US995405A - Method of preparing screens for color photography. - Google Patents

Description

Patented June 13, 19.11.

L. DUGOS DU HAURON L R. DE BERGEGOL. METHOD .OP PRBPARING SOREBNsJ-"OROOLOR PHOTOGRAPHY.

Y APPLIGATIGN FILED JUNE 22, 1910. 95,4959

my mum WTIVESSES:

ravir oserais,

LOUIS DUCOS DU HARON AND RYMOND DE BERCEGOL, 0F JON'VILE-LE-PGNT, FRANCE.

- METHOD OF PREPABJING SCREENS EUR COLOR PHTQGRAEHY.

Original application fled January dents of Joinvillede-lont, Seine, Republic of France, have invented. new and linproved Method of Preparing ncreens tor Color Photography, of which the following isea full, clear, and exact. description, this being a division ot the application tiled. by

us on January 2, i90?, Serial ,NoA itiea, for the manufacture of screens ttor use in coloil 'ihotography.

Our invention relates to the .manufacture l5 of polychromatic screens for usein color photography, under such conditions that the pictures or portions thereof may be multiplied.

,Ve seek to cover a transparei'xt or trans lucent surface, of glass, Celluloid, paper or the like, 'with a very lz rge num ber ot ingly small rectangular figures, such as bands, rectangles, losaenge-shaped ligures, etc., having 'three distinct colors placed 25. closely together' without leaving any interval, and cach ot' these colors covering theoretically one-third of the surface. By doing this in a skilful manner, the process may be carried out rapidly, economically and in every manner suitabie for industrial conditions.

Two things are essential in carrying out our process, to wit: First, the automatic placing or positioning ot the colors relatively to each other, by taking advantage ot the fact that colors dissolved in liquids of diderentcharacterdo not readily mix-that is to say, colors mixed with greasy substances and colors dissolved in water -or in alcohol,

do' not mix easily; second, the application of these colors thus treated, to'parallel lines by means'ot' a ruling machine.

Several forms of the invention are herein illustrated and described in order to render the process easily understood.

figures.

Figure 1 shows on an enlarged scale a portion of the screens obtained by the process;

Figs. 2, 3 and It, show variationS FgliS. a

Specification of Letters Patent.

i?, i907, i tial No. 35G,33l.

1911:, Serial Patented June i3, Miti.

1Qivded and this application filed June 22,

fide View of a machineifor tracing the lines; l `.ig. (i is a plan view; Fig. 7 is an end view; and Tig. S is a section on the line ofthe cutting tool.

"vile select a hard plane surface, preferably one 'or copper, Zinc or iithographic stone, A upon this surface lines, are drawn by et a machine, these lines being paral with' ach other and separated by interl` This being done, the surface is partly relic-ii' and partly in intaglio. r "he parts relierp are next coated, or the intaglio porici with a greasy coloring materiale-for instance, green printing ink. By means or" pressure the series of lines is now reproduced upon a sheet of gelatin, or upon some other appropriate surface adapted to receive an impression; This is now dried. and after drying a formed. This color, tor instance, may be orange, and is so arranged that the lines cross those iirst made. The bare intervals are next colored by applying to the whole surface of the sheet a third color, blue violet, dissolved in water, and to which the greasy colors are impermeable. rEhe screen thus made possesses, as shown upon a large scale in l, large number of comparatively small ligures or designs, which may have the form of squares, rectangles, or losenges, accordingly the ot lines are perpendicular or oblique.

At v is shown the green color, at 7 the orange color, and at b the blue color. At the crossings of the various lines appear small patches oft' black or dark color nwhich present a very slight disadvantage, to wit: that of slightlydarkening the entire screen. The black or ydark lelement n may be avoided, however, by operating as follows: Upon a surface, such as gelatin capable ot dissolving water color, we I lines, substantially as heretofore described, by means of a greasy ink of blue violet color, and then a yellow water color is applied over the entire surface. The material thus applied does not adhere to the greasy lines and only fills the 4intaglio portions comprised between these lines. second series of lines is then drawn by means of a greasy ink of light blue color, cfre being taken tlo cross the lines just mentioned. The `light s (that is, the holes or grooves) are covW tracing of another color lmay be" series first draw a series of l sheet of sure, the unevenness of the glass.

makin the Gelatin 55 1 g e blue lines in' being superposed upon the yellow lines will produce green colors, and in being superposed upon the blue violet color will have little or no effect beyond slightly increasing the intensity of this color. These three operations produce on the gelatin surface blue violet lines and green rectangles, resulting from the superposition of the yellow lines on the light blue lines; and since the lines and the squares are produced by inks having greasy solvents, these lines are not'attacked by the other colorwhose solvent is water.` Finally, over the'ientire surface is applied a layer of red water color which in mixingv with t-he yellow gives the orange red color.

Our process may be used in connection With glass surfaces as follows: Upon a glass we spread gelatin holding in suspension very line grains,.such as those of starch. The she'et is then dried, the result being a slightly grainy surface holding the greasy ink and avoiding blurring, as well as enabling us to obtain, under the press, series of'lines having remarkable clearness. To avoid breaking the glass and also to ren'- der the prints homogeneous, the plate produced by the ruling machine 'must be absolutely smooth, or better still, made up of a soft material, such as ebonite,icelluloid, or very thin metal, placedon a sheet of indiarubber or other lieXible material, so as to eX- a-ctly compensate, when submitted to pres- The two colors in greasy inks are applied as above'described and the gelatin is caused to absorb the water colo-r which now lls the hollows and completes the trichromatic screen. If it happens thatthe third. color is blue violet, there can still be added to the gelatin, before it spreads over the 'transparent support, starch, which in this case must be dissolved. The last operation consists in causing to act in the greasy hollows upon the intaglio portions, causes the starch color.

The present process can also be carried out as follows: l. On a substance permeable to water a first set of greasy lines which may to become of a blue violet be colorless, is drawn; 2. Over the whole color containing tannin,

surface an aqueous alum, or any other substance susceptible of impermeable to color soutions similar to thatfirst applied, is applied; 3. By means of a dissolvent, such as turpentine or mineral essence, etc., the greasy lines are destroyed in order that only the aqueous color lines may re1nain. 4. A second set of greasy lines crossing the preceding lines, and which may be colorless, as the rst ones, is drawn; 5. A second water color, likewise containing tannin, alun etc., is applied over the whole surface; 6". As previoisly done, {said second set of greasy a solution of iodin which lines is destroyed; 7. Finally, the third* water color is applied over the whole surface.

If there be mixed with the water -color a suitable proportion of material having the property of tanning gelatin and filling 'the pores thereof-in other words, if we add to the water color alum, tannin, alcohol, aldehyde, or the like-the space occupied by this color will be thereby rendered impermeable. A second aqueous color is now applied by the saine means, and lafter drying, the third color, which is likewise a water color andv though spread over thewhole surface, will adhere only to the intaglio portions left.

Instead of obtaining the lines by transfer, they'may be drawn directly upon thel 'Y case the procedure is as follows: A sheet of glass or Celluloid is first covered with a material which is permeable to water and which is colored, for example, red. Then by means of a plane `or circular ruling machine we draw small parallel screen. In this grooves which are "separated 'by intervals approximating their width. The sheet thus prepared is dipped for a few seconds into a water color green, for examplefwhich iinpregnates the gelatin 'throughout wherever it has been exposed, leaving unaffected the parts `covered with varnish and merely dyeingsupercially the layer of gelatin.

e surface is nowclean. lt constitutes, in elfect, a screen composed of green and red orange bands arranged side-by 'siderelatively to each other and capable of produce ing, by the two-color process, beautifully colored photographs.

The third color is distributed as follows: There is' spread over a surface provided with two series of bands or lines, a second varnish which is impermeableto water, is colorless, and is designed to serve solely as" a protector; we then hollow out fresh tracks which are a little deeper than those above referred to, in such a manner pasito expose the lower layer "of gelatin which the rst icc lio

bath did not have time to reach. These f tracks intersect the iirst either -perpendi'cularly or obliquely and should be separated b. f spaces equal to twice their own width. The sheet vvisthen dipped for a few seconds into a blue-violet watercolor bathV and a three-color screen is produced. c It has aneXtremely large number of small green and red-orange rectangles, o, e, respectively, intersected by blue-violet lines as shownin Fig. 2 0f ,the accompanying drawings These small figures will be lozenge-shaped if the second series of bands or tracks has been drawn obliquely, as shown in Fig. 3 of the drawings. The colors may mentioned ones obviously he.ar ranged in any desired order.

We may also .take a transparent sheet covered withA a thick layer of gelatin which is supericially colore reen for example. on

which is spread a varnish impermeable Water. 1. having; drawn the lirst series of bands or tracks, the sheetdipg'ied into av second water-color hath as Jor instance, rederange-color, ren a colorless protective varnish is spread thereon, the second deeper series of bands or tracks is drawn and iinally the sheet is dipped into ,hird watercolor bat-h, as, for instance, blue-violet. Celluloid which is sfiperlicially colored green, 'for example, may also be employee; this is corered with col:nl'ess gelatin and the series o' bands or tracks drawn suliiciently deep' for them to ezqpose the colorless Celluloid. rl`he sheet is then colored with a pigment solved in acetone, amyl acetate or any other liquid which will bite into or penetrate the cellnloid. There .is then spread over the whole surface a sec nd layer of `gelatin, then the second deeper series of bands or tracks is drawn, and finally `tht-ire is spread over the whole surface a. third color having; a base of acetone or amyl acetate.

The gelatin having protected the parts olf the surface not acted upon by the chisel or tool` of' the ruling machine, and alter having freed the celluloid from tne gelatin, there will he produced a screen which is capable of resisting water and a large number oi' other liquids.

ln nsinf:Y celluloid the procedure is as follows: The sheet of celluloid is covered with a thin layer oit gelatin which is colored by means` of a water color, then the first series of bands or tracks is drawn through the gelatin; the sheet is colored with a second color having amyl acetate or acetone for its base, which only acl'spon the exposed parts of the Celluloid, the whole is then covered with a second layer of colorless `gelatin; the second series of liands or tracks which are deeper than the former onesl drawn and a third color of the same nature as the second is spread over the sheet.

In all the above cas the vfirst series oi bands or tracks can be drawn in such amanner that the. interval which sol'mrates llleni shall be equal to twice their width7 :is shown in Fig'. 4 oi' the dra wings. Then, after soaking and varnishing', sil'nilar bands or tracks are drawn exlenrlixre` nearly lo the middle oli the space which is afterward soaked in the third color.' ln this i'nanner, the screen is formed solely by bandsl which are parallel lo each other, but this l'n'ocess has the disadvantage of only overcoming` part of the dill]- cultics oipv registration, while the method in which. the lines4 cross ovel'eonn-,s` lheln entirely. Thus, the second series ol' bands or tracks can be hollowcd to the saine extent as the lirst; in this ease, two colors are superposcd and 'lorin at the point at which the series of linesI cross each other as hereinloefore specified and as shown in Fig. l- .small may he used in which these machines a plurality o fixing we will A :tres which are blacl or have a dark e el 1 in most cases, as above secilied the gelatin Tn be replaced by collodion or by any other material which may be easilv spread in a thin layer and colors having water, hases."

i For drawing lines, the ruling machines ehisels are `We'ierably on ls or gravers arranged so as to torni a number of lines at a time. Also,.in order to produce filinlike screens, we. can use a cir-cular rnlingima chine similar to that shown by .va\y\o't` eX- ample in Figs. 5, G, 7 and 8.

employed, and by mountiniY inls machine consist-s oi a movable cylinder l around which the sheet is rolled, and of a chisel or cutting tool i2 which'is lied along by a leading' screw 3, and toothed wheels Ll and 5, of which the wheel 5 is attached to the shaft olil the cylinder' l. ln order that the eye may not he able to distinguish separately the sinallcolored divisions, their dimensions should be made as small as possible, and thus a surface will be obtained which will appear homogeneous and Whitish by transn'iittent light.

ln order to allow the use of rotary pressure, the series-of lines can be drawn on cylinders.

` ln use, the screen inoduced by one of the methods described above, and protected by an Aimpermeable varnish, is covered -With an emulsion which is sensitive to colors, and

vis placed in the plate or liln'i-carrieror frame .oll any suitable photographic apparatus,'the

emulsion being turned toward the inner face ot the said -carrier or 'l'ranxe in such a manner that the rays of light pass through the screen before reaching` the said emulsion. A view will be laken in the ordinary manner and developed, then the negative so obtained will be converted into a positive and after have a photograph having all the natural colors; at the saine time., we can employ the following' process when it appears to be more advantageous by reason of its permitting the production of a large number of prints.

lnstead oi spreadingthe' emulsion on the screen itself, there is placed in the carrier or traine, in the ordinary manner, a sensitized plaie to which the screen is applied, by putting; the colored surface of the latter against the emulsion on the plate. The' View .is laken, then the plate is developed after havino` been separated from the screen. The selectively acted nponY negative thus produced, when lixed, will enable an indenite number ot' black positives to be obtained which, when suitably placed against similar screens will innnediately exhibit by transcapahlc oi absorbing uted vover the Whole surface of the screen,

mitted light all the colorations of the model. Theoretically this adaptation or tting of the screen to the positive, should be made in such a manner that each of the small colored figures should 4coincide with the point of the image which it has selected, but since these thousands of figures or devices are similar to each other, are of equal dimensions and are synnnetrically distribb vreason of the regularity of the Work done by the ruling machine, the registration may easily take place with an infinity of positions.

The transparent support of the improved screens serving for the selection may be colored slightly yellow so as to moderate the activity of the blue-violet rays. The successive crossing of the two series of'lines thus assists the complications of registration in the manufacture of the screens. lNIore- .o\er, the successive soakings each time exactly lilling up the spaces producechit follows that all the small color-compartments are automatically juxtaposed without any space being left between them, a condition which is especially advantageous in the production of phototypes in which the selective effect is produced by light-filtration. The perfect regularity of the4 screens enables them to be applied to any positive produced by a similar screen, and consequently to enable the prints to be multiplied` indelinitely.

Having thus described our invention, We vclaim as new and fiesire to secure by Let ters Patent:

l. The method herein described of making screens with polyclnomatic divisions, which consists in first impressing upon a transparcut support definite spaced figures, next coloring the intervals not covered by the figures by means of a color solution that will enter thesupport in the parts unprotected'by the.A

printing substance but will not 'affect this substance, next rendering impermeable to lcolor solutions the parts of the support already colored, then destroying the printing substance impression and finally coloring the permeable intervals by means of a color that will enter the support.

' 2. The method herein described of making I adestroying the fatty lines by means of a suitable solvent, then impressing a second group of fatty lines crossing the irst group, then applying a second color capable of entering the permeable parts of the support unprotected by the fatty printing substance, said second color being non-miseible with said substance, then rendering impermeable to color solutions the new colored parts of the support, then destroying the second` group of fatty lines by dissolving the same, and finally applying a third color capable of cfr entering the permeable unprotected parts of the support. v

In testimony whereof We have signed our names to this specification in the presence ofvr two subscribing witnesses.

Witnesses f DEAN B. Mason, R. Ennuor.V

Images