US1563959A - Printing color cinematographic films - Google Patents

Description

ec- 1. 1925- l P. D. BREWSTER PRINTING COLOR CINEMATOGRAPHIC FILMS Filed Nov. 151920 mm m on .Q

f I v Patented Dec. 1, 1925.

PERCY: D. BREWSTER, or Elisa" ORANGE, NEW JERSEY PRINTING COLOR omntm'roe'narnrc "Application filedNovember 1 5, 1920. saa1 1w a2 s31;

To all whom it may concern:

Be it known that I, PERCY 1). Bnnws'rizn,

a citizen of the United States of America.

residing at East Orange, in the county of,

Essex and State of New Jersey, have invented certain new and useful Improvements in Printing Color (lineinatographic Films, of which the following is a fulL-cle'ar,

' and exact description.

y In the art of two-color cinematography the practice now commonly in use isto print on one side of a positive film a series of images of one color value, say red, and on the other side the other series-of-color value images, say green, in registry with the first. The negative images from which the positive is'printed may be on separate films, thatis, all-the red images may be on one film and all the green images may be on another film, or the redand green images may be in alternating sequence on a single film, In the former case the two negatives maybe exposed in a camera of the type described and claimed in my copending application Serial No. 355,938, filed'June 29th. 1918, now Patent No;1,359,025;'issued November 16th, 1920. In the'second case-the alternating red and green images may be taken in. alternation, as in the so-called kinemacolor process, but preferably they are taken by means of any suitable camera'of the type, in which the red and green images of each pair aremade by simultaneous exposure, thereby avoiding the effect commonly known as color banding or fringing. In order to have a sharp nnage on the screen when the positive film is projected, it is evident that the images on one side thereof must be in exact registry with the images on the other side. In order to secure this necessary accuracy of registry various methods have been proposed. One of the most successful of these methods involves the use of registry pins, cooperating"with the usual marginal perforations in the positive and negative films, which pins serve to bringthe perforations of one film into registry with the perforations in the other; it being understood of course that the images of one series of negative images have the same positions with respect to the perforations 1n the film as the images on the other film have to'their respective perforations. Obviously, the negative film or films after exposure must be developed and fixed before they can be-printed on a positive, but

in this development and fixation the films suffer more or less shrinkagc, both 'longitudinally and transversely, withthe result that/the rows 'of perforations at the two edges of the developed and fixed fi lnrare closer together thanithe' corresponding rows of perforations on thecundeveloped'and unfiked positive film.' "Consequentlywh'en an attempt is made to register the perforations of the negative with the perforations of the,

positive by means of pins fitting the perforations closely, the pins, if spaced far enough apart to fit the positive perforations, are too far apart to fit the perforations in the negative, and vice versa. It hasbeen proposed, in order to overcome this trouble, to use in printing a full-size registry p n for the positive and negative perforations on one edge of the two films, andat the other edge to use a pin which' -i's narrower (transversely of the films), the idea being that the latter pin will only take care ofso-called vertical registry, that is, will not register"the films transversely'but only longitudinally. My

present invention is designed to obviate the trouble due to shrinkage, and to enable the use offull-size pins at both edges of the two films in printing. According to one method of practising my invention the negative film or films are exposed in the camera, and afterexposure are developed and fixed in the us'ualmanner. They-are then passed through a 'reperforating device by which selected perforations,-or if desired'all theperforations, at one edge of the film are widened by cutting out the celluloid at one or both side edges, preferably on the outside edge only. When the film 'is thus re-perforated' the widened perforations can be made to register. with the correspond ing edges of the negative film or films by meansof pins which fit the negative perforations closely.

. According to another method of practising the invention the negative film or films used in the camera are not perforatedcompletely, but have certain perforations omittedadjacent to each image area; Then,"iu accordance with the exposure in the camera, pilot or master perforations are made 'inthe film or films by suitable punches operating in harmony with the feed and shutter mechanism. After development and fixation of the negative, these master perforations are used as guides for supplying the missing perforations in theredges of'the' film. The

on the film, or they may be punched in they blank spaces at the edges of the film and afterwards enlarged.

. Convenient and effective devices for carrying out my invention are illustrated in the accompanying drawing, in which Fig. 1 illustrates a piece of negative film after development and fixation, and shows by dotted'lines the subsequent enlargement of perforations at one side of the film. Fig. 2 is a side view, partly in section, illustrating mechanism for enlarging, or widening, the registry perforations in the negative film.

Fig. 3 is a detail perspective view illustrating the combined pilot pin and punch used .inFig. 2.

Fig. 4 illustrates a negative film having pilot perforations between sucessive image areas and having u'nperforated spaces at itsedges; also the same film after the missing. perforations in -the edges have been made by punches controlled by the pilot perforations.

Fig. 5 is a detail perspective view illustrating a punching head for punching'the missing perforations of Fig. 4.

.Fig. 6 illustrates a negative film having the pilot perforations in its edges, and the same film after the pilot perforations have been enlarged to the full size of standard perforations. It will be understood that in this figure as well as in Figs. 1 and 4, the amount of shrinkage, indicated by the size of the enlarged or .new perforations, is.

greatly exaggerated.

- Fig. 7 is a detail perspective view illustrating a pu-nching head for enlargingthe pilot. perforations shown in Fig. ,6.

Referring to first Fig. 1, 10 represents a small section ofnegative film on which are shown, in whole or in part, three picture image areas, with the usual perforation at the edges of the film. If after the negative is developed and fixed an unexposed positive film be laid on it, with the perforations at one edge of the positive in exact registry with the perforations on the adjacent edge of the negative, it will be found that the positive perforations at the other edge of the positive will overlap the negative perforations by a substantial amount, as indicated (with considerable exaggeration) by the dotted lines at the right of the fig ure. Evidently a registry pin of the right size to fit thepositive perforations closelyat the right edge ofthe film will not fit the negative perforations without shifting one or the other film sidewise. Hence if the two filmsare held firmly together by full-size pins fitting the perforations in both at the other edge, the entry of a similar pin at the right will result in to enlarge the same.

buckling the or in seriously injuring the perforations. In order to obviate this difiiculty, I propose to enlarge the perforations at one side of the negative, or at least certain selected perforations suitably 7 located with respect to the negative images. For this purpose mechanism such as is shown in Fig. 2 may be conveniently employed. As there illustrated the device comprises a pair of stems 11, 12, mounted to reciprocate in fixed guides 13, 14:, a suitable distance apart on a base 15. The stems themselves are fixed to a cross-head 16 which has a stud '17 cooperating with a lever 18 actuated by the core 19 of a solenoid 20. The latter is in circuit with a source of current indicated diagrammatically at 21, through arotating commutator 22, comprising a disk of insulating material having on its periphery, a conducting contact 23 connected electrically to the shaft 24, with which the brush 25 cooperates. The brush mentioned is connected to one side of the source 21, as shown. Bearing on the periphery of the disk is a brush 26 connected to the other terminal of the solenoid, Evidently as the commutator rotates, the circuit of the solenoid will be alternately closed'and opened, thereby causing the core 19 to be reciprocated, and the stems 11, 12, also to be reciprocated in their guides- In the apparatus illustrated one of the stems, say- 11, carries a registry pin 27 of such cross-sectional size and contour as to fit accurately the perforations on one edge of the negative film. The other stem,'12, carries a registry pin 28'of such cross sectional size and contour asto fit a negative perforation also (at tlie other edge of the film), but at a suitable distance in rear of its point'the pin has a shoulder, preferably at the outer side of the pin, as indicated at 29. constituting a punch for cutting additional celluloid out of the'side of the perforation It will-0f course be understood that the two pins are spaced apart a distance corresponding to the'average amount of shrinkage in negative films.

The two pins work in openings in the guide presser plate 31, overlying a hinged die plate held in place by a button 33. The die plate is provided with an opening 34.; Which the pin 27 enters idly, and with an opening 35 constituting a die member to cooperate with the shoulder 29 for the purpose of cutting out the additional celluloid at the outer edge of the film perforations. Suitable mechanism for passing the film between the presser plate 31 and the die plate 32 in a step-by-step manner is provided, but inasmuch as such mechanisms are well understood, I have deemed it unnecessary to illustrate the same herein. Sufiice it to say that it may be ,of the Geneva-movement type, for example such as i illllStrated in my said Patent No. 1,359,025,.referred to above, which mechanism is designed to advance the filnrone' image space at each step. The connmltator 22 should be connected with the feed mechanism in such a way that the contact 23 will engage'the brush 26 after the film has come to rest; thereby causing cnergization of the solenoid and consequent actuation of the stems 1], 12,- and will pass out of engagement with the brush before the film starts to move in the next feeding step. The movement of the contact 23 out of engagement'with the brush 26 of course breaks the circuit of the solenoid and so al.- lows the springs 36 to raise the punching head and thereby disengage the pins from the film.

After the-negative film has been re-perfo rated, as described above, it may be used in a printing machine havingfull-size pins spaced the. standard distance apart.

In Fig. 4, '37 represents a negative film in which one perforation at each side of each image area is omitted, but having between successive picture areas, pilotperforations 38, 39. In order to take care of longitudinal shrinkage of the film, alternate pilot perforations may be elongated lengthwise of the film, as shown. Preferably these pilot perforations are made by punching devices in the camera in which the negative film is exposed, for example by mechanism of the type illustrated iirmy copending application Serial No. 268,673, filed December 28, 1918. In such cases every fourth tooth on the feed s nrocket or sprockets of the filmfeeding mechanism is omitted. to avoid damage to the film at the points where the perforations are omitted. After the negative film is developed and fixed it is passed through a perforating device of the type illustrated in Fig. 2, but provided with pilot pins to enter the ,)e rforations 3S and 39 c and align the film so that the new perfortlons, punched 1n the blank spaces at the edges of the filnnwill be accurately and uniformly positioned with respect to the images on the film. For this purpose a punching head, such as is shown in'Fig. 5, may be employed. This comprises a head 40 provided with pilot pins 41, 4-2, to cooperate with the. pilotperforations 38, 39. At the ends of the headin aplane between the 1' i.lot'pins, are two stems 4 44, carrying on their ends punches 45. 46. As will be readily understood the pilot pins 41, 42, first enter the pilot perforations andthereby shift the film to a standard'position, after which the punches come down upon the edges of the film and punch therein the missing perforations. These punches are spaced the standard distance apart so that the resulting perforations. as 47, 48, are correspondingly spaced, thereby making it possible. to use these perforations in a standard printing machine having full-size spaced the standard distance apart.

Thefihn shown at 49, Fig. 6, also has certain perforations omitted from its edges. but. their place is supplied by pilot perforations 5 0,"'51. The former, like the perforations 38 in Fig. 4, are preferably circular, but perforations 51 are preferably elongated transversely, so as to take account of transverse shrinkage. To enable film of this ty e to be used in a printing machine with fu l-size registry pins spacedthe standard distance apart, the missing perforations must be supplied. For this purpose a device such as is shown in Fig. 2, but with a punching head of the type shown in Fig. 7 can be used. The device illustrated in the figure just referred to comprises a head carrying stems 53, 54. provided at their ends with pilot pins 55, 56, which in rear of their points are providedavith shoulders 57, 58. constituting punches for male ing the desired perforations. In using the device illustrated the pilot pins enter the pilot perforationsand thereby bring the film accurately to the standard position. The punches then engage thefilm and cut out perforations 59, 60, which are spaced the standard distance apart and which are. uniformly located with respect to the adia-cent images. Hence the negative film with the missing perforations supplied in this manner can be used in a printing achine employing full-size registry pins spaced the standard distance apart.

In printing from the rc-perforatcd.negatives any suitable printing apparatus may be used, as for example any of those described .in my eopending application Serial No. 355,- 958, before referred to, preferably one of the type illustrated diagrammatically in Fi 17. This type of printer is designed for use in a method of two-color cinematography in which the two series of color value images are on separate films. If both series are on one'film, but in alternating sequence, as in a negative of the so-called kinemacolor type, a printing apparatus of the type illustrated in my copending applicatimi Serial No. 224,110 may be used.

, The positive film may be of the kind having a sensitive emulsion on each side, in j when projected on the screen the unitary 1 image, substantially in the colors of the object'photographed, will be produced. Usually one series of the color-valve negative images is made by light predominantly green'in color, and the other series by light for example described in the prior patent to Hoyt Miller, No; 1,214,940, of February 6, 1917 Another printing method which may be employedinstea d of the one described involves printing on only one side of the positive film. In this method a single-coated film is used, on which one series of negative imagesis printed. The positive film is then developed, fixed anddyed,after which the series of stained or dyed images thereon is protected by an insoluble varnish or other coating. On top of this coating another emulsion is laid, upon which the second series of negative images is printed, followed by development, fixation and dyeing.

It is to be understood that the invention i's-not limited to the specific features herein described and illustrated, but can be practised in other ways without departure from its spirit.-

lVhat I claim is-' 1. In the art of color-cinematography, the improvement comprising exposing a negative film in a suitable camera for the production of a series of color value images, developing and fixing the film so exposed, and thereafter re-perforating the film to provide registry perforations a suitable distance apart in uniform relation to the images, for

subsequent use in printing the images-on a positive film.

the negative film by means of registry pins fitting the perforations in the positive film.

3. In the art of color cinematography, the improvement comprising developing and fixing a negative film having a series of perforations at each edge, and thereafter enlarging laterally at least one perforation adjacent to each image on the film, to enable a pair of perforations for each image, one at each side thereof, to be matched with a pair of perforations in the unexposed positive film in printing.

4. Inthe art of color cinematography, the improvement comprising exposing a negative film in a suitable camera for the production of-a series of color value negative images, and at each exposure punching pilot perforations in the film adjacent to the image on the film; developing and fixing the film; thereafter cutting registry perforations in the film; and in cutting the registry perforations, positioning the film by means of pilot pins inserted in the pilot perforations. g i

In testimony whereof I hereto aflix my signature. 7

- PERCY BREWSTER.

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