v Patented lJuly 1 l, 193.9 This invention relates to photo-mechanical to l. my? invention, Ainl'imakirig f a color; printer?r from processes for the reproduction of a multi-colored@ this negativa ...,1. 1. 1;;1. "ff/"'7 original. It relates to the makingl of color .Í.Fig. ¿1d illustrates a corrected color--sep'arationï printer for use in such a process andßmoref'p'ar# positive y`¢;>'1‘•‘printérresulting from my'process..y 'f „ p* ticularly to a color printer which is correctedior­ »Y . Fig. '2.i11ustra'tes 'a' novel picture ' which can'> be -5 the limitations of the best contemporarily avail-_ ' made. according to. one‘embodiment ïof my ‘inven-f: able inks. > . It is an object of vthe invention Ato aA tion.'My invention. is ` primarily-' >~concerned -. ‘ ­ vlvvithï'the method of making a color-correctedcolor printer.. makin‘glrof acorrectedicolor printer Vfromfa pri-L.y Various methods of color correction generally mary. color v'separation ` negative ‘which "has `¿been­ .10 rca1led"‘masking methods” are wellknownii"Itisv made in’anyfof the usual Ways. f Afpo‘s‘itive‘ madey an object of the present invention‘to providea from-i. a fcolorf separatiomnegative ­may­ comprise' method of color correction which" might : ybe the .printers itself> or Vvthe " printer v‘may b'e“ made termed "autographic” and whichdoesnot require“ therefrom7 by any‘f‘suitable duplicating " process.> 15 the use of special masks but employs the original OneVH Well-knov‘vn ‘method I of introducing».` color 15 itself, or more exactly a color separationimagefof correction infth’eï making ‘of fa' color ‘printer com# the original, to act as a mask.y ‘ > f »Y prises` masking ‘certain'of'ïthe color 1Vseparation. The method provided by my` ¿invention ist one, negatives ‘ with .low Lcontrast v‘positives ’ madey from in which neither the negative nor z the color other color separationfnegativesf» Anotherfmethlá.. .¿, 20 printer madev therefrom is maskedl in >the .usual od-l-nam'e'ly 'that for l'which the «above-mentioned.: `20 sense, but a corrected printer» is'madefby. idi'rect. Hahn apparatus `was .intendedLintroduc'es uthek exposure through an ordinary;color’iseparation. colon correctionlduring thefmaking of theînegaë tive,I by exposing the sensitive negative material l negative.It is a special object ofy my`v. invention, , ,f . topro-` to acolor separation“ image 'from-the original; 'i ' vide a photo-mechanical -processins’whichthe: ñrst through a negative mask corresponding‘to‘ 1 density of the blacks and~.îdark grays, ize. .areas ai correcting'ïcolorie.' g: a. redfñlter negative may where all three color printersfhave >a relatively befusedftofcorrect afgreerr ñlter negative)`= and high printing density, are reducedlmoreor less­ second, directly. " ` . ` i i 1: »i :According toümy- invention,.ïa •‘method >.off‘inf i» proportionally)., It is a further object­ of my lnventionïtoïproi troducing color vcorrection is provided which does vide a novel picture ora multi-colored'original not employ either a negativemask (in making the: in which all the neutralfdensity tones are lreduced negative) or a positive mask (in makingy .the­ to a constant value andi‘whic'zhicomprises>` only printer)­ in theusualy sense»r of the fword«mask. color variations. Instead, I `employthe-.original .itself ` as: the mask It is 'also an object of.l the'iinventiontoï pro­` v in ,fither` following.¿mannen`>l` Afcolor- separation -35 I vide a'method of making-‘.suchfa novelipicture; . f negative yis madeiirom >the `originaluand a Yposi--x` Although my invention may- be practiced with tive is made from ¿this :negative :by exposingèra various types yof equipment; .one'fformi'ofß appa-1 photographic‘layer> twice .through the negative, ` - ratus 4which `is particularly «suitable for practice first-'sto ' uniformfillumination r(preferably"gvvhite ing oneembodimenïòf my -invention- is described light).":and second», tofa color. separationqimagè. '40 by F. Hahn in UISJPatent 1,576,118.41v lof the original., -çThislnst .colonia-“a2 correcting: AOther objects and'a’dvar'ita‘ges` of my *invention color;A e. g. in making` amagentagp‘rinter .through will be apparentisfromî the ïfollowingïvdescription afgreen-¿separation negative,>the_,.second exposure; when read in Lfcónnection `v'vithithe. accompanying may;y .be made fbyfa “red >separation image,V thatiàis 45 by illuminating .theënegativeîawith aqredsepara. drawing' Fig. 1a in showsalwel which: f ., „known manner.V.;. v of making:. tion; image “of `fthe .. original. a' This :image may. fbe` a halftone.­, color «".separationf-:negative' from .a a projected image of.theìßoriginalsorfit -mayçbev Vmulti-colored originali? .constitutes .theffiirsti provided l._by; placing; >the .original in fcontact »ewith step of . my q process;y lone. lemlgaodiment „iofff which 3. is. 1iäht.f„.»;'.1‘11e.iwothe negative and;yilluminatinggiti; exposures maybemade With;,_~,c.olored »s 5o 50 shown `in „the -form » of »a ",flow.. cha ‘ v v 2 2,165,407 tives are made. 'I'he complementary colors, i. e., without disturbing this relation. However, vari the colors of the printers are called blue-green, ' ous ‘arrangements may be used. For example, in magenta, and yellow respectively. In certain making the steps shown .in‘Flg. 1b, the negative branches of press-printing work these comple I5' is illuminated by a color separation image of mentary colors are called blue, red and yellow. the original, which image may be a projected one but this latter convention and its accompanying as shown or'it may be the original itself. The confusion will be avoided in this speciñcation. negative I5' may be placed in contact and reg The term "photographic” is used in a broad sense ister with the original II, which is then illu so that “photographic layer” includes those used minated from in front or behind. If illuminated as photo-sensitive resists as well as the usual from in front (i. e. so that the light is reilected 10 silver-halide emulsions. ' . to the lens I3) the density and contrast of the I will now describe the particular embodiment negative I5’ is eüectively doubled since the light of my invention which is illustrated in the ac must transverse it twice. A transparency is the companying drawing. more suitable form of original to be illuminated ' 15 -As shown in Fig. 1a, a multi-colored original from behind. In fact, if the original is a trans 15 II, which may be either a transparency or an parency, all three elements-the original, the opaque painting or color photograph, is photo negative and the sensitive layer I1 may be super graphed by a process camera represented by a imposed in relative contact and illuminated by lens I3, in the image plane of which is placed a colored light. ' ' 20 film or plate I5. In this particular embodiment As shown in Flg.‘1a, I prefer to expose the of the invention a halftone negative is produced negative I 5 through the base. By doing this, the by positioning a halftone screen It at a suitable negative image I5' can be simultaneously placed distance in front of the sensitive layer of the in contact with the sensitive photographic` layer ñlm or plate I5. A primary color filter I2 (red, Il and in register with a. color separation image green, or blue) is mounted in front of the lens of the original as shown in Fig. 1b. If the original 25 I3 in any well-known manner. Any other suit is a transparency, the negative I5 may be ex able method of making a color separation nega posed directly and then both the original and tive may be employed. the negative turned over in making the step After development, this ñlm or plate i5 com shown as Fig. `117. On the other hand, if the 30 prises a color separation negative I5'. As shown original is not a transparency and it is not de 30 in Figs. 1b and 1c, a positive I'I is made from this sirable to make the exposure of the negative I5 color separation negative I5’ by contact print through the base as shown in Fig. la, a reflector ing. In Fig. 1b, the negative I5' is illuminated such as a prism may be placed in front of the by a color separation image of the original, by lens in performing the step shown as Fig. 1b. means of a set-up similar to that shown in Fig. This reflector introduces the lateral inversion 35, la, but employing a color filter I6 which trans necessary to permit the negative image I5’ to be mits a color which is suitable for`correcting the simultaneously in contact with the sensitive sur color printer corresponding to the color separa face of Il and in register with a color separation tion negative I5'. For example, it has been image of the original. found desirable to correct a magenta printer in My invention is applicable to either continuous 40 proportion to the amount of red present in the tone or halftone processes. In a halftone proc original. In making a magenta printer, a green ess, I prefer to introduce the halftone pattern by iilter is used at I2 to make a green separation making each color separation negative through negative i5'. The exposure of ‘the positive i'I il a halftone screen, as shown, but the halftone lustrated in Fig. lb is then made through a red pattern may be introduced at a later stage such 45 ñlter I6. as when the positive' Il is being exposed. If the In addition to this correcting color exposure, original is a transparency and no enlargement or .. the positive Il receives a direct exposure» modu reduction is required, it is possible to perform my lated by the negative I5’ only. This may be ac invention without the use of any camera, by complished in a simple manner as shown in,Fig.