US2577332A - Imbibition printing - Google Patents

Description

DeC- 4, 1951 J. F. KIENNINGl-:R 2,577,332

IL'MBIBITION PRINTING Filed Sept. 27, 1945 l "ri: l F El *ff j? if@ b nl n M m95 I T o d 00E lp'nloilp'egma" l I I f'iG'w/W gf Il? ,g4

Patented Dec. 4, 1951 Nor MFJFlcE 1 2,577,332 IMBIBITION PRINTING John F..`Kenninger,1ios Angeles, Calif., assignor. to Technicolor. Motion Picture, Corporation,

Hollywood; Calif.,v acorporation of Maine Application september 27, 19.45ser1ia1Ne.A 618.830,- e claims. (ol. 11n-149.1)

' ,In printing motionpicturesby imbibition, `from adye: impregnated matrixV toa dye-.absorptive blank, it is customary to employ a reliefmatrixin which the gelatine. ooatin'gis thicker in .the shadows than -in the. highlights and vto use 'a blank.v comprisingn a layer ofv gelatinev or other..

dye-absorptive material. In ordersto obtain-good.

denitionin the picture printed on the blankit is necessary to'employ relatively hard. gelatine andin orderl to maintain intimate contactbe.- tweenthe films Whilethe dyeisbeing imbibed.

by. thefblank from the matrinitis desirable t0- soften the gelatine on the blank temporarily. This is usually accomplishedby passing. the blank through a water bath in transitto the matrix in,v order' to cause the gelatine on the blank. to. swell-somewhat before. it comes into v contact .withthe dye-wet matrix. lf the gelatinebe-softenedl too much it mitigates againstgood definition. in.. theli transfer operation, and if the gelatine be.

softened too little the filmsy do notv adhere in sufficiently. close contact-to.` afford good. transfer,

of ldye. Particularly at the: edges the films tend to separate fromeach other, resultingin lio-called.` edge trouble.. The degreeof softening for optij-` mum definition is somewhat above the point wherey the lms may be .maintained vin intimate contactwith each other throughout .their entire width` -Heretofore it has -been necessary to tolerate imperfect-.definition to maintainthe filmsin intimate contact, and as a practical matter it has been customary to compromise between the twov evils.

'The aforesaid edge troubleresults from the fact thatthe valleysof the vrelief matrix do rnot make goodcontact with the blank along the edges` of thepictures during the` transfer process, as they'would-if the bank Wereswollen withwaterv to a .greater degree; This lack of intimate con- I tact interferes with theY transfer vof f dye .resulting f in imperfect printing along the margins of the pictures.' Ordinarily this edge trouble is confined topa narrowV zone just inside the sprocket holes. In-thefcase of film having a sound-track inside one rowy of sprocket holes the edge trouble is usually confined tothe edges of the pictures along the other row of sprocket holes; on the sound--v track 'side the edges of the pictures are too remote from the sprocket holes to .be subject to the trouble. y

rQbjeots of the present invention are to avoid the aforesaid diiiiculties and to maintain in-v timatev contact between the two films throughout their. entire width,to-counte ract thetendency .for'tlleflms to separate atthaw-edges, 4to permitv the dye-absorptive layer of the blank film to be' hardened to the opti1nur.degree forfgood de ni-, tion, to make it vunnecessary to-soften this. layer4 excessively in `order to make the two films,adhereA in intimate contact during. the transfer process; to reduce lateraLdiifusion'of. dye in the blank,y

to improve the definition of the printed picture,

to afford more rapid'. adhesion between; matrix; and blank, toreduce the length oftime-'theV-.twof fiirnsmust be held inregistry-beforethey adhere in fixed relationship vto each. other without .the aid of registering means, toireduce-fthe dangerof faulty dye transfer due to air. bubbles: er1-1 trapped between the .tWo lmsfwhen they.I are4 brought together, and generally toimproye the artof joining two lmsinfsuperposition for any: purpose.

In one aspect the-present inventon. involvesq feeding-v two films; through a vacguun'l-` chamberand rolling them intointimate contact Witirleaoh` Bywettingfone orf both films to render their faces tacky they ad# here together, andv after theyy enfierge from they vacuum chamber the; atmospheric` pressure holds;

otherf while in the chamber.

them in intimate Contact.y Brest resultsare/obf tained byremovingthe superficial.liquidzadhering to the faces ofL the filmssbefore; they enter; the vacuumchamber., the preferred means-for removing the superficial liquid comprising air jets.;

When" the: lms arev broughty together: :in 'the vacuum chamber they must be. accurately; reg-,1; ister'ed with each. other andi this-'is preferablyq accomplishedl by means ofi anY endlessv belt or sprocket wheeler other endless carrier-travelmg mien-orbital path with register teeth ntting'inff "the sprocket holes of the films.

a' beltohlya part ofr'the orbital path'shouldf bef' disposed' in the vacuum chamber; the-belt entering and leaving f the chamber through air* traps. Likewise the films are preierably'fed to"V theV belt from the outside of thefvacuum'chamber through Vsuitable air traps; When the films are rolled together onA a belt one film maybe seated* on the belt before the beit enters the vacuum chamber, the second lm beingv rolled againstV the first lminside the chamber, but preferably both fil-ms are fed to the belt inside the chamber.

For the purpose of illustrationja typical-ern-v bodiment of the invention is shown in the accompanying 'drawings in whichy 1 is a diagraml of an' imbibition machine;

Fig. l2 is an enlarged view showing the afore-v said vacuum'chamber in'section; n

` Fig. 3 is an. end View of 'one offvtheair sealsjuseol''4 z at4 the, entrances. andexits of the Vailmm. Chamj.' 'ben apart being" brokenl away; and" When using- Fig. 4 is a side view of one of the air seals with parts broken away The particular embodiment chosen for the purpose of illustration comprises a pin belt I trained over sheaves 2 and 3, the belt having marginal rows of teeth or pins 4 adapted to t into the sprocket holes of the blank and matrix films 6 and 1 while the two films travel in superposition on the belt. The blank 6 feeds from a supply roll 8 through an elevator comprising upper rolls 8 rotating about fixed axes and lower rolls I I which are supported by the film loops and which move up and down to accommodate variations in the degree of lm shrinkage and differences in the rate of drive of the belt I and the driven sprocket wheels. From the elevator the blank passes through a pre-wet tank I2 and thence to a roll tank I3 where the blank is seated on the belt by means of a roller I4.

The matrix 1 feeds from a supply7 reel I6 over a driven sprocket wheel I1 thence through an elevator comprising lower iioating rolls'IB, thence through a dye tankrIQ, thence through a wash tank 2| where the superficial dye is washed off, thence over a series of rollers to provide a safety loop and thence under roll 22 where the matrix is seated on the belt in face-to-face contact with the blank 6. To seat the two films more rmly together an endless belt may be trained around the roll 22 and two auxiliary guide rolls, the endless belt 20 having sprocket holes to receive the teeth of belt I. The seating rolls I4 and 22 and the seating belt are disclosed in detail in Patent 1,707,710, granted April 2, 1929 and application Ser. No. -522,711, filed February 17, 1944, now Patent No. 2,437,361, issued March 9, 1948. From the roll tank I3 the two films travel together until they reach the roll 23, during which time the pictures are printed on the blank by imbibition of dye by the blank from the matrix. After leaving the pin belt at roller 23 matrix 1 travels over a series of rolls including floating elevator rolls 25, thence to matrix rinse tank 24, thence to the dry box 26 and thence to the take-up reel 21.

After leaving the pin belt at roller 23 the blank 6 vpasses to the dry box 28 and thence over roll 29 to a take-up reel or to another similar set of apparatus where another color aspect is printed on the blank in superposition to the first, as described for example in copending application of Frank W. Taylor, Serial No. 599,593, filed June 15, 1945, now Patent No. 2,448,691, issued Sept. 7, 1948. Certain of the film rollers may be sprocket wheels and these wheels and the pin belt may be driven in various ways, as for example the way disclosed in the aforesaid copending application.

According to the present invention all of the entrances and exits of the roll tank I3 are sealed and the tank is evacuated. In the illustration there are three entrances 3|, 32 and 33 where the belt I, the blank 6 and the matrix 1 enter the chamber, and one exit 34 where all three leave the chamber. These entrances and exits are preferably located at the ends of narrow extensions of the chamber and the chamber is evacuated through outlets 35, 36, 31 and 38 located near the outer ends of the extensions and an outlet 39 in the chamber itself.

The preferred means for sealing each of the aforesaid entrances and exits comprises a block 40 divided into two parts 4I and 42, which are secured tightly together and which are tightly fitted into the extensions of the chamber I3. The two4 parts of each seal may be secured together and to the chamber in any suitable way as by,y

block 42.

welding. Recesses 43 and 44 areprovided in the opposed faces of the parts 4I and 42 to form a passageway for the belt and films, the width of the passageway being approximately equal to the width of the belt and films. Mounted in circular recesses in the opposed faces of the passageway are rollers 46 and 41 which bear on opposite sides of the film or belt. The circular recesses have a radius approximately equal to thatl of the rollers so that the rollers substantially touch opposite sides of the recesses, thereby preventing substantial entrance of air around the peripheries of the rollers. The rollers 46 in the block 4I are supported .in fixed journals whereas the rollers 41 in the block 42 have stud shafts extending out through slots 48 in the sides of the block 42 where they are journaled in the beni; ends of springs 49 which are bent around studs 5I on the outside of Thus the rollers 41 are floating and are spring-pressed toward the rollers 46. All of the rollers are covered with relatively soft rub- 4 ber so that they conform i-,o the contour of the. belt and films. They may be soft enough to squeeze over the edges of the belt and films to seal the spaces, if any, between the edges of the belt and film and the sides of the passageway through the block 40. The rolls 46 on the pin side of the belt where the belt enters and leaves the chamber I3, as well as the rolls I4 and 22, have annular grooves to accommodate the teeth on the belt 'if' In the case of rolls 46 the soft rubber covering is thick enough to squeeze in between the teeth and present substantial ingress of air.

By bringing the films together in a vacuum and pressing the films intimately together inside the vacuum chamber, the films are held tightly together by the air pressure on their outer facesl somewhat softer. For this purpose a heater 51 is illustrated in Fig. 2.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and `eezluivalents which fall within the scope of the appended claims.

I claim:

l. In imbibition printing cinematographic film2 by transferring dye from one film to another, the

" method which comprises feeding the two films into contact with each other in a zone of reduced pressure while one of the films is wet, and rolling them into intimate contact with each other while in said Zone the films being fed together at an oblique angle defining a tapered crotch between the two films.

2. In imbibition printing cinematographic film method which comprises feeding the tworlms I into contact with each other in a zone of reduced pressure while one of the films is wet, rolling them into intimate contact with each other while in said zone, and holding the lms in registry with teeth fitting in their sprocket holes, the lms being fed together at an oblique angle defining a tapered crotch between the two films.

4. In imbibition printing cinematographic lm by transferring dye from one film. to another, the method which comprises wetting one film to render one face tacky, removing the superficial liquid, feeding the two films into contact with each other in a zone of reduced pressure, while in said Zone rolling them into intimate contact with said face engaging one face` of the other film, and holding the films in registry with teeth fitting in their sprocket holes, the lms being fed together at an oblique angle defining a tapered crotch between the two films.

5. Imbibition printing apparatus for transferring dye from one cinematographic film to another comprising a vacuum chamber forming a zone of reduced pressure having a plurality of lm openings to permit films to pass into the chamber and thence out of the chamber, and a port through which the chamber may be evacuated, air traps for said openings, means for wetting one lm to render one face tacky, means for feeding the lms to and from the chamber through said openings, a pair of rollers in the chamber for rolling the films together with said face in intimate contact with the other lm, and guides for guiding the films to said rollers at an acute angle defining between the two films a tapered crotch through which adherent air bubbles are squeezed out.

6. Imbibition printing apparatus for transferring dye from one cinematographic film to another comprising a vacuum chamber forming a zone of reduced pressure having a plurality of lm openings to permit lms to pass into the chamber and thence out of the chamber and a port through which the chamber may be evacuated, air traps for said openings, means for wetting one lm to render one face tacky, an endless carrier traveling in an orbital path at least a portion of which is disposed in said chamber, the carrier having register teeth fitting in the sprocket holes of the films, means for feeding said films into the chamber through two of said openings respectively, means in the chamber for rolling the films into intimate contact with each other and applying them to said belt with the register teeth projecting through the sprocket holes of the films, guides for guiding the lms to said rollers at an acute angle deiining between the two lms a tapered crotch through which adherent air bubbles are squeezed out, and means for feeding the lms from the chamber.

JOHN F. KIENNINGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,675,743 Young July 3, 1928 1,707,695 Troland Apr. 2, 1929 2,397,827 Williams Apr. 2, 1946

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