalated microcells contains a red filter dye or pigment, the silver precipitating agent, and an oxidation-reduction dye releasing compound containing a modified tinted blue-green dye. The microcells are covered with a silver halide panchromatic emulsion layer containing an oxidized developer trap (not shown in FIG. 6). The silver precipitation layer 656, shown in FIG. 6, is not present. The reflection and spacing layer is a white layer of titanium oxide. The immobilization layer of dye 652 contains an oxidant. The photographic material is exposed through the transparent support 602. A treatment solution containing an electron transfer agent and a silver halide solvent is spread between the imaging element and the imaging element. image of the photographic product. In a preferred form, the pH of the treatment solution causes the coloring of the dye-releasing compounds to be modified by oxidation-reduction to obtain the desired hues. In the ranges in which the silver halide was exposed, the oxidized electron transfer agent, produced by the development of the exposed silver halide, is immediately cross-oxidized with the oxidized developer trap. . Thus, in the microcells corresponding to the exposed silver halide, the oxidation-reduction dye-releasing compounds remain unchanged in their initially immobile form. In ranges in which the silver halide is not exposed, the silver halide solvent present in the treatment solution dissolves the silver halide, with the formation of soluble silver complexes (eg 2491224 AgS203 ), able to migrate into the underlying microcells. In microcells, the physical development of the dissolved silver halide occurs, with formation of silver and oxidized electron transfer agent. The oxidized electron transfer agent reacts with the redox dye-releasing compound and releases the mobile dye which is transferred to layer 652 and immobilized by the mordant. A positive image transferred in color is formed in the layer 652, consisting of the transferred yellow, magenta and blue-green dyes. It is also possible to obtain a positive image in retained colors, since (1) the silver density, produced by chemical development in the emulsion layer, is low compared to the silver density produced by physical development in the microcells and that ( 2) Since the imaging element is separated from the image-receiving element, the redox-promoting dye-releasing compounds, remaining in their initially immobile form in the microcells, can be uniformly reacted with a dye-reducing agent. oxidation, releasing a mobile dye that can be removed from the microcells by washing. One of the functions of microcells in photographic products

  phiquesis to decrease the lateral diffusion of the image. The limits within which lateral diffusion of the image must be maintained depend on the intended photographic application. If an image is to be viewed without being enlarged and if it is desired that the granulation is as small as possible, microcells having a width of between 1 and 200 microns, and preferably between 4 and 100 microns, are suitable in the context of the implementation of the invention. For some photographic applications, in which granulation visible to the naked eye is tolerated, the microcells may have a greater width. If the obtained images are to be enlarged, it is preferable that the microcell widths be located in the lower part of the range indicated above, ie these widths should be about 20 microns. or less. When the microcells of the support are intended to be filled with a photosensitive substance, the lower limit of the size of the microcells depends on the photographic sensitivity that is to be conferred on the product. Reducing the surface area of the microcells decreases the likelihood that incident imaging radiation will reach the microcells. The width of the microcells should be at least 7 microns, preferably at least 8 microns, the optimum being beyond 10 microns, for applications where the microcells are lined with a photosensitive substance. Below 7 microns, the silver halide emulsions filling the microcells suffer a significant loss of sensitivity. The microcells are of sufficient depth to contain the substances which one wishes to place there. Preferably, the size of the microcells is such that these microcells are fully filled. In some embodiments of the invention, however, the microcells are only partially filled. The depth of the microcells is a function of the substances with which they are filled. For example, for photographic applications, the depth of the microcells is chosen so that the product which fills them gives the desired optical density. The depth of the microcells may be equal to, less than or greater than their width. For photographic applications, the depth of the microcells is preferably chosen to correspond to the thickness of a continuous layer of this same substance applied in a conventional manner on a plane support. The depth of the microcells is generally between 1 and 1000 microns. For silver halide emulsions, dyes and dye image forming compounds commonly used with silver halide emulsions, it is generally preferred that the depth of the microcells be between 5 and 20 microns. It is possible to vary the spacing of the adjacent microcells, depending on the desired application and effect. It is generally preferred that the microcells be laterally 0.5 to 5 microns apart, although larger or smaller spacings may be used. For photographic applications, the microcells occupy at least 50% (preferably 80%) of the network surface. When they are very close together, the microcells can occupy up to 99% of the network surface, but they generally occupy no more than 90% of the network surface. The supports of the products according to the invention can be formed from the same types of suostances as those used for obtaining the usual photographic supports. As photographic supports, films of polymeric substances, wood fiber substrates, for example paper, coated with one or more layers of substrate can be used to improve the characteristics of the surface of the substrate with respect to the substrate. adhesion, statism, hardness, abrasion resistance, dimensional stability, or in order to impart antihalation properties to these supports, etc. As films of polymeric substances, cellulose nitrate films, cellulose esters such as triacetate and cellulose diacetate, polystyrene films, polyamide films, homo- and polyvinyl chloride copolymers can be used. vinyl, polyvinyl acetal, polycarbonate, homo- and copolymers of olefins such as polyethylene and polypropylene, and polyesters of aromatic diacids and divalent alcohols such as polyethylene terephthalate. As paper carriers, partially acetylated or barium coated and / or polyolefin coated media carriers, particularly an α-olefin polymer containing from 2 to 10 carbon atoms such as polyethylene, may be used. polypropylene, copolymers of ethylene and propylene, etc.

  Polyolefins such as polyethylene, polypropylene and polyallomers, for example the copolymers of ethylene and propylene described in US 3,478,128, are preferably used as coatings on paper, as described in US Pat. United States of America 3,411,908 and 3,630,740, on polystyrene and polyester supports, as described in US Patent 3,630,742, or may be used as reflective supports. as described in U.S. Patent No. 3,973,963. Preferred cellulose ester supports are cellulose triacetate carriers, as described in U.S. Patents 2,492,977; Nos. 492,978 and 2,739,069, as well as mixed cellulose ester carriers, such as acetopropionate and cellulose acetate butyrate, as described in United States Patent 2,739,070. Preferred polyester mounts are constit As described in US Pat. Nos. 2,627,088, 2,720,503, 2,779,684 and 2,901,466, the polyester films can be formed by a variety of techniques as described in US Pat. United States of America 3,663,683 and 3,504,075 and may be modified as described in United States Patents 3,227,576, 3,501,301, 3,589,905, 3,850,640, 3,888,678, 3. 904,420 and 3,928,697. The products of the invention can use supports that resist dimensional changes at elevated temperatures. These supports may consist of linear condensation polymers which have glass transition temperatures greater than 190 ° C., preferably 220 ° C., such as polycarbonates, polycarboxylic esters, polyamides, polysulfonamides, polyethers, polyimides, poly-sulfonates and copolymers thereof as disclosed in U.S. Patents 3,634,089, 3,772,405, 3,725,070, 3,793,249, 4,076,532, and in Besearch Disclosure, Vol. 106, February 1973, N 10613; Flight. 117, January 1974, No. 11709; Flight. 118, February 1974, No. 11833; Flight. 120, April 1974, N 12012 and 12046; Flight. 134, June 1975, N 13455 40 and in the journal Product Licensing Index, Vol.92, December 1971, N 9205 2491224 29 and 9207. The part of the support, which defines the sidewalls of the microcells can be formed of a large number substances whose structure is not strong enough to allow them to be used alone as supports. This portion may be formed using conventional photopolymerizable or photocure-able substances, for example photoresists. Examples of photosensitive resistances are given in United States Patents 3,640,722, 3,748,132, 3,696,072, 3,748,131, 3,699,025, 3,699,026, 3,737,319, 3,748,133, 3,779. 989, 3782, 938 and 4052357. Other useful photopolymerizable and photocurable materials are described by Kosar in Light-Sensitive Systems: Chemistry and Application of Nonsilver Halide Photographic Processes, Chapters 4 and 5, John Wiley and Sons. 1965. Colloidal photosensitive compositions, such as dichromated colloids such as dichromated gelatin, can also be used as described in Chapter 2 of Kosar's work mentioned above. Silver halide emulsions can also be used and treated in the presence of a complex of a transition metal ion, as described in United States Patents 3,856,524 and US Pat. The advantage of using photosensitive substances to form this part of the support 20 is that the sidewalls and microcells can be simultaneously defined by exposure through a network. Once formed, these elements of the support are no longer sensitive to incident radiation. The part of the support defining the side walls of the cells may also be constituted by the substances normally used as binders for photosensitive substances. These binders have the advantage of being compatible with the photosensitive substances used to fill the microcells. The binders can be polymerized or tanned more strongly than when used in photosensitive compositions, to ensure the dimensional integrity of the side walls they form. The same binders can be used as with silver halide emulsions, especially gelatin, gelatin derivatives and other hydrophilic colloids. Binders are described in Research Disclosure, Vol. 1786, December 1978, No. 17643. The transmission, absorption and reflection characteristics of the support can be varied for different photographic applications. The support may be substantially transparent or reflective, preferably white, like most conventional photographic media. The support can be reflective, for example by making reflective as a

  miroi the walls of the microcells. For some applications, the carrier contains 40 dyes or pigments to make it virtually impenetrable to light. The amount of dye or pigment incorporated may be chosen so that the thinnest regions of the support, for example the regions of the microcells, continue to transmit light while the thicker regions of the support become relatively less penetrable to the surface. light, for example the regions of the sidewalls between adjacent micro-cells. The carrier may contain neutral dyes or dye combinations. The support may also contain absorbing substances which absorb only in a part of the spectrum, for example blue dyes. The carrier may also contain substances which modify the transmission characteristics, but which are not visible, for example ultraviolet absorbing substances. When two supports are used in combination, the transmission, absorption and reflection characteristics of the two supports may be identical or different. When the supports of the products according to the invention are formed by substances used for the usual photographic supports, these supports can be coated with reflective and absorbent substances by well known techniques, which are illustrated in the various patents mentioned above concerning substances useful as supports. In addition, reflective and absorbent substances such as those incorporated directly into the photosensitive compositions can be used, in particular as regards the part of the carrier formed by a binder, a photoresist or dichromated gelatin. Incorporation of high reflectance pigments into the binders is described, for example, in British Patents 504282 and 760775. Absorbent substances which can be incorporated into binders are described in the United States patent. - 2,697,037. It is also possible to incorporate colloidal silver, for example Carey Lea silver used as a blue filter; silver halides in very fine crystals to improve sharpness, as described in British Patent 1,342,687; finely divided carbon to improve sharpness 300u antihalation protection, as described in U.S. Patent 2,327,828; filter and antihalation dyes such as oxonol dyes derived from pyrazolone, described in U.S. Patent 2,274,782, solubilized diaryl azo dyes disclosed in US Pat. No. 2,956,879, dyes solubilized butadienyl and polysyranics disclosed in US Pat. Nos. 3,423,207 and 3,384,487, the merocyanine dyes described in US Pat. No. 2,527,583, merocyanine dyes and oxonol dyes disclosed in US Pat. U.S. Patents 3,486,897; 3,652,284 and 3,718,472; enamino hemioxonol dyes disclosed in U.S. Patent No. 3,976,661 and ultraviolet absorbing substances such as merocyanines; derivatives of the sulfones described in U.S. Patent 3,723,154, the thiazolidones, benzotriazoles and thiazolothiazoles described in U.S. Patents 2,739,888, 3,253,921, 3 250,617 and 2,739,971, the triazoles described in U.S. Patent 3,004,896 and the hemioxonols disclosed in U.S. Patents 3,125,597 and 4,045,229. The dyestuffs and Ultraviolet can be etched, as described in US Pat. Nos. 3,282,699, 3,455,693 and 3,438,779. A preferred embodiment of the present invention is to prepare media containing microcells in the manner described in US Pat. next: exposing a photographic product whose support is transparent through a network, formed of regular hexagons as shown in Figure 1A. Preferably, the photographic product has a negative effect and the exposed areas correspond to those desired to be occupied by the micro-cells while the areas corresponding to the sidewalls of the microcells are not exposed. By a conventional photographic process, an image is formed in the product whose areas intended to be occupied by the microcells have a maximum uniform density, while the areas intended to correspond to the lateral walls of the microcells 20 have a uniform minimum density. The photographic product with its image is then coated with a photosensitive composition capable of forming the sidewalls and thereby defining the lateral boundaries of the microcells. Preferably, this photosensitive layer is a negative-sensitive photoresist, or a dichromated gelatin layer. The layer can be on the

  surface of the photographic product carrying the image, or on the opposite side, that is, in the case of a silver halide product, the dichromate resist or gelatin layer may be applied to the emulsified face of the support, or the back of the support. The resist 30 or the dichromated gelatin layer is then exposed through the image obtained in the photographic material, so that the areas corresponding to the areas whose side walls are to be exposed are exposed. These areas are hardened which leads to the formation of a structure representing the side walls and the unexposed areas are removed by conventional techniques. The image is preferably removed before the product is put into service. For example, in the case of a silver halide product with which by exposure and processing formed a silver image, the silver may be blotted after the microcells have been formed with the photosensitive substance. A positive-effect photoresist can be used. In this case, such a resin is initially in cured form, but is selectively rendered removable in the exposed areas. As a result, with such a photosensitive resist, or other photosensitive substance, it is necessary to invert the original used for the exposure. If an image is present in or on the support corresponding to the sidewalls forming the microcells, this image does not need to be removed for most applications, and may even serve to increase the density of the side walls. forming the microcells. Instead of applying the photosensitive substance to a carrier bearing an image of the pattern to be reproduced, the photosensitive substance may be applied to any support and exposed directly. With this method, it is of course easier to obtain the network of microcells on an enlarged scale, to the extent that it is then possible to reduce the dimensions to the desired scale for the exposure of the photoresist. Another technique for forming the microcells in the carrier is to form the deformable flexible material as a planar product or as a layer applied to a relatively non-deformable support; the microcells can then be formed by stamping. The die for stamping contains bosses whose shape is that which one wishes to impart to the microcells. These bosses can be formed on an initially flat surface by conventional techniques; for example, a photoresist can be applied to this surface, expose this resist through an appropriate original, and then remove the resist in the ranges corresponding to the spaces between the bosses (which correspond to the configuration of the side walls which the 'we want to train in the support). The areas of the array that are not protected by the resist are then etched to reveal the bosses. After the delamination of the resist above the bosses and after cleaning, e.g., weak acid wash, base or other solvent, the stamping die is ready for use. Preferably, such a matrix is made of a metal such as copper and is provided with a reflective metal deposit, for example by vacuum deposition from a chromium or silver vapor. This deposit provides smoother walls at the time of stamping. Many transparent substances can be used to make the supports described above. When a white support is desired, it is possible to use white substances or transparent substances colored by white pigments such as titanium oxide, barite, etc. Any white pigments that can be used for the reflective photographic media are suitable. It is also possible to use pigments other than white pigments, if desired. The pigments are particularly well suited for forming opaque, white or colored supports. When it is desired that the support be transparent but colored, various conventional dyes can be used which are incorporated into the support. For example, the support can be colored yellow to absorb blue light, while transmitting red and green light. In some cases, the part of the support forming the bottom of the microcells, at least for a part of these microcells, is transparent while the part of the support forming the side walls is either opaque or tinted to prevent transmission. light. As discussed above, this result can be achieved by using different substances to form the bottom and sidewalls of the microcells. A preferred technique for obtaining tinted walls and a transparent bottom in a support consisting of a single substance, is the

  next. We start from a transparent film relatively little deformable by a stamping die. Any of the film-forming substances previously mentioned for producing conventional photographic film substrates may be used; these substances are, for example, nitrate or cellulose esters, polyethylene, polystyrene, polyethylene terephthalate, etc. In a solution capable of softening the transparent film, one or more dyes are dissolved to obtain the desired shade for the sidewalls. This solution may be a conventional plasticizing solution of the film. When this solution migrates into the film from one of its faces, it carries with it the dye so that the film is dyed and softened on that face. Then, the film can be stamped on this softened face and made relatively deformable. With this technique, microcells are formed whose side walls are tinted and whose bottom is transparent. The membranes set up to close the microcells of the support 10 may be constituted by any substances that may be selectively destroyed or eliminated in the ranges corresponding to those situated above the microcells. In general, the membranes are formed by film-forming organic polymers. The membranes may be of identical composition to those of the usual photographic supports. As film-forming polymers useful for forming membranes, mention may be made of cellulose nitrate and cellulose esters such as cellulose diacetate and triacetate, polyamides, homopolymers and copolymers of styrene, acrylates and methacrylates, vinyl chloride, polyvinyl acetal and olefins such as ethylene and propylene. When the membranes are intended to be destroyed by heat, for example by means of a laser beam, it is preferred to use the film-forming polymers that are least heat-stable. Simple heating of the membranes to their thermal decomposition temperature is not however the only way to destroy the membranes. Cellulose membranes and, more particularly, cellulose nitrate can be selectively destroyed in the plaques exposed by alpha particles or other particles resulting from nuclear fusion, for example, as described in the US patent. No. 3,501,636. It is also possible to use electron beams to destroy the membranes in the selected ranges. In the separate sets of microcells, any combination of substances known to be useful in an intercalated network may be incorporated. Any of the known additive primary colorants or pigments can be used in the multicolored filters described above. In addition, the primary additive color can be obtained by mixing two primary subtractive pigments or pigments. In general, the primary subtractive pigments and pigments mentioned in Color Index Vol. I and II, 2nd edition. For photographic applications, the incorporation of photosensitive substances 4h and / or image forming in the microcells has the effect of limiting the lateral diffusion of the image. The lateral diffusion of the image is observed in a large number of usual photographic products. It may be due to optical phenomena such as reflection or diffusion of exposure radiation; diffusion phenomena, such as the lateral diffusion of the photosensitive substance and / or the image-forming substance into the photosensitive and / or image-forming layers of the photographic products or, more generally, to an association of both types of phenomena. Especially lateral image diffusion is observed when the photosensitive and / or image-forming substances are dispersed in a binder which is penetrated by the exposure radiation and / or the process fluids. Although the present invention can be practiced with the usual photosensitive and image-forming materials useful in photography, it is evident that incorporation into microcells according to the invention is advantageous for all substances. presenting a lateral diffusion of image visible to the naked eye. A large number of non-silver image forming substances useful in the practice of the invention are described by Kosar in Light-Sensitive Systems Chemistry and Application of Nonsilver Halide Photographic Processes, John Wiley and Sons. , 1965. Generally speaking, any system capable of forming a color image can be used for the implementation of the invention. Preferably, photosensitive silver halides are used in combination with forming substances

  images, to obtain color images. Examples of suitable substances are given in Research Disclosure, Vol. 176, December 1978 No. 17,643, particularly in paragraphs I, III, IV, VI, IX and X. Various dye image transfer systems can be used for carrying out the invention, particularly those use ballast dye-forming couplers or non-dye-forming couplers comprising a movable dye moiety attached in the coupling position. By reaction with an oxidized color developer such as para-phenylenediamine, the mobile or diffusible dye is moved so that it can be transferred to a dye image receiving element. The use of these negative dye image-forming compounds is described in U.S. Patents 3,227,550 and 3,227,552 and British Patent 1,445,797. In an image transfer system particularly advantageous, which uses negative dye image-forming compounds of the class of redox-reducing dye-releasing compounds, a developer 40 participating in a cross-oxidation reaction, or an electron transfer agent; , develops the silver halides and then participates in cross-oxidation with a compound which contains a dye bound by an oxidizable sulfonamido group, such as a group of suonamidophenol, sulphonamidoaniline, sulphonamidoanilide, sulphonamidopyrazolobenzimidazole, sulphonyl midoindole or sulphonamidopyrazole. After cross-oxidation, a hydroxyl ion catalyzed deamidation reaction separates the diffusible dye to which the sulfonamido group is attached. Systems of this type are described in U.S. Patents 3,928,312, 4,053,312, 4,076,529, 4,110,113, 4,199,892, 4,055,428 and 4,198,235, as well as in the US Pat. "Research Disclosure", Vol. 151, article 15157 (November 1976). Other analog systems are also useful such as those using (a) a non-diffusible, dye-releasing hydroquinone as disclosed in U.S. Patents 3,698,897 and 3,725,062, (b) para. Phenylenediamine, as described in Canadian Patent No. 602,607; and (c) a quaternary ammonium compound, as described in United States Patent 3,728,113. In another dye image transfer system particularly When using a negative compound, an electron transfer agent, in oxidized form or, more particularly, an oxidized para-phenylenediamine, is reacted on a ballasted phenolic coupler comprising a dye group attached by a sulfonamido linkage. . A reaction, with cycle closure, makes it possible to form a phenazine with release of a mobile or diffusible dye. Such a method is described, for example, in U.S. Patents 3,443,939 and 3,443,940. In other particularly useful image transfer systems which employ negative compounds, sulfonylamidazones, sulfonylhydrazones and sulfonylcarbonylhydrazides with a ballast group on oxidized para-phenylenediamines to release a diffusible dye which is then transferred to a receptor element as described in US Pat. Nos. 3,628,952 and 3,844 785. In another negative system, a hydrazide can be reacted on silver halides having developable latent image sites, and then decompose the product obtained to release a diffusible and transferable dye, as described in the US Pat. United States 3,245,789 and in "Bulletin Chemical.Society of Japan", Vol. 43, 1.2! 33-37 and in "Research Disclosure", Vol. 28, December 1974, article 12832. All of the dye image transfer systems described above use negative dye image-forming compounds, which are initially non-diffusible and contain a preformed dye which is released by splitting during the imaging reaction. The released dye is diffusible and can be transferred to a receiver element. Positive, initially non-diffusible dye image-forming compounds which release diffusible dyes are also known. It is known, for example, that when the silver halides are developed in an image, the residual silver ions associated in the form of undeveloped silver halides can react on a thiazolidine containing a dye group-substituted ballast group. for imagewise release of a diffusible dye, as described, for example, in US Pat. Nos. 3,719,489 and 3,443,941. Positive dye image-forming compounds, which are initially non-diffusible, particularly advantageous, are those which release a diffusible dye by chemical reactions with anchimeric displacement. The

  The compound, in its initial form, is hydrolyzed in an active form during the development of silver halides with an electron transfer agent. Cross-oxidation of the active dye releasing compound with the oxidized electron transfer agent prevents splitting of the hydroxyl ion-catalyzed dye moiety. Precursors of the class of benzisoxazolones that release hydroxylamine dyes are described in US Patent 4,199,354 and in the journal "Research Disclosure", Vol. 144, Article 14447 (April 1976). Hydroquinolyl carbamate dye-releasing compounds are described in U.S. Patent No. 3,980,479. It is also known that a non-diffusible reducing agent or electron donor may be used in combination. with a non-diffusible ballast group nucleophilic displacement electron accepting compound which, by reduction, displaces a diffusible dye by an anchorimic reaction. The hydrolysis of the electron donor precursor into its active form occurs simultaneously with the development of silver halides by an electron transfer agent. The cross-oxidation of the electron donor with the electron transfer agent in its oxidized form prevents further reaction. The cross-oxidation of the ballast-group electron acceptor compound described above with the non-oxidized residual electron donor may occur. The anchorial movement of the diffusible dye from the ballast electron acceptor compound described above may occur during a ring closure reaction. Dye image transfer of this type is described in U.S. Patent 4,139,379. Other positive systems that employ dye-releasing compounds, which are initially non-diffusible, are also available. For example, US Pat. No. 3,185,567 and British Patent Nos. 2491-2248,880,233 and 880,234 disclose the following. Dye image formers, positive, initially diffusible, the immobilization being carried out by reduction of developable silver halides, either directly or indirectly, by an electron transfer agent. Processes which employ diffusible developing dyes, including developing dyes having an offset absorption maximum, are described, for example, in U.S. Patents 2,774,668, 2,983,606, 3,307,947, and US Pat. , 3,230,085; 3,579,334; 2,756,142; and U.S. Patent Publication T 889,017. In another embodiment, a dye image forming compound which comprises a grouping may be used. dye which is attached to a coupler group initially diffusible. Oxidation of a para-phenylenediamine or hydroquinone classifier may result in the reaction of this oxidized developer on the coupler which contains a dye moiety to form a non-diffusible compound. Such processes are described, for example, in U.S. Patents 2,774,668, 3,087,817, 3,844,785, and 1,157,506, 3,653,896, British Patents 1,157,501, and the French Patent. 287 711 20 and in the journal "Research Disclosure", Vol. 145, item 14521, May 1976. Other diffusion-transfer color image-forming methods are known which utilize positive dye-image-forming compounds and methods for transfer or immobilization of various dyes. . For example, imagewise immobilizing a silver halide developable developer mordant can be used to image-immobilize an initially diffusible dye as described, for example, in US Patent 3,729,314. The development of the silver halides by an electron transfer agent can form a free radical intermediate compound which can imagewise polymerize an initially diffusible dye, as described in the US Patents. 3,585,030 and 3,019,104. The tanning development of a silver halide gelatin emulsion can render the gelatin impermeable to a diffusible dye and thereby oppose the transfer of an imagewise distribution of the diffusible dye. As described in US Pat. No. 2,543,181. The release of gaseous bubbles can also be used by developing silver halides. This is to counter the transfer of diffusible dye, as described, for example, in U.S. Patent 2,774,668. An electron transfer agent which has not been used to Developing silver halides on an image-receiving element to discolor an image of a polymeric dye and form a leuco derivative, such as

  described in U.S. Patent 3,015,561. Numerous diffusion-transfer dye image-forming methods are known which utilize positive dye-image-forming compounds where dyes are not present. present at the beginning of the process, but are formed by reactions occurring in the photographic product or in the dye image-receiving element after the exposure. For example, a diffusible color developer and a diffusable coupler can be reacted, depending on the image, depending on the development of the silver halides, to form a non-diffusible dye, while the residual developer and coupler are converted to the image receptor and the developer is oxidized and then reacts on the coupler to form a transferred image of non-diffusible dye, as described, for example, in United States Patents 2,756,142, 2,559,643 , 2,647,049, 2,661,223,6698,244 and and 1,166,698,798 and British patent 1,157,501. According to another embodiment, the coupler can be reacted with a diazonium salt ( or an azosulfone precursor) solubilized to form a diffusible azo dye prior to transfer, as described, for example, in U.S. Patent No. 3,857,852. In another embodiment, a single coupler can be used. biking The present invention is directed to an intramolecular autocoupling reaction on the image-receiving element to form a non-diffusible dye image, as described, for example, in U.S. Patents 3,537,850 and 3,865,593. In another embodiment, a diffusible amidrazone associated with a diffusible coupler is used and the two compounds are reacted on the image-receiving element to form a non-diffusible dye image as described, for example, in the US Pat. US Pat. No. 3,939,035. Instead of using a diffusible coupler, a diffusible leuco dye can be used which reacts with an oxidized electron transfer agent to form a non-diffusible compound, while the leuco dye The unreacted is transferred to the image receiving element, where it is oxidized to form a dye image, as described, for example, in U.S. Patents 3,880,658, 2,892,710, 2 to992,105, 2,909,430 and 3,065,074. According to another embodiment, diffusible quinone-heterocycloammonium salts can be immobilized depending on the development of the silver halides and transfer the residual salts to a receiving element. where they are converted to cyanine dye or merocyanine dye, as described, for example, in U.S. Patents 3,535,557 and 3,537,852. 2491224 4o Also known are image forming methods. in color transfer-diffusion systems which use dye-image-forming compounds, negative, where the dyes are not present at the beginning of the process but are formed by reactions which occur in the photographic product or in the image receiving element, after exposure. For example, a ballast coupler can be reacted with a color developing agent to form a diffusible dye as described, for example, in U.S. Patents 3,227,550, 3,227,552, 3,791,827, and US Pat. For example, a non-diffusible compound which comprises a coupler moiety on an oxidized para-phenylenediamine can be reacted to release a diffusible coupler that can react on an additional oxidized para-phenylenediamine either before, during, or after releasing the coupler, to form a diffusible dye, as described, for example, in U.S. Patent 3,734,726 and German Patent Application OLS 2,317,134. In another embodiment, reacting a ballast-group amidrazone on an electron transfer agent, depending on the development of the silver halides, to release a diffusible amidrazone, which reacts on a coupler to form a dye on the image-receiving element, as described, for example, in U.S. Patent 3,933,493. When an immobile dye image transferred by oxidation into the receiver element is formed, the receiving element may contain an oxidant in the form of a continuous layer or incorporated in the microcells. Useful oxidants include borates, persulfates, ferricyanides, periodates, perchlorates, triiodides, permanganates, dichromates, manganese dioxide, silver halides, benzoquinones, naphthoquinones, disulfides, nitroxyl compounds, oxidants based on heavy metals or heavy metal chelates, N-bromo-succinimides, nitroso compounds, ether peroxides, and the like. We choose, preferably, the

  oxidants among those having a molecular weight sufficient to be substantially immobile and therefore remain in the receptor element during processing. Preferred non-ionic oxidants include the nitroxyl compounds disclosed in US Patent 4,088,488. Other useful still oxidizers may be selected from those described in the above-cited patents and describing the oxidation in the US Pat. receiving element to form a dye. When the oxidation itself does not result in forming a still dye, for example when the primary function of the oxidant is to form a dye rather than to cause immobilization, it is possible to use the dye image-forming layer, a combination of an oxidant and a mordar or other immobilizing agent. The mordants used to immobilize the dyes in the practice of the invention can be selected from a large number of known mordants. Useful mordants are described, for example, in U.S. Patents 2,548,564, 2,548,575, 2,675,316, 2,713,305, 2,756,149, 2,768,078, 2,839,401, 2,882,156, and 945,006, 2,940,849, 2,952,566, 3,048,487, 3,184,309, 3,271,147, 3,271,148, 3,282,699, 3,408,193, 3,488,706, 3,557,666, 3,625,694, 3,709. 690, 3,758,855, 3,898,088, 3,944,424, 3,639,357, 3,770,439, 3,958,995, in the journal "Research Disclosure", Vol. 120, April 1974, article 12045 and Vol. 167 March 1978, item 16725. Other dye image transfer systems are described in Research Abstraction No. XXIII, No. 17643. The use of silver precipitators is described in connection with various preferred forms of product 600 for color image transfer. A variety of germs or silver precipitants can be used in the image-receiving layers used in the diffusion-transfer processes. These silver precipitating seeds are incorporated into conventional hydrophilic colloidal binder layers such as gelatin and polyvinyl alcohol, these seeds comprising (a) heavy metals, in particular in colloidal form, and the like. salts of these metals; (b) salts whose anions form less soluble silver salts than the silver halides of the photosensitive emulsion to be treated; and (c) non-diffusible polymeric compounds containing reactive functional groups. on silver ions and insolubilize them. Examples of silver precipitation agents include sulfides, selenides, polysulfides, polyselesulfides, thiourea and derivatives thereof, mercaptans, silver halides, gold, platinum, palladium, and the like. mercury, colloidal silver, aminoguanidine sulphate, aminoguanidine carbonate, arsenium oxide, sodium stannite, substituted hydrazones, xanthates, etc. An example of silver precipitating seeds of the class of non-diffusible polymers is represented by polymercaptoacetate vinyl. The sulphides of heavy metals such as lead, silver, zinc, aluminum, cadmium, and bismuth are useful, in particular sulphides of lead and zinc used alone or as a mixture, or complex salts of these metals with thioacetamide, dithio-oxamide or dithiobiuret. Heavy metals, especially noble metals, advantageously in colloidal form are particularly effective. As useful oxidized developer traps, there may be mentioned anti-oxidants with ballast groups or other non-diffusible antioxidants as described in US Pat. Nos. 2,336,327, 2,728,659, 2,360,290 and 2,701. 197. To avoid auto-oxidation, oxidized developer traps can be used in combination with other antioxidants as described in US Pat. No. 3,700,453. In addition to the specific embodiments thereof Of the invention described above, a number of other embodiments can be used. Thus, a dye can be incorporated in the membrane described above to increase its heat absorption characteristics. This has the advantage of making the membrane able to absorb more energy during scanning by the laser beam and thus more effectively use the laser beam used to open the microcells. On the other hand, the remaining elements of the mold, which are not destroyed by heat during the opening of the microcells, can give the support a coloration which may be troublesome for certain applications. Therefore, it is expressly provided according to the invention to incorporate into the membrane a dye capable of being bleached. For example, a dye which can be whitened by heat and / or light can be incorporated into the membrane. In this way, the membrane presents a

  higher absorption during scanning by the laser beam and the remaining membrane elements in the finished product can be transformed into a form which shows little or no coloring. Heat and light-whitenable dyes are well known and described, for example, in U.S. Patents 3,984,248, 3,988,154, 3,988,156, 4,111,699, and 3,769,019. When the membrane is placed on the support, there is, in most cases, sufficient adhesion to firmly hold the membrane in position, such that it closes the microcells. Other techniques for maintaining the membrane in place on the support can also be used, alone or in combination with the techniques described hereinbefore. In most cases, the membrane remains flexible when it has been placed on the support. If desired, the membrane can be treated to increase its rigidity and strength. The treatment chosen depends on the composition of the membrane but, in general, the membranes are formed of polymeric substances whose rigidity and strength can be increased by crosslinking. Effective crosslinking agents may be selected from those generally known, for example, from photographic tannants such as those described in Research Disclosure, Vol. 176, December 1978, No. 17,643. For membranes made of cellulose and cellulose derivatives, the preferred crosslinking agents are epoxides, as described in U.S. Patents 3,047,394 and 3,189,459. And German Patent 1,085,663. As a particularly effective crosslinking agent of the class of epoxides, there may be mentioned 1,4-butanediol-diglycidyl ether, commercially available under the tradename Acryldite. The following nonlimiting examples illustrate the invention. EXAMPLE 1 A mesh of hexagons having a width of 20 microns and a height of about 10 microns is formed by etching on a copper plate. The etched plate obtained is applied to a cellulose acetate photographic film support and the whole is brought into contact, for 6 seconds, with a solvent (dichloromethane: ethanol, 80: 20 by volume) containing 10 mg per 100 ml of yellow azo dye Orange Genacryl-R. The footprint of the hexagonal reliefs remains in the support softened by the solvent, the microcells formed being separated by side walls of 2 microns, as measured on the surface of the support. The yellow dye is absorbed in the regions of the cellulose acetate support surrounding the microcells, but not below the microcells, giving a density in the blue. A membrane is prepared by placing four drops of a commercial casting solution (Microfilm Solution, Sig Manufacturing Company, Montezuma, Iowa) on the surface of the water contained in a 30 x 35 cm dish. The casting solution contains cellulose nitrate, as the film-forming polymer, in an organic solvent comprising as main constituent aromatic liquid hydrocarbons (toluene and xylene) and, in small amounts, a mixture of alcohols, esters and ketones. lower molecular weight aliphatics (isopropyl alcohol, methyl ethyl ketone, 2-methylpropanol, isopropyl acetate and methyl isobutyl ketone). The membrane has a thickness of 0.2 to 0.6 micron. A balsa wood frame forming a 16 cm x 16 cm opening is placed on the membrane so as to protect a region, and the membrane which is outside the frame is folded by crushing against it. . The microcellular support of this membrane is coated by immersing said support 35 in the water contained in the bowl and lifting the support until it comes into contact with the membrane, the microcells being on the upper face of the support . The membrane is thus applied to the surface of the support comprising the microcells. Since most of the microcells now contain water, the whole is dried until no water remains inside the microcells. In order to increase the absorption of light by the membrane, the outer face of the membrane is rapidly passed through the incandescent region of a candle flame. By microscopic examination it can be seen that there is carbon on the outer side of the membrane. In order to open a first set of microcells, irradiation with a 647 nm laser beam, following a network of lines spaced apart from each other, submits the microcellular support provided with the membrane whose face external is coated with a light layer of carbon. The power of the laser beam is 12 to 28 milliwatts per square centimeter and the section of the beam is about 23 microns. When the laser beam reaches the membrane, the cells are opened along a single line or two lines, depending on the power and location of the beam.

  To obtain substances for selectively filling the microcells, three primary subtractive filter dye compositions, as described below, identified as Yellow Dye Dispersion A, Magenta Dye Dispersion B and Blue Dye Dispersion C are prepared. green. In each case, the dye chosen is immobile, which prevents its transfer out of the microcells once it has been introduced. To form the compositions used to fill each of the three separate sets of microcells, two of the subtractive primary dye dispersions identified above are mixed to form a primary additive filter material. A subtractive, initially colorless and colorless, dye-forming coupler is also mixed with the two primary subtractive dye additives. (The movable couplers are, of course, immobile in the microcells, since there is mobility only by contact with a photographic processing solution). Dispersion A of yellow dye A usual dispersion is prepared by homogenizing 40 g of the following yellow dye, 3- [3 - [(2,4-di-t-pentylphenoxy) acetamido] benzamido) -4 (4-methoxyphenylazo) -1- ( 2,4,6-trichlorophenyl-2-pyrazolin-5-one, 120 g of 2- (2-butoxyethoxy) ethyl acetate as an auxiliary solvent and 27.2 g of gelatin diluted to 254 g with After homogenization, the dispersion was cooled to gel, and washed as noodles to remove the auxiliary solvent Magenta Dye Dispersion B A usual dispersion was prepared by homogenizing 40 g of the magenta dye 3- [3- [N- (2,4-di-t-pentylphenoxy) acetamido] -benzamido] -N [4- [N-ethyl-N- (2-hydroxyethyl) -amino] -2-tolylimino -1- , 4,6-trichlorophenyl) -2-pyrazolin-5-one, 80 g of 1,4-cyclohexylenedimethylbis (2-ethylhexanoate) as a permanent solvent, 80 g of cyclohexanone as an auxiliary solvent and 60 g of gelatin. dil until 1000 g with water. After homogenization, the dispersion is cooled to gel and washed as noodles to remove the auxiliary solvent. Dispersion C of blue-green dye A usual dispersion was prepared by homogenizing 40 g of 2- [4- (2,4-di-t-pentylphenoxy) butylcarbamoyl] -N- {-4- / N-ethyl-N- (2 hydroxyethyl) amino-2-tolyl) -1H-naphthoquinone 4-monoimine, 80 g of 1,4cyclohexylenedimethylbis (2-ethylhexanoate) as a permanent solvent, 80 g of cyclohexanone as an auxiliary solvent and 60 g of diluted gelatin to make 1000 g with water. After homogenization, the dispersion is cooled until it becomes a jelly and washed as noodles to remove the auxiliary solvent. Preparation of red, dry dispersion granules 30 g of the yellow dye dispersion A and 30 g of the magenta dye dispersion B were melted together and diluted to 750 ml with water. 3.0 g of the blue-green dye-forming coupler, 1-hydroxy-N- [2- (2-acetamido) -phenethyl] -2-naphthamide, are then dissolved in a minimum amount of ethyl alcohol containing 5% dye. sodium hydroxide and this solution is added to the solution of the dispersions. The resulting mixture is passed through an ultrasonic nebulizer (DeVilbiss Model 65) and then into a heated jacket drying column in which the water evaporates. Dry red granules in the form of microspheres and containing a blue-green dye-forming coupler are thus obtained. These small microspheres are collected and examined under a microscope. Their size is about 3 microns or less. Preparation of green, dry dispersion granules 20 g of yellow dye dispersion A and 40 g of blue-green dye dispersion C are melted together and diluted to 750 ml with water. 3.0 g of the magenta dye-forming coupler, 3- (4h-nitroanilino) -1- (2,4,6-trichlorophenyl) -2-pyrazolin-5-one, are dissolved in a minimum amount of ethyl alcohol. containing 5% sodium hydroxide and this solution is added to the solution of the dispersions. After treatment in the nebulizer and the drying column, green pellets are obtained in the form of microspheres and containing a yellow dye-forming coupler. Preparation of blue, dry dispersion granules 30 g of magenta dye dispersion B and 30 g of blue-green dye dispersion C are melted together and diluted to 750 ml with water. 3.0 g of the yellow dye-forming coupler, 1k- (4-carboxyphenoxy) - was dissolved. -pivolyl-2,4-dichloroacetanilide, in a minimal amount of ethyl alcohol containing 5% sodium hydroxide and this solution is added to the solution of the dispersions. After treatment with the nebulizer and the drying column, dry granules having the form of microspheres containing a dye-forming coupler are obtained.

  yellow. The membrane-coated microcellular support is covered by the green dispersion granules, which has been destroyed along lines spaced apart from each other so as to open a first interlocked set of microcells. The dispersion granules are introduced into the open microcells with a soft rubber blade and the excess granules are removed with a brush. By microscopic examination, it is found that the microcells which have not been reached by the laser beam are still covered by the membrane. The microcellular support coated with the membrane 15 is again scanned with the laser beam at a different angle from that of the first scan. As the first time, the laser beam removes the membrane in the affected regions and thus a second set of open intercalated microcells is obtained. The microcells thus opened are filled with blue dispersion granules by the same method as that described above.

The remainder of the membrane is then removed by means of an adhesive tape and thus the third set of interleaved microcells is opened. The microcells thus filled are filled with red dispersion granules. The excess filler present on the surface of the microcellular support is then removed using an adhesive tape. The network of trichromatic cell filters obtained is placed in an atmosphere of high relative humidity, overnight. The contents of the microcells become less diffusing and appear partially melted.

EXAMPLE 2 The procedure of Example 1 was repeated except that the balsa wood frame was immersed in the water below the membrane and moved upwards to lift the membrane at above the surface of the water. The microcellular support is then gently placed on the membrane so that the membrane closes the microcells. The support on which the membrane is applied is bent so that the face of the support carrying the microcells is convex. Final gelation of the membrane occurs while the carrier has this configuration. EXAMPLE 3 The procedure of Example 1 is repeated, but the composition of the casting solution is varied. The casting solution used to form the membrane was 8.5 g of cellulose acetate and 42.0 g of solvent. The solvent comprises 80 ml of dichloromethane and 20 ml of methanol and contains 0.6 g of Genacryl Blue dye to enhance the absorption of the membrane. There is no carbon on the surface of the membrane. EXAMPLE h The process of Example 1 is repeated, but the composition of the casting solution is modified, the composition comprising 1 g of black Sudan B and 10 drops of dichloromethane per 12 g of casting solution. No carbon is put on the surface of the membrane.

In both Examples 3 and 4, the membranes sufficiently absorb energy from the laser beam to allow their local destruction to open the microcells. 2491224 48

Claims (8)

  1 - Process of forming, in a support comprising a first and second face, a planar array of open microcells on the first face of the support and selectively modifying the contents of a first set of microcells with respect to a second set of microcells interposed with the first set, characterized in that the contents of the microcells are selectively modified by placing, in order to cover the first face, a removable means for closing both the first set and the second set together. microcellules, and selectively removing the closure means of the first set of microcells, to selectively modify the contents of the first set of microcells, without simultaneously modifying the contents of the second set of microcells. 15   2 - Process according to claim 1, characterized in that the closure means comprises a membrane.   3 - Process according to claim 2, characterized in that the membrane consists of a film-forming organic polymer.   4 - Process according to any one of claims 2 or 3, characterized in that the adjacent microcells are separated by lateral walls formed by the support and in that the membrane has a thickness of between 5% and 50%. % of the thickness of the side walls.   5 - Process according to any one of claims 2 to 4, characterized in that the membrane has a thickness between 0.2 micron and 1.0 micron.   6 - Process according to any one of claims 1 to 5, characterized in that a laser beam is used to selectively remove the closure means of the first set of microcells. 30   7 - Process according to any one of claims 1 to 6, characterized in that the width of the microcells is between 1 micron and 200 microns and in that the content of the first set of microcells is modified by introducing selectively into those a photosensitive substance, a dye or a dye precursor. 35   8 - Process according to any one of claims 1 to 7, characterized in that selectively eliminates the closure means of the first set of microcells and in that modifying the contents of this first set of microcells without changing the content of the second set of microcells. 40 9 - Planar array comprising a support having first and second faces 494 and consisting of a plane array of open microcells on said first face, characterized in that it is obtained by a method according to in any one of claims 1 to 8.