US1667477A - Producing color pictures - Google Patents

Description

Patented hApr. 24, 1928.

UNITED STATES 1,667,477 PATENT oFFlcE.

WILLIAM V. D. KELLEY, F BROOKLYN, NEW YORK, ASSIGNOR, :BY MESNE ASSIGN- MENTS, TO PRIZMA, INCORPORATED. A CORPORATION OF NEW JERSEY.

PRODUCING COLOR PICTURES.

Application led February 4, 1920. Serial No. 356,159.

This invention relates to producing color pictures, and has particular .reference toa process and product whereby colors are carried by the positive itself in such manner as to render natural colors on either the additive or the subtractive principle.

At present, a positive transparency having a coating on each side is principally used for natural color reproduction, as in patent to Kelley, 1,259,411, Mar. 12,1918, -and the object of this invention is to provide a process in which two or more colors can be on the same side of the transparent base Without the necessity of recoating,'or securing together separate color transparencies, as have heretofore been proposed. It has also been heretofore proposed to have both colors in one coating, either both dye colors, or one dye and one a metallic tone, or one color being in a suitably treated positive silver image and the other in the gelatine printed from a positive. By the present invention, the cost of oppositely coated positive transparent stock is avoided, since positive transparent stock coated onlone side is decidedly cheaper, and the manipulations and registration diiiculties heretofore encountered in otherprocesses not using oppositely coated positive stock, are reduced,

so that the cost of the product can be materially reduced.

The invention is especially intended for the production of positive colored motion picture film, and permits the use of color 85 value negatives taken successively or simultaneously, or through a screen plate.

In carrying out the invention, the process starts with a special positive transparent stock having excess Asensitive emulsion on one side, one portion either being relatively slow, or carrymg a light retarding fugitive dye, .or being separated from the outer emulsion portion by a coating of fugitive light retarding dye. The first image is printed in the faster emulsion, then developed, washed and treated to fix a suitable dye or tone, without fixing, then dried, and the second image is then printed and developed, both images are fixed, and then one image Y is treated to take one color and the other to take the other color. Stereoscopic pictures can be produced by such process, or registered pictures by employing the registrationmeans and method -disclosed in said 5 patent. Between the first and second printing a rectangle divided into b ings, it may be advantageous to revive the speed of the unprinted emulsion, which may be objectionably slowed up by the developmg of the first, which reviving can be done by a suitable bath.

The invention will now be described for both additive and subtractive work with reference to the accompanying drawing, wherein v Figure 1 shows a negative made through t green design screen, for additive projecion. Y

Figure 2 a negative made through a complementary red design screen the object belack, white, red 'I0 and green sectors,

Figure 3 is a section of the positive stock having the inner emulsionl carrying a fugitive protective dye,

Figure 4 shows the first printing step,

Figure 5 shows the final positive, on the additive principle,

Figure 6 shows the final positive on the subtractive principle; 4

Figure 7 shows a modification using three coatings for three colors; and

FigureS shows a further modification.A

In Figures'l and 2, the negatives of the black, red, ,green and white object B, R, G, W, are made through screens bearing a design of opaque and' transparent portions, such as parallel lines shown, so as to only record on alternating portions. The same character of negative can be produced in other ways, or an ordinary lnegative can be printed through such a screen, the procedure at this point being immaterial to this invention so long as the positives from two complementary negativesare printed in such a designv as to alternate.

After obtaining the negatives, the ,preferred procedure is to take a positive, Figure 3, composed of .a transparent base 1, having an inner coating 2, and an outer coating 3, 'of ordinary silver gelatine emul- 10uv sion. The coating 2 may be slowed up by being dyed with fugitive dye, .as orange-red or yellow or black, as shown to preventbeing acted upon by the first print in coating 3, or may. be made relatively slow, orthe dye 105 may be between the coatings, or all three. The outer coating 3 is next printed thr'ough a design screen like the negat1ves, or otherwise as` by a temporary reslst applied thereto, so as to develop the deslgn spaces 1n 110I vof Figures 1 an i manufacture.

black silver, without affecting the inner coating 2. The desi n after developing is then washed, hardene for ten minutes in 10% formalin solution, and bleached, Without fixing out, preferably with a bleach of peculiar character to render the design transparent, or suiiciently so as to permit the succeeding rint to be made therethrough if desired.

n'developing, the dye in the inner coating Washes out, al suitable one being tartrazin. The outer coating can be dyed if desired,

or the coating last printed be slower', so as not to be affected by the first printing. Another function of the bleach is to prevent developing up of unexposed silver in either coating during the second printing.

A satisfactory bleaching bath is: water 1000 cc., sodium bichromate 2.235 g., ammonium chrome alum 2.392 g., cupric sulphate 12.486 g., sulphuric acid .083 g., potassium bromid 17.853 g., but other baths can be used or the proportions varied. Apparently a copper-chromium mordanting salt is formed in situ with the developed black silver, which will fix acid or azo dyes Without being affected by hypo, or by certain toning baths, lor by `gela-tin dye baths.

The films eed Will now be preferably renewed by a ve minute bath in chromic acid 6.25 g., potassium bromid 12.5 g., water 1000 cc., which revives'the Sensitiveness to light.v

The film is then Washedy and dried, being now ready to be rinted from the negatives d) 2. With or Without reviving this is a novel and useful article of One print can be made in the inner coating 2 through the transparent back in registry with the bleached lines, and the othery print likewise, but in the intervening spaces, so

that both prints are in the inner coatingv 2..

Registration is by a standard pin tightly fittmg like perforations in both negatives and positive on one side, preferably with an opposite, co-operating loose pin, as shown an described in said patent. This method is sufficiently accurate to register images, as well as lines at least as fine as800 to the inch. The images are now developed, and the wholeflm fixed in acid hypo, removing unexposed silver frommthe inner coating, and practically all the undeveloped silver from the outer coating, but leaving the bleached design on the latter capable of fixing a color. After any part has been developed and bleached, a hydroquinone de-v veloper lis better for. the later images as tendin not to redevelop the latent. silver remaining in the lbleached and unfixed images. The bleached design vis novvT dyed with an acid or .azo d e such as Phloxine, Orange Y, Patent lus, etc. As shown in Figure 5, the bleached sections are dyed with a red, complementary to the prints behind `from thegreen negative, and the unbleached sections of the outer coating are stained in silver so that it does not stain with thegelaf-l tine dye.

It will be understood that the second color,

as green-blue in the gelatine is not essential, as the eye will supply this in projection. The film is preferably dried after the first dye, before applying the second.

The positive now comprises black and white, subdivided and complementary key prints in the inner coating, with the bands of red overlying the red negative prints, and with or without the intervening bands of green overlying the' green negative prints, thereby additively giving natural color in projection.

In Figure 6, a subtractive positive is shown. This is made by printing one image, as from the ordinary green-blue value negative in coating 3, then hardening, bleaching and reviving, as before Without fixing. After drying, the second print, as from an ordinary red value negative, is made in coating 2, through the back 1, then developed and both prints fiXed'out as before..

The unbleached print in coating 2 can now be toned blue green, as in a bath of ferrie ferrocyanid, and the 'bleached print in coating 3 dyed complementary red with an acid dye. This projects on the subtractive principle.

' Another Way of making an additive positive, is to print one design screen negative directly on coating 3, then develop, harden, bleach, revive and dry, as above. Then print the other complementary negative displaced relatively thereto on coating 2, so that the positive images in the respective coatings alternate. The bleached image in coating 3 can then be dyed with acid dye, and the image in coating 2 toned a complementary ferrocyanid, a cupric ferricyanid bath can.

be used, which will fiX basic dyes.

It will be seen that the bleach should be of such character as to prevent development of silver during the second printing, and also make the first image transparent Wherever it is desired to print through it to the inner coating. This is true of the bleach here described.

In Figure 7, more than two colors can be produced. On the side having coatings 2, and 3, one print is made in coating 3, then another print from another color value negative i'n coating 4 on the other side. Then the prints in coatings 3 and 4 are developed and bleached Without being fixed, the dye Washed out of coating 2 as before, the speed revived,

and dried. Then the print made in coating 2 from the third negative through the transparent bleached print in coatings 3 or 4. The prints in coatings 3 and 4 are dyed, as magenta and yellow, and the print in coating 2 toned, as blue-green, with ferrie ferrocyanid or cupric ferricyanid, as before, each color being so chosen as to be complementary to the other two.

In Figure S, the same method is carried out to obtain three colors and a black to gray key print. On one side the inner portion 2 next the base l can receive an image and be toned blue-green, the' outer portion 3 being bleached and dyed as magenta. n the other side the portion corresponding to 4 in Figure 6, will receive the black to gray key print, and the outer portion 5 a print to be bleached and dyed yellow. The portions to be bleached will be printed first, then developed, revived and dried, the fugitive dyes washing out of the slower portions, as

2, 4, as before. Then the key-print and the toned print are made in portions 2, 4, through the now transparent bleached images, and all images fixed in hypo, as before. Three color value negatives, and a black and white negative can be used, or four color value negatives properly chosen. Or in using three color value negatives, one can be printed twice, and the second print left uncolored.

Both Figures 7 and. 8 can be used for a three color additive system by changing the printing screen so as to leave spaces for the blue-green toned portions in one inner coating alternating with the bleached and dyed portions in the outer coatings, as in Figure 7, or with a black to gray key print in addition in the inner portionv on one side as in Figure 8.

1Where i speak herein of coatings, I mean v substantially separate coatingsr in that such an excess of silver sensitiveness is present as to lreceive the separate images.

li have found in practice that two emulsions separately applied one over the other adhere so closely as to act and looklike one, except for the increased thickness.`

ln additive work, any desired screen design can be used other than the lines herein illustrated. Also the specific details of coloring can be varied, as it is well understood how to turn negatives into color positives, or

to get color positives by using a printing positive and staining the gelatin, as in the bichromating process. These various methods are all applicable to this process, and I do not restrict myself to any specific order or colors. or materials, except as required by the appended claims. Also other bleaches may be used not having the particular funetions above described, and the reviving step is not to be consideredv absolute-ly essential. The advantage of this process for two This is because the picture on the curtain can be focused on the combined pictures in stead of midway of the base, which is quite material with the usual thickness of base of .005 and of coating of .002.

It will be further understood that the invention is applicable to all kinds of work other than motion pictures, including plates and paper with suitable modifications, and to stereoscopic work andtitles.

What is claimed is:

l. Process for making a color picture upon a support having a sensitive coating including strata of different speeds, consisting in first printing, developing and bleaching a color selection print in the fastener st-ratum, then printing and developing a ,complementary print in the slower stratum, and fixing both.

2. Process for making a `color picture upon a support having two superimposed sensitive sections on one side, consisting in printing, developing and bleaching an image recording color values in one section, printinu and developing a complementary second image in registry in the remaining section, fixing both images, and coloring the images with respectively different colors.

3. Process for making a color picture upon a support having two superimposed sensitive sections of different speeds on one side, consisting in printing, developing and bleaching an image recording color values in the faster.' section, printing and developing a complementary image in the second section, xing both images, and differently coloring said images.

4. Processv for making a color picture upon a support having two superimposed sensitive sections of different speeds on one side, consistin bleaching an image recording color values in tlie faster section, reviving the speed of the other section, printing and developing a complementary image/in the second section, fixing both images, and coloring said images with complementary colors.

v5. Process for making a color picture.

in printing, developing and sists in revivin colorinr a plurality of said images in respectively iierent colors.

6. In the production of two images in different portions of emulsion on the same side of a support from silver salt originally contained in the emulsion, the step whichconthe printing speed of the portion in Whic the second image is to be printed before printing such second image.

7. In the production of two images in different portions of emulsion, the steps consisting in retardin the normal printing speed of portion o` the emulsionl making a color value print in the faster portion, de-

veloping said print and removing the retarding medium, and increasing the printing speed of the portion in which the second image is to be printed before printing such second image.

8. An article of manufacture consisting of a support carrying two coatings on one side, one carrying an image absorbent to dye, and

the other being capable of recording a second image.

'9. An article of manufacture comprising a transparent support carrying on one side two coatings, and on the other side at least one coating, the outer coatings carrying images in different colors, and the inner Acoating carrying an image in a third color.

l0. An article of manufacture comprising a transparent support carrying on one side two coatings, and on the other side at least one coating, the outer coatings carrying dye images in different colors, and the inner coating carrying an image in a third color.

11. A color transparency comprising a transparent base carrying on one side two colored images and on the other side a third colored image and a black to gray key print.

Signed at New York city in the county of New York and State of New York this 27th day of January, A. D. 1920.

WILLIAM V. D. KELLEY.

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