US2668762A

US2668762A - Process of producing screens

Info

Publication number: US2668762A
Application number: US649120A
Authority: US
Inventors: Rubinstein Leon
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-02-20
Filing date: 1946-02-20
Publication date: 1954-02-09
Anticipated expiration: 1971-02-09

Description

Patented F cl). 9, 1954.

UNITED STATES PATENT OFFICE This applicationiis a; continuationoi. my

patent application Serial No; 352,517; filed- August 14, 1940, now abandoned; entitled Screens and Process of Producing the Same.

My? invention relates to screensof various types and to various processes for producing the same. l'talso relates to-the production of a screen-like corrugation on a gelatinous layer on a transparent baseand to the use of this screen for different purposes. It stillfurther relates to means, 1

more? explicitly, an oxidizer, for producing said screen -like corrugation and resists to be used'in' connection with this oxidizer.

One of. theiprincipal objects of my invention is to provide. a new screen embodying a' transparent-base an'd'a gelatinous layer thereon, the outer'face of' which is a screen' like corrugation.

Another object is to combine this? screen with photographic black and" White, and. especially with color separation pictures inorder' to facili tate the manufacture of printingplatesfrom said pictures.

Another object is; to provide means, more "ex"- plicitly, an oxidizer so adapted'to form simul taneously'a screen on the surface ofan" exposed and photographically developed light. sensitive emulsion of "photographic material forblack and white, especially for color separation picturesand With the above and otherbbjectsofthe'invention in. view, the invention consists of the novel methods and'processes" set fortnin the claims hereof and in" the novel" combination of the various elements or parts thereof; and also in the novelproducts therein set forth an'din the novel combination anduse of the various constituents thereof, certainernbodiments of the same. being describedfin this specification.

In accordance with he 'afo irwenticnllconlsists Orin rout-wing; arts The first partcompnses ascrenemboayifir said obj cots};

a transparent baseanda gelatinous layer with a screen lilie patternjthereon; this screen may beusedfor the most" diverse purposes; it is called by me a fmetamor'p'ho'sis screen as it is able to change designs or the likeseen through it in'the most diverse ways;

The second part o fl n iy invention comprises use" of this screen. for photographic purposes by embodying it in a' photographic material. As in. this. case, thei'oxidiaer by whichvthescreen like corrugation is produced eifects', besides this corrugation, also ac'orrction of trlej ranspar:

ency of the pictures themselves;this-screen is" The third. part of. invention? comp-rises the: oxidizers usedforpi'oducing the screens and the fourth comprises various-resists used in combination with-these oxidizers if thesame are used for. retouching or like purposes; 7 H v} I 7 These parts of my'invention will be described each separately as far as this is possible in orderto facilitate the understanding of the invention bythose skilled in this art.

In accordancewitlf 'rny invention, both'the metamorphosis? and the combined screenconsist or a tran's-parent'base and a photographic layer thereon; theeouter face of saidlayer being corrugated like a screen by treatment with an aqu'eoussolution of at least one acid selected from the class consisting of the hydrochloric;- sulphuric, nitric acid groups ancltheir derivatives. As pointed outinthe following, I prefer to use these acids in 'cornbination with' other substances thus. forming"anioxidizer- With. combined" effect.

The: metamorphosis screen consists of a trans"-' parent base and-atleast one antihal'ation thereon; whereb'y the outer? surface of said antihalation layer or layers 'isftreated withsai-d acids" or-witlr the oxidizer 'andthereby corru'gated-like-a screen:

This screen-like corrugation has the appear-- ance 'of a mosaic crystalline structure with in. num'erabl'einin'u eiintersecti'ons and hasithe char-- aot'eristic 'of letting -a 'pictureor other object at depends-onthe distanceof the screen rroni the object or'iJictnr-vievved-through it; c

The screen ill furthermore have"a lenticular' efrectfwhe ris s-gatis impinging-omit and -wil lj'thus V I it? It furthei possessestheiio'wer'tochange text nse -Isharp -lightpassing through 3 tures of screens viewed through it from any fine ruled or reticulated to a very fine grain screen texture.

I propose to make my metamorphosis screen by treating an antihalation layer on a transparent base with a solution containing one or more of the acids enumerated above, or especially with an ox1dizer comprising said acid solution. The treatment may also be carried out only with acid or with an acid and formalin containing solution or the oxidizer mentioned above. DependlIlg on the ingredients of the solution used for the treatment, I have to vary the time of treatment from about one to a few minutes.

I may use a transparent base with a transparent gelatinous, e. g. antihalation layer thereon or I may use a normal photographic material with the emulsion on one and the antihalation layer on the other side of the base. The process of producing is slightly different for both types of initial materials: In the first case the antihalation layer may be treated directly, while in the second case the treatment has also to include removal of the emulsion.

For producing a screen on a material without emulsion i. e. on the antihalation or other gelatmous layer directly, I propose to treat first the surface of this layer with one of the oxidizers set forth below in detail. The timing of this treatment cannot be exactly determined in advance: it depends on the composition of the oxidizer or acid solution and of the gelatinous material used.

By varying the time of treatment, it is also possible to produce different screen textures, i. g. a screen with a more close or more open texure.

After processing the layer or layers with the oxidizer, e. g. by placing it for about 1 to 8 minutes in an oxidizer bath, I treat it with a solution of special hypo having the following composiion:

Pounds Powdered sodium thiosulphate About Powdered sodium sulphite About /4 Dissolved in about 30 liquid ounces of water.

Thereafter, I treat it with hot water in order to uncover the screen, and simultaneously remove the remnants of oxidizer and hypo, and dry the screen thus produced. I carry out this treatment for from about 1 to about 2 minutes; a longer treatment gives an unsatisfactory result as the screen gets a too open texture. I find it of advantage to rinse the layer with cold water before and/or after the hot-water treatment.

When using a photographic material with an emulsion thereon it is necessary to include in the process the step of removing the emulsion. In this case, I place the emulsion containing photographic material for a little longer time than a material without emulsion in the oxidizer, place it thereafter for about the same time in a hypo, for instance in the special hypo mentioned above, and after rinsing the film with a stream of hot water of about 120 Fahrenheit, the entire emulsion is substantially dissolved and can be removed without difliculty. I have to carry out this treatment for about to 1 minute depending whether the emulsion was photographically developed or only exposed to light. The removal can be carried out in various ways: I have found it very easy and simple to remove the emulsion by going over the base and texture of the screen with the hand. It must be noted that the emulsion may also be removed in other 4 known ways if the antihalation layer is pro tected against removal during this treatment. I am quite aware that a saturated solution of sodium hydroxide is adapted to remove completely the emulsion layer. This saturated solution will remove at the same time also the antihalation layer and therefore it is not advisable to use it for my purposes if a dry screen is to be produced. If, however, a damp screen is to be produced, I may use for producing such a damp screen also sodium hydroxide or another derivative of equivalent alkalines; by treating the antihalation layer with a solution of this sodium hydroxide for about 10 to 50 seconds, washing the screen thereafter in cold water and then treating it with glycerine, described below in detail, a damp screen may be produced; this screen, however, has a somewhat irregularly disposed stipple-like corrugation and is therefore not very well adapted for my purposes. I want to stress, however, that the method of producing damp screens with sodium hydroxide or the like substances forms also part of my present invention.

As set forth above, the emulsion may be removed in any conventional way; it is only of importance that the antihalation layer should be treated in accordance with my invention. After removing the emulsion and treating the antihalation layer, the material is dried and the screen is practically ready for use. It must be noted that the screen-like corrugation on the antihalation layer is formed by the combined action of the oxidizer and the hot water, the latter simultaneously removing the emulsion.

The described process of producing my metamorphosis screen shows that all kinds of discarded films which possess an antihalation layer, whether exposed or unexposed, whether still useful or not for ordinary photographic purposes may be utilized for my metamorphosis screen. When using, however, a transparent base with a transparent gelatinous, e. g. antihalation layer, on one or both sides of the base only, there is no necessity of removing the emulsion layer; thus, it is sometimes of advantage to use a special initial material for my metamorphosis screen. As special initial material I propose to use a photographic film of the usual type comprising only the usual film base with the antihalation layer thereon without an emulsion covering the other side of the base. In some cases, it is of advantage to use as initial material a special photographic film base or other transparent base having an antihalation layer on each side of the base.

I want to point out that I may use my metamorphosis screen in dry as well as in damp condition; in both cases, the effect of my screen is different. The damp condition of the screen is preferably produced by treatment with glycerine or the like. In order to preserve this damp condition permanently, I propose to wet the faces of the screen covered by antihalation layers with glycerine and to enclose it between two plates of glass or other transparent material with suitable masks between glass and screen edges in order to protect the screen surface from the glass, and to secure thereafter the edges of these plates together. Thus, it is possible to keep the screen permanently wetted with glycerine, i. e. to keep it in a damp condition.

The damp screen is advantageous for many purposes: Thus, for example, it may be used as a comparative background in retouching of separation negatives or positives or in connection with additive color photography crwith black and white fine screens or" other screen printed matter. Placed in front of an additive color screen, it changes the appearance of the previous texture to that of a fine grain screen much better and in a more brilliant manner than when used in dry condition. Ifhe color particles become more brilliant and have thus observed a silk-' like appearance. The same efiect may be obtained with a black and white screen or any fine printed matter. I

Taking advantage of this property of my screen, I am able to use it for printing color additive pictures. In this case the screen-after complete evaporation of the water from the glycerineis placed in front of the color transparency at such a distance; that all colors of' the color transparency, even of a transparency With such fine screen as a Dufay color additive screen, appear as separate grains on the screen. Plac= ing a light sensitive black andwhite emulsion on the other side of the screen and exposing through the color transparency and my metamorphosis screen, the color components of the picture are printed. on the emulsion without any separate color filter as each color grain acts as filter. It may also be used as a fourth printing step in present processes of three separation negatives or positives, or it may be used in the future when it will be possible to print an additive color transparency or screen on the paper base.

My metamorphosis screen may also be used in front of transparent additive color pictures on films to be projected in cinemas" or the like. In this case, the dry screen is preferable. This is placed in front of the projection window of the projection apparatus at such" a distance that it eliminates only the fine-ruled screen which is visible when additive color pictures are projected in the regular way without my screen. Practically, the screen will be secured to the projector itself, as mostly the distance between screen and film in theprojector has to be less than one inch, for instance, about one half of an inch. I I n g Due to the propertyof my metamorphosis screen which gives in some. cases a completely sharp and in some cases a diffused picture of the object viewed through. it, it is possible tocopy or to reproduce in. a photographic. way photomechanically printed matter-regardless what type of screen is used-and to, eliminate completely in the copy. or reproduction the. screen net of the original photo-mechanicalprint which is always visible on a photo-mechanically printed picture. This process may also be used if it is desired to reproduce any paintings, etchings or the like in a manner giving the impression of a very smooth surface. For this purpose, my screen is placed and fastened at such a distance from the photo-mechanical print that the picture. to be-copied retains all its sharpnessand brilliancy' although the screen netiscompletely eliminated, giving thereby the photo-mechanical print viewed through the screen the appearanceof a-regular photographic print; then thephoto-mechanical print is photographed through the screen;.on the photograph thus obtained no screen net is visible,

it has the appearance of a normal'f original pho-' tographic picture. Whenit' is desiredto copy or reproduce such photo mechanical prints, Iiprefer to use my screen drycondition;

1 similar way, Whfl i't is desired to copy' an old photographic picture: a" great: deer-"cr m teuenin were my be eliminated by using the same method as pointed out aboveforfthe com?- ing of photo-mechanical prints; By this method of copying old photographic pictures, my screen eliminates all the small scratches and the like which are often visible on old photographs and reduces the harshness of larger stains or damaged areas if such are present on the picture. I

My metamorphosis screen may also be used as a photographic difius'er of the typeused for photographic printing purposes. Also in this case, it is advisable to use the screen in dry condition. This method of obtaining diffusion when photographically printing'will greatly reduce the costs of this process, as it is only necese sary to place my screen between two glass plates and a simple and inexpensive diffuser is ready for use. By placing this difiti'ser at diiferent distances from the negative to be printed, it possible to vary the diffusion effect as required.

I further may use my screen to create the im pression of a great number of different designs using thereby, however, one initial design only. This initial design may therefore be a very simple one, for instance skeleton-like appearance, while the designs produced by my screen will be most intricate, of suchsoftness'and so compli} cated as to be very difflctilt to design by hand. This multiplying effect can be attained byplacing my screen before a simple skeleton-like initial design and looking through the screen at this design. It is possible to use designs of whatever type, but I prefer to make myin'itial design by drawing on white paper and photographing it on a contrasty photographic paper or d'ia'positive material; the negative paperor diapo'sitive photograph thus obtained shows white, respectively transparent sharply defined lines on black backfground. It should be noted that the lines of this drawing should be approximately from one quarter of an inch to one eighth of an inch apart so that the lines do not overlap one another unless this is desired, for instance inthe middle part of the design. Due to the screen, one will have the impression of a three-dimensional picture-like design. By varying the distance of the screen from the skeleton-like initial design, it is possible to attain the impression of a varying design when looking through the screen. This effect may be used for different purposes, especially for the textile industry where it is of importance to create difierent textile designs at low cost, which can be easily done by photographing one or more simple skeleton-like designs through my screen, varying between the taking of the pictures the distance between screen and the skeleton like design.

I Want, furthermore, to stress the importance of my metamorphosis screen for television purposes where the quality of the reproduced image :is influenced by the visibility of the scanning lines on the televised image. By securing 'a metamorphosis screen, not in contact with, but at a small distance in front 'of the fluorescent screen of the receiving cathode ray tube used for television purposes, it ispossi'ble to make the scanning lines on the image practically invisible when viewed through the screen, thereby giving the impression of a cinematographic continuous projection. It must be noted that this combina- 4 tion is of special importance for television transmission on large screens as in this case the scanning lines are especially visible; in this case, my screeninaybe applied "with the same' 'r'esultfa's eziplained abovein connectionwith the protection of color additive pictures or it may be applied directly in front of the fluorescent screen of the picture transmitting cathode ray tube. My screen may also be used as a projection screen for televised images or for small-size cinematographic projection. One face of the screen may be silver-covered and thereby its reflecting capacity multiplied.

By using my screen, I may also produce photographic records from black and white or color televised images and eliminate all scanning lines from these photographs.

My new metamorphosis screen may also be .used for all purposes for which frosted or ground glass or the like can be used: thus, its use is of advantage in headlights of automobiles, e. g. in the form of a damp double screen, or for windows of the most diverse kind. It may also be used for fancy lamp shades; in this case, I provide the lamp shades with small holes, e. g. pin holes; by illuminating the lamp shades thus prepared, I obtain an aureola effect around these holes. I may use this effect for other purposes also in order to attain aureola-like color effects, e. g. for illuminating devices for advertising means and the like. I may use my screen also for lamp bulbs and the like. It also has the effect of changing strong illuminating light to a very soft lighting effect which may be used especially in photographic studios for color photography. For this purpose, a damp screen or a double metamorphosis screen is especially well adapted. It has, furthermore, the advantage of absorbing a small, practically imperceptible part only of the light passing through it. A further advantage consists in the even and uniform distribution of the screen-forming corrugation thereby making possible an even distribution of the light passing the screen.

Summarizing, it may be seen from the above description that the production of my new metamorphosis screen is inexpensive and can be carried out easily; that furthermore the screen thus produced has a series of characteristics making it advantageous for a great number of fields in which heretofore either expensive screens have had to be used or in which it has been impossible to attain the required effects by the use of screens.

As set forth above, the second part of my invention comprises the use of this metamorphosis screen for photographic purposes by embodying it in a photographic material. The screen thus produced, called by me a combined screen, is

oxidizer comprising an acid selected from the class consisting of the hydrochloric, sulphuric and nitric acid groups and their derivatives. I prefer to use an oxidizer which besides forming a screen-like pattern in and on said emulsion layer also corrects the transparency of the en- .{tirepicture in a novel manner. ,pattern produced by the oxidizer treatment com- The screen-like prises substantially equally disposed opaque and transparent screen portions, the opaque screen portions, being diiferently blackened in accordance with the light intensity reflected from respective parts of the picture taken or printed, and the transparent screen portions being substantially equally transparent throughout the entire photographic picture. It must be noted that although the transparent portions are more or less equally transparent, their transparency varies between the dark and the light picture portions; thus, in the dark picture portions the transparent screen portions are substantially grey, while in the light parts they are entirely transparent. When using my combined screen for producing printing plates, I propose first to make a black and white or color separation picture on a photographic material provided with a light sensitive emulsion, to treat thereafter the surface of said emulsion after exposure and slightly darker development, as usual with an oxidizer as set forth above in connection with my metamorphosis screen, forming thereby the described screen-like corrugation on the emulsion layer, to print thereafter photographically said screen-like picture on the light sensitive surface of a printing plate, and treat said printing plates in such a manner as to produce ink-retaining cells corresponding to the blackened screen portions, said ink-retaining cells being of substantially equal size but difierent depth in accordance with the different blackening of the opaque screen portions.

If great differences between the opaque and transparent screen portions are desired, I propose to use my combined screen in damp state treated with glycerine.

It is seen that my invention embraces not only the various types of my so-called metamorphosis screens but also my cbmbined screen with the latter difiering from the former by also carrying an image on the photographic emulsion film, and that while I can produce the metamorphosis screens as well as the combined screen by using one of the three acids, sulfuric, hydrochloric, and nitric, and each of them without including any iodine, I obtain an additional advantage when I include iodine along with the acid in producing my combined screen because the presence of the iodine then yields simultaneously with the formation of the screen a correction or clarification of the photographic image on the emulsion film.

As set forth above, my oxidizer is adapted not only to provide a screen-like pattern on the emulsion surface but also to correct the transparency of the photographic picture itself; thus I am able to correct the transparency of photographic black and white and especially color separation pictures and color transparencies produced by additive color photographic processes. This correcting or retouching process may be carried out either for the entire picture or for parts of the picture only. In the latter case, I coat the picture portions on said light sensitive emulsion layer which are not to be treated with a transparent resist, treat the uncoated portion of the picture with an oxidizer solution, controlling constantly the brightening of the portions treated with a densitometer, and remove thereafter the resist.

Having now described in general the difierent fields in which my combined screen may be used and the way in which it has to be used, I want now to proceed with a more detailed description of making my combined screen for color photo- .9 graphic and especially multicolor printing, PHI-.-

poses:

I must make several, etg. three or four, sep aration negatives or positives on a preferably panchromatic emulsion; thereafter I immerse each separation positive or negative in the oxidizer.

After immersing the photographic developed picture for about 4 to 3 minutes in the oxidizer, depending on the composition of the oxidizer, the photographic material, and other conditions, as temperature or the like, the photographic film is washed in cold water e. g. by dipping in a water tank or by holding it under a gentle stream of cold water, moving it preferably in a horizontal or vertical direction until the screen is uncovered. In order to obtain an even design, it is of advantage to watch the photo-graphic material constantly, preferably with a magnifying. glass. When the screen-like pattern has appeared on the emulsion surface, the film is placed in a special hypo bath, the composition of which I described in connection with the pro duction of my metamorphosis screen. Then it is dried in cool air at about 60 to 65 degrees Fahrenheit, preferably in a dustproof place. When the screen thus produced is dry I can-if i-t is-desired and necessary-correct the color values locally, as pointed out above.

.I want to point out that the screen is produced by the combined action of the oxidizer and the cold water, and thus both process steps of treating the photographic developed image with the oxidizer and with the cold water are essential from the point of my invention. After correct processing and drying the emulsion surface assumes a glossy or silk-like appearance; the absence of this glossy appearance of the surface of the combined screen proves that the film has not been properly processed. The completely processed film remains, after drying, permanently hard, if not wetted with glycerine. The surface is so hard that wax or other impressions can be made from it without difiiculty.

,I want also to note that my combined screen hasbesides the properties enumerated abovealso practically all the characteristics and advantages of my metamorphosis screen described inthe first part .of the present description. ithas also theappearance of a mosaic crystalline structure with innumerable minute intersections and has also the characteristics of letting a picture or other object appear completely sharp if placed in'contact with or very close to the screen, but of causing the picture or object to appear diffused if slightly removed from the screen; the difference in effect depends hereby on the distance of the screen from the object or picture viewed through it. In order to make the picture or object to appear diffused, I may also use a damp screen; in this case, the degree of diffusion depends also on the patterns of the screen. In order to produce this damp screen, I :place it, after the screen is somewhat drie-., inglycerine and keep it thus permanently damp. After a certain time, when the water evaporates, it will remain in slightly swollen condition, permanently 'wetted. It will be possible to place the damp screen thus produced in direct contact with a suitable material for reproducing plllp -i The screen will furthermore also have-alenticular reflect-when a strong lightv ray is impinging on it and willthus diffuse sh arp light passing throu h it. When imageless, it further possesses a so the power to hange te tures i w d hr u h it from any line ruled 9r tactics: lated to a very fine grain screen texture.

I want to repeat and emphasize that the screen-like corrugation on the emulsion surface consists of opaque and transparent screen portions, the opaque screen portions being of substantially equal size but differently blackened in accordance with the corresponding parts of the picture taken, while the transparent screen portions are substantially equally transparent throughout the entire picture.

A pointed out above, also the transparent screen portions will vary from grey to entirely transparent in accordance with the blackening of t e original image. By photographically printing this screen-patterned corrugated pictpre on.

the light sensitive surface of any metal, stone, or.

similar printing plate, I receive on this plate a screen-like reproduction of the original black and White picture or color separation negative, which partly looks like a plate produced by the .ofisetprocess, partly like a plate produced by the in, taglio-process. This picture on the printingplate consists of differently blackened stipplerlike opaque portions of substantially equal size, the different blackening of these stippleo-like opaque screen portions corresponding to the blackening of the original black and white pic.- ture or color separation negative. By treating this screen-like surface of the printing plate in such a manner as to produce ink-retaining cells corresponding to the opaque screen portions, I am able to produce a printing surface with inkretaining cells of substantially equal size butdifferent depth in accordance with the different blackening of the opaque screen portions. By using this printing plate for printing purposes, I receive a print with a screen-like pattern consisting of opaque and transparent screen per-.- tions; the opaque screen portions on this print are of equal shape with the ink-retaining.- screen portions on the printing plate, but the diiferent depth of these ink-retaining screen portions results in different blackening of the correspond ing screen portions on the print. Thus, my new process creates a print similar to prints produced by the gravure process. It is thus possible to eliminate the necessity of printing the picture which has to be reproduced on a screen, and it is also possible substantially to eliminate etching or other methods of retouching, such as dot correction of the picture to be reproduced. It must be noted that by using color separation negatives provided with different combined screens, i. e. diiferent screen designs for superimposing and thus creating additive color pic.- tures, these color pictures will give a,much better mix of colors than known heretofore.

' It must be stressed that for producing printingpiates, I prefer to use separation negatives or positives with a preferably damp metamorphosis screen on the other side of the emulsion base; by using such an initial material, i. e. a film base provided with a metamorphosis and combined screen, I get a much better result than with a combined screen alone.

Those familiar with the art of photo-mechanically producing pictures will realize that by using my combined screen in the way described above, it will be possible not only to simplify the process of printing to a great extent, by omitting evera teps. a p i ns n sc een an etchin ut a s to a tain n t onl black and i bu also color prints of highest quality in an easy and inexpensive manner.

III

Having thus described my metamorphosis screen and my combined screen, and the way in which they are produced with the help of my new oxidizers, I want to describe in detail the composition of these oxidizers and the manner in which they are made.

I have found that I can use as oxidizer for all purposes of the character described a composition of matter comprising a substance selected from the iodine group, a substance from the group consisting of formaldehyde and other aldehydes, and at least an acid selected from the class consisting of hydrochloric, sulphuric and nitric acid groups and their derivatives, said substances being dissolved according to the different purposes for which they are to be used in water, glycerine or the like.

I have found that for producing my screens it is preferable to use an oxidizer comprising about one to two parts by volume of at least one substance selected from the group consisting of iodine tinctures and concentrated iodine solutions, about one to two parts by volume of an iodine of the decolorized iodine group, about one to two parts by volume of an aqueous solution containing about 40% formaldehyde, and about one to two parts by volume of an acid selected from the group consisting of hydrochloric, sulphuric and nitric acids and their derivatives, said iodine, formaldehyde and acid being dissolved in about 120 parts by volume of distilled water.

In order to be able to control the formation of the screen on the gelatinous surface, i. e. to vary the softness or contrasts of the screen patterns, I can add to the above described oxidizer sugar or common salt, i. e. sodium chloride. I have found that by the addition of these substances and by varying the quantity added, I am able to produce screen-like corrugations of difierent softness and contrasts. I have furthermore found that for local retouching purposes, in which case a strong oxidizer is needed, it is of advantage to dissolve the iodine, formaldehyde and acid not in water but in glycerine or the like, thus forming a quickly and strongly acting oxidizing solution.

In the following I describe diiferent oxidizer solutions, which I have found to be especially advantageous for my purposes:

1. An oxidizer which has proved to be the best for substantially all my purposes consisting of- Concentrated iodine drams 1 Decolorized iodine N. F. VI do 3 Formalin do 1 Hydrochloric acid (or sulphuric or nitric acid) drams 1 Common salt or sugar oz 2 Distilled water oz 16 I propose to make this oxidizer by first adding to the acid half of the water and separately mixing the concentrated iodine with the decolorized iodine, and thereafter mixing the two solutions together; then the formalin and the salt or sugar are added, and the solution shaken until the salt or sugar is completely dissolved; thereafter the other half of the distilled water has to be added.

The concentrated iodine used is preferably a saturated iodine solution. I produce this saturated iodine solution by dissolvi g y talline 12 iodine in 10 per cent aqueous solution of'potassium iodide until this potassium iodide solution is saturated with iodine. After being filtered, this solution may be used for the oxidizer.

2. Another preferred oxidizer solution consists of-- I prefer to use this solution for extremely dense color transparencies where no white objects are evident.

I prefer to make this oxidizer by mixing the concentrated iodine with half of the water and mixing separately the decolorized iodine with the formalin, and mixing thereafter the two solutions together; thereafter the acid and the salt or sugar are added and the solution is shaken until the heavy particles in the solution disappear and the solution becomes clear. Then the second half of the water is added. No filtering is necessary thereafter, the oxidizer is ready for use.

I want to stress that the oxidizer solutions described above are the most preferred; these oxidizers are made with concentrated iodine solution, prepared as above referred to and I have found that this concentrated iodine is the most preferable for my oxidizers.

3. For color transparencies, I prefer to use an oxidizer solution comprising- If this solution is to be used on paper prints, two ounces of common salt or sugar should be added, except when using nitric acid, in which case salt or sugar should not be added. I propose to make this oxidizer by first placing the acid in a bottle and slowly pouring into this bottle the distilled water, then mixing this acid solution with the tincture of iodine, the decolorized iodine and the formalin, and adding thereafter the second half of the water. No filtering is necessary.

4. For the same purpose I can use also an oxidizer solution comprising- Tincture of iodine U. S. P drams 3 Decolorized tincture of iodine N. F. VI

drams 3 Formalin dn 1 to 3 Hydrochloric acid (or sulphuric, nitric or other equivalent acid) drams 1 Distilled water oz 7 Tincture of iodine U. S. P drams 3 Decolorized tincture of iodine N. F. IV

drams..- 3

13 Formalin cdrams; -l tc 3'- Hydrochloric acid (or sulphuric, nitricor.

other equivalent acid) drams 1 Distilled water oz 7 This oxidizer is prepared in substantially the same way as the above described.

6.- Asa soft oxidizer working very well'on color transparencies and on prints, I prefer to use an oxidizer comprising- Iodine test solution (T. S. U. S. P;') drams 2 r 3 Potassium iodide test solution (T. S.'U. S. P.)

drams 1 Sulphuric acid (or. hydrochloric, nitric or other equivalentv acid).. drams 1 Distilled water "liquid 02.. 7

'7. Another also well-working oxidizer comprises-- Iodine test solution (T. S. U. S. P.) drams N. F; IV decolorized iodine; do Hydrochloric acid (or sulphuric or nitric acid) drams 1 Tincture of iodine (-U. S. P.) alcohol 83%- drams 2' do 2' Formalin Distilled water oz- Churchills tincture of iodine, 'N. F. alcohol 62% drama Decolorized tincture of iodine N. F. IV' do 1 Formalin' do 1' Hydrochloric acid (orsulfuri'c or nitric acid) drams Common salt or'sugar oz 1 Distilled water oz 9. Still another oxidizer adapted for my purposes consists of-- Solution iodine compound (Lugol) U; vS. P.

drams l Decolorized tincture of. iodine N. F. VI

drains ,2- Formalin don..- .2 Hydrochloric acid (or sulphuric or nitric acid) drains-.- 2' Distilled water ..oz-- 14 In the preceding illustrative examples there are included specific amounts of certain respectively individually designated iodine solutions, the particular constitution, and preparation of which follows:

(a) Decolorized iodine N. F. VI is prepared by addition to a solution of 25 grams of potassium iodide in 400 cc. of water of .50 grams Qfiodine and 400 cc. of alcohol and stirring. After the iodine is completely dissolved, 100 cc. of stronger ammonia water (about. 37% NHa) are added and the mixture allowed to stand" until it' becomes M colorless. Thereafter suiilcient alcohol is. added to bring the 'volun-ietov a total-011000 cc.

(1),) Decalorieed iodine N. F.. IV.Digest. 83 grams each of iodineand sodium thiosulphate inv cc. of water, at a gentle heat, until complete solution results. Then add cc. of a1- cohol and. afterwards 65 cc. of. stronger ammonia water-(37%).. 'Sha'ke'the mixture a few minutes until bubbles of gas no longer escape, and the liquid has become colorless with. .a whiteprecipitate, suspended in it. Now cool the mixture,

and; then add sufficient alcohol to makethe.

Place the bottlecontaining. the liquid inv a cold place fora few hours product measure 1,000 cc.

and then filter. lilreserve in a well-stoppered bottle.

(0) Tine-tare ofzio'dine U. .S.'P.-Dissolve '70 grams: of potassium iodide in 50 cc. of distilled water contained in .a bottle graduated to 1,000 ea;v add 70 grams of iociineand agitate the mix-- ture until solution is effected. Then add sufii cient alcohol to make 1,000 cc., and mix thoroughly.

(d) Iodine test solution U. S. P.Dissolve 1 gram of iodine and .3 grams of potassium iodide in 500 ccof distilled water.

(e9 Churchillis tincture of iodine N. F. is an alcoholic solution of iodine and potassium iodide containing "not less than 16 grams and not more than 17 grams of iodine and not less than 3 grams and not over 4 grams of potassium iodide in each 100 cc.

(1) Lugolssolution iodine compound U. S. P. is the standard U. S. Pharmacopoeia solution containing in each 100 cc. not under 4.5 grams and not over 5.5 grams of iodine and not under 9.5 grams: and not over 10.5 grams of potassium iodide.

I want to stress" that for retouching purposes or for correcting only the" transparency of a photographic picture without forming a screen thereon, all of the: above described oxidizers may be used without the addition of acid. In this case, however; the oxidizer is. only adapted for immediate use but will not be durable as a stock solution. By addition of. the acid, it may be made durable for practically unlimited time. The oxidizer maybe used immediately after addition of the acid, but I prefer to use it only about 5 to "7 days thereafter.

Asset forth above, my oxidizer is adapted for correcting the transparency of the entire picsure; this is of great importance in case of color transparencies. Due to various causes, a veil i formed. even upon the most correctly exposed and properly processed color transparencies made by additivecolor processes. This veil prevents the transparenciesfrom appearing to the observer in the natural colors, falsifying thereby the colors to a certain extent and giving the transparency a more or less flat and blurred appearance. especially if the transparency is slightly under or over exposed. The sam veil can be found also on normal black and white or color separation pictures.

By my new .oxidizer it is possible to eliminate this veil. The oxidizer is adapted to work also as reducer (in the photographic sense as to the intensity of the precipitated silver, as opposed. to the purely chemical sense), if this is required and advisable.

It is not advisable: to carry; out the process oi oxidation in strong daylight, as; the oxidizer becomes less active in such light. The length oftimeto hold the color transparency in the 15 oxidizer bath is generally from about 1 to minutes, depending on the density of the trans-' parency. I have found that by holding the color transparency in the oxidizer bath a grey tinge is formed on the surface of the transparency; this tinge disappear after the hypo treatment. In preparing the oxidizer bath, it is necessary to add water only if the solution is used soon after it has been prepared. If it is about 1 or 2 weeks old, usually no addition of water is necessary.

My oxidizer also may be used for a novel method of local color correction by oxidation which comprises the steps of coating the picture portions of the emulsion which are not to be corrected with a transparent resist, immersing the emulsion in an oxidizer bath of the type described, thereby correcting the uncoated parts of the picture, and, after bathing the picture in a special hypo as described above, removing the resist from the emulsion. I want to note that a I may cover the parts not to be treated with the oxidizer either by coating them with a resist in the usual manner or by applying the resist with an air brush; in the first case I will obtain a sharp outline between the treated and untreated image portions, while in the latter case I will obtain a soft merging edge portion between these image parts. In this way, it is possible to correct picture parts of color transparencies. If it is desired to make one or the other color lighter, this can also be done by this process.

Using this process for color separation negatives, I can correct one or the other part of one of the negatives, thereby correcting the final picture attained after combination of the color separation negatives. For such color separation negatives it is preferable to use a solution which is at least a few weeks old and to use thi solution without addition of water as this kind of negative needs a stronger treatment. The oxidizer solutions made "with decolorized tincture of iodine N. F. IV are the most satisfactor for this purpose. The action of the oxidizer on glossy and on mat papers is different; if glossy paper prints are treated with the oxidizer they remain absolutely clear during processing while mat paper prints are covered with a grey veil through the entire picture. This veil disappears by the hypo treatment.

As set forth above, it is also possible to treat photographic prints with my oxidizer and to obtain thereby satisfactory efiects; my new oxidizer is especially adapted for treatment if it is necessary to regulate the contrast or softness of the prints produced in this way. The normal time of treatment is about 1 to 3 minutes depending on the characteristics of light sensitive paper used and on the density of the printed picture. For prints it is advisable to use stock solutions which are a few Weeks old and which contain salt or sugar, except when a solution containing nitric acid is used, in which case no salt or sugar is to be added. It is not advisable to dilute this stock solution or even fresh ones; in diluted state it will not be durable.

I may also use my oxidizer for retouching small parts of pictures, e. g. for removing or lightening dark spots, such as blemishes, freckles, wrinkles, and the like on black and white and color separation pictures or on color transparencies. I

If any of the oxidizer solutions described above were to be used for this local retouching, practically no result would be obtained, as these oxidizer solutions aretoo weak and work too slowly.

16 I therefore propose to use for. this purpose an oxidizer solution comprising- Drams Concentrated iodine or tincture of iodine U. S. P. alcohol 83% 1 Decolorized tincture of iodine N. F. IV 3 Formalin 1 Hydrochloric acid 1 Glycerine (to be added before using) i The components of this solution have to be dissolved in glycerine before the oxidizer is used. If the acid and formalin are omitted from this composition, this local oxidizer decomposes quickly and lasts only a short time, but if composed as above described, it will keep indefinitely, even without addition of glycerine. The addition of glycerine greatly increases the life of the local oxidizer, even when standing in an open vessel ready for use.

This oxidizer has a very strong effect and is to be applied very gently, as otherwise it will make holes in the photographic material. It is not necessary to rub with the brush while applying the oxidizer, as every touch gives almost immediately a retouching result. Immediately after observing that the applied local oxidizer has hadthe required result, the spot to which the oxidizer has been applied has to be treated with a strong hypo. It is important to avoid touching other places with this hypo. After applying the hypo, the retouched photographic picture has to be washed thoroughly. I want to note that when larger areas are to be treated with my oxidizer for retouching purposes, it is advisable to first cover this area with a glycerine water mixture and to carry out the retouching within this area thereafter. 1

The above description of my new oxidizers and of, the processes for correcting the transparency of entire photographic pictures or local large areas, where resists are used, and for retouching small spots onphotographic pictures by these oxidizers, shows clearly the advantages of these oxidizers and .the processes when compared with the means and methods known and used heretofore for these purposes. My new oxidizers are always ready for use, inexpensive in preparation, and adapted for all the purposes enumerated above.

The fourth part of my invention relates to various new resists to be used in combination with my new oxidizers.

I propose to use as resist a composition of matter comprising a transparent substance selected from the group consisting of waxy and resinous substances dissolved in a transparent liquid solvent for said substance. This resist may be produced either as a quick-drying or as a non-. drying resist. It may also be made as a transparent or as an opaque resist.

My quick drying transparent resist comprises preferably Canada balsam and benzol. If it is to be applied in the usual way, I propose to dissolve one part by volume of Canada balsam in about 8 parts by volume of benzol or another solvent for said Canada balsam. If it has to be applied with an air brush, it is advisable to use a'fsolution comprising one part Canada balsam dissolved in about 12 to 16 parts of benzol.

- ;l\/Iy non-drying transparent resist preferably comprises wax, lanolinand white petrolatum. A-

arena-rat is preferred' composition for :"niismomasym re's-ist consists of- Grams Wax, :White or yellow; preferably white 1 Lanolin (wool fat) 2 White petrolatum Between' l2 and 15 iounces Beeswax ;.4 Oil' of turpentine v s .28 Asphalt varnish. (.of .Eimer'eand Amendimake). .el Red pigment .:About 314 White lead carbonate.. -;About .11

This opaque resist cannot .be washed on with cold water; hot water, however, can be .used'for removing it.

I may. use these resists .forthe most diversepurposes:

.One of the principalpurposes of .my new re sists is to cover a part of a picture during oxidation,'thereby holding back the action of an oxidizer ,on this part while otherp'arts'areleft uncovered and may be "processed with the oxidizer in any way desired. 'My'new'resist is especially adapted for this process asit. istran'sp'arent and thus it is possible tocompare during processing thepartsto be treated with the parts remaining untreatedand thereby'to regulate the timing of treatment as necessary. Another purpose oflmy resist consistsin covering a part of a picture while the adjacent part is retouched, e. g. removed. ..Still another .field in .which my resist can be used is to cover p'ictures or paintings, retouched with an air brush,-=with-it; i'f-my trans-- parent quick-drying resist is used, such 'a resist layer preserves the ,paint from :being rubbed or washed off and adds agreatqdealt'o the 'brilliancy of the picture; furthermore, .it :jpreserves :the paintings from cracking or discoloration. .My new quick-drying resist may :also be used ifor plates or I films, for .natural color transparencies; in this case an extremelythin layer. of non-drying transparentresisthasto be applied to .thezcolor screen under the light sensitive emulsion. My opaque quick-drying resisthas ssubstantially the properties of ya transparent resist as described above.

My non-drying transparent :resist has "the property of resisting acids. =It1also rema'insfina non-drying condition while the photographic film or plate is being processed; this expedites the whole process as the resist can be easily and quickly applied and after p'rocessing also-beeasily and completelyrubbed off whenthe film orlate has dried and the resist is no longer needed. This non-drying transparent resist can be used also on prints to cover certain parts if it is desired to process other uncovered parts.

Having thus described the different parts of my invention, viz. the metamorphosis and combined screens, their characteristics and the processes for their production, and having also described in detail my new oxidizers and resists used for these purposes, and also the processes by which these oxidizers and resists are produced and the manner in which they may be made, I want to stress that numerous modifications and adaptations of the embodiments of my invention describedabove couldbe inade without iiepart ing' from the 'scopeof 'my invention.

Without-furtlier analysis, 'th'e foregoing will so fully reveal the gist "o'f this invention that others can by applying current knowledgeireadilyradapt it for vari'ous'applications without lomittingiicer tain features that from the :standpointmf:prior art, fairly constitute essential characteristics-lief thelgeneric or :specific' aspects of this invention, and, therefore, such adaptations shouldzandrare intended to be 'com'prehended within: the meaning and range of equivalence (the appended claims.

vVhat Iblaim is '1. Process :for manufacturingraascreen.-. wvhich comprises the steps JZO'f iwetting ca photographic material consisting: o'f a sgel atinouscantihalation layer and a gelatinous photographic zemuision layer that is more easily.lsolublerthanlsaidrantihalation layer, on :a transparent abase iwith :an aqueous solution :containing iddineieand aan sacid selected from the .group :consisting 20f hydrochlori-c, sulphuric,.;and;nitr ic acids, itreatingzthe thus wetted photographicimaterial withsa hypo solution, thereafter immersing-fit .;in :hot water. thereby: removing theiemulsionlayenancl forming by the combined act'ioniofzasaid ncidnhypoaarrd hot water, a substantially :evenly .distributed screen-like .corriugationz'onf thezanti' halationitlayer of said transparent base.

2. Process .of manufacturin gia Jscre'ennwhich comprises the .steps of' -wetting atphotog'raphic material consisting of argeiatinous antihalation layer and a gelatinous gphotographic Jemulsion layer .ona transparentaphotographic loase,:-said emulsion layer vbeing moreaeasilyrsolubleithan said antihalation layernwith maaqueousioxidizer solution containing formaldehyderand-iani acid selected from the group consisting of thydr'ochloric, sulphuric, .and .-I1ltI'-l0.'.8;0id$, zimmersing the photographic material :zthus 112136313611 .afirstiin hypo and thenzinghot water, ctherebyisremoving the emulsion. layer and formingtby cthe combi'ned action of said .oxidizer,;:hypo, candfhot 'i-waterta tantial y :evenly distributed sscr'eemlike f oor rugation on thefa'ntihalation iayersonssaid transparent base, immersing .the thus ipretreated screen-like photographic imaterial 1in giycerine, :and. enclosing it .between'itwo:transparent-layers in such-a manner :as :to keep it.:continuoi1sly -wetted"with; glycerine.

3. A process of simultaneously forming'ia screen ,onthe. surface oft-the: light sensitive gelatinous emulsion :of iphotogrhapic 'fmaterial for black and white and especially color separation :pictures,-andcorrectingtheatransparency: of the .entire picture, comprisingitreating the's-outensur- .face of said emulsion.:aftertexposurextand.iphotographic development WithLan oxidizerzbath comprising at least" a 'halogennancb formaldehyde and also an acid selectedzfromt'the grouprconsisting of hydrochloric, sulphuric,:randaaiitricsacidsgthereby simultaneously correcting the transparency of the entire picture and forming a screen-like corrugation in and on said emulsion layer, said screen-like corrugation comprising substantially equally disposed opaque and transparent screen portions, said opaque screen portions being differently blackened in accordance with the light intensity reflected from corresponding portions of the picture taken or printed, and said transparent screen portions being substantially equally transparent throughout the entire photographic picture.

4. A process of simultaneously forming a screen 19 and correcting the transparency of a picture, as claimed in claim 3, wherein the halogen is iodine.

5. A process of producing a screen on a transparent base having a gelatinous emulsion layer thereon, comprising the step of corrugating the outer surface of said gelatinous emulsion layer by treatment with an oxidizer solution comprising formaldehyde and a halogen and also at least an acid selected from the group consisting of hydrochloric acid, sulphuric acid and nitric acid.

6. A process of producing a screen, as claimed in claim 5, wherein the halogen is iodine.

7. A process of producing a screen comprising corrugating the outer surface of a gelatinous antihalation layer provided on a transparent base by treatment with an oxidizer comprising formaldehyde and a halogen and also an acid selected from the group consisting of hydrochloric, sulphuric and nitric acids.

8. A process of producing a screen, as claimed in claim 7, wherein the halogen is iodine.

9. A method of producing a damp screen comprising the step of corrugating the outer surface of a gelatinous antihalation layer on a transparant film by treatment with an oxidizer comprising formaldehyde, iodine, and an acid selected from the group consisting of hydrochloric, sulphuric and nitric acids, and keeping the thus corrugated antihalation layer permanently wetted with glycerine.

10. Method of treating a photographic material comprising a transparent film provided with a gelatinous emulsion on said film, comprising the steps of partly opaquing said emulsion in accordance with a color component of a photographed picture, and corrugating said emulsion by treatment with an oxidizer comprising formaldehyde and at least a halogen and also an acid selected from the group consisting of hydrochloric, sulphuric, and nitric acids, said oxidizer treatment correcting the transparency of the entire picture and simultaneously resulting in a screen-like corrugation of said emulsion layer, said screenlike corrugation comprising substantially equally distributed opaque and transparent screen portions, said opaque screen portions being differently blackened in accordance with the light intensity reflected from corresponding parts of the picture taken or printed and said transparent screen portions being substantially equally transparent throughout the entire photographic picture.

11. Method of treating a photographic material, as claimed in claim 10, wherein the halogen is iodine.

12. Method of treating a photographic picture comprising a transparent base, an exposed and photographically developed galatinous emulsion on one side and a gelatinous antihalation layer on the other side of said base, said method comprising the steps of wetting the outer faces of said layers with an oxidizer comprising formaldehyde and at least a halogen and also an acid selected from the group of hydrochloric, sulphuric and nitric acids, thereafter treating said layer faces with a hypo-solution and cold Water and thereafter drying them, said combined oxidizer, hypo and cold water treatment forming a screen-like corrugation on said outer faces of both layers and correcting simultaneously the transparency of the picture on said emulsion layer.

13. Method of treating a photographic picture, as claimed in claim 12, wherein the halogen is iodine.

14. Method of treating a photographic picture comprising a transparent base, an exposed and photographically developed gelatinous emulsion on one side and a gelatinous antihalation layer on the other side of said base, said method comprising the steps of wetting the outer faces of said layers with an oxidizer comprising formaldehyde and at least a halogen and also an acid selected from the group of hydrochloric, sulphuric and nitric acids, thereafter treating said layer faces with a hypo-solution and cold water, thereafter drying them, then immersing the thus pretreated photographic picture in glycerine, and finally enclosing it between two transparent layers in such a manner as to keep it continuously wetted with glycerine, said combined oxidizer, hypo and cold water treatment forming a screenlike corrugation on said outer faces of both layers and correcting simultaneously the transparency of the picture on said emulsion layer and said glycerine treatment causing diflerence in transparency of said layers.

15. Method of treating a photographic picture, as claimed in claim 14, wherein the halogen is iodine.

LEON RUBINSTEIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 381,091 Sutton Apr. 10, 1888 744,223 Ortman Nov. 7, 1903 1,046,089 Lachenmeyer Dec. 3, 1912 1,151,502 Troeger Aug. 24, 1915 1,161,824 Morris Nov. 23, 1915 1,214,940 Miller Feb. 6, 1917 1,234,888 Eppers July 31, 1917 1,257,682 Davis Feb. 26, 1918 1,710,303 Ewald Apr. 23, 1929 1,794,693 Ippers Mar. 3, 1931 1,835,175 Norlander Dec. 8, 1931 1,992,169 Brewster Feb. 26, 1935 2,071,821 Eckardt Feb. 23, 1937 2,467,359 Rubinstein Apr. 12, 1949 FOREIGN PATENTS Number Country Date 24,378 Great Britain of 1910 315,681 Great Britain July 15, 1929

Claims

5. A PROCESS OF PRODUCING A SCREN ON A TRANSPARENT BASE HAVING A GELATINOUS EMULSION LAYER THEREON, COMPRISING THE STEP OF CORRUGATING THE OUTER SURFACE OF SAID GELATINOUS EMULSION LAYER BY TREATMENT WITH AN OXIDIZER SOLUTION COMPRISING FORMALDEHYDE AND A HALOGEN AND ALSO AT LEAST AN ACID SELECTED FROM THE GROUP CONSISTING OF HYDROCHLORIC ACID, SULPHURIC ACID AND NITRIC ACID.